Treatment outcomes of Mycobacterium avium complex pulmonary disease according to disease severity.

Mycobacterium avium complex pulmonary disease (MAC-PD) requires long-term treatment. We analyzed the outcomes of 992 MAC-PD patients according to disease severity and compared the outcomes of intermittent and daily therapy for mild disease. Patients were divided into groups according to severity using the body mass index, age, cavity, erythrocyte sedimentation rate, and sex (BACES) system, and culture conversion rates were evaluated. We also evaluated the effects of intermittent treatment on the culture conversion rates in mild disease group. Using the BACES, 992 patients were divided into mild (n = 331), moderate (n = 503), and severe (n = 158) disease groups, and culture conversion at the end of treatment was achieved in 85% (282/331), 80% (403/503), and 61% (97/158), respectively. Differences in culture conversion among the severity groups were significant (p < 0.001). In patients with mild disease, culture conversion rates were similar between intermittent (84%, 166/198) and daily (87%, 116/133) treatment (p = 0.396), and intermittent antibiotic therapy did not negatively impact culture conversion (adjusted hazard ratio 1.08; confidence interval 0.83-1.41; p = 0.578). MAC-PD patients with mild disease had higher culture conversion rates. Daily and intermittent therapy yielded similar culture conversion rates for mild disease. Treatment strategies with lower pill burden may be applicable in mild MAC-PD.

Amyloid A amyloidosis secondary to avian tuberculosis in naturally infected domestic pekin ducks (Anas platyrhynchos domestica).

To investigate the correlation between avian tuberculosis and duck amyloidosis, the liver, lung, spleen, kidney, duodenum and pectoralis muscle of ducks naturally infected with Mycobacterium avium subsp. avium were used to detect amyloidosis by Congo red staining and potassium permanganate-Congo red staining. The expression level of IL-1ß, IL-6, IL-10, TNF-α and SAA2 were detected by quantitative real-time RT-PCR (qRT-PCR). The results showed that the liver, lung, spleen, kidney, duodenum and pectoralis muscle of the infected ducks exhibited amyloid proteins under ordinary light microscopy and the polarization light under polarized light microscopy. However, no amyloid deposition in potassium permanganate-Congo red staining sections indicated that the amyloidosis was AA amyloidosis. In addition, the expression level of IL-1ß, IL-6, IL-10, TNF-α and SAA2 increased from 4 to 43. This study showed that avian tuberculosis could induce secondary amyloidosis in naturally infected ducks.

Outbreak of Avian Tuberculosis in Commercial Domestic Pekin Ducks ( Anas platyrhynchos domestica).

Avian tuberculosis is a contagious disease affecting various domestic and wild bird species, and is caused by Mycobacterium avium . It is reported extremely rarely in commercial poultry flocks and has not been reported in commercial domestic ducks to date, with domestic ducks reported to be moderately resistant to M. avium infection. Here, we report the outbreak of avian tuberculosis in commercial Pekin duck ( Anas platyrhynchos domestica) flocks. Postmortem and histopathologic findings included nodules presenting in the visceral organs of ducks, and granulomas with central caseous necrosis surrounded by infiltrating lymphocytes. The M. avium pathogen was isolated and further identified by Ziehl-Neelsen staining and PCR based on insert sequence IS901 and the 16S rRNA gene. We highlight that avian tuberculosis not only has economic significance for the duck industry, but also presents a potential zoonotic hazard to humans.

Avian mycobacteriosis caused by Mycobacterium avium subspecies avium in four ornamental birds and in vitro drug sensitivity testing of isolates.

Avian tuberculosis, one of the most important diseases affecting various species of birds, is most often caused by Mycobacterium (M.) avium. This report describes cases of M. avium subsp. avium (MAA) infection in a white-crested Holland dwarf rooster, a male and a female golden pheasant and a male peacock. We also investigated the prevalence of mycobacteria in 60 other birds and 40 alpacas. Tissue samples of necropsied birds were cultured for mycobacteria. From non-necropsied 60 other birds and alpacas only faecal samples were collected. Clinical signs in the affected white-crested Holland cock included gradual loss of body weight and hoarse attempts at crowing during its last 3 weeks, with a dramatic loss of body condition and depression over the final week. Only slight weakening was observed in the peacock just before its death, and the golden pheasants died suddenly. Diagnosis was confirmed by microbiological, molecular and pathological results. Mycobacterium avium subsp. avium strains were isolated from the internal organs of the affected birds. Only one faecal sample from 60 other birds was culture- and PCR-positive for M. avium subsp. avium, while another one was only PCR-positive for M. chelonae. We did not isolate any Mycobacterium spp. from faecal samples of alpacas and all of them were PCR-negative. All 18 isolated M. avium strains were resistant to rifampicin, isoniazid, ethambutol, ethionamide, capreomycin and ofloxacin, and susceptible to cycloserine and streptomycin.

