SOURCE:

Faculty: Pharmaceutical Sciences
Department: Pharm. Microbio & Biotech

CONTRIBUTORS:

Duru, C. I.
Esimone, C. O.
Nwanegbo, E. C.

ABSTRACT:

Bacteremia 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 prevalence of ESBLin Enterobacteriaceae and their patterns of antibiotic resistance in children enrolled into surveillance for community acquired bacteremic syndromes across health facilities in Central and North West-Nigeria.Blood culture from suspected cases of sepsis from children of age less than 5 years were processed using automated Bactec® incubator System from Sept 2008-Dec 2016. Enterobacteriaceae bacteriawere 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. Real time polymerase chain reactionwas used to elucidate the genes responsible for ESBL production. The complete genome of 16 carbapenem resistant ESBL isolates was obtained via Next Seq whole‑genome sequencing.A total of 413 Enterobacteriaceae were screened for ESBL. Of these, 38.74% produced ESBL. Of the ESBL organisms, 65.62% wereKlebsiella pneumonia, 13.12 % wereEnterobacter cloacae, 13.75 % were Escherichia coli, 2.5% were Serratia species, 4.37 %were Pantoea species and 0.62%wereCitrobacter species. 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% andblaCTX-M 83.12% followed by blaSHVgenes 66.25%. Sequencing-based analyses revealed a prevalence of 25% New Delhi metallo-beta-lactamase (NDM) -5- producing ST476 and 6.25% oxacillinase (OXA) -48- producing ST 1788 Klebsiella pneumoniaeisolates. Most of the isolates possessed plasmid replicons; IncF and IncHI2. The plasmid multilocus sequence type (pMLST) showed that IncFII exhibited 3 pMLST as K7:A-:B- K13:A-:B- and K8:A-:B- .
In conclusion, our results indicate a high rate of ESBL resistance to commonly used antibiotics in Enterobacteriaceae bacteremia in children from Central and North-West Nigeria.