Cytotoxicity, morphological and ultrastructural effects induced by the neonicotinoid pesticide, imidacloprid, using a rat Leydig cell line (LC-540).

Imidacloprid is a systemic neonicotinoid insecticide widely used to combat agricultural pests and flea infestations in dogs and cats. Despite its low toxicity to mammals, imidacloprid is reported to cause male reproductive toxicity. This study evaluated the cytotoxic effects of 75-800 µM imidacloprid on a rat Leydig cell line (LC-540). The effect of exposure to 300, 400, and 500 µM imidacloprid on selected cytoskeletal proteins, mitochondrial morphology, lysosomal acidity, and ultrastructure were investigated. Cell viability was markedly reduced after 48 and 72 h of exposure to higher imidacloprid concentrations. The immunocytochemical analysis revealed that the cytoskeletal filaments exhibited disorganization, disruption, and perinuclear aggregation in treated LC-540 cells. Ultrastructurally, cytoplasmic vacuoles, autophagic vacuoles, lysosomes, and mitochondrial damage were detected. Changes in the mitochondrial morphology and lysosomes induced by imidacloprid were confirmed. The cytotoxicity of imidacloprid observed in LC-540 cells might be due to its mitochondrial damage and cytoskeletal protein disruption.

The optimal management of the patient with COVID-19 pneumonia: HFNC, NIV/CPAP or mechanical ventilation?

The recent pandemic has seen unprecedented demand for respiratory support of patients with COVID-19 pneumonia, stretching services and clinicians. Yet despite the global numbers of patients treated, guidance is not clear on the correct choice of modality or the timing of escalation of therapy for an individual patient. This narrative review assesses the available literature on the best use of different modalities of respiratory support for an individual patient, and discusses benefits and risks of each, coupled with practical advice to improve outcomes. On current data, in an ideal context, it appears that as disease severity worsens, conventional oxygen therapy is not sufficient alone. In more severe disease, i.e. PaO2/FiO2 ratios below approximately 200, helmet-CPAP (continuous positive airway pressure) (although not widely available) may be superior to high-flow nasal cannula (HFNC) therapy or facemask non-invasive ventilation (NIV)/CPAP, and that facemask NIV/CPAP may be superior to HFNC, but with noted important complications, including risk of pneumothoraces. In an ideal context, invasive mechanical ventilation should not be delayed where indicated and available. Vitally, the choice of respiratory support should not be prescriptive but contextualised to each setting, as supply and demand of resources vary markedly between institutions. Over time, institutions should develop clear policies to guide clinicians before demand exceeds supply, and should frequently review best practice as evidence matures.

What is in a name? Scientific name changes of potentially poisonous plants and fungi in South Africa.

Changes over the past five decades in the scientific names of some potentially poisonous plants and toxigenic fungi in South Africa are briefly reviewed. Some of the reasons why taxonomists change names are highlighted. In recent years, DNA sequencing data have contributed considerably towards establishing phylogenetic relationships among plants, often resulting in changes in generic circumscription and, consequently, the names of species. Philosophical differences between the phylogenetic and the evolutionary schools of plant classification are briefly explained as these may manifest as different classifications for the same group of plants. Although choice of classification remains the prerogative of the end-user of plant names, in this review, the classifications for plants currently adopted by the South African National Biodiversity Institute (SANBI) in its online database, Plants of Southern Africa (POSA), were followed. Noteworthy generic changes include Pachystigma to Vangueria, Homeria to Moraea, and Urginia to Drimia. Following much controversy, the species native to southern Africa that were formerly treated as Acacia are now classified in either Vachellia or Senegalia, with the genus name Acacia being retained for the mainly Australian members of the group, the latter commonly known as wattles. Former southern African members of Acacia implicated in poisoning include Vachellia erioloba(camel thorn), Vachellia sieberiana var. woodii (paperbark thorn), and Senegalia caffra (common hook thorn).

Solvent suppression techniques for coupling of size exclusion chromatography and 1H NMR using benchtop spectrometers at 43 and 62 MHz.

