TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early c...TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early cephalosporins,TEM and SHV variants have evolved with the ability to hydrolyze the second-and third-generation cephalosporins,monobactams,and evenβ-lactamase inhibitors.Accurate detection ofβ-lactamases is of paramount importance for optimizing antibiotic use and combating antimicrobial resistance(AMR).While genetic detection methods,such as polymerase chain reaction(PCR),are widely employed,their positive results may lack phenotypic correlation due to the low or absent expression of blaSHV and blaTEM in many strains[1].Therefore,a direct protein-level detection method such as targeted proteomics is more precise and clinically relevant.This study highlights the development of a rapid detection method using targeted proteomics with high-resolution accurate mass(HRAM)Orbitrap MS for the direct detection of TEM and SHV in Enterobacteriaceae strains,which offers greater clinical relevance compared to conventional genetic approaches.展开更多
Dear Editor,Bacteriophages(otherwise called phages)are a type of virus that infect bacteria.This viral type has found useful applications in the control of bacterial pathogens in foods and food processing environments...Dear Editor,Bacteriophages(otherwise called phages)are a type of virus that infect bacteria.This viral type has found useful applications in the control of bacterial pathogens in foods and food processing environments.In addition,phages may be useful to prevent colonization and shedding of bacteria into the surrounding environment.展开更多
Klebsiella pneumoniae is an opportunistic pathogen that is an important cause of nosocomial infections. Detection of ESBL producers’ poses a special challenge for clinical microbiology laboratories, although ESBL pro...Klebsiella pneumoniae is an opportunistic pathogen that is an important cause of nosocomial infections. Detection of ESBL producers’ poses a special challenge for clinical microbiology laboratories, although ESBL producing pathogens are able to hydrolyze extended-spectrum penicillins, cephalosporins, and aztreonam, the minimum inhibitory concentrations (MIC) of some and perhaps even all of these agents may be within the susceptible range. The third generation cephalosporins have the reputation for being useful against a broad range of bacterial infections. However, resistance to these agents is something that must still be considered and creates obstacles for their clinical use. A total of 80 multi drug resistant clinical isolates of Klebsiella pneumoniae were obtained from a study on anaerobes associated with Pelvic Inflammatory disease (P.I.D), KEMRI S.S.C No.495. The isolates were identified by standard microbiological procedures. Antimicrobial susceptibility testing was carried out by Kirby-Bauer method. Upon identification, the antibiogram profiles of the isolates were determined and those resistant to third-generation cephalosporins were tested for production of ESBL. ESBL production among the multi drug resistant isolates was detected using the phenotypic confirmatory disc diffusion test (PCDDT) and double disk synergy test (DDST). While using standard double disk synergy test (DDST) as screening method for identifying potential ESBL producers, ceftriaxone was the most efficient antimicrobial in screening isolates as potential ESBL producers followed by cefotaxime.展开更多
Background: β lactamase is a plasmid-encoded enzyme that hydrolyzes β lactam ring of β lactam antibiotics rendering them ineffective. These enzymes, produced by Staphylococcus aureus along with many other organisms...Background: β lactamase is a plasmid-encoded enzyme that hydrolyzes β lactam ring of β lactam antibiotics rendering them ineffective. These enzymes, produced by Staphylococcus aureus along with many other organisms, have hindered the use of many useful and once life-saving β lactam antibiotics from clinical practice. Methods: This study was aimed to compare three test methods-chromogenic, acidimetric and iodometric-for the detection of β lactamase enzyme produced by 404 nosocomial induced S. aureus isolated from two Nepali hospitals, Kathmandu based hospital (KBH) and Lalitpur based Hospital (LBH). The study was carried out following standard methodology during November 2007 to June 2009 in the Department of Microbiology, Institute of Medicine, Kathmandu, Nepal. Sensitivity, specificity, efficiency, positive predictive value, and negative predictive values of the tests were calculated taking penicillin resistance and sensitivity as the standard. Results: Chromogenic method was found to be the most sensitive (98.93%) and efficient (98.51%) test and had a high positive predictive value (99.46%). Sensitivity (98.4%) and efficiency (98.27%) of iodometric method was found to be comparable to chromogenic test;its specificity (96.55 %) and positive predictive value (99.73%) were the highest among the 3 tests. Acidimetric test was the least sensitive (97.33%) and efficient (96.78%). Of note, the sensitivity and specificity of these test methods have been compromised due to the negativity of few penicillin resistant isolates and positivity of some penicillin sensitive isolates, respectively. Conclusion: Chromogenic method was found comparatively to be the best test method for the detection of β lactamase production. However, in contrast to the other two test methods whose reagents can be locally and economically prepared, chromogenic test’s use has been impeded by its cost and unavailability in the local Nepali market.展开更多
Introduction: Enterobacteriaceae causing urinary tract infections (UTI) have developed resistance to the commonly used antibiotics due to emergence of Extended Spectrum Beta-Lactamases (ESBLs) and Carbapenamase produc...Introduction: Enterobacteriaceae causing urinary tract infections (UTI) have developed resistance to the commonly used antibiotics due to emergence of Extended Spectrum Beta-Lactamases (ESBLs) and Carbapenamase producing Enterobactericeae which are a public health problem worldwide. This study aims to determine the prevalence and characterize ESBLs and carbapenamase producing Enterobactericeae. Method: A cross-sectional study was carried out in Gertrude’s Children’s Hospital, Nairobi. 238 urine samples were collected from patients with urinary symptoms attending the outpatient department within the period 2020-2021. The urine were examined macroscopically and microscopically. Identification and antimicrobial susceptibility testing were done using VITEK® 2 Compact system (BioMérieux). Double disc synergy test and modified hodge tests were done as confirmatory tests for ESBLs and Carbapenamase phenotypes respectively. Polymerase Chain Reaction was used for the detection of blaCTX-M, blaTEM, blaSHV, blaKPC and blaOXA-48 genes. Results: From the 238 children sampled the prevalence of UTI caused by Enterobactericeae was 22.3%. The Enterobacteriaceae species isolated were Escherichia coli (84.9%), Klebsiella pneumoniae (5.66%), Proteus mirabillis (5.66%), Enterobacter aerogenes (1.89%) and Morganella morganii (1.89%). The isolated species were resistant to ampicillin. Meropenem had the highest susceptibility. Only E. coli species had the ESBLs (26.4%) and carbapenamase (1.9%) phenotypes. 100% had BlaCTX-M while 50% had blaTEM resistant gene. There was a significant association (p Conclusion: Ampicillin resistance resulted to use of alternative drugs and Meropenem was the drug of choice where increased resistance to the recommended drugs was noted. Further research on resistant genes is recommended.展开更多
