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Research in Microbiology 2023Aim of this study was to investigate the prevalence and genetic environment of the oxazolidinone resistance gene optrA in Streptococcus suis (S. suis) isolates from...
Aim of this study was to investigate the prevalence and genetic environment of the oxazolidinone resistance gene optrA in Streptococcus suis (S. suis) isolates from diseased pigs in China. A total of 178 S. suis isolates were screened for the optrA gene by PCR. The phenotypes and genotypes of optrA-positive isolates were investigated by antimicrobial susceptibility testing, core genome Multilocus Sequence Typing (cgMLST), capsular serotypes determination and whole-genome sequencing (WGS). Fifty-one (28.7%) S. suis isolates were positive for optrA. Phylogenetic analysis indicated that the spread of the optrA among S. suis isolates was primarily due to horizontal transfer. Analysis of S. suis serotypes from diseased pigs revealed substantial diversity. The genetic environment of optrA was complex and diverse and could be divided into 12 different types. Interestingly, we identified a novel integrative and conjugative element ICESsu988S, carrying optrA and erm(T) genes. This is to the best of our knowledge the first report of the optrA and erm(T) co-located on an ICE in S. suis. Our results showed a high prevalence of optrA gene in S. suis isolates in China. Further research is needed to evaluate the importance of ICEs, as they horizontally propagate important clinical resistance genes.
Topics: Animals; Swine; Streptococcus suis; Phylogeny; Prevalence; Drug Resistance, Bacterial; Oxazolidinones; Anti-Bacterial Agents
PubMed: 37149078
DOI: 10.1016/j.resmic.2023.104078 -
Veterinary Sciences Jan 2024This study aimed to update the serotype distribution in Spain by analysing 302 clinical isolates recovered from diseased pigs between 2020 and 2022. The main objectives...
This study aimed to update the serotype distribution in Spain by analysing 302 clinical isolates recovered from diseased pigs between 2020 and 2022. The main objectives were to identify prevalent serotypes, differentiate specific serotypes 1, 14, 2, and 1/2, investigate specific genotypic and phenotypic antimicrobial resistance features, and explore associations between resistance genes and phenotypic resistances. Serotypes 9 (21.2%), 1 (16.2%), 2 (15.6%), 3 (6%), and 7 (5.6%) were the most prevalent, whereas serotypes 14 and 1/2 corresponded with 4.3% and 0.7% of all isolates. Antimicrobial resistance genes, including (O), (B), (B), (E), (M), and (A/E), were analysed, which were present in 85.8%, 65.2%, 7%, 7%, 6.3%, and 1% of the samples, respectively. Susceptibility testing for 18 antimicrobials revealed high resistance levels, particularly for clindamycin (88.4%), chlortetracycline (89.4%), and sulfadimethoxine (94.4%). Notably, seven significant associations ( < 0.0001) were detected, correlating specific antimicrobial resistance genes to the observed phenotypic resistance. These findings contribute to understanding the serotype distribution and its antibiotic resistance profiles in Spain, offering valuable insights for veterinary and public health efforts in managing -associated infections.
PubMed: 38250946
DOI: 10.3390/vetsci11010040 -
PLoS Pathogens Apr 2024Integrative and conjugative elements (ICEs) play a vital role in bacterial evolution by carrying essential genes that confer adaptive functions to the host. Despite...
Type II and IV toxin-antitoxin systems coordinately stabilize the integrative and conjugative element of the ICESa2603 family conferring multiple drug resistance in Streptococcus suis.
Integrative and conjugative elements (ICEs) play a vital role in bacterial evolution by carrying essential genes that confer adaptive functions to the host. Despite their importance, the mechanism underlying the stable inheritance of ICEs, which is necessary for the acquisition of new traits in bacteria, remains poorly understood. Here, we identified SezAT, a type II toxin-antitoxin (TA) system, and AbiE, a type IV TA system encoded within the ICESsuHN105, coordinately promote ICE stabilization and mediate multidrug resistance in Streptococcus suis. Deletion of SezAT or AbiE did not affect the strain's antibiotic susceptibility, but their duple deletion increased susceptibility, mainly mediated by the antitoxins SezA and AbiEi. Further studies have revealed that SezA and AbiEi affect the genetic stability of ICESsuHN105 by moderating the excision and extrachromosomal copy number, consequently affecting the antibiotic resistance conferred by ICE. The DNA-binding proteins AbiEi and SezA, which bind palindromic sequences in the promoter, coordinately modulate ICE excision and extracellular copy number by binding to sequences in the origin-of-transfer (oriT) and the attL sites, respectively. Furthermore, AbiEi negatively regulates the transcription of SezAT by binding directly to its promoter, optimizing the coordinate network of SezAT and AbiE in maintaining ICESsuHN105 stability. Importantly, SezAT and AbiE are widespread and conserved in ICEs harbouring diverse drug-resistance genes, and their coordinated effects in promoting ICE stability and mediating drug resistance may be broadly applicable to other ICEs. Altogether, our study uncovers the TA system's role in maintaining the genetic stability of ICE and offers potential targets for overcoming the dissemination and evolution of drug resistance.
