RESUMO
OBJECTIVE: To determine the time course and certain cardiopulmonary effects of trunk-breathing elephants immobilized with thiafentanil-azaperone. STUDY DESIGN: Prospective descriptive study. ANIMALS: A convenience sample of 10 free-ranging African elephant bulls (estimated weight range: 3000-6000 kg). METHODS: Elephants were immobilized using thiafentanil (15-18 mg) and azaperone (75-90 mg) administered by dart. Once recumbent, the respiratory rate, minute ventilation (VËe), end-tidal carbon dioxide (Pe'CO2), arterial blood pressure and heart rate were recorded immediately after instrumentation and at 5 minute intervals until 20 minutes. Arterial blood gases were analysed at the time of initial instrumentation and at 20 minutes. On completion of data collection, thiafentanil was antagonized using naltrexone (10 mg mg-1 thiafentanil; administered intravenously). A stopwatch was used to record time to recumbency (dart placement to recumbency) and time to recovery (administration of antagonist to standing). Data were compared using a one-way anova. Data are presented as mean ± standard deviation. RESULTS: All elephants were successfully immobilized, and there were no significant changes in cardiopulmonary variables over the monitoring period. Average time to recumbency was 12.5 (± 3.9) minutes. The measured VËe was 103 (± 30) L minute-1. The average heart and respiratory rates over the 20 minute immobilization were steady at 49 (± 6) beats minute-1 and 5 (± 1) breaths minute-1, respectively. The mean arterial blood pressure was 153 (± 31) mmHg. The elephants were acidaemic (pH: 7.18 ± 0.06), mildly hypoxaemic (PaO2: 68 ± 15 mmHg; 9.1 ± 2.0 kPa) and hypercapnic (PaCO2: 52 ± 7 mmHg; 6.9 ± 0.9 kPa). Average time to recovery was 2.2 ± 0.5 minutes. CONCLUSION AND CLINICAL RELEVANCE: African elephant bulls can be successfully immobilized using thiafentanil-azaperone. Recumbency was rapid, the cardiopulmonary variables were stable over time, and recovery was rapid and complete. Mild hypoxaemia and hypercapnia were evident.
Assuntos
Azaperona , Elefantes , Animais , Azaperona/farmacologia , Coleta de Dados , Elefantes/fisiologia , Fentanila/análogos & derivados , Hipnóticos e Sedativos/farmacologia , Imobilização/veterinária , Estudos ProspectivosRESUMO
Mycobacterium bovis infection in wildlife species occurs worldwide. However, few cases of M. bovis infection in captive elephants have been reported. We describe 2 incidental cases of bovine tuberculosis in free-ranging African elephants (Loxodonta africana) from a tuberculosis-endemic national park in South Africa and the epidemiologic implications of these infections.
Assuntos
Elefantes , Mycobacterium bovis , Tuberculose , Animais , Animais Selvagens , África do SulRESUMO
Immunological assays are the basis for many diagnostic tests for infectious diseases in animals and humans. Application in wildlife species, including the African elephant (Loxodonta africana), is limited however due to lack of information on immune responses. Since many immunoassays require both identified biomarkers of immune activation as well as species-specific reagents, it is crucial to have knowledge of basic immunological responses in the species of interest. Cytokine gene expression assays (GEAs) used to measure specific immune responses in wildlife have frequently shown that targeted biomarkers are often species-specific. Therefore, the aim of this study was to identify elephant-specific cytokine biomarkers to detect immune activation and to develop a GEA, using pokeweed mitogen stimulated whole blood from African elephants. This assay will provide the foundation for the development of future cytokine GEAs that can be used to detect antigen specific immune responses and potentially lead to various diagnostic tests for this species.
