Silva Evelyn Cristine, Dias Sthéfany da Cunha, Costa Priscila Cristina, Casas Monique Ribeiro Tiba, Yamatogi Ricardo Seiti, Araújo Junior João Pessoa, Cossi Marcus Vinícius Coutinho, Possebon Fábio Sossai
São Paulo State University (UNESP), Institute for Biotechnology, Tecomarias Avenue, Botucatu, SP 18607-440, Brazil.
Uberlândia Federal University (UFU), Faculty of Veterinary Medicine, João Naves de Ávila Avenue, 2121, Uberlândia, MG 38408-100, Brazil.
J Food Prot. 2025 Jul 21;88(8):100550. doi: 10.1016/j.jfp.2025.100550. Epub 2025 May 31.
The continued development of bullfrog farming holds great potential for expansion. However, these animals serve as reservoirs for various pathogens, including Salmonella, posing a risk to food safety and public health. Therefore, the primary objective of this study was to identify potential sources of Salmonella contamination in a bullfrog production facility in Minas Gerais, Brazil, by characterizing isolates through Pulsed-Field Gel Electrophoresis (PFGE), Multilocus Sequence Typing (MLST), and antimicrobial resistance profiling. A total of eight Salmonella isolates were analyzed, comprising six isolates from bullfrog carcasses and two from breeding tanks. PFGE characterization revealed four distinct profiles, with a clonal relationship among isolates belonging to the same serovar, except for S. Newport, where the profile of the breeding tank isolate differed from that of the carcass isolates. MLST analysis identified three sequence types (STs): ST 32, ST 614, and ST 6855, corresponding to S. Infantis, S. Newport, and S. 6,8:i:-, respectively. Regarding antimicrobial resistance, one isolate was resistant to azithromycin, two were resistant to neomycin, and three were resistant to ciprofloxacin. All isolates were susceptible to cephalexin, meropenem, cefotaxime, ceftriaxone, ampicillin, tobramycin, and cephalothin. The presence of distinct PFGE profiles among isolates of the same serovar suggests multiple sources of pathogen contamination within the production chain, raising significant sanitary concerns. The identified sequence types (STs) are of public health relevance, highlighting the pathogenic potential of these isolates. While most isolates were susceptible to the tested antimicrobials, the detection of azithromycin resistance is particularly concerning. The combined PFGE and MLST data indicate potential cross-contamination within the production chain, emphasizing the need for stringent control measures.
牛蛙养殖的持续发展具有巨大的扩张潜力。然而，这些动物是包括沙门氏菌在内的各种病原体的宿主，对食品安全和公众健康构成风险。因此，本研究的主要目的是通过脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）和抗菌药物耐药性分析来鉴定巴西米纳斯吉拉斯州一家牛蛙生产设施中沙门氏菌污染的潜在来源。共分析了8株沙门氏菌分离株，其中6株来自牛蛙 carcasses，2株来自养殖池。PFGE分析显示有4种不同的图谱，同一血清型的分离株之间存在克隆关系，但纽波特沙门氏菌除外，其养殖池分离株的图谱与 carcass分离株不同。MLST分析确定了3种序列类型（STs）：ST 32、ST 614和ST 6855，分别对应婴儿沙门氏菌、纽波特沙门氏菌和6,8:i:-沙门氏菌。在抗菌药物耐药性方面，1株分离株对阿奇霉素耐药，2株对新霉素耐药，3株对环丙沙星耐药。所有分离株对头孢氨苄、美罗培南、头孢噻肟、头孢曲松、氨苄青霉素、妥布霉素和头孢噻吩敏感。同一血清型分离株中存在不同的PFGE图谱表明生产链中病原体污染的来源多样，引发了重大的卫生问题。所确定的序列类型（STs）具有公共卫生相关性，突出了这些分离株的致病潜力。虽然大多数分离株对所测试的抗菌药物敏感，但阿奇霉素耐药性的检测尤其令人担忧。PFGE和MLST数据相结合表明生产链中存在潜在的交叉污染，强调需要采取严格的控制措施。