This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted ...This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted to humans via faeces or contaminated meat. A total of 280 strains of Escherichia coli and 129 strains of Salmonella spp. resistant to at least one beta-lactam or carbapenem antibiotic were used in this study. PCR analyses revealed the presence of ESBL (extended spectrum beta lactamase) resistance genes in Escherichia coli isolates, with 3.21% (9/280) possessing the CTX-M (Cefotaximase) gene, 15.35% (43/280) had the SHV (Sulfhydril Variable) gene, and 11.42% (32/280) had carbapenemase resistance genes, more specifically IMP (Imipenemase metallo-beta-lactamase). As regards Salmonella spp. strains, only the presence of the SHV (Sulfhydril Variable) gene was identified in 2.32% (3/129) of isolates belonging to the ESBL family, while 26.35% (34/129) and 13.95% (18/129) of isolates respectively possessed the IMP (Imipenemase metallo-beta-lactamase) and NDM (New Delhi metallo-β-lactamase) genes, both of the carbapenemase type. The significant prevalence of resistance genes in bacterial strains isolated from chickens sold outdoors in Ouagadougou raises major public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.展开更多
Background: Urinary tract infection (UTI) is a bacterial infection affecting males and females but is more prevalent in expectant women. ESBLs are bacteria with enzymes that make them resistant to many antibiotics, po...Background: Urinary tract infection (UTI) is a bacterial infection affecting males and females but is more prevalent in expectant women. ESBLs are bacteria with enzymes that make them resistant to many antibiotics, posing a significant health challenge. This study aims to determine the characteristics of ESBL-producing bacteria causing UTIs in expectant women. Methodology: A self-administered survey was carried out;300 expectant women were recruited using a random sampling method. A questionnaire was used to collect socio-demographic information. Urine samples were collected in sterile universal bottles and processed at the JKUAT Zoology laboratory. Urine samples were analyzed using urinalysis, microscopy, culture, and sensitivity testing. ESBL-producing bacteria were identified phenotypically using the double-disc synergy test (DDST) and genotyped for specific resistant genes using PCR. Results: UTI prevalence was 32.7% (98/300). UTI was significantly associated with the history of previous UTI (OR = 0.84, p = 0.02) and multigravida (OR = 0.14 p = 0.01). UTI was common in women aged between 28-37 years in their second trimester. Bacteria isolated were E. coli 57.1% (56/98), S. aureus 21.4% (21/98) K. pneumonia 11.2% (11/98) and Proteus spp 10.4% (10/98). Bacteria antibiotic resistance patterns were E. coli-tetracycline (91.1%), sulfamethoxazole (55.4%), cefotaxime (53.4%) and augmentin (53.4%). S. aureus-sulfamethozaxole (100%) and augmentin (71.4%), K. pneumoniae-sulfame-thoxazole (72.2%) cefotaxime (63.6%), chloramphenicol and tetracycline (54.5%). Proteus spp: tetracycline (100%), nitrofurantoin (90%), cefotaxime and chloramphenicol (50%). The proportion of ESBLs bacterial producers was 37.6% (29/77) and 44.8% (13/29) possessed ESBLs resistant genes;Bla CTX-M 53.8% (7/13), Bla SHV and Bla TEM 23.1% (3/13) each, Bla OXA (0%) was not detected. Conclusion: The study revealed a high proportion of ESBLs producing bacteria responsible for UTI in expectant women. ESBLs screening, routine culture and sensitivity testing will guide on proper management and empirical treatment of UTI patients thus reducing multi-drug resistance.展开更多
Metallo-β-Lactamases (MBLs) and Extended Spectrum β-Lactamses (ESBLs) have emerged world-wide as a significant source of β-lactam resistance. The emergence of MBLs and ESBLs encoded on plasmids among Gram-negative ...Metallo-β-Lactamases (MBLs) and Extended Spectrum β-Lactamses (ESBLs) have emerged world-wide as a significant source of β-lactam resistance. The emergence of MBLs and ESBLs encoded on plasmids among Gram-negative pathogens in hospital dumpsites was investigated. Soils of different government and private hospitals were collected and processed following standard bacteriological techniques. Antimicrobial susceptibility testing was carried out by the disk-diffusion technique using Ceftazidime (30 μg), Cefuroxime (30 μg), Cefotaxime (30 μg), Cefixime (5 μg), Trimethprim-sulfamethoxazole (25 μg), Gentamycin (100 μg) Amoxicillin-Clavunalate (30 μg), Ciprofloxacin (5 μg), Ofloxacin (5 μg), Nitrofurantoin (300 μg) and Imipenem (10 μg). The role of plasmids in resistance was evaluated by subjecting isolates to curing using Sodium Dodecyl Sulfate (SDS). ESBLs production by Double-Disk Synergy Test (DDST) was carried out. Isolates resistant to Imipenem were subjected to a confirmatory test using Modified Hodge’s test and to MBLs production by DDST. Eighty-two Gram-negative isolates comprising of 32 (39.02%) Escherichia coli, 20 (24.39%) Serratia marcescens, 14 (17.07%) Klebsiella pneumonia, 10 (12.28%) Proteus mirabilis and 6 (7.32%) Enterobacter aerogenes were obtained. Susceptibility results revealed a 100% resistance of all isolates to Ceftazidime, Cefuroxime, Cefixime, Amoxycillin-clavulanate and Cefotaxime. A total of 66 (80.48%) isolates harboured plasmids out of which 26 (31.71%) isolates were ESBL producers. MBLs production was observed in 8 (25.00%) E. coli, 2 (2.41%) Klebsiella pneumonia and 2 (2.41%) Proteus mirabilis isolates. All MBLs producing isolates were ESBLs producers. The finding of highly resistant isolates producing ESBLs and MBLs in a hospital environment is quite disturbing and should be addressed urgently.展开更多
