Comparative Study for Biofilm Formation between Clinical Methicillin-Resistant and Methicillin Susceptible Staphylococcus Aureus Isolates

Abstract

One hundred seventy five samples were collected, included, blood ,urine,nasal,ear,sputum and burn from patients in Teaching General Hospital in Baquba city during the period (March to July 2018).The phenotypic and biochemical tests showed that 55 isolates were Staphylococcusaureus bacteria ,21(38.18%) MRSA and 34(61.82%) MSSA.The result of antibiotic resistant were resistance to Pencillin 55(100%),Azithromycin 42(76.36%) and Gentamycin 32(58.18%),followed by Tetracycline 29(52.72%),Ceftaroline 26(47.27%), Ciprofloxacin 11(20%) , 6(10.90%) for each of Rifampin and Chloramphenicol ,the least resistance was to Doxycycline 2(3.63%) followed by Linezolid 3(5.45%). We found that all of S. aureus isolates were produced slime layer by CRA plates 55( 100%),but 17 (80.95 %)of MRSA isolates were black colonies , (9.52%) for each of very black and weak black.In MSSA isolates 3(8.82%)were very black ,21(61.76%)black,9(26.47%)weak black and 1(2.94%)was red. The results of microtiter plates assay showed that all of S. aureus isolates 55(100%) were attached but in several amount . Attachment of MRSA isolates were 3(14.28%)strong,15(71.42%) of isolates were moderate and 3(14.28%) isolates were weak,butinMSSA isolates 5(14.70%)strong,19(55.88%)moderate and 10(29.41%)weak. The frequency of icaA,icaB,icaC genes in MRSA and MSSA isolatesisolateswere (100%)