Clinical Mycoplasma gallisepticum infection in multiplier breeder and meat turkeys caused by F strain: identification by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, restriction endonuclease analysis, and the polymerase chain reaction.

In February 1991, a flock of North Carolina multiplier breeder turkeys experienced respiratory signs, sinusitis, airsacculitis, and increased mortality. Mycoplasma gallisepticum (MG) was isolated, and appropriate control measures were initiated. Ultimately, this outbreak involved several breeder flocks of an integrated turkey production company before the last infected flock was identified in May 1991. During this time, MG was also isolated from a flock of commercial layer-type chickens raised as pullets in close proximity to the index turkey flock. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and restriction endonuclease analysis indicated that these isolates were identical to each other and to examples of the vaccinal F strain. Additionally, MG isolates from the affected turkey breeder and layer flocks were identified as MG F strain by use of an F strain-specific DNA probe and polymerase chain reaction. A separate outbreak of MG disease in several meat-turkey flocks of a Midwest producer/processor yielded isolates identified as F strain by the polymerase chain reaction. These studies demonstrated: 1) the utility of newer technologies for disease outbreak investigations; and 2) the potential of MG F strain to cause disease in breeder and meat turkeys under field conditions.

Mycoplasma gallisepticum isolated from house finches (Carpodacus mexicanus) with conjunctivitis.

An epornitic of conjunctivitis in free-flying house finches (Carpodacus mexicanus) occurred in several mid-Atlantic and eastern states of the USA in 1994. Clinical signs and gross lesions ranged from mild to severe unilateral or bilateral conjunctival swelling with serous to mucopurulent drainage and nasal exudate. Microscopic lesions consisted of chronic lymphoplasmacytic conjunctivitis, rhinitis, and sinusitis. Notably slow-growing mycoplasmas were isolated from conjunctival and/or infraorbital sinus swabs from clinically affected birds. Isolates were identified as Mycoplasma gallisepticum (MG) by direct immunofluorescence and DNA probe-based polymerase chain reactions. These findings suggest that MG is the likely etiology for this epornitic of conjunctivitis in house finches.

Breeder turkey hens seropositive and culture-negative for Mycoplasma synoviae.

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.

Antibody responses of chickens to inoculation with Mycoplasma gallisepticum membrane proteins in immunostimulating complexes.

Membrane proteins of Mycoplasma gallisepticum (MG) strain R were extracted with the detergent Mega-10 and incorporated into immunostimulating complexes (ISCOMs). A membrane protein of approximately 64 kD (p64) molecular weight was a major component of MG ISCOMs. Six-week-old specific-pathogen-free leghorn chickens were inoculated by various routes (subcutaneous; combined intranasal and eyedrop; and combined subcutaneous, intranasal, and eyedrop) with 10 micrograms MG proteins in ISCOMs, or inoculated subcutaneously with 10 micrograms MG proteins in Freund's adjuvant. Subcutaneous inoculation of MG ISCOMs, or MG Freund's adjuvant resulted in higher sero-positive rates (detected by enzyme-linked immunosorbent assay) in serum and respiratory tract washings, compared to combined routes of MG ISCOM inoculation. In chickens inoculated subcutaneously with MG ISCOMs antibodies were first detected at 31 days postinoculation (PI) and the sero-positive rate peaked at 56 days PI. Sero-positive rates started to decline at day 64 PI. In the Freund's adjuvant group, MG antibodies were first detected at day 21 PI, and the sero-positive rate peaked at day 39 PI and did not decline. MG antibodies were detected by ELISA in upper respiratory tract and tracheal washes from chickens inoculated subcutaneously with MG ISCOMs and MG Freund's adjuvant. Immunoblots to MG strain R whole cell proteins showed that respiratory tract washings and sera from chickens inoculated subcutaneously with MG ISCOMs contained immunoglobulins to MG proteins, with a prominent reaction to p64.

Mycoplasma sturni from blue jays and northern mockingbirds with conjunctivitis in Florida.

Northern mockingbirds (Mimus polyglottos) and blue jays (Cyanocitta cristata) in a Florida (USA) wildlife care facility developed clinical signs and gross lesions suggestive of the ongoing outbreak of Mycoplasma gallisepticum (MG) conjunctivitis in house finches (Carpodacus mexicanus) and American goldfinches (Carduelis tristis). Mycoplasmal organisms were cultured from conjunctival/corneal swabs of birds with sinusitis, conjunctivitis, and/or epiphora. All of the isolates tested were identified as Mycoplasma sturni by indirect immunofluorescence. Mycoplasma sturni as well as MG should be considered in the differential diagnosis of songbirds with conjunctivitis.

Molecular epidemiologic investigations of Mycoplasma gallisepticum conjunctivitis in songbirds by random amplified polymorphic DNA analyses.

An ongoing outbreak of conjunctivitis in free-ranging house finches (Carpodacus mexicanus) began in 1994 in the eastern United States. Bacterial organisms identified as Mycoplasma gallisepticum (MG) were isolated from lesions of infected birds. MG was also isolated from a blue jay (Cyanocitta cristata) that contracted conjunctivitis after being housed in a cage previously occupied by house finches with conjunctivitis, and from free-ranging American goldfinches (Carduelis tristis) in North Carolina in 1996. To investigate the molecular epidemiology of this outbreak, we produced DNA fingerprints of MG isolates by random amplification of polymorphic DNA (RAPD). We compared MG isolates from songbirds examined from 1994 through 1996 in 11 states, representing three host species, with vaccine and reference strains and with contemporary MG isolates from commercial poultry. All MG isolates from songbirds had RAPD banding patterns identical to each other but different from other strains and isolates tested. These results indicate that the outbreak of MG in songbirds is caused by the same strain, which suggests a single source; the outbreak is not caused by the vaccine or reference strains analyzed; and MG infection has not been shared between songbirds and commercial poultry.