Detección y caracterización molecular de Chlamydia psittaci y Chlamydia abortus en psitácidos mascotas en la provincia de Buenos Aires, Argentina / Detection and molecular characterization of Chlamydia psittaci and Chlamydia abortus in psittacine pet birds in Buenos Aires province, Argentina

In order to determine the presence and genetic diversity of Chlamydia spp. in the north-eastern area of Buenos Aires province, Argentina, conjunctival, oropharyngeal, cloacal swab and tissues were collected from a total of 90 psittacine pet birds of different age and clinical manifestations. Through molecular methods, Chlamydiaceae was detected in 30% (27/90) of the samples, out of which 70.3% (19/27) were positive for Chlamydia psittaci and 14.9% (4/27) for Chlamydia abortus. Nine C. psittaci positive samples were genotyped by ompA gene sequences, 8 clustered within genotype A and 1 within genotype B. A significant association was observed between the presence of Chlamydia spp. and the manifestation of clinical signs compatible with chlamydiosis, as well as with the age of the birds (younger than one year old). This report contributes to the improvement of our understanding of chlamydial agents in our country.

Con el objetivo de determinar la presencia de Chlamydia spp. en psitácidos del área noreste de la provincia de Buenos Aires y conocer su diversidad genética, se recolectaron y analizaron mediante métodos moleculares hisopados conjuntivales, orofaríngeos, cloacales y tejidos de un total de 90 psitácidos de diferentes edades y con diversas manifestaciones clínicas. El 30% (27/90) de las muestras procesadas fueron positivas para Chlamydiaceae; el 70,3% (19/27) de estas resultaron positivas para Chlamydia psittaci y el 14,9% (4/27) para Chlamydia abortus. Nueve muestras positivas para C. psittaci fueron genotipificadas por secuenciación del gen ompA: 8 correspondieron al genotipo Ay una al genotipo B. Se observó una asociación significativa entre la presencia de Chlamydia spp. y la manifestación de signos clínicos compatibles con clamidiosis, como así también con la edad de las aves (menores de un ano). Este informe contribuye a mejorar nuestro conocimiento de los agentes clamidiales en nuestro país.

A combined retrospective, prospective and experimental study of Ornithobacterium rhinotracheale infection in chickens.

The aim of this study was to examine the histopathological and immunohistochemical changes caused by natural and experimentally-induced Ornithobacterium rhinotracheale infection in the respiratory system of chickens. To this end, three different studies were carried out. The first was a retrospective study of 82 field cases with respiratory disorders compatible with O. rhinotracheale infection. The bacterium was immunohistochemically detected in the lungs in 48 of 82 field cases, and 50 ß-haemolytic (BH) and non-haemolytic (NH) strains were isolated. In the second study, an experimental model of the disease was created using 3-week-old broiler chickens, to identify possible differences of pathogenicity between the BH and NH isolates by the intravenous (IV) and intratracheal (IT) inoculation routes (IR). The group challenged with the NH isolate showed more severe lung lesions than the group challenged with the BH isolate at 7-days postinoculation (p.i.). The 14-day p.i. groups challenged with either the BH or NH isolates by the IT or IV IR had a higher histologic grade of pulmonary and hepatic lesions and a higher total histologic grade of lesions suggesting more severe pathology with longer time of exposure. A direct association between the inoculation routes and the organs affected was shown. Finally, a slaughterhouse study was carried out from October 2014 to May 2015, in which the histologic grade of lesions was significantly higher in immunohistochemically positive for O. rhinotracheale lungs of dead-on-arrival chickens.

Detection and molecular characterization of Chlamydia psittaci and Chlamydia abortus in psittacine pet birds in Buenos Aires province, Argentina.