Assuntos
Citocinas/imunologia , Elefantes/imunologia , Regulação da Expressão Gênica/imunologia , Animais , ImunoensaioRESUMO
OBJECTIVE: To compare induction times and physiological effects of etorphine-azaperone with etorphine-midazolam immobilization in African buffaloes. STUDY DESIGN: Randomized crossover study. ANIMALS: A group of 10 adult buffalo bulls (mean body weight 353 kg). METHODS: Etorphine-azaperone (treatment EA; 0.015 and 0.15 mg kg-1, respectively) and etorphine-midazolam (treatment EM; 0.015 and 0.15 mg kg-1, respectively) were administered once to buffaloes, 1 week apart. Once in sternal recumbency, buffaloes were instrumented and physiological variables recorded at 5 minute intervals, from 5 minutes to 20 minutes. Naltrexone (20 mg mg-1 etorphine dose) was administered intravenously at 40 minutes. Induction (dart placement to recumbency) and recovery (naltrexone administration to standing) times were recorded. Arterial blood samples were analysed at 5 and 20 minutes. Physiological data were compared between treatments using a general linear mixed model and reported as mean ± standard deviation. Time data were compared using Mann-Whitney U test and reported as median (interquartile range) with p ≤ 0.05. RESULTS: Actual drug doses administered for etorphine, azaperone and midazolam were 0.015 ± 0.001, 0.15 ± 0.01 and 0.16 ± 0.02 mg kg-1, respectively. Induction time for treatment EA was 3.3 (3.6) minutes and not different from 3.2 (3.2) minutes for treatment EM. The overall mean arterial blood pressure was significantly lower for treatment EA (102 ± 25 mmHg) than that for treatment EM (163 ± 18 mmHg) (p < 0.001). The PaO2 for treatment EA (37 ± 12 mmHg; 5.0 ± 1.6 kPa) was not different from that for treatment EM (43 ± 8 mmHg; 5.8 ± 1.1 kPa). Recovery time was 0.8 (0.6) minutes for treatment EA and did not differ from 1.1 (0.6) minutes for treatment EM. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment EA was as effective as treatment EM for immobilization in this study. However, systemic arterial hypertension was a concern with treatment EM, and both combinations produced clinically relevant hypoxaemia. Supplemental oxygen administration is recommended with both drug combinations.
Assuntos
Azaperona , Búfalos , Etorfina , Hipnóticos e Sedativos/farmacologia , Animais , Estudos Cross-Over , Etorfina/farmacologia , Imobilização/veterinária , MidazolamRESUMO
Coxiellosis, or Query (Q) fever, a disease caused by the intracellular bacteria Coxiella burnetii, was recently described in a managed breeding herd of white rhinoceros (Ceratotherium simum) in the southeastern United States. Clinical disease often results in abortion and could represent a conservation challenge for this species. In addition to the reproductive and herd management consequences, coxiellosis is also a zoonotic disease. Infection or clinical disease in any free-ranging rhinoceros species in a national park setting has not been previously described. In this study, evidence of prior infection was measured by immunofluorescent antibody titers in 89 serum samples collected from white rhinoceros within private reserves and a national park in South Africa. Total seropositivity was 48/89 (53.9% [95% CI, 43.6-63.9%]). Animals on private reserves had a seropositivity of 21/51 (41.1% [95% CI, 27.1-55.2%]), and national park rhinoceros had a higher rate of seropositivity at 71.0% [95% CI, 55.9-86.2%] (27/38; P= 0.004). Adults had a higher seropositivity compared with subadults (P= 0.03). There was no difference in seropositivity between sexes (P > 0.05). Results demonstrate that South African white rhinoceros populations are exposed to Coxiella, which could result in underrecognized reproductive consequences. Further studies should investigate potential implications for public health and conservation management of this species.
