دراسة جزيئية للجينات البيتا - لاكتاميز في بكتريا Acinetobacter baumannii المقاومة للمضادات الكاربابينيم == Molecular Study of ? - lactamase Genes in Carbapenem Resistant Acienetobacter baumannii (CRAB)
Author name:
ربيع عبد الاله مجيد عبد علي الهنداوي
Supervisor name:
ايمان محمد جار الله
General topic:
Biology
Specific topic:
Life Science
Degree:
Doctorate
University:
University of Babylon - College Of Science - Department Of Biology
Language:
English
University location:
Babylon
First pages:
24T3515 - p.pdf
Abstract:
During the period between April 2016 and January 2017, a total of 1100 clinical specimens (burns, wounds, throat, urine, blood) were collected from two hospitals in Babylon province Al - Hillah Teaching Hospital and Medical City of Mirjan Hospital. All specimens were cultured and 17 Acinetobacter baumannii isolates were obtained from clinical specimens in a percentage of (1.5%) distributed in burn 11 (2.8%), wound 1 (0.6%), throat 1 (2%), urine 3 (0.7%) and blood 1 (0.9%).This study was conducted to determine the presence of carbapenem resistance Acinetobacter baumannii (CRAB) isolates and the prevalence of β - lactamase genes responsible for carbapenem - resistance among clinical isolates of A. baumannii collected from two hospitals in Hillah City. Isolates were identified according to VITEK2 system. Antibiotics susceptibility was assayed by using disks diffusion method according to CLSI recommendations and it’s found 8 isolates was carbapenem resistant.The eight CRAB isolates were tested for biofilm formation by using the tube adherence test and the results showed that 5 of 8 tested isolates (62.5%) were strong for biofilm formation. Two genes related to biofilm formation was investigated (bap & blaPER - 1 genes). Six isolates were positive for the bap gene (75 %) and no isolates had positive for blaPER - 1 gene. The eight CRAB isolates were tested also for the presence of two virulence factor genes include espA (K1 capsular polysaccharide) and ompA (outer membrane protein A), this detection was performed by the conventional PCR technique. The positive result for espA and ompA genes was (62.5%) and (75%) respectively.IIPhenotypic detection of carbapenemase production was performed using the imipenem - EDTA disk and modified Hodge's test (MHT). Then isolates were subjected to monoplex PCR targeting blaCTX, blaTEM, BlaSHV, blaIMP, blaVIM, blaSPM, NDM - 1, NDM - 2, AmpC, OXA - 23, OXA - 24, OXA - 48, OXA - 51, OXA - 58 and OXA - 235 genes, all CRAB isolate gave positive result with MHT and (50%) of these isolates were positive to the imipenem - EDTA disk. PCR experiments showed ; all CRAB isolates were harbored blaOXA - 51 gene, six (75%) isolates were harbored blaCTX gene, four (100%) isolates were harbored blaTEM gene, four (50%) isolates were harbored blaVIM gene, four (50%) isolates were harbored blaSPM gene, seven (87.5%) isolates were harbored NDM - 2 gene, seven (87.5%) isolates were harbored ampC gene, six (75%) isolates were harbored OXA - 23 gene, one (12.5%) isolates were harbored OXA - 24 gene, two (25%) isolates were harbored OXA - 48 gene and one (12.5%) isolates were harbored OXA - 235 gene, while none of these isolates harbored BlaSHV, blaIMP, NDM - 1, NDM - 2 genes. All isolates of A. baumannii appear as MDR, while two isolates appear to be as XDR.These results revealed that CRAB isolates constitute 47% of all A. baumannii that had been isolated from Al - Hillah Teaching Hospital and Medical City of Mirjan Hospital in Babylon province and some of carbapenemase were detected in both phenotypic and genotypic methods (PCR). This underlies the importance of their accurate identifications and reporting to prevent the emergence of complete resistance to the most potent drugs against A. baumannii in Babylon province.
