Department of Microbiology, College of Bioscience, Federal University of Agriculture, Abeokuta, 110212, Ogun State, Nigeria.
Department of Microbiology, Faculty of Science, Lagos State University, Ojoo, Lagos State, Nigeria.
Curr Microbiol. 2024 Sep 17;81(11):360. doi: 10.1007/s00284-024-03850-2.
Powdered infant formula (PIF) is rich in nutrients that support the survival and growth of bacteria that trigger food safety disorders in deprived infants through life-threatening illnesses. The study aims to examine and identify the incidence of pathogenic bacteria of concern in PIF upon reconstitution in lukewarm water. A total of 172 samples consisting of 38 brands of PIF available in the Lagos metropolis were sampled, suspended in water (10 g in 100 mL), and bacteria strains were isolated using combinational enrichment and selective culture techniques. Pure bacterial strains were characterized and identified based on their physiology and 16S rRNA gene sequence homology. While 85 bacterial strains were isolated from the enriched culture system, 20 strains were selectively isolated based on tolerance to sodium deoxycholate. Approximately 13% of the selected bacteria were identified as Cronobacter spp., exhibiting virulence traits including extracellular protease production, coagulation and proteolysis of casein, haem-agglutination, and β-haemolysis of human blood. Approximately 82% of the Cronobacter strains tolerated NaCl (10%) and bile salt; and exhibited resistance to cefotaxime, ceftriaxone, gentamicin, and Amoxicillin-clavulanic acid antibiotics. The presence of Cronobacter spp. in 13% of the PIF brands available to infants calls for concern about the safety of deprived infants that might be fed with such PIF. Consequently, PIF safety alerts need to be activate while further studies on critical points at which the pathogens get introduced to the PIFs need to be identified.
配方粉（PIF）富含营养物质，可支持引发食品安全紊乱的细菌存活和生长，这些细菌会使贫困婴儿罹患危及生命的疾病。本研究旨在检查和识别在温水复溶后 PIF 中有关致病菌的发生率。共采集了 172 个样本，包括拉各斯大都市中可用的 38 个品牌的 PIF，将其悬浮于水中（10 g 于 100 mL 水中），并使用组合增菌和选择性培养技术分离细菌菌株。基于生理特性和 16S rRNA 基因序列同源性对纯细菌菌株进行了特征和鉴定。虽然从富集培养系统中分离出了 85 株细菌，但根据对脱氧胆酸钠的耐受性选择性分离出了 20 株细菌。大约 13%的选定细菌被鉴定为克罗诺杆菌属，具有包括胞外蛋白酶产生、酪蛋白凝固和水解、血红细胞凝集以及人血β溶血等毒力特性。大约 82%的克罗诺杆菌属菌株耐受 10%的 NaCl 和胆汁盐；并对头孢噻肟、头孢曲松、庆大霉素和阿莫西林克拉维酸抗生素表现出耐药性。在可供婴儿食用的 PIF 品牌中，有 13%存在克罗诺杆菌属，这引起了对可能用此类 PIF 喂养的贫困婴儿安全的关注。因此，需要激活 PIF 安全警报，同时需要确定需要识别的引入病原体到 PIF 的关键点。
