POLYMERASE CHAIN REACTION-BASED ASSAYS FOR THE DETECTION AND DIFFERENTIATION OF POULTRY SIGNIFICANT PSEUDOMONADS

ABSTRACT

Pseudomonas genus-specific primers targeting the 16s rRNA gene were used in a real-time polymerase chain reaction (PCR) assay for rapid analysis of Pseudomonas isolated from retail chicken carcasses. A multiplex PCR assay was also designed using specific primers targeting the gyrase B sub-unit gene to rapidly distinguish between several species of poultry significant Pseudomonads. The assays were used to evaluate the species and level of spoilage Pseudomonads on raw chicken carcasses over an 8-day storage period. No Pseudomonas were detected on the chicken carcasses until 4 days after storage using culturing and plating techniques, but the PCR-based assays developed in this research were more sensitive and detected Pseudomonas in carcass rinses performed immediately after processing. With the multiplex PCR assay, it was determined that most of the Pseudomonas spoilage was because of Pseudomonas fluorescens and Pseudomonas fragi.

PRACTICAL APPLICATIONS

Economic losses as a result of spoilage are estimated between 5 and 17 billion dollars annually. In the poultry industry, the Pseudomonads not only cause the majority of this spoilage, but are also primary biofilm formers which may harbor and spread pathogens. Currently, only biochemical assays are available in the food industry for detection and differentiation of Pseudomonads. However, biochemical assays require 5 days for results, are limited to detection of a few species, and often produce erroneous results. The PCR assays developed in this work can reduce detection time to a few hours. Furthermore, these nucleic acid-based assays have the potential to simplify the identification process, reduce food spoilage and foodborne illness, and speed the diagnosis of ill birds.