One hundred strains of Haemophilus ducreyi isolated in Thailand from patients with chancroid were tested by the agar dilution method against 10 antimicrobial agents and typed by outer membrane protein pattern by using sodium dodecyl sulfate gel electrophoresis. All strains produced beta-lactamase and were resistant to tetracycline, kanamycin, and sulfonamides. Most had a decreased susceptibility to trimethoprim (MIC for 50% of the strains [MIC50], 0.5 ,ig/ml) and chloramphenicol (MIC50, 8 ,ug/ml). Strains were susceptible to ciprofloxacin (MIC90, 0.001 ,ug/ml), ceftriaxone (MIC50, 0.0015 ,ug/ml), erythromycin (MIC50, 0.015 ,ug/ml), rosoxacin (MIC50, 0.03 ,ig/ml), and spectinomycin (MIC50, 8 ,ug/ml). The degree of antimicrobial resistance found in Thailand is higher than that reported for H. ducreyi isolated in other regions. Five different outer membrane protein patterns were found by analyzing proteins in the range of 29 to 61 kilodaltons, but 98% of the Thai strains fell into three patterns which did not differ greatly. Outer membrane protein patterns of Thai strains were also seen in strains from other geographic areas. A new outer membrane protein type was found among nine strains isolated in Singapore.
A new paper enzyme-linked immunosorbent assay was developed for the screening and titration of human serum antibodies against the scrub typhus rickettsia, Rickettsia tsutsugamushi. The objetive was to provide a relatively simple method for antibody screening which required neither sophisticated laboratory equipment nor a high degree of technological skill. The technique develops an enzyme product from filter paper saturated with a 5-aminosalicylic acid substrate and enzymatically reacted with a commerically available anti-human immunoglobulin G peroxidase conjugate. The product of the enzymatic reaction can be interpreted visually. Comparison of 351 human sera tested by the immunofluorescent and paper enzyme-linked immunosorbent assays against a three-antigen pool of the Karp, Kato, and Gilliam strains of R. tsutsugamushi demonstrated an agreement of 96%. The sensitivity of the paper enzyme-linked immunosorbent assay as compared to immunofluorescence was 98.2%, and the specificity was 94.4%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.