• Tuberculosis and Respiratory Diseases
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• 제82권1호
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• pp.15-26
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• 2019

The pathogen Mycobacterium avium complex (MAC) is the most common cause of nontuberculous mycobacterial pulmonary disease worldwide. The decision to initiate long-term antibiotic treatment is difficult for the physician due to inconsistent disease progression and adverse effects associated with the antibiotic treatment. The prognostic factors for the progression of MAC pulmonary disease are low body mass index, poor nutritional status, presence of cavitary lesion(s), extensive disease, and a positive acid-fast bacilli smear. A regimen consisting of macrolides (clarithromycin or azithromycin) with rifampin and ethambutol has been recommended; this regimen significantly improves the treatment of MAC pulmonary disease and should be maintained for at least 12 months after negative sputum culture conversion. However, the rates of default and disease recurrence after treatment completion are still high. Moreover, treatment failure or macrolide resistance can occur, although in some refractory cases, surgical lung resection can improve treatment outcomes. However, surgical resection should be carefully performed in a well-equipped center and be based on a rigorous risk-benefit analysis in a multidisciplinary setting. New therapies, including clofazimine, inhaled amikacin, and bedaquiline, have shown promising results for the treatment of MAC pulmonary disease, especially in patients with treatment failure or macrolide-resistant MAC pulmonary disease. However, further evidence of the efficacy and safety of these new treatment regimens is needed. Also, a new consensus is needed for treatment outcome definitions as widespread use of these definitions could increase the quality of evidence for the treatment of MAC pulmonary disease.

• Clinical and Experimental Pediatrics
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• 제64권6호
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• pp.293-300
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• 2021

Background: Understanding the epidemiology and prevalence of febrile urinary tract infection (fUTI) in children is important for risk stratification and selecting appropriate urine sample collection candidates to aid in its diagnosis and treatment. Purpose: This study aimed to analyze the epidemiology, etiology, and changes in antibiotic susceptibility patterns of the first fUTI in children. Methods: This retrospective observational cohort study included children younger than 19 years of age who were diagnosed and treated for their first fUTI in 2006-2016. Electronic medical records were analyzed and radiologic images were evaluated. Results: A total of 359 patients (median age, 5.1 months; interquartile range, 3.0-10.5 months) fit the inclusion criteria; of them, 78.0% (n=280) were younger than 12 months old. The male to female ratio was 5.3:1 for patients aged 0-2 months, 2.1:1 for those 3-5 months, and 1.6:1 for those 6-11 months. Beyond 12 months of age, there was a female predominance. Escherichia coli was the leading cause (83.8%), followed by Enterococcus species (6.7%), and Klebsiella pneumoniae (3.6%). Significant yearly increases in the proportions of multidrug-resistant strains (P<0.001) and extended-spectrum beta-lactamase (ESBL) producers (P<0.001) were observed. In patients with vesicoureteral reflux (VUR), the overall recurrence rate was 53.6% (n=15). A significantly higher recurrence rate was observed when the fUTI was caused by an ESBL versus non-ESBL producer (75.0% vs. 30.0%, P=0.03). Conclusion: fUTI was most prevalent in children younger than 12 months of age and showed a female predominance in patients older than 12 months of age. The proportion of ESBL producers causing fUTI is increasing. Carbapenems, rather than noncarbapenems, should be considered for treating fUTI caused by ESBL-producing enteric gram-negative rods to reduce short-term recurrence rates in children with VUR.

• Pediatric Infection and Vaccine
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• 제20권2호
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• pp.63-70
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• 2013

목 적 : 본 연구에서는 CA-MRSA로 인한 소아의 세균성 근골격계 감염의 임상양상을 연구하기로 하였다. 방 법 : 2000년 9월부터 2012년 8월까지 12년간 분당 차병원에 입원한 18세 이하의 환아 중 혈액과 관절액, 조직이나 고름의 세균 배양검사에서 S. aureus가 동정된 환아를 대상으로 의무기록을 후향적으로 분석하였다. 결 과 : 대상 환아 수는 총 31례였으며 중간값은 7세(최소 17일, 최대 18세)이다. 화농성 관절염으로 진단된 경우는 11례(35.5%), 골수염은 16례(51.6%), 화농성 관절염과 골수염이 병발된 경우는 5례(16.1%)였다. 환아의 혈액이나 관절액, 조직이나 고름 등에서 동정된 S. aureus 31례 중 MSSA는 25례(80.6%), MRSA는 6례(19.4%)였다. 검출된 균주 중 다제내성균은 관찰되지 않았다. MRSA가 배양되었던 6례는 모두 2006년 이후 발생하였다. 모든 증례에서 항생제가 투여되었으며 항생제 투여 기간은 $26.4{\pm}12.7$일이었고, 첫 항생제로 반코마이신을 동반 사용한 경우는 4례(12.9%)였으며 10례(32.3%)에서 최종 항생제로 반코마이신이 투여되었다. 결 론 : 본 연구를 통하여 최근 12년간 세균성 근골격계 감염에서 MRSA의 발생은 연구기간 후반에 편중되었다.

