An ingredient commonly found in antibacterial products does not appear to contribute to antibiotic resistance, say researchers from the University of Manchester, United Kingdom and Proctor and Gamble in Cincinnati, Ohio. Their findings appear in the September 2003 issue of the journal Applied and Environmental Microbiology.
Triclosan is an antibacterial compound frequently found in domestic and clinical applications. Although concentration levels are often low, specific areas such as kitchen sink drains are highly exposed because triclosan is so commonly used in domestic products. Recent research has suggested that exposure to this compound may lead to antibiotic resistance in some bacteria.
In the study, long-term bacterial communities found in sink drains were established and maintained over a period of six months and then subjected to detergents containing triclosan for three months. Cultures were then extracted and susceptibility to four biocides and six antibiotics were analyzed. With the exception of Escherichia coli, results showed that minimal levels of triclosan exposure did not affect antimicrobial susceptibility in environmental communities.
"Long-term exposure of domestic-drain biofilms to sublethal levels of triclosan did not effect bacterial vitality or significantly alter antimicrobial susceptibility," say the researchers. "We conclude therefore that the emergence of antibiotic resistance through triclosan in the kitchen is highly improbable."
(A.J. McBain, R.G. Bartolo, C.E. Catrenich, D. Charbonneau, R.G. Ledder, B.B Price, P. Gilbert. 2003. Exposure of sink drain microcosms to triclosan: population dynamics and antimicrobial susceptibility. Applied and Environmental Microbiology, 69. 9: 5433-5442.)
NEW TEST QUICKLY DIAGNOSES WEST NILE VIRUS INFECTION
A new test differentiating West Nile virus from similar viruses may be useful in quickly diagnosing infections in both clinical and veterinary practices say researchers from New York, Connecticut, Colorado and Canada. Their findings appear in the September 2003 issue of the Journal of Clinical Microbiology.
West Nile virus is one of many pathogens belonging to the flavivirus group. Current methods of diagnosis involve testing antibodies against viral structural proteins, the main one being the E protein As the E protein is found in other flaviviruses such as Dengue virus and St. Louis encephalitis, positive antibody E results are not a definitive diagnosis of West Nile virus. Therefore, additional testing is required to differentiate between the viruses and specifically identify the West Nile virus infection.
The researchers have discovered a protein, called nonstructural protein 5 (NS5) that can differentiate between West Nile virus and Dengue virus or St. Louis encephalitis, as well as between flavivirus vaccination and natural WNV infection. This method also indicates if the infection was incurred recently, all of which would allow for a faster and more efficient diagnosis of West Nile virus.
"Our results demonstrate that the NS5-based immunoassay reliably discriminates between WNV infections and DEN or SLE virus infections and that it differentiates between flavivirus vaccination and natural WNV infection," say the researchers. "These unique features of the NS5-based immunoassay will be very useful for both clinical and veterinary diagnosis of WNV infection."
(S.J. Wong, R.H. Boyle, V. L. Demerast, A. N. Woodmansee, L. D. Kramer, H. Li, M. Drebot, R. A. Koski, E. Fikrig, D. A. Martin, P. Y. Shi. 2003. Immunoassay targeting nonstructural protein 5 to differentiate west nile virus infection from dengue and st. louis encephalitis virus infections and from flavavirus vaccination. Journal of Clinical Microbiology, 41. 9: 4217-4223.)