Investigation of Extended-Spectrum β-Lactamase and Carbapenemase Producing Gram-Negative Bacilli in Rectal Swabs Collected from Neonates and Their Associated Factors in Neonatal Intensive Care Units of Southern Ethiopia

Abstract

Background

Currently extended-spectrum β-lactamase (ESβL) and carbapenemase producing gram-negative bacteria are the greatest concern among the neonatal population with very limited therapeutic options. The aim of this study was to assess the prevalence of ESβL and carbapenemase producing gram-negative bacilli, associated factors and antimicrobial resistance patterns among neonates in intensive care units.

Methods

An institutional-based cross-sectional study was conducted from February to June 2021 on 212 neonates in intensive care units. Risk factors data were collected by using a well-designed questionnaire. A rectal swab sample was collected using a sterile cotton swab and inoculated on MacConkey agar. Bacterial isolates were identified using various biochemical tests. ESβL and carbapenemase were first screened by indicator cephalosporins (cefotaxime (30µg) and ceftazidine (30µg)) and carbapenem (meropenem and ertapenem), respectively. ESβL and carbapenemase were confirmed by a double-disk synergy test and modified carbapenem inactivation methods, respectively. SPSS version 21.0 was used for data analysis. A P-value ≤ 0.05 was considered as statistically significant.

Results

The overall prevalence of ESβL-producing gram-negative bacilli was 72/212 (34%). The predominant ESβL-producing isolate was Klebsiella pneumoniae 23/72 (31.9%) followed by Escherichia coli 17/72 (23.6%). Five (2.4%) carbapenemase-producing gram-negative bacilli were isolated. ESβL-producing isolates showed a high resistance against ampicillin 72/72 (100%), augmentin 69/72 (95.8%) and gentamycin 57/72 (79.2%). The majority 63/72 (87.5%) of isolated ESβL-producing gram-negative bacilli were multi-drug resistant (MDR). Rectal carriage of ESβL by neonates showed a statistically significant association with endotracheal intubation (p = 0.001; AOR = 4.2; 96% CI = (1.8–9.5)), treatment with ampicillin+gentamycin (p = 0.004; AOR = 3.3; 95% CI = (1.5–7.6)) and staying in a neonatal intensive care unit (NICU) between 11 and 20 days (p = 0.042; AOR = 2; 95% CI = (1.0–4.5)).

Conclusion

A high prevalence of ESβL-producing bacterial isolates was observed for commonly used antibiotics which needs further attention. Therefore, continuous and regular follow-ups of drug resistance patterns is important for the proper treatment and management of ESβL and carbapenemase producing gram-negative bacilli.

Keywords:

• extended-spectrum β-lactamase
• carbapenemase
• gram-negative bacilli

Acknowledgments

The authors would like to thank those who were involved in this research.

Abbreviations

AOR, adjusted odd ratio; AST, antimicrobial susceptibility test; CI, confidence interval; CLSI, Clinical Laboratory Standards Institute guidelines; CP-PGNB, carbapenemase-producing gram-negative bacilli; DDS, double-disk synergy test; ESβL, extended spectrum β-lactamase; ESBL-PGNB, extended spectrum β-lactamase producing gram-negative bacilli; GNB, gram-negative bacilli; mCIM, modified carbapenem inactivation method; MDR, multi drug resistant; MHA, Mueller Hinton agar; NICU, neonatal intensive care unit; SOP, standard operating procedures; TSB, trypticase soy broth; TSI, triple sugar iron; WHO, World Health Organization; Spp, species.

Data Sharing Statement

Data cannot be shared publicly because of ethical issues. However the data underlying the results presented in the study are available from the corresponding author on reasonable request.

Author Contributions

All authors contributed to data analysis, drafting or revising the article, have agreed on the journal to which the article will be submitted, gave final approval of the version to be published, and agree to be accountable for all aspects of the work.

Disclosure

The authors declare that they have no competing interests in this work.