Assuntos
Anticorpos Antibacterianos/sangue , Coxiella burnetii/imunologia , Perissodáctilos/sangue , Febre Q/veterinária , Animais , Feminino , Masculino , Febre Q/sangue , Febre Q/epidemiologia , África do Sul/epidemiologiaRESUMO
The lack of species-specific assays for the diagnosis of infectious diseases, such as bovine tuberculosis, poses a threat to the management of wildlife populations, especially for vulnerable species such as cheetah (Acinonyx jubatus). The aim of this study was to identify and develop a cell-mediated immunological cytokine-release assay that could distinguish between Mycobacterium bovis-infected and uninfected cheetahs using commercially available feline cytokine ELISA and domestic cat (Felis catus) recombinant proteins. Antibodies against domestic cat cytokines, tumour necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1ß), and interferon gamma (IFN-γ), were screened for cross-reactivity with plasma cytokines from cheetah whole blood stimulated using QuantiFERON®-TB Gold Plus (QFT) tubes. Evidence of cytokine production in response to QFT mitogen stimulation was observed in all four ELISA assays. However only the Mabtech Cat IFN-γ ELISABasic kit could distinguish between M. bovis-infected (n = 1) and uninfected (n = 1) cheetahs and was therefore selected for further evaluation. A preliminary cheetah specific cutoff value (11 pg/ml) for detecting M. bovis infection using the Mabtech Cat IFN-γ release assay was calculated using a M. bovis uninfected cheetah cohort. Although this study only included one confirmed M. bovis culture-positive and one M. bovis culture-negative cheetah, the Mabtech Cat IFN-γ release assay demonstrated its potential for diagnostic application in this species.
Assuntos
Acinonyx , Doenças do Gato , Mycobacterium bovis , Tuberculose , Animais , Gatos , Citocinas , Testes de Liberação de Interferon-gama/veterinária , Tuberculose/diagnóstico , Tuberculose/veterináriaRESUMO
In South Africa, bovine tuberculosis threatens some of Africa's most iconic wildlife species, including the cheetah (Acinonyx jubatus). The lack of antemortem diagnostic tests for this species strongly hinders conservation efforts. We report use of antemortem and postmortem diagnostic assays to detect Mycobacterium bovis infection in a cheetah.
Assuntos
Acinonyx , Mycobacterium bovis , Tuberculose/veterinária , Animais , Imunoensaio/veterinária , Reação em Cadeia da Polimerase/veterinária , África do Sul , Tuberculose/diagnóstico , Tuberculose/patologiaRESUMO
BACKGROUND: Bovine tuberculosis and tuberculosis are chronic infectious diseases caused by the Mycobacterium tuberculosis complex members, Mycobacterium bovis and Mycobacterium tuberculosis, respectively. Infection with M. bovis and M. tuberculosis have significant implications for wildlife species management, public health, veterinary disease control, and conservation endeavours. RESULTS: Here we describe the first use of the VetMAX™ Mycobacterium tuberculosis complex (MTBC) DNA quantitative real-time polymerase chain reaction (qPCR) detection kit for African wildlife samples. DNA was extracted from tissues harvested from 48 African buffaloes and MTBC DNA was detected (test-positive) in all 26 M. bovis culture-confirmed animals with an additional 12 PCR-positive results in culture-negative buffaloes (originating from an exposed population). Of six MTBC-infected African rhinoceros tested, MTBC DNA was detected in antemortem and postmortem samples from five animals. The PCR was also able to detect MTBC DNA in samples from two African elephants confirmed to have M. bovis and M. tuberculosis infections (one each). Culture-confirmed uninfected rhinoceros and elephants' samples tested negative in the PCR assay. CONCLUSIONS: These results suggest this new detection kit is a sensitive screening test for the detection of MTBC-infected African buffaloes, African elephants and white rhinoceros.
Assuntos
Mycobacterium bovis/isolamento & purificação , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Tuberculose/veterinária , Animais , Búfalos/microbiologia , DNA/análise , Elefantes/microbiologia , Mycobacterium bovis/genética , Mycobacterium tuberculosis/genética , Perissodáctilos/microbiologia , Reação em Cadeia da Polimerase em Tempo Real/métodos , Tuberculose/diagnóstico , Tuberculose/microbiologiaRESUMO
We screened African wild dogs (Lycaon pictus) in Kruger National Park, South Africa, for Mycobacterium bovis infection using an interferon-gamma release assay. We detected M. bovis sensitization in 20 of 21 packs; overall apparent infection prevalence was 83%. These animals experience high infection pressure, which may affect long-term survival and conservation strategies.
