Microbiology of acute purulent pericarditis. A 12-year experience in a military hospital.

OBJECTIVE: To study the aerobic and anaerobic micro-biological and clinical characteristics in 15 cases of acute pericarditis treated over a 12-year period. DESIGN: Retrospective review of microbiological and clinical data. SETTING: Military hospital in Bethesda, Md. RESULTS: Aerobic or facultative bacteria alone were present in 7 specimens (47%), anaerobic bacteria alone in 6 specimens (40%), and mixed aerobic-anaerobic flora in 2 specimens (13%). In total, there were 21 isolates: 10 aerobic or facultative bacteria and 11 anaerobic bacteria, an average of 1.4 per specimen. Anaerobic bacteria predominated in patients with pericarditis who also had mediastinitis that followed esophageal perforation and in patients whose pericarditis was associated with orofacial and dental infections. The predominant aerobic bacteria were Staphylococcus aureus (3 isolates) and Klebsiella pneumoniae (2 isolates), and the predominant anaerobic bacteria were Prevotella species (4 isolates), Peptostreptococcus species (3 isolates), and Propionibacterium acnes (2 isolates). CONCLUSION: The findings in our study highlight the potential importance of anaerobic bacteria in acute pericarditis.

Microbiology of mediastinitis.

OBJECTIVE: To study the microbiologic and clinical characteristics of patients with mediastinitis. METHODS: Retrospective review of clinical and laboratory data of 17 patients treated between 1980 and 1987. RESULTS: Aerobic or facultative bacteria only were present in three patients (18%), anaerobic bacteria only in seven (41%), and mixed aerobic-anaerobic flora in seven (41%). In total, there were 42 isolates, 13 aerobic or facultative and 29 anaerobic bacteria, an average of 2.5 per specimen. Anaerobic bacteria predominated in infections that originated from esophageal perforation and orofacial, odontogenic, and gunshot sources. The predominant aerobes were alpha-hemolytic Streptococcus (three isolates), Staphylococcus aureus (two isolates), and Klebsiella pneumoniae (two isolates). The predominant anaerobes were Prevotella and Porphyromonas species (eight isolates), Peptostreptococcus species (seven isolates), and Bacteroides fragilis group (three isolates). CONCLUSION: These data highlight the polymicrobial aerobic-anaerobic nature of mediastinitis.

Anaerobic osteomyelitis and arthritis in a military hospital: a 10-year experience.

PURPOSE: The methods of collecting, transporting, cultivating, and identifying aerobic bacteria in bone and joint infections have improved markedly since the early 1980s. In addition, many of the anaerobes have been reclassified and renamed. The purpose of this study was to provide more current information regarding the incidence of recovery of anaerobic bacteria from clinical specimens of infected bone and joint. MATERIALS AND METHODS: Specimens from 73 infected bone specimens and 65 infected joints inoculated on media supportive for aerobic and anaerobic bacteria showed bacterial growth. RESULTS: One hundred fifty-seven organisms (2.2 isolates/specimen), consisting of 122 anaerobic bacteria (1.7 isolates/specimen) and 35 facultative or aerobic bacteria (0.5 isolate/specimen), were recovered from the 73 bone specimens. Anaerobic bacteria were recovered with aerobe or facultative bacteria in 24 (33%) instances. The predominant anaerobes were Bacteroides species (49 isolates), anaerobic cocci (45), Fusobacterium species (11), Propionibacterium acnes (7), and Clostridium species (6). Conditions predisposing to bone infections were vascular disease, bites, contiguous infection, peripheral neuropathy, hematogenous spread, and trauma. Pigmented Prevotella and Porphyromonas species were mostly isolated in skull and bite infections (7 of 19), members of the Bacteroides fragilis group in hand and feet infection (12 of 16), and Fusobacterium species in skull, bite, and hematogenous long bone infections. Seventy-four organisms (1.1 isolates/specimen), consisting of 67 anaerobic bacteria (1.0 isolate/specimen) and 7 facultative or aerobic bacteria (0.1 isolate/specimen), were isolated from 65 joint specimens. The predominant anaerobes were P. acnes (24 isolates), anaerobic cocci (17), Bacteroides species (10), and Clostridium species (5). Predisposing conditions to joint infection were trauma, prior surgery, presence of a prosthetic joint, and contiguous infection. P. acnes isolates were associated with prosthetic joints, members of the B. fragilis group with hematogenous spread, and Clostridium species with trauma. The clinical presentation of these cases is discussed. CONCLUSION: These data highlight the importance of anaerobic bacteria in bone and joint infection.

