• Title/Summary/Keyword: predictive microbiology

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Risk Assessment for Salmonellosis in Chicken in South Korea: The Effect of Salmonella Concentration in Chicken at Retail

  • Jeong, Jaewoon;Chon, Jung-Whan;Kim, Hyunsook;Song, Kwang-Young;Seo, Kun-Ho
    • Food Science of Animal Resources
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    • v.38 no.5
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    • pp.1043-1054
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    • 2018
  • Salmonellosis caused by chicken consumption has been a critical issue in food safety worldwide, including in Korea. The probability of illness from consumption of chicken was simulated in study, based on the recipe of Dakgalbi, a commonly eaten chicken dish in Korea. Additionally, the processing stage at slaughterhouses to decrease Salmonella concentration in broilers was modeled to explore its effect on the likelihood of illness. A Monte Carlo simulation model was created using @RISK. Prevalence of Salmonella in chickens at the retail stage was found to be predominantly important in determining the probability of illness. Other than the prevalence, cooking temperature was found to have the largest impact on the probability of illness. The results also demonstrated that, although chlorination is a powerful tool for decreasing the Salmonella concentration in chicken, this effect did not last long and was negated by the following stages. This study analyzes the effects of variables of the retail-to-table pathway on the likelihood of salmonellosis in broiler consumption, and also evaluates the processing step used to decrease the contamination level of Salmonella in broilers at slaughterhouses. According to the results, we suggest that methods to decrease the contamination level of Salmonella such as chlorination had little effect on decreasing the probability of illness. Overall, these results suggest that preventing contamination of broiler with Salmonella must be a top priority and that methods to reduce the concentration of Salmonella in broilers at slaughterhouses hardly contribute to safe consumption of Salmonella-contaminated chicken.

Predictive Value of Excision Repair Cross-complementing Rodent Repair Deficiency Complementation Group 1 and Ovarian Cancer Risk

  • He, Shan-Yang;Xu, Lin;Niu, Gang;Ke, Pei-Qi;Feng, Miao-Miao;Shen, Hong-Wei
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.5
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    • pp.1799-1802
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    • 2012
  • Objective: We aimed to analyze the association between excision repair cross-complementing rodent repair deficiency complementation group 1 (XRCC1) and ovarian cancer risk. Methods: We performed a hospital-based case-control study with 155 cases and 313 controls in China. All Chinese cases with newly diagnosed primary ovarian cancer between May 2005 to May 2010 in our hospital were invited to participate within 2 months of diagnosis. Controls were randomly selected from people who requested general health examinations in the same hospital during the same period. SNPs in EXCC1, ERCC1 C8092A and ERCC1 T19007C, were analyzed by PCR-RFLP method. Results: We observed a non-significantly increased risk of ovarian cancer among individuals with ERCC1 8092TT compared with those with the 8092CC genotype (adjusted OR=1.55, 95% CI%=0.74-2.97). Moreover, 19007TT genotype carriers also showed a non-significant increased risk of ovarian cancer over those with the 19007CC genotype (adjusted OR=1.78, 95% CI%=0.91-3.64). Conclusion: Our firstly investigation of links between polymorphisms in the ERCC1 gene and the risk of ovarian cancer in Chinese population demonstrated no significant association. Further large sample studies in Chinese populations are needed.

Evaluation of Two ELISA and Two Indirect Hemagglutination Tests for Serodiagnosis of Pulmonary Hydatid Disease

  • Eris, Fatma Nur;Akisu, Ciler;Aksoy, Umit
    • Parasites, Hosts and Diseases
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    • v.47 no.4
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    • pp.427-429
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    • 2009
  • To establish a definite diagnosis for pulmonary hydatid disease, combination of radiology and serology is useful. In this study, 19 preoperative sera from patients with surgically confirmed pulmonary hydatidosis, 40 sera from patients with other parasitosis and pulmonary diseases, and 20 sera from healthy donors were evaluated using 4 different serological tests, i.e., the commercial ELISA (ELISA-kit) test, the ELISA (ELISA-lab) test prepared in our laboratory, the commercial indirect hemagglutination assay kit (IHA-kit) test, and the IHA test using sensitized sheep red blood cells with tannic acid (IHA-TA). The ELISA-kit was the most sensitive (84.2%) and the most specific test (100.0%). The ELISA-kit also demonstrated the highest positive (100.0%) and negative (95.2%) predictive values. The sensitivity of the ELISA-lab test, that we prepared, was found to be 73.6%, whereas the IHA-kit test and the IHA-TA test were found to be 73.6% and 68.4%, respectively. The specificity of these tests was 96.6%, 98.3%, and 83.3%, respectively. When all 4 tests were assessed together, it was found that the sensitivity had risen to 94.7%. When the ELISA-kit was assessed with the IHA-kit and IHA-TA together, it was found that the sensitivity was 89.5% and 84.2%, respectively. Likewise, the combination of the ELISA-lab and IHA-kit or IHA-TA allowed us to achieve a sensitivity of 84.2% in cases of pulmonary echinococcosis. In conclusion, the diagnosis would be imminent if least 2 tests were applied together.

