Psittacine Birds Research Articles

Detection of Avian Bornavirus in Wild and Captive Passeriformes in Brazil.

Avian bornaviruses (ABVs) are the causative agents of proventricular dilatation disease (PDD), a fatal neurologic disease considered to be a major threat to psittacine bird populations. We performed a reverse transcription PCR survey to detect the presence of canary avian bornavirus (CnBV) in birds of order Passeriformes related to different clinical manifestations, such as sudden death, neurologic signs, apathy, anorexia, excessive beak growth, and PDD. A total of 227 samples from captive and wild canaries were included, of which 80 samples were captive birds, comprising saffron finches (n = 71) and common canary (n = 9), and 147 samples were wild birds distributed among a variety of several species. Two samples from captive birds (2/80) were positive for ABV, and in wild birds, only one sample was positive for ABV. The positive samples were subjected to DNA sequencing, and only the CnBV-1 serotype was found, which was the first time it was detected outside of Germany (Austria/Hungary), where it was first detected in 2009. Phylogenetic analysis confirmed that avian bornavirus serotype CnBV-1 is present in order Passeriformes in Brazil.

First detection and characterization of Psittaciform bornaviruses in naturally infected and diseased birds in Thailand

In Thailand a proventricular dilation disease (PDD)-like syndrome commonly occurs in captive psittacine birds. The etiology, however, has been unknown to date and studies to detect parrot bornaviruses have never been performed in Southeastern Asia. Therefore, 111 psittacines (22 different species) including birds with suspected PDD based on clinical examination results (n = 65), cage mates of PDD suspected parrots without any clinical signs (n = 39) and dead birds with previous clinic suspicious for PDD (n = 7) were tested for bornaviruses using various reverse transcription polymerase chain reaction (RT-PCR) and realtime RT-PCR protocols, an enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and genome sequencing. Bornaviral infections, indicated by the presence of RNA or antibody positive reactions were detected in 60 birds (54.1%) belonging to 15 psittaciform species and originating from 41 owners. Occurrence of Psittaciform 1 orthobornavirus was confirmed by sequencing of PCR products in 24 of these birds. Parrot bornavirus (PaBV)-5, belonging to the species Psittaciform 2 orthobornavirus and found only in single birds in the United States of America, Japan and Hungary until now, was identified in a macaw. Full genome sequencing revealed features shared with other strains of this virus. PaBV-4 was the prevalent virus type and the viruses grouped in two of the five genetic PaBV-4 subclusters known so far while PaBV-2 was found in a single patient. Forty-five psittacines of the group of PDD-suspected birds (69.2%), 4 dead birds and 11 clinically healthy cage mates were positive in at least one test the latter suggesting inefficient horizontal transmission in natural infections. Lymphoplasmacytic infiltrations (non-purulent inflammation, ganglioneuritis) and bornavirus antigen were detected in diverse tissues confirming PDD as the disease involved. These results may have a major impact on conservation projects including the five near-threatened parrot species living in the wild in Thailand.

Studies on Circo and Polyoma Viruses in Psittacine Birds in Egypt, During 2014-2016

In recent years various psittacine birds have been popular and kept as pet animals in Egypt. Circo and Polyomaviruses and are the main causative agents of Psittisine beak and feather deformities. The main objectives of this study were centered on DNA virus infections in psittacine birds with special refreance to Circovirus and Polyomaviruses. Feather and tissue samples were collected from infected birds and examined using PCR based technology.A total of 50 infected Psittacine birds were examined in which feather and tissue sample were collected and screened for the presence Circo and Polyomaviruses by using PCR technology. PCR was used to amplify C1 gene of Circovirus and T gene of polyomavirus in extracted DNA. The highest prevalence of Circovirus infection in feather samples was shown in red rumped parakeet followed by budgerigar and love birds (41.66, 26.92 and 33.33; respectively). The distribution rate of polyomavirus infection in parakeet, budgerigar and love birds were 23 %, 23.7% and 16.66 % respectively..Co-infection with Polyoma and Circovirus, was detected in, three parakeet, six budgerigars and two love birds with a total percentage of 22%. Apparently healthy psittacine birds can be latently infected with either or both Circo and Polyomavirus without showing any clinical symptoms, and become carriers for and virus shedding disease transmission to other birds. In future studies in Egypt, an attempt to isolate Circo and Polyoma viruses from field cases should be done and the isolates could use for development of bivalent prophylactic vaccine for Egyptian psatticine birds.

