DOI: 10.4046/trd.2009.67.6.517 ISSN: 1738-3536(Print)/2005-6184(Online) Tuberc Respir Dis 2009;67:517-527 CopyrightC2009. The Korean Academy of Tuberculosis and Respiratory Diseases. All rights reserved. 기관지확장증환자의객담균주분석 : 울산지역의일개대학병원보고 울산대학교의과대학울산대학교병원 1 내과학교실, 2 영상의학교실, 3 진단검사의학교실 Original Article 서광원 1, 황세진 1, 성시정 1, 김세진 1, 도기원 1, 허성재 1, 임경훈 1, 홍순형 1, 김동민 1, 전재범 1, 제갈양진 1, 최승원 1, 권운정 2, 정윤성 3, 안종준 1 Bacteriologic Analysis of Expectorated Sputum in Patient with Bronchiectasis Kwang Won Seo, M.D. 1, Se Jin Hwang, M.D. 1, Shi Jung Sung, M.D. 1, Se Jin Kim, M.D. 1, Gi Won Do, M.D. 1, Seong Jae Hur, M.D. 1, Kyung Hun Lim, M.D. 1, Soon-Hyung Hong, M.D. 1, Dong Min Kim, M.D. 1, Jae Bum Jeon, M.D. 1, Yangjin Jegal, M.D. 1, Seung Won Choi, M.D. 1, Woon Jung Kwon, M.D. 2, Joseph Jeong, M.D. 3, Jong-Joon Ahn, M.D. 1 Departments of 1 Internal Medicine, 2 Diagnostic Radiology, 3 Laboratory Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, Ulsan, Korea Background: Bronchiectasis (BE) remains a rare respiratory disease in Korea. This retrospective study was done to investigate the potential pathogenic microorganisms (PPMs) that cause in patients with BE, through the use of sputum specimens. Methods: One hundred eleven adult patients, who had undergone chest computed tomography (CT), sputum gram stain/culture, and BE detected by chest CT, were included in this study. Sputum adequacy was determined by using Murray-Washington classification. Results: The mean (±SD) age of patients was 60.9 (±14.0). The number of PPMs was 167 (67%) in the total 248 isolated organisms. The most frequent PPMs were P. aeruginosa (23.4%), K. pneumoniae (10.5%), and S. aureus (8.4%). The proportion of adequate sputum (AS) was 25.8% in the total sputum specimens. The patients with AS were 41 (37%) and the patients with inadequate sputum (IS) were 70 (63%). The proportion of P. aeruginosa was higher in AS compared to that of IS (44% vs. 19%, p=0.004). The BE score was also higher in P. aeruginosa (+) patients compared to that of P. aeruginosa ( ) patients (10.8 vs. 7.6, p=0.001). Conclusion: Although the proportion of AS in the total sputum was low, PPMs were isolated in most patients with BE. It is likely that P. aeruginosa was isolated in AS and AS patients had higher BE scores. Key Words: Bronchiectasis; Sputum; Microbiology; Bacteriology 서 기관지확장증은기관지벽의구성요소인근육과탄력조직의파괴로인한기관지의비가역적인확장과변형을 Address for correspondence: Jong-Joon Ahn, M.D. Department of Internal Medicine, Ulsan University Hospital, University of Ulsan College of Medicine, 290-3, Jeonhadong, Dong-gu, Ulsan 682-714, Korea Phone: 82-52-250-8870, Fax: 82-52-251-8235 E-mail: jjahn@uuh.ulsan.kr Received: Sep. 7, 2009 Accepted: Oct. 6, 2009 론 특징으로하는질환으로 1,2, 기침, 농성객담, 호흡곤란등이주증상이며반복적인폐감염및객혈이자주동반될수있다 1-5. 이미서구에서는주거환경의개선, 적절한항생제의조기사용, 위생및영양상태의개선, 홍역, 백일해등에대한예방접종도입으로유병률이현저히낮아졌다 1. 한국인에서기관지확장증은과거폐감염의후유증이주된원인이었으며 3-5 현재에도성인에서드물지않은폐질환의하나이다 6. 기관지확장증은기관지의구조적인변화로인해섬모청정기능의장애를동반하므로여러세균들이기관지내에집락화를이루어존재할수있으며실제이균주들은 517
