Escalating Gram Negative Infections and Carbapenem Resistance in ICUs: A Critical Challenge in Tertiary Care

Abstract

Introduction: Nosocomial infections in Intensive Care Units (ICUs) pose a significant healthcare challenge, primarily due to multidrug-resistant (MDR) Gram negative bacteria (GNB). These infections, often caused by Klebsiella spp., Pseudomonas spp., E. coli, and Acinetobacter spp., are exacerbated by the emergence of carbapenem resistance. This study aims to identify the prevalence of GNB in ICU-acquired infections and to explore the mechanisms of carbapenem resistance, including the detection of bla_NDM and bla_KPC genes. Methodology: A total of 165 clinical samples from respiratory specimens, urine, blood, and pus were collected aseptically from ICU patients with nosocomial infections. The isolates were identified using standard microbiological techniques, and antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. Carbapenem resistance was confirmed through the RAPIDEC CarbaNP test, and the presence of bla_NDM and bla_KPC genes was determined using multiplex PCR. Results: The most common pathogen was Klebsiella spp. (35%), followed by Pseudomonas spp. (25%), E. coli (25%), and Acinetobacter spp. (15%). Respiratory samples constituted the majority (56%), with Klebsiella spp. as the predominant isolate. High levels of carbapenem resistance were observed. 85% in Acinetobacter spp., 68% in Klebsiella spp., 62% in E. coli, and 58% in Pseudomonas spp. The RAPIDEC CarbaNP test confirmed carbapenemase production in resistant isolates. PCR identified bla_NDM in six Klebsiella spp. isolates, while none were positive for bla_KPC. Conclusion: The study highlights the alarming prevalence of carbapenem-resistant GNB in ICUs, particularly Klebsiella spp. and Acinetobacter spp. These findings emphasize the urgent need for antibiotic stewardship, infection control measures, and regular surveillance to combat MDR pathogens. Collaborative efforts between clinicians and microbiologists are crucial to mitigating this growing threat.