Genotype And Homology Analysis Of Beta-lactamase In Isolates Of Acinetobacter Baumannii

Objective To investigate genotypes and homology of beta-lactamases of Acinetobacter baumannii from different departments in the first affiliated hospital of Guangxi Medical University, and evaluate the prevalence of nosocomial infection (NI) with Acinetobacter baumannii.Methods Main genotypes of beta-lactamases were detected by PCR and confirmed by sequence test. The genetic identity was determined by the identical numbers and location of bands showed in products of repetitive extragenic palindromic sequence-based PCR(REP-PCR) [one]. .Results⑴Among 46 strains isolated from patients of the first affiliated hospital of Guangxi Medical University, TEM type of beta-lactamases were found in 25 isolates,PER-positive were observed in 5 isolates, and 6 isolates harboured both TEM and PER genes.⑵4 TEM-positive and 2 PER-positive isolates were selected for DNA sequence test. The results of DNA sequence test suggested that the genotypes were TEM-1-like and PER-1-like respectively. (According to GenBank accession number: EF569590).⑶Genes were detected in 46 isolates by using the repetitive extragenic palindromic sequence-based PCR (REP-PCR) method. The products of REP-PCR were separated into 1~5 bands with size < 2000bp fragments.46 isolates of Acinetobacter baumannii were divided into 20 genotypes according to the genetic identity of different strains in which identical numbers and location of bands were recognized. Among 20 genotypes from different isolates, 16 isolates belonged to type A,4 ones belonged to type C and 4 ones to type E, 3 isolates belonged to type J, each 2 in 6 isolates belonged to type H, B and type K respectively, 1 in 13 strains belonged to the other different types. (4) 16 type A strains were isolated from patients in Emergency ICU , Cardiothoracic ICU, Burn and plastic ward, Nephrology, Orthopedic Trauma and hand surgery, respiratory, Kidney transplantation, Hepatological surgery department and paediatrics ICU. 4 type C strains were from patients in department of Neurology, Neurosurgery and Respiratory Medicine. The other 4 type E ones were from patients in Cardiothoracic Surgery ICU, department of Gastrointesterology Surgery and Traditional Chinese Medicine. 3 type J strains were from patients in paediatrics ICU. Those strains belonged to type B, K, and type H were from patients in department of Respiratory Medicine,Orthopedic Trauma and hand surgery and Neurosurgery. The rest strains were distributed in in other different departments.Conclusions⑴TEM type of beta-lactamase is the main genotype of Acinetobacter baumanii, Some isolates were PER-positive beta-lactamase. The others harboured both TEM and PER type.⑵The results of DNA sequence test suggested that the genotypes were TEM-1-like and PER-1-like respectively.⑶46 strains of Acinetobacter baumannii were divided into 20 genetypes. Among 20 genotypes from different isolates, 16 isolates belonged to type A,4 ones belonged to type C and 4 ones to type E, 3 isolates belonged to type J, each 2 in 6 isolates belonged to type H, B and type K respectively, 1 in 13 strains belonged to the other different types. Type A was the main genotype of Acinetobacter baumanii. The rest were scattered in different departments.