Mycobacterium mucogenicum from the Hickman line of an immunocompromised patient.
Gram stain of a positive blood culture is the clinician's first indication of a possible causative infective organism and a guide to suitable antimicrobial therapy prior to cultural and phenotypic identification with susceptibility test results. Occasionally interpretation of a Gram stain can be difficult; if there is a low bacterial load, no organisms may be seen. Such a case is reported, where a positive blood culture taken from the Hickman line of an immunocompromised patient flagged as positive at 5 days' incubation, but no organisms were seen on Gram film. On subculture, a slow growing Gram-positive bacillus was isolated which was initially misidentified and reported as a "diphtheroid" species. The actual identity of this organism and further isolates was later elucidated as Mycobacterium mucogenicum, a rapidly growing non-tuberculous mycobacterium.
Marshall
C
C
Newcastle upon Tyne NHS Foundation Trust, UK. carmarr@aol.com
Samuel
J
J
Galloway
A
A
Pedler
S
S
D000293:Adolescent; D002405:Catheterization, Central Venous / Q000295:instrumentation*; D002408:Catheters, Indwelling; D003937:Diagnosis, Differential; D004165:Diphtheria / Q000175:diagnosis; D004866:Equipment Contamination; D006801:Humans; D016867:Immunocompromised Host; D008297:Male; D009164:Mycobacterium Infections / Q000175:diagnosis* / Q000276:immunology; D009894:Opportunistic Infections / Q000175:diagnosis* / Q000276:immunology