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2.
Exp Physiol ; 100(4): 450-62, 2015 Apr 01.
Article in English | MEDLINE | ID: mdl-25663294

ABSTRACT

NEW FINDINGS: What is the central question of this study? The aim was to determine whether mitochondrial protein content of perilipin 3 (PLIN3) and perilipin 5 (PLIN5) is increased following endurance training and whether mitochondrial PLIN5 protein is increased to a greater extent in endurance-trained rats when compared with sedentary rats following acute contraction. What is the main finding and its importance? Mitochondrial PLIN3 but not PLIN5 protein was increased in endurance-trained compared with sedentary rats, suggesting a mitochondrial role for PLIN3 due to chronic exercise. Contrary to our hypothesis, acute mitochondrial PLIN5 protein was similar in both sedentary and endurance-trained rats. Endurance training results in an increased association between skeletal muscle lipid droplets and mitochondria. This association is likely to be important for the expected increase in intramuscular fatty acid oxidation that occurs with endurance training. The perilipin family of lipid droplet proteins, PLIN(2-5), are thought to play a role in skeletal muscle lipolysis. Recently, results from our laboratory demonstrated that skeletal muscle mitochondria contain PLIN3 and PLIN5 protein. Furthermore, 30 min of stimulated contraction induces an increased mitochondrial PLIN5 content. To determine whether mitochondrial content of PLIN3 and PLIN5 is altered with endurance training, Sprague-Dawley rats were randomized into sedentary or endurance-trained groups for 8 weeks of treadmill running followed by an acute (30 min) sciatic nerve stimulation to induce lipolysis. Mitochondrial PLIN3 protein was ∼1.5-fold higher in red gastrocnemius of endurance-trained rats compared with sedentary animals, with no change in mitochondrial PLIN5 protein. In addition, there was an increase in plantaris intramuscular lipid storage. Acute electrically stimulated contraction in red gastrocnemius from sedentary and endurance-trained rats resulted in a similar increase of mitochondrial PLIN5 between these two groups, with no net change in PLIN3 in either group. Plantaris intramuscular lipid content decreased to a similar extent in sedentary and endurance-trained rats. These results suggest that while total mitochondrial PLIN5 content is not altered by endurance training, PLIN5 does have an acute role in the mitochondrial fraction during muscle contraction. Conversely, mitochondrial PLIN3 does not change acutely with muscle contraction, but PLIN3 content was increased following endurance training, indicating a role in chronic adaptations of skeletal muscle.


Subject(s)
Electric Stimulation , Intracellular Signaling Peptides and Proteins/metabolism , Mitochondria, Muscle/physiology , Muscle Proteins/metabolism , Myocardial Contraction/physiology , Physical Conditioning, Animal/methods , Physical Endurance/physiology , Animals , Male , Perilipin-3 , Perilipin-5 , Rats , Rats, Sprague-Dawley , Vesicular Transport Proteins
3.
Lett Appl Microbiol ; 57(4): 380-4, 2013 Oct.
Article in English | MEDLINE | ID: mdl-23937393

ABSTRACT

UNLABELLED: During the routine fingerprinting of outbreak strains of Bacillus anthracis of European and African origin by means of a 31-marker multi-locus variable number of tandem repeats analysis (MLVA), four cultures, two from the Etosha National Park (ENP), Namibia, and two from an outbreak in the Pyrenees in 1997, were found to harbour different genotypes (GTs). To investigate this further, isolates from 10 samples of blood-soaked soil from beneath anthrax carcasses and 18 clinical swabs taken from carcasses in the ENP were examined by a 31-marker MLVA. While only a single GT was found in any one of the 10 soil samples, four of the 18 swabs (22%) yielded different GTs. Two GTs were isolated from each of a zebra and a springbok and three GTs from each of a second zebra and an elephant. These animals had died in a region of the ENP where deaths caused by anthrax regularly occur every year. The results confirm the indications noted previously that co-infection with more than one GT is probably not especially uncommon. The results show that, for the purpose of analysing genotypes involved in an outbreak, it is important to examine more than a single colony from a clinical sample. SIGNIFICANCE AND IMPACT OF THE STUDY: Multi-locus variable number of tandem repeats analysis (MLVA)-based fingerprinting techniques have been used in many studies worldwide to characterize the occurrence of different genotypes of Bacillus anthracis in outbreaks of wildlife or livestock and to draw conclusions about the source, the possible routes of spread and the temporal and spatial distribution of outbreak strains. Simultaneous isolation of different genotypes from the same host revealed in our study by MLVA highlights the importance of examining more than a single colony from a clinical sample. This conclusion is not specific for MLVA but holds true for every high-resolution method, including full-genome sequencing.


