• The Korean journal of internal medicine
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• 제39권3호
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• pp.448-457
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• 2024

Background/Aims: Improved knowledge of local epidemiology and predicting risk factors of multidrug-resistant (MDR) bacteria are required to optimize the management of infections. This study examined local epidemiology and antibiotic resistance patterns of liver cirrhosis (LC) patients and evaluated the predictors of MDR bacteremia in Korea. Methods: This was a retrospective study including 140 LC patients diagnosed with bacteremia between January 2017 and December 2022. Local epidemiology and antibiotic resistance patterns and the determinants of MDR bacteremia were analyzed using logistic regression analysis. Results: The most frequently isolated bacteria, from the bloodstream, were Escherichia coli (n = 45, 31.7%) and Klebsiella spp. (n = 35, 24.6%). Thirty-four isolates (23.9%) were MDR, and extended-spectrum beta-lactamase E. coli (52.9%) and methicillin-resistant Staphylococcus aureus (17.6%) were the most commonly isolated MDR bacteria. When Enterococcus spp. were cultured, the majority were MDR (MDR 83.3% vs. 16.7%, p = 0.003), particularly vancomycin-susceptible Enterococcus faecium. Antibiotics administration within 30 days and/or nosocomial infection was a significant predictor of MDR bacteremia (OR: 3.40, 95% CI: 1.24-9.27, p = 0.02). MDR bacteremia was not predicted by sepsis predictors, such as positive systemic inflammatory response syndrome (SIRS) or quick Sequential Organ Failure Assessment (qSOFA). Conclusions: More than 70% of strains that can be treated with a third-generation cephalosporin have been cultured. In cirrhotic patients, antibiotic administration within 30 days and/or nosocomial infection are predictors of MDR bacteremia; therefore, empirical administration of broad-spectrum antibiotics should be considered when these risk factors are present.

• 대한미생물학회지
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• 제19권1호
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• pp.11-24
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• 1984

Shigella remains to be an important enteric pathogen in this country for the present. Moreover, most of the isolates have become multiple resistant to various antibiotics which used to be drugs of choice for shigellosis. This study was made as an attempt to assess the present stage of antibiotic resistance and the incidence and transferability of R factors of Shigella. A total of one hundred and seventeen strains of Shigella isolated from patients in Seoul and provincial area between 1982 and 1983 were tested for their resistant to antimicrobial agents and transmission of R-plasmid. Antibiotic susceptibilities were determined by an agar dilution method. Muller hinton agar were used for the assay of drug resistance and tryptic soy broth were used for propagating medium for conjugation. Shigella isolated found to be one or more antibiotics were considered potential donor of R-plasmid. The following results were obtained. 1. Among 117 strains of Shigella isolated, 111 strains(94.9%) were found to be resistant to one or more drugs tested and 97.3% of these resistant strains were multiply resistant, indicating the multiply resistant strains were more than the single resistant strains. Only six strains were susceptible to all drugs tested. 2. Among 117 strains of Shigella isolated, 107 strains(91.5%) were resistant to Tetracyclin(Tc), 106 strains(90.6%) to Chloramphenicol(Cp) and Streptomycin(Sm), 97 strains(82.9%) to Ampicillin(Ap), 68 strains(58.1%) to Cephaloridine(Cr), 10 strains(8.5%) to Nalidixic acid(Na), 5 strains(4.3%) to Kanamycin(Km) and 2 strains(1.7%) to Rifampicin. No strain was resisfant to Amikacin(Ak) and Gentamicin(Gm). 3. All drug-resistant Shigella strains, except three, were multiply resistant to two or more drugs. Fifty eight strains were resistant to five drugs, followed by 26 strains resistant to dour drugs, 12 strains resistant to three drugs and 11 strains resistant to six drugs. 4. The 73% of multiply drug-resistant Shigella transferred their resistance to E. coli by conjugation and the resistance was considered to be mediated by R-plasmid. Resistance to Nalidixic acid and Rifampicin were not transferred by conjugation to recipient. As for the transferability of resistance to each seperate drug, Ap resistance was transferred with 73.2% frequence and Cm and Tc resistance were transferred with approximately 50-60% frequence whereas Sm and Cr resistance were transferred in 19.1-21.4% The other four drugs resistant failed to transfer their resistance to recipient. 5. As for the incidence and transferability of resistance to each seperate drug, the strains resistant to Tc and Cm were encountered most frequently with the rate of 91-92%, whereas transfer of Tc and Cm were low, 51-52%. The incidence of Sm resistance was very high(90.6%) but transferability of drugs resistance was much lower(25.4%). Though the incidence of Km reristance was much lower(4.3%) transferability of Km resistance was considerably higher(60%). 6. The greater the multiplicity of resistance, the greater was the likelihood that part of all of the resistance markers would be transferable.