In order to determine the presence and genetic diversity of Chlamydia spp. in the north-eastern area of Buenos Aires province, Argentina, conjunctival, oropharyngeal, cloacal swab and tissues were collected from a total of 90 psittacine pet birds of different age and clinical manifestations. Through molecular methods, Chlamydiaceae was detected in 30% (27/90) of the samples, out of which 70.3% (19/27) were positive for Chlamydia psittaci and 14.9% (4/27) for Chlamydia abortus. Nine C. psittaci positive samples were genotyped by ompA gene sequences, 8 clustered within genotype A and 1 within genotype B. A significant association was observed between the presence of Chlamydia spp. and the manifestation of clinical signs compatible with chlamydiosis, as well as with the age of the birds (younger than one year old). This report contributes to the improvement of our understanding of chlamydial agents in our country.

Diagnosis of an outbreak of Salmonella typhimurium in chinchillas (Chinchilla lanigera) by pulsed-field gel electrophoresis.

Adult chinchillas (Chinchilla lanigera) that had suddenly died in a commercial farm located in La Plata City, Buenos Aires Province, Argentina, in July 2012 were macroscopically, histopathologically, and microbiologically examined. Salmonella enterica serovar Typhimurium (S. Typhimurium) was isolated from the liver, spleen, heart, lungs, kidneys and intestines from each of the five animals evaluated. The five strains were susceptible to ampicillin, cephalotin, cefotaxime, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, nitrofurantoin and trimethoprim-sulfamethoxazole, and resistant to tetracycline. Each of the five S. Typhimurium isolates was analyzed by XbaI- pulsed-field gel electrophoresis (PFGE), showing an identical electrophoretic profile with 15 defined bands, which was found to be identical to pattern ARJPXX01.0220 of the PulseNet Argentine National database of Salmonella PFGE patterns. This is the first work describing the postmortem diagnosis of an outbreak of salmonellosis in chinchillas by using molecular methods such as PFGE.

Diagnóstico de un brote de Salmonella Typhimurium en Chinchillas (Chinchilla lanigera) mediante la electroforesis en gel de campo pulsado / Diagnosis of an autbreak of Salmonella Typhimurium in chinchillas (Chinchilla lanigera) by pulsed-fiel gel electrophoresis

Empleando estudios anatomopatológicos y microbiológicos se examinó a un grupo de chinchillas (Chinchilla lanigera) adultas que murieron súbitamente en 2012 en una granja de la ciudad de La Plata (Buenos Aires, Argentina). Se aisló Salmonella enterica serovar Typhimurium (S. Typhimurium) del hígado, el bazo, el corazón, los pulmones, los riñones y los intestinos de los cinco animales evaluados. Los cinco aislamientos estudiados (uno por animal) fueron sensibles a ampicilina, cefalotina, cefotaxima, ácido nalidíxico, gentamicina, estreptomicina, cloranfenicol, fosfomicina, nitrofurantoína y trimetoprima-sulfametoxazol, y resistentes a tetraciclina. El análisis de dichos aislamientos por electroforesis en gel de campo pulsado [pulsed-field gel electrophoresis (PFGE)] con XbaI mostró un perfil electroforético idéntico con 15 bandas, idéntico a su vez al patrón ARJPXX01.0220 del banco nacional argentino de datos de PulseNet, que cuenta con patrones de PFGE de Salmonella. El presente trabajo describe por primera vez el diagnóstico postmortem de un brote de salmonelosis en chinchillas usando un método molecular, como la electroforesis en gel en campo pulsado

Adult chinchillas (Chinchilla lanigera) that had suddenly died in a commercial farm located in La Plata City, Buenos Aires Province, Argentina, in July 2012 were macroscopically, histopathologically, and microbiologically examined. Salmonella enterica serovar Typhimurium (S. Typhimurium) was isolated from the liver, spleen, heart, lungs, kidneys and intestines from each of the five animals evaluated. The five strains were susceptible to ampicillin, cephalotin, cefotaxime, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, nitrofurantoin and trimethoprimsulfamethoxazole, and resistant to tetracycline. Each of the five S. Typhimurium isolates was analyzed by XbaI- pulsed-field gel electrophoresis (PFGE), showing an identical electrophoretic profile with 15 defined bands, which was found to be identical to pattern ARJPXX01.0220 of the PulseNet Argentine National database of Salmonella PFGE patterns. This is the first work describing the postmortem diagnosis of an outbreak of salmonellosis in chinchillas by using molecular methods such as PFGE

