Clinical and microbiological characteristics of Staphylococcus lugdunensis

Purpose of reviewThis review provides an update on recent findings about the clinical and microbiological characteristics of Staphylococcus lugdunensis.Recent findingsEuropean Committee on Antimicrobial Susceptibility Testing (EUCAST) and Clinical and Laboratory Standards Institute (CLSI) differ in their methodology and breakpoints for the detection of penicillin and oxacillin resistance in S. lugdunensis. The EUCAST method for beta-lactamase detection recommends a 1-unit penicillin disk and has demonstrated superior performance compared to the 10-unit penicillin disk recommended by CLSI. A similar outcome has been previously reported in Staphylococcus aureus. In addition, there is emerging oxacillin resistance in some geographical areas. Of particular concern is that oxacillin resistance in mecA positive isolates may not be reliably detected by current cefoxitin breakpoints.Coagulase negative staphylococci are now recognised as a heterogenous group of organisms that do not microbiologically or clinically behave the same way. The spectrum of clinical disease is species dependent and is particularly true for S. lugdunensis, which causes an array of clinical infections like that of S. aureus. Further studies are needed to assess the performance of phenotypic tests to detect resistance, to ensure that appropriate antimicrobial therapy is delivered to patients.

Automated summary

The review highlights the differences in methodology and breakpoints for detecting penicillin and oxacillin resistance in S. lugdunensis between EUCAST and CLSI. There is also concern about emerging oxacillin resistance in some geographical areas, particularly in mecA positive isolates.