Staphylococcus aureus is an important food-borne pathogen, which is present on the skin and mucosa of animals. Some of the S. aureus strains are causative agent of food poisoning syndrome. The aim of this study was to investigate the antimicrobial resistance of S. aureus isolates from raw meats in slaughterhouses during 2010. From 17,874 raw meat samples tested, a total of 190 S. aureus were isolated, for which antimicrobial susceptibility to 17 agents was examined using broth dilution method. Among isolates from beef, chicken and pork, 20 (51.3%), 20 (24.7%) and 9 (12.9%) were sensitive to all antimicrobials tested, respectively. Isolates from pork and chicken meats showed much higher resistance, compared to isolates from beef. Penicillin resistance was the most frequent among isolates from beef (35.3%) and pork (75.7%), while tetracycline resistance was among those from chicken meats (48.1%). A total of 3 methicillin resistant S. aureus (MRSA) were detected from beef (5.1%, 2/39) and pork (1.4%, 1/70). Although the prevalence of MRSA was low, the presence of antimicrobial resistant S. aureus such as MRSA suggests that further investigation and strict surveillance on MRSA and antimicrobial resistance are needed.

This study was focused on the determination of antibacterial activity of Scutellaria baicalensis extract against antibiotic resistant bacteria(Salmonella Enteritidis, Staphylococcus aureus and enteroaggregative E. coli). Extract of Scutellaria baicalensis were tested for antibacterial activity by paper disc methods. The Scutellaria baicalensis extract in 0.1 g/㎖ and 0.2 g/㎖ showed a significant antibacterial activity against antibiotic resistant bacteria. Minimum inhibitory concentration (MIC) of Scutellaria baicalensis extract were appeared to 2, 048 ㎍/㎖ at S. Enteritidis, S. aureus and enteroaggregative E. coli. Finally, the growth incubation curve was determined using Scutellaria baicalensis extract against S. Enteritidis, S. aureus and enteroaggregative E. coli. The growth of S. Enteritidis was significantly inhibited within 10 hours by the addition of at least 10, 000 ppm of Scutellaria baicalensis extract. The 10, 000 ppm of Scutellaria baicalensis extract retarded the growth of S. aureus and enteroaggregative E. coli more than 10 hours. In conclusion, Scutellaria baicalensis extract might be useful to control antibiotic resistant bacteria in vitro.

A rare case of primary intraosseous squamous cell carcinoma(PISCC) arising from lining epithelium of a dentigerous cyst is described. The case occurred at the left mandibular 3rd molar region in a 56-year-old Japanese woman. Clinical observation revealed cyst formation with an impacted 3rd molar, a common finding in dentigerous cyst, in the left mandible. Histopathologically, the lining epithelium of the cyst demonstrated transition from epithelial dysplasia to invasive squamous cell carcinoma(SCC). This case was diagnosed as PISCC arising from lining epithelium of a dentigerous cyst.

온도는 곤충의 생활에 영향을 미치는 주요 요인 중 하나로, 장기적인 관점에서 종 풍부도와 지리적인 분포 등에 영향을 미치며, 단기적으로는 활성과 생존 등에 영향을 미친다. 온도에 대한 곤충의 반응은 개체군 동태의 중요한 원동력이 되며, 기후변화영향 평가를 위한 생물기후모델 혹은 분포 모델에 필수적으로 이용되고 있다. 하지만 대부분의 곤충에게 있어서 기후의 평균적인 변화보다는 극한온도로의 변동이 생존에 더 많은 영향을 미칠 수 있다. 변화한 기후에 대한 개체 혹은 개체군의 반응은 공간적․시간적으로 달라질 수 있지만, 아직 이것에 대해 명확하게 밝혀지진 않았다. 온도 변화에 각 개체군의 반응력은 환경변화 영향을 이해하는데 중요한 요소이다. 곤충의 온도 변화에 대한 반응은 온도환경(thermal environment)과 연관된 기계적․생리적 특성을 통해 이루어지며, 환경의 변화와 예측에 대한 동물의 반응 능력과 연관되어 있다. 이러한 온도환경은 생태적으로 적합한 시간척도(시간, 일, 계절 등)에 의해 정량화 될 수 있다. 곤충이 예기치 못한 온도에 노출되었을 때, 생리적 혹은 행동적 메타니즘을 발현함으로써 변화한 온도에 대처를 하지만, 이와 같은 메카니즘은 잘 알려져 있지 않다. 현재까지 약 30여종의 육상절지동물이 rapid cold hardening(RCH)을 보인다고 알려져 있다. RCH는 저온조건 혹은 예측할 수 없는 환경(Environmental predictability hypothesis)에서 생존이 불가능한 온대지방 생물종에서 일반적이지만, 곤충에서 RCH에 대한 연구는 상대적으로 미흡하다. 따라서 본 발표에서는 곤충의 온도내성과 온도에 대한 행동반응에 생태 연구의 방향 및 경향을 살펴보았다.