Reclassification of Bisgaard taxon 37 and taxon 44 as Psittacicella melopsittaci gen. nov., sp. nov., Psittacicella hinzii sp. nov. and Psittacicella gerlachiana sp. nov. within Psittacicellaceae fam. nov. of the order Pasteurellales.

Bacteria isolated from lesions as well as apparently normal tissues of psittacine birds have previously been reported as taxon 37 and taxon 44 of Bisgaard. 16S rRNA gene sequence comparisons revealed a distant relationship to members of Pasteurellaceae at the species, genus and family levels. The polar lipid profile consisted of the major components phosphatidylethanolamine and phosphatidylglycerol. A new family Psittacicellaceae fam. nov. is proposed with the type genus Psittacicella gen. nov. The new genus Psittacicella includes the type species Psittacicella melopsittaci sp. nov. with type strain B96/4T (=CCUG 70858T=DSM 105476T), Psittacicella hinzii sp. nov. with type strain 111T (=CCUG 52861T=CCM 8842T) and Psittacicella gerlachiana sp. nov. with type strain EEAB3T1T (=CCUG 70857T=DSM 105477T). In addition to the major polar lipids, strain 111T possessed the non-identified aminophospholipids APL1 and APL2 and trace amounts of four lipids (L1-L4) whereas strain B94/4T showed the minor unidentified aminophospholipids APL3 and APL2 and trace amounts of unidentified lipid L3. These results demonstrate that strain B96/4T can be distinguished from 111T based on presence/absence of the unidentified lipids APL1 and APL3. The total polar lipid profile of strain EEAB3T1T differed from B96/4Tonly in one minor lipid. Strain B96/4T can further be distinguished from 111T by acid formation from trehalose and raffinose and the α-glucosidase test. Strains 111T and EEAB3T1T can be separated based on acid formation from trehalose and the α-glucosidase test. Strains B96/4T and EEAB3T1T can be separated by acid formation from raffinose and eight signature indels in the RpoB protein.

Chlamydia Persistence: A Survival Strategy to Evade Antimicrobial Effects in-vitro and in-vivo.

The Chlamydiaceae comprise a group of highly adapted bacterial pathogens sharing a unique intracellular lifestyle. Three Chlamydia species are pathogenic to humans: Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci. C. trachomatis is the leading bacterial cause of sexually-transmitted infections and infectious blindness worldwide. Chlamydia pneumoniae is a major cause of community-acquired atypical pneumonia. C. psittaci primarily affects psittacine birds and can be transmitted to humans causing psittacosis, a potentially fatal form of pneumonia. As opposed to other bacterial pathogens, the spread of clinically relevant antimicrobial resistance genes does not seem to be a major problem for the treatment of Chlamydia infections. However, when exposed to stressing conditions, like those arising from exposure to antimicrobial stimuli, these bacteria undergo a temporary interruption in their replication cycle and enter a viable but non-cultivable state known as persistence. When the stressing conditions are removed, Chlamydia resumes replication and generation of infectious particles. This review gives an overview of the different survival strategies used by Chlamydia to evade the deleterious effects of penicillin and IFNγ, with a focus on the different models used to study Chlamydia persistence, their contribution to elucidating the molecular basis of this complex phenomenon and their potential implications for studies in animal models of infection.

Novel Hybrid of Typical Enteropathogenic Escherichia coli and Shiga-Toxin-Producing E. coli (tEPEC/STEC) Emerging From Pet Birds.

Exotic psittacine birds have been implicated as reservoir of diarrheagenic Escherichia coli (E. coli), including enteropathogenic E. coli (EPEC) and Shiga-toxin producing E. coli (STEC). Here, we present a genotypic and phenotypic characterization of typical EPEC/STEC hybrid strains isolated from exotic psittacine birds. The strains were positive for eae, bfpA, and stx2f genes, belong to serotype O137:H6 and ST2678. Two strains were subject to whole genome sequencing, confirming the presence of the virulence factors of both E. coli pathotypes. Phenotypical in vitro tests confirmed their ability to adhere to HeLa cells and cause cytotoxicity to Vero cells. The rabbit ileal loop assays showed the attaching and effacing lesion, in addition to inflammatory process and overproduction of intestinal mucus. This is the first report of hybrid typical EPEC/STEC (O137:H6/ST2678) strains isolated from companion psittacine birds and the results suggest zoonotic risks.

