Objective:To explore the effect of a hydrogel of Piper longum(P.longum)root against biofilm-forming multidrug-resistant(MDR)Staphylococcus aureus(S.aureus)through in vitro,in silico,and in vivo studies.Methods:We isol...Objective:To explore the effect of a hydrogel of Piper longum(P.longum)root against biofilm-forming multidrug-resistant(MDR)Staphylococcus aureus(S.aureus)through in vitro,in silico,and in vivo studies.Methods:We isolated the P.longum root ethanolic extract and the compounds using p-HPLC.In vitro antibacterial and antibiofilm activities of P.longum root extract and isolated alkamide compounds against biofilm-forming MDR S.aureus(ATCC 33591)were assessed using agar diffusion and broth microdilution methods,respectively.In silico investigations were conducted to investigate the interaction of alkamide compounds with three target proteins glycogen synthase kinase 3β(GSK3β),matrix metalloproteinases-8(MMP-8),and inducible nitric oxide synthase(iNOS).In addition,the wound healing effect of P.longum root extract 2%and 5%(w/v)-containing hydrogels was determined in mice.Results:The ethanolic root extract of P.longum and its compounds exhibited in vitro antibacterial activity with minimum inhibitory concentrations between 50µg/mL and 700µg/mL,as well as significantly reduced biofilm formation.Piperdardine isolated from P.longum root extract had the best molecular docking score(-9.7,-9.8,and-9.2 kcal/mol)with target proteins GSK3β,MMP-8,and iNOS.In vivo studies showed that P.longum hydrogels significantly lowered the number of colony-forming units(P<0.05).The P.longum 5%(w/v)hydrogel-treated group showed enhanced wound healing activity,achieving a wound contraction rate of 99.34%on day 14.Furthermore,histopathological analysis confirmed increased re-epithelialization and reduced inflammation in mice treated with P.longum 5%(w/v)hydrogel.Conclusions:P.longum root extract has pharmacological potential as an antibacterial and wound-healing agent,and further research is required to confirm its efficacy and clinical application.展开更多
Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance....Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.Methods:In this article,we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical anti-microbial agents that matches the real clinical situation.The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.Results:In the final model,10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia,with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension.One pig was not inoculated and used as the negative control.Subsequently,the bandages were changed on Days 4,8,11,and 15.At these time points,a filter paper imprint technique(FPIT)was made from each wound for semi-quantitative microbiological evaluation.Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological,histopathological,and molecular-biological examination.The infection with the inoculated S.aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples.The dynamics of the inflammatory markers and clinical signs of infection are also described.Conclusions:A successfully developed porcine model is suitable for in vivo testing of novel short-acting topical antimicrobial agents.展开更多
BACKGROUND Peripherally inserted central catheters(PICCs)are widely used for administering chemotherapy to breast cancer patients due to their long-term indwelling capability,versatility in drug administration,and fle...BACKGROUND Peripherally inserted central catheters(PICCs)are widely used for administering chemotherapy to breast cancer patients due to their long-term indwelling capability,versatility in drug administration,and flexibility.PICCs infection are a relatively common occurrence,yet there were no reported instances that it can metastasise to the lumbar spine.CASE SUMMARY This case report describes a breast cancer patient who developed a methicillinresistant Staphylococcus aureus lumbar vertebral infection secondary to a PICCrelated infection during chemotherapy.Following PICC removal,bacterial culture confirmed the presence of highly virulent methicillin-resistant Staphylococcus aureus.The patient presented with fever and severe lumbar pain.Lumbar magnetic resonance imaging revealed paraspinal muscle edema from L1 to L3 with abnormal signal intensity in the affected regions,suggestive of vertebral osteomyelitis.Prompt initiation of appropriate antibiotic therapy based on the culture results led to significant improvement in the patient’s lumbar pain.CONCLUSION This case highlights the importance of vigilant infection prevention and control measures to minimize the risk of PICC-related complications,such as bloodstream infections and subsequent metastatic infections.展开更多
Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the ...Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.展开更多
Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results r...Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results revealed the efficacy of theaflavin-3,3′-digallate(TFBG),which is a novel polyphenol derived from tea,in targeting the key regulatory protein multiple gene regulator A(MgrA)in S.aureus.Through fluorescence anisotropy,we showed that the half maximal inhibitory concentration(IC50)of TFBG was 26.76μg/mL.TFBG uniquely counters S.aureus by regulating its virulence factors and adhesion processes rather than by killing the bacteria directly.This compound alters the expression of key virulence factors and modulates the transcription levels of genes related to adhesion in S.aureus,ultimately reducing the bacteria’s ability to adhere to fibrinogen and its hemolytic activity.Our assays confirmed that TFBG directly interacts with the MgrA protein in MRSA,and we identified critical binding sites.Our in vivo studies highlighted the potent efficacy of TFBG.TFBG administration is an innovative approach to improve food safety by diminishing MRSA virulence and reducing its pathogenicity.展开更多
