ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vicinal syn-dihydroxylation of D-manno-hept-6-enopyranosides 4 and 10 with OsO4 afforded D-glycer... more Vicinal syn-dihydroxylation of D-manno-hept-6-enopyranosides 4 and 10 with OsO4 afforded D-glycero-α-D-manno-heptopyranosides 5 and 11, respectively, in good yield and with a high degree of stereoselectivity. Compound 5 was converted into DD-Hep p acceptor 8. Glycosylation of acceptor 8 under the agency of N-iodosuccinimide and triflic acid with ethyl 2-O-benzoyl-3,4,6-tri-O-benzyl-7-deoxy-7-(phenyldimethyl)silane-1-thio-L-glycero-α-D-manno-heptopyranoside (22), obtained after hydroxymethylation of aldehyde 17 with (phenyldimethylsilyl)methyl magnesium chloride, followed by protective group manipulations, gave α-linked dimer 23. Oxidative removal of the PhMe2Si moiety in dimer 23, protective group manipulations (→ 26), and condensation with ethyl 1-thio-β-D-glucopyranosyl donor 27 furnished trisaccharide 28. Oxidation of the C-6 in 29 and hydrogenolysis yielded target trisaccharide 2, a fragment of the inner-core lipopolysaccharide region of Vibrio parahaemolyticus, serotype O2.
As part of a program towards the development of novel antibiotics, a convenient method for solid-... more As part of a program towards the development of novel antibiotics, a convenient method for solid-phase synthesis of the cyclic cationic peptide polymyxin B1 and analogues thereof is described. The methodology, based on cleavage-by-cyclization using Kenner's safety-catch linker, yields crude products with purities ranging from 37-67%. Antibacterial assays revealed that analogues 23-26, in which the (S)-6-methyloctanoic acid moiety is replaced with shorter acyl chains, exhibit distinct antimicrobial activity. The results suggest that the length of the acyl chain is rather critical for antimicrobial activity. On the other hand, substitution of the hydrophobic ring-segment D-Phe-6/Leu-7 in polymyxin B1 with dipeptide mimics (i.e. analogues 27-33) resulted in almost complete loss of antimicrobial activity.
The Onderstepoort journal of veterinary research, 2000
Healthy and sick crocodiles of varying sizes were examined from the Olifants River in the central... more Healthy and sick crocodiles of varying sizes were examined from the Olifants River in the central part of the Kruger National Park, the Sabi River in the southern part and the Shingwedzi River in the northern region. Blood was collected for the determination of certain parameters and samples of fat, muscle, kidney and liver tissue were collected and analyzed for their heavy metal content. The results of the blood analyses are within the range recorded in the literature, but the metal analyses were inconclusive as similar data are not available for comparison. The results of the metal analyses are presented here for use as baseline and reference data.
The Onderstepoort journal of veterinary research, 2000
A single troop of free-ranging chacma baboons (Papio ursinus) was found to be infected with tuber... more A single troop of free-ranging chacma baboons (Papio ursinus) was found to be infected with tuberculosis caused by Mycobacterium bovis. It is assumed that some members of the troop originally became infected when feeding on a tuberculous carcass in the veld or on tuberculous material scavenged at a nearby post mortem facility. Subsequently, apparent aerosol transmission took place while sleeping in an unused room. Oral transmission probably also occurred due to continuous contamination of the floor of this room and the common, narrow access (a train bridge crossing the Sabi River) to it with faeces and urine. A macroscopic prevalence of 50 % was found and the disease was noted to progress rapidly in infected baboons. A variety of organs had typical tuberculous lesions, of which the spleen, lungs and mesenteric lymph nodes were consistently, grossly affected. Using Restriction Fragment Length Polymorphism analysis, all but one of the baboon isolates were found to be identical to the ...
