Filmy residue, or "soap scum", on household shower curtains may be a breeding ground for potentially harmful bacteria say researchers from San Diego State University, California, University of Colorado at Boulder, and Washington University in St. Louis, Missouri. Their findings appear in the July 2004 issue of the journal Applied and Environmental Microbiology.
"One household environment that potentially accumulates microbial biofilms is that provided by vinyl shower curtains. Over time, vinyl shower curtains accumulate films, commonly referred to as "soap scum," which microscopy reveals are constituted of lush microbial biofilms," say the researchers.
In the study DNA samples were taken from four vinyl shower curtains in different homes. A broad range of RNA gene sequences were revealed with Sphingomonas spp. and Methylobacterium spp. appearing as the most prominent, both of which are considered to be opportunistic pathogens commonly associated with water reservoirs.
"These results show that shower curtains are a potential source of opportunistic pathogens associated with biofilms," say the researchers. "Frequent cleaning or disposal of shower curtains is indicated, particularly in households with immune-compromised individuals."
(S.T. Kelley, U. Theisen, L.T. Angenent, A. St. Amand, N.R. Pace. 2004. Molecular analysis of shower curtain biofilm microbes. Applied and Environmental Microbiology, 70. 7: 4187-4192.)
New Oral Vaccine May Offer Protection Against Respiratory Disease and Potential Biowarfare Agent
A new experimental vaccine may protect against brucellosis in humans say researchers from Washington, DC and Silver Spring, Maryland. Their findings appear in the July 2004 issue of the journal Infection and Immunity.
Brucella abortus, B. melitensis, and B. suis, the causative agents of brucellosis in humans, are commonly acquired from infected animal products via inhalation, ingestion or traumatized skin. Although fairly well contained in the United States, systemic infection can cause serious respiratory problems and poses great risk of morbidity worldwide. Additionally, Brucella species are acknowledged by the Centers for Disease Control as bioterror threat agents.
"A human vaccine would be valuable for individuals who may be occupationally exposed to brucellae and for persons who consume unpasteurized diary products from areas in which brucellae are endemic," say the researchers.
In the study mice were administered a live oral vaccine containing B. melitensis WR201 bacteria and challenged intranasally with B. melitensis 16M bacteria. Results showed that immunized mice were protected from infection and their lungs remained clear of bacteria.
"We show that levels of strain WR201 are attenuated relative to strain 16M levels when administered orally and induces cellular, humoral, and mucosal immune responses," say the researchers. "These results establish the usefulness of oral vaccination against respiratory challenge with virulent Brucella and suggest that WR201 should be further investigated as a vaccine to prevent human brucellosis."
(M.J. Izadjoo, A.K. Bhattacharjee, C.M. Paranavitana, T.L. Hadfield, D.L. Hoover. 2004. Oral vaccination with Brucella melitensis WR201 protects mice against intranasal challenge with virulent Brucella melitensis 16M. Infection and Immunity, 72. 7: 4031-4039.)
New Patch May Enhance Effects of Flu Virus Vaccine in Aging Population
Researchers from Maryland have developed a patch designed to stimulate the immune system and enhance the effectiveness of the injected flu vaccine. Their findings appear in the July 2004 issue of the Journal of Virology.
The elderly population is one of the groups hardest hit during outbreaks of infectious diseases, such as influenza, due to a decrease in immune system function with age. High mortality rates in humans over the age of sixty-five continue to challenge vaccinologists to explore new means of improving immune responses to the flu virus vaccine.
"During influenza epidemics, the rate of hospitalization in the elderly is high, with up to a 90% mortality rate," say the researchers.
LT-IS, an immunostimulating patch containing the enterotoxin Escherichia coli, is to be applied directly over the flu vaccine injection site. In the study young and old mice were administered the flu virus vaccine, after which some were treated with LT-IS for a period of eighteen hours. Both age groups showed an enhanced antibody response to the vaccine after wearing the patch, while the older mice that received the patch in addition to the vaccine showed responses equal to or greater than that of young mice receiving only the vaccine.
"These results suggest that addition of an LT-IS patch may compensate for the deficient immune function seen in the aged in response to influenza virus vaccination," say the researchers. "Therefore, use of an LT-IS patch could be a new, safe, and simple immunization strategy that may significantly improve the outcome of influenza virus vaccination in the elderly."
(M. Guebre-Xabier, S.A. Hammond, L.R. Ellingsworth, G.M. Glenn. 2004. Immunostimulant patch enhances immune responses to influenza virus vaccine in aged mice. Journal of Virology, 78. 14: 7610-7618.)