The bacteriology of acute maxillary sinusitis

Sinus secretions obtained by antral aspiration from 347 patients with acute maxillary sinusitis were examined bacteriologically. Special attention was paid to the method by which anaerobic bacteria could be recovered. On the total, 485 sinus secretion samples were examined, of these 336 were aspirates, 149 yields of injection-aspirations. Aerobic bacteria were cultured from 263 aspirates and from 100 injection-aspiration samples. Only anaerobes were recovered from 6 sinuses. Bacterial culture was negative in 115 sinuses (24%). The most common pathogens isolated were Haemophilus influenzae (50.5%), Streptococcus pneumoniae (18.5%), Streptococcus pyogenes (5%) and Branhamella catarrhalis (1.5%). A true anaerobic infection was considered to be present in only 7 sinuses (1.5%) indicating that anaerobes are not a significant cause of acute maxillary sinusitis. According to this study the most common pathogen in acute maxillary sinusitis in young adults is H. influenzae. From this follows that in such patients aminopenicillins may be a more appropriate choice than conventional penicillin in the antimicrobial treatment of acute maxillary sinusitis.     

Microbial flora of nose and paranasal sinuses in chronic maxillary sinusitis

Nasal secretions, maxillary sinus aspirates and specimens of the maxillary sinus mucosa were collected in 44 patients aged between 25 and 60 affected by mono- or bilateral chronic maxillary sinusitis, in order to establish the best sampling technique for microbiological purposes, the most frequently involved bacteria and the physiopathological mechanism underlying chronic maxillary disease. The sinusal mucosa resulted to be the most reliable sample as it reduces contamination and microbial variability. Anaerobic bacteria were isolated in nasal swab (15.6%), in maxillary sinus aspirates (30.4%) and in maxillary sinus mucosa (36.4%) of maxillary sinusitis patients. In controls anaerobic bacteria were isolated only in one nasal swab (2.3%), while they could not be isolated in maxillary sinus aspirates and in maxillary sinus mucosa. The presence of anaerobic bacteria in chronic maxillary sinusitis patients and their absence in controls seem to confirm that anaerobic microorganisms represent the main pathogenetic agents of chronic maxillary sinusitis. The possible physiopathological mechanisms underlying chronic maxillary sinus disease are finally discussed.     

Bacteriological findings and antimicrobial susceptibility in chronic sinusitis with nasal polyp

CONCLUSIONS: We recommend amoxacillin/clavulanate, cephalosporins and macrolides rather than penicillin as the first-line drug in chronic sinusitis with nasal polyps. In cases where there is no improvement of symptoms, cultures should be taken from the middle meatus, followed by appropriate selection of second-line antibiotics according to the sensitivity test results. OBJECTIVE: To investigate the causative bacteria and the antimicrobial susceptibility in patients with chronic sinusitis and nasal polyps in Korea. MATERIALS AND METHODS: The bacteriology and antimicrobial susceptibility of maxillary sinus aspirates from 81 patients were evaluated. RESULTS: Aerobes were isolated from 58.0% of the cultures from the middle meatus and from 48.1% of those from the maxillary sinus. Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae were the most prevalent aerobic pathogens. Anaerobes were isolated from 8.6% of the cultures from the middle meatus and from 18.5% of the cultures from the maxillary sinus. The predominant anaerobic organisms were Prevotella and Peptostreptococcus in adults but none of them were cultured in children. A high rate of concordance of the middle meatus and maxillary sinus was noted. Monomicrobial infection was most commonly observed. Ampicillin-resistant H. influenzae isolates were cultured in 46% of the cases. Penicillin resistance rates were 93% for Staph. aureus; 25% of Strep. pneumoniae were intermediate and 25% were resistant.     

Bacteriological findings and antimicrobial susceptibility in chronic sinusitis with nasal polyp

Conclusions. We recommend amoxacillin/clavulanate, cephalosporins and macrolides rather than penicillin as the first-line drug in chronic sinusitis with nasal polyps. In cases where there is no improvement of symptoms, cultures should be taken from the middle meatus, followed by appropriate selection of second-line antibiotics according to the sensitivity test results. Objective. To investigate the causative bacteria and the antimicrobial susceptibility in patients with chronic sinusitis and nasal polyps in Korea. Materials and methods. The bacteriology and antimicrobial susceptibility of maxillary sinus aspirates from 81 patients were evaluated. Results. Aerobes were isolated from 58.0% of the cultures from the middle meatus and from 48.1% of those from the maxillary sinus. Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae were the most prevalent aerobic pathogens. Anaerobes were isolated from 8.6% of the cultures from the middle meatus and from 18.5% of the cultures from the maxillary sinus. The predominant anaerobic organisms were Prevotella and Peptostreptococcus in adults but none of them were cultured in children. A high rate of concordance of the middle meatus and maxillary sinus was noted. Monomicrobial infection was most commonly observed. Ampicillin-resistant H. influenzae isolates were cultured in 46% of the cases. Penicillin resistance rates were 93% for Staph. aureus; 25% of Strep. pneumoniae were intermediate and 25% were resistant.     

