Strains of <i>Klebsiella Pneumoniae</i> from Intensive Care Unit Producing CTX-M-15 Extended Spectrum Beta Lactamases

Abstract

Problem statement: Resistance to third generation cephalosporins due to acquisition and expression of Extended Spectrum β-Lactamase (ESBL) among Gram-negative bacteria is on the increase. Infections involving extended spectrum beta lactamase bacteria are associated with significant morbidity and mortality. Therefore, infections due to ESBL isolates continue to pose a serious challenge to infection management worldwide. Since screening for ESBL is not a common practice in hospitals in Enugu state, this study was undertaken to characterize ESBL genes in K. pneumoniae strains from intensive care unit of the University of Nigeria Teaching Hospital (UNTH) Enugu. Approach: Over a period of 29 months, 57 patients out of 140 receiving treatment in the intensive care unit of the University of Nigeria Teaching Hospitals Enugu were found to be infected with extended-spectrum β-lactamase-producing strains of K. pneumoniae. Species identification of K. pneumoniae strains was performed by Standard Microbiology methods and reconfirmed by MALDI-TOF technology. Phenotypic characterization of Extended Spectrum Beta Lactamase (ESBL) was determined by double disc synergy test and presence of ESBL genes was determined by specific PCR. Results: All ESBL producers were positive in a PCR for bla CTX-M-1 cluster and on sequencing, bla CTX-M-15 were found to be present. Genotypic characterization of extended spectrum beta-lactamase producing K. pneumoniae showed that all isolates carried CTX-M-15and SHV genes, 41(71.9%) carried aac (6')-Ib-cr and bla OXA-1, 19(33%) carried bla TEM. ISEcp1 was found upstream and ORF 477 downstream of bla CTX-M. in all strains. Random amplified polymorphic DNA analysis grouped the strains into two clonal groups-A and B and majority of the strains belong to clonal group A (n = 42). Conclusion: This study shows for the first time the presence of ESBL genes in K. pneumoniae from the ICU of UNTH Enugu and therefore strongly butresses the need for regular screening for ESBLproducing bacteria in clinical specimen in ICU and other wards in Nigerian hospitals.

MOLECULAR CHARACTERIZATION AND IMMUNOPROTECTIVE ACTIVITY OF CAPSULAR POLYSACCHARIDE OF <I>KLEBSIELLA PNEUMONIAE</I> ISOLATED FROM FARM ANIMALS AT TAIF GOVERNORATE

“…were imipenem, ciprofloxacin, norfloxacin, gentamicin and kanamycin (100% each).The superiority of flumequine and gentamicin for the in vitro action in Klebsiella pneumoniae was reported by Sarathbabu et al (2012), who reported that all tested strains of Klebsiella pneumoniae were highly sensitive to gentamicin and flumequine. Also, Iroha et al (2011) reported that all isolated Klebsiella pneumoniae subsp. pneumoniae strains were highly sensitive to enrofloxacin and norfloxacin.…”

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“…For DDST, amoxicillin-clavulanic acid, AMC (20/10µg) was placed at the center of the Mueller-Hinton (MH) agar plate, and CTX (30µg) and CAZ (30µg) disk were each placed at a distance of 15mm from the central disc (AMC). The plates were incubated at 37 o C for 18-24 h. ESBL production was inferred phenotypically when the zones of inhibition of CAZ or CTX were expanded by AMC 2,4 .…”

“…showing less susceptibility to any third-generation cephalosporins (e.g., CAZ, CTX) according to the CLSI protocol were phenotypically defined as ESBL bacteria 2,4,20 . ESBL bacteria were screened for ESBL genes ( bla TEM, bla SHV, bla CTX-M, bla Oxa) using conventional PCR.…”

“…1041 [22] bla Oxa F-5'-ACACAATACATATCAACTTCGC-3' R-5'-AGTG TGTTTAGAATGGTGATC-3' 813 [22] PCR Screening for Colistin Resistance Gene: Colistin-resistant phenotypes were inferred according to the CLSI protocol 4,20 . A conventional PCR technique was used to screen isolates for the presence of colistin resistance genes (mcr 1-3 ) 13,17,25 .…”

“…but are inhibited by β-lactamase inhibitors such as clavulanic acid 2,4,5 . ESBL-producing bacteria are clinically relevant because they exhibit coresistance to other antibiotics 6,7 .…”