• Korean Journal of Fisheries and Aquatic Sciences
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• v.57 no.1
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• pp.15-22
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• 2024

This study assessed microbial contamination in seven fried fish pastes sold in Southeast Asian traditional markets during summer. It measured viable cell count, coliforms, Escherichia coli, fungi, and Staphylococcus spp. It also qualitatively analyzed Vibrio parahaemolyticus, Salmonella spp., Bacillus cereus, Listeria monocytogenes, and Clostridium perfringens. The average viable cell count, coliforms and fungi were detected as 6.34 (3.84-8.13), 2.16 (1.00-3.55), and 3.92 (1.85-7.74) log₁₀ CFU/g, respectively. Staphylococcus spp. was detected at 4.59 (2.10-7.63) log₁₀ CFU/g. Some samples had high contamination levels: viable cell count (8.13 log₁₀ CFU/g), fungi (7.74 log₁₀ CFU/g) and S. aureus (7.63 log₁₀ CFU/g). However, E. coli was not detected in any samples (ND, <1 log₁₀ CFU/g). V. parahaemolyticus, Salmonella spp., B. cereus, L. monocytogenes, and Cl. perfringens were also not detected in the samples. The microbial contamination data provide insight into managing microbial contamination and ensuring the safety of fried fish pastes in traditional summer markets.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.941-947
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• 2005

The contamination frequency of major foodborne pathogenic bacteria was investigated from 213 seafood samples including sliced raw fish and shellfish in Busan and CyeongNam province area. Tested microorganisms were Salmonella spp. Staphyloroccus aureus, Vibrio parahaemolyticus, Escherichia coli O157:H7, Bncillus cereus, Listeria monocytogenes and Campylobacter jejuni. The frequency of isolated microorganisms was V. parahaemolyticus (30.5%), B. cereus (9.9%), S. aureus (3.8%) and other pathogenic bacteria (1.4%). from July to October, total isolation rates were greater than 50% and V. parahaemolyticus was dominant among the microorganisms isolated. The bacteria isolation rate (49.2%) in raw seafoods including shellfishes was higher than one (28.9%) in sliced raw fish. V. parahaemelyticus isolates were resistant to ampicillin (96.9%), amikacin (29.2%) and tetracycline (27.7%), and B. cereus isolates were resistant to ampicillin (100%), Penicillin G (100%), rifampicin (71.4%) and tetracycline (14.3%). The growth of V. parahaemolyticus and B. rereus was greatly inhibited below $10^{\circ}C$, but increased at ambient temperature. Washing seafood with tap water showed to reduce total count of remaining V. parahaemolyticus. Thus temperature control under $10^{\circ}C$, sufficient washing and prompt eating appeared to reduce the risk of food poisoning by these bacteria in seafoods.

• Journal of fish pathology
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• v.18 no.3
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• pp.205-214
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• 2005

The isolates, which has caused considerable damage to the olive flounder farm located in the eastern coast of Korea showed 99% sequence homology in the comparison of 16s rRNA gene of P. damselae subsp. damselae ATCC 33539. The present P. damselae was identical to the biotype No.8 in Pedersen et al. (1997) and the same LPS protein pattern as P. damselac subsp. damselae ATCC 33539. The comparison of infection rates among present P. damselae and Vibrio spp. showed that isolated P. damselae was the highest, followed by V. anguillarium, V. harveyi. and V. ordalii.

• Journal of Microbiology and Biotechnology
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• v.17 no.2
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• pp.325-334
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• 2007

Recently, quorum sensing has been implicated as an important global regulator controlling the production of numerous virulence factors such as capsular polysaccharides in bacterial pathogens. The nucleotide and deduced amino acid sequences of smcR, a homolog of V. harveyi luxR identified from V. vulnificus ATCC29307, were analyzed. The amino acid sequence of SmcR from V. vulnificus was 72 to 92% similar to those of LuxR homologs from Vibrio spp. Functions of SmcR were assessed by the construction of an isogenic mutant, whose smcR gene was inactivated by allelic exchanges, and by evaluating its phenotype changes in vitro and in mice. The disruption of smcR resulted in a significant alteration in biofilm formation, in type of colony morphology, and in motility. When compared with the wild-type, the smcR mutant exhibited reduced survival under adverse conditions, such as acidic pH and hyperosmotic stress. The smcR mutant exhibited decreased cytotoxic activity toward INT 407 cells in vitro. Furthermore, the intraperitoneal $LD_{50}$ of the smcR mutant was approximately $10^2$ times higher than that of parental wild-type. Therefore, it appears that SmcR is a novel global regulator, controlling numerous genes contributing to the pathogenesis as well as survival of V. vulnificus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.202-208
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• 1995

