摘要
Introduction and Aim: Carbapenem resistance among species of Enterobacteriaceae has emerged as a global public health problem that adds to the high cost of care, severity and high mortality of otherwise straightforward infections. Governments around the world are devoting efforts to combat this important threat. The present study was undertaken in our setting to detect and characterize carbapenem resistance among Enterobacteriaceae. Methodology: Confirmed species of Enterobacteriaceae isolated from 225 patients that were admitted in various units of University of Maiduguri Teaching Hospital (UMTH) Maiduguri were screened for carbapenem resistance with meropenem and ertapenem disc (10 μg, Oxoid, England) using clinical and laboratory standards institute (CLSI) breakpoints. Suspected carbapenemase producers were subjected to confirmation using Modified Hodge Test method. Detection of the carbapenemase genes was done by multiplex PCR using KPC, NDM-1 and VIM primers. Results: A total of 225 clinical isolates of Enterobacteriaceae comprising 73 (32.4%) of Klebsiella pneumoniae, 61 (27.1%) of Escherichia coli, 21 (9.3%) of Proteus mirabilis, 18 (8.0%) of Klebsiella oxytoca, 13 (5.8%) of Morganella morganii, 12 (5.3%) of Citrobacter freundii, 12 (5.3%) of Serratia marcescens, 7 (3.1) of Enterobacter aerogenes, 3 (1.4%) of Klebsiella ozaenae, 3 (1.4%) of Hafnia alvei and 2 (0.9%) of Citrobcter sedlakii were isolated. A total of 28 (12.4%) of the isolates screened positive as carbapenemase producers. All the 28 screened isolates were further subjected to confirmation using the Modified Hodge Test for which 23 (10.2%) were confirmed resistant. Therefore a prevalence of 10.2% for carbapenem resistance was recorded in this study. Based on multiplex polymerase chain reaction, the various percentage genotypes of the carbapenemase producers were: 11 (47.8%) for KPC, 2 (8.7%) for VIM while 5 (21.7%) isolates have co-existence of the NDM-1 and VIM genes. However, 5 (21.7%) of the isolates have none of the genes screened for in them. The occurrence of carbapenemase genes among species of Enterobacteriaceae was as follows: 6 (33.3%) for Klebsiella pneumoniae, 4 (22.2%) for Escherichia coli, 4 (22.2%) for Proteus mirabilis, 3 (16.7%) for Serratia marcescens and then 1 (5.6%) for Klebsiella oxytoca. Conclusion: Despite the low use of carbapenem agents in the study area, carbapenem resistance was documented. This calls for an ongoing surveillance and infection control practices of this and other emerging resistance threat in all health centers of Nigeria. Irrational use of antibiotics must be discouraged so as to reduce this resistance threat. Antibiotic stewardship program should be established in all tertiary health centers of Nigeria.
Introduction and Aim: Carbapenem resistance among species of Enterobacteriaceae has emerged as a global public health problem that adds to the high cost of care, severity and high mortality of otherwise straightforward infections. Governments around the world are devoting efforts to combat this important threat. The present study was undertaken in our setting to detect and characterize carbapenem resistance among Enterobacteriaceae. Methodology: Confirmed species of Enterobacteriaceae isolated from 225 patients that were admitted in various units of University of Maiduguri Teaching Hospital (UMTH) Maiduguri were screened for carbapenem resistance with meropenem and ertapenem disc (10 μg, Oxoid, England) using clinical and laboratory standards institute (CLSI) breakpoints. Suspected carbapenemase producers were subjected to confirmation using Modified Hodge Test method. Detection of the carbapenemase genes was done by multiplex PCR using KPC, NDM-1 and VIM primers. Results: A total of 225 clinical isolates of Enterobacteriaceae comprising 73 (32.4%) of Klebsiella pneumoniae, 61 (27.1%) of Escherichia coli, 21 (9.3%) of Proteus mirabilis, 18 (8.0%) of Klebsiella oxytoca, 13 (5.8%) of Morganella morganii, 12 (5.3%) of Citrobacter freundii, 12 (5.3%) of Serratia marcescens, 7 (3.1) of Enterobacter aerogenes, 3 (1.4%) of Klebsiella ozaenae, 3 (1.4%) of Hafnia alvei and 2 (0.9%) of Citrobcter sedlakii were isolated. A total of 28 (12.4%) of the isolates screened positive as carbapenemase producers. All the 28 screened isolates were further subjected to confirmation using the Modified Hodge Test for which 23 (10.2%) were confirmed resistant. Therefore a prevalence of 10.2% for carbapenem resistance was recorded in this study. Based on multiplex polymerase chain reaction, the various percentage genotypes of the carbapenemase producers were: 11 (47.8%) for KPC, 2 (8.7%) for VIM while 5 (21.7%) isolates have co-existence of the NDM-1 and VIM genes. However, 5 (21.7%) of the isolates have none of the genes screened for in them. The occurrence of carbapenemase genes among species of Enterobacteriaceae was as follows: 6 (33.3%) for Klebsiella pneumoniae, 4 (22.2%) for Escherichia coli, 4 (22.2%) for Proteus mirabilis, 3 (16.7%) for Serratia marcescens and then 1 (5.6%) for Klebsiella oxytoca. Conclusion: Despite the low use of carbapenem agents in the study area, carbapenem resistance was documented. This calls for an ongoing surveillance and infection control practices of this and other emerging resistance threat in all health centers of Nigeria. Irrational use of antibiotics must be discouraged so as to reduce this resistance threat. Antibiotic stewardship program should be established in all tertiary health centers of Nigeria.
