Oral microbiota associated with gingiva of healthy, gingivitis and periodontitis cases.

Oral microbes coexist with each other in a symbiotic relationship or as commensals in healthy body. Teeth and oral cavity harbor diverse community of fungi and bacteria. This study focused on bacterial and fungal component of gingiva, where the last occupy little attention. In addition to study the antimicrobial activity of toothpastes, mouth washes and natural oils against microorganisms. Sixty swabs from outer surfaces of gingiva in healthy persons, as well as patients complaining of gingivitis and periodontitis were collected for fungal and bacterial analyses. Sensitivity of the isolated microorganisms to some pharmaceutical preparations and natural oils was also performed. Ten fungal and 9 bacterial species were identified. There is a highly significant variation in the frequency of Klebsiella pneumonia among healthy, gingivitis and periodontitis. Also, Candida tropicalis and cocci bacteria showed significant diversity among the three tested groups. Among pharmaceutical preparations (toothpastes and mouth washes) and natural oils, Paradontax, Hexitol and clove oil showed the best antimicrobial activity against tested fungal and bacterial strains. Although, minimum inhibition concentrations (MICs) of clove oil were high compared to Paradontax and Hexitol, nevertheless, it is highly recommended as both antifungal and antibacterial agent against oral pathogenic microorganisms, because it is a natural compound and nearly devoid of side effects.

Controlling Alternaria cerealis MT808477 Tomato Phytopathogen by Trichoderma harzianum and Tracking the Plant Physiological Changes.

Plant responses during the pathogen infection and the pathogen control reflect its strategies to protect its cells. This work represents the Alternaria cerealis MT808477 as a phytopathogen causing leaf spot disease in tomatoes. A. cerealis was identified morphologically and genetically by 18SrRNA, and its pathogenicity was confirmed by light and scanning electron microscopy. Trichoderma harzianum has the ability to control A. cerealis MT808477 by stimulating various cell responses during the controlling process. The cell behavior during the biological control process was observed by analyses of total phenol, flavonoids, terpenoids, antioxidant, malondialdehyde and antioxidant enzymes (catalase and peroxidase). The extracts of infected tomato leaves were tested against plant and human pathogenic microorganisms. Results showed that the biological control process activates the defense cell strategies by increasing the plant tolerance, and activation of plant defense systems. The total phenol, flavonoids, terpenoids, antioxidant and malondialdehyde were increased after 48 h. Catalase and peroxidase were increased in infected tomato plants and decreased during the biological control process, reflecting the decrease of cell stress. Leaves extract inhibited the growth of nine plant and human pathogenic microorganisms. Biological control represents a safe and effective solution to phytopathogens that decreases plant cell stress by stimulating various defensive agents.

Molecular characterization of Mucor circinelloides and Rhizopus stolonifer strains isolated from some saudi fruits.

Thirteen strains of Mucor circinelloides and nine strains of Rhizopus stolonifer were collected from different Saudi fruits. Also, two strains of M. circinelloides and one strain of R. stolonifer isolated from soil were used in this study to analyze the genetic diversity among these 25 strains. The dendrogram constructed from random amplified polymorphic DNA-polymerase chain reaction results using two primers (V6 and M13) showed no correlation between clustering system and sources of isolation for M. circinelloides strains, while Rhizopus strains clustered according to the sources of isolation. The phylogenetic tree based on the unweighted pair group method with arithmetic average of internal transcribed spacer (ITS) rDNA sequence revealed the variation of the ITS region among Mucor strains as well as Rhizopus strains.