• 생명과학회지
• /
• 제10권4호
• /
• pp.380-387
• /
• 2000

Recently Vibrio sp. are the most frequently isolated microorganism, which causing food poisoning. We investigated the detection of toxin genes and effect of chitosan to toxin genes with PCR. Thirty strains of Vibrio sp. were isolated from sea water and sea products through biological and biochemical tests. Out of 30 strains, 8 were identified as V. parahemolyticus, 7 as V. mimcus, 6 as V. damsela, 5 as V. vulnificus, 4 as V. alginoyticus. In detection of ctx, tdh, and t고 as food poisoning-causing toxin genes, ctx from 7 strains, trh from 4 strains and tdh from 6 strains were detected. Among toxin genes detected strains, we selected V. vulnificus-2 V. damsela-1 and V. parahemolyticus-7. As adding chitosan solution to PCR product of 3 strains, the amplified DNA bands were not detected over 450$\mu\textrm{g}$/$m\ell$ concentrantion of chitosan. Over the result, chitosan is thought to influence the detection of toxin gene.

• 대한임상검사과학회지
• /
• 제48권3호
• /
• pp.202-209
• /
• 2016

본 연구는 methicillin-resistant Staphylococcus aureus(MRSA)로부터, 독소 유전자형과 항생제 내성의 상관 관계를 결정하는 것을 목표로 하였다. 2014년 1월~12월까지 전남 순천의 한 병원 중환자실의 임상검체 2,664건에서 얻어진 MRSA 52균주를 분리하였다. 유전자들이 암호화하고 있는 mecA, 장독소(staphylococcal enterotoxins; sea, seb, sec, seg, seh, sei, sej), 독성 쇼크 증상독소-1 (toxic shock syndrome toxin-1; tst-1), 표피박탈성독소(exfoliative toxin; eta, etb), 백혈구 용해 독소(Panton-Valentine leukocidin; pvl)를 특이적 프라이머를 이용한 multiplex PCR로 증폭 검출 하였다. 독소 유전자 seg와 sei 유전자가 각각 40균주(76.9%)로 가장 많은 보유율을 나타냈으며 다음으로 tst 34균주(65.4%) 순으로 검출 되었으며 eta, etb, sea, sed, see, seh, sej와 pvl 유전자들은 검출 되지 않았다. 2개 이상의 독소 유전자를 동시에 보유한 조합의 MRSA는 40균주(76.9%) 였는데 5개 유전자(seb, sec, seg, sei, tst)를 동시 보유한 조합이 28균주(53.8%)로 가장 많은 분포를 보였으며 다음으로 seg, sei 유전자 동시 보유 조합으로 6균주(11.5%)에서 나타났다. 유전자들 간의 동시 보유율은 72.5~100%로서 특정한 독소 유전자 seb, sec, seg, sei와 tst 유전자간의 상관성이 높게 나타났다. 특정 다수의 독소유전자(seb, sec, seg, sei, tst)를 동시에 보유한 균주들이 개별적 독소 유전자를 보유한 균주(seb, sec, tst)와의 항생제 내성의 상관성은 ciprofloxacin, clindamycin, erythromycin 항생제에 100% 내성을 보임으로서 공통적으로 포함된 seb, sec, tst 유전자와 이 항생제의 내성과는 밀접한 연관이 있음을 알았다.

• 한국산학기술학회논문지
• /
• 제16권5호
• /
• pp.3315-3322
• /
• 2015

황색포도상구균은 임상에서 중요한 병원체로 원내감염의 주 원인균이다. methicillin에 내성인 황색포도상구균(MRSA) 출현은 특히 전 세계적으로 임상과 역학의 주요 문제가 되고 있으며 다른 병원성 세균과 차별되는 특징으로 독성인자를 가지면서 항생제 내성을 빠르게 획득해 가고 있다. 본 연구는 한 종합병원 임상 검체로부터 얻어진 MRSA 101균주의 독소유전자(enterotoxin(se), toxic shock syndrome toxin-1(tst), exfoliative toxin(et), Panton Valentine leukocidin(pvl)) 보유 분포와 이들 독소 유전자 보유 균주들간의 항생제 내성과의 상관성을 비교 분석 하고자 하였다. 독소유전자중 가장 많이 분리된 seg 유전자가 59균주(58.4%)에서 검출되었으며 70균주(69.3%)에서 두개 이상의 독소 유전자가 검출되었다. 독소유전자 보유조합으로 seb, sec, seg, sei, tst가 19균주(18.8%)에서 발견되었으며 다음으로 빈번한 조합은 sec, seg, sei로 11균주(10.9%)로 나타났다. seb, sec, seg, sei, tst 동일한 독소유전자 조합을 갖고 있는 19균주(18.8%)들은 Ampicillin, Benzylpenicillin, Ciprofloxacin, Clindamycin, Gentamicin, Erythromycin, Telithromycin, Tetracycline 항생제 내성이 100% 였다. 독소유전자 보유수가 많은 균주들은 항생제 내성이 높은 상관성을 확인하였다. 향후 MRSA 균주의 내성이 확산되지 않도록 효과적인 치료와 철저한 감염관리가 선행되어야 할 것이다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제16권3호
• /
• pp.425-429
• /
• 2003

