Dermatophilus Congolensis Research Articles

Dermatophilus dermatitis enzootic in deer in New York State and vicinity.

In a recent 2-year period Dermatophilus congolensis infection, ranging from mild to very severe, was found in 15 white-tailed deer (Odocoileus virginianus) taken in southeastern New York State (12) adjacent New Jersey (2) and central Vermont (1). The host range for Dermatophilus congolensis is given.

Deoxyribonucleic Acid Base Composition of Dermatophilus congolensis and Geodermatophilus obscurus

The base compositions of the deoxyribonucleic acids (DNAs) extracted from four representative strains of Dermatophilus congolensis and six of Geodermatophilus obscurus, which are described in the literature as belonging to the family Dermatophilaceae (Actinomycetales), were determined. The range of guanine plus cytosine contents (G+C) of their DNAs was 57.4 to 58.7 mol% for D. congolensis and 72.9 to 74.6 mol% for G. obscurus. This difference in DNA base composition is considered great enough to suggest a substantial genetic heterology between the two groups of organisms.

Sequential pathological changes in natural and experimental dermatophilosis in Bunaji cattle

Differences in histopathological changes between experimentally and naturally induced dermatophilosis were slight; natural infections persisted longer as they tended to be complicated by other concurrent dermatoses. Sequential pathological changes in bovine dermatophilosis included congestion, dermal oedema and neutrophilic infiltration of dermal papilae and epidermis by the third day; degenerative changes of cells in the upper portion of the stratum spinosum and invasion of the keratinised layer and hair follicles by the filamentous forms of Dermatophilus congolensis by the fourth day; regenerative processes involving the basal cells and selective cellular destruction in the spinous layer and further hair follicle invasion by D congolensis by the ninth day; and proliferative changes characterised by parakeratosis, hyperkeratosis, acanthosis and dermal sclerosis by the 15th day. It is postulated that cattle with hair follicles parasitised by D congolensis are carriers and are responsible for perpetuation of bovine dermatophilosis from one season to the next.

Dermatophilus Congolensis. A Bacteriological, In Vitro Antibiotic Sensitivity and Histopathological Study of Natural Infection in Sudanese Cattle

Dermatophilus congolensis was isolated in culture from 36 of 39 field cases of streptothricosis in cattle in the Sudan. The morphological and cultural characteristics and the in vitro sensitivity of the organism to antibiotics are outlined. The lesions were characterised by thick scab, degeneration of the epidermis and a granulomatous reaction in the dermis.

Subcutaneous infection with Dermatophilus congolensis in a cat

Dermatophilus congolensis was isolated from a chronic inflammatory lesion in a lymph node from a cat. The organism was successfully transmitted to the skin of sheep and laboratory animals where it produced an exudative dermatitis and when injected subcutaneously into a cat an abscess developed. The salient characteristics of the organism and its accompanying pathology are described. This work provides further evidence that, although D. congolensis is usually restricted to the skin, it is capable of producing lesions elsewhere.

Ticks (Acarina, Ixodoidea) of the northern regions of the Somali Democratic Republic

AbstractIn this survey of distribution and prevalence of adult ticks (Acarina, Ixodoidea) parasitising domestic animals in the northern regions of the Somali Democratic Republic, 26 species were identified. The ten most common species were widely distributed withHyalomma anatolicum anatolicumKoch,H. dromedariiKoch,H. erythraeumTonelli-Rondelli,H. impeltatumSchulze & Schlottke andRhipicephalus sanguineusgroup more common in the drier vegetation zones, andH. marginatum rufipesKoch,H. truncatumKoch,R. e. evertsiNeum.,R. pravusDön. andR. pulchellus(Gerst.) more common in the wetter woodland, evergreen and forested zones. Four species,Amblyomma gemmaDön.,A. variegatum(F.),Boophilus decoloratusKoch andR. simusKoch, were confined to the wooded zones above 1200 m altitude. Species collected less frequently wereArgas persicus(Oken),Amblyomma falsomarmoreumTonelli-Rondelli,H. anatolicum excavatumKoch,H. m. marginatumKoch,H. m. turanicumPom.,H. puntHoogst., Kaiser & Pedersen,Ornithodoros savignyi(Aud.),R. armatusPocock andR. longicoxatusNeum.Ambylomma lepidumDön. was represented only by a few specimens introduced on nomadic livestock.Nearly 60% of the total number of ticks collected wereR. pulchellus. This species is considered to be the main vector of Nairobi sheep disease (NSD) virus in northern Somalia. NSD is the most important tickborne disease in sheep and goats and causes considerable economic losses to the Somali livestock industry.A. gemmaandA. variegatumare probably the vectors ofCowdria ruminantium(heartwater) in sheep and goats in the western highlands. These two ticks are also incriminated in the spread ofDermatophilus congolensisinfection (streptothricosis).R. e. evertsimay be the vector ofBabesia motasiin sheep and goats.Boophilus decoloratusis probably the vector ofBabesia bigeminain cattle in the western highlands. Various tick species may be associated with bacterial abscesses of feet and lymph nodes in sheep and goats.

