• 한국동물위생학회지
• /
• 제43권1호
• /
• pp.31-37
• /
• 2020

Clostridial bacteria are zoonotic agents, which cause severe necrotizing enteritis, pseudo-membrane colitis, enterotoxemia to both humans and animals. The objective of this study was to monitor the antibiotic resistance of Clostridium isolates on clinical specimens from wild animals in Seoul zoo for 5 years. Clostridium isolates were verified by using Vitek2 compact machine. Antibiotic susceptibility was assessed by antibiotic disc diffusion test, which was followed by Kirby-Bauer disc diffusion test method. The frequency of Antimicrobial resistance of Clostridium isolate was the greatest in gentamicin (87%), then in order of amikacin (80%). There were 55.6% of Clostridium isolates showed multiple drug resistance (MDR). These results showed that a lot of Clostridial bacteria from wild animals in Seoul zoo were acquired antibiotic resistance. Because of the wild animal's aggressive manner, it has been hard to collect clinical samples from wild animals in a zoo to exam antibiotic susceptibility. For these reasons, empirical use of antibiotics has been performed in frequently. It may cause to increase the emergence of antibiotic resistance bacteria. In addition, the antibiotic resistance bacteria from zoo animals can be spread to other wild animals which inhabit around the zoo. Therefore, regular monitoring of antibiotic resistance Clostridial bacteria is important to protect animals and humans from Clostridial diseases.

• 한국수산과학회지
• /
• 제54권4호
• /
• pp.377-387
• /
• 2021

Fecal contamination levels of discharge water from inland pollution sources were investigated in Iwon-myeon (Taean-gun), South Korea. Gram-negative bacteria were isolated during the investigation and the antimicrobial resistance patterns of the isolates were examined to estimate their impact on the coastal environment. The ranges of total coliform and fecal coliform of 12 samples from four major inland pollution sources were 79-490,000 MPN/100 mL and 2.0-490,000 MPN/100 mL, respectively, with the highest level of fecal contamination at Station No. 3. A total of 137 strains (14 genus) were isolated, of which 86 strains (62.8%) were Enterobacteriaceae. The identified isolates were as follows: Pseudomonas spp. (35 strains), Klebsiella spp. (20 strains), Serratia spp. (20 strains), and Escherichia spp. (19 strains). The isolated Gram-negative bacteria showed the highest antimicrobial resistance to ampicillin (81.8%), followed by amoxicillin/clavulanic acid (64.2%), ceftiofur (61.3%), and cefoxitin (59.1%). Antimicrobials in which less than 10% of isolates showed antimicrobial resistance were ciprofloxacin (3.6%) and gentamicin (2.2%). Resistance to one or more antimicrobials was observed in 121 strains (88.3%) and 84 strains (61.3%) showed a tendency for multiple antimicrobial resistance.

• 한국임상수의학회지
• /
• 제32권2호
• /
• pp.158-161
• /
• 2015

세균성 피부염은 항생제 치료가 필요한 흔한 질환이다. 최근 항생제 내성 세균이 전 세계적으로 증가하고 있는 추세이다. 본 연구에서는 개 피부염 병변에서 분리한 S. pseudintermedius의 항생제 내성 유전자 발현을 조사하고, 이를 디스크 감수성 시험결과와 비교하였다. 총 7개의 S. pseudintermedius 균주가 연구에 포함되었다. 세균 동정은 16S rDNA 염기 서열 분석으로 실시하였다. 조사 결과 분리한 S. pseudintermedius 모두가 1개 이상의 항생제 내성유전자(mecA, blaZ and aac[6']/aph[2"])를 보유하였다. 전체 분리균주가 blaZ 유전자에 양성을 보였으나, 두 개 균주만이 amoxicillin/clavulanate에 내성을 나타냈다. Gentamicin 내성을 나타낸 5개 균주 중, 1개는 aac(6')/aph(2") 유전자에 대한 PCR 검사에서 음성을 나타냈다. 이 결과는 내성 유전자 검출 PCR 기법과 디스크 감수성 시험 기법이 항생제 내성을 검사하는 데에 있어 상호보완적인 관계를 가짐을 제시한다.