KW Seo et al: Bacteriologic analysis of sputum in bronchiectasis 폐감염의원인균이될수있다 1. 기관지확장증환자에서동정되는병원균의종류에따라치료및예후가달라지게되므로 7,8 정확한병원균배양을통한치료가권장되며 9, 또한기관지확장증환자에서폐렴이발생한다면심한폐쇄성폐질환에서폐렴이발생한경우와마찬가지로정확한병원균동정을위해양질의적절한객담검체를얻어야하며 10-12, 이를위해검체의이송, 처리에있어서도정도관리가필요하다 9. 기존의한국인기관지확장증환자의객담배양균주분석은주로적절한객담검체여부와관계없이동정된균주의분석이었기에 3-5 적절한객담에서배양된균주에대해서는매우제한적인자료만있는상황이다 13. 이에저자들은기관지확장증환자에서객담등검체에서배양된균주전체와적절한객담검체에서배양된균주의분포를먼저비교해보고, 다음으로적절한객담검체검출환자군과부적절한객담검체검출환자군간의균주비교및 Pseudomonas aeruginosa (P. aeruginosa) 배양양성환자군과음성환자군간의차이에대해서알아보고자하였다. 대상및방법 1. 대상환자군 2006년 1월 1일부터 2007년 5월 31일까지울산대학교의과대학울산대학교병원호흡기내과외래로방문한기관지확장증환자들과폐렴및객혈로입원한환자들중흉부컴퓨터단층촬영 (computed tomography, CT) 에서기관지확장증이있고 1회이상객담에서균배양양성결과가있는환자를대상으로후향적으로의무기록및자료를조사하였다. 암환자, 결핵환자 ( 객담항산성균도말양성및배양양성자, 객담도말및배양음성자중임상적으로결핵에합당하다고판단되어항결핵제제투약중인환자 ), 면역저하자 ( 장기간스테로이드또는면역억제제복용자, 만성신부전환자 ) 는제외하였다. 2. 객담분석 1) 그람염색 (Gram stain) 및적절한객담의판정검사를위해수거된객담중농성부분을선택하여그람염색후저해상렌즈 ( 100) 시야당상피세포와호중구를분석하였다. Murray-Washington 분류법 10 을이용하여 IV군 (10 25 상피세포및 >25 호중구 ) 또는 V군 (< 10 상피세포및 >25 호중구 ) 을적절한객담검체로판정하였으며그외의군들은부적절한객담검체로판정하였다. 2) 균배양접종 14 객담검체를 blood agar와 MacConkey agar에접종하였으며, blood agar에접종한것이마른뒤에 Hemophilus influenzae의증식을돕기위해 Staphylococcus균을처리하였다. 경기관흡인액, 폐천자검체는 thioglycollate broth 및혐기성배양을시행하였다. 진균배양은 Sabouraud agar에추가접종하였다. 배양은 5% CO 2 incubator에넣어 37 o C에서 24시간배양을하였다. 3) 잠재적병원균주 (potentially pathogenic microorganisms) 및비잠재적병원균주 (non-potentially pathogenic microorganisms) 의정의기존의연구들 15-17 에서정의된기준을참조하였으며잠재적병원균주들은 Haemophilus influenzae, Streptococcus pneumoniae, Moraxella catarrhalis, Gram-negative bacilli, Pseudomonas aeruginosa 및 Staphylococcus aureus를포함한다. 비잠재적병원균주들은 Streptococcus viridans, Neisseria species, Candida species, Corynebacterium species, Haemophilus parainfluenzae 및 coagulase-negative Staphylococcus 등이다. 그외기존연구들에서언급되지않았으나본연구에서배양된균주들은 Chow 18 를참조하여분류하였다. 3. 흉부 CT에서의기관지확장증의점수화흉부 CT는 16-slice CT 장비 (SOMATOM Sensation 16; Siemens AG, Forchheim, Germany) 를사용하였으며환자들의기관지확장증정도를분류하기위해 Smith의기관지확장증분류법 19 을사용하였다. 환자의양폐를 6개의폐엽으로나누었으며 ( 설상엽을 1개의독립된폐엽으로간주함 ) 각폐엽마다기관지확장증의정도에따라 5점 (0: 기관지확장증없음 ; 1: 25% 미만 ; 2: 25 49%; 3: 50 74%; 4: 75% 이상 ) 으로구별하여점수화하였다 ( 최대점수 24 점 ). 영상의학과전문의가흉부 CT를판독하였으며 Smith 의기관지확장증분류법에따라각환자의기관지확장증 CT 점수를측정하였다. 4. 통계적분석모든측정치들은평균값과표준편차로나타내었으며적절한객담검체군과부적절한객담검체군간의비교, P. aeruginosa 배양양성환자군과배양음성환자군간의비교는 Student t-test 및카이제곱검정으로검증하였다. 모든데이터는전산화되어 SPSS 14.0 for Windows (SPSS Inc., Chicago, IL, USA) 통계패키지를이용하여통계분석 518