Experimental infection of domesticated animals and the fowl with Dermatophilus congolensis

Rabbits, camels, calves, sheep, goats and donkeys were successfully infected by skin scarification with Dermatophilus congolensis. This is the first time that the camel has been shown to be susceptible to experimental infection. In contrast to the natural disease the lesions did not spread and regressed after 20 to 52 days. The histological changes were scab formation and degeneration, necrosis and micro-abscess formation in the superficial epidermal layer and the hair follicle sheaths. The fowl was refractory to infection by this route. Cutaneous lesions and foreign body granulomas were induced by embedding infected thorns in the skin of calves and rabbits. A tuberculin-type reaction was induced when the organism and Freund's adjuvant were inoculated intradermally. Calves and rabbits injected s.c. and rabbits i.p. failed to develop cutaneous lesions. The i.v. route also failed to produce skin lesions except at the site of injection in rabbits. Various gross internal lesions were observed in calves and rabbits inoculated i.v. and rabbits i.p. An anaphylactic-like reaction occurred in calves repeatedly inoculated i.v. Resistance to reinfection by scarification occurred. The histological changes in internal organs indicated severe inflammatory responses.

Effects of various induced local environmental conditions and histopathological studies in experimental Dermatophilus congolensis infection on the bovine skin

Although localised to the site of inoculation, experimental cutaneous streptothricosis was readily produced on scarified and/or defatted bovine skin infected with nutrient broth cultures of Dermatophilus congolensis. There was no difference in the extent and duration of lesions produced by either method. D congolensis failed to infect intact normal skin. Simulated rainfall and insect bite did not effect spread and production of generalized streptothricosis. On the other hand, localised experimental lesions regressed more rapidly when subjected to simulated rainfall. The histopathological changes were characterised by invasion of hair follicles by the germinating hyphae and mycelia of D gongolensis, accumulation of neutrophilic exudate beneath the infected epidermis, migration of some neutrophils through the epidermis resulting in intra-epidermal microabscess formation and regeneration of new epidermis from follicular sheath epithelium.

Spontaneous dermatophilosis in twin white-tailed deer fawns.

Twin white-tailed deer (Odocoileus virginianus) fawns captured in Morris County, New Jersey, displayed papular, darkly pigmented scabs principally on the skin overlying the nasal bones, dentary, commissure of the lips and ears. Histopathological and bacterial examinations revealed Dermatophilus congolensis. The epidermitis caused by this bacterium apparently had developed within the first 12 to 14 days after birth and had begun to regress by one month of age. The location of the lesions suggested transmission during nursing from an infected doe. This is believed to be the first confirmed report of this zoonotic disease in white-tailed deer, with isolation of the etiologic agent, outside the State of New York. Epizootiological considerations are discussed.

Streptothricosis in the Domestic Donkey (Equus Asinus Asinus). II. Bacteriological and Immunological Relationships of the strains of Dermatophilus Congolensis Isolated

Fourteen Nigerian strains of Dermatophilus congolensis , including seven obtained from donkeys, were compared by cultural and biochemical tests and by means of the agar gel precipitation reaction. No differences related to host origin were found but five serologically different types were identified. The donkey isolates includes three of these types. On compara quatorze races nigériennes de Dermatophilus congolensis , parmi lesquelles sept provenaient des ânes, par des épreuves biochimiques et des épreuves de culture, et en utilisant la réaction de précipitation agar gel. On ne trouva aucune différence alliée à l’origine de l’hôté mais on put identifier cinq espèces sérologiques différentes. Les isolés provenus des anes comprenaient trois de ces espèces. Vierzehn nigerische Stämme von Dermatophilus congolensis , einschliesslich 7 von Eseln gewonnen, wurden verglichen mit Hilfe von Kulturund biochemischen Tests und der Agar-Gel-Praezipitations-Reaktion. Man fand keine den Ursprungswirten entsprechende Unterschiede; doch wurden 5 serologisch verschiedene Typen identifiziert. Bei den von Eseln gewonnenen Erregern fanden sich 3 dieser Typen. Se compararon catorce cepas nigerianas de Dermatophilus congolensis , incluyendo siete obtenidas de burros, mediante pruebas de cultivo y bioquímicas así como por la reacción de la precipitación de la gela de agar. No se encontraron diferencias relacionadas al huésped de origen pero se identificaron cinco tipos serológicamente distintos. Los aislamientos del burro incluyeron tres de estos tipos.

Perinatal lamb mortality in Western Australia. 4. Neonatal infections.

SummaryInfection was found in 14.5% of dead lambs classified as delayed or late post‐parturient deaths or in 7.5% of the 4,417 lambs autopsied. Eighteen species of bacteria were isolated from these acquired neonatal infections. Many infections resulted from umbilical contamination at birth, some by ingestion, some were superimposed complications upon an already existing condition such as starvation, others occurred as post‐marking sequellae. Neonatal infections were divided into hebdomadal (first week) and post‐hebdomadal (7 to 28 days). The microorganisms isolated from hebdomadal deaths were Cl. septicum, C. pyogenes, Staph, aureus, Past. haemolytica, Past, multocida, and E. coli, from post‐hebdomadal deaths Staph, aureus, F. necrophorum, C. pyogenes, Corynebacterium spp, E. coli, Cl. septicum, Cl. perfringens, Past, haemolytica. Streptococcus spp, pleomorphic gram‐negative rod, A. lignieresii, Dermatophilus congolensis and miscellaneous species. It was estimated that acquired neonatal infections were responsible for one‐thirteenth of the perinatal lamb deaths in the agricultural area of Western Australia or for approximately 1% of births.

