Clostridium perfringens (C. perfringens) may cause diarrhea and enterotoxemia in adult and young livestock, leading to problems in the production and management of farms. Four hundred fecal samples were collected from 25 goat farms located in Gyeongsangbuk-do Province in the Republic of Korea. Sixteen C. perfringens strains were isolates from fecal samples, and the isolates were identified as type A (n=11) and type D (n=5). Additionally, α- and ε-toxin genes were detected in 16 and 5 strains by PCR, respectively, and the enterotoxin gene was presented in 2 strains. The antibiotic susceptibility test was performed using the disk diffusion method and E-test method. In the disk diffusion method, ampicillin (n=16) and chloramphenicol (n=15) were highly susceptible to 16 C. perfringens isolates. In the E-test method, ampicillin, amoxicillin, amoxicillin/clavulanic acid and meropenem were susceptible to more than 14 of 16 C. perfringens isolates. This study indicates that administration of antibiotics such as ampicillin, amoxicillin/clavulanic acid and meropenem can prevent and treat C. perfringens infections in goats.

목 적: 콘택트렌즈 케이스에서 분리한 균주들을 동정하고, Serratia marcescens 균주들에 대해 항생 제 감수성 검사를 시행하였다. 방 법: 총 65개의 콘택트렌즈 케이스를 수거하여 분리한 균주들을 16s rRNA gene 염기서열을 분석하여 동정하였고, Serratia marcescens 균주들을 Nalidixic acid(30㎍), Ciprofloxacin(5㎍), Ofloxacin(5㎍), Levofloxacin(5㎍) 항생제를 이용하여 디스크 확산법으로 항생제 감수성 검사를 실시하였다. 결 과: 30개의 콘택트렌즈 케이스에서 세균이 검출되었으며, 균주로는 Achromobacter sp. 8균주, Achromobacter xylosoxidans 3균주, Achromobacter spanius 1균주, Pandoraea pnomenusa 1균주, Serratia marcescens 17균주가 동정되었다. Serratia marcescens 균주에 대한 항생제 감수성 검사에서는 Nalidixic acid, Ciprofloxacin, Ofloxacin, Levofloxacin 모두 감수성으로 나타났다. 결 론: 콘택트렌즈 케이스에서 분리한 균주들을 16S rRNA gene 염기서열을 분석하여 동정한 결과 모두 30 균주가 동정되었으며, 콘택트렌즈 케이스에서 많이 분리 동정된 Serratia marcescens 균주에 대한 Quinolone 계 항생제 감수성 검사에서 모두 감수성으로 나타났다. 그러나 항생제의 지속적인 사용으로 내성 균주들이 나타날 것으로 예측되며 Quinolone 항생제의 내성 발생률에 대한 체계적인 연구와 관리가 필요한 것으로 사료된다.

본 연구는 들깻잎과 들깻잎 생산환경을 대상으로 31개의 시료를 채취하여 S. aureus 를 분리 하였다. 분리된 S. aureus 31주의 toxicity를 평가하고자 독소유전자와 항생제 내성을 검색하였다. 그 결과 분리된 균주에서 4개의 서로다른 독소유전자 패턴은 확인하였으며 sea와 sed유전자를 동시에 보유하는 균주는 4균주 (12.9%)였고, sed 유전자를 보유하는 균주는 9균주 (29.0%)였으며 see 유전자를 보유 하는 균주는 1균주 (3.2%)였다. 한편 seb와 sec 유전자를 보유하는 균주는 없었다. 항생제 내성평가결과, 12제의 항생제(penicillin, ampicillin, oxacillin, amoxicillin-clavulanic acid, cefazolin, cephalothin, imipenem, gentamicin, tetracycline, ofloxacin, norfloxacin, and erythromycin)에 내성을 보인 균주는 7균주 (22.6%)였다. 또한 분리된 균주의 2균주 (2.6%)는 5제의 항생제(penicillin, ampicillin, amoxicillin- clavulanic acid, gentamycin, and telithromycin)에 내성을 보였고 MRSA (Methicilline Resistant Staphylococcus aureus)는 포장지, 장갑, 들깻잎에서 발견되었다. 따라서 본 연구결과는 들깻잎에 오염된 S. aureus에 의하여 독소형식중독이 발생할 가능성을 시사하며 들깻잎과 생산 환경에서 항생제 저항성 S. aureus가 검출되어 의약계뿐만 아니라 농업현장에서도 항생제내성균주 출현을 예방하는 대책이 요구된다.

