Characterization of previously identified novel DNA fragment associated with Pathogenicity Island III536 reveals new blaCTX-M gene.

In the Kingdom of Bahrain a high percentage of extra-intestinal infectious diseases are reported as urinary tract infections UTIs. These UTIs are repeatedly diagnosed as multidrug resistant isolates. In a recent investigation, a novel DNA segment was identified in a UTI cefotaxime resistant Escherichia coli isolate. The DNA sequence was associated to pathogenicity island III536 locus. The current work is investigating/elucidating the genomic context of the newly identified locus in the UTI isolate using Single Genome Specific Primer-PCR (SGSP-PCR) approach. The isolate was characterized and redefined as strain EC1091 (genotype: blaTEM, blaCTX-M, gyrB, chuA, yjaA, TSpE4.C2) and its novel genomic contents were found to acquire antibiotic resistance genes: blaCTX-M and aac (3). The blaCTX-M was found to be a new beta-lactamase allele with no significant BLASTN results in the National Center for Biotechnology Information (NCBI), but a protein PSI-BLAST against non-redundant database revealed a remote similarity to CTX-M proteins.