@article{avakian_ley_1993, title={INHIBITION OF MYCOPLASMA-GALLISEPTICUM GROWTH AND ATTACHMENT TO CHICK TRACHEAL RINGS BY ANTIBODIES TO A 64-KILODALTON MEMBRANE-PROTEIN OF MYCOPLASMA-GALLISEPTICUM}, volume={37}, ISSN={["0005-2086"]}, DOI={10.2307/1592018}, abstractNote={A Mycoplasma gallisepticum (MG) strain R protein of 64 kilodaltons (p64) was partially digested from the surface of the bacterium by trypsin. Monospecific polyclonal anti-p64 IgG inhibited attachment of MG to chick tracheal rings by as much as 69%. However, trypsin treatment of viable MG cells did not reduce attachment to tracheal rings or hemagglutination titer. Anti-p64 IgG inhibited growth of MG strain R in broth and on solid media, inhibited the uptake of radiolabeled thymidine, but did not inhibit hemagglutination. Anti-p64 IgG inhibited growth of eight MG strains on solid medium. The degree of growth inhibition varied widely depending on the strain and correlated positively with the reported virulence of the MG strains with one exception (A5969). An IgG monoclonal antibody to p64 (MyG 001) inhibited growth of MG strain R on solid and in broth media. The strong attachment-inhibition activity of anti-p64 IgG may result from its growth-inhibiting activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of MG strains suggested that p64 is expressed in higher amounts in vitro in virulent strains (R, S6) than in strains of low virulence (F, M876, K503, K703, K730). P64 should be used to immunize chickens to determine if it can stimulate a growth and attachment-inhibiting response in the respiratory tract.}, number={3}, journal={AVIAN DISEASES}, author={AVAKIAN, AP and LEY, DH}, year={1993}, pages={706–714} }
 @article{avakian_ley_1993, title={PROTECTIVE IMMUNE-RESPONSE TO MYCOPLASMA-GALLISEPTICUM DEMONSTRATED IN RESPIRATORY-TRACT WASHINGS FROM M-GALLISEPTICUM-INFECTED CHICKENS}, volume={37}, ISSN={["0005-2086"]}, DOI={10.2307/1592017}, abstractNote={Chickens inoculated with Mycoplasma gallisepticum (MG) produced IgA, IgM, and IgG detectable in washings from the upper respiratory tract (URTW; nasal sinuses and turbinates) and lower respiratory tract (LRTW; trachea, lungs, and air sacs). URTW and LRTW from infected chickens had significant protective effects in a MG-inoculated tracheal-ring-organ-culture system. Protective effects in vitro correlated positively with total MG-specific immunoglobulin titer, but not IgA titer, as determined by enzyme-linked immunosorbent assay. URTW and LRTW from infected chickens inhibited attachment of MG to tracheal-ring-organ cultures in a dose-dependent manner. This suggests that chickens produce a protective immune response to MG that locates in the respiratory tract and that attachment inhibition may be responsible for this protective effect.}, number={3}, journal={AVIAN DISEASES}, author={AVAKIAN, AP and LEY, DH}, year={1993}, pages={697–705} }
 @article{avakian_ley_berkhoff_ficken_1992, title={BREEDER TURKEY HENS SEROPOSITIVE AND CULTURE-NEGATIVE FOR MYCOPLASMA-SYNOVIAE}, volume={36}, ISSN={["0005-2086"]}, DOI={10.2307/1591785}, abstractNote={Four flocks of clinically normal turkey breeder hens were shown to have suspect and positive Mycoplasma synoviae (MS) hemagglutination-inhibition (HI), enzyme-linked immunosorbent assay, and, in some cases, serum plate agglutination serology in the absence of MS isolation. In all cases, HI serology for Mycoplasma gallisepticum (MG) and M. meleagridis was negative. Acholeplasma laidlawii was isolated from some hens in each of these MS-seropositive culture-negative flocks. Immunoblotting was used to help determine if this positive MS serology was a result of cross-reactive antibodies to A. laidlawii or to some other Mycoplasma species. When sera from two of the flocks were reacted with MS antigen in immunoblotting, a strong and characteristic MS immunoblot profile was seen. Immunoblotting gave no evidence of a strong antibody response to A. laidlawii, M. iowae, or MG. This suggests the presence (or earlier presence) of MS in these flocks that is difficult to isolate by routine methods. Furthermore, this work shows that immunoblotting can be an important tool in the diagnosis of poultry diseases.}, number={3}, journal={AVIAN DISEASES}, author={AVAKIAN, AP and LEY, DH and BERKHOFF, JE and FICKEN, MD}, year={1992}, pages={782–787} }
