Development of an appropriate PCR system for the reclassification of Streptococcus suis

Ishida, Sarahmi; Tien, Le Hong Thuy; Osawa, Ro; Tohya, Mari; Nomoto, Ryohei; Kawamura, Y.; Takahashi, Tatsuhumi; Kikuchi, Naoya; Kikuchi, Ken; Sekizaki, Tsutomu

doi:10.1016/j.mimet.2014.09.003

Cited by 89 publications

(95 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Chromosomal DNA was prepared by using a method described previously (15). The species identity of the 486 isolates was determined to be S. suis by amplification of the 16S rRNA, recN, and thrA genes (13,18,19).…”

Section: Methodsmentioning

confidence: 99%

Novel Capsular Polysaccharide Loci and New Diagnostic Tools for High-Throughput Capsular Gene Typing in Streptococcus suis

Qiu

Bai

Lan

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

Streptococcus suis is an important pathogen of pigs and may cause serious disease in humans. Serotyping is an important tool for detection and epidemiological studies of S. suis. Thirty-three reference serotypes and nine novel cps loci (NCLs) are recognized in S. suis. To gain a better understanding of the prevalence and genetic characteristics of NCLs, we investigated the serotype identity of 486 isolates isolated between 2013 and 2015 in China by capsular gene typing methods. Two hundred seventy-six isolates carried NCLs belonging to 16 groups, 8 of which appear to have not been reported previously. These isolates showed autoagglutination, polyagglutination, or nonagglutination with reference antisera and thus were nonserotypeable. Almost all isolates carrying the unknown NCLs were encapsulated, with various capsular thicknesses, indicating that they are most likely novel serotypes. To simultaneously identify the currently recognized 17 NCLs, an 18-plex detection system using the Luminex xTAG universal array technology was developed. Our data also provide valuable genetic information for monitoring the variations within NCLs by investigating the genetic characteristics of different subtypes within NCLs. IMPORTANCENonserotypeable Streptococcus suis isolates have been reported in many studies, and 9 novel cps loci (NCLs) have already been identified in nonserotypeable isolates. Moreover, novel cps loci are continually being found. The main purpose of this study was to investigate the prevalence and characteristics of NCLs in S. suis isolates recovered between 2013 and 2015 in China. This study provides valuable genetic information for monitoring the variations within NCLs. Meanwhile, a fast and cost-effective 18-plex detection system that can simultaneously identify the currently recognized 17 NCLs was developed in this study. This system will serve as a valuable tool for detecting known and identifying additional novel cps loci among nonserotypeable S. suis isolates. Streptococcus suis is an important pathogen of pigs and may cause serious disease in humans (1-3). Clinically healthy pigs can carry S. suis in their nasopharynx, contributing to the dissemination of this pathogen (4, 5). Moreover, a potential role of isolates from healthy pigs is as donors to transfer the new adaptive phenotypes to pathogenic isolates (6). The capsular polysaccharide (CPS) shields S. suis from host phagocytes and is a major virulence factor (7). Antisera to CPSs are used to distinguish antigenic differences among them. Serotyping is also an important epidemiological method for S. suis surveillance. This reflects the importance of including isolates from healthy pigs to better understand the diversity and evolution of CPSs in S. suis populations.A total of 35 serotypes (types 1 through 34 and type 1/2) of S. suis have been identified by different studies in the 1980s and 1990s (8-11). In 2005, strains of serotypes 32 and 34 were reclassified as Streptococcus orisratti (12). The CPS synthesis genes are known to be clustered ...

show abstract

Section: Methodsmentioning

confidence: 99%

Novel Capsular Polysaccharide Loci and New Diagnostic Tools for High-Throughput Capsular Gene Typing in Streptococcus suis

Qiu

Bai

Lan

et al. 2016

Appl Environ Microbiol

View full text Add to dashboard Cite

show abstract

“…All S. suis isolates, except for type and reference strains, were identified by recN PCR, as described previously (Ishida et al, 2014), and were serotyped with specific antisera. The serotyping of S. suis was performed using the co-agglutination test and capsular reaction test, as described previously (Higgins and Gottschalk, 1990), with commercial antisera (Statens Serum Institut, Copenhagen, Denmark).…”

Section: Bacterial Strains and Culture Conditionsmentioning

confidence: 99%

“…In accordance with these findings, Tien le et al (2013) reported that a recN sequence analysis revealed complete concordance with the DNA-DNA reassociation results, which suggested that recN was a suitable target for the rapid detection of S. suis. Ishida et al (2014) described a PCR-targeted recN, designated recN PCR, which is specific for authentic S. suis; however, markedly higher sensitivity and more robustness against inhibitory substances is needed for the detection of food contamination.…”

