[Evaluation of 3 culture media for isolating mycobacteria from extrapulmonary samples]. / Evaluación de tres medios de cultivo para el aislamiento de microbacterias en muestras extrapulmonares.

OBJECTIVE: To compare three different media (Middlebrook 7H11, Löwenstein-Jensen and MB-Check System) for the isolation of mycobacteria from extrapulmonary samples in a routine medium-size microbiology laboratory. MATERIAL AND METHODS: Extrapulmonary samples were processed for mycobacterial isolation during a 22-month period, and the three media above described were evaluated in paralell during the usual routine work. RESULTS: 907 extrapulmonary specimens were processed during the study period, being the MB-Check system the most sensitive medium for detection of mycobacterial growth (79.3%) compared with Middlebrook 7H11 (62.2%) and Löwenstein-Jensen (71.8%), increasing the overall sensitivity in 11.1%. However, the fastest medium for detection of mycobacterial growth was Middlebrook 7H11 (18.2 days) compared with Löwenstein-Jensen (21.6 days) and MB-Check (23.8 days), despite the higher rates of contamination detected in Middlebrook 7H11 (61.4% compared with 10.8% for Löwenstein-Jensen and 6.1% for MB-Check). CONCLUSIONS: The combination of the three studied media is a useful alternative for isolation of mycobacteria from extrapulmonary specimens in medium-size laboratories.

Surgical wound infections due to Propionibacterium acnes: a study of 10 cases.

Ten cases of surgical wound infection in which Propionibacterium acnes was probably the aetiologic agent were reviewed; in five the organism was isolated in pure culture. Six patients underwent a neurosurgical procedure. The average time for development of infection was 17.5 days (range 1-30 days). All patients were cured by surgical drainage and, in nine cases, with appropriate antimicrobial therapy. In conclusion, P. acnes must be considered as a cause of surgical wound infections especially after neurosurgery.