[Acceptability and influencing factors of pre-exposure prophylaxis among men who have sex with men in Guangxi].

OBJECTIVE: To study the acceptability of pre-exposure prophylaxis (PrEP) to prevent the transmission of HIV among men who have sex with men (MSM) in Guangxi, China. METHODS: Snow-balling methods were used to recruit 650 MSM in Guangxi. Questionnaires and interview were administrated to these 650 men, using a self-designed questionnaire and face to face interviews to collect information on HIV-related risk behaviors, knowledge and acceptability of PrEP. RESULTS: After an introduction on PrEP by interviewers, followed by as the statement-'If PrEP was effective, safe and free of charge', 597 (91.9%) of the 650 MSM claimed that they would accept it, with the main reason as the recognition of 'PrEP can decrease the risk of HIV infection'. For those who refused to use it, most of them said that were afraid of the side-effect and doubted on the effectiveness of PrEP. Data from logistic regression analysis showed that those who had found partners through friends (OR = 6.21, P = 0.020) and those who would advise his friend to use PrEP (OR = 39.32, P = 0.000) were more likely to accept PrEP. Those who thought they could protect themselves from HIV infection (OR = 0.32, P = 0.010) or not having sex with the ones who refused to use a condom (OR = 0.34, P = 0.010) were less likely to accept PrEP. CONCLUSION: Effectiveness, safety and cost seemed to be the main influential factors related to the acceptability of PrEP. Peer education might improve the acceptability of PrEP.

Expression of a serine protease gene prC is up-regulated by oxidative stress in the fungus Clonostachys rosea: implications for fungal survival.

BACKGROUND: Soil fungi face a variety of environmental stresses such as UV light, high temperature, and heavy metals. Adaptation of gene expression through transcriptional regulation is a key mechanism in fungal response to environmental stress. In Saccharomyces cerevisiae, the transcription factors Msn2/4 induce stress-mediated gene expression by binding to the stress response element. Previous studies have demonstrated that the expression of extracellular proteases is up-regulated in response to heat shock in fungi. However, the physiological significance of regulation of these extracellular proteases by heat shock remains unclear. The nematophagous fungus Clonostachys rosea can secret an extracellular serine protease PrC during the infection of nematodes. Since the promoter of prC has three copies of the stress response element, we investigated the effect of environmental stress on the expression of prC. METHODOLOGY/PRINCIPAL FINDINGS: Our results demonstrated that the expression of prC was up-regulated by oxidants (H(2)O(2) or menadione) and heat shock, most likely through the stress response element. After oxidant treatment or heat shock, the germination of conidia in the wild type strain was significantly higher than that in the prC mutant strain in the presence of nematode cuticle. Interestingly, the addition of nematode cuticle significantly attenuated the production of reactive oxygen species (ROS) induced by oxidants and heat shock in the wild type strain, but not in prC mutant strain. Moreover, low molecule weight (<3 kD) degradation products of nematode cuticle suppressed the inhibitory effect of conidial germination induced by oxidants and heat shock. CONCLUSIONS/SIGNIFICANCE: These results indicate that PrC plays a protective role in oxidative stress in C. rosea. PrC degrades the nematode cuticle to produce degradation products, which in turn offer a protective effect against oxidative stress by scavenging ROS. Our study reveals a novel strategy for fungi to adapt to environmental stress.