STAPHYLOCOCCUS HAEMOLYTICUS UNDER REPORTED BECAUSE OF FALSE POSITIVE SLIDE COAGULASE TEST: IMPLICATIONS FROM TWO CASE REPORTS

Staphylococcus haemolyticus is a common coagulase negative staphylococcus (CONS) that is a commensal of the urethra and periurethral area in both sexes. It is feared for its multi-drug resistance and is associated with urinary tract infection (UTI), soft tissue infection and blood stream infection (BSI). Here we discuss two cases, one with urinary tract infection and another with urethral discharge presenting at the outdoor in our hospital. We isolated S. haemolyticus on culture in pure form from both cases, where after the identification was confirmed by Vitek2 compact AES. Slide coagulase test was misleading as both isolates were positive by this test rendering wrong reporting as S. aureus. Both isolates were confirmed to be CONS by tube coagulase test. Antibiotic susceptibility testing showed that multi drug resistance is not encountered in community acquired infection with S. haemolyticus. Slide coagulase test was misleading as both isolates were positive for the test rendering wrong reporting as S. aureus. Interpretation of susceptibility to different drugs, on the basis of this erroneous identification, leading to the suspicion of Methicillin and / or Vancomycin resistance, leads to the patients being advised ineffective drugs for clearing the infection. However, if tube coagulase test is taken into consideration and CONS is detected, as in our case, correct identification is made possible and correct treatment strategies may be devised.