Bacillus cereus is a common foodborne pathogen. Accidently eating food contaminated by B. cereus will cause vomiting or diarrhea, and even death in severe cases. In the present study, a B. cereus strain was isolated from spoiled rice by streak culture. The pathogenicity and drug resistance of the isolated strain were analyzed by drug sensitivity test and PCR amplification of virulence-associated gene respectively. Cultures of the purified strain were injected intraperitoneally into mice to examine their effects on intestinal immunity-associated factors and gut microbial communities, to provide references for the pathogenic mechanism and medication guidance of these spoilage microorganisms. The results showed that the isolated B. cereus strain was sensitive to norfloxacin, nitrofurantoin, tetracycline, minocycline, ciprofloxacin, spectinomycin, clindamycin, erythrocin, clarithromycin, chloramphenicol, levofloxacin, and vancomycin, but resistant to bactrim, oxacillin and penicillin G. The strain carries seven virulence-associated genes including hblA, hblC, hblD, nheA, nheB, nheC and entFM, which are involved in diarrhea-causing toxins production. After infecting mice, the isolated B. cereus strain was found to cause diarrhea in mice, and the expression levels of immunoglobulins and inflammatory factors in the intestinal mucosae of the challenged mice were significantly up-regulated. Gut microbiome analysis showed that the composition of gut microbial community in mice changed after infection with B. cereus. The abundance of the uncultured_bacterium_f_Muribaculaceae in Bacteroidetes, which is a marker of body health, was significantly decreased. On the other hand, the abundance of uncultured_bacterium_f_Enterobacteriaceae, which is an opportunistic pathogen in Proteobacteria and a marker of dysbacteriosis, was significantly increased and was significantly positively correlated with the concentrations of IgM and IgG. These results showed that the pathogenic B. cereus carrying diarrhea type virulence-associated gene can activate the immune system by altering the composition of gut microbiota upon infection.
Animals ; Mice ; Bacillus cereus/metabolism* ; Food Microbiology ; Immunity, Mucosal ; Diarrhea ; Microbiota ; Enterotoxins/genetics*

Objective: To assess the risk of foodborne diseases caused by Cronobacter sakazakii in infant formula powder from retail to feeding and provide formulate suggestions for safe feeding of infants at home. Methods: This study used the special monitoring and risk monitoring data of infant formula powder in Heilongjiang Province and combined data at home and abroad. The @RISK software was used to evaluate the disease risk caused by Cronobacter sakazakii in the process of infant formula powder from retail to feeding. Results: According to the results of this quantitative risk assessment, the risk of foodborne diseases caused by Cronobacter sakazakii at the current consumption pattern in Heilongjiang Province was 5.158×10^-5 persons/million (40.0 ℃ and 50.0 ℃), 1.072×10^-7 persons/million (60.0 ℃), 5.544×10^-14 persons/million (70.0 ℃). When the feeding time of infant formula powder was adjusted to 0-2 h and 2-3 h respectively, the above prediction results did not change. When it was adjusted to 3-4 h, the risk increased. If it was adjusted to 4-24 h, the number of Cronobacter sakazakii increased by 14-24 orders of magnitude at room temperature. If the initial pollution concentration (after flushing) was adjusted to 1 MPN/ml, the average disease risk per meal was 805.7 persons/million (40.0 ℃ and 50.0 ℃), 1.7 persons/million (60.0 ℃) and 9.1 × 10^-7 persons/million (70.0 ℃). The results of sensitivity analysis showed that the water temperature (70.0 ℃), initial pollution concentration, room storage time and temperature were important factors of risk. Conclusion: Controlling the contamination level of Cronobacter sakazakii in infant formula powder, controlling the feeding time within 3 h, storing in refrigerator and mixing with water with temperature not lower than 70.0 ℃ are effective measures to prevent infants from eating infant formula powder infected by Cronobacter sakazakii.
Infant ; Humans ; Cronobacter sakazakii ; Infant Formula ; Food Microbiology ; Powders ; Risk Assessment ; Foodborne Diseases

