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Tips from the Journals of the American Society for Microbiology

American Society for Microbiology

POTENTIAL TREATMENT FOR PATIENTS WITH HEPATITIS B

Researchers from The Scripps Research Institute in La Jolla, California report that the compound Interleukin-18 (IL-18) may control replication of the Hepatitis B virus (HBV) and be an effective therapy for patients already being treated for chronic hepatitis. Their results appear in the November 2002 issue of the Journal of Virology.

In the study, HBV-infected mice were treated with IL-18 and then monitored for varying levels of HBV DNA in the liver. HBV DNA levels significantly decreased after four hours and were almost undetectable after twenty-four hours.

"In conclusion, our observation that IL-18 can inhibit HBV replication in the livers of these transgenic mice, especially in concert with IL-12, raises the possibility that both of these cytokines may contribute to the control of HBV replication during natural HBV infection," say researchers. "Thus we suggest that IL-18, alone or together with IL-12, might have therapeutic potential for the treatment of patients with chronic HBV infection."

(K. Kimura, K. Kakimi, S. Weiland, L.G. Guidotti, F.V. Chisari. 2002. Interleukin-18 inhibits Hepatitis B Virus replication in the livers of transgenic mice. Journal of Virology, 76: 10702-10707.)

ENGINEERED BACTERIA DETECT POLLUTANTS

Researchers from the United Kingdom have genetically engineered a bacterium to detect herbicidal pollution in the environment. They report their findings in the October 2002 issue of the journal Applied and Environmental Microbiology.

The use of engineered bacteria, also known as biosensors, to detect pollutants in the environment is nothing new, say the researchers from the University of Abedeen and the University of Cambridge. "However, existing biosensors show a poor response to herbicides, a key class of environmental pollutants."

In the study, the researchers genetically engineered the cyanobacterium Synechoscystis , adding a gene from a firefly to make it glow in the presence of a broad range of herbicides and other pollutants including heavy metals. According to the researchers, this new biosensor is simpler, more rapid, more accurate and more economical than other methods.

"This biosensor is expected to provide new opportunities for the rapid screening of environmental samples or for the investigation of potential environmental damage," say the researchers.

(C.Y. Shao, C.J. Howe, A.J.R. Porter and L.A. Glover. 2002 . Novel cyanobacterial biosensor for detection of herbicides. Applied and Environmental Microbiology, 68: 5026-5033.)

ANTIBODIES TO TREAT SEVERE E. COLI INFECTIONS

A strategy utilizing human antibodies against a bacterial toxin may be an effective therapy for some of the most severe E. coli infections, say researchers from Tufts University in the October 2002 issue of the journal Infection and Immunity.

Hemolytic-uremic syndrome (HUS), a leading cause of kidney failure in children, is associated with infection by E. coli O157:H7 bacteria that produce a compound known as Shiga toxin. HUS usually develops several days after the onset of bloody diarrhea associated with food- or water-borne infection with the bacteria. There is currently no effective treatment available.

In their study the researchers have developed human antibodies that recognize and neutralize the Shiga toxin. These antibodies not only neutralized over 85% of the Shiga toxin in cell cultures, but also significantly increased survival when administered to experimentally infected mice.

"Presently, no effective treatment or prophylaxis for HUS is available clinically," say the researchers "However, passive antibody therapy holds promise."

(J. Mukherjee, K. Chios, D. Fishwild, D. Hudson, S. O'Donnell, S.M. Rich, A. Donohue-Rolfe and S. Tzipori. 2002. Production and characterization of protective human antibodies against Shiga-toxin 1. Infection and Immunity, 70: 5896-5899.)

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