Evaluation of the safety profile of the vaccine candidate Brucella melitensis 16MΔvjbR strain in goats.

Small ruminant brucellosis is caused by the Gram negative cocci-bacillus Brucella (B.) melitensis, the most virulent Brucella species for humans. In goats and sheep, middle to late-term gestation abortion, stillbirths and the delivery of weak infected offspring are the characteristic clinical signs of the disease. Vaccination with the currently available Rev. 1 vaccine is the best option to prevent and control the disease, although it is far from ideal. In this study, we investigate the safety of the B. melitensis 16MΔvjbR strain during a 15-month period beginning at vaccination of young goats, impregnation, delivery and lactation. Forty, 4 to 6 months old, healthy female crossbreed goats were randomly divided into four groups (n = 10) and immunized subcutaneously with a single vaccine dose containing 1x109 CFU of B. melitensis 16MΔvjbR delivered in alginate microcapsules or non-encapsulated. Controls received empty capsules or the commercially available Rev.1 vaccine. Seven months post-vaccination, when animals were sexually mature, all goats were naturally bred using brucellosis-free males, and allowed to carry pregnancies to term. Blood samples to assess the humoral immune response were collected throughout the study. At two months post-delivery, all dams and their offspring were euthanized and a necropsy was performed to collect samples for bacteriology and histology. Interestingly, none of the animals that received the vaccine candidate regardless of the formulation exhibited any clinical signs associated with vaccination nor shed the vaccine strain through saliva, vagina or the milk. Gross and histopathologic changes in all nannies and offspring were unremarkable with no evidence of tissue colonization or vertical transmission to fetuses. Altogether, these data demonstrate that vaccination with the mutant strain 16MΔvjbR is safe for use in the non-pregnant primary host.

Brucellosis in Colombia: Current Status and Challenges in the Control of an Endemic Disease.

Brucellosis is a zoonosis of nearly worldwide distribution. The disease is considered to be endemic in most of the developing countries with a substantial impact on both human and animal health as well as on the economy. The aim of this scoping review is to provide an overview of the brucellosis status in Colombia and the factors associated with its persistence, to highlight the strengths and gaps of the adopted countermeasures and to supply evidence to policy-makers on the best approaches to mitigate the disease burden. Due to the presence of brucellosis in several susceptible production livestock systems scattered throughout the country, a plan for its control, prevention and eradication was established almost 20 years ago. However, despite extensive efforts, brucellosis prevalence has fluctuated over the years without any trend of decreasing. The restricted budget allocated for brucellosis control is a limiting factor for the success of the program. For instance, the absence of indemnities for farmers results in infected animals remaining on farms which potentially increases the risk of disease spread. Likewise, disease surveillance is restricted to Brucella abortus and excludes other Brucella species of importance, such as B. melitensis and B. suis. The countermeasures are mostly focused on cattle and only a few actions are in place for the management of brucellosis in other livestock species. In humans, cases of brucellosis are annually diagnosed, although the disease remains highly underreported. High impact educational and training programs are required to address the disease in a comprehensive manner, including vulnerable groups, such as traditional smallholders and low-productivity regions, as well as other stakeholders, such as healthcare and veterinary authorities. Important financial investments based on sustained cooperation between governmental institutions, industry, and farmers are important for developing affordable and effective strategies to control the disease.

Caprine brucellosis: A historically neglected disease with significant impact on public health.

Caprine brucellosis is a chronic infectious disease caused by the gram-negative cocci-bacillus Brucella melitensis. Middle- to late-term abortion, stillbirths, and the delivery of weak offspring are the characteristic clinical signs of the disease that is associated with an extensive negative impact in a flock's productivity. B. melitensis is also the most virulent Brucella species for humans, responsible for a severely debilitating and disabling illness that results in high morbidity with intermittent fever, chills, sweats, weakness, myalgia, abortion, osteoarticular complications, endocarditis, depression, anorexia, and low mortality. Historical observations indicate that goats have been the hosts of B. melitensis for centuries; but around 1905, the Greek physician Themistokles Zammit was able to build the epidemiological link between "Malta fever" and the consumption of goat milk. While the disease has been successfully managed in most industrialized countries, it remains a significant burden on goat and human health in the Mediterranean region, the Middle East, Central and Southeast Asia (including India and China), sub-Saharan Africa, and certain areas in Latin America, where approximately 3.5 billion people live at risk. In this review, we describe a historical evolution of the disease, highlight the current worldwide distribution, and estimate (by simple formula) the approximate costs of brucellosis outbreaks to meat- and milk-producing farms and the economic losses associated with the disease in humans. Successful control leading to eradication of caprine brucellosis in the developing world will require a coordinated Global One Health approach involving active involvement of human and animal health efforts to enhance public health and improve livestock productivity.

