Antimicrobial Susceptibility of Community and Hospital Acquired Bacteria
Somwang Danchaivijitr MD*, Chertsak Dhiraputra MD**, Yong Rongrungruang MD*, Malai Worajitr PhD***, Duangporn Jintanothaitavorn MSc****
Affiliation : *Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, **Department of Microbiology, Faculty of Medicine Siriraj Hospital, ***Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, ****Center for Nosocomial Infection Control, Faculty of Medicine Siriraj Hospital
Objectives : To study the antibiotic susceptibility of common community- and hospital-acquired bacteria in
Thailand.
Materials and Methods : Eight common bacterial pathogens were studied in 24 hospitals across Thailand in
2002-2003. Isolates of clinically proven infections were tested for their susceptibility by agar-based disc
diffusion method.
Results : A total of 9,091 isolates of target bacteria were studied. Community and hospital acquired bacteria
accounted for 54.9% and 45.1% respectively. Community acquired Escherichia coli, Klebsiella pneumoniae,
Acinetobacter spp., Enterobacter spp., Staphylococcus aureus were more susceptible to antimicrobials com-
pared to hospital acquired strains. The difference in susceptibility of community-acquired vs hospital ac-
quired Pseudomonas aeruginosa, Coagulase-negative staphylococci and Enterococcus spp. was less impres-
sive indicating the spread of hospital strains into the community. Bacteria isolated from the blood stream were
more susceptible to antimicrobials compared to those from the lower respiratory tract, urinary tract and
surgical sites. Acinetobacter spp. and Enterococcus spp. were less susceptible to antimicrobials compared to
others.
Conclusion : Decreased susceptibility to antimicrobials was found in all bacteria tested. The susceptibility to
commonly used antimicrobials of community-acquired bacteria decreased to a critical level indicating the
widespread resistant bacteria to the community.
Keywords : Antimicrobial susceptibility, Community-acquired bacteria, Hospital-acquired bacteria
