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Delayed growth of M. tuberculosis and M. avium in liquid media after addition of saponin, polypropylene glycol and sodium polyanetholesulphonate

Abstract number: P1945

Gamboa F., Bustillo J., Alvarado A.

Objective: The ISOLATOR 10 lysis-centrifugation system (Wampole Laboratories, Cranbury, N.J.) is a technique with excellent results in the recovery of mycobacteria from blood specimens. This system contains saponin (SAP), polypropylenglycol (PPG), and sodium polyanetholsulphonate (SPS). This study is aimed at determining the effect of SAP, PPG and SPS onto the Mycobacterium tuberculosis (4 strains) and Mycobacterium avium (4 strains) growth in MGIT and Septi-Chek AFB liquid media.

Methods: SAP, PPG, and SPS were prepared at different concentrations and 0.1 ml of each was added (individually, in pairs, and all of three mixed) to MGIT and Septi-Chek AFB liquid media. Then, liquid culture media were individually inoculated by using two different concentrations (1000 and 100000 CFU/ml) of each of the eight mycobacterial strains used in this study. The media were incubated at 37°C and its growth was daily surveilled and monitored.

Results: Mycobacterial growth was not prevented but delayed (longer to detect the growth with regard to positive control) by SAP, PPG, and SPS. This is why three substances concentrations delaying mycobacteria growth range from 14–28 mg/ml, 4–8 ml/l, and 10–15 g/l, respectively.

Conclusion:Mycobacterium tuberculosis and Mycobacterium avium growth in concentrations 1000 and 100000 CFU/ml was delayed by three substances when added alone or in mixture onto MGIT and Septi-Chek AFB liquid culture media. These results suggest it is necessary to propose strategies in order to reduce SAP, PPG, and SPS concentrations which are present in sediment of blood processed by ISOLATOR 10 lysis-centrifugation system, that are finally going to be inoculated in MGIT and Septi-Chek AFB liquid media.

Session Details

Date: 19/04/2008
Time: 00:00-00:00
Session name: 18th European Congress of Clinical Microbiology and Infectious Diseases
Subject:
Location: Barcelona, Spain
Presentation type:
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