Topics: Streptococcus suis; Toxin-Antitoxin Systems; Bacterial Proteins; Drug Resistance, Multiple, Bacterial; Streptococcal Infections; Anti-Bacterial Agents; Conjugation, Genetic; Animals; Interspersed Repetitive Sequences
PubMed: 38640137
DOI: 10.1371/journal.ppat.1012169 -
Veterinary Research Jan 2024Streptococcus suis is a zoonotic pathogen that causes a major health problem in the pig production industry worldwide. Spain is one of the largest pig producers in the...
Streptococcus suis is a zoonotic pathogen that causes a major health problem in the pig production industry worldwide. Spain is one of the largest pig producers in the world. This work aimed to investigate the genetic and phenotypic features of invasive S. suis isolates recovered in Spain. A panel of 156 clinical isolates recovered from 13 Autonomous Communities, representing the major pig producers, were analysed. MLST and serotyping analysis revealed that most isolates (61.6%) were assigned to ST1 (26.3%), ST123 (18.6%), ST29 (9.6%), and ST3 (7.1%). Interestingly, 34 new STs were identified, indicating the emergence of novel genetic lineages. Serotypes 9 (27.6%) and 1 (21.8%) prevailed, followed by serotypes 7 (12.8%) and 2 (12.2%). Analysis of 13 virulence-associated genes showed significant associations between ST, serotype, virulence patterns, and clinical features, evidencing particular virulence traits associated with genetic clusters. The pangenome was generated, and the core genome was distributed in 7 Bayesian groups where each group included a variable set of over- and under-represented genes of different categories. The study provides comprehensive data and knowledge to improve the design of new vaccines, antimicrobial treatments, and bacterial typing approaches.
Topics: Animals; Swine; Streptococcus suis; Spain; Bayes Theorem; Multilocus Sequence Typing; Virulence; Genomics
PubMed: 38268053
DOI: 10.1186/s13567-024-01267-0 -
Veterinary Microbiology Jun 2024Streptococcus suis is an important pathogen causing severe disease in pigs and humans, giving rise to economic losses in the pig production industry. Out of 65 S. suis...
Streptococcus suis is an important pathogen causing severe disease in pigs and humans, giving rise to economic losses in the pig production industry. Out of 65 S. suis isolates collected from diseased pigs in Switzerland between 2019 and 2022, 57 isolates were thoroughly examined by phenotypic and whole genome sequence (WGS) based characterization. The isolates' genomes were sequenced allowing for a comprehensive analysis of their distribution in terms of serovar, sequence type (ST), clonal complex (CC), and classical virulence markers. Antimicrobial resistance (AMR) genes were screened, and phenotypic susceptibility to eight classes of antimicrobial agents was examined. Serovar 6, devoid of any resistance genes, was found to be most prevalent, followed by serovars 1, 3, 1/2, and 9. Thirty STs were identified, with ST1104 being the most prevalent. Serovar 2 and serovar 1/2 were associated with CC1, potentially containing the most virulent variants. Based on single nucleotide polymorphism (SNP) analyses, fifteen isolates belonged to one of seven putative transmission clusters each consisting of two or three isolates. High phenotypic AMR rates were detected for tetracyclines (80%) and macrolides (35%) and associated with the resistance genes tet(O) and erm(B), respectively. In contrast, susceptibility to β-lactam antibiotics and phenicols was high. Determination of phenotypic AMR profiling, including the minimum inhibitory concentrations (MICs) of the tested antimicrobial agents, sets a baseline for future studies. The study provides valuable insights into the genetic diversity and antimicrobial susceptibility of Swiss S. suis isolates, facilitating the identification of emerging clones relevant to public health concerns.
Topics: Animals; Streptococcus suis; Swine; Swine Diseases; Switzerland; Genetic Variation; Streptococcal Infections; Anti-Bacterial Agents; Microbial Sensitivity Tests; Whole Genome Sequencing; Drug Resistance, Bacterial; Virulence; Serogroup; Polymorphism, Single Nucleotide
PubMed: 38608374
DOI: 10.1016/j.vetmic.2024.110084 -
Tropical Biomedicine Mar 2024Streptococcus suis is a bacterium of clinical importance in diverse animal hosts including companion animals and humans. Companion animals are closely associated in the...