Reticulo-ruminal milk accumulation (ruminal drinking) in five pre-ruminant white-tailed deer (Odocoileus virginianus) in Texas

Ruminal drinking is a condition that has been extensively reported in pre-ruminant calves, and is characterized by an insufficient esophageal groove reflex that causes ingested milk to spill into the reticulum and/or rumen instead of entering the abomasum directly. In calves, milk that spills into the rumen undergoes rapid microbial fermentation, producing lactic acid and other volatile fatty acids, and lowering the ruminal pH. This reduced ruminal pH predisposes the animals to ulceration and necrosis of the rumen mucosa, as well as maldigestion and recurrent tympany. We investigated five cases of ulcerative rumenitis in white-tailed deer (WTD: Odocoileus virginianus) fawns from 2009 to 2014. Four of these fawns were females with ages ranging from 2 to 30 days. Clinical findings in the fawns included poor body condition, severe diarrhea, and sudden death. Gross changes consistently observed included large amount of milk and milk curds in the rumen, reticulum and occasionally omasum, white-colored and bloody diarrhea, severe muscle wasting with extensive loss of visceral fat. On microscopic examination, the most consistent finding among three of the animals was multifocal necroulcerative rumenitis admixed with basophilic globular material (milk), while the other two animals had unremarkable histopathologic findings. Aerobic and anaerobic bacterial cultures of samples collected revealed mixed bacterial growth suggestive of secondary opportunistic invasion. Molecular diagnostics ruled out the possibility of Bluetongue and Epizootic Hemorrhagic viral infections. This report describes for the first time, clinical, gross, and microscopic changes associatedwith reticulo-ruminal milk accumulation in WTD fawns across farms in Texas, and complements those of earlier studies in calves.

Reticulo-ruminal milk accumulation (ruminal drinking) in five pre-ruminant white-tailed deer (Odocoileus virginianus) in Texas

Ruminal drinking is a condition that has been extensively reported in pre-ruminant calves, and is characterized by an insufficient esophageal groove reflex that causes ingested milk to spill into the reticulum and/or rumen instead of entering the abomasum directly. In calves, milk that spills into the rumen undergoes rapid microbial fermentation, producing lactic acid and other volatile fatty acids, and lowering the ruminal pH. This reduced ruminal pH predisposes the animals to ulceration and necrosis of the rumen mucosa, as well as maldigestion and recurrent tympany. We investigated five cases of ulcerative rumenitis in white-tailed deer (WTD: Odocoileus virginianus) fawns from 2009 to 2014. Four of these fawns were females with ages ranging from 2 to 30 days. Clinical findings in the fawns included poor body condition, severe diarrhea, and sudden death. Gross changes consistently observed included large amount of milk and milk curds in the rumen, reticulum and occasionally omasum, white-colored and bloody diarrhea, severe muscle wasting with extensive loss of visceral fat. On microscopic examination, the most consistent finding among three of the animals was multifocal necroulcerative rumenitis admixed with basophilic globular material (milk), while the other two animals had unremarkable histopathologic findings. Aerobic and anaerobic bacterial cultures of samples collected revealed mixed bacterial growth suggestive of secondary opportunistic invasion. Molecular diagnostics ruled out the possibility of Bluetongue and Epizootic Hemorrhagic viral infections. This report describes for the first time, clinical, gross, and microscopic changes associatedwith reticulo-ruminal milk accumulation in WTD fawns across farms in Texas, and complements those of earlier studies in calves.(AU)