Correlation between PFGE Groups andmrp/epf/slyGenotypes of HumanStreptococcus suisSerotype 2 in Northern Thailand

Abstract

Streptococcus suis infection is a severe zoonotic disease commonly found in Northern Thailand where people often consume raw pork and/or pig's blood. The most frequent clinical presentations are meningitis, sepsis, and endocarditis with higher rate of mortality and hearing loss sequelae. To clarify the correlation between pulsed-field gel electrophoresis (PFGE) groups and mrp/epf/sly genotypes of S. suis serotype 2, 62 patient and 4 healthy pig isolates from Northern Thailand were studied. By PFGE analysis, at 66% homology, most human isolates (69.4%) and 1 pig isolate were in group A, whereas 14.5% of human isolates and 3 out of 4 pig isolates were in group D. According to mrp/epf/sly genotypes, 80.6% of human isolates were identified in mrp + epf − sly − and only 12.9% were in mrp − epf − sly + genotypes; in contrast, 1 and 3 pig isolates were detected in these two genotypes, respectively. Interestingly, all isolates of S. suis serotype 2 classified in PFGE groups A, B, and E were set in mrp + epf − sly − genotypes. These data show a close correlation between PFGE groups and mrp/epf/sly genotypes of human S. suis serotype 2.

Capsular serotypes, virulence-associated genes and antimicrobial susceptibility of <i>Streptococcus suis</i> isolates from pigs in Korea

“…Moreover, most of the isolates belonging to serotypes 3 and 2 in this study showed the genotype epf − / mrp + / sly − , which is consistent with a previous report in Thailand demonstrating that 80.6% of S. suis isolates from humans were of serotype 2 with the epf − / mrp + / sly − genotype [36]. Recently, the number of human cases of S. suis infection has increased in Asia, including Korea [4, 14, 26, 36], warning of the possible transmission of S. suis from pigs to humans with regular exposure to pigs, such as those working in the pig industry. Moreover, pork is the most popular meat in Korea; therefore, even people who do not have direct contact with pigs might also be at risk of infection via consumption of insufficiently cooked pork or from contact with the raw meat during cooking [26].…”

“…Previous studies, including those using experimental pig infection models, showed that serotype 2 strains with the epf + / mrp + genotype are highly virulent to pigs [ 15 , 39 , 41 ]. Moreover, most of the isolates belonging to serotypes 3 and 2 in this study showed the genotype epf − / mrp + / sly − , which is consistent with a previous report in Thailand demonstrating that 80.6% of S. suis isolates from humans were of serotype 2 with the epf − / mrp + / sly − genotype [ 36 ]. Recently, the number of human cases of S. suis infection has increased in Asia, including Korea [ 4 , 14 , 26 , 36 ], warning of the possible transmission of S. suis from pigs to humans with regular exposure to pigs, such as those working in the pig industry.…”

Streptococcus suis in Brazil: Genotypic, Virulence, and Resistance Profiling of Strains Isolated from Pigs between 2001 and 2016

“…Previously, Mai et al [31] reported that human S. suis strains also grouped by isolation year. Similarly, Tharavichitkul et al [32] and Huang et al [33] described the tendency to cluster pulsotypes with virulence profiles, which was also observed in S. suis strains isolated from rabbits [34].…”

Serotype- and virulence-associated gene profile of <i>Streptococcus suis</i> isolates from pig carcasses in Chiang Mai Province, Northern Thailand

“…No variant phenotype of mrp was found in the isolates, whereas the epf variant ( epf *) was detected in one isolate of serotype 4. All serotype 2 isolates presented the same genotype, mrp−/epf – /sly+ , in contrast to strains isolated from humans in the same geographical region that carried the mrp + /epf − /sly − genotype (80.6%) [ 22 ]. These results indicate a difference within serotype 2; strains from humans presented only the mrp gene, while strains from pigs presented only the sly gene.…”