Streptococcus equi subsp. zooepidemicus infections associated with guinea pigs.
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ABSTRACT:
SUBMITTER: Gruszynski K
PROVIDER: S-EPMC4285269 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:By screening a genomic lambda library of Streptococcus equi subsp. zooepidemicus, we have cloned and sequenced a gene, termed fnz, encoding a fibronectin (Fn)-binding protein called FNZ. On the basis of the deduced amino acid sequence of FNZ, the mature protein has a molecular mass of approximately 61 kDa. Analysis of FNZ reveals a structural organization similar to that of other cell surface proteins from streptococci and staphylococci. The Fn-binding activity is localized to two domains in the C-terminal part of FNZ. One domain is composed of five repeats, which contain a motif similar to what has earlier been found in other Fn-binding proteins in streptococci and staphylococci. The first and second repeats are separated by a short stretch of amino acids, including the motif LAGESGET, which is an important part of the second Fn-binding domain. This motif is also present in an Fn-binding domain (UR) in protein F of Streptococcus pyogenes. A fusion protein covering the Fn-binding domain of FNZ inhibits the binding of the 29-kDa N-terminal fragment of Fn to cells of various streptococcal species as well as to Staphylococcus aureus.
| S-EPMC174328 | biostudies-other
Project description:We describe a case of an infant with recurrent bacteremia caused by Streptococcus equi subsp. zooepidemicus, likely transmitted from mother to infant. Our case highlights the importance of an epidemiological history and molecular diagnostics in ascertaining insights into transmission, pathogenesis, and optimal management.
| S-EPMC4540932 | biostudies-literature
Project description:Streptococcus equi subsp. zooepidemicus is an opportunistic pathogen. It has caused a very large economic loss in the swine industry of China and has become a threat to human health. We announce the complete genome sequence of S. equi subsp. zooepidemicus strain ATCC 35246, which provides opportunities to understand its pathogenesis mechanism and genetic basis.
| S-EPMC3187426 | biostudies-literature
Project description:Investigations of 2 cases of high mortality in cull sows and feeder pigs from a buying station in Ohio and cull sows at an abattoir in Tennessee were conducted at the Iowa State University Veterinary Diagnostic Laboratory. The animals were presented as weak, lethargic, and some with high fever. Rapidly escalating mortality was reported to be as high as 30-50% within groups at the buying station over 8-10 d, and 30-40% over 5-7 d at the abattoir. Splenomegaly and red lymph nodes were the most consistent macroscopic findings, with scant fibrinous polyserositis observed in one sow. The microscopic lesions of vasculitis, fibrin thrombi, fibrinosuppurative polyserositis, and intralesional bacteria were consistent with acute bacterial septicemia. Bacterial culture isolated Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) from multiple organs, including spleen, lung, and kidney. PCR tests were negative for African swine fever virus, classical swine fever virus, Erysipelothrix rhusiopathiae, porcine reproductive and respiratory syndrome virus, porcine circovirus 2, and Salmonella spp. Porcine circovirus 3 was inconsistently detected at low levels by PCR, with a lack of associated lesions. Next-generation sequencing identified S. zooepidemicus and porcine partetravirus in the serum sample of the feeder pig from the buying station. Phylogenetic analysis of the szP gene indicated that the S. zooepidemicus isolates from Ohio and Tennessee are in genotype VI. We conclude that the cause of these high mortality events in swine was S. zooepidemicus septicemia.
| S-EPMC7438661 | biostudies-literature
Project description:Draft genome sequences of two outbreak isolates of Streptococcus equi subsp. zooepidemicus from a Pennsylvania swine herd affected with high mortality and morbidity are reported here. The genome analysis revealed that the isolates are closely related to a virulent strain originally identified in China.
