Detection of class 1 integron in Acinetobacter baumannii isolates collected from nine hospitals in Turkey

Abstract

ObjectiveTo investigate the antibiotic resistance genes inserted into class 1 and class 2 integrons in Acinetobacter baumannii (A. baumannii) isolates obtained from nine different cities in Turkey. MethodsA collection of 281 A. baumannii clinical isolates were collected from nine diferent state hospitals in Turkey and were confirmed as A. baumannii by conventional biochemical, API testing and bla-OXA-51 specific PCR. The isolates were examined by PCR for existence of class 1 and 2 integron gene cassettes. ResultsThey were characterized by antimicrobial susceptibility testing and the highest resistance rates were determined for piperacillin (90.03%), ciprofloxacin (87.54%), cefepime and trimethoprim/sulfamethoxazole (81.13%). The lowest resistance rates was for cefotaxime (3.55%). class I integrons were detected in 6.4% (18/281) of A. baumannii strains and no class 2 integron was detected. The gene cassettes of class 1 integrons AacC1-AAC(3) I-aadA1, AacC1-aadA1, AAC(3)-I, AAC(3)-I -AAC(3)-I -aadA1, TEM-1, AAC(3)-I-aadA1 – AAC(3)-I -AAC(3)-I, AAC(3)-I -AAC(3)-I -AAC(3)-I -aadA1, AAC(3)-I – aadA1, AAC(3)-I-AAC(3)-I, AAC(3)-I-aadA1-AAC(3)-I-aadA1, AAC(3)-I-AAC(3)-I-aadA1-AAC(3)-I-aadA1 were detected in eighteen strains. The aac genes family were most frequently found integrated into the class 1 integrons and it was followed by aadA genes and TEM-1 genes. ConclusionsThis is an extensive study on the distribution of class 1 integron among A. baumannii in Turkey. In addition to these, two new alleles were observed. Their percentage rates of similarity to other cassettes are 95% aadA1 (TKA18) and 89% aadA1 (ANKA3).