Streptococcus pyogenes Su strain cells 1KE (0.1mg) powder and solvent for suspension for injection vials

Trueperella pyogenes can cause various infections in the organs and tissues of different livestock (including pigs, cows, goats, and sheep), including mastitis, endometritis, pneumonia, or abscesses. Moreover, diseases induced by T. pyogenes cause significant economic losses in animal husbandry. In recent large-scale investigations, T. pyogenes has been identified as one of the main pathogens causing endometritis in lactating cows. However, the main treatment for the above-mentioned diseases is still currently antibiotic therapy. Understanding the impact of endometritis associated with T. pyogenes on the fertility of cows can help optimize antibiotic treatment for uterine diseases, thereby strategically concentrating the use of antimicrobials on the most severe cases. Therefore, it is particularly important to continuously monitor the prevalence of T. pyogenes and test its drug resistance. This study compared the uterine microbiota of healthy cows and endometritis cows in different cattle farms, investigated the prevalence of T. pyogenes, evaluated the genetic characteristics and population structure of isolated strains, and determined the virulence genes and drug resistance characteristics of T. pyogenes. An amount of 186 dairy cows were involved in this study and 23 T. pyogenes strains were isolated and identified from the uterine lavage fluid of dairy cows with or without endometritis.

Abstract licence: CC BY

Background: Cancer remains a leading cause of mortality globally. Conventional treatment modalities, including radiation and chemotherapy, often fall short of achieving complete remission, highlighting the critical need for novel therapeutic strategies. One promising approach involves the oncolytic potential of Group A Streptococcus (GAS) strains for tumor treatment. This study aimed to investigate the oncolytic efficacy of S. pyogenes GUR and its M protein knockout mutant, S. pyogenes strain GURSA1, which was genetically constructed to minimize overall toxicity, against mouse hepatoma 22A, pancreatic cancer PANC02, and human glioma U251 cells, both in vitro and in vivo, using the C57BL/6 mouse model. Methods: The in vitro oncolytic cytotoxic activity of GAS strains was studied against human glioma U251, pancreatic cancer PANC02, murine hepatoma 22a, and normal skin fibroblast cells using the MTT assay and the real-time xCELLigence system. A syngeneic mouse model of hepatoma and pancreatic cancer was used to evaluate the in vivo oncolytic effect of GAS strains. Statistical analysis was conducted using Student’s t-test and Mann–Whitney U-test with GraphPad Prism software. Results: The in vitro model showed that the live S. pyogenes GUR strain had a strong cytotoxic effect (67.4 ± 1.9%) against pancreatic cancer PANC02 cells. This strain exhibited moderate (38.0 ± 1.8%) and weak (16.3 ± 5.4%) oncolytic activities against glioma and hepatoma cells, respectively. In contrast, the S. pyogenes GURSA1 strain demonstrated strong (86.5 ± 1.6%) and moderate (36.5 ± 1.8%) oncolytic activities against glioma and hepatoma cells. Additionally, the S. pyogenes GURSA1 strain did not exhibit cytotoxic activity against healthy skin fibroblast cells (cell viability 104.2 ± 1.3%, p = 0.2542). We demonstrated that tumor treatment with S. pyogenes GURSA1 significantly increased the lifespan of C57BL/6 mice with hepatoma (34 days, p = 0.040) and pancreatic cancer (32 days, p = 0.039) relative to the control groups (24 and 28 days, respectively). Increased lifespan was accompanied by a slowdown in tumor progression, as evidenced by a reduction in the growth of hepatoma and pancreatic cancer tumors under treatment with GAS strains in mice. Conclusions: Both S. pyogenes GUR and S. pyogenes GURSA1 strains demonstrated strong oncolytic activity against murine hepatoma 22a, pancreatic cancer PANC02, and human U251 glioma cells in vitro. In contrast, S. pyogenes GUR and GURSA1 did not show toxicity against human normal skin fibroblasts. The overall survival rate and lifespan of mice treated with S. pyogenes GURSA1, a strain lacking the M protein on its surface, were significantly higher compared to the control and S. pyogenes GUR strain groups.

