• Title/Summary/Keyword: Listeria spp

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Changes of Indicator Microorganisms and Pathogenic Bacteria in Spinach during Cook-Chill Process (시금치의 cook-chill 가공 중 오염지표균 및 병원성세균의 변화)

  • Kim, Hye-Jung;Park, Jae-Kap;Lee, Dong-Sun;Paik, Hyun-Dong
    • Korean Journal of Food Science and Technology
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    • v.34 no.5
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    • pp.927-930
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    • 2002
  • Spinach minimally processed using cook-chill and sous vide techniques was vacuum-packed in low gas permeable plastic film, pasteurized at $70^{\circ}C$ for 2 min, cooled rapidly at $3^{\circ}C$, and stored at 3 and $10^{\circ}C$. Contents of mesophilic bacteria, psychrophilic bacteria, anaerobic bacteria, spore-forming bacteria, total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were measared to identify the degree of food contamination. Number of mesophilic bacteria, detected at $2.2{\times}10^8\;cfu/g$ in raw spinish, decreased to about $6.0{\times}10^3\;cfu/g$ after cook-chill process. During the storage at 3 or $10^{\circ}C$, levels of mesophilic, psychrophilic and anaerobic bacteria increased, whereas total coliforms, yeast and molds, fecal Streptococcus, and Enterobacteriacea were not detected. Twelve strains of Aeromonas hydphila, Escherichia coli O157:H7, Plesiomonas shigelloides, Pseudomonas aeruginosa, Salmonella spp., Shigella spp., Yersinia enterocolitica, Bacillus cereus, Campylococcus spp., Clostridium perfringens, Listeria monocytogenes, and Staphylococcus aureus were examined for detecting the presence of pathogenic bacteria in spinach. B. cereus and C. perfringens were isolated from raw, washed, and cook-chilled spinach, whereas A. hydrophila was isolated only from washed spinach. S. aureus was isolated from raw and washed spinach, but not from cook-chilled spinach. Other pathogenic organisms were not detected in raw, washed, and cook-chilled spinach.

Comparison of the Sanitary Conditions of Raw Milk Cheese and Pasteurized Milk Cheese Sold in the Market: A Preliminary Study (시중에 판매되고 있는 비살균 치즈와 살균 치즈의 위생상태 비교: 예비연구)

  • Lim, Hyun-Woo;Kim, Se-Hyung;Chon, Jung-Whan;Bae, Dongryeoul;Song, Kwang-Young;Jeong, Dongkwan;Seo, Kun-Ho
    • Journal of Dairy Science and Biotechnology
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    • v.37 no.1
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    • pp.33-39
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    • 2019
  • The purpose of this study was to explore the microbiological safety of various cheeses made from raw milk currently imported and sold in Korea. A total of 12 cheeses were considered for the study - 4 kinds of imported cheese made from raw milk, 4 kinds of imported cheese made from pasteurized milk, and 4 kinds of domestic cheese made from pasteurized milk, and aerobic count, presence of E. coli, Salmonella spp., and Listeria monocytogenes were investigated. Results from this study showed that in the 12 different kinds of cheese tested, E. coli, Salmonella spp., and Listeria monocytogenes were negative. Therefore, the sanitary conditions of imported cheese made from raw milk, imported cheese made from pasteurized milk, and domestic cheese made from pasteurized milk are considered safe. The mean aerobic count in the 12 types of tested cheese was below 4.0 log CFU/g. In conclusion, various cheeses produced from raw milk or pasteurized milk currently sold in Korea have been found to be hygienic and safe. In the future, raw milk cheeses produced and sold in Korea will require long-term research not only to ensure safety but also to produce new, high-quality products.

Survey on the contamination of microorganisms in pork from slaughterhouse in Incheon area (인천지역 도축장에서 생산된 돼지고기의 미생물 오염도 조사)

