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Food poisoning outbreaks are commonly caused by bacterial contamination. These incidents can be minimized by using antimicrobial films that are suitable for use as packaging material. These films can be made by immobilizing an antibacterial agent to a non-toxic polymer matrix. Titanium dioxide (TiO2), when irradiated with ultraviolet light, produces free radicals capable of killing bacteria. Sodium alginate (SA) is an edible polymer taken from brown algae. Both TiO2 and SA are approved by the U.S. Food and Drug Administration as an additive in food. Therefore, composites made from SA and TiO2 are considered safe. SA/TiO2 nanocomposite films can be activated by both fluorescent and black light lamps. As evidenced by the percent color removal of methylene blue, the photocatalytic activity appeared to be higher when exposed to black light. SA/TiO2 composite films were exposed to fluorescent and black light lamps for 5 h in the presence of Escherichia coli and Staphylococcus aureus. Under fluorescent lamps, the photocatalytic activity of the SA/TiO2 composite films was enough to at least inhibit the proliferation of both bacteria. However, exposure of the 5% SA/TiO2 composite film to black light resulted to a 0 log count for both bacteria. These results showed that SA/TiO2 composite films can therefore be used in the food industry as an antibacterial film. [ABSTRACT FROM AUTHOR]

[This corrects the article DOI: 10.1371/journal.ppat.1006882.].

Invasive amebic diseases caused by Entamoeba histolytica are increasing among men who have sex with men and co-infection of ameba and HIV-1 is an emerging problem in developed East Asian countries. To characterize the clinical and epidemiological features of invasive amebiasis in HIV-1 patients, the medical records of 170 co-infected cases were analyzed retrospectively, and E. histolytica genotype was assayed in 14 cases. In this series of HIV-1-infected patients, clinical presentation of invasive amebiasis was similar to that described in the normal host. High fever, leukocytosis and high CRP were associated with extraluminal amebic diseases. Two cases died from amebic colitis (resulting in intestinal perforation in one and gastrointestinal bleeding in one), and three cases died from causes unrelated to amebiasis. Treatment with metronidazole or tinidazole was successful in the other 165 cases. Luminal treatment was provided to 83 patients following metronidazole or tinidazole treatment. However, amebiasis recurred in 6 of these, a frequency similar to that seen in patients who did not receive luminal treatment. Recurrence was more frequent in HCV-antibody positive individuals and those who acquired syphilis during the follow-up period. Various genotypes of E. histolytica were identified in 14 patients but there was no correlation between genotype and clinical features. The outcome of metronidazole and tinidazole treatment of uncomplicated amebiasis was excellent even in HIV-1-infected individuals. Luminal treatment following metronidazole or tinidazole treatment does not reduce recurrence of amebiasis in high risk populations probably due to amebic re-infection.