Bovis Bacteria Research Articles

Unveiling insights into bovine tuberculosis: A comprehensive review.

The frequent zoonotic disease known as "bovine tuberculosis" is brought on by the Mycobacterium bovis bacteria, which can infect both people and animals. The aim of this review article is to provide an explanation of the etiology, history, epidemiology, pathogenesis, clinical symptoms, diagnosis, transmission, risk factors, public health importance, economic impact, treatment, and control of bovine tuberculosis. Primarily, bovine tuberculosis affects cattle, but other animals may also be affected. Bovine tuberculosis is present throughout the world, with the exception of Antarctica. Cattle that contract bovine tuberculosis might suffer from a persistent, crippling illness. In the early stages of the disease, there are no symptoms. The tuberculin test is the primary method for detecting bovine tuberculosis in cows. Depending on its localized site in the infected animal, M. bovis can be found in respiratory secretions, milk, urine, feces, vaginal secretions, semen, feces, and exudates from lesions (such as lymph node drainage and some skin lesions). This illness generally lowers cattle productivity and could have a negative financial impact on the livestock business, particularly the dairy industry. The most effective first-line anti-tuberculosis chemotherapy consists of isoniazid, ethambutol, rifampin, and streptomycin. Second-line drugs used against bovine tuberculosis include ethionamide, capreomycin, thioacetazone, and cycloserine. To successfully control and eradicate bovine tuberculosis, developed nations have implemented routine testing and culling of infected animals under national mandatory programs.

Lipoproteins Are Potent Activators of Nuclear Factor Kappa B in Mammary Epithelial Cells and Virulence Factors in Mycoplasma bovis Mastitis.

Mastitis due to Mycoplasma bovis is a worldwide problem, which leads to significant economic losses and affects animal welfare. However, the mechanisms by which M. bovis establishes and maintains intra-mammary infections (IMI) in dairy cows are largely unknown. To study in further detail the pathogenesis of M. bovis IMI, time- and cost-effective experimental models are needed. To this end, we established and characterized an in vitro murine mammary alveolar epithelial (EpH4) cell-based model and an in vivo murine mastitis model. Our results showed that live and UV-treated M. bovis field strain 161791 and its lipid-associated membrane proteins (LAMP) activated nuclear factor kappa B (NF-kB) in EpH4 cells in a dose-dependent manner. In the murine mastitis model, temporal and spatial dynamics of inflammation in the mammary tissues were evident. Live M. bovis elicited diffuse inflammation affecting the whole challenged gland peaking at 48 h post infection (pi) in contrast to LAMP challenge, which elicited only focal inflammation peaking at 24 h and resolving at 48 h pi. Inflammation was characterized by massive neutrophil recruitment into the milk spaces and by elevated expression of the inflammatory mediators TNF-α, KC, iNOS and NF-kB dependent genes: A20 and IkBα. Moreover, the presence of intraepithelial bacterial communities in glands challenged with live M. bovis bacteria was shown. The developed models can be used efficiently for future characterization of M. bovis virulence factors and host immune response to IMI.

Successive use of shared space by badgers and cattle: implications for Mycobacterium bovis transmission

AbstractManaging infectious disease demands understanding pathogen transmission. In Britain, transmission of Mycobacterium bovis from badgers (Meles meles) to cattle hinders the control of bovine tuberculosis (TB), but the mechanism of such transmission is uncertain. As badgers and cattle seldom interact directly, transmission might occur in their shared environment through contact with contamination such as faeces, urine and saliva. We used concurrent GPS collar tracking of badgers and cattle at four sites in Cornwall, southwest Britain, to test whether each species used locations previously occupied by the other species, within the survival time of M. bovis bacteria. Although analyses of the same data set showed that badgers avoided cattle, we found no evidence that this avoidance persisted over time: neither GPS‐collared badgers nor cattle avoided space which had been occupied by the other species in the preceding 36 h. Defining a contact event as an animal being located <5 m from space occupied by the other species within the previous 36 h, we estimated that a herd of 176 cattle (mean herd size in our study areas) would contact badgers at least 6.0 times during an average 24‐h period. Similarly, we estimated that a social group of 3.5 badgers (mean group size in our study areas) would contact cattle at least 0.76 times during an average night. Such frequent successive use of the same shared space, within the survival time of M. bovis bacteria, could potentially facilitate M. bovis transmission via the environment.