Tuberculosis and Respiratory Diseases Vol. 67. No. 6, Dec. 2009 을실시하였으며, p값이 0.05 미만인경우통계적유의성을인정하였다. 결과 1. 대상환자들의임상적특성연구기간중조사에포함된환자는 111명이었으며남자는 53명 (47.7%), 여자는 58명 (52.3%) 이었다. 연령분포는 19 96세 ( 중앙연령 60세, 평균연령 60.9±14.0세 ) 였으며입원병력이있는환자는 74명 (66.7%), 외래환자는 37명 (33.3%) 의분포를보였다. 연구기간중객담배양양성검체는 248개이었으며, 이중적절한검체로판정된것은 63개 (25.4%), 부적절한검체는 185개 (74.6%) 로분류되었다. 대상환자들의평균객담배양양성검체의갯수는 2.2 (±1.8) 개이었으며, 평균객담배양균주의갯수는 1.7 (±1.0) 개이었다. 전체환자중에서적절한객담검체가 1회이상검출된환자는 41명 (36.9%) 이었고, 평균적절한객담검체수는 0.6 (±0.9) 개를보였다. 전체환자 111명중 2개이상균주를보균하고있는환자수는 29명 (26.1%) 이었으며검출된총균주는 39균주이었고, 1회이상배양된균주의수는총 187개였다. 평균기관지확장증점수는 8.3 (±4.1) 점이었고점수 1 7점을경도, 8 15 점을중등도, 16점이상을중증도로분류하였을때경도기관지확장증은 42명 (37.8%), 중등도기관지확장증은 50명 (45%), 증증기관지확장증은 4명 (3.6%) 이었다. 15명 (13.5%) 은중증도를정확하게판단하기어려웠다. P. aeruginosa 가 1회이상배양된환자는 31 명 (27.9%) 이었고기관지경검사력환자는 48명 (43.2 %), 중환자실입원병력환자는 3명 (2.7 %) 이었다 (Table 1). 2. 전체배양균주분포대상환자 111명에게서배양된전체균주 ( 중복포함 ) 248개중 S. viridans 61개 (24.6%) 를포함한비잠재적병원균주는 81개 (32.7%) 였으며, 잠재적병원균주는총 167 개 (67.3 %) 로 P. aeruginosa 58개 (23.4%), Klebsiella pneumoniae (K. pneumonia) 26개 (10.5%), Staphylococcus aureus (S. aureus) 21개 (8.4%) (Methicillin resistant S. aureus [MRSA] 15개 [6.0%], Methicillin sensitive S. aureus [MSSA] 6개 [2.4%]), A. baumannii 15개 (6.1%), E. faecalis 9개 (3.6%), S. pneumoniae 8개 (3.2%), 기타 30개 (12.1%) 순이었다 (Table 2). Table 1. Baseline characteristics of the 111 patients evaluated Characteristics Values Age, mean±sd, yr 60.9±14* Sex Men (%) 53 (47.7) Women (%) 58 (52.3) History of hospitalization (%) 74 (66.7) No. of specimen (SD) 2.2 (1.8) No. of organism (SD) 1.7 (1.0) No. of patient with AS (%) 41 (36.9) No. of AS (SD) 0.6 (0.9) Bronchiectasis score (SD) 8.3 (4.1) No. of patient with score 1 7 (%) 43 (38.7) No. of patient with score 8 14 (%) 48 (43.2) No. of patient with score 15 21 (%) 5 (4.5) Not checked 15 (13.5) No. of patient with P. aeruginosa (%) 31 (27.9) No. of patient with bronchoscopy (%) 48 (43.2) No. of patient with ICU adm. history (%) 3 (2.7) No: number; SD: standard deviation; AS: adequate sputum specimen; ICU: intensive care unit; adm: admission. *Range, 19 06. 3. 배양균주의검체적절성에따른분석 배양된균주중에서적절한객담검체에서분리된균주는총 63개였으며이중에서 P. aeruginosa 23개 (36.5%) 로가장많은빈도를차지하였고다음으로비잠재적병원균주가 12개 (19.0%), K. pneumoniae 6개 (9.5%), MRSA 5개 (7.9%), A. baumannii 3개 (4.8%), H. influenzae 3개 (4.8%), E. faecalis 2개 (3.2%), S. pneumoniae 2개 (3.2%), 기타 7개 (11.1%) 순으로나타났다. 반면부적절한객담검체에서분리된균주는 185개로이중에서비잠재적병원균주가 69개 (37.3%) 로가장많은빈도를보였으며다음으로 P. aeruginosa 35개 (18.9%), K. pneumoniae 20개 (10.8%), S. aureus 16개 (8.7%) (MRSA 10개 [5.5%], MSSA 6개 [3.2%]), A. baumannii 12개 (6.5%), E. faecalis 7개 (3.8%), S. pneumoniae 6개 (3.2%), 기타 20개 (10.8%) 순으로나타났다. 적절한객담검체에서는 MSSA 없이 MRSA만이배양되었고, H. influenzae 도적절한객담검체에서만배양되었다 (Table 2). 4. 적절한객담검체검출환자군과부적절한객담검체검출환자군간비교 전체 111 명환자중에서적절한객담검체검출환자군 519
KW Seo et al: Bacteriologic analysis of sputum in bronchiectasis Table 2. Microorganisms isolated in sputum specimens Microorganisms Total AS IS RRM PPMs 167 (67.3) 51 (80.9) 116 (62.7) 115 (61.5) Pseudomonas aeruginosa 58 (23.4) 23 (36.5) 35 (18.9) 31 (16.6) Klebsiella pneumoniae 26 (10.5) 6 (9.5) 20 (10.8) 23 (12.3) Staphylococcus aureus 21 (8.4) 5 (7.9) 16 (8.7) 14 (7.5) MRSA 15 (6.0) 5 (7.9) 10 (5.5) 9 (4.8) MSSA 6 (2.4) 0 6 (3.2) 5 (2.7) Acinetobacter baumannii 15 (6.1) 3 (4.8) 12 (6.5) 6 (3.2) Enterococcus