Feline tuberculosis caused by Mycobacterium bovis

Strengthening a One Health approach to emerging zoonoses

Given the enormous global impact of the COVID-19 pandemic, outbreaks of highly pathogenic avian influenza in Canada, and manifold other zoonotic pathogen activity, there is a pressing need for a deeper understanding of the human-animal-environment interface and the intersecting biological, ecological, and societal factors contributing to the emergence, spread, and impact of zoonotic diseases. We aim to apply a One Health approach to pressing issues related to emerging zoonoses, and propose a functional framework of interconnected but distinct groups of recommendations around strategy and governance, technical leadership (operations), equity, education and research for a One Health approach and Action Plan for Canada. Change is desperately needed, beginning by reorienting our approach to health and recalibrating our perspectives to restore balance with the natural world in a rapid and sustainable fashion. In Canada, a major paradigm shift in how we think about health is required. All of society must recognize the intrinsic value of all living species and the importance of the health of humans, other animals, and ecosystems to health for all.

Mycobacterium bovis BCG Danish Strain 1331 isolated from a periarticular lesion in a domestic cat

A 7-year-old male neutered domestic shorthair outdoor cat was referred for chronic left forelimb lameness, which had been treated with intra-articular injections of triamcinolone acetonide. A soft tissue swelling around the elbow joint, extending from the distal humerus to the proximal ulna, was surgically explored and biopsy samples obtained. Mycobacterium bovis was cultured from samples from the soft tissue and bone. The mycobacteria from the media were killed and the DNA extracted and tested on a multiplex real-time PCR for the absence of specific genes and the presence of mycobacterial genus markers. The PCR revealed bacillus Calmette-Guérin Danish Strain 1331; this was also isolated from the prescapular lymph node, muscle and bone, obtained at post mortem examination. Badgers had been vaccinated with the bacillus Calmette-Guérin vaccine SSI (Statens Serum Institute) in the area where the cat lived, in the spring and autumn of the previous year. To the authors' knowledge, this is the first report of infection with M. bovis bacillus Calmette-Guérin Danish Strain 1331 in a domestic cat, potentially associated with annual vaccination of badgers in the proximity of the cat's home.

Unusual Manifestation of a Mycobacterium bovis SB0950 Infection in a Domestic Cat

Mycobacterium bovis is the main agent of bovine tuberculosis, but has also zoonotic potential. An 8-month-old female domestic shorthaired cat imported from Ukraine developed wound complications after abdominal surgery. A second surgery performed in Germany showed a focal, partly cystic mass within the mesentery. Despite antimicrobial treatment, the cat did not recover and was humanely destroyed. Grossly, several abdominal lymph nodes were enlarged. Histopathology revealed a mild to moderate, multifocal, granulomatous to pyogranulomatous, partially necrotizing inflammation, most prominent in the abdominal cavity. Within the lesions there were acid-fast bacilli within the cytoplasm of macrophages demonstrated by Ziehl-Neelsen staining. Further investigations revealed M. bovis SB0950 in the affected tissues.

The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2017

This report of the European Food Safety Authority and the European Centre for Disease Prevention and Control presents the results of zoonoses monitoring activities carried out in 2017 in 37 European countries (28 Member States (MS) and nine non-MS). Campylobacteriosis was the commonest reported zoonosis and its EU trend for confirmed human cases increasing since 2008 stabilised during 2013-2017. The decreasing EU trend for confirmed human salmonellosis cases since 2008 ended during 2013-2017, and the proportion of human Salmonella Enteritidis cases increased, mostly due to one MS starting to report serotype data. Sixteen MS met all Salmonella reduction targets for poultry, whereas 12 MS failed meeting at least one. The EU flock prevalence of target Salmonella serovars in breeding hens, laying hens, broilers and fattening turkeys decreased or remained stable compared to 2016, and slightly increased in breeding turkeys. Salmonella results on pig carcases and target Salmonella serovar results for poultry from competent authorities tended to be generally higher compared to those from food business operators. The notification rate of human listeriosis further increased in 2017, despite Listeria seldom exceeding the EU food safety limit in ready-to-eat food. The decreasing EU trend for confirmed yersiniosis cases since 2008 stabilised during 2013-2017. The number of confirmed shiga toxin-producing Escherichia coli (STEC) infections in humans was stable. A total of 5,079 food-borne (including waterborne) outbreaks were reported. Salmonella was the commonest detected agent with S. Enteritidis causing one out of seven outbreaks, followed by other bacteria, bacterial toxins and viruses. The agent was unknown in 37.6% of all outbreaks. Salmonella in eggs and Salmonella in meat and meat products were the highest risk agent/food pairs. The report further summarises trends and sources for bovine tuberculosis, Brucella, Trichinella, Echinococcus, Toxoplasma, rabies, Coxiella burnetii (Q fever), West Nile virus and tularaemia.

