■美国(US)的猪肉加工厂每六个月或十二个月停止运行24-48小时,以使用雾化进行剧烈消毒(IS),发泡,和进一步的抗微生物治疗,以破坏可能含有病原体和腐败生物的天然生物膜。这种处理对环境微生物的短期变化的影响尚不清楚。细菌群落的恢复速度也是如此。
■从地漏中收集拭子样品,以提供美国两家猪肉加工厂之前的代表性环境微生物,during,在IS程序之后。从冷却成品屠体的四个冷却器以及切割台附近的四个位置收集样品。每个样品通过总中温菌计数(TMC)来表征,总嗜冷剂计数(TPC),和其他指示细菌;它们的生物膜形成能力,形成的生物膜对季铵化合物的耐受性(300ppm,QAC),和保护共同接种的肠道沙门氏菌的能力。此外,使用鸟枪宏基因组测序确定细菌群落组成。
■IS程序破坏存在的细菌,但程度不同,取决于植物和植物面积。是减少TPC和TMC,最多1.5Log10CFU,仅在2-3天内恢复到IS前水平。IS对冷却器中微生物的影响是多种多样的,减少2-4Log10,需要2到4周才能恢复到IS前水平。生产线附近的结果好坏参半,一种植物几乎没有明显的变化,而在另一个,两条加工线显示4至6个Log10减少。对QAC的抗性和生物膜对沙门氏菌的保护在植物之间以及植物的区域之间也不同。在属水平上对细菌的群落分析表明,IS减少了物种多样性,并且这种破坏导致了新的群落组成,在某些情况下,即使在15至16周后也没有恢复到IS之前的状态。
■此处发现的结果表明,使用IS破坏美国猪肉加工设施中病原体或腐败微生物的存在可能不会产生预期效果。
UNASSIGNED: Pork processing plants in the United States (US) cease operations for 24-48 h every six or twelve months to perform intense
sanitization (IS) using fogging, foaming, and further antimicrobial treatments to disrupt natural biofilms that may harbor pathogens and spoilage organisms. The impact such treatments have on short-term changes in environmental microorganisms is not well understood, nor is the rate at which bacterial communities return.
UNASSIGNED: Swab samples were collected from floor drains to provide representative environmental microorganisms at two US pork processing plants before, during, and after an IS procedure. Samples were collected from four coolers where finished carcasses were chilled and from four locations near cutting tables. Each sample was characterized by total mesophile count (TMC), total psychrophile count (TPC), and other indicator bacteria; their biofilm-forming ability, tolerance of the formed biofilm to a quaternary ammonium compound (300 ppm, QAC), and ability to protect co-inoculated Salmonella enterica. In addition, bacterial community composition was determined using shotgun metagenomic sequencing.
UNASSIGNED: IS procedures disrupted bacteria present but to different extents depending on the plant and the area of the plant. IS reduced TPC and TMC, by up to 1.5 Log10 CFU only to return to pre-IS levels within 2-3 days. The impact of IS on microorganisms in coolers was varied, with reductions of 2-4 Log10, and required 2 to 4 weeks to return to pre-IS levels. The results near fabrication lines were mixed, with little to no significant changes at one plant, while at the other, two processing lines showed 4 to 6 Log10 reductions. Resistance to QAC and the protection of Salmonella by the biofilms varied between plants and between areas of the plants as well. Community profiling of bacteria at the genus level showed that IS reduced species diversity and the disruption led to new community compositions that in some cases did not return to the pre-IS state even after 15 to 16 weeks.
UNASSIGNED: The results found here reveal the impact of using IS to disrupt the presence of pathogen or spoilage microorganisms in US pork processing facilities may not have the intended effect.