Survey of pathogens in threatened wild red-tailed Amazon parrot (Amazona brasiliensis) nestlings in Rasa Island, Brazil

ABSTRACT The red-tailed Amazon parrot (Amazona brasiliensis) is a threatened species of psittacine bird that inhabit coastal regions of Brazil. In view of the threat of this species, the aim of this study was to perform a health evaluation in wild nestlings in Rasa Island, determining the prevalence of enterobacteria and infectious agents according to type of nest. Blood samples were collected from 64 birds and evaluated for antibodies of Chlamydia psittaci by commercial dot-blot ELISA. Cloacal and oropharyngeal swabs samples were collected from 23 birds from artificial wooden nests, 15 birds from PVC nests and 2 birds from natural nests for microbiological analysis. Swab samples were collected from 58 parrots for C. psittaci detection by PCR and from 50 nestlings for Avian Influenza, Newcastle Disease and West Nile viruses' detection analysis by real-time RT-PCR. Ten bacterial genera and 17 species were identified, and the most prevalent were Escherichia coli and Klebsiella oxytoca. There was no influence of the type of nest in the nestlings' microbiota. All samples tested by ELISA and PCR were negative. There is currently insufficient information available about the health of A. brasiliensis and data of this study provide a reference point for future evaluations and aid in conservation plans.

Clinical and serological tests for arboviruses in free-living domestic pigeons (Columba livia)

BACKGROUND In this study, we evaluated the role of free-living domestic pigeons (Columba livia) as a reservoir of arboviruses in the city of Belém, state of Pará, Brazil. We investigated the presence of antibodies against the most prevalent arboviruses. OBJECTIVES This study was aimed at evaluating some clinical and physical parameters of domestic pigeons, including the presence of antibodies to Amazon-endemic arboviruses. METHODS Eighty-five healthy pigeons were captured in Mangal das Garças Park, in Belém, and were bled. Upon capture, the birds were subjected to a clinical examination in search of alterations that could indicate the presence of arboviruses. Blood samples were converted to serum and tested using the haemagglutination inhibition (HI) technique with a panel of 19 antigens of arboviruses circulating in the Amazon. The confirmation assay for the positive reactions to the viral species tested by HI was a neutralisation test in new-born Swiss albino mice (Mus musculus) [mouse neutralisation test (MNT)]. FINDINGS A total of 10 (11.8%) serum samples tested positive for antiflavivirus antibodies by HI. All the samples positive for the HI test were subjected to MNT for detection of viruses and yielded negative results (logarithmic neutralisation index < 1.7). MAIN CONCLUSION The results represent the first serological detection of antiarbovirus antibodies in domestic pigeons as potential hosts of arboviruses in Brazil. The detection of haemagglutination-inhibiting antibodies against genus Flavivirus indicated that there was recent contact between the analysed domestic pigeons and these arboviruses. Further studies are needed to evaluate the role of free-living pigeons in the maintenance cycle and spread of arboviruses in the Amazon.

Genotypic characterization of psittacid herpesvirus isolates from Brazil

Abstract Thirty-six isolates of psittacid herpesvirus (PsHV), obtained from 12 different species of psittacids in Brazil, were genotypically characterized by restriction fragment length polymorphism (RFLP) analysis and PCR amplification. RFLP analysis with the PstI enzyme revealed four distinct restriction patterns (A1, X, W and Y), of which only A1 (corresponding to PsHV-1) had previously been described. To study PCR amplification patterns, six pairs of primers were used. Using this method, six variants were identified, of which, variants 10, 8, and 9 (in this order) were most prevalent, followed by variants 1, 4, and 5. It was not possible to correlate the PCR and RFLP patterns. Twenty-nine of the 36 isolates were shown to contain a 419 bp fragment of the UL16 gene, displaying high similarity to the PsHV-1 sequences available in GenBank. Comparison of the results with the literature data suggests that the 36 Brazilian isolates from this study belong to genotype 1 and serotype 1.

