• 한국식품저장유통학회지
• /
• 제14권2호
• /
• pp.194-200
• /
• 2007

전통발효식품의 기능성 및 저장성을 증진시킬 목적으로 전통된장으로부터 효소활성 및 항균활성이 우수한 CH-14 균주를 분리하여 그 특성을 검토하였다. 분리한 CH-14 균주는 그람양성, catalase 양성, oxidase 음성, 내생포자 및 편모를 가지는 간균으로 세포의 크기는 $0.5-0.7{\times}3.5-4.2{\mu}m$이었다. 최종 분리균을 Bergey's Manual of Systematic Bacteriology 및 Bergey's Manual of Determinative Bacteriology와 API 50 CHL Kit에 의한 당 발효실험의 결과를 토대로, Bacillus subtilis로 밝혀져 Bacillus subtilis CH-14로 명명하였다. 최적배지의 조성을 검토한 결과, 탄수원은 2% cellobiose, 질소원은 yeast extract와 peptone을 각각 0.5%씩 혼합 첨가하는 것이 효과적이었다. 무기염은 0.05%의 $MgSO_4{\cdot}7H_2O$가 적당하였다. 최적 생육온도 범위는 $30^{\circ}C-45^{\circ}C$이었으며, 초기 pH 범위는 pH 4.5-10.0이었다. 배양시간에 따른 항균물질의 생산성을 검토한 결과, 배양 24시간이 최대의 활성을 나타내었다. 다양한 종류의 유해미생물에 대한 최소저해농도(MIC)를 검토한 결과, E. coli와 P. mirabilis에 대해서는 5 mg/mL, S. aureus, S. enteritidis, V. parahaemolyticus에 대해서는 10mg/mL를 나타내었다.

• Journal of Animal Science and Technology
• /
• 제62권4호
• /
• pp.543-552
• /
• 2020

For efficient prevention and treatment of enteric colibacillosis, understanding about latest virulence factors and antimicrobial resistance of Escherichia coli is essentially needed. The aim of this study was to survey antimicrobial resistance and determine the prevalence of fimbriae and enterotoxin genes among 118 pathogenic E. coli isolates obtained from Korean pigs with diarrhea between 2016 and 2017. The genes for the toxins and adhesins were amplified by polymerase chain reaction (PCR). The susceptibility of the E. coli isolates to antimicrobials were tested using the standard Kirby-Bauer disk diffusion method. The most prevalent fimbrial antigen was F18 (40.7%), followed by F4 (16.9%), and the most prevalent combinations of toxin genes were Stx2e (21.2%), STb:EAST-1 (19.5%), and STa:STb (16.9%), respectively. Among the pathotypes, enterotoxigenic E. coli (ETEC) was the most predominant (67.8%), followed by Shiga-toxin producing E. coli (STEC, 23.7%). We confirmed high resistance rates to chloramphenicol (88.1%), tetracycline (86.4%), streptomycin (86.4%), and ampicillin (86.4%). And the majorities of isolates (90.7%) showed multi-drug resistance which means having resistance to 3 or more subclasses of antimicrobials. Results of this study can be a source of valuable data for investigating the epidemiology of and control measures for enteric colibacillosis in Korean piggeries.

• Journal of Microbiology and Biotechnology
• /
• 제19권7호
• /
• pp.734-741
• /
• 2009

Recently, strains of methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to vancomycin (VCM) have been clinically isolated. The antibacterial activity of a new drug, linezolid (LZD), in such a strain was evaluated by measuring bacterial metabolic activity. A total of 73 MRSA strains having various susceptibilities to VCM were subjected to a novel and highly sensitive chemiluminescence-based assay. LZD MIC in the tested strains, measured by the microbroth dilution method, was within the range 1-4 mg/l (mostly ${\leq}2$mg/l), except for one LZD-resistant strain (NRS127; MIC=7 mg/l), and showed no correlation with VCM resistance. The chemiluminescence assay demonstrated that bacterial metabolic activity was strongly suppressed with increasing LZD concentration. The chemiluminescence intensity curve had a low baseline activity without tailing in most strains. The present results suggest that LZD has strong antibacterial activity against MRSA strains, and would be effective for treatment of infections that are poorly responsive to VCM. The chemiluminescence assay facilitated sensitive and discriminative susceptibility testing within a relatively short time.

• 대한수의학회지
• /
• 제38권3호
• /
• pp.574-580
• /
• 1998

Anthrax caused by Bacillus anthracis is one of the most important zoonotic diseases in the worldwide. To control and prevent the disease effectively, several methods such as development of a fast and specific diagnostic method and vaccine, education etc, have been carried out. However, it still has a problem in the control and prevention. To control, the most important method is the prevention of direct or indirect contact of the causative agent with susceptible host. Therefore, we developed a fast and specific detection method, polymerase chain reaction, of B anthracis from soil and infected animals because the organism could survive long time in the environment including soil due to formation of spore. With the method, virulence genes of B anthracis were successfully amplified from experimentally infected soil and mice. Up to $4.2{\times}10$ of the organisms per gram could be detected with the PCR method from experimentally infected soil. These results suggested that this PCR method could be effectively used not only to detect B anthracis in soil and infected animal but also to provide the information to prevent the disease.

