• Journal of Food Hygiene and Safety
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• v.25 no.3
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• pp.220-225
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• 2010

Distribution of foodborne E. coli strains, antimicrobial resistant genes and antimicrobial susceptibility have been carried out on E. coli isolated from commercial and cooked foods distributed food in Seoul. Of total 1,313 samples, fifty samples(3.8%) were found E. coli that included one of the ETEC and EPEC, respectively. The serotype of ETEC in seasoning raw meat was E. coli O26 and produced Verotoxin 2. Fifty percentage of total isolates were susceptible to all antimicrobial agents. Specially, there were ampicillin(36%), amoxicillin/clavulanic acid(32%) and tetracycline(22%) etc. Resistant gene (tetB) were found in four tetracycline resistant E. coli strains, and TEM gene was found in one ampicillin resistant E. coli isolate.

• Korean Journal of Veterinary Service
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• v.31 no.2
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• pp.195-205
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• 2008

Yersinia enterocolitica is a zoonotic agent, and to cause food poisoning. This study was carried out to get some basic information for the control of Yersinia infection. A total of 1,680 samples were collected from beef and pork carcasses from January 2006 to December 2007 in Seoul. The isolation rate was higher in pork carcass than in beef carcass. Five (0.59%) Yersinia enterocolitica were isolated from the 840 of beef carcasses, and eighteen(2.14%) were isolated from the 840 of pork carcasses. Among 23 strains, 22 were classified into biotype 1A, and one was biotype 6. In serotyping of Y enterocolitica isolates, 21 strains were untypable (UT), and 2 were O5 and O8 respectively. In PCR, Ail gene was not detected in all of 23 strains that determined non-pathogenic. In antimicrobial susceptibility test, twelve strains (52.2%) of 23 isolates showed the multi -resistant patterns with over 3 drugs. PFGE was performed after the genomic DNA of twenty three isolates, which was digested with Xba I. the 23 isolates showed 12 ($A{\sim}L$) PFGE type.

• Journal of Microbiology and Biotechnology
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• v.7 no.6
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• pp.423-428
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• 1997

Vibrio vulnificus is a halophilic gram-negative human pathogen, which affects people with underlying liver diseases or a suppressed immune system, often leading to primary septicemia with a mortality rate of higher than 60%. In an effort to develop an oral vaccine against V. vulnificus infection, we prepared a whole cell killed vaccine of V. vulnificus on a large scale and compared the immunogenicity and protective efficacy of the vaccine administered in three formulation forms in rabbits. Since V. vulnificus O-antigen serotypes 1, 2, 3, 4, 5, and 7 account for more than 95% of clinical isolates, we prepared cell lysates from these six serotype strains and mixed in equal amounts for a vaccine. The vaccine was administered to rabbits intramuscularly (i.m.), orally as granules or as enteric-coated granules. In rabbits, all three formulation forms elicited a high level of serum IgG antibody reactive not only to the six strains but also to other O-antigen serotypes 6, 8 and 9, indicating cross-reactivities among the strains. Immunotherapeutic efficacy of the antisera was also evaluated by a passive immunization assay, which revealed that the orally immunized antisera as well as the i.m. immunized antisera was protective against a subsequent lethal challenge of V. vulnificus. These data demonstrate that oral immunization with a V. vulnificus whole cell lysate vaccine induced a systemic immune response and suggest the feasibility of development of this vaccine preparation as an oral vaccine.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.771-779
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• 2023

Biofilms are a significant concern in the food industry. The utilization of plant-derived compounds to inactivate biofilms on food contact surfaces has not been widely reported. Also, the increasing negative perception of consumers against synthetic sanitizers has encouraged the hunt for natural compounds as alternatives. Therefore, in this study we evaluated the antimicrobial activities of ethanol extracts, acetone extracts, and essential oils (EOs) of seven culinary herbs against Salmonella enterica serotype Typhimurium and Listeria innocua using the broth microdilution assay. Among all tested extracts and EOs, the ethanol extract of Piper betle L. exhibited the most efficient antimicrobial activities. To evaluate the biofilm inactivation effect, S. Typhimurium and L. innocua biofilms on pitted and smooth stainless steel (SS) coupons were exposed to P. betle ethanol extract (12.5 mg/ml), sodium hypochlorite (NaClO; 200 ppm), hydrogen peroxide (HP; 1100 ppm), and benzalkonium chloride (BKC; 400 ppm) for 15 min. Results showed that, for the untreated controls, higher sessile cell counts were observed on pitted SS versus smooth SS coupons. Overall, biofilm inactivation efficacies of the tested sanitizers followed the trend of P. betle extract ≥ BKC > NaClO > HP. The surface condition of SS did not affect the biofilm inactivation effect of each tested sanitizer. The contact angle results revealed P. betle ethanol extract could increase the surface wettability of SS coupons. This research suggests P. betle extract might be utilized as an alternative sanitizer in food processing facilities.

