• Title/Summary/Keyword: Cross-Contamination

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Microbial contamination including Vibrio cholerae in fishery auction markets in West Sea, South Korea

  • Choi, Yukyung;Lee, Yewon;Lee, Soomin;Kim, Sejeong;Lee, Jeeyeon;Ha, Jimyeong;Oh, Hyemin;Shin, Il-Shik;Yoon, Yohan
    • Fisheries and Aquatic Sciences
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    • v.22 no.11
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    • pp.26.1-26.7
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    • 2019
  • Background: The monitoring of pathogens of fishery auction markets is important to obtain safe fishery products regarding hygiene and sanitation. In this study, aerobic, coliform, Escherichia coli, and Vibrio cholerae were monitored in the fishery products and environmental samples obtained from fishery auction markets. Methods: The fishery products (flounder, octopus, skate, rock cod, sea bass, snail, monkfish, flatfish, comb pen shell, corb shell, conger eel, hairtail, croaker, and pilchard) were placed in filter bags, and the environmental samples (samples from the water tanks at the fishery auction markets, seawater from the fishery distribution vehicles, ice from wooden or plastic boxes, and surface samples from wooden and plastic boxes used for fish storage) were collected. Aerobic bacteria, E. coli, and coliform in the samples were enumerated on aerobic count plates and E. coli/coliform count plates, respectively. For V. cholerae O1 and V. cholerae non-O1 quantification, most probable number (MPN)-PCR analysis was performed. Results: Aerobic and coliform bacteria were detected in most samples, but E. coli was not detected. Wooden boxes were contaminated with high levels of aerobic and coliform bacteria in all seasons (spring, summer, and fall). During fall, V. cholerae non-O1 were detected in snails, hairtails, croakers, flatfishes, pilchards, plastic boxes, and water samples. Conclusions: These results indicate an increased prevalence of V. cholerae contamination in fishery products in fall, including food contact samples, which can be vehicles for cross-contamination.

Syringe Reuse Issues in Automated Contrast Injection System in Dynamic Magnetic Resonance Imaging (조영제 자동주입기를 활용한 자기공명영상 동적검사 시 실린지 재사용의 문제)

  • Son, Soon-Yong
    • The Journal of the Korea Contents Association
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    • v.19 no.11
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    • pp.445-450
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    • 2019
  • This study proves that syringe reuse of automated injection system entails a risk of contrast media reflux and saline solution contamination which are pumped by a piston into the patients' venous cannula in the dynamic MR images, we will be aware of the serious problem. To quantify the contrast media contamination effect on the saline solution, identical volume of the saline solution was collected before and after the contrast injection to the patients' venous cannula following T1 weighted image scanning to verify whether signal intensities differences are observed. The signal intensity of saline solution after the contrast injection was significantly higher than that of saline before injection by 523.43%. This result is due to the backflow that contaminates the saline solution on the opposite side when the contrast agent is injected. In conclusion, the syringe used to inject contrast medium. causes cross-contamination due to contrast reflux. Therefore, even if the same patient's examination is used for quantitative analysis, the error should be avoided by changing the acquisition sequence or replacing the syringe.

INFLUENCE OF ARTIFICIAL SALIVA CONTAMINATION ON BONDING OF DENTIN ADHESIVES TO DENTIN (인공타액 오염이 수종 상아질접착제와 상아질간의 결합에 미치는 영향)

