ABSTRACT
OBJECTIVE: The blaOXA resistance genes and ISAba1 were examined in 70 samples from lower respiratory tract of hospitalized patients. MATERIALS AND METHODS: Of the 67 isolates obtained, almost half (46.3%) of them were from endotracheal aspirate, and most were collected from the intensive care units of the reanimation (37.3%) and internal medicine (32.8%) units. RESULTS: Three samples from the internal medicine intensive care unit had positive cultures. Of the multidrug resistant (MDR) samples, 70 isolates (>50%) were moderately sensitive, while fewer (10%) were resistant to tigecycline. In contrast, 100% were sensitive to colistin. All strains were found to be positive for blaOXA-23-like and blaOXA-51-like genes, whereas no blaOXA-40-like and blaOXA-58-like genes were detected. The ISAba1 positivity rate was 90.0%. Pattern 5 was mainly identified among the 22 different patterns. Of note, 50% of Pattern 5 was found in the patients of the internal medicine intensive care unit, and a third was associated with ventilator-associated pneumonia. Importantly, the internal medicine unit's equipment was found to be culture positive. CONCLUSION: Findings obtained from this study suggest that isolates can easily spread through the hospital via isolate cross-contamination caused by health personnel. These contaminating isolates may be able to maintain their presence within the hospital for a long time.
Subject(s)
Acinetobacter Infections/drug therapy , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Anti-Bacterial Agents/pharmacology , Drug Resistance, Multiple, Bacterial/genetics , beta-Lactamases/genetics , Acinetobacter Infections/microbiology , Acinetobacter baumannii/drug effects , Adult , Aged , Aged, 80 and over , Bacterial Proteins/genetics , Colistin/pharmacology , DNA, Bacterial/genetics , Drug Resistance, Multiple, Bacterial/drug effects , Female , Genes, Bacterial , Humans , Intensive Care Units , Male , Microbial Sensitivity Tests , Middle Aged , Molecular Typing , Multiplex Polymerase Chain Reaction , Tertiary Care CentersABSTRACT
We determined the antibiotic susceptibility and genetic mechanisms of resistance in clinical strains of Acinetobacter baumannii from Istanbul, Turkey. A total of 101 clinical strains were collected between November 2011 and July 2012. Antimicrobial susceptibility was performed using the Vitek 2 Compact system and E-test. Multiplex PCR was used for detecting bla(OXA -51-like), bla(OXA -23-like), bla(OXA -40-like) and bla(OXA -58-like) genes. ISAba1, bla(IMP -like), bla(VIM -like), bla(GES), bla(VEB), bla(PER -2), aac-3-Ia and aac-6'-Ib and NDM-1 genes were detected by PCR and sequencing. By multiplex PCR, all strains were positive for bla(OXA -51), 79 strains carried bla(OXA -23) and one strain carried bla(OXA -40). bla(OXA -51) and bla(OXA -23) were found together in 79 strains. ISAba1 element was detected in 81 strains, and in all cases it was found upstream of blaOXA -51 . GES-type carbapenemases were found in 24 strains (GES-11 in 16 strains and GES-22 in 8 strains) while bla(PER -2), bla(VEB -1), bla(NDM -1), blaIMP - and blaVIM -type carbapenemases were not observed. Aminoglycoside modifying enzyme (aac-3-Ia and aac-6'Ib) genes were detected in 13 and 15 strains, respectively. Ninety-seven (96%) A. baumannii strains were defined as MDR and of these, 98% were extensively drug resistant (sensitive only to colistin). Colistin remains the only active compound against all clinical strains. As seen in other regions, OXA-type carbapenemases, with or without an upstream ISAba1, predominate but GES-type carbapenemases also appear to have a significant presence. REP-PCR analysis was performed for molecular typing and all strains were collected into 12 different groups. To our knowledge, this is the first report of GES-11 and OXA-40 in A. baumannii from Turkey.
