Oral Candida albicans isolates from HIV-infected individuals in Hong Kong, Australia, Germany and England were characterised using a biotyping system based on enzyme profiles, carbohydrate assimilation patterns and boric acid resistance of the yeasts. A total of 44 biotypes were found amongst the 117 oral C. albicans isolates examined. The major biotype A1R accounted for 17.9% of all isolates while the second commonest biotype was A1S (11.1% of isolates). Whereas these two biotypes were isolated from all the regions studied, there were a number of other biotypes unique to individual countries. The data indicate that there are many different sub-strains of oral C. albicans in HIV-infected patients, some of which are globally prevalent. However, further work is required to ascertain the diversity of oral C. albicans biotypes, if any, in health and disease.
PIP: 11-96% of patients with HIV infection develop oral candidosis at some point during the progression of HIV infection to AIDS. In the early stages of HIV infection, the development of oral candidosis is highly predictive of worsening immunodeficiency. Despite its importance as a sentinel opportunistic infection in HIV disease, however, little is known about the epidemiology of the major etiological agent, Candida albicans, associated with the disease. The authors conducted a study to identify the different biotypes of C. albicans isolated from oral samples of HIV-infected patients from Hong Kong, Australia, Germany, and England, and to gain insight into their geographic distribution. 33 isolates from Hong Kong, 37 from Australia, 30 from Germany, and 17 from England were characterized using a biotyping system based upon enzyme profiles, carbohydrate assimilation patterns, and boric acid resistance of the yeasts. 44 biotypes were identified. A1R and A1S were the two major biotypes, accounting for 17.9% and 11.1% of all isolates, respectively, isolated from all the regions studied. Some other biotypes were unique to individual countries. This study therefore found that there are many different sub-strains of oral Candida albicans in HIV-infected patients, some of which are globally prevalent.