ABSTRACT
BACKGROUND: Increasing prevalence of community-acquired infections (CAIs) due to Escherichia coli and Klebsiella pneumoniae producing extended-spectrum beta-lactamase (ESBL), especially the Cefotaxime-Munich (CTX-M) type, carbapenemase, and New Delhi metallo-ß-lactamase (NDM), has been reported globally posing a serious public health threat that has complicated treatment strategies for Gram-negative bacterial infections. While most of the reports in this regard are based on hospitalized patients from the urban community, there is a paucity of data in a rural community presenting with CAIs. MATERIALS AND METHODS: A total of 1275 strains of E. coli and K. pneumoniae isolated over a period of 3 years from patients with CAIs were subjected to the detection of ESBL by double-disc synergy test; carbapenemase by modified Hodge test; metallo-ß-lactamase by MIC test strip metallo-ß-lactamase (MBL); and bla TEM, bla SHV, bla CTX-M, and bla NDM genes by polymerase chain reaction. RESULTS: Among 1275 E. coli and K. pneumoniae isolated during the study period, 773 (60.6%), 102 (8%), and 28 (2.2%) isolates were detected as ESBL, carbapenemase and MBL producers, respectively. Of the 773 ESBL producers, 635 (82.1%) were found to harbor bla CTX-M genes, and of the 102 carbapenemase producers, 12 (11.8%) were found to harbor bla NDM genes. Gene sequencing of all the 12 NDM-positive isolates revealed bla NDM-1 genes. Antibiotic resistance pattern of the ESBL-positive isolates revealed a high degree of co-resistance to noncephalosporin antibiotics such as amoxyclav, co-trimoxazole, chloramphenicol, and fluoroquinolones. CONCLUSION: The present study showed the increasing the prevalence of ESBL including CTX-M variety, carbapenemase production by E. coli and K. pneumoniae isolates, and spread of NDM-1 in the patients from the rural community of North India.
ABSTRACT
BACKGROUND/PURPOSE: The re-emergence of an epidemic strain of dengue virus type-3 (DENV-3) in Delhi in 2003 and its persistence in subsequent years marked a changing trend in dengue virus circulation in this part of India. Its evolving phylogeny over the past decade has not been studied in detail as yet. METHODS: Reverse transcription polymerase chain reaction and sequencing of the CprM gene junction of DENV-3 from different outbreaks since 2003 was carried out. Thirty CprM DENV-3 sequences from this study were compared with 46 other previously reported CprM DENV-3 sequences from India and other countries. Multiple sequence alignment and phylogenetic trees were constructed to determine the extent of genetic heterogeneity and trace the phylogeny of DENV-3. RESULTS: Thirty CprM DENV-3 sequences (Accession numbers AY706096-99, DQ645945-52, EU181201-14, and EU846234-36) were submitted to GenBank. The CprM junction was found to be AT rich (approximately 53%). Nucleotide sequence alignment revealed only nucleotide substitutions. Phylogenetic analysis indicated sustained evolution of a distinct Indian lineage of DENV-3 genotype III in Delhi. CONCLUSION: Active circulation of DENV-3 genotype III over the last decade in Delhi was evident and worrying. This genotype has been implicated in several outbreaks in South-East Asia and other parts of the world.