Subject(s)
Animals, Wild/microbiology , Anthrax/veterinary , Bacillus anthracis/genetics , Bacillus anthracis/isolation & purification , Coinfection/veterinary , Animals , Anthrax/epidemiology , Anthrax/microbiology , Bacillus anthracis/classification , Coinfection/microbiology , Disease Outbreaks , Elephants , Equidae , Europe/epidemiology , Genotype , Minisatellite Repeats , Namibia/epidemiology , Soil Microbiology
4.
J Microbiol Methods ; 92(3): 264-9, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23357124

ABSTRACT

The simple polychrome methylene blue (PMB) staining procedure for blood or tissue smears from dead animals (M'Fadyean reaction) established in 1903 remained accepted as a highly reliable, rapid diagnostic test for anthrax for six decades while that disease was still common in livestock throughout the world. Improvements in disease control led to anthrax becoming rare in industrialized countries and less frequent in developing countries with the result that quality controlled, commercially produced PMB became hard to obtain by the 1980s. Mixed results with alternative methylene blue-based stains then led to diagnosis failures, confusion among practitioners and mistrust of this procedure as a reliable test for anthrax. We now report that, for laboratories needing a reliable M'Fadyean stain at short notice, the best approach is to have available commercially pure azure B ready to constitute into a solution of 0.03 g azure B in 3 ml of 95% ethanol or methanol to which is then added 10 ml of 0.01% KOH (0.23% final azure B concentration) and which can then be used immediately and through to the end of the tests. Stored in the dark at room temperature, the shelf life is at least 12 months. Smears should be fixed with ethanol or methanol (95-100%), not by heat, and the stain left for 5 min before washing off for optimum effect.


Subject(s)
Anthrax/diagnosis , Bacillus anthracis/cytology , Bacterial Capsules/metabolism , Bacteriological Techniques/methods , Coloring Agents/metabolism , Staining and Labeling/methods , Anthrax/microbiology
5.
Mol Aspects Med ; 30(6): 481-9, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19723532

ABSTRACT

Anthrax is the archetype zoonosis; no other infectious disease affects such a wide range of species, including humans, although most susceptible are herbivorous mammals. Although the disease appears to have been recognized for centuries, it has yet to be established scientifically how animals contract it. While primarily a disease of warmer regions, it has long been spread to cooler zones through the trade of infected animals or contaminated animal products. Today it is still endemic in many countries of Africa and Asia and non-endemic countries must remain alert to the possibility of imports from such endemic areas resulting in outbreaks in their own livestock. The epidemiology of anthrax is becoming understood better with new systems coming on stream for distinguishing different genotypes and this is covered in detail. Clinical signs and pathology in animals are described.