Bacterial examination of sinusitis using antral puncture and irrigation

Aerobic bacterial examination for sinusitis was conducted using specimens from maxillary sinuses collected by antral puncture in 540 patients--284 men and 256 women aged 6-89 years--between May 1999 and April 2000. We obtained 528 strains of bacteria. Our results were as follows: 1. We obtained 303 pathogens from 540 patients. In acute sinusitis, the most frequently found was Streptococcus pneumoniae (30.4%), followed by Hemophilus influenzae (27.7%). In chronic cases, the most frequently found was Streptococcus pneumoniae (16.0%), followed by Hemophilus influenzae (15.1%) and Staphylococcus epidermidis (12.6%). 2. We found an increase in bacteria resistant to multiple drugs, with 11.1% of the Staphylococcus aureus isolates methicillin-resistant in acute sinusitis and 40% methicillin-resistant in chronic sinusitis, and that 30.6% of Streptococcus pneumoniae isolates were penicillin-resistant. 3. Ciclacillin was effective against 64.7% of all pathogens isolated in this study, cefpodoxime proxetil effective against 6.5%, and cefixime effective against 2.4%. 4. In considering pathogens, we therefore choose antibiotics and make a maxillary aspiration puncture.     

Predictive value of nasal bacterial culture for etiological agents in acute maxillary sinusitis

Nasal secretion, aspiration yield and lavage content from the sinus were studied for bacteria in 175 patients (247 sinuses) with acute maxillary sinusitis. The same pathogen was cultured from the nose and aspiration fluid in 91% of cases of acute purulent sinusitis. This indicated a significant predictive value of the nasal bacteriological culture for presence of pathogenic bacteria in the sinus in purulent cases. In cases with no growth of pathogens in the aspirate, the nasal culture showed pathogenic bacteria in about 50%. Examination of the aspiration fluid may occasionally give false negative result in purulent maxillary sinusitis (at least 3% in the present series). In these cases, culture of the irrigation yield may prove helpful.     

Microbiology of acute exacerbation of chronic sinusitis

OBJECTIVES: We undertook to evaluate the microbiology of acute exacerbation of chronic sinusitis (AECS). METHODS: Repeated aspirations of maxillary sinus secretions by endoscopy were performed in 7 patients over a period of 125 to 242 days. RESULTS: Bacteria were recovered for all 22 aspirates, and the number of isolates was between 2 and 4. A total of 54 isolates were isolated: 16 aerobic and facultative bacteria and 38 anaerobic bacteria. The aerobic bacteria were Haemophilus influenzae (7 isolates), Streptococcus pneumoniae (3), Moraxella catarrhalis (3), Staphylococcus aureus (2), and Klebsiella pneumoniae (1). The anaerobic bacteria included pigmented Prevotella and Porphyromonas spp (19), Peptostreptococcus spp (9), Fusobacterium spp (8), and Propionibacterium acnes (2). A change in the types of isolates was noted in all consecutive cultures obtained from the same patients as different organisms emerged and previously isolated bacteria were no longer recovered. An increase in antimicrobial resistance was noted in 6 instances. CONCLUSIONS: This study illustrates the microbial dynamics of AECS in which anaerobic and aerobic bacteria prevail, and highlights the importance of obtaining cultures from patients with AECS for guidance in selection of proper antimicrobial therapy.     

