• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1559-1567
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• 2015

The combination of trimethoprim (TMP) and sulfamethoxazole (SMX) has been shown to be active against Mycobacterium tuberculosis (Mtb) in clinical tuberculosis (TB) treatment. However, the mechanism of action of TMP-SMX against Mtb is still unknown. To unravel this, we have studied the effect of TMP and SMX by deleting the folP2 gene in Mycobacterium smegmatis (Msm), and overexpressing the Mtb and Msm folP1/2 genes in Msm. Knocking out of the folP2 gene in Msm reduced the minimum inhibitory concentration of SMX 8-fold compared with wild type. Overexpression of the folP1 genes from Mtb and Msm increased the MICs by 4- and 2-fold in Msm for SMX and TMP, respectively. We show a strong correlation between the expression of folP1 and folP2 genes and TMP-SMX resistance in mycobacteria. This suggests that a combination of FolP2 inhibitor and SMX could be used for TB treatment with a better outcome.

• 한국동물위생학회지
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• 제32권3호
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• pp.227-239
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• 2009

At the present study, it was aimed to detect virulence genes and antimicrobial resistance genes among 102 strains of 12 Salmonella serotypes isolated from pigs and cattle. In polymerase chain reaction (PCR), invA was detected from all strains of Salmonella spp., spvC was detected from Salmonella enterica serotype Enteritidis (S. Enteritidis) (100%), S. Bradenburg (75%), and S. Typhimurium (20.4%). Drug resistance related genes of 12 types were detected from all strains. TEM ($bla_{TEM}$) gene was detected from 51 (92.7%) of 55 $\beta$-lactams (54 ampicillin or 1 amoxicillin) resistance strains. 55 (100%) of 55 chloramphenicol resistance strains, 3 (100%) of 3 gentamicin resistance strains and 5 (100%) of 5 kanamycin resistance strains did contain cml, aadB, and aphA1-Iab, respectively. strB (89.9%), strA (88.4%), aadA2 (84.1%) and aadA1 (72.5%) were detected from 69 streptomycin resistance strains. sulII and dhfrXII were detected from 49 (100%) of 49 sulfamethoxazole/trimethoprim resistance strains, but sulI was not detected. tetA (97.9%) and tetB (21.6%) were detected from 97 tetracycline resistance strains. int gene was detected from 58 (56.9%) of 102 strains. 54 S. Typhimurium of 102 Salmonella spp. were attempted to detect drug resistance genes. TEM was detected from 44 (95.7%) of 46 $\beta$-lactams (45 ampicillin or 1 amoxicillin) resistance strains. cmlA was detected from 51 (100%) of 51 chloramphenicol resistance strains. aadA2 (100%), strA (100%), strB (100%), and aadA1 (79.6%) were detected from 54 streptomycin resistance strains. sulII (100%) and dhfrXII (100%) were detected from 49 sulfamethoxazole/trimethoprim resistance strains. tetA was detected from 54 (100%) of 54 tetracycline resistance strains. int gene was detected from 54 (100%) of 54 strains. The major drug resistance pattern and resistance gene profile were ampicillin, chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim and tetracycline (ACSSuT) and TEM, cmlA, aadA1, aadA2, strA, strB, sulII, dhfrXII, tetA and int, respectively.

• Parasites, Hosts and Diseases
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• 제53권3호
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• pp.321-327
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• 2015

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.

• 미생물학회지
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• 제49권2호
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• pp.146-149
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• 2013

