Mycoplasma species in psittacine birds with respiratory disease

Absence of Mycoplasma spp. in nightingales (Luscinia megarhynchos) and blue (Cyanistes caeruleus) and great tits (Parus major) in Germany and its potential implication for evolutionary studies in birds

Mycoplasma spp. are important pathogens in poultry and cause high economic losses for poultry industry worldwide. In other bird species (e.g. white storks, birds of prey, and several waterfowl species), Mycoplasma spp. are regularly found in healthy individuals, hence, considered apathogenic or part of the microbiota of the upper respiratory tract. However, as Mycoplasma spp. are absent in healthy individuals of some wild bird species, they might play a role as respiratory pathogen in these bird species, e.g. Mycoplasma gallisepticum in house finches. The knowledge on the occurrence of Mycoplasma spp. in wild birds is limited. To evaluate the relevance of Mycoplasma spp. in free-ranging nightingales and tits, 172 wild caught birds were screened for the presence of mycoplasmas. The birds were sampled via choanal swabs and examined via molecular methods (n = 172) and, when possible, via culture (n = 142). The Mycoplasma sp. was determined by sequencing the 16S rRNA gene and 16S-23S Intergenic Transcribed Spacer Region. All birds were tested negative for mycoplasmas via PCR and/or mycoplasmal culture. Hence, free-ranging nightingales and tits do not show any mycoplasma in their microbial flora of the respiratory tract. Therefore, these songbird species may suffer from clinical mycoplasmosis when being infected. We hypothesize that birds relying on their vocal ability for reproduction have excluded mycoplasmas from their respiratory flora compared to other bird species.

Mycoplasma hafezii sp. nov., isolated from the trachea of a peregrine falcon (Falco peregrinus)

Mycoplasma species are well known pathogens in avian medicine, especially in poultry. However, several Mycoplasma species have been regularly found in the respiratory tract of birds of prey which seem to be commensals in these bird species. In previous studies, an unknown Mycoplasma species which caused false positive results in a Mycoplasma meleagridis-specific PCR, was isolated from a tracheal swab of a clinically healthy, captive, adult peregrine falcon (Falco peregrinus). The isolate appeared in typical fried-egg-shaped colonies on SP4 agar plates and was dependent on sterol for growth. Acid was produced from glucose, but no arginine or urea was hydrolysed. The temperature range for growth was 28-44 °C, with an optimum at 37 °C. Strain M26^T was serologically distinct from all species of the genus Mycoplasma with 16S rRNA gene sequence similarity ≥94 %. Biochemical, serological and molecular biological properties demonstrate that this organism represents a novel species of the genus Mycoplasma, for which the name Mycoplasma hafezii sp. nov. is proposed; the type strain is M26^T (NCTC 13928, DSM 27652).

OCCURRENCE AND RELEVANCE OF MYCOPLASMA STURNI IN FREE-RANGING CORVIDS IN GERMANY

Several Mycoplasma spp. are well-known pathogens in poultry. In birds of prey, White Storks ( Ciconia ciconia ), and some waterfowl (Anatidae, Pelecanidae) species, mycoplasmas occur commonly and seem to be apathogenic or commensal and most likely belong to the physiologic microbial flora of the respiratory tract. In other bird species, such as Common Nightingales ( Luscinia megarhynchos ) and tits (Paridae), Mycoplasma spp. are absent in healthy birds. In corvids, the prevalence and role of Mycoplasma spp. in disease remains unclear. In previous studies, Mycoplasma sturni was detected in diseased corvids; however, those studies included only a limited sample size or preselected individuals. We collected tracheal swabs of 97 free-ranging Corvidae, including 68 randomly selected individuals from hunting bags and 29 birds that had been admitted to a veterinary clinic. Tracheal swabs were examined for Mycoplasma spp. using culture and genus-specific PCR. If Mycoplasma spp. were detected, the species were identified by sequencing the 16S ribosomal (r) RNA gene and 16-23S rRNA intergenic transcribed spacer region. Five of 68 (7%) of the hunted birds and nine of 29 (31%) of the birds admitted to the veterinary clinic were PCR positive. In 13 of 14 PCR-positive samples, mycoplasmas were cultured and M. sturni was the only mycoplasmal species identified. None of the positive corvids from the hunting bags had clinical signs, whereas five of nine birds admitted to the veterinary clinic showed apathy, lameness, injuries, or fractures, which may not be associated with mycoplasmal infections. These data support the notion that M. sturni is the Mycoplasma sp. most frequently found in corvids, though its prevalence and ability to cause disease may involve interaction with other aspects of bird health.

Description and prevalence of Mycoplasma ciconiae sp. nov. isolated from white stork nestlings (Ciconia ciconia)

The mycoplasma strain ST 57T was isolated from the trachea of a clinically healthy, free-ranging white stork nestling in Nielitz, Mecklenburg-Western Pomerania, Germany. Strain ST 57T grew in fried-egg-shaped colonies on mycoplasma (SP4) agar plates and was dependent on sterol for growth. The organism fermented glucose and did not hydrolyse arginine or urea. The optimal growth temperature was 37 °C, with a temperature range from 23 to 44 °C. Strain ST 57Tcould not be identified as a representative of any of the currently described mycoplasma species by alignment of the 16S rRNA gene sequence or 16S-23S intergenic transcribed spacer region, or by immunobinding assays. Thus, this organism appears to be a representative of a novel species, for which the name Mycoplasma ciconiae sp. nov. is proposed. The type strain is ST 57T (=ATCC BAA-2401T=DSM 25251T). Four further strains of this species are included in this description (ST 24=DSM 29908, ST 56 Clone 1=DSM 29054, ST 99=DSM 29909, ST 102=DSM 29010). The prevalence of this mycoplasma species in clinically healthy, white stork nestlings in northern Germany was determined. Our species-specific PCR detected 57.8 % (48/83) of the samples positive for M. ciconiae sp. nov. As this species appears to be widespread in the healthy free-ranging white stork population, we conclude that this species is either apathogenic or an opportunistic pathogen in white storks.

Detecção molecular e isolamento de Mycoplasma spp. em psitacídeos no estado de Pernambuco, Brasil

Objetivou-se com este estudo investigar a ocorrência de Mycoplasma spp., Mycoplasma galissepticum (MG) e Mycoplasma synoviae (MS) em psitacídeos de cativeiro localizado no estado de Pernambuco, Brasil. Foram estudadas 85 aves provenientes do Parque Estadual Dois Irmãos, localizado no estado do Pernambuco, Brasil. De cada psitacídeo analisado foram obtidas três amostras por meio de swabs da cloaca, palato e conjuntiva totalizando 255 amostras. As amostras coletadas foram submetidas à extração de DNA e à reação em cadeia da polimerase (PCR), sendo as positivas submetidas ao isolamento em ágar Frey. O DNA de Mycoplasma spp. foi detectado em 16,47% (14/85) dos psitacídeos estudados. Das 255 amostras analisadas, 6,66% (17/255) foram positivas para a presença de Mycoplasma spp., sendo 41,18% (7/17) provenientes da conjuntiva, 35,29% (6/17) do palato e 23,53% (4/17) da cloaca. Nenhuma amostra foi positiva para MG ou MS na PCR. Os resultados obtidos permitem confirmar a presença do DNA de Mycoplasma spp. em conjuntiva, palato e cloaca nas aves estudadas. Foram detectadas colônias semelhantes a membros da classe Mollicutes em 17,64% das amostras (3/17). Esse é o primeiro relato da presença de Mycoplasma spp. em psitacídeos de cativeiro no Nordeste do Brasil.