Bacillus cereus: A review of "fried rice syndrome" causative agents.

"Fried rice syndrome" originated from the first exposure to a fried rice dish contaminated with Bacillus cereus. This review compiles available data on the prevalence of B. cereus outbreak cases that occurred between 1984 and 2019. The outcome of B. cereus illness varies dramatically depending on the pathogenic strain encounter and the host's immune system. B. cereus causes a self-limiting, diarrheal illness caused by heat-resistant enterotoxin proteins, and an emetic illness caused by the deadly toxin named cereulide. The toxins together with their extrinsic factors are discussed. The possibility of more contamination of B. cereus in protein-rich food has also been shown. Therefore, the aim of this review is to summarize the available data, focusing mainly on B. cereus physiology as the causative agent for "fried rice syndrome." This review emphasizes the prevalence of B. cereus in starchy food contamination and outbreak cases reported, the virulence of both enterotoxins and emetic toxins produced, and the possibility of contaminated in protein-rich food. The impact of emetic or enterotoxin-producing B. cereus on public health cannot be neglected. Thus, it is essential to constantly monitor for B. cereus contamination during food handling and hygiene practices for food product preparation.

Prebiotics metabolism by gut-isolated probiotics.

There are numerous species of bacteria resides in the lumen of human colon. The word 'colon', resembles colony or the colonization of microbiota of which plays an important role in the fermentation of prebiotics. The standpoint of prebiotic nowadays is well reported for attenuating gut dysbiosis in many clinical studies tested on animals and human. However, because of the huge amount of gut microbiome, the attempt to connect the dots between bacterial population and the host are not plainly discernible. Thus, a need to analyse recent research on the pathways of prebiotic metabolism adopted by commonly studied probiotics i.e. Bifidobacteria and Lactobacillus. Several different substrate-dependent gene expressions are induced to break down oligosaccharide molecules shown by those probiotics. The hydrolysis can occur either by membrane bound (extracellular) or cytoplasmic (intracellular) enzyme of the enteric bacteria. Therefore, this review narrates several prebiotic metabolisms occur during gut fermentation, and metabolite production i.e. organic acids conversion.

In vitro antimicrobial efficacy of Cassia alata (Linn.) leaves, stem, and root extracts against cellulitis causative agent Staphylococcus aureus.

BACKGROUND: Cellulitis is a common skin disease encountered in medical emergencies in hospitals. It can be treated using a combination of antibiotics therapy; however, the causative agent Staphylococcus aureus has been reported to develop resistance towards the currently used antibiotics. Therefore, the search for more alternative herbal origin antimicrobial agents is critical. AIM: In this study, maceration and Soxhlet extraction of the whole plant of Cassia alata Linn. (leaves, roots, and stem) were performed using four solvents with different polarities, namely n-hexane, ethyl acetate, ethanol and distilled water. The crude extracts were screened using agar well diffusion, colorimetric broth microdilution, grid culture and bacterial growth curve analysis against Staphylococcus aureus. The phytochemicals in the crude extracts were identified using Gas Chromatography-Mass Spectrometry (GC-MS). RESULTS: Agar-well diffusion analysis revealed that extraction using ethyl acetate showed the largest inhibition zone with an average diameter of 15.30 mm (root Soxhlet extract) followed by 14.70 mm (leaf Soxhlet extract) and 13.70 mm (root maceration extract). The lowest minimum inhibitory and minimum bactericidal concentration in root Soxhlet extract using ethyl acetate was 0.313 and 0.625 µg µL-1, respectively. Our study proved that crude extract of the plant suppressed the growth of S. aureus as evidenced from a significant regression extension (p < 0.06, p = 0.00003) of lag phase for 6 h after the treatment with increased concentration. Based on the GC-MS analysis, 88 phytochemicals consist of fatty acids, esters, alkanes, phenols, fatty alcohols, sesquiterpenoids and macrocycle that possibly contributed to the antimicrobial properties were identified, 32 of which were previously characterized for their antimicrobial, antioxidant, and anti-inflammatory activities. CONCLUSION: Ethyl acetate crude extract was better than the other investigated solvents. The root and stem of C. alata showed significant antimicrobial efficacy against S. aureus in this study. The remaining 56 out of 88 phytochemicals of the plant should be intensively studied for more medicinal uses.