  • Ryu, Mee-Ae;Yang, Kyu-Ho;Oh, Won-Mann
    • Restorative Dentistry and Endodontics
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    • v.17 no.2
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    • pp.383-397
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    • 1992
  • The purpose of this study was to evaluate the influence of artificial saliva contamination on bonding of several dentin adhesives to dentin. Sixty - three human molar teeth extracted within a month were used. Each tooth was sectioned longitudinally in a buccolingual direction to obtain 126 specimens. These specimens were randomly divided into three groups and were treated by Scotchbond 2, Gluma and All bond. Each group was subdivided into three subgroups; normal group not contaminated with artificial saliva, contaminated with artificial saliva and dried group, and contaminated with artificial saliva and washed and dried group. Enamel/dentin bonding agent(Dental Adhesive of Scotchbond 2) was applied and light cured on the treated dentin surfaces. Thereafter P - 50 were cured on them, and specimens were stored in $37^{\circ}C$ artificial saliva for 24 hours before measuring shear bond strength. Shear bond strengths were determined using an universal testing machine with cross head speed 1mm/min and SEM examinations were conducted to evaluate the resin - dentin interface and degree of penetrating resin string into the dentinal tubules. The following results were obtained. 1. Normal groups not contaminated with artificial saliva showed greater shear bond strength than any other group contaminated with artificial saliva(P<0.01). 2. The shear bond strengths showed no significant difference between washed groups with distilled water and not washed groups after contamination with artificial saliva(P>0.05). 3. In normal groups, the shear bond strength of A group was significantly greater than in any other group(P<0.01). 4. In Sand G groups, fractures after shear bond strength tests occured adhesively on resintooth interface in all specimens. But in A groups, fracture of the normal group occured cohesively in dentin and fracture of the contaminated groups occured adhesively and cohesively. 5. On SEM examination, the number of resin strings penetrated into dentinal tubules were the greatest in normal groups, followed by, in descending order, washed groups and not washed groups after contamination with artificial saliva.

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Verification of the HACCP System in School Foodservice Operations - Focus on the Microbiological Quality of Foods in Heating Process and After-Heating Process - (학교급식소의 HACCP 시스템 적합성 검증 -가열조리 및 가열조리 후처리 공정의 미생물적 품질평가를 중심으로-)

  • 전인경;이연경
    • Journal of Nutrition and Health
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    • v.36 no.10
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    • pp.1071-1082
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    • 2003
  • The objective of this study was to evaluate and improve the microbiological quality of HACCP application in school foodservice operations. The microbiological quality of foods and utensils were evaluated two times at each critical control point (CCP) with 3M petrifilm in five Daegu elementary schools. Two processes were evaluated: Heating process and after-heating process. The CCPs of the heating process were receiving, cooking and serving temperatures. The CCPs of the after-heating process were personal hygiene, cross contamination avoidance and serving temperature. After the first experiment, 31 employees of five schools were classroom educated, trained on-site, and pre- and post-tested on HACCP-based sanitation with the goal of improving the microbiological quality of the foodservice. Scores representing knowledge of holding, thawing, washing, food temperature, sanitizing and food-borne illness increased after education. In the heating process, internal food temperatures in the first and second experiments were higher than 74$^{\circ}C$, the holding temperature in the first experiment was less than 6$0^{\circ}C$. In the second experiment, the serving temperature improved to a satisfactory level. The microbiological quality in the second experiment improved by decreasing the time from cooking to serving. In the after-heating process, the ingredients were boiled before being cut in the first experiment. In the second experiment, ingredients were cut before being boiled, improving microbiological quality. Also in the second experiment, cooking just before serving food improved its microbiological quality through time-temperature control. These results strongly suggest it is essential to measure microbiological quality regularly and to educate employees on HACCP continuously, especially time-temperature control and cross contamination avoidance in order to improve foodservice quality.

Evauation of Management & Hygienic Status of High School Foodservice using ATP Bioluminescence Assay (고등학교 급식시설 운영실태 및 ATP Bioluminescence를 이용한 위생상태 조사연구)

  • Kye, Seung-Hee;Hwang, Seong-Hee
    • The Korean Journal of Food And Nutrition
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    • v.30 no.3
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    • pp.515-524
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    • 2017
  • An investigation was conducted to evaluate the hygienic status of 53 high school foodservice systems in Gyeonggi province by using hygiene management guide checklist, ATP bioluminescence assay of food utensils were conducted during process. The 5 hygiene management guide checklist groups about personal hygiene, cooking facilities control, cross contamination control, cook and storage control, management control were checked by experts and had good grades but there were some inadequate behaviors on observation. Total cleaning levels were inadequate, including hand, rubber gloves, aprons, knives, food tray, machine and instruments. The possibility of cross contamination is also noted in handles for refrigerators, ovens, food dryers, hand washing. It was also noted that there were too much work on the nutritionist and cook, additional personnel need to be added. lack of space, deterioration of facilities were identified in some high school foodservice systems. ATP bioluminescence assay was conducted on surface of food facilities, ATP ranged $1,393{\pm}5,041.2RLU$ on yellow gloves, $244{\pm}258.7RLU$ on pink gloves, $3,780{\pm}11,418.6RLU$ on apron, $49,056{\pm}62,831.4RLU$ on refrigerator grip, $41,422{\pm}61,259.8RLU$ in oven, $31,407{\pm}41,344.9RLU$ on hand cleaning board.