Dermatophilus congolensis Chronic Nodular Disease in Man

Dermatophilus congolensis is a common infectious agent among animals. However, infectivity in man has only rarely been observed. We report the association of D. congolensis with a chronic nodular disease in an 8-year-old boy. The time of exposure to the organism was unknown but may have occurred in utero. Testing of the immunologic system reveals a deficiency of B-lymphocytes bearing Fc receptors as well as impairment of lymphokine production. It is possible that an immunologic deficiency has permitted a chronic infestation with D. congolensis in a manner similar to that described for some cases of chronic mucocutaneous candidiasis.

A Comparative Serological Study of Dermatophilus Congolensis Antigens Prepared by Different Methods

SUMMARY Dermatophilus congolensis antigens, prepared by three different methods, were tested by the agar-gel diffusion and indirect haemagglutination techniques against known positive antisera. The results indicate that the most effective and economical method of antigen preparation consists of concentrating the supernatant fluid obtained from a six-day-old nutrient broth culture of the organism.

Pitted Keratolysis and Dermatophilus congolensis

Pitted keratolysis is a multifocal superficial erosion of the stratum corneum, usually limited to the soles of the feet. A causative agent has been described previously, but its identity is unclear. While studying a lesion of pitted keratolysis, we found an actinomycete with the morphologic appearance of<i>Dermatophilus congolensis</i>, the cause of dermatophilosis in animals. From our study of this case and from a review of the literature we believe that<i>D congolensis</i>was a causal factor in this lesion and that it was probably the causative agent of some cases of pitted keratolysis described previously.

Bacteriology of Nigerian strains of Dermatophilus congolensis.

Fifty-three strains of “Dermatophilus congolensis” were isolated from lesions of streptothricosis from 36 cattle, 11 sheep, 4 goats and 2 horses in Nigeria. The bacteriological characteristics of these strains were identical to those of the strain isolated from lesions of mycotic dermatitis from a Scottish sheep.

Ultrastructure of the Actinomycele Ceodermatophilus Obscurus

Geodermatophilus, a new generic taxon of the Dermatophylaceae (Actinomycetales), was first described by Luedemann and shown to display close similarities to Dermatophilus congolensis, previously described in our laboratory.Although Geodermatophilus has been studied by electron microscopy, the present investigation was undertaken to clarify further some ultrastructural aspects of this organism in relation to those of D. congolensis. Standard procedures for chemical fixation, as well as recently developed methods for physical fixation, were chosen but the present report is concerned only with results of thin sections. Cells from 16 hr. to 15-day-old cultures, in the medium described by Luedemann, were fixed with cacodylate buffered glutaraldehyde followed by osmium tetroxide in veronal acetate buffer, or according to Kellenberger et al. Dehydration was in ethanol and embedding in Epon 812.

Pathogenicity of Dermatophilus and Geodermatophilus.

Cutaneous infection in laboratory animals could not be induced with any of several strains of Geodermatophilus. A model for consistent production of streptotrichosis in rabbits, with cultures of Dermatophilus congolensis, is presented.

Dermatophilosis in owl monkeys.

Dermatophilosis was diagnosed in recently imported owl monkeys (Aotustrivirgatus). Characteristic papillomatous, exudative lesions were present on the skin of all the legs, the tail, back, ears and head of 1 animal. Similar, isolated lesions were noted on another animal. Dermatophilus congolensis was easily detected on Giemsa-stained smears from skin crusts of both animals. The organism was also isolated on brain-heart infusion agar. A characteristic histologic reaction, with typical organisms, was noted in a skin biopsy. The skin lesions regressed approximately 1 month after initial symptoms. The disease was experimentally transmitted to 3 other species of monkeys: rhesus (Macaca mulatta), cynomolgus (Macaca fascicularis) and squirrel monkeys (Saimiri sciureus). These experimental infections also regressed spontaneously.

An outbreak of contagious pustular dermatitis associated with Dermatophilus congolensis infection.

Abstract Extract Professional opinion was sought by a Taupo district farmer when he noticed what he took to be advanced cases of scabby mouth amongst one group of 3- to 4-month-old Romney lambs. These affected animals, and other groups of clinically normal lambs, had a 1 been “inoculated” with scab-by mouth vaccine by the farmer, at docking time 11 weeks previously. Most grazing on the farm was improved and in good condition after a wet and warm spring. Only the affected group of lambs and their ewes had been grazing on an unusually fibrous pasture.

Mycotic dermatitis in sheep. II. Dermatophilus congolensis and its reactions to compounds in vitro.

Mycotic dermatitis in sheep. II. Dermatophilus congolensis and its reactions to compounds in vitro.