PDF(Pubmed)
Abstract：
BACKGROUND: Staphylococcus aureus (S. aureus) is a highly virulent pathogen that causes food-borne illness, food poisoning, skin and soft tissue infections, abscesses, mastitis, and bacteremia. It is common for meat and meat products to become contaminated with S. aureus due to dirty hands, food storage conditions, food production processes, and unhygienic conditions, causing food poisoning. Therefore, we aimed to isolate S. aureus strain from the raw beef and reveal virulence genes and antibiotic resistance profile from isolated S. aureus strains.
METHODS: In this study, 100 samples of raw beef were collected from 4 major market stalls in Ulaanbaatar city, Mongolia. S. aureus was detected according to the ISO 6888-1:2021 standard, and the nucA gene encoding the species-specific thermonuclease was amplified and confirmed by polymerase chain reaction (PCR). In the strains of S. aureus isolated from the samples, the genes encoding the virulence factors including sea, sed, tsst, eta, etb, and mecA were amplified by multiplex PCR. These genes are encoded staphylococcal enterotoxin A, enterotoxin D, toxic shock syndrome toxin, exotoxin A, exotoxin B and penicillin-binding protein PBP 2A, respectively. Antibiotic sensitivity test was performed by the Kirby-Bauer disc diffusion method. The Clinical and Laboratory Standard Institute guidelines as CLSI M100-S27 was used for analysis of the data.
RESULTS: Thirty-five percent of our samples were detected contaminated with of the S. aureus strains. Subsequently, antibiotic resistance was observed in the S. aureus contaminated samples. Among our samples, the highest rates of resistance were determined against ampicillin (97.1%), oxacillin (88.6%), and penicillin (88.6%), respectively. Three genes including mecA, sea, and tsst from six virulence genes were detected in 17% of S. aureus strain-contaminated samples by multiplex PCR. The sed, etb and eta genes were detected in the 2.9%, 11.4% and 5.7% of our samples, respectively.
CONCLUSIONS: The results show that S. aureus related contamination is high in the raw beef for retail sale and prevalent S. aureus strains are resistant to all antibiotics used. Also, our results have demonstrated that there is a high risk for food poisoning caused by antibiotic resistant S. aureus in the raw beef and it may establish public health issues. Genes encoding for both heat-resistant and nonresistant toxicity factors were detected in the antibiotic resistant S. aureus strains and shown the highly pathogenic. Finally, our study is ensuring to need proper hygienic conditions during beef\'s preparation and sale.
METHODS: In this study, 100 samples of raw beef were collected from 4 major market stalls in Ulaanbaatar city, Mongolia. S. aureus was detected according to the ISO 6888-1:2021 standard, and the nucA gene encoding the species-specific thermonuclease was amplified and confirmed by polymerase chain reaction (PCR). In the strains of S. aureus isolated from the samples, the genes encoding the virulence factors including sea, sed, tsst, eta, etb, and mecA were amplified by multiplex PCR. These genes are encoded staphylococcal enterotoxin A, enterotoxin D, toxic shock syndrome toxin, exotoxin A, exotoxin B and penicillin-binding protein PBP 2A, respectively. Antibiotic sensitivity test was performed by the Kirby-Bauer disc diffusion method. The Clinical and Laboratory Standard Institute guidelines as CLSI M100-S27 was used for analysis of the data.
RESULTS: Thirty-five percent of our samples were detected contaminated with of the S. aureus strains. Subsequently, antibiotic resistance was observed in the S. aureus contaminated samples. Among our samples, the highest rates of resistance were determined against ampicillin (97.1%), oxacillin (88.6%), and penicillin (88.6%), respectively. Three genes including mecA, sea, and tsst from six virulence genes were detected in 17% of S. aureus strain-contaminated samples by multiplex PCR. The sed, etb and eta genes were detected in the 2.9%, 11.4% and 5.7% of our samples, respectively.
CONCLUSIONS: The results show that S. aureus related contamination is high in the raw beef for retail sale and prevalent S. aureus strains are resistant to all antibiotics used. Also, our results have demonstrated that there is a high risk for food poisoning caused by antibiotic resistant S. aureus in the raw beef and it may establish public health issues. Genes encoding for both heat-resistant and nonresistant toxicity factors were detected in the antibiotic resistant S. aureus strains and shown the highly pathogenic. Finally, our study is ensuring to need proper hygienic conditions during beef\'s preparation and sale.