Bacteriology of chronic sinusitis and acute exacerbation of chronic sinusitis

OBJECTIVE: To establish the microbiological characteristics of acute exacerbation of chronic sinusitis (AECS). SETTING: Academic medical center. PATIENTS: Thirty-two patients with chronic sinusitis and 30 patients with AECS. MAIN OUTCOME MEASURE: The aerobic and anaerobic microbiology of maxillary AECS and chronic maxillary sinusitis. RESULTS: A total of 81 isolates (33 aerobic and 48 anaerobic) were recovered from the 32 cases (2.5 per specimen) with chronic sinusitis. Aerobes alone were recovered in 8 specimens (25%), anaerobes only were isolated in 11 (34%), and mixed aerobes and anaerobes were recovered in 13 (41%). The predominant aerobic and facultative bacteria were Enterobacteriaceae and Staphylococcus aureus. The predominant anaerobic bacteria were Peptostreptococcus subspecies, Fusobacterium subspecies, anaerobic gram-negative bacilli, and Propionibacterium acnes. Twenty-one beta-lactamase-producing bacteria were recovered from 17 specimens (53%). A total of 89 isolates (40 aerobic and facultatives, and 49 anaerobic) were recovered from the 30 patients (3.0 per specimen) with AECS. Aerobes were recovered in 8 instances (27%), anaerobes only in 11 (37%), and mixed aerobes and anaerobes were recovered in 11 (37%). The predominant aerobes were Streptococcus pneumoniae, Enterobacteriaceae, and S aureus. The predominant anaerobes were Peptostreptococcus subspecies, Fusobacterium subspecies, anaerobic gram-negative bacilli, and P acnes. Thirty-six beta-lactamase-producing bacteria were recovered from 28 specimens (53%). CONCLUSIONS: This study demonstrates that the organisms isolated from patients with AECS were predominantly anaerobic and were similar to those generally recovered in patients with chronic sinusitis. However, aerobic bacteria that are usually found in acute infections (eg, S pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis) can also emerge in some of the episodes of AECS.     

Immune response to Fusobacterium nucleatum and Prevotella intermedia in patients with chronic maxillary sinusitis

Our objective was to study the immune response to 2 anaerobic bacteria in patients with chronic maxillary sinusitis. Immunoglobulin G class antibody titers to Fusobacterium nucleatum and Prevotella intermedia were measured by enzyme-linked immunosorbent assay. Serum levels in the patients were determined on the day sinus aspiration for culture was done, and 75 to 90 days later, after completion of antimicrobial therapy, Prevotella intermedia was isolated from 16 aspirates, and F. nucleatum from 12. Median antibody levels at day 1 for F. nucleatum and P. intermedia were significantly higher in patients whose serum aspirates harbored these organisms than at days 75 to 90 in those who were cured (p < .05). However, the levels stayed elevated in the 5 patients who did not improve. The elevated antibody levels to F. nucleatum and P. intermedia, known oral pathogens, suggest a potential pathogenic role for these organisms in chronic maxillary sinusitis.     

Evaluation of drug sensitivity of the microorganisms isolated from chronic sinusitis treated by beta lactam antibiotics

The drug sensitiveness to beta-lactam antibiotics of the bacterial flora, taken by sinus puncture from 115 patients with unior bilateral acute exacerbation of chronic maxillary sinusitis was analysed. About 90% of the isolated pathogens, as well as in subgroup treated with amoxicillin with potassium clavulanate and in subgroup treated with cefuroxime axetil showed antibiotic sensitivity. Among isolated pathogens before the treatment, 4 (9.5%) were resistant to the amoxicillin with potassium clavulanate disks in subgroup A and 3 (7.3%) to the cefuroxime axetil in subgroup B. There was only one pathogen isolated in the control evaluation in both group after the treatment.     

Differential diagnosis of purulent and non-purulent acute maxillary sinusitis in young adults

In acute maxillary sinusitis, purulence could best be assessed from sinus washings, but evaluation based on aspirates was also reliable, provided that the amount of secretion was adequate. Injection-aspirates were of negligible diagnostic value in this respect. Sinus washings and aspirates which were clinically defined as purulent were almost invariably indicative of bacterial infection. The bacterial etiology was most accurately obtained by sinus aspiration. Only 14.5% of cultured specimens were negative for pathogenic bacteria. In maxillary sinusitis, judged to be non-purulent, 52.5% of cultures grew a pathogen. The most common pathogen was Haemophilus influenzae, which accounted for 90% of these isolations. There was a clear correlation between occurrence of many PMNs and pathogen positive culture in non-purulent cases. Thus, antimicrobial therapy which is effective against Haemophilus influenzae seems indicated in most cases of non-purulent maxillary sinusitis.     