Sanitary Conditions for Cold and Frozen Food Storage Warehouses in Korea (국내 식품 냉장.냉동 창고 위생관리 수준 분석)

  • Choi, Eun-Ji;Kim, Mee-Hye;Bahk, Gyung-Jin
    • Journal of Food Hygiene and Safety
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    • v.26 no.4
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    • pp.283-288
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    • 2011
  • We surveyed the sanitary conditions for 17 cold and frozen food storage warehouses in Korea, using the following 5 inspections items: "putting into warehouse (A)", "prevention of cross-contamination (B)", "storage management (C)", "temperature control (D)", and "management of records and documents (E)", We included 20 detailed items. The results of distribution for frequency by five major inspection items showed that "(E)" was the highest, the next "(D)", "(C)"; and "(B)" was the lowest. In the correlation of inspection scores between total scores, "(B)" and "(C)" were highly related to the total score, therefore, the higher score of "(B)" or "(C)", the higher for the total score. In details of inspection items, "the management of cross-contamination upon taking product out of the warehouse" had the lowest score with a mean, of $2.67{\pm}1.80$, and also ranked as first of the 20 items.

Microbiological Quality Evaluation for Implementation of a HACCP System in Day-Care Center Foodservice Operations I. Focus on Heating Process and After-Heating Process (보육시설급식소의 HACCP시스템 적용을 위한 미생물적 품질평가 I. 가열조리 및 가열조리후 처리 공정을 중심으로)

  • 민지혜;이연경
    • Journal of Nutrition and Health
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    • v.37 no.8
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    • pp.712-721
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    • 2004
  • The objective of this study was to evaluate the microbiological quality of heating and after-heating processed foods for implementation of a HACCP system in day-care center foodservice operations. The evaluating points were microbial assessment and temperature of foods during receiving, cooking, and serving in heating process. In non-heating process, in addition to monitoring microbial assessment of food during preparation, cooking, and serving steps, the microbial populations of employees' hands and utensils and serving temperature were also evaluated. Microbiological quality was assessed using 3M Petrifilm$^{TM}$ to measure total plate count and coliforms for foods and utensils and Staphylococcus aureus for hands in five Gumi day-care centers. Microbiological quality assessment for foods and utensils is summarized as follows. Microbiological quality of the heating processed foods was satisfactory for cooking and serving steps. The internal temperature of food was above 74$^{\circ}C$. However, temperature control before the serving step was not achieved due to inappropriate time management between the cooking and serving steps. In the after-heating process, the total plate counts of boiled mungbean sprouts salad, blanched spinach salad, com vegetable salad were below the standard at the serving step. The majority of samples showed that coliforms exceeded the norm, which is thought to be the result of the cross-contamination from utensils. These results suggest that it is essential to educate employees on the importance of hand washing and of avoiding cross-contamination by using clean, sanitized equipment to serve food in the after-heating process. Establishing Sanitation Standard Operating Procedures (SSOPs) is an essential part of any HACCP system in day-care center foodservice operations.

Inactivation Activity of Bronze Alloy Yugi for Reduction of Cross-Contamination of Food-borne Pathogen in Food Processing (식품제조 환경에서 식품위해세균의 교차오염 감소를 위한 청동합금 유기의 살균효과)