A semi-purified corn-based diet containing 50 mg/kg of pure (not less than 90%) fumonisin B1 (FB1... more A semi-purified corn-based diet containing 50 mg/kg of pure (not less than 90%) fumonisin B1 (FB1), isolated from culture material of Fusarium moniliforme strain MRC 826, was fed to a group of 25 rats over a period of 26 months. A control group of 25 rats received the same diet without FB1. Five rats from each group were killed at 6, 12, 20 and 26 months. The liver was the main target organ in the FB1-treated rats and the hepatic pathological changes were identical to those previously reported in rats fed culture material of F.moniliforme MRC 826. All FB1-treated rats that died or were killed from 18 months onwards suffered from a micro- and macronodular cirrhosis and had large expansile nodules of cholangiofibrosis at the hilus of the liver. Ten out of 15 FB1-treated rats (66%) that were killed and/or died between 18 and 26 months developed primary hepatocellular carcinoma. Metastases to the heart, lungs or kidneys were present in four of the rats with hepatocellular carcinoma. No ...
Journal of the South African Veterinary Association, 1979
An outbreak of mortality in a flock of mutton merino sheep in which 109 out of 568 sheep died in ... more An outbreak of mortality in a flock of mutton merino sheep in which 109 out of 568 sheep died in the south-western Cape Province, is described. It was characterized by haemorrhagic septicaemia, anaemia, leucocytopaenia and haemorrhagic tendencies. Mortalities followed unseasonal and heavy summer rain, extended over a period of 6 months and were associated with the uninterrupted consumption of sheep cubes processed on the farm severly fungus-infested wheat, barley and rye straw for a period of at least one month. The main clinical signs occurred in two phases: an elevated body temperature, listlessness, epistaxis and intermittent haemorrhagic diarrhoea during the first phase of the outbreak, and a progressively worsening anaemia, leucocytopaenia and less severe haemorrhagic tendencies and a terminally elevated body temperature during the second phase. The predominant autopsy findings were purpuric haemorrhage on serosal and mucosal surfaces and in most of the organs, enterorrhagia an...
Ten strains of Diplodia maydis isolated from commercial corn samples and grown on whole yellow co... more Ten strains of Diplodia maydis isolated from commercial corn samples and grown on whole yellow corn at 25 degrees C for 6 weeks were toxic to ducklings and rats. The degree of toxicity depended on the incubation period and temperature. Minimum incubation periods of 3 to 4 weeks and 6 weeks were necessary to cause mortality in ducklings and rats, respectively. Cultures incubated at 31 and 25 degrees C were much more toxic than those kept at 16 and 20 degrees C. Heat treatments at 80 to 90 degrees C destroyed most of the toxicity of moldy meal. Mild lesions of a similar histopathological nature were found in subclinically and lethally poisoned rats. These included toxic myocarditis, enteritis, focal renal tubular necrosis, degeneration and peripheral necrosis of the islets of Langerhans, and a generalized venous congestion.
The Onderstepoort journal of veterinary research, 2001
Tuberculosis, caused by Mycobacterium bovis, was diagnosed for the first time, in a kudu cow from... more Tuberculosis, caused by Mycobacterium bovis, was diagnosed for the first time, in a kudu cow from a commercial game ranch in the Malelane area of the Mpumalanga Province close to the Kruger National Park. This diagnosis has important implications for the eradication of the disease in commercial and communal livestock in the area. Kudus are considered to be a potential maintenance host and, because of discharging fistulae in the parotid area where the lymph nodes are commonly infected, they have the potential of disseminating bacteria over wide areas. Cognisance should be taken of the presence of tuberculosis in a species other than domesticated cattle in this area and its implications for the control of tuberculosis in cattle.
The Onderstepoort journal of veterinary research, 2001
Five kudus (Tragelaphus strepsiceros), three bulls and two cows, within the Greater Kruger Nation... more Five kudus (Tragelaphus strepsiceros), three bulls and two cows, within the Greater Kruger National Park complex, were diagnosed with generalized tuberculosis caused by Mycobacterium bovis. The lesions seen in these animals were similar to those previously reported in kudus and included severe tuberculous lymphadenitis of the nodes of the head and neck (that resulted in noticeable uni- or bilateral swelling beneath the ear), thorax, and the mesentery. All the animals also suffered from severe granulomatous pneumonia. The lesions in the lungs were more severe cranially and had a miliary distribution elsewhere in the lungs. Based on the DNA patterns of the M. bovis isolates, at least some of these kudus were infected with strains commonly present in tuberculous buffaloes, lions, cheetahs, and baboons in the Park whereas other strains from these kudus were quite different and may reflect another source of infection. The presence of tuberculous kudus in the Park is expected to complicat...
