Identification of a novel mycoplasma species from an Oriental white-backed vulture (Gyps bengalensis)

Detection of a novel enterotropic Mycoplasma gallisepticum-like in European starling (Sturnus vulgaris) around poultry farms in France

Recent outbreaks of highly pathogenic avian influenza in southwest France have raised questions regarding the role of commensal wild birds in the introduction and dissemination of pathogens between poultry farms. To assess possible infectious contacts at the wild-domestic bird interface, the presence of Mycoplasma gallisepticum (MG) was studied in the two sympatric compartments in southwest France. Among various peridomestic wild birds (n = 385), standard PCR primers targeting the 16S rRNA of MG showed a high apparent prevalence (up to 45%) in cloacal swabs of European starlings (Sturnus vulgaris, n = 108), while the MG-specific mgc2 gene was not detected. No tracheal swab of these birds tested positive, and no clinical sign was observed in positive birds, suggesting commensalism in the digestive tract of starlings. A mycoplasma strain was then isolated from a starling swab and its whole genome was sequenced using both Illumina and Nanopore technologies. Phylogenetic analysis showed that it was closely related to MG and M. tullyi, although it was a distinct species. A pair of specific PCR primers targeting the mgc2-like gene of this MG-like strain was designed and used to screen again the same avian populations and a wintering urban population of starlings (n = 50). Previous PCR results obtained in starlings were confirmed to be mostly due to this strain (20/22 positive pools). In contrast, the strain was not detected in fresh faeces of urban starlings. Furthermore, it was detected in one cloacal pool of white wagtails, suggesting infectious transmissions between synanthropic birds with similar feeding behaviour. As the new Starling mycoplasma was not detected in free-range ducks (n = 80) in close contact with positive starlings, nor in backyard (n = 320) and free-range commercial (n = 720) chickens of the area, it might not infect poultry. However, it could be involved in mycoplasma gene transfer in such multi-species contexts.

MOLECULAR IDENTIFICATION AND SEQUENCE CHARACTERIZATION OF MYCOPLASMAS IN FREE-LIVING BIRDS OF PREY

Mycoplasma spp. have been detected in birds of prey, but their prevalence in free living raptors and their significance to birds' health need further investigation. Molecular techniques have been increasingly used to identify mycoplasmas in various avian species, due to the fastidious nature of these pathogens hampering traditional bacteriologic tests. This study reports the identification of 23 novel mycoplasma sequences during the monitoring of 62 birds of prey on admission to wildlife centers in Sardinia, Italy. Molecular investigation performed on pharyngeal swabs revealed 26 birds positive to Mycoplasma (42%). Sequence analysis based on 16S rRNA, 16S-23S rRNA intergenic spacer, and RNA polymerase β subunit (rpoB) gene highlighted cluster assignment and phylogenetic relationships among the identified types, classified within the hominis group. Additionally, Ornithobacterium rhinotracheale , associated with respiratory disease in poultry, was identified in 17 birds (27%). Potential coinfection and mycoplasma opportunistic nature present implications for raptor species conservation.

Seroepidemiologic Survey of Potential Pathogens in Obligate and Facultative Scavenging Avian Species in California

Throughout the world, populations of scavenger birds are declining rapidly with some populations already on the brink of extinction. Much of the current research into the factors contributing to these declines has focused on exposure to drug residues, lead, and other toxins. Despite increased monitoring of these declining populations, little is known about infectious diseases affecting scavenger bird species. To assess potential infectious disease risks to both obligate and facultative scavenger bird species, we performed a serosurvey for eleven potential pathogens in three species of scavenging birds in California: the California condor (Gymnogyps californianus), turkey vulture (Cathartes aura) and golden eagle (Aquila chrysaetos). California condors were seropositive for avian adenovirus, infectious bronchitis virus, Mycoplasma gallisepticum, avian paramyxovirus-2, West Nile virus (WNV) and Toxoplasma gondii. Golden eagles were seropositive for avian adenovirus, Chlamydophila psittaci and Toxoplasma gondii, and turkey vultures were seropositive for avian adenovirus, Chlamydophila psittaci, avian paramyxovirus-1, Toxoplasma gondii and WNV. Risk factor analyses indicated that rearing site and original release location were significantly associated with a positive serologic titer to WNV among free-flying condors. This study provides preliminary baseline data on infectious disease exposure in these populations for aiding in early disease detection and provides potentially critical information for conservation of the endangered California condor as it continues to expand its range and encounter new infectious disease threats.

