Group B Streptococcus(GBS;Streptococcus agalactiae)is a gram-positive coccus that colonizes the gastrointestinal and genital tracts in adults,as well as the upper respiratory tract in infants.While it has been thought...Group B Streptococcus(GBS;Streptococcus agalactiae)is a gram-positive coccus that colonizes the gastrointestinal and genital tracts in adults,as well as the upper respiratory tract in infants.While it has been thought that GBS only results in invasive disease in pregnant females and neonates,recent literature has suggested an increasing incidence of invasive GBS among non-pregnant individuals within the United States.展开更多
Objective:To assess the burden of Group B Streptococcus(GBS)and analyze the distribution of scrotypes in relation to their source.The review highlights data gaps in transmission dynamics and regional food consumption ...Objective:To assess the burden of Group B Streptococcus(GBS)and analyze the distribution of scrotypes in relation to their source.The review highlights data gaps in transmission dynamics and regional food consumption practices,which are esscntial for designing cffective public health strategies and advancing vaccine development.Methods:Scarches were conducted in Web of Science,MEDLINE,Science Direct,PubMcd,and Scopus databases to find studies related to GBS during 1990-2025.Eligible studies were those that described prevalence,scrotype distribution or scquence type(ST)of GBS in Southeast Asian countries.Random-cffects meta-analysis was used to pool data.Results:A total of 26 studies met the inclusion criteria from cight countries.The pooled estimate of maternal GBS colonization was 15.1%,with scrotypesII,v,ⅡI,V,and I a accounting for the majority of cases(91.24%)in the Southcast Asia studies.Data on ST was limited;however,ST1 was found to be predominant in Malaysia and Thailand,while ST283 was notably linked to the consumption of raw fish.Conclusions:The pooled estimate of the maternal colonization with GBS was 15.1%which is cquivalent to many other primary and review reports worldwide.Distribution of scrotype and ST is needed to be studied in Southcast Asian countries to devise cffective preventive measures.These findings underscore thc importance of surveillance and tailored prevention strategies to combat GBS infections in Southcast Asia.展开更多
BACKGROUND Pericarditis is the inflammation of the pericardial sac due to a variety of stimuli that ultimately trigger a stereotyped immune response.This condition accounts for up to 5%of emergency department visits f...BACKGROUND Pericarditis is the inflammation of the pericardial sac due to a variety of stimuli that ultimately trigger a stereotyped immune response.This condition accounts for up to 5%of emergency department visits for nonischemic chest pain in Western Europe and North America.The most common symptoms of clinical presentation are chest pain and shortness of breath with associated unique electrocardiographic changes.Acute pericarditis is generally self-limited.However,some cases may be complicated by either tamponade or a large pericardial effusion,which carries a significant risk of recurrence.Risk factors for acute pericarditis include viral infections,cardiac surgery,and autoimmune disorders.A rarer cause of pericardial inflammation includes pneumonia,which can induce purulent pericarditis that has been increasingly rare since the advent of antibiotics.Purulent pericarditis carries a high fatality rate,especially in the setting of tamponade,and is invariably deadly without the administration of antibiotics.Bedside transthoracic echocardiogram is a quick and helpful method that can aid in the diagnosis and management.CASE SUMMARY We present the case of a 62-year-old woman who sought medical attention at the emergency department(ED)due to a 5-day history of chest pain,shortness of breath,and subjective fevers.Laboratory findings in the ED were significant for leukocytosis and elevated erythrocyte sedimentation rate and C-reactive protein.A chest X-ray revealed a new focal density within the left lower lung base,and a bedside point-of-care ultrasound showed a pericardial fluid collection.The patient was subsequently admitted,where she underwent pericardiocentesis.Fluid cultures from drainage grew streptococcus pneumoniae.She was started on broadspectrum antibiotics immediately after the procedure.The patient was ultimately discharged in stable condition with cardiology and infectious disease follow-up.CONCLUSION This case report emphasizes a unique complication of community-acquired pneumonia.Purulent pericarditis due to streptococcus pneumonia occurs via intrathoracic spread of the organism to the pericardium.This condition is virtually fatal without the administration of antibiotics.Therefore,in the context of suspected pneumonia and a new pericardial fluid collection on imaging,clinicians should suspect purulent pericarditis until proven otherwise,which requires emergent intervention.展开更多
In the realm of medical rarity,the convergence of infective endocarditis with the development of an aortic root abscess stands as a formidable challenge,often bearing a grim prognosis.Recognizing this perilous conditi...In the realm of medical rarity,the convergence of infective endocarditis with the development of an aortic root abscess stands as a formidable challenge,often bearing a grim prognosis.Recognizing this perilous condition requires a vigilant eye.Embolic events stemming from infective endocarditis can precipitate acute coronary syndrome,adding another layer of complexity to diagnosis and treatment.展开更多