Risk factors associated with Chlamydia psittaci infections in psittacine birds and bird handlers.

The aim of this study was to determine the prevalence and potential risk factors associated with Chlamydia psittaci infections in psittacine birds and bird handlers in Egypt. A total of 190 swabs were collected from psittacine birds (n=120) and bird handlers (n=70) and were tested by polymerase chain reaction to detect the C. psittaci ompA gene. Chlamydia psittaci DNA was detected in 63 (52·5%) of 120 samples collected from psittacine birds. The occurrence of C. psittaci infections was high in Cockatiel birds (60%), followed by Fischer's lovebird (51%) and Rosy-faced lovebird (47·5%). Bird age, location (pet markets and households), housing (caged and aviary), and sampling season were considered significant risk factors for C. psittaci infections in psittacine birds. Of the 70 sputum swabs collected from bird handlers, only 4 (6%) were positive for C. psittaci. Positive cases were closely associated with older persons (≥30years) who had respiratory signs and handled birds in pet markets. Further, wearing protective gloves and washing hands when handling psittacine birds decreased the frequency of C. psittaci infections in bird handlers. The prevalence of C. psittaci infections in psittacine birds in Egypt is high, which has a potential threat to human health in this area. Thus, dissemination of effective prevention and control measures is essential to prevent the spread of C. psittaci among psittacine birds, as well as among humans in contact with birds. Results from this study highlighted the risk factors associated with C. psittaci infections in psittacine birds and bird handlers in Egypt and will aid in developing prevention and control measures to reduce the risk of C. psittaci infection.

Establishment of rapid detection method and surveillance of budgerigar fledgling disease virus using a TaqMan Real-Time PCR

Budgerigar fledgling disease virus (BFDV) infection causes sudden death, abdominal distention, and feather abnormality in psittacine birds. In this study, we developed a TaqMan Real-time PCR assay to detect BFDV by targeting a conserved region in VP1 gene. The detection limit of the assay was 30 DNA gene copies, 1000 times more sensitive than conventional PCR. The coefficients of variation were less than 1.09% in either intra- or inter-assays, indicating high reproducibility. By using this method, the prevalence of BFDV in China was evaluated. 56 feces samples were collected from four psittacine birds breeding facilities in China. The results showed 28 out of 56 samples were positive for BFDV in Real-Time PCR assay, while only 19 samples were positive in PCR assay. Three facilities were positive for BFDV with positive rates from 60% to 87.5%. Further sequence analysis of VP1 genes from the positive samples indicated that VP1 genes fell into two different lineages in phylogenetic tree, suggesting that different genotypes BFDV are co-circulating in China.

From the cage to the wild: introductions of Psittaciformes to Puerto Rico.

Introduced psittacine birds can become highly invasive. In this study, we assessed invasions of Psittaciformes in Puerto Rico. We reviewed the literature, public databases, citizen science records, and performed in situ population surveys across the island to determine the historical and current status and distribution of psittacine species. We used count data from Ebird to determine population trends. For species whose populations were increasing, we modelled their potential distribution using niche modeling techniques. We found 46 Psittaciformes in Puerto Rico, of which 26% are only present as pets, at least 29 species have been reported in the wild, and of those, there is evidence that at least 12 species are breeding. Our results indicate that most introduced species which have been detected as established still persist, although mostly in localized areas and small populations. Clear evidence of invasiveness was found for Brotogeris versicolurus and Myiopsitta monachus, which have greatly expanded their range in recent years. Psittacara erythrogenys and Eupsittacula canicularis also showed population increases, although to a lesser degree. The niche models predicted suitable areas for the four species, and also indicate the potential for range expansion. We discuss the factors leading to invasion success, assess the potential impacts, and we discuss possible management strategies and research prospects.

Lipid-Related Lesions in Quaker Parrots ( Myiopsitta monachus).

