최근 2년간 전라남도 및 광주지역의 지역사회 획득성 요로감염에 이환된 여성 환자에서 동정된 Escherichia coli의 Ciprofloxacin 내성패턴

김경영,김철성,임동훈 대한비뇨의학회 2008 Investigative and Clinical Urology Vol.49 No.6

Purpose: The overuse of ciprofloxacin has recently increased the resistance of the Escherichia coli(E. coli). We studied the prevalence od the ciprofloxacin-resistant(CR) E. coli that were isolated from female patients with community-acquired urinary tract infection(CAUTI), and we demonstrated the resistant rate to other antibiotics to help physicians choose the suitable antibiotics to properly treat CAUTI. Materials and Methods: From January 2006 to December 2007, we retrospectively analyzed 910 female patients with CAUTI. Among them, we chose 387 patients infected by E. coli and we evaluated the resistance rate to ciprofloxacin and its relationship with age, the disease causing the UTI and the previous antibiotics. We also compared the resistance to ciprofloxacin with that of other antibiotics, including cephalosporin and the other antibiotics recommended by the guidelines of the Infectious Diseases Society of America(IDSA). Results: The incidence of UTI by E. coli increased with age(p<0.001), and it was highest in the 7th decade (59.0%). One hundred seventeen (30.2%) patients showed ciprofloxacin resistance. It was significantly related to an increased age(p=0.034), complicated UTI(p=0.04) and a previous history of antibiotic use(p=0.023). Trimethoprim/sulfamethoxazole(TMP/SMX) and fosfomycin showed similar resistance rates like ciprofloxacin; 31.8 and 28.2%, respectively. On the other hand, nitrofurantoin showed a low resistant rate of 5.7%. The resistance to cephalosporin was low in general; the lowest was cefepime(5.9%). Conclusions: Our results imply that the empirical use of ciprofloxacin for female patients with CAUTI is questionable, and especially for patients older than 40 years old, patients with complicated UTI and patients with a previous history of antibiotic use. Nitrofurantoin and cephalosporin can be useful agents for the treatment of female CAUTI. (Korean J Urol 2008; 49:540-548) Purpose: The overuse of ciprofloxacin has recently increased the resistance of the Escherichia coli(E. coli). We studied the prevalence od the ciprofloxacin-resistant(CR) E. coli that were isolated from female patients with community-acquired urinary tract infection(CAUTI), and we demonstrated the resistant rate to other antibiotics to help physicians choose the suitable antibiotics to properly treat CAUTI. Materials and Methods: From January 2006 to December 2007, we retrospectively analyzed 910 female patients with CAUTI. Among them, we chose 387 patients infected by E. coli and we evaluated the resistance rate to ciprofloxacin and its relationship with age, the disease causing the UTI and the previous antibiotics. We also compared the resistance to ciprofloxacin with that of other antibiotics, including cephalosporin and the other antibiotics recommended by the guidelines of the Infectious Diseases Society of America(IDSA). Results: The incidence of UTI by E. coli increased with age(p<0.001), and it was highest in the 7th decade (59.0%). One hundred seventeen (30.2%) patients showed ciprofloxacin resistance. It was significantly related to an increased age(p=0.034), complicated UTI(p=0.04) and a previous history of antibiotic use(p=0.023). Trimethoprim/sulfamethoxazole(TMP/SMX) and fosfomycin showed similar resistance rates like ciprofloxacin; 31.8 and 28.2%, respectively. On the other hand, nitrofurantoin showed a low resistant rate of 5.7%. The resistance to cephalosporin was low in general; the lowest was cefepime(5.9%). Conclusions: Our results imply that the empirical use of ciprofloxacin for female patients with CAUTI is questionable, and especially for patients older than 40 years old, patients with complicated UTI and patients with a previous history of antibiotic use. Nitrofurantoin and cephalosporin can be useful agents for the treatment of female CAUTI. (Korean J Urol 2008; 49:540-548)