• 대한임상검사과학회지
• /
• 제36권2호
• /
• pp.76-88
• /
• 2004

본 연구에서는 임상검체에서의 Enterococcus sp.의 균종별 분리현황을 조사하고, 분리균의 항생제 감수성 양상을 알아보는 한편, aminoglycoside계 항생제에 내성을 나타내는 균주를 대상으로 Rep-PCR을 실시하여 유전적인 다양성을 알아보고자 하였다. 각종 임상검체로부터 E. faecalis 49주, E. faecium 34주, E. avium 9주, E. gallinarum 4주, E. casseliflavus 3주, E. hirae 1주 등 총 100주를 분리하였다. 대부분 외래를 통하기보다는 입원환자의 검체로부터 분리됨을 관찰하면서 원내감염의 원인균 중의 하나임을 알 수 있었다. Urine과 pus, sputum에서 대부분의 균들이 분리되었고 E. faecalis와 E. faecium이 주 종을 이루었다. 항생제 감수성양상으로는 disk법과 ViteK GPS-430의 MIC결과와 유사하게 관찰 되었으며, 대부분의 Enterococcus sp.가 cephalosporin계 항생제에는 80% 정도의 내성을 보였다. E. faecalis의 경우 항생물질에 대해 고른 감수성양상을 볼 수 있었고, E. faecium의 경우 다른 Enterococcus sp.와는 차별적으로 항생물질에 대해 높은 내성 양상을 볼 수 있었다. 또한 vancomycin에 대한 내성을 보이는 Enterococcus sp.는 전체 10%정도를 차지하였고 aminoglycoside계 항생제인 amikacin과 gentamicin에 대해서 높은 고도내성을 나타냈었고, streptomycin의 경우에는 50% 정도의 내성률을 나타내었다. Aminoglycoside계 항생제에 내성을 보이는 Enterococcus sp.를 대상으로 Rep-PCR을 실시하여 유전자 분획유형을 분석하였으나 유전적 다양성에 있어 크게 차이를 보이지 않아 DNA양상의 기원이 크게 다르지 않다는 것으로 생각되었다.

• 한국식품위생안전성학회지
• /
• 제25권2호
• /
• pp.122-128
• /
• 2010

2009년 4월부터 12월까지 서울시 보건환경연구원 미생물 관리팀에 의뢰된 냉동식품 100건을 대상으로 일반세균수, 대장균군수, 대장균과 장구균의 오염도를 조사였으며, 분리된 장구균을 대상으로 하여 항생제 감수성 검사를 실시하였다. 일반세균수는 평균 검출량이 $4.3{\times}10^4CFU/g$ 이고 대장균군수는 평균 검출량이 $4.3{\times}10^3CFU/g$ 이고 대장균은 100건 모두에서 불검출되어 0.0%의 검출률을 보였다. 100건의 검체 중 총 22건에서 장구균이 분리되었으며 이 가운데 12주는 E. faecium, 7주는 E. faecalis, 2주는 E. gallinarum, 1주는 E. hirae이었다. 분리균주의 항생제 내성률을 검사 한 결과, 내성을 나타내는 항생제들은 erythroycin, rifampin, teracycline ciprofloxacin, chlorampenicol, penicillin이며, vancomycin, ampicillin, gentamicin, strepomycin, linezolid에 대해서는 모두 감수성이었다. 또 22건의 분리 균주 중에서 2종 이상의 항생제에 다제 내성을 나타낸 균주가 15주나 되며 가장 많은 형태로는 6균주의 장구균에서 나타난 E-RA에 대한 것이었다.

• 환경생물
• /
• 제29권4호
• /
• pp.286-295
• /
• 2011

Bacteria resistant to various antibiotics have recently become an issue of the utmost importance. Resistant strains are not uncommon, even in municipal drinking water sources. The health threat posed by resistant, pathogenic bacteria has serious ramifications for both public health and agriculture. In this study, we isolated antibiotic resistant bacteria from water samples from the Han River, Korea, which is contaminated by the wastewater from many industrial complexes, hospitals, agricultural and animal husbandry estates, and from wastewater treatment facilities. We determined the degrees of resistance to various antibiotics exhibited by the isolated strains. The similarities between the isolated $E.$ $coli$ strains were examined, using the pulsed field gel electrophoresis and multilocus sequence typing, in order to trace their origins and to explore the syntechnic adaptations and pathogenicity of the various strains and relate these to their genetic sequence. A total of 25 $E.$ $coli$ strains were isolated from six stations along the Han River. All the 25 strains exhibited resistance to ampicillin. We also investigated resistance to amoxicillin, clavulanic acid, cefazolin, cofoxitin, cefotaxime, cefpodoxime, ceftriaxone, cefepime, nalidixic acid, aztreonam, ciprofloxacin, streptomycin, gentamicin, chloramphenicol and imipenem. Based on the ESBL detection, 14 strains belonged to the ESBL producing strains. The number of the clonal complex producing strains was 5 among the 14 isolated strains. The 5 strains were included in the 168, 23, 38, 469, 156 clonal complex, respectively. The rest 9 strains were not included in the clonal complex, but showed independent STs.