Assuntos
Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Mycobacterium bovis , Tuberculose/veterinária , Animais , Animais Selvagens , Cães , Geografia Médica , Vigilância em Saúde Pública , África do Sul/epidemiologiaRESUMO
Bovine tuberculosis (bTB), caused by Mycobacterium bovis infection, causes morbidity and mortality in free-ranging lions in bTB-endemic areas of South Africa. However, the only currently used diagnostic test is the tuberculin skin test (TST). This test is logistically challenging to perform because it requires immobilization of lions twice in a 72-hr period. Blood-based diagnostic tests, such as serological assays, have been previously reported for M. bovis detection in lion populations, and have the advantage of only requiring a single immobilization. In addition, serological assays can be used for retrospective testing. Therefore, the aim of this study was to test free-ranging lions with the STAT-PAKt (Chembio Diagnostics Systems, Medford, NY 11763, USA) and DPPt VetTB (Chembio Diagnostics Systems) serological assays and compare those results with the tuberculin skin test. The serological assays were also used to determine prevalence in bTB-endemic and uninfected lion populations. The results showed that the serological assays could distinguish between M. bovis culture-positive and -negative lions. In addition, antigen-specific humoral responses were present in lions that had clinical signs of bTB disease or were shedding M. bovis antemortem. Although the seroprevalence of M. bovis infection in Kruger National Park lions was similar to that obtained from antemortem mycobacterial culture (4.8 and 3.3%, respectively), it was less than that estimated by the TST (72%). These findings support the hypothesis that assays based on cell-mediated immune responses are more sensitive than serology is in detecting M. bovis infection in lions. However, serological assays can have a role in bTB disease detection in lions and are especially useful for retrospective studies.
Assuntos
Leões , Mycobacterium bovis/isolamento & purificação , Tuberculose/veterinária , Animais , Prevalência , Estudos Soroepidemiológicos , África do Sul/epidemiologia , Teste Tuberculínico/veterinária , Tuberculose/diagnóstico , Tuberculose/epidemiologiaRESUMO
During 2016-2017, when Kruger National Park, South Africa, was under quarantine to limit bovine tuberculosis spread, we examined 35 white and 5 black rhinoceroses for infection. We found 6 infected white rhinoceroses during times of nutritional stress. Further research on Mycobacterium bovis pathogenesis in white rhinoceroses is needed.
Assuntos
Animais Selvagens , Conservação de Recursos Energéticos , Mycobacterium bovis , Tuberculose Bovina/epidemiologia , Animais , Bovinos , Vigilância em Saúde Pública , África do Sul/epidemiologiaRESUMO
BACKGROUND: Bovine tuberculosis (bTB) caused by Mycobacterium bovis has previously been diagnosed in warthogs and infection can be highly prevalent (> 30%) in endemic areas. Thus, warthogs could potentially be an important species to consider as sentinels for disease surveillance. However, disease surveillance is dependent on availability of accurate diagnostic assays and only a few diagnostic tests have been investigated for warthogs. Furthermore, the tests that have been used in this species require laboratory equipment and trained personnel to obtain results. Therefore, this study investigated the use of the intradermal tuberculin test (ITT) to screen warthogs for bTB, which can be done with minimal equipment and under field conditions by most veterinarians and other qualified professionals. Changes in skin fold thickness measurements at the bovine purified protein derivative (PPD) administration site, between 0 and 72 h, were compared with differential changes between the bovine and avian PPD sites, for 34 warthogs, to evaluate the performance when different interpretation criteria for the ITT was used. RESULTS: Using an increase of 1.8 mm or more at the bovine PPD site as a cut-off for positive responders, 69% of 16 M. bovis culture-positive warthogs had a positive test result, with 100% of the 18 culture-negative warthogs considered as test negative. When a differential of 1.2 mm or more in skin fold thickness at the bovine PPD compared to the avian PPD site was used as a cut-off for the comparative ITT, 81% of culture-positive warthogs were considered as test positive, with 100% of culture-negative warthogs considered as test negative. CONCLUSION: The findings in this study suggest that the ITT is a promising tool to use when screening warthogs for M. bovis infection.