Staphylococcus aureus is a major pathogen for cattle, causing various forms of subclinical and clinical mastitis and could be a causative agent of food poisoning, it produces various superantigenic exotoxins which have a great public health significance. A total of 72 S. aureus clinical isolates from dairy farms located in Kyunggi Province Korea were examined for the species identification by biochemical method, and for the detection of $\beta$-lactamase, enterotoxin and other exotoxins genes by PCR. The results of species identification by biochemical method agreed with those of PCR done with species specific primer STA-AU. $\beta$-lactamase is an enzyme closely associated with the resistance to antibiotic penicillin, which is an important means of treatment of mastitis, all the isolates were positive for the presence of genes encoding $\beta$-lactamase, which were reproduced in penicillin susceptibility disc assay. Six types of toxin genes, Staphylococcal enterotoxin (SE)A, SEB, SEC, SEE, toxic shock syndrome toxin (TSST-1) and exfoliative toxin A (ET A) were detected in 72 isolates by PCR associated genotypic method in this study, none of the isolates carried the genes for enterotoxin D (SED) and exfoliative toxin B (ETB). The occurrence rate of exotoxin genes rated as 12.5%, and the precision of the PCR identification results has been confirmed using the reference strains.

• 한국환경보건학회지
• /
• 제42권4호
• /
• pp.255-265
• /
• 2016

Objectives: Mobile phones have become one of the most essential accessories in daily life. However, they may act as reservoir of infectious pathogens if they are used without hygienic practices in their handling. Therefore, this study aimed to isolate food-borne pathogens from mobile phones and investigate the characteristics of toxin genes and antibiotic susceptibility patterns. Methods: A total of 146 mobile phones were collected from 83 middle- and 63 high-school students in Busan. The surfaces of the mobile phones were aseptically swabbed. Results: Among the food-borne pathogens, Staphylococcus aureus, Bacillus cereus and Escherichia coli were detected in 26 (17.8%), 20 (13.7%) and four (2.7%) samples, respectively. There were no statistically significant differences according to school level, gender or phone type. None of four E. coli strains had pathogenic toxic genes. All of the B. cereus strains carried at least three different toxin genes among the nine enterotoxin and emetic toxin genes. Three out of 20 B. cereus strains (15%) possessed emetic toxin genes, which are rarely detected in food-poisoning cases in Korea. Among the 26 strains of S. aureus, the detection rate of staphylococcal enterotoxin genes, toxic shock syndrome toxin (tsst) and factors essential for methicillin resistance (femA) were 84.6%, 7.7% and 100%, respectively. In the antibiotic susceptibility test, there was no methicillin-resistant S. aureus (MRSA) or vancomycin-resistant S. aureus (VRSA). Conclusion: The results show that students' mobile phones in Busan were contaminated by food-borne pathogens which carried various toxic genes. Therefore, regular phone disinfection and hand hygiene is important in order to reduce cross-contamination.

• 한국수산과학회지
• /
• 제56권6호
• /
• pp.826-832
• /
• 2023

Clostridium perfringens causes diarrhea and other diseases in humans and animals. We investigated the prevalence, toxin gene profiles, and antimicrobial resistance of C. perfringens isolated from commercial jeotgal sample. C. perfringens was isolated from 11 of 22 commercial jeotgals. All C. perfringens strains were positive for the alpha toxin gene, but not for the beta, epsilon, iota, CPE or NetB toxin genes; therefore, all strains were identified as type A C. perfringens. However, the beta2 toxin gene was identified in 54.5% of isolates. Disk diffusion susceptibility tests showed that most isolates were resistant to kanamycin (90.9%), nalidixic acid (72.7%), oxacillin (54.5%), erythromycin (27.3%), ciprofloxacin (9.1%) and clindamycin (9.1%). However, all strains were susceptible to 14 other antimicrobial including amoxicillin, ampicillin, and chloramphenicol. The average minimum inhibitory concentrations against C. perfringens of clindamycin, kanamycin, and nalidixic acid were 128.0, 128.0, and 54.0 ㎍/mL, respectively. These results provide new insight into the necessity for sanitation of commercial jeotgal, and provide evidence to help reduce the risk of contamination with antimicrobial-resistant bacteria.

• BMB Reports
• /
• 제38권4호
• /
• pp.386-390
• /
• 2005

Based on the reported cDNA sequences of $BmK{\alpha}Txs$, the genes encoding toxin $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$ were amplified by PCR from the Chinese scorpion Buthus martensii Karsch genomic DNA employing synthetic oligonucleotides. Sequences analysis of nucleotide showed that an intron about 500 bp length interrupts signal peptide coding regions of $BmK{\alpha}Tx11$ and $BmK{\alpha}Tx15$. Using cDNA sequence of $BmK{\alpha}Tx11$ as probe, southern hybridization of BmK genome total DNA was performed. The result indicates that $BmK{\alpha}Tx11$ is multicopy genes or belongs to multiple gene family with high homology genes. The similarity of $BmK{\alpha}$-toxin gene sequences and southern hybridization revealed the evolution trace of $BmK{\alpha}$-toxins: $BmK{\alpha}$-toxin genes evolve from a common progenitor, and the genes diversity is associated with a process of locus duplication and gene divergence.