Diagnosis of an outbreak of Salmonella typhimurium in chinchillas (Chinchilla lanigera) by pulsed-field gel electrophoresis. / Diagnosis of an outbreak of Salmonella typhimurium in chinchillas (Chinchilla lanigera) by pulsed-field gel electrophoresis.

Adult chinchillas (Chinchilla lanigera) that had suddenly died in a commercial farm located in La Plata City, Buenos Aires Province, Argentina, in July 2012 were macroscopically, histopathologically, and microbiologically examined. Salmonella enterica serovar Typhimurium (S. Typhimurium) was isolated from the liver, spleen, heart, lungs, kidneys and intestines from each of the five animals evaluated. The five strains were susceptible to ampicillin, cephalotin, cefotaxime, nalidixic acid, gentamicin, streptomycin, chloramphenicol, fosfomycin, nitrofurantoin and trimethoprim-sulfamethoxazole, and resistant to tetracycline. Each of the five S. Typhimurium isolates was analyzed by XbaI- pulsed-field gel electrophoresis (PFGE), showing an identical electrophoretic profile with 15 defined bands, which was found to be identical to pattern ARJPXX01.0220 of the PulseNet Argentine National database of Salmonella PFGE patterns. This is the first work describing the postmortem diagnosis of an outbreak of salmonellosis in chinchillas by using molecular methods such as PFGE.

Tracheitis in a broiler chicken flock caused by dual infection with Cryptosporidium spp. (Apicomplexa: Cryptosporiidae) and non-hemolytic Ornithobacterium rhinotracheale

Broiler chickens aged 41-day-old from a flock of a broiler complex, presenting depression, reduced food intake, facial edema, dyspnea, gasping, sneezing, and 5% mortality were studied. At necropsy, opaque thoracic and abdominal air sacs and mucous tracheal content were observed. Histopathology of tracheas showed multifocal hyperplasia of mucosa with a large number of small, round and ovoid basophilic organisms on their surface, which were identified as Cryptosporidium spp. In addition, there was an inflammatory response due to infiltration of mononuclear cells and heterophils in the submucosa. Small pin-point colonies without hemolytic activity were isolated from tracheal samples and identified as Ornithobacterium rhinotracheale by conventional and real time polymerase chain reaction (PCR). Results of tracheal histopathology, bacteriology, and PCR identification provided the diagnosis of tracheal cryptosporidiosis associated with non-hemolytic O. rhinotracheale secondary infection. This report describes the unusual dual infection with Cryptosporidium spp. and non-hemolytic O. rhinotracheale causing tracheitis in broiler chickens.

Pulmonary aspergillosis due to Aspergillus flavus infection in a captive Eclectus parrot (Eclectus roratus)

A 2-year-old captive, male Eclectus parrot (Eclectus roratus), with a previous history of neurologic signs episodes, was found dead in its cage without premonitory signs in a private aviary. At necropsy, yellow and caseous nodules were observed in the lungs. Microscopically, the nodules were composed of granulomas that had a necrotic center with intralesional hyphae typical of Aspergillus spp. and a peripheral inflammatory cell response composed of macrophages and multinucleated giant cells. The mycologic culture allowed the isolation and identification of A. flavus from lung samples. The gross and microscopic lesions, in combination with the mycologic identification provided the diagnosis of pulmonary aspergillosis due to A. flavus infection. To the authors´ knowledge, this is the first report of mycotic pneumonia caused by A. flavus infection in Psittaciformes. 

