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Biomedical subjects

M M Zaki

Publications and source records attributed to M M Zaki.

At least 19 recordsLinked to original sources
PubMed1981

The isolation of pathogenic fungi and actinomycetes from soil in Egypt.

140 soil samples from the Assiut governorate were examined for pathogenic fungi and actinomycetes. The paraffin-bait technique and a modified sodium citrate-utilizing procedure were used for recovery of Nocardia strains. Five isolations of N. brasiliensis were made by the sodium citrate method while 3 isolates were obtained by the other method. N. gypsoides was isolated for the first time, only the the modified method. It appears that the latter method suppresses to a great extent the growth of saprophytic fungi, hence increasing the possibility of the isolation of Nocardia spp. The effect of keratin enrichment on the isolation of dermatophytes from soil by the hair-bait technique was also investigated. Pretreatment of samples with dog hair or feathers increased the yield of isolates of Microsporum gypseum, Trichophyton terrestre and to a lesser extent, T. mentagrophytes, M. canis was recovered from soil only after its enrichment with dog hair. It is suggested that enrichment with other forms of keratinous material, either separately or in combination, might increase the recovery of keratinophilic fungi from soil.

Egypt↗
PubMed1980

The effect of the herbicide atrazine on rhizosphere microflora of broad bean plants, infested with Fusarium oxysporum f. fabae and Rhizoctonia solani.

The effect of the herbicide atrazine on Fusarium oxysporum f. fabae and Rhizoctonia solani, the causative agents of wilt and rot, respectively, as well as rhizosphere microflora of broad bean plants was studied. The herbicide was applied at intervals of 30, 20, 10, and 0 days before sowing. Atrazine application reduced both densities and per cent of infection of these two pathogenic fungi, R. solani, however, was sensitive to atrazine itself, while F. oxysporum was affected by atrazine by-products. Rhizosphere flora, i.e., total microbial flora, actinomycetes, phosphate-dissolving bacteria, and fungal flora, were not affected by atrazine, but were deleteriously reduced by its by-products at early stages of plant growth. However, rhizosphere flora attained the normal levels after atrazine by-products had completely disappeared from soil (1 month after application), except for actinomycetes. Therefore, it is recommended to apply atrazine within 20 days before sowing for weed control as well as for controlling wilt and root rot infestations.

Actinomycetaceae↗
PubMed1979

Changes in metabolic activities of Fusarium oxysporum f. fabae and Rhizoctonia solani in response to Dithan A-40 fungicide.

The effect of different concentrations of Dithan A-40 fungicide on the metabolic activities of the wilt fungus Fusarium oxysporum f. fabae and the root rot agent Rhizoctonia solani was studied. All toxicant concentrations reduced energy generation, total phosphorus and nitrogen content of both fungi. In addition, the toxicant caused a shift in free amino acids pool. As a result of these changes, the mycelium dry weight of both fungi was greatly reduced. R. solani was more sensitive to the toxic effect of Dithan A-40 than F. oxysporum.

Amino Acids↗
PubMed1979

Factors affecting the microbial and chemical composition of silage. IV. Effect of wilting on maize silage.

The effect of wilting on the microbial and chemical composition of ensiled maize plants was studied. Wilting stimulated high densities of lactic acid bacteria, with the decrease in counts of undesirable flora, i.e., yeasts, moulds, proteolytic and saccharolytic anaerobes, causing spoilage of silage. Moreover, wilting decreased the losses of dry matter, total acidity, and butyric acid content of silage. Accordingly, wilting proved to be a favourable treatment for the production of good quality silage from maize plants.

Acids↗
PubMed1978

Factors affecting the microbial and chemical composition of silage. III. Effect of urea additions on maize silage.

The effect of urea additions on the microbiological and chemical properties of silage, produced from young maize plants (Darawa stage), was studied. Urea treatments, i.e., 0.25%, 0.50%, 0.75%, and 1.00%, stimulated higher densities of the desired microorganisms than the control, while undesired organisms showed lower counts (proteolytic and saccharolytic anaerobes). Addition of 0.25 to 0.50% or urea resulted in the production of high quality silage with pleasant small and high nutritive value, as confirmed by the various microbiological and chemical analyses conducted. Higher levels (0.75 and 1.00%) of urea decreased the quality of the product.

Animal Feed↗
PubMed1976

Relation between the toxogenicity and pyogenicity of Corynebacterium ovis in experimentally infected mice.

Suspensions of Corynebacterium ovis subjected to physical and chemical treatment failed to kill inoculated mice but were able to produce sterile pyogenic lesions. It appears that the exotoxin is different from the pyogenic factor and that the latter is attached to a heat-stable substance in the bacterial cell. Mice immunised with antitoxin showed local non-spreading lesions when subsequenly inoculated with washed C ovis cells while unprotected control mice showed a spreading type of infection when similarly injected. Antitoxin did not prevent the formation of pus but hindered the spread of infection from the site of inoculation to the internal organs.

Animals↗