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Background Many drugs have been restricted in the treatment of gastric ulcers (GU). So, herbal medicines are now in great demand for their better cultural acceptability, compatibility, and minimal side effects. Therefore, our study aimed to assess the protective efficacy of Aloe vera gel and Geranium robertianum extracts against Aspirin®-induced GU in Wistar rats. Methods Antioxidant activity and chemical composition of both herbs were analysed. Then, we divided forty female Wistar rats into five groups: a negative control group, a positive control group of Aspirin®-induced GU, and pretreated groups with Aloe Vera, geranium, and Famotidine (reference drug). The locomotor disability, anxiety-like behaviour, and ultrasonography were assessed. Ultimately, scarification of animals to determine gastric juice pH and ulcer index. Then the collection of stomach and liver for histopathological and immunohistochemical examinations, besides tracing the oxidative stress biomarkers and related genes. Results High content of polyphenols was revealed in both extracts. The pretreatment with Aloe vera gel and geranium showed significant antioxidant activities with free radical scavenging and ferric-reducing power (FRAP). Moreover, they improved the stomach architecture and alleviated anxiety-like behaviour and motor deficits. They significantly reduced the expression of proinflammatory cytokine (TNF-α), inflammatory, and oxidative stress genes (NF-KB, HO-1, Nrf-2) while increasing the Keap-1 in gastric mucosa. Conclusion Data presented a significant protective effect of Aloe vera gel and geranium against Aspirin®-induced GU; they reduced gastric mucosal injury with potential anxiolytic effects through their anti-inflammatory and antioxidant properties. Therefore, they may be considered promising agents for preventing or treating gastric ulceration.

Although the understanding of the mechanical properties and fracture behaviour of bone is continuously improving, as yet it's far from complete. So, this paper represents an experimental study about the effect of static and dynamic loads under different parameters on intact bone and human hip joints. The same test will be applied on the human hip joints after insertion of the artificial femur component in the bone. A special test-rig was designed in order to fix both natural and artificial implant and expose them to a state of loading similar in magnitude and direction to that encountered in the human-being.A comparison between the stress-strain distribution of the intact and artificially implanted bones were conducted by using strain gauges. The results showed that the stresses were reversed after insertion of the artificial femoral component and the stresses were maximum at the near of the tip of the prothesis. Also, the absence of the collar-calcar causes a severe reduction of the stresses which may be due to important metabolic changes.

THIS STUDY aimed to evaluate the efficacy of applying spores and chitinase enzyme of Streptomyces parvulus strain 10d in biological control of damping-off disease caused by Rhizoctonia solani in green beans (Phaseulus vulgaris) and compare it with Rhizolex fungicide application. Five seeds of green bean were sown in plastic pots, filled with either sterilized or non-sterilized soils, infested with R. solani inoculum (5g/kg soil). Pots were kept in the greenhouse for 45 days from sowing. Pre-emergence damping-off was recorded 15 day from planting and post-emergence damping-off and survival rate were recorded 30 days from planting. Plants growth characteristics were recorded 45 days of sowing.Results showed that Rhizolex treatment had the best survival rate and lowest root–rot severity (79 and 25%), followed by crude enzyme treatment (76 and 25%), then spores’ treatment (75 and 27%, respectively), in infested and non-sterilized soils.For plant growth characteristics, in infested and non-sterilized soil, spores’ treatment had the best effect on plant height (41.5cm), followed by crude enzyme (39.5cm) and Rhizolex treatments (34.6cm). Numbers of leaves/plant were the highest in Rhizolex (17), followed by spores (15) and enzyme treatments (14). Numbers of pods/plant were 14 in Rhizolex treatment and 11 in crude enzyme and spores’ treatments. The highest dry weight was recorded in spores’ treatment followed by Rhizolex treatment (10 and 7 g/plant, respectively). Conclusions: results suggest that using chitinolytic Streptomyces strain 10d for the biological control of R. salani and damping-off disease of green bean plants can be an attractive alternative for pesticides in organic agriculture.