Cefprozil in the treatment of chronic maxillary sinusitis. Clinical and microbiological effectiveness and penetration into sinuses examination

40 patients with exacerbation of a chronic maxillary sinusitis were examined. Sinus puncture was performed (sinoject) in all of the patients. Before the treatment (500 mg cefprozil orally twice a day, the recommended duration of therapy was ten days) and on the fifth day, the microorganisms from sinus were isolated (the bacteriological culture, antibiogram and MIC were determined). On the second and the fifth day, blood cefprozil level and the presence of cefprozil in the washings from maxillary sinuses were investigated. RESULTS: 17 pathogens were isolated from maxillary sinuses, only two of them were anaerobic. The bacterial strains: Staphylococcus (55%), E.coli (15%), Klebsiella (10%) and 20% of others, were found. Four of them (23.5%) were resistant to cefprozil. In all patients cefprozil was identified in maxillary sinuses (0.87-2.52 ug/ml). The value of MIC were from 0.094 to 2.0 ug/ml. A satisfactory clinical response was observed in 92.5% persons but the eradication of pathogens was obtained in 70%. The adverse clinical events (diarrhea) were observed only in one patient (2.5%). CONCLUSIONS: cefprozil well penetrates into inflammable mucous membrane of maxillary sinuses. Cefprozil obtains efficient bactericidal concentration in relation to sensitive bacteria on the fifth day of therapy. It is also well tolerated by the patients.     

Bacteriologic findings in patients with chronic sinusitis

We studied the bacteriology of maxillary sinus aspirates obtained from patients diagnosed with chronic sinusitis. We recovered 659 strains from 510 aspirates; of these, 572 (86.8%) were aerobes and 87 (13.2%) were anaerobes. Aerobes only were recovered from 310 of the 510 specimens (60.8%) and anaerobes only from 31 (6.1%). Among the 572 aerobic bacteria, the most prevalent organisms were Streptococcus viridans (158 strains [27.6%]), Streptococcus pneumoniae (67 [11.7%]), Corynebacterium species (66 [11.5%]), Staphylococcus aureus (54 [9.4%]), Moraxella catarrhalis (38 [6.6%]), Hemophilus parainfluenzae (33 [5.8%]), and group C beta-hemolytic streptococci (26 [4.5%]). Among the 87 recovered anaerobes were species of Peptostreptococcus (32 strains [36.8%]), Prevotella (22 [25.3%]), Actinomyces (13 [14.9%]), Propionibacterium (11 [12.6%]), Fusobacterium (8 [9.2%]), and Veillonella (1 [1.1%]). Beta-lactamase production was detected in 115 of the 572 aerobic strains (20.1%) and in 10 of the 87 anaerobic strains (11.5%). We found that the prevalence and type of organisms we identified in chronic sinusitis did not differ substantially from those reported in previous studies. Our study is one of the more extensive reports on the type and prevalence of pathogens in chronic sinusitis that has been published to date.     

Microbiology of middle meatus in chronic rhinosinusitis

BACKGROUND: Nasal endoscopy allows the collection of middle meatus secretion samples and is an alternative method for determining microorganisms in rhinosinusitis. This study assessed endoscopically collected middle meatus secretions in patients with chronic rhinosinusitis (CRS) and compared those findings with ipsilateral maxillary sinus aspirates and microbiological data of healthy individuals. METHODS: Middle meatus samples were collected from 114 CRS patients for aerobic, anaerobic, and fungal cultures; maxillary sinus secretions were collected from 13 of these patients. Twenty-three healthy volunteers served as controls. RESULTS: Aerobes were isolated in 86% of CRS patients, anaerobes were isolated in 8% of CRS patients, and fungi were isolated in 11% of CRS patients; the most frequent microorganisms were Staphylococcus aureus (36%), coagulase-negative Staphylococcus (20%), and Streptococcus pneumoniae (17%). Middle meatus and maxillary sinus cultures presented the same pathogens in 80% of cases. In healthy individuals, coagulase-negative Staphylococcus (56%), S. aureus (39%), and S. pneumoniae (9%) were the most frequent isolates. CONCLUSION: The culture of endoscopically collected middle meatus secretions is effective in identifying microorganisms in CRS patients.     

