Antistaphylococcal metabolite from Aureobasidium pullulans: production and characterization

NE Kalantar, RL Deopurkar, BP Kapadnis

 

Abstract

Aureobasidium pullulans (NI.3) isolated from the leaves of Dracaena reflexa variegate produced intracellular antimicrobial metabolite the yield of which was 700-800 U from about 0.7-0.85 g of dry biomass. The antistaphyloccocal metabolite showed strong activity against different Staphylococcus spp. The MICs ranged from 1.25 to 3.6 U/ml. The metabolite was only moderately sensitive to temperature. After keeping at 400C and 700C for one hour it lost only 20% and 60% of its activity respectively. However, it was completely inactivated upon exposure to 1210C for 20 min. The antistaphyloccocal metabolite was insensitive to various protein-denaturing detergents and enzymes like trypsin, proteinase K, lipase and lysozyme. The activity was fairly stable over a wide range of pH (5.7–8). When S. aureus was grown in the medium in presence of antimicrobial metabolite (10 U/ml) the number of CFU started to decrease. However, most of the cells had lost their viability after nine hours exposure. A slower killing of the S. aureus was noted when cells were kept in buffer containing antimicrobial metabolite (5 U/ml). Antimicrobial metabolite induced efflux of potassium ions from cells of Staphylococcus indicating the channel forming activity.

KeywordsAureobasidium, antistaphylococcal activity, potassium efflux

African Journal of Clinical and Experimental Microbiology Vol. 6 (3) 2005: 177-187

Species of fungi associated with skin diseases of different age groups in plateau state, Nigeria

AO Ogaraku, CIC Ogbonna, VC Nwokedi

 

Abstract

A survey was carried out on the species of fungi associated with skin diseases of thirty subjects of different age groups in Plateau State, Nigeria. The age groups included 1-10, 11-20, 21-30, 31-40 and 41-50 years, accounting for 27%, 38%, 23%, 8% and 4% of total number of individuals with fungal infections respectively. The skin diseases involved included ringworms, dermatitis, burns, impetigo and boils. The fungal isolates included Microsporium canis, M. audouinii, M. ferrugineum, Trichophyton mentagrophytes, T. megninii and Aspergillus niger, with frequencies of occurrence in the skin lesions being 80%, 60%, 40%, 60%, 60% and 20% respectively. The implications of the results are discussed.

Keywords: fungi, skin disease, age groups, Plateau State

African Journal of Clinical and Experimental Microbiology Vol. 6 (3) 2005: 188-191

Effect of trypanosoma congolense and Trypanosoma brucei mixed infection on the pattern of haematological changes in murine trypanosmosis

JN Abenga, SA Sands, OGC Ezebuiro

 

Abstract

The effect of Trypanosoma congolense and T. brucei mixed infection on the pattern of haematological changes was demonstrated in a rat model. At the end of 21 days post infection (PI), anaemia which was characterised by drop in the packed cell volume (PCV), was found to be significantly (P<0.05) severer in rats with mixed infection than those infected with T. congolense or T. brucei. Similar pattern of drop in the total white blood cell (WBC), differential WBC, and platelet counts was observed in the group with mixed infection. It was concluded that even though T. congolense and T. brucei may cause milder haematological changes in animals compared to T. vivax, mixed infection by these parasites may cause severer haematological changes in the natural hosts.

Keywords: mixed infections, pattern of haematological changes, rats, Trypanosoma congolense, Trypanosoma brucei

African Journal of Clinical and Experimental Microbiology Vol. 6 (3) 2005: 193-197