Subject(s)
Animal Diseases , Anthrax , Zoonoses , Africa/epidemiology , Animal Diseases/epidemiology , Animal Diseases/pathology , Animal Diseases/transmission , Animals , Animals, Domestic/microbiology , Anthrax/epidemiology , Anthrax/pathology , Anthrax/transmission , Asia/epidemiology , Bacillus anthracis/genetics , Bacillus anthracis/pathogenicity , Birds/microbiology , Carnivora/microbiology , Communicable Diseases/epidemiology , Communicable Diseases/pathology , Communicable Diseases/transmission , Disease Outbreaks , Genotype , Humans , Spores, Bacterial/metabolism , Zoonoses/epidemiology , Zoonoses/transmission
6.
Onderstepoort J Vet Res ; 75(2): 95-102, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18788202

ABSTRACT

Sera from 19 wild caught vultures in northern Namibia and 15 (12 wild caught and three captive bred but with minimal histories) in North West Province, South Africa, were examined by an enzyme-linked immunosorbent assay (ELISA) for antibodies to the Bacillus anthracis toxin protective antigen (PA). As assessed from the baseline established with a control group of ten captive reared vultures with well-documented histories, elevated titres were found in 12 of the 19 (63%) wild caught Namibian birds as compared with none of the 15 South African ones. There was a highly significant difference between the Namibian group as a whole and the other groups (P < 0.001) and no significant difference between the South African and control groups (P > 0.05). Numbers in the Namibian group were too small to determine any significances in species-, sex- or age-related differences within the raw data showing elevated titres in four out of six Cape Vultures, Gyps coprotheres, six out of ten White-backed Vultures, Gyps africanus, and one out of three Lappet-faced Vultures, Aegypius tracheliotus, or in five of six males versus three of seven females, and ten of 15 adults versus one of four juveniles. The results are in line with the available data on the incidence of anthrax in northern Namibia and South Africa and the likely contact of the vultures tested with anthrax carcasses. It is not known whether elevated titre indicates infection per se in vultures or absorption of incompletely digested epitopes of the toxin or both. The results are discussed in relation to distances travelled by vultures as determined by new tracking techniques, how serology can reveal anthrax activity in an area and the issue of the role of vultures in transmission of anthrax.


Subject(s)
Anthrax/veterinary , Antibodies, Bacterial/blood , Antigens, Bacterial/immunology , Bacillus anthracis/immunology , Bird Diseases/epidemiology , Falconiformes , Africa, Southern/epidemiology , Age Factors , Animals , Anthrax/epidemiology , Anthrax/transmission , Bird Diseases/transmission , Enzyme-Linked Immunosorbent Assay/methods , Enzyme-Linked Immunosorbent Assay/veterinary , Female , Food Chain , Male , Seroepidemiologic Studies , Sex Factors , Species Specificity
7.
Vet Rec ; 160(4): 113-8, 2007 Jan 27.
Article in English | MEDLINE | ID: mdl-17259452

ABSTRACT

A massive outbreak of anthrax in the wildlife of the Malilangwe Wildlife Reserve in Zimbabwe between August and November 2004 resulted in the death of almost all the reserve's estimated 500 kudu (Tragelaphus strepsiceros). Other species badly affected were nyala (Tragelaphus angasi), bushbuck (Tragelaphus scriptus), waterbuck (Kobus ellipsiprymnus) and roan antelope (Hippotragus equinus), which suffered losses of approximately 68 per cent, 48 per cent, 44 per cent and 42 per cent of their populations, respectively. Buffalo (Syncerus caffer) were also badly affected and although their population suffered only a 6 per cent loss, the numbers of deaths ranked second highest after kudu. To the authors' knowledge, this is the first record of anthrax in wildlife in Zimbabwe.


Subject(s)
Antelopes , Anthrax/veterinary , Disease Outbreaks/veterinary , Ruminants , Animals , Animals, Wild , Anthrax/epidemiology , Anthrax/prevention & control , Anthrax Vaccines/administration & dosage , Bacillus anthracis/immunology , Female , Male , Seasons , Vaccination/veterinary , Zimbabwe/epidemiology
8.
Vaccine ; 22(25-26): 3340-7, 2004 Sep 03.
Article in English | MEDLINE | ID: mdl-15308358