Microbiology of chronic frontal sinusitis

OBJECTIVES: To determine bacterial and fungal organisms that are present in patients undergoing surgery for chronic frontal sinusitis. STUDY DESIGN: Retrospective, nonrandomized study. METHODS: Retrospective, nonrandomized bacterial and fungal cultures were performed on 46 sinus aspirates obtained by frontal sinus trephination performed on 30 consecutive patients with chronic frontal sinusitis. RESULTS: Six patients were having sinus surgery for the first time, 19 patients had undergone prior functional endoscopic sinus surgery without instrumentation of the frontal sinus/recess, and the third group included 5 patients who had undergone prior frontal sinus/recess surgery. Preoperative computed tomography scan of the frontal sinuses revealed complete opacification in 63% (29/46 frontal sinuses) and partial opacification in 22% (10/46), and no data were available for 15% (7/46). Aerobic cultures revealed that 38% (13/35 cultures) had no growth, 21% (7/35) grew Staphylococcus aureus, 21% (7/35) grew coagulase-negative Staphylococcus, 9% (3/35) grew Haemophilus influenzae, and 26% (9/35) grew a variety of other organisms. Anaerobic cultures were positive in 3% (1/32) of sinuses, and fungal cultures were positive in 4% (1/24). Haemophilus influenzae was most common in primary cases, whereas coagulase-negative Staphylococcus was most common in patients undergoing revision frontal sinus surgery. There were no other significant differences between cultures from patients undergoing revision frontal sinus surgery, revision functional endoscopic sinus surgery without prior frontal surgery, and primary surgery. CONCLUSIONS: This study suggests that organisms involved in chronic inflammatory disease of the frontal sinus may change after previous sinus surgery. The study failed to support a significant role for anaerobes. The role for coagulase-negative Staphylococcus as a potential pathogen or a contaminating agent remains unclear.     

Bacteriology of recurrent exacerbation of postoperative course in chronic rhinosinusitis in relation to asthma

Objectives

Co-mobidity of asthma is known to result in a poor prognosis of post-endoscopic sinus surgery (post-ESS). Bacterial infection may play a key role in recurrent pathophysiology of sinusitis in post-ESS.

Methods

Forty-two patients with CRS associated with asthma undergoing ESS were enrolled. Bacterial culture was performed from the sinus cavity at the time of acute infectious episodes. Recurrence of sinonasal disease was analyzed in terms of steroid responsiveness and peak expiratory flow (PEF).

Results

Totally 75 aspirates were obtained during post-ESS; 2 repeat aspirates from 10 patients, 3 from 5 patients, and 4 from 2 patients. Only 6 specimens (8.0%) obtained from 5 patients (11.9%) showed no growth whereas 83 isolates were recovered from 69 specimens. Sixteen patients had at least one episode of a significant decline of PEF. All except one patient complained of symptoms and signs of upper respiratory infections prior to a depression of PEF. Positive culture was obtained in 10 out of 11 patients examined at the time of acute exacerbation of CRS.

Conclusion

Bacterial infection may play a critical role of recurrent polyps and refractory symptoms during post-ESS follow-up. Moreover, worsening of sinusitis accompanies asthma exacerbation.     

Bacterial infection after endoscopic sinus surgery: a controlled prospective study

OBJECTIVES/HYPOTHESIS: The objective was to determine whether infections occurring after endoscopic sinus surgery represent overgrowth of sinonasal flora versus de novo bacterial infection. STUDY DESIGN: Prospective controlled cohort study. METHODS: A cohort of adult patients was prospectively followed after endoscopic sinus surgery. Baseline postoperative control cultures of the ethmoid sinus were obtained. Patients with acute infectious exacerbations of chronic rhinosinusitis had endoscopic culture, and these results were compared with baseline culture data. RESULTS: One hundred thirteen patients were followed for a mean period of 14.5 months after endoscopic sinus surgery. Baseline postoperative culture data revealed that the ethmoid labyrinth was sterile in 23% of cases, carried oral flora in 18% of cases, and was colonized in 60% of cases. Gram-positive cocci, particularly staphylococcal species, were the most common colonizing organisms (41% of cases). Twenty acute exacerbations were cultured in 17 patients during the follow-up period. All infectious cultures recovered bacteria; one culture recovered only oral flora. Gram-positive cocci predominated (56% of isolates) with Staphylococcus aureus being the most common isolate (28%). Of the 36 isolates, only 9 isolates (25%) corresponded to bacteria identified at the time of baseline culture. CONCLUSION: Although the postoperative sinonasal cavity may be colonized by bacteria after endoscopic sinus surgery, infections arising postoperatively most commonly represent de novo infections by bacteria other than colonizing bacteria. Empirical therapy based on baseline data may be misleading; acute exacerbations of chronic rhinosinusitis after endoscopic sinus surgery should be cultured to guide optimal antibiotic therapy.     