Induction of Resistance to BRAF Inhibitor Is Associated with the Inability of Spry2 to Inhibit BRAF-V600E Activity in BRAF Mutant Cells

( Jun Ho Ahn ),( Byeal I Han ),( Mi Chael Lee ) 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.4

The clinical benefits of oncogenic BRAF inhibitor therapies are limited by the emergence of drug resistance. In this study, we investigated the role of a negative regulator of the MAPK pathway, Spry2, in acquired resistance using BRAF inhibitor-resistant derivatives of the BRAF-V600E melanoma (A375P/Mdr). Real-time RT-PCR analysis indicated that the expression of Spry2 was higher in A375P cells harboring the BRAF V600E mutation compared with wild-type BRAF-bearing cells (SK-MEL-2) that are resistant to BRAF inhibitors. This result suggests the ability of BRAF V600E to evade feedback suppression in cell lines with BRAF V600E mutations despite high Spry2 expression. Most interestingly, Spry2 exhibited strongly reduced expression in A375P/Mdr cells with acquired resistance to BRAF inhibitors. Furthermore, the overexpression of Spry2 partially restored sensitivity to the BRAF inhibitor PLX4720 in two BRAF inhibitor-resistant cells, indicating a positive role for Spry2 in the growth inhibition induced by BRAF inhibitors. On the other hand, long-term treatment with PLX4720 induced pERK reactivation following BRAF inhibition in A375P cells, indicating that negative feedback including Spry2 may be bypassed in BRAF mutant melanoma cells. In addition, the siRNA-mediated knockdown of Raf-1 attenuated the rebound activation of ERK stimulated by PLX4720 in A375P cells, strongly suggesting the positive role of Raf-1 kinase in ERK activation in response to BRAF inhibition. Taken together, these data suggest that RAF signaling may be released from negative feedback inhibition through interacting with Spry2, leading to ERK rebound and, consequently, the induction of acquired resistance to BRAF inhibitors.

소아의 지역사회 획득 장구균 요로감염의 임상 양상

김성헌,임택진,김혜영,박수은,김수영,Kim, Seong Heon,Lim, Taek Jin,Kim, Hye Young,Park, Su Eun,Kim, Su Young 대한소아신장학회 2013 Childhood kidney diseases Vol.17 No.1

