Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico-Químicas y Naturales, Universidad Nacional de Río Cuarto, Córdoba, Argentina.
FEMS Microbiol Lett. 2011 May;318(2):183-8. doi: 10.1111/j.1574-6968.2011.02258.x. Epub 2011 Mar 25.
Streptococcus uberis is an important pathogen that has been implicated in bovine mastitis but the virulence factors associated with pathogenesis are not well understood. The aim of this work was to examine 11 putative and known virulence-associated genes by PCR in 78 S. uberis strains isolated from infected animals in Argentina. Additionally, the distribution of virulence patterns over various herds was determined. Not all genes were present in the strains but all of the detected virulence-associated genes were present in combination. Forty-seven (60.3%) isolates carried seven to 10 virulence-associated genes. Further analysis revealed 58 virulence patterns. Different patterns were found within the same herd and among herds, demonstrating that strains with different virulence patterns were able to cause mastitis. Despite the large number of strains with different virulence patterns, strains with identical patterns was found. Detection of virulence-associated genes in individual S. uberis strains isolated from infected animals revealed one to 10 virulence genes. This may indicate that other virulence factors could be involved. The present study reveals the occurrence and distribution of 11 virulence-associated genes among S. uberis isolates from bovine mastitis in various herds and contributes to a better understanding of the pathogenicity of this bacterium.
停乳链球菌是一种重要的病原体，与奶牛乳腺炎有关，但与发病机制相关的毒力因子尚未完全了解。本研究旨在通过 PCR 检测从阿根廷感染动物中分离的 78 株停乳链球菌中 11 种假定和已知的与毒力相关的基因。此外，还确定了各种牛群中不同的毒力模式分布。并非所有基因都存在于菌株中，但所有检测到的与毒力相关的基因都存在于组合中。47（60.3％）株携带 7 至 10 种与毒力相关的基因。进一步分析显示存在 58 种毒力模式。在同一牛群和不同牛群中发现了不同的模式，表明具有不同毒力模式的菌株能够引起乳腺炎。尽管存在大量具有不同毒力模式的菌株，但也发现了具有相同模式的菌株。从感染动物中分离的单个停乳链球菌菌株中检测到 1 至 10 种毒力相关基因。这可能表明还涉及其他毒力因子。本研究揭示了不同牛群中乳腺炎停乳链球菌分离株中 11 种与毒力相关基因的发生和分布，有助于更好地了解该细菌的致病性。
