The finding strongly suggested that repeated MRSA infections were frequently caused by relapse of previous infecting strains.
A potential effect modification by H. pylori or smoking was assessed by including interaction terms in the regression models, for infection status (negative or positive), virulence of the infecting strains (H. pylori negative, CagA negative or CagA positive) and smoking status (never or ever).
It is unclear whether repeated MRSA infections in pediatric patients are caused by relapse of previous infecting strains or by acquiring new strains from extrinsic sources.
Furthermore, to our knowledge although biofilms have been implicated to be involved in chronic infections, no studies have characterized biofilm production from isolates recovered from relapsed infections where the clonal identity was proven identical to the initial infecting strains.
Tissue biopsies (n = 2) were collected from each dog 49 days post-tick infestation (dpi) and the ospC genotype of the infecting strains determined by direct PCR of DNA extracted from tissue or by PCR after cultivation of spirochetes from biopsy samples.
The hypothesis is that common variants would be more likely to be found in infecting strains.
In addition, the pattern of gene expression may also vary depending on the genetic background of infecting strains.
S-PM2 is a phage capable of infecting strains of unicellular cyanobacteria belonging to the genus Synechococcus.
