Phenotypic detection of ESBL and MBL producing Klebsiella pneumoniae in critically ill patients with nosocomial pneumonia

Document Type : Original Article


1 Department of Microbiology and Immunology, Faculty of Pharmacy, Assiut University, Assiut, Egypt

2 Department of Medical Microbiology and Immunology, Faculty of Medicine, Assiut university, Assiut, Egypt

3 Department of Chest Diseases, Faculty of Medicine, Assiut University, Assiut, Egypt


Background:  Drug-resistant bacteria are major determinants of hospital-acquired infections that are particularly troublesome in intensive care units (ICU). Klebsiella pneumoniae (K. pneumoniae) is one of the most prevalent causes of nosocomial pneumonia. To overcome the problem of antibiotic-resistant pathogens and stop their spreading, it is crucial to describe the pattern of resistance to antibiotics particularly to the β-lactam group. Therefore, in this study we aimed to determine the rates of extended-spectrum β-lactamases (ESBL) and metallo β- lactamases (MBL) producing K. pneumoniae isolates in severely ill hospitalized patients suffering from nosocomial pneumonia. Methods: This was a cross-sectional study that included one hundred patients with hospital acquired pneumonia (HAP) and admitted to Respiratory Intensive Care Unit (RICU) in Assiut University Hospitals, Egypt. Sputum samples were collected and subjected to microbiological analyses to isolate the pathogens. Then, screening, and phenotypic confirmatory tests for ESBL and MBL production among K. pneumoniae isolates were carried out. Results: The prevalence of K. pneumoniae was 48%. Preliminary screening showed that all isolates were resistant to Ceftazidime (CAZ) and Cefotaxime (CTX), 45/48 (93.75%) were resistant to imipenem (IMP). Confirmatory testing showed that 10/48 (20.83%) isolates were ESBL producers, while 36/48 (80%) isolates were MBL producers and 2/48 (4.17%) were ESBL and MBL producers. Conclusion: The rate of β-lactamases production by K. pneumoniae is seriously high, the most frequent type of β-lactamase in K. pneumoniae was the MBL, followed by ESBL. The application of infection control measures and antimicrobial stewardship are highly recommended to decrease emergence and spread of drug-resistant strains.


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