Assuntos
Antígenos de Bactérias/imunologia , Mycobacterium bovis , Suínos/microbiologia , Teste Tuberculínico/veterinária , Tuberculose/veterinária , Animais , Feminino , Masculino , Suínos/imunologia , Tuberculose/diagnóstico , Tuberculose/imunologiaRESUMO
Tuberculosis (TB) was diagnosed in four Asian elephants ( Elephas maximus) in a zoo in the United States. The first case was detected by isolation of Mycobacterium tuberculosis during routine trunk wash (TW) culture testing of a herd of eight elephants. Retrospective antibody analyses revealed seroconversion 1 yr before diagnosis. Serological testing of the whole elephant herd identified two additional suspect bulls with detectable antibody, but which remained culture-negative and had no clinical signs of disease. In the following months, M. tuberculosis, identical to the isolate from the index case, was isolated from TW samples of these two elephants. A fourth elephant seroconverted nearly 4 yr after the first TB case was detected, and M. tuberculosis was isolated from a TW sample collected 1 mo later. All four infected elephants received anti-TB therapy. Two treated elephants were eventually euthanized for reasons unrelated to M. tuberculosis and found to be culture-negative on necropsy, although one of them had PCR-positive lung lesions. One infected animal had to be euthanized due to development of a drug-resistant strain of M. tuberculosis; this animal did not undergo postmortem examination due to risk of staff exposure. The fourth animal is currently on treatment. Serial serological and culture results of the other four herd mates have remained negative.
Assuntos
Surtos de Doenças/veterinária , Elefantes/microbiologia , Tuberculose/veterinária , Animais , Animais de Zoológico , Feminino , Masculino , Muco/microbiologia , Mycobacterium tuberculosis , Tuberculose/microbiologiaRESUMO
In 2016, an emaciated black rhinoceros (Diceros bicornis) was found in Kruger National Park, South Africa. An interferon-γ response was detected against mycobacterial antigens, and lung tissue was positive for Mycobacterium bovis. This case highlights the risk that tuberculosis presents to rhinoceros in M. bovis-endemic areas.
Assuntos
Mycobacterium bovis/isolamento & purificação , Perissodáctilos/microbiologia , Tuberculose/veterinária , Animais , Feminino , África do Sul/epidemiologia , Tuberculose/epidemiologia , Tuberculose/microbiologiaRESUMO
A case of fatal Mycobacterium tuberculosis infection was diagnosed postmortem in a captive 33-yr-old male black rhinoceros (Diceros bicornis) after a nonspecific illness in April 2013. Retrospective testing of sera from this individual revealed that it had been seroreactive by ElephantTB STAT-PAK, dual-path platform VetTB, and multi-antigen print immunoassay for over 12 yr prior to death. Although samples collected at the time of intradermal tuberculin test performed in October 2000 were nonreactive in all three serologic assays, the animal appeared to seroconvert approximately 2.5 wk after the skin test administration. The antibody response remained detectable for the duration of the animal's life (12+ yr), indicating ongoing immunologic stimulation. The current case report supports the use of serologic assays for diagnosis of TB in black rhinoceros and may provide information for earlier detection. However, further research is needed to develop tools for recognition of mycobacterial infections in rhinoceros.