• Tuberculosis and Respiratory Diseases
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• 제70권2호
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• pp.105-112
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• 2011

Pneumonia is frequently encountered in the clinical fields, both as a cause for admission and as a complication of the underlying disorder or as the course of treatment. Pneumonia is the second most common hospital-acquired infection and is associated with the highest morbidity and mortality rates among hospital-acquired infections. The guidelines for the management of hospital-acquired pneumonia by the American Thoracic Society include identifying individuals who have recently received antibiotics therapy or have been in medical facilities; these individuals are at higher risk for infection with multiple drug resistant organisms. Individuals, who have acquired pneumonia according to this clinical scenario, have what is known as healthcare-associated pneumonia (HCAP). Patients with HCAP should be considered to have potentially drug-resistant pathogens and should receive broad spectrum empiric antibiotic therapy directed at the potentially resistant organisms. In this paper, the diagnosis, risk factors, and treatment of HCAP are discussed.

• 약학회지
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• 제52권1호
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• pp.33-36
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• 2008

Staphylococcus aureus KH13 and Staphylococcus aureus KH28 were resistant to chloramphenicol, ampicillin, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tobramycin, and norfloxacin. A plasmid (pKH13) and two plasmids (pKH14, pKH15) were isolated from Staphylococcus aureus KH13 and Staphylococcus aureus KH28, respectively and complete nucleotide sequences of three plasmids were determined. It was found that pKH13 and pKH15 mediated chloramphenicol resistance and pKH14 was a cryptic plasmid.

• 한국동물위생학회지
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• 제26권2호
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• pp.95-103
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• 2003

Isolates of 70 Proteus mirabilis were tested against 10 different antibiotics by a disc diffusion method as recommended by National Committee for Clinical Laboratory Standards (NCCLS). The isolates were resistant in order of tetracycline(100.0%), enrofloxacin(95.7%), ampicillin(74.3%), choramphenicol(62.9%), cephalothin(58.6%), streptomycin(50%), kanamycin(47.2%), neomycin(35.8%), gentamicin(15.7%), and amikacin(2.9%). In the antibiotic resistant patterns, 37 kinds of multiple resistance patterns of P mirabilis isolates were detected. The highest resistant pattern was ampicillin-cephalothin-chloramphenicol-enrofloxacin-tetracycline(11.6%).

• 대한임상검사과학회지
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• 제43권2호
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• pp.68-74
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• 2011