비브리오균은 해양 및 하구 환경에서 상재하는 균으로 그람 음성 간균, 호염성, 비포자형성의 특징을 가지고 있다. 질병과 관련된 균주로는 Vibrio parahaemolyticus, Vibrio vulnificus, Vibrio cholera 등이 있다. 매년 어패류의 섭취 등을 통해 식중독 사고가 빈번하게 발생하고 있으며, 이에 본 연구에서는 서해안 6곳에서 패류를 채취하여 비브리오균의 분포도를 모니터링하고, 이들의 항생제 내성을 분석하였다. 총 120건의 패류를 TCBS 평판배지와 API 20E kit 기법으로 동정하였을 때 23.3%의 시료에서 비브리오균이 검출되었다. 이들 분리균주들의 항생제 내성을 16종의 항생제에 대해 분석한 결과 82.1%가 각각 vancomycin과 ampicillin에 대해 내성을 보였고, rifampin (71.4%)과 cephalothin (53.6%)에 대한 내성비율도 다른 항생제들에 비해 상대적으로 높은 것으로 나타났다. 분리균주들의 항생제 감수성은 chloramphenicol (92.9%), sulfamethoxazole/trimethoprim (92.9%)과 tetracycline (96.4%)에 대해 가장 높았다. 분리균주들의 약 71.4%가 vancomycin과 ampicillin을 포함하여 3개 이상의 항생제에 대해 다중내성을 보였다.

• 한국임상수의학회지
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• 제8권1호
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• pp.59-63
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• 1991

돼지의 이유자돈 설사병을 효과적으로 치료, 예방하고자 Enrofloxacin(Baytril premix)을 사료에 혼합투여하여 설사 발생여부, 증체량, 사료요구율, 돈분내 대장균수의 변화, 분리한 대장균의 항균물질에 대한 감수성을 조사하여 다음과 같은 결과를 얻었다. 1. 이유자돈에 Baytril premix를 급여하였던 바 대조구보다 62일령에서 체중은 3.2kg의 통계적 유의차이를 보여(p<0.01) 현저한 증체효과 나타내었으며, 사료요구율도 계선되었고 설사발생도 예방할 수 있었다. 2. Baytril Premix를 급여한 자돈의 분변내 대장균수는 3.14$\times$$10^{8}$에서 5일후 2$\times$$10^{7}$ 개/g 10일후 1$\times$$10^{5}$개/g으로 현저히 감소하였다. 3. 공시농장에서 분리한 E. coli 10중의 항균물질에 대한 감수성은 baytril, gentamicin 및 trimeoprim＋sulfamethoxazole에 감수성이 우수하였다.다.

• 한국임상수의학회지
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• 제8권1호
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• pp.47-52
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• 1991

A total of 2,024 quarters of 515 dairy cattle in Kangweon area were examined for incidence of subclinical mastitis. Milk samples from cattle infected with subclinical mastitis were studied bacteriologically and the bacterial strains isolated were further examined for sensitivity to 12 antibacterial agents. And the status of carrying out the mastitis control program in 28 dairy farms was examined. The results obtained were summerized as follows ; 1. A total of 308(59.8%) of 515 cattle and 656(32.4%) of 2,024 quarters were found to be infected with subclinical mastitis. 2. The 277 strains of etiological agents were isolated from 358 subclinical quarters. These were identified as Staphylococcus aureus(14.4%), other staphylococci(36.5%), Streptoccus agalatiae(8.7%), other streptococci(30.7%), Bacillus spp.(1.8%), Corynebacterium spp.(1.4%) and coliform(0.7%). 3. The 109 strains of streptococci and 141 strains of staphylococci were examined for sensitivity to 12 antibacterial agents. All the strains of streptococci were sensitive to penicillin, ampicillin and cephalothin, and they were also sensitive to erythromycin(88.1%), clindamycin(83.5%), enrofloxacin(75.2%), trimethoprim＋sulfamethoxazole(67.9%), The strains of staphylococci were sensitive to cephalothin(97.2%), gentamicin(83.0%). enroflozacin(80.9%), trimethoprim＋sulfamethoxazole(78.0%), erythromycin(71.6%) and clindamycin(71.6%). But all the strains resisted to colistin. 4. In the 28 dairy farms examined, condition of udder before washing was dirty in most of the farms (89.7%). Hygiene of milking equipment was only good in the 5 farms(17.9%). Teat preparation before milking was good in the 6 farms(21.4%). The farms in which teat dipping after milking was conducted were 46.4%. Dry cow treatment for the complete herd was carried out in most of the farms(89.3%) but mastitis checking was only carried out in the 8 farms(28.6%) irregularly.