faecalis 9 (3.6) 2 (3.2) 7 (3.8) 5 (2.7) Streptococcus pneumoniae 8 (3.2) 2 (3.2) 6 (3.2) 8 (4.3) Enterobacter cloacae 4 1 3 4 Haemophilus influenzae 3 3 (4.8) 0 3 Alcaligenes faecalis 2 1 1 2 Escherichia coli 2 1 1 2 Enterobacter aerogenes 2 0 2 2 Enterococcus faecium 2 0 2 2 Proteus vulgaris 2 1 1 1 Pseudomonas mendocina 2 1 1 2 Others 11 (4.4)* 3 (4.8) 9 (4.9) 10 (5.3) Non-PPMs 81 (32.7) 12 (19.1) 69 (37.3) 72 (38.5) Streptococcus viridans 61 (24.6) 10 (15.9) 52 (28.1) 52 (27.8) Streptococcus salivarius 6 1 5 5 Streptococcus acidominimus 5 0 5 5 Gemella morbillorum 2 0 2 2 Staphylococcus haemolyticus 2 0 2 2 Staphylococcus simulans 2 1 1 2 Others 3 0 2 4** Total 248 (100) 63 (100) 185 (100) 187 (100) AS: adequate sputum specimen; IS: inadequate sputum specimen; RRM: removal of repeated microorganisms that were cultured from same patient; PPMs: potentially pathogenic microorganisms; Non-PPMs: non-potentially pathogenic microorganisms; MRSA: Methicillin resistant Staphylococcus aureus ; MSSA: Methicillin sensitive Staphylococcus aureus. *Streptococcus haemolyticus 1, Aeromonas hydrophilia 1, Candida albicans 1, Citrobacter braakii 1, Enterobacter amnigenus 1, Klebsiella oxytoca 1, Moraxella species 1, Serratia marcescens 1, Stenotrophomonas maltophilia 1, Streptococcus agalactiae 1, Streptococcus dysgalactiae 1, Corynebacterium xerosis 1, Klebsiella oxytoca 1, Moraxella species 1, Streptococcus haemolyticus 1, Stenotrophomonas maltophilia 1, Serratia marcescens 1, Enterobacter amnigenus 1, Citrobacter braakii 1, Candida albicans 1, Aeromonas hydrophilia 1, Streptococcus agalactiae 1, Streptococcus dysgalactiae 1, Aeromonas hydrophilia 1, Candida albicans 1, Citrobacter braakii 1, Enterobacter amnigenus 1, Klebsiella oxytoca 1, Moraxella species 1, Serratia marcescens 1, Stenotrophomonas maltophilia 1, Streptococcus agalactiae 1, Streptococcus dysgalactiae 1, Corynebacterium xerosis 1, Staphylococcus auricularis 1, Staphylococcus epidermidis 1, Staphylococcus auricularis 1, Staphylococcus epidermidis 1, **Corynebacterium xerosis 1, Staphylococcus auricularis 1, Staphylococcus epidermidis 1, Streptococcus haemolyticus 1. 은 41명 (36.9%), 부적절한객담검체검출환자군은 70명 (63.1%) 이었으며두군간평균나이는 61.2세와 60.7세로차이가없었다. 또한성비, 입원병력, 기관지경검사력그리고중환자실입원병력도역시차이가없었다. 그러나평균배양검체수는적절한객담검체검출환자군에서부적절한객담검출환자군에비해유의하게많았으며 (3.0 vs. 1.8, p=0.003), 동정된균주수 (2.0 vs. 1.5, p= 0.03), P. aeruginosa 배양양성환자의비율 (43.9% vs. 18.6%, p=0.004), 그리고기관지확장증점수 (10.5 vs. 7.2, p<0.001) 모두적절한객담검체검출환자군에서유의하게높았다 (Table 3). 5. 입원환자및외래환자의비교입원병력이있는환자는 74명 (66.7%), 외래환자는 37 520