This study was carried out to investigate antibiotic resistances of 181 isolates in Staphylococcus aureus isolated from 450 specimens which were a General Hospital personnel in Cheonan province. Of the 181 isolates, 89 isolates (49.2%) were methicillin resistant and 92 isolates were susceptible. They were resistant to penicillin (80.1%), clindamycin (18.8%), oxacillin (49.2%), cefepime (28.2%), cefotetan (34.3%), ampicillin (66.3%), gentamicin (27.6%), tetracycline (17.7%) and erythromycine (43.1%), also. In resistant rates of the 89 MRSA, 5 antibiotics were more than 50%, but in those of the 92 MSSA, only 1 antibiotics was. Also they showed very highly multi-drug resistance patterns to 15 antibiotics as follow : One hundred and forty five isolates(82.3%) showed antibiotic resistance to more than one kind of the 15 kinds antibiotics. In the multiple resistant patterns, one drug resistant isolates were 18 isolates (9.9%), 2 drugs 29 (16.0%), 3 drugs 21 (11.6%), 4 drugs 29 (16.0%), and more than 5 drugs were 52 isolates (28.7%). The number of more than 5 drugs resistant strains in MSSA were only 1 strain, but those in MRSA were 51 isolates (57.3%). Forty five isolates (24.9%) produced enterotoxin serotype C and all MRSA.

There are many researches about the contribution of virginiamycin use in animals to quinupristin/dalfopristin (Q/D) resistance in humans. In this study, the prevalence and mechanisms of streptogramin resistance in Enterococcus faecium from chickens were investigated. A total of 170 E. faecium isolates from 38 chicken farms was tested for antimicrobial susceptibility. Eleven (6.5%) E. faecium isolates were found to be resistant to Q/D. The vatE and ermB genes were detected in 2 (18%) and 6 (55%) of Q/D-resistant E. faecium respectively. By using pulsed-field gel electrophoresis (PFGE), 6 distinct PFGE patterns were identified. These data indicate that Q/D resistance among E. faecium from chickens remains low despite the long history of virginiamycin use. However, we have to concern over antimicrobial resistance in bacteria originated from animals, including the possibility of transfer of resistance genes from animal to human.

This study was carried out to investigate the antimicrobial resistance pattern and distribution of resistance gene determinants in fecal E. coli from chicken. Antimicrobial susceptibility test was performed on a total of 109 fecal E. coli isolates from chicken, collected in Gyeonggi, Chungbuk, Jeonnam and Jeonbuk province from March to November 2003, by the disk agar diffusion method. Eighteen commonly used antimicrobial agents approved in Korea as veterinary medicine were tested: ampicillin (AM), amoxicillin/clavulanic acid (AMC), cephalothin (CF), cefozolin (CZ), cefoxitin (FOX), cefotaxime (CTX), cefepime (FEP), imipenem (IPM), streptomycin (S), gentamicin (GM), amikacin (AN), ciprofloxacin (CIP), enrofloxacin (ENO), norfloxacin (NOR), trimethoprim/sulfamethoxazole (SXT), erythromycin (E), chloramphenicol (C) and tetracycline (TE). Higher resistance rates (≥50%) were observed against 9 antimicrobial agents including AM, CF, S, CIP, ENO, NOR, SXT, E and TE. Resistance was most frequent for TE in 105 E. coli isolates (96.3%). Twenty-two isolates (20.2%) of the isolates showed multiple antimicrobial resistance to 8, and 19 isolates (17.4%) showed to 7 antimicrobial agents. The distribution of the resistance gene determinants for S and TE was assessed by PCR in resistant isolates. Thirty isolates possessed the strA, strB, and aadA gene, 25 isolates possessed the strA and strB gene among the 66 streptomycin-resistant isolates. Fifty one isolates possessed only the tetA gene, 22 isolates possessed the tetA and tetB gene, 11 isolates possessed only the tetB gene among the tetracycline-resistant isolates.

