Optimization of a whole blood gamma interferon assay for the detection of sheep infected with Mycobacterium avium subspecies paratuberculosis

The capacity of a commercially available gamma interferon (IFNγ) assay to detect infected sheep early in the pathogenesis of Johne's disease enables the removal of such animals from the flock before bacterial shedding and pasture contamination. However, nonspecific IFNγ responses in the assay have meant that to achieve high-test specificity, there has been a reduction in sensitivity. Although the optimal conditions for the use of the assay in cattle have been well documented, there have been few studies optimizing the assay for use in sheep. The current study details the effect of anticoagulant, duration of incubation, cell concentration, blood storage temperature, time of stimulation of cells with antigen relative to time of sample collection, and temperatures during transit on IFNγ synthesis. Maximal IFNγ synthesis occurred with incubation periods of 48 hr in blood collected into heparinized tubes. Decreasing the leukocyte population by diluting the total peripheral blood leukocyte concentration was associated with a decreasing IFNγ response. Conversely, concentrating the peripheral blood concentration 2-fold resulted in an increase in the IFNγ production. In field studies, immediate incubation of blood samples with antigen at 37°C resulted in larger IFNγ responses; however, significantly lower IFNγ values were obtained if the samples were transported at ambient temperature. The results of this study indicate that optimization of the IFNγ assay may enable increased synthesis of IFNγ during the stimulation phase of the assay and that future work may determine whether this translates to increased sensitivity of the assay in detecting early infections in sheep. Bovigam assay, gamma interferon, Johne's disease, paratuberculosis, sheepResearch was funded by Meat and Livestock Australia (MLA

Q Fever Knowledge, Attitudes and Vaccination Status of Australia’s Veterinary Workforce in 2014

Q fever, caused by Coxiella burnetii, is a serious zoonotic disease in humans with a worldwide distribution. Many species of animals are capable of transmitting C. burnetii, and consequently all veterinary workers are at risk for this disease. An effective Q fever vaccine has been readily available and used in Australia for many years in at-risk groups, and the European Centre for Disease Prevention and Control has recently also called for the use of this vaccine among at-risk groups in Europe. Little is known about attitudes towards this vaccine and vaccine uptake in veterinary workers. This study aimed to determine the Q fever vaccination status of veterinarians and veterinary nurses in Australia and to assess and compare the knowledge and attitudes towards Q fever disease and vaccination of each cohort. An online cross-sectional survey performed in 2014 targeted all veterinarians and veterinary nurses in Australia. Responses from 890 veterinarians and 852 veterinary nurses were obtained. Binary, ordinal and multinomial logistic regression were used to make comparisons between the two cohorts. The results showed that 74% of veterinarians had sought vaccination compared to only 29% of veterinary nurses. Barriers to vaccination among those not vaccinated did not differ between cohorts, and included a lack of perceived risk, financial expense, time constraints, and difficulty in finding a vaccine provider. Poor knowledge and awareness of Q fever disease and vaccination were additional and notable barriers for the veterinary nursing cohort, suggesting veterinary clinics and veterinarians may not be meeting their legal responsibility to educate staff about risks and risk prevention. Further evaluation is needed to identify the drivers behind seeking and recommending vaccination so that recommendations can be made to improve vaccine uptake

One health in our backyard: Design and evaluation of an experiential learning experience for veterinary medical students

