College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China; Jiangsu Key Laboratory of Zoonoses, Yangzhou, Jiangsu 225009, China.
College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 225127, China.
Food Res Int. 2022 Dec;162(Pt B):112060. doi: 10.1016/j.foodres.2022.112060. Epub 2022 Oct 20.
In this study, twenty-two baby foods including cereal-based products and powdered infant formula (PIF) obtained from local markets were comprehensively investigated for their bacterial contamination using culture-dependent and high-throughput sequence (HTS) methods. In addition, the genetic diversity and biofilm-forming capacity of the most abundant species were analyzed using random amplified polymorphic DNA (RAPD) and crystal violet staining assay, respectively. Results showed that 170 mesophilic isolates collected from 22 samples were clustered into 15 genera and 41 species. Bacillus (77.65%) was the most prevalent genus, followed by Paenibacillus (7.06%), Alkalibacillus (3.53%), and Lysinibacillus (2.35%). Bacillus licheniformis (49.41%) proved to be the most dominant species in infant foods, and a high genetic diversity with six different RAPD profiles was observed. A total of 87.5% of B. licheniformis isolates were identified as strong biofilm formers, and heterogeneous biofilm-forming ability was observed among the isolates sharing the same RAPD pattern. HTS analysis revealed an 18-fold higher biodiversity at the genus level, and a significantly different bacterial community of infant foods was dominated by Lactococcus, Streptococcus, and Bifidobacterium. Foodborne pathogens including Bacillus cereus, and potentially pathogenic microorganisms such as Acinetobacter baumannii, were identified in infant foods by HTS. The current results could expand the crucial information about bacterial contamination of baby foods.
在这项研究中，我们采用培养依赖和高通量测序（HTS）方法，对当地市场上的 22 种婴儿食品（包括谷物产品和配方奶粉）进行了全面的细菌污染调查。此外，我们还分别使用随机扩增多态性 DNA（RAPD）和结晶紫染色试验分析了最丰富物种的遗传多样性和生物膜形成能力。结果表明，从 22 个样本中采集的 170 个嗜温菌分离株聚类为 15 个属和 41 个种。芽孢杆菌（77.65%）是最常见的属，其次是类芽孢杆菌（7.06%）、耐碱芽孢杆菌（3.53%）和短小芽孢杆菌（2.35%）。地衣芽孢杆菌（49.41%）被证明是婴儿食品中最主要的优势种，具有 6 种不同 RAPD 图谱的高遗传多样性。共有 87.5%的地衣芽孢杆菌分离株被鉴定为强生物膜形成者，并且具有相同 RAPD 模式的分离株之间表现出异质的生物膜形成能力。HTS 分析显示，在属水平上的生物多样性高出 18 倍，婴儿食品中的细菌群落主要由乳球菌、链球菌和双歧杆菌组成，且具有显著差异。通过 HTS 鉴定到了婴儿食品中的食源性致病菌如蜡样芽孢杆菌，以及潜在的致病性微生物如鲍曼不动杆菌。本研究结果可以扩展关于婴儿食品细菌污染的重要信息。