• Korean Journal of Microbiology
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• v.49 no.3
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• pp.228-236
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• 2013

Campylobacter jejuni is one of important food-borne pathogens causing human gastroenteritis. We isolated 42 strains of C. jejuni from diarrhea patients and 4 food-poisoning outbreaks in 2010, Gyeonggi-do. In this study, 42 strains were tested for genetic characteristics, the serotype distribution and antimicrobial resistant rate. The presence of hipO (100%), cdtB (100%), and mutated gyrA (95.2%) genes was detected in C. jejuni by polymerase chain reaction (PCR). Detection of mutated gyrA gene correlated with ciprofloxacin resistance. Forty isolates had mutated gyrA gene and were actually resistant to ciprofloxacin. Furthermore, comparing the gyrA DNA sequence data, ciprofloxacin-resistant isolates had a mutation of the DNA sequence from ACA (threonine) to ATA (isoleucine). But 41 strains (97.6%) of patient isolates were susceptible to erythromycin and azithromycin. A total of 35.7% among 42 C. jejuni isolates were identified into 4 different serotypes. The serotype distribution of C. jejuni strains were shown to be HS2(B), HS3(C), HS4(D), HS19(O). To investigate the genotypes of C. jejuni isolated in Gyeonggi province, repetitive sequence polymerase chain reaction (rep-PCR) analysis and SmaI-digested pulsed-filed gel electrophoresis (PFGE) profile analysis were performed. From the PFGE analysis of 42 C. jejuni strains, 12 clusters of PFGE profile were obtained. On the other hand, 11 clusters of rep-PCR profile were obtained from 42 strains of C. jejuni.

• Journal of Life Science
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• v.17 no.3 s.83
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• pp.386-395
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• 2007

A total of 27 strains of Vibrio parahaemolyticus (18 strains isolated from Korea and 9 strains from Japan) were serotyped and examined for biochemical characteristics, antimicrobial susceptibility patterns, cytotoxicity assay, thermostable direct hemolysin (TDH) production and molecular epidemiology. Using polymerase chain reaction (PCR) method and DNA probe hybridization method, the strains were tested for toxR, tdh, trh and ORF 8 genes. The V. parahaemolyticus isolated from patients were belonged to 8 different serotypes : O3:K6, O1:K38, O3:K57, O4:K9, O4:Kl2, O4:K68, O5:Kl5 and O6:K46. Urease-positive strain possessed the trh gene, and conversely, urease-negative strains lacked the gene, indicating that urease production by V. parahemolyticus strains strongly correlates with the possession of the trh gene. Most strains showed multiple resistant to more than three antibiotics and the antibiogram could be classified into 6 group (I to VI). All of the O3:K6 strains isolated in South Korea and Japan producted TDH at high levels. The TDH titers ranged between 256 and 2.048, and the average titer was 1009. To distinguish the new and increasingly common V. parahaemolyticus strains from clinical isolates, ORF 8 is a useful genetic marker. After Southern hybridization, the HindIII restriction fragment patterns of the tdh gene were grouped one type, respectively. One type showed two bands one of which was 4.3kb and the other was 11.5kb in size. Variation between the O3:K6 serotype are minor when compared to the differences seen with the non O3:K6 strains. The migration patterns of Not I -digested of the total DNA of the O3:K6 strains were similar, and only slight variations were observed between the serotypes. By contrast, the O3:K6 strains and non O3:K6 had markedly different profiles. In conclusion, Random amplified polymorphic DNA (RAPD) profile using appropriate primers was an effective epidemiological marker.

• Fisheries and Aquatic Sciences
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• v.5 no.2
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• pp.79-86
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• 2002

