阿尔及利亚健康奶牛鼻腔内金黄色葡萄球菌的定植：抗生素耐药性、肠毒素基因和生物膜形成。

Nasal carriage of Staphylococcus aureus in healthy dairy cows in Algeria: antibiotic resistance, enterotoxin genes and biofilm formation.

机构信息

Laboratory of Analytical Biochemistry and Biotechnology (LABAB), University Mouloud Mammeri, Tizi Ouzou, Algeria.

Laboratory of Biotechnologies Related to Animal Reproduction, Institute of Veterinary Sciences, University of Saad Dahlab, Blida 1.Blida, Tizi Ouzou, Algeria.

出版信息

BMC Vet Res. 2024 Jun 7;20(1):247. doi: 10.1186/s12917-024-04103-x.

DOI:10.1186/s12917-024-04103-x

PMID:38849892

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11157847/

Abstract

BACKGROUND

Staphylococcus aureus can colonize and infect a variety of animal species. In dairy herds, it is one of the leading causes of mastitis cases. The objective of this study was to characterize the S. aureus isolates recovered from nasal swabs of 249 healthy cows and 21 breeders of 21 dairy farms located in two provinces of Algeria (Tizi Ouzou and Bouira).

METHODS

The detection of enterotoxin genes was investigated by multiplex PCRs. Resistance of recovered isolates to 8 antimicrobial agents was determined by disc-diffusion method. The slime production and biofilm formation of S. aureus isolates were assessed using congo-red agar (CRA) and microtiter-plate assay. Molecular characterization of selected isolates was carried out by spa-typing and Multi-Locus-Sequence-Typing (MLST).

RESULTS

S. aureus was detected in 30/249 (12%) and 6/13 (28.6%) of nasal swabs in cows and breeders, respectively, and a total of 72 isolates were recovered from positive samples (59 isolates from cows and 13 from breeders). Twenty-six of these isolates (36.1%) harbored genes encoding for staphylococcal enterotoxins, including 17/59 (28.8%) isolates from cows and 9/13 (69.2%) from breeders. Moreover, 49.1% and 92.3% of isolates from cows and breeders, respectively, showed penicillin resistance. All isolates were considered as methicillin-susceptible (MSSA). Forty-five (76.3%) of the isolates from cows were slime producers and 52 (88.1%) of them had the ability to form biofilm in microtiter plates. Evidence of a possible zoonotic transmission was observed in two farms, since S. aureus isolates recovered in these farms from cows and breeders belonged to the same clonal lineage (CC15-ST15-t084 or CC30-ST34-t2228).

CONCLUSIONS

Although healthy cows in this study did not harbor methicillin-resistant S. aureus isolates, the nares of healthy cows could be a reservoir of enterotoxigenic and biofilm producing isolates which could have implications in human and animal health.

摘要

背景

金黄色葡萄球菌可以定植并感染多种动物物种。在奶牛群中，它是乳腺炎病例的主要原因之一。本研究的目的是从位于阿尔及利亚两个省（提济乌祖和布维拉）的 21 个奶牛场的 249 头健康奶牛和 21 头种牛的鼻腔拭子中分离金黄色葡萄球菌，并对其进行特征描述。

方法

采用多重 PCR 法检测肠毒素基因的存在。采用纸片扩散法检测分离株对 8 种抗菌药物的耐药性。采用刚果红琼脂（CRA）和微量滴定板测定法评估金黄色葡萄球菌分离株的黏液产生和生物膜形成能力。通过 spa 分型和多位点序列分型（MLST）对选定的分离株进行分子特征描述。

结果

在奶牛和种牛的鼻腔拭子中，分别检测到 30/249（12%）和 6/13（28.6%）样本中存在金黄色葡萄球菌，从阳性样本中总共分离出 72 株分离株（59 株来自奶牛，13 株来自种牛）。其中 26 株（36.1%）分离株携带编码葡萄球菌肠毒素的基因，包括 17 株（28.8%）来自奶牛的分离株和 9 株（69.2%）来自种牛的分离株。此外，来自奶牛和种牛的分离株中分别有 49.1%和 92.3%对青霉素耐药。所有分离株均被认为是耐甲氧西林金黄色葡萄球菌（MSSA）。来自奶牛的 45 株（76.3%）分离株为黏液产生菌，52 株（88.1%）分离株在微量滴定板上具有形成生物膜的能力。在两个农场中观察到可能存在人畜共患病传播的证据，因为从这些农场的奶牛和种牛中分离到的金黄色葡萄球菌分离株属于同一克隆谱系（CC15-ST15-t084 或 CC30-ST34-t2228）。