The characterisation of polymeric materials in their full complexity of chain length, monomeric composition, branching and functionalization is a tremendous challenge and is best tackled by tailored multi-dimensional coupled analytical and detection techniques. Herein, we focus on the improvement of an affordable but information rich 2D-method for polymer analysis: the online hyphenation of benchtop 1H NMR spectroscopy with size exclusion chromatography (SEC). The main benefit of this approach is correlated information of chain length (SEC) to chemical composition (1H NMR). Our setup combines SEC onflow with a benchtop NMR spectrometer at 43 or 62 MHz with chemical shift resolution as a robust detector. A detailed comparison of the two instruments is included considering, that only the 43 MHz instrument is equipped with a dedicated z-gradient enabling pulse sequences such as WET. The main challenge of this method is the very low concentration of species of interest after chromatographic separation. At typical SEC conditions, the analyte dilution is typically more than a factor of 1000:1 in a protonated solvent. Therefore, an efficient solvent signal suppression is needed. In this article, several suppression pulse sequences are explored like WET, WEFT, JNR and a simple one-pulse approach - some for the first time on this hardware. By choosing an optimal method, signal strength ratios of solvent to analyte of 1:1 or better are achievable on flow. To illustrate the broad range of possible applications, three typical cases of analyte to solvent signal proximity (no overlap, partial and full overlap) are discussed using typical polymers (PS, PMMA, PEMA) and solvents (chloroform and THF). For each case, several suppression methods are compared and evaluated using a set of numerical criteria (analyte signal suppression and broadening, solvent signal suppression, remaining solvent signal width).

Putative neuromycotoxicoses in an adult male following ingestion of moldy walnuts.

A tremorgenic syndrome occurs in dogs following ingestion of moldy walnuts, and Penicillium crustosum has been implicated as the offending fungus. This is the first report of suspected moldy walnut toxicosis in man. An adult male ingested approximately eight fungal-infected walnut kernels and after 12 h experienced tremors, generalized pain, incoordination, confusion, anxiety, and diaphoresis. Following symptomatic and supportive treatment at a local hospital, the man made an uneventful recovery. A batch of walnuts (approximately 20) was submitted for mycological culturing and identification as well as for mycotoxin analysis. Penicillium crustosum Thom was the most abundant fungus present on walnut samples, often occurring as monocultures on isolation plates. Identifications were confirmed with DNA sequences. The kernels and shells of the moldy walnuts as well as P. crustosum isolates plated on yeast extract sucrose (YES) and Czapek yeast autolysate (CYA) agars and incubated in the dark at 25 °C for 7 days were screened for tremorgenic mycotoxins and known P. crustosum metabolites using a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. A relatively low penitrem A concentration of only 1.9 ng/g was detected on the walnut kernels when compared to roquefortine C concentrations of 21.7 µg/g. A similar result was obtained from P. crustosum isolates cultured on YES and CYA, with penitrem A concentrations much lower (0.6-6.4 µg per g mycelium/agar) compared to roquefortine C concentrations (172-1225 µg/g). The authors surmised that besides penitrem A, roquefortine C might also play an additive or synergistic role in intoxication of man.

Multimycotoxin analysis of South African Aspergillus clavatus isolates.

Aspergillus clavatus poisoning is a neuromycotoxicosis of ruminants that occurs sporadically across the world after ingestion of infected feedstuffs. Although various toxic metabolites are synthesized by the fungus, it is not clear which specific or group of mycotoxins induces the syndrome. A. clavatus isolates were deposited in the culture collection of the Biosystematics Division, Plant Protection Research Institute, Agricultural Research Council during incidences of livestock poisoning (1988-2016). Six isolates were still viable and these plus three other South African isolates that were also previously deposited in the collection were positively identified as A. clavatus based on morphology and ß-tubulin sequence data. The cultures were screened for multiple mycotoxins using a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method. Twelve A. clavatus metabolites were detected. The concentrations of the tremorgenic mycotoxins (i.e., tryptoquivaline A and its related metabolites deoxytryptoquivaline A and deoxynortryptoquivaline) were higher than patulin and cytochalasin E. Livestock owners should not feed A. clavatus-infected material to ruminants as all the South African A. clavatus isolates synthesized the same compounds when cultured under similar conditions.

Lead ingestion as a potential contributing factor to the decline in vulture populations in southern Africa.