Prediction of Listeria monocytogenes Growth Kinetics in Sausages Formulated with Antimicrobials as a Function of Temperature and Concentrations

  • Bang, Woo-Suk;Chung, Hyun-Jung;Jin, Sung-Sik;Ding, Tian;Hwang, In-Gyun;Woo, Gun-Jo;Ha, Sang-Do;Bahk, Gyung-Jin;Oh, Deog-Hwan
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1316-1321
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    • 2008
  • This study was conducted to develop a model to describe the effect of antimicrobials [potassium sorbate (PS), potassium lactate (PL), and combined PL and sodium diacetate (SDA, PLSDA)] on the growth parameters of Listeria monocytogenes such as specific growth rate (SGR) and lag phase periods (LT) in air-dried raw sausages as a function of storage temperature (4, 10, 16, and $25^{\circ}C$). Results showed that the SGR of L monocytogenes was dependent on the storage temperature and level of antimicrobials used. The most effective treatment was the 4% PLSDA, followed by the 2% PLSDA and 4% PL and 0.2% PS exhibited the least antimicrobial effect. Increased growth rates were observed with increasing storage temperatures from 4 to $25^{\circ}C$. The growth data were fitted with a Gompertz equation to determine the SGR and LT of the L. monocytogenes. Six polynomial models were developed for the SGR and LT to evaluate the effect of PS (0.1, 0.2%) and PL (2,4%) alone and PLSDA (2, 4%) on the growth kinetics of L. monocytogenes from 4 to $25^{\circ}C$.

Machine learning based anti-cancer drug response prediction and search for predictor genes using cancer cell line gene expression

  • Qiu, Kexin;Lee, JoongHo;Kim, HanByeol;Yoon, Seokhyun;Kang, Keunsoo
    • Genomics & Informatics
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    • v.19 no.1
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    • pp.10.1-10.7
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    • 2021
  • Although many models have been proposed to accurately predict the response of drugs in cell lines recent years, understanding the genome related to drug response is also the key for completing oncology precision medicine. In this paper, based on the cancer cell line gene expression and the drug response data, we established a reliable and accurate drug response prediction model and found predictor genes for some drugs of interest. To this end, we first performed pre-selection of genes based on the Pearson correlation coefficient and then used ElasticNet regression model for drug response prediction and fine gene selection. To find more reliable set of predictor genes, we performed regression twice for each drug, one with IC50 and the other with area under the curve (AUC) (or activity area). For the 12 drugs we tested, the predictive performance in terms of Pearson correlation coefficient exceeded 0.6 and the highest one was 17-AAG for which Pearson correlation coefficient was 0.811 for IC50 and 0.81 for AUC. We identify common predictor genes for IC50 and AUC, with which the performance was similar to those with genes separately found for IC50 and AUC, but with much smaller number of predictor genes. By using only common predictor genes, the highest performance was AZD6244 (0.8016 for IC50, 0.7945 for AUC) with 321 predictor genes.

