• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.365-371
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• 2005

The antimicrobial resistance patterns to the 10 antimicrobial agents of potential pathogenic vibrios isolated from seawater and a variety of farmed fishes, including oliver flounder (Payalichthys olivaceus), black rock fish (Sebastes schlegeli), red sea bream (Pagyus major) and sea bass (Lateolabyax japonicus), were investigated from May to October, 2004. A total of 314 strains of the genus vibrios were isolated from 126 collected samples, and the number of isolated strains of Vibrio payahaemolyticus and Vibrio alginolyticus were 194 and 120, respectively. Apparently $98.5\%$ of V. parahaemolyticus and $100\%$ of V. alginolyticus isolates demonstrated antimicrobial resistance against at least one antimicrobial agent. The resistance of V. parahaernolyticus isolates to ampicillin ($97.9\%$) was highest, followed by oxolinic acid ($26.8\%$), amikacin ($19.1\%$) and tetracycline and amoxicillin/clavulanic acid ($6.7\%$). V. alginolyticus isolates were resistant to ampicillin ($100\%$), solfamethoxazoleit,imethopenem ($25\%$), amikacln ($21.7\%$), amoxicillin/clavulanic acid ($15.8\%$), ciprofloxacin ($13.3\%$), and tetracycline and doxycycline ($11.7\%$). The rate of multiple antimicrobial resistance to at least four antimicrobials was higher in the V. alginolyticus isolates ($20.8\%$) than in the V. parahaemolyticus ($6.7\%$).

• The Journal of the Korean Society for Microbiology
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• v.14 no.1
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• pp.1-9
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• 1979

A bacteriological survey was carried out to get hold of the distribution of pathogenic enteric bacteria in Korea. The total number of 2,013 specimens were obtained from various sources; 1,407 specimens from marine products circulated in the markets, sewage, and 606 rectal swabs from persons. All the specimens were collected in Seoul, Chumunjin(Kangwondo), and Gwangcheon(Chungcheongnam-do) during 1978. The isolation and identification of enteric pathogens from the specimens were performed by means of bacteriological studies. 1. The isolation rates of the pathogenic enterobacteria among the total 2,013 specimens are as follows: Salmonella species 0.05%(1 strain), Shigella species 0.50%(10 strains), and Vibrio parahaemolyticus 0.35%(7 strains). 2. One salmonella strain was isolated from marine products circulated in the market in Seoul. Its serotype was identified as group $C_1$. 3. Ten shigella strains were isolated from various sources: 0.45% from natural environments and 0.05% from rectal swabs. The distribution of shigella serotype was identified as Sh. boydii 90%(9 strains), Sh. sonnei 10%(1 strain). 4. Seven strains of V. parahaemolyticus were isolated from natural environments. In addition, 40 strains of halophilic vibrios nontypable with anti-K antisera were also isolated. Of the 7 strains, the 2 strains were agglutinated with type K-32, each 1 strain of the others with K-17, K-19, K-36, K-39, K-56.

• Fisheries and Aquatic Sciences
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• v.5 no.3
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• pp.178-182
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• 2002

The authors identified 68 Vibrio strains from Gwangan beach seawater from June to October in 2001. We identified them as 19 strains of Vibrio alginolyticus, 15 strains of V. vulnificus, 15 strains of V. parahaemolyticus, 11 strains of V. cholerae non O1, 7 strains of V. fluvialis and just one strain of V. hollisae. They showed their typical biochemical characteristics by API 20E kit (bioMerieux), respectively. It was examined whether their cultural supernatants had enzymatic activities such as hemolysin, protease or urease. The 46 strains showed hemolytic activities and/or protease activities. But we could not find any strain which had urease activity. All isolates of V. cholerae non O1 showed $\beta$ hemolysis. The others showed $\alpha$ hemolysis or did not show clear zones on sheep blood agar plates. These results of Kanagawa phenomenon were not always correspondant with hemolytic activities of cultural supernatants at late log phase. Some strains had higher hemolytic activities despite of showing protease activities on skim milk agar plates and in litmus milk media. On the other hand, some strains showed protease activities but did not show hemolytic activities. Therefore we could guess that there were the relationships between hemolysins and proteases produced by pathogenic vibrios.

