Antifungal Susceptibility Study Of Penicillium Marneffei In Vitro Between The Wild-Rhizomys Pruinosus Isolates And Clinical Isolates In Guangxi

Objective In order to provide a theoretical reference for the choice of clinical treatment to Penicilliosis marneffei(PSM) with efficient and low toxici- ty antifungal drugs,and then analyz the relevance of Penicillium marneffei(PM) between the isolates from wild-Rhizomys and clinical patients base on the expe- riment results. These provide a theoretical reference for the studies of the trans- mission and pathogenesis of PSM.Method According to the M27-A2 and M38-A programs promulgated by Clinical and Laboratory Standards Institute(CLSI formerly the NCCLS),an antifungal drug susceptibility test in vitro had been conducted for the mycelial forms(25°C) and yeast forms (37°C) of PM between fourteen wild-Rhizomys isolates and twenty-five clinical isolates with the new antifungal drugs voricon- azole(VCZ) and the commonly used antifungal drugs just like Itraconazole (ICZ),fluconazole (FCZ),terbinafine (TBF) and amphotericin B (AMB). We measured the minimum inhibitory concentration (MIC) of each drug on both the mycelial and yeast forms of the two different source isolates respectively,and then compared the MICs of one drug for the wild-Rhizomys isolates and clinical isolates in same forms,and compared the MICs of the same drug for the yeast and mycelial forms of the same isolates.Base on the comparison,we analy- zed the difference of the susceptibility of new antifungal drug VCZ and the other four commonly used antifungal drugs, and analyzed the relevance of the wild-Rhizomys isolates and clinical isolates.Furthermore,we discussed the relat- ionnship of the results of antifungal susceptibility test of twenty-five clinical isolates in yeast forms and the treatment of the twenty-five corresponding patie- nts, and base on these we analyzed the clinical significance of the antifungal susceptibility test in vitro.Results:(1) The MICs of new antifungal drug VCZ for the two different source isolates were the lowest one in the five drugs used in the experiment,and the MICs of commonly used antifungal drugs ICZ and TBF were lower than AMB and FCZ, but higher than VCZ, the highest FCZ, Intermediated AMB; (2) There were not exactly different between the MICs of the same drugs for clinic- al isolates and wild-Rhizomys isolates under the same temperature, P>0.05; (3)The MICs of the same drug for the yeast and mycelial forms of the same isolate were not exactly the same; (4)The results of antifungal susceptibility test of twenty-five clinical isolates in yeast forms and the treatment of the twenty-fi ve corresponding patients were not exactly the same.Conclusions :(1) The PM of clinical and wild-Rhizomys isolates both are the most susceptible to VCZ in the experiment,and the two different source iso- lates also show greater susceptibilities to ICZ and TBF than to AMB and FCZ, while AMB moderately sensitive,and FCZ less sensitive; (2) Under the same temperature,the two different source isolates show greater similar susceptibiliti- es to the same antifungal drug, and this indicate the two different source isolates may have some possible relevance; (3) The PM yeast and mycelial forms display not exactly the same susceptibilities to the same antifungal drugs, this indicat the sensitivity of PM to the same antifungal drugs will be affected when their forms changed; (4) The results of antifungal susceptibility test in vitro are only the theoretical reference for the choice of clinical treatment to PSM .