• 한국동물위생학회지
• /
• 제30권2호
• /
• pp.233-241
• /
• 2007

Tuberculin positive cattle without gross tubercle lesions should be confirmed by the bacteriological examination to determine the state of the infection. To overcome the time-consuming and laborious identification by culture and biochemical tests, polymerase chain reaction (PCR) has been used to identify Mycobacterium bovis. Due to various lipids in the cell wall of Mycobacterium spp, novel methods of DNA extraction from Mycobacterium spp have been developed. In this study, a newly developed guanidium isothiocyanate/silica DNA extraction method was directly applied to specimens from the tuberculin positive cattle. DNAs were directly extracted from the lymph nodes and the major polymorphic tandem repeat (MPTR) and mycobacterial protein of BCG 70 (MPB70) were amplified using PCR. The DNA extraction method using guanidium isothiocyanate/silica was efficient and safe, and the MPTR and MPB70 primers were specific to M bovis. Therefore, MPTR and MPB70 PCRs will be useful for the detection of M bovis in the lymph node from skin-test positive cattle.

• 농업과학연구
• /
• 제19권1호
• /
• pp.28-32
• /
• 1992

태국의 토양으로부터 분리한 젤라틴 분해능을 갖는 광합성세균 T-20주(株)는 직경이 $0.6{\sim}0.7{\mu}m$의 적색 간균으로써, Bacteriochlorophyll a의 흡수극대는 870nm이었고 또한, 퀴논종(種)은 UQ-8을 나타내었다. 유기 화합물로써 citrate, aspirate, glutamate, fractose 등을 이용하였다. 이상의 결과로부터 T-20주는 Bergey's Manual of Systematic Bacteriology(1989)에 기재된 Rhodocyclus gelatinosus와 일치한다.

• 대한수의학회지
• /
• 제36권4호
• /
• pp.829-837
• /
• 1996

Clostridium perfringens has been identified as a causative organism in necrotic enteritis in chicken. The bacterium has been classified into five toxigenic types (A through E) based on the pattern of the production of major lethal toxins. Seroneutralization with mice or guinea pigs usually has been used to type the organism. Of the types, types A and C of the bacterium had been recognized as the major pathogenic types in chicken. In this experiment, we isolated nine field strains of C perfringens from chicken showing necrotic enteritis in clinical symptoms and pathologic findings and identified by biochemical tests. In order to type the organism, a multiplex polymerase chain reaction (PCR) was used with primers on major lethal toxin genes instead of seroneutralization. Amplification of only a toxin gene with the PCR suggested that the disease in chicken was due to type A of C perfringens in Korea. Furthermore, the PCR method can be replaced with seroneutralization to type C perfringens in future.

• 한국동물위생학회지
• /
• 제44권3호
• /
• pp.157-162
• /
• 2021

The abnormal meat could caused by abscess, fibrosis and granuloma in the region of the neck by adverse effect of vaccination or antibiotic injection under swine practice. In this study, the incidence of abnormal meat due to antibiotics injection was investigated using marbofloxacin from different manufacturers. To evaluate the incidence of abnormal meat via antibiotic treatment, a total of 440 pigs with the age of 140~150 days old were selected. Two hundred of pigs were assigned as a control group and 2 mL of saline was inoculated daily for three days. Two hundred forty of pigs were used as treatment group and further divided into 6 groups, consisting of 16% of original marbofloxacin treated, 10% of original marbofloxacin treated and 4 different kinds of generic marbofloxacin treated groups respectively. When test animals were slaughtered, incidence, type and size of induced abnormal meat were recorded. In the result of this study, statistical analysis found significantly lower incidence of abnormal meat formation was in 16% original marbofloxacin treated groups compared to the other tested groups (P<0.05). In the summary, antibiotic treatment could produce abnormal meat formation but the 16% of original marbofloxacin had the most minimal abnormal meat formation effect.

• 한국어병학회지
• /
• 제4권2호
• /
• pp.71-77
• /
• 1991

1. 1991년(年) 8월(月)부터 10일(日)까지 제주도내(濟州道內) 넙치양식장 4개소(個所)의 병어에서 연쇄구균을 분리하였다. 2. 분리균(分離菌)은 $10^{\circ}C$, $45^{\circ}C$, 6.5% Nacl, pH 9.6 및 0.1% methylene blue milk 에서는 발육(發育)되지 않았고 또한 Indole 및 $H_2S$도 생성하지 못하였으며 $\beta$ 용혈성(溶血性)을 나타내었다. 3. 이상(以上)의 성상(性狀)에서 분리균(分離菌)은 Bergey's Manual of Determinative Bacteriology 및 Bergey's Manual os Systematic Bacteriology I 및 II에 근거(根據)를 두어 검색(檢索)한 결과(結果) Streptococcus pyogenes 및 Streptococcus epuisimilis와 유사하지만 약간의 차이(差異)가 있으므로 Streptococcus sp.로 하였다. 4. 분리균(分離菌)의 약제(藥劑) 감수성(感受性) 시험결과(試驗結果) Spiramycin 및 Erythromycin에 높은 감수성(感受性)을 나타냈으나 Penicillin에는 내성(耐性)을 나타냈다. 5. 분리균(分離菌)의 병원성(病原性) 시험결과(試驗結果) $1.1{\times}10^3cells$/100g 어체중 이상(以上) 접종(接種)하였을 때는 폐사(斃死) 미수(尾數)가 발생(發生)하였으나 그 이하(以下)의 접종(接種) 농도(濃度)에서는 폐사(斃死)가 발생(發生)하지 않았다.

• 대한미생물학회지
• /
• 제35권5_6호
• /
• pp.367-367
• /
• 2000