Tuberculous Cow Research Articles

A neutrophil-based test as an auxiliary tool for substantiating the diagnosis of bovine tuberculosis.

Bovine tuberculosis (bTB) is still a prominent threat to animal health; lacking an efficient vaccine, other than BCG to get rid of tuberculosis, the most effective way for this is culling and slaughtering the infected animals. There are several cellular, serological, and molecular tests for the diagnosis of the disease but the most practical one at the field level is the double skin testing with bovine and aviary tuberculins. This is not a very specific test but is sensitive enough to identify most diseased animals; adjunct practical tests are desirable to strengthen the utility of skin tests. All lymphoid and myeloid cells participate, in diverse grades, in the immune response to tuberculosis with neutrophils playing an unintended pathologic role. The study aimed to investigate the response of neutrophils to agents present in the sera of tuberculous cows. We have developed a neutrophil-based test (N BT) to identify diseased cows within a herd suspected of having tuberculosis; a positive N BT correlates with a positive double skin test. In this test, healthy neutrophils are incubated with the sera of healthy or tuberculous cows for 3 and 6 h, and the nuclear morphologic changes are recorded and analyzed. Sera from tuberculous but not from healthy cows induce nuclear alterations including pyknosis, swelling, apoptosis, and sometimes NETosis, in healthy neutrophils, and CFP 10 and ESAT 6 participate in the phenomenon. We propose the N BT as an auxiliary tool for substantiating the diagnosis of bTB reinforcing the PPD test outcome to help decide whether or not a cow should be sacrificed.

Cytokine Expression in Peripheral Blood Mononuclear Cell Cultures Obtained from Cattle with Different Stages of Natural Mycobacterium bovis Infection

In bovine tuberculosis (bTB), cellular, humoral, or both types of immune responses have been observed. The purpose of this study was to examine the immune status of tuberculous cows based on the differential cytokine gene expression associated with Th1 (IFN-γ, IL-2), or Th2 (IL-4, IL-10) responses. Twenty-three (23) cows belonging to a dairy herd located in a rural region of the State of Hidalgo, México, were selected for the study. Single Intradermal Comparative Cervical Tuberculin (SICCT) Test, Interferon-Gamma (IFN-γ) Release Assay (BOVIGAM), and Enzyme-Linked Immunosorbent Assay (ELISA) were used for detection of cattle infected by M. bovis. Thirteen cows were positive to all the tests (Group 1); ten cows were positive only to ELISA (Group 2), and the remaining Group (Group 3, control) included cows negative to all the tests. Peripheral blood mononuclear cells (PBMC) from animals were in vitro stimulated by bovin purified protein derivative (PPD), avian PPD, and Concanavalin A (Con A) mitogen for 72h. Changes in the levels of expression of mRNA of the respective cytokines was measured by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using β-actin gene as internal control. In group 1, PPD bovis and Con A-stimulated cells exhibited high production of IFN-γ, IL-2 and IL-4, but not IL-10. In contrast, PPD avium-stimulated cells displayed a low production of cytokine transcripts. In group 2, cells showed a significant production of IL-10 in response to bovine PPD (P< 0.001). In the control group, a high production of IFN-γ and IL-2 was observed only in Con A-stimulated cells. Post-mortem examinations in animals of group 1 showed slight and medium lesions in lymph nodes, whereas in group 2, the lesions were more extensive. Results indicate differences on gene expression levels of cytokines considered to determine balance in Th1/Th2 response among the evaluated groups. In addition, high levels of antibodies against M. bovis and high IL-10 expression in PBMC together are indicators of progressive bTB when both tuberculin test and IFN-γ assay are negative in tuberculous anergic cattle. Inclusion of serology and IL-10 cytokine expression in in the diagnosis checklist improves detection of infected cattle to help control bovine tuberculosis.

Use of the Human Vaccine, Mycobacterium bovis Bacillus Calmette Guérin in Deer.