Tuberculosis and Respiratory Diseases Vol. 67. No. 6, Dec. 2009 명 (33.3%) 으로두군간의나이, 배양균주의종류, 적절한검체의검출수그리고기관지확장증점수에서차이를보이지않았다. 6. P. aeruginosa 배양양성환자와배양음성환자의비교 객담에서 1회이상 P. aeruginosa가배양되었던환자는전체 111명환자중 31명 (27.9%) 이었다. P. aeruginosa 배양환자군의평균나이는배양음성군과차이가없었다 (64.4세 vs. 69.6세, p=0.10). 그외성비, 입원병력, 기관지경검사력, 중환자실입원병력에서도차이가없었다. 그러나평균배양검체수는 P. aeruginosa 배양양성환자군에서 P. aeruginosa 배양음성환자군에비해더많았 으며 (3.3 vs. 1.8, p=0.004), 동정된균주수도더많았다 (2.2 vs. 1.5, p=0.02). 또한 P. aeruginosa 배양양성환자군에서 P. aeruginosa 배양음성환자군에비해적절한객담검체의평균검출개수는많았으며 (1.2 vs. 0.3, p=0.002), 적절한객담검체검출비율도유의하게높았다 (58% vs. 29%, p=0.004). 기관지확장증점수도역시 P. aeruginosa 배양양성환자군에서유의하게더높았다 (10.8 vs. 7.6, p=0.001) (Table 4). 또한 P. aeruginosa 배양양성환자군이배양음성환자군에비해적절한객담검체가검출될확률이 3.78 배 ( 신뢰구간, 1.238 5.343) 높았으며, P. aeruginosa 배양양성과적절한객담검체의검출은감마값 0.549로통계적으로유의한일치성이있었다 (kappa 0.267, p=0.006). Table 3. The comparison of patients with adequate sputum specimen and inadequate sputum specimen Variables AS (n=41) Adequacy of sputum specimen IS (n=70) p-value Age, mean (SD), yr 61.2 (14.2) 60.7 (13.9) 0.852 Women, % 48.8 54.3 0.575 Hospitalization history, % 63.4 68.6 0.578 Sputum No. (SD) 3.0 (2.4) 1.8 (1.1) 0.003 Isolated organism No. (SD) 2.0 (1.3) 1.5 (0.9) 0.033 Patients with isolation of P. aeruginosa, % 43.9 18.6 0.004 BE score (SD) 10.5 (4.0) 7.2 (3.8) 0.000 Bronchoscopy history, % 56.1 57.1 0.915 ICU admission history, % 4.9 1.4 0.279 No: number; AS: adequate sputum specimen; IS: inadequate sputum specimen; SD: standard deviation; BE: bronchiectasis; ICU: intensive care unit. Table 4. The comparison of patients with P. aeruginosa and without P. aeruginosa Variables P. aeruginosa (+) (n=31) P. aeruginosa ( ) (n=80) p-value Age, mean (SD), yr 64.4 (14.9) 69.6 (13.5) 0.101 Women, % 61.3 48.8 0.235 Hospitalization history, % 61.3 68.8 0.454 Sputum No. (SD) 3.3 (2.6) 1.8 (1.1) 0.004 Isolated organism No. (SD) 2.2 (1.6) 1.5 (0.7) 0.023 AS, % 58.1 28.8 0.004 AS No. (SD) 1.2 (1.4) 0.3 (0.5) 0.002 BE score (SD) 10.8 (4.8) 7.6 (3.7) 0.001 Bronchoscopy history, % 35.5 46.3 0.304 ICU admission history, % 6.5 1.3 0.129 No: number; AS: adequate sputum specimen; SD: standard deviation; BE: bronchiectasis; ICU: intensive care unit. 521
KW Seo et al: Bacteriologic analysis of sputum in bronchiectasis Figure 1. Total patients with isolated P. aeruginosa. Black bar ( ) represents adequate sputum specimen (AS) and white bar ( ) represents inadequate sputum specimen (IS). No: number. Figure 3. Antimicrobial resistance in the K. pneumoniae isolates for each antibiotics ( ). AMK: amikin; AMP: ampicillin; AMP/SBT: ampicillin/sulbactam; ATM: aztreonam; CFZ: cefazolin; FEP: cefepime; CFX: cefoxitin; CFT: ceftriaxone; CIP: ciprofloxacin; ESBL: extended spectrum ß-lactamase; GEN: gentamicin; IMP: imipenem; PIP/ TZC: piperacillin/tazocin; TOB: tobramycin. (4.5±2.9 vs. 1.9±1.3, p=0.004) 및기관지확장증점수 (12.7±4.3 vs. 8.7±4.3, p=0.04) 는적절한객담검체검출군에서유의하게높았다. 8. P. aeruginosa 균주의항생제내성률 Figure 2. Antimicrobial resistance in the P. aeruginosa isolates for each antibiotics ( ). AMK: amikin; ATM: aztreonam; FEP: cefepime; CTZ: ceftazidime; CIP: ciprofloxacin; GEN: gentamicin; IMP: imipenem; PIP: piperacillin; TCA: Ticarcillin+Clavulanate; TOB: tobramycin. 