• 한국식품과학회지
• /
• 제42권3호
• /
• pp.361-367
• /
• 2010

쌀밥의 미생물 안전성을 평가하기 위하여 쌀을 취반한 후 세균을 분석하였다. 전국에서 생산되는 생쌀 30개를 수집하여 취반 후에 중온성 호기성균과 MYP선택배지에서 Bacillus cereus group를 분리 동정하여 그의 분포도와 독소유전자를 분석하였다. 취반 직후의 쌀밥 27%에서 1-3 log CFU/g정도의 총 중온성 호기균과 거의 같은 정도로의 Bacillus spp.가 존재하는 것으로 나타났다. 그러나 균이 검출되지 않은 시료들도 증균한 후에는 B. cereus group균들이 검출되어 사실상 대부분의 시료에서 Bacillus spp.가 분포하고 있는 것을 알 수 있었다. 이들 시료로부터 37개의 분리하여 동정한 균주는 B. thuringiensis, B. cereus, B. valismortis, B. pumilus, B. coagulans, B. licheniformis, Geobacillus stearo-thermophilus, Brevibacillus laterosporus 등으로 나타났다. 분리 균주중 20개(54%)의 분리주가 B. thuringiensis로 나타났고 그 다음으로 9개(27%)의 B. cereus이였다. 그리고 3개(8%)의 B. valismortis와 각각 1개(3%)의 B. pumilus, B. coagulans, B. licheniformis, Geobacillus stearothermophilus, Brevibacillus laterosporus이였다. B. thuringiensis는 모두에서 non-hemolytic toxin gene(nhe)을 가지고 있었고 9개의 B. cereus중 7균주가 emetic toxin 유전자를 함유하고 있었다. 따라서 쌀밥에는 B. thuringiensis가 B. cereus보다 더 높은 빈도로 분포되어 있고 B. cereus는 설사형 독소유전자 보다는 구토형 독소를 더 많이 가지고 있었다. 취반 후 쌀밥을 상온에서 보관하여 발생되는 B. cereus 식중독은 설사형보다 구토형일 가능성이 더 많을 것으로 보인다.

• Journal of Microbiology and Biotechnology
• /
• 제27권8호
• /
• pp.1449-1456
• /
• 2017

The prevalence and toxin characteristics of Bacillus thuringiensis isolated from 39 organic vegetables were investigated. B. thuringiensis was detected in 30 out of the 39 organic vegetables (76.9%) with a mean value of 2.60 log CFU/g. Twenty-five out of the 30 B. thuringiensis isolates (83.3%) showed insecticidal toxicity against Spodoptera exigua. The hblCDA, nheABC, and entFM genes were found to be the major toxin genes, but the ces gene was not detected in any of the tested B. thuringiensis isolates. The hemolysin BL enterotoxin was detected in all 30 B. thuringiensis isolates (100%). The non-hemolytic enterotoxin complex was found in 27 out of 30 B. thuringiensis isolates (90.0%). The B. thuringiensis tested in this study had similar toxin gene characteristics to B. cereus, which possessed more than one toxin gene. B. thuringiensis could have the potential risk of foodborne illness based on the toxin genes and toxin-producing ability.

• 한국동물위생학회지
• /
• 제39권2호
• /
• pp.87-92
• /
• 2016

Porcine edema disease (ED) is a communicable disease of pigs caused by infection with Shiga toxin (Stx)-producing Escherichia coli (STEC) which expresses F18 fimbriae and/or Stx type 2e (Stx2e). While STEC causes a severe illness including hemorrhagic colitis and hemolytic-uremic syndrome in humans, it induces damage to the vascular endothelium, which results in edema, hemorrhage, and microthrombosis, leading in high mortality in pigs. In the present study, we cultured Stx2e-producing E. coli field isolates from conventional pig farms that experienced sudden deaths previously with symptoms similar to porcine edema disease, which were further investigated with Shiga toxin profiles. A total of 43 strains were identified from the collected samples by F18 or Stx2e specific PCR. Based on the PCR, 42 isolates out of 43 isolates were proved to carry one of F18 or Stx2e genes and 14 isolates to carry both F18 and Stx2e genes. All of the 30 isolates that harbored Stx2e gene induced the cytopathic effect (CPE) in vero cells and especially, the isolate 150229 produced the highest level of Shiga toxin. Therefore, we identified the virulence genes (F18 and Stx2e) and demonstrated Shiga toxin-producing abilities from porcine edema disease causing E. coli filed isolates. These results suggested that one of the isolates could be a vaccine antigen candidate against STEC through further investigating to elicit an immune response.