Antibiogram and Genetic Characterization of Carbapenem-Resistant Gram-Negative Pathogens Incriminated in Healthcare-Associated Infections

Rabab R Makharita; Iman El-Kholy; Helal F Hetta; Moahmed H Abdelaziz; Fatma I Hagagy; Amera A Ahmed; Abdelazeem M Algammal

doi:10.2147/IDR.S276975

Antibiogram and Genetic Characterization of Carbapenem-Resistant Gram-Negative Pathogens Incriminated in Healthcare-Associated Infections

Infect Drug Resist. 2020 Nov 4:13:3991-4002. doi: 10.2147/IDR.S276975. eCollection 2020.

Authors

Rabab R Makharita^{1

2}, Iman El-Kholy³, Helal F Hetta^{4

5}, Moahmed H Abdelaziz², Fatma I Hagagy², Amera A Ahmed^{2

6}, Abdelazeem M Algammal⁷

Affiliations

¹ Biology Department, Faculty of Science and Arts, University of Jeddah, Khulais, Jeddah, Saudi Arabia.
² Botany Department, Faculty of Science, Suez Canal University, Ismailia 41522, Egypt.
³ Ain Shams Specialized Hospital, Faculty of Medicine, Ain Shams University, Cairo 11556, Egypt.
⁴ Department of Medical Microbiology and Immunology, Faculty of Medicine, Assuit University, Assuit 71515, Egypt.
⁵ Department of Internal Medicine, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0595, USA.
⁶ Ministry of National Guard, Health Affairs, King Abdulaziz Medical City, Jeddah, Saudi Arabia.
⁷ Department of Bacteriology, Immunology and Mycology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522, Egypt.

Abstract

Purpose: Carbapenems are considered the most efficient antibiotic used in the treatment of nosocomial infections. Carbapenem-resistant Gram-negative rods are becoming a serious hazard in hospitals threatening public health. The aim of the current study was to investigate the prevalence of carbapenem-resistant Gram-negative pathogens incriminated in healthcare-associated infections, along with antimicrobial resistance profiles, carbapenemase and metallo-β-lactamase production, and their molecular characterization.

Methods: A total of 186 clinical specimens were collected from 133 patients at various hospitals in Cairo, Egypt. The obtained specimens were subjected to bacteriological examination, antimicrobial susceptibility testing, detection of carbapenemase production using the modified Hodge test (MHT), the metallo-β-lactamase production using the EDTA combined disc test (CDT), and PCR-based detection of the bla _KPC and bla _GES resistance genes. The identification of the highly resistant retrieved isolates was then confirmed by 16S rRNA gene sequencing.

Results: The most common isolated Gram-negative species was Klebsiella pneumoniae (40.9%), followed by Acinetobacter baumannii (18.8%), Pseudomonas aeruginosa (17.3%), Escherichia coli (15.4%), Enterobacter aerogenes (5.3%), and Proteus mirabilis (2.4%). The prevalence of carbapenem-resistant isolates was 36.1% (n=75). However, 86.5% of the recovered clinical isolates were susceptible to colistin. The MHT revealed that 33.6% (n=70) of the tested strains were positive for carbapenemase production, while the CDT showed that 33.17% (n=69) of the examined strains were metallo-β-lactamase producers. The PCR revealed that 98.6% (74/75) of the tested strains possessed the bla _KPC gene; moreover, 97.3% (73/75) of the examined strains harbored the bla _GES gene.

Conclusion: This study displayed the emergence of carbapenem-resistant Gram-negative pathogens incriminated in healthcare-associated infections. The accurate identification of carbapenem-resistant bacterial pathogens is pivotal for the treatment of patients, in addition to propelling appropriate contamination control measures to restrain the fast spread of such pathogens. Colistin showed a potent in vitro antimicrobial activity against the carbapenem-resistant strains.

Keywords: 16S rRNA gene; antibiotic resistance; blaGES; blaKPC; carbapenem-resistance; gram-negative rods.