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Background: Salmonella bongori infect mainly cold-blooded hosts, but infections by S. bongori in warm-blooded hosts have been reported. We hypothesized that S. bongori might have diverged into distinct phylogenetic lineages, with some being able to infect warm-blooded hosts., Results: To inspect the divergence status of S. bongori, we first completely sequenced the parakeet isolate RKS3044 and compared it with other sequenced S. bongori strains. We found that RKS3044 contained a novel T6SS encoded in a pathogenicity island-like structure, in addition to a T6SS encoded in SPI-22, which is common to all S. bongori strains so far reported. This novel T6SS resembled the SPI-19 T6SS of the warm-blooded host infecting Salmonella Subgroup I lineages. Genomic sequence comparisons revealed different genomic sequence amelioration events among the S. bongori strains, including a unique CTAG tetranucleotide degeneration pattern in RKS3044, suggesting non-overlapping gene pools between RKS3044 and other S. bongori lineages/strains leading to their independent accumulation of genomic variations. We further proved the existence of a clear-cut genetic boundary between RKS3044 and the other S. bongori lineages/strains analyzed in this study., Conclusions: The warm-blooded host-infecting S. bongori strain RKS3044 has diverged with distinct genomic features from other S. bongori strains, including a novel T6SS encoded in a previously not reported pathogenicity island-like structure and a unique genomic sequence degeneration pattern. These findings alert cautions about the emergence of new pathogens originating from non-pathogenic ancestors by acquiring specific pathogenic traits.

Mycobacterium avium is the most commonly encountered mycobacterium species among non-Mycobacterium tuberculosis complex (nontuberculous mycobacteria) isolates worldwide and frequently causes lymphadenitis in children. During a multi-centre study in The Netherlands that was performed to determine the optimal treatment for mycobacterial lymphadenitis, concern was expressed in the media about the possible role of birds as sources of these M. avium infections, referred to as 'bird tuberculosis.' To examine the involvement of birds in mycobacterial lymphadenitis, 34 M. avium isolates from lymphadenitis cases were subjected to IS1245 restriction fragment length polymorphism (RFLP) typing. This genotyping method enables the distinction of the subspecies M. avium subsp. hominissuis and the 'bird-type' M. avium spp. avium. Highly variable RFLP patterns were found among the lymphadenitis M. avium isolates, and all belonged to the M. avium hominissuis subspecies. A relation to pet birds in the etiology of mycobacterial lymphadenitis could not be established, and the source of the infections may be environmental.

Systemic candidosis and concomitant aspergillosis and zygomycosis were diagnosed immunohistochemically in two Amazon parakeets (Amazona aestiva). In the bird with systemic candidosis, subacute necrotic lesions were present in the lung and the gastrointestinal tract, whereas chronic giant cell-containing granulomas were located in the liver, heart, spleen and on the serosal lining of the small intestine. Although the lesions in the liver, heart and spleen most likely developed as a result of haematogenous spread, the granulomas on the serosal surface may have developed after a local transmural intestinal invasion. In the second bird, aspergillosis and zygomycosis were restricted to the lung, whereas some zygomycetes were found in the air sacs as well as in the heart and kidneys. In all organs the zygomycotic lesions were dominated by thrombosing vasculitis, supporting haematogenous dissemination.

Tenacity studies of Cryptococcus neoformans in bird droppings originated from different ornamental birds and chickens showed that there is less chance for this fungus species to survive in non-sterile or bacteria-free droppings of large parakeets and chickens in comparison with droppings of small parakeets. Survival rates of Cr. neoformans in buffer solutions with pH-values ranging from 8.5-9.5 allow to conclude that this species is not alkali-sensitive. Therefore, the increase of pH is not regarded responsible for the survival of Cr. neoformans in bird droppings. Possibly fungistatic substances present in droppings are involved.

A recombinant system for the major capsid VP1 protein of budgerigar fledgling disease virus has been established. The VP1 gene was inserted into a truncated form of the pFlag-1 vector and expressed in Escherichia coli. The budgerigar fledgling disease virus VP1 protein was purified to near homogeneity by immunoaffinity chromatography. Fractions containing highly purified VP1 were pooled and found to constitute 3.3% of the original E. coli-expressed VP1 protein. Electron microscopy revealed that the VP1 protein was isolated as pentameric capsomeres. Electron microscopy also revealed that capsid-like particles were formed in vitro from purified VP1 capsomeres with the addition of Ca2+ ions and the removal of chelating and reducing agents.

A 33-year-old previously healthy woman was seen at this hospital after a week of fever and nonproductive cough. A roentgenogram of the chest showed consolidation in the left upper and middle lung fields. Transbronchial lung biopsy from left S1 + 2 revealed an increase of mononuclear leukocytes within the interstitial spaces and slight cell infiltration with in the alveoli. Bronchoalveolar lavage cellular constituents showed 47% alveolar macrophage, 38% lymphocytes and 15% neutrophils. She had kept a parakeet, which died just after her illness. We could isolated organisms from the liver, spleen, kidney, lung, heart and bowel of her pet bird revealing C. psittaci by Giemsa stain, three days after it was buried in the ground. She was given three hundred mg of ofloxacin per day orally for fourteen days and the clinical effect was good. The in vitro activity of ofloxacin was 0.75 microgram/ml.