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, CO2, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin® (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

Oral viridans streptococci are recognized as one of the etiological agents of a variety of infectious diseases such as dental caries and infective endocarditis. Although antimicrobial susceptibility tests for these fastidious bacterial species are now established and standardized, a comparison between the broth microdilution and broth macrodilution tests has not previously been performed. This comparison was performed in the present study using the tests adopted by the Clinical and Laboratory Standards Institute (CLSI) and seven clinical isolates of oral viridans streptococcal strains. A modified broth macrodilution susceptibility test method was also included in this analysis, in which the media was not supplemented with horse blood. The susceptibility interpretation category agreements were measured at 83% (broth microdilution versus broth macrodilution) and 71% (broth microdilution versus modified broth macrodilution). The interpretation category agreement between the broth macrodilution and modified broth macrodilution tests was also 83%. These data indicate that the interpretation of antibiotic susceptibility test results for oral viridans streptococci are influenced by the methods used.

One hundred isola tes of Staphylococcus aureus were obtained from feces samples of patients with food poisoning. The a ntibiotic susceptibility against vari ous antibiotics was examined by disc diffusion test . The S. aureus isolates had 92% resista nce to peni cillin. They also had 30% resistance to ampicillin and erythromycin. respect ively. The percentage of re sistance to oxacillin was 14%. Three vancomycin resistant isolates were also found. The minimal inhibitory co ncen tra ti on(MIC)s of antibiotics were examll1ed Antibiotics-intermediate S a ureus isolates were not det ected by disc dif fu sion t est

In order to investigate the classification and antibiotic resistance of Salmonella species 718 isolates were isolated from patient in Seoul from 1996 to 2001. The two hundred and ninety eight isolates (41.5%) were identified as Sal. Enteritidis, followed by Sal. Typhi 218 isolates (30.4%), and Sal. Typhimurium 87 isolates (12.1%). The identified Salmonella species were most resistant to tetracycline (32.7%), followed by streptomycin (28.0%), ticarcillin (18.1%) and ampicillin (12.4%). Among isolates, 34.7% of Sal. Enteritidis were resistant to tetracycline, 32.3% to streptomycin, 23.2% to ticarcillin, 13.5% to ampicillin, respectively. 13.8% of Sal. Typhi were resistant to streptomycin, 10.6% to tetracycline, respectively. 66.7% of Sal. Typhimurium were resistant to tetracycline, 42.5% to streptomycin, 28.7% to ticarcillin, 26.4% to ampicillin and 17.2% to chloramphenicol, respectively. Of 718 isolates, 324 isolates (45.1%) were resistant to 1 or more drugs and 64 isolates (19.8%) were resistant to 1 drug, 132 isolates (40.7%) were resistant to 2 drugs, 50 isolates (15.4%) were resistant to 3 drugs, 27 isolates (8.3%) to 4 drugs, 27 isolates (8.3%) to 5 drugs, 22 isolates (6.8%) to 6 drugs. The most prevalent multiple resistant pattern was tetracycline-kanamycin (35.5%), followed by tetracycline-kanamycin-ticarcillin (8.3%), and tetracycline-kanamycin-ticarcillin-ampicillin (7.4%). Antibiotic resistant rate of Sal. Typhimurium was 73.6%, followed by Sal. Enteritidis 53.7% and Sal. Typhi 19.3%. Most Sal. Enteritidis was resistant to 1 drug or 2 drugs, whereas Sal. Typhi and Sal. Typhimurium were more resistant to 5 (16.7%) or 6 drugs (26.6%). The old generation antibiotics such as ampicillin, tetracycline, and streptomycin were annually more resistant than the new generation antibiotics such as ceftriaxone, ciprofloxacin or cefoxitin.

Spaceflights results in the reduction of immune status of human beings and increase in the virulence of microorganisms, especially gram negative bacteria. The growth of Klebsiella pneumoniae is enhanced by catecholamines and during spaceflight, elevation in the levels of cortisols occurs. So it is necessary to know the changes in physiology, virulence, antibiotic resistance and gene expression of K. pneumoniae under microgravity conditions. The present study was undertaken to study effect of simulated microgravity on growth, morphology, antibiotic resistance and cross stress resistance of K. pneumoniae to various stresses. The susceptibility of simulated microgravity grown K. pneumoniae to ampicillin, penicillin, streptomycin, kanamycin, hygromycin and rifampicin were evaluated. The growth of bacteria was found to be fast compared with normal gravity grown bacteria and no significant changes in the antibiotic resistance were found. The bacteria cultured under microgravity conferred cross stress resistance to acid, temperature and osmotic stress higher than the normal gravity cultured bacteria but the vice versa was found in case of oxidative stress.