Genotypic Determination of Carbapenamase Gene Production in Clinical Isolates of <i>Klebsiella pneumoniae</i> in the University of Port-Harcourt Teaching Hospital

Abstract

Carbapenem resistance among Enterobacteriaceae, especially Klebsiella pneumoniae and Escherichia coli, has remained a challenge in infectious disease management. Although several resistance mechanisms have been documented that neutralize the efficacy of carbapenems, the expression of carbapenemases is the most prominent. Carbapenemase producing Klebsiella pneumoniae has been identified as a major public health threat because of the potential for rapid plasmid mediated spread of the resistance genes among bacterial species and resulting limited therapeutic options available. These pathogens could express resistance to almost all available antibiotics and are associated with high morbidity and mortality. This cross-sectional study was carried out in the University of Port Harcourt Teaching Hospital, Nigeria. A total of 225 clinical isolates of Klebsiella pneumoniae from wounds, urine, blood, sputum and cerebrospinal fluid were recruited. All isolates were screened for Carbapenem resistance using Ertapenem (10µg; Oxoid, England) according to CLSI guidelines. All non-susceptible isolates were then tested for phenotypic carbapenemase production using the Modified Hodge test (MHT). The MHT positive isolates were thereafter, subjected to Polymerase Chain Reaction to detect the presence of blaKPC resistance gene. The study showed that 8.4% (19/225) of Klebsiella pneumoniae isolates were not susceptible to Ertapenem. Out of these, 6.2% (14/225) expressed carbapenemase production by the modified Hodge test. However, on molecular analysis, only six (6) of these isolates possessed the blaKPC gene giving a 2.7% genotypic prevalence of Klebsiella pneumoniae carbapenemase among the isolates. Critically ill patients are more likely to develop infections by blaKPC-producing Klebsiella pneumoniae. It is therefore pertinent that the approach to prevention and control of infections by multi-drug resistant Klebsiella pneumoniae isolates must be multi-pronged to effectively counteract the various mechanisms that may be responsible. From control of prescribing and dispensing patterns, rational use of antimicrobials, institution of antimicrobial stewardship programs, optimization of infection prevention and control measures to effective surveillance; a well-coordinated approach is necessary to reduce the prevalence and spread of this pathogens since the blaKPC resistance gene is plasmid mediated and associated with high rates of both inter and intra-species transfer among bacteria.