An appropriately performed conventional blood culture can facilitate choice of therapy in resource-constrained settings-comparison with BACTEC 9050.

AIMS

Comparison of conventional blood culture with BACTEC 9050 for rate and time to detection of microorganisms.

SETTINGS AND DESIGN

A prospective study was carried out in a multispecialty tertiary care teaching hospital.

SUBJECTS AND METHODS

A total of 835 paired specimens (797 blood and 38 nonblood specimens) were collected and processed according to standard microbiological procedures by both conventional method as well as by BACTEC 9050 automated culture system. Clinical details of patients were recorded. Data were analyzed for time to detection and isolation rate by the two systems and compared.

RESULTS

Overall culture positivity for BACTEC 9050 and the conventional system was 32% and 19.88%, respectively. Eighty-five demonstrated concordant growth, 136 specimens were culture positive by BACTEC only, and 38 specimens were culture positive by conventional only. Twelve contaminants in BACTEC and nine contaminants in conventional system were detected. Using BACTEC 9050, higher isolation was observed for Acinetobacter spp., coagulase negative Staphylococcus spp., Streptococcus spp., and Candida spp. A total of 410 patients were on antimicrobial treatment and culture positivity was significantly higher with BACTEC 9050 (P < 0.0001). There was a significant difference in the mean time to detection with BACTEC 9050 recovering 86.8% of isolates within 48 h (P < 0.0001).

CONCLUSIONS

Although BACTEC 9050 demonstrated a significantly higher recovery of microorganisms from blood, an appropriately performed conventional blood culture can facilitate the choice of therapy.