Primary isolation of Candida species from urine specimens using chromogenic medium.

CHROMagar Candida (CaC) is a chromogenic medium that can be used to detect Candida species, including Candida albicans, Candida krusei, Candida tropicalis, and perhaps Candida glabrata. We evaluated the utility of CaC to detect candiduria in high-risk patients and the potential usefulness of this information in directing initial antifungal therapy in those later identified with candidaemia. CaC was compared in parallel to standard laboratory methods (SM) for the detection of Candida from urine collected from high-risk units and wards. Of 893 samples, Candida was recovered by CaC from 104 compared with 35 using SM. No isolates detected by SM were undetected by CaC. More than one Candida species were recovered by CaC in 19 of the 104 (18.3%); only two mixed cultures were detected by SM. The identification was more rapid with CaC. Five of 69 patients with candiduria detected by CaC developed candidaemia on or after the date of urine culture. SM recovered fungus in only two of these patients. CaC can be used as primary media for the detection of Candida species from urine specimens. Primary isolation by CaC may enable clinicians to make earlier, directed selection of antifungal agents and potentially reduce patient morbidity and mortality.

A unique murine monoclonal antibody recognizing HLA-B53, B37, B51, B52, +/-B44.

Monoclonal antibodies have played an important role in studying the biochemistry of the HLA-Class I molecules. Some murine anti-HLA mAbs can identify configurations of HLA epitopes that have never been reported in human allosera. One of these configurations is identified by an IgM mAb designated as: BHA-1441. This antibody was produced using a lymphoblastoid cell line typed as: A*02, A*25; B*38, B*4402/4405; C*0501, C*07, BW4, as the immunogen. A lymphocytotoxicity test of this mAb over a panel of 109 frozen, 452 fresh and, later, 44 DNA typed T cells revealed its specificity as B53, 37, 51, 52, +/- 44. All of the antigens recognized by this mAb share the Bw4 motif at positions 81-83, except for the HLA-B37, which shares only 82L and 83R. Furthermore, while B37 and B44 cross-react due to the aspartic acid (D) substitution at position 156, the reactivity with B53, B5 (51,52), B37 and 60% of B44 cells, makes it unlikely that the target epitope could be due only to the primary amino-acid sequence. The antibody-binding site might involve changes in tertiary structure and peptides bound by the MHC. BHA-1441 is an interesting tool to study and type the HLA-B53 antigen and its cross-reactive epitopes.

A one-step monoclonal antibody typing procedure that simplifies HLA class I and class II typing.

We have developed monoclonal antibodies to most HLA specificities, making it possible for us to devise a simple, rapid, one-step microcytotoxicity test. The test is performed by adding 1 microliter of cells to 1 microliter of antibody-complement mixture predotted on the microtest tray. The reactions are read following a 1-hour incubation period (30 minutes in some instances). The analysis of reactions seen on testing 105 class I antibodies and 50 class II antibodies is shown. A comparison of typing by the standard NIH method and the new one-step procedure showed a > 96% concordance in the 500 T cells and 200 B cells we examined. Class I and class II typing could be performed using B cells, thus obviating the need to isolate both T and B cells for HLA typing.