The antibacterial effect of topical ozone on the treatment of MRSA skin infection.

Skin can be infected by many types of microorganisms, most commonly by gram­positive strains of Staphylococcus and Streptococcus spp. Treatment of Staphylococcus aureus (S. aureus) infections, particularly that of methicillin resistant Staphylococcus aureus (MRSA), is a challenge in clinical practice. Ozone therapy has proven to be one of the strongest antiseptics against the majority of microorganisms involved in skin infections. The purpose of the present study was to evaluate the microbicidal effects of topical ozone therapy on S. aureus and MRSA, and determine the clinical efficacy of ozone therapy on patients with MRSA skin infection. Microbicidal effects of ozonated oil and ozonated water were determined by plating and Kirby Bauer methods. Clinical efficacy and safety of topical ozone were evaluated in two cases with skin MRSA infection. The killing rates of ozonated oil for S. aureus and MRSA were greater when compared with the control oil group. Almost 100% of S. aureus were eliminated by ozonated oil following 5 min. Almost 100% MRSA were eliminated by ozonated oil following 15 min. In addition, 100% S. aureus and 100% MRSA were eliminated by ozonated water in 1 min. The inhibition zone diameters of ozonated oil for S. aureus and MRSA were 17 and 13 mm, respectively, which were significantly larger than the control group. Both cases of skin MRSA infection were completely healed with ozone therapy. In conclusion, ozone therapy is a potential treatment for S. aureus and MRSA skin infection as it has great efficacy, few side effects and low­costs.

Epidemiology and Molecular Characterizations of Azole Resistance in Clinical and Environmental Aspergillus fumigatus Isolates from China.

Azole resistance in Aspergillus fumigatus has emerged as a worldwide public health problem. We sought here to demonstrate the occurrence and characteristics of azole resistance in A. fumigatus from different parts of China. A total of 317 clinical and 144 environmental A. fumigatus isolates from 12 provinces were collected and subjected to screening for azole resistance. Antifungal susceptibility, cyp51A gene sequencing, and genotyping were carried out for all suspected azole-resistant isolates and a subset of azole-susceptible isolates. As a result, 8 (2.5%) clinical and 2 (1.4%) environmental A. fumigatus isolates were identified as azole resistant. Five azole-resistant strains exhibit the TR34/L98H mutation, whereas four carry the TR34/L98H/S297T/F495I mutation in the cyp51A gene. Genetic typing and phylogenetic analysis showed that there was a worldwide clonal expansion of the TR34/L98H isolates, while the TR34/L98H/S297T/F495I isolates from China harbored a distinct genetic background with resistant isolates from other countries. High polymorphisms existed in the cyp51A gene that produced amino acid changes among azole-susceptible A. fumigatus isolates, with N248K being the most common mutation. These data suggest that the wide distribution of azole-resistant A. fumigatus might be attributed to the environmental resistance mechanisms in China.

[Association of polymorphism on HLA-DRB1*04 alleles with outcome of hepatitis B virus infection].

OBJECTIVE: To investigate the relation between the alleles of HLA-DRB1*04 and outcome of HBV infection. METHODS: The alleles of HLA-DRB1*04 were detected by polymerase chain reaction-sequence specific primer (PCR-SSP). The frequency of allele of HLA-DRB1*04 in four groups[106 asymptomatic HBsAg carriers (group ASC), 93 chronic hepatitis B patients (group CHB), 77 patients with hepatitis B cirrhosis and 102 cases of spontaneous recovery after HBV infection (control group)] were studied, and the frequency of that in different replication of HBV was also studied. RESULTS: The frequency of allele of HLA-RB1*04 in groups ASC, CHB and hepatitis B cirrhosis was markedly higher than that of control group (25.94%, 26.34%, 27.92% respectively versus 14.22%, P< 0.01); the frequency of HLA-DRB1*0401 in groups ASC, CHB and hepatitis B cirrhosis was also higher than that of control group (20.91%, 24.49%, 22.09% respectively versus 8.62%, P< 0.05, P< 0.01,P< 0.05 respectively); the frequency of HLA-DRB1*0405 in groups ASC, CHB and hepatitis B cirrhosis was lower than that of control group (3.64%, 2.04%, 3.49% respectively versus 15.52%, P< 0.01, P< 0.01, P< 0.05 respectively ). There was no statistical significance in the allele frequency of HLA-DRB1*04 among groups ASC, CHB and hepatitis B cirrhosis (P> 0.05), and the same result was observed in different replication of HBV (P> 0.05). CONCLUSION: HLA-DRB1*04 gene is one of the factors which determine the outcomes of HBV infection, while it has no influence on HBV replication.