Kinetic Behavior of Salmonella on Low NaNO2 Sausages during Aerobic and Vacuum Storage

Jimyeong Ha,Eunji Gwak,Mi Hwa Oh,Beomyoung Park,Jeeyeon Lee,Sejeong Kim,Heeyoung Lee,Soomin Lee,Yohan Yoon 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.2

Abstract This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO2). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO2 (0 and 10 ppm) followed by aerobic or vacuum storage at 10°C and 15°C for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (p<0.05) with 10 ppm NaNO2 concentration than with 0 ppm NaNO2. The GR values of Salmonella decreased (p<0.05) as NaCl concentration increased, especially at 10oC. This result indicates that 10 ppm NaNO2 may increase Salmonella growth at low NaCl concentrations, and that NaCl plays an important role in inhibiting Salmonella growth in sausages with low NaNO2.

High Prevalence of Listeria monocytogenes in Smoked Duck: Antibiotic and Heat Resistance, Virulence, and Genetics of the Isolates

Park, Eunyoung,Ha, Jimyeong,Oh, Hyemin,Kim, Sejeong,Choi, Yukyung,Lee, Yewon,Kim, Yujin,Seo, Yeongeun,Kang, Joohyun,Yoon, Yohan Korean Society for Food Science of Animal Resource 2021 한국축산식품학회지 Vol.41 No.2

This study aimed at determining the genetic and virulence characteristics of the Listeria monocytogenes from smoked ducks. L. monocytogenes was isolated by plating, and the isolated colonies were identified by PCR. All the obtained seven L. monocytogenes isolates possessed the virulence genes (inlA, inlB, plcB, and hlyA) and a 385 bp actA amplicon. The L. monocytogenes isolates (SMFM2018 SD 1-1, SMFM 2018 SD 4-1, SMFM 2018 SD 4-2, SMFM 2018 SD 5-2, SMFM 2018 SD 5-3, SMFM 2018 SD 6-2, and SMFM 2018 SD 7-1) were inoculated in tryptic soy broth (TSB) containing 0.6% yeast extract at 60℃, followed by cell counting on tryptic soy agar (TSA) containing 0.6% yeast extract at 0, 2, 5, 8, and 10 min. We identified five heat resistant isolates compared to the standard strain (L. monocytogenes ATCC13932), among which three exhibited the serotype 1/2b and D-values of 5.41, 6.48, and 6.71, respectively at 60℃. The optical densities of the cultures were regulated to a 0.5 McFarland standard to assess resistance against nine antibiotics after an incubation at 30℃ for 24 h. All isolates were penicillin G resistant, possessing the virulence genes (inlA, inlB, plcB, and hlyA) and the 385-bp actA amplicon, moreover, three isolates showed clindamycin resistance. In conclusion, this study allowed us to characterize L. monocytogenes isolates from smoked ducks, exhibiting clindamycin and penicillin G resistance, along with the 385-bp actA amplicon, representing higher invasion efficiency than the 268-bp actA, and the higher heat resistance serotype 1/2b.