Pulmonary Aspergillosis due to Aspergillus flavus Infection in a Captive Eclectus Parrot (Eclectus roratus)

A 2-year-old captive, male Eclectus parrot (Eclectus roratus), with a previous history of neurologic signs episodes, was found dead in its cage without premonitory signs in a private aviary. At necropsy, yellow and caseous nodules were observed in the lungs. Microscopically, the nodules were composed of granulomas that had a necrotic center with intralesional hyphae typical of Aspergillus spp. and a peripheral inflammatory cell response composed of macrophages and multinucleated giant cells. The mycologic culture allowed the isolation and identification of A. flavus from lung samples. The gross and microscopic lesions, in combination with the mycologic identification provided the diagnosis of pulmonary aspergillosis due to A. flavus infection. To the authors´ knowledge, this is the first report of mycotic pneumonia caused by A. flavus infection in Psittaciformes.(AU)

Tracheitis in a Broiler Chicken Flock Caused by Dual Infection with Cryptosporidium spp. (Apicomplexa: Cryptosporiidae) and Non-hemolytic Ornithobacterium rhinotracheale

Broiler chickens aged 41-day-old from a flock of a broiler complex, presenting depression, reduced food intake, facial edema, dyspnea, gasping, sneezing, and 5% mortality were studied. At necropsy, opaque thoracic and abdominal air sacs and mucous tracheal content were observed. Histopathology of tracheas showed multifocal hyperplasia of mucosa with a large number of small, round and ovoid basophilic organisms on their surface, which were identified as Cryptosporidium spp. In addition, there was an inflammatory response due to infiltration of mononuclear cells and heterophils in the submucosa. Small pin-point colonies without hemolytic activity were isolated from tracheal samples and identified as Ornithobacterium rhinotracheale by conventional and real time polymerase chain reaction (PCR). Results of tracheal histopathology, bacteriology, and PCR identification provided the diagnosis of tracheal cryptosporidiosis associated with non-hemolytic O. rhinotracheale secondary infection. This report describes the unusual dual infection with Cryptosporidium spp. and non-hemolytic O. rhinotracheale causing tracheitis in broiler chickens.(AU)

Dispharynx nasuta (Nematoda:Acuariidae) infection causing proventricular lesions and death in three captive rosellas (Psittaciformes:Psittacidae).

Two adult male Crimson rosellas (Platycercus elegans) and an adult female eastern rosella (Platycercus eximius) were found dead in their cages in a private aviary in March 2009, April 2010, and February 2010, respectively, without premonitory signs. Their postmortem examination showed pectoral muscle atrophy and a distended proventriculus. The proventricular mucosal surface was covered with a gelatinous, whitish material, where a large number of nematode parasites identified as Dispharynx nasuta were present. A histologic examination revealed a hyperplastic mucosa, spirurid nematodes in the mucosal layer and inflammatory mononuclear cells in the lamina propria. This is the first report of a D. nasuta infection associated with proliferative proventriculitis and subsequent death in psittacine birds.

Pneumonia in broiler chicken flocks associated with -hemolytic Ornithobacterium rhinotracheale infection

Broiler chickens aged 40 and 46-days-old from two neighboring flocks belonging to a commercial broiler complex, presenting facial edema, severe respiratory signs and 10% mortality were analyzed. Pneumonic lesions and opaque thoracic and abdominal air sacs with foamy exudate were seen at postmortem examination. Histopathology of lungs showed fibrinoheterophilic pneumonia in both cases. Small pin point colonies with extensive -hemolytic activity were isolated from tracheal and lung tissue samples and identified as Ornithobacterium rhinotracheale by polymerase chain reaction (PCR). Results of lung histopathology, bacteriological isolation and PCR identification confirmed the diagnosis of pneumonia caused by -hemolytic O. rhinotracheale infection in both broiler chicken flocks. This paper appears to be the first report of -hemolytic O. rhinotracheale field isolates obtained from broiler chickens associated with severe respiratory signs and pneumonia.

