Usefulness of a microimmunodiffusion test for the detection of Penicillium marneffei antigenemia,antibodies, and exoantigens

Eight sera from culturally-proven cases of penicilliosis marneffei and their corresponding isolates were examined for circulating antibody(ies) and antigen, and exoantigens, respectively, using a microimmunodiffusion (MID) test. Two of the 8 sera produced strong precipitins (1-2) when reacted against control Penicillium marneffei antigen (5-week-old shaken cultures at 25 C) in the presence of control rabbit anti-P. marneffei serum. Five of the 8 sera produced a strong precipitin line when reacted against control hyperimmune serum to P. marneffei. These five sera, and one additional serum, which tested negative for antibody to P. marneffei, demonstrated the presence of antigen by reacting only against the anti-P. marneffei serum. Serological evaluations of the sera revealed that the MID test is capable of detecting antibody and antigen in AIDS patients having penicilliosis marneffei infections. Exoantigen analysis of the 8 P. marneffei isolates, which were previously identified using this conventional and time-consuming macro- and micro-morphological characteristics, showed the presence of 1 to 4 specific exoantigens in MID. With the exoantigen analysis, the identity of all of the isolates was confirmed as P. marneffei. Our studies indicated that the serological tests are useful for detecting circulating antibody and/or antigen in patients' sera, and that the exoantigen test is reliable for confirming the identity of P. marneffei cultures. This revised version was published online in June 2006 with corrections to the Cover Date.     

Antigenic relationships among pathogenic Beauveria bassiana with Engyodontium album (=B. alba) and non-pathogenic species of the genus Beauveria

Exoantigenic extracts of 15 isolates belonging to hyalohyphomycosis-causing Beauveria bassiana (1), and Engyodontium album (1), as well as other species of the genus Beauveria (one isolate each of B. brogniartii, B. densa, B. stephanoderis, B. velata, B. vermiconia and six isolates of unknown Beauveria species) were studied. Aqueous-merthiolated extracts derived from 10-day-old Sabouraud's dextrose agar slant cultures (25 °C) were concentrated (25X), and reacted against rabbit anti-B. bassiana serum in the presence of partially purified homologous antigen (20X) prepared from 5-week-old shaken cultures (30 °C), using a microimmunodiffusion procedure. Beauveria bassiana reference antigen and antiserum reacted to produce four bands of identity. With the exception of E. album, which was negative, extracts of the isolates of B. brogniartii, B. densa, B. stephanoderis, B. velata, B. vermiconia and the unknown Beauveria species all produced 2-4 lines of identity against the homologous anti-B. bassiana serum. These results suggested that all the species of the genus Beauveria tested were antigenically related to B. bassiana. Engyodontium album demonstrated antigenic distinctness, however, from B. bassiana and thus supported the validity of this taxon. This revised version was published online in August 2006 with corrections to the Cover Date.