Sensitivity of the BacT/ALERT FA-medium for detection of Pseudomonas aeruginosa in pre-incubated blood cultures and its temperature-dependence.
The BacT/ALERT FA-medium was evaluated to detect Pseudomonas aeruginosa in pre-incubated blood samples. As published previously its predecessor the BacT/ALERT FAN-medium failed to detect P. aeruginosa in delayed entry samples. It is now reported that FA-medium tolerates a longer pre-incubation period at 36 degrees C, i.e. 8 h, before detection of P. aeruginosa fails in experimentally inoculated blood cultures. In clinical blood samples the frequency of false-negative results concerning P. aeruginosa was reduced from 46.9 % (FAN-medium) to 9.1 % (FA-medium). If media inoculated with P. aeruginosa are pre-incubated at room temperature for 24 h, false-negative results are not observed. Various micro-organisms (Haemophilus influenzae, Streptococcus pneumoniae, Enterobacteriaceae, Staphylococcus aureus, Enterococcus faecalis, Candida glabrata) were recognized after pre-incubation at room temperature with similar sensitivity compared to pre-incubation at 36 degrees C. It is concluded that FA-medium detects P. aeruginosa in delayed entry samples with increased sensitivity and pre-incubation at room temperature is superior to pre-incubation at 36 degrees C.
Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Trogerstrasse 9, 81675 Munich, Germany.
Irene
I
Seegmüller
Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Trogerstrasse 9, 81675 Munich, Germany.
Ursula
U
Eschenbach
Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Trogerstrasse 9, 81675 Munich, Germany.
Klaus
K
Kamereck
Institute of Medical Microbiology, Immunology and Hygiene, Technical University of Munich, Trogerstrasse 9, 81675 Munich, Germany.
Thomas
T
Miethke
D001431:Bacteriological Techniques; D001769:Blood / Q000382:microbiology; D003470:Culture Media; D005188:False Negative Reactions; D006801:Humans; D011550:Pseudomonas aeruginosa / Q000254:growth & development* / Q000302:isolation & purification*; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D013696:Temperature
D003470:Culture Media; D011933:Reagent Kits, Diagnostic