Isolation of Alloiococcus otitidis from the External Ear in Children

Gómez-Hernando, C.; Toro, Carlos; Gutiérrez, M.; Enríquez, Ana; Baquero, Margarita

doi:10.1007/s100960050230

Cited by 12 publications

(18 citation statements)

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“…otitidis is a bacterium which requires special growth medium, and it is very difficult to culture (5,6). So far, only a few clinical strains of A. otitidis has been isolated (5,6,8,16). However, previous studies by Hendolin et al showed that A. otitidis was never detected by culture, but it was detected by PCR more frequently than other middle ear pathogens (13,14).…”

Section: Discussionmentioning

confidence: 99%

“…Half of each specimen was used for culture to detect bacterial pathogens. Culture for S. pneumoniae was performed using sheep blood agar; culture for H influenzae was performed using chocolate agar; culture for M. catarrhalis was performed using blood and chocolate agar; and culture for A. otitidis was performed using sheep blood agar, chocolate agar, and brain heart infusion agar with 5% rabbit blood as recommended in the literature (5,6,8). The incubation was extended to 14 days because A. otitidis shows very slow growth (5,6).…”

Section: Patient Populationmentioning

confidence: 99%

“…Studies concerning the prevalence of A. otitidis in OME have been performed only in Finland (13,14,18) and in the United Kingdom (2). Other than in these two countries, only a few clinical strains of A. otitidis have been isolated in the United States (5, 6), Turkey (16), Spain (8), and Brazil (5). In Asian countries, even the isolation of A. otitidis has not been reported yet.…”

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High Incidence of Alloiococcus otitidis in Children with Otitis Media, Despite Treatment with Antibiotics

et al. 2006

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Acute otitis media (AOM) and otitis media with effusion (OME) are common diseases in childhood. Alloiococcus otitidis is a newly recognized species of gram-positive bacterium which was recently discovered as a pathogen associated with OME. Although some studies show that A. otitidis is frequently detected in children with OME, no study is available concerning the clinical efficiency of antibiotics against this organism. The prevalence of A. otitidis in 116 middle ear effusion specimens from 36 AOM and 52 OME patients was examined by culture and PCR. In addition, the prevalence of the bacterium was retrospectively investigated in relation to antibiotic use. A. otitidis was detected in 20 (50%) AOM and 47 (61%) OME specimens. The organism was the most frequent bacterium in AOM as well as in OME and was highly detected even in patients who had been treated with antibiotics, such as beta-lactams or erythromycin. The incidence of A. otitidis in our study was higher than that in Western countries, and our results suggest that drug-resistant strains of A. otitidis may be frequently spread in Japanese children. Our study suggests that antibiotics such as beta-lactams or erythromycin may not be sufficiently effective to eliminate this organism. Further investigation is expected to reveal the clinical role of the organism in otitis media.Acute otitis media (AOM) and otitis media with effusion (OME) are common diseases and important otological problems in childhood (3, 4). Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are the three major pathogens in AOM as well as in OME (4,20).In 1989, an unknown gram-positive coccus was recovered from middle ear effusions of children with OME (6). This organism was determined to be a new species of bacterium by 16S rRNA analysis and was named Alloiococcus otitis (1); later the name was revised to Alloiococcus otitidis (9). This organism is difficult to detect in middle ear effusions by conventional culture, because it shows slow growth in vitro and could hinder recovery of the organism from clinical specimens (6). On the other hand, by PCR, A. otitidis was detected in about 50% of OME patients, a higher rate than for the three major pathogens (2, 14). These studies suggest that A. otitidis is one of the major pathogens of OME.However, only a limited number of studies of A. otitidis have been conducted, and no clinical study of A. otitidis is available, although a few studies are available concerning the prevalence or the bacteriological character of this organism. Studies concerning the prevalence of A. otitidis in OME have been performed only in Finland (13,14,18) and in the United Kingdom (2). Other than in these two countries, only a few clinical strains of A. otitidis have been isolated in the United States (5, 6), Turkey (16), Spain (8), and Brazil (5). In Asian countries, even the isolation of A. otitidis has not been reported yet. In addition, as regards the detection of A. otitidis in AOM patients, only the study by Leskinen et al. (19) is available...

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Section: Discussionmentioning

confidence: 99%

Section: Patient Populationmentioning

confidence: 99%

mentioning

confidence: 99%

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High Incidence of Alloiococcus otitidis in Children with Otitis Media, Despite Treatment with Antibiotics

et al. 2006

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“…Except for the paucity of A. otitis isolates, these results corroborate those of the molecularly based microbial survey and provide further evidence that S. auricularis and C. otitidis are numerically dominant constituents of the healthy human ear canal microbiota. Because A. otitis is a fastidious microbe (7,8,12,15,21), it is likely that cultivation underestimates the abundance of this organism in ear canal specimens.…”

Section: Discussionmentioning

confidence: 99%

“…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%

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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High frequency of Alloiococcus otitidis in the nasopharynx and in the middle ear cavity of otitis-prone children

Harimaya

Takada

Somekawa

et al. 2006

International Journal of Pediatric Otorhinolaryngology

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Isolation of Alloiococcus otitidis from the External Ear in Children

Cited by 12 publications

References 8 publications

High Incidence of Alloiococcus otitidis in Children with Otitis Media, Despite Treatment with Antibiotics

High Incidence of Alloiococcus otitidis in Children with Otitis Media, Despite Treatment with Antibiotics

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

High frequency of Alloiococcus otitidis in the nasopharynx and in the middle ear cavity of otitis-prone children

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