ABSTRACT

Institution of a policy of vaccination in endangered species with a vaccine not previously administered to it cannot be undertaken lightly. This applies even more in the case of cheetah (Acinonyx jubatus) with their unusually monomorphic gene pool and the potential restrictions this places on their immune responses. However, the recently observed mortalities from anthrax in these animals in the Etosha National Park, Namibia, made it imperative to evaluate vaccination. Black rhinoceros (Diceros bicornis), another endangered species in the park, have been vaccinated for over three decades but the effectiveness of this has never been evaluated. Passive protection tests in A/J mice using sera from 12 cheetahs together with enzyme immunoassay indicated that cheetah are able to mount seemingly normal primary and secondary humoral immune responses to the Sterne 34F2 live spore livestock vaccine. Overall protection rates in mice injected with the sera rose and fell in concert with rises and declines in antibody titres, although fine analysis showed that the correlation between titre and protection was complex. Once a high level of protection (96% of mice 1 month after a second booster in the cheetahs) had been achieved, the duration of substantial protection appeared good (60% of the mice 5 months after the second booster). Protection conferred on mice by sera from three of four vaccinated rhino was almost complete, but, obscurely, none of the mice receiving serum from the fourth rhino were protected. Sera from three park lions with naturally acquired high antibody titres, included as controls, also conferred high levels of protection. For the purposes of wildlife management, the conclusions were that vaccination of cheetah with the standard animal anthrax vaccine causes no observable ill effect in the animals and does appear to confer protective immunity. At least one well-separated booster does appear to be desirable. Vaccination of rhino also appears to be justified from the limited data obtained.


Subject(s)
Acinonyx/immunology , Anthrax Vaccines/therapeutic use , Anthrax/prevention & control , Anthrax/veterinary , Artiodactyla/immunology , Animals , Anthrax Vaccines/adverse effects , Antibodies, Bacterial/analysis , Antibodies, Bacterial/biosynthesis , Antibodies, Bacterial/therapeutic use , Enzyme-Linked Immunosorbent Assay , Female , Immunization, Passive , Male , Mice
9.
Curr Top Microbiol Immunol ; 271: 1-19, 2002.
Article in English | MEDLINE | ID: mdl-12224519

ABSTRACT

The familiarity with the ancient disease anthrax from the second millennium B.C. through the second millennium A.D. is reviewed, providing the backdrop to the modern understanding of this disease as covered in the remainder of the volume. By means of an overview of the aetiology, ecology, epidemiology, clinical manifestations, pathology and bacteriology of the naturally acquired disease, this opening chapter also lays down the groundwork for the subsequent state-of-the-art chapters.


Subject(s)
Anthrax , Bacillus anthracis , Africa South of the Sahara/epidemiology , Animals , Anthrax/diagnosis , Anthrax/epidemiology , Anthrax/transmission , Anthrax/veterinary , Asia, Central/epidemiology , Asia, Southeastern/epidemiology , China/epidemiology , Disease Transmission, Infectious , Ecology , Endemic Diseases/veterinary , Haiti/epidemiology , Humans , Insect Vectors , Occupational Diseases/diagnosis , Occupational Diseases/microbiology , Zoonoses
10.
Vaccine ; 19(31): 4409-16, 2001 Aug 14.
Article in English | MEDLINE | ID: mdl-11483266

ABSTRACT

Passive transfer of lymphocytes and sera from mice immunised using two different formulations containing recombinant protective antigen (rPA) have been used to further elucidate the mechanism of protection against Bacillus anthracis infection. The results demonstrated that an antibody response maybe important in protection against B. anthracis infection, under the conditions tested. The results provide further data for the development of an improved anthrax vaccine.