Background Mastitis caused by Staphylococcus aureus(S.aureus)is one of the most intractable problems for the dairy industry,causing significantly reduced milk yields and early slaughter of cows worldwide.MicroRNAs(miR...Background Mastitis caused by Staphylococcus aureus(S.aureus)is one of the most intractable problems for the dairy industry,causing significantly reduced milk yields and early slaughter of cows worldwide.MicroRNAs(miRNAs)can post-transcriptionally regulate gene expression and studies in recent years have shown the importance of miRNA-associated gene regulation in S.aureus-induced mastitis.Results In this study,to investigate the role of miR-223 in mastitis,we performed experiments to overexpress and suppress miR-223 in an immortalized bovine mammary epithelial cell line(MAC-T)infected with S.aureus.Overexpression of miR-223 in MAC-T cells repressed cell apoptosis and necrosis induced by S.aureus infection,whereas suppression of miR-223 had the opposite effect.Transcriptome expression profiling with weighted gene co-expression network analysis(WGCNA)and gene set variation analysis(GSVA)showed that miR-223 affects apoptosis and inflammation-related pathways.Furthermore,differentially expressed(DE)genes were evaluated,and genes exhibiting contrasting expression trends in the miR-223 overexpressed and suppressed groups were assessed as potential target genes of miR-223.Potential target genes,including CDC25B,PTPRF,DCTN1,and DPP9,were observed to be associated with apoptosis and necroptosis.Finally,through integrative analysis of genome-wide association study(GWAS)data and the animal quantitative trait loci(QTL)database,we determined that target genes of miR-223 were significantly enriched in single-nucleotide polymorphisms(SNP)and QTLs related to somatic cell count(SCC)and mastitis.Conclusion In summary,miR-223 has an inhibitory effect on S.aureus-induced cell apoptosis and necrosis by regulating PTPRF,DCTN1,and DPP9.These genes were significantly enriched in QTL regions associated with bovine mastitis resistance,underscoring their relevance in genetic regulation of disease resilience.Our findings provide critical genetic markers for enhancing mastitis resistance,particularly S.aureus-induced mastitis,through selective breeding.This work offers valuable insights for developing cattle with improved resistance to mastitis via targeted genetic selection.展开更多
Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacill...Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.展开更多
Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus he...Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus helveticus WXD191 were extracted and purified.Structure analysis suggested that the EPS contained Ara,Man,Gal,GalN,Glc,GlcN,and GlcA,with a molecular of 84.2 kDa.Methylation combined with nuclear magnetic resonance(NMR)spectroscopy analysis revealed that the backbone of EPS (was→3)-β-D-Galp-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3-Man-1→2-Man-1→2,6-Man-1→2,6-Man-1→).Congo red analysis and circular dichroism(CD)spectrum indicated the existence ofα-helices.Crystalline characteristics,scanning electron microscopy,and thermogravimetric analysis revealed that EPS formed thermally stable amorphous with a small amount of microcrystalline structure and a rough and porous surface.Meanwhile,the S.aureus bloodstream infection model was used to evaluate the protection efficiency for systemic infection induced by S.aureus and found that the EPS could enhance survival as well as reduce bacterial burden and proinflammatory chemokines.Collectively,these results suggested that EPS isolated from L.helveticus was a competitive candidate for defense against S.aureus infection.展开更多
Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying...Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying dampness,detoxifying,and relieving itching,making it suitable for treating acute and subacute dermatitis or eczema.Objectives:To evaluate the clinical efficacy of topical Taxi San in treating atopic dermatitis patients with dampness-heat syndrome and its inhibitory effect against Staphylococcus aureus(S.aureus)colonization.Methods:50 patients with atopic dermatitis were enrolled from the Dermatology Department of Shaanxi Provincial Hospital of Traditional Chinese Medicine,with bilateral symmetrical lesions selected as target sites.The control-side lesions were treated with boric acid solution wet compresses,while the treatment-side lesions received Taxi San solution wet compresses,both administered twice daily for 14 d.Clinical efficacy was evaluated using the Scoring Atopic Dermatitis(SCORAD),Investigator Global Assessment(IGA),Dermatology Life Quality Index/Children’s Dermatology Life Quality Index(DLQI/CDLQI),adverse events(AEs)and S.aureus colonization density,which were compared between the groups.The antibacterial efficacy of Taxi San was further investigated through in vitro antibacterial tests.Results:After 14 d of treatment with Taxi San,erythema and pimples were reduced on the treated sides.Additionally,the SCORAD,IGA,and DLQI/CDLQI scores showed significant decreases(P<0.05).S.aureus colonization on the treated sides declined markedly from 78%to 4.76%.Compared to the control sides,the reduction in S.aureus colonization following 14 d of Taxi San treatment was statistically significant(P<0.05).Furthermore,in vitro antibacterial assays demonstrated that the minimum inhibitory concentration of Taxi San against the seven tested S.aureus strains was 0.125 g/mL.Conclusions:Taxi San effectively reduces S.aureus colonization and ameliorates clinical symptoms in atopic dermatitis patients with dampness-heat syndrome,demonstrating high therapeutic potential and safety.展开更多
[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and la...[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.展开更多
[Objective] To produce drug resistance, seek non-toxic environmental so as to change the current biological drugs that did not excessive use of antibiotics. [Methods] A strain of Bacillus was purified and isolated fro...[Objective] To produce drug resistance, seek non-toxic environmental so as to change the current biological drugs that did not excessive use of antibiotics. [Methods] A strain of Bacillus was purified and isolated from fresh and healthy in- testines of grass carps. Biochemical identification was carried out by conventional bacterial biochemical test method. Two pairs of primers were designed, 16S rRNA detection and sequencing analysis were carried out. Drug sensitive test was carried out by agar diffusion method. In vitro inhibition test on Staphylococcus aureus was carried out by Oxford cup method. [Results] The isolated bacterium had basically the same biochemical characters as Bacillus subtilis; and the homology reached 100%. Thus, the isolated bacterium was identified to be Bacillus subtilis. It was insensitive to amoxicillin, ampicillin, penicillin G and so on, but sensitive to amikacin, cefalexin, ciprofloxacin and cefradine. The inhibitory effects of Bacillus subtilis on Staphylococ- cus aureus were significant. The minimum inhibitory concentration （MIC） was 2.8×10^8×2^-5/ml and minimum bactericidal concentration （MBC） was 2.8×10^8×2^-2/ml. [Conclusions] The isolated Bacillus subtilis could be used to prevent and control diseases caused by Staphylococcus aureus, and reduce the abuse of antibiotics.展开更多