• KSBB Journal
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• 제32권2호
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• pp.153-159
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• 2017

The purpose of this study was to investigate the probiotic properties of lactic acid bacterial strains isolated from human feces. The properties were tested on the basis of guideline for probiotic selection protocol such as tolerance for acid or bile salt, autoaggregation, antibiotic resistance, and antimicrobial activity. Total 25 lactic acid bacteria were isolated from human feces, and their antibacterial activity was tested against Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Vibrio parahaemolyticus, V. alginolyticus using an agar diffusion assay. Among them, 4 selected strains were identified by analysis of their 16S rRNA, as Lactobacillus rhamnosus MG316, L. acidophilus MG501, L. reuteri MG505, and L. gasseri MG570. Results show that resistance to low pH and bile salts. Also, the selected strains were resistant to bile acid up to 3% and their autoaggregation rates were as high as 60%. All strains tested were resistance to nalidixic acid and kanamycin.

• 대한수의학회지
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• 제54권2호
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• pp.91-99
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• 2014

An antimicrobial susceptibility test was conducted to compare the resistance rates among Campylobacter spp. isolates from dogs (n = 50) raised under diverse conditions and humans (n = 50). More than 60% of Campylobacter (C.) jejuni from dogs and humans showed resistance to nalidixic acid, enrofloxacin and ciprofloxacin. C. jejuni isolates from humans showed higher resistance to tetracycline (83.3%) and ampicillin (91.3%) than those from dogs. None of the C. jejuni or Campylobacter coli isolates from humans or dogs were resistant to erythromycin. Overall, 85% of Campylobacter spp. isolates showed a multidrug resistant phenotype. Nucleotide sequencing analysis of the gryA gene showed that 100% of $NA^R/CIP^R$ C. jejuni isolates from dogs and humans had the Thr-$86^{th}$-Ile mutation, which is associated with fluoroquinolone resistance. flaA PCR restriction fragment length polymorphism (RFLP) typing to differentiate the isolates below the species level revealed 12 different clusters out of 73 strains. The human isolates belonged to eight different RFLP clusters, while five clusters contained dog and human isolates.

• 대한족부족관절학회지
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• 제25권2호
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• pp.100-107
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• 2021

Purpose: The present study aimed to develop guidelines regarding initial choice of antibiotics for diabetic foot ulcers (DFU) by investigating bacterial isolates. Materials and Methods: This study included 223 DFU patients that visited a single tertiary hospital and underwent bacterial culture between January 2016 and February 2020. The study was conducted in two parts: 1) to compare bacterial isolates and wound healing according to comorbidities such as chronic kidney disease (CKD) and peripheral artery disease (PAD), and 2) to compare bacterial isolates according to wound depth using the Wagner classification. Results: Of the 223 patients, 43 had CKD (group A), 56 had PAD (group B), 30 had CKD and PAD (group C), and 94 had none of these comorbidities (group D). The isolation rate for multidrug-resistant gram-negative bacteria (MRGNB) and gram-negative to gram-positive bacteria ratio were highest in group C (p=0.018, p=0.038), and the proportion that achieved wound healing was lowest in group C (p<0.001). In the second part of the study, subjects were classified into 5 grades by wound depth using the Wagner classification; 13 grade I, 62 grade II, 60 grade III, 70 grade IV, and 17 grade V. No significant difference was observed between these grades in terms of isolation rates or gram-negative to gram-positive bacteria ratios. Conclusion: This study suggests antibiotics that cover gram-negative bacteria including MRGNB produces better results in the presence of CKD and PAD and that initial antibiotic choice should be based on the presence of CKD and PAD rather than wound depth.