Detection of infectious bronchitis virus in chickens and other avian species using reverse transcription-polymerase chain reaction

The current study was conducted to investigate the incidence of IBV in commercial chicken farms suspected of having IBV infection, as well as other available avian species [turkeys, pigeons, parrots and canaries] revealed respiratory manifestations. Reverse-transcriptase polymerase chain reactions [RT-PCRs] were used to examine RNA extracted from tracheal swabs as well as corresponding harvested inoculated allantoic fluids. The universal oligonucleotide primers used were based on conserved sequences of IBV nucleocapsid [N] protein to ensure a very wide detection range. The overall RT-PCRs detection rates were 24/65 [37%] for the swab samples and 18/65 [28%] for allantoic harvests, while the revealing rates varied between 12/15 [80%], 10/15 [66.7%] in chickens, 5/15 [33.3%], 3/15 [20%] in turkeys, 3/15 [20%], 3/15 [20%] in pigeons and 4/15 [26.7%]. 2/15 [13.3%] in parrots for the swab samples and allantoic harvests respectively. It could be concluded that: RT-PCR using this universal oligonucleotide primer can be used to screen field samples suspected of containing IBVs. Once positive samples are identified, they are inoculated into embryonating chicken eggs for traditional virus isolation, serotyping and gene sequences. In addition; there is a real threat of IB spreading among chickens and other avian species[indeed, present in Turkeys, Pigeons and parrots]. However, it remains unclear how this virus emerged in that birds so further studies are recommended. For the author knowledge no previous statement of IBV infection in other avian species in Egypt were recorded

Apoptosis induced in vivo by new type gosling viral enteritis virus

In this study, apoptosis was induced by new type gosling viral enteritis virus (NGVEV) in experimentally infected goslings is reported in detail for the first time. After 3-day-old goslings were orally inoculated with a NGVEV-CN strain suspension, the time course of NGVEV effects on apoptotic morphological changes of the internal tissues was evaluated. These changes were observed by histological analysis with light microscopy and ultrastructural analysis with transmission electron microscopy. DNA fragmentation was assessed with a terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) assay and DNA ladder analysis. A series of characteristic apoptotic morphological changes including chromatin condensation and margination, cytoplasmic shrinkage, plasma membrane blebbing, and formation of apoptotic bodies were noted. Apoptosis was readily observed in the lymphoid and gastrointestinal organs, and sporadically occurred in other organs after 3 days post-infection (PI). The presence and quantity of TUNEL-positive cells increased with infection time until 9 days PI. DNA extracted from the NGVEV-infected gosling cells displayed characteristic 180~200 bp ladders. Apoptotic cells were ubiquitously distributed, especially among lymphocytes, macrophages, monocytes, and epithelial and intestinal cells. Necrosis was subsequently detected during the late NGVEV-infection phase, which was characterized by cell swelling, plasma membrane collapse, and rapidly lysis. Our results suggested that apoptosis may play an important role in the pathogenesis of NGVE disease.

West Nile virus activity in Latin America and the Caribbean / La actividad del virus del Nilo occidental en América Latina y el Caribe

OBJECTIVES. West Nile virus (Flavivirus: Flaviviridae; WNV) has spread rapidly throughout the Caribbean Basin since its initial detection there in 2001. This report summarizes our current knowledge of WNV transmission in tropical America. METHODS. We reviewed the published literature and consulted with key public health officials to obtain unpublished data. RESULTS. West Nile virus infections first appeared in human residents of the Cayman Islands and the Florida Keys in 2001, and in apparently healthy Jamaican birds sampled early in 2002. Serologic evidence of WNV infection in 2002 was detected in horses, chickens and resident free-ranging birds in Guadeloupe, the Dominican Republic, and eastern Mexico. In 2003, WNV spread in Mexico and northern Central America, and serologic evidence was detected in the Bahamas, Puerto Rico and Cuba. In 2004, the first serologic evidence of WNV activity in South American ecosystems surfaced in September-October in Colombia and Trinidad, where domestic animals circulated WNV-neutralizing antibodies. CONCLUSIONS. The sparse reports of equine, human and avian disease in Latin America and the Caribbean is puzzling. Isolates are needed to evaluate viral attenuation or other possible explanations for reduced disease burden in tropical ecosystems.