Pseudomonas aeruginosa is an aerobic, Gram-negative, glucose-nonfermenting bacterium, which has emerged as a serious opportunistic pathogen. Recently, outbreaks of carbapenem resistant P. aeruginosa give rise to significant therapeutic challenges for treating nosocomial infections. The genes of metallo-${\beta}$-lactamase (MBL), a powerful carbapenemase, are carried as a part of the mobile gene cassettes inserted into integrons playing an important role in rapid dissemination of antibiotic resistance genes among bacterial isolates. In this study, we investigated the prevalence of integron in imipenem resistant P. aeruginosa isolates. A total of 61 consecutive, non-duplicate, and imipenem resistant P. aeruginosa strains were isolated from a university hospital in the Chungcheong province of Korea. We employed repetitive extragenic palindromic sequence-based PCR (rep-PCR) method for the selection of clonally different P. aerusinosa strains. PCR and DNA sequencing were conducted for the detection of integrons. Twenty-one clonally different P. aeruginosa strains were isolated. Only one (P28) of the strains harbored $bla_{VIM-2}$ that was found as gene cassettes in class 1 integrons. Four of 21 carbapenem resistant P. aeruginosa strains harbored class 1 integron containing aminoglycoside resistance determinant. All of the integrons detected in the study contained more than one resistance gene cassette, which can mediate resistance to multiple antibiotics. To prevent further spreading of the multi-drug resistant P. aeruginosa, conseguent monitoring and clinical polices are required.

• 대한임상검사과학회지
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• 제48권3호
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• pp.202-209
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• 2016

본 연구는 methicillin-resistant Staphylococcus aureus(MRSA)로부터, 독소 유전자형과 항생제 내성의 상관 관계를 결정하는 것을 목표로 하였다. 2014년 1월~12월까지 전남 순천의 한 병원 중환자실의 임상검체 2,664건에서 얻어진 MRSA 52균주를 분리하였다. 유전자들이 암호화하고 있는 mecA, 장독소(staphylococcal enterotoxins; sea, seb, sec, seg, seh, sei, sej), 독성 쇼크 증상독소-1 (toxic shock syndrome toxin-1; tst-1), 표피박탈성독소(exfoliative toxin; eta, etb), 백혈구 용해 독소(Panton-Valentine leukocidin; pvl)를 특이적 프라이머를 이용한 multiplex PCR로 증폭 검출 하였다. 독소 유전자 seg와 sei 유전자가 각각 40균주(76.9%)로 가장 많은 보유율을 나타냈으며 다음으로 tst 34균주(65.4%) 순으로 검출 되었으며 eta, etb, sea, sed, see, seh, sej와 pvl 유전자들은 검출 되지 않았다. 2개 이상의 독소 유전자를 동시에 보유한 조합의 MRSA는 40균주(76.9%) 였는데 5개 유전자(seb, sec, seg, sei, tst)를 동시 보유한 조합이 28균주(53.8%)로 가장 많은 분포를 보였으며 다음으로 seg, sei 유전자 동시 보유 조합으로 6균주(11.5%)에서 나타났다. 유전자들 간의 동시 보유율은 72.5~100%로서 특정한 독소 유전자 seb, sec, seg, sei와 tst 유전자간의 상관성이 높게 나타났다. 특정 다수의 독소유전자(seb, sec, seg, sei, tst)를 동시에 보유한 균주들이 개별적 독소 유전자를 보유한 균주(seb, sec, tst)와의 항생제 내성의 상관성은 ciprofloxacin, clindamycin, erythromycin 항생제에 100% 내성을 보임으로서 공통적으로 포함된 seb, sec, tst 유전자와 이 항생제의 내성과는 밀접한 연관이 있음을 알았다.

• 대한임상검사과학회지
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• 제36권2호
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• pp.89-97
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• 2004

Many strains of Staphylococcus aureus were isolated from pus samples from primary, secondary, and tertiary medical institutions and were subjected to an antibiotic sensitivity test. Ciprofloxacin, clindamycin, erythromycin, gentamicin, oxacillin penicillin, tetracycline, trimethoprim/sulfamethoxazole, vancomycin and teicoplanin were used for the antibiotic sensitivity test. The strains showed hightest resistance to penicillin(91%), but all of strains tested were susceptible to vancomycin and teicoplanin. The isolated multi-drug(penicillin-tetracycline-ciprofloxacin-clindamycin-erythromycin- oxacillin-gentamicin) resistant S. aureus were analyzed genotypically using an AP-PCR(Arbitrarily Primed polymerase chain reaction) with an arbitrary 3 primers. Based on the result for genotype analysis, the genotypes identified by S1 primer did not coincide with those of S2 or E2 primers. Genotypes identified by S2 primer did not coincide with those of S1 or E2 primers. Also genotypes identified by the E2 primer did not coincide with those of S1 or S2 primers. Therefore, an analysis of AP-PCR test with multiple primers will provide more sensitive identification. A strain from a secondary medical institution and a strain from a tertiary medical institution which showed the same genotype for S1, S2, and E2 primers are required for further epidemiological study.