Streptococcus suis is a bacterium of clinical importance in diverse animal hosts including companion animals and humans. Companion animals are closely associated in the living environment of humans and are potential reservoirs for zoonotic pathogens. Given the zoonotic potential of S. suis, it is crucial to determine whether this bacterium is present among the companion animal population. This study aimed to detect Streptococcus suis in companion animals namely cats and dogs of the central west coast of Peninsular Malaysia and further characterize the positive isolates via molecular and genomic approach. The detection of S. suis was done via bacterial isolation and polymerase chain reaction assay of gdh and recN gene from oral swabs. Characterization was done by multiplex PCR serotyping, as well as muti-locus sequence typing, AMR gene prediction, MGE identification and phylogenomic analysis on whole genome sequence acquired from Illumina and Oxford Nanopore sequencing. Among the 115 samples, PCR assay detected 2/59 of the cats were positive for S. suis serotype 8 while all screened dog samples were negative. This study further described the first complete whole genome of S. suis strain SS/UPM/MY/F001 isolated from the oral cavity of a companion cat. Genomic analysis revealed a novel strain of S. suis having a unique MLST profile and antimicrobial resistance genes of mefA, msrD, patA, patB and vanY. Mobile genetic elements were described, and pathogenic determinants matched to human and swine strains were identified. Phylogenetic tree analysis on the core genome alignment revealed strain SS/UPM/MY/F001 was distinct from other S. suis strains. This study provided insight into the detection and genomic features of the S. suis isolate of a companion cat and highlighted its potential for antimicrobial resistance and pathogenicity.
Topics: Cats; Animals; Streptococcus suis; Streptococcal Infections; Cat Diseases; Dogs; Whole Genome Sequencing; Dog Diseases; Malaysia; Phylogeny; Pets; Drug Resistance, Bacterial; Zoonoses; Multilocus Sequence Typing; Genome, Bacterial; Anti-Bacterial Agents; Humans; Bacterial Zoonoses
PubMed: 38852139
DOI: 10.47665/tb.41.1.012 -
Virulence Dec 2024The arginine deiminase system (ADS) has been identified in various bacteria and functions to supplement energy production and enhance biological adaptability. The...
The arginine deiminase system (ADS) has been identified in various bacteria and functions to supplement energy production and enhance biological adaptability. The current understanding of the regulatory mechanism of ADS and its effect on bacterial pathogenesis is still limited. Here, we found that the XRE family transcriptional regulator XtrSs negatively affected virulence and significantly repressed ADS transcription when the bacteria were incubated in blood. Electrophoretic mobility shift (EMSA) and lacZ fusion assays further showed that XtrSs directly bind to the promoter of ArgR, an acknowledged positive regulator of bacterial ADS, to repress ArgR transcription. Moreover, we provided compelling evidence that could utilize arginine via ADS to adapt to acid stress, while Δ enhanced this acid resistance by upregulating the ADS operon. Moreover, whole ADS-knockout increased arginine and antimicrobial NO in the infected macrophage cells, decreased intracellular survival, and even caused significant attenuation of bacterial virulence in a mouse infection model, while Δ consistently presented the opposite results. Our experiments identified a novel ADS regulatory mechanism in , whereby XtrSs regulated ADS to modulate NO content in macrophages, promoting intracellular survival. Meanwhile, our findings provide a new perspective on how evade the host's innate immune system.
Topics: Animals; Mice; Arginine; Bacterial Proteins; Gene Expression Regulation, Bacterial; Hydrolases; Macrophages; Streptococcal Infections; Streptococcus suis
PubMed: 38251714
DOI: 10.1080/21505594.2024.2306719 -
Microbes and Infection Dec 2023Streptococcus suis is a causative agent of swine and human infections. Genomic analysis indicated that eight S. suis serotype 5 strains recovered from human patients...
Comparative genome analysis of Streptococcus suis serotype 5 strains from humans and pigs revealed pathogenic potential of virulent, antimicrobial resistance, and genetic relationship.