Multidrug therapy of Mycobacterium avium subsp. avium infection in experimentally inoculated budgerigars (Melopsittacus undulatus).

The aim of the study was to determine whether the four-month experimental therapy of mycobacteriosis in budgerigars may cause a complete recovery. A group of nine budgerigars was infected with a Mycobacterium avium subsp. avium isolate with proven pathogenicity for budgerigars. Five weeks post-inoculation, multidrug therapy was started. Another group comprising six birds received the same treatment but no infection, and the third group also comprising six birds was kept without infection or treatment as a control. The adopted antibiotic regimen included clarithromycin 61 mg/kg b.w., moxifloxacin 25 mg/kg b.w. and ethambutol 60 mg/kg b.w. administered by crop gavage every 12 h for 18 weeks. Despite a significant improvement in the condition of the infected, treated birds, the four-month therapy was not sufficient for the complete recovery of all.

Multifocal respiratory and vertebral mycobacteriosis in a red-tailed hawk (Buteo jamaicensis).

An adult, female, free-ranging red-tailed hawk (Buteo jamaicensis) was presented to a rehabilitation facility for an inability to stand. On examination, it displayed bilateral exaggeration of the pelvic limb reflexes with extensor muscle rigidity, intact superficial pain response, and positive withdrawal reflexes. A complete blood count identified moderate leukocytosis characterized by moderate heterophilia. No abnormalities were appreciable on radiographic evaluation. After initial improvement, it regressed and was euthanized 27 days after presentation. Necropsy and histologic investigation identified reduction in the diameter of the vertebral canal and spinal cord at cervical segments 8-9 with coalescing granulomas and intralesional acid-fast bacilli within the intertrabecular space, left side of the clavicular air sac, and cranial left lung. Bacterial culture and genetic sequencing from respiratory lesions identified Mycobacterium avium avium. Real time-polymerase chain reaction of paraffin-fixed spinal tissue tested positive for M. avium complex. Mycobacteriosis should be considered when peripheral neurologic deficits are present in raptors.

Mycobacterium avium subsp. avium found in raptors exposed to infected domestic fowl.

We report a case of a falcon breeding facility, where raptors (both diurnal and nocturnal) were raised in contact with domestic fowl (Gallus gallus f. domesticus) infected by Mycobacterium avium subsp. avium. Fecal and environmental samples from 20 raptors and four common ravens (Corvus corax) were collected. Mycobacterium a. avium DNA was detected in feces of four raptors (bald eagle [Haliaeetus leucocephalus], eagle owl [Bubo bubo], barn owl [Tyto alba], and little owl [Athene noctua]) using triplex quantitative real-time PCR. As both the flock of domestic fowl and one of the infected raptors had the same origin (zoological collection), they might have had a common source of colonization/infection. However, the detection of M. a. avium in feces of three other raptors may point at transmission of the agent between the birds in the facility. Contact of raptors with domestic fowl infected by M. a. avium may pose a risk for transmission of the infection for them; however, raptors from the falcon breeding facility seemed to be relatively resistant to the infection.

Mycobacteriosis in ostriches (Struthio camelus) due to infection with Mycobacterium bovis and Mycobacterium avium complex.

Avian tuberculosis rarely affects ratites compared to other bird species and is typically caused by Mycobacterium avium species. This study describes the pathological and microbiological findings in three adult ostriches with mycobacteriosis, in one of which Mycobacterium bovis was isolated from the lesions. Post mortem examinations on ostriches from two different zoological collections in Ireland revealed multifocal caseous granulomas affecting the spleen and liver in all cases, with additional involvement of intestines in two cases. In one case, granulomas were present within the pharynx, at the thoracic inlet and multifocally on the pleural surface. Acid-fast bacilli were observed in all lesions. Mycobacterium sp. of the M. avium complex was isolated from the intestinal lesions in the two cases with intestinal involvement, and M. bovis sp. oligotype SB0140 was cultured from the liver of the third ostrich. This represents the first reported case of M. bovis infection in an ostrich. Avian tuberculosis due to M. bovis is rare and to date has been reported in only parrots and experimentally inoculated birds. Mycobacterium bovis needs to be considered as a possible cause of tuberculosis in ostriches because the lesions are similar to those observed with M. avium complex infection.