목적: 장구균은 원내 감염의 중요한 세균으로 최근 그 빈도가 많아지며, 항생제 내성을 갖는 경우도 증가하면서 활발한 연구가 이루어지고 있다. 하지만 소아의 지역사회 획득 요로감염의 원인으로서 장구균에 대한 연구는 소수에 불과하여 이에 저자들은 부산 경남 지역에서 발생하는 장구균에 의한 지역사회 획득 요로감염의 임상적 특징과 항생제 감수성 등을 조사하고자 하였다. 방법: 20010년 1월부터 2013년 1월까지 첫 번째 요로감염으로 부산대학교 어린이병원에 입원 하였던 18세 미만의 환자 중 장구균과 대장균이 배양된 환자를 대상으로 하여 의무 기록을 후향적으로 분석하였다. 의무 기록을 통해 환자의 성별, 진단 시 연령, 기저 신 질환, 최근 항생제 복용력, 영상 검사의 결과, 세균의 항생제 감수성, 처음 사용한 항생제에 대한 반응 유무 등을 조사하였다. 결과: 2010년 1월부터 2013년 1월까지 첫 번째 요로감염이 확인되어 치료한 환자는 201명으로 이 중 대장균은 154명(76.6%)에서 분리되었고, 장구균은 11명(5.5%)에서 분리되었으며 배양된 장구균은 모두 Enterococcus feacalis였다. 장구균이 배양된 집단에서 배뇨방광요도조영술 검사를 시행한 7명 중 4명(57.1%)에서 방광요관역류가 발견되었고, 이들 모두 DMSA 신스캔에서 신 반흔을 보였으며 현재까지 3명의 환자가 방광요관역류에 대한 비뇨기과적 교정 시술을 시행 받았다. 대장균이 배양된 집단에서는 121명의 환자에서 배뇨방광요도조영술 검사가 시행되어 23명이 방광요관역류로 진단되었고, 현재까지 11명이 비뇨기과적 교정술을 시행 받았다. 대장균에 의한 요로감염 환자들과 비교하였을 때 장구균 요로감염 환자에서 방광요관역류와 수술적 교정술의 빈도가 통계학적으로 의미 있게 높았다. 분리된 장구균의 항생제 감수성 검사에서 ampicillin, vancomycin, linezolid에 대해서는 100% 감수성을 보였으며 tetracycline에 대해서는 100% 내성을 보였고 Trimethoprim/sulfamethoxazole에는 71.4%, quinolone계열인 ciprofloxacin에는 20% 내성을 나타냈다. 결론: 부산 경남 지역의 지역사회 획득 장구균 요로감염은 흔하지 않지만, 근본적인 요로계의 이상을 동반할 가능성이 높으므로 환자에 대한 영상학적 평가가 이루어져야 할 것으로 생각된다. Purpose: Recently, enterococcus spp. have become one of the most common nosocomial pathogens with increasing rates of multi-drug resistance. However, study on enterococcal urinary tract infections (UTIs) in children is very limited, especially community acquired UTIs. We studied the clinical characteristics of enterococcus spp. in community acquired UTIs and antibiotic resistance within our urban area. Methods: All children with first episode of community acquired UTIs due to enterococcus spp. and Echerichia coli who were admitted in Pusan National University Children's Hospital between January 2010 and January 2013 were included in our study. We retrospectively reviewed their medical records. Results: During the study period, 201 patients were identified to have first episode of community acquired UTIs. 154 cases were E.coli UTIs (76.6%) and 11 cases were enterococcal UTIs (5.5%) and all enterococcus spp. were Enterococcus feacalis. In enterococcal UTI group, voiding cystourethrogram(VCUG) was performed in 7/11 patients and demonstrated 4 vesicoureteral refluxes (VURs) with renal scar and 3 patients underwent corrective surgery. In E.coli UTI group, VCUG was performed in 121/154 patients and demonstrated 23 VURs and 11 patients underwent corrective surgery. Enterococcal group had significant high rate of underlying urinary abnormalities and surgical corrections compared with E. coli group. All enterococcus spp. were susceptible to ampicillin, vancomycin and linezolid, but all were resistant to tetracycline. They also showed 71.4% resistance to trimethoprim-sulfamethoxazole and 20% resistance to ciprofloxacin. Conclusion: Community acquired enterococcal UTIs in children were rare within our urban area. However, they could be indicative of severe underlying urinary tract abnormalities.

Altered expression of cellular proliferation, apoptosis and the cell cycle-related genes in lung cancer cells with acquired resistance to EGFR tyrosine kinase inhibitors

Lee, Tae-Gul,Jeong, Eun-Hui,Min, Il Jae,Kim, Seo Yun,Kim, Hye-Ryoun,Kim, Cheol Hyeon D.A. Spandidos 2017 Oncology letters Vol.14 No.2