The only vaccine ever approved for human tuberculosis was developed a century ago from an isolate of Mycobacterium bovis derived from a tuberculous cow. Initial safety and efficacy studies of an attenuated version of this isolate were conducted in cattle and other animals. In 1921 the first human, an infant, was orally dosed with this attenuated strain that came to be known as M. bovis bacillus Calmette-Guérin (BCG); named for Albert Calmette and Camille Guérin, the two French scientists that developed the strain. Since 1921, billions of people have been vaccinated with BCG making it the oldest, most widely used, and safest vaccine in use today. It is also the tuberculosis vaccine most studied for use in wildlife, including deer. While BCG vaccination of deer may not reliably prevent infection, it consistently decreases lesion severity, minimizing large, necrotic lesions, which often contain large numbers of bacilli. It is believed that decreased lesion severity correlates with decreased disease transmission; however, this hypothesis remains to be proven. Safety studies in white-tailed deer show BCG may persist in lymphoid tissues for up to 12 months; a factor to be considered in deer used for food. Beyond efficacy and safety, methods of vaccine delivery to free-ranging deer are also under investigation, both in the laboratory and in the field. The ideal delivery method is effective, efficient and safe for non-target species, including livestock. Ingestion of BCG by cattle is of special concern as such cattle may present as “false positives” using currently approved diagnostic methods, thus interfering with efforts by animal health agencies to monitor cattle for tuberculosis. An effective BCG vaccine for deer would be of value in regions where free-ranging deer represent a potential source of M. bovis for livestock. Such a vaccine would also be beneficial to farmed deer where M. bovis represents a serious threat to trade and productivity.

TB or not TB?

<scp>TB</scp> or not <scp>TB</scp>?

Detection of Mycobacterium bovis DNA in nasal swabs from tuberculous cattle by a multiplex PCR

Detection of tuberculosis in cattle relies on the intradermal tuberculin test (ITT), but a definitive diagnosis requires identification of the pathogen after the animal is slaughtered. DNA in nasal swabs from 50 cows was analyzed by m-PCR, targeting for the RvD1-Rv2031c and IS6110 sequences. M. bovis was identified in two of 34 tuberculous cows (5.9%). The use of mPCR of nasal swabs as an in vivo diagnostic tool for bovine tuberculosis is suggested.

Occurrence of false-positive results in three Paratuberculosis - ELISAs performed in a tuberculous herd

The interference of bovine tuberculosis (TB) on the efficacy of paratuberculosis (PTB) diagnostic tests has been evaluated. A group of 32 tuberculous cows identified by both intradermal tests and gamma-interferon assay, 16 of them confirmed by the recovery of M.bovis from tissues, was tested by three different PTB- ELISAs, being two commercials and one in-house. The rest of the adult animals of the herds, totalizing 216 TB-negative animals, were also tested as a control group. Fecal culture for PTB was negative in all animals, but seven (21.8%) tuberculous cows produced false-positive reactions when tested by various PTB-ELISAs, leading to a misdiagnosis. Tuberculosis impairs the specificity of serological tests for paratuberculosis diagnosis and should be considered for the reliability of PTB control programs.