Aerobic and anaerobic microbiology of empyema. A retrospective review in two military hospitals.

The microbiology and clinical features of empyema were studied retrospectively in 197 patients whose specimens yielded bacterial growth after inoculation for aerobic and anaerobic bacteria. Three hundred forty-three organisms (216 aerobic or facultative and 127 anaerobic organisms) were isolated. Aerobic bacteria were isolated in 127 (64 percent) patients, anaerobic bacteria in 25 (13 percent), and mixed aerobic and anaerobic bacteria in 45 (23 percent). The predominant aerobic or facultative organisms were Streptococcus pneumoniae (70 isolates), Staphylococcus aureus (58), Escherichia coli (17), Klebsiella pneumoniae (16), and Haemophilus influenzae (12). The predominant anaerobes were pigmented Prevotella and Porphyromonas species (24), Bacteroides fragilis group (22), anaerobic cocci (36), and Fusobacterium species (20). beta-Lactamase-producing organisms were recovered in 49 (38 percent) of 128 tested specimens. These included all 42 tested S aureus and 15 B fragilis group, 4 of 9 K pneumoniae, 3 of 9 H influenzae, 3 of 8 pigmented Prevotella and Porphyromonas species, and 2 of 6 E coli. Most patients from whom S pneumoniae and H influenzae were recovered had pneumonia, and most patients with S aureus had pneumonia, aspiration pneumonia, and lung abscesses. The recovery of anaerobic bacteria was mostly associated with the concomitant diagnosis of aspiration pneumonia, and lung, subdiaphragmatic, dental, and oropharyngeal abscesses. These data highlight the importance of anaerobic bacteria in selected cases of empyema.

Aerobic and anaerobic bacteriology of wounds and cutaneous abscesses.

The aerobic and anaerobic microbiologic characteristics of 584 wounds and 676 skin or soft-tissue abscesses were studied and correlated with the infection site. In wounds, aerobic or facultative bacteria only were present in 223 specimens (38%), anaerobes only in 177 specimens (30%), and mixed flora in 184 specimens (32%). In total there were 1470 isolates, 558 aerobic and 912 anaerobic, an average of 2.5 isolates per wound (1.6 anaerobic and 0.9 aerobic isolates). In abscesses, aerobic or facultative bacteria were recovered in 177 specimens (26%), anaerobes only in 243 specimens (36%), and mixed flora in 256 specimens (38%). In total there were 1702 isolates, 602 aerobic and 1100 anaerobic, an average of 2.5 isolates per abscess. The highest rates of anaerobes in wounds were in the inguinal, buttocks, and trunk areas and in abscesses in the perirectal, external genitalia, neck, and inguinal areas. The predominant aerobic organisms were Staphylococcus aureus (363 isolates), group A streptococci (98 isolates), and Escherichia coli (97 isolates). The predominant anaerobic organisms were Bacteroides species (986 isolates), Peptostreptococcus species (559 isolates), Clostridium species (153 isolates), and Fusobacterium species (109 isolates). The predominance of certain isolates in certain anatomical sites was correlated with their distribution in the normal flora adjacent to the infected site. These data highlight the polymicrobial nature of wounds and cutaneous abscesses.

Clinical features and aerobic and anaerobic microbiological characteristics of cellulitis.

