Open AccessInsights on carbapenem-resistant Pseudomonas aeruginosa
Author(s) -
Márió Gajdács,
Krisztina Kárpáti,
Anette Stájer,
Stefania Anna Lucia Zanetti,
Matthew Gavino Donadu
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.2021.1.105-112
Subject(s) - meropenem , pseudomonas aeruginosa , microbiology and biotechnology , carbapenem , cefepime , imipenem , colistin , broth microdilution , ceftazidime , ertapenem , cloxacillin , ciprofloxacin , aztreonam , antibiotics , minimum inhibitory concentration , biology , antibiotic resistance , bacteria , ampicillin , genetics
Pseudomonas aeruginosa (P. aeruginosa) is ubiquitous in nature, and may be a causative agent in severe, life-threatening infections. In >60% of cases, β-lactam antibiotics are used in the therapy of P. aeruginosa infections, therefore the emergence of carbapenem-resistant P. aeruginosa (CRPA) is a signicant clinical concern. In this study, phenotypic methods were used to characterize fty-four (n = 54) P. aeruginosa isolates, which were included based on their suspected non-susceptibility to meropenem. Minimum inhibitory concentrations (MICs) of meropenem, ceftazidime, cefepime, ciprofloxacin, gentamicin, 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). AmpC and eux pump overexpression was studied using agar plates containing cloxacillin and phenylalanine-arginine β-naphthylamide (PAβN), respectively. Assessment of biolm-formation was carried out using the crystal violet tube-adherence method. 38.9% of the strains showed meropenem MICs in the resistant range (>8 mg/L). Eux-pump overexpression and AmpC-hyperproduction was seen in 44.4% and 35.2% of isolates, respectively. 88.8% of the isolates were characterized as strong biolm-producers. On the other hand, the presence of carbapenemases was suspected in a minority (16.7%) of tested isolates. As safe and eective therapeutic options in carbapenem-resistant Gram-negative infections are severely limited, characterization of these isolates using phenotypic and molecular-based methods is important to provide insights into the epidemiological features of these pathogens.