Antimicrobial Resistance of Acinetobacter baumannii: Six Years of National Antimicrobial Resistance Surveillance Thailand (NARST) Surveillance
Surang Dejsirilert MSc*, Surapee Tiengrim MSc**, Pathom Sawanpanyalert MD, DrPh*, Nalinee Aswapokee MD**, Kumthorn Malathum MD, PhD***
Affiliation : * National Institute of Health, Department of Medical Sciences, Nonthaburi, Thailand ** Unit of Infectious Diseases, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand *** Division of Infectious Diseases, Faculty of Medicine Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
Objective : To determine the prevalence, clinical epidemiology, and antimicrobial susceptibilities of
Acinetobacter baumannii in Thailand from 2000 to 2005.
Material and Method: Twenty-eight hospitals participated in the National Antimicrobial Resistance
Surveillance Thailand program. All data were reviewed and analyzed for the prevalence, clinical epidemiology,
and antimicrobial susceptibilities of the clinical isolates of A. baumannii from 2000 to 2005.
Results : The number of clinical isolates of Acinetobacter spp. increased from 8,699 isolates in 2000 to 14,071
isolates in 2005. The most common species, identified by biochemical and growth characteristics, was A.
baumannii. More than 50% of all isolates were from the respiratory tract specimens. The percentage of
resistance has been increasing, particularly multi-drug-resistant (MDR) or carbapenem-resistant phenotypes.
Of carbapenem-resistant strains, the prevalence was 2.1% and 46.7% in 2000 and 2005, respectively. Most
carbapenem-resistant strains were also MDR. The prevalence of MDR strains was highest in the Central
region and Bangkok. Cefoperazone/sulbactam was the antimicrobial against largest proportion Acinetobacter
spp., although the prevalence of resistance to this agent is on the upward trend.
Conclusion : A standardized technique to identify the organisms to the species level should be determined to
be used in the surveillance system. Because the prevalence of Acinetobacter spp. resistant to multiple classes
of antimicrobials including carbapenems and cefoperazone/sulbactam are increasing, there is an urgent need
for a more active surveillance system, more stringent infection control efforts, and powerful antimicrobial
stewardship programs in all healthcare sectors to minimize the further spread of this MDR strain.
Keywords : Acinetobacter baumannii, Anti-infective agents, Drug resistance, Bacterial, Microbial sensitivity tests, Population surveillance, Thailand