OBJECTIVES: To investigate the aerobic and anaerobic microbiological characteristics of cellulitis and correlate them with the infection site. DESIGN: Of 342 specimens, 64 obtained using needle aspiration and 278 using swabs were studied over 10 years. RESULTS: Bacterial growth was noted in 15 (23%) of the 64 needle aspirates and 259 (93%) of the 278 swab aspirates. The microbial results of the 15 specimens obtained through needle aspiration are separately presented. Aerobic or facultative bacteria only were present in 138 (53%) of swab samples, anaerobic bacteria only in 69 (27%), and mixed aerobic-anaerobic flora in 52 (20%). In total, there were 582 isolates, 247 aerobic or facultative and 335 anaerobic bacteria, with an average of 2.2 isolates per specimen. The predominance of certain isolates in different anatomical sites correlated with their distribution in the normal flora adjacent to the infected site. The highest recovery rates of anaerobes was from the neck, trunk, groin, external genitalia, and leg areas. Aerobes outnumbered anaerobes in the arm and hand. The predominant aerobes were Staphylococcus aureus, group A streptococci, and Escherichia coli. The predominant anaerobes were Peptostreptococcus sp, Bacteroides fragilis group, Prevotella and Porphyromonas sp, and Clostridium sp. Certain clinical findings correlated with the following organisms: swelling and tenderness with Clostridium sp, Prevotella sp, S aureus, and group A streptococci; regional adenopathy with B fragilis group; bulbous lesions with Enterobacteriaceae; gangrene and necrosis with Peptostreptococcus sp, B fragilis group, Clostridium sp, and Enterobacteriaceae; foul odor with Bacteroides sp; and gas in tissues with Peptostreptococcus sp, B fragilis group and Clostridium sp. Certain predisposing conditions correlated with the following organisms: trauma with Clostridium sp; diabetes with Bacteroides sp, Enterobacteriaceae, and S aureus; and burn with Pseudomonas aeruginosa. CONCLUSION: These data highlight the polymicrobial nature of cellulitis.

Aerobic and anaerobic microbiology of superficial suppurative thrombophlebitis.

OBJECTIVE: To study the aerobic and anaerobic microbiologic characteristics of superficial suppurative thrombophlebitis. DESIGN: Retrospective review of microbiologic and clinical data. SETTING: Navy Hospital in Bethesda, Md. RESULTS: Sixty-one isolates, 36 aerobic and 25 anaerobic, were isolated from samples obtained from 42 patients. Aerobic bacteria only were found in 26 (62%) patients; anaerobic only, in 11 (26%); and mixed aerobic and anaerobic bacteria, in five (12%). The predominant aerobic bacteria were Staphylococcus aureus (n = 9), Escherichia coli (n = 7), Pseudomonas aeruginosa (n = 4), and Klebsiella sp (n = 3). The most frequently recovered anaerobic bacteria were Peptostreptococcus sp (n = 8), Propionibacterium acnes (n = 6), Bacteroides fragilis group (n = 5), Prevotella intermedia (n = 3), and Fusobacterium nucleatum (n = 3). Propionibacterium acnes and Peptostreptococcus sp were associated with cannula-related superficial suppurative thrombophlebitis; B fragilis and Enterobacteriaceae, with abdominal surgery or pathology; and S aureus and P aeruginosa and Citrobacter sp, with burns. CONCLUSION: These data illustrate the importance of anaerobic bacteria in superficial suppurative thrombophlebitis.

Microbiology of liver and spleen abscesses.

