Institute for Food Safety and Hygiene, Vetsuisse Faculty University of Zurich, Winterthurerstrasse 272, 8057 Zurich, Switzerland.
BMC Vet Res. 2011 Jan 27;7:6. doi: 10.1186/1746-6148-7-6.
Methicillin-resistant coagulase-negative staphylococci (MR-CNS) are of increasing importance to animal and public health. In veterinary medicine and along the meat and milk production line, only limited data were so far available on MR-CNS characteristics. The aim of the present study was to evaluate the prevalence of MR-CNS, to identify the detected staphylococci to species level, and to assess the antibiotic resistance profiles of isolated MR-CNS strains.
After two-step enrichment and growth on chromogenic agar, MR-CNS were detected in 48.2% of samples from livestock and chicken carcasses, 46.4% of samples from bulk tank milk and minced meat, and 49.3% of human samples. Using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS), 414 selected MR-CNS strains belonged to seven different species (S. sciuri, 32.6%; S. fleurettii, 25.1%; S. haemolyticus, 17.4%; S. epidermidis, 14.5%, S. lentus, 9.2%; S. warneri, 0.7%; S. cohnii, 0.5%). S. sciuri and S. fleurettii thereby predominated in livestock, BTM and minced meat samples, whereas S. epidermidis and S. haemolyticus predominated in human samples. In addition to beta-lactam resistance, 33-49% of all 414 strains were resistant to certain non-beta-lactam antibiotics (ciproflaxacin, clindamycin, erythromycin, tetracycline).
A high prevalence of MR-CNS was found in livestock production. This is of concern in view of potential spread of mecA to S. aureus (MRSA). Multiresistant CNS strains might become an emerging problem for veterinary medicine. For species identification of MR-CNS isolated from different origins, MALDI-TOF MS proved to be a fast and reliable tool and is suitable for screening of large sample amounts.
耐甲氧西林凝固酶阴性葡萄球菌（MR-CNS）对动物和公共卫生的重要性日益增加。在兽医领域以及肉类和奶制品生产线上，目前仅有限的数据可用于描述 MR-CNS 的特征。本研究旨在评估 MR-CNS 的流行率，鉴定所检测到的葡萄球菌到种水平，并评估分离的 MR-CNS 菌株的抗生素耐药谱。
经过两步富集和显色琼脂培养，从牲畜和鸡胴体样本中检测到 48.2%、大容量奶罐奶和肉末样本中检测到 46.4%、人样本中检测到 49.3%的 MR-CNS。使用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF MS），对 414 株选定的 MR-CNS 菌株进行鉴定，属于七个不同的种（松鼠葡萄球菌，32.6%；藤黄微球菌，25.1%；溶血葡萄球菌，17.4%；表皮葡萄球菌，14.5%；缓慢葡萄球菌，9.2%；沃氏葡萄球菌，0.7%；科氏葡萄球菌，0.5%）。松鼠葡萄球菌和藤黄微球菌在牲畜、BTM 和肉末样本中占优势，而表皮葡萄球菌和溶血葡萄球菌在人样本中占优势。除了β-内酰胺类药物耐药性外，414 株菌中 33-49%的菌株对某些非β-内酰胺类抗生素（环丙沙星、克林霉素、红霉素、四环素）有耐药性。
在牲畜生产中发现了高比例的耐甲氧西林凝固酶阴性葡萄球菌。鉴于 mecA 向金黄色葡萄球菌（MRSA）的潜在传播，这令人担忧。多耐药 CNS 菌株可能成为兽医领域的一个新问题。对于从不同来源分离的 MR-CNS 的种属鉴定，MALDI-TOF MS 被证明是一种快速可靠的工具，适用于大量样本的筛选。