보육교사의 자기지도성이 회복탄력성에 미치는 영향

홍지명 ( Jimyeong Hong ),박예현 ( Yehyun Park ) 아시아문화학술원 2019 인문사회 21 Vol.10 No.1

보육교사의 역할과 자질의 중요성이 강조됨에 따라 교사의 내적 요인에 대한 관심이 증가하고 있다. 이에 본 연구는 보육교사의 자기지도성과 회복탄력성의 관계와 자기지도성이 회복탄력성에 미치는 영향력을 알아보는데 목적이 있다. 연구대상은 J지역 어린이집에 재직 중인 보육교사 255명이며, 자료 분석은 SPSS 22.0 프로그램을 이용하여 Pearson의 상관분석과 단순회귀분석, 위계적 중다회귀 분석을 실시하였다. 연구결과 첫째, 보육교사의 자기지도성과 회복탄력성은 정적 상관관계가 있는 것으로 나타났다. 둘째, 보육교사의 자기지도성은 회복탄력성 및 하위 요인에 유의미한 영향을 미쳤으며 자기지도성의 하위 요인 또한 회복탄력성에 유의미한 영향을 미치는 것으로 나타났다. 결론적으로 본 연구는 보육교사의 자기지도성이 회복탄력성을 높이는 관련 변인이 됨을 밝힘과 동시에 보육교사의 자기지도성과 회복탄력성 증진을 위한 심리적ㆍ행정적 지원 방안과 프로그램 개발의 기초자료로 활용될 수 있으며 이를 통해 보육의 질을 높일 수 있음을 시사한다. As the importance of the roles and qualities of child care teachers is emphasized, the interest of teachers’ internal factors is increasing. The purpose of this study is to investigate the relationship between self-leadership and resilience of child care teachers and the influence of self-leadership on resilience. The subjects of this study were 255 teachers working in J district. The data were analyzed using SPSS 22.0 program, Pearson 's correlation analysis, simple regression analysis, hierarchical multiple regression analysis Respectively. The results of this study are as follows: First, there is a positive correlation between self-leadership and resilience of child care teachers. Second, the self-leadership of the child care teachers had a significant effect on the resilience and sub factors, and the sub factors of self-leadership had a significant effect on the resilience. In conclusion, this study suggests that self-leadership of the teacher is a related variable to increase resilience, and it is also used as basic data for the development of psychological and administrative support programs and programs to promote self-direction and resilience of child care teachers, and suggests that the quality of child care can be enhanced.

Kinetic Behavior of Salmonella on Low NaNO₂ Sausages during Aerobic and Vacuum Storage

Ha, Jimyeong,Gwak, Eunji,Oh, Mi-Hwa,Park, Beomyoung,Lee, Jeeyeon,Kim, Sejeong,Lee, Heeyoung,Lee, Soomin,Yoon, Yohan,Choi, Kyoung-Hee Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.2

This study evaluated the growth kinetics of Salmonella spp. in processed meat products formulated with low sodium nitrite (NaNO₂). A 5-strain mixture of Salmonella spp. was inoculated on 25-g samples of sausages formulated with sodium chloride (NaCl) (1.0%, 1.25%, and 1.5%) and NaNO₂ (0 and 10 ppm) followed by aerobic or vacuum storage at 10℃ and 15℃ for up to 816 h or 408 h, respectively. The bacterial cell counts were enumerated on xylose lysine deoxycholate agar, and the modified Gompertz model was fitted to the Salmonella cell counts to calculate the kinetic parameters as a function of NaCl concentration on the growth rate (GR; Log CFU/g/h) and lag phase duration (LPD; h). A linear equation was then fitted to the parameters to evaluate the effect of NaCl concentration on the kinetic parameters. The GR values of Salmonella on sausages were higher (p<0.05) with 10 ppm NaNO₂ concentration than with 0 ppm NaNO₂. The GR values of Salmonella decreased (p<0.05) as NaCl concentration increased, especially at 10℃. This result indicates that 10 ppm NaNO₂ may increase Salmonella growth at low NaCl concentrations, and that NaCl plays an important role in inhibiting Salmonella growth in sausages with low NaNO₂.

Mathematical Model for Predicting the Growth Probability of Staphylococcus aureus in Combinations of NaCl and NaNO2 under Aerobic or Evacuated Storage Conditions

Jeeyeon Lee,Eunji Gwak,Jimyeong Ha,Sejeong Kim,Soomin Lee,Heeyoung Lee,Mi-Hwa Oh,Beom-Young Park,Nam Su Oh,Kyoung-Hee Choi,Yohan Yoon 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.6

The objective of this study was to describe the growth patterns of Staphylococcus aureus in combinations of NaCl and NaNO2, using a probabilistic model. A mixture of S. aureus strains (NCCP10826, ATCC13565, ATCC14458, ATCC23235, and ATCC27664) was inoculated into nutrient broth plus NaCl (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and NaNO2 (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm). The samples were then incubated at 4, 7, 10, 12 and 15°C for up to 60 d under aerobic or vacuum conditions. Growth responses [growth (1) or no growth (0)] were then determined every 24 h by turbidity, and analyzed to select significant parameters (p<0.05) by a stepwise selection method, resulting in a probabilistic model. The developed models were then validated with observed growth responses. S. aureus growth was observed only under aerobic storage at 10-15°C. At 10-15°C, NaCl and NaNO2 did not inhibit S. aureus growth at less than 1.25% NaCl. Concentration dependency was observed for NaCl at more than 1.25%, but not for NaNO2. The concordance percentage between observed and predicted growth data was approximately 93.86%. This result indicates that S. aureus growth can be inhibited in vacuum packaging and even aerobic storage below 10°C. Furthermore, NaNO2 does not effectively inhibit S. aureus growth.

