Polymorphonuclear cells and reactive oxygen species in contagious bovine pleuropneumonia: New insight from in vitro investigations

Abstract Reactive oxygen species (ROS) are suggested to play a role in the pathogenesis of contagious bovine pleuropneumonia, a severe respiratory disorder caused by Mycoplasma mycoides subsp. mycoides ( Mmm ). The present study investigated the generation of ROS by different strains of Mmm , as well as their effect on the oxidative response of bovine neutrophils. The production of ROS was indirectly measured using a luminol-based chemiluminescence assay. Our results confirm that Mmm can produce ROS via the metabolism of glycerol, significant differences existing between African and European strains. Mmm was capable of adhering to the external surface of neutrophils. Interestingly, Mmm enhanced the respiratory burst of bovine neutrophils. This activity was particularly pronounced with the African field strain and in presence of glycerol. Taken together, our data argue in favour of a major role for neutrophils as the main source of ROS in contagious bovine pleuropneumonia

Plasma levels of TNF-α, IFN-γ, IL-4 and IL-10 during a course of experimental contagious bovine pleuropneumonia

<p>Abstract</p> <p>Background</p> <p>Contagious Bovine Pleuropneumonia (CBPP), caused by <it>Mycoplasma mycoides </it>subsp. <it>mycoides</it>, is widespread in sub-Saharan Africa. The current live vaccine T1/44 has limited efficacy and occasionally leads to severe side effects in the animals. A better understanding of the immune responses triggered by <it>Mycoplasma mycoides </it>subsp. <it>mycoides </it>and their role in disease progression will help to facilitate the design of a rational vaccine. Currently, knowledge of cytokines involved in immunity and immunopathology in CBPP is rather limited. The aim of this study was to characterize the <it>in vivo </it>plasma concentrations of the cytokines TNF-α, IFN-γ, IL-4, IL-10 and the overall role of CD4⁺T cells in the development of cytokine levels during a primary infection. Plasma cytokine concentrations in two groups of cattle (CD4⁺T cell-depleted and non-depleted cattle) experimentally infected with <it>Mycoplasma mycoides </it>subsp. <it>mycoides </it>were measured and their relationship to the clinical outcomes was investigated.</p> <p>Results</p> <p>Plasma cytokine concentrations varied between animals in each group. Depletion of CD4⁺T cells did not induce significant changes in plasma levels of TNF-α, IL-4, and IL-10, suggesting a minor role of CD4⁺T cells in regulation or production of the three cytokines during the time window of depletion (1-2 weeks post depletion). Unexpectedly, the IFN-γ concentrations were slightly, but statistically significantly higher in the depleted group (p < 0.05) between week three and four post infection. Three CD4⁺T cell-depleted animals that experienced severe disease, had high levels of TNF-α and IFN-γ. Only one severely diseased non-depleted animal showed a high serum concentration of IL-4 post infection.</p> <p>Conclusions</p> <p>Comparison of most severely diseased animals, which had to be euthanized prior to the expected date, versus less severe diseased animals, irrespective of the depletion status, suggested that high TNF-α levels are correlated with more severe pathology in concomitance with high IFN-γ levels.</p

Namibia: un esempio di cooperazione internazionale per lo studio delle patologie emergenti

L'Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise è impegnato da anni nella ricerca e sperimentazione mirate ad approfondire la conoscenza delle malattie esotiche, cioè di quelle malattie che non sono presenti sul territorio nazionale. Per poter raggiungere tali obiettivi, è importante impegnarsi nella creazione di una rete di collaborazioni con Laboratori ed Enti di ricerca a livello nazionale ed internazionale. I rapporti che l'Istituto ha instaurato soprattutto con la Namibia e più di recente Botswana si stanno rivelando di notevole aiuto per la reciproca crescita tecnico-scientifica. L'Istituto coopera con i Servizi Veterinari della Namibia fornendo supporto tecnico-scientifico e nel 2005, ha allestito un proprio Laboratorio di Virologia, presso il Central Veterinary Laboratory di Windhoek, nel quale, personale dell'Istituto e namibiano, in unita' di intenti, condividono le competenze diagnostiche e la ricerca scientifica. Scopo del seguente lavoro è descrivere le attività svolte nell'ambito di questo rapporto di collaborazione

Namibia: an example of international cooperation in the study of emerging diseases

The Istituto Zooprofilattico Sperimentale dell’Abruzzo e del Molise ‘G. Caporale’ (IZS A&M) has been engaged for many years in research and studies designed to increase knowledge and expertise when dealing with ‘exotic diseases’ namely, those diseases which are not present in a country. To achieve these objectives, it is important to create cooperation networks with laboratories and research organisations at national and international levels. The relationship between the IZS A&M with Namibia in particular and, more recently with Botswana, are proving to be very valuable to mutual technical/scientific growth. In 2005, the National Reference Centre for the Study of Exotic Diseases set up its own Virology Laboratory at the Windhoek Central Veterinary Laboratory where the Namibian and IZS A&M personnel, working towards common goals, share diagnostic responsibilities and scientific research. The authors describe the activities involved in this joint project

