RESUMO

Infections can have far-reaching sublethal effects on wildlife, including reduced maintenance of external structures. For many wildlife taxa, daily maintenance of external structures (termed preening in birds) is critical to fitness, but few studies have examined how infections alter such maintenance. Mycoplasma gallisepticum is a common pathogen in free-living House Finches (Haemorhous mexicanus), where it causes mycoplasmal conjunctivitis. Despite documented behavioral changes associated with M. gallisepticum infections in finches, no studies have examined how preening behavior may change with infection and how potential differences in preening may affect feather quality. To test this, we experimentally inoculated captive House Finches with M. gallisepticum or a control treatment, and we collected behavioral and feather quality data to detect potential changes in feather maintenance due to infection. We found that finches infected with M. gallisepticum preened significantly less often, and within the infected treatment, birds with the highest conjunctivitis severity preened the least often. However, there was no difference in the quality scores for secondary flight feathers collected from control versus infected birds. We also assayed feather water retention and found that the degree of water retention correlated with our feather quality scores, such that feathers with poor scores retained more water. However, as with quality scores, feather water retention did not differ with infection; this may be due to the controlled environment that the birds experienced while in captivity. Our data suggest that, in addition to sickness behaviors previously observed in finches, M. gallisepticum infection decreases other behaviors critical to survival, such as preening. While the consequences of reduced preening on feather maintenance were not apparent in captive conditions, further work is needed to determine whether House Finches in the wild that are infected with M. gallisepticum experience a fitness cost, such as increases in ectoparasite loads, due to this reduced feather maintenance.

Assuntos

RESUMO

The present work recorded the impact of using Mycoplasma gallisepticum vaccines on post-vaccinal response and protection against challenge with Newcastle disease virus. Specific pathogen-free chickens were divided into eight groups of forty chickens each. Group G1 was vaccinated with Mycoplasma gallisepticum live attenuated and Mycoplasma gallisepticum inactivated vaccines. Group G2 was vaccinated with Mycoplasma gallisepticum live attenuated, Mycoplasma gallisepticum inactivated and Newcastle disease inactivated vaccines. Group G3 was vaccinated with Mycoplasma gallisepticum live attenuated vaccine. Group G4 was vaccinated with Mycoplasma gallisepticum live attenuated and Newcastle disease inactivated vaccines. Group G5 was vaccinated with Mycoplasma gallisepticum inactivated vaccine. Group G6 was vaccinated with Mycoplasma gallisepticum inactivated and Newcastle disease inactivated vaccines. Group G7 was vaccinated with Newcastle disease inactivated vaccine. Group G8 was kept as non-vaccinated control. The Newcastle disease hemagglutination inhibition antibodies and mortality percentages were measured. Group G7 recorded the best protective Newcastle disease hemagglutination inhibition antibody titer (7 log2). Group G2 recorded a marginal satisfactory antibody titer (6 log2) after vaccination by the three tested vaccines. The remaining groups revealed unsatisfactory titers ranged from 0-5. The protection levels for G2, G4, G6 and G7 ranged from 70percent to 100percent, but only G2 and G7 were considered protected. G1, G3, G5 and G8 showed typical clinical signs of Newcastle disease. The Mycoplasma gallisepticum vaccines couldn't improve the response to Newcastle disease inactivated vaccine. The results suggest that Mycoplasma gallisepticum vaccination is immunosuppressive rather than immunomodulatory in Newcastle disease vaccination(AU)

