Acinetobacter Baumannii Resistance With Beta Lactamase Gyra Gene Type And The Relationship Between Research

Objective:To collect and analyze Acinetobacter baumanii which cause nosocomial infection from the first affiliated hospital of Shanxi medical university, in order to study the clinical distribution, resistance characteristics and tendency.The correspondence with β-lactamase and β-lactam antibiotic-resistant, gyrA gene type and quinolones antibiotic-resistant from phenotype and genotype to discuss. These can provide references to proper use of antibiotic drugs and prevent broadcasting of resistant strain.Methods:(1) Totally448strains of Acinetobacter baumanii were retrospectively analyzed by clinical laboratory dissociation from the first affiliated hospital of Shanxi medical university of2010. The VITEK-Ⅱ of Biomerieux were used to identified the448strains. Drug sensitivity test was performed by K-B method of CLSI. WHONET5.4software was used to analyze the data.(2)63strains of multidrug resistant Acinetobacter baumanii were collected from the first affiliated hospital of Shanxi medical university of2010. PCR was used to detect β-lactamase and gyrA gene. AmpC enzyme sequence comparisons were made to ATCC17978(GenBank accession no. NC009085) in GenBank. gyrA gene sequence comparisons were made to the wild-type A. baumannii gyrA (GenBank accession no. X82165) in DNAman.Results:(1) In the448strains of A. baumanii, a strain resisting all current antibiotics is noted, besides β-lactam antibiotic which resistant rate is58.5%(except for β-lactamase inhibitors and carbopenems), quinolones antibiotic resistant rate is49%. Pneumology department take a large proportion in all departments and sputum samples have the highest separation rate.(2) In the63strains of multidrug resistant A.baumanii, AmpC enzyme positive rate was66.7%, coincidence rate was96%with ATCC17978in Genbank. TEM-1type and CTX-M type positive rate respectively was96.8%andll.1%. SHV type was not be detected. gyrA gene positive rate was15.9%and all contained synonymous mutations at93codon. The mutation way is CGA→CGT. Amino acid is still arginine.Conclusion:(1) The situation of Acinetobacter baumanii resistance is very seriously in the first affiliated hospital of Shanxi medical university and have spread trend. Pneumology department and Neurology department have a high detection rate. We should strengthen clinical monitoring. Cefoperazone/sulbactam and Minocycline are the most effective antibiotic in our hospital presently.(2) AmpC enzyme and ESBLs TEM-1type play the important role in β-lactam antibiotic-resistant. gyrA gene positive rate is not high and all have synonymous mutations which do not cause mutations effect, this suggests that gyrA gene is not the main reason of quinolones antibiotic-resistant highly in our hospital. We need more experiments to study and discuss others drug resistant mechanism.