دراسة لبعض عوامل الفوعة للعنقوديات السالبة لمخثر البلازما المعزولة من خمج الجلد من مستشفيات السليمانية == A study on some virulence factors of coagulase negative staphylococci isolated from skin infection in sullaimaniya hospitals
Author name:
نرمين نصر الدين فتحي
Supervisor name:
ﻤﻲ ﻁﺎﻟﺏ فليح
General topic:
Biology
Specific topic:
Microbiology
Degree:
Master
University:
University of Baghdad
Language:
English
University location:
Baghdad
First pages:
24T3170 - p.pdf
Abstract:
Out of 110 clinical samples taken from different sources of burn and wound infections, 22 isolates (20%) of coagulase negative staphylococci (CNS) were isolated. The most common isolated species among CNS was S. epidermidis which was accounted for 11 isolates (50%), S. haemolyticus was the second with 3 isolates (13.64%), followed by S. hominis and S. sciuri with two isolates for each species (9.1%) and one isolate (4.54%) for each species including S. cohnii, S. lugdunensis, S. saprophyticus, S. xylosus. Some virulence factors of CNS were detected including the hemolysins, which were determined in 10 isolates (45.4%), lipase production in 15 isolates (68.1%), 9 isolates (81.8%) of S. epidermidis were positive for lipase activity, and the proteolytic isolates of CNS were 11 isolates (50%). The production of slime layer by Congo red agar method revealed 7 isolates (31.8%) of CNS and 3 isolates (27.2%) of slime layer - producing S. epidermidis, while production of this layer by tube method was determined in 2 isolates (18.18%) of 11 isolates of S. epidermidis. The ability of S. epidermidis to adhere to abiotic materials and biofilm formation in vitro was done by using polystyrene microtitre plates which appeared in 2 isolates (18.1%). Sensitivity test of the isolates using 18 antimicrobial agents showed that the vancomycin was the more effective on CNS which was susceptible to this antibiotic and reached to (90.9%), and the incidence resistance to β - lactams antibiotics was very obvious in cefotaxim (100%), penicillin (95.5%) and in amoxycillin (72%). The effect of subinhibitory concentration of antibiotics on the adherence ability of S. epidermidis was done and the results revealed that the clindamycin was the best antibiotic, while the vancomycin was the lees affecting on the adhering of S. epidermidis.
