Abstract

A culture-independent and two culture-dependent real time (rt-) PCR approaches were developed toquantitatively identify Listeria monocytogenes in raw milk and soft cheeses. The optimised rt-PCRrevealed 100% inclusivity and exclusivity. DNA- and cell-based standard curves showed a good linearityof response (R2
0.987 and R2
0.998, respectively) for five orders of magnitude (39  105 e3  100 genome equivalents and 106e101 CFU equivalents, respectively) with about 100% relative accuracyand inter-assay variability 0.90%. Up to 1 genome equivalent/and 10 CFU/reaction were quantifiedin the DNA and cell standard curves, respectively. The rt-PCR was then combined with a liquid-(MPN technique) or a solid- (ALOA and PALCAM) based enumeration. The diagnostic sensitivity of thedifferent approaches was investigated in artificially contaminated raw milk and soft cheeses. The rt-PCRculture-independent approach performed well in raw milk and (with a lower sensitivity) in stracchinocheese-based standard curves. MPN/rt-PCR was the best approach to enumerate low levels ofL. monocytogenes in raw milk and stracchino cheese, while the ALOA-based rt-PCR quantification wasmore effective than the PALCAM-based. These performances were confirmed when 23 real samples ofraw milk and soft cheeses by both the rt-PCR approaches were assayed.

Autore Pugliese

• Fusco Vincenzina

Tutti gli autori

• Quero G.M.; Santovito E.; Visconti A.; Fusco V.

Titolo volume/Rivista

Lebensmittel-Wissenschaft + Technologie

Anno di pubblicazione

2014

ISSN

0023-6438

ISBN

Non Disponibile

Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

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Numero di citazioni Scopus

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Ultimo Aggiornamento Citazioni

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Settori ERC

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Codici ASJC

Non Disponibile