Contagious bovine pleuropneumonia: humoral and pathological events in cattle infected by endotracheal intubation or by exposure to infected animals

Results of trials in which cattle were infected by endotracheal intubation of Mycoplasma mycoides var. mycoides small colony (MmmSC) cultures or by contact exposure to animals affected by contagious bovine pleuropneumonia (CBPP) are numerous. However, an analysis of the effects of the two different routes of infection on disease outcome is lacking. This study analyses the disease outcome in cattle infected by the two methodologies. Data originate from two controlled trials conducted in Namibia under field conditions. Intubation appears to be responsible for chronic evolution of the disease while in-contact infected animals develop more severe infection inducing mortality. Our results seem to suggest that the mode of infection may condition the disease outcome and should be taken into consideration in studies on the pathogenesis of CBPP

Standardisation of an indirect enzyme-linked immunosorbent assay for the detection

An indirect enzyme-linked immunosorbent assay (ELISA) was evaluated for the detection of Brucella antibodies in milk from water buffalo (Bubalus bubalis Linnaeus, 1758). The test accuracy was evaluated on milk samples from the Campania Region in Italy. A total of 100 negative samples were collected from 10 officially brucellosis-free herds in Salerno Province, while 30 positive samples were collected from 3 herds in Caserta Province, where animals gave positive results to the official tests and it was here that Brucella abortus biovar 1 had been isolated. Test sensitivity was 100%, with a confidence interval (CI) of 90.8%-100%, while specificity was 98% (CI 93%-99.4%) on individual milk samples. To simulate bulk milk samples from herds infected at various levels of infection, dilutions from 1:10 to 1:100 of positive milk samples in negative milk were also used. The probability of detecting antibodies in positive milk samples was higher than 50% up to a dilution of 1:50 in negative milk. Considering the average national water buffalo herd size, the probability of identifying infection in a water buffalo herd by bulk milk testing is 50% (CI 33.1%-66.9%) in the worst case scenario of a single infected animal contributing to the bulk milk

Preliminary report of transfrontier disease surveillance in free-ranging buffalo in the Caprivi Strip, Namibia

A capture operation to ascertain the health status of free-ranging buffalo (Syncerus caffer) from six areas in the Caprivi Strip in the north-east corner of Namibia is described. In-depth reports on buffalo capture operations and their cost, with detailed descriptions of diseases for research purposes, sampling techniques, field processing of samples and laboratory-related costs are still lacking in the literature. This paper describes materials, methods and the related costs of a disease surveillance operation conducted among buffalo in Namibia. The survey attempted to provide information designed to improve the control of infectious diseases in the Caprivi Strip, a key area bordering Angola, Zambia, Botswana and Zimbabwe

Rapporto preliminare dell’attività di sorveglianza delle malattie transfrontaliere nei bufali africani nella regione del Caprivi, Namibia

Questo lavoro descrive le fasi organizzative e lo svolgimento delle operazioni di cattura nel Caprivi, a nordest della Namibia, per accertare lo stato sanitario dei bufali africani. Un report completo, che descriva le operazioni di cattura e i costi sostenuti oltre alle finalità di ricerca, le tecniche di campionamento, la lavorazione dei campioni in campo e le spese di laboratorio è assente in letteratura. In questo lavoro vengono descritti materiali, metodi e relativi costi di un’operazione di sorveglianza svolta sui bufali in Namibia. L’attività di sorveglianza qui descritta vuole fornire delle indicazioni preliminari che permettano di migliorare le strategie di controllo delle malattie infettive nel Caprivi, che è una zona di grande importanza sanitaria al confine con Angola, Zambia, Botswana e Zimbabwe

An ELISA for the evaluation of gamma interferon production in cattle vaccinated with Brucella abortus strain RB51

The results of an enzyme-linked immunosorbent assay (ELISA) implemented for the detection of gamma interferon (g-interferon) production in cattle vaccinated with Brucella abortus strain RB51 are presented. A purified protein fraction derived from RB51 (RB51 brucellin) has been used as antigenic stimulus for whole blood. The test was evaluated for 300 days in ten heifers vaccinated at calfhood with 10 × 109 colony-forming units of RB51 and in five control heifers. All animals came from officially brucellosis-free herds. Vaccinated animals started to give positive results from day 17 post vaccination (pv) until day 239 pv. All vaccinated animals gave a positive reaction at least once (with a stimulation index exceeding 2.5). Nevertheless, if sampling on day 20 pv is excluded (90% of vaccinated animals gave positive results), the sensitivity of the test varies from 20% to 70%, with a 40% average. A stimulation index over 2.5 was also recorded in three control animals. The results suggest that the g-interferon test is not suitable for the detection of cattle vaccinated with RB51, either at the individual or at the herd level