Browsing by Author "Miller, Michele A."

Now showing 1 - 8 of 8
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    Adaptation and diagnostic potential of a commercial cat interferon gamma release assay for the detection of Mycobacterium bovis infection in African lions (Panthera leo)
    (MDPI, 2022-07) Gumbo, Rachiel; Sylvester, Tashnica T.; Goosen, Wynand J.; Buss, Peter E.; De Klerk-Lorist, Lin-Mari; Van Schalkwyk, O. Louis; McCall, Alicia; Warren, Robin M.; Van Helden, Paul D.; Miller, Michele A.; Kerr, Tanya J.
    Mycobacterium bovis (M. bovis) infection in wildlife, including lions (Panthera leo), has implications for individual and population health. Tools for the detection of infected lions are needed for diagnosis and disease surveillance. This study aimed to evaluate the Mabtech Cat interferon gamma (IFN-γ) ELISABasic kit for detection of native lion IFN-γ in whole blood samples stimulated using the QuantiFERON® TB Gold Plus (QFT) platform as a potential diagnostic assay. The ELISA was able to detect lion IFN-γ in mitogen-stimulated samples, with good parallelism, linearity, and a working range of 15.6–500 pg/mL. Minimal matrix interference was observed in the recovery of domestic cat rIFN-γ in lion plasma. Both intra- and inter-assay reproducibility had a coefficient of variation less than 10%, while the limit of detection and quantification were 7.8 pg/mL and 31.2 pg/mL, respectively. The diagnostic performance of the QFT Mabtech Cat interferon gamma release assay (IGRA) was determined using mycobacterial antigen-stimulated samples from M. bovis culture-confirmed infected (n = 8) and uninfected (n = 4) lions. A lion-specific cut-off value (33 pg/mL) was calculated, and the sensitivity and specificity were determined to be 87.5% and 100%, respectively. Although additional samples should be tested, the QFT Mabtech Cat IGRA could identify M. bovisinfected African lions.
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    Biopsy and tracheobronchial aspirates as additional tools for the diagnosis of bovine tuberculosis in living European bison (bison bonasus)
    (MDPI, 2020-11-02) Didkowska, Anna; Orłowska, Blanka; Witkowski, Lucjan; Katarzyna, Olbrych; Brzezinska, Sylwia; Augustynowicz-Kopec, Ewa; Krajewska-Wędzina, Monika; Bereznowski, Andrzej; Bielecki, Wojciech; Krzysiak, Michał; Rakowska, Alicja; Olech, Wanda; Miller, Michele A.; Waters, Wade R.; Lyashchenko, Konstantin P.; Anusz, Krzysztof
    ENGLISH ABSTRACT: The diagnosis of bovine tuberculosis (BTB) in living wildlife remains a complex problem, and one of particular importance in endangered species like European bison (Bison bonasus). To identify infection and avoid the unnecessary culling of such valuable individuals, current best practice requires the collection and culture of material from living animals, as mycobacteria isolation remains the gold standard in BTB diagnosis. However, such isolation is challenging due to the need for the immobilization and collection of appropriate clinical material, and because of the sporadic shedding of mycobacteria. In the present study, we evaluated the potential of sampling for the detection of BTB in a group of seven living European bison suspected of being infected with Mycobacterium caprae. The specimens were collected both as swabs from the nasal and pharyngeal cavities, tracheobronchial aspirates (TBA), ultrasound-guided biopsies from lateral retropharyngeal lymph nodes, and post mortem, from mandibular, retropharyngeal and mediastinal lymph nodes. Clinical samples were tested for mycobacterial species via mycobacteriological culture and PCR. M. caprae was isolated from collected material in two out of four living infected individuals (TBA, biopsy) and mycobacterialDNAwas detected in three out of four (TBA, pharyngeal swab) bison. This is the first report of isolation of M. caprae in living European bison. Our findings demonstrate the value of diagnostic tests based on both molecular testing and culture in European bison and confirm the respiratory shedding of viable M. caprae in this host species.
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    Cytokine gene expression assay as a diagnostic tool for detection of Mycobacterium bovis infection in warthogs (Phacochoerus africanus)
    (Nature Research (part of Springer Nature), 2019) Roos, Eduard O .; Scott, Leere A.; Ndou, Sedzani; Olea-Popelka, Francisco; Buss, Peter E.; De Klerk-Lorist, Lin-Mari; Warren, Robin M.; Van Helden, Paul D.; Sylvester, Tashnica T .; Miller, Michele A.; Parsons, Sven D. C.