• The Journal of the Korean Society for Microbiology
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• v.19 no.1
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• pp.73-77
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• 1984

Vibrio vulnificus is an organism capable of causing septicemia and wound infection in compromised patients. The source of infection is known to be raw oysters and others. The prevalence of the organism in Korean sea water and shellfish is not known. The authors surveyed shellfish and other specimens obtained mainly from a market in Seoul and from ones in Inchon. Five cultures of V. vulnificus were isolated from oyster and clam samples. Two isolates had typical characteristics of the strains isolated from patients, i.e., definite hemolysis and typical biochemical reactions. However, other 2 isolates were sucrose positive, although the identity were confirmed by Center for Disease Control. We do not know wether such strains are pathogenic or not. For the isolation of V. vulnificus from environmental samples, TCBS agar and VV agar were not very selective or differential. We isolated our strains with the use of OF-lactose agar and SPS agar. However OF-lactose agar did not support good growth of V. vulnificus, while SPS agar did not suppress other vibrios.

• Journal of fish pathology
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• v.33 no.2
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• pp.127-138
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• 2020

We attempted to isolate and identify potentially pathogenic bacteria from geoduck clam (Panopea japonica) larvae, juvenile and adult, focusing on Vibrios. The isolates were identified by molecular approach and biochemical characterization. In particular, we applied MLSA (multilocus sequence analysis) to the isolated Vibrios for clear identification and phylogenetic relationships, by combining 16s rDNA and several houskeeping genes (pyrH, recA, rpoA). We obtained 141 isolates; 10 from healthy adults, 52 from moribund adults with blisters and 79 from larvae. 46 from the moribund adults and 39 from the larvae were identified as Vibrio species, while the rest of these samples and all the isolates from healthy adult were identified as marine general bacteria. Among Vibrio species, Vibrio splendidus was the most frequently identified from the moribund adults and clustered with the known V. splendidus in GenBank by MLSA. However, it was still unclear that V. splendidus was the cause of blisters because the artificial infection experiment was not conducted and V. splendidus was isolated also from the larvae. Further studies are necessary to clarify the etiological agent of the blisters found in geoduck clam in this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.3
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• pp.361-366
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• 1997

To determine the physiological, biochemical characteristics and toxicity of hemolysin produced by a novel sucrose positive Vibrio (Vibrio sp. D5) isolated from estuary of Kum river, it was compared with already known sucrose positive Vibrio. Salinity, pH, temperature and conductivity of place where Vibrio sp. D5 was isolated were $4.7\%_{\circ},\;7.6,\;24^{\circ}C$ and $7800{\mu}MHOS$, respectively. Physiological and biochemical characteristics distingiushed Vibrio sp. D5 from other sucrose positive Vibrio: V. alginoipicus, V. cholerae, V. cincinnatiensis, V. fluvialis, V. furnissii and V. metschnikovii. The range of salinity and pH for growth of Vibrio sp. D5 were $0.5\%\~7.5\%$ and $4.5\~9.5$, respectively. Vibrio sp. D5 exhibited typical yellow colony on TCBS agar plate and curved rod type upon transmission electron microscopy (TEM). Vibrio sp. D5 had lethal toxicity against mouse in case of intraperitoneal injection with its culture and showed hemolysin activity on human blood agar and sheep blood agar. Ubrio sp. D5 also demonstrated vascular permeability activity toward rat. From the above results, Vibrio sp. D5 was ascertained to be a novel pathogenic Vibrio.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.107-113
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• 1994