Mathematical Models to Predict Staphylococcus aureus Growth on Processed Cheeses

  • Kim, Kyungmi;Lee, Heeyoung;Moon, Jinsan;Kim, Youngjo;Heo, Eunjeong;Park, Hyunjung;Yoon, Yohan
    • Journal of Food Hygiene and Safety
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    • v.28 no.3
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    • pp.217-221
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    • 2013
  • This study developed predictive models for the kinetic behavior of Staphylococcus aureus on processed cheeses. Mozzarella slice cheese and cheddar slice cheese were inoculated with 0.1 ml of a S. aureus strain mixture (ATCC13565, ATCC14458, ATCC23235, ATCC27664, and NCCP10826). The inoculated samples were then stored at $4^{\circ}C$ (1440 h), $15^{\circ}C$ (288 h), $25^{\circ}C$ (72 h), and $30^{\circ}C$ (48 h), and the growth of all bacteria and of S. aureus were enumerated on tryptic soy agar and mannitol salt agar, respectively. The Baranyi model was fitted to the growth data of S. aureus to calculate growth rate (${\mu}_{max}$; ${\log}CFU{\cdot}g^{-1}{\cdot}h^{-1}$), lag phase duration (LPD; h), lower asymptote (log CFU/g), and upper asymptote (log CFU/g). The growth parameters were further analyzed using the square root model as a function of temperature. The model performance was validated with observed data, and the root mean square error (RMSE) was calculated. At $4^{\circ}C$, S. aureus cell growth was not observed on either processed cheese, but S. aureus growth on the mozzarella and cheddar cheeses was observed at $15^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. The ${\mu}_{max}$ values increased, but LPD values decreased as storage temperature increased. In addition, the developed models showed acceptable performance (RMSE = 0.3500-0.5344). This result indicates that the developed kinetic model should be useful in describing the growth pattern of S. aureus in processed cheeses.

The Diagnostic Usefulness of Pleural Fluid Adenosine deaminase with Lymphocyte/Neutrophil Ratio in Tuberculous Pleural Effusion (결핵성 흉막삼출액에서 흉수 Adenosine Deaminase치와 림프구/호중구 비의 진단적 유용성)

  • Shin, Min Khi;Ham, Hyun Seok;Lee, Dong Won;Cho, Yoo Ji;Jeong, Yi Yeong;Kim, Ho Cheol;Lee, Jong Deok;Hwang, Young Sil
    • Tuberculosis and Respiratory Diseases
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    • v.57 no.2
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    • pp.132-137
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    • 2004
  • Background : The measurement of adenosine deaminase(ADA) level in pleural fluid is useful in the diagnosis of tuberculous(TB) pleural effusion. However, ADA is also elevated in other diseases such as malignancy, bacterial infections, empyema, and collagen vascular disease, ADA alone has limited value. The object of this study is to determine diagnostic usefulness of the combined use of ADA value with lymphocyte/neutrophil ratio(L/N ratio) rather than the use of ADA alone. Method : We evaluated 198 patients(age=$55.9{\pm}12.9$, M/F=2.7:1) with pleural effusion who had admitted in Gyeong-sang National University Hospital from Jan. 1999 to Dec. 2001. retrospectively. Patients were divided into four diagnostic groups: TB pleural effusion(n=91), parapneumonic effusion(n=65), malignant effusion(n=21), and transudative effusion(n=13). The ADA level, differential cell count, biochemistry, cytology, and microbiology of each diagnostic groups were evaluated. The sensitivity, specificity, negative predictive value(npv), positive predictive value(ppv) and efficiency were calculated at each ADA values and combined ADA value with various L/N ratios. Results : The ADA level in TB pleural effusion was significantly higher than that of parapneumonic effusion, malignant pleural effusion, and transudative effusion(p<0.05). Sensitivity, specificity, ppv, npv and efficiency at $ADA{\geqq}50$ IU/L in the diagnosis of TB pleural effusion were 89.0%, 82.2%, 81.0%, 89.8% and 85.5% respectively. When $ADA{\geqq}50$ IU/L was combined with lymphocyte/neutrophil $ratio{\geqq}0.75$, sensitivity, specificity, ppv, npv, and efficiency were 83.5%, 96.3%, 95.0%, 87.9% and 90.5% respectively. Specificity, ppv and efficiency were increased with combination of ADA value and L/N ratio. Conclusion : Combination of ADA value and L/N ratio in pleural effusion is more useful than ADA value alone in the diagnosis of TB pleural effusion.

