• 대한수의학회지
• /
• 제63권2호
• /
• pp.16.1-16.6
• /
• 2023

Salmonella spp. are pathogens involved in most salmonellosis in rabbits. This study examined Salmonella disease in rabbits raised in Thua Thien Hue, Vietnam. Two hundred and 56 rectal swabs of rabbits were taken, and a carrier rate of 33.98% was found. In addition, all the isolated Salmonella spp. strains were 100% motile; positive for H₂S, catalase, Voges Proskauer, coagulase, citrate, maltose, and dextrose; and negative for indole, methyl red, urease, oxidase, sucrose, and lactose. The Kirby-Bauer method showed that these Salmonella strains were susceptible to doxycycline (93.2%), tetracycline (84.1%), and levofloxacin (65.9%). On the other hand, they were highly resistant to streptomycin (95.5%), ampicillin (93.2%), colistin (40.9%), and gentamicin (34.1%). Furthermore, polymerase chain reaction used to screen for virulence and specific genes of Salmonella strains showed that all Salmonella strains isolated carried InvA, fimA, and Stn.

• Journal of Microbiology and Biotechnology
• /
• 제26권1호
• /
• pp.171-179
• /
• 2016

In this study, we compared the virulence-associated factors of Acinetobacter baumannii complex species. Sixty-three isolates of five A. baumannii complex species, including 19 A. baumannii, 15 A. nosocomialis, 13 A. seifertii, 13 A. pittii, and 3 A. calcoaceticus isolates, were included in this study. For all isolates, biofilm formation, A549 cell adherence, resistance to normal human serum, and motility were evaluated. A. baumannii complex isolates showed diversity in biofilm formation, A549 cell adherence, and serum resistance, and no strong positive relationships among these virulence characteristics. However, A. seifertii showed relatively consistent virulence-associated phenotypes. In addition, A. baumannii clone ST110 exhibited consistently high virulence-associated phenotypes. Motility was observed in seven isolates, and all four A. baumannii ST110 isolates showed twitching motility. Although some inconsistencies in virulence-associated phenotypes were seen, high virulence characteristics were observed in A. seifertii, which has been mainly reported in Korea and shows high rates of colistin resistance.

• 한국수산과학회지
• /
• 제27권3호
• /
• pp.292-298
• /
• 1994

식중독 원인균으로 알려진 Vibrio mimicus(V. mimicus)의 분포 상태와 이의 생리적 특성을 조사하기 위하여 1993년 1월부터 9월까지 민락동과 광안리 해수욕장 부근의 해수를 채취하여 V. mimicus의 월별 분포 상태를 실험하였으며, 여기서 분리된 균주 중에서 항생제 내성이 강한 균으로 분리, 동정된 V. mimicus K-1의 생리적 성질과 배양 특성을 조사하였다. 수온이 $16.3^{\circ}C$인 4월부터 검출되기 시작하여 8월까지 검출되었으나, 수온이 $15^{\circ}C$ 이하인 겨울철(1, 2, 3월)에는 전혀 검출이 되지 않았다. 분포 정도는 최소 0.4(MPN/100ml)에서 최고 70((MPN/100ml)으로 지역에 따라 차이가 있었다. V. mimicus K-1은 $37^{\circ}C$, pH 7.5, 그리고 염도 $0.5\%$에서 각각 최대의 증식율을 보였다. 그리고 항생제 (colistin, erythromycin, bacitracin, tetracycline, penicillin)에 대해서 내성을 나타내었다. 자외선(30W, 50m)에 대해서는 상당히 내성이 약했으며, 70초간 조사 후에는 검출이 되지 않았다. 열에 의한 치사율은 $50^{\circ}C$에서 5.7분, $60^{\circ}C$에서 2.1분, 그리고 $70^{\circ}C$에서는 0.7분 만에 최초균수의 $90\%$이상이 사멸하였다.

• Journal of Microbiology and Biotechnology
• /
• 제28권7호
• /
• pp.1178-1184
• /
• 2018

The spread of antibiotic-resistant Enterobacteriaceae in the community is one of the main challenges for antibiotic treatment of community-onset infections. We evaluated the microbiological and molecular characteristics of stool samples from adults with comprehensive health examinations. Of 109 fecal samples, bacterial growth was observed in 86 samples and 61 gram-negative bacterial isolates were identified, of which 45 were Escherichia coli isolates (73.8%). Two isolates of Raoultella showed imipenem resistance, and both E. coli and Citrobacter freundii showed intermediate resistance to imipenem. Colistin resistance was identified in isolates of Klebsiella variicola and Salmonella subterranean, but no isolates carried mcr-1. As for E. coli genotypes, 35 sequence types were identified. $bla_{TEM-1}$, $bla_{TEM-30}$, and $bla_{CTX-M}$ were identified in 15, 1, and 4 E. coli isolates, respectively. In addition, all four Klebsiella pneumoniae isolates carried $bla_{SHV}$. Many genotypes that have been identified in isolates causing human infections were found in isolates in this study. There is a need to control the rise and spread of antibiotic-resistant pathogens by fecal carriage.

