Occurrence, antibiotics and disinfectants resistance of extended spectrum β-lactamases producing e. Coli and k. Pneumonia and the genes encoding for the resistance in kenya

ABSTRACT

Extended-spectrum beta-lactamases (ESBLs) are enzymes that mediate resistance to βlactam antibiotics by opening the beta-lactam ring of penicillin derived antibiotics, and another family of antibiotics, rendering them inactive against the bacteria they are intended to kill. The ESBLs were first identified in 1939 and since then, they have proliferated worldwide and have been found in a number of different bacteria, such as Klebsiella pneumonia, and Escherichia coli among others. These bacterial strains can cause severe and life-threatening infections, resulting in increased morbidity, mortality, and cost in treating these infections. Since these bacterial strains are not adequately identified in many Kenyan public health facilities, key information on prevalence, antibiotic and disinfectants susceptibility is inadequate. The main aim of this study was to determine the occurrence, antibiotic and disinfectant susceptibility in ESBLs producing E.coli and K.pneumonia, and genes encoding for the resistance. Analytical profile index (API) method was used to identify the presence of E.coli or K. pneumonia among the Gram negative bacteria. Double disc synergy method was used to test for the presence of ESBL enzymes in these two bacteria isolates. Disc diffusion method was used in Antimicrobial susceptibility testing while disinfectants susceptibility testing was done using classic method of successive dilutions. Polymerase chain reaction (PCR) was used totest for the presence of β-lactamases genes (blaTEM, blaSHV, blaCTX-M and blaOXA-1). Identification of the sub-types of the mother genes was done by sequencing method. Among the gram negative isolates identified, 21% were ESBL E.coli and 20% were ESBLs K.pneumonia. The study indicates that, antimicrobial resistance was high, Ampicillin (100%), sulfamethoxazole-trimethoprim combination (89%), and tetracycline (87%), cefuroxime (100%), ceftazidime (88%) and ceftriaxone (94%) and aztreonam (100%). Relatively lower resistance was recorded for gentamicin (56 %,) and meropenem (8% in E. coli and 18%, in K.pneumonia). All the six disinfectants were effective at recommended use concentration, losing affectivity with decreasing concentration. All the four ESBL genes (blaCTX-M, blaTEM, blaSHV and blaOXA) were identified from the study isolates. The most predominant enzyme in E.coli was CTX-M (29/36 while in K. pneumonia, SHV genes was the most predominant (22/34).Nine (9) sub-types of TEM (TEM-1, 186, 198, 219, 2018, 115, 154, 163, 169) were obtained while 5 sub-types of SHV (SHV-1, 12, 32,101 and 11) were obtained. Majority of both strains harboredbla combination of ESBL genes. Two of the identified sub-types TEM 208 and 219 are described for the first time. In phylogeny analysis, the different beta lactamase genes of blaSHV and blaTEM clustered separately with each forming a distinct cluster. Antimicrobial resistance to the ESBLs is high and this compares well with reports from other parts of the world. Updates of trends for regional epidemiological data on antimicrobial resistance are crucial in order to promote appropriate antimicrobial therapy as well as an effective infection control and clinical care management