The global popularity of ready-to-eat (RTE) meat products continues to rise due to their convenience; however, this trend also brings potential risks, since RTE meat products can be susceptible to microbial contaminations by various foodborne pathogens or spoilage bacteria. This study is focused on comprehensively investigating the bacterial contamination of RTE meat products in Yangzhou, China with both cultivable and high-throughput sequencing (HTS) approaches. In addition, risk-related phenotypes of the strains in RTE meat products, including biofilm formation, bacterial motility, and spoilage enzyme production, were also explored. Results showed that 90 strains collected from 25 RTE samples belonged to 20 and 50 different genera and species. The genus of Bacillus was the most dominant, accounting for 40% of total isolates, followed by Salmonella (10%), Pseudomonas (10%), and Staphylococcus (7.8%). HTS analysis revealed a markedly distinct bacterial population, with Streptococcus and Acinetobacter being most dominant in RTE meat products. Most of the meat-derived strains were identified as strong biofilm formers with high swarming (0.87–5.35 cm) and swimming (0.88–7.89 cm) activity, and had good capacity to produce proteases (0.88–4.87 A/h·mL at 28 ℃, and 0.82–1.21 A/h·mL at 7 ℃) and lipases (4.25–83.12 nmol/min·mL at 28 ℃, and 6.28–45.93 nmol/min·mL at 7 ℃). This work offers novel insights into the potential microbiological risks of strains in RTE meat products, and further promotes the development of advanced methods for RTE meat product preservation.

Bacillus cereus is one of the major spore-forming bacteria with great genetic diversity in raw milk, dairy raw materials, and finished dairy products, and is widely present in the entire dairy production line. Due to the biofilm formation of B. cereus and the heat resistance of its spores, traditional cleaning and disinfection procedures cannot completely remove the spores, resulting in the presence of B. cereus in the final dairy products. Although much work has been done to identify B. cereus from various dairy samples, an updated knowledge of this spore precursor is still needed. This review describes the prevalence of B. cereus from raw milk to commercial dairy products, the biofilm formation of B. cereus and its ability to cause spoilage in dairy products, and the possible prevention methods.