Pathology of mycobacteriosis in birds.

Avian mycobacteriosis is a disease that affects companion, captive exotic, wild, and domestic birds. The disease in birds is generally caused by Mycobacterium avium subsp avium but more than 10 other species of mycobacteria infect birds. Oral route of infection appears to be the primary mode of transmission. In some cases, the extensive involvement of the respiratory system suggests an airborne mode of transmission. Molecular diagnostic techniques have improved the ability to confirm the disease. Avian mycobacteriosis is an important veterinary and economic risk in birds and mammals. Exposure of humans to infected birds may cause a zoonotic infection.

Identification of proteins from tuberculin purified protein derivative (PPD) by LC-MS/MS.

The tuberculin purified protein derivative (PPD) is a widely used diagnostic antigen for tuberculosis, however it is poorly defined. Most mycobacterial proteins are extensively denatured by the procedure employed in its preparation, which explains previous difficulties in identifying constituents from PPD to characterize their behaviour in B- and T-cell reactions. We here described a proteomics-based characterization of PPD from several different sources by LC-MS/MS, which combines the solute separation power of HPLC, with the detection power of a mass spectrometer. The technique is able to identify proteins from complex mixtures of peptide fragments. A total of 171 different proteins were identified among the four PPD samples (two bovine PPD and two avium PPD) from Brazil and UK. The majority of the proteins were cytoplasmic (77.9%) and involved in intermediary metabolism and respiration (24.25%) but there was a preponderance of proteins involved in lipid metabolism. We identified a group of 21 proteins that are present in both bovine PPD but were not detected in avium PPD preparation. In addition, four proteins found in bovine PPD are absent in Mycobacterium bovis BCG vaccine strain. This study provides a better understanding of the tuberculin PPD components leading to the identification of additional antigens useful as reagents for specific diagnosis of tuberculosis.

Diagnosis of avian tuberculosis in Swinhoe's pheasants using conventional and molecular-based techniques.

Avian tuberculosis was diagnosed via histopathology, microbiology, and molecular biology in two of six pheasants from a local sanctuary bird house in Taiwan. Swinehoe's pheasant (Lophura swinhoii) is a near-threatened species in Taiwan. The infected birds showed clinical signs such as fatigue, inappetence, diarrhea, and fluffing of feathers. On postmortem, nonmineralized caseogranulomas were present in the brain, heart, lung, liver, spleen, costal membranes, and intestinal tracts. The presence of granulomas in the lungs of the infected pheasants may suggest that exposure to the infective agent was via the respiratory route rather than the alimentary route. Histopathologic findings were typical of avian tuberculosis, including acid-fast bacilli and centrally located caseous necrosis surrounded by epitheloid macrophages, lymphocytes, and multinucleated giant cells. Laboratory confirmation was made based on lesions and via Ziehl-Neelsen acid-fast stain, polymerase chain reaction, nucleic acid sequencing, and a reliable assay protocol for identification of diseases bioactive amplification with probing assay.

An outbreak of avian mycobacteriosis caused by Mycobacterium intracellulare in little blue penguins (Eudyptula minor).

Mycobacterium intracellulare (MIT) was diagnosed postmortem by culture and supporting histopathology in seven birds from a flock of little blue penguins (Eudyptula minor) at the Henry Doorly Zoo (HDZ). These birds represented 20% of the deaths in the population over a 4 yr period. Clinical signs in affected birds included severe respiratory distress characterized by open-mouth breathing with chronic debilitation. On exam, plaques were noted in the larynx, trachea, and soft tissue of the caudal oropharynx. Index cases were identified on necropsy in two birds on loan to another institution in 2003. Following a case confirmed antemortem at the HDZ, a three-drug protocol of rifampin (15 mg/kg p.o. s.i.d.), ethambutol (15 mg/kg p.o. s.i.d.), and clarithromycin (10 mg/kg p.o. s.i.d.) was started on this bird in 2004 and extended to the entire flock in 2005. Gastric wash, fecal samples, and throat plaques were obtained antemortem on five birds within the flock, selected because of the presence of oral plaques, and tested by culture followed by a polymerase chain reaction assay. MIT was detected in gastric washes from four birds and in throat plaques from all five. Three more birds died during treatment. After the seventh bird died, antimicrobial susceptibility testing performed in July 2007 indicated that the MIT was now resistant to most antibiotics tested, including rifampin and ethambutol. The treatment regimen was changed to minocycline (10 mg/kg p.o. b.i.d.) and clarithromycin (10 mg/kg p.o. s.i.d.). Oral plaques were not seen on monthly rechecks of the flock through November 2008. The proposed mechanism of transmission is exposure to wild birds but the source has not been determined. These cases of avian mycobacteriosis caused by MIT are the first known cases reported in little blue penguins.

