Detection of a CTX-M group 2 beta-lactamase gene in a Klebsiella pneumoniae isolate from a tertiary care hospital, Trinidad and Tobago

Abstract

BackgroundIdentification of the prevalence and spread of ESBL-mediated antibiotic resistance is essential especially in the hospital setting. It is for this reason, more and more studies are highlighting the importance of complementing phenotypic ESBL-detection techniques with molecular techniques in order to understand the basis and extent of this form of resistance among clinically evolved bacterial populations, especially those belonging to the Enterobacteriaceae family. However, in Trinidad and Tobago and other Caribbean countries, very little is known regarding ESBL detection rates and/or the prevalence of genes conferring ESBL resistance.MethodologySixty-six Klebsiella pneumoniae isolates from clinical specimens phenotypically identified by the Microscan Walkaway-96 System as potential ESBL-producers were analysed in this study. Screening and confirmation of these isolates as ESBL producers was done by the Clinical and Laboratory Standards Institute (CLSI) approved methods. Polymerase chain reaction amplification of beta-lactamase genes bla TEM, bla SHV, bla CTX-M1, bla CTX-M2 and bla AmpC was performed to identify mechanisms of β-lactam resistance.ResultsESBL-producing K. pneumoniae was confirmed in 78.8% (41/52) from isolates collected from a variety of sources during the period, April–July 2015. bla SHV (84.8%) and bla CTX-M (46.9%) were the predominant β-lactamase genes identified. A single K. pneumoniae isolate possessed a bla CTX-M group 2 beta-lactamase gene. RAPD analysis identified a number of epidemiologically related isolates. However, current isolates were unrelated to isolates from previous years.ConclusionThis study revealed that among K. pneumoniae isolates exhibiting extended spectrum β-lactam resistance, there was a high prevalence of bla SHV and bla CTX-M genes. This result highlights the need for a reliable epidemiological apparatus that involves the molecular characterisation of ESBL resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s12941-017-0209-x) contains supplementary material, which is available to authorized users.

Urinary Tract Infections in Benin: Exploring the Virulence Factors and Antibiotic Resistance and Virulence Genes among Bacterial Isolates

“…Among Bla-CTX-M identified, Bla-CTX-M15 (33.92%) and Bla-CTX-M2 (33.92%) are the most identified. The high prevalence of Bla-CTX-M15 has been reported in Africa and around the world [36,37,38]. None carbapenem resistance gene has been identified among the isolates.…”

Extended Spectrum Beta-Lactamase (ESBL) Produced by Gram-Negative Bacteria in Trinidad and Tobago

“…This method has the advantage of a short turnaround time of 24 h and requires only a small amount of DNA when processed for bacterial analysis. This method has been applied to ESBL studies [ 8 , 96 ].…”

“…Many other CTX-M enzymes have also been detected in Trinidad and Tobago. A novel CTX-M-2 enzyme was detected in Klebsiella pneumoniae in patients treated in a hospital located in the country [ 6 ], and 58.8% CTX-M occurrence was also reported in the country detected in Escherichia coli [ 7 ] and 46.9% of both CTX-M types 1 and 2 from Klebsiella pneumoniae isolates [ 8 ]. There was a large outbreak in 2000–2002 in Calgary, Canada, in which there were infections caused by organisms, including Klebsiella pneumoniae that produced CTX-M-14 [ 44 , 45 ].…”

Multiple-Antibiotic Resistance and Presence of CTX-M Genes among Enterobacteriaceae Isolates from Different Sources in Iwo, Osun State, Nigeria

“…The multiple antibiotic resistant enterobacteria isolates (MDR ≥3) were sub-cultured onto fresh agar plates and grown overnight, genomic DNA were then extracted from the new bacteria growths according to [10].…”