En el presente trabajo se registró el impacto de la utilización de vacunas contra Mycoplasma gallisepticum sobre la respuesta posvacunal y la protección frente al reto con el virus de la enfermedad de Newcastle. Pollos libres de patógenos específicos se distribuyeron en ocho grupos de cuarenta pollos cada uno. El grupo G1 se vacunó con vacunas vivas atenuadas e inactivadas contra Mycoplasma gallisepticum. Al grupo G2 se le aplicaron las vacunas: viva atenuada contra Mycoplasma gallisepticum, inactivada contra Mycoplasma gallisepticum e inactivada contra la enfermedad de Newcastle. El grupo G3 se inmunizó con la vacuna viva atenuada contra Mycoplasma gallisepticum; el G4, con las vivas atenuadas contra Mycoplasma gallisepticum e inactivada contra la enfermedad de Newcastle; el G5, con la vacuna inactivada contra Mycoplasma gallisepticum; el G6 con las vacunas inactivadas contra Mycoplasma gallisepticum y la enfermedad de Newcastle; el G7, con la vacuna inactivada contra la enfermedad de Newcastle y el G8 se mantuvo como control no vacunado. Se midieron los anticuerpos de inhibición de la hemaglutinación contra el virus de la enfermedad de Newcastle y los porcentajes de mortalidad. El grupo G7 registró el mejor título de anticuerpos inhibidores de la hemaglutinación contra la enfermedad de Newcastle (7 log2). El grupo G2 registró un título de anticuerpos marginalmente satisfactorio (6 log2) tras la vacunación con las tres vacunas ensayadas. Los demás grupos revelaron títulos insatisfactorios que oscilaban entre 0 y 5. Los niveles de protección de los grupos G2, G4, G6 y G7 oscilaron entre el 70 por ciento y el 100 por ciento, pero sólo G2 y G7 se consideraron protegidos. Los grupos G1, G3, G5 y G8 mostraron signos clínicos típicos de la enfermedad de Newcastle. Las vacunas contra Mycoplasma gallisepticum no pudieron mejorar la respuesta a la vacuna inactivada contra la enfermedad de Newcastle. Los resultados revelan que la vacunación con Mycoplasma gallisepticum es más inmunosupresora que inmunomoduladora en la vacunación contra la enfermedad de Newcastle(AU)

Assuntos

RESUMO

Mycoplasma gallisepticum (MG) is among the most significant problems in the poultry industry worldwide, representing a serious threat to international trade. Despite the fact that the mgc2 gene has been widely used for diagnostic and molecular characterization purposes, there is a lack of evidence supporting the reliability of this gene as a marker for molecular epidemiology approaches. Therefore, the current study aimed to assess the accuracy of the mgc2 gene for phylogenetic, phylodynamic, and phylogeographic evaluations. Furthermore, the global phylodynamic expansion of MG is described, and the origin and extension of the outbreak caused by MG in Ecuador were tracked and characterized. The results obtained strongly supported the use of the mgc2 gene as a reliable phylogenetic marker and accurate estimator for the temporal and phylogeographic structure reconstruction of MG. The phylodynamic analysis denoted the failures in the current policies to control MG and highlighted the imperative need to implement more sensitive methodologies of diagnosis and more efficient vaccines. Framed in Ecuador, the present study provides the first piece of evidence of the circulation of virulent field MG strains in Ecuadorian commercial poultry. The findings derived from the current study provide novel and significant insights into the origin, diversification, and evolutionary process of MG globally.

RESUMO

This study aimed to compare method-based and newly developed sample-based methods for Mycoplasma gallisepticum (MG) detection in different samples of breeder flocks suffering from respiratory disease problems by using culture, real-time PCR (rPCR) and ELISA from chicks and embryonated eggs. Overall, 450 samples of 19-day-old chicken embryos trachea, 450 samples of 8-day-old chicken tracheal swabs and 900 blood samples of 20-, 27-, 34-, 40- and 46-week-old breeder chickens from 5 flocks were sampled for 26 weeks, and were all tested for MG by culture, MG-rPCR and MG-ELISA. Culturing assays and rPCR were applied to 450 mixture samples from 19-day-old chicken embryos trachea and 450 tracheal swab samples (each pooled into groups of 3) from 8-day-old chicks from the same flocks. Also, 900 blood samples from the same 5 breeder flocks suffering from respiratory disease problems were tested by MG-ELISA. In individual sample-based analyses, 55 (18.3%) of the 300 pooled swab samples were positive for MG using culture methods, and 106 (35.3%) of the same samples were found positive by rPCR (sensitivity, specificity). The ELISAs indicated that 252 (28%) of the 900 breeding blood samples were MG seropositive. Using age-based analyses, the most positive period was 46 weeks, followed by 40 weeks, 34 weeks, 27 weeks and at least 20 weeks, in order of decreasing seropositivity. When comparing the culture and rPCR results of the two different sampling methods, chicken embryos trachea yielded more positive results than did tracheal swabs from the same flocks. In conclusion, rPCR is a highly specific, sensitive and reliable method for MG identification.

