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. 2022 Mar 24:13:828279.
doi: 10.3389/fmicb.2022.828279. eCollection 2022.

Analysis of Key Control Points of Microbial Contamination Risk in Pork Production Processes Using a Quantitative Exposure Assessment Model

Tengteng Yang  1   2 , Ge Zhao  1 , Yunzhe Liu  1 , Lin Wang  1 , Yubin Gao  1 , Jianmei Zhao  1 , Na Liu  1 , Xiumei Huang  1 , Qingqing Zhang  1 , Junhui Liu  1 , Xiyue Zhang  1 , Junwei Wang  1 , Ying Xu  2
Affiliations

Analysis of Key Control Points of Microbial Contamination Risk in Pork Production Processes Using a Quantitative Exposure Assessment Model

Tengteng Yang et al. Front Microbiol. .

Abstract

Pork is one of the most common foods causing microbial foodborne diseases. Since pork directly enters the market after slaughtering, the control of microbial contamination in the slaughtering processes is the key to ensuring the quality and safety of pork. The contamination level of Escherichia coli, a health-indicator bacterium, can reflect the risk level of potential pathogens. In order to assess the E. coli exposure risk of pork during slaughtering and to identify the key control points, we established an E. coli quantitative exposure assessment model for swine-slaughtering processes in slaughterhouses of different sizes. The model simulation data indicated the E. coli contamination pattern on the surfaces of swine carcasses during slaughtering. The changes in E. coli contamination were analyzed according to the simulation data of each slaughtering process. It was found that the number of E. coli after trimming in big and small slaughterhouses increased to the maximum values for the whole processes, which were 3.63 and 3.52 log10 CFU/100 cm2, respectively. The risk contribution of each slaughtering process to the E. coli contamination on the surface of terminal swine carcasses can be determined by correlation analysis. Because the absolute value of correlation coefficient during the trimming process was maximum (0.49), it was regarded as the most important key control point. This result can be further proved via the multilocus sequence typing of E. coli. The dominant sequence type before trimming processes was ST10. ST1434 began to appear in the trimming process and then became the dominant sequence type in the trimming and pre-cooling processes. The model can provide a theoretical basis for microbial hygiene supervision and risk control in swine-slaughtering processes.

Keywords: key control points; microbial contamination risk; multilocus sequence typing; quantitative exposure assessment model; swine-slaughtering processes.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

FIGURE 1
FIGURE 1
Escherichia coli contamination of surfaces of swine carcasses in slaughterhouses of different sizes. (A) Number of E. coli in all swine slaughterhouses. (B) Number of E. coli in small swine slaughterhouses. (C) Number of E. coli in big swine slaughterhouses. **means the statistical difference between this process and the previous process is extremely significant (P < 0.01).
FIGURE 2
FIGURE 2
Probability distribution of Escherichia coli contamination of swine carcasses after pre-cooling in slaughterhouses of different sizes. (A) Probability distribution of E. coli contamination of swine carcasses after pre-cooling in all swine slaughterhouses. (B) Probability distribution of E. coli contamination of swine carcasses after pre-cooling in small swine slaughterhouses. (C) Probability distribution of E. coli contamination of swine carcasses after pre-cooling in big swine slaughterhouses. N5- Log number of E. coli on swine carcasses after pre-cooling.
FIGURE 3
FIGURE 3
Escherichia coli contamination simulated by exposure model of slaughterhouses of different sizes. (A) E. coli contamination simulated by exposure model of all slaughterhouses. (B) E. coli contamination simulated by exposure model of small swine slaughterhouses. (C) E. coli contamination simulated by exposure model of big swine slaughterhouses.
FIGURE 4
FIGURE 4
Sensitivity analysis of each slaughtering processes in the model. (A) Sensitivity analysis of each slaughtering process in all swine slaughterhouses. (B) Sensitivity analysis of each slaughtering process in small swine slaughterhouses. (C) Sensitivity analysis of each slaughtering process in big swine slaughterhouses. Lcp-Log number of Escherichia coli changed through pre-cooling;Lct-Log number of E. coli changed through trimming;Lcw-Log number of E. coli changed through washing;Lce- Log number of E. coli changed through eviscerating;Las- Log number of E. coli after skinning.
FIGURE 5
FIGURE 5
Isolation rate of Salmonella in different slaughtering processes.
FIGURE 6
FIGURE 6
The minimum spanning tree of 51 strains of Escherichia coli.
See this image and copyright information in PMC

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