Poultry Diagnostic and Research Center, Department of Population Health, College of Veterinary Medicine, University of Georgiagrid.213876.9, Athens, Georgia, USA.
Georgia Poultry Laboratory Network, Gainesville, Georgia, USA.
Appl Environ Microbiol. 2022 Apr 26;88(8):e0020422. doi: 10.1128/aem.00204-22. Epub 2022 Apr 6.
Poultry remains a considerable source of foodborne salmonellosis despite significant reduction of Salmonella incidence during processing. There are multiple entry points for Salmonella during production that can lead to contamination during slaughter, and it is important to distinguish the serovars present between the different stages to enact appropriate controls. National Salmonella data from the U.S. Department of Agriculture-Food Safety Inspection Service (USDA-FSIS) monitoring of poultry processing was analyzed from 2016 to 2020. The overall Salmonella incidence at processing in broiler carcasses and intact parts (parts) decreased from 9.00 to 6.57% over this period. The incidence in parts was higher (11.15%) than in carcasses (4.78%). Regional differences include higher proportions of serovars Infantis and Typhimurium in the Atlantic and higher proportion of serovar Schwarzengrund in the Southeast. For Georgia, the largest broiler-producing state, USDA-FSIS data were compared to Salmonella monitoring data from breeder flocks over the same period, revealing serovar Kentucky as the major serovar in breeders (67.91%) during production but not at processing, suggesting that it is more effectively removed during antimicrobial interventions. CRISPR-SeroSeq was performed on breeder samples collected between 2020 and 2021 to explain the incongruence between pre- and postharvest and showed that 32% of samples contain multiple serovars, with up to 11 serovars found in a single flock. High-resolution sequencing identifies serovar patterns at the population level and can provide insight to develop targeted controls. The work presented may apply to other food production systems where Salmonella is a concern, since it overcomes limitations associated with conventional culture. Salmonella is a leading cause of bacterial foodborne illness in the United States, with poultry as a significant Salmonella reservoir. We show the relative decrease in Salmonella over a 5-year period from 2016 to 2020 in processed chicken parts and highlight regional differences with respect to the prevalence of clinically important Salmonella serovars. Our results show that the discrepancy between Salmonella serovars found in pre- and postharvest poultry during surveillance are due in part by the limited detection depth offered by traditional culture techniques. Despite the reduction of Salmonella at processing, the number of human salmonellosis cases has remained stable, which may be attributed to differences in virulence among serovars and their associated risk. When monitoring for Salmonella, it is imperative to identify all serovars present to appropriately assess public health risk and to implement the most effective Salmonella controls.
尽管在加工过程中沙门氏菌的发病率显著降低，但家禽仍然是食源性沙门氏菌病的一个重要来源。在生产过程中有多个沙门氏菌进入点，这可能导致屠宰过程中的污染，因此重要的是要区分不同阶段存在的血清型，以实施适当的控制。美国农业部-食品安全检验局（USDA-FSIS）对 2016 年至 2020 年期间家禽加工的国家沙门氏菌数据进行了分析。在此期间，肉鸡胴体和完整部位（部位）加工过程中的沙门氏菌总发病率从 9.00%降至 6.57%。部位的发病率（11.15%）高于胴体（4.78%）。区域差异包括大西洋地区婴儿和肠炎沙门氏菌的比例较高，东南部地区施瓦茨格伦德血清型的比例较高。对于乔治亚州，最大的肉鸡生产州，将 USDA-FSIS 数据与同期种鸡群的沙门氏菌监测数据进行了比较，结果表明，在生产过程中，肯塔基血清型是主要的血清型（67.91%），但不在加工过程中，这表明在抗菌干预期间，它更有效地被清除。对 2020 年至 2021 年间收集的种鸡样本进行了 CRISPR-SeroSeq 分析，以解释收获前和收获后之间的不一致性，并表明 32%的样本含有多种血清型，在单个鸡群中发现了多达 11 种血清型。高分辨率测序可确定种群水平的血清型模式，并可为制定有针对性的控制措施提供依据。本研究提出的方法可能适用于其他关注沙门氏菌的食品生产系统，因为它克服了与传统培养相关的局限性。沙门氏菌是美国细菌性食源性疾病的主要原因，家禽是沙门氏菌的重要储存库。我们展示了 2016 年至 2020 年期间加工鸡肉部位中沙门氏菌相对减少的情况，并强调了与临床重要沙门氏菌血清型流行有关的区域差异。我们的研究结果表明，在监测期间，在收获前和收获后的家禽中发现的沙门氏菌血清型之间的差异部分是由于传统培养技术提供的检测深度有限。尽管在加工过程中沙门氏菌减少，但人类沙门氏菌病病例数量保持稳定，这可能归因于血清型之间的毒力差异及其相关风险。在监测沙门氏菌时，必须确定所有存在的血清型，以适当评估公共健康风险，并实施最有效的沙门氏菌控制措施。
