College of Food and Bioengineering, Henan University of Science and Technology, Luoyang, China.
Heilongjiang Feihe Dairy Co., Ltd., Beijing, China.
Foodborne Pathog Dis. 2021 Jan;18(1):8-15. doi: 10.1089/fpd.2020.2802. Epub 2020 Aug 28.
This study was conducted to reveal the genotyping, antimicrobial susceptibility, and biofilm formation of isolated from powdered food products in China. Five hundred powdered food samples were collected from five provinces in China: 100 samples each of powdered infant formula (PIF), soy milk powder (SMP), lotus root powder (LRP), walnut powder (WP), and rice flour (RF). The genotyping of isolates was analyzed using multilocus sequence typing; meanwhile, antimicrobial susceptibility, and ability of biofilms formation on stainless steel tube of isolates were evaluated. Forty-two strains were detected with an overall contamination rate of 8.4%, as well as, the highest contamination rate was found in SMP (10%), followed by LRP (9%), WP (9%), RF (8%), and PIF (6%). These isolates were divided into 22 sequence types (STs); among them, ST32 (4/42, 9.5%) was the predominant ST. Phylogenetic relationships showed that the 42 strains of were divided into three groups (group I, group II, and group III). Antimicrobial susceptibility testing indicated that all isolates were susceptible to tetracycline, gentamicin, erythromycin, and chloramphenicol, while resistant to ampicillin, cefepime, oxacillin, and rifampin. The analysis of ability of biofilm formation on stainless steel tube showed optical density (OD) value of 66.7% of isolates was greater than 1. The OD level of isolates belonging to group III was higher compared with the other two groups, and OD values of HB1 and HN5 were greater than 2. These findings improved the understanding of the characteristics of isolated from powdered food products in China, and provided a theoretical basis for the prevention and control of in food industry.
本研究旨在揭示中国粉状食品中分离出的 的基因分型、抗菌药敏性和生物膜形成情况。从中国五个省份采集了 500 份粉状食品样品：100 份婴儿配方粉（PIF）、豆奶粉（SMP）、藕粉（LRP）、核桃粉（WP）和米粉（RF）各 100 份。采用多位点序列分型分析分离株的基因分型；同时，评估了分离株对不锈钢管的抗菌药敏性和生物膜形成能力。共检出 42 株 ，总污染率为 8.4%，其中 SMP 的污染率最高（10%），其次是 LRP（9%）、WP（9%）、RF（8%）和 PIF（6%）。这些分离株分为 22 个序列型（ST）；其中，ST32（4/42，9.5%）是主要的 ST。系统发育关系表明，42 株 分为三组（组 I、组 II 和组 III）。药敏试验表明，所有分离株均对四环素、庆大霉素、红霉素和氯霉素敏感，而对氨苄西林、头孢吡肟、苯唑西林和利福平耐药。不锈钢管生物膜形成能力分析显示，66.7%的 分离株的吸光度（OD）值大于 1。属于组 III 的分离株的 OD 值高于其他两组，HB1 和 HN5 的 OD 值大于 2。这些发现提高了对中国粉状食品中分离出的 特性的认识，为食品工业中 防控提供了理论依据。