• 한국수산과학회지
• /
• 제35권2호
• /
• pp.115-121
• /
• 2002

R plasmid의 분포와 새로운 conjugation 방법 개발을 위하여, 한국의 남해안과 동해안의 양식현장의 어류질병관련 세균으로부터 항균제 다제 내성균을 분리하였다. 분리균 134종에서 10균주가 chlorarnphenicol, tetracycline, streptomycin, ampicillin, colistin, nalidixic acid, oxolinic acid, kanamycin 등에 대한 다제내성의 특성을 가지고 있었으며 이중 V. damsela JE1 한 균주는 chloram-phenicol과 tetracycline에 대한 내성전달 특성을 갖는 R plasmid 와 ampicillin과 kanamycin에 대한 유전자를 chromosome 등에 함유하고 있었다. 분리된 어병세균의 다제내성 특성이 R plasmid에 기인하는 것인지의 확인은 다양한 장내세균의 선택배지로 최근 개발된 CC 배지에서 각기 다른 균주들이 나타내는 증식여부 또는 집락 색깔의 차이를 이용하여 donor, recipient 그리고 transconjugant를 구별할 수 있는 방법을 적용하였다. Conjugation의 최적화를 위해 여러 가지 조건을 비교한 결과, V. damsela JE1의 R plasmid의 전달은 filter mating법을 사용하는 것이 broth mating법보다 약 100배 이상의 높은 성공률을 보여 주었으며 이때 사용온도는 30$^{\circ}C$ 이상, mating 시간은 24시간에서 가장 높은 전달 빈도를 나타내었다. R plasmid를 함유한 V. damsela JE1이 분리된 4개월 후, 동일 양식장의 동일 그룹의 넙치 장내세균에서 분리한 다제내성균 Sphingomonas sp. 3균주는 V. damsela JE1에서 분리된 것과 같은 크기의 R plasmid를 함유하고 있었으며, 그 특성 또한 V. damsela JE1의 R plasmid와 마찬가지로 다제 내성 중 Cm과 Tc에 대한 유전자만이 recipient로 전달되어 장내 세균총이 R plasmid의 reservoir로서의 역할을 하고 있음을 확인하였다.

• 대한미생물학회지
• /
• 제16권1호
• /
• pp.29-34
• /
• 1981

Species and antimicrobial susceptibility of nonfermenting gram-negative bacilli(NFB) isolated from clinical materials at Yonsei Medical Center during the period of September 1980 to August 1981 were analyzed and the following results were obtained. 1. NFB were isolated from 17.1% of sputum, 14.8% of pus, 5.0% of urine, 3.3% of throat and 1.4% of blood specimens. 2. Among the isolates 57.6% were Pseudomonas aeruginosa and 32.7% were Acinetobacter calcoaceticus. P. maltophilia and P. cepacia were 3.2% and 2.8% respectively. Other bacteria were rarely isolated. 3. The monthly isolation rates were high during the June to November period(8.8-12.0%), and low during the December to May period(4.2-8.4%). 4. Many of the isolates showed resistance to various antimicrobials. Although there were variations depending on the bacterial species, amikacin, colistin, gentamicin, tobramycin and co-trimoxazole showed more antibacterial activities than other antimicrobials.

• 대한수의학회지
• /
• 제23권2호
• /
• pp.173-178
• /
• 1983

This paper deals with the isolation of citrate-utilizing variants of Escherichia coli ($Cit^+$ E. coli) from the animals, their biochemical reactivity and antibiotic susceptibility, and whether the citrate utilizing ability is transmissible. One hundred arid twenty-three isolates of $Cit^+$ E. coli were obtained from cattle and pigs. but from other animals, no isolates were obtaied. Antibiotic susceptibility testing of $Cit^+$ E. coli was performed by the agar dilution method, using the following 9 antibiotics, chloramphenicol(CP), tetracycline(TC), streptomycine(SM), kanamycin(KM), colistin(CL), gentamicin(GM), cephaloridine(CR), aminobenzycillin and nalidixic acid(NA). All the variants tested were susceptible to KM, CL, GM, CR and NA. Of all the variants, 80(65%) were resistant to the drugs tested and resistance to TC and SM was most frequent. The transmission of the ability to utilize citrate on Simmons citrate agar at $37^{\circ}C$ was demonstrated in 78(67.8%) out of the 115 $Cit^+$ E. coli. There were no significant difference in the transfer rates of citrate utilizing ability between resistant and susceptible variants to above 9 drugs. Of 123 isolates, 8 were lost their citrate utilizing ability, spontaneously.

