Bioprospecting Studies of Actinomycete Bioactive Compound on Bla CTX-M -Extended -Spectrum Beta- Lactamase (ESBL) Producing Escherichia Coli and Klebsiella Species

Abstract Forty one Extended Spectrum Beta Lactamase (ESBL) producing E. coli and Klebsiella species were analyzed for the presence of bla CTX-M genes by Uniplex Polymerase Chain Reaction (PCR) in which 15 isolates harbored bla CTX-M genes. Transconjugation studies were carried out to demonstrate the transfer of antibiotic resistance using E. coli K12J62-2 (F – rif r lac -) strain among which UTEC31 and UTK2 strains showed successful transconjugation. Sequence analysis revealed the presence of bla CTX-M-15 genes. Antibacterial activity of Streptomyces sp PUT23 was evaluated against CTX-M ESBL producing E. coli and Klebsiella sp. was determined. The ethyl acetate extract showed inhibitory activity and Reversed phase thin layer chromatography (RP-TLC) analysis revealed two fractions, EFI and EF2. Bioautogram of EF2 fraction demonstrated inhibitory activity with a minimum inhibitory concentration (MIC) value 156 μg/ml. The EF2 fraction was identified as a flavonoid upon chemical characterization. Sequencing of 16S rRNA gene and phylogenetic analysis of Streptomyces sp. strain PUT23 revealed its close relatedness to S. griseus. This study revealed the rapid spread and dominance of CTX-M producing E. coli and Klebsiella sp. in the suburban community of South Chennai, Tamil Nadu which has to be considered as a serious public health issue. There is an urgent need for newer and effective antimicrobials and bioactive compounds derived from Streptomyces species proved to be a promising and efficient resource. Further characterization and purification of EF2 fraction are needed and could be used in the formulation of new therapeutics against ESBL mediated infections.