Molecular Characterization of invasiveEnterobacteriaceaefrom Pediatric Patients in Central and Northwestern Nigeria

Abstract

BackgroundBacteremia is a leading cause of death in developing countries but etiologic evaluation is infrequent and empiric antibiotics are not evidence-based. Very little is known about the types of extended-spectrum β-lactamases (ESBL) in pediatric bacteremia patients in Nigeria. We evaluated the patterns of ESBL resistance in children enrolled into surveillance for community acquired bacteremic syndromes across health facilities in Central and Northwestern Nigeria. MethodBlood culture from suspected cases of sepsis from children age less than 5 years were processed using automated Bactec® incubator System from Sept 2008-Dec 2016. Enterobacteriacea were identified to the species level using Analytical Profile Index (API20E®) identification strip and antibiotic susceptibility profile was determined by the disc diffusion method. The multidrug resistant strains were then screened and confirmed for extended spectrum beta lactamase (ESBL) production by the combination disc method as recommended by Clinical and Laboratory Standard Institute (CLSI). Real time PCR was used to elucidate the genes responsible for ESBL production characterize the resistance genes ResultOf 21,000 children screened from Sept 2008-Dec 2016, 2,625(12.5%) were culture-positive. A total of 413 Enterobacteriaceae available for analysis were screened for ESBL. ESBL production was detected in 160/413(38.7%), comprising Klebsiella pneumoniae 105/160(65.6%), Enterobacter cloacae 21/160(13.1%), Escherichia coli 22/160(13.8%), Serratia species 4/160(2.5%), Pantoea species 7/160(4.4%) and Citrobacter species 1/160(0.6%). Of the 160 ESBL-producing isolates, high resistance rates were observed among ESBL-positive isolates for Ceftriaxone (92.3%), Aztreonam (96.8%), Cefpodoxime (96.25%), Cefotaxime (98.75%) and sulphamethoxazole-trimethoprim (90%), while 87.5 %, 90.63%, and 91.87% of the isolates were susceptible to Imipenem, Amikacin and Meropenem respectively. Frequently detected resistance genes were blaTEM 83.75%) (134/160), and, blaCTX-M 83.12% (133/160) followed by blaSHVgenes 66.25% (106/160). Co-existence of blaCTX-M, blaTEM and blaSHV was seen in 94/160 (58.8%), blaCTX-M and blaTEM in 118/160 (73.8%), blaTEM and blaSHV in 97/160 (60.6%) and blaCTX-M and blaSHV in 100/160 (62.5%) of isolates tested. ConclusionOur results indicate a high prevalence of ESBL resistance to commonly used antibiotics in Enterobacteriaceae isolates from bloodstream infections in children in this study. Careful choice of antibiotic treatment options and further studies to evaluate transmission dynamics of resistance genes could help in the reduction of ESBL resistance in these settings.