Investigation and Analysis of Staphylococcus aureus Contamination in Food in Yantai City, China: Based on a 14-Year Continuous Monitoring.

Staphylococcus aureus is a foodborne zoonotic pathogen that threatens food safety and public health. However, few people have conducted long-term and systematic studies on S. aureus contamination in food in Yantai City. To investigate the contamination situation of S. aureus in food and improve the ability of early warning and control of foodborne diseases, a total of 2384 samples from 17 categories were collected from 13 monitoring points in Yantai City, from 2010 to 2023. Forty-four samples were positively detected for S. aureus, with a detection rate of 1.85% (44/2384). The detection rate of S. aureus was highest in Zhifu District (4.12%), followed by Penglai District (2.45%), Zhaoyuan District (2.37%), Kaifa District (2.19%), and Longkou District (1.98%). Positive detection rates were higher in frozen rice and flour products at 8.82% (6/68), quick-frozen dishes at 5.56% (1/18), aquatic products at 4.05% (3/74), and meat and meat products at 3.55% (27/760). Positive detection rates in samples from the first, second, third, and fourth quarters were 0% (0/44), 2.21% (20/906), 2.13% (22/1033), and 0.50% (2/401), respectively. Positive detection rates in bulk and prepackaged samples were 2.33% (36/1546) and 0.95% (8/838), respectively, with statistically significant differences (χ² = 5.66, p < 0.05). Positive detection rates were significantly different for samples collected from different sampling stages, of which at production and processing stages was 7.78% (20/257), catering stages 1.38% (10/727), and distribution stages 1% (14/1400) (χ² = 56.41, p < 0.05). Frozen rice and flour products, quick-frozen dishes, aquatic products, and meat and meat products are the main food products contaminated with S. aureus, and the resulting secondary contamination is a hidden danger for the occurrence of foodborne diseases, which should be given sufficient attention.