Co-Existence of Carbapenemase-Encoding Genes in Acinetobacter baumannii from Cancer Patients

Reham Wasfi; Fatma Rasslan; Safaa S Hassan; Hossam M Ashour; Ola A Abd El-Rahman

doi:10.1007/s40121-020-00369-4

Co-Existence of Carbapenemase-Encoding Genes in Acinetobacter baumannii from Cancer Patients

Infect Dis Ther. 2021 Mar;10(1):291-305. doi: 10.1007/s40121-020-00369-4. Epub 2020 Nov 12.

Authors

Reham Wasfi¹, Fatma Rasslan², Safaa S Hassan³, Hossam M Ashour^{4

5}, Ola A Abd El-Rahman²

Affiliations

¹ Department of Microbiology and Immunology, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA), Giza, Egypt.
² Department of Microbiology and Immunology, Faculty of Pharmacy (Girls), Al-Azhar University, Cairo, Egypt.
³ Department of Clinical Pathology, National Cancer Institute, Cairo University, Cairo, Egypt.
⁴ Department of Integrative Biology, College of Arts and Sciences, University of South Florida, St. Petersburg, FL, USA. hossamking@mailcity.com.
⁵ Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University, Cairo, Egypt. hossamking@mailcity.com.

Abstract

Introduction: Acinetobacter baumannii is an opportunistic pathogen, which can acquire new resistance genes. Infections by carbapenem-resistant A. baumannii (CRAB) in cancer patients cause high mortality.

Methods: CRAB isolates from cancer patients were screened for carbapenemase-encoding genes that belong to Ambler classes (A), (B), and (D), followed by genotypic characterization by enterobacterial-repetitive-Intergenic-consensus-polymerase chain reaction (ERIC-PCR) and multilocus-sequence-typing (MLST).

Results: A total of 94.1% of CRAB isolates co-harbored more than one carbapenemase-encoding gene. The genes bla_NDM, bla_OXA-23-like, and bla_KPC showed the highest prevalence, with rates of 23 (67.7%), 19 (55.9%), and 17 (50%), respectively. ERIC-PCR revealed 19 patterns (grouped into 9 clusters). MLST analysis identified different sequence types (STs) (ST-268, ST-195, ST-1114, and ST-1632) that belong to the highly resistant easily spreadable International clone II (IC II). Genotype diversity indicated the dissemination of carbapenem-hydrolyzing, β-lactamase-encoding genes among genetically unrelated isolates. We observed a high prevalence of metallo-β-lactamase (MBL)-encoding genes (including the highly-resistant bla_NDM gene that is capable of horizontal gene transfer) and of isolates harboring multiple carbapenemase-encoding genes from different classes.

Conclusion: The findings are alarming and call for measures to prevent and control the spread of MBL-encoding genes among bacteria causing infections in cancer patients and other immunocompromised patient populations.

Keywords: Cancer; Carbapenem-resistant Acinetobacter baumannii (CRAB); Metallo-β-lactamase (MBL); Multilocus sequence typing (MLST).