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

• 한국임상수의학회지
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• 제27권2호
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• pp.125-129
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• 2010

2년령 암컷 포메라니안이 교통사고로 인한 골반골절로 내원하여 골절 교정수술을 받았다. 그러나 수술 후 술부에서 감염으로 인한 화농성 삼출물이 발생하였고, 분리한 세균의 항생제 감수성 검사 결과 penicillins, cephalosporins, aminoglycosides, quinolones, 그리고 trimethoprim/sulfamethoxazole에 내성이 관찰되었다. 분리한 세균의 동정 및 extended-spectrum $\beta$-lactamase (ESBL) 확진시험을 통해 ESBL 생성 Klebsiella pneumoniae임을 확인하였다. 치료를 위한 Carbapenem계 항생제의 감수성 시험 결과에 따라 meropenem을 선택하여 치료에 이용하였다. 분리된 세균에서 ESBL 유전자의 분자생물학적 검사 결과 TEM-1 ESBL 유전자가 있음을 확인하였으며, 보호자의 손바닥에서 분리된 세균에서도 TEM-1, SHV-1 ESBL 유전자가 검출되었다.

• 상하수도학회지
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• 제28권2호
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• pp.235-248
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• 2014

The widespread occurrence of dissolved endocrine disrupting compounds(EDCs) and pharmaceutical active compounds(PhACs) in water sources is of concern due to their adverse effects. To remove these chemicals, adsorption of EDCs/PhACs on granular activated carbon(GAC) was investigated, and bisphenol A, carbamazepine, diclofenac, ibuprofen, and sulfamethoxazole were selected as commonly occurring EDCs/PhACs in the aquatic environment. Various adsorption isotherms were applied to evaluate compatability with each adsorption in the condition of single-solute. Removal difference between individual and competitive adsorption were investigated from the physicochemical properties of each adsorbate. Hydrophobicity interaction was the main adsorption mechanism in the single-solute adsorption with order of maximum adsorption capacity as bisphenol A > carbamazepine > sulfamethoxazole > diclofenac > ibuprofen, while both hydrophobicity and molecular size play significant roles in competitive adsorption. Adsorption kinetic was also controled by hydrophobicity of each adsorbate resulting in higher hydrophobicity allowed faster adsorption on available adsorption site on GAC. EDCs/PhACs adsorption on GAC was determined as an endothermic reaction resulting in better adsorption at higher temperature ($40^{\circ}C$) than lower temperature ($10^{\circ}C$).

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1238-1243
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• 2009

The susceptibilities of major enterohemorrhagic Escherichia coli (EHEC) strains to antimicrobial agents and the cytotoxicity of these agents were examined using a total of 38 strains of E. coli O26, O111, and O157, which are the major serogroups of EHEC. Among the 38 strains, 35, 36, and 36 were susceptible to amikacin, imipenem, and norfloxacin, respectively. These antimicrobial agents were further examined to determine their cytotoxicity on Vero cells as well as their effect on the release of Shiga toxins along with trimethoprim/sulfamethoxazole. Each of the E. coli O26, O111, and O157 strains containing both the stx1 and stx2 genes were grown in the absence or presence of these agents at 1/4 minimal inhibitory concentration for 6 h, 12 h, and 18 h. At the concentrations used in this study, none of the agents significantly altered cell count compared with the control group. The level of cytotoxicity in the imipenem group was lower at 12 hand 18 h than their respective controls. In contrast, the level of cytotoxicity in cultures treated with trimethoprim/sulfamethoxazole, norfloxacin, and amikacin was increased. The strains were also examined for the release of Shiga toxins 1 and 2 following treatment with the agents, which were measured by the reversed passive latex agglutination (RPLA) method. The RPLA assay showed a suppression of release of Shiga toxin 2 in the strain cultures containing imipenem. These results indicate that imipenem may be a safe and effective agent for inhibition of these bacteria, which has clinical implications for the treatment of EHEC infections.