Heterogeneous localisation of membrane proteins in Staphylococcus aureus

The bacterial cytoplasmic membrane is the interface between the cell and its environment, with multiple membrane proteins serving its many functions. However, how these proteins are organised to permit optimal physiological processes is largely unknown. Based on our initial findings that 2 phospholipid biosynthetic enzymes (PlsY and CdsA) localise heterogeneously in the membrane of the bacterium Staphylococcus aureus, we have analysed the localisation of other key membrane proteins. A range of protein fusions were constructed and used in conjunction with quantitative image analysis. Enzymes involved in phospholipid biosynthesis as well as the lipid raft marker FloT exhibited a heterogeneous localisation pattern. However, the secretion associated SecY protein, was more homogeneously distributed in the membrane. A FRET-based system also identified novel colocalisation between phospholipid biosynthesis enzymes and the respiratory protein CydB revealing a likely larger network of partners. PlsY localisation was found to be dose dependent but not to be affected by membrane lipid composition. Disruption of the activity of the essential cell division organiser FtsZ, using the inhibitor PC190723 led to loss of PlsY localisation, revealing a link to cell division and a possible role for FtsZ in functions not strictly associated with septum formation

Uso de álcool e drogas e sua influência sobre as práticas sexuais de adolescentes de Minas Gerais, Brasil Alcohol and illicit drug use and its influence on the sexual behavior of teenagers from Minas Gerais State, Brazil

Os achados provêm de um estudo transversal de 5.981 estudantes de escolas públicas de Minas Gerais, Brasil. Avaliou-se a influência do uso de drogas sobre as práticas sexuais. Dos rapazes com relacionamento casual que referiram ter utilizado drogas ilícitas, 55,7% disseram usar preservativos de forma consistente (em todas as relações sexuais), enquanto entre os que nunca fizeram uso de tais substâncias, esse percentual foi de 65,4%. Entre os rapazes com relacionamento fixo, que utilizaram droga ilícita, o uso consistente de preservativos foi referido por 42,7%, ao passo que, para os que nunca fizeram uso dessas substâncias, esse percentual foi de 64,1%. No subgrupo dos rapazes com parceria fixa que nunca utilizaram drogas ilícitas, o uso consistente do preservativo foi menos freqüente entre os que utilizaram cigarro e/ou álcool do que entre os que não referiram este uso (60,7% vs. 71,1%). As moças apresentaram menor proporção de uso consistente do preservativo do que os rapazes, independentemente do tipo de parceria, sem influência aparente dos padrões de consumo. Os achados sugerem a necessidade de integrar a prevenção do uso de drogas à de infecções sexualmente transmissíveis/gravidez indesejada.<br>This article summarizes the findings of a survey including 5,981 students from public schools in Minas Gerais State, Brazil. The analysis assessed the influence of drug use on sexual practices. Among the boys engaged in relationships with casual partners who stated having used illicit drugs, 55.7% reported consistent condom use, as compared to 65.4% among those not reporting such habits. Among boys engaged in relationships with stable partners who reported illicit drug use, consistent condom use was reported by 42.7%, versus 64.1% among those not reporting such habits. In the subgroup of boys engaged in stable relationships who did not report illicit drug use, consistent condom use was less frequent among those that used alcohol/cigarettes, compared to those who did not drink or smoke (60.7% vs. 71.1%). Girls were less likely than boys to use condoms consistently, regardless of the nature of their relationships, without a noticeable influence of drug use. Policies to prevent drug abuse, sexually transmitted diseases, and unplanned pregnancy should be fully integrated