Thirty one staphylococci out of 50 were BF forming (according to icaAD gene detection by polymerase chain reaction and/or microtitre plate assay) and 19 non-BF forming isolated from clinical specimens and intravascular catheters of patients admitted to the pediatric hospital of Ain-Shams University. Antibiotic susceptibility testing was performed for all isolates using disk diffusion test for cefoxitin, gentamicin and rifampicin and HiComb MIC Test for vancomycin, erythromycin, ciprofloxacin, sulphamethizole and teracycline. An increase in the resistance of the staphylococcal isolates, particularly the coagulase negative, was noted. No statistical significant difference was detected between BF forming and non BF Staphylococci, however, 48.8% of BF forming strains were methicillin resistant (MR) and all were associated with multiple-resistance to antibiotics as 16% were resistant to 3 antibiotics, 32% to 4 antibiotics, 39% to 5 antibiotics, and 13% to all antibiotics tested. A high resistance was detected MR staphylococcal isolates to erythromycin (92.9%), gentamicin (60.7%), and ciprofloxacin (89.3%) showing a statistical significant difference when compared to methicillin sensitive Staphylococci (63.6%, 9%, 66.7%, respectively). Finally we conclude that there is an increase in the resistance of staphylococcal isolates to different antibiotics and BF formation is associated with multi-resistance to antibiotics.
Staphylococci, Biofilm, Antibiotics, Disk Diffusion, Minimal Inhibitory Concentration