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

Background: Currently extended-spectrum beta-lactamase (ES beta L) 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 ES beta L 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. ES beta L and carbapenemase were first screened by indicator cephalosporins (cefotaxime (30 mu g) and ceftazidine (30 mu g)) and carbapenem (meropenem and ertapenem), respectively. ES beta L 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 ES beta L-producing gram-negative bacilli was 72/212 (34%). The predominant ES beta L-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. ES beta L-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 ES beta L-producing gram-negative bacilli were multi-drug resistant (MDR). Rectal carriage of ES beta L 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 ES beta L-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 ES beta L and carbapenemase producing gram-negative bacilli.

Automated summary

This study found a high prevalence of ES beta L-producing gram-negative bacilli among neonates, with a significant association between rectal carriage of ES beta L and factors such as endotracheal intubation, specific antibiotic treatments, and length of stay in the neonatal intensive care unit. Continuous monitoring of drug resistance patterns is crucial for effective treatment and management of these bacteria.