The incidence of multidrug-resistant strains of Staphylococcus aureus continues to increase in hospitals and the community all over the world. As the importance of miner surgery in dentistry gets greater recently, the frequency in use of antibiotics has been increasing. Although several cases of acquired infection in oral cavity in dental hospital has been reported, the research on isolation of S. aureus and evaluation of its antibiotic resistance from outpatients in the dental clinic has not been found yet. The aim of this study was to evaluate the antimicrobial resistance of S. aureus isolates. The isolation rate of S. aureus were 41.7% in dental hospital personnel, 60.4% in outpatients and 62% in dental hygiene students. S. aureus which showed resistance to penicillin were 88.6%, ampicillin 88.6%, erythromycin 8.6%, tetracycline 4.3%, oxacillin 4.3%, cefoteten 4.3%. Six strains of S. aureus showed the susceptible to all antibiotics tested. Sixty-four(91.4%) strains were multiple antibiotic resistance. Fifty-two strains(72.8%) resisted to AM-P. and Seven strains(10.0%) resisted to AM-P-E, AM-P-GM, AM-P-TE.

The electron transport chain (ETC) delivers electrons from many substrates to reduce molecular oxygen to water. ETC accomplishes the stepwise transfer of electrons through series of protein complexes conferring oxidation‐reduction reactions with concomitant transport of p roton across membrane, g enerating a proton g radient which leads ATP s ynthesis b y F0F1ATPase. Bacterial ETC initiates with oxidation of NADH by NADH dehydrogenase complex (complex I). Therefore, damage of complex I leads to insufficient function of ETC and accumulation of NADH inside the cell. Contribution of ETC activity and its consequent changes of NADH levels to bacterial damage response against reactive oxygen and nitrogen species (ROS/RNS) has been poorly understood. In this study, by constructing ndh mutant Salmonella lacking complex I NADH dehydrogenase 2, we evaluated the effect of ETC deficiency to bacterial resistance against ROS and RNS. The growth of ndh mutant Salmonella is impaired in the culture media containing hydrogen peroxide, but rather accelerates in the media containing nitric oxide donors. Data suggest that redox potential of NADH accumulated inside the cell by ETC blockage may affect inversely to bacterial resistance against reactive oxygen species and reactive nitrogen species.

서울시내에서 유통되는 식품과 식품접객업소(집단급식소 포함)의 조리식품을 대상으로 식중독 원인균 분석 및 위생미생물 검사를 실시한 결과, 분리된 대장균의 항생제 감수성 시험을 통하여 이들의 내성 정도를 파악하고, 내성 유전자와 병원성유전자의 분포도 알아보았다. 모두 1313건 의 샘플 중 50건에서 대장균이 검출되어 3.8%의 검출률을 보였다. 이중 육회 1건에서 장출혈성대장균 O26 1건, 김밥 에서 장병원성대장균 1건이 각각 검출되었다. 50건의 대장 균중 50%가 16종의 항생제에 모두 감수성을 보였으며 내성이 높게 나타난 항생제는 ampicillin(36%), amoxicillin/ clavulanic acid(32%) 그리고 tetracycline(22%)의 순이었다. 이들의 내성유전자 분포는 TEM이 1건, tetB 4건이 각각 검출되었다.

From April to December in 2009, microbial investigation is accomplished for 100 frozen foods asked to microbial control team that corresponds with total aerobic viable bacteria, coliform group, Escherichia coli,Enterococcus spp. and antibiotic resistance patterns of Enterococcus spp. isolates are investigated. Average of total aerobic viable bacteria numbers is 4.3 × 10⁴CFU/g. Average of coliform group numbers is 4.3 × 10³ CFU/g. Average of Enterococcus spp. numbers is 1.8 × 10³ CFU/g. Escherichia coli from 100 frozen foods is not detected and detection rate is 0.0%. 22 Enterococcus spp. are isolated from 100 frozen foods. 12 of 22 Enterococcus spp. strains are identified as E. faecium. 7 of 22 Enterococcus spp. strains are identified as E. faecalis. 2 of 22 Enterococcus spp. strains are identified as E. gallinarum. 1 of 22 Enterococcus spp. strains is identified as E. hirae. Enterococcus spp. isolates show a high resistance to erythromycin, rifampin, tetracycline, ciprofloxacin, chlorampenicol, penicillin and a susceptibility to vancomycin, ampicillin, gentamicin, strepomycin, linezolid. 15 of 22 Enterococcus spp. strains are multi-resistant and the most frequent multi-resistant pattern is erythromycin-rifampin for 6 Enterococcus spp. strains.

