Research Publications (Food Safety)

Bacillus cereus is a Gram-positive endospore-forming foodborne pathogen that causes lethal food poisoning and significant economic losses, usually through biofilm- and endospore-induced recurrent cross- and postprocessing contamination. Due to the lack of critical inhibitory targets and control strategies, B. cereus biofilm contamination is a problem that urgently needs a solution.

Bacillus cereus is one of the most important spoilage microorganisms in milk. The heat-resistant protease produced is the main factor that causes rotten, bitter off-flavors and age gelation during the shelf-life of milk. In this study, 55 strains of B. cereus were evaluated, of which 25 strains with protease production ability were used to investigate proteolytic activity and protease heat resistance. The results showed that B.

Consumption of seaweeds, often categorized as a superfood, is becoming popular in western countries. Algae can be marketed fresh, but are usually sold dehydrated to ensure longer shelf life. The consumption, often as ready to eat, open up possible risks for public health because of foodborne pathogens that can contaminate the raw material during harvesting or manipulation.

Bacillus toyonensis is a group of Gram-positive bacteria belonging to the Bacillus cereus group and used in some cases as probiotics or biocontrol agents. To our knowledge, B. toyonensis from the deep sea (depth >1,000 m) has not been documented. Here, we report the isolation and characterization of a B. toyonensis strain, P18, from a deep sea hydrothermal field. P18 is aerobic, motile, and able to grow at low temperatures (4°C) and high concentrations of NaCl (8%).

Midgut microbiota can participate in the detoxification and metabolism processes in insects, but there are few reports on the relationship between midgut microbiota and insecticide resistance in mosquitoes. In this study, we performed metagenomic sequencing on a susceptible strain (SS), a field-collected Hainan strain (HN), and a deltamethrin-resistant strain (RR) of Culex pipiens quinquefasciatus to understand the diversity and functions of their midgut microbiota.

Bacteria are the causative agents of numerous diseases. Ever increasing number of bacterial infections has generated the need to find new antibiotic materials and new ways to combat bacterial infections. Our study investigated Azadirachta indica (AI) as an alternate source of antibiotic compounds. Phytochemical and GC-MS analysis revealed presence of flavonoids, phenolic compounds, terpenoids and terpenes.

This study describes the simultaneous Bacillus cereus growth and cereulide formation, in culture medium and cereal-, dairy-, meat-, and vegetable-based food matrices. First, bacterial growth experiments were carried out under a wide range of temperatures (from 9 to 45°C), using the emetic reference strain F4810/72, in the above-mentioned matrices. Then, the generated data were put in a modeling framework where the response variable was a vector of two components: the concentration of B.

Bacillus cereus is an important food-borne pathogenic bacteria and a putrid microorganism in the dairy industry. Raw and pasteurized buffalo milk play important roles in the dairy market in southwestern China. However, the reports on the prevalence and characterization of B. cereus strains isolated from the above sources are lacking. In this study, 150 raw buffalo milk samples and 300 pasteurized buffalo milk samples were collected from 3 provinces in southwestern China.

Bacillus cereus is a human pathogenic bacterium found in foods with the potential to cause emesis and diarrhea. This study estimated the presence, toxigenic and genomic diversity of B. cereus s.l. obtained from cassava starch samples collected in bakeries and powdered food companies in Medellín (Colombia). Bacillus cereuss.l. was found in 43 of 75 (57%) cassava starch samples and 98 isolates were obtained.

Human breast milk (HBM) is a source of essential nutrients for infants and is particularly recommended for preterm neonates when their own mother’s milk is not available. It provides protection against infections and decreases necrotizing enterocolitis and cardiovascular diseases. Nevertheless, HBM spoilage can occur due to contamination by pathogens, and the risk of a shortage of HBM is very often present. B.

The emetic toxin cereulide is a 1.2 kDa dodecadepsipeptide produced by the food pathogen Bacillus cereus. As cereulide poses a serious health risk to humans, sensitive and specific detection, as well as toxin purification and quantification, methods are of utmost importance.