Background: New educational approaches are needed to improve student understanding of the wider sociological and ecological determinants of health as well as professional responsibilities in related areas. Field trips allow students to observe interaction between plant, animal and human communities, making them an ideal tool for teaching One Health concepts. Methods: Veterinary medical students participated in a field trip to a local parklands area, frequented by humans, dogs, horses, and wildlife. Students rotated through 5 learning activities (‘stations’) that focused on: (1) response to exotic animal disease incursion (equine influenza); (2) impact of cultures and belief systems on professional practice; (3) management of dangerous dogs; (4) land use change, biodiversity and emerging infectious disease; and (5) management of environmentally-acquired zoonoses (botulism). Intended learning outcomes were for students to: evaluate the various roles and responsibilities of veterinarians in society; compare the benefits and risks associated with human-animal and animal-animal interactions; and evaluate the contributions made by various professionals in safeguarding the health and welfare of animals, humans and the environment. Following the field trip, students participated in a debrief exercise and completed an online survey on their experiences. Results: Feedback from students collected in 2016/2017 (n = 211) was overwhelmingly positive. The learning experience at each station was rated as 4 (‘Good’) or 5 (‘Very Good’) out of 5 by 82–96% of students. Responses to closed- and open-ended questions − as well as outputs generated in the debrief session − indicated that students achieved the learning outcomes. Overall, 94% of students agreed or strongly agreed that they had a better understanding of One Health because of the field trip. Conclusions: Field trips to local parklands are effective in promoting learning about One Health and can be incorporated into the core curriculum to maximize student exposure at relatively low cost. Keywords: One health, Field trip, Experiential learning, Veterinary education, Cultural competence, Zoonoses, Animal behavio

Effect of Coxiella burnetii infection on milk constituents and cow behaviour

Context. The role of Coxiella burnetii in intramammary infection (IMI) in dairy cows is not fully understood. Aims. The objective of this study was to investigate changes in milk constituents and behaviour such as daily activity (arbitrary unit/day) and daily rumination (min/day) in cows exposed to C. burnetii. Methods. In total, 1029 quarter milk samples were manually collected from 48 cows before and after alveolar milk ejection in the automatic milking rotary at the University of Sydney’s dairy farm. Each milk sample was analysed for the following parameters: immunoglobulin G (cIgG) against C. burnetii via ELISA, somatic cell count (SCC), total immunoglobulin G (tIgG), lactate dehydrogenase (LDH), serum albumin (SA), milk protein%, milk fat%, and subjected to microbiological culture. The daily activity and daily rumination changes were recorded using heat-and rumination long-distance tags across 21 days before detection of IMI (n = 42 cows). Linear and logistic mixed models were used, with ‘cow’ and ‘quarter nested within cow’ as random effects. Results. The presence of cIgG was quarter-specific; the cIgG+ quarters (n = 64) had significantly greater tIgG (P < 0.001), LDH (P < 0.001), SA (P < 0.001) and milk protein% (P = 0.002) than did cIgG− quarters (n = 279). The cIgG+ quarters had significantly greater SCC, tIgG, LDH and SA responses than did controls (P < 0.05), but lower responses than did Gram-negative coliform IMI (P < 0.05). Gram-positive IMI caused by coagulase positive/negative Staphylococcus, Streptococcus uberis, Streptococcus dysgalactiae, Corynebacterium spp. in cIgG+ quarters resulted in greater tIgG, LDH and SA responses than in control quarters (P < 0.05). Coagulase-positive Staphylococcus IMI was associated with the presence of cIgG as assessed by Fisher’s exact test (P < 0.05). The cIgG+ group had a significant (P < 0.05) reduction in daily rumination compared with the cIgG− group in the study period. Conclusions and implications. The cIgG antibody responses are quarter specific with greater tIgG, LDH, SA and milk protein in the affected quarters, as well as behavioural changes in the cow, and therefore might be useful for detection of C. burnetii IMI