The Onderstepoort journal of veterinary research, 2001
The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was d... more The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is cu...
The Onderstepoort journal of veterinary research, 1997
This is the first report on the occurrence of Parafilaria bassoni in the African buffalo (Synceru... more This is the first report on the occurrence of Parafilaria bassoni in the African buffalo (Syncerus caffer). Previously this parasite has been recorded only in springbok (Antidorcas marsupialis) in Namibia. Haemorrhagic perforations (bleeding points), the usual lesions seen in infected animals, were caused by gravid female parasites ovipositing embryonated eggs. These lesions occurred mainly on the dorsal and lateral sides of buffaloes. Complications of these lesions developed in a small number of buffaloes because of secondary bacterial infection [subcutaneous abscesses (3/178)] and as a consequence of a localized Type 1 hypersensitivity [large cutaneous ulcers (7/178)]. Red-billed oxpeckers (Buphagus erythrorynchus) appeared to play an important role in the epidemiology of this parasite as well as in the pathogenesis of the lesions. They reduced the likelihood of spread by ingesting blood containing embryonated eggs, and caused the development of large ulcers by feeding on superfic...
The Onderstepoort journal of veterinary research, 1996
Tuberculosis, caused by Mycobacterium bovis, was recently diagnosed in a cheetah (Acinonyx jubatu... more Tuberculosis, caused by Mycobacterium bovis, was recently diagnosed in a cheetah (Acinonyx jubatus), two lions (Panthera leo) and a chacma baboon (Papio ursinus) from the Kruger National Park (KNP). It is assumed that they contracted the disease directly or indirectly from tuberculous buffaloes in the park. Tuberculous granulomatous lesions in the lungs were extensive and constituted the predominant changes in all three animal species. These pulmonary lesions included tuberculous bronchiolitis and cavitation which would facilitate dissemination of M. bovis into the environment. Spread of the disease to free-ranging species (in which it has not previously been reported) that may act as maintenance hosts of the infection, is a matter of serious concern.
The Onderstepoort journal of veterinary research, 1996
Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in t... more Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in the Kruger National Park (KNP). The index case was a 2-year-old, emaciated bull which had been found recumbent and obviously ill, near the south-western boundary of the KNP, in July 1990. During a follow-up random sampling of 57 buffalo, from two herds in close proximity to this initial case, nine more suspect cases were found. Mycobacterium bovis was isolated from a lung and thoracic lymph node, respectively, of two of these cases. Histopathologically, all nine of these animals had granulomatous lesions compatible with a diagnosis of mycobacteriosis, but acid-fast organisms could be demonstrated in only one animal.
... Group A South Africa and contiguous areas Great Limpopo TFCA; Hluhluwe-Umfolozi; Shashe-Limpo... more ... Group A South Africa and contiguous areas Great Limpopo TFCA; Hluhluwe-Umfolozi; Shashe-Limpopo Facilitator/Recorder: Roy Bengis/Philip ... Richard Kock/Elizabeth Wambwa Members Day 1: George Gitau, Fumi Mizutani, Elizabeth Muthiani, Jacob Mwanzia, Jesse Njoka ...
The Onderstepoort journal of veterinary research, 1995
A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of Afr... more A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early...
Journal of the South African Veterinary Association, 1993
The tissue damage and subsequent healing of skin, linea alba and intestinal wall incisions made w... more The tissue damage and subsequent healing of skin, linea alba and intestinal wall incisions made with a CO2-laser and a stainless steel surgical blade were evaluated clinically and histologically in dogs (n = 10). The amount of blood lost in each type of skin incision was measured by taking the pre- and postoperative mass of surgical swabs. The tissues were sutured and the skin incisions examined every day. The animals were subsequently euthanased (Day 12) and all incisions examined histologically. A delay in the healing process was observed in the laser incisions of the skin during the first 4 d, but there was no difference in the healing rate of the intestinal wounds or of the linea alba. The blood loss due to the laser incisions was significantly less than that caused by the surgical blade. It was concluded that the CO2-laser can be used with confidence when incising the skin and intestine and that, due to its precision, the surgical blade is by far a more accurate method to incis...