Investigation of characteristics and factors associated with avian mycobacteriosis in zoo birds.

The objective of the current study was to identify factors associated with avian mycobacteriosis in zoo birds. Inventory data, population health records, and necropsy data from eligible birds in the Zoological Society of San Diego's (ZSSD) collection from 1991-2005 (n = 13,976) were used to describe disease incidence, prevalence, and postmortem findings. A matched case-control study was then conducted to identify factors describing demographic, temporal, and enclosure characteristics, along with move and exposure histories. Cases (disease-positive birds; n = 167) were matched in a 17 ratio with controls (disease-negative birds; n = 1169) of similar age and taxonomic grouping. Potential risk factors were evaluated using univariate and multivariable conditional logistic regression. Disease prevalence and incidence were estimated for the study period at 1.2% and 3 cases/(1,000 bird-years at risk), respectively. Lesion characteristics and order prevalence are described. In the multivariable model, case birds were more likely to have been previously housed with a bird with mycobacterial disease involving the intestinal tract (odds ratio [OR] = 5.6, P < 0.01) or involving only nonintestinal sites (OR = 2.0, P < 0.01). Cases were more likely to have been imported into the collection than hatched at the ZSSD (OR = 4.2, P < 0.01). Cases were moved among ZSSD enclosures more than controls (OR = 1.1 for each additional move, P < 0.01). Findings will help guide future management of this disease for zoo bird populations.

Experimental infection of budgerigars (Melopsittacus undulatus) with five Mycobacterium species.

The aim of the present study was to determine the susceptibility of budgerigars (Melopsittacus undulatus) to infections with different Mycobacterium species. For inoculations the following Mycobacterium species were used: Mycobacterium avium subsp. avium, Mycobacterium bovis subsp. bovis, Mycobacterium tuberculosis subsp. tuberculosis, Mycobacterium intracellulare and M. fortuitum subsp. fortuitum. The bacterial suspension was administrated intramuscularly and all the birds were monitored for 70 days starting from the day of inoculation. During the experiment clinical examination, X-ray scans, plate agglutination tests, tuberculin tests, faeces smear preparations and culture of mycobacteria were performed. The study showed that M. bovis subsp. bovis was the most pathogenic Mycobacterium species for budgerigars. After inoculation, the bacilli induced tuberculosis-typical, clinical signs and necropsy findings. In two out of six birds infected with M. bovis subsp. bovis radiological changes were also visible. Birds inoculated with other Mycobacterium species did not show any typical symptoms of infection, and only the results of histopathological and bacteriological examinations indicated the presence of infection.

Mycobacterium avium subsp. avium distribution studied in a naturally infected hen flock and in the environment by culture, serotyping and IS901 RFLP methods.

Mycobacterium avium subsp. avium (MAA) of serotype 2 and genotype IS901+ and IS1245+ was cultured from 21 naturally infected hens (Gallus domesticus) from one smallholder aviary. From a total of 330 samples taken from hens, 124 mycobacteria were detected. Out of which MAA was detected in 103 (35.7%) of 288 tissues, in 4 (19.0%) of 21 swabs of cloacae and in 9 (42.9%) of 21 faeces samples, 8 other conditionally pathogenic mycobacterial species were also isolated. Tuberculous (TB) lesions were found in the liver, spleen and intestinal organs of seven hens. The isolates of MAA (n=58) from 16 infected hens (7 with TB lesions and 9 without TB lesions) were found to be of 3 IS901 RFLP types AE (n=48), AD (n=4) and E (n=6), where these MAA isolates are highly virulent to hens. Mixed infections with IS901 RFLP types (AE and AD) and (AE and E) were also evident in seven hens. From a total of 35 examined environmental samples, 23 mycobacterial isolates were detected. Out of which four (17.4%) MAA isolates of IS901 RFLP type AE and 19 (82.6%) other isolates of conditionally pathogenic mycobacteria were detected. The finding of identical IS901 RFLP types from both tissues and faecal isolates confirms that infected domestic hens are the principal source of infection for other susceptible hosts and lead to the contamination of the surrounding environment. The presence of different IS901 RFLP types in tissue isolates may indicate the repeated incidence of MAA infection and the occurrence of polyclonal infection.