Assuntos
Perissodáctilos , Testes Sorológicos/veterinária , Tuberculose Pulmonar/veterinária , Animais , Animais de Zoológico , Masculino , Tuberculose Pulmonar/sangue , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/patologiaRESUMO
It was observed previously that end-expired carbon dioxide (P(E)CO2) decreased when immobilized black rhinoceroses (Diceros bicornis) were moved from sternal to lateral recumbency. These experiments were designed to test whether greater alveolar ventilation or greater pulmonary dead space in lateral recumbency explains this postural difference in P(E)CO2. Twenty-one (9 male, 12 female; 15 [3.5-26] yr old) wild black rhinoceroses were immobilized with etorphine and azaperone and positioned in either sternal or lateral recumbency. All rhinoceroses were hypoxemic and had lactic and respiratory acidemia. The animals in lateral recumbency were more acidemic, had higher lactate, and lower arterial oxygen that those in sternal recumbency; however, arterial carbon dioxide was similar between groups. Both P(E)CO2 and mixed expired carbon dioxide pressure were lower in lateral than sternal recumbency. Although there was no difference in tidal volume or arterial carbon dioxide, both the breathing rate and minute ventilation were greater in lateral recumbency. The physiologic dead space ratio and dead space volume were approximately two times larger in lateral recumbency; hence, the decrease in P(E)CO2 in lateral recumbency can be attributed to increased dead space ventilation not increased alveolar ventilation. Positioning immobilized rhinoceroses in lateral recumbency does not confer any advantage over sternal in terms of ventilation, and the increase in minute ventilation in lateral recumbency can be considered an energetic waste. Although arterial oxygen was superior in sternal recumbency, further studies that measure oxygen delivery (e.g., to the muscles of locomotion) are warranted before advice regarding the optimal position for immobilized rhinoceroses can be given with confidence.
Assuntos
Imobilização , Perissodáctilos/fisiologia , Espaço Morto Respiratório/fisiologia , Animais , Animais Selvagens , Feminino , Masculino , NamíbiaRESUMO
Animal tuberculosis significantly challenges global health, agriculture, and wildlife conservation efforts. Mycobacterial cultures are resource-intensive, time-consuming, and challenged by heterogeneous populations. In this study, we employed a culture-independent approach, using targeted long-read-based next-generation sequencing (tNGS), to investigate the mycobacterial composition in 60 DNA samples extracted from Mycobacterium bovis infected culture-confirmed African buffalo tissue. We detected mycobacterial DNA in 93.3% of the samples and the sensitivity for detecting Mycobacterium tuberculosis complex (MTBC) was 91.7%, demonstrating a high concordance of our culture-independent tNGS approach with mycobacterial culture results. In five samples, we identified heterogenous mycobacterial populations with various non-tuberculous mycobacteria, including members of the Mycobacterium avium complex (MAC), M. smegmatis, and M. komaniense. The latter Mycobacterium species was described in South Africa from bovine nasal swabs and environmental samples from the Hluhluwe-iMfolozi Park, which was the origin of the buffalo samples in the present study. This finding suggests that exposure to environmental mycobacteria may confound detection of MTBC in wildlife. In conclusion, our approach represents a promising alternative to conventional methods for detecting mycobacterial DNA. This high-throughput technique enables rapid differentiation of heterogeneous mycobacterial populations, which will contribute valuable insights into the epidemiology, pathogenesis, and microbial synergy during mycobacterial infections.
Assuntos
Búfalos , Sequenciamento de Nucleotídeos em Larga Escala , Mycobacterium bovis , Tuberculose , Animais , Búfalos/microbiologia , Mycobacterium bovis/genética , Mycobacterium bovis/isolamento & purificação , Tuberculose/microbiologia , Tuberculose/veterinária , Tuberculose/diagnóstico , África do Sul/epidemiologia , DNA Bacteriano/genética , Bovinos , Microbiota/genéticaRESUMO
Animal tuberculosis, caused by Mycobacterium bovis, presents a significant threat to both livestock industries and public health. Mycobacterium bovis tests rely on detecting antigen specific immune responses, which can be influenced by exposure to non-tuberculous mycobacteria, test technique, and duration and severity of infection. Despite advancements in direct M. bovis detection, mycobacterial culture remains the primary diagnostic standard. Recent efforts have explored culture-independent PCR-based methods for identifying mycobacterial DNA in respiratory samples. This study aimed to detect M. bovis in nasal swabs from goats (Capra hircus) cohabiting with M. bovis-infected cattle in KwaZulu-Natal, South Africa. Nasal swabs were collected from 137 communal goats exposed to M. bovis-positive cattle and 20 goats from a commercial dairy herd without M. bovis history. Swabs were divided into three aliquots for analysis. The first underwent GeneXpert® MTB/RIF Ultra assay (Ultra) screening. DNA from the second underwent mycobacterial genus-specific PCR and Sanger sequencing, while the third underwent mycobacterial culture followed by PCR and sequencing. Deep sequencing identified M. bovis DNA in selected Ultra-positive swabs, confirmed by region-of-difference (RD) PCR. Despite no other evidence of M. bovis infection, viable M. bovis was cultured from three communal goat swabs, confirmed by PCR and sequencing. Deep sequencing of DNA directly from swabs identified M. bovis in the same culture-positive swabs and eight additional communal goats. No M. bovis was found in commercial dairy goats, but various NTM species were detected. This highlights the risk of M. bovis exposure or infection in goats sharing pastures with infected cattle. Rapid Ultra screening shows promise for selecting goats for further M. bovis testing. These techniques may enhance M. bovis detection in paucibacillary samples and serve as valuable research tools.
