Gosbell IB

Hinrichs JH

Nomura-M

ABSTRACT
          
            The distinct epidemiology of original hospital-associated methicillin-resistant
            Staphylococcus aureus
            (HA-MRSA) and early community-associated MRSA (CA-MRSA) is largely unexplained.
            S. aureus
            carries either five or six rRNA operon copies. Evidence is provided for a scenario in which MRSA has adapted to the hospital environment by rRNA operon loss (six to five copies) due to antibiotic pressure. Early CA-MRSA, in contrast, results from wild-type methicillin-susceptible
            S. aureus
            (MSSA) that acquired
            mecA
            without loss of an rRNA operon. Of the HA-MRSA isolates (
            n
            = 77), 67.5% had five rRNA operon copies, compared to 23.2% of the CA-MRSA isolates (
            n
            = 69) and 7.7% of MSSA isolates (
            n
            = 195) (
            P
            &lt; 0.001). In addition, 105 MSSA isolates from cystic fibrosis patients were tested, because these patients are repeatedly treated with antibiotics; 32.4% of these isolates had five rRNA operon copies. For all subsets, a correlation between resistance profile and rRNA copy number was found. Furthermore, we showed that
            in vitro
            antibiotic pressure may result in rRNA operon copy loss. We also showed that without antibiotic pressure,
            S. aureus
            isolates containing six rRNA copies are more fit than isolates with five copies. We conclude that HA-MRSA and cystic fibrosis isolates most likely have adapted to an environment with high antibiotic pressure by the loss of an rRNA operon copy. This loss has facilitated resistance development, which promoted survival in these niches. However, strain fitness decreased, which explains their lack of success in the community. In contrast, CA-MRSA isolates retained six rRNA operon copies, rendering them fitter and thereby able to survive and spread in the community.
          </jats:p

A. C. Fluit

M. D. Jansen

T. Bosch

W. T. M. Jansen

L. Schouls

M. J. Jonker

C. H. E. Boel

Crossref

Antimicrobial Agents and Chemotherapy

rRNA Operon Copy Number Can Explain the Distinct Epidemiology of Hospital-Associated Methicillin-Resistant Staphylococcus aureus

rRNA Operon Copy Number Can Explain the Distinct Epidemiology of Hospital-Associated Methicillin-Resistant Staphylococcus aureus

Abstract

Similar works

Full text

Available Versions

Crossref