Acute phase response in two consecutive experimentally induced E. coli intramammary infections in dairy cows

<p>Abstract</p> <p>Background</p> <p>Acute phase proteins haptoglobin (Hp), serum amyloid A (SAA) and lipopolysaccharide binding protein (LBP) have suggested to be suitable inflammatory markers for bovine mastitis. The aim of the study was to investigate acute phase markers along with clinical parameters in two consecutive intramammary challenges with <it>Escherichia coli </it>and to evaluate the possible carry-over effect when same animals are used in an experimental model.</p> <p>Methods</p> <p>Mastitis was induced with a dose of 1500 cfu of <it>E. coli </it>in one quarter of six cows and inoculation repeated in another quarter after an interval of 14 days. Concentrations of acute phase proteins haptoglobin (Hp), serum amyloid A (SAA) and lipopolysaccharide binding protein (LBP) were determined in serum and milk.</p> <p>Results</p> <p>In both challenges all cows became infected and developed clinical mastitis within 12 hours of inoculation. Clinical disease and acute phase response was generally milder in the second challenge. Concentrations of SAA in milk started to increase 12 hours after inoculation and peaked at 60 hours after the first challenge and at 44 hours after the second challenge. Concentrations of SAA in serum increased more slowly and peaked at the same times as in milk; concentrations in serum were about one third of those in milk. Hp started to increase in milk similarly and peaked at 36–44 hours. In serum, the concentration of Hp peaked at 60–68 hours and was twice as high as in milk. LBP concentrations in milk and serum started to increase after 12 hours and peaked at 36 hours, being higher in milk. The concentrations of acute phase proteins in serum and milk in the <it>E. coli </it>infection model were much higher than those recorded in experiments using Gram-positive pathogens, indicating the severe inflammation induced by <it>E. coli</it>.</p> <p>Conclusion</p> <p>Acute phase proteins would be useful parameters as mastitis indicators and to assess the severity of mastitis. If repeated experimental intramammary induction of the same animals with <it>E. coli </it>is used in cross-over studies, the interval between challenges should be longer than 2 weeks, due to the carry-over effect from the first infection.</p

Proteomic Analyses of Host and Pathogen Responses during Bovine Mastitis

The pursuit of biomarkers for use as clinical screening tools, measures for early detection, disease monitoring, and as a means for assessing therapeutic responses has steadily evolved in human and veterinary medicine over the past two decades. Concurrently, advances in mass spectrometry have markedly expanded proteomic capabilities for biomarker discovery. While initial mass spectrometric biomarker discovery endeavors focused primarily on the detection of modulated proteins in human tissues and fluids, recent efforts have shifted to include proteomic analyses of biological samples from food animal species. Mastitis continues to garner attention in veterinary research due mainly to affiliated financial losses and food safety concerns over antimicrobial use, but also because there are only a limited number of efficacious mastitis treatment options. Accordingly, comparative proteomic analyses of bovine milk have emerged in recent years. Efforts to prevent agricultural-related food-borne illness have likewise fueled an interest in the proteomic evaluation of several prominent strains of bacteria, including common mastitis pathogens. The interest in establishing biomarkers of the host and pathogen responses during bovine mastitis stems largely from the need to better characterize mechanisms of the disease, to identify reliable biomarkers for use as measures of early detection and drug efficacy, and to uncover potentially novel targets for the development of alternative therapeutics. The following review focuses primarily on comparative proteomic analyses conducted on healthy versus mastitic bovine milk. However, a comparison of the host defense proteome of human and bovine milk and the proteomic analysis of common veterinary pathogens are likewise introduced

dierenfaculteit_NR06_2009:Dierenfaculteit

ABSTRACT A serosurvey for viruses associated with reproductive disorders was conducted in 25 conventional Belgian farms. Serum antibody titers for porcine reproductive and respiratory syndrome virus (PRRSV), porcine circovirus type 2 (PCV2), porcine parvovirus (PPV), porcine enteroviruses (PEV) and swine influenza viruses (SIV) were determined in gilts and sows. All the animals were seropositive for PCV2 and &gt;95% were seropositive for all 4 embryopathogenic PEV serotypes. Consequently, special preventive measures appear to be unnecessary for these viruses. In 1 farm, non-vaccinated gilts were found to run a risk of developing PPVinduced reproductive disorders. Vaccination against PPV could exclude this risk. In 10 farms, gilts seronegative for one or more specific SIV subtypes were introduced into a herd that had previously been infected with the same subtypes. Vaccination of gilts against SIV may prevent reproductive disorders in gilts and respiratory problems in their offspring. In 1 farm, newly purchased gilts that were possibly shedding PRRSV were introduced into a PRRSV seronegative sow herd. Serological screening prior to purchase or vaccination of the sows could have resolved this dangerous situation

Towards a History of Mass Violence in the Etat Indépendant du Congo, 1885-1908

The present article provides an up-to-date scholarly introduction to mass violence in the Etat Indépendant du Congo (Congo Free State, EIC). Its aims are twofold: to offer a point of access to the extensive literature and historical debates on the subject, and to make the case for exchanging the currently prevalent top-down narrative, with its excessive focus on King Leopold's character and motives, for one which considers the EIC's culture of violence as a multicausal, broadly based and deeply engrained social phenomenon. The argument is divided into five sections. Following a general outline of the EIC's violent system of administration, I discuss its social and demographic impact (and the controversy which surrounds it) to bring out the need for more regionally focused and context sensitive studies. The dispute surrounding demographics demonstrates that what is fundamentally at stake is the place the EIC's extreme violence should occupy in the history of European ‘modernity’. Since approaches which hinge on Leopoldian exceptionalism are particularly unhelpful in clarifying this issue, I pause to reflect on how such approaches came to dominate the distinct historiographical traditions which emerged in Belgium and abroad before moving on to a more detailed exploration of a selection of causes underlying the EIC's violent nature. While state actors remain in the limelight, I shift the focus from the state as a singular, normative agent, towards the existence of an extremely violent society in which various individuals and social groups within and outside of the state apparatus committed violent acts for multiple reasons. As this argument is pitched at a high level of abstraction, I conclude with a discussion of available source material with which it can be further refined and updated