RESUMO
Hypervariable region sequencing of the 16S ribosomal RNA (rRNA) gene plays a critical role in microbial ecology by offering insights into bacterial communities within specific niches. While providing valuable genus-level information, its reliance on data from targeted genetic regions limits its overall utility. Recent advances in sequencing technologies have enabled characterisation of the full-length 16S rRNA gene, enhancing species-level classification. Although current short-read platforms are cost-effective and precise, they lack full-length 16S rRNA amplicon sequencing capability. This study aimed to evaluate the feasibility of a modified 150 bp paired-end full-length 16S rRNA amplicon short-read sequencing technique on the Illumina iSeq 100 and 16S rRNA amplicon assembly workflow by utilising a standard mock microbial community and subsequently performing exploratory characterisation of captive (zoo) and free-ranging African elephant (Loxodonta africana) respiratory microbiota. Our findings demonstrate that, despite generating assembled amplicons averaging 869 bp in length, this sequencing technique provides taxonomic assignments consistent with the theoretical composition of the mock community and respiratory microbiota of other mammals. Tentative bacterial signatures, potentially representing distinct respiratory tract compartments (trunk and lower respiratory tract) were visually identified, necessitating further investigation to gain deeper insights into their implication for elephant physiology and health.
Assuntos
Bactérias , Elefantes , Microbiota , RNA Ribossômico 16S , Animais , Elefantes/microbiologia , Elefantes/genética , RNA Ribossômico 16S/genética , Bactérias/genética , Bactérias/classificação , Microbiota/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Sistema Respiratório/microbiologia , Animais de Zoológico/microbiologia , Análise de Sequência de DNA/métodos , Animais Selvagens/microbiologia , FilogeniaRESUMO
This study investigated the presence of Mycobacterium bovis (M. bovis) DNA in archived human sputum samples previously collected from residents who reside adjacent to the M. bovis-endemic Hluhluwe-iMfolozi wildlife park, South Africa (SA). Sixty-eight sputum samples were GeneXpert MTB/RIF Ultra-positive for M. tuberculosis complex (MTBC) DNA but culture negative for M. tuberculosis. Amplification and Sanger sequencing of hsp65 and rpoB genes from DNA extracted from stored heat-inactivated sputum samples confirmed the presence of detectable amounts of MTBC from 20 out of the 68 sputum samples. Region of difference PCR, spoligotyping and gyrB long-read amplicon deep sequencing identified M. bovis (n = 10) and M. tuberculosis (n = 7). Notably, M. bovis spoligotypes SB0130 and SB1474 were identified in 4 samples, with SB0130 previously identified in local cattle and wildlife and SB1474 exclusively in African buffaloes in the adjacent park. M. bovis DNA in sputum, from people living near the park, underscores zoonotic transmission potential in SA. Identification of spoligotypes specifically associated with wildlife only and spoligotypes found in livestock as well as wildlife, highlights the complexity of TB epidemiology at wildlife-livestock-human interfaces. These findings support the need for integrated surveillance and control strategies to curb potential spillover and for the consideration of human M. bovis infection in SA patients with positive Ultra results.