Cronobacter Support
05-19-2009, 03:47 PM
1st International Conference on Cronobacter Poster Abstract 42
Validation study of an E.sakazakii TaqMan(R) RT-PCR kit with Infant Formula
Cronobacter sakazakii is an emerging pathogen involved in sporadic situations of serious infections in just born babies of up to 4-6 weeks of age. It is an opportunistic pathogen that can cause meningitis, necrotizing enterocolitis and sepsis in premature or immuno-compromised babies. C sakazakii is a ubiquitous micro-organism and its control in food processing plants requires strict hygiene measures. Even when it is possible to pasteurise recontamination can occur on the manufacturing and packaging phases. The current reference analytical method for the Cronobacter sakazakii detection (technique ISO 22964) requires a minimum of 4 days. There is a need to develop new analytical methods that allow better time to results which also offer the same or better specificity and sensitivity than the reference method. The PCR technique allows the rapid detection of micro-organisms by using specific DNA primers. In order to validate the PCR based analysis technique we analysed 3 different infant formulas artificially inoculated with C. sakazakii following the ISO 22964 method and the new TaqManŽ PCR Enterobacter Sakazakii amplification/detection kit of Applied Biosystems in parallel. We carried out 36 analyses (12 samples per validation) tested on 3 different days. Each group of analyses had 3 negative control samples (not inoculated) and 9 contaminated samples (artificially inoculated). Of the 27 artificially inoculated samples, 3 of them were not detected by either of the 2 evaluated techniques (ISO 22964 or Real-Time PCR) and for this reason they were considered to be negative. The results obtained in the 3 validations show that the ISO 22964 technique and the Real Time PCR detect the same 24 positive samples; the advantage of the second technique is that the results are obtained in approximately 27 hours when the ISO 22964 technique requires a minimum of 4 days (7 including biochemical confirmation).
Nuria Queralt
Applied Biosystems, Spain.
Validation study of an E.sakazakii TaqMan(R) RT-PCR kit with Infant Formula
Cronobacter sakazakii is an emerging pathogen involved in sporadic situations of serious infections in just born babies of up to 4-6 weeks of age. It is an opportunistic pathogen that can cause meningitis, necrotizing enterocolitis and sepsis in premature or immuno-compromised babies. C sakazakii is a ubiquitous micro-organism and its control in food processing plants requires strict hygiene measures. Even when it is possible to pasteurise recontamination can occur on the manufacturing and packaging phases. The current reference analytical method for the Cronobacter sakazakii detection (technique ISO 22964) requires a minimum of 4 days. There is a need to develop new analytical methods that allow better time to results which also offer the same or better specificity and sensitivity than the reference method. The PCR technique allows the rapid detection of micro-organisms by using specific DNA primers. In order to validate the PCR based analysis technique we analysed 3 different infant formulas artificially inoculated with C. sakazakii following the ISO 22964 method and the new TaqManŽ PCR Enterobacter Sakazakii amplification/detection kit of Applied Biosystems in parallel. We carried out 36 analyses (12 samples per validation) tested on 3 different days. Each group of analyses had 3 negative control samples (not inoculated) and 9 contaminated samples (artificially inoculated). Of the 27 artificially inoculated samples, 3 of them were not detected by either of the 2 evaluated techniques (ISO 22964 or Real-Time PCR) and for this reason they were considered to be negative. The results obtained in the 3 validations show that the ISO 22964 technique and the Real Time PCR detect the same 24 positive samples; the advantage of the second technique is that the results are obtained in approximately 27 hours when the ISO 22964 technique requires a minimum of 4 days (7 including biochemical confirmation).
Nuria Queralt
Applied Biosystems, Spain.