Microbiology of Normal External Auditory Canal

Stroman, David W.; Roland, Peter S.; Dohar, Joseph E.; Burt, Wayne V.

doi:10.1097/00005537-200111000-00035

Cited by 127 publications

(117 citation statements)

References 14 publications

(16 reference statements)

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“…Similarly, we were able to isolate bacteria from 75.5% of the patients with CSOM. In addition to pathogenic bacteria, the normal flora that always exist in the exter- nal auditory canal include S. auricularis, S. epidermidis, S. capitis, and Corynebacterium [10,11] . We found that the rates of isolation of pathogenic bacteria, including PA, MRSA, and MSSA, were high.…”

Section: Discussionmentioning

confidence: 99%

Change in Detection Rate of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa and Their Antibiotic Sensitivities in Patients with Chronic Suppurative Otitis Media

Kim

Kim²,

Kim³

et al. 2015

Int Adv Otol

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OBJECTIVE:To investigate changes in Pseudomonas aeruginosa (PA) and methicillin-resistant Staphylococcus aureus (MRSA) and their antibiotic sensitivities over 13 years in patients diagnosed with chronic suppurative otitis media (CSOM). MATERIALS and METHODS:The current study reports on a retrospective analysis of the outcomes of 2256 outpatients who visited the Department of Otorhinolaryngology clinics of 3 tertiary medical centers and who were diagnosed with chronic otitis media (COM) or chronic cholesteatomatous otitis media (CCOM) from January 2001 to December 2013. Aural discharge was collected from each patient. Infectious bacteria were identified, and their antibiotic sensitivities were determined. RESULTS:The most frequent age range of patients diagnosed with CSOM was 41 to 50 years. In patients aged more than 30 years, CSOM was more frequent in females than in males, whereas in those aged less than 30 years, it was more frequent in males. Regardless of age, the isolated MRSA strains showed high sensitivity to vancomycin, teicoplanin, and trimethoprim/sulfamethoxazole, whereas the isolated PA strains showed high sensitivity to cefepime, amikacin, and ceftazidime. The isolation rate of MRSA in patients with CSOM slightly decreased over the 13-year study period; however, PA resistance to quinolones and aminoglycosides showed a tendency to increase. CONCLUSION:Bacteria isolated from patients with CSOM showed little change between 2001 and 2013, whereas their antibiotic resistance showed changes; in particular, increased PA resistance to quinolones was observed. Empirical antibiotic treatment can lead to bacterial resistance, and changes in antimicrobial agents commonly used to treat CSOM should be considered.

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Section: Discussionmentioning

confidence: 99%

Change in Detection Rate of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa and Their Antibiotic Sensitivities in Patients with Chronic Suppurative Otitis Media

Kim

Kim²,

Kim³

et al. 2015

Int Adv Otol

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“…Several recent studies, however, have reported the isolation or detection of A. otitis and/or C. otitidis in the outer ear canals and nasopharynges of healthy individuals (6,12,29). Using a PCR assay specific for A. otitis, Durmaz et al (6) detected the presence of this microbe in 4 of 50 (8%) nasopharynx swabs and 3 of 95 (3%) outer ear canal swabs.…”

Section: Discussionmentioning

confidence: 99%

“…Significantly, one of the seven positive swabs was obtained from a child with no symptoms of chronic otitis media (1 of 23 healthy individuals), indicating that A. otitis is resident in the ear canals of healthy individuals (6). Stroman et al (29) subjected cerumen and outer ear canal swabs, collected from 164 healthy individuals, to cultivation in order to survey the normal microbiota of the ear. Of the 624 total organisms that were characterized, 48 (8%) A. otitis and 74 (12%) C. otitidis isolates were identified (29).…”

Section: Discussionmentioning

confidence: 99%

Culture-Independent Molecular Analysis of Microbial Constituents of the Healthy Human Outer Ear

