GENOTYPIC CHARACTERIZATION OF ptk GENE ASSOCIATED WITH BIOFILM FORMATION IN THE CLINICAL ISOLATES OF A. baumanni
KAYAL VENNILA MAHENDRAN
Department of Microbiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences [SIMATS], Saveetha University, P. H. Road, Chennai, Tamil Nadu - 600077, India.
A. S. SMILINE GIRIJA
Department of Microbiology, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences [SIMATS], Saveetha University, P. H. Road, Chennai, Tamil Nadu - 600077, India.
VIJAYASHREE J. PRIYADHARSINI
BRULAC, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences [SIMATS], Saveetha University, P.H.Road, Chennai, Tamil Nadu - 600077, India.
*Author to whom correspondence should be addressed.
Abstract
Background: ptk associated biofilm formation in Acinetobacter baumannii elevates the virulence property which in turn is highly influencing the pattern of drug susceptibility among hospitalized patients. This study is thus aimed to molecularly characterize ptk gene and to evaluate its co-occurrence among the multi-drug resistant strains from the clinical isolates of A. baumannii.
Methodology: Semi-quantitative adherent bioassay was performed to detect the formation of biofilm by the 73 MDR strains of A. baumannii. Genomic DNA was eventually extracted and were screened for ptk by a series of Polymerase Chain Reactions (PCR) followed by sequencing of the amplicons obtained from the representative strains.
Results: Biofilm assay reflected the following quantitative results: 58.9%, 31.5% and 0.9% as high grade, low grade and negative biofilm formers respectively. ptk gene was observed in 22 MDR strains (30.1%) of A. baumannii. Co-occurrence of ptk gene was 100% among the β-lactam inhibitor, cephems, carbapenems and aminoglycosides resistant strains which was followed by 90.9% among fluroquinolones, 86.3% among efflux pumps and 95.45% among folate resistant strains of A. baumannii.
Conclusion: The findings of the study suggest that the periodical monitoring of the frequency of ptk associated biofilms in MDR strains of A. baumannii, as a preventive measure. However the study indicates and paves way for further studies in future to monitor its association in variation in the drug resistance pattern among the strains.
Keywords: Genotypic characterization, Acinetobacter baumannii, multi-drug resistant, MDR strains