Among the currently recognized pathogenic vibrios, V. vulnificus and V. cholerae non O1 are the most serious bacteria from the point of view of sea food hygiene in Korea. In this paper, the authors compared the hemolytic activities of the crude hemolysin produced by V. vulnificus and V. cholerae non O1 isolated from shellfish collected in Chungmoo, Korea. The authors also attempted to improve the purification method of V. vulnificus hemolysin(VVH) and tried to make antiserum with the purified hemolysin. VVH was produced in abundance in heart infusion broth containing $2\%$ NaCl in a shaking cultivation process(140rpm) at $37^{\circ}C$ for 15 hours. While hemolysin production patterns of V. cholerae non O1 were quite different by the strain during the culture times compared with the V. vulnificus. Hemolytic activity of the VVH on sheep erythrocytes was stronger than those of rabbit, but hemolytic activities of the hemolysin produced by V. cholerae non O1 on rabbit erythrocytes were as much as twice as strong as on those of sheep and horse. VVH was purified by two steps of hydrophobic column chromatography on Phenyl-Sepharose HP with Fast Protein Liquid Chromatography(FPLC). Purification fold and yield of VVH was much improved by changing the elution buffer's pH from 6.0 to 9.8 and adding $1\%$ CHAPS(a zwitter ionic detergent) and $50\%$ ethylene glycol to the 10mM glycine buffer during the repeated hydrophobic column chromatography. Homogeneity of the purified hemolysin was shown by polyacrylamide gel electrophoresis. According to the five times repeated purification results, the specific activity was increased 27500 times and the yield was improved by $23.4\%$ on average. About $250{\mu}g$ of purified hemolysin was harvested from the 2400ml of culture supernatant of V. vulnificus. Molecular weight of VVH was estimated to be 50KDa by the SDS-PAGE and the neutralization scores of the obtained antiserum acting against VVH were $2000{\sim}8500$.

• Journal of fish pathology
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• v.29 no.1
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• pp.35-43
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• 2016

In comparison to the numbers of such studies of fish, few studies have been carried out on the immunity, physiology and ecology of abalone, while studies on abalone disease are also extremely rare. Moreover, mass mortality of cultured abalone due to pathogenic bacteria has not been reported in the southern coast of Korea. However, Vibrio-like bacteria have been isolated from dead abalone, which indicates that a review is required in order to determine the cause of abalone mortality. Use of an antimicrobial agent to minimize the damage caused by disease in abalone farms is common, but the therapeutic effects are insignificant. Demand for probiotics has increased, but research on the development of probiotics for use in abalone culture is very rare. Therefore, the present study isolated KC16-2 from fermented kimchi soup and investigated the characteristics of the isolate as a candidate probiotic bacterium in abalone. KC16-2 was identified as Bacillus amyloliquefaciens (B. amyloliquefaciens KC16-2) based on its biochemical properties and 16S rRNA gene sequence. B. amyloliquefaciens KC16-2 showed inhibitory effects against the growth of various vibrios in vitro, and kept the numbers constant until four days after inoculation in marine water at a temperature of $15{\sim}25^{\circ}C$, indicating the possible use of KC16-2 as a probiotic, except in the winter. The growth of KC16-2 was inhibited by bile salt, but the numbers increased over time suggesting the bacteria were still alive in the abalone's digestive tract. Abalone fed with a diet including KC16-2 for 12 weeks showed good growth, but showed no significant differences from the control group. However, the mortality of the abalone supplied the probiotic diet was reduced to half that of the control group in a challenge test with Vibrio tubiashii. Therefore, we suggest that B. amyloliquefaciens KC16-2 could be used as a probiotic bacterium for control of the mortality of abalone caused by opportunistic pathogenic vibrios.