Probabilistic Models to Predict Listeria monocytogenes Growth at Low Concentrations of NaNO2 and NaCl in Frankfurters

Eunji Gwak,Mi Hwa Oh,Beom Young Park,Heeyoung Lee,Soomin Lee,Jimyeong Ha,Jeeyeon Lee,Sejeong Kim,Kyoung Hee Choi 한국축산식품학회 2015 한국축산식품학회지 Vol.35 No.6

This study developed probabilistic models to describe Listeria monocytogenes growth responses in meat products with low concentrations of NaNO2 and NaCl. A five-strain mixture of L. monocytogenes was inoculated in NBYE (nutrient broth plus 0.6% yeast extract) supplemented with NaNO2 (0-141 ppm) and NaCl (0-1.75%). The inoculated samples were then stored under aerobic and anaerobic conditions at 4, 7, 10, 12, and 15°C for up to 60 d. Growth response data [growth (1) or no growth (0)] for each combination were determined by turbidity. The growth response data were analyzed using logistic regression to predict the growth probability of L. monocytogenes as a function of NaNO2 and NaCl. The model performance was validated with the observed growth responses. The effect of an obvious NaNO2 and NaCl combination was not observed under aerobic storage condition, but the antimicrobial effect of NaNO2 on the inhibition of L. monocytogenes growth generally increased as NaCl concentration increased under anaerobic condition, especially at 7-10°C. A single application of NaNO2 or NaCl significantly (p<0.05) inhibited L. monocytogenes growth at 4-15°C, but the combination of NaNO2 or NaCl more effectively (p<0.05) inhibited L. monocytogenes growth than single application of either compound under anaerobic condition. Validation results showed 92% agreement between predicted and observed growth response data. These results indicate that the developed model is useful in predicting L. monocytogenes growth response at low concentrations of NaNO2 and NaCl, and the antilisterial effect of NaNO2 increased by NaCl under anaerobic condition.

Electrospray ionization tandem mass fragmentation pattern of camostat and its degradation product, 4-(4-guanidinobenzoyloxy)phenylacetic acid

Soonho Kwon(권순호),Hye-Jin Shin(신혜진),Jimyeong Park(박지명),Kyoung-Ryul Lee(이경률),Young-Jin Kim(김영진),Sanghoo Lee(이상후) 한국분석과학회 2011 분석과학 Vol.24 No.2

Mathematical Model for Predicting the Growth Probability of Staphylococcus aureus in Combinations of NaCl and NaNO₂ under Aerobic or Evacuated Storage Conditions

Lee, Jeeyeon,Gwak, Eunji,Ha, Jimyeong,Kim, Sejeong,Lee, Soomin,Lee, Heeyoung,Oh, Mi-Hwa,Park, Beom-Young,Oh, Nam Su,Choi, Kyoung-Hee,Yoon, Yohan Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.6

The objective of this study was to describe the growth patterns of Staphylococcus aureus in combinations of NaCl and $NaNO_2$, using a probabilistic model. A mixture of S. aureus strains (NCCP10826, ATCC13565, ATCC14458, ATCC23235, and ATCC27664) was inoculated into nutrient broth plus NaCl (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and $NaNO_2$ (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm). The samples were then incubated at 4, 7, 10, 12 and $15^{\circ}C$ for up to 60 d under aerobic or vacuum conditions. Growth responses [growth (1) or no growth (0)] were then determined every 24 h by turbidity, and analyzed to select significant parameters (p<0.05) by a stepwise selection method, resulting in a probabilistic model. The developed models were then validated with observed growth responses. S. aureus growth was observed only under aerobic storage at $10-15^{\circ}C$. At $10-15^{\circ}C$, NaCl and $NaNO_2$ did not inhibit S. aureus growth at less than 1.25% NaCl. Concentration dependency was observed for NaCl at more than 1.25%, but not for $NaNO_2$. The concordance percentage between observed and predicted growth data was approximately 93.86%. This result indicates that S. aureus growth can be inhibited in vacuum packaging and even aerobic storage below $10^{\circ}C$. Furthermore, $NaNO_2$ does not effectively inhibit S. aureus growth.