Toxin–antitoxin(TA)systems,which are prevalent in bacteria and archaea,play diverse roles in bacterial physiology and have been proposed to be significant in stress adaptation.Despite the extensive characterization o...Toxin–antitoxin(TA)systems,which are prevalent in bacteria and archaea,play diverse roles in bacterial physiology and have been proposed to be significant in stress adaptation.Despite the extensive characterization of numerous TA systems in various bacteria,the investigation of these systems within Streptococcus suis is still limited.Here,we systematically analyzed the type Ⅱ TA systems of 95 S.suis genomes available in the GenBank database using TAfinder.A total of 612 putative type Ⅱ TA systems were retrieved and classified into 10 categories by phylogenetic analysis.Notably,an elevated occurrence of these TA systems was observed among the important prevalent serotypes 2,4,5,9,14,Chz,NCL1,and NCL3 strains.The following study identified the activities of TA systems using 2 strategies and confirmed the regulatory effect of HigBA on the type Ⅶ secretion system in S.suis by measuringβ-galactosidase activity and transcriptional changes.Moreover,we unveiled a hitherto uncharacterized,highly prevalent novel TA system,with the composition of antitoxin–toxin–antitoxin(SS-ATA),which regulates the downstream two-component signaling system.Altogether,this study systematically analyzed the type Ⅱ TA systems within S.suis,highlighting the widespread distribution of Hig BA and SS-ATA as important regulatory elements in S.suis.展开更多
BACKGROUND The Streptococcus salivarius(S.salivarius)group,which produces the enzyme urease has been identified as a potential contributor to ammonia production in the gut.Researchers have reported that patients with ...BACKGROUND The Streptococcus salivarius(S.salivarius)group,which produces the enzyme urease has been identified as a potential contributor to ammonia production in the gut.Researchers have reported that patients with minimal HE had an increased abundance of the S.salivarius group,which is a specific change in the gut microbiota that distinguishes them from healthy individuals.The correlation between the aggregation of specific bacterial species and fibrosis progression in chronic liver disease(CLD)is yet to be fully elucidated.AIM To quantify S.salivarius using digital PCR(dPCR)as a liver fibrosis marker of CLD.METHODS This study retrospectively analysed 52 patients with CLD.To quantify S.salivarius in patients with CLD using dPCR,we evaluated the specificity and sensitivity of S.salivarius bacterial load using dPCR for a type strain.Next,we evaluated the clinical usefulness of dPCR for S.salivarius load quantification for detecting liver fibrosis in patients with CLD.The liver fibrosis stage was categorized into mild and advanced fibrosis based on pathological findings.RESULTS The dPCR assay revealed that S.salivarius was highly positive for the tnpA gene.The lower limit of quantification for dPCR using the tnpA gene with a 1μL template comprising 1.28×102 CFU/mL was 4.3 copies.After considering the detection range in dPCR,we adjusted the extracted DNA concentration to 5.0×10-4 ng/μL from 200 mg stool samples.The median bacterial loads of S.salivarius in stool sample from patients with mild and advanced fibrosis were 1.9 and 7.4 copies/μL,respectively.The quantification of S.salivarius load was observed more frequently in patients with advanced fibrosis than in those with mild fibrosis(P=0.032).CONCLUSION Quantifying of S.salivarius load using digital PCR is a useful biomarker for liver fibrosis in patients with CLD.展开更多
Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immun...Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immunity.Macrophages perform essential antimicrobial functions in the innate immune system by engulfing and killing pathogens.Previously,a dna K mutant strain that showed impaired phagocytosis resistance ability was screened from the transposon mutant library of SS2,but the specific mechanism is unclear.In this study,we further demonstrated that DnaK was required for SS2 to be antiphagocytosed by macrophages and survive in adverse environments.A mouse challenge experiment indicated that DnaK promoted bacteremia and systemic dissemination of SS2,enhancing bacterial pathogenicity.Western blot and immunofluorescence results indicated that DnaK could be secreted by SS2 and was able to enter RAW264.7 macrophages.Then,the endocytic receptor LRP1 regulated by DnaK was identified through RNA sequencing(RNA-Seq).We found that DnaK decreased both the mRNA and protein levels of LRP1.Knockdown of the LRP1β-chain(LRP1β)significantly decreased the phagocytosis rate of the SS2 strain ZY05719,suggesting that LRP1 is a phagocytic receptor of SS2.Furthermore,inhibitor treatment assays revealed that DnaK decreased LRP1 protein levels through the transcription factor PPARγand the ubiquitin-proteasome system.In summary,DnaK contributes to the phagocytosis resistance of SS2 by decreasing LRP1 protein levels in macrophages,providing new insights into the antiphagocytosis mechanisms of SS2 and helping to understand its pathogenesis.展开更多
