ESBL‐production in Escherichia coli and Klebsiella pneumoniae isolates from Nigeria

Abstract The worldwide increase in infections caused by extended‐spectrum beta‐lactamase‐ (ESBL) and AmpC‐producing Enterobacteriaceae (ESBL‐E) is a concern. Surveillance is extensive in Europe, North America, and Asia. Yet, there is no summarizing surveillance in Africa. This study aimed to perform a preliminary investigation on the prevalence of ESBL‐E in the northeastern part of Nigeria. However, of the 60 samples collected, we were able to culture 15 Escherichia coli and 7 Klebsiella spp. only. In the collection of clinical hospital samples, we found eight of 15 E. coli isolates to be ESBL (53%) and two out of seven Klebsiella spp. to be ESBL/AmpC (29%). Due to the limitations of this study, our findings cannot take a broad view on the prevalence of ESBL‐E, in Nigeria and other parts of Africa. Yet, to know which genes encode ESBL in Nigeria, and to know exact prevalence of every ESBL gene would be of importance.


Abstract
The worldwide increase in infections caused by extended-spectrum beta-lactamase-(ESBL) and AmpC-producing Enterobacteriaceae (ESBL-E) is a concern. Surveillance is extensive in Europe, North America, and Asia. Yet, there is no summarizing surveillance in Africa. This study aimed to perform a preliminary investigation on the prevalence of ESBL-E in the northeastern part of Nigeria. However, of the 60 samples collected, we were able to culture 15 Escherichia coli and 7 Klebsiella spp. only. In the collection of clinical hospital samples, we found eight of 15 E. coli isolates to be ESBL (53%) and two out of seven Klebsiella spp. to be ESBL/AmpC (29%). Due to the limitations of this study, our findings cannot take a broad view on the prevalence of ESBL-E, in Nigeria and other parts of Africa. Yet, to know which genes encode ESBL in Nigeria, and to know exact prevalence of every ESBL gene would be of importance. were ESBL-screening test-positive. ESBL-or AmpC production was phenotypically confirmed by the MAST test, performed as a combined-disk method, using disks containing cefpodoxime ±ESBL and/ or AmpC inhibitors (MAST®, Merseyside, UK) (Hertz et al., 2015).

K E Y W O R D S
Of the 60 samples collected, one was without any bacterial growth. In the remaining 59 samples, we were able to culture 15 E. coli and 7 Klebsiella spp. (6 K. pneumoniae and 1 Klebsiella oxytoca) only. Results of antibiotic susceptibility testing are found in Figure 1. Of the 15 identified E. coli, eight produced ESBL, but none produced AmpC. The majority of E. coli were resistant to trimethoprim (n = 13), sulfamethizol (n = 13), and ciprofloxacin (n = 10), yet none were resistant to mecillinam (n = 0) or nitrofurantoin (n = 0) ( Figure 1). Of the seven Klebsiella spp., one produced ESBL and one produced AmpC. Besides resistance to ampicillin, which is intrinsic in K. pneumoniae and K. oxytoca, resistance was low among Klebsiella spp. None of the isolates were found to be carbapenemase producers.

CONS ENT FOR PUB LIC ATION
All authors have read the data note and agreed to it being submitted for publication.

ACK N OWLED G EM ENT
We thank the personnel at the Department of Clinical Microbiology at Hvidovre Hospital, and especially Christian Østergaard for permission to use laboratory facilities.

CO N FLI C T O F I NTE R E S T
None declared.

AUTH O R S CO NTR I B UTI O N
All authors meet the authorship criteria, and nobody who qualifies for authorship has been omitted from the list; authors have approved the acknowledgement of their contributions. All authors contributed to the study design, interpretation of the data, intellectual discussion and/or revision of the data note. FBH, JDK, and KOO participated in the planning of laboratory research and were responsible for the original study idea and study design. ISA, JOO, and JL performed the sample collection. FJ helped with collaboration between our countries. FBH wrote the initial draft of the data note.
F I G U R E 1 Resistance pattern for the 22 samples found as monoculture of Escherichia coli or Klebsiella spp. Here, the pathogens were considered to be the true pathogen. The number shown is the number of isolates resistant to the antibiotic. Eight E. coli isolates were found to be ESBL producing and two Klebsiella pneumoniae isolates were ESBL and AmpC producing, respectively. ESBL: extended-spectrum beta-lactamase

ETHICS STATEMENT
All patients in this nonintervention study were treated with care by healthcare professionals, in line with all other patients with similar infections and according to current guidelines. No further information from patients was obtained. The project did not involve any health risks and was in no way at the expense of the subject. All data were anonymized. Thus, no ethical approval or consent was necessary.

DATA ACCESSIBILITY
All data associated with the study is presented in the article.