<P>Non-small cell lung cancers harboring somatic gain-of-function mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain respond well to treatment with EGFR tyrosine kinase inhibitors (TKIs) including gefitinib and erlotinib. However, all patients who experience a marked improvement with these drugs eventually develop disease progression due to the acquisition of drug resistance. Approximately half of the cases with acquired resistance to EGFR TKIs can be accounted for by a second-site mutation in exon 20 of the EGFR kinase domain (T790M). However, the changes of gene expression involved in EGFR TKI resistance due to the T790M mutation remain poorly defined. The present study established lung cancer cell lines that were resistant to gefitinib or erlotinib, and these cell lines were verified to contain the <I>EGFR</I> T790M mutation. The differential expression of genes associated with acquired resistance was verified in the present study by mRNA microarray analysis. Among the genes whose expression was significantly altered, genes whose expression was altered in gefitinib- and erlotinib-resistant cells were focused on. Notably, a total of 1,617 genes were identified as being differentially expressed in gefitinib- and erlotinib-resistant cells. Indeed, Gene ontology analysis revealed altered expression of genes involved in the regulation of cellular proliferation, apoptosis, and the cell cycle in EGFR TKI-resistant cells. The present results demonstrate distinctive gene expression patterns of EGFR TKI-resistant lung cancer cells with the <I>EGFR</I> T790M mutation. The present study can provide key insights into gene expression profiles involved in conferring resistance to EGFR TKI therapy in lung cancer cells.</P>

The genomic landscape associated with resistance to aromatase inhibitors in breast cancer

Kirithika Sadasivam,Jeevitha Priya Manoharan,Hema Palanisamy,Subramanian Vidyalakshmi Korea Genome Organization 2023 Genomics & informatics Vol.21 No.2

Aromatase inhibitors (AI) are drugs that are widely used in treating estrogen receptor (ER)-positive breast cancer patients. Drug resistance is a major obstacle to aromatase inhibition therapy. There are diverse reasons behind acquired AI resistance. This study aims at identifying the plausible cause of acquired AI resistance in patients administered with non-steroidal AIs (anastrozole and letrozole). We used genomic, transcriptomic, epigenetic, and mutation data of breast invasive carcinoma from The Cancer Genomic Atlas database. The data was then separated into sensitive and resistant sets based on patients' responsiveness to the non-steroidal AIs. A sensitive set of 150 patients and a resistant set of 172 patients were included for the study. These data were collectively analyzed to probe into the factors that might be responsible for AI resistance. We identified 17 differentially regulated genes (DEGs) among the two groups. Then, methylation, mutation, miRNA, copy number variation, and pathway analyses were performed for these DEGs. The top mutated genes (FGFR3, CDKN2A, RNF208, MAPK4, MAPK15, HSD3B1, CRYBB2, CDC20B, TP53TG5, and MAPK8IP3) were predicted. We also identified a key miRNA - hsa-mir-1264 regulating the expression of CDC20B. Pathway analysis revealed HSD3B1 to be involved in estrogen biosynthesis. This study reveals the involvement of key genes that might be associated with the development of AI resistance in ER-positive breast cancers and hence may act as a potential prognostic and diagnostic biomarker for these patients.

성인원외폐렴의 원인미생물에대한 전향적 다기관 연구 : 성인원외폐렴의 원인으로 세균의 역할을 중심으로

우준희,강재명,김양수,신완식,류진홍,최정현,김양리,정희진,어수택,박춘식,정문현,정기석,이찬주,류지소 대한감염학회 2001 감염 Vol.33 No.1