Streptococcus suis serotype 2(SS2)is an emerging zoonotic pathogen that causes meningitis in humans and pigs.This pathogen generates substantial economic losses in the swine industry while posing a significant threat ...Streptococcus suis serotype 2(SS2)is an emerging zoonotic pathogen that causes meningitis in humans and pigs.This pathogen generates substantial economic losses in the swine industry while posing a significant threat to public health security.The mechanisms through which SS2 penetrates the brain and induces meningitis remain incompletely understood.This study examines the role and mechanism of SS2 collagenase-like protease(Clp)in facilitating bacterial passage across the blood-brain barrier(BBB).The research demonstrates that SS2 Clp enhanced virulence and tissue colonization while promoting BBB degradation in mice.The Δclp mutant exhibited reduced ability to traverse human brain microvascular endothelial(hCMEC/D3)cell monolayers compared to wild-type SS2,while the addition of recombinant protein rClp increased permeability.Furthermore,rClp significantly enhanced SS2 adhesion to hCMEC/D3,suppressed the expression of intercellular tight junction proteins ZO-1,Occludin,and Claudin-5 independent of its enzyme activity,and triggered hCMEC/D3 apoptosis through cell receptor ligand apoptosis and mitochondrial apoptosis pathways,partially dependent on its enzyme activity,leading to BBB disruption and enhanced permeability.Additionally,Clp enhanced the infiltration of macrophages(F4/80+),monocytes(F4/80-Ly6C+),and neutrophils(Ly6G+)into the brain following SS2 infection.These findings establish that SS2 Clp is essential for bacterial passage across the BBB,offering a theoretical foundation for improved prevention and treatment strategies for SS2-induced meningitis.展开更多
Streptococcus suis(S.suis)is a major disease impacting pig farming globally.It can also be transferred to humans by eating raw pork.A comprehensive study was recently carried out to determine the indices throughmultip...Streptococcus suis(S.suis)is a major disease impacting pig farming globally.It can also be transferred to humans by eating raw pork.A comprehensive study was recently carried out to determine the indices throughmultiple geographic regions in China.Methods:The well-posed theorems were employed to conduct a thorough analysis of the model’s feasible features,including positivity,boundedness equilibria,reproduction number,and parameter sensitivity.Stochastic Euler,Runge Kutta,and EulerMaruyama are some of the numerical techniques used to replicate the behavior of the streptococcus suis infection in the pig population.However,the dynamic qualities of the suggested model cannot be restored using these techniques.Results:For the stochastic delay differential equations of the model,the non-standard finite difference approach in the sense of stochasticity is developed to avoid several problems such as negativity,unboundedness,inconsistency,and instability of the findings.Results from traditional stochastic methods either converge conditionally or diverge over time.The stochastic non-negative step size convergence nonstandard finite difference(NSFD)method unconditionally converges to the model’s true states.Conclusions:This study improves our understanding of the dynamics of streptococcus suis infection using versions of stochastic with delay approaches and opens up new avenues for the study of cognitive processes and neuronal analysis.Theplotted interaction behaviour and new solution comparison profiles.展开更多
Background:Bacterial pneumonia remains a leading cause of morbidity and mortality worldwide despite the widespread availability of antibiotics.Novel pneumonia therapies and biomarkers are urgently needed to improve ou...Background:Bacterial pneumonia remains a leading cause of morbidity and mortality worldwide despite the widespread availability of antibiotics.Novel pneumonia therapies and biomarkers are urgently needed to improve outcomes and advance personalized therapy.Using an established baboon model of S.pneumoniae pneumonia,we sought to characterize the temporal dynamics of pneumonia host responses to identify novel potential diagnostic and therapeutic molecular targets.Methods:We performed whole blood transcriptomics,unbiased proteomics,and peripheral cytokine measurements serially in baboons inoculated with S.pneumoniae(n=23)or saline(n=10)and modeled the peripheral blood host response using principal components analysis and complex sparse logistic regression.Differentially expressed genes were analyzed for pathway analysis.Results:Inoculated animals developed characteristic signs and symptoms of pneumonia.A 39-gene signature was derived that classified S.pneumoniae infection with high accuracy(auROC 0.9 and 0.99 at 24 and 48 h post-inoculation,respectively).Similar performance was observed for 48-h biomarker signatures derived from peripheral blood plasma proteomic and cytokine measurements(both auROC>0.9).The gene signature retained strong diagnostic performance(auROC=0.88)when transformed to human orthologs and applied to patients with acute respiratory illness(n=34)or healthy controls(n=20).Pathway analysis at 48 h identified downregulation of mitophagy and glucocorticoid signaling in peripheral blood.Conclusions:We report novel peripheral blood gene and protein expression signatures of S.pneumoniae pneumonia that could improve pneumonia diagnosis and found distinct pathways that may be amenable to modulation.Our findings illustrate how non-human primate models of bacterial pneumonia can successfully translate biomarker discoveries to patients.展开更多
