Abstract
Background:
Milk and its products are very sensitive to spoilage if they are kept under unsuitable conditions which may provide favorable circumstances for the growth of specific spoilage organisms, Pseudomonas fluorescens accounted as the most dominant indicator for milk spoilage.
Aim:
This study highlights to monitor the prevalence of P. fluorescens as a spoilage indicator organism in cow raw milk and its contact surfaces represented by teat surfaces and milk tanks in Nineveh province.
Methods:
A total of 150 samples from cows' raw milk, teat surfaces and milk tank swabs were collected from different locations of Nineveh province from October 2023 till February 2024.The P. fluorescens was detected by using conventional cultivation methods supported by molecular detection of the target pathogen using polymerase chain reaction technique.
Results:
Out of 150 samples 48(32%) were positive for the prevalence of P. fluorescens by traditional methods and 39(26%) were positive using PCR assay according to the 16SPflu gene yielded a band at 850 bp. The P. fluorescens was recovered at 19(38%) from raw milk. Teat surfaces revealed a higher isolation rate 11(22%) compared to milk tanks 9(18%). The mean counts of Pseudomonas in cows raw milk revealed 4.38, 6.29 and 7.37 log CFU/ml for the zero, three and six days of storage in chilling temperature. Results of DNA sequencing of the 16SrRNA gene revealed 12 strains recorded in the GenBank nucleotide sequence database.
Conclusion:
Our results shed light on the risk of P. fluorescens prevalence as spoilage indicator in raw milk and surrounded surfaces which inevitable to apply the hygienic procedures during milk collecting, processing and preservation to increase the shelf life of the products and ensure milk safety and consumer health.

Key words: Pseudomonas fluorescens, Milk spoilage, Teat surfaces, Milk tanks