• 미생물학회지
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• 제23권4호
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• pp.282-290
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• 1985

Small size antibiotic resistance plasmids having molecular weights less than 10 Mdal were isolated and characterized from ten clinically isolated multiple resistant Staphylococcus aureus. Agarose gel electrophoresis profiles and antibiotic resistance patterns divided these strains into four groups. Strain 2-23-6, the representative strain of a group of five strains conferred two plasmids of molecular weights $1.6{\times}10^6\;dal\;and\;2.0{\times}10^6$ dal. The small plasmid (pSBK 112) specified macrolides, lincosamides and streptogramin type B (MLS) resistance gene which are expressed constitutively. Lage plasmid (pSBK 125) specified chloramphenicol resistance gene which is inducible. Strain 10-5 conferred a $3.0{\times}10^6$ dal plasmid (pSBK 141) which carry an inducible ampicillin resistance gene and strain P-H-2 conferred and $1.6{\times}10^6$ dal plasmid (pSBK 190) which carry a constitutive MLS resistance gene. Strain D-H-1 conferred four plasmids of molecular weights $0.8{\times}10^6$ dal (pSBK 201), $1.6{\times}10^6$ dal (pSBK 202), $2.5{\times}10^6$ dal (pSBK 203), and $1.2{\times}10^7$ dal (pDBK 204), respectively. Among those four plasmids, only pSBK 203 specified chloramphenicol resistance gene. Curing of constitutive MLS resistance using acriding orange or ethidium bromide in 2-23-6 and P-H-2 strains produced 'inducible' MLS resistance strains which are less resistant to MLS than the wild type strains, suggesting that there are two resistance genes in both strains; one is constitutive and the other is inducible.

• 한국식품과학회지
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• 제42권4호
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• pp.508-513
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• 2010

2006년부터 2008년까지 3년간 시판 수산물 2,239건에서 분리한 V. parahaemolyticus에 대한 항생제 감수성 결과는 다음과 같았다. 어류 789건을 검사하여 42주(5.3%)의 V. parahaemolyticus가 분리 동정되었으며, 패류 735건 중 27건(3.7%), 연체류 387건 중 12건(3.1%), 기타 수산물 328건 중 12건(3.7%), 총 93건(4.2%)에서 V. parahaemolyticus가 분리 동정되었다. 내성률이 높은 항생제는 ampicillin 93.5%, cephalothin 90.3%, streptomycin 87.1%, ticarcillin 55.9%, 그리고 amikacin 40.9%이었으며, 감수성률이 높은 항생제는 nalidixic acid, chloramphenicol 및 ampicillin/sulbactam trimethoprim/sulfamethoxazole 98.9%, gentamicin 및 tetracycline 82.8%, ceftriaxone 63.4%이었다. 중등도 내성률은 kanamycin 79.6%, ciprofloxacin 64.5%, amikacin 47.3%, cefoxitin 43.0%순이었다. 항생제 내성양상은 3제 내성이 37.6%, 4제 내성 24.7%, 5제 내성 17.2%, 6제 내성 11.8%, 2제 내성6.5%, 7제 내성 2.2% 순이었으며, 가장 많은 내성 양상은 AM-CF-S의 3제 내성(22.6%), AM-CF-S-TIC 4제 내성(18.3%), AM-AN-CF-S-TIC 5제 내성(9.7%) 순이었다.