Puksin Bay located in the northwestern pan of Tongyeong, Korea has been contaminated by municipal wastewaters. In Puksin Bay, red tides have occured almost every year since the early 1980's. This experiment was carried out two times in a month in the winter in 1990, the summer' 1991, and the winter in 1994 so as to clarify the distribution marine bacteria and coliform groups in Puksin Bay. The water quality of Puksin Bay was not only move polluted than that of any other costal area around Tongyeong, but also its water quality was investigated to keep going bad. Viable cell counts in Puksin Bay were $4.9\times10^3/ml$ in 1990's winter, $3.6\times10^6/ml$ in 1991's summer, and $2.1\times10^4/ml$ in 1994's winter. The variation of seasonal total and fecal coliform MPN/100ml in Puksin Bay were $6.7\times10^2\;and\;2.6\times10^2$ in 1990's winter, $1.5\times10^4$ and $5.4\times10^3$ in 1991's summer, and $1.5\times10^3$ and $5.6\times10^2$ in 1994's winter, respectively. The changes of stational total coliform MPN/100m1 from station 1 to station 8 in Puksin Bay were 95,000, 1600, 1,000, 182, 151, 94, 43 and 13 in winter, and 110,000, 29,000, 2,400, 4,100, 1,700, 1,700, 810 and 150 in 1991's summer, and 3,381, 1928, 1582, 256, 161, 59 and 23 in 1994's winter. During the study period, the number of viable cell was ranged from $10^4\;to\;10^7/ml$ and 307 bacteria strains were isolated from Puksin Bay. The dominant species were Acinetobacter spp. 86 $(28.3\%)$, Pseudomonas spp. 51 $(16.6\%)$, Flavobacterium spp. 41 $(13.4\%)$, Escherichia coli 36 $(11.7\%)$, and Vibrio spp. 27$(8.8\%)$. The results obtained in this study indicate that this bay is getting to contaminate far more with municipal wastewaters and cultivation of the shellfish and finfish in this bay is not proper. When municiple wastewaters keep flowing into this bay, any other coastal area around Tongyeong may be contaminated.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.1
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• pp.7-11
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• 1990

As the putrefaction of fish is greatly relied on the microorganisms inhabited in the viscera of them, we investigated the microfloral changes in the viscera of sardine, Sardinops melanosticta, which has been caught a lot in adjacent sea of Korea but showed rapid spoilage, after storages with various temperature. The following results were obtained. Viable cell counts at $25^{\circ}C$ of the viscera of sardine were $1.6\times10^5/g$ at the fresh sample, $1.5\times10^5/g$ at the frozen sample, $2.9\times10^8/g$ at the spoiled samples. The most predominant microbial genera from the fresh sardine were Moraxella spp.($31.4\%$) and Pseudomonas spp.($28.6\%$), but Enterobacteriaceae($83.1\%$) was in spoiled sample. While Moraxella spp.($46.2\%$) and Flavobacterium-Cytophaga($21.0\%$) were predominant in the frozen sample and Enterobacteriacear($69.6\%$) was in the thawed-spoiled sample. The rates of proteolytic enzyme producing bacteria were $20\%$ in the fresh sample, $22\%$ in the frozen sample but the rates were increased to $52\%,\;29\%$ in the spoiled sample and the thawed-spoiled sample respectively.

• Fisheries and Aquatic Sciences
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• v.21 no.2
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• pp.6.1-6.10
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• 2018