Vulture populations in southern Africa have been on the decline for years, which unlike the Asian vulture crisis, has no one specific cause. Reasons attributable are deliberate and secondary poisonings, drowning, power line injuries, electrocutions, traditional medicine ("muti" trade) and calcium deficiencies. However, lead toxicity as a potential causal factor is hardly mentioned. The potential for lead toxicity needs to be considered as substantial game hunting occurs in the region with little regulatory control on bullet types. In this study, we determined the whole blood lead concentrations of captive and wild vulture populations in South Africa and Namibia (n=185). Results were compared to previous published ranges indicative of background exposure (<10µg/dL), non-toxic point exposure based upon the range established from captive birds and subclinical exposure. In general, whole blood lead concentrations were higher for wild African White-backed vultures (Gyps africanus)(AWBV) than Cape vultures (G. coprotheres)(CGV) at 15.54±12.63µg/dL vs 12.53±8.88µg/dL (non-significantly different), while in the Bearded vultures (Gypaetus barbatus) no indication of exposure was evident. Very similar exposures resulted irrespective of the birds being in captivity or under wild, free-roaming conditions. A proportion of wild birds did, however, appear to be exposed to another source of lead than purely environmental (±12% and 30.6% for AWBV and CGV respectively). One bird, which had a whole blood concentration of 100µg/dL, died soon after capture. To find the relationship between whole blood lead concentration and likely exposure factors, birds were compared by their rural/urban location, vicinity to mines and surrounding soil lead concentrations. With no relationship being present for the latter factors, we believe that this is evidence that the portion of southern African vultures being exposed to unknown source of lead, which we suggest arises from leaded ammunition remaining from hunting.

Evidence of a role for GTP cyclohydrolase-1 in visceral pain.

BACKGROUND: The enzyme guanosine triphosphate-cyclohydrolase-1 (GCH-1) is a rate limiting step in the de novo synthesis of tetrahydrobiopterin (BH4) a co-factor in monoamine synthesis and nitric oxide production. GCH-1 is strongly implicated in chronic pain based on data generated using the selective GCH-1 inhibitor 2,4-diamino-6-hydroxypyrimidine (DAHP), and studies which have identified a pain protective GCH-1 haplotype associated with lower BH4 production and reduced pain. METHODS: To investigate the role for GCH-1 in visceral pain we examined the effects of DAHP on pain behaviors elicited by colorectal injection of mustard oil in rats, and the pain protective GCH-1 haplotype in healthy volunteers characterized by esophageal pain sensitivity before and after acid injury, and assessed using depression and anxiety questionnaires. KEY RESULTS: In rodents pretreatment with DAHP produced a substantial dose related inhibition of pain behaviors from 10 to 180 mg/kg i.p. (p < 0.01 to 0.001). In healthy volunteers, no association was seen between the pain protective GCH-1 haplotype and the development of hypersensitivity following injury. However, a substantial increase in baseline pain thresholds was seen between first and second visits (26.6 ± 6.2 mA) in subjects who sensitized to esophageal injury and possessed the pain protective GCH-1 haplotype compared with all other groups (p < 0.05). Furthermore the same subjects who sensitized to acid and possessed the haplotype, also had significantly lower depression scores (p < 0.05). CONCLUSIONS & INFERENCES: The data generated indicate that GCH-1 plays a role in visceral pain processing that requires more detailed investigation.

Rice sucrose transporter1 (OsSUT1) up-regulation in xylem parenchyma is caused by aphid feeding on rice leaf blade vascular bundles.

The role of the sucrose transporter OsSUT1 in assimilate retrieval via the xylem, as a result of damage to and leakage from punctured phloem was examined after rusty plum aphid (Hysteroneura setariae, Thomas) infestation on leaves from 3-week-old rice (Oryza sativa L. cv Nipponbare) plants. Leaves were examined over a 1- to 10-day infestation time course, using a combination of gene expression and ß-glucuronidase (GUS) reporter gene analyses. qPCR and Western blot analyses revealed differential expression of OsSUT1 during aphid infestation. Wide-field fluorescence microscopy was used to confirm the expression of OsSUT1-promoter::GUS reporter gene in vascular parenchyma associated with xylem elements, as well as in companion cells associated with phloem sieve tubes of large, intermediate and small vascular bundles within the leaf blade, in regions where the aphids had settled and were feeding. Of great interest was up-regulation of OsSUT1 expression associated with the xylem parenchyma cells, abutting the metaxylem vessels, which confirmed that OsSUT1 was not only involved in loading of sugars into the phloem under normal physiological conditions, but was apparently involved in the retrieval of sucrose leaked into the xylem conduits, which occurred as a direct result of aphid feeding, probing and puncturing of vascular bundles. The up-regulation of OsSUT1 in xylem vascular parenchyma thus provides evidence in support of the location within the xylem parenchyma cells of an efficient mechanism to ensure sucrose recovery after loss to the apoplast (xylem) after aphid-related feeding damage and its transfer back to the symplast (phloem) in O. sativa leaves.