The quail populations are considered to be one of the largest among the poultry species. Although quail egg and meat production are growing rapidly, still, quail farming practices and welfare aspects are not well established. Stocking density is one of the factors that can significantly affect the welfare, health, and performance of birds, but according to The Expert Group for Technical Advice on Organic Production, no allowed space standards have been reported for new hybrids and different breeds of quail. This review presents an overview of 1) the benefits of egg and meat of quail, 2) the global market of quail products, 3) the factors affecting the stocking density rate, and 4) the effects of stocking density rates and housing systems on the social behavior, welfare, physiological indices, and performance parameters of broiler and laying quail. Conclusively, larger space and enriched aviaries reduce aggressive behavior, and improve the quail welfare and immunological indices. However, the effect of stocking density on some blood biochemical indices and growth performance parameters showed mixed results. A better understanding of the relationship between housing, health, growth performance, and welfare aspects would assist in the implementation of welfare-economic standards for quail production. According to available data, stocking density ranges for broiler and laying Japanese quail are suggested; however, these stocking rates should be tested under different conditions.

Infectious bronchitis virus (IBV) affects both vaccinated and unvaccinated flocks worldwide, with a significant impact on the poultry industry. The aim of the present study is to characterize an emerging variant pathogenic IBV originating from field outbreaks in vaccinated Egyptian layer flock. Samples were collected from disease-suspected flock with a history of administration of live and inactivated IBV vaccines (Ma5 type). Virus propagation in embryonated chicken eggs (ECEs), after three successive passages, revealed typical IBV lesions such as curling and dwarfism. The reported isolate was identified by a real-time reverse transcriptase PCR assay targeting nucleocapsid (N) gene and, further characterized by full-length spike (S1) gene sequencing. Phylogenetic analysis revealed clustering of the isolated virus within 4/91 genotype of GI-13 lineage. Deduced amino acid sequences identity revealed 75–76% and 88–90% similarity with the currently used classic (H120, Ma5, and M41) and variant vaccine strains (4/91 and CR88) in Egypt, respectively. Recombination analysis gave an evidence for distinct patterns of origin for the studied isolate providing another example of intra-genotypic recombination among IBVs and the first example of recombination within the GI-13 lineage in the Egyptian field. The studied isolate (IBV/CK/EG/Fadllah-10/2019) emerged as a result of recombination between the variant group (Egy/var I genotype, GI-23 lineage) as a major parent and the CR88 variant vaccine strain (4/91 genotype, GI-13 lineage) as minor parent. Our data suggest that both mutation and recombination may be contributing to the emergence of IBV variants which ascertain the importance of disease monitoring in vaccinated flocks as well as re-appropriation for the current vaccine strategies. Electronic supplementary material The online version of this article (10.1007/s11262-019-01693-9) contains supplementary material, which is available to authorized users.

Parasitic isopods have received considerable attention as they cause series impacts on their hosts either alone or with other environmental stresses such as water pollution. The present study investigated the infestation status with isopods among the fry collected from the natural sources .Also to demonstrate the effects of different salinity and temperature combination on the survival rates of the identified isopods under the laboratory conditions. In March 2017,a total of 16 thousand mugiliid fry were sampled from The Fry Collection center at Al Behera Governorate ,Egypt and examined for the presence of isopods .Samples were found infested with a rate of 10.6% , the result which practically documented that isopods were introduced into lake Qarun through dumping millions of infected fry from this source without biosecurity procedures. The isolated juvenile isopods were morphologically and molecularly identified as Livoneca redmanii species by using 16S rRNA gene and recorded in the GenBank with accession number: MK584629. The effects of variables of salinity/ temperature combination on the survival% of the identified juveniles showed that the best survival rate(100%) was recorded in salinity 15 -20% at temperature 25⁰C while the lethal combination was in salinity 10, 20,50 and 60% at temperature 35⁰C . Statistical analysis using A-two way ANOVA indicated a significant interaction between the effect of different degree of temperature and variance of salinity% on the survival of L. redmanii juveniles. Analysis of one way ANOVA indicated that the most effective temperature of overall mean temperature affected on survival of juvenile stage was 35 C⁰ while the most effective salinity percentage on survival of Juvenile from overall mean of salinity % was 10%. Results of this study provided applicable procedures which can be recommended as a precaution measures and for eliminating the isopod juvenile stages among the mugiliid fry.