To study the aerobic and anaerobic microbiology of liver and spleen abscesses and correlate the results with predisposing factors, potential causes and routes of infection, clinical and laboratory data of 48 patients with liver abscesses and 29 with spleen abscesses treated between 1970 and 1990 were reviewed retrospectively. In liver abscesses, a total of 116 isolates (2.4 isolates/specimen) was obtained; 43 were aerobic and facultative species (0.9 isolates/specimen) and 73 were anaerobic species or microaerophilic streptococci (1.5 isolates/specimen). Aerobic bacteria only were isolated from 12 (25%) abscesses, anaerobic bacteria only from eight (17%), and mixed aerobic and anaerobic bacteria from 28 (58%); polymicrobial infection was present in 38 (79%). The predominant aerobic and facultative isolates were Escherichia coli (11 isolates), Streptococcus group D (8), Klebsiella pneumoniae (5) and Staphylococcus aureus (4). The predominant anaerobes were Peptostreptococcus spp. (18 isolates), Bacteroides spp. (13), Fusobacterium spp. (10), Clostridium spp. (10) and Prevotella spp. (4). There were 12 isolates of micro-aerophilic streptococci. S. aureus and beta-haemolytic streptococci were associated with trauma; Streptococcus group D, K. pneumoniae and Clostridium spp. with biliary disease; and Bacteroides spp. and Clostridium spp. with colonic disease. In splenic abscesses, a total of 56 isolates (1.9 isolates/specimen) was obtained; 23 were aerobic and facultative species (0.8 isolates/specimen), 31 were anaerobic species or micro-aerophilic streptococci (1.1 isolates/specimen) and two were Candida albicans. Aerobic bacteria only were isolated from nine (31%) abscesses, anaerobic bacteria from eight (28%), mixed aerobic and anaerobic bacteria from 10 (34%) and C. albicans in two (7%); polymicrobial infection was present in 16 (55%). The predominant aerobic and facultative isolates were E. coli (5 isolates), Proteus mirabilis (3), Streptococcus group D (3), K. pneumoniae (3) and S. aureus (4). The predominant anaerobes were Peptostreptococcus spp. (11 isolates), Bacteroides spp. (5), Fusobacterium spp. (3) and Clostridium spp. (3). S. aureus, K. pneumoniae and Streptococcus group D were associated with endocarditis, E. coli with urinary tract and abdominal infection, Bacteroides spp. and Clostridium spp. with abdominal infection and Fusobacterium spp. with respiratory infection.

Microbiology of chronic maxillary sinusitis: comparison between specimens obtained by sinus endoscopy and by surgical drainage.

The aerobic and anaerobic microbiology of sinus aspirates obtained during surgery was compared with culture of samples obtained by endoscopy. Six patients with chronic maxillary sinusitis were evaluated. Polymicrobial flora was found in all specimens (two-to-five isolates/sample). A total of 24 isolates (18 anaerobic, five aerobic and one micro-aerophilic) was obtained from sinus aspirates, and 25 isolates (16 anaerobic and nine aerobic) were found in endoscopic specimens. The predominant organisms were Prevotella spp., Fusobacterium nucleatum, Peptostreptococcus spp. and Staphylococcus spp. Concordance in the type and concentration of organisms was found in all cases. Sixteen of the 18 anaerobes isolated from sinus aspirates were also found in the concomitant endoscopic sample. Five aerobic isolates were found in both sinus aspirates and endoscopic samples and their concentration was similar. However, four aerobic gram-positive bacteria (<10(4) cfu/sample) were found only in endoscopy samples. This pilot study demonstrates the usefulness of endoscopic aspiration in the isolation of bacteria from chronically infected maxillary sinuses.

Microbiology of the transition from acute to chronic maxillary sinusitis.

Repeated aspirations of sinus secretions by endoscopy was performed in five patients over a period of 34-50 days and, ultimately, surgical drainage was done in three who presented with acute maxillary sinusitis that did not respond to antimicrobial therapy and became chronic. The aspirates were cultured for aerobic and anaerobic bacteria. Most of the bacteria isolated from the first culture were aerobic or facultative bacteria: Streptococcus pneumoniae (three isolates), Haemophilus influenzae non-type-b (two) and Moraxella catarrhalis (one). Three of these cultures yielded bacteria that were resistant to the antimicrobial agents prescribed for treatment. Failure to respond to therapy was associated with the emergence of resistant aerobic and anaerobic bacteria in subsequent aspirates. These organisms included Fusobacterium nucleatum, pigmented Prevotella and Porphyromonas spp. and Peptostreptococcus spp. Eradication of the infection was achieved in all instances following the administration of antimicrobial agents effective against these bacteria, and in three instances by surgical drainage. This study illustrates the microbial dynamics of maxillary sinusitis that did not respond to antimicrobial therapy.

Aerobic and anaerobic microbiology of dacryocystitis.