Section: Introductionmentioning

confidence: 99%

Development of loop-mediated isothermal amplification to detect Streptococcus suis and its application to retail pork meat in Japan

Arai

Tohya

Yamada

et al. 2015

International Journal of Food Microbiology

Self Cite

View full text Add to dashboard Cite

“…We used 16S rRNA primers (20) to amplify a nearly complete 16S rRNA gene from the 78 isolates. The recN and gdh genes were also analyzed for taxonomic assignment, as was done previously (21)(22)(23). The API 20 Strep biochemical identification system (bioMérieux, Hazelwood, MO) was also used to identify the strains.…”

Section: Methodsmentioning

confidence: 99%

Eight Novel Capsular Polysaccharide Synthesis Gene Loci Identified in Nontypeable Streptococcus suis Isolates

Zheng

Liu

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

cStreptococcus suis is an important pathogen of pigs and may cause serious disease in humans. Serotyping is one of the important diagnostic tools and is used for the epidemiological study of S. suis. Nontypeable S. suis strains have been reported in many studies; however, the capsular polysaccharide (CPS) synthesis cps loci of nontypeable strains have not been analyzed. In this study, we investigated the genetic characteristics of cps loci in 78 nontypeable strains isolated from healthy pigs. Eight novel cps loci (NCLs) were found, and all of them were located between the orfZ-orfX region and the glf gene. All NCLs possess the wzy and wzx genes, strongly suggesting that the CPSs of these NCLs were synthesized using the Wzx/Wzy-dependent pathway. The cps genes found in the 78 isolates were assigned to 96 homology groups (HGs), 55 of which were NCL specific. The encapsulation of the 78 isolates was also examined using transmission electron microscopy. Fifty-three isolates were found to have a capsule, and these were of varied thicknesses. Our data enhance our understanding of the cps gene cluster diversity of nontypeable S. suis strains and provide insight into the evolution of the S. suis capsular genes. Streptococcus suis is an important pathogen of pigs (1) and may cause serious disease in humans (2-4). Serotyping is one of the important tools for diagnosis and is used in epidemiological studies of S. suis. A total of 35 S. suis serotypes (serotypes 1 through 34 and 1/2) are known on the basis of the antigenic differences in their capsular polysaccharides (CPSs) (5-8) and the coagglutination test. The S. suis cps gene clusters of the 35 serotypes have been sequenced, and the cps gene clusters were shown to be diverse among different serotypes (9). The predicted products of the cps genes found in the 35 serotypes were assigned to 291 homology groups (HGs). The precise function of many cps genes is still unknown.The synthesis and export of bacterial polysaccharides are mediated by three pathways known as the Wzx/Wzy-dependent pathway, the synthase-dependent pathway, and the ABC transporter-dependent pathway. The Wzx/Wzy-dependent pathway is most commonly used in Streptococcus pneumoniae capsular biosynthesis (10). Although the precise function of most of the cps genes of S. suis is still unknown, the CPSs of all serotypes of S. suis are also thought to be synthesized by the Wzx/Wzy-dependent pathway. This pathway involves the synthesis of the polysaccharide repeat units, which are initially built on the inner face of the cytoplasmic membrane; transport of the repeat units to the outer face of the membrane by Wzx flippase; and then polymerization of the repeat units by Wzy polymerase. Wzy-dependent polymers usually contain various sugars and glycosidic linkages. The specificity of the Wzy polymerase determines the linkage that it catalyzes between sugars on the growing chain and the next repeat unit. Therefore, the wzy gene is serotype specific. Hence, the serotype-specific wzy gene is an ideal target to discrimin...

show abstract

Development of an appropriate PCR system for the reclassification of Streptococcus suis

Cited by 89 publications

References 21 publications

Novel Capsular Polysaccharide Loci and New Diagnostic Tools for High-Throughput Capsular Gene Typing in Streptococcus suis

Novel Capsular Polysaccharide Loci and New Diagnostic Tools for High-Throughput Capsular Gene Typing in Streptococcus suis

Development of loop-mediated isothermal amplification to detect Streptococcus suis and its application to retail pork meat in Japan

Eight Novel Capsular Polysaccharide Synthesis Gene Loci Identified in Nontypeable Streptococcus suis Isolates

Contact Info

Product

Resources

About