Universidade Estadual de Campinas (UNICAMP), Faculdade de Engenharia de Alimentos, Departamento de Ciência de Alimentos e Nutrição, Campinas, São Paulo, Brazil.
Universidade Estadual de Campinas (UNICAMP), Faculdade de Engenharia de Alimentos, Departamento de Ciência de Alimentos e Nutrição, Campinas, São Paulo, Brazil; Universidade Estadual de Campinas (UNICAMP), Instituto de Biologia, Departamento de Genética, Evolução, Microbiologia e Imunologia, Campinas, São Paulo, Brazil.
Food Microbiol. 2024 Sep;122:104570. doi: 10.1016/j.fm.2024.104570. Epub 2024 May 28.
Cronobacter spp. are bacterial pathogens isolated from a wide variety of foods. This study aims at evaluating the occurrence of Cronobacter spp. in low water activity functional food samples, detect the presence of virulence genes, and determine the antibiotic susceptibility of strains. From 105 samples, 38 (36.2%) were contaminated with Cronobacter spp. The species identified by polymerase chain reaction (PCR) and sequencing analyses (rpoB and fusA genes, respectively) were C. sakazakii (60.3%), C. dublinensis (25.4%), C. turincensis (9.5%), and C. malonaticus (4.8%). Nineteen fusA alleles were identified, including four new alleles. The virulence genes were identified by PCR and all isolates were positive for ompX and sodA genes, 60.3% to cpa gene, and 58.7% to hly gene. Using the disk diffusion method, antibiotic susceptibility to twelve antibiotics was assessed twice, separated by a 19-month period. In the first test, the isolates showed diverse antibiotic susceptibility profiles, with nineteen isolates (30.2%) being multi-drug resistant (resistant to three or more antibiotic classes), in the second, the isolates were susceptible to all antibiotics. Cronobacter spp. in functional foods demonstrates the need for continued investigation of this pathogen in foods, and further research is needed to clarify the loss of resistance of Cronobacter strains.
克罗诺杆菌属是从各种食品中分离出来的细菌病原体。本研究旨在评估低水分活度功能性食品样品中克罗诺杆菌属的发生情况，检测毒力基因的存在，并确定菌株的抗生素敏感性。从 105 个样本中，有 38 个（36.2%）被克罗诺杆菌属污染。通过聚合酶链反应（PCR）和测序分析（分别为 rpoB 和 fusA 基因）鉴定的物种为阪崎克罗诺杆菌（60.3%）、都柏林克罗诺杆菌（25.4%）、图林根克罗诺杆菌（9.5%）和迟钝爱德华菌（4.8%）。鉴定了 19 种 fusA 等位基因，包括 4 种新等位基因。通过 PCR 鉴定了毒力基因，所有分离株均对 ompX 和 sodA 基因呈阳性，60.3%对 cpa 基因呈阳性，58.7%对 hly 基因呈阳性。使用纸片扩散法，在 19 个月的间隔内两次评估了 12 种抗生素的抗生素敏感性。在第一次测试中，分离株显示出不同的抗生素敏感性谱，有 19 个分离株（30.2%）对三种或更多类抗生素具有耐药性，在第二次测试中，分离株对所有抗生素均敏感。功能性食品中的克罗诺杆菌属表明需要继续对食品中的这种病原体进行调查，需要进一步研究以阐明克罗诺杆菌属菌株耐药性的丧失。
