■无乳链球菌(S.无乳)是引起牛乳腺炎的病原体,在畜牧业中造成相当大的经济损失。了解我国奶牛乳腺炎患者无乳链球菌的分布及耐药特点,进行了多位点序列分型(MLST),并分析了该地区细菌的血清型和耐药性特征。
■根据MLST对总共21株牛无乳链球菌进行了表征,分子血清分型,抗菌药物敏感性试验,和耐药基因的存在。
■血清型主要为Ia和II,占所有血清型的47.6%和42.9%,分别。通过MLST鉴定了五种序列类型(ST)。以ST103和ST1878菌株为主,比率分别为52.4%和28.6%,分别。后者是一部小说,以前未表征的序列类型。90%以上的无乳链球菌对青霉素敏感,苯唑西林,头孢菌素,头孢噻呋酯,庆大霉素,氟苯尼考和磺胺甲恶唑。该菌对四环素有较高的耐药性(85.7%),克林霉素(52.1%)和红霉素(47.6%)。通过PCR检测抗性基因,结果显示,47.6%,33.3%和38.1%的分离株携带tet(M),tet(O)和erm(B)基因,分别。
■这项研究的结果表明,无乳链球菌显示出高水平的抗微生物耐药性。有必要监测乳腺炎的病原体以防止这些细菌的传播。
UNASSIGNED: Streptococcus agalactiae (S. agalactiae) is a pathogen causing bovine mastitis that results in considerable economic losses in the livestock sector. To understand the distribution and drug resistance characteristics of S. agalactiae from dairy cow mastitis cases in China, multilocus sequence typing (MLST) was carried out and the serotypes and drug resistance characteristics of the bacteria in the region were analysed.
UNASSIGNED: A total of 21 strains of bovine S. agalactiae were characterised based on MLST, molecular serotyping, antimicrobial susceptibility testing, and the presence of drug resistance genes.
UNASSIGNED: The serotypes were mainly Ia and II, accounting for 47.6% and 42.9% of all serotypes, respectively. Five sequence types (STs) were identified through MLST. The ST103 and ST1878 strains were predominant, with rates of 52.4% and 28.6%, respectively. The latter is a novel, previously uncharacterised sequence type. More than 90% of S. agalactiae strains were susceptible to penicillin, oxacillin, cephalothin, ceftiofur, gentamicin, florfenicol and sulfamethoxazole. The bacteria showed high resistance to tetracycline (85.7%), clindamycin (52.1%) and erythromycin (47.6%). Resistant genes were detected by PCR, the result of which showed that 47.6%, 33.3% and 38.1% of isolates carried the tet(M), tet(O) and erm(B) genes, respectively.
UNASSIGNED: The results of this study indicate that S. agalactiae show a high level of antimicrobial resistance. It is necessary to monitor the pathogens of mastitis to prevent the transmission of these bacteria.