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Investigation of VIM, IMP, NDM-1, KPC AND OXA-48 enzymes in Enterobacteriaceae strains
Yelda Demir1, Yasemin Zer1, Ilkay Karaoglan2
1Department of Medical Microbiology, Medical Faculty, Gaziantep University, Gaziantep, Turkey.
Abstract:
Gram-negative bacteria especially Enterobacteriaceae species have become an increasing etiologic agent of nosocomial infections. The development of resistance to carbapenems have become an increasing problem in the treatment of nosocomial infections. Especially carbapenamases are common for Enterobacteriaceae strains. This study was performed to detect the types of carbapenemases in Enterobacteriaceae strains isolated from various clinical samples. Enterobacteriaceae species were isolated from urine, blood, tracheal aspirates, wound, and other respiratory samples. Susceptibility of isolates to imipenem, meropenem and ertapenem was tested. Carbapenemase genes were studied using HyplexSuperBug ID kit. VIM (1-13), IMP (1-22), NDM-1, KPC(1-10) and OXA-48 genes were investigated. Ninety-five isolates of Enterobacteriaceae spp. were included in the study. Sixty isolates were resistant to imipenem, meropenem and ertapenem and 20 isolates were found resistant to imipenem or ertapenem while 15 were susceptible to all carbapenems. Among the isolates with carbapenem resistance, 57 were positive for one carbapenemase gene and susceptible isolates did not have carbapenemase gene. OXA-48 was found in 49 of the isolates (86%), NDM-1 in 6 (10.5%) isolates, VIM in 2 isolates. IMP and KPC gene loci were not identified. Carbapenemase genes play a crucial role in the development and spread of resistant strains.
Insights
Carbapenemase genes, particularly OXA-48, are prevalent in Enterobacteriaceae causing hospital infections. Identifying these carbapenem-resistant Enterobacteriaceae (CRE) is crucial for effective treatment strategies.
Area of Science:
- Microbiology
- Infectious Diseases
- Molecular Biology
Background:
- Gram-negative bacteria, especially Enterobacteriaceae, are a growing cause of nosocomial infections.
- Carbapenem resistance in these bacteria poses a significant treatment challenge.
- Carbapenemases are frequently identified in Enterobacteriaceae strains.
Purpose of the Study:
- To detect and characterize carbapenemase genes in Enterobacteriaceae isolated from clinical samples.
- To investigate the prevalence of specific carbapenemase types, including VIM, IMP, NDM-1, KPC, and OXA-48.
Main Methods:
- Enterobacteriaceae isolates were obtained from various clinical specimens (urine, blood, respiratory, wound).
- Antimicrobial susceptibility testing was performed for imipenem, meropenem, and ertapenem.
- Carbapenemase gene detection was conducted using the HyplexSuperBug ID kit.
Main Results:
- Ninety-five Enterobacteriaceae isolates were analyzed. Of these, 60 were resistant to all tested carbapenems, 20 showed intermediate resistance, and 15 were susceptible.
- Carbapenemase genes were detected in 57 of the resistant isolates; susceptible isolates lacked these genes.
- OXA-48 was the most common carbapenemase gene, found in 49 isolates (86%), followed by NDM-1 in 6 isolates (10.5%) and VIM in 2 isolates. IMP and KPC genes were not detected.
Conclusions:
- Carbapenemase genes are critical drivers in the emergence and dissemination of carbapenem-resistant Enterobacteriaceae.
- The high prevalence of OXA-48 highlights its importance in hospital-acquired infections caused by Enterobacteriaceae.
- Molecular detection of carbapenemase genes is essential for guiding antimicrobial therapy and infection control.
