Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Botany- Microbiology

This study aims at evaluation of some natural antimicrobial compuonds against biofilm formation among resistant Enterococcus clinical isolates. It also include a compartive study between the clinical isolates from different clinical samples and the healthy carrier samples 51 Clinical samples (36) from urine ,(9) from blood ,(3) from wound, (2) from pus , and (1) from Vagina . Carriers samples were all isolated from stool samples, these isolates were collected and identified according to Bergeys Manual of Systematic Bacteriology. The antibiotic sensitivity test was undertaken for all the clinical and the carrier isolates, the results revealed that the highest antibiotic resistance for the clinical isolates was exhibited against tetracycline (84%) followed by erythromycin(82%) then norofloxacin (56%) , chloramphenicol (37.2%), ampicillin (30 ,7%) , doxycycline (35%) , gentamycin (31.3%) and vancomycin(19%), while in carriers isolates the highest antibiotics resistance was for tetracycline (67%) followed by doxycycline (59%) , erythromycin (36%) then chloramphenicol (16%) , ampicillin (10%), norofloxacin (8%) , levofloxacin (6%) gentamycin (2%) and finally vancomycin(2%) 70.5% of clinical isolates and 34.6% of carrier isolates were multi drug resistant. The virulence factors included in Enterococcus faecalis were studied, the results showed that some organisms have the ability to liquefy the gelatin, form biofilm , make haemolysis . All the isolates produce esp gene . Ability to produce biofilm in clinical isolates was higher than in carrier isolates 15 Essenial oils were tested for their antimicrobial activity against MDR enterococci , cod liver , ginger , blue chamomile , wheat germ, paserly, chamomile , olive , and anise were not effective to tested organism

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