Journal of the South African Veterinary Association, 1994
A necropsy conducted on an emaciated 8-year-old female African buffalo (Syncerus caffer) in the K... more A necropsy conducted on an emaciated 8-year-old female African buffalo (Syncerus caffer) in the Kruger National Park, revealed gross pathological changes compatible with generalised bovine tuberculosis. Macroscopic lesions in the lungs and associated lymph nodes were of a caseous necrotic nature with liquefied foci. Mycobacterium bovis was cultured from pulmonary lesions. The distribution and the characteristics of the lesions are described and the conclusion is made that the initial route of infection was aerogenous with secondary bacterial metastasis to the intestine. It would also appear that the spread of infection within the animal was extremely rapid. The conjecture is made that due to the cavernous state of the pulmonary lesions, the animal was probably highly infective at the time of death. Environmental factors that may have had an influence on the pathogenesis of the disease are seasonal rainfall fluctuations, extreme temperature variations and harsh ultra-violet exposure.
ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance t... more ABSTRACT ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Vicinal syn-dihydroxylation of D-manno-hept-6-enopyranosides 4 and 10 with OsO4 afforded D-glycer... more Vicinal syn-dihydroxylation of D-manno-hept-6-enopyranosides 4 and 10 with OsO4 afforded D-glycero-α-D-manno-heptopyranosides 5 and 11, respectively, in good yield and with a high degree of stereoselectivity. Compound 5 was converted into DD-Hep p acceptor 8. Glycosylation of acceptor 8 under the agency of N-iodosuccinimide and triflic acid with ethyl 2-O-benzoyl-3,4,6-tri-O-benzyl-7-deoxy-7-(phenyldimethyl)silane-1-thio-L-glycero-α-D-manno-heptopyranoside (22), obtained after hydroxymethylation of aldehyde 17 with (phenyldimethylsilyl)methyl magnesium chloride, followed by protective group manipulations, gave α-linked dimer 23. Oxidative removal of the PhMe2Si moiety in dimer 23, protective group manipulations (→ 26), and condensation with ethyl 1-thio-β-D-glucopyranosyl donor 27 furnished trisaccharide 28. Oxidation of the C-6 in 29 and hydrogenolysis yielded target trisaccharide 2, a fragment of the inner-core lipopolysaccharide region of Vibrio parahaemolyticus, serotype O2.
As part of a program towards the development of novel antibiotics, a convenient method for solid-... more As part of a program towards the development of novel antibiotics, a convenient method for solid-phase synthesis of the cyclic cationic peptide polymyxin B1 and analogues thereof is described. The methodology, based on cleavage-by-cyclization using Kenner's safety-catch linker, yields crude products with purities ranging from 37-67%. Antibacterial assays revealed that analogues 23-26, in which the (S)-6-methyloctanoic acid moiety is replaced with shorter acyl chains, exhibit distinct antimicrobial activity. The results suggest that the length of the acyl chain is rather critical for antimicrobial activity. On the other hand, substitution of the hydrophobic ring-segment D-Phe-6/Leu-7 in polymyxin B1 with dipeptide mimics (i.e. analogues 27-33) resulted in almost complete loss of antimicrobial activity.
The Onderstepoort journal of veterinary research, 2000
Healthy and sick crocodiles of varying sizes were examined from the Olifants River in the central... more Healthy and sick crocodiles of varying sizes were examined from the Olifants River in the central part of the Kruger National Park, the Sabi River in the southern part and the Shingwedzi River in the northern region. Blood was collected for the determination of certain parameters and samples of fat, muscle, kidney and liver tissue were collected and analyzed for their heavy metal content. The results of the blood analyses are within the range recorded in the literature, but the metal analyses were inconclusive as similar data are not available for comparison. The results of the metal analyses are presented here for use as baseline and reference data.