The Quaker parrot has been used as a psittacine model to study clinical lipidology and lipid-related disorders. However, while Quaker parrots appear to be anecdotally susceptible to a variety of spontaneous dyslipidemic disorders and lesions caused by excess lipid accumulation, epidemiologic data are lacking. A multicenter retrospective study on 652 pathology submissions (411 necropsies and 243 biopsies) from Quaker parrots was performed by recording the final pathological diagnoses, age, and sex for each bird. The prevalence of lesions associated with lipid metabolism, such as hepatic lipidosis, atherosclerosis, xanthomas, adipose tumors, coelomic steatitis/steatonecrosis, endogenous lipid pneumonia, and acute pancreatic necrosis/pancreatitis, was reported. Multiple logistic regression models were used to characterize the effects of sex and age on these lesions, and the prevalence of hepatic lipidosis and atherosclerosis was compared to those in a random sample of control psittacine birds. The raw prevalence of atherosclerosis and hepatic lipidosis was 5.6% (95% confidence interval [CI], 3.4%-7.8%) and 21.2% (95% CI, 17.2%-25.1%), respectively. While the prevalence of atherosclerosis was similar to other psittacine species, hepatic lipidosis was more common in Quaker parrots. Quaker parrots also showed a unique susceptibility to acute pancreatic necrosis with a prevalence of 12.9% (95% CI, 9.7%-16.1%). Male parrots were found to be more susceptible than females to lipid accumulation lesions ( P = .0024), including atherosclerosis ( P = .018) and hepatic lipidosis ( P < .001). This retrospective study confirms the high susceptibility of Quaker parrots to lipid-related disorders and presents epidemiological data that may be useful to avian clinicians, pathologists, and researchers using Quaker parrots.

Complete Genome Sequence of Psittacine Adenovirus 1, Identified from Poicephalus senegalus in Italy.

Using a metagenomics approach, we were able to determine for the first time the full-genome sequence of a psittacine adenovirus 1 isolate that was recovered from the liver of a dead Senegal parrot (Poicephalus senegalus) in Italy. The results of the phylogenetic investigations revealed the existence of high genetic diversity among adenoviruses circulating in psittacine birds.

Retrospective Evaluation of Clinical Signs and Gross Pathologic Findings in Birds Infected With Mycobacterium genavense.

Mycobacterium genavense is regarded as the primary cause of mycobacteriosis in passerine and psittacine birds kept in captivity. Mycobacterium genavense is a potential zoonotic pathogen; therefore, early antemortem detection in birds is needed. In humans, infections with M genavense are found predominantly in immunocompromised people. To investigate clinical signs and pathologic lesions and to determine the prevalence of coinfections in birds infected with M genavense, we reviewed records of 83 birds in which DNA from M genavense had been detected via real-time polymerase chain reaction. To evaluate clinical signs in birds presented as patients, results of standardized examinations of 60 birds and radiographic results from 37 birds were investigated. Necropsy results of 82 of the 83 birds were evaluated, including results of additional parasitologic, bacteriologic, and virologic examinations. Birds included in the study comprised 15 species in the orders Passeriformes, Psittaciformes, Coliiformes, Columbiformes, Coraciiformes, and Ciconiiformes. A wide range of clinical manifestations were documented, including neurologic disorders, ocular manifestations, and gastrointestinal signs. Of the 60 birds examined clinically, 15% showed no clinical signs. Coinfections with a wide range of pathogens were detected in 52% (43 of 83) of the tested birds. Coinfections included Macrorhabdus ornithogaster, circovirus, polyomavirus, avian bornavirus, adenovirus, Mycobacterium avium ssp. avium/ silvaticum, Mycoplasma species, Salmonella species, Escherichia coli, Aspergillus species, and various parasites. The high number of coinfections may reflect an impaired immune status in the birds examined. These results also suggest a broad host range for M genavense, and the existence of various clinical signs that may be strongly associated with coinfections with other pathogens.

Molecularly Confirmed Acute, Fatal Sarcocystis falcatula Infection in the Rainbow Lorikeets ( Trichoglossus moluccanus) at the Philadelphia Zoo.