Risk assessment of vibriosis by Vibrio cholerae and Vibrio vulnificus in whip-arm octopus consumption in South Korea

Oh, Hyemin,Yoon, Yohan,Ha, Jimyeong,Lee, Jeeyeon,Shin, Il-Shik,Kim, Young-Mog,Park, Kwon-Sam,Kim, Sejeong The Korean Society of Fisheries and Aquatic Scienc 2021 Fisheries and Aquatic Sciences Vol.24 No.6

This study evaluated the risk of foodborne illness from highly pathogenic Vibrio spp. (Vibrio vulnificus and V. cholerae) by raw whip-arm octopus (Octopus minor) consumption. In total 180 samples of raw whip-arm octopus were collected from markets and examined for the prevalence of V. vulnificus and V. cholerae. Predictive models describing the kinetic behavior of Vibrio spp. in raw whip-arm octopus were developed, and the data on amounts and frequency of raw whip-arm octopus consumption were collected. Using the collected data, a risk assessment simulation was conducted to estimate the probability of foodborne illness raw whip-arm octopus consumption using @RISK. Initial contamination levels of Vibrio spp. in raw whip-arm octopus were -3.9 Log colony-forming unit/g, as estimated by beta distribution fitting. The developed predictive models were appropriate to describe Vibrio spp. in raw whip-arm octopus during distribution and storage with R² values of 0.946-0.964. The consumption frequency and daily consumption amounts of raw whip-arm octopus per person were 0.47% and 57.65 g, respectively. The probability of foodborne illness from raw whip-arm octopus consumption was estimated to be 8.71 × 10^-15 for V. vulnificus and 7.08 × 10^-13 for V. cholerae. These results suggest that the risk of Vibrio spp. infection from raw whip-arm octopus consumption is low in South Korea.

Probabilistic Models to Predict Listeria monocytogenes Growth at Low Concentrations of NaNO₂ and NaCl in Frankfurters

Gwak, Eunji,Oh, Mi-Hwa,Park, Beom-Young,Lee, Heeyoung,Lee, Soomin,Ha, Jimyeong,Lee, Jeeyeon,Kim, Sejeong,Choi, Kyoung-Hee,Yoon, Yohan Korean Society for Food Science of Animal Resource 2015 한국축산식품학회지 Vol.35 No.6

This study developed probabilistic models to describe Listeria monocytogenes growth responses in meat products with low concentrations of NaNO₂ and NaCl. A five-strain mixture of L. monocytogenes was inoculated in NBYE (nutrient broth plus 0.6% yeast extract) supplemented with NaNO₂ (0-141 ppm) and NaCl (0-1.75%). The inoculated samples were then stored under aerobic and anaerobic conditions at 4, 7, 10, 12, and 15℃ for up to 60 d. Growth response data [growth (1) or no growth (0)] for each combination were determined by turbidity. The growth response data were analyzed using logistic regression to predict the growth probability of L. monocytogenes as a function of NaNO₂ and NaCl. The model performance was validated with the observed growth responses. The effect of an obvious NaNO₂ and NaCl combination was not observed under aerobic storage condition, but the antimicrobial effect of NaNO₂ on the inhibition of L. monocytogenes growth generally increased as NaCl concentration increased under anaerobic condition, especially at 7-10℃. A single application of NaNO₂ or NaCl significantly (p<0.05) inhibited L. monocytogenes growth at 4-15℃, but the combination of NaNO₂ or NaCl more effectively (p<0.05) inhibited L. monocytogenes growth than single application of either compound under anaerobic condition. Validation results showed 92% agreement between predicted and observed growth response data. These results indicate that the developed model is useful in predicting L. monocytogenes growth response at low concentrations of NaNO₂ and NaCl, and the antilisterial effect of NaNO₂ increased by NaCl under anaerobic condition.