Assuntos

RESUMO

This study aimed to compare method-based and newly developed sample-based methods for Mycoplasma gallisepticum (MG) detection in different samples of breeder flocks suffering from respiratory disease problems by using culture, real-time PCR (rPCR) and ELISA from chicks and embryonated eggs. Overall, 450 samples of 19-day-old chicken embryos trachea, 450 samples of 8-day-old chicken tracheal swabs and 900 blood samples of 20-, 27-, 34-, 40- and 46-week-old breeder chickens from 5 flocks were sampled for 26 weeks, and were all tested for MG by culture, MG-rPCR and MG-ELISA. Culturing assays and rPCR were applied to 450 mixture samples from 19-day-old chicken embryos trachea and 450 tracheal swab samples (each pooled into groups of 3) from 8-day-old chicks from the same flocks. Also, 900 blood samples from the same 5 breeder flocks suffering from respiratory disease problems were tested by MG-ELISA. In individual sample-based analyses, 55 (18.3%) of the 300 pooled swab samples were positive for MG using culture methods, and 106 (35.3%) of the same samples were found positive by rPCR (sensitivity, specificity). The ELISAs indicated that 252 (28%) of the 900 breeding blood samples were MG seropositive. Using age-based analyses, the most positive period was 46 weeks, followed by 40 weeks, 34 weeks, 27 weeks and at least 20 weeks, in order of decreasing seropositivity. When comparing the culture and rPCR results of the two different sampling methods, chicken embryos trachea yielded more positive results than did tracheal swabs from the same flocks. In conclusion, rPCR is a highly specific, sensitive and reliable method for MG identification.(AU)

Assuntos

RESUMO

The objective of this study was to identify the species and characterize the genetic relationships among mycoplasma isolates from commercial layer hen flocks using 16S-23S rDNA intergenic spacer region (IGSR) sequencing. Twenty-one isolates were obtained from samples collected from commercial layer flocks in four Brazilian states: São Paulo, Minas Gerais, Rio de Janeiro and Espírito Santo. The isolates were recovered from the São Paulo, Rio de Janeiro and Espírito Santo states. Eleven isolates were originated from tracheal swabs, five from shell gland swabs and five from ovary fragment collection. The 16S-23S rDNA IGSR of isolates were amplified by PCR, and the obtained products were subsequently sequenced. The consensus of each isolate was compared to the available sequences using Nucleotide BLAST® to determine the mycoplasma species. A phylogenetic analysis of the Mycoplasma gallisepticum (MG) sequences was performed. Pairwise analyses showed homologies of 99% to 100% with the previously characterized sequences listed in GenBank®. Four Mycoplasma gallinaceum were isolated from three flocks and seven M. pullorum isolates were obtained from a single flock. The other 10 isolates were all identified as MG and were obtained from four flocks. The 16S-23S rDNA IGSR sequencing was a good method to identify Mycoplasma species isolated from field samples, providing fast and reliable results at relatively low costs. The results were also satisfactory for the single-locus sequence typing of MG isolates.

Assuntos

RESUMO

The objective of this study was to identify the species and characterize the genetic relationships among mycoplasma isolates from commercial layer hen flocks using 16S-23S rDNA intergenic spacer region (IGSR) sequencing. Twenty-one isolates were obtained from samples collected from commercial layer flocks in four Brazilian states: São Paulo, Minas Gerais, Rio de Janeiro and Espírito Santo. The isolates were recovered from the São Paulo, Rio de Janeiro and Espírito Santo states. Eleven isolates were originated from tracheal swabs, five from shell gland swabs and five from ovary fragment collection. The 16S-23S rDNA IGSR of isolates were amplified by PCR, and the obtained products were subsequently sequenced. The consensus of each isolate was compared to the available sequences using Nucleotide BLAST® to determine the mycoplasma species. A phylogenetic analysis of the Mycoplasma gallisepticum (MG) sequences was performed. Pairwise analyses showed homologies of 99% to 100% with the previously characterized sequences listed in GenBank®. Four Mycoplasma gallinaceum were isolated from three flocks and seven M. pullorum isolates were obtained from a single flock. The other 10 isolates were all identified as MG and were obtained from four flocks. The 16S-23S rDNA IGSR sequencing was a good method to identify Mycoplasma species isolated from field samples, providing fast and reliable results at relatively low costs. The results were also satisfactory for the single-locus sequence typing of MG isolates.(AU)

