Analysis of Cronobacter contamination characteristics in cereal-based supplementary food for infants in Taizhou

Abstract

ObjectiveTo investigate the contamination， molecular typing characteristics， and drug resistance of Cronobacter in cereal-based infant food in Taizhou.MethodsAll samples were detected qualitatively and quantitatively according to GB 4789.40—2016. Isolated strains were typed using pulse field gel electrophoresis （PFGE）， and antibiotic susceptibility tests were performed using the micro-broth dilution method.ResultsForty-one strains were isolated from 335 samples. The total detection rate was 12.2%， and the quantitative results were 0.36-7.5 MPN/100 g. The cooked sample （46.9%） had the highest detection rate among edible samples， and the sample purchased online （24.0%） had the highest detection rate among purchased samples. Forty-one strains were divided into 34 PFGE patterns with similarity rates of 45.1%-100.0%， and some strains from different enterprises or different branches of one enterprise belonged to the same clone. Their insensitivity rates to cefazolin and nitrofurantoin were 48.8% and 39.0%， respectively， and 9 strains were insensitive to both.ConclusionSome cereal-based supplementary foods for infants were contaminated with Cronobacter in Taizhou. It is necessary to pay attention to the risk of Cronobacter infection in infants caused by cooked food and food purchased online.

Keywords

• cereal-based supplementary food
• cronobacter
• antibiotic susceptibility test
• pulsed field gel electrophoresis