  • 황원무;이성모;황현순;한정희
    • Korean Journal of Veterinary Service
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    • v.27 no.1
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    • pp.7-15
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    • 2004
  • For measuring general bacterial count and Escherichia coli count, the standard plate count was used to conduct a test on 113 cases of pork carcass surfaces from slaughterhouses in Incheon area from January to February 2003. And Salmonella spp, Staphylococcus aureus and Listeria monocytogenes was used to conduct a test on 68 cases of pork carcass surfaces and 76 cases of feces, that is to say, a total of 144 cases. The results were obtained as follows: In the case of general bacterial count, 29 cases(25.7%) were in the range of 100∼999 and 62 cases(54.9%) were in the range of 1,000∼9,999 and 22 cases(19.4%) were in the range of 10,000∼99,999. Meanwhile as regards E coli count, 22 cases(19.4%) were in the range of 1∼9 and 69 cases(61.2%) were in the range of 10∼99 and 22 cases(19.4%) were in the range of 100∼999. On 68 cases of pork carcass surfaces, 7 strains(10.2%) of Salmonella spp, and 12 strains(17.6%) of S aureus were detected and 27 strains(39.7%) of L monocytogenes, respectively. As for the detected Salmonella spp, 6 strains of the B group, 3 strains of S enterica subsp salame and 2 strains of S typhimurium were detected, respectively. On 76 cases of feces, 14 strains(18.4%) of Salmonella spp, and 15 strains(19.7%) of L monocytogenes and 14 strains(18.4%) of S aureus were detected respectively. As for the detected Salmonella spp, 6 strains of the B group, 4 strains of S derby and 8 strains of the C group, 5 strains of S rissen were detected, respectively. All of 42 strains of L monocytogenes were type 1. As a result of conducting a toxin test on the detected S aureus, all of 26 strains were found to be non-toxin.

Inhibition Activity Against Pathogenic Organism of Probiotic Bacteria and Characterization of Inhibition Activity of Isolated Bacteria from Calf Dejecta (Probiotic균주의 Pathogenic Organism에 대한 억제 활성과 송아지분변 분리균주의 억제활성 특성)

  • 배임희;변정열;배귀석;이상석;장문백;윤영호
    • Journal of Animal Science and Technology
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    • v.48 no.6
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    • pp.907-920
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    • 2006
  • This study was conducted to investigate the inhibitory activity of Lactobacillus spp., Bacillus ssp., and calf fecal isolates against pathogenic Salmonella typhimurium, E. coli, Listeria monocytogenes, and Staphylococcus aureus. Among thirteen strains of Lactobacillus ssp. tested, Lactobacillus helveticus CU631 showed the highest inhibition against three pathogens, whereas Bacillus spp. showed a weak inhibitory activity. Four calf fecal isolates were identified as Lactobacillus pentosus CU13, CU05, Pediococcus pentosaceus CUR02, and Lactobacillus lactis ssp. lactis CUM14. The whole cell and cell wall components of L. rhamnosus CU02 and L. pentosus CU13 were active in the inhibition of L. monocytogenes. The medium components and levels, which affect on the inhibitory activity, were revealed as Tween 80 1.0%, peptone 3.0%, yeast extract 3.0%, glucose 3.0%, beef extract 3.0%, and NaCl 1.0~3.0%, respectively. Inhibitory activity of the supernatant culture medium was not affected by catalase and proteinase K treatment but affected by heat treatment at 80℃ and netralization, which implies that the inhibitory activity is due to the production of organic acids during the growth. L. pentosus CU13 and L. rhamnosus CU02 exhibited broad inhibition spectrum against 16 out of 21 strains including some pathogens. Oral administration of L. rhamnosus CU02 to the mice infected with E. coli O157:H7 was proven to be effective to recover their body weight during the experimental period.

Distribution of Microorganisms and Foodborne Pathogens in Yukae (육회 중에 분포하는 미생물과 주요 식중독 세균의 조사)

  • Lee, Si-Hyung;Kim, Jin-Man;Kim, Myung-Hee
    • the MEAT Journal
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    • s.35 winter
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    • pp.34-45
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    • 2008
  • People can be exposed to various microorganisms when they eat yukae (seasoned raw meat) because yukae is eaten raw. The purpose of this study was to find out microbial distribution in yukae. In this experiment, 5 restaurants serving yukae were chosen in Daegu area. Mesophilic microorganisms and coliforms were measured by Korean Food Standards Codex. Analyses of Salmonella spp., Listeria monocytogenes, Staphylococcus aureus and Escherichia coli O157:H7 were conducted. As results, mesophilic microorganisms ranged 6.6$\times$103-2.7$\times$105 CFU/g and coliforms ranged 8.9$\times$101-2.1$\times$105 CFU/g. Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 were not detected in all 5 samples. However, Staphylococcus aureus was detected in 1 sample out of 5 samples. Hygiene practice during production, processing and cooking process is required.