Streptococcus (S.) pyogenes is usually associated with mild infections of the pharynx and skin.However,in some cases,this microorganism can cause potentially lethal invasive infections,such as bacteremic pneumonia,ski...Streptococcus (S.) pyogenes is usually associated with mild infections of the pharynx and skin.However,in some cases,this microorganism can cause potentially lethal invasive infections,such as bacteremic pneumonia,skin and soft-tissue infections,sepsis,meningitis,necrotizing fasciitis,and streptococcal toxic shock syndrome.^([1,2])Although S.pyogenes is currently considered a rare cause of pneumonia,with most cases occurring in patients following influenza,the mortality rate for invasive infections is high.^([3,4])We present a case of S.pyogenes bacteremic pneumonia in a woman with no severe comorbidities,which led to a fatal outcome 9h after admission to the hospital on the third day of the disease onset.展开更多
[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []V...[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.展开更多
The objectives of this study were to investigate antimicrobial resistance of Streptococcus uberis and Streptococcus parauberis isolated from cows with bovine clinical mastitis in China and to examine the distribution ...The objectives of this study were to investigate antimicrobial resistance of Streptococcus uberis and Streptococcus parauberis isolated from cows with bovine clinical mastitis in China and to examine the distribution of resistance-and virulence-related gene patterns.Antimicrobial susceptibility was determined by the E-test.Genes encoding antimicrobial resistance and invasiveness factors were examined by PCR.A total of 27 strains were obtained from 326 mastitis milk samples.Streptococcus parauberis isolates(n=11)showed high resistance to erythromycin(90.9%),followed by tetracycline(45.5%),chloramphenicol(36.4%)and clindamycin(27.3%).Streptococcus uberis isolates(n=16)were highly resistant to tetracycline(81.3%)and clindamycin(62.5%).Both species were susceptible to ampicillin.The most prevalent resistance gene in S.uberis was tetM(80.0%),followed by blaZ(62.5%)and ermB(62.5%).However,tetM,blaZ,and ermB genes were only found in 27.3,45.5,and 27.3%,respectively,of S.parauberis.In addition,all of the isolates carried at least one selected virulence-related gene.The most prevalent virulence-associated gene pattern in the current study was sua+pauA/skc+gapC+hasC detected in 22.2%of the strains.One S.uberis strain carried 7 virulence-associated genes and belonged to the sua+pauA/skc+gapC+cfu+hasA+hasB+hasC pattern.More than 59.3%of analysed strains carried 4 to 7 virulence-related genes.Our findings demonstrated that S.parauberis and S.uberis isolated from clinical bovine mastitis cases in China exhibited diverse molecular ecology,and that the strains were highly resistant to antibiotics commonly used in the dairy cow industry.The data obtained in the current study contribute to a better understanding of the pathogenesis of bacteria in mastitis caused by these pathogens,and the findings are relevant to the development of multivalent vaccines and targeted prevention procedures.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 address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical record...Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.展开更多
文摘Group B Streptococcus(GBS;Streptococcus agalactiae)is a gram-positive coccus that colonizes the gastrointestinal and genital tracts in adults,as well as the upper respiratory tract in infants.While it has been thought that GBS only results in invasive disease in pregnant females and neonates,recent literature has suggested an increasing incidence of invasive GBS among non-pregnant individuals within the United States.
文摘Objective:To assess the burden of Group B Streptococcus(GBS)and analyze the distribution of scrotypes in relation to their source.The review highlights data gaps in transmission dynamics and regional food consumption practices,which are esscntial for designing cffective public health strategies and advancing vaccine development.Methods:Scarches were conducted in Web of Science,MEDLINE,Science Direct,PubMcd,and Scopus databases to find studies related to GBS during 1990-2025.Eligible studies were those that described prevalence,scrotype distribution or scquence type(ST)of GBS in Southeast Asian countries.Random-cffects meta-analysis was used to pool data.Results:A total of 26 studies met the inclusion criteria from cight countries.The pooled estimate of maternal GBS colonization was 15.1%,with scrotypesII,v,ⅡI,V,and I a accounting for the majority of cases(91.24%)in the Southcast Asia studies.Data on ST was limited;however,ST1 was found to be predominant in Malaysia and Thailand,while ST283 was notably linked to the consumption of raw fish.Conclusions:The pooled estimate of the maternal colonization with GBS was 15.1%which is cquivalent to many other primary and review reports worldwide.Distribution of scrotype and ST is needed to be studied in Southcast Asian countries to devise cffective preventive measures.These findings underscore thc importance of surveillance and tailored prevention strategies to combat GBS infections in Southcast Asia.