[Objective] This study aimed to analyze the antibacterial activity of herbal preparations against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis. [Method] The crude drug solutions of four different...[Objective] This study aimed to analyze the antibacterial activity of herbal preparations against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis. [Method] The crude drug solutions of four different prescriptions for Zengrujianniusan were prepared through reflux extraction. Their antibacterial activity in vitro against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis were investigated. [Result] All the four different prescriptions exhibited antibacterial activity against S. aureus and S. agalactiae. Among them, prescription Ⅲ was extremely sensitive, and had the best bactericidal effect. The other three prescriptions were highly sensitive. [Conclusion] This study provides a theoretical basis for the development of herbal preparations for the treatment of cow mastitis.展开更多
Objective:To determine the antibiotic resistance profile(ARP)of Staphylococcus(S.)aureus isolates and molecular typing of the methicillin-resistant S.aureus(MRSA)isolates from Tuanku Mizan Armed Forces Hospital(TMAFH)...Objective:To determine the antibiotic resistance profile(ARP)of Staphylococcus(S.)aureus isolates and molecular typing of the methicillin-resistant S.aureus(MRSA)isolates from Tuanku Mizan Armed Forces Hospital(TMAFH),Kuala Lumpur.Methods:The ARP and presence of the pvl gene were determined for 209 S.aureus isolates from clinical specimens.Of these,123 were methicillin-susceptible S.aureus(MSSA)isolates and 86 were MRSA isolates.All MRSA isolates were characterized using SCCmec typing and spa typing.Descriptive analysis was performed to compare the demographic data with the phenotypic and genotypic variables of the S.aureus isolates.Results:No vancomycin-intermediate and-resistant S.aureus(VISA and VRSA,respectively)were detected among the study isolates.The MSSA isolates showed low resistance rates to all tested antibiotics,were commonly invasive(28/42,66.7%),and mostly harboured pvl(35/42,83.3%).Meanwhile,MRSA isolates showed high resistance to penicillin(86/86,100%),ampicillin(86/86,100%),sulbactam/ampicillin(86/86,100%),cefuroxime(81/86,94.19%),cefoperazone(76/86,88.37%),azithromycin(56/86,65.12%),and erythromycin(54/86,62.79%).The majority of MRSA isolates were of SCCmec type IVh(65/86,75.58%),spa type t032(55/85,63.95%),and grouped into spaCC-t022(66/85,77.65%).The t032 type was found to be associated with resistance traits to azithromycin and erythromycin(P<0.05).We also found several spa types that are typically associated with hospital-,community-,and livestock-associated MRSA co-existing in our MRSA population.Conclusions:This study reflected the consistent absence of VISA and VRSA and corroborated the clonal shifting of MRSA isolates in the Malaysian MRSA isolates.展开更多
Objective: to analyze the clinical distribution and drug resistance of Staphylococcus aureus (SAU) and Methicillin Resistant Staphylococcus aureus (MRSA). Methods: we retrospectively analyzed the clinically separated ...Objective: to analyze the clinical distribution and drug resistance of Staphylococcus aureus (SAU) and Methicillin Resistant Staphylococcus aureus (MRSA). Methods: we retrospectively analyzed the clinically separated SAU and clinical and drug susceptibility data in our hospital from 2016 to 2020, and used the WHONET5.6 software for statistical analysis. Results: a total of 1138 SAU strains were isolated in 5 years, of which 25.6% (291/1138) were MRSA. The positive rates of MRSA from 2016 to 2020 were 32.0%, 23.8%, 21.0%, 31.6%, and 21.4%. Wound pus (46.9%) was the most common source of SAU specimens, followed by respiratory tract (29.3%) and blood (11.1%), and the departments were mainly orthopedics (15.2%), ICU (9.2%) and general surgery (8.5%), among them, MRSA mainly isolated from respiratory tract (41.9%), wound pus (39.2%) and blood (9.6%) specimens. The departments with high MRSA positive rates are cardiothoracic surgery (59.1%), respiratory medicine (52.9%) and neurosurgery (49.6%). The resistance rates of SAU to gentamicin, rifampicin, levofloxacin, trimethoprim-sulfamethoxazole and tetracycline showed a certain downward trend, and no strains insensitive to vancomycin, teicoplanin and linezolid were found. The resistance rate of MRSA to most antibacterial drugs is higher than that of Methicillin Sensitive Staphylococcus aureus (MSSA), and the resistance rate to penicillin, erythromycin and clindamycin is high (> 50%). The resistance rate to gentamicin, levofloxacin and tetracycline is high (> 30%). Conclusion: the resistance of SAU to most antibacterial drugs and the positive rate of MRSA show a downward trend. glycopeptides and linezolid are still the best antibacterial drugs, which should be considered for severe infections.展开更多
Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus （MRSA） isolated from pigs and retail foods from different geographical areas in China and further to study the routes a...Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus （MRSA） isolated from pigs and retail foods from different geographical areas in China and further to study the routes and rates of transmission of this pathogen from animals to food. Methods Seventy-one MRSA isolates were obtained from pigs and retail foods and then characterized by multi-locus sequencing typing （MLST）, spa typing, multiple-locus variable number of tandem repeat analysis （MLVA）, pulsed-field gel electrophoresis （PFGE）, and antimicrobial susceptibility testing. Results All isolated MRSA exhibited multi-drug resistance （MDR）. Greater diversity was found in food-associated MRSA （7 STs, 8 spa types, and 10 MLVA patterns） compared to pig-associated MRSA （3 STs, 1 spa type, and 6 MLVA patterns）. PFGE patterns were more diverse for pig-associated MRSA than those of food-associated isolates （40 vs. 11 pulse types）. Among the pig-associated isolates, CC9-ST9-t899-MC2236 was the most prevalent clone （96.4%）, and CC9-ST9-t437-MC621 （20.0%） was the predominant clone among the food-associated isolates. The CC9-ST9 isolates showed significantly higher antimicrobial resistance than other clones. Interestingly, CC398-ST398-t034 clone was identified from both pig- and food-associated isolates. Of note, some community- and hospital-associated MRSA strains （t030, t172, t1244, and t4549） were also identified as food-associated isolates. Conclusion CC9-ST9-t899-MC2236-MDR was the most predominant clone in pigs, but significant genetic diversity was observed in food-associated MRSA. Our results demonstrate the great need for improved surveillance of MRSA in livestock and food and effective prevention strategies to limit MDR-MRSA infections in China.展开更多
Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. ...Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. aureus （MRSA） from methicillin-sensitive S. aureus （MSSA）. Methods A total of 100 5. aureus strains isolated from clinical specimens and farm workers were collected and analyzed by MALDI-TOF-MS. And data obtained were interpreted with biotyper software. Results Ninety-two strains were identified by MALDI-TOF-MS as 5. aureus at a level of secure genus and probable species, and 4 strains were identified at probable genus after their cultivation, spectral collection and data preprocessing. One strain was identified as 5. aureus with lower score. It was revealed that identification of 5. aureus by MALDI-TOF-MS was highly correlated with typing by biochemical and serological methods with an accuracy as high as 97%. The biotyper cluster analysis showed that 100 isolates were divided into 2 types at the distance level of 400. Higher peak intensity in the mass of both 3784 Da and 5700 Da was observed in MRSA, whereas that was absent from MSSA. Conclusion MALDI-TOF-MS is considered as a simple, high-throughput and accuracy for the identification of S from MSSA. rapid and highly reproducible technique with aureus and it can reliably differentiate MRSA展开更多
This study was conducted to determine genetic diversity and antimicrobial susceptibility profiles of Staphylococcus aureus recovered from bovine mastiffs in Zhejiang Province, China. Out of 3178 quarter milk samples f...This study was conducted to determine genetic diversity and antimicrobial susceptibility profiles of Staphylococcus aureus recovered from bovine mastiffs in Zhejiang Province, China. Out of 3178 quarter milk samples from 846 lactating cows, among which 459 cows （54.3%） were found HMT positive, 890 quarters （28%） were found having subclinical mastitis. From 75 representative S. aureus isolates, 16 distinct types were identified by pulsed-field gel electrophoresis （PFGE）. Four major PFGE types （A, B, C, and D） accounted for 82.7% of all isolates, and type A （41.3%） was observed in multiple herds across the studied areas. Each region was found to have a predominant type： Hangzhou type A （64.1%）, Ningbo type C （34.5%） and type B （23.1%）, Jinhua type D （53.3%）, and Taizhou type C （62.5%）. Results of antimicrobial susceptibility tests showed that 90.7% of the isolates were resistant to at least one antimicrobial. Resistance to penicillin and ampicillin （77.3%）, tetracycline （60.0%）, or erythromycin （48.0%） was observed. The bacteria resistant to multiple antibiotics such as penicillin, ampicillin, tetracycline, and erythromycin were commonly found. The information obtained from this study is useful for designing specific control programs for bovine S. aureus mastitis in this region.展开更多
Staphylococcus aureus is the most common etiological pathogen of bovine mastitis. The resistant strains make the disease difficult to cure. The aim of this study was to characterize the genetic nature of the antimicro...Staphylococcus aureus is the most common etiological pathogen of bovine mastitis. The resistant strains make the disease difficult to cure. The aim of this study was to characterize the genetic nature of the antimicrobial resistance in S. aureus cultured from bovine mastitis in Northwest China in 2014. A total of 44 S. aureus were isolated for antimicrobial resistance and resistance-related genes. Antimicrobial resistance was determined by disc diffusion and the corresponding resistance genes were detected by PCR. Phenotype indicated that S. aureus isolates were resistant to penicillin （84.09%）, erythromycin （20.45%）, tetracycline （15.91%）, gentamicin （9.09%）, tobramycin （6.82%）, kanamycin （6.82%） and methicillin （2.27%）. 9.09% of the S. aureus isolates were classified as multidrug resistant. In addition, genotypes showed that the isolates were resistant to rifampicin （100%, rpoB）, penicillin （95.45%, blaZ）, tetracycline （22.73%, tetK, tetM, alone or in combination）, erythromycin （22.73%, ermB or ermC）, gentamicin/tobramycin/kanamycin （2.27%, aacA-aphD）, methicillin （2.27%, mecA） and vancomycin （2.27%, vanA）. Resistance to tetracycline was attributed to the genes tetK and tetM （r=0.558, P〈0.001）. This study noted high-level geno- and phenotypic antimicrobial resistance in S. aureus isolates from bovine mastitis cases in Northwest China.展开更多
基金supported by NPDF fellowship grants from the Central Council for Research in Ayurvedic Sciences,Ministry of AYUSH,Govt.of India(HQ-ESTT012/60/2022-ESTT/6783).
文摘Objective:To explore the effect of a hydrogel of Piper longum(P.longum)root against biofilm-forming multidrug-resistant(MDR)Staphylococcus aureus(S.aureus)through in vitro,in silico,and in vivo studies.Methods:We isolated the P.longum root ethanolic extract and the compounds using p-HPLC.In vitro antibacterial and antibiofilm activities of P.longum root extract and isolated alkamide compounds against biofilm-forming MDR S.aureus(ATCC 33591)were assessed using agar diffusion and broth microdilution methods,respectively.In silico investigations were conducted to investigate the interaction of alkamide compounds with three target proteins glycogen synthase kinase 3β(GSK3β),matrix metalloproteinases-8(MMP-8),and inducible nitric oxide synthase(iNOS).In addition,the wound healing effect of P.longum root extract 2%and 5%(w/v)-containing hydrogels was determined in mice.Results:The ethanolic root extract of P.longum and its compounds exhibited in vitro antibacterial activity with minimum inhibitory concentrations between 50µg/mL and 700µg/mL,as well as significantly reduced biofilm formation.Piperdardine isolated from P.longum root extract had the best molecular docking score(-9.7,-9.8,and-9.2 kcal/mol)with target proteins GSK3β,MMP-8,and iNOS.In vivo studies showed that P.longum hydrogels significantly lowered the number of colony-forming units(P<0.05).The P.longum 5%(w/v)hydrogel-treated group showed enhanced wound healing activity,achieving a wound contraction rate of 99.34%on day 14.Furthermore,histopathological analysis confirmed increased re-epithelialization and reduced inflammation in mice treated with P.longum 5%(w/v)hydrogel.Conclusions:P.longum root extract has pharmacological potential as an antibacterial and wound-healing agent,and further research is required to confirm its efficacy and clinical application.
