) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
University of Baghdad
College Name
College of Science
Department
Biology
Full Name as written
in Passport
MARWA HAMEED MUTSHER
e-mail
Marwa_1981_a@yahoo.com
Career
Assistant Lecturer
⃰
Assistant Professor
Master
⃰
Thesis Title
Lecturer
Professor
PhD
Biofilm Formation by The External Fixators contaminating Klebsiella
pneumoniae and Its Antibiotic Resistance
Year
2008
Summary
Out of 100 clinical samples taken from infected external fixation devices used in
Abstract
orthopedic surgery 98 bacterial isolates grown in aerobic conditions had been
diagnosed. The higher ratio 51% (50 isolates) of the total number of the isolates
occupied by gram negative bacteria while gram positive bacteria represented the
rest 49% (48 isolate) , Klebsiella pneumoniae was the most common aetiological
agent of these infections which accounted 74% (37 isolates) of the total number of
gram negative bacterial isolates.
The sensitivity test against different antibiotics was done. It was found that all
K. pneumoniae isolates (100%) were sensitive to Amikacin and resistant to
Ampicillin, Cefalexine, Cefalothin, Cefotaxime, Ciprofloxacin, and Rifampin .
While their resistance percetage to the antibiotics Ceftazidime, Streptomycin,
Tobramycin, Gentamycin, Neomycin, Nitrofurantoin, Norfloxacin, Tetracycline,
and Nalidixic acid were 94.5% , 86.5% , 86.5% , 67.5% , 59.5% , 37.8% , 35.1% ,
32.5% , 24.3% respectively.
Minimum inhibitory concentrations to K. pneumoniae isolates had been
determined for the antibiotics Cefotaxime, Ceftazidime, Nalidixic acid, and
Amikacin , they were 1024 Mcg/ml , 128 Mcg/ml , 64 Mcg/ml , and 16 Mcg/ml
respectively for the isolate K13 , and they were 1024 Mcg/ml , 64 Mcg/ml, 16
Mcg/ml, and 4 Mcg/ml respectively for the isolate K51.
) ‫أنموذج ( أ ) الخاص برسائل الماجستير و اطاريح الدكتوراة ( اخر شهادة‬
Minimum bactericidal concentrations for the same antibiotics had been
estimated and they were higher than 1024 Mcg/ml, 1024 Mcg/ml, 128 Mcg/ml, and
32 Mcg/ml respectively for K13 isolate, and higher than 1024 Mcg/ml, 256
Mcg/ml, 32 Mcg/ml, and 8 Mcg/ml respectively for the isolate K51.
The ability of K.pneumoniae isolates to produce slime layer was detected , the
results revealed that 83.3% (31 isolates) were slime layer producers by tube
method, while 97.3% (36 isolates) were slime producers by congo red method.
The virulence of
K.pneumoniae
isolates isolated from external fixators
infections had been detected via detection the crystal violet binding ability of these
isolates, all the isolates were virulent.
The ability of K.pneumoniae isolates to produce the biofilm had been tested
by using microtiter plates , results revealed that all the isolates were biofilm
producers with different thickness degrees, absorbance values rendered between
(0.111-2.899) , K13 was the best biofilm producer isolate, it,s absorbance value
was 2.899 .
The effect of subinhibitory concentrations of the antibiotics Cefotaxime,
Ceftazidime, Nalidixic acid, and Amikacin , on biofilms formed by K13 and K51
isolates in microtiterplates in different ages , 24 hr and 48 hr had been tested ,
results revealed that these concentrations inhibited bacterial adhesion on polysteren
surface and consequently causes biofilm detachment , also it was demonstrated that
aged biofilms are more resistant to antimicrobial agents .
Minimum inhibitory concentrations for the biofilm had been estimated, and the
results revealed that these concentrations were three to four times higher than
minimum inhibitory concentrations for the planktonic K.pneumoniae isolates.