Mycoplasma corogypsi-associated polyarthritis and tenosynovitis in black vultures (Coragyps atratus)

Three wild American black vultures (Coragyps atratus) were presented to rehabilitation centers with swelling of multiple joints, including elbows, stifles, hocks, and carpal joints, and of the gastrocnemius tendons. Cytological examination of the joint fluid exudate indicated heterophilic arthritis. Radiographic examination in 2 vultures demonstrated periarticular soft tissue swelling in both birds and irregular articular surfaces with subchondral bone erosion in both elbows in 1 bird. Prolonged antibiotic therapy administered in 2 birds did not improve the clinical signs. Necropsy and histological examination demonstrated a chronic lymphoplasmacytic arthritis involving multiple joints and gastrocnemius tenosynovitis. Articular lesions varied in severity and ranged from moderate synovitis and cartilage erosion and fibrillation to severe synovitis, diffuse cartilage ulceration, subchondral bone loss and/or sclerosis, pannus, synovial cysts, and epiphyseal osteomyelitis. No walled bacteria were observed or isolated from the joints. However, mycoplasmas polymerase chain reactions were positive in at least 1 affected joint from each bird. Mycoplasmas were isolated from joints of 1 vulture that did not receive antibiotic therapy. Sequencing of 16S rRNA gene amplicons from joint samples and the mycoplasma isolate identified Mycoplasma corogypsi in 2 vultures and was suggestive in the third vulture. Mycoplasma corogypsi identification was confirmed by sequencing the 16S-23S intergenic spacer region of mycoplasma isolates. This report provides further evidence that M. corogypsi is a likely cause of arthritis and tenosynovitis in American black vultures. Cases of arthritis and tenosynovitis in New World vultures should be investigated for presence of Mycoplasma spp, especially M. corogypsi.

Mycoplasma neophronis sp. nov., isolated from the upper respiratory tract of Canarian Egyptian vultures (Neophron percnopterus majorensis)

Six strains with the typical characteristics of mycoplasmas were isolated from the tracheae of six Canarian Egyptian vultures (Neophron percnopterus majorensis). The results of biochemical, serological and molecular genetic studies showed that the isolates were nearly identical and that they could be considered as representing a novel species of the genus Mycoplasma . Colonies possessed the typical fried-egg appearance and electron micrographs revealed a pleomorphic cellular morphology with the lack of a cell wall. The isolates hydrolysed arginine and required sterol for growth but did not ferment glucose or hydrolyse urea. We propose that the isolates be assigned to a novel species,Mycoplasma neophronis sp. nov. The type strain is G.A.T ( = DSM 24097T = ATCC BAA-2157T). The antiserum of strain G.A.T has been deposited in the Mollicutes collection at Purdue University (Indiana, USA).

RNA polymerase beta subunit (rpoB) gene and the 16S-23S rRNA intergenic transcribed spacer region (ITS) as complementary molecular markers in addition to the 16S rRNA gene for phylogenetic analysis and identification of the species of the family Mycoplasmataceae

Conventional classification of the species in the family Mycoplasmataceae is mainly based on phenotypic criteria, which are complicated, can be difficult to measure, and have the potential to be hampered by phenotypic deviations among the isolates. The number of biochemical reactions suitable for phenotypic characterization of the Mycoplasmataceae is also very limited and therefore the strategy for the final identification of the Mycoplasmataceae species is based on comparative serological results. However, serological testing of the Mycoplasmataceae species requires a performance panel of hyperimmune sera which contains anti-serum to each known species of the family, a high level of technical expertise, and can only be properly performed by mycoplasma-reference laboratories. In addition, the existence of uncultivated and fastidious Mycoplasmataceae species/isolates in clinical materials significantly complicates, or even makes impossible, the application of conventional bacteriological tests. The analysis of available genetic markers is an additional approach for the primary identification and phylogenetic classification of cultivable species and uncultivable or fastidious organisms in standard microbiological laboratories. The partial nucleotide sequences of the RNA polymerase β-subunit gene (rpoB) and the 16S-23S rRNA intergenic transcribed spacer (ITS) were determined for all known type strains and the available non-type strains of the Mycoplasmataceae species. In addition to the available 16S rRNA gene data, the ITS and rpoB sequences were used to infer phylogenetic relationships among these species and to enable identification of the Mycoplasmataceae isolates to the species level. The comparison of the ITS and rpoB phylogenetic trees with the 16S rRNA reference phylogenetic tree revealed a similar clustering patterns for the Mycoplasmataceae species, with minor discrepancies for a few species that demonstrated higher divergence of their ITS and rpoB in comparison to their neighbor species. Overall, our results demonstrated that the ITS and rpoB gene could be useful complementary phylogenetic markers to infer phylogenetic relationships among the Mycoplasmataceae species and provide useful background information for the choice of appropriate metabolic and serological tests for the final classification of isolates. In summary, three-target sequence analysis, which includes the ITS, rpoB, and 16S rRNA genes, was demonstrated to be a reliable and useful taxonomic tool for the species differentiation within the family Mycoplasmataceae based on their phylogenetic relatedness and pairwise sequence similarities. We believe that this approach might also become a valuable tool for routine analysis and primary identification of new isolates in medical and veterinary microbiological laboratories.

