Dataset Information

Comparison of Characteristics of Streptococcus dysgalactiae subsp. equisimilis Isolates Causing Repetitive vs Single Infections.

ABSTRACT: No study has described Streptococcus dysgalactiae subsp. equisimilis (SDSE) isolates that cause repetitive infections (recurrence and reinfection). We compared the microbiological characteristics of SDSE causing repetitive infections with those causing single infections. Three patients with invasive infections were identified based on their medical records, and multiple SDSE isolates were collected at intervals over three weeks, using a laboratory repository. Isolates from 12 patients with single-episode infections served as controls. Six isolates were collected from three patients with first and second episodes of infection. All isolates causing either repetitive or single-episode infection were subjected to emm typing, multilocus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE), and random amplified polymorphic DNA (RAPD) analyses. Amplification of five virulence genes (sicG, prtF1, prtF2, lmb, and cbp), biofilm formation (BF), and cell invasion abilities (CIAs) were measured as virulent phenotypes. We observed close genetic similarities in the data obtained by emm typing, MLST, PFGE, and RAPD in four isolates from two patients, suggesting recurrence, whereas two isolates from one patient indicated genetic differences in these data, suggesting re-infection. The presence of the five virulence genes and the BF and CIA measurements appeared not to contribute to repetitive infections, compared with isolates causing single-episode infection. In conclusion, clinicians encountering patients with repetitive infections should be aware of both possibilities: recurrence with closely related strains and reinfection with different strains.

SUBMITTER: Fujita T

PROVIDER: S-EPMC6502950 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Streptococcus dysgalactiae subsp. equisimilis (SDSE) is an emerging human pathogen that causes severe invasive streptococcal diseases. Recent reports have shown that SDSE exhibits high pathogenicity with different mechanisms from that of Streptococcus pyogenes, although the two streptococci possess some common virulence factors such as streptolysin, streptokinase, and cell-binding proteins. To date, only a few studies have examined the variety of mechanisms expressing the pathogenicity of SDSE. Among nine SDSE clinical isolates sequenced in this study, we present in vitro and in vivo analyses of KNZ01 and KNZ03, whose emm and multilocus species types (MLSTs) are prevalent in Japan and other countries. For the comparison of pathogenicity, we also utilized the ATCC 12394 strain. The whole-genome analysis showed that KNZ03 and ATCC 12394 are categorized into an identical clonal complex by MLST and are phylogenetically close. However, the three strains exhibited different characteristics for pathogenicity in vitro; ATCC 12394 showed significant cytotoxicity to human keratinocytes and release of streptolysin O (SLO) compared to KNZ01 and KNZ03; KNZ03 exhibited significantly high hemolytic activity, but did not secrete SLO. KNZ01 and KNZ03 adhered to human keratinocytes at a higher rate than ATCC 12394; KNZ03 showed a higher rate of survival after a brief (30 min) incubation with human neutrophils compared to the other two strains; also, KNZ01 grew more rapidly in the presence of human serum. In vivo subcutaneous infection commonly resulted in ulcer formation in the three strains 7 days after infection. KNZ01-infected mice showed significant body weight loss 2 days after infection. Besides, on post-infection day 2, only KNZ01 remained in the cutaneous tissues of mice. Scanning electron microscopy analysis revealed that KNZ01 formed an extracellular structure (biofilm), which was probably composed of cell wall-anchoring proteins, in the presence of glucose and human serum. The extracellular structure of ATCC 12394 was also changed dramatically in response to culture conditions, whereas that of KNZ03 did not. Our study proposed that each SDSE strain possesses different virulence factors characteristics for mediating pathogenicity in humans.

Dataset Information

Comparison of Characteristics of Streptococcus dysgalactiae subsp. equisimilis Isolates Causing Repetitive vs Single Infections.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets