Anaerobic RSH-dependent tellurite reduction contributes to Escherichia coli tolerance against tellurite

BACKGROUND: Tellurium is a rare metalloid that exerts high toxicity on cells, especially on bacteria, partly due to reactive oxygen species (ROS) generation. Moreover, it has also been observed that tellurite can target free cell thiols groups (RSH) (i.e. reduced glutathione (GSH)), enhancing the cellular redox imbalance. Additionally, in vitro experiments have suggested that several enzymes can reduce tellurite (IV) to its elemental form (0); where RSH present on their active sites may be responsible for the process. Nevertheless, the mechanisms implemented by bacteria for tellurite reduction and its role in resistance have not been evaluated in vivo. RESULTS: This work shows that tellurite reduction to elemental tellurium is increased under anaerobic conditions in E. coli cells. The in vivo tellurite reduction is related to the intracellular concentration of total RSH, in the presence and absence of oxygen. This metabolization of tellurite directly contributes to the resistance of the bacteria to the oxyanion. CONCLUSIONS: We demonstrated that in vivo tellurite reduction is related to the intracellular thiol concentration, i.e. large availability of cellular RSH groups, results in a more significant reduction of tellurite. Furthermore, we observed that, when the bacterium exhibits less resistance to the oxyanion, a decreased tellurite reduction was seen, affecting the growth fitness. Together, these results let us propose that tellurite reduction and the intracellular RSH content are related to the oxyanion bacterial resistance, this tripartite mechanism in an oxygen independent anaerobic process.

Biosocial and awareness profile of adolescent clients and utilization patterns of the services at an ARSH clinic at Patna, Bihar

Background: Adolescents constitute about 21% of India’s population. Realizing the special needs of adolescents, GOI launched the adolescent reproductive and sexual health (ARSH) program in 2006. ‘Yuva’ clinic was established for the first time in Bihar in 2012 at Patna Medical College for providing services as per ARSH protocols. This study aimed at analyzing the biosocial and awareness profile of the adolescent clients vis a vis ARSH strategy, and the utilization of services at the clinic.Methods: Cross-sectional study using semi-structured questionnaire.Results: Total of 1180 adolescents (950 males, 230 females) was studied. Sixty-six percent males, 74.8% females were urban; about 90% were unmarried. Majority were from upper middle class. No females but 66.6% and 86.7% of males were taking alcohol and tobacco respectively. More than 90% of attendees reported regular physical exercise; 36.8% males and 58% females had abnormal BMIs. Seventy-six percent were nutritionally aware, 24.06% aware about reproductive and sexual health (RSH), and 64.74% about ARSH services. Rural and SES were significantly associated with the adolescents’ awareness of nutrition, RSH, and services available. Females had significantly more knowledge regarding RSH. Sixty-seven percent availed counseling services and 1.35% was referred, 50.6% came for clinical services out of which 69.8% remained unmet.Conclusions: ARSH clinic is a useful initiative. However there are gaps in services vis-a-vis ARSH strategies. If addressed, clinic is likely to attract more adolescents and achieve the objectives of improving their health and capacity to deal with their myriad problems in a better wa