Analysis Of The Disinfectant Resistant Gene And The Homology In Acinetobacter Baumannii Of Clinical Isolated

bjective: To investigate the clinical distribution, carbapenemase carrying states and the drug-resistant features to the 133 strains of Acinetobacter baumannii witch were isolated from the first affiliated hospital of Sichuan medical university and the first People’s hospital of Zigong from October 2013 to August 2014, and then provide scientific basis to the clinical use of antibiotics. To analyze the disinfectant resistant gene of qac E?1 in Acinetobacter baumannii clinical isolated, and provide experimental evidence for the prevention and control of nosocomial infection. Meanwhile, to analysis the molecular epidemiology of carbapenemase-positive Acinetobacter baumannii witch were isolated from the first affiliated hospital of Sichuan medical university and the first People’s hospital of Zigong. Methods: From October 2013 to August 2014, a total of 133 strains of Acinetobacter baumannii were collected in the two hospitals. To analysis the clinical distribution and test the carbapenemase phenotype by the modified Hodge test, then divide all strains into carbapenemase-positive group and carbapenemase-negative group. Bacterial susceptibility test were performed by Micro Scan Walk Away 96 Plus automated system, and then the sensitivity results of 18 commonly used antibiotics were obtained. The disinfectant resistant gene of qac E?1 was amplified by polymerase chain reaction(PCR), and then to compare whether there were differences between the carbapenemase-positive group and carbapenemase-negative group. At the same time, to select one positive strain of qac E?1 gene randomly to be sequenced. The molecular epidemiology characteristic of the carbapenemase-positive group was studied by repetitive element PCR(rep-PCR). Results: 133 strains of Acinetobacter baumannii were mainly isolated from sputum specimens, accounting for 73.7%, followed bysecretion samples, accounting for 13.5%. The department distribution was mainly in the intensive care unit(ICU) of 56 strains, accounting for 42.1%, followed by respiratory department of 27 strains, accounting for 20.3%. The modified Hodge test divided all strains into two groups, carbapenemase-positive group of 97 strains, carbapenemase-negative group of 36 strains. Except cefoperazone/sulbactam and sulfamethoxazole with lower resistant rate of 29.3% and 35.3%, the rest of 16 kinds of antibiotics showed widespread resistance. Among 133 strains of Acinetobacter baumannii, there were 112 strains carrying qac E?1 gene, and the total positive rate was 84.2%. While in the carbapenemase-positive and carbapenemase-negtive groups, there were 84 and 28 strains carrying qac E?1 gene, with the positive rate of 86.6% and 77.8% respectively, and there were no significant differences between the two groups(P>0.05). The comparison of the sequencing result and the corresponding sequence on Gene Bank was 98% in similarity. Acinetobacter baumannii of carbapenemase-positive group were divided into 4 genotypes by rep-PCR, and 66 strains were classified as type A which was the major epidemic clones. Conclusions:1.The respiratory tract was the main way of Acinetobacter baumannii infection in clinical, and there was a trend of concentration in department obviously. 2. Acinetobacter baumannii of clinical isolates were resistant to variety of antibiotics except cefoperazone/sulbactam, and the situation of drug resistance was serious. 3. The detection rate of disinfectant resistant gene of qac E?1 was high in the affiliated hospital of Luzhou medical college and the first People’s hospital of Zigong, and there were no significant differences between the carbapenemase-positive group and the carbapenemase-negative group. 4. The main prevalent genotype of the carbapenemase-positive strains was type A.