Dissemination of NDM-mediated carbapenem resistance in biofilm-forming Acinetobacter baumannii in some Egyptian hospitals

Gaballah, Mohamed H.; Hefny, Hamido Mohamed; Mansy, Moselhy Salah; M. Hassan, Reem

doi:10.21608/mid.2024.306729.2097

Dissemination of NDM-mediated carbapenem resistance in biofilm-forming Acinetobacter baumannii in some Egyptian hospitals

Document Type : Original Article

Authors

¹ Microbiology and Immunology Department, Faculty of Pharmacy (Boys), Al-Azhar University, Cairo, Egypt

² Clinical Pathology Department, Faculty of Medicine, Cairo University, Egypt

10.21608/mid.2024.306729.2097

Abstract

Background: Carbapenem-resistant A. baumannii pose a serious threat, limiting treatment options for severe infections induced by this emerging pathogen. Aim of the work: This study aimed to evaluate the antimicrobial resistance profile and detect resistance mechanisms in imipenem-resistant A. baumannii from various Egyptian hospitals. Methods: A total of 59 A. baumannii isolated from various clinical specimens (blood, sputum, wound swap, urine and endotracheal tubes) collected from the microbiology lab of different Egyptian hospitals. Isolates were identified using conventional bacteriological methods. Antimicrobial susceptibility was tested using Kirby-Bauer disc diffusion method. Biofilm formation was determined spectrophotometrically using microtiter plate method. Metallo-β-lactamase (MBL) resistance was determined by combined disk test (CDT). Multiplex PCR evaluated MBL-encoding genes in imipenem-resistant isolates. Additionally, PCR was used to detect class 1 integrons in MBL-producing isolates. Results: Strong biofilm production was observed in 74% (17/23) of isolates. Class 1 integron was detected in 78.9 % (15/19) of MBL producing isolates. Out of 23 isolates 19 (32.2%) were MBL producers by CDT. Among the 19 (32.2%) CDT-positive isolates, 11 (57.9%) isolates harboured MBL encoding gene (bla_NDM). Conclusion: Our findings highlight the emergence and dissemination of bla_NDM in our hospitals, coupled with their biofilms and MBL production ability, represents a major public health challenge. The presence of class 1 integrons in all isolates carrying MBL-encoding gene, suggesting the critical role of Class 1 integrons in the dissemination of resistance genes.

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