Frequency of adverse events following Q fever immunisation in young adults

Q fever is a zoonosis of concern in many countries. Vaccination is the most effective means of prevention, and since 1989, Australia has had a licensed Q fever vaccine, Q-VAX((R)). This vaccine was also used in the Netherlands in 2011 following the largest recorded Q fever outbreak globally. There is a paucity of available data regarding adverse events following immunisation (AEFI) for young adult females. Such data are important for informing future vaccination recommendations both within Australia and internationally. This study collected Q fever vaccine (Q-VAX((R))) AEFI data in veterinary and animal science students at Australian universities. Students were enrolled at the time of vaccination and were emailed a link to an online AEFI survey one week later. Of the 60% (499/827) that responded, 85% were female and the median age was 18 years. Local injection site reactions (ISRs) occurred in 98% (95%; CI 96-99%) of respondents, of which 30% (95% CI 24-32%) were severe. Systemic AEFI occurred in 60% (95%; CI 55-64%) of respondents within the seven days following immunisation. Medical attention was sought by 19/499 (3.8%) respondents, of whom one sought treatment at a hospital emergency department. Females were more likely than males to experience any local ISR (odds ratio [OR] 9.3; 95% CI 2.5-33.8; p < 0.001), ISRs of greater severity (OR 2.5; 95% CI 1.5-4.2; p < 0.001), and any systemic AEFI (OR 1.9; 95% CI 1.1-3.1; p = 0.016). These safety data suggest that a high frequency of adverse events following immunisation should be expected in young adults, particularly females. However, the consequences of Q fever disease are potentially far more debilitating

Comparison of culture and a multiplex probe PCR for identifying <i>Mycoplasma</i> species in bovine milk, semen and swab samples

<div><p><i>Mycoplasma</i> spp. are a major cause of mastitis, arthritis and pneumonia in cattle, and have been associated with reproductive disorders in cows. While culture is the traditional method of identification the use of PCR has become more common. Several investigators have developed PCR protocols to detect <i>M</i>. <i>bovis</i> in milk, yet few studies have evaluated other sample types or other important <i>Mycoplasma</i> species. Therefore the objective of this study was to develop a multiplex PCR assay to detect <i>M</i>. <i>bovis</i>, <i>M</i>. <i>californicum</i> and <i>M</i>. <i>bovigenitalium</i>, and evaluate its analytical performance against traditional culture of bovine milk, semen and swab samples. The PCR specificity was determined and the limit of detection evaluated in spiked milk, semen and swabs. The PCR was then compared to culture on 474 field samples from individual milk, bulk tank milk (BTM), semen and swab (vaginal, preputial, nose and eye) samples. Specificity analysis produced appropriate amplification for all <i>M</i>. <i>bovis</i>, <i>M</i>. <i>californicum</i> and <i>M</i>. <i>bovigenitalium</i> isolates. Amplification was not seen for any of the other Mollicutes or eubacterial isolates. The limit of detection of the PCR was best in milk, followed by semen and swabs. When all three <i>Mycoplasma</i> species were present in a sample, the limit of detection increased. When comparing culture and PCR, overall there was no significant difference in the proportion of culture and PCR positive samples. Culture could detect significantly more positive swab samples. No significant differences were identified for semen, individual milk or BTM samples. PCR identified five samples with two species present. Culture followed by 16S-23S rRNA sequencing did not enable identification of more than one species. Therefore, the superior method for identification of <i>M</i>. <i>bovis</i>, <i>M</i>. <i>californicum</i> and <i>M</i>. <i>bovigenitalium</i> may be dependent on the sample type being analysed, and whether the identification of multiple target species is required.</p></div

Survey data relating to Q fever knowledge, attitudes and vaccination status of Australia’s veterinary workforce in 2014

This data collection is associated with the accepted publication ‘Q fever knowledge, attitudes and vaccination status of Australia’s veterinary workforce in 2014’v| |v Publication abstract: Q fever, caused by Coxiella burnetii, is a serious zoonotic disease in humans with a worldwide distribution. Many species of animals are capable of transmitting C. burnetii, and consequently all veterinary workers are at risk for this disease. An effective Q fever vaccine has been readily available and used in Australia for many years in at-risk groups and the European Centre for Disease Prevention and Control has recently called for the use of this vaccine among at-risk groups in Europe. Little is known about attitudes towards this vaccine and vaccine uptake in veterinary workers. This study aimed to determine the Q fever vaccination status of veterinarians and veterinary nurses in Australia and to assess and compare the knowledge and attitudes towards Q fever disease and vaccination of each cohort. An online cross-sectional survey performed in 2014 targeted all veterinarians and veterinary nurses in Australia. Responses from 890 veterinarians and 852 veterinary nurses were obtained. Binary, ordinal and multinomial logistic regression were used to make comparisons between the two cohorts. The results showed that 74% of veterinarians had sought vaccination compared to only 29% of veterinary nurses. Barriers to vaccination among those not vaccinated did not differ between cohorts, and included a lack of perceived risk, financial expense, time constraints, and difficulty in finding a vaccine provider. Poor knowledge and awareness of Q fever disease and vaccination were additional and notable barriers for the veterinary nursing cohort, suggesting veterinary clinics and veterinarians may not be meeting their legal responsibility to educate staff about risks and risk prevention. Further evaluation is needed to identify the drivers behind seeking and recommending vaccination so that recommendations can be made to improve vaccine uptake