• 한국축산식품학회지
• /
• 제26권3호
• /
• pp.394-401
• /
• 2006

Forty Clostridium perfringens isolates were obtained from twelve animal products, following the examination of eighty six beef, pork, broiler chicken and salami meat products, and eleven milk powder products. There were 21 isolates from salami stored at $25^{\circ}C$, 3 isolates from pork, 4 isolates from beef, 9 isolates from broiler chicken, and 3 isolates from milk powder. Only the cpa gene encoding a toxin among the 5 toxin genes tested (cpa, cpb, etx, iap, and cpe) was detected in all forty isolates, suggesting contamination with C. perfringens type A. DNA fingerprinting analysis using PCR of the tRNA intergenic spacer (tDNA-PCR) and the 16S-23S internal transcribed spacer (ITS-PCR), and randomly amplified polymorphic DNA (RAPD) analysis were attempted to differentiate the isolates. RAPD analysis was the most discriminating method among the three PCR analyses. Isolates from the same products tended to show similar RAPD patterns. Antimicrobial susceptibility tests showed that some isolates from broiler chickens had the same antibiogram with multiple resistance to streptomycin, colistin, and ciprofloxacin. Antibiograms were similar between isolates from the same livestock products, but differed considerably between the products.

• Childhood Kidney Diseases
• /
• 제19권2호
• /
• pp.143-147
• /
• 2015

Purpose: Burkholderia cepacia is an aerobic, glucose-non-fermenting, gram-negative bacillus that mainly affects immunocompromised and hospitalized patients. Burkholderia cepacia has high levels of resistance to many antimicrobial agents, and therapeutic options are limited. The authors sought to analyze the incidence, clinical manifestation, risk factors, antimicrobial sensitivity and outcomes of B. cepacia urinary tract infection (UTI) in pediatric patients. Methods: Pediatric patients with urine culture-proven B. cepacia UTI between January 2000 and December 2014 at Samsung Medical Center, a tertiary referral hospital in Seoul, Republic of Korea, were included in a retrospective analysis of medical records. Results: Over 14 years, 14 patients (male-to-female ratio of 1:1) were diagnosed with B. cepacia UTI. Of 14 patients with UTI, 11 patients were admitted to the intensive care unit, and a bladder catheter was present in 9 patients when urine culture was positive for B. cepacia. Patients had multiple predisposing factors for UTI, including double-J catheter insertion (14.2%), vesico-ureteral reflux (28.6%), congenital heart disease (28.6%), or malignancy (21.4%). Burkholderia cepacia isolates were sensitive to piperacillin-tazobactam and sulfamethoxazole-trimethoprim, and resistant to amikacin and colistin. Treatment with parenteral or oral antimicrobial agents including piperacillin-tazobactam, ceftazidime, meropenem, and sulfamethoxazole-trimethoprim resulted in complete recovery from UTI. Conclusion: Burkholderia cepacia may be a causative pathogen for nosocomial UTI in pediatric patients with predisposing factors, and appropriate selection of antimicrobial therapy is necessary because of high levels of resistance to empirical therapy, including aminoglycosides.

• 대한수의학회지
• /
• 제19권2호
• /
• pp.121-126
• /
• 1979

대장균 설사중에 걸린 어린 돼지, 송아지, 어린 양에서 분리한 대장균 126주의 항생제와 화학요법제(15종)에 대한 감수성을 disc diffusion technique로 조사한 성적은 다음과 같다. 1. 어린 돼지에서 분리한 62주의 대장균은 gentamicin(GM)에 100%, colistin(CL)에 96.8%, kanamycin(KM)에 93.5%, neomycin(NM)에는 91.9%가 감수성을 가지고 있었으나 ampicillin(AM), erythromycin(EM), lincomycin (LM), novobiocin (NB), penicillin (PC), streptomycin(SM), tetracycline(TC), sulfaisodimidin(SU)에는 내성을 가지고 있었다. chloramphenicol(CP), sulfamethoxazole-trimethoprim(SXT), cephalosporin(CE)에는 각각 75.8%, 64.5%, 50%가 감수성이 있었다. 2. 송아지에서 분리한 32주의 대장균은 GM에 100%, CL에는 87.5%, SXT에는 66.7%가 감수성이 있었으나 CP와 KM에는 각각 40.6%, SU에는 56.2% NM에는 62.5%, SM에는 87.5%가 내성을 가지고 있었다. EM, LM, NB, PC에는 전혀 감수성이 없었으며 AM, SM, TC에도 고도의 내성을 가지고 있었다. 3. 어린 양에서 분리한 32주의 대장균은 GM과CL에 100%, CP에 96.9%, KM과 NM에 90.6%가 감수성이 있었다. SM과 SU에도 71.9%나 감수성이 있었으나 CM, EM, LM, PC, TC에는 대부분 내성을 가지고 있었다. AM에는 21.9%가 감수성이 있었다. 4. 2종류 이상의 약제에 내성을 가진 대장균의 AM, CE, CP, CL, GM, KM, NM. SM, TC, SU등 10종의 약제에 대한 multiple drug resistance pattern(MDRP)을 조사한 바 돼지 유래 약제내성 대장균의 MDRP는 18가지였으며 이중 가장 빈도가 높은 것은 AM, CE, SM, TC, SU 내성형으로 전체의 24.2%나 되었다. 송아지 유래 약제내성 대장균의 MDRP는 17가지였으며, AM, CE, CP, KM, NM, SM, TC, SU 내성형이 28.1%로 가장 빈도가 높았다. 반면에 어린 양에서 분리한 대장균의 MDRP는 9가지였으며 AM, CE, SU의 3약제 내성형이 40.6%로 가장 많았다.