A tale of two neglected systems-structure and function of the thin- and thick-walled sieve tubes in monocotyledonous leaves.

There is a large body of information relating to the ontogeny, development and the vasculature of eudicotyledonous leaves. However, there is less information available concerning the vascular anatomy of monocotyledonous leaves. This is surprising, given that there are two uniquely different phloem systems present in large groups such as grasses and sedges. Monocotyledonous leaves contain marginal, large, intermediate, and small longitudinal veins that are interconnected by numerous transverse veins. The longitudinal veins contain two metaphloem sieve tube types, which, based upon their ontogeny and position within the phloem, are termed early (thin-walled) and late (thick-walled) sieve tubes. Early metaphloem comprises sieve tubes, companion cells and vascular parenchyma (VP) cells, whilst the late metaphloem, contains thick-walled sieve tubes (TSTs) that lack companion cells. TSTs are generally adjacent to, or no more than one cell removed from the metaxylem. Unlike thin-walled sieve tube (ST) -companion cell complexes, TSTs are connected to parenchyma by pore-plasmodesma units and are generally symplasmically isolated from the STs. This paper addresses key structural and functional differences between thin- and thick-walled sieve tubes and explores the unique advantages of alternate transport strategies that this 5-7 million years old dual system may offer. It would seem that these two systems may enhance, add to, or play a significant role in increasing the efficiency of solute retrieval as well as of assimilate transfer.

Toward a highly-detailed 3D pelvic model: approaching an ultra-specific level for surgical simulation and anatomical education.

The surgical anatomy of the pelvis is highly complex. Anorectal and urogenital dysfunctions occur frequently after pelvic oncological surgery and are mainly caused by surgical damage of the autonomic nerves. A highly-detailed 3D pelvic model could increase the anatomical knowledge and form a solid basis for a surgical simulation system. Currently, pelvic surgeons still rely on the preoperative interpretation of 2D diagnostic images. With a 3D simulation system, pelvic surgeons could simulate and train different scenes to enhance their preoperative knowledge and improve surgical outcome. To substantially enrich pelvic surgery and anatomical education, such a system must provide insight into the relation between the autonomic network, the lymphatic system, and endopelvic fasciae. Besides CT and MR images, Visible Human Datasets (VHDs) are widely used for 3D modeling, due to the high degree of anatomical detail represented in the cryosectional images. However, key surgical structures cannot be fully identified using VHDs and radiologic imaging techniques alone. Several unsolved anatomical problems must be elucidated as well. Therefore, adequate analysis on a microscopic level is inevitable. The development of a comprehensive anatomical atlas of the pelvis is no straightforward task. Such an endeavor involves several anatomical and technical challenges. This article surveys all existing 3D pelvic models, focusing on the level of anatomical detail. The use of VHDs in the 3D reconstruction of a highly-detailed pelvic model and the accompanying anatomical challenges will be discussed.

The pathology of acute Nolletia gariepina poisoning of cattle.

Toxicity in cattle by the shrub Nolletia gariepina was induced experimentally by intraruminal administration of 3 g/kg dried, milled plant material as a single dose. The animals had to be starved for 24 hours before dosing, as dosing on a full rumen did not induce any signs of toxicity during 5 days of observation and clinical pathology monitoring. Clinical signs were not specific and varied according to the duration (acute versus subacute) of the toxicological process. Clinical pathological parameters indicated renal and to a lesser extent hepatic damage, with raised serum concentrations of urea, creatinine, aspartate aminotransferase (AST) and gamma glutamyl transferase (GGT). Increased urinary sodium and potassium concentration and GGT activity, as well as proteinuria, were evident. Histological and electron microscopic examinations revealed acute renal tubular epithelial cell degeneration and necrosis, especially of the proximal convoluted tubules. Mild hepatocellular degeneration was also noticeable.

A fluorescent investigation of subcellular damage in H9c2 cells caused by pavetamine, a novel polyamine.

