{'fraction_non_alphanumeric': 0.05368731563421829, 'fraction_numerical': 0.04129793510324484, 'mean_word_length': 4.435897435897436, 'pattern_counts': {'":': 0, '<': 2, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Surveillance and examination of microbial contamination in ice cream in China


 This study investigated the microbial contamination of ice cream in China. A total of 2,887 ice cream samples were collected from different regions of China. Contamination by the aerobic plate count (APC), coliforms, and three foodborne pathogens, such as Listeria monocytogenes, Staphylococcus aureus, and Salmonella spp., was detected in the samples. L. monocytogenes isolates were further analyzed for antibiotic susceptibility and multi-locus sequence typing (MLST). The results showed that APC was more than 10 5 CFU/g in 6.10% (176/2887) and coliform was more than 10 2 CFU/g in 15.69% (453/2887) of all samples. The positive rates of S. aureus, L. monocytogenes, and Salmonella spp. were 0.66%, 0.62%, and 0.10%, respectively. Of these, S. aureus contamination was more than 10 2 CFU/g in two samples, and L. monocytogenes in the positive sample was in the range of 0.3–240 MPN/g, with a median of 4.3 MPN/g. The hygienic status of the packaged samples was much better than that of the bulk samples (P < 0.05). Catered samples were more frequently and heavily contaminated than samples from retail and wholesale outlets (P < 0.05). No significant differences were observed in samples bought from urban and rural areas (P >0.05). For 18 L. monocytogenes strains isolated from ice cream, the resistance rate of nine antibiotics was 5.56% (1/18). By MLST, the L. monocytogenes strains were classified into 9 sequence types (STs), of which ST8 was most common (6 isolates). These above results indicate that a potential health risk to the public may be caused by ice cream, particularly susceptible populations.