• Journal of Food Hygiene and Safety
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• v.25 no.4
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• pp.367-375
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• 2010

The bacteriological and physiochemical analysis of sea water and sediments in Tongyeong harbor was conducted to evaluate sanitary conditions. The samples were collected at 8 stations established once a month from June, 2008 to May, 2009. During the study period, the range of temperature was from 6.7 to $25.2^{\circ}C$, transparency ranged from 1.2 to 2.6 m, chemical oxygen demand ranged from 1.90 to 2.92 mg/L, dissolved oxygen ranged from 6.2 to 10.5 mg/L, dissolved nitrogen ranged from 0.052 to 0.098 mg/L, phosphate ranged from 0.044 to 0.065 mg/L, respectively. Seafood, if eaten raw, carries the risk of food poisoning. Seafood poisoning is often cause by pathogenic microorganism originating from fecal contamination, such as Salmonella sp., Shigella sp. and norovirus. Fecal coliforms are an important indicator of fecal contamination. Therefore, data on fecal coliform are very important for evaluating the safety of fisheries in coastal areas. So, we investigated the sanitary indicate bacteria. The coliform group and fecal coliform MPN's of sea water in Tongyeong harbor were ranged from < 1.8~22,000/100 mL (GM 164.9 MPN/100 mL) and < 1.8~7,900 MPN/100 mL (GM 33.7 MPN/100 mL), respectively. Total coliform were detected 97.0% in 96 of samples and 68.9% of total coliforms were fecal coliforms. These results similar to another seawater detection ratio of total coloforms and fecal coliforms. The Vibrios was isolated and identified with VITEK system. Four hundred eighty strains that were obtained from sea water samples in Tongyeong harbor Detection ratio Vibrio alginolyticus, 34.2%, Vibrio parahaemolyticus, 13.8%, Vibrio vulnificus 10.0%, and V. mimicus 12.5% respectively. Vibrio cholerae O1, was not detected. During the study period, the ranges of water content, ignition loss, COD, and acid volatile sulfates in sediments in Tongyeoung harbor were 41.0~57.4%, 7.8~10.5%, 6.51~9.30 mg/g, 0.04~0.09 mg/g, respectively. Heavy metals in sediment of Tongyeoung harbor were Cd, $0.10{\pm}0.05$; Cu, $4.79{\pm}8.20$; As, $1.95{\pm}0.17$; Hg, $0.10{\pm}0.07$; $Cr^{6+}$, $0.34{\pm}0.12$; Zn, $125.33{\pm}16.40$; Ni, $16.43{\pm}1.93$ mg/kg.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.236-243
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• 2004

Antimicrobial effect of chitosan and its oligosaccharides was examined on Vibrios sp., Edwardsiella tarda and Streptococcus sp., which are major pathogenic bacteria inducing bacterial diseases of acquacultured flounder. Chitosan oligosaccharides (COS ) were produced by enzymatic hydrolysis of chitosan in an ultrafiltration mombrane bioreactor system which was established with three membranes with different molecular weight cut-off (MWCO) 1,000, 5,000 and 10,000, and fractionated into three kinds of COS, based on their molecular weight sizes. The three kinds of COS were as follows : relatively high molecular weight COS [HMW-COS, molecular weight distribution of 7,000 to 24,000 Da〕, medium molecular weight COS 〔MMW-COS, 1,500 to 6,000 Da〕, and low molecular weight COS 〔LMW-COS, 1,000 to 1,500 Da). Chitosan and HMW-COS effectively inhibited the growths of Vibrio sp. and Streptococcus sp. and their antimicrobial activities were superior to the others with smaller molecular weights. This result suggested that antimicrobial effect of chitosan preparations extremely depend on their molecular weight sizes. Antimicrobial effect of chitosan and HMW-COS on E. tarda was improved by longer inoculation times. Scanning electron microscopy in morphological change of E. tarda treated with chitosan preparations showed that chitosan and HMW-COS bound to the cells and suppressed the growth of the cells. This observation appears to prove the fact that positive charged amines of chitosan electrostatically bind to negative charged compounds of cell walls.