Subject(s)
Anthrax/prevention & control , Bacillus anthracis/immunology , Disease Models, Animal , Immunization, Passive/methods , Adoptive Transfer/methods , Animals , Anthrax/blood , Anthrax/mortality , Anthrax Vaccines/therapeutic use , Immunization Schedule , Immunoglobulin G/blood , Lymphocyte Transfusion , Mice , Mice, Inbred A , Mice, Inbred BALB C , Mice, Inbred C57BL , Mice, Inbred CBA , Mice, SCID , Models, Immunological , Spores, Bacterial/immunology
11.
J Appl Microbiol ; 87(2): 237-40, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10475956

ABSTRACT

The word 'problem' is seen with some frequency in relation to clear differentiation between Bacillus anthracis and B. cereus. In fact, although the close relationship of these two species is undisputed, it is only in the case of a few borderline isolates, rarely encountered in practice, that any sort of identification problem exists. Until recently this was only important to the taxonomist who found it unsatisfactory not to be able to identify definitively such isolates. To most others, if the isolate was unable to produce anthrax in a laboratory animal, it was discarded as irrelevant without being named, or it was called B. cereus or given a name such as B. anthracis similis, or even a totally unrelated name. More recently, in view of the new light in which B. anthracis is increasingly seen, resulting from its putative association with bioaggression, clear identification has become a more critical issue. This paper reviews the current state of the art and suggests the way forward for the future.


Subject(s)
Bacillus anthracis , Animals , Anthrax/microbiology , Bacillus/classification , Bacillus/genetics , Bacillus/isolation & purification , Bacillus anthracis/classification , Bacillus anthracis/genetics , Bacillus anthracis/isolation & purification , Bacterial Typing Techniques , Genetic Variation , Genome, Bacterial , Humans
12.
J Appl Microbiol ; 87(2): 306-8, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10475977

ABSTRACT

The IgG anti-protective antigen subclass antibody response of individuals who had been infected with anthrax was compared with that of healthy individuals immunized with the UK licensed anthrax vaccine. The predominant subclass in both groups was IgG1. In addition, IgG3 was seen in convalescent serum while vaccinees produced IgG2, IgG3 and IgG4 subclass. The significance of these results is discussed. Further work is required to determine the role of antibodies in mediating protective immunity in man.


Subject(s)
Anthrax/immunology , Antibodies, Bacterial/immunology , Bacillus anthracis/immunology , Immunity , Vaccines , Anthrax/prevention & control , Antigens, Bacterial , Humans , Immunoglobulin G/immunology , United Kingdom , Vaccination
13.
J Appl Microbiol ; 87(2): 318-20, 1999 Aug.
Article in English | MEDLINE | ID: mdl-10475980

ABSTRACT

The achievements of a World Health Organization Anthrax Working Group, established in 1990, have been the production of two editions of guidelines on anthrax surveillance and control and the formulation of templates to assist countries in the construction of their surveillance and control programmes. The latter was made possible by the active participation of the Department of Animal Production and Health, Ministry of Agriculture, Food and Fisheries, Zambia and the Livestock Development Programme, Mongu, Western Province, Zambia in a model country programme designed by the Working Group for the purpose. This paper elaborates on these achievements, particularly the lessons learned from the experience of Western Province, Zambia.


Subject(s)
Anthrax/epidemiology , Anthrax/prevention & control , Communicable Disease Control , Animals , Data Collection , Humans , Practice Guidelines as Topic , World Health Organization
14.
J Appl Microbiol ; 84(4): 667-76, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9633664

ABSTRACT

Tests for airborne movement of anthrax spores downwind from three heavily contaminated carcass sites were carried out under a range of wind conditions. Anthrax spores were detected in just three of 43 cyclone or gelatin filter air samples taken at distances of 6, 12 and 18 m from the sites. In addition, nine positives resulted during sampling sessions in which the site was mechanically disturbed, with a further five positives being found in sessions subsequent to those in which the site had been disturbed. The three positive samples not related to man-made disturbance were associated with the highest winds experienced during the study. Despite colony counts exceeding 100 on the culture plates in three instances, calculations showed that these represented very low worst case probable spore inhalation rates for animals or humans exposed to such levels. The low number of positives, the clear pattern of rapidly declining numbers of anthrax spores with distance downwind from the centres of the sites apparent on settle plates, and the persisting levels of contamination despite wind and rain, collectively suggest that the anthrax spores were associated with fairly heavy particles, although this was not seen by electron microscopy on soil samples from the sites. Overall, the findings are interpreted as indicating that it is very unlikely that Etosha animals contract anthrax by the inhalation route while simply in transit near or across a carcass site. The significance of the observations in relation to weather conditions in the Etosha, other studies on particulate aerosols in the region, and reports of long-distance airborne movement of microbes, is discussed.


