Identification of BcenGI15 genomic island harboring ST839 clone in a population of Burkholderia cenocepacia complex from a major tertiary care hospital in Northern India

Abstract

ABSTRACTIntroductionBurkholderia cepacia complex (Bcc) is a non-fermenting Gram-negative bacilli (NFGNB) cluster with high genome plasticity and large genome size. As a major nosocomial pathogen, it is known to cause bacteremia, infections in cystic fibrosis patients. One of the factors contributing to multidrug resistance, virulence, and fitness is through chromosomally encoded genetic elements. They carry advantageous genes benefitting the host, thus its crucial to understand their stability and transfer in population. In an earlier study, we have reported a novel genomic island BcenGI15 in a unique clone of Bcc, ST824, involved in a major sepsis outbreak of a pediatric ward in an Indian hospital. In the present study, we have carried out screening of this genomic island by polymerase chain reaction (PCR) in an extensive collection of Bcc isolates from a major tertiary care hospital in Northern part of India.Materials and methods90 isolates obtained from routine patient specimens over a period of 9 years revived from glycerol stock and identified as Burkholderia cenocepacia based on conventional biochemical tests, recA PCR-based restriction fragment length polymorphism (RFLP), and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Isolates were screened for genomic island BcenGI15 via PCR using attL gene primers. Island positive isolates were subjected to multilocus sequence typing (MLST) and antibiotic susceptibility testing.ResultsThe PCR in 16/90 (17.77%) isolates came positive for the presence of BcenGI15. Multi-locus sequence typing (MLST) revealed that all the positive isolates are clonal and belong to a dominant sequence type (ST) ST839.ConclusionMLST data analysis suggested presence of BcenGI15 in two different STs (ST824, ST839) from hospitals in north and west part of India. This suggests probable movement and selection for this element in Indian population of Bcc isolates.