基金Supported by the Ministry of Health of the Czech Republic,Grant/Award Number:NU22-05-00475 and NV19-05-00214。
文摘Background:In view of the ever-increasing representation of Staphylococcus spp.strains resistant to various antibiotics,the development of in vivo models for evaluation of novel antimicrobials is of utmost importance.Methods:In this article,we describe the development of a fully immunocompetent porcine model of extensive skin and soft tissue damage suitable for testing topical anti-microbial agents that matches the real clinical situation.The model was developed in three consecutive stages with protocols for each stage amended based on the results of the previous one.Results:In the final model,10 excisions of the skin and underlying soft tissue were created in each pig under general anesthesia,with additional incisions to the fascia performed at the base of the defects and immediately inoculated with Staphylococcus aureus suspension.One pig was not inoculated and used as the negative control.Subsequently,the bandages were changed on Days 4,8,11,and 15.At these time points,a filter paper imprint technique(FPIT)was made from each wound for semi-quantitative microbiological evaluation.Tissue samples from the base of the wound together with the adjacent intact tissue of three randomly selected defects of each pig were taken for microbiological,histopathological,and molecular-biological examination.The infection with the inoculated S.aureus strains was sufficient during the whole experiment as confirmed by both FPIT and from tissue samples.The dynamics of the inflammatory markers and clinical signs of infection are also described.Conclusions:A successfully developed porcine model is suitable for in vivo testing of novel short-acting topical antimicrobial agents.
基金Supported by the Shandong Province Medical and Health Technology Development Plan,No.202204011069.
文摘BACKGROUND Peripherally inserted central catheters(PICCs)are widely used for administering chemotherapy to breast cancer patients due to their long-term indwelling capability,versatility in drug administration,and flexibility.PICCs infection are a relatively common occurrence,yet there were no reported instances that it can metastasise to the lumbar spine.CASE SUMMARY This case report describes a breast cancer patient who developed a methicillinresistant Staphylococcus aureus lumbar vertebral infection secondary to a PICCrelated infection during chemotherapy.Following PICC removal,bacterial culture confirmed the presence of highly virulent methicillin-resistant Staphylococcus aureus.The patient presented with fever and severe lumbar pain.Lumbar magnetic resonance imaging revealed paraspinal muscle edema from L1 to L3 with abnormal signal intensity in the affected regions,suggestive of vertebral osteomyelitis.Prompt initiation of appropriate antibiotic therapy based on the culture results led to significant improvement in the patient’s lumbar pain.CONCLUSION This case highlights the importance of vigilant infection prevention and control measures to minimize the risk of PICC-related complications,such as bloodstream infections and subsequent metastatic infections.
文摘Staphylococcus aureus (S. aureus) is a bacterial pathogen for humans and animals. These bacteria can resist against many antibiotics and this resistance constitute an alarming worldwide human health threat due to the morbidity and mortality. Phage therapy is one of the alternative treatments. The aim of this study was to isolate and characterize lytic phages of S. aureus from different wastewater sources in Bobo-Dioulasso, Burkina Faso. Eight strains of S. aureus were isolated from different clinical samples and were used to isolate phages. The isolation and host range of phages were done by the spot test. Phages were purified by the double-layer method. Similar phages after the determination of the host range were characterized using restriction enzymes. A total of 27 phages were obtained after isolation and purification. Nine of the 27 isolates reported a broad host range (≥67%). The results of enzymatic digestion allowed to consider that all phage isolates that presented the same host range and the same genetic fingerprint are the same phage strain;whereas phages that presented the same host range and different genetic fingerprints are different phage strains. Thus, a total of 15 distinct phages isolates specific to S. aureus were characterized. This study highlighted the abundance and lytic capacity of phages isolated from wastewater from Bobo-Dioulasso’s environment against clinical strains of S. aureus. The lytic capacity of these Staphyphages could be an effective alternative tool to combat bacteria multi-resistance.
文摘Addressing the uncontrolled spread and increase in antibiotic resistance in methicillin-resistant Staphylococcus aureus(MRSA)will require new control strategies,particularly to improve the safety of food.Our results revealed the efficacy of theaflavin-3,3′-digallate(TFBG),which is a novel polyphenol derived from tea,in targeting the key regulatory protein multiple gene regulator A(MgrA)in S.aureus.Through fluorescence anisotropy,we showed that the half maximal inhibitory concentration(IC50)of TFBG was 26.76μg/mL.TFBG uniquely counters S.aureus by regulating its virulence factors and adhesion processes rather than by killing the bacteria directly.This compound alters the expression of key virulence factors and modulates the transcription levels of genes related to adhesion in S.aureus,ultimately reducing the bacteria’s ability to adhere to fibrinogen and its hemolytic activity.Our assays confirmed that TFBG directly interacts with the MgrA protein in MRSA,and we identified critical binding sites.Our in vivo studies highlighted the potent efficacy of TFBG.TFBG administration is an innovative approach to improve food safety by diminishing MRSA virulence and reducing its pathogenicity.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFF1000902,2021YFD1200903)the National Science Foundation for Young Scientists of China(Grant No.32302706)the Beijing Dairy Industry Innovation Team(Grant No.BAIC06).
文摘Background Mastitis caused by Staphylococcus aureus(S.aureus)is one of the most intractable problems for the dairy industry,causing significantly reduced milk yields and early slaughter of cows worldwide.MicroRNAs(miRNAs)can post-transcriptionally regulate gene expression and studies in recent years have shown the importance of miRNA-associated gene regulation in S.aureus-induced mastitis.Results In this study,to investigate the role of miR-223 in mastitis,we performed experiments to overexpress and suppress miR-223 in an immortalized bovine mammary epithelial cell line(MAC-T)infected with S.aureus.Overexpression of miR-223 in MAC-T cells repressed cell apoptosis and necrosis induced by S.aureus infection,whereas suppression of miR-223 had the opposite effect.Transcriptome expression profiling with weighted gene co-expression network analysis(WGCNA)and gene set variation analysis(GSVA)showed that miR-223 affects apoptosis and inflammation-related pathways.Furthermore,differentially expressed(DE)genes were evaluated,and genes exhibiting contrasting expression trends in the miR-223 overexpressed and suppressed groups were assessed as potential target genes of miR-223.Potential target genes,including CDC25B,PTPRF,DCTN1,and DPP9,were observed to be associated with apoptosis and necroptosis.Finally,through integrative analysis of genome-wide association study(GWAS)data and the animal quantitative trait loci(QTL)database,we determined that target genes of miR-223 were significantly enriched in single-nucleotide polymorphisms(SNP)and QTLs related to somatic cell count(SCC)and mastitis.Conclusion In summary,miR-223 has an inhibitory effect on S.aureus-induced cell apoptosis and necrosis by regulating PTPRF,DCTN1,and DPP9.These genes were significantly enriched in QTL regions associated with bovine mastitis resistance,underscoring their relevance in genetic regulation of disease resilience.Our findings provide critical genetic markers for enhancing mastitis resistance,particularly S.aureus-induced mastitis,through selective breeding.This work offers valuable insights for developing cattle with improved resistance to mastitis via targeted genetic selection.