Disseminated mycobacteriosis in a bald eagle (Haliaeetus leucocephalus).

A mature bald eagle (Haliaeetus leucocephalus) was diagnosed with mycobacterial infection after being presented for an inability to fly, emaciation, and a swelling of the left tibiotarsal-tarso metatarsal joint. Results of a complete blood cell count revealed a persistent, marked leukocytosis, with heterophilia, monocytosis, and anemia. Radiographs revealed lysis of the left distal tibiotarsus and soft-tissue swelling around the left tibiotarsal-tarsometatarsal joint, multiple pulmonary opacities, and an enlarged liver. Endoscopic evaluation and biopsy of caseated material within the left caudal coelom revealed acid-fast organisms. The eagle was euthanatized, and results of necropsy and histologic evaluation revealed caseated granulomas of the intestine, lungs, air sacs, and subcutaneous regions of the hock. Results of culture, a polymerase chain reaction testing, and direct deoxyribonucleic acid (DNA) sequencing for mycobacterial 16S ribosomal ribonucleic acid DNA determined this organism most likely to be Mycobacterium avium.

Avian tuberculosis in naturally infected captive water birds of the Ardeideae and Threskiornithidae families studied by serotyping, IS901 RFLP typing, and virulence for poultry.

Avian tuberculosis was detected in one flock of 38 water birds of the families Ardeideae (n = 20) and Threskiornithidae (n = 18). Mycobacterium avium subsp. avium (MAA, serotype 1, genotype IS901+ and IS1245+) was more often (p = 0.01) detected in tissue and/or faecal samples in 18 (90.0%) birds form the Ardeideae family: little egret (Egretta garzetta), buff-backed heron (Bubulcus ibis), great white egret (Egretta alba), and bittern (Botaurus stellaris) in comparison to two (11.1%) birds from the Threskiornithidae family: sacred ibis (Threskiornis aethiopicus). Avian tuberculosis was not diagnosed in spoonbills (Platalea leucorodia). Tuberculous lesions were found in nine birds. MAA isolates of IS901 RFLP type F-C3 were present in all of the 20 infected birds and in all environmental isolates. A mixed infection with the MAA isolates of three RFLP types F-C3 (tissue isolate), G-C3, and T-C3 (faecal isolates) was found in one sacred ibis. All 20 tissue isolates of IS901 RFLP type F-C3 from 20 birds and 8 environmental MAA isolates were fully virulent in pullets, whilst the isolates of RFLP types G-C3 and T-C3 were non-virulent in pullets. All of the tested MAA isolates had the same IS1245 RFLP "bird profile". In 12 of 20 infected birds with MAA M.a. hominissuis isolates of serotypes 4, 8, 9 and genotype IS901- and IS1245+ were detected and in 8 other birds mycobacteria not belonging to the M. avium complex were found. The presence of MAA in the environment may be a source for further spread of the causal agent of avian tuberculosis among other groups of animals in zoological gardens, farm animals, and also among their keepers.

Mycobacteriosis in gang gang cockatoos (Callocephalon fimbriatum).

This report presents three cases of mycobacteriosis in gang gang cockatoos (Callocephalon fimbriatum) that highlight the potential variation in clinical presentation of this important avian disease. The first case was a female gang gang cockatoo with widespread skeletal disease that presented with a chronic history of weight loss and nonpainful, bilaterally symmetric, distal-wing and leg nodular swellings. The second case was a mature female in good muscle condition with a nodular granulomatous pericarditis and myocarditis causing severe hydropericardium and cardiac tamponade; it was presented for respiratory distress. The third case was one of alimentary mycobacteriosis that presented with a chronic history of weight loss. Some difficulties associated with confirming a premortem diagnosis of mycobacteriosis are discussed.

Avian tuberculosis in a wild turkey.

A liver from a hunter-harvested wild turkey (Meleagris gallopavo) from Kansas was evaluated by the Southeastern Cooperative Wildlife Disease Study. Grossly, the liver contained several grayish-white masses ranging from 0.5-3 cm in diameter. These masses were scattered throughout the parenchyma and bulged from the capsular surface. Histologic examination revealed multifocal to coalescing granulomas with low numbers of acid-fast bacilli within multinucleated giant cells at the periphery of the granulomas. Culture of the liver yielded Mycobacterium avium subspecies avium and low numbers of Staphylococcus intermedius.