Introduction:Understanding the prevalence and dissemination pathways of the clinically relevant extended-spectrumβ-lactamase(ESBL)genes and ESBL-producing Escherichia coli(E.coli)within the Yellow River is essential ...Introduction:Understanding the prevalence and dissemination pathways of the clinically relevant extended-spectrumβ-lactamase(ESBL)genes and ESBL-producing Escherichia coli(E.coli)within the Yellow River is essential from a One Health perspective to control antibiotic resistance dissemination from environmental reservoirs to human populations.Methods:Water samples were collected from the Yellow River and two of its major tributaries in Henan Province during 2023 and 2024.TaqMan quantitative polymerase chain reaction(qPCR)was used to quantify the abundance of the ESBL gene bla_(CTX-M-G9).Twenty-three E.coli isolates underwent whole-genome sequencing(WGS),and 167 publicly available E.coli genomes from diverse sources were incorporated into the comparative phylogenetic analysis.Results:The bla_(CTX-M-G9) gene was ubiquitous across all sampling sites,exhibiting significantly higher relative abundance during the dry season compared to the flat season.The multidrug-resistant E.coli sequence type(ST)6802 carrying bla_(CTX-M-14) emerged as the predominant clone.Strong positive correlations were observed between bla_(CTX-M-G9) abundance and plasmids carried by E.coli ST6802 in the Yellow River,providing evidence for clonal expansion during the dry season.Furthermore,comparative phylogenetic analysis integrating human,animal,and environmental isolates demonstrated that ST6802 strains from this study were closely related to those previously identified in anaerobic digestion systems treating pig manure in China,suggesting an animal-to-environment transmission pathway.Conclusion:These findings emphasize the urgent need to implement targeted interventions that prevent the transmission of antibiotic resistance from animal sources into aquatic environments,thereby protecting public health and preserving the integrity of critical water resources.展开更多
To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms ...To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms Methods A total of 282 clinical isolates of E coli and 180 of K pneumoniae were collected from different districts of Zhejiang Province Inhibitor potentiated broth dilution tests were performed for detecting extended spectrum β lactamases Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics Results The prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 34 0% and 38 3%, respectively The average prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 35 7% The resistance prevalence of extended spectrum β lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin tazobactam, cefoperazone sulbactam, amikacin and ciprofloxacin All these strains were sensitive to imipenem Conclusion The results in this study showed that the prevalence of extended spectrum β lactamases was high, while extended spectrum β lactamase producing strains were resistant to most antimicrobial agents except imipenem展开更多
Objective:To find out the antibacterial activity of Valeriana jatamansi(V.jatamansi)rhizomes against the extended-spectrumβ-lactamases(ESBLs)producing isolates of Enterobacteriaceae family.Methods:Confirmation of ESB...Objective:To find out the antibacterial activity of Valeriana jatamansi(V.jatamansi)rhizomes against the extended-spectrumβ-lactamases(ESBLs)producing isolates of Enterobacteriaceae family.Methods:Confirmation of ESBLs producing Escherichia coli,Enterobacter aerogenes,Klebsiella pneumoniae and Hafnia alvei isolated from urinary tract infections was performed by double disc diffusion assay.Antimicrobial susceptibility of all ESBLs producing isolates was determined by disc diffusion method following guidelines of Clinical and Laboratory Standards Institute.Successive extraction of rhizomes of V.jatamansi was performed with hexane,chloroform and methanol using Soxhelt apparatus.These extracts were tested against the ESBLs producing isolates using well diffusion method.Results:Hexane extract showed significant results as compared to chloroform and methanol extracts with the maximum zone of inhibition(21 mm)while ciprofloxacin and amikacin were used as standard drugs.Conclusions:Findings of the study suggested that hexane extract of V.jatamansi can be used in combination with other antibiotics as alternative treatment for urinary tract infections caused by ESBLs producing strains of Enterobacteriaceae.展开更多
DearEditor,Klebsiella pneumoniae,a member of the Enterobacterales,is a common resident of the gastrointestinal tract of humans and animals and is also ubiquitous in the environment.Klebsiella pneumoniae is also a comm...DearEditor,Klebsiella pneumoniae,a member of the Enterobacterales,is a common resident of the gastrointestinal tract of humans and animals and is also ubiquitous in the environment.Klebsiella pneumoniae is also a common pathogen recovered from clinical samples and is able to cause a wide range of infections including life-threatening bacteremia,meningitis,and pneumonia[1].β-Lactams,especially third-generation cephalosporins and carbapenems,are mainstay antimicrobial options for infections caused by the Enterobacterales such as K.pneumoniae.Worryingly,K.pneumoniae has emerged as a major carrier of antimicrobial resistance determinants including those encoding extended-spectrumβ-lactamases(ESBL)and carbapenem-hydrolyzingβ-lactamases(carbapenemases).展开更多
Objective To evaluate the activity of six β-lactams in combination with three β-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro.Methods A total of 105 multidrug-resistant tuberculosis (MDR-TB)s...Objective To evaluate the activity of six β-lactams in combination with three β-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro.Methods A total of 105 multidrug-resistant tuberculosis (MDR-TB)strains from different regions of Henan province from January to September 2020 were included in this study.展开更多
