Genetic variability of Mycoplasma synoviae detected in commercial layers in southeastern Brazil / Variabilidade genética de Mycoplasma synoviae detectado em poedeiras comerciais do sudeste do Brasil

Este estudo teve como objetivo caracterizar genótipos de M. synoviae circulantes em poedeiras comerciais, na Região Sudeste do Brasil. Para estabelecer a relação evolutiva entre as cepas de MS, foi analisada a sequência genética do gene vlhA de 11 cepas de MS identificadas no Rio de Janeiro e em São Paulo, de 10 outras cepas de MS identificadas no Brasil e cujas sequências foram depositadas no banco de dados GenBank, e da cepa vacinal MSH. O método da máxima verossimilhança e o modelo de Kimura com dois parâmetros foram utilizados para comparar as cepas. As sequências obtidas foram depositadas no Genbank, sob os números de acesso OP279775 a OP279785. Foi possível verificar a presença de diferentes cepas circulantes no Brasil, com alta similaridade entre as cepas do Rio de Janeiro pela análise do gene vlhA. As duas cepas paulistas detectadas no presente estudo possuem o baixo percentual (68%) de similaridade, demonstrando a variabilidade das cepas dessa localidade.

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.(AU)

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.

Prevalência e estudo genético de Mycoplasma gallisepticum e M. synoviae em poedeiras comerciais, na região centro-oeste do estado de São Paulo, Brasil / [Prevalence and genetic study of Mycoplasma gallisepticum and M. synoviae strains from commercial laying hens in the Midwest region of Sao Paulo state, Brazil]

O objetivo deste trabalho foi estudar a prevalência de MG e MS e a filogenia das cepas circulantes, comparando-as com outras já descritas em poedeiras comerciais no Brasil. Foram coletados 140 suabes traqueais de poedeiras comerciais com sinais respiratórios em seis granjas da região centro-oeste de São Paulo. As amostras foram avaliadas por PCR, com posterior sequenciamento e análise filogenética das cepas identificadas. Das 140 amostras, 16,4% foram positivas para MG e 68,6% para MS. Houve diferença significativa nas frequências de MG e MS por granja, segundo o teste G de independência (P<0,05). Todas as cepas identificadas de MG e MS de granjas distintas apresentaram similaridade tanto pela lipoproteína para MG quanto pela região 16s rRNA para MS. Neste estudo, foi possível observar altas prevalências dos agentes estudados, sendo a de MS maior que a de MG. Foi detectada infecção mista por MG e MS em 11,4% das amostras e sabe-se que esses micoplasmas podem agir de forma sinérgica, agravando o quadro respiratório. As cepas circulantes identificadas, pela análise das regiões gênicas da lipoproteína para MG e 16S rRNA para MS, são similares em todas as granjas estudadas.(AU)

The aim of this study was to evaluate the prevalence of MG and MS and the phylogeny of the circulating strains, comparing them with others already described in commercial laying hens from Brazil. A total of 140 tracheal swabs were collected from commercial laying hens with respiratory signs in six farms from the western region of São Paulo state. The samples were analyzed by PCR with subsequent sequencing and phylogenetic analysis of the identified strains. From the 140 samples, 68.6% were positive for MS and 16.4% for MG. There was a significant difference in the frequencies of MG and MS per farm according to G Test of independence (P<0.05). All strains identified as MG and MS from distinct farms presented similarity both by lipoprotein to MG and by 16s rRNA region to MS. In this study, it was possible to observe a high prevalence of MS compared to MG. Mixed MG and MS infection was detected in 11.4% of the samples. These mycoplasmas may act synergistically, worsening the respiratory signs. The circulating strains identified by analysis of the lipoprotein for MG and 16S rRNA for MS are similar on all poultry farms studied.(AU)

Prevalência e estudo genético de Mycoplasma gallisepticum e M. synoviae em poedeiras comerciais, na região centro-oeste do estado de São Paulo, Brasil / [Prevalence and genetic study of Mycoplasma gallisepticum and M. synoviae strains from commercial laying hens in the Midwest region of Sao Paulo state, Brazil]

O objetivo deste trabalho foi estudar a prevalência de MG e MS e a filogenia das cepas circulantes, comparando-as com outras já descritas em poedeiras comerciais no Brasil. Foram coletados 140 suabes traqueais de poedeiras comerciais com sinais respiratórios em seis granjas da região centro-oeste de São Paulo. As amostras foram avaliadas por PCR, com posterior sequenciamento e análise filogenética das cepas identificadas. Das 140 amostras, 16,4% foram positivas para MG e 68,6% para MS. Houve diferença significativa nas frequências de MG e MS por granja, segundo o teste G de independência (P<0,05). Todas as cepas identificadas de MG e MS de granjas distintas apresentaram similaridade tanto pela lipoproteína para MG quanto pela região 16s rRNA para MS. Neste estudo, foi possível observar altas prevalências dos agentes estudados, sendo a de MS maior que a de MG. Foi detectada infecção mista por MG e MS em 11,4% das amostras e sabe-se que esses micoplasmas podem agir de forma sinérgica, agravando o quadro respiratório. As cepas circulantes identificadas, pela análise das regiões gênicas da lipoproteína para MG e 16S rRNA para MS, são similares em todas as granjas estudadas.(AU)

The aim of this study was to evaluate the prevalence of MG and MS and the phylogeny of the circulating strains, comparing them with others already described in commercial laying hens from Brazil. A total of 140 tracheal swabs were collected from commercial laying hens with respiratory signs in six farms from the western region of São Paulo state. The samples were analyzed by PCR with subsequent sequencing and phylogenetic analysis of the identified strains. From the 140 samples, 68.6% were positive for MS and 16.4% for MG. There was a significant difference in the frequencies of MG and MS per farm according to G Test of independence (P<0.05). All strains identified as MG and MS from distinct farms presented similarity both by lipoprotein to MG and by 16s rRNA region to MS. In this study, it was possible to observe a high prevalence of MS compared to MG. Mixed MG and MS infection was detected in 11.4% of the samples. These mycoplasmas may act synergistically, worsening the respiratory signs. The circulating strains identified by analysis of the lipoprotein for MG and 16S rRNA for MS are similar on all poultry farms studied.(AU)