Background: The tertiary system of nucleotide chain (NC) - gold nanoparticles (NPs) - carbon nanotube (CNT) represents a great interest in the modern research and application of the bio-nano-technologies. The application aspects include, for example, the development of electronic mobile diagnostic facilities, nanorobotic design for a drug delivery inside living cell, and so on. The small NC chain represents an important stage in the understanding of the interaction mechanism of a full DNA or RNA molecule with NP and CNT. In this regard, one has to mention the development of the DNA-CNT devices for the purposes of diagnostic applications in the chemical or drug delivery. Methods: For the NC-NP-CNT system, we have built up a series of the molecular dynamics (MD) models with different NC-NP configurations and performed their MD analysis. The entire system (the NC chain, gold NPs and CNT) was allowed to interact with each other by the only VdW forces. The Lennard-Jones short-ranged interaction was assumed between the NC, NP and CNT. For the CNT a many body Tersoff potential having a quantum-chemistry nature was used. So far, the so-called hybrid MD approach was realized, where the quantum-chemistry potential in combination with a classical trajectory calculation applied . Results: The peculiarities of the NC-NP interaction and bond formation inside of a CNT matrix were investigated along with the structural and dynamical behavior. The correlation effects between the weak Van der Waals (VdW) forces and intramolecular vibrations were enlighten for the molecular system consisting of a small nucleotide chain (NC), gold nanoparticles (NPs) and carbon nanotube (CNT) using molecular dynamics (MD) simulation method. Conclusion: The NC intermolecular motions were estimated from MD data thereby building the distance distributions, the angular and dihedral (torsional) bond energy graphs versus simulation time at different temperatures from T=100 K up to 300 K. The MD simulation results have shown that depending on the relative NC-NP position a different scenario of bonding between the NC-NP, within CNT matrix, is possible. We have observed the possibilities of formation of weak, strong and intermediate bonds between the NP-NC, which are overestimated by a presence of CNT matrix as confined environment. The NC chain can form with a particular gold atom a close contact, while with another under the same positional and temperature conditions the weak resultant bonding formation might be possible. We estimated the fluctuations in the NP-NC bonding processes for a single gold atomic case (models 1-3, NC-1NP-CNT), for the two (model 4-6, NC-2NP-CNT) and three (model 7, NC-3NP-CNT) gold particle ones. Thus, a concurrent effect between the NC intramolecular vibrations and a weak VdW interaction between the NC and gold NP were studied in detail.

Skin wounds are the most prevalent daily affections intruding fishes in an aquaculture facility. Such skin affections are considered to be the most common portals of entry for disease agents affecting fishes. This persistent phenomenon necessitates a comprehensive search for an efficient healing therapy to combat the ongoing dermal damage and its pathological consequences. In the current study, the core hypothesis has been vigorously tested through the experimental application of hemodialysate (Solcoseryl®) solution in several exposure methods including bath, intraperitoneal (I.P.), intramuscular (I.M.), and local infiltration routes. All tested routes were capable of inducing different degrees of healing in Nile tilapia (Oreochromis niloticus). The core hypothesis of the current research has been experimentally accomplished through assessing the resultant healing degrees based on both gross as well as tissue alteration dynamics among total of 5 experimental groups. Each group consisted of 10 fishes/aquarium. The swift tissue healing of the induced wounds in Nile tilapia were completely achieved 4 days post I.M. injection of the Solcoseryl® solution (10 μl/50 g fish as a single dose) with an excellent healing grade (+++++). However, bath treatment (1 ml/Lwater as a single dose) and local infiltration (10 μl/50 g fish as a single dose) have proved to be second on the race (complete healing was achieved 6 days post treatment with very good grade (+++)). This study demonstrates the clinical value of fish models in establishment of new approach for combating prevalent invasive skin affections in aquaculture.

Mass mortalities of angelfish eggs accompanied with very low hatchability were reported in a private ornamental fish farm in Egypt. Examined eggs were badly damaged by water mould that was decisively confirmed as Saprolegnia species. Presumptive identification of the ten retrieved isolates was initially suggestive of Saprolegnia species. Mycological investigations have revealed that only 7 out of 10 isolates were capable of producing sexual stages. Therefore, using molecular tools such as PCR coupled with partial sequencing of inter-transcribed spacer (ITS) gene was one of the most important approaches to distinguish Saprolegnia parasitica from other water moulds. The sequences of ITS gene data derived from eight isolates showed 100% similarity with S. parasitica ATCC90312 sequence and the remaining two isolates were different in one nucleotide (99.9%). The phylogenetic analysis of ITS genes grouped the ten isolates with other S. parasitica in one clad. Further, to control such fungal infection, the efficacy of povidone iodine as surface disinfectant for angelfish and their fertilized eggs were tested. By trial, it was obvious that the obtained post-rinsing results were highly suggestive for the efficacy of povidone iodine as an efficient antifungal disinfectant for both fish and eggs.

