Author name:
ريام سليم هندي الزيادي
Supervisor name:
غانم عبود جابر المولى
Abstract:
لحصول على عزلات Staph. epidermidisتم جمع (160 عينة) من حالات سريرية مختلفة كالتهاب المجاري البولية, التهابات جلدية, البلعوم, الانف, والاذن. تم الحصول على 51 (875¸31?) عزلة للمكورات العنقودية الجلدية Staph. epidermidis خلال فترة امتدت من ايلول 2014 الى كان | In order to isolate Staph. epidermidis, 160 clinical specimens were collected from (urinary tract infection, skin infection, pharynx, nose, and ear). Only 51(31.875 %) Staph. epidermidis isolates were obtained during a period from September 2014 to January 2015, depending on some biochemical tests and VITEK2 system. The Staph. epidermidis was given (gram stain, catalase , urase) positive, (coagulase, manital fermentation, oxidase, motility) negative, non haemolytic to human blood with some exception, most of the strain were able to produce biofilm, and (100%), (64.70%), (74.50%) resistant to penicillin G, ampicillin, and amoxicillin respectively. The Staphylococcus species identified during study were 44 (27.5%) isolates of Staph. aureus, 5 (3.125 %) Staph. haemolyticus, 4 (2.5 %) Staph. saprophyticus, 8 (4%) isolates other Staphylococcus spp. such as Staph. hominis ssp. hominis, Staph. capatis, Staph. xylose, Staph. simulanus, Staph. lentus, and 48 (30 %) from unknown genera. To isolate bacterioghages from sewage water, several sewage water samples were assayed using plaque assay of double agar overlay as a source of Staph. epidermidis phages. The bacteriophages were described depending on plaques size and shapes, phage 1 was the most predominant and frequent in the bacterial lawn and able to infect other S. species such as S. aureus. It has been selected to study it is titer, latent, rise period, and burst size were calculated. The effect of temperature, pH , and NaCl ions on it is original titer were studied.The results revealed a gradual decreasing in the phage titer with increasing dilution number. Latent period extended to (30 minutes) , while rise period was started with (40 minutes) extending to (60 minutes) , burst size was 2.346. Each temperature at several incubation periods , pH , and NaCl ions was significantly varied depending on phage titer. The optimum temperature was 40 ° C, while the 80 ° C was represented the inhibitor temperature. L.S.D. at level (0.05) for interaction was 39.552. The pH 6.5 - 7.5 represented the optimal pH for the best phage activity while the phage titer beginning to declining in above and below this range of optimal pH, L.S.D. at level 0.05 was 17.898 , the optimum NaCl ions concentrations were (0.1 M and 0.25 M), while the titer was significantly decreased with increasing the NaCl ion concentration in the culture solution, the L.S.D. at level 0.05 was (10.696). In conclusion of this study found that Phage1 was considered as predominant phage because of their ability to infect other Staphylococci species such as Staph. aureus.
