Jessica Santos Streauslin, Daniel W Nielsen, Kent J Schwartz, Rachel J Derscheid, Drew R Magstadt, Eric R Burrough, Phillip C Gauger, Loni L Schumacher, Michael C Rahe, Alyona Michael, Panchan Sitthicharoenchai, Christopher L Siepker, Franco Matias Ferreyra, Marcelo Nunes de Almeida, Rodger Main, Laura K Bradner, Xiao Hu, Ganwu Li, Ana Paula S Poeta Silva, Orhan Sahin, Bailey L Arruda
{"title":"Characterization of neurologic disease-associated <i>Streptococcus suis</i> strains within the United States swine herd and use of diagnostic tools.","authors":"Jessica Santos Streauslin, Daniel W Nielsen, Kent J Schwartz, Rachel J Derscheid, Drew R Magstadt, Eric R Burrough, Phillip C Gauger, Loni L Schumacher, Michael C Rahe, Alyona Michael, Panchan Sitthicharoenchai, Christopher L Siepker, Franco Matias Ferreyra, Marcelo Nunes de Almeida, Rodger Main, Laura K Bradner, Xiao Hu, Ganwu Li, Ana Paula S Poeta Silva, Orhan Sahin, Bailey L Arruda","doi":"10.1128/jcm.00374-24","DOIUrl":null,"url":null,"abstract":"<p><p><i>Streptococcus suis</i> negatively impacts swine health, posing diagnostic and preventative challenges. <i>S. suis</i> can induce disease and also quietly reside on mucosal surfaces. The limited use of diagnostic tools to identify disease-associated strains and rule out differential diagnoses, alongside the complex ecology of <i>S. suis</i>, poses significant challenges in comprehending this important pathogen and defining pathotypes. This study evaluated 2,379 <i>S</i>. <i>suis</i> central nervous system (CNS) isolates from diagnostic submissions between 2015 and 2019. Isolates originating from submissions with histologic evidence of CNS infection (<i>n</i> = 1,032) were further characterized by standard and advanced diagnostic techniques. We identified 29 <i>S</i>. <i>suis</i> serotypes and 4 reclassified serotypes as putative causes of CNS disease. Among these, serotypes 1 and 7 emerged as the predominant putative causes of CNS infection (32% of submissions). Furthermore, 51 sequence types (STs), of which 15 were novel, were detected with ST1 predominating. Through whole-genome sequencing of 145 isolates, we observed that five commonly used virulence-associated genes (VAGs; <i>epf</i>, <i>mrp</i>, <i>sly</i>, <i>ofs</i>, and <i>srtF</i>) were not present in most disease-associated isolates, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) yielded false-positive results in 7% of isolates. These data indicate that (i) clinical signs and site of isolation alone are insufficient for defining a pathotype, (ii) <i>S. suis</i> serotypes and STs associated with CNS infection are more diverse than previously reported, (iii) MALDI-TOF MS may need to be supplemented with additional diagnostic tools for precise <i>S. suis</i> identification, and (iv) VAGs remain an unreliable means for identifying isolates associated with CNS disease.IMPORTANCE<i>Streptococcus suis</i> is an important and complex systemic bacterial pathogen of swine. Characterization of <i>S. suis</i> strains originating from pigs with histologic confirmation of neurologic disease is limited. Review of swine diagnostic submissions revealed that fewer than half of cases from which <i>S. suis</i> was isolated from the brain had histologic evidence of neurologic disease. This finding demonstrates that clinical signs and site of isolation alone are not sufficient for identifying a neurologic disease-associated strain. Characterization of strains originating from cases with evidence of disease using classic and advanced diagnostic techniques revealed that neurologic disease-associated strains are diverse and commonly lack genes previously associated with virulence.</p>","PeriodicalId":15511,"journal":{"name":"Journal of Clinical Microbiology","volume":null,"pages":null},"PeriodicalIF":6.1000,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Clinical Microbiology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1128/jcm.00374-24","RegionNum":2,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/10/8 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Streptococcus suis negatively impacts swine health, posing diagnostic and preventative challenges. S. suis can induce disease and also quietly reside on mucosal surfaces. The limited use of diagnostic tools to identify disease-associated strains and rule out differential diagnoses, alongside the complex ecology of S. suis, poses significant challenges in comprehending this important pathogen and defining pathotypes. This study evaluated 2,379 S. suis central nervous system (CNS) isolates from diagnostic submissions between 2015 and 2019. Isolates originating from submissions with histologic evidence of CNS infection (n = 1,032) were further characterized by standard and advanced diagnostic techniques. We identified 29 S. suis serotypes and 4 reclassified serotypes as putative causes of CNS disease. Among these, serotypes 1 and 7 emerged as the predominant putative causes of CNS infection (32% of submissions). Furthermore, 51 sequence types (STs), of which 15 were novel, were detected with ST1 predominating. Through whole-genome sequencing of 145 isolates, we observed that five commonly used virulence-associated genes (VAGs; epf, mrp, sly, ofs, and srtF) were not present in most disease-associated isolates, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) yielded false-positive results in 7% of isolates. These data indicate that (i) clinical signs and site of isolation alone are insufficient for defining a pathotype, (ii) S. suis serotypes and STs associated with CNS infection are more diverse than previously reported, (iii) MALDI-TOF MS may need to be supplemented with additional diagnostic tools for precise S. suis identification, and (iv) VAGs remain an unreliable means for identifying isolates associated with CNS disease.IMPORTANCEStreptococcus suis is an important and complex systemic bacterial pathogen of swine. Characterization of S. suis strains originating from pigs with histologic confirmation of neurologic disease is limited. Review of swine diagnostic submissions revealed that fewer than half of cases from which S. suis was isolated from the brain had histologic evidence of neurologic disease. This finding demonstrates that clinical signs and site of isolation alone are not sufficient for identifying a neurologic disease-associated strain. Characterization of strains originating from cases with evidence of disease using classic and advanced diagnostic techniques revealed that neurologic disease-associated strains are diverse and commonly lack genes previously associated with virulence.
期刊介绍:
The Journal of Clinical Microbiology® disseminates the latest research concerning the laboratory diagnosis of human and animal infections, along with the laboratory's role in epidemiology and the management of infectious diseases.