慢性鼻窦炎病原学变迁的研究

目的:了解慢性鼻窦炎病原学分布的变迁。方法:术中收集2010年全年111例(实验组)上颌窦或筛窦脓性分泌物,分别进行需氧菌和真菌培养,同时以30例健康受试者作为对照组,其培养结果与2005年的各种数据比较,分析病原微生物的分布变化。结果:实验组共培养出15种病原微生物,主要为肺炎克雷伯菌、甲型链球菌、鲍曼不动杆菌、表皮葡萄球菌、铜绿假单胞菌、白色念珠菌等;需氧菌和真菌培养阳性率为81.8%,其中革兰阳性菌37.8%,革兰阴性菌54.4%,各种真菌7.8%;对照组检测出表皮葡萄球菌、流感嗜血杆菌、甲型链球菌、卡他布兰汉菌和金黄色葡萄球菌5种细菌,与实验组比较差异有统计学意义(χ2=0.009,P<0.01);与2005年数据(革兰阳性菌56.3%,革兰阴性菌43.7%,真菌阳性率1.4%)比较,其分布特征有明显差异。结论:细菌感染是慢性鼻窦炎的重要原因之一;细菌分布结构从原来的革兰阳性菌变成现在的以革兰阴性菌为主,真菌感染也不容忽视。应用抗生素治疗宜先进行细菌培养与药敏试验。     

Quantitative analysis of mucin and lectin in maxillary sinus fluids in patients with acute and chronic sinusitis

OBJECTIVES: Sinusitis is characterized by quantitative and qualitative changes in mucus biosynthesis that contribute to sinus disease. In general, patients with acute sinusitis complain of purulent rhinorrhea, whereas those with chronic sinusitis complain of mucoid or mucopurulent rhinorrhea Locally produced mucin largely contributes to the high viscoelasticity of mucus in sinusitis. In this study, the authors attempt to quantify the concentrations of mucin and lectin in the maxillary sinus fluids from these patients. STUDY DESIGN: To assess the concentrations of mucin and lectin in aspirates of 11 acutely and 11 chronically inflamed maxillary sinuses, the concentration of mucin was measured by enzyme-linked immunosorbent assay (ELISA) and that of lectin by sandwiched enzyme-linked lectin assay (ELLA). RESULTS: The concentrations of mucin and lectin that were measured using monoclonal antibodies (HCS 4, HCS 14, and HCS 18) and Ulex europaeus agglutinin-1 (UEA-1) in chronic sinusitis were higher than those in acute sinusitis. The concentration of total protein in chronic sinusitis was lower than that in acute sinusitis. Each mucin and lectin versus total protein ratio in chronic sinusitis was higher than that in acute sinusitis. CONCLUSIONS: These data suggest that hypersecretion in chronic sinusitis may result from locally increased mucin production. Comprehension of this mechanism may be a strategy to prevent the viscous cycle of paranasal sinus fluids in chronic sinusitis.     

The microbiology of ethmoid and maxillary sinuses in patients with chronic sinusitis

PURPOSE: To investigate aerob-anaerob microorganisms growth in maxillary and ethmoid sinuses by evaluating aspiration materials from patients with chronic sinusitis. Patients and Methods: The study was performed prospectively, and there were 31 patients (23 men, 8 women; mean age, 31.4+/-14.15, between 18-65 years) who had endoscopic sinus surgery because of chronic sinusitis. During the operation, when the maxillary sinus ostium and ethmoid sinus were opened, readily aspirated materials from sinuses were evaluated regarding aerob and anaerob bacteria. Nose and throat swap samples were collected preoperatively to determine the upper respiratory tract flora and also to understand the relationship between the flora and the microorganisms aspirated from sinuses. RESULTS: Total aerob bacteria count, which was isolated from preoperative nasal swab cultures, was 36, and aerob-anaerob bacteria count that included cultures taken from maxillary and ethmoid sinuses during the functional endoscopic sinus surgery was 42. For each 2 samples, the most common isolated aerob bacteria were coagulase (-) staphylococci. Microorganisms were isolated in 87.0% of 27 patients, in which cultures taken from maxillary and ethmoid sinuses during the functional endoscopic sinus surgery were included. It is determined that the isolated aerob bacteria rate was 90.4%, and the isolated anaerob bacteria rate was 14.2%. All of the 6 samples in which anaerob bacteria isolated were all maxillary sinus aspiration materials. Microorganisms that isolated from the nose and the sinuses were similar with the rate of 25.8%, and microorganisms that isolated from the throat cultures and sinuses were similar with the rate of 22.5%. CONCLUSIONS: This study reveals the aerob and anaerob microbiology of the maxillary and ethmoid sinuses so the treatment of chronic sinusitis will be easier.