ABSTRACT
Background: clostridium difficile [C. difficile] infection is one of the most important diseases in healthcare facilities and community. Ribotypes 027 and 078 are known as hyper- virulent strain of C. difficile in molecular study. PCR-ribotyping is a suitable method to interpret the relation of C. difficile isolated from food and hospital
Objectives: in the present study, the clostridim difficile binary toxin [cdtB] and ribotype pattern evaluated in toxigenic C. difficle isolated from beef
Methods: detection of cdtB in 12 toxigenic C. difficile [encoding tcdA and tcdB gene] isolated from 100 beef samples was determined through PCR. Afterwards, PCR-ribotyping was performed to examine the ribotype patterns of C. difficile
Results: cdtB gene was not detected in any positive isolate. Ten different patterns were observed in 12 toxigenic isolates. No similarity existed in the ribotypes of our study with ribotypes 027 and 078
Conclusions: albeit ribotyp 027 and 078 were not found in our study, the isolation of toxigenic C. difficile with new ribotypes in Iran may indicate the probable hazard of this bacterium in public health. Comprehensive research about C. difficile in different food sources is recommended on a national level
ABSTRACT
Doogh is an Iranian traditional beverage based on yoghurt. In this product, serum separation occurs during storage due to its low pH. In recent years, studies have been conducted on the stabilization of doogh using hydrocolloids. The objective of this study was to compare the effects of different species of gum tragacanth [Astragalus gossypinus, Astragalus rahensis, and Astragalus fluccosus] on the stabilization and rheological properties of this typical Iranian dairy drink during storage. Gum solutions were added to Doogh samples prepared from yoghurt made with skim milk. Phase separation was measured using graduated cylinders during storage [30 days], and particle size distribution at ambient temperature was determined by laser diffractometery. Furthermore, steady and unsteady rheological tests were carried out using a controlled shear rate rheometer [CSR] at 3°C. Finally, sensory analysis was performed with 30 panelists familiar with the product, using a 5-point hedonic scale. In the samples containing 0.3% [w/w] A. gossypinus no phase separation occurred during the 30-day period. The data on particle size distribution indicated that addition of gum tragacanth resulted in a reduction in the size of aggregated particles, specially in the sample containing A. gossypinus. The apparent viscosity in this sample was higher than in the other samples. Also, its sensitivity to frequency [range = 0.01-10 Hz] was much less, which is very important from an industrial point of view. In addition, based on the sensory evaluation data, the sample containing A. gossypinus was the most acceptable product. The higher content of uronic acid and insoluble part of A. gossypinus can be the most probable reasons for the stabilized dispersion caused by A. gossypinus as compared to that caused by the other two species at the same concentration [0.3% w/w] in doogh