Comparison of culture and multiplex PCR for detecting bovine field samples as positive or negative for <i>M</i>. <i>bovis</i>, <i>M</i>. <i>californicum</i> or <i>M</i>. <i>bovigenitalium</i>.

<p>Comparison of culture and multiplex PCR for detecting bovine field samples as positive or negative for <i>M</i>. <i>bovis</i>, <i>M</i>. <i>californicum</i> or <i>M</i>. <i>bovigenitalium</i>.</p

Vector-borne and zoonotic diseases of dogs in North-west New South Wales and the Northern Territory, Australia

Abstract Background Vector-borne diseases of dogs in Australian Aboriginal communities are relatively unexplored. These dogs represent a unique group with variable ecto- and endo-parasitic burdens, nutritional stresses and a general lack of veterinary intervention. We investigated haemoprotozoal and bacterial pathogen prevalences in relation to erythrocyte and platelet numbers in dogs from North-West New South Wales (N-W NSW) and the Northern Territory (NT; Central Australia). Methods Real-time PCR (qPCR) amplification of Anaplasma platys, Babesia vogeli, Mycoplasma haemocanis, Candidatus Mycoplasma haematoparvum and Bartonella spp., serological screening for Coxiella burnetii, and Bartonella spp. and haematological analyses were performed on dogs from the two cohorts (96 dogs in total). Brucella suis serology was determined additionally for the N-W NSW cohort. Results Anaplasma platys (n = 26 dogs), Babesia vogeli (n = 7), Candidatus Mycoplasma haematoparvum (n = 10 dogs), and Mycoplasma haemocanis (n = 14) were detected in the sample population (n = 96) using qPCR. There were significant associations between (i) A. platys and anaemia (OR 8.7, CI 2.4–31.7; P < 0.001), thrombocytopenia (OR 12.1, CI 3.4–43.2; P < 0.001) and breed (OR 16.1, CI 2.1–121.5; P = 0.007), and (ii) between B. vogeli and anaemia (OR 11.8, CI 2.3–61.6; P = 0.003). Neither protozoal nor bacterial DNA loads, estimated using qPCR, were positively correlated with anaemia or thrombocytopenia. Haemotropic mycoplasmas were not associated with any haematologic abnormality. Four dogs from the NT were seropositive for Coxiella burnetii, while no dogs were seropositive for Brucella suis or to a panel of Bartonella spp. antigens. Despite directed efforts, Bartonella DNA was not detected in blood from any of the cohorts studied. A sample of dogs from the NT recruited specifically for Bartonella α-proteobacteria growth medium enrichment blood culture were also Bartonella PCR negative. Conclusions Vector-borne pathogens occur in dogs free ranging near Aboriginal communities, with higher detection rates in NT than N-W NSW. The preponderant haematologic abnormalities were anaemia and thrombocytopenia, likely attributable to A. platys and B. vogeli infections, but also probably affected by nutritional, parasitic, lactational and environmental stressors. The absence of Bartonella spp. is of importance to the Australian setting, and work needs to be extended to tropical coastal communities where fleas are present as well as ticks. Dogs living in and around Aboriginal communities may provide valuable sentinel information on disease infection status of human public health significance