Subject(s)
Air Microbiology , Anthrax/microbiology , Bacillus anthracis/isolation & purification , Spores, Bacterial/isolation & purification , Animals , Bacteriological Techniques , Equidae/microbiology , Microscopy, Electron, Scanning , Namibia , Soil Microbiology
15.
Vaccine ; 16(8): 810-7, 1998 May.
Article in English | MEDLINE | ID: mdl-9627938

ABSTRACT

The efficacy of recombinant Bacillus anthracis Protective Antigen (rPA) produced in Bacillus subtilis and formulated in Alhydrogel or MPL-TDM-CWS (Ribi adjuvant) has been tested and compared to the licensed UK human vaccine in guinea pigs challenged by the aerosol route with the Ames strain of B. anthracis. rPA combined with the Ribi adjuvant was found to be the only formulation to provide 100% protection from challenge. Analysis of immunological parameters in the individual animals revealed significant differences between the rPA/Ribi vaccine group and rPA/Alhydrogel and human vaccine groups for antigen specific lymphocyte proliferation, PA neutralisation and antigen specific IgG2 levels, but indicated no significant differences in PA-specific IgG1 levels. rPA formulated in Alhydrogel induced a mainly IgG1 response whilst the rPA/Ribi vaccine produced a predominantly IgG2 response.


Subject(s)
Anthrax/prevention & control , Bacillus anthracis/immunology , Adjuvants, Immunologic , Aerosols , Aluminum Hydroxide/pharmacology , Animals , Anthrax/immunology , Antibodies, Bacterial/biosynthesis , Cell Wall Skeleton/pharmacology , Cord Factors/pharmacology , Evaluation Studies as Topic , Female , Guinea Pigs , Immunity, Cellular/drug effects , Immunoglobulin G/biosynthesis , Immunoglobulin G/immunology , Lipid A/analogs & derivatives , Lipid A/pharmacology , Lung/immunology , Lung/microbiology , Lymphocyte Activation , Macrophage Activation , Male , Spores, Bacterial
16.
Vet Rec ; 141(10): 244-7, 1997 Sep 06.
Article in English | MEDLINE | ID: mdl-9308148

ABSTRACT

Following an outbreak of anthrax in an intensive pig rearing unit in north Wales in 1989 a study was initiated by the Ministry of Agriculture, Fisheries and Food to assess public health risks during such an outbreak. Of 50 pigs infected by the addition of Bacillus anthracis spores to their feed, two died of anthrax six and eight days later. The remainder were observed for 21 days and exhibited only mild and transient clinical signs of disease. As judged by the results of bacteriological culture of appropriate tissues from the survivors, it was concluded that meat from healthy pigs killed 21 days after the latest case during an outbreak would not pose a public health risk.


Subject(s)
Anthrax/transmission , Anthrax/veterinary , Disease Outbreaks/veterinary , Meat/microbiology , Public Health , Swine Diseases/transmission , Animal Feed/microbiology , Animal Husbandry , Animals , Bacillus anthracis/pathogenicity , Risk Factors , Swine , Wales/epidemiology
18.
FEMS Microbiol Lett ; 128(2): 113-8, 1995 May 01.
Article in English | MEDLINE | ID: mdl-7750728

ABSTRACT

Sequences based on the conserved 20 bp inverted repeat of IS231 variants were used as polymerase chain reaction-based fingerprinting primers of the member species of the Bacillus cereus group (B. anthracis, B. cereus, B. thuringiensis and B. mycoides), because of their close association with transposons, principally Tn4430 in B. thuringiensis. Fingerprints of B. anthracis were simple, and specifically allowed its identification and sub-differentiation from other members of the group. Fingerprints for B. cereus were strain-specific; those for B. thuringensis gave a 1650 bp product, characteristic of IS231 variants A-F. The same reaction conditions gave one or two bands for both B. anthracis and B. cereus that differed by restriction endonuclease mapping from the B. thuringiensis PCR product and established IS231 restriction maps; this does not preclude some kind of relationship between these products and IS231.