基金supported by research grants from the Guangdong Province Basic and Applied Basic Research Fund Project(2022A1515110447)Open Fund Project of the State Key Laboratory of Applied Microbiology in South China(SKLAM006-2022)+1 种基金74th batch of general funding from the China Postdoctoral Science Foundation(2023M740774)Guangdong Provincial People’s Hospital,Postdoctoral Research Launch Fund(BY012022017)。
文摘Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.
基金funding from multiple sources including the Science and Technology Major Project of the Inner Mongolia Autonomous Region of China(2021ZD0013)the Key Scientific and Technological Research Program of Inner Mongolia Autonomous Region(2021GG0156)+1 种基金Inner Mongolia Key Laboratory for Molecular Regulation of the Cell(2021PT0002)the National Natural Science Foundation of China(32060800).
文摘Staphylococcus aureus infection is a global public health problem,searching and developing green alternatives for antibiotics are urgently required.In this study,the exopolysaccharides(EPS)produced by Lactobacillus helveticus WXD191 were extracted and purified.Structure analysis suggested that the EPS contained Ara,Man,Gal,GalN,Glc,GlcN,and GlcA,with a molecular of 84.2 kDa.Methylation combined with nuclear magnetic resonance(NMR)spectroscopy analysis revealed that the backbone of EPS (was→3)-β-D-Galp-(1→3)-β-D-GlcpNAc-(1→4)-β-D-GlcpA-(1→3-Man-1→2-Man-1→2,6-Man-1→2,6-Man-1→).Congo red analysis and circular dichroism(CD)spectrum indicated the existence ofα-helices.Crystalline characteristics,scanning electron microscopy,and thermogravimetric analysis revealed that EPS formed thermally stable amorphous with a small amount of microcrystalline structure and a rough and porous surface.Meanwhile,the S.aureus bloodstream infection model was used to evaluate the protection efficiency for systemic infection induced by S.aureus and found that the EPS could enhance survival as well as reduce bacterial burden and proinflammatory chemokines.Collectively,these results suggested that EPS isolated from L.helveticus was a competitive candidate for defense against S.aureus infection.
基金supported by the Shaanxi Provincial Research and Innovation Team for Atopic Dermatitis of Traditional Chinese Medicine(No.TZKN-CXTD-02)the Key Industry Innovation Chain Project of Shaanxi Province(No.2021ZDLSF04-12).
文摘Background:Atopic dermatitis is a chronic inflammatory skin disorder characterized by recurrent eczema-like rashes and severe itching.Taxi San is an external herbal formulation with the effects of clearing heat,drying dampness,detoxifying,and relieving itching,making it suitable for treating acute and subacute dermatitis or eczema.Objectives:To evaluate the clinical efficacy of topical Taxi San in treating atopic dermatitis patients with dampness-heat syndrome and its inhibitory effect against Staphylococcus aureus(S.aureus)colonization.Methods:50 patients with atopic dermatitis were enrolled from the Dermatology Department of Shaanxi Provincial Hospital of Traditional Chinese Medicine,with bilateral symmetrical lesions selected as target sites.The control-side lesions were treated with boric acid solution wet compresses,while the treatment-side lesions received Taxi San solution wet compresses,both administered twice daily for 14 d.Clinical efficacy was evaluated using the Scoring Atopic Dermatitis(SCORAD),Investigator Global Assessment(IGA),Dermatology Life Quality Index/Children’s Dermatology Life Quality Index(DLQI/CDLQI),adverse events(AEs)and S.aureus colonization density,which were compared between the groups.The antibacterial efficacy of Taxi San was further investigated through in vitro antibacterial tests.Results:After 14 d of treatment with Taxi San,erythema and pimples were reduced on the treated sides.Additionally,the SCORAD,IGA,and DLQI/CDLQI scores showed significant decreases(P<0.05).S.aureus colonization on the treated sides declined markedly from 78%to 4.76%.Compared to the control sides,the reduction in S.aureus colonization following 14 d of Taxi San treatment was statistically significant(P<0.05).Furthermore,in vitro antibacterial assays demonstrated that the minimum inhibitory concentration of Taxi San against the seven tested S.aureus strains was 0.125 g/mL.Conclusions:Taxi San effectively reduces S.aureus colonization and ameliorates clinical symptoms in atopic dermatitis patients with dampness-heat syndrome,demonstrating high therapeutic potential and safety.
基金Supported by the National Natural Science Foundation of China(30771596)~~
文摘[Objective] The effect of different culture conditions on type 5 capsular polysaccharide production of Staphylococcus aureus from diary cattle was studied to provide simple way for CP production and preparation and laid foundation for carrying out new polysaccharide vaccine research. [Method] Staph-ylococcus aureus was isolated from milk sample of sick dairy cattle and capsular polysaccharide serotypes were identified. Type 5 capsular polysaccharide was cultured on BHI,solid columbia and mod110 culture media. Glucose and lactose were taken as carbon sources for every culture media in solid and liquid state. Therefore 9 different culture conditions were taken to study the effect of culture conditions on capsular polysaccharide production. [Result] Different culture conditions indicated that compared with columbia culture media, BHI culture media could decline capsular polysaccharide production and mod110 culture media could increase capsular polysaccharide production. While for same culture media, solid culture media was better for capsular polysaccharide production,meanwhile,taken lactose as carbon source could increase capsular polysaccharide production.
