Coagulase-negative staphylococci: Pathogenesis, occurrence of antibiotic resistance genes and in vitro effects of antimicrobial agents on biofilm-growing bacteria.

Coagulase-negative staphylococci: Pathogenesis, occurrence of antibiotic resistance genes and in vitro effects of antimicrobial agents on biofilm-growing bacteria. J Med Microbiol. 2016 Oct 19;: Authors: Szczuka E, Jabłońska L, Kaznowski A Abstract Coagulase-negative staphylococci (CoNS) are opportunistic pathogens that particularly cause infections in patients with implanted medical devices. The present research was performed to study the virulence potential of 53 clinical isolates of Staphylococcus capitis, Staphylococcus auricularis, Staphylococcus lugdunensis, Staphylococcus simulans, Staphylococcus cohnii, and Staphylococcus caprae. All clinical strains were clonally unrelated. Isolates carried genes encoding resistance to β-lactam (mecA) (15%), aminoglycosides aac(6')/aph(2'') (11%), aph (3')-IIIa (15%), ant(4')-Ia (19%) and MLSB erm(A) (4%), erm(B) (13%), erm(C) (41%), msr(A) (11%) antibiotics. CoNS isolates (64%) were able to form biofilms. Confocal laser scanning microscopy revealed that these biofilms formed a three-dimensional structure composed mainly of living cells. All biofilm-positive strains carried the ica operon. In vitro studies demonstrated that a combination treatment with tigecycline and rifampicin was more effective against biofilms than ciprofloxacin and rifampicin. The minimum biofilm eradication concentration values were 0.062-0.5µg/ml for tigecycline/rifampicin and 0.250-2µg/ml for ciprofloxacin/rifam...
Source: Journal of Medical Microbiology - Category: Microbiology Authors: Tags: J Med Microbiol Source Type: research