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Streptococcus equi subsp. zooepidemicus (S. zooepidemicus) is one of the important zoonotic and opportunistic pathogens. In recent years, there has been growing evidence that supports the potential role of S. zooepidemicus in severe diseases in horses and other animals, including humans. Furthermore, the clinical isolation and drug resistance rates of S. zooepidemicus have been increasing yearly, leading to interest in its in-depth genomic analysis. In order to deepen the understanding of the S. zooepidemicus characteristics and genomic features, we investigated the genomic islands, mobile genetic elements, virulence and resistance genes, and phenotype of S. zooepidemicus strain ZHZ 211 (ST147), isolated from an equine farm in China. We obtained a 2.18 Mb, high-quality chromosome and found eight genomic islands. According to a comparative genomic investigation with other reference strains, ZHZ 211 has more virulence factors, like an iron uptake system, adherence, exoenzymes, and antiphagocytosis. More interestingly, ZHZ 211 has acquired a mobile genetic element (MGE), prophage Ph01, which was found to be in the chromosome of this strain and included two hyaluronidase (hyl) genes, important virulence factors of the strain. Moreover, two transposons and two virulence (virD4) genes were found to be located in the same genome island of ZHZ 211. In vitro phenotypic results showed that ZHZ 211 grows faster and is resistant to clarithromycin, enrofloxacin, and sulfonamides. The higher biofilm-forming capabilities of ZHZ 211 may provide a competitive advantage for survival in its niche. The results expand our understanding of the genomic, pathogenicity, and resistance characterization of Streptococcus zooepidemicus and facilitate further exploration of its molecular pathogenic mechanism.

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In the study, a comprehensive investigation on potential bacterial pathogens affecting largemouth bass (Micropterus salmoides) was performed. Monthly surveys were conducted from April to October 2024. Diseased largemouth bass exhibited diverse clinical symptoms, such as rot of gill and fin, ulcers on body surface, and petechial hemorrhages in liver. Following isolation and identification, a total of 21 potential bacterial pathogens (numbered strain 1 to 21, respectively) were identified. The genus Aeromonas had the highest proportion (67.14%), among which the frequency of Aeromonas veronii was 24.60%. TEM analysis revealed that the bacterial strains exhibited three predominant shapes (rod-shaped, spherical, and curved) with length ranging from 0.5 to 3 μm. Flagellar structures were observed in strains 1–4, 6–8, 11–17, and 19–21, with variations in number and growth sites. Three isolates (strains 9, 10, 18) demonstrated Gram-positive characteristic, and strains 5, 11, and 18 have capsule structures. Strains 5, 9, 10, and 18 were non-motile, and strains 1–4, 6, 7, 9–11, 16–18, and 21 exhibited β-hemolysis. Physiological and biochemical characteristics of the 21 bacterial isolates were comprehensively analyzed. Antibiotic sensitivity testing revealed that florfenicol and enrofloxacin exhibited excellent antibacterial effects. These data will enrich the potential bacterial diseases information and promote the healthy development of the largemouth bass industry.

Abstract licence: CC BY

Biofilms are extracellular constituents composed of polysaccharides and other substances necessary for bacteria to defend themselves against foreign enemies. Amylase of Streptococcus pyogenes is an enzyme that degrades polysaccharides and other substances and produces nutrients for invasion of epithelial cells. S. salivarius is an oral commensal bacterium that shows antibacterial activity against S. pyogenes. We investigated the relationship between S. pyogenes and S. salivarius to determine whether the amylase of S. pyogenes affects the biofilm of S. salivarius. The amyA gene-deficient strains were generated from S. pyogenes 1529 and MDYK strains, and the amylase production ability of the wild-type and gene-deficient strains were compared. Amylase production in mutant strain was significantly reduced compared to the wild-type strain. Next, the biofilm-forming ability of S. pyogenes was compared between wild-type and mutant strains, and significantly increased biofilm-forming ability was observed in the gene-deficient strains. Next, S. salivarius was cultured to create biofilms, and then wild-type and mutant strains of S. pyogenes were added to the culture. Significantly, the biofilms of S. salivarius with the gene-deficient strains were higher than those with the wild strains. As the biofilm-forming ability of S. salivarius co-cultured with S. pyogenes was compared, the biofilm-forming ability of S. salivarius co-cultured with the mutant strain of S. pyogenes was also significantly increased. These results were common findings for the 1529 and MDYK strains of S. pyogenes. Our results suggest that amylase from S. pyogenes inhibits biofilm formation in S. salivarius.

Abstract licence: CC BY-NC-SA