Oseltamivir Resistance in Influenza A(H6N2) Caused by an R292K Substitution in Neuraminidase Is Not Maintained in Mallards without Drug Pressure.

Background: Wild waterfowl is the natural reservoir of influenza A virus (IAV); hosted viruses are very variable and provide a source for genetic segments which can reassort with poultry or mammalian adapted IAVs to generate novel species crossing viruses. Additionally, wild waterfowl act as a reservoir for highly pathogenic IAVs. Exposure of wild birds to the antiviral drug oseltamivir may occur in the environment as its active metabolite can be released from sewage treatment plants to river water.

Influenza A(H7N9) virus acquires resistance-related neuraminidase I222T substitution when infected mallards are exposed to low levels of oseltamivir in water.

Influenza A virus (IAV) has its natural reservoir in wild waterfowl, and new human IAVs often contain gene segments originating from avian IAVs. Treatment options for severe human influenza are principally restricted to neuraminidase inhibitors (NAIs), among which oseltamivir is stockpiled in preparedness for influenza pandemics. There is evolutionary pressure in the environment for resistance development to oseltamivir in avian IAVs, as the active metabolite oseltamivir carboxylate (OC) passes largely undegraded through sewage treatment to river water where waterfowl reside.

Identification of in vivo released products of Onchocerca with diagnostic potential, and characterization of a dominant member, the OV1CF intermediate filament.

A sensitive and specific test for the routine diagnosis of active Onchocerca infection is currently lacking. A major drawback in the development of such a test has been the paucity of knowledge of suitable parasite antigens that can serve as targets in antigen-detection assays. In the present investigation, we employed mass spectrometry, bioinformatics and molecular techniques to identify and characterize several potentially diagnostic Onchocerca antigens in the in vivo nodular fluid, which is being investigated for the first time.

Preparation and characterization of specific monoclonal antibodies for the detection of adult worm infections in onchocerciasis.

Suitable molecular tests for monitoring the viability of adult worms of Onchocerca in vivo are required to accelerate the development of new macrofilaricides in river blindness (onchocerciasis). Hence, three monoclonal antibodies (MAbs) were prepared and evaluated in a sandwich enzyme-linked immunosorbent assay (ELISA) for their abilities to detect circulating adult worm antigens in onchocercal bovine and human sera. The MAbs did not cross-react with a number of control antigens, which included extracts of Ascaris suum, Loa loa, and O.

Delayed anti-kappa response in kappa-deficient mice after neonatal, oral immunization with kappa-containing IgG.

Antibody responses to kappa (kappa)-light (L) chain are absent in normal (Ckappa+/+) animals because of tolerance due to the abundance of kappa-L chains expressed on more than 95% of all B cells and serum Ig.When heterozygous kappa-sufficient (Ckappa+/-) females are bred with homozygous kappa-deficient (Ckappa-/-) males, half of their offspring will become kappa-deficient but have received kappa-L chain containing maternal Ig, mainly IgG and IgA, through placental and intestinal transmission. The kappa-containing maternal Ig persists for more than 2 months in the circulation of the offspring.