Microbiology of Subperiosteal Orbital Abscess and Associated Maxillary Sinusitis Itzhak Brook, MD, MSc; Edith H. Frazier, MSc

Aspirate of pus from eight subperiosteal orbital abscesses (SPOAs) and their corresponding infected sinuses were studied for aerobic and anaerobic bacte- ria. 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. Concor- dance 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 P-lactamase-produc- ing organisms were present in nine specimens. These data confirm the importance of anaerobic bacteria in sinusitis and demonstrate their predominance in the associated SPOA.

LARYNGOSCOPE, 106101&1013,1996

INTRODUCTION Subperiosteal orbital abscess (SPOA) is a known

complication of paranasal sinusitis.l.2 The develop- ment of SPOA may lead to rapid elevation of orbital pressure that can cause visual impairment and fur- ther intracranial extension of the infection.3 The se- questration of the infection within the abscess, where antibiotic penetration is poor, can lead to perpetuation of the infection.

Because of the serious potential complications, the management of SPOA is an important medical and surgical emergency. Recognition of the potential pathogens can assist in the proper management of the infection.

Studies that separately investigated the microbi- ology of SPOA4-6 and sinusitis7 found the microbiolo- gy to be most of the time monomicrobial, and occasion- ally polymicrobial due to aerobic and anaerobic

From the Departments of Pediatrics and Infectious Diseases, Naval Medical Center, Bethesda, Md.

The opinions and assertions contained herein are the private ones of the writers and are not to be construed as official or reflecting the views ofthe United States Navy or the Naval Service a t large.

Editor’s Note: This Manuscript was accepted for publication April 9, 1996.

Send Reprint Requests to Itzhak Brook, MD, MSc, POB 70412, Chevy Chase, MD 20813-0412.

bacteria of oral flora origin. Some studies did not speci- fy whether the origin of the organism(s1 was the sinus or SPOA.8-10 However, the role of anaerobic bacteria in SPOA was not well studied in most past reports, as methods for their recovery were inadequate or were not consistently utilized.4,5,7-10 The unique microbiol- ogy of sinusitis associated with SPOA and the correla- tion between the organisms at both sites has not been studied before and was not reported separately before. The retrospective report describes the microbiology of eight SPOA and their corresponding sinusitis.

MATERIALS AND METHODS From June 1978 to June 1990, eight aspirates of SPOA

and their corresponding maxillary sinusitis were processed for aerobic and anaerobic bacteria by the Clinical Microbiol- ogy Laboratory at the Naval Medical Center in Bethesda, Maryland. Bacterial growth was present in all instances. Patients’ ages ranged from 19 to 52 years, and five were men and three were women (Table I). Antimicrobials were given to three patients prior to drainage, amoxicillin to patients 2 and 6, and erythromycin to patient 7.

Cultures of SPOA and sinuses were obtained using aseptically performed puncture and aspiration prior to sur- gical incision and drainage. The material was placed into a syringe that was immediately sealed and transported to the laboratory within 30 minutes, or it was collected on a swab that was dipped into the pus and introduced into anaerobic transport system (Port-A-Cul, BBL Microbiology Systems, Cockeysville, Md.), that was generally transported to the laboratory within 2 hours.

For anaerobic bacteria, the material was plated onto prereduced vitamin K,-enriched Brucella blood agar, an anaerobic blood agar plate containing colistin and nalidixic acid, and an enriched thioglycolate broth (containing hemin and vitamin Kl),ll inoculated in GasPak jars (BBL Microbi- ology Systems), and examined at 48 and 96 hours. Plates that showed growth were held until the organisms were processed and identified. All cultures that showed no growth were held for at least 7 days. Anaerobes were identified us- ing the Minitek system (BBL Microbiology Systems). In ad- dition to these tests, other carbohydrate tests (Scott Labora- tories, Fiskeville, R.I.) and gas liquid chromatography11 were performed as needed to identify the organisms.

