Detection of multidrug-resistant Klebsiella species with overexpressed efflux pumps in neonatal intensive care units at Menoufia University Hospitals

Background: Neonatal bloodstream infections caused by multidrug-resistant Klebsiella pneumoniae present a major public health challenge in developing countries, with efflux pumps being a key resistance mechanism in Gram-negative pathogens. This study aimed to detect Klebsiella pneumoniae infections in NICUs, analyze antimicrobial susceptibility patterns, and assess the role of efflux pumps in resistance. Methods: A total of 44 Klebsiella pneumoniae isolates were collected from the blood of 205 clinically suspected neonates out of 405 admitted cases to the NICU at Menoufia University Hospitals. Identification of the isolates was confirmed using the Vitek system, which was also employed to determine their antimicrobial susceptibility. The role of efflux pumps in antimicrobial resistance was investigated using the acridine orange phenotypic method, along with multiplex PCR amplification targeting multidrug efflux genes (acrAB, tolC, and ompK35). Results: The study found 34.1% of admitted neonates with suspected bloodstream infections. Infections were correlated with prematurity, low birth weight, intrauterine distress, and invasive interventions. Gram-positive neonates had a discharge rate of 70%, whereas Gram-negative cases had a 51.3% discharge rate and 26.9% mortality. Klebsiella pneumoniae (32%) was the most common pathogen. About 25% were multidrug-resistant, and 29.5% were pan-drug resistant Penicillin and Cephalosporins exhibited alarming resistance levels (from 63% up to 100%). Efflux pumps genes were predominant in 81.8% of isolates. Conclusion: Neonates faced bloodstream infections, mainly associated with prematurity and invasive procedures, with Klebsiella pneumoniae as the primary pathogen exhibiting multidrug resistance driven by efflux pump mechanisms, underscoring their critical role in antimicrobial resistance.