Background : Communite-acquired peumonia (CAP) is one of the leading causes of mortality and morbidity. Despite progress in diagnostic techniques and treatments, management of pneumonia remains challenging, because the precise etiology remains uncertain in as many as 49% of cases. The limitaions of identifying etiologic agents make it necessary to use empiric antibiotics in almost all patients, and furthermore emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric antibiotic regimen. For the optimal choice of empirical antibiotics, we should know the frequency of etiologic agents and antimicrobial resistance rates in the community. Methods : A prospective multicenter study of community-acquired pneumonia in Korea was carried out between May 1997 and April 2000. The microbiologic diagnosis was based on the results of sputum culture, blood culture and pleural culture. Results : Five hundred eighty eight cases of community-acquired peumonia in 562 patients admitted to the hospitals. The mean age was 59.9 with male predominance (58.3%), and 370 (63%) had underlyin gillness. The etiologic agents were identified in 38.3%, and the list of individual agents, in decreasing order, was Streprococcus pneumoniae (21.7%), Klebsiella pneumoniae (14.8%) Pseudomonas aeruginosa (9.8%), Staphylococcus aureus (9.5%), viridans group streptococci (5.7%), Enterobacter cloacae (4.2%), Hemophillus Influenza (3.8%), The rates of admission to the intensive care unit was 10.4%. The motality was 7.1%. Susceptible rates of S. pneumoniae to penicillin was 36.6% and showed multidrug resistant. Forty percents of S. aureus were methicillin-resistant S. aureus. K. penumoniae were susceptible to cephalosporin and quinolone. Conclusion : In Korea, S.pneumoniae is the most important agent causing community-acquired pneumonia. Susceptible rates of S. pneumoniae to penicillin was 36.6% and showed multidrug resistant. Gram negative bacteria such as K. pneumoniae, P. aeruginosa showed high incidence when compared with that of other countries. Most of them had underlying diseases including bronchiectasis and chronic obstructive pulmonary diseases. (Korean J Infect Dis 33:1∼7, 2001)

Induction of Resistance to BRAF Inhibitor Is Associated with the Inability of Spry2 to Inhibit BRAF-V600E Activity in BRAF Mutant Cells

Ahn, Jun-Ho,Han, Byeal-I,Lee, Michael The Korean Society of Applied Pharmacology 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.4

The clinical benefits of oncogenic BRAF inhibitor therapies are limited by the emergence of drug resistance. In this study, we investigated the role of a negative regulator of the MAPK pathway, Spry2, in acquired resistance using BRAF inhibitor-resistant derivatives of the BRAF-V600E melanoma (A375P/Mdr). Real-time RT-PCR analysis indicated that the expression of Spry2 was higher in A375P cells harboring the BRAF V600E mutation compared with wild-type BRAF-bearing cells (SK-MEL-2) that are resistant to BRAF inhibitors. This result suggests the ability of BRAF V600E to evade feedback suppression in cell lines with BRAF V600E mutations despite high Spry2 expression. Most interestingly, Spry2 exhibited strongly reduced expression in A375P/Mdr cells with acquired resistance to BRAF inhibitors. Furthermore, the overexpression of Spry2 partially restored sensitivity to the BRAF inhibitor PLX4720 in two BRAF inhibitor-resistant cells, indicating a positive role for Spry2 in the growth inhibition induced by BRAF inhibitors. On the other hand, long-term treatment with PLX4720 induced pERK reactivation following BRAF inhibition in A375P cells, indicating that negative feedback including Spry2 may be bypassed in BRAF mutant melanoma cells. In addition, the siRNA-mediated knockdown of Raf-1 attenuated the rebound activation of ERK stimulated by PLX4720 in A375P cells, strongly suggesting the positive role of Raf-1 kinase in ERK activation in response to BRAF inhibition. Taken together, these data suggest that RAF signaling may be released from negative feedback inhibition through interacting with Spry2, leading to ERK rebound and, consequently, the induction of acquired resistance to BRAF inhibitors.

Induction of Resistance to BRAF Inhibitor Is Associated with the Inability of Spry2 to Inhibit BRAF-V600E Activity in BRAF Mutant Cells