文摘BACKGROUND Pericarditis is the inflammation of the pericardial sac due to a variety of stimuli that ultimately trigger a stereotyped immune response.This condition accounts for up to 5%of emergency department visits for nonischemic chest pain in Western Europe and North America.The most common symptoms of clinical presentation are chest pain and shortness of breath with associated unique electrocardiographic changes.Acute pericarditis is generally self-limited.However,some cases may be complicated by either tamponade or a large pericardial effusion,which carries a significant risk of recurrence.Risk factors for acute pericarditis include viral infections,cardiac surgery,and autoimmune disorders.A rarer cause of pericardial inflammation includes pneumonia,which can induce purulent pericarditis that has been increasingly rare since the advent of antibiotics.Purulent pericarditis carries a high fatality rate,especially in the setting of tamponade,and is invariably deadly without the administration of antibiotics.Bedside transthoracic echocardiogram is a quick and helpful method that can aid in the diagnosis and management.CASE SUMMARY We present the case of a 62-year-old woman who sought medical attention at the emergency department(ED)due to a 5-day history of chest pain,shortness of breath,and subjective fevers.Laboratory findings in the ED were significant for leukocytosis and elevated erythrocyte sedimentation rate and C-reactive protein.A chest X-ray revealed a new focal density within the left lower lung base,and a bedside point-of-care ultrasound showed a pericardial fluid collection.The patient was subsequently admitted,where she underwent pericardiocentesis.Fluid cultures from drainage grew streptococcus pneumoniae.She was started on broadspectrum antibiotics immediately after the procedure.The patient was ultimately discharged in stable condition with cardiology and infectious disease follow-up.CONCLUSION This case report emphasizes a unique complication of community-acquired pneumonia.Purulent pericarditis due to streptococcus pneumonia occurs via intrathoracic spread of the organism to the pericardium.This condition is virtually fatal without the administration of antibiotics.Therefore,in the context of suspected pneumonia and a new pericardial fluid collection on imaging,clinicians should suspect purulent pericarditis until proven otherwise,which requires emergent intervention.
文摘In the realm of medical rarity,the convergence of infective endocarditis with the development of an aortic root abscess stands as a formidable challenge,often bearing a grim prognosis.Recognizing this perilous condition requires a vigilant eye.Embolic events stemming from infective endocarditis can precipitate acute coronary syndrome,adding another layer of complexity to diagnosis and treatment.
基金supported by the National Key Research and Development Program of China(2022YFD1800904)the National Natural Science Foundation of China(31972650 and 32102673)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(KYCX22_0780)the China Postdoctoral Science Foundation(2020M682297)。
文摘Toxin–antitoxin(TA)systems,which are prevalent in bacteria and archaea,play diverse roles in bacterial physiology and have been proposed to be significant in stress adaptation.Despite the extensive characterization of numerous TA systems in various bacteria,the investigation of these systems within Streptococcus suis is still limited.Here,we systematically analyzed the type Ⅱ TA systems of 95 S.suis genomes available in the GenBank database using TAfinder.A total of 612 putative type Ⅱ TA systems were retrieved and classified into 10 categories by phylogenetic analysis.Notably,an elevated occurrence of these TA systems was observed among the important prevalent serotypes 2,4,5,9,14,Chz,NCL1,and NCL3 strains.The following study identified the activities of TA systems using 2 strategies and confirmed the regulatory effect of HigBA on the type Ⅶ secretion system in S.suis by measuringβ-galactosidase activity and transcriptional changes.Moreover,we unveiled a hitherto uncharacterized,highly prevalent novel TA system,with the composition of antitoxin–toxin–antitoxin(SS-ATA),which regulates the downstream two-component signaling system.Altogether,this study systematically analyzed the type Ⅱ TA systems within S.suis,highlighting the widespread distribution of Hig BA and SS-ATA as important regulatory elements in S.suis.