• 한국산학기술학회논문지
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• 제18권3호
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• pp.85-93
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• 2017

요로감염은 병원 내 감염의 주요한 부분이며 최근 항생제의 남용 등으로 인해 요로감염에서의 효과적인 항생제의 선택이 제한받고 있다. 연구자들은 본 병원을 방문하여 시행한 요배양검사에서 의미있는 균이 동정된 외래 및 입원 환자의 요로감염의 주요 원인균과 항생제 감수성을 조사하여 요로감염의 치료에 도움을 주고자 하였다. 2010년 1월 1일부터 2015년 12월 31일까지 6년간 본 병원에서 시행한 요배양검사에서 의미 있는 원인균이 동정된 외래 및 입원환자를 대상으로 하였으며 균집락 단위(colony forming unit: CFU)가 $10^5/ml$이상인 환자를 대상으로 하였다. 배양된 동정균주에서 가장 흔한 원인균은 E.coli로 28.1%의 비율이었다. E.coli의 경우 남성에서는 2010년부터 2015년까지 빈도의 차이는 없었으나 여성의 경우 2014년 이후 그 빈도가 점차 감소하였다. 항생제 감수성 결과 가장 흔한 균주인 E.coli의 감수성 검사에서는 ampicillin 72.2%, TMP/SMX (trimethoprim/sulfamethoxazole) 44.9%, ciprofloxacin 41.3%의 내성율을 보였으며, cefazolin 12.4%, 2,3,4세대 cephalosporin에는 5% 이하의 낮은 내성율을 보였다. 요로감염의 원인균은 시간이 지날수록 다양해지고 빈도 또한 변화를 보인다. 따라서 TMP/SMX와 ciprofloxacin 등 기존 항생제에 대한 내성도 또한 비교적 높은 것으로 나타나 향후 요로감염에 대한 경험적인 항생제의 사용에 대해 더욱 신중한 선택을 해야 할 것으로 생각한다.

• 대한임상검사과학회지
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• 제38권1호
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• pp.26-33
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• 2006

Recently, the rapid increase in extended-spectrum ${\beta}$-lactamase (ESBL) producing clinical isolates has become a serious problem. In this study, the epidemiologic features and molecular characteristics of ESBL among clinical isolates of Escherichia coli and Klebsiella pneumoniae, antibiotic susceptibility testing, genotype of the ESBL and patterns of chromosomal DNA from PFGE (pulsed field gel electrophoresis) were observed. A total of 53 ESBL-producing clinical isolates (30 of E. coli and 23 of Klebsiella pneumoniae) were collected from two university hospitals in the period of June to July in 2002 and 2003 respectively. The antibiotic resistance frequency of those 53 strains was tested by the disk agar diffusion method with the result that all the strains were resistant to cephalothin. To other antibiotics, the resistance rates of E. coli (30 isolates) were in order of ceftazidime (90.0%), cefotaxime and aztreonam (respectively 83.3%). Also, the resistance rates of K. pneumoniae (23 isolates) were in order of aztreonam (78.3%), ceftazidime (73.9%) and cefotaxime (65.3%). Also the sensitivity of ceftazidime-clavulanic acid were 100% in E. coli and 95.7% in K. pneumoniae. And the sensitivity of cefotaxime-clavulanic acid was 96.7% in E. coli and 91.3% in K. pneumoniae. The types of the ESBL genes were determined by using polymerase chain reaction (PCR). Among the 30 isolates of ESBL-producing E. coli, 6 (20.0%) have SHV only, 5 (16.7%) have TEM only and, 18 (60.0%) have both of TEM and SHV. Among the 23 isolates of ESBL-producing K. pneumoniae, 7 (30.4%) have SHV only, 2 (8.7%) have TEM only, and 14 (60.9%) have both of TEM and SHV. These results show that 52 strains, with only one exception, were confirmed as either TEM or SHV. The patterns of Xba I-digested chromosomal DNA of ESBL-producing E. coli and K. pneumoniae isolates were analyzed by PFGE. PFGE patterns of E. coli and K. pneumoniae were multiclonal, but many strains were grouped into a few types. Therefore, it seems that there were clonal outbreaks or possible horizontal spread. In conclusion, the TEM and SHV ${\beta}$-lactamase are most widely spread in E. coli and K. pneumoniae in Korea. As these types are usually carried by plasmids, the spread of these ${\beta}$-lactamase genes could compromise the future usefulness of third generation cephalosporins for the treatment of infections caused by E. coli and K. pneumoniae.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1490-1499
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• 2016