Evaluation of an ELISA kit for the Serodiagnosis of Pulmonary Tuberculosis by Using Mixed Antigens of Mycobacterium Tuberculosis (폐결핵진단에서 결핵균 혼합항원을 이용한 혈청학적 검사의 유용성에 관한연구)

  • Park, Seung-Kyu;Kim, Phil-Ho;Kim, Seung-Chul;Choi, In-Hwan;Cho, Sang-Nae;Song, Sun-Dae
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.5
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    • pp.558-567
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    • 2000
  • Background : Recently, serologic techniques for tuberculosis have been developed and some of them, which are focusing on detection of serum antibodies mainly directed against specific 38-kDa Mycobacterium tuberculosis, have already been introduced into the markel. In this study, diagnostic significance of a new serologic test(ELISA kit) for pulmonary tuberculosis was evaluated. Method : Serologic test with newly developed ELISA kit was performed upon 474 individuals, who include 333 active pulmonary tuberculosis patients, 80 healthy cases, and 61 tuberculosis contact cases. This serologic test was based on the ELISA technique and designed to detect antibodies to mixed complex antigens including 38-kDa, which were developed by Erume Biotech Co., Seoul. Active pulmonary tuberculosis was diagnosed by sputum AFB smear and culture methods. Results : The seropositivities using this ELISA kit were 82.1% and 73.6% in smear-positive and negative groups among active pulmonary tuberculosis, respectively. And, it also showed that seronegativities were 97.5% and 85.2% in healthy and contact groups, respectively. As a whole, the results of our study using the ELISA kit as a diagnostic method for pulmonary tuberculosis showed 80.0% sensitivity for active pulmonary tuberculosis, 97.5% specificity, 96.1% positive predictive value, and 65.0% negative predictive value when the prevalence of tuberuclosis in the samples was 60.1%. Conclusion : Our results reveal that the detection of antibody its reaction with 38-kDa antigen of M. tuberculosis is not sufficient to be accepted as single diagnostic method for pulmonary tuberculosis. However, they suggest that ELISA kit may be considered as an adjunctive test to standard diagnostic techniques of pulmonary tuberculosis.

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Is there any Potential Clinical Impact of Serum Phosphorus and Magnesium in Patients with Lung Cancer at First Diagnosis? A Multi-institutional Study

  • Kouloulias, Vassilis;Tolia, Maria;Tsoukalas, Nikolaos;Papaloucas, Christos;Pistevou-Gombaki, Kyriaki;Zygogianni, Anna;Mystakidou, Kyriaki;Kouvaris, John;Papaloucas, Marios;Psyrri, Amanda;Kyrgias, George;Gennimata, Vasiliki;Leventakos, Konstantinos;Panayiotides, Ioannis;Liakouli, Zoi;Kelekis, Nikolaos;Papaloucas, Aristofanis
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.1
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    • pp.77-81
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    • 2015
  • Background: The aim of the study was to determine whether the expression of baseline phosphorus (P) and magnesium (Mg) levels were prognostic in terms of stage and overall survival (OS) in newly diagnosed non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) patients. Materials and Methods: Retrospectively, 130 patients were selected at the time of diagnosis oflung cancer (100 with NSCLC and 30 with SCLC), before the initialization of any chemo-radiotherapy. The median age was 67 (range 29-92). IA, IB, IIA, IIB, IIIA, IIIB and IV stages were present in 3, 4, 19, 6, 25, 8, and 65 patients, respectively. After centrifugation, the levels of serum P and Mg were measured using the nephelometric method/ photometry and evaluated before any type of treatment. Results: Higher than normal levels of P were found in 127/130 patients, while only four patients had elevated Mg serum values. In terms of Spearman test, higher P serum values correlated with either stage (rho=- 0.334, p<0.001) or OS (rho=-0.212, p=0.016). Additionally, a significant negative correlation of Mg serum levels was found with stage of disease (rho=-0.135, P=0.042). On multivariate cox-regression survival analysis, only stage (p<0.01), performance status (p<0.01) and P serum (p=0.045) showed a significant prognostic value. Conclusions: Our study indicated that pre-treatment P serum levels in lung cancer patients are higher than the normal range. Moreover, P and Mg serum levels are predictive of stage of disease. Along with stage and performance status, the P serum levels had also a significant impact on survival. This information may be important for stratifying patients to specific treatment protocols or intensifying their therapies. However, larger series are now needed to confirm our results.

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
    • Food Science of Animal Resources
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    • v.36 no.6
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    • pp.752-759
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    • 2016
  • 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.