Pneumonia in Broiler Chicken Flocks Associated with ß-Hemolytic Ornithobacterium rhinotracheale Infection

Broiler chickens aged 40 and 46-days-old from two neighboring flocks belonging to a commercial broiler complex, presenting facial edema, severe respiratory signs and 10% mortality were analyzed. Pneumonic lesions and opaque thoracic and abdominal air sacs with foamy exudate were seen at postmortem examination. Histopathology of lungs showed fibrinoheterophilic pneumonia in both cases. Small pin point colonies with extensive ß-hemolytic activity were isolated from tracheal and lung tissue samples and identified as Ornithobacterium rhinotracheale by polymerase chain reaction (PCR). Results of lung histopathology, bacteriological isolation and PCR identification confirmed the diagnosis of pneumonia caused by ß-hemolytic O. rhinotracheale infection in both broiler chicken flocks. This paper appears to be the first report of ß-hemolytic O. rhinotracheale field isolates obtained from broiler chickens associated with severe respiratory signs and pneumonia.(AU)

Influence of photoinhibition on the morphology and function of pituitary lactotropes in male golden hamsters.

Inhibition of prolactin (PRL) secretion has been previously shown in pituitaries from male and female hamsters exposed to short photoperiods. The purpose of the present study was to analyze the possible quantitative immunohistochemical and ultrastructural changes of PRL cells in male golden hamsters undergoing regression and spontaneous recrudescence, correlating the morphological findings with circulating PRL levels. Thus, adult male golden hamsters were exposed for 8, 16, 22 and 28 weeks to either short photoperiods (SP: 6 h light, 18 h darkness) or long photoperiods (LP: 14 h light, 10 h darkness). Pituitaries were processed for both light and electron microscopy, and serum levels of PRL were assessed by radioimmunoassay (RIA). Volume density (VD = cell area/reference area) and cell density (CD = number of cells/reference area) of lactotropes were measured with an image analysis system (Imaging Technology, Software Optimas 5.2). One hundred lactotropes were recorded for measuring several ultrastructural parameters. When analyzing the lactrotrope cell population from animals submitted to SP, the VD and CD were found to be significantly (p < 0.05) diminished with respect to those of the groups submitted to LP at weeks 8, 16 and 22. However, at week 28 a spontaneous recrudescence appeared. The lactotropes from animals submitted to LP for 8, 16, 22 and 28 weeks exhibited numerous large electrondense secretory granules. The rough endoplasmic reticulum (RER) presented some flat cisternae and numerous free ribosomes. Animals submitted to SP for 8 weeks showed a number of medium and large secretory granules, and the RER exhibited mainly numerous free ribosomes. In those animals submitted to SP for 16 and 22 weeks, lactotropes were found smaller and showed small and medium-sized secretory granules decreased in number. The Golgi complex exhibited some immature granules and dilated cisternae, while the RER did not present differences with respect to the 8-week SP group. The hamsters submitted to SP for 28 weeks presented medium and large secretory granules, and the RER exhibited dilated irregular cisternae. The ultrastructural morphometric parameters showed a decrease (p < 0.05) in the number of secretory granules and exocytotic profiles, as well as a diminution (p < 0.05) in the areas of Golgi complex, RER, secretory granules, and individual mean area of secretory granule during the 16 and 22 weeks of SP. Serum PRL levels were severely reduced under SP. This decrease was greater at 16 weeks than at 8 weeks of exposure. When hamsters were kept for 22 weeks under SP, PRL levels started their recovery. Thus, at the end of the experiment, the PRL values returned to near those of LP group. In summary, we found quantitative immunohistochemical and ultrastructural, as well as biochemical changes that suggest an inhibition of synthesis, storage and release of PRL in male golden hamsters submitted to SP, with a spontaneous recrudescence appearing at the end of the study.