An infant with disseminated bacillus Calmette-Guerin infection (BCGitis)

The bacillus Calmette Guerin (BCG) vaccine contains live attenuated Mycobacte-rium bovis bacteria. There is a long-standing controversy surrounding the efficacy of BCG against TB and whether it should be used. BCG is associated with significant adverse effects, including life-threatening disseminated BCG infection in children with primary immunodefi-ciency (PID). Here, we present a case report of an infant diagnosed with severe combined im-munodeficiency disease and disseminated BCGitis. There are no clear guidelines for the most suitable treatment for disseminated BCG disease. Hematopoietic stem cell transplantation (HSCT) is needed in urgent cases. BCGitis is known to exacerbate clinically after HSCT while immune reconstitution occurs. During this time, rapidly expanding peripheral T cells of the graft result in a severe inflammatory response, lymphadenitis, multiple abscesses, and sepsis, and fatal multiple organ failure is possible. Modification of the transplant procedure and the use of immunosuppressive medications and prednisolone to treat cytokine reactions at the time of overwhelming immune reconstitution are usually necessary.

Investigation of phenotypic variations amongst Mycoplasma bovis field German isolates using SDS-PAGE

Mycoplasma bovis is a major bacterial pathogen causing widespread respiratory disease, mastitis, and arthritis in cattle. Ineffective drugs treatments, culling of infected cows and loss of milk production can lead to significant economic losses in dairy farms. The early detection of cows excreting M. bovis bacteria to prevent mastitis outbreak is necessary. In our study the percentage of M. bovis infection among dairy herd was recorded by cultivation in combination with digitonin test and confirmed by species specific PCR as 4%. The protein profile of the isolated field German strains was compared to M. bovis reference strain Donetta PG45 using SDS-PAGE. The pattern of the reference strain was different from that of field strains as well as a marked heterogenicity among the field strains was noticed.

Longevity of Mycobacterium bovis in brushtail possum (Trichosurus vulpecula) carcasses, and contact rates between possums and carcasses

AIM: To determine, for a variety of environmental conditions, how long Mycobacterium bovis might remain viable inside the carcass of a brushtail possum (Trichosurus vulpecula) that died of bovine tuberculosis (Tb), and to measure the rate of contact between free-ranging possums and possum carcasses. METHODS: Lesions of M. bovis were simulated by inoculating excised spleens weighing 0.5–1 g with 0.2 mL liquid culture containing approximately 5 x 107 cfu M. bovis/mL. Simulated lesions were inserted into possum carcasses (n=48) at the peripheral lymph nodes. Carcasses were placed in the field at two sites (a tussock grassland and a podocarp-broadleaved forest site) and in two seasons (summer and winter) for up to 62 days. Survival rates of M. bovis were estimated by sampling the simulated lesions over time, and culturing the recovered lesion to determine if any viable M. bovis bacteria were present. The time taken for a free-ranging possum to first encounter a dead possum in its home range was estimated by live-trapping possums and fitting them with proximity loggers (n=13). A ‘contact’ was recorded if these possums came within 40–50 cm of proximity loggers fitted to possum carcasses. RESULTS: There were strong seasonal and site effects in the survival rate of M. bovis in possum carcasses. In the grassland habitat, no viable bacilli were cultured from any carcass after 3 days in summer, whereas in winter all samples were culture-positive for the first 20 days, and some were still positive after 27 days. The survival rates for forest habitat were intermediate between the results for grassland, and there were no culture-positive carcasses after 9 days in summer or 27 days in winter. In summer, infected carcasses (n=6) were first encountered by possums a mean 1.9 (range 0.4–6.7) days after placement. CONCLUSIONS: Possum carcasses were contacted by free-ranging possums within the period that viable M. bovis were shown to survive in a carcass. The risk of such infection is likely to be most significant in winter or in areas with microhabitats where the survival of M. bovis is high. However, the generally low survival rate of M. bovis in possum carcasses and the low frequency of possum-to-carcass contacts indicate this route of transmission alone could not maintain Tb in a possum population.

Between-herd prevalence of Mycoplasma bovis in bulk milk in Flanders, Belgium

Mycoplasma bovis (M. bovis) is a highly infectious pathogen of cattle causing pneumonia, polyarthritis, otitis, and less frequently, subcutaneous abscesses, abortions and meningitis.Ineffective drugs treatments, culling of infected cows and loss of milk production can lead to significant economic loss on dairy farms. The early detection of cows excreting M. bovis bacteria to prevent mastitis outbreaks is warranted. Reports suggest that the risk of M. bovis mastitis is higher in larger dairy herds.The objective of this study is to estimate the herd-level prevalence of M. bovis in Flanders, Belgium by culturing bulk tank milk samples taken from dairy farms.Three bulk tank milk samples per dairy herd were taken over four weeks, with collection intervals of two weeks. Culturing was done after pre-incubation using modified Hayflicks media to increase the chances of recovery of bacteria. For the identification of M. bovis, tDNA intergenic spacer PCR was used.In three herds (1.5%) of the 200 herds sampled, M. bovis was isolated from one of the three consecutive bulk tank milk samples. We conclude that in Flanders in 2009 at least 1.5% of the dairy herds had one or more cows excreting M. bovis in the milk.The frequent monitoring of bulk tank milk to detect the presence of M. bovis, especially in expanding herds on farms that often purchase replacement animals, should be encouraged in order to detect the presence of M. bovis and to monitor the success of control procedures following an outbreak of mycoplasmal mastitis in the herd.