With the increase of the use of antibiotics and invasive procedures, infections caused by multidrug-resistant Acinetobacter baumannii(MRAB) are increasing. We screened the antibiotic producing strain B-51 for antibacterial activity against MRAB from the soils and studied the effects of culture medium on the antibiotic production of B-51. The medium conditions for maximum antibiotic productivity of B-51 was 2% glycerol, 0.5% soybean meal, 0.01% CaCl2, 0.01% MgSO4, 7H2O and 0.01% KH2PO4 at an initial pH of 6.0, at 30℃ for 76 h.

파김치에서 분리한 마늘 내성 유산균인 Lactobacillus plantarum TJ-LP-002 균주의 균체생육과 항균활성에 영향을 미치는 배양조건 및 배지조건을 조사하였다. 선정 유산균의 배양 상등액 내에는 acetic acid, citric acid, lactic acid, tartaric acid와 같은 유기산이 존재하였고, 배양 중에 lactic acid와 acetic acid의 생성이 크게 증가하는 것으로 확인되었다. 단백질분해효소를 비롯한 각종 효소 처리에 의해 항균활성이 소실되지 않아, 선정 유산균이 생산하는 항균활성은 단백질성 물질이 아닌 산 생성에 의한 작용일 것으로 판단되었다. 항생제와 생균제의 병용 가능성을 확인하기 위하여 선정 유산균의 항생제 감수성을 조사한 결과, neomycin sulfate, spectinomycin dihydrochloride, lincomycin hydrochloride에 내성을 나타내었고, streptomycin sulfate에는 감수성을 나타내었으며, ampicillin trihydrate, chloramphenicol, erythromycin, tetracycline hydrochloride, kanamycin sulfate에는 중간 내성을 나타내었다. L. plantarum TJ-LP-002는 배양온도 30oC, 초기 pH 7.0, 24시간의 배양 조건에서 최적의 균체생육과 항균활성을 나타내었으며, 탄소원은 glucose 3%(w/v), 질소원은 yeast extract 3%(w/v) 첨가 시에 균체생육과 항균활성이 높게 나타났다. 무기염류는 manganese sulfate와 ammonium citrate가 항균활성에 많은 영향을 주는 것으로 나타났으며, 각 성분을 단독 첨가하는 것보다 혼합 첨가하는 것이 더 우수한 영향을 나타내는 것으로 확인되었다.

From April 2008 to January 2009, a total 458 raw milk samples were randomly collected from 15 stock raising farms located in northern area of Kyunggi province and cultured for the presence of Enterococci spp. A total 170 enterococcal isolates were recovered from the raw milk samples. Enterococcus faecalis was predominant species recovered (64.7%), followed by E. faecium (18.8%), E. avium (5.9%), E. gallinarum (5.9%) and E. durans (4.7%). Antimicrobial resistance patterns of 170 Enterococci spp. against ampicillin, erythromycin, tetracyclin, chloramphenicol, vancomycin, ciprofloxacin and streptomycin were tested. According to the result, they showed high level resistance to erythromycin and streptomycin (82,9% and 93,5% respectively), moderately resistance to ampicillin, chloramphenicol and tetracyclin (50%, 45.9% and 32%, respectively) but fortunately, vancomycin and ciprofloxacin are still effective against this species.

저온 스트레스에 대한 내성을 지닌 신품종 톨 페스큐를 개발할 목적으로 CaMV35S 프로모터 하류에 NDP kinase 2 유전자가 항상적으로 발현하도록 제작한 벡터를 Agrobacterium법을 이용하여 톨 페스큐에 도입하였다. Hygromycin이 첨가된 선발배지에서 내성을 나타내며 재분화된 형질전환 식물체를 pot로 이식하여 기내순화 시킨 후, Southern blot 분석을 실시하여 본 결과, NDP kinase 2 유전자가 형질전환 식물체의 g