Subject(s)
Bacillus anthracis/isolation & purification , Bacillus cereus/isolation & purification , Bacillus anthracis/classification , Bacillus cereus/classification , Base Sequence , DNA Fingerprinting , DNA Primers , DNA, Bacterial/genetics , Genetic Variation , Molecular Sequence Data , Restriction Mapping , Species Specificity
19.
Lett Appl Microbiol ; 20(4): 209-11, 1995 Apr.
Article in English | MEDLINE | ID: mdl-7766114

ABSTRACT

The potential of the Biolog system for the identification of Bacillus anthracis was evaluated. In-house generated databases allowed the correct identification of 19 of 20 isolates of B. anthracis within 24 h. Five strains of the closely related B. cereus/thuringiensis group were misidentified as B. anthracis. For this reason the test could only serve as a primary screen with further testing being required to confirm identity. In addition 20% of all the strains of bacilli examined during the study gave unreadable reaction profiles due to false-positive reactions.


Subject(s)
Bacillus anthracis/isolation & purification , Microbiological Techniques , False Positive Reactions , Information Systems , Software
20.
Onderstepoort J Vet Res ; 61(1): 71-83, 1994 Mar.
Article in English | MEDLINE | ID: mdl-7898901

ABSTRACT

Analysis of mortality records has revealed distinct patterns in the incidence of anthrax in elephant and plains ungulates. The seasonal peak among the former is in November at the end of the dry season, while among the latter it occurs in March towards the end of the rainy season. Among elephants, there has been a notable spread of the disease to the west of the Park. Age and sex analyses indicate that, except for zebra, proportionally greater numbers of adult males die of anthrax among the species predominantly affected; however, zebra carcases are difficult to sex. In a study to identify possible environmental sources of infection, B. anthracis was detected in 3.3% of 92 water and 3.0% of 230 soil samples collected at different times of the year from 23 sites not associated with known cases of anthrax. Slight seasonal differences were noted with 5.7% positives occurring in the cold-dry period (May to August), 3.5% in the hot-dry season (September to December) and 1.4% in the hot-wet season (January to April). Higher rates (26.0% of 73 samples) were found in water from waterholes in the western part of the Park at the time of an outbreak in elephants. The possible importance of scavenger faeces was confirmed with > 50% of vulture, jackal and hyaena faeces collected from the vicinity of confirmed anthrax carcases yielding B. anthracis, sometimes in substantial numbers, while no spores were found in faeces not associated with known anthrax carcases. Despite terminal B. anthracis levels of usually > 10(7) cfu/milliliters in the blood of animals dying of anthrax, spore levels in soil contaminated by such blood at sites of anthrax carcases ranged from undetectable to a few tens of thousands. The rapid loss of viability in soil and water of anthrax bacilli was monitored experimentally and the importance of soil type demonstrated. Survival and extent of sporulation of the bacilli in water were shown to be dependent on the rate at which the blood was diluted out. Other relevant parameters examined were background flora, pH and sunlight.


Subject(s)
Anthrax/epidemiology , Anthrax/veterinary , Bacillus anthracis/isolation & purification , Animals , Animals, Wild/microbiology , Anthrax/microbiology , Bacillus anthracis/radiation effects , Feces/microbiology , Female , Incidence , Male , Namibia , Seasons , Soil Microbiology , Sunlight , Ultraviolet Rays , Water Microbiology
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