Extended spectrum β-lactamases occur commonly in the aerobic Gram negative bacteria (AGNB) such as E. coli, Klebsiella spp., Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., etc. and have the ability to make...Extended spectrum β-lactamases occur commonly in the aerobic Gram negative bacteria (AGNB) such as E. coli, Klebsiella spp., Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., etc. and have the ability to make these organisms resistant to cephalosporins (e.g. ceftazidime, ceftriaxone, cefotaxime etc.), penicillins, and monobactams, i.e. aztreonam. However theses antibiotics become sensitive in the presence of clavulanic acid, an extended spectrum beta-lactamase (ESBL) inhibitor. ESBL enzymes do not influence cephamycins or carbapenems, i.e. meropenem, imipenem, etc. Major problems in surgery is wound infections after operations. High risks of wound infections are due to being immune-comprised on antibiotics, prolonged hospitalization and other factors in many cases. The current research determined various aerobic gram negative bacteria in post-operative wound infections at the College of Medical Laboratory Technology, the National Institute of Health, Islamabad, Pakistan. It also determined the frequency of ESBL in the organisms and established their susceptibility profile during the time period of the research. Infections caused by ESBL producers are a major problem in our post-operative patients. The commonest isolate was E. coli and the commonest ESBL producer was Klebsiella spp. Double disk synergy test is an effective method for screening of such isolates, and the practice of incorporating this test along with the routine sensitivity is recommended.展开更多
To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ- lactam antibiotics,the outer mem brane permeability rate of30 P.aeruginosa strains to5 β- lactam antibiotics was m easured ...To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ- lactam antibiotics,the outer mem brane permeability rate of30 P.aeruginosa strains to5 β- lactam antibiotics was m easured and their production ofβ- lactamase and theβ- lactam ase genes they carried detected. Furthermore,the relationship between the perm eability,β- lactam ase and the clinical effects ofβ- lactam antibiotics was observed. By using 1 4C- penicillin and liquid- scintillant isotope assay,the affinity of penicillin binding proteins(PBPs) was m easured and their roles in the resistant m echanism studied.Itwas revealed thatthe perm eability rate was higher in sensitive strains than in resistantones(P<0 .0 5 ) .All strains harbored1- 4 β- lactamase genes and produced β- lactam ase.Higher permeability rate and higher degree of stability toβ- lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the perm eability andβ- lactam ase. These results suggested that the permeability of outer mem brane andβ- lacta- mase,but not PBPs,played im portant roles in the resistant mechanism of P. aeruginosa toβ- lac- tam antibiotics and affected the clinical therapeutic effectiveness of som e patients.展开更多
Multidrug resistant（MDR） pathogen infections are serious threats to hospitalized patients because of the limited therapeutic options. A novel group of antibiotic candidates, antimicrobial peptides（AMPs）, have rece...Multidrug resistant（MDR） pathogen infections are serious threats to hospitalized patients because of the limited therapeutic options. A novel group of antibiotic candidates, antimicrobial peptides（AMPs）, have recently shown powerful activities against both Gram-negative and Gram-positive bacteria. Unfortunately, the viability of using these AMPs in clinical settings remains to be seen, since most still need to be evaluated prior to clinical trials and not all of AMPs are potent against MDR clinical isolates. To find a connection between the characteristics of several of these AMPs and their effects against MDR pathogens, we selected 14 AMPs of animal origin with typical structures and evaluated their in vitro activities against clinical strains of extensive drugresistant Acinetobacter baumannii, methicillinresistant Staphylococcus aureus, extended spectrum β-lactamase-producing Pseudomonas aeruginosa and extended spectrum β-lactamase-producing Escherichia coli. Our results showed that these peptides＇ hydrophilic/hydrophobic characteristics, rather than their secondary structures, may explain their antibacterial effects on these clinical isolates. Peptides that are amphipathic along the longitudinal direction seemed to be effective against Gramnegative pathogens, while peptides with hydrophilic terminals separated by a hydrophobic intermediate section appeared to be effective against both Gramnegative and Gram-positive pathogens. Among these, cathelicidin-BF was found to inhibit all of the Gram-negative pathogens tested at dosages of no more than 16 mg/L, killing a pandrug-resistant A. baumannii strain within 2 h at 4×MICs and 4 h at 2×MICs. Tachyplesin III was also found capable of inhibiting all Gram-negative and Gram-positive pathogens tested at no more than 16 mg/L, and similarly killed the same A. baumannii strain within 4 h at 4×MICs and 2×MICs. These results suggest that both cathelicidin-BF and tachyplesin III are likely viable targets for the development of AMPs for clinical uses.展开更多
Objective To investigate the relationship between the consumption of antibacterial agents and resistance rate of Klebsiela pneumoniae(KP)in the hospital respiratory unit for 3 consecutive years in 2005-2007.Methods Th...Objective To investigate the relationship between the consumption of antibacterial agents and resistance rate of Klebsiela pneumoniae(KP)in the hospital respiratory unit for 3 consecutive years in 2005-2007.Methods The total antibacterial consumption expressed as defined DDDs/100BD,as well as resistance rate of total KP and producing ESBLs KP were collected,and their correlation was analyzed.Results The rate of resistance of KP to cefoperazone/sulbactam,Cefepime,Imipenem,Moxifloxacin was significantly positively associated with the consumption of Cefotaxime,Ceftazidime,Moxifloxacin,Amikacin respectively;A significant positive association was observed between the rate of resistance of KP to Piperacillin/Tazobactam,Ceftriaxone and the consumption of Imipenem;The rate of resistance of KP to Piperacillin,Cefotaxime,Ciprofloxacin was significantly positively associated with the consumption of Levofloxacin.ESBLs producing bacilli of KP were detected in 44 of 75 isolates(58.7%),The rate of resistance of producing ESBLs KP to Piperacillin/Tazobactam,Ceftriaxone was significantly positively associated with the consumption of Imipenem,Ceftazidime;A significant positive association was observed between the rate of resistance of producing ESBLs KP to Piperacillin,Imipenem and the consumption of Moxifloxacin.There was no significant correlation in other drugs.Conclusions A relationship existed between antimicrobial consumption and rates of resistance of KP in the hospital respiratory unit.We must use antibiotics carefully and with reason to control and lessen the drug resistance of bacterial.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.:32141003,82330110,and 81803593)the CAMS Innovation Fund for Medical Sciences(CIFMS),China(Grant Nos.:2021-I2M-1-030,and 2021-I2M-1-039)+1 种基金the Fundamental Research Funds for the Central Universities,China(Grant No.:3332018094)the National Science and Technology Infrastructure of China(Project No.:National Pathogen Resource Center-NPRC-32).