文摘BACKGROUND The Streptococcus salivarius(S.salivarius)group,which produces the enzyme urease has been identified as a potential contributor to ammonia production in the gut.Researchers have reported that patients with minimal HE had an increased abundance of the S.salivarius group,which is a specific change in the gut microbiota that distinguishes them from healthy individuals.The correlation between the aggregation of specific bacterial species and fibrosis progression in chronic liver disease(CLD)is yet to be fully elucidated.AIM To quantify S.salivarius using digital PCR(dPCR)as a liver fibrosis marker of CLD.METHODS This study retrospectively analysed 52 patients with CLD.To quantify S.salivarius in patients with CLD using dPCR,we evaluated the specificity and sensitivity of S.salivarius bacterial load using dPCR for a type strain.Next,we evaluated the clinical usefulness of dPCR for S.salivarius load quantification for detecting liver fibrosis in patients with CLD.The liver fibrosis stage was categorized into mild and advanced fibrosis based on pathological findings.RESULTS The dPCR assay revealed that S.salivarius was highly positive for the tnpA gene.The lower limit of quantification for dPCR using the tnpA gene with a 1μL template comprising 1.28×102 CFU/mL was 4.3 copies.After considering the detection range in dPCR,we adjusted the extracted DNA concentration to 5.0×10-4 ng/μL from 200 mg stool samples.The median bacterial loads of S.salivarius in stool sample from patients with mild and advanced fibrosis were 1.9 and 7.4 copies/μL,respectively.The quantification of S.salivarius load was observed more frequently in patients with advanced fibrosis than in those with mild fibrosis(P=0.032).CONCLUSION Quantifying of S.salivarius load using digital PCR is a useful biomarker for liver fibrosis in patients with CLD.
基金funded by the National Key Research and Development Program of China(2021YFD1800400)the National Natural Science Foundation of China(32373018)+2 种基金Jiangsu Agriculture Science and Technology Innovation Fund,China(CX(23)1029)the Excellent Research Innovation Team in Universities in Anhui Province,China(2022AH010088)the Shennong Scholar Project of Anhui Agricultural University,China(rc392101)。
文摘Streptococcus suis serotype 2(SS2)is a zoonotic pathogen that can cause acute infection,such as septicemia in pigs and streptococcal toxic shock-like syndrome(STSLS)in humans,indicating that SS2 can evade innate immunity.Macrophages perform essential antimicrobial functions in the innate immune system by engulfing and killing pathogens.Previously,a dna K mutant strain that showed impaired phagocytosis resistance ability was screened from the transposon mutant library of SS2,but the specific mechanism is unclear.In this study,we further demonstrated that DnaK was required for SS2 to be antiphagocytosed by macrophages and survive in adverse environments.A mouse challenge experiment indicated that DnaK promoted bacteremia and systemic dissemination of SS2,enhancing bacterial pathogenicity.Western blot and immunofluorescence results indicated that DnaK could be secreted by SS2 and was able to enter RAW264.7 macrophages.Then,the endocytic receptor LRP1 regulated by DnaK was identified through RNA sequencing(RNA-Seq).We found that DnaK decreased both the mRNA and protein levels of LRP1.Knockdown of the LRP1β-chain(LRP1β)significantly decreased the phagocytosis rate of the SS2 strain ZY05719,suggesting that LRP1 is a phagocytic receptor of SS2.Furthermore,inhibitor treatment assays revealed that DnaK decreased LRP1 protein levels through the transcription factor PPARγand the ubiquitin-proteasome system.In summary,DnaK contributes to the phagocytosis resistance of SS2 by decreasing LRP1 protein levels in macrophages,providing new insights into the antiphagocytosis mechanisms of SS2 and helping to understand its pathogenesis.
基金supported by the National Key Research and Development Program of China(2021FYD1800405)the National Natural Science Foundation of China(32072823).
文摘Streptococcus suis serotype 2(SS2)is an emerging zoonotic pathogen that causes meningitis in humans and pigs.This pathogen generates substantial economic losses in the swine industry while posing a significant threat to public health security.The mechanisms through which SS2 penetrates the brain and induces meningitis remain incompletely understood.This study examines the role and mechanism of SS2 collagenase-like protease(Clp)in facilitating bacterial passage across the blood-brain barrier(BBB).The research demonstrates that SS2 Clp enhanced virulence and tissue colonization while promoting BBB degradation in mice.The Δclp mutant exhibited reduced ability to traverse human brain microvascular endothelial(hCMEC/D3)cell monolayers compared to wild-type SS2,while the addition of recombinant protein rClp increased permeability.Furthermore,rClp significantly enhanced SS2 adhesion to hCMEC/D3,suppressed the expression of intercellular tight junction proteins ZO-1,Occludin,and Claudin-5 independent of its enzyme activity,and triggered hCMEC/D3 apoptosis through cell receptor ligand apoptosis and mitochondrial apoptosis pathways,partially dependent on its enzyme activity,leading to BBB disruption and enhanced permeability.Additionally,Clp enhanced the infiltration of macrophages(F4/80+),monocytes(F4/80-Ly6C+),and neutrophils(Ly6G+)into the brain following SS2 infection.These findings establish that SS2 Clp is essential for bacterial passage across the BBB,offering a theoretical foundation for improved prevention and treatment strategies for SS2-induced meningitis.
