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عزل وتشخيص بكتريا Streptococcus spp المسببة لالتهاب اللوزتين من الاطفال وتاثير بعض عزلات بكتريا حامض اللبنيك عليها == Isolation And Identification of Streptococcus Spp Caused Tonsillitis From Children And The Effect of Some Lactic Acid Bacteria (Lab) Strains On It
Author name:
رند ثائر عبد اللطيف
Supervisor name:
ندى صباح رزوقي
General topic:
Biology
Specific topic:
Microbiology
Degree:
Master
University:
University of Baghdad - College Of Science For Girls
Language:
Arabic
University location:
Baghdad
First pages:
24T2743 - p.pdf
Abstract:
بحثت الدراسة جمع 100 مسحة من اطفال مصابين بالتهاب اللوزتين الحاد والمزمن ممن راجعوا استشارية الانف والاذن والحنجرة في مستشفى اليرموك التعليمي للمدة مابين كانون الاول للعام 2013 ولغاية اذار للعام 2014. وكانت نتيجة الزرع المختبري موجبة في 67 مسحة منها وبالا | In this study 100 swabs were collected from infected children with acute and chronic tonsillitis who attended at Al - Yarmook Teaching Hospital (Eear Nose Tonsils consultation clinic) from December 2013 until March 2014. The result of laboratory culture were positive in 67 samples. Depending on their cultural, morphological and biochemical characterization of bacterial isolates : (37.31%) of them were identified as Streptococcus pyogenes bacteria and the diagnosis is confirmed by the use of Remel Rapid STR System. Whereas (34.33%) belong to S.parasanguinis, (11.94%) S.mitis, (11.94%) S.oralis and (4.48%) S.thoraltensis were identification of them are confirmed by using Vitek - 2 System also. As well as Sensitivity test for S.pyogenes cultures for some of the antibiotics done and the results revealed that all cultures were sensitive to tetracycline and chloramphenicol drugs 100%, while it was different in their sensitivity for other drugs. According to age (2 - 13) years revealed the highest percentage of infection for both male and female, however the percentage of acute and chronic tonsillitis was higher in males than females. In this study, during investigation of the antagonist action of lactic acid bacterial isolates against these pathogenic bacteria, results revealed that the method of L.acidophilus discs gave a high inhibition zones with a diameter of 11.3 mm, while L.fermentum discs yielded a high inhibition zones with a diameter of 7 mm 24 hrs following incubation in comparison with well diffusion method by using suspension of L.acidophilus produced a high inhibition zones with a diameter 7.25 mm 48 hrs after incubation. L.fermentum suspension produced a high inhibition zones with 10 mm diameter 24 hrs following incubation. Also the study included measurement of the inhibition activity for bacteriocins produced by L.acidophilus bacteria against the pathogenic bacteria S.pyogenes on nutrient agar by well diffusion method in which results revealed stability of the bacteriocins effects under different PH (4, 5, 6) with percent (100, 60, 50)% respectively for 24 hrs at higher stability and the highest stability of bacteriocins during PH was 4 with percent 100%, while it lost a lot of its activity with acidic PH less than 2 and basal pH more than 8. During the study the effect of Nacl, Kcl and MgSo4 with different concentrations (1 - 5%) with constant inhibitory effect for bacteriocins produced by L.acidophilus against pathogenic S.pyogenes, The result revealed that Nacl had little effect in inhibition zone with 1&2% concentrations. The salt MgSo4 and Kcl showed reduction in the inhibitory activity with 1, 2, 3% concentration, however the higher concentration of salt caused great reduction as 5% concentration led to loss of inhibitory activity for bacteriocins completely.Also this study showed light on the inhibitory effect of probiotics suspensions against the adhesion property of S.pyogenes after treated with L.acidophilus and L.fermentum.where the Result shown that L.acidophilus inhibit the adhesion of S.pyogenes with percent 68.92% either L.fermentum inhibit the adhesion of this pathogenic bacteria to epithelial cell with percent 30.28%. The study is consisted of showed the inhibitory action for suspensions of L.acidophilus and L.fermentum on biofilm formation by S.pyogenes, it was noticed the action of L.acidophilus in the side more than from the action of L.fermentum. During the study of the effect of suspension and filter of L.acidophilus and L.fermentum on the production of Hemolysin enzyme by S.pyogenes, it was noticed that the ability of suspension belong to L.acidophilus and L.fermentum to reduce the diameter of hemolysis zone which was beta type more than the ability of filter L.acidophilus and L.fermentum to reduce of the hemolysis zone which was beta type.