Tips from the journals of the American Society for Microbiology

Published: Monday, August 25, 2008 - 21:29 in Health & Medicine

Based Hand Sanitizer May Minimize Viral Transmission, Including Norovirus A newly developed ethanol-based hand sanitizer may significantly impact public health by minimizing the transmission of multiple viruses, including norovirus, from food handlers and care providers. The researchers from the University of Ottawa, Ontario, Canada, and North Carolina State University, Raleigh report their findings in the August 2008 issue of the journal Applied and Environmental Microbiology.

The annual number of food-related infections in the U.S. is an estimated 76 million, with norovirus accounting for up to 59% of the viral cases. Contamination of ready-to-eat items by food handlers largely attributes to the high rate of infections, emphasizing the importance of proper hand hygiene. In addition to washing with soap and water some organizations such as the U.S. Centers for Disease Control and Prevention and the World Health Organization recommend the use of alcohol-based hand sanitizers citing such advantages as faster and greater microbial kill, ease of use and time savings, as well as independence from sinks and running water.

In the study the researchers formed a synergistic blend of ethanol, polyquaternium polymer and organic acid and tested its capability to inhibit human and animal viruses. When compared with a benchmark alcohol-based hand sanitizer, results showed higher levels of reduced infectivity of human rotavirus, adenovirus type 5, poliovirus type 1, and norovirus, as well as feline calicivirus and murine norovirus type 1 from the new ethanol-based sanitizer.

"Based on these results, we conclude that this new ethanol-based hand sanitizer is a promising option for reducing the transmission of enteric viruses, including norovirus, by food handlers and care providers," say the researchers.

(D.R. Macinga, S.A. Sattar, L. Jaykus, J.W. Arbogast. 2008. Improved inactivation of nonenveloped enteric viruses and their surrogates by a novel alcohol-based hand sanitizer. Applied and Environmental Microbiology, 74. 16: 5047-5052.)


New Oral Vaccine May Protect Against Bubonic Plague

Researchers from the Institut Pasteur in Paris, France used a less virulent ancestor to the highly infectious bubonic plague to develop a potentially safe, efficient and inexpensive live oral vaccine. They report their findings in the August 2008 issue of the journal Infection and Immunity.

Transmitted by infected fleas, Yersinia pestis is the causative agent responsible for bubonic and pneumonic plague. Both highly contagious, the bubonic form of the disease is the most common in the world and can be treated; however, pneumonic plague is almost always fatal within 3 days of infection. Pneumonic plague can also be generated into aerosols and transmitted from human to human placing it at serious risk for use as weapon of bioterrorism.

Yersinia pseudotuberculosis shares a genetic identity rate of 95% with Y. pestis, but is much less virulent and rarely attributed to disease-related fatalities. In the study 41 strains of Y. pseudotuberculosis were screened for low pathogenicity. Researchers identified one strain (IP32680) which was then tested and found to persist in the mouse intestine for 2 months following intragastric and subcutaneous inoculation without any clinical signs of disease. The previously inoculated mice were then challenged intravenously with Y. pestis following which low levels of the bacteria were found in the organs and blood. Finally, IP32680 was administered orally and results showed that one dose protected 75% of mice, while two doses protected 88%.

"We report that oral inoculation with a Y. pseudotuberculosis strain, selected for its very low virulence, induces an efficient immunity against bubonic plague without causing adverse reactions," say the researchers. "This demonstrates that a live attenuated Y. pseudotuberculosis can be a promising vaccine against bubonic plague."

(T. Blisnick, P. Ave, M. Huerre, E. Carniel, C.E. Demeure. 2008. Oral vaccination against bubonic plague using a live avirulent Yersinia pseudotuberculosis strain. Infection and Immunity, 76. 8: 3808-3816.)


Oral Administration of Lactobacillus from Breast Milk May Treat Common Infection in Lactating Mothers

Oral administration of lactobacillus strains found in breast milk may provide an alternative method to antibiotics for effectively treating mastitis, a common infection that occurs in lactating mothers say researchers from Spain. They report their findings in the August 2008 issue of the journal Applied and Environmental Microbiology.

Mastitis, inflammation of one or more lobules of the mammary gland, occurs in anywhere from 3 to 33% of lactating mothers and of those incidences 75 to 95% are diagnosed within the first twelve weeks postpartum. While Staphylococcus aureus and Staphylococcus epidermidis are considered to be the main infectious agents associated with mastitis, increased multi-drug resistance to antibiotics are making such infections difficult to treat, therefore prompting researchers to explore alternative treatment options.

In prior studies researchers collected lactobacillus strains from the breast milk of healthy mothers and found the probiotic potential of Lactobacillus gasseri and Lactobacillus salivarious to be comparable to strains currently used in commercial probiotic products. Here the researchers randomly divided twenty women diagnosed with staphylococcal mastitis into two groups, a probiotic group and a control. The probiotic group received the same daily dosage of L. salivarius and L. gasseri for four weeks, both of which were originally isolated from breast milk. Results showed that on day zero staphylococcal counts in both groups were similar. At day fourteen women in the probiotic group were displaying no clinical signs of mastitis, but infection in the control group persisted. Finally, on day thirty the staphylococcal count was lower in the probiotic group and L. salivarius and L. gasseri were detected in milk samples from six of the ten women.

"In conclusion, L. salivarius CECT5713 and L. gasseri CECT5714 appear to be an efficient alternative for the treatment of lactational infectious mastitis during lactation," say the researchers.

(E. Jimenez, L. Fernandez, A. Maldonado, R. Martin, M. Olivares, J. Xaus, J.M. Rodriguez. 2008. Oral administration of Lactobacillus strains isolated from breast milk as an alternative for the treatment of infectious mastitis during lactation. Applied and Environmental Microbiology, 74. 15: 4650-4655.)

Source: American Society for Microbiology

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