Influenza viruses A/duck/Hokkaido/5/77 (Hav7N2), A/budgerigar/Hokkaido/1/77 (Hav4Nav1), A/Kumamoto/22/76 (H3N2), A/Aichi/2/68 (H3N2), and A/New Jersey/8/76 (Hsw1N1) were experimentally inoculated into Pekin ducks. Of these, the influenza viruses of duck and budgerigar origin replicated in the intestinal tract of the ducks. The infected ducks shed the virus in the feces to high titers, but did not show clinical signs of disease and scarcely produced detectable serum antibodies. Using immunofluorescent staining, we demonstrated that the target cells of the duck virus in ducks were the simple columnar epithelial cells which form crypts in the large intestines, especially in the colon. After primary infection, the birds resisted reinfection with the duck virus at least for 28 days, but from 46 days onward they were susceptible to reinfection. These infections were quickly restricted by a brisk secondary immune response, reflected in the rapid appearance of high titers of antibody after reinoculation. In contrat to the avian influenza viruses, the remaining three influenza viruses of human origin did not replicate in the intestinal tract but did cause a serum antibody response.

Plaque-purified and non-plaque-purified velogenic viscerotropic Newcastle disease viruses (VVNDVs) were inoculated into golden-mantled rosellas (Platycercus eximius). VVNDV produced acute clinical disease in this species: all birds died within 6 days postexposure. There was no difference between the two inoculation groups in clinical signs. Seven tissues and five tissue swabs were collected from each of 15 birds. The VVNDV concentration in each specimen was titrated, and the concentrations were compared. The lung and trachea had the highest concentrations of virus in both the tissue suspensions and the swab suspensions. The average virus concentrations of the lung were 10(5.9) 50% embryo lethal doses (ELD50) per 0.1 ml for the tissue suspension and 10(4.9) for the swab. The average virus concentrations of the trachea were 10(5.6) ELD50 per 0.1 ml of tissue suspension and 10(4.6) for the swab.

The feces of 125 psittacine birds, representing 12 species, were cultured on selective media to determine the presence of Escherichia coli. Only 13.6% (17) of the birds yielded E. coli.

Serological and physico-chemical properties of parakeet/Netherlands/449/75 (449) virus indicated a close relationship to paramyxovirus/Turkey/Wisconsin/68.

A virus suspected of causing high death rates in fledgling budgerigars in Georgia and Texas aviaries was isolated in budgerigar embryo fibroblasts inoculated with tissue homogenates from affected birds. Virus was most easily recovered from tissues containing many intranuclear inclusion bodies. Cytopathic effect on fibroblasts of all four isolates was characterized by a swollen nucleus followed by rounding and detachment of the affected cell from the monolayer. Properties suggesting the B-931 isolate belongs to the papovaviridae family are (1) presence of DNA; (2) insensitivity to treatment with CHCl3; and (3) presence of cubic viral particles 42 to 49 nm in diameter in the nucleus of infected chicken embryo fibroblasts. The isolate did not hemagglutinate erythrocytes of chickens, turkeys, budgerigars, guinea pigs, or type O humans and was basically stable against heating and freeze-thawing. An examination of fledgling budgerigars from infected aviaries demonstrated that sick birds carried more virus than healthy birds.

An upper respiratory condition that resulted in 20% mortality in a flock of yellow-naped Amazon parrots was apparently caused by a concomitant infection of mycoplasmas and bacteria. Mycoplasma gallisepticum (MG), M. iowae, and an unidentified mycoplasma were isolated from the affected parrots. Budgerigars were experimentally infected with a parrot strain of MG designated MG(P) 1669 as well as with the R strain of MG and the F10-2 strain of M. synoviae (MS). Air-sac lesions were evident in all groups of challenged budgerigars, and MS and MG were cultured from the tracheas, air sacs, and lungs of the budgerigars up to 5 weeks postexposure. Serological findings were ambiguous and therefore considered unreliable. White leghorn and commercial broiler chickens challenged with the MG(P) 1669 isolate did not exhibit any significant air-sac lesions relative to the controls. However, MG was cultured from both groups of experimentally infected birds. Eight weeks after exposure, the white leghorns were seropositive to all MG antigens used in the agglutination test.

Using a Chlamydia-ELISA test to detect the agent in cloacal swabs in budgerigars and other parakeets, the following findings may be summarised: --10/25 Breeders of budgerigars (40 per cent) housed birds shedding the agent, involving ten per cent of all birds tested, average shedding being 28 per cent in positive lofts. --4/15 Pet shops (27 per cent) were found to have positive birds on sale, at least three per cent of all tested birds being shedders, the proportion of shedders averaging nine per cent per infected pet shop. --In the flocks of five breeders of psittaciformes, which were known positive flocks from the outset average shedding was eighteen per cent. The test may also be used for detecting the agent in organs. The shedding pattern in known positive birds was apparently decreasing, when a large dose of corticosteroids was administered, shedding recurred. The possibility of a cage bird sanitation scheme is discussed.

Pacheco's disease herpesvirus was determined to be the agent responsible for the death of about 200 psittacine birds comprising five species. Clinical signs, necropsy lesions, and virus isolation and identification methods are described.

'Wet vent', the principal clinical sign of which is diarrhoea, is common in budgerigars. In a survey of 83 cases examined post mortem 21 causes were found. The most common causes were enteritis, mainly of a non-infectious nature (18 cases), 'going light' (15 cases), abnormal gizzard structure (nine cases) and nephrosis (six cases).