Globalization of the trade in agricultural commodities has contributed signii¬cantly to the discussion about potential hazards involved and has increased in particular the awareness of mycotoxins. Safety awareness in food and feed production has also risen due to the simple fact that methods for testing residues and undesirable substances have become noticeably more sophisticated and more available at all points of the supply chain. Mycotoxins comprise of a family of fungal toxins, many of which have been implicated as chemical progenitors of toxicity in man and animals. There are four classes of mycotoxins of major concern namely aflatoxins, zearalenone, ochratoxins, and fumonisins. Formation of mycotoxins varied betweenspecies as well as within a given species. A variety of physical, chemical, and biological methods to counteract the mycotoxin problem have been reported, but large-scale, practical, and cost-effective methods for detoxifying mycotoxin-containing feedstuffs are currently not available. Detoxii¬cation strategies for the contaminated foods and feeds should be done to reduce or eliminate the adverse actions of mycotoxin to improve food safety and prevent economic losses. The most recent approach to the problem has been the addition to the animal's diet of nonnutritive sorbents that sequester mycotoxins, reduce their gastrointestinal absorption and avoiding their toxic effects on livestock and toxin carryover into animal products. This review comments on the potential hazards of several mycotoxins together with prevention strategy for fungal and mycotoxin contamination. Key words: Mycotoxins, detoxification, aflatoxins, zearalenone, ochratoxins, prevention.

Global climatic change, as defined by the U.S. Global Change Research Act of 1990 (GCRA), “means changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life”. Climatic changes are the most drastic variables interacting with all live aspects of the world's development equation. Global warming, melting glaciers, sea level rise with increased coastal erosions, increased rate of lake evaporation, green house effects, increased ocean acidity, increased rates of biological invasions and deteriorated biodiversity are the interacting variables. There is a very clear fact that climatic change is not a country made product, however, it is a trans-continental issue. The abrupt surge in the catastrophic consequences of climatic changes was primarily derived from the hydrologic changes in global water that gradually moved forward toward the land. This fact puts the aquatic species on the top list of the most impacted creatures. As an ideal example for the regional impacts of global climatic changes, the coastal zones of the Levantine Mediterranean Sea at the basins of countries like Egypt, Israel and Lebanon are on an ongoing process of continuous coastal land erosions with subsequent fisheries recession due to critical damage of the breeding habitats of the native fishes at such pristine areas of the world. Further, the historical opening of Suez Canal in 1869 was a triggering force behind the development of many ecological changes in the Levantine Mediterranean as well as the Egyptian territories from the Red Sea basin. Such climatic changes have favoured the move of some invasive species like Rabbit fish and Erythrean mytilid mussel from the Red Sea to the Mediterranean Sea with their consequent huge negative impacts on the native biodiversity of the southeast Mediterranean. Other detrimental factors that will ultimately lead to great impact on the aquatic biodiversity are the inland aquaculture, eutrophication; aquatic habitat destruction and fragmentation. Thus, without a real creative international initiative to save the world's ecosystem from the colossal destructive effects of climatic changes, there will be possible endangering effects on all living creatures on planet earth.

Fish, pathogen and environment are three counterparts who are sharing the same circle of life. To keep fish up to their optimal health, environment should be competently improved and pathogen count/virulence should be seized. Using of bioactive immunostimulants to achieve these objectives is the hypothesis under assessment. Thus, the present study was performed to evaluate the use of shrimp shells derived chitosan as an immunostimulant as well as preventive regime against Aeromonas hydrophila infection of Nile tilapia and to assess its antibacterial/aquatic bio-remediating effects. Results achieved by feeding 1% chitosan as preventive/therapeutic regimes have revealed a remarkably enhanced several innate immunological parameters (e.g., Phagocytic activity/index, NBT, Lysozyme activity and ACH50), increased resistance against A. hydrophila and strikingly improved water quality compared to the 0.5 and 2% chitosan containing diets. Conclusively, experimental results suggest the commercial usage of chitosan as an efficient immunostimulant and bio-remediating agent in aquaculture.