The protozoan parasite Sarcocystis falcatula is an important cause of clinical disease in several avian intermediate hosts. The host range of S. falcatula is wide, and numerous outbreaks of acute sarcocystosis have been reported in passerine and psittacine birds in captivity in the Americas. Previous diagnosis was performed by serologic methods, light, and/or electron microscopic examinations with limited molecular confirmation. Here, we report histological and molecular diagnosis of acute, fatal S. falcatula infections in rainbow lorikeets ( Trichoglossus moluccanus) at the Philadelphia Zoo. Pulmonary sarcocystosis was suspected antemortem in 3 lorikeets (3-5 yr old); these birds died despite antiprotozoal therapy. The predominant lesion was pneumonia associated with S. falcatula-like schizonts in pulmonary vascular endothelium. The multilocus PCR-DNA sequencing ( 18S rDNA, 28S rDNA, ITS-1, and cox1) of frozen lung tissue confirmed S. falcatula infections in all 3 birds. Our results and previous studies suggest that acute pulmonary form of sarcocystosis is a major contributor of death to Old World psittacine birds.

Isolation of Salmonella Typhimuriumin from Some Psittaciformes Species and Detection of Antibiotic Resistant Genes In Egypt

This study was conducted to isolate and identify Salmonella as one of important zoonotic microorganisms from different spp. of captive bred psittaciformes. A total of 300 psittaciformes (were collected from private wildlife farms, pet shops and households) belonging to 15 different species were clinically examined and samples, ((219) fecal samples, (72) cloacal samples and internal organs (intestine, liver, lung, spleen and kidney) from 9 freshly dead birds) were taken for detection of salmonella infections using traditional methods of isolation and polymerase chain reaction (PCR) based on inv A gene as a confirmatory accurate technique on isolated strains, estimation of the antibiotic susceptibility and detection of resistance genes. The result revealed that, the incidence of the infection constituted 3.33% (10 isolates) of total number of investigated psittacine birds and the most common affected psittacines were (5) rosy-faced lovebirds, (4) budgerigars and (1) green rosella which were bought from illegal wildlife trafficking. All 10 isolates were Salmonella Typhimurium confirmed by PCR based on invA gene. The antibiotic sensitivity tests revealed that, all 10 isolates were highly susceptible (100%) in vitro to amoxicillin / clavulanic acid, ciprofloxacin and gentamycin, while 100% of the isolates exhibited complete resistance to doxycycline and sul./ trimethprim. Detection of resistance genes was tested by PCR targeting (tet1, tet 2, sul 1and sul2) antimicrobial genes. Resistant genes were detected of Salmonella Typhimuruim isolates. (6) Against tetracycline A tet A gene, (7) tetracycline gene B tet B and (7) sulphonamide gene 1 sul 1, meanwhile all strains were negative for sul 2 resistant gene.

Molecular detection and characterization of beak and feather disease virus in psittacine birds in Tehran, Iran.

Beak and feather disease virus (BFDV), a member of genus circovirus, is a small, non-enveloped, single stranded DNA virus. Although BFDVs are among the most well studied circoviruses, there is little to no information about BFDVs in Iran. The aim of the present study was to detect and identify BFDV molecules from the birds referred to the avian clinic of The Faculty of Veterinary Medicine, Tehran University, Iran. A total of 55 DNA samples were extracted from birds from nine different species of the order psittaciformes. A robust conventional polymerase chain reaction (PCR) was applied to detect the rep gene of the virus. Ten out of 55 samples, from four different species, were tested positive for BFDVs in PCR (Melopsittacus undulates (4), Psittacula Krameri (3), Psittacus erithacus (2), Platycercus eximius (1)). Molecular identification of the detected BFDVs was performed based on their rep gene sequences. The phylogenetic analysis revealed that the Iranian BFDVs from this study were clustered into four genetically distinct clades belonging to different genetic subtypes of BFDVs (L1, N1, T1, and I4). Although the relation between the samples and their related subtypes in the tree are discussed, further studies are needed to elucidate the host specificity and incidence of the BFDVs from different genetic subtypes.

Chlamydiosis in Backyard Chickens (Gallus gallus) in Italy.

