Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product
Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus (S. aureus) are the cause of Saphylococcal food poisoning (SFP) outbreaks. Thus, estimation of the time to detection (TTD) of SEs, that is, the time required to reach the SEs detection limit, is essential for food preservation and q...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-07-01
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| Series: | Frontiers in Microbiology |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fmicb.2018.01536/full |
| _version_ | 1818028436433666048 |
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| author | Jieyun Hu Lu Lin Min Chen Weiling Yan |
| author_facet | Jieyun Hu Lu Lin Min Chen Weiling Yan |
| author_sort | Jieyun Hu |
| collection | DOAJ |
| description | Staphylococcal enterotoxins (SEs) produced by Staphylococcus aureus (S. aureus) are the cause of Saphylococcal food poisoning (SFP) outbreaks. Thus, estimation of the time to detection (TTD) of SEs, that is, the time required to reach the SEs detection limit, is essential for food preservation and quantitative risk assessment. This study was conducted to explore an appropriate method to predict the TTD of SEs in cooked chicken product under variable environmental conditions. An S. aureus strain that produces staphylococcal enterotoxin A (SEA) was inoculated into cooked chicken meat. Initial inoculating concentrations (approximately 102, 103, 104 CFU/g) of S. aureus and incubation temperatures (15 ± 1, 22 ± 1, 29 ± 1, and 36 ± 1°C) were chosen as environmental variables. The counting of S. aureus colonies and the detection of SEA were performed every 3 or 6 h during the incubation. The TTD of SEA was considered a response of S. aureus to environmental variables. Linear polynomial regression was used to model the effects of environmental variables on the TTD of SEA. Result showed that the correlation coefficient (R2) of the regressed equation is higher than 0.98, which means the obtained equation was reliable. Moreover, the minimum concentration of S. aureus for producing a detectable amount of SEA under various environmental conditions was approximately 6.32 log CFU/g, which was considered the threshold for S. aureus to produce SEA. Hence, the TTD of SEA could be obtained by calculating the time required to reach the threshold by using an established S. aureus growth predictive model. Both established methods were validated through internal and external validation. The results of graphical comparison, RMSE, SEP, Af, and Bf showed that the accuracy of both methods were acceptable, and linear polynomial regression method showed more accurately. |
| first_indexed | 2024-12-10T05:03:46Z |
| format | Article |
| id | doaj.art-2a4a56e061b249719928167c105ee705 |
| institution | Directory Open Access Journal |
| issn | 1664-302X |
| language | English |
| last_indexed | 2024-12-10T05:03:46Z |
| publishDate | 2018-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Microbiology |
| spelling | doaj.art-2a4a56e061b249719928167c105ee7052022-12-22T02:01:18ZengFrontiers Media S.A.Frontiers in Microbiology1664-302X2018-07-01910.3389/fmicb.2018.01536347127Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken ProductJieyun Hu0Lu Lin1Min Chen2Weiling Yan3Shanghai Food Research Institute, Shanghai, ChinaShanghai Food Research Institute, Shanghai, ChinaShanghai Municipal Center for Disease Control and Prevention, Shanghai, ChinaShanghai Food Research Institute, Shanghai, ChinaStaphylococcal enterotoxins (SEs) produced by Staphylococcus aureus (S. aureus) are the cause of Saphylococcal food poisoning (SFP) outbreaks. Thus, estimation of the time to detection (TTD) of SEs, that is, the time required to reach the SEs detection limit, is essential for food preservation and quantitative risk assessment. This study was conducted to explore an appropriate method to predict the TTD of SEs in cooked chicken product under variable environmental conditions. An S. aureus strain that produces staphylococcal enterotoxin A (SEA) was inoculated into cooked chicken meat. Initial inoculating concentrations (approximately 102, 103, 104 CFU/g) of S. aureus and incubation temperatures (15 ± 1, 22 ± 1, 29 ± 1, and 36 ± 1°C) were chosen as environmental variables. The counting of S. aureus colonies and the detection of SEA were performed every 3 or 6 h during the incubation. The TTD of SEA was considered a response of S. aureus to environmental variables. Linear polynomial regression was used to model the effects of environmental variables on the TTD of SEA. Result showed that the correlation coefficient (R2) of the regressed equation is higher than 0.98, which means the obtained equation was reliable. Moreover, the minimum concentration of S. aureus for producing a detectable amount of SEA under various environmental conditions was approximately 6.32 log CFU/g, which was considered the threshold for S. aureus to produce SEA. Hence, the TTD of SEA could be obtained by calculating the time required to reach the threshold by using an established S. aureus growth predictive model. Both established methods were validated through internal and external validation. The results of graphical comparison, RMSE, SEP, Af, and Bf showed that the accuracy of both methods were acceptable, and linear polynomial regression method showed more accurately.https://www.frontiersin.org/article/10.3389/fmicb.2018.01536/fullpredictive microbiologyStaphylococcus aureusStaphylococcal enterotoxinstime to detectioncooked chicken |
| spellingShingle | Jieyun Hu Lu Lin Min Chen Weiling Yan Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product Frontiers in Microbiology predictive microbiology Staphylococcus aureus Staphylococcal enterotoxins time to detection cooked chicken |
| title | Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product |
| title_full | Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product |
| title_fullStr | Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product |
| title_full_unstemmed | Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product |
| title_short | Modeling for Predicting the Time to Detection of Staphylococcal Enterotoxin A in Cooked Chicken Product |
| title_sort | modeling for predicting the time to detection of staphylococcal enterotoxin a in cooked chicken product |
| topic | predictive microbiology Staphylococcus aureus Staphylococcal enterotoxins time to detection cooked chicken |
| url | https://www.frontiersin.org/article/10.3389/fmicb.2018.01536/full |
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