文摘TEM and SHV are among the most prevalentβ-lactamases contributing toβ-lactam antibiotic resistance in clinical settings,leading to treatment challenges and increased mortality rates.Except for penicillin and early cephalosporins,TEM and SHV variants have evolved with the ability to hydrolyze the second-and third-generation cephalosporins,monobactams,and evenβ-lactamase inhibitors.Accurate detection ofβ-lactamases is of paramount importance for optimizing antibiotic use and combating antimicrobial resistance(AMR).While genetic detection methods,such as polymerase chain reaction(PCR),are widely employed,their positive results may lack phenotypic correlation due to the low or absent expression of blaSHV and blaTEM in many strains[1].Therefore,a direct protein-level detection method such as targeted proteomics is more precise and clinically relevant.This study highlights the development of a rapid detection method using targeted proteomics with high-resolution accurate mass(HRAM)Orbitrap MS for the direct detection of TEM and SHV in Enterobacteriaceae strains,which offers greater clinical relevance compared to conventional genetic approaches.
基金Research University Grant Scheme(RUGSgrant number 9329400)University Putra Malaysia,partly funded the research
文摘Dear Editor,Bacteriophages(otherwise called phages)are a type of virus that infect bacteria.This viral type has found useful applications in the control of bacterial pathogens in foods and food processing environments.In addition,phages may be useful to prevent colonization and shedding of bacteria into the surrounding environment.
文摘Klebsiella pneumoniae is an opportunistic pathogen that is an important cause of nosocomial infections. Detection of ESBL producers’ poses a special challenge for clinical microbiology laboratories, although ESBL producing pathogens are able to hydrolyze extended-spectrum penicillins, cephalosporins, and aztreonam, the minimum inhibitory concentrations (MIC) of some and perhaps even all of these agents may be within the susceptible range. The third generation cephalosporins have the reputation for being useful against a broad range of bacterial infections. However, resistance to these agents is something that must still be considered and creates obstacles for their clinical use. A total of 80 multi drug resistant clinical isolates of Klebsiella pneumoniae were obtained from a study on anaerobes associated with Pelvic Inflammatory disease (P.I.D), KEMRI S.S.C No.495. The isolates were identified by standard microbiological procedures. Antimicrobial susceptibility testing was carried out by Kirby-Bauer method. Upon identification, the antibiogram profiles of the isolates were determined and those resistant to third-generation cephalosporins were tested for production of ESBL. ESBL production among the multi drug resistant isolates was detected using the phenotypic confirmatory disc diffusion test (PCDDT) and double disk synergy test (DDST). While using standard double disk synergy test (DDST) as screening method for identifying potential ESBL producers, ceftriaxone was the most efficient antimicrobial in screening isolates as potential ESBL producers followed by cefotaxime.
文摘Background: β lactamase is a plasmid-encoded enzyme that hydrolyzes β lactam ring of β lactam antibiotics rendering them ineffective. These enzymes, produced by Staphylococcus aureus along with many other organisms, have hindered the use of many useful and once life-saving β lactam antibiotics from clinical practice. Methods: This study was aimed to compare three test methods-chromogenic, acidimetric and iodometric-for the detection of β lactamase enzyme produced by 404 nosocomial induced S. aureus isolated from two Nepali hospitals, Kathmandu based hospital (KBH) and Lalitpur based Hospital (LBH). The study was carried out following standard methodology during November 2007 to June 2009 in the Department of Microbiology, Institute of Medicine, Kathmandu, Nepal. Sensitivity, specificity, efficiency, positive predictive value, and negative predictive values of the tests were calculated taking penicillin resistance and sensitivity as the standard. Results: Chromogenic method was found to be the most sensitive (98.93%) and efficient (98.51%) test and had a high positive predictive value (99.46%). Sensitivity (98.4%) and efficiency (98.27%) of iodometric method was found to be comparable to chromogenic test;its specificity (96.55 %) and positive predictive value (99.73%) were the highest among the 3 tests. Acidimetric test was the least sensitive (97.33%) and efficient (96.78%). Of note, the sensitivity and specificity of these test methods have been compromised due to the negativity of few penicillin resistant isolates and positivity of some penicillin sensitive isolates, respectively. Conclusion: Chromogenic method was found comparatively to be the best test method for the detection of β lactamase production. However, in contrast to the other two test methods whose reagents can be locally and economically prepared, chromogenic test’s use has been impeded by its cost and unavailability in the local Nepali market.