Listeria spp. were isolated from the samples submitted from various seafood plants such as raw materials, products, swab samples of plants floor and conveyor belts through the whole processing procedures. All the samples were collected from 3 kinds of seafood plants such as a imitation crab meat plant, jeotgal plant and frozen seafood plant. And also serotypes of the identified L. monocytogenes were determined. Among the 301 strains of isolated Llsteria spp., 96 strains, 179 strains and 26 strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. While among the 145 strains of Listeria spp. isolated from the imitation crab meat plant, $74\;(51.0\%)$ strains, $64\;(44.1\%)$ strains and $7\;(4.8\%)$ strains were identified as L. monocytogenes, L. innocua and L. welshimeri, respectively. In the case of the 126 strains of Listeria spp. isolated from the frozen seafood plant, $22\;(17.5\%)$ strains of L. monocytogenes,$93\;(73.8\%)$ strains of L. innocua, and $11\;(8.5\%)$ strains of L. wdshimeri were detected. Among the 30 strains isolated from a jeotgal plant, $22\;(73.3\%)$ strains of L. innocua and $8\;(26.7\%)$ strains of L. welshimeri were detected. The detection rates of L. monocytogenes, one of the very important food poisoning bacteria especially in frozen and/or refrigerated seafoods, were relatively high as $77.1\%$ (74/96 strains) in a imitation crab meat plant and $22.9\%$ (22/96 strains) in a frozen seafood plant, but not detected from jeotgal plant. Distribution of L. monocytogenes serotypes and characterization were examined. The serotypes of 96 L. monocytogenes isolated from pork skin, pork fat, the floor and conveyor belts were 1/2a $(59.4\%)$, l/2b $(6.2\%)$, 1/2c $(12.5\%)$ and unknown serotypes $(21.9\%)$. Unknown serotypes were divided into three specific groups by the O antigen they have.

• The Journal of Korean Society of Virology
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• v.26 no.2
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• pp.181-189
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• 1996

Fecal samples of calf diarrhea were taken on farms in Jeju island, rotavirus was isolated and cytopathic effect (CPE) was determined after infection to MA104 cell. Morphological evaluation on electron microscopy proved it as rotavirus. Also, its infection to MA104 cell was reidentified using a fluorescence antibody method. Genotype of Jeju island bovine rotavirus (JBR) analyzed through PAGE was 4: 2: 3: 2 pattern, which was unique in bovine and that analyzed through general PAGE was somewhat different from NCDV, UK, KK3, A5-3A, 61A, B223 and similar to N stool-5, N culture-5 and Kawatabi (Japan). By titration after plaquing, the level was $1-3\;{\times}\;10^6\;PFU/ml$, which was lower than those of NCDV and UK. Electrophoresis analysis of RNA-RNA hybridization, ELISA, and first and second PCR products of VP7 and VP4 in 1% agarose ($TAE+1{\mu}l$ EtBr) revealed that the rotavirus was a serotype of G6P11.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.743-751
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• 2017

During slaughtering, animal blood is typically discarded, resulting in water pollution. However, this discarded blood has valuable components, such as immunoglobulin (Ig). Although several studies have been conducted to develop methods for effective recycling of slaughterhouse blood, they have not been commercially utilized in Korea. Here, we extracted an Ig-rich fraction from porcine blood that was then subjected to various in vitro tests, including pathogen growth inhibition, antigenic cross-reactivity, and anti-toxin activity. The porcine immunoglobulin concentrate (PIC) was effectively purified by eliminating other components, such as albumin, and consisted of approximately $63.2{\pm}2.9%$ IgG and $7.2{\pm}0.4%$ IgM on a protein basis. The results showed that it significantly suppressed the growth of pathogenic bacteria, and bound to all tested pathogens, including both gram-positive and gram-negative species, although the degree of activity differed according to strain. The PIC bound to two types of lipopolysaccharide (LPS) obtained from Escherichia coli O111:B4 and Salmonella enterica serotype typhimurium in a concentration-dependent manner. In addition, the PIC restored the proliferation activity of the lymphoblast K-562 cells when co-incubated with pathogenic LPS. These results confirm that the PIC prepared in this study is a potentially valuable functional food material or diet supplement as an alternative to antibiotics that can protect animals from pathogenic bacteria.

• Clinical and Experimental Pediatrics
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• v.57 no.2
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• pp.96-99
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• 2014

Hemolytic uremic syndrome (HUS) is one of the most common causes of acute renal failure in childhood and is primarily diagnosed in up to 4.5% of children who undergo chronic renal replacement therapy. Escherichia coli serotype O157:H7 is the predominant bacterial strain identified in patients with HUS; more than 100 types of Shiga toxin-producing enterohemorrhagic E. coli (EHEC) subtypes have also been isolated. The typical HUS manifestations are microangiopathic hemolytic anemia, thrombocytopenia, and renal insufficiency. In typical HUS cases, more serious EHEC manifestations include severe hemorrhagic colitis, bowel necrosis and perforation, rectal prolapse, peritonitis, and intussusceptions. Colonic perforation, which has an incidence of 1%-2%, can be a fatal complication. In this study, we report a typical Shiga toxin-associated HUS case complicated by small intestinal perforation with refractory peritonitis that was possibly because of ischemic enteritis. Although the degree of renal damage is the main concern in HUS, extrarenal complications should also be considered in severe cases, as presented in our case.