Mycobacteriosis caused by Mycobacterium genavense in birds kept in a zoo: 11-year survey

Abstract

We report on a disease in 27 birds (1 bird belonging to the order Coraciiformes, 3 to Piciformes, 4 to Galliformes, 7 to Psittaciformes, and 12 to Passeriformes) caused by fastidious mycobacteria. All birds were caged at the Antwerp Zoo and died suddenly between 1983 and 1994. Seventeen birds had no previous signs of disease, and 10 birds showed emaciation. Gross necropsy findings were generally nonspecific, but all the birds were smear positive for acid-fast bacilli (AFB). Histopathologic evaluation performed on 14 birds revealed predominantly intracellular AFB. Extracellular AFB were more abundant in advanced lesions, especially in necrotic areas. In the intestine the mucosal area was generally heavily infiltrated, suggesting an intestinal origin of the infection. There was extensive invasion of the lungs in most birds. In 11 birds sparse growth was obtained after at least 6 months of incubation on Löwenstein-Jensen medium or on Ogawa medium supplemented with mycobactin. Subculture was unsuccessful in all instances. The 16S rRNA gene sequence of the cultured organisms or tissues from seven birds revealed the characteristic signature sequence for Mycobacterium genavense. Direct bird-to-bird transmission in the zoo was unlikely, and the pathogenicity of M. genavense in birds seems to be limited. The source of M. genavense in nature and the epidemiology of the disease in birds remain obscure. As suspected for human cases of M. genavense infection, an oral route of infection has been suggested, and contaminated local water distribution systems may have been the source of the infection. Our study confirms that infections caused by M. genavense should be suspected in birds (especially in Passeriformes and Psittaciformes orders) that die suddenly without previous symptoms and that have AFB in tissues that are difficult to grow on conventional media.

Mycobacterium genavenseinfection in two aged ferrets with conjunctival lesions

“…In particular, the very small coccobacillary morphology of organisms packed within macrophages in microscopic preparations was typical of M genavense. While the niche of M genavense has not been defined, primary involvement of the gastrointestinal tract in generalised disease in birds 9,12,13,22 would suggest an environmental origin. 13 The gastrointestinal tract is the most commonly implicated portal of entry for disseminated mycobacterial infections of environmental origin in humans also.…”

Mycobacterium genavense infection in a patient with long‐standing chronic lymphocytic leukaemia

“…With few exceptions, it has been found to cause disseminated disease in severely immunocompromised HIV-infected individuals. Case reports from several continents [3,7,8] and the isolation of the organism from pet animals [9,10], as well as from the gastrointestinal tract of healthy humans [11], indicate that M. genavense is a ubiquitous environmental pathogen.…”

Drug Susceptibility of Non-tuberculous Strains of Mycobacterium Isolated from Birds from Poland

“…M. genavense is very difficult to be cultured on the media, and its diagnostics are mainly based on molecular methods (Hoop et al 1993;Portaels et al 1996;Ledwoń et al 2009;Palmieri et al 2013). Therefore, the drug susceptibility tests used in this study may not be useful for testing of these mycobacteria.…”

“…Granulomatous lesions without calcification are a prominent feature. The disease is rare in the wellorganized poultry sector due to improved farm practices, but occurs in backyard poultry, zoos and aviaries (Portaels et al 1996;Shitaye et al 2008;Dhama et al 2011;Pfeiffer et al 2017). Mycobacterioses also pose a constantly and increasingly growing threat to human health, especially in people with weakened immunity (Schitaye et al 2008;Slany et al 2016;Titmarsh 2017).…”