In ovo inoculation of duck embryos with different strains of Bacillus cereus to analyse their synergistic post-hatch anti-allergic potentialities.

BACKGROUND: Bacillus cereus is a Gram-positive, facultative anaerobic bacteria with few strains reported to be used as probiotics for animals and birds in recent times if the doses are formulated properly. OBJECTIVES: To analyse the synergistic anti-allergic potentiality of different Bacillus cereus strains on experimental in ovo and in vitro duck model, as probiotic immune stimulant. MATERIALS AND METHODS: Different strains of Bacillus cereus from 29 isolates were identified through 16S rRNA gene sequencing from the milk samples of buffalo breeds of South Asia. The probiotic properties were tested in aspects of gram staining, catalase test, coagulase, test, bile salt tolerance, pH tolerance and phenol tolerance test. MIC50 and MIC90 levels were profiled using nine different antibiotics, and antimicrobial activity against eight different enteric pathogens was assessed. Finally, the test strains of Bacillus cereus (Colony Forming Unit [CFU] 30X1011 ) were combined-infused at different concentrations in embryonated duck eggs to assess the post-hatch anti-allergic effects against histamine-induced allergic reaction and their immunoglobulin E (IgE) level was tested. RESULTS: Molecular identification confirmed the test strains as B. cereus HKS 1-1, B. cereus LOCK 1,002 and B. cereus BF2, which were all motile, spore-forming, catalase-positive and rod-shaped. All were 0.3% bile salt, 0.4% phenol and pH tolerant. Two-way ANOVA test P values revealed that B. cereus BF2 was statistically significant (p < .0014) in bile salt tolerance test. B. cereus HKS 1-1 was significant in phenol and pH tolerance at p < .0002 and p < .0489, respectively. Besides, the test strains showed antibiotic sensitivity and antimicrobial activity to different enteric pathogens. In vivo model referred the test strains as effective in partial allergy reduction at same CFU but at different concentrations with p < .0001 among the groups. CONCLUSION: The isolated and characterized strains of B. cereus showed partial immune-stimulating potentiality against experimentally induced allergic reaction.

Antidiarrheal Efficacy of Probiotic Bacteria in Castor Oil Induced Diarrheal Mice.

Probiotics may offer a safe intervention for diarrheal diseases. The aim of the present study was the assessment of the antidiarrheal property of probiotic bacteria. For their antidiarrheal efficacy assessment, yogurt was prepared using the isolated bacteria from selective regional yogurt of Bangladesh, and mice model trails were conducted using castor oil induced diarrheal mice. The probiotic treatment was applied on three mice groups, each having 6 mice and their respective doses were 50 mL/kg body weight in treatment group (TG) 1, 100 mL/kg body weight in TG2, and 150 mL/kg body weight in TG3. A four week treatment of probiotic significantly (P<0.001) reduced the percentage (67.37%) of diarrhea in TG3 (150 mL yogurt/kg body weight). All the treatment groups showed a significant (P<0.001) increase in the latent periods, reduced the total fecal output, and frequency and fecal water content compared to the negative control group. Serum electrolytes (Na+ and K+) and total protein levels were higher in the TG3 compared to the negative control group. Further research regarding molecular characterization and identification of specific genes and proteins of interest may help to develop the next generation bacteriocins and antidiarrheal drugs.