A comparative study of influenza virus neuraminidases, using automated techniques

Antigenic Relationships in Avian Influenza A Viruses: Identification of Two Viruses Isolated from Turkeys in Great Britain during 1969-1970

“…The neuraminidase of virus strain A/TURKEY/SCOTLAND/70 cross-reacted only with A/DUTCH and virus 'N' (Table I). The antigenic similarity of the neuraminidases of A/DUTCH and virus 'N' confirms previous findings (Kendal & Madeley, 1969).…”

“…Antisera were prepared in chickens by the schedules previously described (Kendal & Madeley, 1969) depending on the virulence of each virus for chickens.…”

“…In previous reports we identified eight different antigenic combinations of haemagglutinin and neuraminidase in the avian influenza A viruses studied (Kendal & Madeley, 1969;Madeley, Allan & Kendal, I970. Two more influenza viruses have since been isolated from turkeys in Great Britain, and these are now compared with those previously examined.…”

Studies with Avian Influenza A Viruses: Serological Relations of the Haemagglutinin and Neuraminidase Antigens of Ten Virus Isolates

“…In those tests (Table 4) shown as negative the sera gave no greater inhibition than that shown by normal sera. We found previously (Kendal & Madeley, 1969) that even low titre specific antibody inhibited up to 80 ~, suggesting that no specific cross-reactions were masked by the inhibitory activity of normal serum components. The present NI tests also confirmed completely our previous findings using the smaller sialo-lactose as enzyme substrate (Kendal & Madeley,t969), and in our system the size of the enzyme substrate did not appear to affect the results of the test.…”

“…Antigenic groupings were found which were similar in each test, but the authors compared only a few strains by NI (Webster & Pereira, 1968 ). We have reported (Kendal & Madeley, 1969) an examination of ten strains of avian influenza viruses by NI using bovine sialo-lactose as substrate. It has been suggested (Fazekas de St Groth, 1963;Rafelson, Schneir & Wilson, 1963) that this material is too small to be a good substrate for NI tests.…”