안준호,한별이,이미가엘 한국응용약물학회 2015 Biomolecules & Therapeutics(구 응용약물학회지) Vol.23 No.4

The clinical benefi ts of oncogenic BRAF inhibitor therapies are limited by the emergence of drug resistance. In this study, we investigated the role of a negative regulator of the MAPK pathway, Spry2, in acquired resistance using BRAF inhibitor-resistant derivatives of the BRAF-V600E melanoma (A375P/Mdr). Real-time RT-PCR analysis indicated that the expression of Spry2 was higher in A375P cells harboring the BRAF V600E mutation compared with wild-type BRAF-bearing cells (SK-MEL-2) that are resistant to BRAF inhibitors. This result suggests the ability of BRAF V600E to evade feedback suppression in cell lines with BRAF V600E mutations despite high Spry2 expression. Most interestingly, Spry2 exhibited strongly reduced expression in A375P/Mdr cells with acquired resistance to BRAF inhibitors. Furthermore, the overexpression of Spry2 partially restored sensitivity to the BRAF inhibitor PLX4720 in two BRAF inhibitor-resistant cells, indicating a positive role for Spry2 in the growth inhibition induced by BRAF inhibitors. On the other hand, long-term treatment with PLX4720 induced pERK reactivation following BRAF inhibition in A375P cells, indicating that negative feedback including Spry2 may be bypassed in BRAF mutant melanoma cells. In addition, the siRNA-mediated knockdown of Raf-1 attenuated the rebound activation of ERK stimulated by PLX4720 in A375P cells, strongly suggesting the positive role of Raf-1 kinase in ERK activation in response to BRAF inhibition. Taken together, these data suggest that RAF signaling may be released from negative feedback inhibition through interacting with Spry2, leading to ERK rebound and, consequently, the induction of acquired resistance to BRAF inhibitors.

7개 대학 병원에서 조사한 지역사회 폐렴의 원인균

정문현,김성민,강문원,최희정,정희진,이경원,한성우,송재훈,신형식,김의종,최강원,김민자,박승철,배현주,정윤섭,김준명,백경란,신완식,이규만,김양리 대한감염학회 1997 감염 Vol.29 No.5

