Enteropathogenicity of Bacillus cereus isolated from some Nigerian foods.

BACKGROUND: Bacillus cereus is a soil bacterium and has been isolated from cooked and uncooked rice, milk and dairy products, meat, spices, garlic, vegetables, cereals and infant formulae. OBJECTIVE: To report on the enteropathogenicity of B. cereus isolated from Nigerian foods. METHODS: Forty-five Bacillus cereus isolates classified as diarrhoeal and emetic strains were assayed for enterotoxin production. Thirty extractions were from diarrhoeal strains and 15 from emetic strains. RESULTS: Forty-five Bacillus cereus isolates classified as diarrhoeal and emetic strains were assayed for enterotoxin production. Of the 30 toxin extractions from B. cereus classified as diarrhoeal strains, 18 (60%) gave positive ileal-loop reactions, while 15 toxin extractions from emetic strains of B. cereus gave negative ileal-loop reactions. CONCLUSION: The work has demonstrated the distribution and toxigenicity of B. cereus in various Nigerian foods. An appreciable number of Nigerian food isolates are capable of causing diarrhoea. Forty percent of the enterotoxigenic isolate were mild to severe enterotixin producers, with 31% mild, 6.7% moderate and 2.2% severe.

Single-drug chemotherapy of canine transmissible venereal tumor with cyclophosphamide, methotrexate, or vincristine.

During a 21-month period, 48 dogs with spontaneous canine transmissible venereal tumor (clinical stage, T1-T3) were presented to the Veterinary Teaching Hospital, Ahmadu Bello University, Zaria, Nigeria, and were divided into one control and four treatment groups to test the efficacy of single-agent chemotherapeutic drugs. The dogs were not randomly assigned to groups because each chemotherapeutic agent was not continuously available during the test period. Group I consisted of four dogs that received oral cyclophosphamide (50 mg/M2 body surface area [BSA]) on the first four days for six weeks. No therapeutic response was noted in any of the four dogs. Group II consisted of ten dogs that received intravenous (IV) cyclophosphamide (50 mg/M2 BSA) for four consecutive days per week for six weeks. Two of the ten had a partial remission. Group III consisted of eight dogs that received oral methotrexate (2.5 mg/M2 BSA) every other day for six weeks. No therapeutic response was noted in any of the eight dogs. Group IV consisted of 20 dogs that were administered IV vincristine sulfate (0.5 mg/M2 BSA) weekly until a response was noted. Complete remission occurred in each of the 20 dogs. One dog had recurrence within 12 months. Group V was the untreated control group, consisting of six dogs among which no spontaneous remission was seen. Instead, tumor progression was noted. Adverse responses to medication, anorexia, vomiting, diarrhea, and weight loss were seen only with dogs treated with cyclophosphamide and methotrexate.

Viral-like particles associated with naturally occurring transmissible venereal tumor in two dogs: preliminary report.

Naturally occurring canine transmissible venereal tumors in 2 dogs were examined ultrastructurally, using a transmission electron microscope. Typical nondegenerating cells of various shapes with normal cytoplasmic organellae were seen. Degenerating and necrotic cells characterized by loss of normal organellae with vacuolations of the cytoplasm were in all sections studied. Icosahedral electron-dense particles (22 nm diameter) were in the degenerating and necrotic cells. The uniqueness of this finding is not known. The shape and size of the particles indicate that there may be viral involvement.