Basic And Clinical Study On Cryptococcosis

This study focused on phylogenetic relationships among five serotypes of two varieties of C. neoformans; and management of central nerve system infection of C. neoformans, cutanous and pulmonary cryptococcosis. A preliminary study on construction of recombinant of disruption of Candida albicans calmodulin-encoding gene was done. The whole work was classified into four parts as follows:Part one: Characterization and Sequence Analysis of 28S rDNA of C. neoformansObjective: To investigate genetic relationships among five serotypes of two varieties of C. neoformans. Methods: PCR mediated DGGE (denaturing gradient gel electrophoresis) and sequence analysis of 28S rDNA of C. neoformans were conducted including twenty-one reference strains, C. neoformans capsular-deficient strain CAP 10, and nineteen clinical isolates from non-HTV patients. Results: The results of DGGE and analysis of nucleotide sequences of 28S rDNA showed identical patterns and nucleotide sequences in variety neoformans (serotype A and D, except serotype AD), distinct from those of variety gattii (serotye B and C). The patterns and sequences of serotype AD coincided with those of variety gattii. The patterns and nucleotide sequences of C. neoformans capsular-deficient strain CAP 10(serotype D) and serotype A and D were identical. Of the nineteen clinical isolates, seveteen had patterns of serotype A and D, and the remainders had patterns of serotype B and C. Conclusions: PCR mediated DGGE integrated with sequence analysis of 28S rDNA is a valuable tool for molecular classification of C. neoformans. The clinical isolates of var. neoformans predominated in Chinese non-HTV patients. Serotype AD is genetically close to C. neoformans var. gattii rather than var. neofaormans. The data of this study seems not to be in favor of previous study that serotype A has been considered as var. grubii, a new variety of C. neoformans.Part two: A Retrospective Study on Comparison of Three Atifungal Protocols of Cryptococcal MeningitisObjective: To compare the efficacies of three different antifungal protocols in the treatment of cryptococcal meningitis. Methods: fifty-three consecutive patients with CNS cryptococcal infection were classified as three groups according to the antifungal regimens applied: 8 patients in Group I received intravenous amphotericin B alone or combined with 5-flucytosine, 5 patients in Group II received intravenous fluconazole alone or with 5-flucytosine, and 40 patients in Group III received the two-phase therapy, active therapy and maintenance therapy. In the active therapy, the patients received intrathecal and intravenous administration of amphotericin B alone or with 5-flucytosine until the mycology culture of CSF became negative,followed by oral fluconazole or itraconazole as maintenance therapy until direct microscopic examination of CSF was negative once a week for three consecutive weeks. Results: The results showed that in Group I, five were cured, two improved, one died and one relapsed. In Group II, two were cured, one improved and two died. In Group III, forty except one were cured without recurrence. The differences of therapeutic efficacy between group in and group I and between group III and group II were statistically significant (P<0.005) and (P<0.001) accordingly, but no statistically significant difference was found between group I and group II (P>0.05). Conclusion: These results indicate that the two-phase protocol is suitable for the treatment of non-HTV cryptococcal infection of CNS. Part three: Clinical Analysis of Cutaneous and Pulmonary CryptococcosisObjective: To investigate an appropriate approach of management of cutaneous and pulmonary cryptococcosis. Methods: a retrospective analysis of the cases of cutaneous and pulmonary cryptococcosis among the 58 cases of cryptococcosis hospitalized from 1986-2001 in Shanghai Changzheng Hospital was done. Results: CNS cryptococcal infection accounted for 94.8% (55/58). Pulmonary cryptococcosis for 10.3% (6/58) and 4 out of 6 cases were complicated with CNS cryptococ...