Gousiekte, which can be translated literally as "quick disease", is one of the six most important plant toxicoses that affect livestock in South Africa. It is a plant-induced cardiomyopathy of domestic ruminants characterised by the sudden death of animals within a period of 4-8weeks after the initial ingestion of the toxic plant. The main ultrastructural change in sheep hearts is degradation of myofibres. In this study, fluorescent probes were used to investigate subcellular changes induced by pavetamine, the toxic compound that causes gousiekte, in H9c2 cells. The sarcoplasmic reticula (SR) and mitochondria showed abnormalities that were not present in the control cells. The lysosomes of treated cells were more abundant and enlarged than those of the control cells. There was increased activity of cytosolic hexosaminidase and acid phosphatase, indicating increased lysosomal membrane permeability. Lysosomes play an important role in both necrosis and apoptosis. The degradation of the myofibres may be a consequence of the increased lysosomal membrane permeability. Pavetamine was also found to cause alterations in the organisation of F-actin. F-actin in the nucleus is a transcription regulator and can therefore influence protein synthesis. Actin filament organisation also regulates the cardiac L-type Ca(2+) channels. Fluorescent staining demonstrated that pavetamine may damage a number of organelles, all of which can influence the proper functioning of the heart.

Damage to some contractile and cytoskeleton proteins of the sarcomere in rat neonatal cardiomyocytes after exposure to pavetamine.

Pavetamine, a cationic polyamine, is a cardiotoxin that affects ruminants. The animals die of heart failure after a period of four to eight weeks following ingestion of the plants that contain pavetamine. This immunofluorescent study was undertaken in rat neonatal cardiomyocytes (RNCM) to label some of the contractile and cytoskeleton proteins after exposure to pavetamine for 48 h. Myosin and titin were degraded in the RNCM treated with pavetamine and the morphology of alpha-actin was altered, when compared to the untreated cells, while those of beta-tubulin seemed to be unaffected. F-actin was degraded, or even absent, in some of the treated cells. On an ultrastructural level, the sarcomeres were disorganized or disengaged from the Z-lines. Thus, all three contractile proteins of the rat heart were affected by pavetamine treatment, as well as the F-actin of the cytoskeleton. It is possible that these proteins are being degraded by proteases like the calpains and/or cathepsins. The consequence of pavetamine exposure is literally a "broken heart".

Cytotoxicity and ultrastructural changes in H9c2(2-1) cells treated with pavetamine, a novel polyamine.

Intake of pavetamine, a novel polyamine, synthesized by certain rubiaceous plants, is the cause of gousiekte ("Quick disease") in ruminants. The disease is characterized by a latent period of 4-8 weeks, followed by heart failure. The aim of this study was to firstly investigate the cytotoxicity in H9c2(2-1) cells using the MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide) and LDH (lactate dehydrogenase) release assays. Maximum cell death occurred after pavetamine exposure of cells for 72h at a concentration of 200muM (55%+/-9.84), as measured by the MTT assay. LDH release was only observed after 72h exposure to pavetamine. Secondly, the ultrastructural changes induced by pavetamine in H9c2(2-1) cells were investigated. Changes in the mitochondria and sarcoplasmic reticula were observed. The nucleus was not affected during the first 48h exposure of cells to pavetamine and no chromatin condensation occurred. However, after 72h exposure to pavetamine, the nucleus became fragmented and membrane blebbing occurred. It was concluded that the ultimate cell death of H9c2(2-1) cells treated with pavetamine, was through necrosis and not apoptosis. Thirdly, the effect of pavetamine on the mitochondrial membrane potential (DeltaPsi) was evaluated by using the JC-1 (5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide) and TMRM (tetramethylrhodamine methyl ester perchlorate) probes. Pavetamine treatment led to significant hyperpolarization of the mitochondrial membrane potential. Cyclosporin A (CsA), an inhibitor of the mitochondrial permeability transition pore, did not reduce the cytotoxicity of pavetamine significantly, indicating that the MPTP (mitochondrial permeability transition pore) plays no role in the cytotoxicity of pavetamine.

Evaluation of bone impingement prediction in pre-operative planning for shoulder arthroplasty.