The objective of this research was to evaluate the safety of the 6/85 strain vaccine strain of Mycoplasma gallisepticum in turkeys by backpassing the vaccine strain up to 10 times by contact infection in turkeys and challenging turkeys with the resulting backpassaged strain. The vaccine strain, however, did not spread to in-contact turkeys, and it was necessary to reisolate the organism before challenging turkeys for the next passage. The challenge strain, therefore, was one that had been backpassaged four times in turkeys, with a total in vivo time in turkeys of 66 days. The backpassaged 6/85 vaccine strain was no different in pathogenicity than the original vaccine strain, except that at 10 days postchallenge, it was isolated in higher numbers from air sacs. Both the original 6/85 vaccine strain and the backpassaged strain were apathogenic in turkeys, except for a slightly increased diameter of the tracheal mucosa at 10 days postchallenge; at 20 days postchallenge the tracheal mucosal thickness was no different from that of controls.

Pathogenic Candida albicans was isolated from water and fish samples collected during an emergent event of mass mortalities among the juvenile Nile tilapia (Oreochromis niloticus), Sharp toothed catfish (Clarias gariepinus) along the stream of Mariotteya drainage. Investigations indicated that fish mortalities were confined to the area of Shubramant and Aboul Noumros (North to Sakara 7 drainage). C. albicans was isolated from the lesions associated with multiple skin ulcers in both Nile tilapia juveniles and Sharp toothed catfish. Assessment of the field and laboratory data has indicated that Mariotteya environmental disaster was a multifactorial problem. The fish mass kills were initially flared up through the dumping of the improperly treated nasty organic and inorganic chemicals from Elhawamdia sugar factory and municipal sewage. The physical stagnation of the stream, high levels of ammonia, phenol and polycyclic aromatic hydrocarbons (PAHs) and low levels of dissolved oxygen (DO) were all incriminated as the initial stimulus behind biological invasion of pathogenic bacteria (Pseudomonas fluorescence) and yeast (C. albicans). Pathologically, fishes were dying from both respiratory and osmoregulatory failure induced by the severe damage of both gills and skin. It has been implied that such environmental pollutants have direct damaging effects on gills, skin and fins with consequent suppression of the skin’s natural innate components. The adversely confronted immunological barriers were further exacerbated by the possible synergistic interactions of P. fluorescence dermotropic toxins followed by the secondary invasion of the pathogenic C. albicans.

Two HPAI H5N1 viruses were isolated from vaccinated layer and broiler commercial poultry farms in Egypt at years 2011 and 2013; respectively. By phylogenetic analysis, the viruses fall into two genetically diverse clades: (i) A/chicken/Egypt/VRLCU67/2011 classified as a variant virus, clade 2.2.1.1; and (ii) A/chicken/Egypt/13VIR3729-4/2013 classified as a classic virus, clade 2.2.1. Cross HI-test confirmed that the reaction between the two viruses is weak; furthermore, it showed the antigenic diversity between viruses belong to different clades and antigenic groups. Antigenic relatedness was calculated between six AI antigens and their antisera representing the different clades and antigenic groups circulated in Egyptian field; including the A/chicken/Egypt/VRLCU67/2011 strain which showed very low R-values with the other viruses’ groups; ranging from 17 % to zero. Results demonstrated the genetic and antigenic diversity of the variant viruses and how can the vaccine seed be a weak point in the vaccination program that could be broken by the drifted viruses antigenically distant from the vaccine strain.

Traditional live Infectious Bursal Disease virus (IBDV) vaccines were thought to have some degree of adverse effect on bursa of fabricous of chickens, which in turn may interfere with antibodies production against other poultry vaccines. In this study, 15 broiler flocks vaccinated against avian influenza (AI) virus were sampled for serum. The flocks have received IBDV vaccination either by the conventional live vaccines or with the new recombinant subunit vaccine. Haemagglutination inhibition (HI) test were carried on sera using different AI antigens. Sera measured by the variant A/chicken/Egypt/VRLCU67/2011(H5N1) isolate showed significant difference (P

Flavobacterium columnare (F. columnare), the dermotropic Gram negative yellow pigmented bacteria was isolated from different sites of skin ulcerations in the Nile tilapia (Oreochromis niloticus) and Nile catfish (Clarias gariepinus) collected from an earthen pond located at an aquaculture station in Sharkiya Province, Lower Egypt during an acute episode of mass kills during the early summer of 2009. An acute infection with F. columnare was behind the emergent event of mass mortalities among both populations. Many of the Nile tilapias exhibited typical signs of hole - in- the head like lesions from which F. columnare together with the myxosporean spore, Myxobolus tilapiae (M. tilapiae) were retrieved. Most of the cohabitating infected Nile catfishes exhibited severe form of saddle back like ulcer. The identities of the retrieved isolates were confirmed using morphological, biochemical and molecular tools. The research lead us to conclude that the two diverse etiological agents (F. columnare and M. tilapiae) under the triggering effect of the abrupt change in the water quality measures (abrupt rise in the water temperature, ammonia, pH, sharp decrease in dissolved oxygen) have synergized together to induce the above mentioned pathology with the consequent reemergence of fish mass mortalities.

