Skip to main content

Altered #receptor-binding #specificity of #gull-adapted #H13 avian #influenza viruses corresponds to their unique host preferences

Highlights

• H13 HAs exhibit binding specificity for fucosylate α2-3 sialosides.

• The 130-loop and K227 are critical for H13 HA binding specificity.

• Fucosylated α2-3 sialosides are widely distributed in slaty-backed gulls.


Abstract

Avian influenza viruses (AIVs) recognize α2-3 sialosides as receptors. Previous studies showed that the structural diversity within α2-3 sialosides is related to the host specificity of AIVs. H13 AIVs are primarily isolated from gulls, although almost all AIV subtypes have been isolated from ducks, the natural hosts of AIVs. To elucidate the molecular basis of the host specificity of H13 viruses to gulls, the receptor-binding specificity of H13 hemagglutinins (HAs) and the distribution of viral receptors in gulls were investigated. The results revealed that recombinant HA (rHA) of H13 viruses had a binding preference for fucosylated α2-3 sialosides, which were distributed widely in the respiratory tract and intestines of gulls but not in the colon of ducks. Moreover, the receptor-binding specificity of mutant rHAs revealed that amino acids in the 130-loop and at position 227 of H13 HA were critical for the preference for fucosylated α2-3 sialosides. The results of the present study suggest that the binding specificity of H13 HA to fucosylated α2-3 sialosides is a key factor for the host susceptibility of H13 viruses to gulls.

Source: Virology, https://www.sciencedirect.com/science/article/abs/pii/S0042682225000728?via%3Dihub

____

Comments

Popular posts from this blog

#USA, APHIS Confirms {Avian #Influenza #H5N1} #D11 #Genotype in Dairy #Cattle in #Nevada

On January 31, 2025, the USDA Animal and Plant Health Inspection Service (APHIS) National Veterinary Services Laboratories (NVSL) confirmed by whole genome sequence the first detection of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b, genotype D1.1 in dairy cattle .  This confirmation was a result of State tracing and investigation, following an initial detection on silo testing under the USDA’s National Milk Testing Strategy (NMTS) in Nevada.  USDA APHIS continues to work with the Nevada Department of Agriculture by conducting additional on-farm investigation, testing, and gathering additional epidemiological information to better understand this detection and limit further disease spread.  This is the first detection of this virus genotype in dairy cattle (all previous detections in dairy cattle have been HPAI H5N1 clade 2.3.4.4b, genotype B3.13 ).  Genotype D1.1 represents the predominant genotype in the North American flyways this past fall an...

#USA, After #Birdflu Detected in Local #Cat, County #Health Officials Say #Pet Owners Should Contact Veterinarian When Their Pets are Sick

Redwood City — State veterinary and health officials have confirmed a case of H5N1 (bird flu) in a domestic stray cat in San Mateo County.  The infection, which is not related to the recent instance of bird flu in a backyard flock , was found in a stray cat in Half Moon Bay that had been taken in by a family .  When it showed symptoms, they took it to Peninsula Humane Society, whose veterinarians examined it and requested testing. Lab results confirmed H5N1.  It is not known how the cat was infected and it was euthanized due to its condition. Cats may be exposed to bird flu by consuming infected bird , being in environments contaminated with the virus and consuming unpasteurized milk from infected cows or raw food. Inside domestic animals, such as cats and dogs, that go outside are also at risk of infection.​​​​​​​ According to the Centers for Disease Control and Prevention, the risk of cats spreading H5N1 to people is extremely low, though it is possible for cats to spre...

#USA, Novel #Influenza A #H5N1 Virus: One Pediatric Case in #California {FluView}

 {Excerpt} One confirmed human infection with influenza A(H5) virus was reported to CDC this week. To date, human-to-human transmission of influenza A(H5) virus has not been identified in the United States. This case was reported by the California Department of Public Health and occurred in a child less than 18 years old with no known contact with influenza A(H5N1) virus-infected animals or humans . The investigation into the source of infection for this case is ongoing , and no human-to-human transmission has been identified. A specimen from the individual was tested at a public health laboratory using the CDC influenza A(H5) assay before being sent to CDC for further testing. The specimen was positive for influenza A(H5) virus using diagnostic RT-PCR at CDC. Additional analysis including genetic sequencing is underway. In response to this detection, additional case investigation and contact monitoring are being conducted by public health officials in California. There have now be...