Identification and Characterization of a Bacteriocin from the Newly Isolated Bacillus subtilis HD15 with Inhibitory Effects against Bacillus cereus.

Natural antimicrobial substances are needed as alternatives to synthetic antimicrobials to protect against foodborne pathogens. In this study, a bacteriocin-producing bacterium, Bacillus subtilis HD15, was isolated from doenjang, a traditional Korean fermented soybean paste. We sequenced the complete genome of B. subtilis HD15. This genome size was 4,173,431 bp with a G + C content of of 43.58%, 4,305 genes, and 4,222 protein-coding genes with predicted functions, including a subtilosin A gene cluster. The bacteriocin was purified by ammonium sulfate precipitation, Diethylaminoethanol-Sepharose chromatography, and Sephacryl gel filtration, with 12.4-fold purification and 26.2% yield, respectively. The purified protein had a molecular weight of 3.6 kDa. The N-terminal amino acid sequence showed the highest similarity to Bacillus subtilis 168 subtilosin A (78%) but only 68% similarity to B. tequilensis subtilosin proteins, indicating that the antimicrobial substance isolated from B. subtilis HD15 is a novel bacteriocin related to subtilosin A. The purified protein from B. subtilis HD15 exhibited high antimicrobial activity against Listeria monocytogenes and Bacillus cereus. It showed stable activity in the range 0-70°C and pH 2-10 and was completely inhibited by protease, proteinase K, and pronase E treatment, suggesting that it is a proteinaceous substance. These findings support the potential industrial applications of the novel bacteriocin purified from B. subtilis HD15.

High Hepatitis C Infection Rate Among Baby Boomers in an Urban Primary Care Clinic: Results from the HepTLC Initiative.

OBJECTIVE: CDC recommends that all people born between 1945 and 1965 be tested for hepatitis C virus (HCV). We hypothesized that HCV testing in a large, urban primary care clinic would reveal higher rates of HCV infection than previously published. METHODS: Through the Hepatitis Testing and Linkage to Care initiative, the primary care clinic at MedStar Washington Hospital Center in Washington, DC, provided HCV antibody (anti-HCV) testing and linkage to care from October 2012 through September 2013 for patients born between 1945 and 1965 without previously noted risk factors. We collected data on age, race/ethnicity, sex, anti-HCV and HCV ribonucleic acid (RNA) results, risk factors in those who tested anti-HCV positive, and health insurance type and made comparisons using c(2) and Student's t-tests. RESULTS: Of 1,123 patients tested, the mean age was 57 years, 742 (66.1%) were women, 969 (86.3%) were black/African American, and 654 (58.2%) had public health insurance. Of the 99 (8.8%) patients who tested anti-HCV positive, the mean age was 58 years, 54 were men, and 93 were black/African American; 41 of 74 anti-HCV-positive patients were intravenous drug users. Of 82 anti-HCV-positive patients, 51 were HCV RNA positive. Of the black/African American patients tested, 49 of 317 men (15.5%) and 44 of 652 women (6.7%) were anti-HCV positive (p,0.001). The HCV prevalence rate in the birth cohort (8.8%) was significantly higher than the U.S. (3.3%) and DC (2.5%) rates (p,0.001), and the HCV prevalence rate among black/African American men in DC (15.5%) was substantially higher than the prevalence rate reported by CDC (8.1%). CONCLUSION: Testing initiatives in primary care settings need to be more rigorously upheld, and internal champions are needed to advocate for increased screening to ensure linkage to care and engagement in the HCV care cascade.