Rafidain Journal of Science

The maximum Percentage inhibition of growth of Aspergillus flavus (which can cause a wide spectrum of diseases ranging from allergic to a life-threatening invasive disease Aspergillosis). P. chrysogenum and P. expansum whose mycotoxins can cause significant health risks ranging from the infections of fruits, vegetables and milk products to immune compromised individuals), by an organic dye (Gentian Violet) were 78.8, 77.7 and 76.6% respectively. While that of inorganic boric acid of (2%) maximum concentrations inhibition were (44.4, 52.2 and 61.1 %) respectively. This results was attributed to the amphiphilic properties of this dye i.e. its high solubility in both aqueous (hyrophilic) and organic (lipophilic) phases and became effective at site in the body (the cell membrane) and it must also be able to reach that sites.

Out of 200 fecal specimens from patients admitted to the various hospitals in Erbil city suffering from acute and persistent diarrhea, it was found that the bacterial pathogens were recovered from 69 patients representing 34.5%. All bacterial isolates were identified by unique features of morphological, cultural, biochemical and serological characteristics. The enteropathogenic Escherichia coli (EPEC) was the most common group isolated from 33(16.5%) of the patients followed by Salmonella, Klebsiella, Enterobacter, Proteus, Morganella in ratios 13(6.5), 7(3.5), 6(3%), 2(1%), 2(1%) respectively. In addition, amplification of plasmid DNA content by antibiotics in some isolated bacterial species has been studied and the results showed enormous increase in plasmid DNA concentrations in amplified cultures of Klebsiella oxytoca, Salmonella and E. coli isolates after treatment with 150 µg/ml chloramphenicol reaching to more than six folds of increase when compared with their concentrations in unamplified cultures. Also, in amplified cultures of other K. oxytoca and E. coli isolates but in presence of 150 µg/ ml tetracycline, the folds of plasmid DNA amplification appear to be in the range of 6.87 to 11.25.

In this study strains of Escherichia coli that isolated from children diarrhoea cases had been improved to produce different enterotoxines, heat stable enterotoxin ( ST ) and heat labil enterotoxin ( LT ) inducing positive responses by biological tests such as suckling infant mouse and rapid skin permeability test ( for ST enterotoxin ) and delayed permeability test of rabbit. ( for LT enterotoxin ) Histological effect of crud culture of Escherichia coli on the mucosal intestine of infant mouse had been studied and showed significant tissue damage .lncluding detachment Exfoliation and sloughing of the surtace epithial cell of mucosa of infat mouse.
These data Supported the idea that the enterotoxin is an important virulance factor in Escherichia coli associated diarrhoea that attak the mucosal intestine of infant mouse and microvilli of it .