Infective endocarditis due to Streptococci and Enterococci: A 3-year retrospective study

Infective endocarditis (IE) is an infection of the heart valves with an aggregation of bacteria in a fibrin plaque called vegetation.

This is a retrospective study of all infective endocarditis cases due to alpha haemolytic streptococci and enterococci.

All cases of infective endocarditis cases due to alpha haemolytic streptococci and enterococci in a period of three years from 1^st January 2010 to 31^st December 2012 were included. Isolation of the same organism from more than one set of blood cultures was taken as a confirmed case of infective endocarditis. Clinical and serological parameters were recorded using a proforma.

Native valve endocarditis was more common with only five prosthetic valves being involved. Out of 89 clinically suspected cases of IE in the three years from Jan 2010 to Dec 2012, for which blood was sent for culture, 63(70.78%) samples were positive by culture. Of these, 42/63(66.66%) were due to alpha-lytic Streptococci, enterococci and rare gram positive cocci. The rare ones included Enterococcus gallinarum, abiotropha defective, Vagococcus fluvialis and Nutritionally Variant Streptococci(NVS). High level Aminoglycoside resistance(HLAR) was also encountered. The varied and important features of these isolates are discussed. Complications and treatment are described.

From a clinical microbiology point of view, the major challenge faced by the microbiologist in diagnosis of IE is proper aseptic collection of sample before starting antibiotics with a need for multiple samples to detect and also to prove the causative organism. Sensitivity reporting can be a difficult task in the context of NVS, HLAR and gram positives that are slow growing. Congestive failure and embolisation occurs even when the antibiotic treatment is successful.When patients go in for complications, it is very rarely due to wrong antibiotics.