목 적 : 폐렴은 많이 발생하면서 사망률이 크게 줄지 않는 질환이며, 이를 적절히 치료하기 위해서는 원인균의 상대적 빈도, 기저 질환에 따른 변화, 항균제 내성률, 사망에 관련된 인자들을 알아야 한다. 원인균의 빈도는 지역마다 차이가 있고 국내에서는 항균제 내성률이 높아 지역사회에서 발생한 폐렴을 치료하기 위한 경험적 항균제 선택에 도움이 되기 위해 서울 소재 6개 대학 병원과 천안의 1개 대학 병원이 참여하여 위의 사항들에 대해 조사를 하였다. 방 법 : 1995년에 내과에 입원했던 16세 이상 환자를 대상으로 했다. 퇴원 진단명이 폐렴 또는 폐결핵인 병록지을 찾았고, 이중에서 병원 감염을 제외하였다. 특이도를 높이기 위해, 이들 중에서 호흡기 증상이 있고 발열이나 저체온이 있으면서 흉부 X-선에서 이상 음영이 있는 환자만을 대상으로 했다. 폐결핵은 위의 기준에 입원 초기에 항균제 치료를 하고 입원 7일 이후에야 항결핵제가 투여된 경우만을 폐렴의 원인균으로 하였다. 혈액 배양에서 양성, 객담에서 항상균이나 M. tuberculosis가 증명된 경우, 혈청학적으로 항체가가 4배 이상 증가된 경우, 조직에서 원인균이 진단된 경우는 확정(definitive) 원인균으로 하였고, 객담에서 배양된 균이 그람 도말과 일치할때, 항결액제에 대한 반응으로 진단한 폐결핵, 단일 항체가 양성이고 이에 대해 항균제를 사용했을 때는 가능(probable) 원인균으로 정의하였다. 다세균 감염균은 각각 다 른 원인균으로 처리하였다. 임상 조사와 함께 임상병리과에서 S. pneumoniae, H. influenzae, M. catarrhalis, mycoplasma, 항상균에 대해 검사 의뢰 건수, 배양 양성수, 항균제 감수성 결과를 조사하였다. 결 과 : 폐렴의 증례 정의에 부합하지 않은 135명과 폐결핵의 정의에 해당하지 않는 230명을 제외하고 남은 246명의 평균 나이는 58.2세이고 남성이 142명(58.2%) 이었고, 71%의 환자에서 기저 질환이 있었다. 진단 방법의 시행 횟수는 혈액 배양 77.6%, 혈청 검사 18.3%, 기관지경 검사는 4.1%였고, 세균의 항원 검사를 한 예는 없었다. 원인균이 밝혀진 예는 77명(31.3%)이었다. 다세균 감염이 4명에서 있었고, 원인균의 상대적 빈도는 결핵 20명(확정 17, 가능 3: 6개 병원 자료), 폐렴구균 18(확정8 가능 10)명과 폐렴구균이 아닌 Streptococcus 3명 (모두 확정), H. influenzae 11명(모두 가능), 그람음성간균 11명(확정 7, 가능 4) (K. pneumoniae 8건), Mycoplasma 5명(확정 1, 가능 4), S. aureus 4명(확정 2, 가능 2), mucormycosis 1명(확정)이었다. 평균 입원 기간은 19일이고, 중환자실 입원률과 인공 호흡기 사용율은 각각 18%와 9.3%였다. 사망률은 13.8%였고 사망까지 평균 기간은 14.6일 이었다. 다변량 분석에서 사망을 예측할 수 있는 인자는 저체온과 빈호흡이었다. 임상병리과에서 배양되었던 모든 폐렴구균의 Penicillin 내성률은 서울 3개 병원에서 82-88%, 천안에서 72%였다. 폐렴 환자의 혈액에서 배양된 7주는 모두 Penicillin에 감수성이 있었다. K. pneumoniae 8주 모두 cefotaxime과 gentamicin에 감수성을 보였다. 결 론 : 후향적 조사이고 병원마다 원인균 진단에 차이가 있지만, 원인이 밝혀진 경우에는 결핵과 폐렴균이 흔하였고, 무균 부위에서 배양된 폐렴구균의 항균제 내성률은 낮았다. 원인이 밝혀지지 않은 경우가 많고, 혈청검사로 진단되는 원인균이 드물며, 분리균주가 적어 항균제 내성 정도를 추정하기 어려워, 이를 밝히기 위한 전향적 조사가 필요하다. Background : Community-acquired pneumonia (CAP) is one of the leading causes of mortality and morbidity, but its management is still challenging. The limitation of diagnostic methods to identify etiologic agents rapidly make it necessary to use empiric antibiotics in almost all patients, and furthermore the discovery of new respiratory pathogens and the emergence of antibiotic-resistant organisms pose difficulties to the selection of an empiric regimen. To clarify the factors necessary for the optimal choice of empirical antibiotics, such as the frequency of etiologic agents, the attributable rates to death and antimicrobial resistance rates in the community, six university hospitals in Seoul and one university hospital in Cheonan were participating in this study. Methods : medical records of adults (>15 years of age) hospitalized for CAP or pulmonary tuberculosis between April 1995 and March 1996, were reviewed. Patients who satisfied all of the following criteria were included in the study: (1) fever or hypothermia; (2) respiratory symptoms; and (3) pulmonary infiltrates on chest roentgenogram. To exclude cases of pulmonary tuberculosis whose roentgenographic features were so typical that it could be easily differentiated from conventional pneumonia, two additional criteria were required for inclusion: antibiotic treatment during the first week of hospital admission and initiation of anti-tuberculosis medications thereafter. Organisms isolated from sterile body sites, acid-fast bacilli or Mycobacterium tuberculosis isolated from sputum, pathogens diagnosed by a 4-fold rising titer of antibodies to “atypical”pathogens, or pathogens revealed by histopathology were defined as definitive cause of pneumonia; isolates from sputum withcompatible Gram stain, pathogens diagnosed by a single diagnostic titer plus use of a specific antimicrobial agent, or tuberculosis diagnosed by clinucal response to anti- tuberculosis medications were considered probable cause of pneumonia. The records of the clinical microbiology were reviewed for isolates of S. pneumoniae, H. influenzae, M. catarrhalis, Mycobacterium or acid-fast bacilli, and Mycoplasma. Then the frequency of these agents, antimicrobial resistance rates of resiratory pathogens from all body sites, and their clinical significance were evaluated. Results: After excluding 365 patients (230 with pulmonary tuberculosis and 135 with CAP) who were screened for inclusion but did not meet the inclusion criteria,246 persons were enrolled in this study. Their mean age was 58.2 years old with slight male predominance (58.2%), and 171(71%) patients had underlying illnesses. Blood cultures were performed on 191 (77.6%) patients and serologic tests on 44(18.3%) patients. The etiologic agents were identified in 31.3%, and the list of individual agents, in decreasing order, was pulmonary tuberculosis (17 definite and 3 probable: data of six hospitals), S. pneumoniae (8 definite and 10 probable), non-pneumococci (3 definite), aerobic gram-negative bacilli (7 definite and 4 probable), Haemophilus spp. (11 probable), mycoplasma (1 definite and 4 probable), polymicrobial infections (2 definite and 2 probable: E. coli and S. agalactiae, M. tuberculosis and S. aureus, S. pneumoniae and H. influenzae and A. baumannii and K. pneumonias), S. aureus (2 definite and 2 probable) , and mucormycosis (1 definite). Among gram-negative bacilli, K. pneumoniae was the most common agent (8isolates). therates of admission to the intensive care unitand of using assisted ventilation were 18% and 9.3%, respectively. The mortality was 13.8% and logistic regression analysis showed that hypothermia and tachypnea were associated with death. Hospital stay averaged 19 days. Susceptible rates of S. pneumoniae isolated from all body sites to penicillin ranged from 8% to 28% but seven isolated from blood of patients with pneumonia were susceptible to penicillin. Also all 8 isolated of k> pneumoniae from patients with pneumonia were susceptible to cefotaxime and gentamicin. Conclusion: In Korea, in addition to S. pneumoniae, M. tuberculosis is an important agent causing community-acquired pneumonia. The low incidence of etiologic diagnosis is probably related to infrequent requesting of test "atypical" pathogens and does not represent the true incidence of infections by "atypical" pathogens, which well be answered by a prospective study. The antimicrobial resistance rates of major respiratory pathogens from sterile body sites are low, however, because of a small number of the isolates this result needs confirmation by a nationwide surveillance of antimicrobial resistance.