Revisão: tuberculose genital em bovinos e bubalinos

Objetivo: Apresentar uma revisão sobre a tuberculose genital em bovinos e búfalos. Fontes Pesquisadas: Foram consultados os acervos das bibliotecas da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo (FMVZ/USP) e do Instituto Biológico de São Paulo; além da base de dados MEDLlNE, cuja pesquisa atingiu um período retrospectivo de 30 anos. Síntese dos Dados: A tuberculose é uma doença de significativa importância econômica, causando grandes prejuízos à pecuária e implicações à saúde pública. O aspecto zoonótico da tuberculose tem diminuído pela obrigatoriedade da pasteurização do leite. Porém, em alguns países, esse caráter da doença ainda persiste devido ao hábito de se consumir o leite cru e queijos produzidos sem tratamento térmico. Estima-se que 5% das vacas tuberculosas desenvolvam infecção genital, ocasionando principalmente lesões no útero (metrite), e I% a 2% podem desenvolver mastite tuberculosa. Tuberculose genital nos machos é mais rara, no entanto, pode ocasionar lesões em praticamente todo aparelho reprodutivo. Em búfalos, a incidência de tuberculose é maior do que em bovinos, e as lesões se distribuem por todos os órgãos, incluindo o aparelho reprodutor com lesões de endométrio. Comentários Finais: Estima-se que a prevalência de tuberculose bovina no Brasil seja de 0,9% a 2,9%. Contudo, não se caracteriza como uma doença da reprodução, ainda que sua ocorrência não seja tão rara no sistema reprodutivo de bovinos e bubalinos. Pode causar ainda transtornos reprodutivos, como infertilidade e repetições de cio, representando assim uma via pouco comum de transmissão da doença.

Effect of dexamethasone treatment of tuberculous cattle on results of the gamma-interferon test for Mycobacterium bovis

The purpose of this project was to determine the effect of dexamethasone (DEX) treatment of tuberculous cows on antigen-stimulated gamma-interferon (γ-IFN) production in a commercial Mycobacterium bovis γ-interferon test (γ-IFN test) developed for diagnosis of bovine tuberculosis. In the γ-IFN test an enzyme-linked immunosorbent assay is used to detect bovine γ-IFN in the plasma from whole blood samples cultured with M. bovis and Mycobacterium avium tuberculin purified protein derivatives (PPDs). DEX is a synthetic glucocorticoid commonly used as a potent anti-inflammatory agent, and experimentally as a model of stress-induced immunosuppression in cattle. DEX treatment has previously been associated with decreased lymphocyte response to mitogens in cattle, which led to the current hypothesis that DEX treatment would suppress stimulated γ-IFN production resulting in false negative results in the γ-IFN test. In replicate studies using naturally infected dairy cows, blood was drawn daily for at least 2 days prior to DEX treatment, during 3 days of DEX treatment, and for at least 9 days post-DEX. Results of the γ-IFN test were evaluated by optical density (OD), and by three OD calculation methods: two different methods suggested by the manufacturer, and a method adapted from the evaluation of a bovine γ-IFN test used in Australia. Prior to DEX treatment all cows had positive γ-IFN tests by each calculation method. As early as 24 h after the first DEX injection a decline in PPD-stimulated γ-IFN production was reflected in OD data for all cows. Calculated γ-IFN test results were negative after DEX treatment for all but one cow, which was known to produce relatively large amounts of γ-IFN as measured by this test. The degree of γ-IFN suppression, and the number of days that γ-IFN test results were negative after DEX treatment (1–8 days), varied by cow and by data calculation method. Treatment with DEX is associated with suppressed PPD-stimulated γ-IFN production, which may be reflected as false negative results in the γ-IFN test depending on the data calculation method applied. The results have implications for the management conditions and medical treatment schedule under which samples for the γ-IFN test are collected.

Epidemic of bovine tuberculosis cases originating from an infected beef herd in Oklahoma, USA

Although the prevalence of bovine tuberculosis has diminished in the USA, there have been surprising recent discoveries of the infection in Pennsylvania (1989), North Dakota (1988), New Mexico (1985) and Mississippi (1983). In August 1989, US Department of Agriculture (USDA) inspectors at a Missouri slaughter establishment found an aged beef-type cow of Oklahoma origin with tuberculosis during routine necropsy. The study reports procedures, results and the progress of investigations after finding the tuberculous slaughter-cow. The tuberculous cow came from a herd of beef cattle (Farm A) in northeastern Oklahoma. Farm A purchased the cow at a local auction market in October 1988; the cow ultimately originated from another local farm (Farm B). All cattle on Farm B had dispersed at the time Farm A acquired the tuberculous cow. Regulatory officials investigated all known sales of cattle from Farm B and discovered 12 additional cases of tuberculosis (one in Kansas and 11 in Oklahoma). The cases involved the exposure of over 4400 cattle on 87 premises (seven states) to the infection. The source of infection for Farm B was not determined. The epidemic of tuberculosis cases in the current study stressed the importance of surveillance by USDA inspectors at slaughter establishments, and also rapid and decisive action in bovine tuberculosis eradication efforts.

