Background and objective: Lactobacilli are excellent antibacterial agents; however, scientific study on their combined action against human pathogenic bacteria is skimpy. The current study determines the antibacterial activity of commercially available probiotic lactobacilli and the curd lactobacilli, alone and in combination, against clinical bacterial isolates.Methods and findings: Two curd lactobacilli (Lactobacillus animalis and L. gasseri) and two commercially available probiotic lactobacilli (L. acidophilus and L. rhamnosus) strains were tested for their antibacterial activity against the clinical bacterial isolates: Escherichia coli and Klebsiella pneumoniae, following agar-overlay method. The 'R' values (width of clear zones) due to their action against the indicator bacteria were recorded, and growth inhibitory indices (GIIs) were calculated from their combined action. The commercial lactobacilli strains, for which the 'R' values ranged 8-12 mm, from single action, had synergistic activity when used in combination against E. coli (GII: 0.56), while the curd lactobacilli strains having 'R' values 6.5-9.5 mm had synergistic activity against both E. coli and K. pneumoniae (GIIs: 0.65-0.74). The lactobacilli strains isolated were multidrug resistant. Conclusion:The current findings suggest the usefulness of natural curd lactobacilli as well as the commercially available lactobacilli strains, alone or in combination, or in combination with some conventionally used antibiotics, as therapeutics against bacterial infection to humans.

Background and Objectives: Lactobacilli are used as probiotics, but scientific investigation of such strains is scanty. The current study aims to isolate and identify Lactobacillus strains from curd samples for probiotic characterization and antibiotic resistance determination. Methods and Findings:Ten curd samples (homemade and commercially available) were screened for the presence of lactobacilli, and the isolates were identified by cultural methods, gram-staining and biochemical tests, and thereafter subjected to acid-, bile salt-and sodium chloride tolerance, and antibiotic susceptibility tests. Among 10 Lactobacillus strains, isolated one from each of the 10 curd samples, 2 were found as Lactobacillus fermentum (L. fermentum) and Lactobacillus casei (L. casei), which showed tolerance to bile salts (0.3%), low-pH value of 3, and low level of resistance to all the test antibiotics viz., ampicillin, chloramphenicol, cefotaxime, gentamicin and tetracycline, having MICs 8-32 μg/ml, except ciprofloxacin (MICs 2-4 μg/ml). Conclusion:The findings of the current study meet the criteria, for the curd isolates of L. fermentum and L. casei, as being potential probiotic organisms, and curd, which is one of the highly-consumed dairy products, could be an important source of such probiotic bacterial strains.

Chagas disease (ChD), also known as American trypanosomiasis, is caused by the trypanosomatid protozoan Trypanosoma cruzi (T. cruzi) that in its natural life-cycle is transmitted through triatomine vectors. Parasitological studies are useful to confirm acute cases, while the diagnosis of chronic T. cruzi infection relies on serological methods. There is no vaccine to prevent the infection, and the treatment is restricted to nifurtimox and benznidazole; and hence, new effective drugs with lower side-effects are urgently needed. The current review updates the facts and phenomena related to ChD, which is becoming an emerging health problem in non-endemic areas too, making the disease a grave global concern.

Aims: The current study determines the antibacterial activity of 'Bakul' (Mimusops elengi) leaf, seed and bark extracts against gram-negative clinical bacterial isolates as well as the standard bacterial strains. Methods:The disc diffusion method was followed to determine the antibacterial activity of M. elengi leaf, seed and bark extracts against the clinical isolates of Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris and Pseudomonas aeruginosa. The antibiotic susceptibility of the bacterial isolates was determined by disc diffusion. Results:The concentration dependent activity of the extracts against the bacteria was recorded with zone diameter of inhibition 7-21 mm. The extracts in combination with antibiotics (cefpodoxime, gentamycin and ciprofloxacin) had growth inhibitory indices (GIIs), 0.5-0.6, 0.5-0.89 and 0.73-0.82 against E. coli, K. pneumoniae and Pr. vulgaris clinical isolates, respectively, while for the standard strains (E. coli, K. pneumoniae and Ps. aeruginosa) the GIIs ranged 0.56-0.86. Most of the extracts were tested positive for the presence of flavonoids, glycosides, steroids, terpenoids, quinone and phenol. Conclusion:The M. elengi leaf, seed and bark extracts, in combination with antibiotics, had synergistic interactions against all the standard bacterial strains and Pr. vulgaris clinical isolate, while both synergistic and additive interactions were recorded against E. coli and K. pneumoniae clinical isolates.

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