    ENGLISH ABSTRACT: Mycobacterium bovis infection has been described in many wildlife species across Africa. However, diagnostic tests are lacking for many of these, including warthogs (Phacochoerus africanus). Most literature on suids has focused on using serological tools, with few studies investigating the use of cell-mediated immune response (CMI) assays. A recent study showed that warthogs develop measurable CMI responses, which suggests that cytokine gene expression assays (GEAs) may be valuable for detecting M. bovis-infection, as shown in numerous African wildlife species. Therefore, the aim of the study was to develop GEAs capable of distinguishing between M. bovis-infected and uninfected warthogs. Whole blood was stimulated using the QuantiFERON-TB Gold (In-Tube) system, using ESAT-6 and CFP-10 peptides, before determining the relative gene expression of five reference (B2M, H3F3A, LDHA, PPIA and YWHAZ) and five target (CXCL9, CXCL10, CXCL11, IFNG and TNFA) genes through qPCR. The reference gene H3F3A was the most stably expressed, while all target genes were significantly upregulated in M. bovis-infected warthogs with the greatest upregulation observed for CXCL10. Consequently, the CXCL10 GEA shows promise as an ante-mortem diagnostic tool for the detection of M. bovis-infected warthogs.
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    Editorial : Bovine Tuberculosis—International perspectives on epidemiology and management
    (Frontiers Media, 2019-06-25) Byrne, Andrew W.; Allen, Adrian R.; O'Brien, Daniel J.; Miller, Michele A.
    Introduction: Bovine tuberculosis (bTB) remains a prominent zoonotic pathogen on the world stage, with significant impacts on animal and human health, and economic well-being. Eradication is hampered by a complex epidemiology, which in many countries involves wildlife hosts. Indeed, despite advances in understanding gleaned from national programs of bTB eradication, much of our understanding of transmission mechanisms, diagnostics, control, and multi-host infection systems remains opaque. In this collection of Frontiers in Veterinary Science, as editors, we felt these limitations could best be addressed by adopting an international perspective. Localism understandably focuses on the fine details of problems at hand, but can perhaps overlook issues that only become apparent when compared to the experiences of others. Below we summarize the papers published in this truly international collection, and highlight some themes. We trust readers will find these articles as stimulating to read as they were to edit.
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    Novel molecular transport medium used in combination with Xpert MTB/RIF ultra provides rapid detection of Mycobacterium bovis in African buffaloes
    (Nature Research (part of Springer Nature), 2021) Clarke, Charlene; Smith, Katrin; Goldswain, Samantha J.; Helm, Christopher; Cooper, David V.; Kerr, Tanya J.; Kleynhans, Leanie; Van Helden, Paul D.; Warren, Robin M.; Miller, Michele A.; Goosen, Wynand J.
    ENGLISH ABSTRACT: Mycobacterium bovis is the causative agent of bovine tuberculosis (bTB) in wildlife. Confirmation of M. bovis infection relies on mycobacterial culture, which is time-consuming. Collection and transportation of infectious material also pose a human health risk. PrimeStore Molecular Transport Medium (MTM) has been shown to effectively inactivate infectious organisms, making it a safe method for handling infectious samples. This study investigated an in-field sampling technique for rapid, safe detection of M. bovis in buffalo tissues. Potentially infected tissues from bTB test-positive buffaloes were swabbed at post-mortem examination and stored in PrimeStore MTM at ambient temperature until Xpert MTB/RIF Ultra testing was performed. Additionally, tissue samples were frozen and transported before homogenisation for culture and Ultra testing. Oral swabs were collected from M. bovis-unexposed buffaloes as a negative control cohort. Mycobacterium tuberculosis complex (MTBC) DNA was detected by Ultra in 13/16 tissue swabs and 9/16 matched tissue homogenates from culture-confirmed M. bovis-positive buffalo tissues. MTBC DNA was not detected in swabs from M. bovis-unexposed animals, showing the potentially high specificity of Ultra with PrimeStore swabs. PrimeStore MTM sample processing, in combination with the Ultra assay, has the potential to provide a safe, rapid post-mortem screening test for M. bovis in buffaloes.
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    Relationships between housing and management factors and clinical health events in elephants in North American zoos
    (Public Library of Science, 2019-06-06) Edwards, Katie L.; Miller, Michele A.; Carlstead, Kathy; Brown, Janine L.