Bacillus cereus is a ubiquitous soil bacterium responsible for two types of food-associated gastrointestinal diseases. While the emetic type, a food intoxication, manifests in nausea and vomiting, food infections with enteropathogenic strains cause diarrhea and abdominal pain. Causative toxins are the cyclic dodecadepsipeptide cereulide, and the proteinaceous enterotoxins hemolysin BL (Hbl), nonhemolytic enterotoxin (Nhe) and cytotoxin K (CytK), respectively.

The medicinal plants, like Alhagi maurorum, has received great attentions, especially by food scientists and manufacturers as natural food preservatives due to their antimicrobial and antioxidant activities.

Bacillus cereus is one of the important foodborne pathogens that can be found in various foodstuffs; causing diarrheal and/or emetic syndromes. This study aimed to evaluate the prevalence, antimicrobial susceptibility profile, pathogenic potential, and genotypic diversity of B. cereus isolated from diverse food products from markets in Cairo, Egypt. A total of 39 out of 165 food samples were positive for B.

The antibacterial effect of volatile compounds in millets and cereal by‐products was investigated. Hexane extracts of rice bran (RB), corn cob (CC), green (GM), and yellow millets (YM) showed antibacterial activities against Escherichia coli ATCC 35150, Bacillus cereus ATCC 14579, Helicobacter pylori MH179991, and Staphylococcus aureus ATCC 13150 with minimum inhibitory concentration (MIC) ranging from 2.5 to 5 mg/ml.

Members of the Bacillus cereus group are spore-forming organisms commonly associated with food poisoning and intestinal infections. Moreover, some strains of the group (i.e., B. cereus sensu stricto and Bacillus thuringiensis) can cause bacteremia in humans, mainly in immunocompromised individuals. Here we performed the genetic characterization of 17 human clinical strains belonging to B. cereus group isolated from blood culture.

The lesser-known traditionally processed meat products such as beef kargyong, pork kargyong, satchu, and khyopeh are popular food items in the Himalayan state of Sikkim in India. The present study aimed to assess the microbiological safety of traditional meat products by identifying the potential spoilage or pathogenic bacteria, detecting the enterotoxins, and screening the antibiotic susceptibility patterns.

Abstract

Main conclusion

The presence of Bacillus cereus plays a key role in clubroot suppression and improves plant biomass in pak choi. B. cereus is reported for the first time as a novel biocontrol agent against clubroot.

Author(s): Yiying Huang, Steve H. Flint, Shubo Yu, Yu Ding, Jon S. Palmer

Avocado Hass (Persea americana Mill) peel extract (APE) has the potential as a natural ingredient to substitute for chemical preservatives.

Author(s): Hui Guo, Pengfei Yu, Shubo Yu, Juan Wang, Junhui Zhang, Ying Zhang, Xiyu Liao, Shi Wu, Qinghua Ye, Xiaojuan Yang, Tao Lei, Haiyan Zeng, Rui Pang, Jumei Zhang, Qingping Wu, Yu Ding

Flagellar motility is considered an important virulence factor in different pathogenic bacteria. In Listeria monocytogenes the transcriptional repressor MogR regulates motility in a temperature-dependent manner, directly repressing flagellar- and chemotaxis genes. The only other bacteria known to carry a mogR homolog are members of the Bacillus cereus group, which includes motile species such as B.

Bacillus cereus is the fourth most common cause of foodborne illnesses that produces a variety of pore-forming proteins as the main pathogenic factors. B. cereus hemolysin II (HlyII), belonging to pore-forming β-barrel toxins, has a C-terminal extension of 94 amino acid residues designated as HlyIICTD. An analysis of a panel of monoclonal antibodies to the recombinant HlyIICTD protein revealed the ability of the antibody HlyIIC-20 to inhibit HlyII hemolysis.

Bacteria survive metal stress by several mechanisms and metal binding is one such mechanism which has been screened in the present study to investigate the survival strategies of metal resistant bacteria. The production of siderophores, a metal chelating agent, was detected by chrome azurol S agar assay. The changes in cell wall studied by analyzing the peptidoglycan and teichoic acid content indicated an increase in the cell wall content.

Production and world consumption of spices are constantly increasing. Although the antimicrobial properties of some spices are well documented, their use in the agri‐food industry is also responsible for microbial contamination and spoilage. Bacterial spores introduced by spices can withstand different preparation processes, particularly thermal treatments, leading to food alterations during storage.