Brandão Marcelo Luiz Lima, Umeda Natália Scudeller, Jackson Emily, Forsythe Stephen James, de Filippis Ivano
Laboratory of Food and Sanitizes, Microbiology Department, National Institute of Quality Control in Health, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.
Pathogen Research Group, Nottingham Trent University, School of Science and Technology, Ciftorn Lane, Nottigham, NG11 8NS, United Kingdom.
Food Microbiol. 2017 May;63:129-138. doi: 10.1016/j.fm.2016.11.011. Epub 2016 Nov 24.
Several Cronobacter species are opportunistic pathogens that cause infections in humans. The aim of this study was to detect Cronobacter spp. from 90 samples of retail foods in Brazil, and characterize the strains by phenotypic tests, molecular assays and antibiotic susceptibility. Three isolation methodologies were evaluated using different selective enrichments and the isolates were identified using Vitek 2.0, PCRs protocols, fusA allele sequencing and multilocus sequence typing (MLST). Thirty-eight samples (42.2%) contained Cronobacter spp., and the highest percentage was found in flours (66.7%, 20/30), followed by spices and herbs (36.7%, 11/30), and cereal mixes for children (23.3%, 7/30). The 45 isolates included four species: C. sakazakii (n = 37), C. malonaticus (n = 3), C. dublinensis (n = 3), and C. muytjensii (n = 2); that presented 20 different fusA alleles. MLST analysis revealed 32 sequence types (STs), 13 of which were newly identified. All strains were sensitive to all antibiotics (n = 10) tested. The combination of CSB/v enrichment with DFI plating was considered the most efficient for Cronobacter spp. isolation. This study revealed the presence of Cronobacter spp. in foods commercialized in Brazil and the isolates showed a high diversity after MLST analysis and included two strains of the C. sakazakii ST4 neonatal meningitic pathovar.
几种阪崎肠杆菌属细菌是可导致人类感染的机会致病菌。本研究的目的是从巴西的90份零售食品样本中检测阪崎肠杆菌属细菌，并通过表型试验、分子分析和抗生素敏感性对菌株进行鉴定。使用不同的选择性增菌方法评估了三种分离方法，并使用Vitek 2.0、PCR方案、fusA等位基因测序和多位点序列分型（MLST）对分离株进行鉴定。38份样本（42.2%）含有阪崎肠杆菌属细菌，其中面粉中的检出率最高（66.7%，20/30），其次是香料和草药（36.7%，11/30），以及儿童谷物混合物（23.3%，7/30）。45株分离株包括四个种：阪崎肠杆菌（n = 37）、丙二酸阪崎肠杆菌（n = 3）、都柏林阪崎肠杆菌（n = 3）和穆氏阪崎肠杆菌（n = 2）；呈现出20种不同的fusA等位基因。MLST分析揭示了32种序列类型（STs），其中13种是新鉴定的。所有菌株对所测试的所有10种抗生素均敏感。CSB/v增菌与DFI平板接种相结合被认为是分离阪崎肠杆菌属细菌最有效的方法。本研究揭示了巴西商业化食品中存在阪崎肠杆菌属细菌，并且经MLST分析后分离株显示出高度的多样性，其中包括两株阪崎肠杆菌ST4新生儿脑膜炎致病型菌株。