The Onderstepoort journal of veterinary research, 2000
A single troop of free-ranging chacma baboons (Papio ursinus) was found to be infected with tuber... more A single troop of free-ranging chacma baboons (Papio ursinus) was found to be infected with tuberculosis caused by Mycobacterium bovis. It is assumed that some members of the troop originally became infected when feeding on a tuberculous carcass in the veld or on tuberculous material scavenged at a nearby post mortem facility. Subsequently, apparent aerosol transmission took place while sleeping in an unused room. Oral transmission probably also occurred due to continuous contamination of the floor of this room and the common, narrow access (a train bridge crossing the Sabi River) to it with faeces and urine. A macroscopic prevalence of 50 % was found and the disease was noted to progress rapidly in infected baboons. A variety of organs had typical tuberculous lesions, of which the spleen, lungs and mesenteric lymph nodes were consistently, grossly affected. Using Restriction Fragment Length Polymorphism analysis, all but one of the baboon isolates were found to be identical to the ...
A semi-purified corn-based diet containing 50 mg/kg of pure (not less than 90%) fumonisin B1 (FB1... more A semi-purified corn-based diet containing 50 mg/kg of pure (not less than 90%) fumonisin B1 (FB1), isolated from culture material of Fusarium moniliforme strain MRC 826, was fed to a group of 25 rats over a period of 26 months. A control group of 25 rats received the same diet without FB1. Five rats from each group were killed at 6, 12, 20 and 26 months. The liver was the main target organ in the FB1-treated rats and the hepatic pathological changes were identical to those previously reported in rats fed culture material of F.moniliforme MRC 826. All FB1-treated rats that died or were killed from 18 months onwards suffered from a micro- and macronodular cirrhosis and had large expansile nodules of cholangiofibrosis at the hilus of the liver. Ten out of 15 FB1-treated rats (66%) that were killed and/or died between 18 and 26 months developed primary hepatocellular carcinoma. Metastases to the heart, lungs or kidneys were present in four of the rats with hepatocellular carcinoma. No ...
Journal of the South African Veterinary Association, 1979
An outbreak of mortality in a flock of mutton merino sheep in which 109 out of 568 sheep died in ... more An outbreak of mortality in a flock of mutton merino sheep in which 109 out of 568 sheep died in the south-western Cape Province, is described. It was characterized by haemorrhagic septicaemia, anaemia, leucocytopaenia and haemorrhagic tendencies. Mortalities followed unseasonal and heavy summer rain, extended over a period of 6 months and were associated with the uninterrupted consumption of sheep cubes processed on the farm severly fungus-infested wheat, barley and rye straw for a period of at least one month. The main clinical signs occurred in two phases: an elevated body temperature, listlessness, epistaxis and intermittent haemorrhagic diarrhoea during the first phase of the outbreak, and a progressively worsening anaemia, leucocytopaenia and less severe haemorrhagic tendencies and a terminally elevated body temperature during the second phase. The predominant autopsy findings were purpuric haemorrhage on serosal and mucosal surfaces and in most of the organs, enterorrhagia an...
Ten strains of Diplodia maydis isolated from commercial corn samples and grown on whole yellow co... more Ten strains of Diplodia maydis isolated from commercial corn samples and grown on whole yellow corn at 25 degrees C for 6 weeks were toxic to ducklings and rats. The degree of toxicity depended on the incubation period and temperature. Minimum incubation periods of 3 to 4 weeks and 6 weeks were necessary to cause mortality in ducklings and rats, respectively. Cultures incubated at 31 and 25 degrees C were much more toxic than those kept at 16 and 20 degrees C. Heat treatments at 80 to 90 degrees C destroyed most of the toxicity of moldy meal. Mild lesions of a similar histopathological nature were found in subclinically and lethally poisoned rats. These included toxic myocarditis, enteritis, focal renal tubular necrosis, degeneration and peripheral necrosis of the islets of Langerhans, and a generalized venous congestion.
