Identification of Two Pathogenic Avian Mycoplasmas as Strains of Mycoplasma pullorum

Abstract

Two mycoplasma strains were isolated from dead turkey embryos. Growth properties, biochemical and serological characteristics, and protein profiles indicated that these strains were closely related to Mycoplasrna pllorum CKKT (T = type strain). This was confirmed by 16s rRNA sequence analysis, and the phylogenetic position of M. pullorurn was established. Pathogenicity studies showed that the two strains, as well as M. pullorurn CKKT, induced a statistically significant level of mortality after inoculation into chicken embryos.Mycoplasma gallisepticum, Mycoplasma synoviae, Mycoplasma meleagridis, and Mycoplasma iowae are known to be pathogenic for turkeys (13,34). Other species, such as Mycoplasma cloacale, Mycoplasma gallinaceurn, Mycoplasma gallopavonis, Mycoplasma iners, and Mycoplasma lipofaciens, may be isolated from turkeys but have not been clearly associated with pathogenicity. Recently, we isolated two mycoplasma strains, one from a dead turkey embryo found in a specific-pathogen-free (SPF) flock (strain 94254) and one from a dead turkey embryo which occurred in a field flock (strain 95098GC). In these two flocks, the hatchability percentages (average, 87.7%) were lower than the expected values (more than 95%). Preliminary experiments indicated that the mycoplasma strains did not seem to be related to any of the species mentioned above but resembled Mycoplasma pullorum, a species not known to be pathogenic for turkeys (14). In order to determine if the two newly isolated strains belonged to the species M. pullorurn, we analyzed their cultural, biochemical, and serologic properties and compared them to the type strain of M. pullorurn, strain CKK. We also evaluated the pathogenicities of the three strains for chicken and turkey embryos. To confirm our results and because the phylogenetic position of M. pullorurn has not been established previously, we analyzed the 16s rRNA sequences of the three strains. MATERIALS AND METHODS Mycoplasma strains. The following strains were used: Mycoplasrna anatissynoviae WVU 1853T (= ATCC 25204T), and M. rneleagn'dis 17529T (= ATCC 25294T). One additional mycoplasma field strain, strain 90000, which is serologically related to M. pullorum and was isolated from pheasant trachea (17), was included. Mycoplasmas were grown in FM4 medium supplemented with yeast extract and pig serum (11).Isolation procedure. Strain 94254 was isolated from 12 dead turkey embryos found in an SPF flock. SPF flocks are repeatedly tested (every 6 weeks) for the presence of any specific pathogens, including viruses and bacteria. The vitellus from each dead embryo was isolated and placed in FM4 medium. After 24 h of incubation, cultures were plated onto FM4 solid medium, and 1 day later medium-size colonies that did not have the typical fried-egg appearance (rounded without a central point) were observed. For each embryo, two colonies were Biochemical tests. Biochemical tests were performed as previously described (23). These tests included tests for digitonin sensitivity, glucose fermentation, argin...

The characterization of Mycoplasma synoviae EF-Tu protein and proteins involved in hemadherence and their N-terminal amino acid sequences

“…According to 16S rRNA gene analysis M. synoviae belongs to the M. hominis group, while M. gallisepticum is included in the M. pneumoniae group [12,13]. Within the M. hominis group are also avian Mycoplasma species M. gallinarum, M. gallinaceum, M. meleagridis and M. pullorum [12] in which mAb R reacted with their 43-kDa proteins, which are probably EF-Tu. In the M. hominis group are also M. pulmonis, M. orale, M. bovis and M. fermentans, whose EF-Tu proteins reacted with mAb R in this study.…”

“…This EF-Tu sequence has 90% identity with the EF-Tu of M. hominis and a lower % identity with the EF-Tu of M. gallisepticum with which M. synoviae shares host speci¢city, tissue tropism, antigenic determinants and DNA sequences [1,7]. According to 16S rRNA gene analysis M. synoviae belongs to the M. hominis group, while M. gallisepticum is included in the M. pneumoniae group [12,13]. Within the M. hominis group are also avian Mycoplasma species M. gallinarum, M. gallinaceum, M. meleagridis and M. pullorum [12] in which mAb R reacted with their 43-kDa proteins, which are probably EF-Tu.…”

Short communication. Strain heterogeneity in Mycoplasma pullorum isolates identified by random amplified polymorphic DNA techniques

“…Two isolates with the biochemical and serological characteristics of M. pullorum have been isolated from adult turkeys and dead turkey embryos in France (Moalic et al, 1997). En 1997 se aislaron micoplasmas en el curso de investigaciones de campo en pollos con un brote de enfermedad respiratoria localizada en la zona oeste de Cuba.…”

The characterization ofMycoplasma synoviaeEF-Tu protein and proteins involved in hemadherence and their N-terminal amino acid sequences

“…In Mycoplasma hominis , EF‐Tu has a molecular mass of 43 kDa and represents about 2% of the total cellular protein [11]. M. synoviae is within the M. hominis phyletic group [12] but there are no data about its EF‐Tu protein or tuf gene.…”