Department of Veterinary Medicine and Surgery, University of Missouri, Columbia 65211.
Department of Pathology and Microbiology, University of Montreal, Quebec, Canada J2S 2M2.
J Dairy Sci. 2018 Apr;101(4):3213-3225. doi: 10.3168/jds.2017-13974. Epub 2018 Feb 4.
The purpose of this study was to describe the prevalence and distribution of staphylococcal species on the teat and inguinal skin of dairy heifers across the various stages of the heifer life cycle. The cross-sectional study included 106 Holstein heifers with an age range of 0 d to 27 mo that were selected from 11 different groups, based on housing type and age, on a single dairy operation. A composite swabbing sample including all 4 teats and a second composite sample including both inguinal regions of each heifer were collected using gas-sterilized electrostatic dusters (Swiffers; Procter and Gamble, Cincinnati, OH). Swabbing samples were mixed with 10 mL of sterile saline, agitated, and cultured on mannitol salt agar plates. At 24 h, plates were read and up to 10 staphylococcal colonies were saved for further analysis. Staphylococcal isolates were speciated using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry or PCR amplification and partial sequencing of rpoB or tuf. The prevalence of staphylococci was compared between the inguinal and teat regions using the chi-squared or Fisher's exact test, as applicable. Logistic regression models were used to investigate the relationship between a heifer's age (treated as a quantitative continuous variable) and the probability of isolating a given staphylococcal species from a given body site (inguinal region or teats). Overall, the most common species identified were Staphylococcus haemolyticus followed by Staphylococcus chromogenes, Staphylococcus xylosus, Staphylococcus devriesei, and Staphylococcus sciuri. Staphylococcus aureus was more prevalent on the teat than in the inguinal region, whereas Staphylococcus arlettae was more prevalent in the inguinal region than on the teat. All other staphylococcal species were as likely to be found on the teat skin as the inguinal region skin. Isolation from the inguinal and teat skin was associated with age for Staphylococcus agnetis, S. chromogenes, S. devriesei, Staphylococcus equorum, S. haemolyticus, Staphylococcus lentus, S. sciuri, Staphylococcus vitulinus, and S. xylosus. The probability of finding S. chromogenes and S. agnetis on the teat and inguinal region increased with age, whereas the probability of S. devriesei and S. haemolyticus decreased with age. This study provides further insight into the ecology of staphylococcal species involved in heifer mastitis.
本研究旨在描述奶牛犊牛在整个生命周期的各个阶段中，在乳头上和腹股沟皮肤上葡萄球菌的流行情况和分布情况。本横断面研究包括 11 个不同群体的 106 头荷斯坦奶牛，这些群体基于畜舍类型和年龄进行选择，来自于一个单一的奶牛场。使用气体消毒的静电除尘器（Swiffers；Procter and Gamble，Cincinnati，OH）采集每个奶牛的 4 个乳头的复合拭子样本和每个奶牛的两个腹股沟区域的第二个复合拭子样本。将拭子样本与 10 mL 无菌生理盐水混合，搅拌，并在甘露醇盐琼脂平板上培养。在 24 小时时，读取平板并保存多达 10 个葡萄球菌菌落进行进一步分析。使用基质辅助激光解吸/电离飞行时间质谱或 rpoB 或 tuf 的 PCR 扩增和部分测序来对葡萄球菌分离株进行分类。使用卡方检验或 Fisher 确切检验（视情况而定）比较腹股沟和乳头区域的葡萄球菌流行情况。使用逻辑回归模型研究奶牛年龄（视为定量连续变量）与从特定身体部位（腹股沟区域或乳头）分离特定葡萄球菌的概率之间的关系。总的来说，最常见的鉴定物种是溶血葡萄球菌，其次是产色葡萄球菌、木糖葡萄球菌、解糖葡萄球菌和松鼠葡萄球菌。金黄色葡萄球菌在乳头上比在腹股沟区域更常见，而阿莱塔葡萄球菌在腹股沟区域比在乳头上更常见。所有其他葡萄球菌物种在乳头皮肤上的发现率与腹股沟皮肤相同。腹股沟和乳头皮肤的分离与葡萄球菌 agnetis、chromogenes、devriesei、equorum、haemolyticus、lentus、sciuri、vitulinus 和 xylosus 的年龄有关。在乳头上和腹股沟区域发现 chromogenes 和 agnetis 的概率随着年龄的增长而增加，而 devriesei 和 haemolyticus 的概率随着年龄的增长而降低。本研究进一步深入了解了参与奶牛乳腺炎的葡萄球菌的生态学。