Background: Tapuy is an indigenous fermented rice wine produced in the Northern areas of the Philippines. Fermented foods and drinks have gained interest due to their associated health benefits, attributable to probiotic bacteria in the food items. However, pathogenic bacteria may also be present in fermented food and pose health risks, signifying a need for standardization. Currently, there is limited knowledge on the bacterial content of tapuy. Objectives: This study aimed to characterize the bacterial diversity and community structure of culturable bacteria in traditionally fermented tapuy samples, to perform standardization of tapuy fermentation, and to compare the bacterial diversity and community structure of culturable bacteria in laboratory fermented tapuy with that of the traditional samples. Methods: Tapuy samples were obtained from four municipalities in Benguet, Philippines. Laboratory fermentation of tapuy was performed simultaneously with the fermentation in the sampling site using a standardized protocol. Samples were plated on de Man, Rogosa, and Sharpe (MRS) agar and NA, and the colonies were harvested for DNA extraction. DNA samples were sent for 16S rDNA metagenomic sequencing. Results. Metagenomic analysis revealed the presence of many bacterial species that were previously unreported in tapuy. Traditional tapuy samples were composed primarily of members of the genera Bacillus and Lactobacillus in varying proportions. Potential probiotic bacteria were abundant in Kapangan (97.42%) and Sablan (99.89%) field samples. B. wiedmannii was present in all samples and was identified as a harmful species. Laboratory fermentation increased the abundance of potential probiotic bacteria in Itogon and La Trinidad samples (differences of 75.36% and 78.36%, respectively). It decreased the quantity of B. wiedmannii in La Trinidad (a difference of 97.1%). Laboratory fermented samples generally exhibited higher bacterial diversity and species richness compared to field samples. Conclusions Traditionally fermented tapuy samples contained a significant proportion of potential probiotic bacteria belonging to the genera Bacillus and Lactobacillus. Laboratory fermented samples were found to have higher bacterial diversity and richness compared to field samples. The significant presence of potential probiotic bacteria suggests that tapuy is a good candidate for development into functional food and a good source of likely probiotic species that could be explored for health applications. The presence of harmful bacteria suggests the need for possible standardization of fermentation practices.
Food Microbiology ; Fermented Foods ; Wine

Aims: This study aimed to evaluate the effect of thermal treatment on the storage stability of Lactobacillus acidophilus La-14 tamarind juice with or without beta-glucans. Methodology and results: Lactobacillus acidophilus incorporated with 6% (w/v) beta-glucans displayed the highest viability (17.28 log10 CFU/mL) as compared to other beta-glucans concentrations (0-8% w/v). The L. acidophilus with or without beta-glucans survived more than 80% after 5 h of sequential digestion. Tamarind juice was subjected to different thermal treatments (76 °C for 30 sec or 90 °C for 60 sec) and incorporated with L. acidophilus with or without betaglucans. Lactobacillus acidophilus in tamarind juice without thermal treatment showed the highest viability (8.69 log10 CFU/mL), followed by thermal treatment at 76 °C for 30 sec (>7 log10 CFU/mL), and thermal treatment at 90 °C for 60 sec showed the lowest viability (>4 log10 CFU/mL), after 21 days at 4 °C. The pH, titratable acidity and viscosity of all L. acidophilus-tamarind juices demonstrated no changes throughout 21 days at 4 °C. Furthermore, thermal-treated tamarind juice (90 °C for 60 sec) incorporated with L. acidophilus displayed the least change in total soluble solids (1.99 °Brix), while thermal-treated tamarind juice (90 °C for 60 sec) with L. acidophilus and beta-glucans had the lowest color change (∆E = 4.46), after 21 days of storage at 4 °C. Conclusion, significance and impact of study Thermal treatments (90 °C for 60 sec) had contributed to the stability of L. acidophilus-tamarind juice with beta-glucans over 21 days of cold storage. This study shows thermal treated tamarind juice with L. acidophilus and beta-glucans is a potential functional non-dairy beverage catered for lactose intolerance individuals.
Lactobacillus acidophilus ; Food Microbiology