et al. 2003

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Molecular-phylogenetic sequence analyses have provided a new perspective on microbial communities by allowing the detection and identification of constituent microorganisms in the absence of cultivation. In this study we used broad-specificity amplification of ribosomal DNA (rDNA) genes to survey organisms present in the human outer ear canal. Samples were obtained from 24 individuals, including members of three extended families, in order to survey the resident microbiota and to examine microbial population structures in individuals related by familial or household associations. To examine the stability of the microbial populations, one individual was sampled four times and another twice over a 14-month period. We found that a distinct set of microbial types was present in the majority of the subjects sampled. The two most prevalent rDNA sequence types that were identified in multiple individuals corresponded closely to those of Alloiococcus otitis and Corynebacterium otitidis, commonly thought to be associated exclusively with infections of the middle ear. Our results suggest, therefore, that the outer ear canal may serve as a reservoir for normally commensal microbes that can contribute to pathogenesis upon introduction into the middle ear. Alternatively, culture analyses of diseases of the middle ear may have been confounded by these contaminating commensal organisms.The indigenous microbiota of humans plays a variety of roles in the maintenance of health in the host. Commensal microbes of the gastrointestinal tract, for instance, stimulate the immune system, aid mineral and vitamin absorption by the intestine, synthesize nutrients used by the host, and ward off colonization by potentially pathogenic organisms (16). By analogy, similar functions likely are assumed by the microbiota indigenous to other sites of the human body, such as the skin or genital tract. Despite the many contributions of commensal microorganisms to human health, relatively little is known about the identities of these organisms. Traditionally, the identification and enumeration of microbial species has depended entirely upon pure-culture techniques. However, the difficulty with which some types of organisms are cultured, particularly fastidious and/or anaerobic microbes, means that the more easily grown species in a mixed microbial community are likely to be overrepresented by cultivation and plate counts. In many complex natural environments, for example, Ͻ1% of the viable microbes present can be cultured under standard conditions (24).Recently, culture-independent molecular methods of microbial identification and characterization have been developed and applied in the context of microbial ecology. Several of these techniques involve the use of rRNA gene sequences as tools for species identification by means of phylogenetic sequence analysis. rRNA genes can be amplified by PCR directly from mixed-community DNA preparations (e.g., representative of both host and resident microbes in the case of clinical samples) and cloned, and individ...

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“…[28][29][30][31] In addition, these organisms are present in the healthy external auditory canal, and thus the external auditory canal may be a source of AOE. 32 Some individuals appear more susceptible to AOE on a genetic basis (those with type A blood group). 33 The subspecies of Pseudomonas causing AOE may be different from those causing other Pseudomonas infections.…”

mentioning

confidence: 99%

Clinical Practice Guideline: Acute Otitis Externa

Rosenfeld

Schwartz

Cannon

et al. 2014

Otolaryngol.--head neck surg.

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128

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Objective. This clinical practice guideline is an update and replacement for an earlier guideline published in 2006 by the American Academy of Otolaryngology-Head and Neck Surgery Foundation. This update provides evidence-based recommendations to manage acute otitis externa (AOE), defined as diffuse inflammation of the external ear canal, which may also involve the pinna or tympanic membrane. The variations in management of AOE and the importance of accurate diagnosis suggest a need for updating the clinical practice guideline. The primary outcome considered in this guideline is clinical resolution of AOE.Purpose. The primary purpose of the original guideline was to promote appropriate use of oral and topical antimicrobials for AOE and to highlight the need for adequate pain relief. An updated guideline is needed because of new clinical trials, new systematic reviews, and the lack of consumer participation in the initial guideline development group. The target patient is aged 2 years or older with diffuse AOE. Differential diagnosis will be discussed, but recommendations for management will be limited to diffuse AOE, which is almost exclusively a bacterial infection. This guideline is intended for primary care and specialist clinicians, including otolaryngologists-head and neck surgeons, pediatricians, family physicians, emergency physicians, internists, nurse practitioners, and physician assistants. This guideline is applicable in any setting in which patients with diffuse AOE would be identified, monitored, or managed.Action Statements. The development group made strong recommendations that (1) clinicians should assess patients with AOE for pain and recommend analgesic treatment based on the severity of pain and (2) clinicians should not prescribe systemic antimicrobials as initial therapy for diffuse, uncomplicated AOE unless there is extension outside the ear canal or the presence of specific host factors that would indicate a need for systemic therapy. The development group made recommendations that (1) clinicians should distinguish diffuse AOE from other causes of otalgia, otorrhea, and inflammation of the external ear canal; (2) clinicians should assess the patient with diffuse AOE for factors that modify management (nonintact tympanic membrane, tympanostomy tube, diabetes, immunocompromised state, prior radiotherapy); (3) clinicians should prescribe topical preparations for initial therapy of diffuse, uncomplicated AOE; (4) clinicians should enhance the delivery of topical drops by informing the patient how to administer topical drops and by performing aural toilet, placing a wick, or both, when the ear canal is obstructed; (5) clinicians should prescribe a non-ototoxic preparation when the patient has a known or suspected perforation of the tympanic membrane, including a tympanostomy tube; and (6) clinicians should reassess the patient who fails to respond to the initial therapeutic option within 48 to 72 hours to confirm the diagnosis of diffuse AOE and to exclude other causes of illness. Keyw...

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Microbiology of Normal External Auditory Canal

Abstract: Turcellaotitidis and A. otitidis were present with a much higher frequency than previously described, lending evidence that they be considered normal otic flora. Corynebacterium auris, previously reported only in children, was isolated from normal adults.

Cited by 127 publications

References 14 publications

Change in Detection Rate of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa and Their Antibiotic Sensitivities in Patients with Chronic Suppurative Otitis Media

Change in Detection Rate of Methicillin-Resistant Staphylococcus aureus and Pseudomonas aeruginosa and Their Antibiotic Sensitivities in Patients with Chronic Suppurative Otitis Media

Culture-Independent Molecular Analysis of Microbial Constituents of the Healthy Human Outer Ear

Clinical Practice Guideline: Acute Otitis Externa

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