Background:The emergence of drug resistance among diarrheagenic Escherichia coli (E. coli) in the pediatric population is an important cause of morbidity and mortality in developing countries.Material and Methods:Isolation and identification of E. coli strains from stool specimens are carried out according to standard techniques. Antibiotic susceptibility testing was performed using disc-diffusion method. Plasmid profiling and conjugation experiments were done to analyze the antibiotic resistance transfer from one bacterium cell to another through plasmid.Results:Out of 170 pediatric diarrheal samples, 105 (61.76%) E. coli strains were isolated. About 90% of E. coli strains were resistant to most of the antimicrobial agents tested. All the isolates were resistant to ampicillin, imipenem and cotrimoxazole and were sensitive to amikacin. The resistance to antibiotics shows 29 different antibiotic resistance patterns. About 67 (64%) strains of E. coli isolates harbored plasmids, and 51 (76.1%) of them were able to transfer their plasmids. The plasmid sizes ranged from 1.0 to 25 kb, the most common plasmid of size 4.8 kb being detected in all the plasmid-harbored E. coli strains. The results of transconjugation show that all the transconjugant colonies were carrying 4.8-kb plasmid and were resistant to ampicillin, imipenem and cotrimoxazole.Conclusion:There is an increase in the prevalence of drug resistance among E. coli isolates, and conjugal transfer of plasmids has greatly contributed to the rapid spread of antibiotic resistance among E. coli isolates.
A gram-positive, pyridine-degrading microorganism identified as Bacillus coagulans has been isolated from contaminated soil by enrichment culture technique. Pyridine was used as sole source of carbon, nitrogen, and energy. Bacillus coagulans has a unique potential to reduce nitrogen from aromatic ring to ammonia and subsequently heterotrophically to nitrite and nitrate. The maximum degradation of pyridine was 94.1% within 72 h at 30 degrees C with a 7.57-h doubling time. The study suggests possible existence of aromatic degradation and heterotrophic nitrification in Bacillus coagulans.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.