基金Supported by the Cooperation Subject(09003699)the Project of Jiangxi Education Department(GJJ12237)the Project of Science and Technology Department of Jiangxi(20122BBF60082)~~
文摘[Objective] To produce drug resistance, seek non-toxic environmental so as to change the current biological drugs that did not excessive use of antibiotics. [Methods] A strain of Bacillus was purified and isolated from fresh and healthy in- testines of grass carps. Biochemical identification was carried out by conventional bacterial biochemical test method. Two pairs of primers were designed, 16S rRNA detection and sequencing analysis were carried out. Drug sensitive test was carried out by agar diffusion method. In vitro inhibition test on Staphylococcus aureus was carried out by Oxford cup method. [Results] The isolated bacterium had basically the same biochemical characters as Bacillus subtilis; and the homology reached 100%. Thus, the isolated bacterium was identified to be Bacillus subtilis. It was insensitive to amoxicillin, ampicillin, penicillin G and so on, but sensitive to amikacin, cefalexin, ciprofloxacin and cefradine. The inhibitory effects of Bacillus subtilis on Staphylococ- cus aureus were significant. The minimum inhibitory concentration （MIC） was 2.8×10^8×2^-5/ml and minimum bactericidal concentration （MBC） was 2.8×10^8×2^-2/ml. [Conclusions] The isolated Bacillus subtilis could be used to prevent and control diseases caused by Staphylococcus aureus, and reduce the abuse of antibiotics.
基金Supported by Science and Technology Development Program of Shijiazhuang City(08150132A)China Spark Program(2012GA6200025)~~
文摘[Objective] This study aimed to analyze the antibacterial activity of herbal preparations against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis. [Method] The crude drug solutions of four different prescriptions for Zengrujianniusan were prepared through reflux extraction. Their antibacterial activity in vitro against Staphylococcus aureus and Streptococcus agalactiae in cow mastitis were investigated. [Result] All the four different prescriptions exhibited antibacterial activity against S. aureus and S. agalactiae. Among them, prescription Ⅲ was extremely sensitive, and had the best bactericidal effect. The other three prescriptions were highly sensitive. [Conclusion] This study provides a theoretical basis for the development of herbal preparations for the treatment of cow mastitis.
基金The study was funded by the UPNM Short Term Grant (UPNM/2019/GPJP/SP/1).
文摘Objective:To determine the antibiotic resistance profile(ARP)of Staphylococcus(S.)aureus isolates and molecular typing of the methicillin-resistant S.aureus(MRSA)isolates from Tuanku Mizan Armed Forces Hospital(TMAFH),Kuala Lumpur.Methods:The ARP and presence of the pvl gene were determined for 209 S.aureus isolates from clinical specimens.Of these,123 were methicillin-susceptible S.aureus(MSSA)isolates and 86 were MRSA isolates.All MRSA isolates were characterized using SCCmec typing and spa typing.Descriptive analysis was performed to compare the demographic data with the phenotypic and genotypic variables of the S.aureus isolates.Results:No vancomycin-intermediate and-resistant S.aureus(VISA and VRSA,respectively)were detected among the study isolates.The MSSA isolates showed low resistance rates to all tested antibiotics,were commonly invasive(28/42,66.7%),and mostly harboured pvl(35/42,83.3%).Meanwhile,MRSA isolates showed high resistance to penicillin(86/86,100%),ampicillin(86/86,100%),sulbactam/ampicillin(86/86,100%),cefuroxime(81/86,94.19%),cefoperazone(76/86,88.37%),azithromycin(56/86,65.12%),and erythromycin(54/86,62.79%).The majority of MRSA isolates were of SCCmec type IVh(65/86,75.58%),spa type t032(55/85,63.95%),and grouped into spaCC-t022(66/85,77.65%).The t032 type was found to be associated with resistance traits to azithromycin and erythromycin(P<0.05).We also found several spa types that are typically associated with hospital-,community-,and livestock-associated MRSA co-existing in our MRSA population.Conclusions:This study reflected the consistent absence of VISA and VRSA and corroborated the clonal shifting of MRSA isolates in the Malaysian MRSA isolates.
文摘Objective: to analyze the clinical distribution and drug resistance of Staphylococcus aureus (SAU) and Methicillin Resistant Staphylococcus aureus (MRSA). Methods: we retrospectively analyzed the clinically separated SAU and clinical and drug susceptibility data in our hospital from 2016 to 2020, and used the WHONET5.6 software for statistical analysis. Results: a total of 1138 SAU strains were isolated in 5 years, of which 25.6% (291/1138) were MRSA. The positive rates of MRSA from 2016 to 2020 were 32.0%, 23.8%, 21.0%, 31.6%, and 21.4%. Wound pus (46.9%) was the most common source of SAU specimens, followed by respiratory tract (29.3%) and blood (11.1%), and the departments were mainly orthopedics (15.2%), ICU (9.2%) and general surgery (8.5%), among them, MRSA mainly isolated from respiratory tract (41.9%), wound pus (39.2%) and blood (9.6%) specimens. The departments with high MRSA positive rates are cardiothoracic surgery (59.1%), respiratory medicine (52.9%) and neurosurgery (49.6%). The resistance rates of SAU to gentamicin, rifampicin, levofloxacin, trimethoprim-sulfamethoxazole and tetracycline showed a certain downward trend, and no strains insensitive to vancomycin, teicoplanin and linezolid were found. The resistance rate of MRSA to most antibacterial drugs is higher than that of Methicillin Sensitive Staphylococcus aureus (MSSA), and the resistance rate to penicillin, erythromycin and clindamycin is high (> 50%). The resistance rate to gentamicin, levofloxacin and tetracycline is high (> 30%). Conclusion: the resistance of SAU to most antibacterial drugs and the positive rate of MRSA show a downward trend. glycopeptides and linezolid are still the best antibacterial drugs, which should be considered for severe infections.
