The antimicrobial mechanism of electrochemically activated water against Pseudomonas aeruginosa and Escherichia coli as determined by SDS-PAGE analysis.

AIMS: To expose bacteria to anolyte and subsequently investigate the effect of anolyte on the protein profiles of treated bacteria. METHODS AND RESULTS: Proteins were extracted from bacteria treated with different concentrations of anolyte and analysed using SDS-PAGE. Fewer and more faint protein bands were observed for concentrated halide anolyte treated bacteria when compared to untreated bacteria while extra protein bands were observed for bacteria exposed to dilute concentrations. CONCLUSIONS: The undiluted and the 10(-1) dilution of halide derived anolyte was effective in killing the test bacteria. Anolyte caused bacterial death by complete destruction of proteins or by causing oxidative stress which resulted in protein fragmentation. SIGNIFICANCE AND IMPACT OF THE STUDY: The results of this study provide information on the antimicrobial mechanism of anolyte on other bacteria for which the information is currently unavailable.

Household contact investigation of multidrug-resistant and extensively drug-resistant tuberculosis in a high HIV prevalence setting.

SETTING: Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) are now a nationwide epidemic in South Africa. Epidemiological data suggest nosocomial transmission as the primary route of spread; however, transmission among household contacts has not yet been investigated. OBJECTIVE: To determine the incidence rates of MDR- and XDR-TB among household contacts of MDR- and XDR-TB index cases diagnosed between January 2005 and September 2008 in a high human immunodeficiency virus prevalence setting. DESIGN: Prospective, observational study evaluating adult household contacts for active TB by culture and drug susceptibility testing at index case diagnosis and again 1 year later. Outcomes were incidence and time to diagnosis of MDR- and XDR-TB. RESULTS: A total of 1766 contacts of 221 MDR-TB and 287 XDR-TB index cases were screened. Of 793 contacts of MDR-TB index cases, 14 (1.8%) were diagnosed with MDR-TB (incidence 1765/100 000); 19 (2.0%) of 973 XDR-TB contacts had XDR-TB (incidence 1952/100 000). Median time to diagnosis of household cases was 70 days (interquartile range 57-89). CONCLUSION: Incidence rates of MDR- and XDR-TB among household contacts were extremely high, with most secondary cases occurring shortly after the diagnosis of the index case. Active case finding of drug-resistant TB is a high-yield public health activity and must be a priority, as early diagnosis may stem further disease spread and improve survival.