Aj. Morris et al., CLINICAL IMPACT OF BACTERIA AND FUNGI RECOVERED ONLY FROM BROTH CULTURES, Journal of clinical microbiology, 33(1), 1995, pp. 161-165
We prospectively evaluated 356 bacteria and fungi recovered from broth
enrichment tubes from cultures with sterile direct plates to determin
e the clinical impact of isolates recovered only from broth cultures,
These ''broth only'' isolates (BOI) were classified as contaminants or
true on the basis of review of patient charts, True isolates were con
sidered clinically relevant only if they altered or should have altere
d patient management, Of 356 BOI, 259 (73%) were considered contaminan
ts (mostly coagulase-negative staphylococci and propionibacterium spp.
) and 97 (27%) were considered true. For individual microorganisms, 9
of 9 (100%) Staphylococcus aureus isolates, 13 of 13 (100%) members of
the family Enterobacteriaceae, 10 of 12 (83%) fungi, 7 of 10 (70%) en
terococci, 7 of 11 (64%) other gram-negative bacilli, 13 of 31 (45%) a
naerobic bacteria, 10 of 24 (42%) streptococci, 22 of 140 (16%) coagul
ase-negative staphylococci, 6 of 92 (7%) Propionibacterium spp., and 0
of 14 (0%) diphtheroids and Bacillus spp, were classified as true, El
even of 97 (11%) patients with true BOI had clinically relevant isolat
es, Fifty-nine of the 97 (61%) patients with true isolates already wer
e on therapy, and no change was made because of the BOI, Six (6%) pati
ents with contaminants received therapy for their BOI, We conclude tha
t broth inoculated as an adjunct to direct plating seldom yields resul
ts that favorably alter patient management and could be omitted for mo
st specimens without compromising patient care,