In shoulder arthroplasty, malpositioning of prostheses often leads to reduced postoperative range of motion (ROM) and complications such as impingement, loosening, and dislocation. Furthermore, the risk of impingement complications increases when reverse total prostheses are used. For this purpose a pre-operative planning system was developed that enables surgeons to perform a virtual shoulder replacement procedure. The present authors' pre-operative planning system simulates patient-specific bone-determined ROM meant to reduce the risk of impingement complications and to improve the ROM of patients undergoing shoulder replacement surgery. This paper describes a validation experiment with the purpose of ratifying the clinical applicability and usefulness of the ROM simulation module for shoulder replacement surgery. The experiment was performed on cadaveric shoulders. A data connection was set up between the software environment and an existing intra-operative guidance system to track the relative positions of the bones. This allowed the patient-specific surface models to be visualized within the software for the position and alignment of the tracked bones. For both shoulders, ROM measurements were recorded and tagged with relevant information such as the type of prosthesis and the type of movement that was performed. The observed ROM and occurrences of impingement were compared with the simulated equivalents. The median deviation between observed impingement angles and simulated impingement angles was -0.30 degrees with an interquartile range of 5.20 degrees (from -3.40 degrees to 1.80 degrees). It was concluded that the ROM simulator is sufficiently accurate to fulfil its role as a supportive instrument for orthopaedic surgeons during shoulder replacement surgery.

Potential plant poisonings in dogs and cats in southern Africa.

Plant poisoning occurs less commonly in dogs and cats than in herbivorous livestock, but numerous cases have been documented worldwide, most of them caused by common and internationally widely cultivated ornamental garden and house plants. Few cases of poisoning of cats and dogs have been reported in southern Africa, but many of the plants that have caused poisoning in these species elsewhere are widely available in the subregion and are briefly reviewed in terms of toxic principles, toxicity, species affected, clinical signs, and prognosis. The list includes Melia azedarach (syringa), Brunfelsia spp. (yesterday, today and tomorrow), Datura stramonium (jimsonweed, stinkblaar), a wide variety of lilies and lily-like plants, cycads, plants that contain soluble oxalates, plants containing cardiac glycosides and other cardiotoxins and euphorbias (Euphorbia pulcherrima, E. tirucalli). Poisoning by plant products such as macadamia nuts, onions and garlic, grapes and raisins, cannabis (marijuana, dagga) or hashish and castor oil seed or seedcake is also discussed. Many of the poisonings are not usually fatal, but others frequently result in death unless rapid action is taken by the owner and the veterinarian, underlining the importance of awareness of the poisonous potential of a number of familiar plants.

Putative Aspergillus niger-induced oxalate nephrosis in sheep.

A sheep farmer provided a maize-based brewer's grain (mieliemaroek) and bales of Eragrostis curvula hay to ewes and their lambs, kept on zero-grazing in pens. The 'mieliemaroek' was visibly mouldy. After 14 days in the feedlot, clinical signs, including generalised weakness, ataxia of the hind limbs, tremors and recumbency, were noticed. Six ewes died within a period of 7 days. A post mortem examination was performed on 1 ewe. The carcass appeared to be cachectic with mild effusions into the body cavities; mild lung congestion and pallor of the kidneys were observed. Microscopical evaluation revealed nephrosis and birefringent oxalate crystals in the renal tubules when viewed under polarised light. A provisional diagnosis of oxalate nephrosis with subsequent kidney failure was made. Amongst other fungi, Aspergillus niger was isolated from 'mieliemaroek' samples submitted for fungal culture and identification. As A. niger is known to synthesise oxalates, a qualitative screen to detect oxalic acid in the mieliemaroek and purified A. niger isolates was performed using high-performance liquid chromatography (HPLC). Oxalic acid was detected, which supported a diagnosis of soluble oxalate-induced nephropathy.

Zoonotic tuberculosis and brucellosis in Africa: neglected zoonoses or minor public-health issues? The outcomes of a multi-disciplinary workshop.

Late in 2007, veterinary, medical and anthropological professionals from Europe and Africa met in a 2-day workshop in Pretoria, South Africa, to evaluate the burden, surveillance and control of zoonotic tuberculosis and brucellosis in sub-Saharan Africa. Keynote presentations reviewed the burden of these diseases on human and livestock health, the existing diagnostic tools, and the available control methods. These presentations were followed by group discussions and the formulation of recommendations. The presence of Mycobacterium bovis and Brucella spp. in livestock was considered to be a serious threat to public health, since livestock and animal products are the only source of such infections in human beings. The impact of these pathogens on human health appears to be relatively marginal, however, when compared with Mycobacterium tuberculosis infections and drug resistance, HIV and malaria. Appropriate diagnostic tools are needed to improve the detection of M. bovis and Brucella spp. in humans. In livestock, the 'test-and-slaughter' approach and the pasteurization of milk, which have been used successfully in industrialized countries, might not be the optimal control tools in Africa. Control strategies should fit the needs and perceptions of local communities. Improved intersectoral and international collaboration in surveillance, diagnosis and control, and in the education of medical and veterinary personnel, are advocated.