文摘Introduction: Enterobacteriaceae causing urinary tract infections (UTI) have developed resistance to the commonly used antibiotics due to emergence of Extended Spectrum Beta-Lactamases (ESBLs) and Carbapenamase producing Enterobactericeae which are a public health problem worldwide. This study aims to determine the prevalence and characterize ESBLs and carbapenamase producing Enterobactericeae. Method: A cross-sectional study was carried out in Gertrude’s Children’s Hospital, Nairobi. 238 urine samples were collected from patients with urinary symptoms attending the outpatient department within the period 2020-2021. The urine were examined macroscopically and microscopically. Identification and antimicrobial susceptibility testing were done using VITEK® 2 Compact system (BioMérieux). Double disc synergy test and modified hodge tests were done as confirmatory tests for ESBLs and Carbapenamase phenotypes respectively. Polymerase Chain Reaction was used for the detection of blaCTX-M, blaTEM, blaSHV, blaKPC and blaOXA-48 genes. Results: From the 238 children sampled the prevalence of UTI caused by Enterobactericeae was 22.3%. The Enterobacteriaceae species isolated were Escherichia coli (84.9%), Klebsiella pneumoniae (5.66%), Proteus mirabillis (5.66%), Enterobacter aerogenes (1.89%) and Morganella morganii (1.89%). The isolated species were resistant to ampicillin. Meropenem had the highest susceptibility. Only E. coli species had the ESBLs (26.4%) and carbapenamase (1.9%) phenotypes. 100% had BlaCTX-M while 50% had blaTEM resistant gene. There was a significant association (p Conclusion: Ampicillin resistance resulted to use of alternative drugs and Meropenem was the drug of choice where increased resistance to the recommended drugs was noted. Further research on resistant genes is recommended.
文摘This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted to humans via faeces or contaminated meat. A total of 280 strains of Escherichia coli and 129 strains of Salmonella spp. resistant to at least one beta-lactam or carbapenem antibiotic were used in this study. PCR analyses revealed the presence of ESBL (extended spectrum beta lactamase) resistance genes in Escherichia coli isolates, with 3.21% (9/280) possessing the CTX-M (Cefotaximase) gene, 15.35% (43/280) had the SHV (Sulfhydril Variable) gene, and 11.42% (32/280) had carbapenemase resistance genes, more specifically IMP (Imipenemase metallo-beta-lactamase). As regards Salmonella spp. strains, only the presence of the SHV (Sulfhydril Variable) gene was identified in 2.32% (3/129) of isolates belonging to the ESBL family, while 26.35% (34/129) and 13.95% (18/129) of isolates respectively possessed the IMP (Imipenemase metallo-beta-lactamase) and NDM (New Delhi metallo-β-lactamase) genes, both of the carbapenemase type. The significant prevalence of resistance genes in bacterial strains isolated from chickens sold outdoors in Ouagadougou raises major public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.
文摘Background: Urinary tract infection (UTI) is a bacterial infection affecting males and females but is more prevalent in expectant women. ESBLs are bacteria with enzymes that make them resistant to many antibiotics, posing a significant health challenge. This study aims to determine the characteristics of ESBL-producing bacteria causing UTIs in expectant women. Methodology: A self-administered survey was carried out;300 expectant women were recruited using a random sampling method. A questionnaire was used to collect socio-demographic information. Urine samples were collected in sterile universal bottles and processed at the JKUAT Zoology laboratory. Urine samples were analyzed using urinalysis, microscopy, culture, and sensitivity testing. ESBL-producing bacteria were identified phenotypically using the double-disc synergy test (DDST) and genotyped for specific resistant genes using PCR. Results: UTI prevalence was 32.7% (98/300). UTI was significantly associated with the history of previous UTI (OR = 0.84, p = 0.02) and multigravida (OR = 0.14 p = 0.01). UTI was common in women aged between 28-37 years in their second trimester. Bacteria isolated were E. coli 57.1% (56/98), S. aureus 21.4% (21/98) K. pneumonia 11.2% (11/98) and Proteus spp 10.4% (10/98). Bacteria antibiotic resistance patterns were E. coli-tetracycline (91.1%), sulfamethoxazole (55.4%), cefotaxime (53.4%) and augmentin (53.4%). S. aureus-sulfamethozaxole (100%) and augmentin (71.4%), K. pneumoniae-sulfame-thoxazole (72.2%) cefotaxime (63.6%), chloramphenicol and tetracycline (54.5%). Proteus spp: tetracycline (100%), nitrofurantoin (90%), cefotaxime and chloramphenicol (50%). The proportion of ESBLs bacterial producers was 37.6% (29/77) and 44.8% (13/29) possessed ESBLs resistant genes;Bla CTX-M 53.8% (7/13), Bla SHV and Bla TEM 23.1% (3/13) each, Bla OXA (0%) was not detected. Conclusion: The study revealed a high proportion of ESBLs producing bacteria responsible for UTI in expectant women. ESBLs screening, routine culture and sensitivity testing will guide on proper management and empirical treatment of UTI patients thus reducing multi-drug resistance.
文摘Metallo-β-Lactamases (MBLs) and Extended Spectrum β-Lactamses (ESBLs) have emerged world-wide as a significant source of β-lactam resistance. The emergence of MBLs and ESBLs encoded on plasmids among Gram-negative pathogens in hospital dumpsites was investigated. Soils of different government and private hospitals were collected and processed following standard bacteriological techniques. Antimicrobial susceptibility testing was carried out by the disk-diffusion technique using Ceftazidime (30 μg), Cefuroxime (30 μg), Cefotaxime (30 μg), Cefixime (5 μg), Trimethprim-sulfamethoxazole (25 μg), Gentamycin (100 μg) Amoxicillin-Clavunalate (30 μg), Ciprofloxacin (5 μg), Ofloxacin (5 μg), Nitrofurantoin (300 μg) and Imipenem (10 μg). The role of plasmids in resistance was evaluated by subjecting isolates to curing using Sodium Dodecyl Sulfate (SDS). ESBLs production by Double-Disk Synergy Test (DDST) was carried out. Isolates resistant to Imipenem were subjected to a confirmatory test using Modified Hodge’s test and to MBLs production by DDST. Eighty-two Gram-negative isolates comprising of 32 (39.02%) Escherichia coli, 20 (24.39%) Serratia marcescens, 14 (17.07%) Klebsiella pneumonia, 10 (12.28%) Proteus mirabilis and 6 (7.32%) Enterobacter aerogenes were obtained. Susceptibility results revealed a 100% resistance of all isolates to Ceftazidime, Cefuroxime, Cefixime, Amoxycillin-clavulanate and Cefotaxime. A total of 66 (80.48%) isolates harboured plasmids out of which 26 (31.71%) isolates were ESBL producers. MBLs production was observed in 8 (25.00%) E. coli, 2 (2.41%) Klebsiella pneumonia and 2 (2.41%) Proteus mirabilis isolates. All MBLs producing isolates were ESBLs producers. The finding of highly resistant isolates producing ESBLs and MBLs in a hospital environment is quite disturbing and should be addressed urgently.