摘要：
背景：金黄色葡萄球菌(S.金黄色葡萄球菌)是一种导致食源性疾病的高毒力病原体，食物中毒,皮肤和软组织感染，脓肿,乳腺炎,和菌血症.这是常见的肉类和肉类产品被金黄色葡萄球菌污染，由于肮脏的手，食品储存条件,食品生产过程，和不卫生的条件，导致食物中毒。因此,我们旨在从生牛肉中分离金黄色葡萄球菌菌株，并揭示分离的金黄色葡萄球菌菌株的毒力基因和抗生素抗性谱。
方法：在本研究中，从乌兰巴托市的4个主要市场摊位收集了100个生牛肉样品，蒙古。根据ISO6888-1:2021标准检测金黄色葡萄球菌，并扩增编码物种特异性热核酸酶的nucA基因，并通过聚合酶链反应（PCR）进行确认。在从样品中分离出的金黄色葡萄球菌菌株中，编码毒力因子的基因包括海，SED,tsst,eta,ETB,通过多重PCR扩增mecA。这些基因编码葡萄球菌肠毒素A,肠毒素D,中毒性休克综合征毒素，外毒素A,外毒素B和青霉素结合蛋白PBP2A，分别。抗生素敏感性试验通过Kirby-Bauer圆盘扩散法进行。临床和实验室标准研究所指南如CLSIM100-S27用于数据分析。
结果：我们的样本中有35%被金黄色葡萄球菌菌株污染。随后，在金黄色葡萄球菌污染样品中观察到抗生素耐药性.在我们的样品中，对氨苄青霉素的耐药率最高(97.1%)，苯唑西林(88.6%),和青霉素（88.6%），分别。包括mecA在内的三个基因,海,通过多重PCR在17％的金黄色葡萄球菌菌株污染样品中检测到六个毒力基因的tsst。sed,在2.9%中检测到ETB和ETA基因，11.4%和5.7%的样品，分别。
结论：结果表明，零售生牛肉中金黄色葡萄球菌相关污染较高，流行的金黄色葡萄球菌菌株对所有使用的抗生素均具有耐药性。此外，我们的研究结果表明,生牛肉中由耐抗生素金黄色葡萄球菌引起的食物中毒风险很高,这可能会引起公共卫生问题.在抗生素抗性金黄色葡萄球菌菌株中检测到编码耐热和非抗性毒性因子的基因，并显示出高致病性。最后,我们的研究是确保在牛肉的制备和销售过程中需要适当的卫生条件。
方法：在本研究中，从乌兰巴托市的4个主要市场摊位收集了100个生牛肉样品，蒙古。根据ISO6888-1:2021标准检测金黄色葡萄球菌，并扩增编码物种特异性热核酸酶的nucA基因，并通过聚合酶链反应（PCR）进行确认。在从样品中分离出的金黄色葡萄球菌菌株中，编码毒力因子的基因包括海，SED,tsst,eta,ETB,通过多重PCR扩增mecA。这些基因编码葡萄球菌肠毒素A,肠毒素D,中毒性休克综合征毒素，外毒素A,外毒素B和青霉素结合蛋白PBP2A，分别。抗生素敏感性试验通过Kirby-Bauer圆盘扩散法进行。临床和实验室标准研究所指南如CLSIM100-S27用于数据分析。
结果：我们的样本中有35%被金黄色葡萄球菌菌株污染。随后，在金黄色葡萄球菌污染样品中观察到抗生素耐药性.在我们的样品中，对氨苄青霉素的耐药率最高(97.1%)，苯唑西林(88.6%),和青霉素（88.6%），分别。包括mecA在内的三个基因,海,通过多重PCR在17％的金黄色葡萄球菌菌株污染样品中检测到六个毒力基因的tsst。sed,在2.9%中检测到ETB和ETA基因，11.4%和5.7%的样品，分别。
结论：结果表明，零售生牛肉中金黄色葡萄球菌相关污染较高，流行的金黄色葡萄球菌菌株对所有使用的抗生素均具有耐药性。此外，我们的研究结果表明,生牛肉中由耐抗生素金黄色葡萄球菌引起的食物中毒风险很高,这可能会引起公共卫生问题.在抗生素抗性金黄色葡萄球菌菌株中检测到编码耐热和非抗性毒性因子的基因，并显示出高致病性。最后,我们的研究是确保在牛肉的制备和销售过程中需要适当的卫生条件。
