Molecular Identification of Rhizosphere Trichoderma spp. and Their Antagonistic Impact Against Some Plant Pathogenic Fungi

The main aim of this study was to molecular identification and determine the antagonistic impact of rhizosphere Trichoderma spp. against some phytopathogenic fungi, including (Magnaporthe grisea) pyricularia oryzae, Rhizoctonia solani and Macrophomina phasolina. Four Trichoderma isolates were isolated from rhizosphere soils of the different host plants in different locations of Egyptian governorates. The morphological characterization of isolated Trichoderma as well as using of (ITS1-5.8S-ITS2) ribosomal gene sequence acquisition and data analyses. By comparing the results of DNA sequences of ITS region, the fungi represented one isolate were positively identified as T. asperellum (1 isolate T1) and one as T. longibrachiatum (1 isolate T2) and two as Trichoderma harzianum (2 isolates T3 and T4). The results showed similarity value of (5.8S-ITS) region sequence of the two isolates, T1 (T. asperellum) and T2 (T. longibrachiatum) of (99%, 99%), respectively. The similarity value of (5.8S-ITS) region sequence with isolates of T3, T4 (T. harzianum) of (99%). On the other side, the results of molecular identification of phytopathogenic fungi represented high similarity value of (5.8S-ITS) region sequence and were identified as P.oryzae, R. solani and M. phasolina (99, 96 and 99%) respectively. Variations and genetic relationships among 4 Trichoderma isolates were investigated by using the Rapid Amplification of Polymorphic DNA (RAPD) profiles using ten random primers. All Trichoderma isolates were assessed for their antagonistic impact on phytopathogens P. oryzae, R. solani and M. phasolina. Though T. harzianum isolates were more affects than T. longibrachiatum and T. asperellum isolates, the percent inhibitory effect among T. harzianum isolates were vary much (44.8 to 91.6%). The inhibitory effect of T. asperellum isolates ranged from 42.2 to (86.0%), while T. longibrachiatum exhibiting affect ranged between (47.5%) to (83.8%)

Cytotoxic effect of Gliotoxin from Candida spp. isolated from clinical sources against cancer and normal cell lines

Background: Invasive fungal infections have become more common during the past two decades. Candida species are the most common human fungal infections. Internal injuries characterize these infections because of virulence factors, such as gliotoxin, which is a fungal toxin that is thought to be antibacterial, antifungal, and antiviral. Objectives: To test the ability of Candida species obtained from clinical sources to produce gliotoxin as a virulence factor and investigate its cytotoxicity effects against some selected cell lines.  Materials and Methods: One hundred and ten clinical isolates of Candida species were obtained from patients attending hospitals in Baghdad from September 2021 to March 2022. They were diagnosed and characterized by routine laboratory methods and cultures. The capability of Candida isolates to secrete the gliotoxin was tested and measured by analytical methods. The cytotoxicity of produced gliotoxin was applied against normal and cancer cell lines. Results: The 110 yeast isolates were diagnosed and identified as follows: Candida albicans, Candida tropicalis, Candida parapsilosis, Candida glabrata, Candida Krusei, Candida kefyr, Candida lusitaniae, Candida rugosa. Twenty-eight Candida isolates showed gliotoxin production. The cytotoxicity effects of gliotoxin were reported against lymphocytes and AMGM and AMJ13 cell lines in different concentrations. The highest cytotoxic effect was noticed in the concentration of 400 µg/mL of gliotoxin. Conclusion: The results indicated that the pathogenicity of Candida was distributed among all ages, both sexes, and several types of sources of clinical isolates. Gliotoxin had an effect on normal and cancer cells. Received: Feb., 2023 Accepted: Aug. 2023 Published: Oct. 202

Effect of leaves Extracts of Duranta repens on growth and activity of some types of Pathogenic Bacteria and Some types of Fungi

A study were conducted to examinate the effect of organic and aqueous (Hot, Cold) Extracts from leaves of Duranta repens on the growth and activities of the following types of Bacteria:- Staphylococcus aureus,Streptococcus pyogens ,Escherichia coli,Klebsilla pneumonia, in addition to the yeast Candida albicans and the fungi Aspergullis niger ,Aspergulls flavus.The result showed that gram Positive Bacteria is more sensitive to the extracts than gram negative bacteria with Minimum inhibitory concentration (MIC) value (50,25,50,100)% and Minimum Bactericidal Concentration (MBC) value (100,50,200,100)% for all types Bacteria respectively . The most active extract against A.niger ,A,flavus was cold and hot aqueous extract from the leaves with diameter growth of colony value of ( 0.93,0.37)cm for A.niger in 20 % concentration compared with organic extract (0.26)cm, and the inhibition zone value of cold and hot extract to A.flavus (0.90,0.80)cm respectively compared with organic extract (7.056)cm