A field visit was conducted in March 2002 to identify viruses infecting the faba bean ( Vicia faba ) crop in four governorates (Fayoum, Beni Suef, El-Nobareia and Bihera) in Egypt. A total of 71 faba bean samples with symptoms of viral infection (leaf rolling, yellowing and mosaic) were collected. These were tested at the Virology Laboratory of ICARDA, Syria, for seven viruses using the tissue-blot immunoassay procedure (Makkouk & Comeau, 1994). Specific rabbit polyclonal antisera were used to test for Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus , family Geminiviridae ; provided by H. J. Vetten, BBA, Braunschweig, Germany); for Broad bean stain virus (BBSV, genus Comovirus , family Comoviridae ); for Bean yellow mosaic virus (BYMV, genus Potyvirus , family Potyviridae ) and for Pea seed borne mosaic virus (PSbMV, genus Potyvirus , family Potyviridae ). In addition, three specific monoclonal antibodies were used to detect Faba bean necrotic yellows virus (FBNYV, genus Nanovirus , family Nanoviridae ) (Franz et al ., 1996); Bean leaf roll virus (BLRV, family Luteoviridae ) (4B10; Katul, 1992) and Beet western yellows virus (BWYV, genus Polerovirus , family Luteoviridae ) (ATCC PVAS-647; American Type Culture Collection, Manassas, VA, USA). Serological tests showed that BYMV, an aphid-transmitted and seedborne virus that was identified in 89% of samples tested, was the most common virus. In most of the fields surveyed, BYMV symptoms were noted to occur at high levels (80–100% infection). PSbMV was detected in nine samples (one from Fayoum and eight from Beni Suef); FBNYV was detected in 11 samples (all from Beni Suef). CpCDV, a leafhopper-transmitted virus, was, by contrast, detected in only two samples collected from the El-Nobareia governorate showing leaf rolling, yellowing and stunting. BWYV, BLRV and BBSV were not detected in any of the samples tested. In Egypt, FBNYV, BYMV and PSbMV have previously been reported in faba bean (Makkouk et al ., 1994), but this is the first record of CpCDV affecting faba bean in Egypt. CpCDV is the only member of the Geminivirus that is reported to naturally infect faba bean.

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.

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.

Summary The effect of the fungicide Dithan A-40 and the insecticide Cyolane on rhizosphere and soil microflora of broad bean plants cultivated in artificially infested soil with Fusarium oxysporum f. fabae was studied. F. oxysporum inoculation depressed the total microbial flora, actinomycetes and phosphate dissolvers while stimulated total fungi and Fusarium spp. in rhizosphere and soil. Application of Dithan A-40 or Cyolane, in general, stimulated different microbial groups except for total fungi and Fusarium spp. However, stimulation was more obvious in Cyolane treatment. Fungal spectra, in turn, showed a considerable sxift in pesticides treatments. Moreover, wilt incidence was significantly reduced in post-emergence infections, especially in Dithan A-40 treatment.

Summary The effect of the organophosphorus insecticide Nuvacron or Dipterex on rhizospherie microflora of broad bean plants infested with Fusarium oxysporum f. fabae or Rhizoctonia solani, wilt and root rot fungi, respectively, was studied. Moreover, influence of these insecticides on wilt and root rot incidence was also included. Soil inoculation with both phytopathogenic fungi proved inhibitory of normal rhizospherie flora. Nuvacron or Dipterex at the two levels applied, initially depressed densities of normal microflora, then counts progressively increased thereafter. The only exception was noted for phosphate dissolvers which showed a vast increase, indicating their activities in the mineralization of these organophosphorus insecticides. Despite the activity of insecticides applied in depressing the densities of Fusarium and Rhizoctonia spp. in rhizosphere only Nuvacron at the levels applied proved being effective in the control of wilt incidence. Unexpectedly, both insecticides significantly increased the spread of root rot disease. It is, therefore, recommended to apply Nuvacron not only for insect control, but also for achieving economic levels of wilt control.

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.

Summary 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 .