  • Lee, Eun-Jin;Park, Jong-Hyun
    • Journal of Food Hygiene and Safety
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    • v.23 no.4
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    • pp.309-313
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    • 2008
  • To investigate the antibacterial activity of the traditional bronze alloy Yugi, the cultures of Salmonella spp., Escherichia coli O157, Enterobacter sakazakii, and Bacillus cereus were exposed to the metal coupons of bronze, copper, tin, and stainless steel, and the sterilizing activities were analyzed. Antibacterial efficacy of copper coupon toward S. Typhimurium, E. coli, and E. sakazakii were the highest among them and those were followed by bronze, tin, and then stainless steel in the activity order. However, there was little sterilizing activity on Gram-positive B. cereus. Minimal inhibitory concentrations of cupric ion were 25 ppm for S. Typhimurium, E. coli, and E. sakazakii, and 50 ppm for B. cereus. Yugi bronze alloy showed more rigidity and practicality in comparison with copper, and has been used in Korea. Therefore, the bronze alloy may be more effective to reduce the cross-contamination of S. Typhimurium, E. coli, and E. sakazakii than stainless steel in food processing surface.

Prevalence and characterization of pathogenic Escherichia coli from carcasses and environmental samples of cattle and pig slaughterhouses (소와 돼지 도축장 도체 및 환경에서 분리된 병원성대장균 분포 및 특성조사)

  • Hong, Serim;Kang, Hye Jeong;Moon, Jin-San;Yoon, Soon-Seek;Kim, Ha-Young
    • Korean Journal of Veterinary Service
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    • v.45 no.3
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    • pp.191-199
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    • 2022
  • We investigated the virulence genes, O-serotypes, antimicrobial resistance of pathogenic E. coli isolated from carcasses (n=455) and environmental (n=372) samples of 11 cattle and 12 pig slaughterhouses from December 2020 to December 2021. E. coli were isolated from nine carcasses (2.0%), three slaughter facilities (1.4%), two utensils (2.7%) and three abattoir workers (3.5%) from four cattle and four pig slaughterhouses. Among all isolates, 13 STEC (76.5%) were identified, followed by four EPEC (23.5%). As a result of the antibiotic susceptibility test, all isolates were resistant to at least one antimicrobial, of which 70.6% isolates showed multidrug resistance patterns. The serotypes were diverse in pigs compared to cattle, with serotypes O18, O66, O109 in cattle and O9, O76, O85, O100, O153, and O159 in pigs. In a single cattle slaughterhouse, eight STEC O66 were isolated from various types of sample (4 slaughter animal surfaces, 3 gloves, and 1 knife) with two antimicrobial resistance patterns (CHL-FIS-STR and CHL-FIS). Those two types of strain were suspected cross-contamination from utensils to slaughter animal surfaces. These results showed that pathogenic E. coli were detected in carcasses and various environmental samples in cattle and pig slaughterhouses. Nationwide monitoring and hygiene management are required to prevent cross-contamination of STEC isolate slaughterhouses.

Simple and rapid colorimetric detection of African swine fever virus by loop-mediated isothermal amplification assay using a hydroxynaphthol blue metal indicator

  • Park, Ji-Hoon;Kim, Hye-Ryung;Chae, Ha-Kyung;Park, Jonghyun;Jeon, Bo-Young;Lyoo, Young S.;Park, Choi-Kyu
    • Korean Journal of Veterinary Service
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    • v.45 no.1
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    • pp.19-30
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    • 2022
  • In this study, a simple loop-mediated isothermal amplification (LAMP) combined with visual detection method (vLAMP) assay was developed for the rapid and specific detection of African swine fever virus (ASFV), overcoming the shortcomings of previously described LAMP assays that require additional detection steps or pose a cross-contamination risk. The assay results can be directly detected by the naked eye using hydroxynaphthol blue after incubation for 40 min at 62℃. The assay specifically amplified ASFV DNA and no other viral nucleic acids. The limit of detection of the assay was <50 DNA copies/reaction, which was ten times more sensitive than conventional polymerase chain reaction (cPCR) and comparable to real-time PCR (qPCR). For clinical evaluation, the ASFV detection rate of vLAMP was higher than cPCR and comparable to OIE-recommended qPCR, showing 100% concordance, with a κ value (95% confidence interval) of 1 (1.00~1.00). Considering the advantages of high sensitivity and specificity, no possibility for cross-contamination, and being able to be used as low-cost equipment, the developed vLAMP assay will be a valuable tool for detecting ASFV from clinical samples, even in resource-limited laboratories.