基金supported by the Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia[KFU250259].
文摘Streptococcus suis(S.suis)is a major disease impacting pig farming globally.It can also be transferred to humans by eating raw pork.A comprehensive study was recently carried out to determine the indices throughmultiple geographic regions in China.Methods:The well-posed theorems were employed to conduct a thorough analysis of the model’s feasible features,including positivity,boundedness equilibria,reproduction number,and parameter sensitivity.Stochastic Euler,Runge Kutta,and EulerMaruyama are some of the numerical techniques used to replicate the behavior of the streptococcus suis infection in the pig population.However,the dynamic qualities of the suggested model cannot be restored using these techniques.Results:For the stochastic delay differential equations of the model,the non-standard finite difference approach in the sense of stochasticity is developed to avoid several problems such as negativity,unboundedness,inconsistency,and instability of the findings.Results from traditional stochastic methods either converge conditionally or diverge over time.The stochastic non-negative step size convergence nonstandard finite difference(NSFD)method unconditionally converges to the model’s true states.Conclusions:This study improves our understanding of the dynamics of streptococcus suis infection using versions of stochastic with delay approaches and opens up new avenues for the study of cognitive processes and neuronal analysis.Theplotted interaction behaviour and new solution comparison profiles.
基金Bill and Melinda Gates Foundation,Grant/Award Number:OPP1017554。
文摘Background:Bacterial pneumonia remains a leading cause of morbidity and mortality worldwide despite the widespread availability of antibiotics.Novel pneumonia therapies and biomarkers are urgently needed to improve outcomes and advance personalized therapy.Using an established baboon model of S.pneumoniae pneumonia,we sought to characterize the temporal dynamics of pneumonia host responses to identify novel potential diagnostic and therapeutic molecular targets.Methods:We performed whole blood transcriptomics,unbiased proteomics,and peripheral cytokine measurements serially in baboons inoculated with S.pneumoniae(n=23)or saline(n=10)and modeled the peripheral blood host response using principal components analysis and complex sparse logistic regression.Differentially expressed genes were analyzed for pathway analysis.Results:Inoculated animals developed characteristic signs and symptoms of pneumonia.A 39-gene signature was derived that classified S.pneumoniae infection with high accuracy(auROC 0.9 and 0.99 at 24 and 48 h post-inoculation,respectively).Similar performance was observed for 48-h biomarker signatures derived from peripheral blood plasma proteomic and cytokine measurements(both auROC>0.9).The gene signature retained strong diagnostic performance(auROC=0.88)when transformed to human orthologs and applied to patients with acute respiratory illness(n=34)or healthy controls(n=20).Pathway analysis at 48 h identified downregulation of mitophagy and glucocorticoid signaling in peripheral blood.Conclusions:We report novel peripheral blood gene and protein expression signatures of S.pneumoniae pneumonia that could improve pneumonia diagnosis and found distinct pathways that may be amenable to modulation.Our findings illustrate how non-human primate models of bacterial pneumonia can successfully translate biomarker discoveries to patients.
文摘Streptococcus (S.) pyogenes is usually associated with mild infections of the pharynx and skin.However,in some cases,this microorganism can cause potentially lethal invasive infections,such as bacteremic pneumonia,skin and soft-tissue infections,sepsis,meningitis,necrotizing fasciitis,and streptococcal toxic shock syndrome.^([1,2])Although S.pyogenes is currently considered a rare cause of pneumonia,with most cases occurring in patients following influenza,the mortality rate for invasive infections is high.^([3,4])We present a case of S.pyogenes bacteremic pneumonia in a woman with no severe comorbidities,which led to a fatal outcome 9h after admission to the hospital on the third day of the disease onset.