Assuntos

RESUMO

In 1994, an endemic poultry pathogen, Mycoplasma gallisepticum (MG), was identified as the causative agent of a novel disease in house finches ( Haemorhous mexicanus). After an initial outbreak in Maryland, MG spread rapidly throughout eastern North American populations of house finches. Subsequently, MG spread slowly through the northern interior of North America and then into the Pacific Northwest, finally reaching California in 2006. Until 2009, there were no reports of MG in the southwestern United States east of California. In August 2011, after reports of house finches displaying conjunctivitis characteristic of MG infection in Arizona, we trapped house finches at bird feeders in central Arizona (Tempe) and southern Arizona (Tucson and Green Valley) to assay for MG infection. Upon capture, we noted whether birds exhibited conjunctivitis, and we collected choanal swabs to test for the presence of MG DNA using PCR. We detected MG in finches captured from Green Valley (in ∼12% of birds captured), but not in finches from Tucson or Tempe. Based on resampling of house finches at these sites in July 2014, we suggest that central Arizona finches likely remain unexposed to MG. We also suggest that low urban connectivity between arid habitats of southern and central Arizona or a reduction in the prevalence of MG after its initial arrival in Arizona may be limiting the spread of MG from south to north in Arizona. In addition, the observed conjunctivitis-like signs in house finches that were negative for MG by PCR may be caused primarily by avian pox virus.

Assuntos

RESUMO

Backyard poultry farms in Trinidad and Tobago (T&T) play a vital role in providing food and income for rural communities. There is currently no information on the presence and circulation of pathogens in backyard poultry farms in T&T, and little is known in relation to the potential risks of spread of these pathogens to the commercial poultry sector. In order to address this, serum samples were collected from 41 chickens on five backyard farms taken from selected locations in Trinidad. Samples were tested for antibodies to seven priority pathogens of poultry by enzyme-linked immunosorbent assay (ELISA). Antibodies were detected in 65% (CI 95%: 50-78%) of the sampled birds for Infectious bronchitis virus (IBV), 67.5% (CI 95%: 52-80%) for Infectious bursal disease virus (IBDV), 10% (CI 95%: 4-23%) for Newcastle disease virus (NDV), 0% (CI 95%: 0-0%) for Avian influenza virus (AIV), 0% (CI 95%: 0-0%) for West Nile virus (WNV), 31.7% (CI 95%: 20-47%) for Mycoplasm gallisepticum/synoviae and 0% (CI 95%: 0-0%) for Salmonella enterica serotype Enteritidis. These results reveal the presence and circulation of important pathogens of poultry in selected backyard farms in Trinidad. The results provide important information which should be taken into consideration when assessing the risks of pathogen transmission between commercial and backyard poultry farms, as well as between poultry and wild birds.

RESUMO

: In 1994 Mycoplasma gallisepticum was found to be the etiologic agent of House Finch ( Haemorhous mexicanus) conjunctivitis, a rapidly expanding epidemic caused by a genetically discrete, House Finch-associated strain of M. gallisepticum (HFMG). While most prominent in House Finches, HFMG has been reported in other members of the family Fringillidae, including American Goldfinches ( Spinus tristis), Purple Finches ( Haemorhous purpureus), Pine Grosbeaks ( Pinicola enucleator), and Evening Grosbeaks ( Coccothraustes vespertinus). Herein we report two new potential host species of HFMG strain, the Lesser Goldfinch ( Spinus psaltria), belonging to the Fringillidae family, and the Western (California) Scrub Jay ( Aphelocoma californica), belonging to the Corvidae family. The latter is one of only two reports of HFMG being found outside the Fringillidae family, and of these is the only one reported outside of captivity. Furthermore, non-HFMG M. gallisepticum was identified in an American Crow ( Corvus brachyrhynchos), indicating presence of additional strains in wild birds. Strain typing of M. gallisepticum isolates was done via HFMG-specific quantitative PCR analysis and validated using random amplified polymorphic DNA analysis. Our results suggested an expanded host range of HFMG strain, and further suggested that the host range of HFMG was not limited to members of the family Fringillidae.

Assuntos