The intention of this study was to identify the bacterial pathogens infecting Oreochromis niloticus (Nile tilapia) and Clarias gariepinus (African catfish), and to establish the antibiotic susceptibility of fish bacteria in Uganda. A total of 288 fish samples from 40 fish farms (ponds, cages, and tanks) and 8 wild water sites were aseptically collected and bacteria isolated from the head kidney, liver, brain and spleen. The isolates were identified by their morphological characteristics, conventional biochemical tests and Analytical Profile Index test kits. Antibiotic susceptibility of selected bacteria was determined by the Kirby-Bauer disc diffusion method. The following well-known fish pathogens were identified at a farm prevalence of; Aeromonas hydrophila (43.8%), Aeromonas sobria (20.8%), Edwardsiella tarda (8.3%), Flavobacterium spp. (4.2%) and Streptococcus spp. (6.3%). Other bacteria with varying significance as fish pathogens were also identified including Plesiomonas shigelloides (25.0%), Chryseobacterium indoligenes (12.5%), Pseudomonas fluorescens (10.4%), Pseudomonas aeruginosa (4.2%), Pseudomonas stutzeri (2.1%), Vibrio cholerae (10.4%), Proteus spp. (6.3%), Citrobacter spp. (4.2%), Klebsiella spp. (4.2%) Serratia marcescens (4.2%), Burkholderia cepacia (2.1%), Comamonas testosteroni (8.3%) and Ralstonia picketti (2.1%). Aeromonas spp., Edwardsiella tarda and Streptococcus spp. were commonly isolated from diseased fish. Aeromonas spp. (n = 82) and Plesiomonas shigelloides (n = 73) were evaluated for antibiotic susceptibility. All isolates tested were susceptible to at-least ten (10) of the fourteen antibiotics evaluated. High levels of resistance were however expressed by all isolates to penicillin, oxacillin and ampicillin. This observed resistance is most probably intrinsic to those bacteria, suggesting minimal levels of acquired antibiotic resistance in fish bacteria from the study area. To our knowledge, this is the first study to establish the occurrence of several bacteria species infecting fish; and to determine antibiotic susceptibility of fish bacteria in Uganda. The current study provides baseline information for future reference and fish disease management in the country.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.21-27
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• 2016

The objectives of this study are to produce monoclonal antibodies (MAbs) against Vibrio parahaemolyticus and to develop an immuno-selective filtration (ISF) method for the rapid and sensitive detection of V. parahaemolyticus. The characterization of the MAb produced from HKVP 4H9-9 hybridoma cell was validated by enzyme-linked immunosorbent assay (ELISA) and western blot. The produced MAb was specific to V. parahaemolyticus and showed weak cross-reaction to V. alginolyticus, V. vulnificus and Staphylococcus aureus. After optimization of the method, $5{\times}10^1cell/mL$ of V. parahaemolyticus in a pure culture could be detectable. Although weak cross-reactivity to V. vulnificus, V. alginolyticus and Staphylococcus aureus was observed, the ISF was confirmed to be highly specific to V. parahaemolyticus. Especially, the ISF showed the most sensitivity compared to the immunoassays currently reported is easier to perform and quicker than ID-ELISA.

• Journal of Food Hygiene and Safety
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• v.27 no.4
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• pp.356-365
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• 2012

There have been growing concerns among people about food safety due to insufficient information on foodborne pathogens. In this study, we developed a risk priority of 15 foodborne pathogens. For the priority determination we collected risk profile criteria information from CODEX Alimentarius Commission and developed countries. The basis for criteria we selected from information of surveillance were frequency and severity of disease, frequency of consumption and probability of cross-contamination. We also considered foodborne pathogens which have been managed in developed countries though those pathogens are not currently managed appropriately in Korea. Priorities were divided into three groups following these consideration. The first priority group includes Norovirus, pathogenic E. coli, Salmonella spp, Clostridium botulinum and Listeria monocytogenes. The second priority group includes Vibrio parahaemolyticus, Stapylococcus aureus, Campylobacter jejuni and Bacillus cereus, and the third priority group includes Clostridium perfringens, Yersinia enterocolitica, Shigella spp, Cronobacter sakazakii and Hepatitis A virus. Our results could be applied to prevent foodborne illness from fresh produce.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.2
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• pp.180-184
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• 2019

Aerobic bacteria, coliforms, Escherichia coli, and pathogenic bacteria were investigated in laver Porphyra sp. samples from various regions of Korea. The mean bacterial counts were $6.9{\pm}0.87log\;CFU/g$ (range 4.0 to 7.7) log CFU/g in dried laver, $2.83{\pm}4.36log\;CFU/g$ in roasted laver, and $4.93{\pm}1.43log\;CFU/g$ in seasoned laver. Coliforms were most abundant (mean count: $2.1{\pm}1.01log\;CFU/g$) in dried laver. No pathogenic bacteria, including Staphylococcus aureus, Salmonella spp. Vibrio parahaemolyticus, or Listeria monocytogenes, were detected in any of the samples. Aerobic microorganisms were the most diverse microorganisms in dried laver. Staphylococcus spp. were predominant, but S. aureus was not detected. Standardization of laver production is necessary to ensure a hygienic product because laver products are often ingested without heating or cooking, and the production process is simple.