基金funded by the National Key R&D Program of China(2016YFD0401102)(the National Key Research and Development Program of China,the Ministry of Science and Technology of China)China Food Safety Talent Competency Development Initiative:CFSA 523 Program(1311613106702)
文摘Objective To investigate the genotypic diversity of Methicillin-resistant Staphylococcus aureus （MRSA） isolated from pigs and retail foods from different geographical areas in China and further to study the routes and rates of transmission of this pathogen from animals to food. Methods Seventy-one MRSA isolates were obtained from pigs and retail foods and then characterized by multi-locus sequencing typing （MLST）, spa typing, multiple-locus variable number of tandem repeat analysis （MLVA）, pulsed-field gel electrophoresis （PFGE）, and antimicrobial susceptibility testing. Results All isolated MRSA exhibited multi-drug resistance （MDR）. Greater diversity was found in food-associated MRSA （7 STs, 8 spa types, and 10 MLVA patterns） compared to pig-associated MRSA （3 STs, 1 spa type, and 6 MLVA patterns）. PFGE patterns were more diverse for pig-associated MRSA than those of food-associated isolates （40 vs. 11 pulse types）. Among the pig-associated isolates, CC9-ST9-t899-MC2236 was the most prevalent clone （96.4%）, and CC9-ST9-t437-MC621 （20.0%） was the predominant clone among the food-associated isolates. The CC9-ST9 isolates showed significantly higher antimicrobial resistance than other clones. Interestingly, CC398-ST398-t034 clone was identified from both pig- and food-associated isolates. Of note, some community- and hospital-associated MRSA strains （t030, t172, t1244, and t4549） were also identified as food-associated isolates. Conclusion CC9-ST9-t899-MC2236-MDR was the most predominant clone in pigs, but significant genetic diversity was observed in food-associated MRSA. Our results demonstrate the great need for improved surveillance of MRSA in livestock and food and effective prevention strategies to limit MDR-MRSA infections in China.
文摘Objective To develop a matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS） approach to identify Staphylococcus aureus （5. aureus） and differentiate methicillin-resistant 5. aureus （MRSA） from methicillin-sensitive S. aureus （MSSA）. Methods A total of 100 5. aureus strains isolated from clinical specimens and farm workers were collected and analyzed by MALDI-TOF-MS. And data obtained were interpreted with biotyper software. Results Ninety-two strains were identified by MALDI-TOF-MS as 5. aureus at a level of secure genus and probable species, and 4 strains were identified at probable genus after their cultivation, spectral collection and data preprocessing. One strain was identified as 5. aureus with lower score. It was revealed that identification of 5. aureus by MALDI-TOF-MS was highly correlated with typing by biochemical and serological methods with an accuracy as high as 97%. The biotyper cluster analysis showed that 100 isolates were divided into 2 types at the distance level of 400. Higher peak intensity in the mass of both 3784 Da and 5700 Da was observed in MRSA, whereas that was absent from MSSA. Conclusion MALDI-TOF-MS is considered as a simple, high-throughput and accuracy for the identification of S from MSSA. rapid and highly reproducible technique with aureus and it can reliably differentiate MRSA
基金Project (No. 2005C12015) supported by the Science and Technology Department of Zhejiang Province, China
文摘This study was conducted to determine genetic diversity and antimicrobial susceptibility profiles of Staphylococcus aureus recovered from bovine mastiffs in Zhejiang Province, China. Out of 3178 quarter milk samples from 846 lactating cows, among which 459 cows （54.3%） were found HMT positive, 890 quarters （28%） were found having subclinical mastitis. From 75 representative S. aureus isolates, 16 distinct types were identified by pulsed-field gel electrophoresis （PFGE）. Four major PFGE types （A, B, C, and D） accounted for 82.7% of all isolates, and type A （41.3%） was observed in multiple herds across the studied areas. Each region was found to have a predominant type： Hangzhou type A （64.1%）, Ningbo type C （34.5%） and type B （23.1%）, Jinhua type D （53.3%）, and Taizhou type C （62.5%）. Results of antimicrobial susceptibility tests showed that 90.7% of the isolates were resistant to at least one antimicrobial. Resistance to penicillin and ampicillin （77.3%）, tetracycline （60.0%）, or erythromycin （48.0%） was observed. The bacteria resistant to multiple antibiotics such as penicillin, ampicillin, tetracycline, and erythromycin were commonly found. The information obtained from this study is useful for designing specific control programs for bovine S. aureus mastitis in this region.
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,China (1610322015007)the Key Technology R&D Program of China during the 12th Five-Year Plan period (2012BAD12B03)the Natural Science Foundation of Gansu Province,China (145RJYA311)
文摘Staphylococcus aureus is the most common etiological pathogen of bovine mastitis. The resistant strains make the disease difficult to cure. The aim of this study was to characterize the genetic nature of the antimicrobial resistance in S. aureus cultured from bovine mastitis in Northwest China in 2014. A total of 44 S. aureus were isolated for antimicrobial resistance and resistance-related genes. Antimicrobial resistance was determined by disc diffusion and the corresponding resistance genes were detected by PCR. Phenotype indicated that S. aureus isolates were resistant to penicillin （84.09%）, erythromycin （20.45%）, tetracycline （15.91%）, gentamicin （9.09%）, tobramycin （6.82%）, kanamycin （6.82%） and methicillin （2.27%）. 9.09% of the S. aureus isolates were classified as multidrug resistant. In addition, genotypes showed that the isolates were resistant to rifampicin （100%, rpoB）, penicillin （95.45%, blaZ）, tetracycline （22.73%, tetK, tetM, alone or in combination）, erythromycin （22.73%, ermB or ermC）, gentamicin/tobramycin/kanamycin （2.27%, aacA-aphD）, methicillin （2.27%, mecA） and vancomycin （2.27%, vanA）. Resistance to tetracycline was attributed to the genes tetK and tetM （r=0.558, P〈0.001）. This study noted high-level geno- and phenotypic antimicrobial resistance in S. aureus isolates from bovine mastitis cases in Northwest China.
