Direct Detection of Burkholderia cepacia in Susceptible Pharmaceutical Products Using Semi Nested PCR
Burkholderia cepacia has recently received a considerable attention as one of the major risks in susceptible pharmaceutical products. This microorganism can easily propagate and cause vast and severe contamination, especially to the water supplies for pharmaceutical companies. Moreover, it proliferates within the products and can cause severe infections for humans. Therefore, fast and sensitive detection of these bacteria is of a great demand. The present study introduces improved application of a polymerase chain reaction assay with relatively high sensitivity and specificity for the direct detection of B. cepacia from the aqueous pharmaceutical products. A semi nested polymerase chain reaction approach using the primer set BCR1/BCR2 followed by BCR1/Mr yielding a 465 bp fragment of the recA gene was applied and tested using both crude lysate from isolated colonies and DNA directly extracted from artificially prepared and spiked reference syrup. The polymerase chain reaction assay showed no interference with other bacterial reference and environmental strains tested, including Staphylococcus aureus ATCC(r) 6538, Pseudomonas aeruginosa ATCC(r) 9027, Escherichia coli ATCC(r) 8739, Salmonella abony NCTC(r) 6017, Bacillus subtilis ATCC(r) 6633, Micrococcus luteus, Staphylococcus warneri, Pseudomonas fluorescens, Pseudomonas putida, and Ralstonia pickettii. Moreover, this semi nested assay showed a detection limit of around 10 colony forming units per sample and could detect B. cepacia strains isolated from a municipal pre treated potable water tank. Comparing the results for detection of B. cepacia in 100 randomly collected commercial syrup preparations using both conventional standard method and polymerase chain reaction assay revealed that B. cepacia was detected in two samples using polymerase chain reaction assay while all samples showed negative results by conventional culturing and biochemical methods. These results highlight the advantage of using this polymerase chain reaction assay to detect B. cepacia in contaminated pharmaceutical products and even water for pharmaceutical purposes, without the need of culturing or pre enrichment, where it may give false negative results and may be misidentified when biochemically tested.
PDA Journal of Pharmaceutical Science and Technology