| S-EPMC7561694 | biostudies-literature
Project description:Streptococcus equi subsp. equi (SEE) is a host-restricted equine pathogen considered to have evolved from Streptococcus equi subsp. zooepidemicus (SEZ). SEZ is promiscuous in host range and is commonly recovered from horses as a commensal. Comparison of a single strain each of SEE and SEZ using whole-genome sequencing, supplemented by PCR of selected genes in additional SEE and SEZ strains, was used to characterize the evolution of SEE. But the known genetic variability of SEZ warrants comparison of the whole genomes of multiple SEE and SEZ strains. To fill this knowledge gap, we utilized whole-genome sequencing to characterize the accessory genome elements (AGEs; i.e., elements present in some SEE strains but absent in SEZ or vice versa) and methylomes of 50 SEE and 50 SEZ isolates from Texas. Consistent with previous findings, AGEs consistently found in all SEE isolates were primarily from mobile genetic elements that might contribute to host restriction or pathogenesis of SEE. Fewer AGEs were identified in SEZ because of the greater genomic variability among these isolates. The global methylation patterns of SEE isolates were more consistent than those of the SEZ isolates. Among homologous genes of SEE and SEZ, differential methylation was identified only in genes of SEE encoding proteins with functions of quorum sensing, exopeptidase activity, and transitional metal ion binding. Our results indicate that effects of genetic mobile elements in SEE and differential methylation of genes shared by SEE and SEZ might contribute to the host specificity of SEE. IMPORTANCE Strangles, caused by the host-specific bacterium Streptococcus equi subsp. equi (SEE), is the most commonly diagnosed infectious disease of horses worldwide. Its ancestor, Streptococcus equi subsp. zooepidemicus (SEZ), is frequently isolated from a wide array of hosts, including horses and humans. A comparison of the genomes of a single strain of SEE and SEZ has been reported, but sequencing of further isolates has revealed variability among SEZ strains. Thus, the importance of this study is that it characterizes genomic and methylomic differences of multiple SEE and SEZ isolates from a common geographic region (viz., Texas). Our results affirm many of the previously described differences between the genomes of SEE and SEZ, including the role of mobile genetic elements in contributing to host restriction. We also provide the first characterization of the global methylome of Streptococcus equi and evidence that differential methylation might contribute to the host restriction of SEE.
| S-EPMC8754150 | biostudies-literature
Project description:The acquisition of superantigen-encoding genes by Streptococcus pyogenes has been associated with increased morbidity and mortality in humans, and the gain of four superantigens by Streptococcus equi is linked to the evolution of this host-restricted pathogen from an ancestral strain of the opportunistic pathogen Streptococcus equi subsp. zooepidemicus. A recent study determined that the culture supernatants of several S. equi subsp. zooepidemicus strains possessed mitogenic activity but lacked known superantigen-encoding genes. Here, we report the identification and activities of three novel superantigen-encoding genes. The products of szeF, szeN, and szeP share 59%, 49%, and 34% amino acid sequence identity with SPEH, SPEM, and SPEL, respectively. Recombinant SzeF, SzeN, and SzeP stimulated the proliferation of equine peripheral blood mononuclear cells, and tumor necrosis factor alpha (TNF-?) and gamma interferon (IFN-?) production, in vitro. Although none of these superantigen genes were encoded within functional prophage elements, szeN and szeP were located next to a prophage remnant, suggesting that they were acquired by horizontal transfer. Eighty-one of 165 diverse S. equi subsp. zooepidemicus strains screened, including 7 out of 15 isolates from cases of disease in humans, contained at least one of these new superantigen-encoding genes. The presence of szeN or szeP, but not szeF, was significantly associated with mitogenic activity in the S. equi subsp. zooepidemicus population (P < 0.000001, P < 0.000001, and P = 0.104, respectively). We conclude that horizontal transfer of these novel superantigens from and within the diverse S. equi subsp. zooepidemicus population is likely to have implications for veterinary and human disease.
| S-EPMC2976332 | biostudies-literature
Project description:Streptococcus equi subsp. zooepidemicus (S. zooepidemicus), is a β-hemolytic Streptococcus belonging to the Lancefield group C; it is a rare human pathogen, but in horses, it is frequently associated with endometritis. This study aimed to isolate S. zooepidemicus strains, associated with bacterial endometritis in mares, and to define their antimicrobial resistance profile. Twenty-three isolates were recovered from one hundred ninety-six equine uterine swabs (11.7%). Bacterial identification was carried out by Api 20 Strep and confirmed by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS), while antimicrobial susceptibility testing was performed by disk diffusion method on Muller Hinton agar plates. The antibiotic resistance profiles of the isolates revealed a high percentage of resistance to amikacin (95.6%), ampicillin (73.9%) and tetracycline (69.6%), while ceftiofur and ceftriaxone were highly effective with 82.6% and 78.3% of the isolates inhibited, respectively. An intriguing value of resistance to penicillin (34.8%), which represents the first-choice antibiotic in equine S. zooepidemicus infections, was observed. Furthermore, a high prevalence of multidrug-resistant strains (82.6%) was recorded. Continuous surveillance of this potential zoonotic pathogen and an appropriate antimicrobial stewardship program with the promotion of correct use of antimicrobials, after a proper diagnosis, are needed to allow an effective therapy.