OBJETIVOS: El virus del Nilo occidental (VNO, familia Flaviviridae, género Flavivirus) se ha propagado rápidamente por toda la cuenca del Caribe desde que se detectó por primera vez en 2001. En este informe se resumen nuestros conocimientos actuales acerca de la transmisión del VNO en zonas tropicales del continente americano. MÉTODOS: Revisamos todo lo que se ha publicado sobre el tema y consultamos a autoridades de salud clave para obtener datos inéditos. RESULTADOS: Las infecciones por el virus del Nilo occidental aparecieron por primera vez en seres humanos residentes de las Islas Caimán y de los Cayos de la Florida en 2001, y en pájaros de aspecto sano de los cuales se obtuvieron muestras a principios de 2002. En 2002 se encontraron pruebas serológicas de infección por el VNO en caballos, pollos y aves de corral no estabuladas oriundas de Guadalupe, la República Dominicana y la parte oriental de México. En 2003, el VNO se diseminó dentro de México y por la parte norte de Centroamérica y se encontraron pruebas serológicas en las Bahamas, Puerto Rico y Cuba. En 2004, las primeras pruebas serológicas de actividad vírica en ecosistemas sudamericanos se detectaron en septiembre y octubre en Colombia y Trinidad, donde se observaron anticuerpos neutralizantes contra el VNO en animales domésticos. CONCLUSIONES: Estos informes esporádicos de enfermedad equina, humana y aviar en América Latina y el Caribe son desconcertantes. Es necesario aislar las cepas para determinar si la atenuación del virus u otro factor explica la carga de enfermedad reducida en ecosistemas tropicales.

Caracterización antigénica de un virus de la bronquitis infecciosa, aislado en pollos de traspatio en Yucatán, México / Antigenic characterization of an infectious bronchitis virus isolated in backyard chicken in the state of Yucatan, Mexico

La producción animal de traspatio es una actividad tradicional en México, cuya finalidad es solucionar algunos problemas de la difícil situación económica de los campesinos. Los pollo son la especie más común en dicho sistema en Yucatán y son alimentados con subproductos, En estudios previos se encontró que las enfermedades respiratorias constituyen las más importantes en estos animales. En el presente estudio se obtuvo un aislamiento del virus de la bronquitis infecciosa en pollos de engorda introducidos al traspatio del poblado Sinanché, Yucatán, México; aquél se denominó SIN6. La caracterización antigénica de este aislamiento se realizó mediante la prueba de inhibición de la hemaglutinación, utilizando antígeno hemaglutinante producido a partir de 11 serotipos de referencia del virus de la bronquitis infecciosa (Massachusetts 41, Arkansas, Connecticut, Holte, CVL/9, 793/B, Holandés 274, Holandés 1466, Australiano "T", italiano 624, y Chileno 368), y antisueros contra estos serotipos y el Iowa 97; de este último no se logró obtener antígeno a pesar de repetidos intentos. El aislamiento SIN6 tuvo una relación antigénica baja con todos los serotipos de referencia, lo que indica que probablemente es un serotipo nuevo, aunque estudios de secuencia genética son necesarios para confirmarlo. El serotipo CVL/9 presentó una fuerte relación antigénica con todos los demás, esta circunstancia lo hace un candidato para la producción de una vacuna universal contra la bronquitis infecciosa

Hemagglutinating and fusogenic activities of Newcastle disease virus: studies on receptor binding specificity and pH-induced conformational changes

Vaccinal and wild strains of Newcastle Disease virus (NDV) were analyzed for cell receptor binding and fusogenic biological properties associated with their HN (hemagglutinin-neuraminidase) and F (fusion protein) surface structures respectively. The evaluation of the biological activities of HN and F was carried out respectively by determination of hemagglutinating titers and hemolysis percentages, using erythrocytes from various animal origins at different pH values. Significant differences in hemagglutination titers for some strains of NDV were detected, when interacting with goose, sheep, guinea-pip and human "O" group erythrocytes at neutral pH. Diversity of hemolysis percentagens was observed between different NDV strains at acid pH. These analysis were developed to evaluate particular aspects of the actual influence of the receptor specifity and pH on the receptor binding and fusogenic processes of Newcastle Disease viruses.