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TURICELLA OTITIDIS MASTOIDITIS IN A HEALTHY CHILD

2001; Lippincott Williams & Wilkins; Volume: 20; Issue: 1 Linguagem: Inglês

10.1097/00006454-200101000-00020

1532-0987

Adrian Dana, Robert Fader, David Sterken,

Streptococcal Infections and Treatments

Turicella otitidis, a coryneform bacterium, has been associated with acute otitis media. A 5-year-old girl developed acute mastoiditis. Turicella was isolated from the right and left middle ear fluid. In 1993 two groups independently described coryneform bacteria isolated from middle ears. 1, 2 All isolates were reportedly from patients with otitis media, but clinical descriptions were incomplete. This coryneform bacterium has now been defined as a member of a new genus and has been dubbed Turicella otitidis. We report the first case of mastoiditis caused by T. otitidis. Case report. A 5-year-old girl was in good health until 2 weeks before admission when she developed a cough and fever. The symptoms improved without treatment. Six days before admission the fever recurred and she complained of bilateral ear pain. Forty-eight hours later she was evaluated by her physician who diagnosed pneumonia and otitis. Azithromycin was prescribed. After 48 h of treatment the fever was decreasing, but the left ear pain became much more severe. Pain was especially evident when she was touched behind the left auricle. The family administered one dose of amoxicillin/clavulanate and one dose of cefpodoxime in addition to the prescribed azithromycin. The patient was admitted 2 days later with continued left ear pain and left postauricular swelling. At the time of admission the patient was afebrile. The examination revealed red and bulging tympanic membranes bilaterally. The left pinna was pushed forward. The left postauricular area was erythematous and tender. The left tonsillar lymph node was tender and ∼1.5 cm in size. The chest was clear to auscultation. The remainder of the examination was unremarkable. Initial laboratory examination revealed a white blood cell count of 8300/mm 3. The erythrocyte sedimentation rate was 125 mm/h. Computed tomography scan of the temporal bones with intravenous contrast revealed opacification of the mastoid air cells bilaterally. The chest roentgenogram was normal. The child was admitted and underwent bilateral tympanocentesis and tympanostomy tube placement after disinfection of the canals. The patient was given intravenous cefotaxime and had an excellent clinical response. Therapy was continued with intravenous ceftriaxone at home. Microbiology. A direct Gram stain of clinical material revealed many Gram-positive bacilli with coryneform morphology. Left and right middle ear specimens grew T. otitidis in pure culture on trypticase soy agar with 5% sheep blood and on chocolate agar (Becton Dickinson Microbiology Systems, Cockeysville, MD). At 48 h of incubation in 5% CO2 the colonies were 1 to 2 mm in diameter, convex, whitish and creamy. The organism exhibited a positive catalase reaction and a positive leucine aminopeptidase test (REMEL, Lexena, KS). When tested in the API “Rapid Coryne” identification system (bioMérieux/Vitek, Inc., Hazelwood, MO), the organism produced a biocode of 2100004 at 48 h (Table 1). Although not in the codebook, this biocode has been described previously for Turicella isolates. 3 The organism was also CAMP test-positive with Staphylococcus aureus (ATCC 25923) but not with Rhodococcus equi.Table 1: Reactions obtained from API Rapid CoryneSusceptibility testing was performed by a modification of disk diffusion and E-test methodology. 4 Briefly the isolate was suspended in 0.45% saline, the turbidity was adjusted to a 0.5 McFarland standard and the organism was inoculated onto Mueller-Hinton sheep blood agar (Becton Dickinson Microbiology Systems). After application of the antibiotic strips and disk, the agar was incubated at 35°C for 24 h in ambient air. Although standardized breakpoint criteria for Gram-positive bacilli are not available, the organism appeared susceptible to penicillin (MIC 0.06 μg/ml), ceftriaxone (MIC 0.0125 μg/ml) and vancomycin (MIC 0.05 μg/ml) but resistant to erythromycin (MIC >256 μg/ml). No zone of inhibition was evident when azithromycin was tested by disk diffusion. Discussion. To our knowledge this is the first reported case of T. otitidis mastoiditis. T. otitidis is implicated as the causative agent because the specimens were obtained through an intact tympanic membrane, Gram-positive bacilli were the predominant organisms on Gram stain and T. otitidis grew in pure culture. Additionally the patient’s symptoms progressed while receiving treatment with azithromycin, an antibiotic to which the organism was resistant. Literature review revealed reports of 25 cases of middle ear disease attributed to T. otitidis in 24 patients. In 1993 Funke et al. 1 reported 8 cases of otitis in 7 patients from whom T. otitidis was isolated. That same year Simonet et al. 2 reported 16 children with acute otitis media from which T. otitidis was isolated from tympanocentesis specimens. Renaud et al. 5 reported isolation of the organism from a 6-month-old with otitis after repair of a cleft palate. Of the 25 reported cases 3 were adults ages 17 to 53 years. The remainder of the cases were children <3 years of age. In 22 cases T. otitidis was isolated in pure culture. Five isolates from 4 patients were obtained from spontaneously draining ears. More recently Fernandez Perez et al. 6 reported a 7-year-old boy who had a cervical abscess caused by T. otitidis. This case is the only report of extraotic infection caused by T. otitidis. Our isolate appeared susceptible to penicillin, third generation cephalosporins and vancomycin. It exhibited resistance to macrolide antibiotics. This susceptibility pattern is consistent with previous reports. Funke et al. 7 reported antimicrobial sensitivity patterns for 146 isolates of T. otitidis that were highly susceptible to beta-lactams. The isolates were also susceptible to ciprofloxacin, gentamicin, rifampin and tetracycline. About 25% of the isolates were resistant to clindamycin and erythromycin. Because coryneform bacteria are often dismissed as contaminants by the laboratory or the clinician, the true importance of T. otitidis as a middle ear pathogen is unknown. The case of mastoiditis reported here indicates that the organism can, on occasion, cause more serious disease. Predominance of Gram-positive rods on Gram stain or the isolation of a pure culture of “diphtheroids” from middle ear specimens should alert the clinician to the possibility of T. otitidis.