Open AccessInsights on carbapenem-resistant Acinetobacter baumannii
Author(s) -
Matthew Gavino Donadu,
Stefania Anna Lucia Zanetti,
Ádám László Nagy,
Ibrahim Ádám Barrak,
Márió Gajdács
Publication year - 2021
Publication title -
acta biologica szegediensis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.212
H-Index - 28
eISSN - 1588-4082
pISSN - 1588-385X
DOI - 10.14232/abs.2021.1.85-92
Subject(s) - meropenem , acinetobacter baumannii , tigecycline , colistin , broth microdilution , microbiology and biotechnology , carbapenem , imipenem , ertapenem , acinetobacter , levofloxacin , gentamicin , antibiotics , medicine , minimum inhibitory concentration , biology , antibiotic resistance , bacteria , pseudomonas aeruginosa , genetics
Acinetobacter baumannii (A. baumannii) is an important nosocomial pathogen, which may be a causative agent in a wide-range of human pathologies. Carbapenems are usually considered the last safe and eective choice of drugs for the treatment of Gram-negative infections. The emergence of carbapenem-resistant A. baumannii (CRAB) is a critical public health issue as they leave clinicians with limited therapeutic options. In this study, phenotypic methods were used to characterize sixty-two (n = 62) A. baumannii isolates, which were included based on their suspected non-susceptibility to meropenem. Minimum inhibitory concentrations (MICs) of meropenem, levofloxacin, gentamicin, sulfamethoxazole/trimethoprim, tigecycline were determined using E-tests, while colistin MICs were determined using broth microdilution. The isolates were subjected to the modied Hodge test (MHT), the modied carbapenem-inactivation method (mCIM) and the imipenem/EDTA combined disk test (CDT). Eux pump overexpression was studied using agar plates containing phenylalanine-arginine β-naphthylamide (PAβN). Assessment of biolm-formation was carried out using the crystal violet tube-adherence method. 64.5% of the strains showed meropenem MICs in the resistant range (>8 mg/L), resistance rates were similarly high to the other tested antibiotics. The MHT and mCIM assay were positive in 79.0% and 67.7% of cases, respectively; the presence of an MBL was suggested for 29.0% of isolates. Eux-pump overexpression was seen in 12.9% of isolates. 54.8% of the isolates were characterized as strong biolm-producers. Microbiology laboratories have an important role in dierentiating the distinct mechanisms by which these pathogens develop the CRAB phenotype, as plasmid-borne carbapenemases are signicant from the standpoint of public health microbiology.