7. P. aeruginosa 배양양성환자중검체적절성에따른분석 P. aeruginosa 배양양성환자 31명중에서적절한객담검체가검출된환자가 17명 (54.8%) 으로부적절한검체만검출된환자 14명 (45.2%) 보다많았으며, 적절한객담검체가검출된환자중에서 9명 (52.9%) 은 1회이상부적절한객담검체가동반검출되었다 (Figure 1). 또한적절한검체군또는부적절한객담검체군두군간에나이, 검출된균주수에서는차이가없었으나평균배양균주수 Ciprofloxacin 에대해서 41.9% 로내성률이가장높았으며, gentamicin 32.3%, ticarcillin/clavulanate 26.1%, aztreonam 25.8%, cefepime 25.8%, ceftazidime 23.8%, piperacillin 21.7%, imipenem 19.4%, tobramycin 19.4% 순이었으며 amikin이 9.7% 로가장내성률이낮았다 (Figure 2). 또한 P. aeruginosa가검출된객담검체를적절한객담검체군과부적절한객담검체군으로나누어 P. aeruginosa에대한각각의항생제내성률을비교분석하였을때 ciprofloxacin 내성률만이적절한객담검체군에서부적절한객담검체군에비해유의하게높게차이를보였다 (58.8% vs. 21.4%, p=0.036). 9. K. pneumoniae 균주의항생제내성률 Ampicillin 에대해서 100% 내성을보였고, cefazolin 43.5%, ampicillin/sulbactam 39.1%, cefoxitin 31.8%, ceftriaxone 26.1%, aztreonam 22.7%, ciprofloxacin 17.4%, piperacillin/tazobactam 13.0%, amikin 8.7%, gentamicin 8.7%, tobramycin 8.7% 순의내성률을보였으며, cefe- 522
Tuberculosis and Respiratory Diseases Vol. 67. No. 6, Dec. 2009 pime 과 imipenem 의내성률이각각 4.5% 와 0% 로가장낮았다 (Figure 3). Extended spectrum ß-lactamase (ESBL) 양성은 1개의검체에서관찰되었으나부적절한검체였다. 또한 ceftriaxone 에대한내성률은적절한객담검체군에서부적절한객담검체군에비해유의하게내성률이높았다 (66.7% vs. 11.8%, p=0.008). Ciprofloxacin에대한내성률도적절한객담검체군에서부적절한객담검체군에비해내성률이높았다 (50% vs. 16%, p=0.01). 그외의 imipenem 을제외한나머지약제들에대해서는적절한객담검체군에서내성률이높은경향을보였으나통계적으로유의한차이를보이지는않았다. 고찰기관지확장증의발생률및유병률에대한전세계적인체계적자료는없으나항생제와백신이도입된 20세기부터는감소되고있다고추정한다 20. 한국인에서의기관지확장증유병률에대한체계적인조사도없는상황이나과거폐감염이기관지확장증의주요발생원인이었고 3-5, 또한이전의국내기관지확장증관련보고 3,4 를보면환자의주연령대가 20 30 대였으나, 비교적최근의연구였던한조사 13 에서는환자의평균나이가 50세였으며본연구의환자평균나이도 60.9세인점을미루어볼때점차환자들이고령화되는추세로판단되며, 따라서국내에서도환자의수가점차감소되고있다고추정해볼수있다. 그러나최근미국에서는비결핵성마이코박테리아폐질환과관련되어기관지확장증환자가다시증가하고있다는보고 21,22 가있는데, 국내기관지확장증환자중특정군에서폐비결핵성마이코박테리아증의빈도가높은소견 23 을고려해볼때서구에서와같이다시증가될가능성도있어체계적인조사가향후필요할것으로생각된다. 본연구에서는 111 명환자에서분리된전체균주 248 개중가장많이검출된균주는비잠재적병원균주인 S. viridans로 24.6% 였으며, 잠재적병원균주는총 67.3% 로이중 P. aeruginosa가 23.4% 로가장많았고, K. pneumoniae 10.5%, S. aureus 8.4% (MRSA 6.0%), A. baumannii 6.1% 등의순서였다. 반면, 적절한객담검체에서분리된균주 63개중에서잠재적병원균주는 80.1% 였으며, 이중 P. aeruginosa가 36.5% 로가장많았으며 K. pneumoniae 9.5%, MRSA 7.9%, A. baumannii 4.8%, H. influenzae 4.8% 순이었다. S. viridans도 15.9% 에서동정되었고, 비잠재적병원균주의대부분을차지하였다. 이전에발표된기관지확장증환자의균주배양에대한국내보고는객담의적절성언급이없는자료가대부분이다. Chung 등 4 이입원환자 41명에서배양된 33개객담검체에서 Normal flora 75.8%, Hemophilus species 12.1%, B. antitratium 9.1%, K. pneumoniae 6.1%, Pseudomonas species 3% 순으로보고하였고, Rho 등 3 의보고에서는입원환자 111명에서배양된객담에서 Normal throat flora 32.4%, H. influenzae 및 P. aeruginosa 18.9%, A. faecalis 15.3%, ß-hemolytic streptococci 8.1% 등의순서였다. Shin 등 5 은기관지확장증으로수술받은환자 42명에서배양된 39균주를보고하였는데 α-hemolytic streptococcus 45%, Pseudomonas 29%, N. menigitidis 17%, Staphyococcus 17% 의결과를보였고, Chung 과 Chung 24 은기관지확장증으로수술을받은환자 80명에서얻은 80 개의균주에서 α-hemolytic streptococcus 48.8%, Klebsiella 21.3%, P. aeruginosa 10%, S. aureus 6.2% 등의순으로보고하였다. 최근 Lee 등 13 은 HRCT로진단된 49명의안정된상태의기관지확장증환자들에서본연구와동일한기준의적절한객담만을세균배양에이용하여 21명의객담에서집락균을동정하였고이중 15명 (71%) 에서 P. aeruginosa를동정되어가장많은집락균을차지하였다. 