PURPOSE: To investigate the aerobic and anaerobic microbiology of dacryocystitis. METHOD: Retrospective review of the 62 clinical and microbiologic records collected between 1980 and 1990. RESULTS: Aerobic or facultative bacteria were recovered in 32 cases (52%), anaerobic bacteria only in 20 cases (32%), mixed aerobic and anaerobic bacteria in seven cases (11%), and fungi in three cases (5%). A total of 94 organisms (1.5 per specimen), which included 56 aerobic or facultative anaerobic organisms, 35 anaerobic organisms, and three fungi, were recovered. The predominant aerobic and facultative bacteria were Staphylococcus aureus (15 isolates), Staphylococcus epidermidis (13 isolates), and Pseudomonas species (seven isolates). The most frequently recovered anaerobes were Peptostreptococcus species (13 isolates), Propionibacterium species (12 isolates), Prevotella species (four isolates), and Fusobacterium species (three isolates). The predominant fungus was Candida albicans (two isolates). Polymicrobial infection was present in 28 cases (45%). CONCLUSION: These data highlight the potential importance of anaerobic bacteria in dacryocystitis.

Bacteriology and beta-lactamase activity in acute exacerbation of chronic bronchitis.

OBJECTIVES: To assess the bacteriology of beta-lactamase (BL) enzyme activity in sputum of 40 patients with acute exacerbation of chronic bronchitis (AECB). METHODS: The microbiology, BL production by the different isolates, and BL contents in the sputum were determined. RESULTS: Eighty-four isolates were recovered (2.1 isolates per specimen), 44 aerobic and facultative (1.1 isolates per specimen), and 40 anaerobic (1.0 isolate per specimen). Aerobic bacteria were recovered in only 9 (22.5%) specimens, anaerobic bacteria in 9 (22.5%), and mixed aerobic and anaerobic bacteria were found in 22 (55%). The predominant aerobic isolates were Streptococcus pneumoniae (15 isolates), Haemophilus influenzae (11), Moraxella catarrhalis and Klebsiella pneumoniae (4 each). The predominant anaerobes were Peptostreptococcus sp. (19), Prevotella sp. (11), and Fusobacterium sp.(6). Mixed flora were present in 25 (62.5%) specimens, and the number of isolates varied from 2 to 5 per specimen. Thirty-nine beta-lactamase-producing bacteria (BLPB) were isolated in 33 (82.5%) of the 40 cases. The predominant aerobic BLPB were H. influenzae, M. catarrhalis, K. pneumoniae, Staphylococcus aureus, and Escherichia coli. The predominant anaerobic BLPB were Prevotella sp. and Fusobacterium sp. Beta-lactamase activity was detected in 26 (79%) of 33 of specimens in which BLPB were isolated, and in none of the seven specimens that did not harbor BLPB. CONCLUSIONS: The rapid detection of BL activity in sputum specimens may have implications for the antimicrobial management with AECB.

The microbiology of mucopyocele.

OBJECTIVE: To evaluate the aerobic and anaerobic microbiology of mucopyocele. STUDY DESIGN: Retrospective review of clinical and microbiologic records of patients with mucopyocele between June 1982 and September 1997. METHODS: Aspirates of 36 mucopyocele were processed for aerobic and anaerobic bacteria. RESULTS: One hundred six bacterial isolates, 42 aerobic and facultatives and 64 anaerobic, were recovered. The predominant aerobic isolates were Staphylococcus aureus (6 isolates), alpha-hemolytic streptococci (6), Hemophilus spp. (5), and Gram-negative bacilli (6). The predominant anaerobes were Peptostreptococcus sp. (22), Prevotella sp. (15), Fusobacterium sp. (5), and Propionibacterium acnes(5). Thirty-three beta-lactamase-producing bacteria were isolated from 23 patients. CONCLUSIONS: These findings illustrate the polymicrobial aerobic and anaerobic bacteriology of mucopyocele.

Microbiology of subperiosteal orbital abscess and associated maxillary sinusitis.

Aspirate of pus from eight subperiosteal orbital abscesses (SPOAs) and their corresponding infected sinuses were studied for aerobic and anaerobic bacteria. Polymicrobial flora was found in all instances, and the number of isolates varied from two to five. Anaerobes were recovered from all specimens. The predominant isolates were Peptostreptococcus spp, Prevotella spp, Fusobacterium spp, Staphylococcus aureus, and microaerophilic streptococci. Concordance in the microbiological findings between SPOA and the infected sinus was found in all instances. However, certain organisms were only present at one site and not the other. Fourteen beta-lactamase-producing organisms were present in nine specimens. These data confirm the importance of anaerobic bacteria in sinusitis and demonstrate their predominance in the associated SPOA.

