The virus neutralization (VN) test was used to determine potency of the infectious bronchitis (IB) vaccine. The results of VN, hemagglutination inhibition (HI), and enzyme-linked immunosorbent assay (ELISA) were compared with those of the IBV M41. The r values between VN and HI titers and the ELISA antibody titer were 0.8782 and 0.0336, respectively, indicating a high correlation between VN and...

In the present study, the replication kinetics of nephropathogenic (B1648) and respiratory (Massachusetts-M41) IBV strains were compared in vitro in respiratory mucosa explants and blood monocytes (KUL01(+) cells), and in vivo in chickens to understand why some IBV strains have a kidney tropism. B1648 was replicating somewhat better than M41 in the epithelium of the respiratory mucosa explants ...

Positive-strand RNA (+RNA) viruses rearrange cellular membranes during replication, possibly in order to concentrate and arrange viral replication machinery for efficient viral RNA synthesis. Our previous work showed that in addition to the conserved coronavirus double membrane vesicles (DMVs), Beau-R, an apathogenic strain of avian Gammacoronavirus infectious bronchitis virus (IBV), induces re...

Infectious bronchitis virus (IBV) causes respiratory disease leading to loss of egg and meat production in chickens. Although it is known that macrophage numbers are elevated in the respiratory tract of IBV infected chickens, the role played by macrophages in IBV infection, particularly as a target cell for viral replication, is unknown. In this study, first, we investigated the ability of IBV ...

cDNAs prepared from viral genomic RNA purified from two strains of infectious bronchitis virus (IBV) (Beaudette and M41) have been cloned into pBR322. Three of these clones, which contain the complete sequences of mRNA A for both strains, except for the leader sequences which are only present on the subgenomic messenger RNAs, have been sequenced using the dideoxy method. The sequences are simil...

a study has been carried out for determining of cross-immunity between massachusetts (mass) m41 and iranian ir/773/2001 (793/b) strains of infectious bronchitis virus. two groups of 20 three weeks old spf chickens vaccinated subcutaneously with two oil-emulsions inactivated infectious bronchitis vaccines (mass m41 and iranian ir/773/2001 strains) that had been manufactured in razi institute in ...

Sixteen monoclonal antibodies (Mcabs) were prepared against infectious bronchitis virus strain M41, all of them reacting with the peplomer protein. One of them, Mcab 13, was able to neutralize the virus and to inhibit hemagglutination. Competition binding assays allowed the definition of five epitopes, designated as A, B, C, D, and E, of which epitopes A and B are overlapping. Furthermore, the ...

We report a case of an axillary abscess with Streptococcus pyogenes complicated by venous thrombosis. Bacterial etiology and typing were obtained by PCR and sequencing of the 16S rRNA and M-protein genes from abscess material. The bacterium was of serotype M41, and serology indicated that it had expressed procoagulant factors.

The binding of viruses to host cells is the first step in determining tropism and pathogenicity. While avian infectious bronchitis coronavirus (IBV) infection and avian influenza A virus (IAV) infection both depend on α2,3-linked sialic acids, the host tropism of IBV is restricted compared to that of IAV. Here we investigated whether the interaction between the viral attachment proteins and the...

A study has been carried out for determining of cross-immunity between Massachusetts (Mass) M41 and Iranian IR/773/2001 (793/B) strains of infectious bronchitis virus. Two groups of 20 three weeks old SPF chickens vaccinated subcutaneously with two oil-emulsions inactivated Infectious Bronchitis Vaccines (Mass M41 and Iranian IR/773/2001 strains) that had been manufactured in Razi institute in ...