본연구를이전보고와비교해볼때과거에비해 P. aeruginosa 및 K. pneumoniae가기관지확장증환자에서주된집락균으로변화하고있으며, 이전에는보고되지않았던 MRSA, A. baumannii가점차늘고있음을확인할수있었다. 한편외국문헌에보고된기관지확장증환자에서동정된균주를비교하면적절한검체에서분석한결과 8,25 와검체의적절성여부에대한언급없이분석한결과 26,27 모두 H. influenzae 및 P. aeruginosa가가장많았다. 본연구에서는 H. influenzae 가적었고, K. pneumoniae, MRSA, A. baumannii가비교적높게검출되었는데, 외국보고들은주로안정적인기관지확장증환자를대상으로하였으나본연구는감염등으로인해급성악화가동반된환자들을대상으로하여대상군이다르고, 악화증상이생긴환자의경우이미항생제를사용한후내원하였을가능성이있으며또한항생제에대한내성률차이등의지역적인특성이원인일것으로생각한다. 건강한비흡연자의하부기관지에는무균상태이나 28 만성폐쇄성폐질환환자, 기관지확장증환자등에서는종종잠재적병원균주가집락형성을하고있으며폐감염의잠재적인위험인자로간주되고있다 7,29. 523
KW Seo et al: Bacteriologic analysis of sputum in bronchiectasis Cabello 등 15 은 Murray 등 16 의저서를참조하여건강인과폐암, 만성폐쇄성폐질환, 기관지확장증및기관절개술환자들에서의배양된균주를잠재적병원균주군및비잠재적병원균주군으로분류하였다. 이후호흡기계의균주와관련된연구들 25,30-32 에서 Cabello 등의분류법이사용되고있으며 Banerjee 등 33 은 67명의임상적으로안정적인만성폐쇄성폐질환환자들에서채취한객담검체의배양균에따라잠재적병원균주군과비잠재적병원균주군으로구분하였을때잠재적병원균주군에서염증표지자들과 St. George's Respiratory Questionnaire의점수가유의하게높음을확인하였다. 따라서면역억제상태가아닌환자들에게서의이러한분류는참조할만한타당성을가진다고판단된다. 그러나 Banerjee 등 33 의연구에서도객담의호중구의수는비잠재적병원균주군에서잠재적병원균주군과유사하였으며비교적최근까지 Moraxella catarrhalis가병원균으로간주되지않았었고비잠재적병원균주의기관지염증유발에대한정보가미약하다는점 34 등은이런분류의타당성을위해서는더많은후속연구가필요함을시사한다하겠다. 본연구에서 111명환자로부터분리된전체균주 248 개중가장많이검출된균주는비잠재적병원균주인 S. viridans로 24.6% 였으며적절한객담검체에서도분리된균주 63개중 S. viridans가 15.9% 로 P. aeruginosa (36%) 다음으로많았다. 이와같은결과는본연구와같이적절한검체의기준인 Murray-Washington 분류법에서 IV, V 군만을대상으로조사한 Angrill 등 25 의연구에비해낮은수치이다. 77명의임상적으로안정적인기관지확장증을대상으로조사한그의연구에서는객담분석에서 S. viridans가 55% 로전체잠재적병원균 52% 보다도높게검출되었다. 또한기관지폐포세척술결과분석에서도 S. viridans가 24% 로 H. influenzae 32% 다음으로높게검출되었다. 본연구의환자군이대부분임상적악화상태의환자들로구성되어있었기때문에 S. viridans 가상대적으로낮게검출되었을것으로생각한다. 그러나기관지확장증환자의적절한객담검체에서분리된 S. viridans의임상적의미는밝혀진바없다. 실제로환자의기관지확장증부위의염증에관여하는것인지, 단순히균집락화만하고있는방관자 (bystander) 인지는향후추가적인연구가필요할것으로생각된다. 본연구에서 P. aeruginosa 배양양성환자중에서적절한객담검체가검출된환자 (54.8%) 가부적절한검체만검출된환자 (45.2%) 보다많았지만한편으로는적절한검 체가검출된환자중에서 52.9% 은 1회이상부적절한객담검체가동반검출되었는데, 이는비록처음에는부적절한검체로나왔다고하더라도상황에따라반복검사를통해적절한검체로나올수있음을시사하는결과이다. Angrill 등 25 은 Murray-Washington 분류상 IV, V군에해당하는적절한검체의객담은기관지경을이용한기관지폐포세척을통한균주분석을대체할만한유용한검사라고제시하였다. 본연구의결과에서도적절한객담검체환자군에서잠재적병원균주의빈도가월등히유의하게높았고, 또한적절한객담환자군에서 P. aeruginosa가배양빈도가더높았으며, 기관지확장증점수도유의하게높은점등으로미루어적절한객담에서동정된균주분석이보다정확한감염원인균을추정하는데근거가될것으로생각되며 Angrill 등의결과와부합한다. 그러나기관지경검사를시행하는환자에서는검체보호솔질법 (protected specimen brush) 이나기관지폐포세척술 (bronchoalveolar lavage) 을통한정량적균배양이가장좋은균주확진방법 35,36 으로추천되고있으므로적절한검체를통한균배양의의미를일률적으로적용하는것은경계해야한다고생각한다. 한편객담의그람염색의일치도를확인하는것은병원균을규명하는데중요한역할 37 을하므로객담균주분석을할때참고하여오염균의과증식으로인한오류를배제하여야할것으로사료된다. P. aeruginosa 배양양성환자군에서 P. aeruginosa 배양음성환자군보다기관지확장증점수가 10.8 점과 7.6점으로유의하게더높은결과를보였는데이는기관지확장증범위정도가더심할수록 P. aeruginosa 감염이많음을의미하며, 본연구가후향적조사였기때문에임상적차이를분석하지는못하였으나기관지확장증환자중 P. aeruginosa 배양양성환자군이배양음성환자군보다더심한임상상, 즉더많은급성악화및입원 8, 폐기능저하 7,8 를보이는다른연구들에부합하는결과이다. 그러나 P. aeruginosa는일반적인다른병원체 (pathogen) 와달리균이자랐다고해도병원체가아닌경우가많으며 7, 또한일반적인항생제치료에서내성을보이는균으로양성선택 (positive selection) 될가능성이있다 38. 한편 Costerton 39 은 1984년에 P. aeruginosa가인체감염에서생체막 (biofilms) 을형성하여생존할것이라는가설을제시하였으며, 이후 P. aeruginosa의당질층 (glycocalyx) 이자연적인생체막의역할을하여항생제와같은외부의공격에대하여방어막의역할을하는것으로밝혀졌 524