| S-EPMC8773361 | biostudies-literature
Project description:BackgroundThe M-like protein, also known as SzP, is expressed on the surface of Streptococcus equi subsp. zooepidemicus (S. zooepidemicus). Previous studies demonstrated that SzP is similar to M protein of group A Streptococcus in the structure and characteristics of antiphagocytosis. The M protein is an adhesin that can bind to the host cells, however it is not known whether the SzP of S. zooepidemicus also functions as an adhesin. We conducted an investigation to determine SzP as an adhesin, and one SzP epitope was identified to be responsible for mediating binding to HEp-2 cells.MethodsThe gene encoding SzP was expressed in E. coli, and the purified recombinant SzP (rSzP) was recognized by rabbit anti-S. zooepidemicus antibodies using immunoblot. Furthermore, the adherence of S. zooepidemicus to HEp-2 cells was inhibited by anti-rSzP antibodies in a dose-dependent manner. We employed a random 12-peptide phage display library for screening of immunodominant mimics of the SzP, which were recognized by an anti-SzP specific monoclonal antibody (mAb 2C8). Initial positive phage clones were identified by ELISA, followed by assays to determine the adherence-inhibiting ability of the peptide.ResultsTen out of fourteen selected positive clones showed high reactivity that effectively inhibited the binding of mAb 2C8 to rSzP. The motif XSLSRX was highly conserved among six of the ten clones.ConclusionCollectively, our findings suggest that the motif XSLSRX may represent an immunodominant mimic epitope of the SzP of S. zooepidemicus strain ATCC 35246, and that the same epitope may be used to mediate SzP binding to HEp-2 cells.
| S-EPMC2567331 | biostudies-literature
Project description:The pathogen Streptococcus equi subsp. zooepidemicus is associated with a wide range of animals, including humans, and outbreaks frequently occur in pigs, equines, and goats. Thus far, few studies have assessed interactions between the host immune system and S. equi subsp. zooepidemicus and how these interactions explain the wide host spectrum of S. equi subsp. zooepidemicus Neutrophils, the first line of innate immunity, possess a defense mechanism called neutrophil extracellular traps (NETs), which primarily consist of DNA and granule proteins that trap bacteria via charge interactions. Extracellular nucleases play important roles in the degradation of the DNA backbone of NETs. Here, two related extracellular nucleases, nuclease and 5'-nucleotidase (named ENuc and 5Nuc, respectively, in this study), were identified as being encoded by the SESEC_RS04165 gene and the SESEC_RS05720 gene (named ENuc and 5Nuc, respectively), and three related gene deletion mutant strains, specifically, the single-mutant ?ENuc and ?5Nuc strains and the double-mutant ?ENuc ?5Nuc strain, were constructed. The ?ENuc and ?5Nuc single-mutant strains and the ?ENuc ?5Nuc double-mutant strain demonstrated lower virulence than wild-type S. equi subsp. zooepidemicus when the mouse survival rate was evaluated postinfection. Furthermore, wild-type S. equi subsp. zooepidemicus more frequently traversed the bloodstream and transferred to other organs. Wild-type S. equi subsp. zooepidemicus induced fewer NETs and was able to survive in NETs, whereas only 40% of the ?ENuc ?5Nuc double-mutant cells survived. S. equi subsp. zooepidemicus degraded the NET DNA backbone and produced deoxyadenosine, primarily through the action of ENuc and/or 5Nuc. However, the double-mutant ?ENuc ?5Nuc strain lost the ability to degrade NETs into deoxyadenosine. Deoxyadenosine decreased RAW 264.7 cell phagocytosis to 40% of that of normal macrophages. IMPORTANCE:Streptococcus equi subsp. zooepidemicus causes serious bacteremia in its hosts. However, little is known about how S. equi subsp. zooepidemicus interacts with the host innate immune system, particularly innate cells found in the blood. S. equi subsp. zooepidemicus is capable of evading NET-mediated killing via the actions of its potent extracellular nucleases, ENuc and 5Nuc, which directly degrade the NET DNA backbone to deoxyadenosine. In previous studies, other pathogens have required the synergism of nuclease and 5'-nucleotidase to engage in this self-protective process; however, ENuc and 5Nuc both possess nuclease activity and 5'-nucleotidase activity, highlighting the novelty of this discovery. Furthermore, deoxyadenosine impairs phagocytosis but not the intracellular bactericidal activity of macrophages. Here we describe a novel mechanism for S. equi subsp. zooepidemicus extracellular nucleases in NET degradation, which may provide new insights into the pathogen immune evasion mechanism and the prevention and treatment of bacterial disease.
| S-EPMC5203633 | biostudies-literature