The Onderstepoort journal of veterinary research, 2001
Tuberculosis, caused by Mycobacterium bovis, was diagnosed for the first time, in a kudu cow from... more Tuberculosis, caused by Mycobacterium bovis, was diagnosed for the first time, in a kudu cow from a commercial game ranch in the Malelane area of the Mpumalanga Province close to the Kruger National Park. This diagnosis has important implications for the eradication of the disease in commercial and communal livestock in the area. Kudus are considered to be a potential maintenance host and, because of discharging fistulae in the parotid area where the lymph nodes are commonly infected, they have the potential of disseminating bacteria over wide areas. Cognisance should be taken of the presence of tuberculosis in a species other than domesticated cattle in this area and its implications for the control of tuberculosis in cattle.
The Onderstepoort journal of veterinary research, 2001
Five kudus (Tragelaphus strepsiceros), three bulls and two cows, within the Greater Kruger Nation... more Five kudus (Tragelaphus strepsiceros), three bulls and two cows, within the Greater Kruger National Park complex, were diagnosed with generalized tuberculosis caused by Mycobacterium bovis. The lesions seen in these animals were similar to those previously reported in kudus and included severe tuberculous lymphadenitis of the nodes of the head and neck (that resulted in noticeable uni- or bilateral swelling beneath the ear), thorax, and the mesentery. All the animals also suffered from severe granulomatous pneumonia. The lesions in the lungs were more severe cranially and had a miliary distribution elsewhere in the lungs. Based on the DNA patterns of the M. bovis isolates, at least some of these kudus were infected with strains commonly present in tuberculous buffaloes, lions, cheetahs, and baboons in the Park whereas other strains from these kudus were quite different and may reflect another source of infection. The presence of tuberculous kudus in the Park is expected to complicat...
The Onderstepoort journal of veterinary research, 2001
The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was d... more The presence of bovine tuberculosis (Mycobacterium bovis) in the Kruger National Park (KNP) was determined for the first time in 1990. It was diagnosed in an African buffalo (Syncerus caffer) bull, which was found recumbent and in an emaciated and moribund state near the south-western boundary fence. This prompted an investigation into the bovine tuberculosis (BTB) status of the KNP, with emphasis on its epidemiological determinants and risk factors. This report documents the findings of surveys that were conducted from 1990 to 1996. It was found that BTB had entered the KNP ecosystem relatively recently (+/- 1960), and has found favourable circumstances for survival and propagation in a fully susceptible and immunologically naive buffalo population. Indications are that it entered the KNP from across the southern river boundary, where the presence of infected domestic cattle herds had been documented. From there the infection spread through the southern buffalo population and is cu...
The Onderstepoort journal of veterinary research, 1997
This is the first report on the occurrence of Parafilaria bassoni in the African buffalo (Synceru... more This is the first report on the occurrence of Parafilaria bassoni in the African buffalo (Syncerus caffer). Previously this parasite has been recorded only in springbok (Antidorcas marsupialis) in Namibia. Haemorrhagic perforations (bleeding points), the usual lesions seen in infected animals, were caused by gravid female parasites ovipositing embryonated eggs. These lesions occurred mainly on the dorsal and lateral sides of buffaloes. Complications of these lesions developed in a small number of buffaloes because of secondary bacterial infection [subcutaneous abscesses (3/178)] and as a consequence of a localized Type 1 hypersensitivity [large cutaneous ulcers (7/178)]. Red-billed oxpeckers (Buphagus erythrorynchus) appeared to play an important role in the epidemiology of this parasite as well as in the pathogenesis of the lesions. They reduced the likelihood of spread by ingesting blood containing embryonated eggs, and caused the development of large ulcers by feeding on superfic...
The Onderstepoort journal of veterinary research, 1996
Tuberculosis, caused by Mycobacterium bovis, was recently diagnosed in a cheetah (Acinonyx jubatu... more Tuberculosis, caused by Mycobacterium bovis, was recently diagnosed in a cheetah (Acinonyx jubatus), two lions (Panthera leo) and a chacma baboon (Papio ursinus) from the Kruger National Park (KNP). It is assumed that they contracted the disease directly or indirectly from tuberculous buffaloes in the park. Tuberculous granulomatous lesions in the lungs were extensive and constituted the predominant changes in all three animal species. These pulmonary lesions included tuberculous bronchiolitis and cavitation which would facilitate dissemination of M. bovis into the environment. Spread of the disease to free-ranging species (in which it has not previously been reported) that may act as maintenance hosts of the infection, is a matter of serious concern.
The Onderstepoort journal of veterinary research, 1996
Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in t... more Bovine tuberculosis was diagnosed for the first time in an African buffalo (Syncerus caffer) in the Kruger National Park (KNP). The index case was a 2-year-old, emaciated bull which had been found recumbent and obviously ill, near the south-western boundary of the KNP, in July 1990. During a follow-up random sampling of 57 buffalo, from two herds in close proximity to this initial case, nine more suspect cases were found. Mycobacterium bovis was isolated from a lung and thoracic lymph node, respectively, of two of these cases. Histopathologically, all nine of these animals had granulomatous lesions compatible with a diagnosis of mycobacteriosis, but acid-fast organisms could be demonstrated in only one animal.
... Group A South Africa and contiguous areas Great Limpopo TFCA; Hluhluwe-Umfolozi; Shashe-Limpo... more ... Group A South Africa and contiguous areas Great Limpopo TFCA; Hluhluwe-Umfolozi; Shashe-Limpopo Facilitator/Recorder: Roy Bengis/Philip ... Richard Kock/Elizabeth Wambwa Members Day 1: George Gitau, Fumi Mizutani, Elizabeth Muthiani, Jacob Mwanzia, Jesse Njoka ...
The Onderstepoort journal of veterinary research, 1995
A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of Afr... more A cluster of four deaths in late December 1993, marked the onset of an outbreak of disease of African elephants (Loxodonta africana) in the Kruger National Park (KNP) in South Africa, which has an estimated population of 7,500 elephants. Mortalities peaked in January 1994, with 32 deaths, and then declined steadily to reach pre-outbreak levels by September, but sporadic losses continued until November. During the outbreak altogether 64 elephants died, of which 53 (83%) were adult bulls. Archival records revealed that, in addition to the usual losses from known causes such as poaching and intraspecific fighting, sporadic deaths from unexplained causes had, in fact, occurred in widely scattered locations from at least 1987 onwards, and from that time until the perceived outbreak of disease there had been 48 such deaths involving 33 (69%) adult bulls. Carcases had frequently become decomposed or had been scavenged by the time they were found, but seven of eight elephants examined early...
Journal of the South African Veterinary Association, 1993
The tissue damage and subsequent healing of skin, linea alba and intestinal wall incisions made w... more The tissue damage and subsequent healing of skin, linea alba and intestinal wall incisions made with a CO2-laser and a stainless steel surgical blade were evaluated clinically and histologically in dogs (n = 10). The amount of blood lost in each type of skin incision was measured by taking the pre- and postoperative mass of surgical swabs. The tissues were sutured and the skin incisions examined every day. The animals were subsequently euthanased (Day 12) and all incisions examined histologically. A delay in the healing process was observed in the laser incisions of the skin during the first 4 d, but there was no difference in the healing rate of the intestinal wounds or of the linea alba. The blood loss due to the laser incisions was significantly less than that caused by the surgical blade. It was concluded that the CO2-laser can be used with confidence when incising the skin and intestine and that, due to its precision, the surgical blade is by far a more accurate method to incis...
Journal of the South African Veterinary Association, 1994
A necropsy conducted on an emaciated 8-year-old female African buffalo (Syncerus caffer) in the K... more A necropsy conducted on an emaciated 8-year-old female African buffalo (Syncerus caffer) in the Kruger National Park, revealed gross pathological changes compatible with generalised bovine tuberculosis. Macroscopic lesions in the lungs and associated lymph nodes were of a caseous necrotic nature with liquefied foci. Mycobacterium bovis was cultured from pulmonary lesions. The distribution and the characteristics of the lesions are described and the conclusion is made that the initial route of infection was aerogenous with secondary bacterial metastasis to the intestine. It would also appear that the spread of infection within the animal was extremely rapid. The conjecture is made that due to the cavernous state of the pulmonary lesions, the animal was probably highly infective at the time of death. Environmental factors that may have had an influence on the pathogenesis of the disease are seasonal rainfall fluctuations, extreme temperature variations and harsh ultra-violet exposure.
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Papers by N. Kriek