    ENGLISH ABSTRACT: Elephants experience a number of health issues that can contribute to their well-being and survival. In managed populations, housing conditions and management practices can influence individual health, so potential risk factors associated with morbidity or mortality should be identified to ensure the best possible standards of care. The goal of this study was to determine if the number of clinical events experienced could be a useful welfare indicator in zoo elephants, and to determine factors associated with key pathologies. We used an epidemiological approach to investigate how intrinsic (species, sex, age) and extrinsic (housing, management) factors were associated with both the total number of clinical events, and each of the four most prevalent pathology types (gastrointestinal issues, skin lesions, lameness, foot lesions), over a 12-month period. The study included 220 (127 African; 93 Asian) elephants housed at 61 facilities across North America. More than 1100 clinical events were identified. Species and sex differences were apparent in the types of pathology encountered, and unsurprisingly, the number of clinical events was positively correlated with age. Factors relating to housing (percent time with indoor/outdoor choice, space experience inside, number of unique environments an elephant was housed in, percent time on soft substrate) and management (enrichment diversity, spread of feeding opportunities) were also related to the number of clinical events. However, relationships were often counter to our initial hypotheses, highlighting caution in assuming cause and effect from correlational analyses such as these. Other welfare indicators such as serum and fecal glucocorticoids and serum prolactin were also associated with health status, being higher or more variable in individuals with a greater number of events. This approach provides insight into housing and management factors related to the health of these species in zoos, and in some cases, may reflect management changes that have already been made to mitigate existing or anticipated health concerns.
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    Review of diagnostic tests for detection of mycobacterium bovis infection in South African wildlife
    (Frontiers Media S.A, 2021-01) Bernitz, Netanya; Kerr, Tanya J.; Goosen, Wynand J.; Chileshe, Josephine; Higgitt, Roxanne L.; Roos, Eduard O.; Meiring, Christina; Gumbo, Rachiel; De Waal, Candice; Clarke, Charlene; Smith, Katrin; Goldswain, Samantha; Sylvester, Taschnica T.; Kleynhans, Léanie; Dippenaar, Anzaan; Buss, Peter E.; Cooper, David V.; Lyashchenko, Konstantin P.; Warren, Robin M.; Van Helden, Paul D.; Parsons, Sven D. C.; Miller, Michele A.
    Wildlife tuberculosis is a major economic and conservation concern globally. Bovine tuberculosis (bTB), caused byMycobacteriumbovis (M. bovis), is themost common form of wildlife tuberculosis. In South Africa, to date, M. bovis infection has been detected in 24 mammalian wildlife species. The identification of M. bovis infection in wildlife species is essential to limit the spread and to control the disease in these populations, sympatric wildlife species and neighboring livestock. The detection of M. bovis-infected individuals is challenging as only severely diseased animals show clinical disease manifestations and diagnostic tools to identify infection are limited. The emergence of novel reagents and technologies to identify M. bovis infection in wildlife species are instrumental in improving the diagnosis and control of bTB. This review provides an update on the diagnostic tools to detect M. bovis infection in South African wildlife but may be a useful guide for other wildlife species.
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    Serum health biomarkers in African and Asian elephants : value ranges and clinical values indicative of the immune response
    (MDPI, 2020-09-27) Edwards, Katie L.; Miller, Michele A.; Siegal-Willott, Jessica; Brown, Janine L.
    Serum biomarkers indicative of inflammation and disease can provide useful information regarding host immune processes, responses to treatment and prognosis. The aims of this study were to assess the use of commercially available anti-equine reagents for the quantification of cytokines (tumor necrosis factor-alpha (TNF- ), interferon-gamma (IFN- ), interleukins (IL) 2, 6, and 10) in African (Loxodonta africana, n = 125) and Asian (Elephas maximus, n = 104) elephants, and alongside previously validated anti-human reagents for acute-phase proteins (serum amyloid A and haptoglobin), calculate species-specific biomarker value ranges. In addition, we used opportunistically collected samples to investigate the concentrations of each biomarker during identified clinical cases of illness or injury, as a first step to understanding what biomarkers may be useful to managing elephant health. Immune biomarkers were each elevated above the calculated species-specific value ranges in at least one clinical case, but due to variability in both clinical and non-clinical samples, only serum amyloid A was significantly higher in clinical compared to non-clinical paired samples, with tendencies for higher TNF- and IL-10. We also detected increased secretion of serum amyloid A and all five cytokines following routine vaccination of a single Asian elephant, indicating that these biomarkers can be beneficial for studying normal immune processes as well as pathology. This study indicates that assays developed with commercial reagents can be used to quantify health biomarkers in wildlife species and identifies several that warrant further investigation to elucidate immune responses to various pathologies.