title: Imipenem Treatment Induces Expression of Important Genes and Phenotypes in a Resistant Acinetobacter baumannii Isolate.
abstract: Acinetobacter baumannii has emerged as a notorious multidrug-resistant pathogen, and development of novel control measures is of the utmost importance. Understanding the factors that play a role in drug resistance may contribute to the identification of novel therapeutic targets. Pili are essential for A. baumannii adherence to and biofilm formation on abiotic surfaces as well as virulence. In the present study, we found that biofilm formation was significantly induced in an imipenem-resistant (Imp(r)) strain treated with a subinhibitory concentration of antibiotic compared to that in an untreated control and an imipenem-susceptible (Imp(s)) isolate. Using microarray and quantitative PCR analyses, we observed that several genes responsible for the synthesis of type IV pili were significantly upregulated in the Imp(r) but not in the Imp(s) isolate. Notably, this finding is corroborated by an increase in the motility of the Imp(r) strain. Our results suggest that the ability to overproduce colonization factors in response to imipenem treatment confers biological advantage to A. baumannii and may contribute to clinical success.
authors.affiliation: Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia Department of Medical Microbiology, College of Medicine, University of Dammam, Al Khobar, Saudi Arabia a.baumannii@yahoo.com hamimah@ummc.edu.my.
authors.forename: Ghulam Nasser
authors.initials: GN
authors.lastname: Dhabaan
authors.affiliation: Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sazaly
authors.initials: S
authors.lastname: AbuBakar
authors.affiliation: Cluster Biotechnology, Mapleton, Queensland, Australia Biovate, Mapleton, Queensland, Australia.
authors.forename: Gustavo Maia
authors.initials: GM
authors.lastname: Cerqueira
authors.affiliation: Department of Clinical Dentistry, Faculty of Health Sciences, UiT the Arctic University of Norway, Tromsø, Norway.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al-Haroni
authors.affiliation: Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sui Ping
authors.initials: SP
authors.lastname: Pang
authors.affiliation: Tropical Infectious Diseases Research and Education Center, Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia a.baumannii@yahoo.com hamimah@ummc.edu.my.
authors.forename: Hamimah
authors.initials: H
authors.lastname: Hassan
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics*; D036781:Fimbriae Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D015378:Imipenem / Q000008:administration & dosage / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents; D036781:Fimbriae Proteins; D015378:Imipenem