 @article{avakian_ley_kleven_1992, title={COMPARISON OF MYCOPLASMA-SYNOVIAE ISOLATES BY IMMUNOBLOTTING}, volume={21}, ISSN={["0307-9457"]}, DOI={10.1080/03079459208418884}, abstractNote={SDS-polyacrylamide gel electrophoresis (PAGE) and immunoblot profiles using antisera from M. synoviae F10-2AS-inoculated chickens detected heterogeneity among 10 M. synoviae isolates. This variation was primarily seen in immunoblots as a difference in the molecular size of immunoreactive proteins below 50 kDa and corresponded to an area of variability seen in SDS-PAGE. No two isolates had the same immunoblot profile below 50 kDa. Hyperimmune antiserum to a M. synoviae F10-2AS protein of 41 kDa (p41) reacted with protein(s) ranging from 41 to 48 kDa in nine of 10 isolates and strongly with one of 87 kDa in one isolate. The immunoreactivity of antiserum from inoculated chickens and the hyperimmune antiserum to p41 varied from intense to weak with the 10 M. synoviae isolates. All of the highly immunogenic proteins of M. synoviae F10-2AS, including p41, partitioned into the Triton X-114 detergent phase, indicating that they are amphiphilic in nature and integral membrane proteins. The data suggest that M. synoviae is capable of varying the molecular size of a highly immunogenic integral membrane protein.}, number={4}, journal={AVIAN PATHOLOGY}, author={AVAKIAN, AP and LEY, DH and KLEVEN, SH}, year={1992}, pages={633–642} }
 @article{avakian_ley_mcbride_1992, title={HUMORAL IMMUNE-RESPONSE OF TURKEYS TO STRAIN-S6 AND A VARIANT MYCOPLASMA-GALLISEPTICUM STUDIED BY IMMUNOBLOTTING}, volume={36}, ISSN={["0005-2086"]}, DOI={10.2307/1591718}, abstractNote={Two putative variant Mycoplasma gallisepticum (MG) strains (M876 and M35), originally isolated from commercial turkeys, were compared with eight well-characterized MG strains by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). SDS-PAGE protein profiles indicated that the variant strains were correctly classified as MG based on homologous patterns in species-specific regions of the electrophoretic profiles. However, differences in protein profiles also indicated that variant strains M876 and M35 were different from each other and the other MG strains tested. Immunoblotting was used to assess the humoral immune response of turkeys to infection with the S6 reference strain or M876 variant strain of MG. Immunoblots using antisera to M876 showed that seroconversion to this isolate was slower, and to fewer MG proteins when compared with immunoblots using antisera to S6. Immunoblot analyses further indicated that pooled antisera from turkeys inoculated with either S6 or M876 reacted with each of 10 MG strains tested. However, pooled S6 antisera reacted with greater intensity and with more MG proteins than did pooled M876 antisera. The species-specific immunodominant proteins with the greatest potential for use as antigens in serologic tests appeared to be those of 64 (p64) and 56 (p56) kilodaltons molecular mass.}, number={1}, journal={AVIAN DISEASES}, author={AVAKIAN, AP and LEY, DH and MCBRIDE, MAT}, year={1992}, pages={69–77} }
 @article{avakian_kleven_ley_1991, title={COMPARISON OF MYCOPLASMA-GALLISEPTICUM STRAINS AND IDENTIFICATION OF IMMUNOGENIC INTEGRAL MEMBRANE-PROTEINS WITH TRITON-X-114 BY IMMUNOBLOTTING}, volume={29}, ISSN={["1873-2542"]}, DOI={10.1016/0378-1135(91)90139-7}, abstractNote={Pooled chicken antisera from 33 and 77 days post Mycoplasma gallisepticum strain R contact-exposure reacted with cell proteins of 19 M. gallisepticum strains. These pooled antisera reacted with more proteins and with greater intensity to reference strains (R, PG31, S6, and A5969) and nine field strains than they did with six other field strains including three (703, 503, and 730) that have been described as serological variants. Following extraction with Triton X-114 the majority of immunogenic M. gallisepticum proteins partitioned exclusively or primarily into the detergent phase indicating that they are integral membrane proteins. This included three immunogenic species-specific proteins (p64, p56 and p26). M. gallisepticum p56 was detected, by immunoblotting, in 18 of 19 strains suggesting that it could serve as an antigen for serological tests. P26 was evident in 13 of 19 strains. Hyperimmune antiserum to p64 reacted with a 64 kDa protein in 19 M. gallisepticum strains, but did not react with seven other avian Mycoplasma spp. There was no evidence found supporting the view that p64 is the hemagglutinin of M. gallisepticum.}, number={3-4}, journal={VETERINARY MICROBIOLOGY}, author={AVAKIAN, AP and KLEVEN, SH and LEY, DH}, year={1991}, month={Nov}, pages={319–328} }