In this study, 69 lactobacilli isolated from Tibetan Qula, a raw yak milk cheese, were screened for their potential use as probiotics. The isolates were tested in terms of: Their ability to survive at pH 2.0, pH 3.0, and in the presence of 0.3% bile salts; tolerance of simulated gastric and intestinal juices; antimicrobial activity; sensitivity against 11 specific antibiotics; and their cell surface hydrophobicity. The results show that out of the 69 strains, 29 strains (42%) had survival rates above 90% after 2 h of incubation at pH values of 2.0 or 3.0. Of these 29 strains, 21 strains showed a tolerance for 0.3% bile salt. Incubation of these 21 isolates in simulated gastrointestinal fluid for 3 h revealed survival rates above 90%; the survival rate for 20 of these isolates remained above 90% after 4 h of incubation in simulated intestinal fluid. The viable counts of bacteria after incubation in simulated gastric fluid for 3 h and simulated intestinal fluid for 4 h were both significantly different compared with the counts at 0 h (p<0.001). Further screening performed on the above 20 isolates indicated that all 20 lactobacilli strains exhibited inhibitory activity against Micrococcus luteus ATCC 4698, Bacillus subtilis ATCC 6633, Listeria monocytogenes ATCC 19115, and Salmonella enterica ATCC 43971. Moreover, all of the strains were resistant to vancomycin and streptomycin. Of the 20 strains, three were resistant to all 11 elected antibiotics (ciprofloxacin, erythromycin, tetracycline, penicillin G, ampicillin, streptomycin, polymyxin B, vancomycin, chloramphenicol, rifampicin, and gentamicin) in this study, and five were sensitive to more than half of the antibiotics. Additionally, the cell surface hydrophobicity of seven of the 20 lactobacilli strains was above 70%, including strains Lactobacillus casei 1,133 (92%), Lactobacillus plantarum 1086-1 (82%), Lactobacillus casei 1089 (81%), Lactobacillus casei 1138 (79%), Lactobacillus buchneri 1059 (78%), Lactobacillus plantarum 1141 (75%), and Lactobacillus plantarum 1197 (71%). Together, these results suggest that these seven strains are good probiotic candidates, and that tolerance against bile acid, simulated gastric and intestinal juices, antimicrobial activity, antibiotic resistance, and cell surface hydrophobicity could be adopted for preliminary screening of potentially probiotic lactobacilli.

• 생태와환경
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• 제46권3호
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• pp.360-366
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• 2013

본 연구는 하수 및 가축분뇨 처리장 방류수, 하천수를 이용하여 반코마이신 내성 장구균(Vancomycin Resistant Enterococci, VRE)의 검출여부를 확인하고 검출된 장구균의 표현형을 분석함으로써 하천에 대한 공공처리시설의 방류수에 포함되어있는 엔테로코커스의 영향을 파악하여 항생제 내성균이 환경에 미치는 영향 및 항생제 내성 연구에 기초 자료가 되고자 하였다. 엔테로코커스의 동정시험 결과 모두 32균주가 검출되었고 이는 모두 E. faecium으로 동정되었다. Multiplex PCR 시행한 결과 32균주 모두 Van A 표현형에 해당하는 반코마이신 내성 장구균으로 확인되었다. 조사지점별 세균의 E. faecium 집락수의 측정 결과 하수처리장 지역에서 평균적으로 가장 높게 나타났고, 하천 지역의 경우 상류지점에서 하류 지점으로 갈수록 세균의 colony 숫자도 늘어나는 것으로 조사되었다. 하수처리장 방류수 시료 26균주에 대한 최소억제농도 검사 결과, 19개의 항생제 중 내성, 감수성을 보인항생제 수는 각각 14, 5종으로 내성을 보이는 항생제의 수가 약 70% 이상으로 대부분을 차지하였다. 하천 시료 6균주에 대한 최소억제농도 검사 결과, 19개의 항생제 중 내성, 감수성을 보인 항생제 수는 각각 14, 5종으로 내성을 보이는 항생제의 수가 약 70% 이상으로 대부분을 차지하여 하수처리장 방류수 시료의 검사 결과와 동일하였다.