Study On The Isolation, Cultivation And Drug Sensitivity Test Of Pathogenic Bacteria Of Tinea Unguium

objective: To collect the tinea unguium samples from different areas and in different stages in Qingdao region. We discriminated and identified the strains of the fungi caused the disease through cultivations and tests under microscope. Thus we can select the ideal methods of the isolation, cultivation and identification of the fungi and also get the message of the distribution characters and the strain diversities of pathogenic bacteria of tinea unguium in this region. Also we determined the MIC (minimum inhibitory concentration) of terbinafine HCl against the fungi by using M38-A proposal recommend by NCCLS. Thus our study can guide the prevention and treatment of the disease in clinical. Methods: This study included 120 cases of toenail onychomycosis with age from 18 to 70 years old (mean age: 38 years old). The samples were collected in different stages of onychomycosis and from different districts of Qingdao region (eight departments of dermatology in different hospitals) and the samples were randomly divided into eight groups(A, B₁, B₂, C₁, C₂, D₁, D₂ and E groups. We used the KOH methods of microscope combined with mycosel and PDA methods to isolation the tinea unguium. And then we cultured the fungi using flat plate and microculture methods. At the same time, we identified the fungi by comparing them with standard fungi strains. Also we determined the MIC (minimum inhibitory concentration) of terbinafine HCl against the fungi obtained from clinical samples by using M38-A proposal recommend by NCCLS. Results: We isolated and culture 4 kinds of different strains of tinea unguium from 120 cases of toenail onychomycosis. They were trichophyton rubrum, tinea barbae trichophyta, rpidermophyton floccosum and xulan trichophyta with percentages of 62.5%, 22.5%, 9.2% and 5.8% respectively. And terbinafine effectively inhibited all the fungi tested. Conclusion: Our results indicated that the isolation and cultivation method in this study increase the detection rate of the clinical tinea unguium. Trichophyton rubrum is the main pathogenic bacteria of tinea unguium in Qingdao region. On the other hand, xulan trichophyta is the most seldom cause of the disease. This is consistent with the other regions of China. And our MIC results may help to establish standard protocol in susceptibility test on trichophyton rubrum, tinea barbae trichophyta andpidermophyton floccosum. And this may instruct the clinical treatment and new drug evaluation.