Until recently, Chlamydia psittaci was considered to be the only etiological agent of avian chlamydiosis, but two new avian species, Chlamydia gallinacea and Chlamydia avium, have recently been described in poultry and pigeons or psittacine birds, respectively. The aim of this study was to explore the occurrence of C. psittaci and C. gallinacea in backyard chickens in Italy. Cloacal swabs were taken from 160 asymptomatic chickens reared in 16 backyard farms. Samples were tested for C. psittaci and C. gallinacea by specific real-time polymerase chain reaction assays, with 24 (15%) of the 160 chickens resulting positive for C. gallinacea. To attempt chlamydial isolation, new samples were obtained from two farms harboring a high prevalence (60% and 70%, respectively) of C. gallinacea-positive chickens. In total, eight C. gallinacea and one C. psittaci isolates were successfully recovered from 13 chickens. C. gallinacea was confirmed to be the endemic chlamydial species in chickens, with a high ompA intraspecies diversity. The presence of viable C. psittaci and C. gallinacea demonstrated by isolation from chickens in backyard farms poses a potential public health problem.

Superficial Chronic Ulcerative Dermatitis (SCUD) in Psittacine Birds: Review of 11 Cases (2008-2016).

We reviewed 11 cases of superficial chronic ulcerative dermatitis (SCUD) in psittacine birds that presented to an exotic animal practice over an 8-year period. African grey parrots ( Psittacus erithacus) were overrepresented, accounting for 55% of SCUD-affected birds. All affected birds were hand-reared pets and bonded strongly to their owners. In all cases, fungal culture results were negative. The most commonly cultured bacteria were Enterobacter cloacae (27%), followed by Escherichia coli, and Staphylococcus aureus (both 18%). An underlying cause of behavioral self-mutilation with secondary infection of dermatitis lesions by opportunistic bacteria was suspected in 10 of 11 cases. The axillae were the most common anatomic sites affected (45%). In two cases, more than one site was affected concurrently. Mean age of birds affected was 11.4 years. Two birds had suffered from SCUD previously, with 1 bird having suffered from 3 previous episodes and was euthanized as a result. All birds were treated with systemic antibiotics, topical antibacterial preparations, and systemic nonsteroidal anti-inflammatory drugs. A neck collar was applied in all cases. Median time to clinical resolution was 2 months (range, 1-21 months). Excluding the bird that was euthanized, all birds showed a positive response to treatment.

Feather picking / self-mutilating in psittacine birds. Recent data for the control

Feather picking /self-mutilating is the most frequent and serious problem of psittacine birds that the avian practitioners have to deal with in practice. The etiologic agents of this behavior may be infectious, parasitic, nutritional, but the most interesting among them are psychological (housing, environment, attention seeking etc). It is very difficult to establish accurate diagnosis, although some laboratory examinations may be helpful. Especially the behavioral history may be important for the identification of psychological causatives. Therapy of feather picking is not always possible. Pharmaceutical treatment, primarily with psychotropic drugs, improvement of the housing conditions and nutrition, closer relationship with the persons that the birds live with, may be useful to reduce or even to solve this problem. The prognosis is circumspect, because sometimes, in spite of the therapy, there is no improvement or it is temporary. Feather picking disorder is described in the present study. Recent data on the causative agents and the control of the disorder are also reported.

In this issue – December 2017

In this issue – December 2017

Proventricular dilatation disease (PDD) outbreak in blue-and-gold macaws (Ara ararauna) in the State of Santa Catarina, southern Brazil

ABSTRACT: Proventricular dilatation disease (PDD) is a lethal and important disease of captive psittacine birds, and affects a wide range of species, including endangered ones, and lacks an effective treatment. This report describes PDD in three blue-and-gold macaws (Ara ararauna) in southern Brazil. All three macaws originated from the same aviary and presented similar clinical signs including anorexia, apathy, emaciation and prostration. At necropsy, one of the macaws presented an enlarged proventriculus. Histologically, lymphoplasmacytic infiltrates was observed in the ganglia and nerves of the esophagus, crop, proventriculus, ventriculus, heart, adrenal glands, and adrenal medulla of all three cases. Two macaws had meningoencephalomyelitis and one had myocarditis. Immunohistochemistry identified PaBV antigen in the brain, proventricular, ventricular ganglia, and epicardial ganglia, and cardiomyocytes of all three macaws.