基金Supported by the National Key Research and Development Program of China(2022YFC3204703)the Natural Science Foundation of Henan Province of China(242300420335)the Specialized Project of High-level Talents in Henan Agricultural University(30501469,30501989).
文摘Introduction:Understanding the prevalence and dissemination pathways of the clinically relevant extended-spectrumβ-lactamase(ESBL)genes and ESBL-producing Escherichia coli(E.coli)within the Yellow River is essential from a One Health perspective to control antibiotic resistance dissemination from environmental reservoirs to human populations.Methods:Water samples were collected from the Yellow River and two of its major tributaries in Henan Province during 2023 and 2024.TaqMan quantitative polymerase chain reaction(qPCR)was used to quantify the abundance of the ESBL gene bla_(CTX-M-G9).Twenty-three E.coli isolates underwent whole-genome sequencing(WGS),and 167 publicly available E.coli genomes from diverse sources were incorporated into the comparative phylogenetic analysis.Results:The bla_(CTX-M-G9) gene was ubiquitous across all sampling sites,exhibiting significantly higher relative abundance during the dry season compared to the flat season.The multidrug-resistant E.coli sequence type(ST)6802 carrying bla_(CTX-M-14) emerged as the predominant clone.Strong positive correlations were observed between bla_(CTX-M-G9) abundance and plasmids carried by E.coli ST6802 in the Yellow River,providing evidence for clonal expansion during the dry season.Furthermore,comparative phylogenetic analysis integrating human,animal,and environmental isolates demonstrated that ST6802 strains from this study were closely related to those previously identified in anaerobic digestion systems treating pig manure in China,suggesting an animal-to-environment transmission pathway.Conclusion:These findings emphasize the urgent need to implement targeted interventions that prevent the transmission of antibiotic resistance from animal sources into aquatic environments,thereby protecting public health and preserving the integrity of critical water resources.
文摘To investigate the epidemiological status of extended spectrum β lactamase (ESBL) producing Escherichia coli (E. coli) and Klebsiella pneumoniae (K. pneumoniae) and the drug resistance profiles of such organisms Methods A total of 282 clinical isolates of E coli and 180 of K pneumoniae were collected from different districts of Zhejiang Province Inhibitor potentiated broth dilution tests were performed for detecting extended spectrum β lactamases Etests were performed to detect the drug resistance of these strains against nine commonly used antibiotics Results The prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 34 0% and 38 3%, respectively The average prevalence of extended spectrum β lactamases in E coli and K pneumoniae was 35 7% The resistance prevalence of extended spectrum β lactamase producing strains to ceftazidime and cefotaxime was 40% and 26% respectively, so were those to cefepime, cefoxitin, piperacillin tazobactam, cefoperazone sulbactam, amikacin and ciprofloxacin All these strains were sensitive to imipenem Conclusion The results in this study showed that the prevalence of extended spectrum β lactamases was high, while extended spectrum β lactamase producing strains were resistant to most antimicrobial agents except imipenem
文摘Objective:To find out the antibacterial activity of Valeriana jatamansi(V.jatamansi)rhizomes against the extended-spectrumβ-lactamases(ESBLs)producing isolates of Enterobacteriaceae family.Methods:Confirmation of ESBLs producing Escherichia coli,Enterobacter aerogenes,Klebsiella pneumoniae and Hafnia alvei isolated from urinary tract infections was performed by double disc diffusion assay.Antimicrobial susceptibility of all ESBLs producing isolates was determined by disc diffusion method following guidelines of Clinical and Laboratory Standards Institute.Successive extraction of rhizomes of V.jatamansi was performed with hexane,chloroform and methanol using Soxhelt apparatus.These extracts were tested against the ESBLs producing isolates using well diffusion method.Results:Hexane extract showed significant results as compared to chloroform and methanol extracts with the maximum zone of inhibition(21 mm)while ciprofloxacin and amikacin were used as standard drugs.Conclusions:Findings of the study suggested that hexane extract of V.jatamansi can be used in combination with other antibiotics as alternative treatment for urinary tract infections caused by ESBLs producing strains of Enterobacteriaceae.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC2308800)the Natural Science Foundation of Sichuan Province(Grant No.2023NSFSC1697)the 1.3.5 Project for Disciplines of Excellence,West China Hospital of Sichuan University(Grant No.ZYGD22001).
文摘DearEditor,Klebsiella pneumoniae,a member of the Enterobacterales,is a common resident of the gastrointestinal tract of humans and animals and is also ubiquitous in the environment.Klebsiella pneumoniae is also a common pathogen recovered from clinical samples and is able to cause a wide range of infections including life-threatening bacteremia,meningitis,and pneumonia[1].β-Lactams,especially third-generation cephalosporins and carbapenems,are mainstay antimicrobial options for infections caused by the Enterobacterales such as K.pneumoniae.Worryingly,K.pneumoniae has emerged as a major carrier of antimicrobial resistance determinants including those encoding extended-spectrumβ-lactamases(ESBL)and carbapenem-hydrolyzingβ-lactamases(carbapenemases).
文摘Objective To evaluate the activity of six β-lactams in combination with three β-lactamase inhibitors against mycobacterium tuberculosis(MTB) in vitro.Methods A total of 105 multidrug-resistant tuberculosis (MDR-TB)strains from different regions of Henan province from January to September 2020 were included in this study.