Aerobic and anaerobic microbiology of acute suppurative parotitis.

Aspirates of pus from acute suppurative parotitis were studied for aerobic and anaerobic bacteria. Bacterial growth was present in 23 specimens. A total of 36 bacterial isolates (20 anaerobic and 16 aerobic and facultative) were recovered, accounting for 1.6 isolates per specimen (0.9 anaerobic and 0.7 aerobic and facultative). Anaerobic bacteria only were present in 10 (43%) patients, aerobic and facultatives in 10 (43%), and mixed aerobic and anaerobic flora in 3 (13%). Single bacterial isolates were recovered in 9 infections, 6 of which were Staphylococcus aureus and 3 were anaerobic bacteria. The predominant bacterial isolates were S. aureus (8 isolates), Bacteroides sp. (6 isolates, including 4 Bacteroides melaninogenicus group), and Peptostreptococcus sp. (5). beta-Lactamase-producing organisms were recovered from 11 (73%) of the 15 specimens tested. This study highlights the polymicrobial nature and importance of anaerobic bacteria in acute suppurative parotitis.

Aerobic and anaerobic microbiology of peritonsillar abscess.

Thirty-four aspirates of pus from peritonsillar abscesses that were studied for aerobic and anaerobic bacteria showed bacterial growth. A total 107 bacterial isolates (58 anaerobic and 49 aerobic and facultative) were recovered, accounting for 3.1 isolates per specimen (1.7 anaerobic and 1.4 aerobic and facultatives). Anaerobic bacteria only were present in 6 (18%) patients, aerobic and facultatives in 2 (6%), and mixed aerobic and anaerobic flora in 26 (76%). Single bacterial isolates were recovered in 4 infections, 2 of which were Streptococcus pyogenes and 2 were anaerobic bacteria. The predominant bacterial isolates were Staphylococcus aureus (6 isolates), Bacteroides sp (21 isolates, including 15 Bacteroides melaninogenicus group), and Peptostreptococcus sp (16) and S. pyogenes (10). beta-Lactamase-producing organisms were recovered from 13 (52%) of 25 specimens tested. This retrospective study highlights the polymicrobial nature and importance of anaerobic bacteria in peritonsillar abscess.

Microbiology and management of chronic maxillary sinusitis.

OBJECTIVE: Assessment of the microbiology and management of patients who suffered from chronic maxillary sinusitis was studied retrospectively. DESIGN: Retrospective analysis of microbiology and antimicrobial therapy of 68 patients who underwent the Caldwell-Luc procedure for chronic sinusitis had not received antimicrobials before surgery and whose cultures showed bacterial growth. SETTING: This study was performed at the Naval Hospital in Bethesda, Md. INTERVENTION: Amoxicillin-clavulanic acid was given to 18 patients, amoxicillin or ampicillin to 25, cefaclor to 17, and erythromycin to eight. RESULTS: A total of 183 isolates (123 anaerobic and 60 aerobic) were recovered. Anaerobic organisms only were recovered from 35 (51%), specimens, and aerobic or facultative bacteria only in 12 (18%), and mixed aerobic and anaerobic flora in 21 (31%). Thirty-four aerobic and anaerobic beta-lactamase-producing bacteria were isolated from 28 patients. The 18 patients who received amoxicillin-clavulanic acid had the most rapid and complete response to therapy, none required a change in therapy, and surgical drainage was required in one case. Of 25 patients who received amoxicillin or ampicillin, eight required a change of therapy due to clinical failure (32%), including three who also had surgical drainage. Of 17 that received cefaclor, five had an antibiotic change (29%), one with surgical drainage. Of the eight who were treated with erythromycin, three needed antibiotic change (38%), two with surgical drainage. Resistant organisms were recovered from most of the patients that required therapeutic change. CONCLUSIONS: These findings indicate the major role of aerobic and anaerobic beta-lactamase-producing bacteria organisms in the polymicrobial etiology of chronic maxillary sinusitis and illustrate the superiority of therapy effective against these bacteria.

