Improved antibiotic susceptibility test of Orientia tsutsugamushi by flow cytometry using monoclonal antibody.
Orientia tsutsugamushi causes scrub typhus, which is endemic in many countries in the Asia-Pacific region including Korea. Recent emergence of doxycycline-resistant strains from Thailand has underlined the importance of the susceptibility tests of O. tsutsugamushi to antibiotics. To improve the flow cytometric technique for the susceptibility test, we applied a monoclonal antibody (MAb) in the quantification of O. tsutsugamushi. With using MAb FS15, we determined the doxycycline susceptibility of two strains, Boryong and AFSC-4 strain which is reported to be doxycycline-sensitive and resistant, respectively. The growth of both strains was inhibited to below 10% of the control in the presence of 0.1 microg/mL or higher concentrations of doxycycline. We suggest that our approach is more quantitative and reproducible than the conventional microscopic methods.
Kim
Mi-Jeong
MJ
Department of Microbiology, Center for Advanced Medical Education by BK21 Project, Inha University College of Medicine, Incheon, Korea.
Kim
Mee-Kyung
MK
Kang
Jae-Seung
JS
D000911:Antibodies, Monoclonal / Q000276:immunology*; D005434:Flow Cytometry / Q000379:methods*; D008826:Microbial Sensitivity Tests / Q000379:methods*; D012285:Orientia tsutsugamushi / Q000187:drug effects* / Q000254:growth & development
D000911:Antibodies, Monoclonal