For aerobic bacteria, sheep blood (5%), chocolate, and MacConkey’s agar plates were inoculated at 37°C aerobically (MacConkey) and under 5% CO, (blood and chocolate), and

Laryngoscope 106: August 1996

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examined at 24 and 48 hours. Aerobic bacteria were identified using conventional meth- ods.12 p-lactamase ac- tivity was determined on isolates recovered from samples using the chromogenic cephalo- sporin analog 871312 methodology.13

RESULTS Polymicrobial

flora was found in all instances, and the number of isolates varied from 2 to 5. Anaerobic bacteria were isolated from all SPOA and sinuses (Table I). They were the sole bacterial iso- lates in two SPOA (patients 2, 5 ) and one sinus (patient 2). A total of 27 isolates (3.4 isolates per spec- imen; 17 strict ana- erobic, 8 aerobic or facultative, and 2 mi- croaerophilic) were recovered from the si- nuses, and 28 isolates (3.5 isolates per site; 20 strict anaerobic, 6 aerobic or facultative, and 2 microaerophil- ic) were found in the SPOA. The predomi- nant anaerobic iso- lates were Pepto- streptococcus spp (in six corresponding ab- scesses and sinus as- pirates, and one each in a sinus and a SPOA), Fusobacteri- urn spp (in three cor- responding abscesses and sinus aspirates, and two isolates in a SPOA), Preuotella spp (in two corre- sponding abscesses and sinus aspirates, four in abscesses only and 2 in sinuses on- ly), Staphylococcus aureus (in two corre

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101 1 Laryngoscope 106: August 1996

sponding abscesses and sinus aspirates, and one in ab- scess), and Streptococcus milleri (in one corresponding abscess and sinus aspirate, and one abscess).

Concordance in the microbiological findings be- tween the subperiosteal abscess and the maxillary si- nus flora was found in all instances. However, certain organisms were only present at one site-and not at the other sites.

Fourteen p-lactamase-producing organisms were present in 5 SPOA and 4 sinuses. These were S aureus (5 isolates), Fusobacterium nucleatum (51, Prevotella sp (31, andHaemophilus influenzae (1).

All patients were treated surgically and by an- timicrobials initially intravenously and subsequently orally for a total of 20 to 36 days (Table I). The antimi- crobials were clindamycin (in 3 instances), oxacillin sodium (31, amoxicillin-clavulanate potassium (3), a cephalosporin (21, penicillin (21, ticarcillin-clavulanate (21, vancomycin hydrochloride (11, metronidazole (11, and chloramphenicol(1). After surgical and med- ical therapy, all were cured from the sinusitis and its complications.

DISCUSSION This study confirms the importance of anaerobic

bacteria in SPOA and their predominance in the asso- ciated sinusitis.14J5 Anaerobic bacteria were previ- ously recovered from chronically infected sinuses. 1 4 ~ 5

Although several aerobic bacteria such as Streptococ- cus sp and H influenme were isolated in several in- stances, the recovery of mainly anaerobic bacteria from all of our patients suggest the chronic nature of their infection. The concordance in recovery of organ- isms in paired infections suggests the sinus origin of the infection, with subsequent extension into the sub- periosteal space. The anaerobic organisms recovered from the infected sinuses and associated SPOA are part of oral flora,l6 which is the most probable original source of the bacteria.

Similarly to Harris6 and Williams,g we also recov- ered microaerophilic streptococci and S aureus from SPOA and sinuses. However, we isolated a higher number of anaerobic isolates per infected site than most previous reports.7.9Jo This may be due to the strict and specific methods utilized in our study for the transportation and cultivation of specimens for anaer- obic bacteria.

Although surgical drainage is of primary impor- tance, administration of antimicrobial therapy is an essential part of the management of patients with si- nusitis and SPOA and other related complications.

A growing number of anaerobic gram-negative bacilli (i.e., pigmented Prevotella sp and Fusobacteri- um sp) have acquired resistance to penicillin through the production of the enzyme p-lactamase.17 This has also been observed in this report, where 9 of the 16

SPOA and sinus specimens contained such organisms. Penicillin was considered the drug of choice for the therapy of such infections because of the susceptibility of most oral pathogens; however, the growing resis- tance of these strains limits the use ofthis drug.18

The isolation of penicillin-resistant organisms in patients with SPOA and the associated sinusitis may require the administration of antimicrobial agents al- so effective against these organisms. Antimicrobial agents that generally provide coverage for methicillin- susceptible S aureus as well as aerobic and anaerobic bacteria include cefoxitin, clindamycin, imipenem, and cilastatin, and the combinations of a penicillin (i.e., ticarcillin) and a p-lactamase inhibitor (i.e., clavulanate). Metronidazole should be administered combined with an agent effective against aerobic or facultative streptococci and S aureus. A glycopep- tide (i.e., vancomycin) should be administered in cases where methicillin-resistant S aureus is present or suspected.

The recovery of multiple aerobic and anaerobic or- ganisms from SPOA even after at least 3 days of ap- propriate antimicrobial therapy3 suggests the need to use adequate doses of antimicrobials with good tissue penetration, for extended periods, combined when needed with surgical drainage. The isolation of polymicrobial aerobic-anaerobic flora in all of our pa- tients suggests an important role for these organisms in sinusitis and the associated SPOA. However, fur- ther prospective studies that will include larger num- bers of patients to evaluate the prevalence of these or- ganisms in SPOA are warranted.

