Souad Regguem, Mossadak Hamdi Taha, Leila Bouayad
Laboratory of Food Hygiene and Quality Insurance System (HASAQ), Higher National Veterinary School, Rue Issad Abbes, Oued Smar, Algiers 16000, Algeria.
Vet World. 2021 Sep;14(9):2317-2324. doi: 10.14202/vetworld.2021.2317-2324. Epub 2021 Sep 4.
There is a worldwide controversy about the choice of microbial flora for use as process hygiene indicators. This study aimed to evaluate the pertinence of using either coliforms or Enterobacteriaceae (EB) as process hygiene indicators in the pasteurized milk production line. Two flora families and total flora were used as bacterial indicators in some stages of pasteurized milk production line to identify the origin of post-pasteurization contamination and compare the results obtained for each flora. In addition, the bacteriological profile of isolated coliforms and EB was developed.
One thousand and two hundred samples of pasteurized cow milk and surfaces (pipes and tank) at various processing stages were taken from two dairies in the northern region of Algeria. The total microbial flora (TF), total coliforms (TC), thermotolerant coliforms, and EB were enumerated, following the recommendations of ISO 4833:2006, ISO 4832:2006, and ISO 21528-2:2017 methods, respectively. The bacteriological profile was determined using the API 20E and 10S tests (bioMérieux, France). Furthermore, the cleaning efficiency and disinfection protocol of surfaces were evaluated using contact agar slides 1 (Liofilchem™, Italy).
Enumeration of the different indicators shows that the highest contamination rate is recorded by the total flora in the two units, 3.28 and 3.78 log CFU/mL, respectively. EB (-0.60 log CFU/mL) at post-pasteurization stage in Unit 1 and coliforms (0.44 log CFU/mL) at the pasteurized packaged milk stage in Unit 2 are the least significant germ families. The lowest compliance rates of bacterial contamination were reported for total flora (82-85%) at the three sampled sites in Unit 2. In comparison, the highest was reported in Unit 1 (99.8%) and 2 (98%) by the EB indicator. Assessing the surface cleaning and disinfection protocol compliance shows that the tank records the highest non-compliance rates for EB and TF (4% and 3%) in Unit 2. EB are represented in both units by various species. in Unit 1 and in Unit 2 are the common species of the three indicator families. and in Unit 1, , , , , and in Unit 2 are the most time persistent bacterial genera along the production line. , , and are common genera in both units.
The results obtained show no difference in the use of EB or TC as hygiene indicators. However, if the objective is to identify the species of bacterial populations, using EBs are the most appropriate.
关于选择何种微生物菌群作为过程卫生指标，在全球范围内存在争议。本研究旨在评估在巴氏杀菌牛奶生产线中使用大肠菌群或肠杆菌科（EB）作为过程卫生指标的相关性。在巴氏杀菌牛奶生产线的某些阶段，将两个菌群家族和总菌群用作细菌指标，以确定巴氏杀菌后污染的来源，并比较每种菌群获得的结果。此外，还分析了分离出的大肠菌群和EB的细菌学特征。
从阿尔及利亚北部地区的两个乳品厂采集了1200份不同加工阶段的巴氏杀菌牛奶及表面（管道和罐体）样本。分别按照ISO 4833:2006、ISO 4832:2006和ISO 21528-2:2017方法的建议，对总微生物菌群（TF）、总大肠菌群（TC）、耐热大肠菌群和EB进行计数。使用API 20E和10S测试（法国生物梅里埃公司）确定细菌学特征。此外，使用接触琼脂玻片1（意大利Liofilchem™）评估表面的清洁效率和消毒方案。
对不同指标的计数表明，两个工厂中总菌群的污染率最高，分别为3.28和3.78 log CFU/mL。工厂1巴氏杀菌后阶段的EB（-0.60 log CFU/mL）和工厂2巴氏杀菌包装牛奶阶段的大肠菌群（0.44 log CFU/mL）是最不显著的菌群家族。工厂2三个采样点的总菌群细菌污染合规率最低（分别为82 - 85%）。相比之下，工厂1（99.8%）和工厂2（98%）的EB指标报告的合规率最高。对表面清洁和消毒方案合规性的评估表明，工厂2的罐体记录了EB和TF的最高不合规率（分别为4%和3%）。两个工厂中的EB均由多种物种组成。工厂1的 和工厂2的 是三个指标菌群的常见物种。工厂1的 、 和工厂2的 、 、 、 和 是生产线上最持久的细菌属。 、 和 是两个工厂中的常见属。
获得的结果表明，使用EB或TC作为卫生指标没有差异。然而，如果目标是识别细菌种群的物种，使用EB是最合适的。