• Journal of Microbiology and Biotechnology
• /
• 제13권6호
• /
• pp.872-880
• /
• 2003

Three vectors, pSG1, 2, and 3, which facilitate in vivo expression technology (IVET) in Gram-negative bacteria, were developed. Vectors pSG1and 2 are derivatives of ColE1, and pSG3 is a derivative of an R6K replicon. These vectors contain oriT sites that allow mobilization when the RK2 Tra functions are provided in trans. These vectors contain promoterless lacZ (pl-lacZ) and promoterless aph (pl-aph) transcriptionally fused together, which allow qualitative and quantitative measurements of the expression of genes in the genome of bacterial cells. pSG1 and 3 contain gentamicin-resistance genes, and pSG2 carries a streptomycin-/spectinomycin-resistance gene, allowing for selection of recombinants generated by a single crossover between a library fragment cloned into a pSG vector and the identical region in the genome of a bacterial species from which the library fragment originated. These vectors were successfully applied to the generation of random fusions at high rates in the genomes of four representative Gram-negative bacteria. In addition, the expression level of ${\beta}-galactosidase$ and the degree of resistance to kanamycin in cells with fusions generated by these vectors were found to be linearly correlated, proving that these vectors can be used for IVET.

• 한국동물위생학회지
• /
• 제23권1호
• /
• pp.77-91
• /
• 2000

This study was conducted to investigate the antibiotic resistance and plasmid profiles of 58 salmonella spp isolated from mesenteric lymphnodes of slaughter pigs in Kyoungbuk province during the period from September 1997 to June 1998. The results obtained are as follow that all isolates were susceptible to amikacin, gentamicin, ciprofloxacin and enrofloxacin, and the majority of isolates were highly susceptible to norfloxacin, colistin, nalidixic acid and apramycin while they were moderately susceptible to kanamycin, cephalothin, chloramphenicol, ampicillin, trimethoprim and penicillin. The majority of isolates were over 90% resistant rates to lincomycin, sulfadimethoxine, vancomycin, methicillin and erythromycin. The plasmid profiles of 58 salmonella spp are developed 1 to 4 fractions, 0.9 to 29.5 Kb molecular range sizes and U strains (45.5%) were showed plasmid profiles by agarose gel electrophoresis. 5 derby harbored 29.5 Kb and 7 Kb, and S schwarzengrund had 14 Kb and 0.9 Kb harboring sizes. Four of 10 S agona and 2 of 4 S typhimurium were harbored 3.1 Kb and n.5 Kb, respectively. Thirty-five untypable strains are developed variable size fractions its showed small size plasmid profile less than 6 Kb and 22 (62.8%) of them had no detectable plasmids.

• 한국동물위생학회지
• /
• 제22권1호
• /
• pp.85-92
• /
• 1999

This study was investigated resistance on disinfectants and antibiotics of Clostridium chauvoei isolated from dairy farm in Kyongbuk province. The results obtained were summarized as follows ; C chauvoei isolated from dairy farm were susceptible to norfloxacin, penicillin, tetracycline, erythromycin, enrofloxacin, bacitracin, tyrosine, cephalothin and cefazolin but resistant to gentamicin, kanamycin, sulfamethoxazole＋trimethoprim, amikacin, neomycin streptomycin, colistin. In effect on disinfectants, C chauvoei was inhibited completely to growth in mercuric bichloride ($HgCl_2$), harasol(sodium hypochloride 4-6%), long-life(high boiling tar acids et al), and phenol($C_6$$H_5$OH), but growth in all-stop(didecyl dimethyl ammonium chloride 10%), powercide(potassium monopersulphate 50% et al), antec vercon-s(triple salt 50% et al), and taego-51(6-alkyl-2.6-diaza-hexane-carbonic acid-1ㆍHCl et al). The effect of disinfectant was excellent in mercuric bichloride and harasol.

• Journal of Microbiology and Biotechnology
• /
• 제20권10호
• /
• pp.1446-1449
• /
• 2010

A total of 1,444 coagulase-negative staphylococci (CNS) isolates from bovine mastitic milk samples collected during 2003-2008 in Korea were identified to the species level. Of 14 species identified, S. simulans, S. haemolyticus, and S. sciuri accounted for over 60% of the isolates. All the CNS isolates were tested for susceptibility to eight antimicrobials commonly used in dairy cattle. With a few exceptions, similar resistance patterns were observed among the CNS species: penicillin and ampicillin showed the lowest activity, whereas amikacin, cephalothin, and gentamicin were highly effective. About 39% (557/1,444) of the CNS isolates were pan-susceptible, whereas 12% (175/1,444) showed resistance to four or more antimicrobials tested.