Chemical Destruction of Mycobacterium bovis in Milk

The tuberculocidal activity of phenol and 1-Stroke Environ was tested using five Mycobacterium bovis strains added separately to five samples of untreated cows milk. The tuberculocidal activity of each disinfectant was significantly improved (P = .005) by increasing exposure temperature from 4 to 23 C or by increasing exposure time from 1 to 6 h or by increasing disinfectant concentrations two-fold.Environ diluted 1:8 or phenol diluted 1:32 killed each of the five strains of M. bovis suspended in untreated milk (6 mg/ml) during a 6-h exposure at 23 C. Either disinfectant could be used to destroy M. bovis in unsalable milk from tuberculous cows scheduled for slaughter.

Further Developments in Human and Bovine Antituberculosis Chemoprophylaxis with Isoniazid in Italy

1. Calves submitted to chemoprophylaxis after primary infection resulting from exposure to tuberculous cows acquired an immunity which protected them against a massive parenteral reinfection with bovine tubercle bacilli. This immunity corresponds to that obtained by BCG vaccination and is present even if the reinfection occurs six months after discontinuance of chemoprophylaxis. 2. Large-scale trials with chemoprophylaxis on human beings have been carried out in Italy since April, 1956. Chemoprophylaxis has been used in selected groups exposed to tuberculosis in households and schools. These groups include all tuberculin-positive children under five years and adolescents in families with a tuberculous background, especially when living with tuberculous individuals. 3. The procedure might be expected to be beneficial in adults who had had tuberculosis, in tuberculous subjects in order to avoid relapses, as well as in silicotic and siderotic miners. 4. Chemoprophylaxis should be integrated with antituberculosis vaccination and nonspecific prophylaxis which still are the bases of the prevention of tuberculosis.

A tuberculous cow

A tuberculous cow

British Food Journal Volume 45 Issue 6 1943

British Food Journal Volume 45 Issue 6 1943

British Food Journal Volume 32 Issue 10 1930

British Food Journal Volume 32 Issue 10 1930

British Food Journal Volume 32 Issue 8 1930

British Food Journal Volume 32 Issue 8 1930

The isolation of tubercle bacilli from captive wild animals

Summary 1. The type of infecting bacillus was determined in seven captive wild animals (including one bird). Three bovine and four human strains of tubercle bacilli were recorded. One of the bovine and two of the human strains appeared to be of less than standard virulence. 2. Attention is drawn to the fact that in lupus, and in tuberculosis of horses and of captive wild animals, a considerable proportion of strains isolated have been of subnormal virulence. This finding is in marked contrast with the almost uniformly high virulence of strains isolated from other tuberculous lesions in man, and from tuberculous cows and pigs.

Elimination of the Tuberculous Cow: Administrative Results at Berwick- upon-Tweed, by D. BOYD, Sanitary Inspector, Berwick-upon-Tweed

Elimination of the Tuberculous Cow: Administrative Results at Berwick- upon-Tweed, by D. BOYD, Sanitary Inspector, Berwick-upon-Tweed

British Food Journal Volume 30 Issue 7 1928

British Food Journal Volume 30 Issue 7 1928

The Problem of the Tuberculous Cow, by ARTHUR GOFTON, F.R.C.V.S., Chief Veterinary Inspector, Edinburgh. (Member.)

The Problem of the Tuberculous Cow, by ARTHUR GOFTON, F.R.C.V.S., Chief Veterinary Inspector, Edinburgh. (Member.)

The Elimination of the Tuberculous Cow

The Elimination of the Tuberculous Cow