Detection of methicillin resistance, staphylokinase activity and biofilm formation in S. aureus isolated from clinical samples

Abstract EN

Present study was conducted for the isolation, identification, molecular detection and antibiotic sensitivity patterns of Staphylococcus aureus obtained from Hospitals in Erbil City-Kurdistan Region-Iraq.

From 630 specimens collected, ninety eight isolates of S.

aureus were obtained.

Some isolates were further confirmed by PCR with amplification of nuc and spa genes, the results showed that nuc gene was amplified in all chosen isolates except one isolate, whereas spa amplicons showed the polymorphism in two of chosen isolates, and not amplified in three of them.

There was a relationship between the virulence factors where 82.65% of coagulase positive isolates were staphylokinase (Sak) producers; and a relationship between Sak production, biofilm formation and methecillin resistance S.

aureus (MRSA), where 68 (83.95%) from 81 of Sak producers isolates were MRSA while from 84 MRSA isolates 68 (80.95%) were Sak producers; 75 (89.28%) of MRSA were biofilm formers and vice versa.

A negative correlation was seen between Sak production and biofilm formation.

Antimicrobial sensitivity screening showed variable susceptibility of isolates with low resistance in all isolates (1.02%, 4.08%, 6.12%, 14.28%, 18.36% and 39.79% for Gen, Amx and Cip, Van, Azm, Ery, and PenG respectively), and the highest resistance rate was 98.97% for Nit and Sul.

All 98 S.

aureus isolates were distributed in 38 groups as an anti-biogram ranging from the most multi-resistant group to the most sensitive group.

Most isolates were methicillin resistant (85.71%) and it was shown that 31 isolates of 98 isolates carried the mecA gene