Tuberculosis and Respiratory Diseases Vol. 67. No. 6, Dec. 2009 다. 다른보고에의하면시험관내실험에서최소억제농도 (minimal inhibitory concentration) 1,000배이상농도의항생제에도생체막속에묻혀있는균주가생존할수있다고한다 40. 따라서기관지확장증과같이기관지의구조적인이상, 즉비가역적인확장과변형및이로인한장기적인객담의저류초래는 P. aeruginosa의생체막형성의요소가되며 P. aeruginosa가만성폐질환, 특히기관지확장증및낭성섬유증 (cystic fibrosis) 환자에서높게검출되는이유라고추정해볼수있다. 본연구에서는일부환자에서객담검사가편중되어특정균주의빈도가높아지는치우침을배제하고자중복배양균주배제후균주분석을하였는데전체적인순서에는변화가없었지만 P. aeruginosa는상대적으로감소하고, K. pneumoniae는증가하였다. 이는 P. aeruginosa가배양된환자들에서보다집중적으로객담검사를많이하였기때문이다. 본연구에서 P. aeruginosa 균주의항생제내성률은 ciprofloxacin 약제에대해서 41.9%, gentamicin 32.3% 였는데이는지역사회병원외래에서경구용 ciprofloxacin 과 gentamicin 주사제의사용이많았음을추정하게하는결과로생각된다. King 등 8 의보고에서도 gentamicin 내성률이 14% 에서평균 5.7년코호트기간이후에 39% 로증가되어유사한내성률을보이고있다. K. pneumoniae의항생제내성률분석에서는약제가개발되어사용된기간이비교적긴 cefazolin (43.5%), ampicillin/sulbactam (39.1%), ceftriaxone (26.1%) 등에는내성률의증가가관찰되나 aminoglycoside (8.7%) 와최근개발된 cefepime, imipenem 에서는내성률이각각 4.5% 와 0% 로가장낮았으며 ESBL 양성인 K. pneumoniae는 1예로아직은드물었다. 그러나 ceftriaxone 에대한항생제내성률은부적절한객담검체군에서는 11.8% 에지나지않았으나적절한객담검체군에서는 66.7% 로유의하게높아향후항생제내성이점차심각한문제가될것을시사하고있다. 본연구의제한점은첫째, 후향적조사였기때문에자료의객관성및통일을위해자료분류상일관성이부족한것으로판단된객혈환자의정량적분류및분석, 흡연력, erythromycin 투약력, 폐기능검사및환자들의주요증상등의자료를포함하지않아분석에한계가있었다. 둘째로본연구가현재까지의국내보고중에는가장많은환자와검체를포함하였으나환자의절대수가많지않고또한단일병원자료이므로연구결과를보편화하기에는무 리가있다고생각한다. 마지막으로비결핵성마이코박테리아의검출이축소되었을가능성이다. 최근국내외여러보고에서기관지확장증과비결핵성마이코박테리아의관련성이보고되고있으나본연구에서는 2명의환자에서만 Mycobacterium avium complex, Mycobacterium kansasii가각각동정된것으로확인되었다. 이는본연구의환자선정기준에서결핵환자가배제가되면서비결핵성마이코박테리아증환자가배제가되었기때문으로생각된다. 이상의결과를종합하면기관지확장증환자 111명에서얻은전체객담검체에서동정된균주는잠재적병원균주가 67.3% 였고 P. aeruginosa, K. pneumonia, S. aureus, A. baumannii 순이었으며, 적절한객담검체군에서도그순서는마찬가지였다. 적절한객담검체군에서 P. aeruginosa 배양양성환자가더많았으며 P. aeruginosa 배양양성환자에서기관지확장증의중증도가심하며, 특히 P. aeruginosa 균주와 A. baumannii, MRSA 및 K. pneumoniae 등의원내폐렴에서중요한비중을차지하는균주의동반감염이상대적으로많아이의확산을줄이기위한지속적인연구가필요할것으로생각된다. 또한향후전향적인조사를통해국내기관지확장증의유병률및안정상태의환자의기관지내잠재적병원균주의분포, 그리고감염등의급성악화상태의병원균주양상등에대한비교도필요할것으로사료된다. 참고문헌 1. Swartz MN. Chapter 132. Bronchiectasis. In: Fishman AP, Elias JA, Fishman JA, Grippi MA, Kaiser LR, Senior RM, editors. Fishman's pulmonary diseases and disorders. 3rd ed. New York: McGraw-Hill; 1998. p. 2045-70. 2. Barker AF. Bronchiectasis. N Engl J Med 2002;346: 1383-93. 3. Rho YH, Kim YW, Park CS, Lee YH, Kim SY, Kim KY, et al. Clinical review of 147 cases of bronchiectasis. Korean J Med 1982;25:155-63. 4. Chung HY, Cho DI, Yoo JI, Rhu MS. Clinical studies on relationship with sinusitis and bronchiectasis. Tuberc Respir Dis 1978;25:165-9. 5. Shin YG, Im JS, Choi HH. Clinical study of bronchiectasis. Korean J Thorac Cardiovasc Surg 1993;26: 294-7. 6. Korea National Statistical Office. The annual prevalence day of each chronic illness in Korea (Population per 525
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