메티실린내성 황색포도알균에 의한 지역사회획득 폐렴 2예

남지형,송준화,하원철,이정우,원기범,김성자,이영현 東國大學校醫學硏究所 2007 東國醫學 Vol.14 No.1

지역사회획득 폐렴은 병원이 아닌 지역사회에서 발생한 폐렴으로 비교적 흔하게 발병하며 감염성 질환에 의한 사망의 중요한 원인이다. 병원내 감염 폐렴의 대표적인 원인균으로 알려져 있는 메티실린내성 황색포도알균에 의한 지역사회획득 폐렴이 점차 증가추세에 있으며 기존의 vancomycin 계통의 항생제 외에 여러 항생제에 감수성을 보이는 경향이 있어 치료의 폭이 넓다. 지역사회획득 페렴에 대한 적절한 치료와 항생제 남용이나 vancomycin 내성 획득 환자를 줄이기 위해서 메티실린내성 황색포토알균에 의한 원내 폐렴과 지역사회획득 폐렴을 구별하는 것이 중요하다. Community acquired pneumonia (CAP) is a common infectious disease acquired from community and an important cause of death in infectious diseases. Methicillin-resistant Staphylococcus aureus (MRSA) is the most common cause of hospital-acquired pneumonia (HAP), but there are increasing cases of community-acquired pneumonia caused by MRSA which is susceptible to several antibiotics including vancomycin. It is important to differentiate HAP from CAP for more effective treatments to reduce the overuse of antibiotics and the development of vancomycin resistance.