ACKNOWLEDGMENTS The authors acknowledge the efforts of the staffs

of Clinical Microbiology Laboratory and the clinical wards at the Naval Medical Center, and the secretari- al assistance of Sarah Blaisdell.

BIBLIOGRAPHY

1. Smith AT, Spencer JT. Orbital complications resulting from lesions of the sinuses. Ann Otol Rhino1 Laryngol. 1948;57:

2. Chandler JR, Langenbrunner DJ, Stevens ER. The pathogene- sis of orbital complications in acute sinusitis. LARYNGO- SCOPE. 1970;80:1414-1428.

3. Harris GJ. Subperiosteal inflammation of the orbit. A bacterio- logical analysis of 17 cases. Arch Ophthalmol. 1988;106:

4. Garcia CE, Cunningham MJ, Clary RA, et al. The etiologic role of frontal sinusitis in pediatric orbital abscesses. Am J Oto- laryngol. 1993;14:449-452.

5. Skedros DG, Haddad J Jr, Bluestone CD, et al. Subperiosteal orbital abscess in children: diagnosis, microbiology, and management. ~ Y N G O S C O P E . 1993;103:28-32.

6. Harris GJ. Subperiosteal abscess of the orbit. Age as a factor in the bacteriology and response to treatment. Ophthalmology.

7. Skau NK, Nielsen KO, Osgaard 0, et al. Intracranial and or- bital complications of frontal and ethmoidal sinusitis. Acta

5-27.

947-952.

1994;101:585-595.

OtoEa~ngOl S ~ p p l (Stockh). 1984;(~~ppl412):91-94.

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8. Spires JR, Smith FLJH. Bacterial infections of the orbital and periorbital soft-tissues in children. LARYNGOSCOPE. 1986;96:

9. Williams BJ. Subperiosteal abscesses ofthe orbit due to sinusi- tis in childhood. Aust N Z JOphthalmol. 1991;19:29-36.

10. Arjmand EM, Lusk RP, Muntz HR. Pediatric sinusitis and sub- periosteal orbital abscess formation: Diagnosis and treat- ment. Otolaryngol Head Neck Surg. 1993;109:886-894.

11. Sutter VL, Citron DM, Edelstein MAC, et al. Wadsworth Anaerobic Bacteriology Manual. 4th ed. Belmont, Calif.: Star Publishing; 1985.

12. Lennette EH, Ballows A, Hausler WJ, et al. Manual of Clinical Microbiology. 4th ed. Washington, D.C.: American Society of Microbiology; 1985.

13. OCallaghan CH, Morris A, Kirby SM, et al. Novel method for

763-767.

detection of beta-lactamase by using a chromogenic ceph- alosporin substrate. Antimicrob Agents Chemother. 1972;l:

14. Frederick J , Braude AI. Anaerobic infections of the paranasal sinuses. NEngl JMed. 1974;290:135-7.

15. Brook I. Bacteriology of chronic maxillary sinusitis in adults. Ann Otol Rhino1 Laryngol. 1989;98:426-428.

16. Socransky SS, Manganiello SD. The oral microbiota of man from birth to senility. JPeriodontol. 1971;42:485-496.

17. Brook I, Calhoun L, Yocum P. Beta-lactamase-producing iso- lates of Bacteroides species from children. Antimicrob Agents Chemother. 1980;18:164-166.

18. Brook I. Beta-lactamase-producing bacteria recovered after clinical failures with various penicillin therapy. Arch Oto- laryngol. 1984;110;228-231.

283-288.

Third Colloquium and Workshops on Laryngeal Disorders Hands-on Laboratories Is Set

The Department of Otolaryngology-Head and Neck Surgery and Center for Laryngeal and Voice Dis- orders, Johns Hopkins Medical Institutions, is spon- soring the Third Colloquium and Workshops on La- ryngeal Disorders, September 27-28, 1996, at the Renaissance Harborplace Hotel and Johns Hopkins Medical Institutions, Baltimore, Maryland.

This two-day program, which will incorporate lec-

tures and hands-on labs, will be of interest to special- ists in otolaryngology, head and neck surgery and in speech pathology. AMA Category I credit; other appro- priate credit is pending. For more information, please contact Program Coordinator, Johns Hopkins Medical Institutions, Office of Continuing Education, Turner Building, 720 Rutland Avenue, Baltimore, MD 21205; (410) 955-2959.

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