文摘Extended spectrum β-lactamases occur commonly in the aerobic Gram negative bacteria (AGNB) such as E. coli, Klebsiella spp., Proteus spp., Pseudomonas aeruginosa, Acinetobacter spp., etc. and have the ability to make these organisms resistant to cephalosporins (e.g. ceftazidime, ceftriaxone, cefotaxime etc.), penicillins, and monobactams, i.e. aztreonam. However theses antibiotics become sensitive in the presence of clavulanic acid, an extended spectrum beta-lactamase (ESBL) inhibitor. ESBL enzymes do not influence cephamycins or carbapenems, i.e. meropenem, imipenem, etc. Major problems in surgery is wound infections after operations. High risks of wound infections are due to being immune-comprised on antibiotics, prolonged hospitalization and other factors in many cases. The current research determined various aerobic gram negative bacteria in post-operative wound infections at the College of Medical Laboratory Technology, the National Institute of Health, Islamabad, Pakistan. It also determined the frequency of ESBL in the organisms and established their susceptibility profile during the time period of the research. Infections caused by ESBL producers are a major problem in our post-operative patients. The commonest isolate was E. coli and the commonest ESBL producer was Klebsiella spp. Double disk synergy test is an effective method for screening of such isolates, and the practice of incorporating this test along with the routine sensitivity is recommended.
基金This project was supported by a grant from Natural Sci-ences Foundation of China(No. 395 70 84 6 )
文摘To study the resistant mechanism and clinical significance of pseudomonas aeruginosa toβ- lactam antibiotics,the outer mem brane permeability rate of30 P.aeruginosa strains to5 β- lactam antibiotics was m easured and their production ofβ- lactamase and theβ- lactam ase genes they carried detected. Furthermore,the relationship between the perm eability,β- lactam ase and the clinical effects ofβ- lactam antibiotics was observed. By using 1 4C- penicillin and liquid- scintillant isotope assay,the affinity of penicillin binding proteins(PBPs) was m easured and their roles in the resistant m echanism studied.Itwas revealed thatthe perm eability rate was higher in sensitive strains than in resistantones(P<0 .0 5 ) .All strains harbored1- 4 β- lactamase genes and produced β- lactam ase.Higher permeability rate and higher degree of stability toβ- lactamase indicated better clinical therapeutic effects. The affinity of PBPs changed little without regard to the perm eability andβ- lactam ase. These results suggested that the permeability of outer mem brane andβ- lacta- mase,but not PBPs,played im portant roles in the resistant mechanism of P. aeruginosa toβ- lac- tam antibiotics and affected the clinical therapeutic effectiveness of som e patients.
基金This study was supported by the Peking Union Medical College （PUMC） Youth Fund and the Fundamental Research Funds for the Central Universities, China （333203084）
文摘Multidrug resistant（MDR） pathogen infections are serious threats to hospitalized patients because of the limited therapeutic options. A novel group of antibiotic candidates, antimicrobial peptides（AMPs）, have recently shown powerful activities against both Gram-negative and Gram-positive bacteria. Unfortunately, the viability of using these AMPs in clinical settings remains to be seen, since most still need to be evaluated prior to clinical trials and not all of AMPs are potent against MDR clinical isolates. To find a connection between the characteristics of several of these AMPs and their effects against MDR pathogens, we selected 14 AMPs of animal origin with typical structures and evaluated their in vitro activities against clinical strains of extensive drugresistant Acinetobacter baumannii, methicillinresistant Staphylococcus aureus, extended spectrum β-lactamase-producing Pseudomonas aeruginosa and extended spectrum β-lactamase-producing Escherichia coli. Our results showed that these peptides＇ hydrophilic/hydrophobic characteristics, rather than their secondary structures, may explain their antibacterial effects on these clinical isolates. Peptides that are amphipathic along the longitudinal direction seemed to be effective against Gramnegative pathogens, while peptides with hydrophilic terminals separated by a hydrophobic intermediate section appeared to be effective against both Gramnegative and Gram-positive pathogens. Among these, cathelicidin-BF was found to inhibit all of the Gram-negative pathogens tested at dosages of no more than 16 mg/L, killing a pandrug-resistant A. baumannii strain within 2 h at 4×MICs and 4 h at 2×MICs. Tachyplesin III was also found capable of inhibiting all Gram-negative and Gram-positive pathogens tested at no more than 16 mg/L, and similarly killed the same A. baumannii strain within 4 h at 4×MICs and 2×MICs. These results suggest that both cathelicidin-BF and tachyplesin III are likely viable targets for the development of AMPs for clinical uses.
文摘Objective To investigate the relationship between the consumption of antibacterial agents and resistance rate of Klebsiela pneumoniae(KP)in the hospital respiratory unit for 3 consecutive years in 2005-2007.Methods The total antibacterial consumption expressed as defined DDDs/100BD,as well as resistance rate of total KP and producing ESBLs KP were collected,and their correlation was analyzed.Results The rate of resistance of KP to cefoperazone/sulbactam,Cefepime,Imipenem,Moxifloxacin was significantly positively associated with the consumption of Cefotaxime,Ceftazidime,Moxifloxacin,Amikacin respectively;A significant positive association was observed between the rate of resistance of KP to Piperacillin/Tazobactam,Ceftriaxone and the consumption of Imipenem;The rate of resistance of KP to Piperacillin,Cefotaxime,Ciprofloxacin was significantly positively associated with the consumption of Levofloxacin.ESBLs producing bacilli of KP were detected in 44 of 75 isolates(58.7%),The rate of resistance of producing ESBLs KP to Piperacillin/Tazobactam,Ceftriaxone was significantly positively associated with the consumption of Imipenem,Ceftazidime;A significant positive association was observed between the rate of resistance of producing ESBLs KP to Piperacillin,Imipenem and the consumption of Moxifloxacin.There was no significant correlation in other drugs.Conclusions A relationship existed between antimicrobial consumption and rates of resistance of KP in the hospital respiratory unit.We must use antibiotics carefully and with reason to control and lessen the drug resistance of bacterial.