Detection of Viable Mycobacterium bovis in Lungs and Livers Sold in Butchers' Shops in Buenos Aires, Argentina

Although Mycobacterium bovis is the major etiological agent of tuberculosis in bovines, it can infect other mammalians. Previously reported cases of tuberculosis caused by M. bovis in cats from the Autonomous City of Buenos Aires (CABA) led to the conclusion that the main source of infection for these felines was the ingestion of raw bovine lungs. Thus, for this study, we collected samples of bovine viscera from butchers' shops of the Greater Buenos Aires (GBA) and the CABA to assess presence and viability of these mycobacteria in bovine lungs (including the lymph nodes) and livers. We analyzed 216 different samples and obtained 5 isolates of M. bovis (4 from lungs and 1 from liver) by culture analysis. We also confirmed the presence of different isolates by polymerase chain reaction, spoligotyping, and MIRU-VNTR assays. The results obtained in this work emphasizes the need of social education for food hygiene, and to change the habit of feeding pets with raw viscera, which carries the risk of epizootic and zoonotic transmission. Moreover, control and eradication programs of bovine tuberculosis should be strengthened and improved.

An outbreak of tuberculosis due to Mycobacterium bovis infection in a pack of English Foxhounds (2016-2017)

Mycobacterium bovis can cause tuberculosis (TB) in social mammals including lions, cattle and man, but canine infections are considered rare. In 2016/17 we investigated a M. bovis TB outbreak in a pack of approximately 180 Foxhounds within the bovine TB Edge Area of England. We employed a combination of immunological tests including an interferon gamma release assay (IGRA) and a serological assay (DPP VetTB, Chembio). Test‐positive hounds were euthanased and subjected to post‐mortem examination (PME). Overall 164 hounds were tested; 97 (59%) responded positively to at least one test. Eighty‐five (52%) dogs responded to M. bovis antigens by IGRA while only 21 (12.9%) had detectable serological responses. At PME three hounds (3.1%) had visible lesions (VL) due to M. bovis infection, later confirmed by culture. Samples from 24 non‐VL hounds were cultured and M. bovis infection was confirmed in a further three hounds (11%). This study is the first investigation and report of an outbreak of M. bovis TB in a canine species. We establish that, in principle, diagnostic tests used for identifying infected individuals of other species can effectively be used in the dog. Further work is urgently needed to establish the sensitivity and specificity of the testing approach used in this study for future clinical application.

Mycobacterioses in dogs and cats from Buenos Aires, Argentina

Mycobacterioses can produce nonspecific clinical signs in dogs and cats that make diagnosis difficult. Furthermore, the full characterization of mycobacterial agents is not always possible or practical. We characterized mycobacteria detected through cytology in 12 dogs and 7 cats with generalized clinical signs from the province of Buenos Aires in Argentina. In dogs, molecular testing confirmed the presence of Mycobacterium avium subsp. hominissuis (MAH) in 8 cases and M. fortuitum in 1 case. All dogs were Miniature Schnauzers, suggesting that this breed may be more susceptible to M. avium than other dog breeds. The cat isolates were 2 M. bovis, 1 M. fortuitum, and 1 MAH. Mycobacterial interspersed repetitive unit-variable-number tandem repeat patterns suggested possible links with cattle, swine, and humans studied previously in Argentina. The results show that pets may act as susceptible hosts with the potential risk of transmitting the infection to humans and other animals.

TB Summit 2014: prevention, diagnosis, and treatment of tuberculosis-a meeting report of a Euroscicon conference

World TB Day commemorates Dr Robert Koch’s first announcement on March 24, 1882, that the bacterium Mycobacterium tuberculosis is the causative agent of tuberculosis. Currently, the event comprises of several conferences, meetings and activities held all over the world with the singular intention of raising public awareness about the global health emergency.

In spite of having discovered the etiological agent of tuberculosis more than a century ago, a sizeable population still contract the disease every year and fall prey to it. In 2012, an estimated 8.6 million people developed the disease with 1.3 million succumbing to it. The number of TB deaths in children is unacceptably large, given that most are preventable. However, the challenge appears to be shifting toward attempts to control the rise and spread of the drug resistant variants of the microbe. To achieve this, a concerted effort from academia, clinical practice, and industry has been put forth.

The TB Summit 2014 attempted to raise awareness as well as bring together experts involved in different aspects of tuberculosis research to help establish a more collective approach to battle this age-old disease.