Identification and characterization of novel Mycoplasma spp. belonging to the hominis group from griffon vultures

Mycoplasmas are commensals and pathogens of various avian species, and are also regularly found in birds of prey, although their significance to birds' health remains unclear. Here we describe two novel Mycoplasma isolated from the upper respiratory tract of four Eurasian griffon vultures (Gyps fulvus) housed in a wildlife recovery centre in Sardinia (Italy). By sequencing the 16S rRNA gene and the entire 16S/23S intergenic spacer region, the new strains were classified within the Mycoplasma taxonomy at the group and cluster levels, showing that the two isolates fall into the Mycoplasma synoviae and Mycoplasma hominis clusters of the hominis group, respectively. We combined molecular tools and immunoblotting methods in order to further characterize these isolates, and antigenic analyses overall confirmed the molecular findings. Different levels of pathogenicity and prevalence of these strains might have different implications for the conservation and reintroduction of vultures.

Mycoplasmas isolated from stone curlews (Burhinus oedicnemus) used in falconry in the United Arab Emirates

The aim of this study was to evaluate the risk of transmission of Mycoplasma spp. from quarry to hunting falcons in the Middle East. Groups of 17 houbara bustards (Chlamydotis undulata) and 29 stone curlews (Burhinus oedicnemus) kept at three different private collections in Dubai were evaluated for the presence of Mycoplasma. Additionally, 10 falcons used for hunting were investigated for comparison. The falcons showed no clinical signs and were examined within the scope of a routine health check. From all birds, conjunctival and choanal swabs were taken and analyzed via polymerase chain reaction and culture. Although mycoplasmas were not recovered from choanal and conjunctival swabs taken from the houbara bustards, Mycoplasma gypis and M. falconis were isolated from the majority (28/29; 97%) of the stone curlews from choanal and conjunctival swabs. Most of the birds had no associated pathologic findings. Mycoplasma falconis was also detected in samples collected from 2 of the 10 falcons, and M. buteonis was isolated from the majority of falcons (6/10 falcons) from choanal (n = 5) and conjunctival (n = 1) swabs. Mycoplasma gypis could also be isolated from tissue samples (liver, oviduct, syrinx) of one dead stone curlew. This study presents the first isolation of mycoplasmas from stone curlews.

Application of cell culture enrichment for improving the sensitivity of mycoplasma detection methods based on nucleic acid amplification technology (NAT)

Herein, we present data demonstrating that the application of initial cell culture enrichment could significantly improve mycoplasma testing methods based on the nucleic acid amplification technology (NAT) including a polymerase chain reaction (PCR)/microarray method. The results of the study using Vero cells demonstrated that this cell culture is able (1) to support efficient growth of mycoplasmas of primary interest, i.e., species found to be cell line contaminants, (2) to increase the sensitivity of NAT assay to the detection limits of the conventional broth/agar culture methods, and (3) to reduce the time required for mycoplasma testing fourfold in comparison with the conventional methods. Detection and identification of mycoplasmal agents were conducted using a modified PCR/microarray assay based on genetic differences among Mollicutes in the 16S-23S rRNA intergenic transcribed spacer (ITS). The application of nano-gold/silver enhancement technology instead of previously used fluorescent dyes significantly simplified the readout of microarray results and allowed us to avoid using expensive scanning equipment. This modification has the potential to expand the implementation of microarray techniques into laboratories involved in diagnostic testing of mycoplasma contamination in cell substrates and potentially in other biological and pharmaceutical products.

Prevalence of mycoplasmas in eggs from birds of prey using culture and a genus-specific mycoplasma polymerase chain reaction

Mycoplasmas are commensals and pathogens of different avian species, especially poultry and passeriforms. The role of mycoplasmas in raptors has not yet been completely determined, and especially not the possibility of vertical transmission. Therefore 424 raptor eggs were examined for the occurrence of mycoplasmas using culture, and 155 of these eggs with a Mycoplasma genus-specific polymerase chain reaction (PCR) assay. This PCR was tested for its sensitivity and specificity, especially for use in a bird population of unknown mycoplasma status (prevalence and species). The size of the amplified PCR product was large (1013 base pairs) to enable use of the product for species differentiation by sequencing. Culture and PCR yielded only one positive result, in an egg of a Northern Goshawk (Accipiter gentilis). The isolate was identified as Mycoplasma lipofaciens using an immunobinding assay, as well as by sequencing part of its 16S rRNA gene.