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Distribution of Microorganisms and Foodborne Pathogens in Yukae (육회 중에 분포하는 미생물과 주요 식중독 세균의 조사)

  • Lee, Si-Hyung;Kim, Jin-Man;Kim, Myung-Hee
    • Food Science of Animal Resources
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    • v.27 no.2
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    • pp.197-202
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    • 2007
  • People can be exposed to various microorganisms when they eat yukae(seasoned raw meat) because yukae is eaten raw. The purpose of this study was to find out microbial distribution in yukae. In this experiment, 5 restaurants serving yukae were chosen in Daegu area. Mesophilic microorganisms and coliforms were measured by Korean Food Standards Codex. Analyses of Salmonella spp., Listeria monocytogenes, Staphylococcus aureus and Escherichia coli O157:H7 were conducted. As results, mesophilic microorganisms ranged $6.6{\times}10^3-2.7{\times}10^5\;CFU/g$ and coliforms ranged $8.9{\times}10^1-2.1{\times}10^5CFU/g$. Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 were not detected in all 5 samples. However, Staphylococcus aureus was detected in 1 sample out of 5 samples. Hygiene practice during production, processing and cooking process is required.

Microfloras of otitis externa and normal external ear canals in dogs (개에서 외이도염 및 정상외이도에서 분리한 세균총에 대한 연구)

  • Kim, Ki-hyang;Choi, Won-phil
    • Korean Journal of Veterinary Research
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    • v.39 no.3
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    • pp.566-574
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    • 1999
  • This study was conducted to examine the outbreak rate and the causative agents of otitis externa in 26 dogs (49 ears ; 23 dogs = bilateral, 3 dogs = unilateral), and the normal microfloras of external ear canal in 68 dogs(133 ears ; 65 dogs = bilateral, 3 dogs = unilateral ) in Taegu, 1997. The breed, living environment, sex, age and season distribution of otitic dogs were as follows : Dogs with erect and hairy ears(42.3%), pendulous and hairy ears(38.5%), indoor(92.3%), female(65.4%) and below one year old(38.5%) were more prevalent. According to season, otitis externa was mainly occurred between July and October. The major causative agents of canine otitis externa were Malassezia pachydermatis (32.7%), Staphylococcus aureus (26.5%) and S intermedius (16.3%). In the microorganism isolated 39 otitic ear canals, single infection was 53.8% and mixed infection was 46.2%. The normal microfloras of canine external ear canal were fungi including M pachydermatis, Aspergillus spp, Microsporum canis, Alternaria spp, Verticillium spp and Yeast, and bacteria including Staphylococcus spp(10 species including S xylosus), Bacillus spp, Corynebacterium spp, Listeria spp, Actinomyces pyogenes and Escherichia coli. No growth was 34.6%.

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Bactericidal Effect of Bacteriocin of Lactobacillus plantarum K11 Isolated from Dongchimi on Escherichia coli O157

  • Lim, Sung-Mee;Im, Dong-Soon
    • Journal of Food Hygiene and Safety
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    • v.22 no.3
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    • pp.151-158
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    • 2007
  • Among 68 strains of lactic acid bacteria (LAB) isolated from Dongchimi, a strain K11 was selected due to its bactericidal activity against Escherichia coli O157 The strain K11 was identified as Lactobacillus plantarum, based on physiological and biochemical characteristics. In the late exponential phase, La. plantarum K11 showed maximum bacteriocin activity (12,800 BU/mL) and maintained until the early stationary phase. The bacteriocin activity was completely inactivated by all the proteolytic enzymes such as pepsin, protease, proteinase K, papain, chymotrypsin, and trypsin, but the activity was not affected by catalase, a-amylase, lysozyme, and lipase, suggesting proteinaceous nature of the bacteriocin. Additionally, this activity was not affected in the pH range from 3.0 to 9.0 and under storage conditions like 30 days at -20,4, or $25^{\circ}C$. Although the bacteriocin activity was absolutely lost after 15 min treatment at 121, it was relatively stable at $70^{\circ}C$ for 60 min or $100^{\circ}C$ for 30 min. The activity was disappeared by treatment with acetone, benzene, ethanol, or methanol, but it was not affected by treatment with chloroform or hexane. The antibacterial activity of the bacteriocin was good against some LAB including Lactobacillus spp., Enterococcus spp., and Streptococcus spp., but not against food-borne pathogens such as Bacillus spp., Listeria spp., and Staphylococcus spp. as well as yeasts and molds. Especially, some intestinal bacteria such as Enterobacter aerogenes and E. coli were significantly affected by the bacteriocin of La, plantarum K11. Furthermore, the addition of 640 BU/mL resulted in the complete clearance of E. coli O157 after 10 hr.