GPCs (long chains) in the Gram film

Long chains of GPCs in the gram film maybe an indication of:

 

1) Strep. pneumoniae

2) Enterococcus sp.

3) Beta haemolytic streptococci

4) viridans Streptococci

 

When faced with a mixed growth of an enterococcus and an organism that has been colonially identified as a Staph, the Enterococcus species can be determined with amoxicillin because E. faecalis is sensitive to amoxicillin, E. faecium is resistant.

 

The identification of the Staph here is tricky - the isolate may auto agglutinate if a strep is present. If you are faced with a GNB on a blood culture, there maybe a problem in identifying resistance to a particular antibiotic (e.g. cipro). This can occur if there is a heavy growth and the zone around the disc may not be seen or be significant. Plates should be put up again with smaller innoculums.