Bacteriology and beta-lactamase activity in acute and chronic maxillary sinusitis.

OBJECTIVE: To assess the bacteriology and beta-lactamase enzyme activity in aspirates of 10 acutely and 13 chronically inflamed maxillary sinuses. RESULTS: The predominant organisms isolated in acute sinusitis were Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis, and those found in chronic sinusitis were Prevotella species, Fusobacterium species, and Peptostreptococcus species. Four beta-lactamase-producing organisms (BLPOs) were isolated in four specimens (40%) obtained from acutely inflamed sinuses, and 14 BLPOs were recovered from 10 chronically inflamed sinuses (77%). The predominant BLPOs in acute sinusitis were H influenzae, and M catarrhalis; those in chronic sinusitis were Staphylococcus aureus, Prevotella species, Fusobacterium species, and Bacteroides fragilis. CONCLUSIONS: Beta-lactamase activity was detected in 12 (three in acute and nine in chronic sinusitis) of the 14 aspirates that contained BLPOs. The detection of beta-lactamase activity in sinus aspirates provides support for the role of BLPOs in the failure of penicillin therapy in sinusitis.

Microbiology of periapical abscesses and associated maxillary sinusitis.

Aspirate of pus from 5 periapical abscesses of the upper jaw and their corresponding maxillary sinusitis were studied for aerobic and anaerobic bacteria. Polymicrobial flora were found in all instances, where the number of isolates varied from 2 to 5. Anaerobes were recovered from all specimens. The predominant isolates were Prevotella sp., Porphyromonas sp., Fusobacterium nucleatum, and Peptostreptococcus sp. Concordance in the microbiological findings between periapical abscess and the maxillary sinus flora was found in all instances. However, certain organisms were only present at one site and not the other. Five beta-lactamase-producing organisms were present in the five specimens. These data confirm the importance of anaerobic bacteria in periapical abscesses and demonstrate their predominance in maxillary sinusitis that is associated with them.

Microbiology of subphrenic abscesses: a 14-year experience.

The objective of the review was to study the aerobic and anaerobic microbiology of subphrenic abscesses in relation with predisposing conditions. A retrospective review of clinical and laboratory data of 52 patients treated between 1974 and 1988 was conducted. Forty-three (83%) patients developed the abscesses after an operative procedure. These included 11 patients after colonic, 9 patients after gastric or duodenal, 7 patients after abdominal trauma, 7 patients after biliary, and 6 patients after appendix surgery. A total of 194 organisms (3.7 isolates/specimen), 83 aerobic (1.6/specimen), and 111 anaerobes (2.1/specimen) were recovered. Aerobic bacteria only were recovered in 7 (13%) abscesses, anaerobic bacteria only in 11 (21%), and mixed aerobic and anaerobic bacteria in 34 (65%). Polymicrobial infection was present in 47 (90%). The predominant aerobic isolates were Escherichia coli (28 isolates), Enterococcus group D(9), and Staphylococcus aureus (9). The predominant anaerobes were Peptostreptococcus species (33 isolates), Bacteroides fragilis group (25), Clostridium species (13), and Prevotella species (6). The number of isolates/site varied. The number of anaerobic bacteria/site outnumbered or was equal to the number of aerobic or facultatives in all instances, except in abscesses after biliary surgery. Their number/site was especially high in abscesses after appendectomy, and the number of aerobic and anaerobic bacteria was the lowest after gastric or duodenal surgery. S. aureus predominated after gastric, duodenal and posttrauma surgery; B. fragilis predominated after colonic, appendix, and postabdominal trauma surgery; Enterococcus group D predominated after biliary surgery; Fusobacterium and Prevotella species predominated after gastric or duodenal surgery; and Clostridium species predominated after colonic or appendix surgery. These data highlight the polymicrobial aerobic-anaerobic nature of subphrenic abscesses and their correlation with predisposing surgery.