基金Supported by National Natural Science Foundation of China(31072155)Natural Science Foundation of Jiangsu Province(BK2010068)+1 种基金Fund for Independent Innovation of Agricultural Science in Jiangsu Province[CX(11)2060]Special Fund for Agroscientific Research in the Public Interest(201303041)~~
文摘[Objective] This study aimed to establish a method for quantitative detection of mRNA transcriptional level of SS2 adhesive related-factors of Streptococcus suis serotype 2 （SS2） by fluorescent quantitative PCR. []Vlethod] The gene fragments en- coding SS2 adhesive related-factors MRP, FBPS and CPS2J and a housekeeping gene aroA were amplified by reverse transcription PCR from the total RNA of SS2, cloned, and sequenced. The recombinant plasmids containing the target genes were constructed, and used as templates in Real-time PCR. [Result] Dynamic curves, stan- dard curves and melting curves of the adhesive related-factors and aroA were ob- tained by the optimized Real-time PCR system. The standard curves showed a good linear relationship between template copy number and circulation number, and the correlation coefficients （FF） of the standard curves were over 0.995. Also, these as- says were highly specific a^d there was single specific melting peak for every gene. Moreover, the assays were highly sensitive and had a detection limit of 1.0×102 copies in 1 μl of initial templates. Finally, it was highly repeatable and had a coeffi- cient of variation less than 2% for intra-assay. [Conclusion] This study will provide a way to reveal the adhesion mechanism of SS2 to different host cells at molecular level.
基金This study was supported by the National Key Research and Development Project of China(2017YFD0502200)the National Natural Science Foundation of China(31802232)the International Science and Technology Cooperation Project of Gansu Province,China(17YF1WA169).
文摘The objectives of this study were to investigate antimicrobial resistance of Streptococcus uberis and Streptococcus parauberis isolated from cows with bovine clinical mastitis in China and to examine the distribution of resistance-and virulence-related gene patterns.Antimicrobial susceptibility was determined by the E-test.Genes encoding antimicrobial resistance and invasiveness factors were examined by PCR.A total of 27 strains were obtained from 326 mastitis milk samples.Streptococcus parauberis isolates(n=11)showed high resistance to erythromycin(90.9%),followed by tetracycline(45.5%),chloramphenicol(36.4%)and clindamycin(27.3%).Streptococcus uberis isolates(n=16)were highly resistant to tetracycline(81.3%)and clindamycin(62.5%).Both species were susceptible to ampicillin.The most prevalent resistance gene in S.uberis was tetM(80.0%),followed by blaZ(62.5%)and ermB(62.5%).However,tetM,blaZ,and ermB genes were only found in 27.3,45.5,and 27.3%,respectively,of S.parauberis.In addition,all of the isolates carried at least one selected virulence-related gene.The most prevalent virulence-associated gene pattern in the current study was sua+pauA/skc+gapC+hasC detected in 22.2%of the strains.One S.uberis strain carried 7 virulence-associated genes and belonged to the sua+pauA/skc+gapC+cfu+hasA+hasB+hasC pattern.More than 59.3%of analysed strains carried 4 to 7 virulence-related genes.Our findings demonstrated that S.parauberis and S.uberis isolated from clinical bovine mastitis cases in China exhibited diverse molecular ecology,and that the strains were highly resistant to antibiotics commonly used in the dairy cow industry.The data obtained in the current study contribute to a better understanding of the pathogenesis of bacteria in mastitis caused by these pathogens,and the findings are relevant to the development of multivalent vaccines and targeted prevention procedures.
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 Research Grants from Universiti Putra Malaysia(UPM/800-3/3/1/GPB/2020/9683800)Ministry of Higher Education under the Fundamental Research Grant Scheme(FRGS/1/2023/WAB04/UPM/01/4).
文摘Objective:To address the lack of research on invasive group B Streptococcus(GBS)infections in Malaysia and Southeast Asia through a comprehensive analysis of GBS isolates obtained from hospitals.Methods:Medical records from patients with GBS infection isolated from the sterile site,such as blood and cerebrospinal fluid from 14 July 2019 to 15 December 2020,were reviewed from six major hospitals in Peninsular Malaysia.Inclusion criteria were invasive GBS,sterile sites and non-repeated GBS isolated from the same patients in the same admission.Viable isolates were re-identified for GBS and serotyped.Results:A total of 118 patients were eligible,with a majority of non-pregnant adults(76.3%).Over half of the patients(62.7%)had underlying medical conditions,with diabetes as the most common disease,followed by respiratory disease,renal disease,cardiovascular disease and skin and soft tissue disease.The most common manifestations were sepsis,followed by soft tissue abscess,diabetic foot ulcer,wet gangrene and cellulitis.The overall mortality was 7.6%.The most common serotype was serotype桋.Conclusions:Invasive GBS infection among non-pregnant adults showed a rising trend,particularly among diabetic individuals.The study underscores the importance of reducing risk factors and highlights the necessity of developing GBS vaccination as a preventive strategy for both infants and adults.