Strain variability is one of the most important factors to influence the accuracy of foodborne pathogens risk assessment, such as Listeria monocytogenes, Salmonella spp. Strain-to-strain variation is defined as the inherent differences among identically treated strains of the same microbial species. The differences cannot be eliminated by changing test methods or improving test protocols. This review addresses presently related studies of strain variability. Based on the effect of strain variability on the outcome of risk assessment, we summarize sources of variabilities in food chain, strain phenotypic variabilities and the methods to integrate strain variability in growth and inactivation into predictive modelling, and indicate the inadequacies in the study of strain variability. We suggest further study the mechanism of strain variability, expand the comparison of variability among different sources, and integrate the variability of gene expression, protein and cell metabolism into the predictive modelling.
Food Microbiology ; Listeria monocytogenes/genetics* ; Risk Assessment ; Salmonella/genetics*

Clostridia inhabiting in jiupei and pit mud plays key roles in the formation of flavour during the fermentation process of Luzhou-flavour baijiu. However, the differences of Clostridial communities between jiupei and pit mud remains unclear. Here, the species assembly, succession, and metabolic capacity of Clostridial communities between jiupei and pit mud were analysed by high-throughput sequencing and pure culture approaches. The ratio of Clostridial biomass to bacterial biomass in the pit mud was relatively stable (71.5%-91.2%) throughout the fermentation process. However, it varied widely in jiupei (0.9%-36.5%). The dominant Clostridial bacteria in jiupei were Clostridium (19.9%), Sedimentibacter (8.8%), and Hydrogenispora (7.2%), while Hydrogenispora (57.2%), Sedimentibacter (5.4%), and Caproiciproducens (4.9%) dominated in the Clostridial communities in pit mud. The structures of Clostridial community in pit mud and jiupei were significantly different (P=0.001) throughout fermentation. Isolated Clostridial strains showed different metabolic capacities of volatile fatty acids in pure culture. Spatial and temporal heterogeneity of Clostridial communities existed in the baijiu fermentation pit, which was closely related to the main flavour components of Luzhou-flavour baijiu.
Alcoholic Beverages ; microbiology ; Bacteria ; classification ; metabolism ; Clostridium ; physiology ; Fatty Acids, Volatile ; metabolism ; Fermentation ; Food Microbiology

Objective: This study aimed to evaluate the genetic diversity, virulence, and antimicrobial resistance of isolates from clinical patients, tap water systems, and food. Methods: Ninety isolates were obtained from Ma'anshan, Anhui province, China, and subjected to multi-locus sequence typing (MLST) with six housekeeping genes. Their taxonomy was investigated using concatenated sequences, while their resistance to 12 antibiotics was evaluated. Ten putative virulence factors and several resistance genes were identified by PCR and sequencing. Results: The 90 isolates were divided into 84 sequence types, 80 of which were novel, indicating high genetic diversity. The isolates were classified into eight different species. PCR assays identified virulence genes in the isolates, with the enterotoxin and hemolysin genes , , , and found in 47 (52.2%), 13 (14.4%), 22 (24.4%), and 12 (13.3%) of the isolates, respectively. The majority of the isolates (≥ 90%) were susceptible to aztreonam, imipenem, cefepime, chloramphenicol, gentamicin, tetracycline, and ciprofloxacin. However, several resistance genes were detected in the isolates, as well as a new variant. Conclusions Sequence type, virulence properties, and antibiotic resistance vary in isolates from clinical patients, tap water systems, and food.
Aeromonas ; drug effects ; genetics ; isolation & purification ; pathogenicity ; Anti-Bacterial Agents ; pharmacology ; China ; Drinking Water ; microbiology ; Drug Resistance, Bacterial ; Food Microbiology ; Genetic Variation ; Gram-Negative Bacterial Infections ; microbiology ; Species Specificity ; Virulence