A Study of the Persistence of Mycobacterium bovis in the Environment under Natural Weather Conditions in Michigan, USA.

Reisolation of Mycobacterium bovis from inoculated substrates was used to follow the persistence of viable M. bovis bacteria exposed to natural weather conditions over a 12-month period. Environmental factors were recorded continuously, and factors affecting M. bovis persistence (i.e., temperature, season, and substrate) were studied using survival analysis and Cox's proportional hazards regression. Persistence of M. bovis in the environment was significantly shorter in the spring/summer season, characterized by the highest average daily temperatures over the 12-month period. M. bovis persisted up to 88 days in soil, 58 days in water and hay, and 43 days on corn. These studies demonstrate that M. bovis bacteria persist long enough to represent a risk of exposure for cattle and/or wildlife and strengthen evidence that suggests cattle farm biosecurity and efforts to eliminate supplemental feeding of white-tailed deer will decrease the risk of bovine TB transmission among and between cattle and deer populations.

Malpractice Issues in Radiology:Res Ipsa Loquitur

1475 phy, most likely due to contamination of the contrast medium or spinal needle used for the myelography. The plaintiff’s expert asserted that the fault lay with the radiologist or technologists under his supervision at the time. The expert witness retained by the defense, in his deposition, disagreed that the defendant–radiologist was responsible for the complication that arose from the myelographic procedure. The expert pointed out that the myelogram kit or the contrast medium itself may have been contaminated with the S. bovis bacteria before they were placed in the hands of the defendant–radiologist. The expert went on to testify that, although unusual, S. bovis infection secondary to a myelogram is a known risk of the procedure and can occur without negligence. He also added that the bacteria could possibly have already been in the patient’s bloodstream and that the meningitis simply had not become symptomatic until the time of the myelography. After completion of the depositions of both expert witnesses, the defendant–radiologist, and other individuals who were involved with the myelogram CT procedure, the defense attorney moved for dismissal of the lawsuit, asserting that the plaintiff failed to present sufficient evidence to support the res ipsa theory. The trial judge agreed with the defense attorney’s argument and dismissed the lawsuit. The plaintiff then appealed the dismissal to the Illinois Appellate Court.

Probiotics and manipulation of rumen development and function

There is good evidence that the bacterial and fungal probiotics are effective in the manipulation of rumen development and function. The effects of adherent Streptococcus bovis preparations were manifested by significant increase of adherent S. bovis bacteria and alpha amylase activity in the rumen wall of young ruminants. Fungal probiotics based on Saccharomyces cerevisiae and Aspergillus oryzae are rapidly gaining acceptance as a means of improving productivity in adult ruminants. However, fungal probiotics may also have a complementary role to bacterial probiotics in young animals. Dietary yeast improved performance of calves and lambs in terms of feed intake and live weight gain and Aspergillus foetidus was effective in altering rumen fermentation in newly weaned lambs.

Preliminary observations of interaction between bacteriophages and Streptococcus bovis bacteria on ruminal epithelium primoculture

Five Streptococcus bovis strains (47/3.59/2,4/1.46/2 and 44/9) isolated from calf ruminal fluid samples were examined for the adherence to cultured ruminal epithelium cells. Four strains (47/3. 59/2,4/1 and 46/2) were able to attach to the cultured epithelial cells. However, S. bovis 47/3 strain attached to the target cells in significantly greater numbers than the other strains. Strain 44/9 did not adhere to cells of ruminal epithelium. The adherent bacteria were observed on the surface of differentiated (mainly keratinized) cells of ruminal epithelium primoculture only. The different effect of F4, F5 and F6 bacteriophages was ascertained on S. bovis bacteria adhering to rumen epithelial primoculture, A significant decrease in the number of adherent bacteria was shown after cultivation of strains 47/3 and 4/1 with F6 bacteriophage and 47/3 strain with F4 phage. The F5 bacteriophage had no significant effect on these bacteria.