Genomic insights into extensively drug-resistant Pseudomonas aeruginosa isolated from a diarrhea case in Kolkata, India.

Aim: To characterize extensively drug-resistant Pseudomonas aeruginosa from a patient with diarrhea. Materials & methods: Antimicrobial susceptibility was tested by the disk diffusion method. The P. aeruginosa genome was sequenced to identify virulence, antibiotic resistance and prophages encoding genes. Results: P. aeruginosa had a wide spectrum of resistance to antibiotics. Genomic analysis of P. aeruginosa revealed 76 genes associated with antimicrobial resistance, xenobiotic degradation and the type three secretion system. Conclusion: This is the first report on diarrhea associated with P. aeruginosa. Since no other organism was identified, the authors assume that the patient had dysbiosis due to antibiotic exposure, leading to antibiotic-associated diarrhea. The in vivo toxicity expressed by the pathogen may be associated with T3SS.

Region-specific genomic signatures of multidrug-resistant Helicobacter pylori isolated from East and South India.

Helicobacter pylori is a ubiquitous bacterium and contributes significantly to the burden of chronic gastritis, peptic ulcers, and gastric cancer across the world. Adaptive phenotypes and virulence factors in H. pylori are heterogeneous and dynamic. However, limited information is available about the molecular nature of antimicrobial resistance phenotypes and virulence factors of H. pylori strains circulating in India. In the present study, we analyzed the whole genome sequences of 143 H. pylori strains, of which 32 are isolated from two different regions (eastern and southern) of India. Genomic repertoires of individual strains show distinct region-specific signatures. We observed lower resistance phenotypes and genotypes in the East Indian (Kolkata) H. pylori isolates against amoxicillin and furazolidone antibiotics, whereas higher resistance phenotypes to metronidazole and clarithromycin. Also, at molecular level, a greater number of AMR genes were observed in the east Indian H. pylori isolates as compared to the southern Indian isolates. From our findings, we suggest that metronidazole and clarithromycin antibiotics should be used judicially in the eastern India. However, no horizontally acquired antimicrobial resistance gene was observed in the current H. pylori strains. The comparative genome analysis shows that the number of genes involved in virulence, disease and resistance of H. pylori isolated from two different regions of India is significantly different. Single-nucleotide polymorphisms (SNPs) based phylogenetic analysis distinguished H. pylori strains into different clades according to their geographical locations. Conditionally beneficial functions including antibiotic resistance phenotypes that are linked with faster evolution rates in the Indian isolates.