As the main factor leading to foodborne illnesses, foodborne pathogens have been attached great importance by people. The development of simple, rapid, high-sensitivity and low-cost food-borne pathogen detection methods is of great significance in reducing the incidence of foodborne diseases. Biosensor technology is a new micro-analysis technology developed by multi-disciplinary cross-infiltration. It has the characteristics of high sensitivity and fast analysis speed, and is widely used in the detection of food-borne pathogens. This paper introduces the basic principles of biosensors, summarizes the application of common biosensors in the detection of foodborne pathogens, and prospects for future development.
Biosensing Techniques ; Food Microbiology ; Foodborne Diseases ; Humans

This study aimed to investigate the prevalence and molecular characteristics of Listeria monocytogenes in cooked products in Zigong City, China. The overall occurrence of the L. monocytogenes in the ready-to-eat (RTE) shops and mutton restaurants surveyed was 16.2% (141/873). An occurrence of 13.5% was observed in RTE pork, 6.5% in RTE vegetables, and more than 24.0% in either cooked mutton or cooked haggis. Serotype 1/2b (45.4%), 1/2a (33.3%), and 1/2c (14.2%) were the predominant types. By comparing the clonal complexes (CCs) based on multilocus sequence typing (MLST) of the L. monocytogenes from cooked foods in Zigong City and 33 listeriosis cases from different districts of China, CC87, CC9, CC8, and CC3 were showed to be prevalent in cooked products and CC87 and CC3 were the first two frequent types in the 33 clinic-source strains. All CC87 stains harbored the newly reported Listeria pathogenicity island 4 (LIPI-4) gene fragment ptsA, and all CC3 strains possessed the Listeria pathogenicity island 3 (LIPI-3) gene fragment llsX. These may increase the occurrence of the strains belonging to CC87 and CC3 in listeriosis cases in China and also underline the risk of infection owing to the consumption of the cooked products from Zigong. ST619 (serotype 1/2b) harbored both llsX and ptsA, indicating a potential hypervirulent sequence type in Zigong.
China ; epidemiology ; Cooking ; Fast Foods ; microbiology ; Food Contamination ; Food Microbiology ; Humans ; Listeria monocytogenes ; genetics ; pathogenicity ; Listeriosis ; epidemiology ; microbiology ; Meat ; microbiology ; Multilocus Sequence Typing ; Prevalence ; Seasons

Foodborne disease is one of the most important public health issues worldwide. China faces various and unprecedented challenges in all aspects of the food chain. Data from laboratory-based foodborne disease surveillance systems from 2013 to 2016, as well as different regions and ages, can be found along with differences in the patterns of pathogens detected with diverse characteristics. Vibrio parahaemolyticus has been the leading cause of infectious diarrhea in China, especially among adults in coastal regions. Salmonella has been a serious and widely distributed pathogen responsible for substantial socioeconomic burden. Shigella was mostly identified in Northwest China and the inland province (Henan) with less-developed regions among children under 5 years. Data from foodborne disease outbreak reporting system from 2011 to 2016 showed that poisonous animals and plant factors responsible for most deaths were poisonous mushrooms (54.7%) in remote districts in southwest regions. The biological hazard that caused most cases reported (42.3%) was attributed to V. parahaemolyticus, the leading cause of foodborne outbreaks. In this review, we summarize the recent monitoring approach to foodborne diseases in China and compare the results with those in developed countries.
Bacteria ; classification ; isolation & purification ; China ; epidemiology ; Disease Outbreaks ; Food Microbiology ; Foodborne Diseases ; epidemiology ; microbiology ; Forecasting ; Humans ; Laboratories ; Mushroom Poisoning ; epidemiology ; Population Surveillance ; Public Health