Department of Biological Sciences, University of Botswana, Private Bag UB00704, Gaborone, Botswana.
J Food Prot. 2012 Apr;75(4):637-42. doi: 10.4315/0362-028X.JFP-11-438.
The objective of the study was to provide baseline data on the prevalence and antimicrobial susceptibility of Salmonella in different types of raw meat sausages directly accessible to the consumers in Gaborone, Botswana. A total of 300 raw sausages comprising 79 beef, 78 pork, 72 chicken, and 71 mutton samples were concurrently analyzed for the presence of Salmonella using a conventional culture method and a validated PCR method. The PCR assay results were in full concordance with those of the conventional culture method for the detection of Salmonella. Sixty-five (21.7%) of 300 samples were positive for Salmonella by both the conventional culture method and PCR assay. Even though more chicken samples contained Salmonella than did any other sausage type, the difference in the presence of Salmonella among the four sausages types was not significant. Eleven serotypes were identified, and Salmonella enterica subsp. salamae II was most prevalent in all the sausage types. Beef sausages generally had higher mesophilic bacterial counts than did the other three sausage types. However, higher microbial counts were not reflective of the presence of salmonellae. Susceptibility of the Salmonella enterica serotypes to 20 antimicrobial agents was determined, and Salmonella Muenchen was resistant to the widest array of agents and was mostly isolated from chicken sausages. Regardless of the meat of origin, all 65 Salmonella isolates were resistant to at least four antimicrobial agents: amikacin, gentamicin, cefuroxime, and tombramycin. This resistance profile group was the most common in all four sausage types, comprising 90% of all Salmonella isolates from beef, 71% from pork, 63% from mutton, and 35% from chicken. These results suggest that raw sausages pose a risk of transmitting multidrug-resistant Salmonella isolates to consumers.
本研究的目的是提供博茨瓦纳哈博罗内市消费者可直接接触的不同类型生肉香肠中沙门氏菌的流行率和抗菌药物敏感性的基线数据。使用常规培养方法和经验证的 PCR 方法,对 300 份生香肠(包括 79 份牛肉、78 份猪肉、72 份鸡肉和 71 份羊肉)进行沙门氏菌检测。PCR 检测结果与常规培养方法完全一致,均能检测到沙门氏菌。传统培养法和 PCR 法均检测到 300 个样本中有 65 个(21.7%)为沙门氏菌阳性。尽管鸡肉样本中沙门氏菌的检出率高于其他任何一种香肠类型,但四种香肠类型中沙门氏菌的存在差异无统计学意义。鉴定出 11 种血清型,所有香肠类型中均以沙门氏菌肠炎亚种 II 最为常见。牛肉香肠的嗜温菌总数通常高于其他三种香肠类型。然而,较高的微生物计数并不反映沙门氏菌的存在。对 20 种抗菌药物的沙门氏菌血清型的药敏性进行了测定,沙门氏菌慕尼黑对最广泛的抗菌药物具有耐药性,主要从鸡肉香肠中分离出来。无论肉源如何,所有 65 株沙门氏菌分离株均对至少四种抗菌药物具有耐药性:阿米卡星、庆大霉素、头孢呋辛和妥布霉素。该耐药谱群在所有四种香肠类型中最为常见,占牛肉分离株的 90%、猪肉分离株的 71%、羊肉分离株的 63%和鸡肉分离株的 35%。这些结果表明,生香肠可能会将耐药性的沙门氏菌分离株传播给消费者。