Genetic relatedness and molecular characterization of multi-drug resistant acinetobacter baumannii. (2019)

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dc.contributor.author Makke, Ghiwa
dc.date.accessioned 2019-11-26T10:36:16Z
dc.date.available 2019-11-26T10:36:16Z
dc.date.copyright 2019 en_US
dc.date.issued 2019-11-26
dc.date.submitted 2019-04-01
dc.identifier.uri http://hdl.handle.net/10725/11579
dc.description.abstract Acinetobacter baumannii is a Gram-negative organism associated with a broad range of severe nosocomial infections and linked to prolonged hospital stay of immunocompromised patients. We used whole-genome sequencing (WGS) to characterize 41 isolates of A. baumannii collected from a hospital in Lebanon. Resistance profiles were determined through antibiotic susceptibility testing (AST) and confirmed by the detection of resistance genes in the sequenced genomes. The plasmid content was analyzed both in silico and using the Acinetobacter baumannii – PCR based replicon typing (AB-PBRT) method. Multi-locus sequence typing (MLST), pulsed-field gel electrophoresis (PFGE) and whole-genome SNP analysis were performed to investigate the possibility of an outbreak scenario and the relatedness between the isolates. Most of the isolates (95%; n=39) were resistant to cephalosporins, quinolones, aminoglycosides as well as to carbapenems, and were accordingly classified as being extensive drug resistant (XDR) and were referred to as carbapenem resistant Acinetobacter baumannii (CRAB). in silico analysis revealed the presence of 20 different resistance determinants each conferring resistance to one of the following: minoglycosides, β-lactams, sulfonamides, tetracyclines, or Macrolide-Lincosamide-Streptogramin (MLS). Gr2 (90%; n=37) and Gr6 (70.7%; n=29) plasmids were detected in 93% (n=38) of the isolates. ST- 636 (48.7%; n=20), ST-2 (24.4%; n=10), ST-2-like (21.9%; n=9), ST- 396 (2.5%; n=1) and ST-388 (2.5%; n=1) were the only detected sequence types. All ST-636 isolates carried blaOXA-66 and blaOXA-72, whereas ST-2 and ST-2-like isolates carried blaOXA-66 and blaOXA-23. To our knowledge, this is the first comprehensive wholegenome based characterization of CRAB associated with nosocomial infections in Lebanon, as well as in the Middle East. Our findings revealed that the studied MDR A. baumannii isolates were circulating in the hospital and were linked to two separate outbreaks during the same period infecting several immunocompromised patients and representing a leading cause of mortality. en_US
dc.language.iso en en_US
dc.subject Lebanese American University -- Dissertations en_US
dc.subject Dissertations, Academic en_US
dc.subject Acinetobacter infections en_US
dc.subject Multidrug resistance en_US
dc.subject Acinetobacter -- Molecular aspects en_US
dc.subject Acinetobacter -- Genetic aspects en_US
dc.title Genetic relatedness and molecular characterization of multi-drug resistant acinetobacter baumannii. (2019) en_US
dc.type Thesis en_US
dc.term.submitted Spring en_US
dc.author.degree MS in Molecular Biology en_US
dc.author.school SAS en_US
dc.author.idnumber 201304055 en_US
dc.author.commembers Khalaf, Roy
dc.author.commembers Nawas, Tarek
dc.author.department Natural Sciences en_US
dc.description.embargo 12M en_US
dc.description.physdesc 1 hard copy: xii, 47 leaves: col. ill.; 30 cm. available at RNL. en_US
dc.author.advisor Tokajian, Sima
dc.keywords Acinetobacter baumannii en_US
dc.keywords CRAB en_US
dc.keywords WGS en_US
dc.keywords PFGE en_US
dc.keywords SNPs en_US
dc.keywords Outbreak en_US
dc.description.bibliographiccitations Bibliography: (leaves 37-47). en_US
dc.identifier.doi https://doi.org/10.26756/th.2019.145 en_US
dc.author.email ghiwa.makke@lau.edu.lb en_US
dc.identifier.tou http://libraries.lau.edu.lb/research/laur/terms-of-use/thesis.php en_US
dc.publisher.institution Lebanese American University en_US
dc.author.affiliation Lebanese American University en_US

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