Streptococcus suis is a causative agent of swine and human infections. Genomic analysis indicated that eight S. suis serotype 5 strains recovered from human patients and pigs carried many virulence-associated genes and markers defining pathogenic pathotypes. The strains were sequence types diverse and clustered within either minimum core genome group 3 (MCG-3) or MCG-7-3. Almost all the serotype 5 strains were non-susceptible to penicillin, ceftriaxone, erythromycin, and levofloxacin. Resistance to tetracycline and clindamycin was observed in all strains. The antimicrobial resistance genes tet(O), tet(O/W/32/O), tet(W), tet(44), erm(B), ant(6)-Ia, lsaE, and lnuB were found in these strains. Moderate-to-large numbers of substitutions were observed in three penicillin-binding proteins (PBP)-PBP1A, PBP2B, and PBP2X-in the penicillin-non-susceptible serotype 5 isolates that were involved in β-lactam-non-susceptibility. Comparative genomics between the serotype 5 and 2 strains revealed that only 15 genes absent from the serotype 2 strains were shared by all the serotype 5 strains. However, some additional genes were present only in some of the serotype 5 strains. This study highlighted the pathogenic potential of virulent serotype 5 strains in humans and pigs and the need for increased monitoring of penicillin-non-susceptibility in S. suis serotypes other than for serotype 2.
PubMed: 38070594
DOI: 10.1016/j.micinf.2023.105273 -
Virulence Dec 2023is a zoonotic Gram-positive bacterium that causes invasive infections such as sepsis and meningitis, threatening public health worldwide. For successful establishment...
is a zoonotic Gram-positive bacterium that causes invasive infections such as sepsis and meningitis, threatening public health worldwide. For successful establishment of infection, the bacterium should subvert the innate effectors of immune defence, including the cathelicidin family of host-defence peptides that combat pathogenic bacteria by directly disrupting cell membranes and coordinating immune responses. Here, our study shows that an extracellular endopeptidase O (PepO) of contributes to assisting the bacterium to resist cathelicidin-mediated killing, as the deletion of the gene makes more sensitive to the human cathelicidin LL-37, as well as its mouse equivalent, mCRAMP. This protease targets and cleaves both LL-37 and mCRAMP, degrading them into shorter peptides with only a few amino acids, thereby abrogating their ability to kill . By cleaving LL-37 and mCRAMP, PepO impairs their chemotactic properties for neutrophil migration and undermines their anti-apoptosis activity, which is required for prolonging neutrophil lifespan. Also, PepO inhibits the ability of LL-37 and mCRAMP to promote lysosome development in macrophages. Moreover, the loss of PepO attenuates organ injury and decreases bacterial burdens in a murine model of bacteraemia. Taken together, these data provide novel insights into the role of the intrinsic proteolytic characteristics of PepO in -host interaction. Our findings demonstrate that utilizes the PepO protease to cleave cathelicidins, which is an immunosuppressive strategy adopted by this bacterium to facilitate pathogenesis.
Topics: Animals; Humans; Mice; Cathelicidins; Antimicrobial Cationic Peptides; Immune Evasion; Streptococcus suis; Metalloendopeptidases; Bacteria
PubMed: 38010345
DOI: 10.1080/21505594.2023.2283896 -
Methods in Molecular Biology (Clifton,... 2024Streptococcus suis is an important zoonotic pathogen causing severe infections in pigs and humans. Serotyping of S. suis strains is crucial for epidemiological...
Streptococcus suis is an important zoonotic pathogen causing severe infections in pigs and humans. Serotyping of S. suis strains is crucial for epidemiological surveillance, outbreak investigations, and understanding the pathogenesis of this bacterium. Here, we describe a step-by-step approach that enhances a previously developed pipeline by utilizing a computational script for efficient and accurate typing of S. suis strains. The pipeline is implemented in Perl programming language and leverages the Short Read Sequence Typing for Bacterial Pathogens (SRST2) tool. It integrates various bioinformatics techniques and utilizes multiple databases, including a serotype database, cpsH confirmation database, multi-locus sequence typing (MLST) database, recN species-specific gene database, and virulence gene database. These databases contain comprehensive information on S. suis serotypes, genetic markers, and virulence factors. The script can utilize paired-end or single-end fastq files as input and first confirms the species by sequence read data aligning to the recN gene, ensuring the accurate identification of S. suis strains. The pipeline next performs MLST typing and virulence factor identification using SRST2 while in a parallel processes it performs in silico serotyping of the strains. The pipeline offers a streamlined and semiautomated approach to serotyping S. suis strains, facilitating large-scale studies and reducing the manual effort required for data analysis.
Topics: Streptococcus suis; Multilocus Sequence Typing; Computational Biology; Animals; Software; Virulence Factors; Humans; Swine; Serotyping; Bacterial Typing Techniques; Computer Simulation; Databases, Genetic; Streptococcal Infections
PubMed: 38884907
DOI: 10.1007/978-1-0716-3898-9_2