Bacterial interference between pathogens in otitis media and alpha-haemolytic Streptococci analysed in an in vitro model

Bacterial interference studied by means of agar methods has shown a decreased number of inhibitory alpha-haemolytic Streptococci among otitis-prone children. Additional information was gained regarding the interplay between alpha-haemolytic Streptococci (AHS) and otitis media (OM) pathogens by comparing the bacterial interference in broth with the interference activity studied using agar overlay methods. We found, that non-typeable Haemophilus influenzae (NTHI) and Moraxella catarrhalis are readily inhibited by AHS in broth. Streptococcus pneumoniae was more bacteriostatically inhibited. If two OM pathogens were inoculated simultaneously, an isolate of AHS with poor inhibitory activity was not able to inhibit the growth, in contrast to an isolate of AHS with good inhibitory activity. The initial amount of AHS inoculated with M. catarrhalis seemed to play a decisive role with respect to the inhibitory activity. M. catarrhalis developed reduced susceptibility against AHS both in vivo and in vitro. In vivo studies showed that children with secretory otitis media had fewer isolates of AHS in their nasopharynx with the ability to inhibit all the test pathogens than healthy children (p < 0.001). Although the factor(s) responsible for the inhibitory activity have thus far not been defined, we could exclude low pH and nutrition depletion as the inhibitory mechanism of AHS with good inhibitory activity.     

Inhibition of OM pathogens by alpha-hemolytic streptococci from healthy children, children with SOM and children with rAOM

The present study was undertaken to elucidate the inhibitory activity of the normal nasopharyngeal flora against the three most common otitis media (OM) pathogens in healthy children, children with secretory otitis media (SOM) and children with recurrent otitis media (rAOM). Isolates of alpha-hemolytic streptococci (AHS) and OM pathogens were recovered from the tubal orifice in each child. The samples were taken from 20 healthy children under general anesthesia, from 19 children with SOM and 20 children with rAOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The AHS sampled from the tubal orifice of the healthy children were able to inhibit 92% of the S. peumoniae isolates, 74% of the non-typable H. influenzae isolates and 89% of the M. catarrhalis isolates. The corresponding figures for children with SOM and children with rAOM were: 73% of the S. pneumoniae isolates, 58 and 54% of the non-typable H. influenzae isolates and 86 and 89% of the M. catarrhalis isolates. The AHS from children with SOM and children with rAOM were significantly less capable of inhibiting the S. peumoniae and the H. influenzae isolates (P<0.001). There was no significant difference between the three groups of children regarding inhibitory activity against M. catarrhalis. The results suggest that the inhibitory activity of the normal bacterial flora at the tubal orifice against pneumococci and H. influenzae may be reduced in children with SOM and rAOM.     

Bacterial adherence to pharyngeal cells: in vitro studies with alpha-haemolytic streptococci and Haemophilus influenzae

We examined the adherence to pharyngeal cells of alpha-haemolytic Streptococci (AHS) and Haemophilus influenzae, representing normal flora and otitis media (OM) pathogens, respectively. The bacteria were incubated with epithelial cells brushed from the tonsils, adenoid or tubal orifice of children and adults. Adherence varied among the clinical isolates of AHS and H. influenzae. AHS adhered better to epithelial cells from a child compared with those sampled from an adult. The bacteria adhered better to cells from the tubal orifice compared with those sampled from the adenoid. The selective attachment of AHS to certain cells but not to others could not be correlated to apoptotic/necrotic cells versus viable cells. Incubation of epithelial cells with an isolate of AHS with good inhibitory activity against OM pathogens showed almost no adherence of bacteria to the epithelial cells after 12 and 24 h of incubation. If, however, an isolate of AHS with weak inhibitory activity was incubated with the cells, the bacteria that were attached to the epithelial cells from the beginning showed overgrowth in the broth and increasing attachment to the cells after 12 and 24 h. Thus the inhibitory activity of AHS could also affect the adherence of potential pathogens to the mucosal surfaces. The adherence pattern may at least partially explain the difference in susceptibility to OM between children and adults.     

Bacterial Adherence to Pharyngeal Cells: In Vitro Studies with Alpha-haemolytic Streptococci and Haemophilus influenzae

We examined the adherence to pharyngeal cells of alpha-haemolytic Streptococci (AHS) and Haemophilus influenzae , representing normal flora and otitis media (OM) pathogens, respectively. The bacteria were incubated with epithelial cells brushed from the tonsils, adenoid or tubal orifice of children and adults. Adherence varied among the clinical isolates of AHS and H. influenzae . AHS adhered better to epithelial cells from a child compared with those sampled from an adult. The bacteria adhered better to cells from the tubal orifice compared with those sampled from the adenoid. The selective attachment of AHS to certain cells but not to others could not be correlated to apoptotic/necrotic cells versus viable cells. Incubation of epithelial cells with an isolate of AHS with good inhibitory activity against OM pathogens showed almost no adherence of bacteria to the epithelial cells after 12 and 24 h of incubation. If, however, an isolate of AHS with weak inhibitory activity was incubated with the cells, the bacteria that were attached to the epithelial cells from the beginning showed overgrowth in the broth and increasing attachment to the cells after 12 and 24 h. Thus the inhibitory activity of AHS could also affect the adherence of potential pathogens to the mucosal surfaces. The adherence pattern may at least partially explain the difference in susceptibility to OM between children and adults.     

In vitro inhibition of S. pneumoniae, nontypable H. influenzae and M. catharralis by alpha-hemolytic streptococci from healthy children

The present study aimed to investigate the inhibitory activity of the normal epipharyngeal flora against the three most common acute otitis media (AOM) pathogens in healthy children, and to study if the inhibitory activity differs between alpha-hemolytic streptococci (AHS) sampled from the tubal orifice and from those sampled from the adenoid. A total number of ten isolates of AHS were collected from the tubal orifice and the adenoid, respectively, in ten children undergoing adenoidectomy or tonsillectomy. None of the children had a history of otitis media, neither secretory otitis media (SOM) nor AOM. The method used to test the bacterial interference in vitro was a modified agar overlay method. The results showed that the AHS from nasopharynx were able to inhibit the majority of the S. pneumoniae, nontypable Haemophilus influenzae and Moraxella catharralis isolates tested. The AHS isolates from the tubal orifice inhibited growth of 93% of S. pneumoniae, 79% of H. influenzae and 84% of M. catharralis isolates. The corresponding figures among isolates from the adenoid were 76, 48 and 62%. This difference in the inhibitory capacity between the AHS isolates collected from the adenoid, compared with the AHS collected from the tubal orifice, is statistically significant (P<0.01) and implies that it is important to know the exact sampling locality before conclusions are made concerning the significance of bacterial interference in the upper airways.     

Is hydrogen peroxide responsible for the inhibitory activity of alpha-haemolytic streptococci sampled from the nasopharynx?

OBJECTIVE: The inhibitory effect of alpha-haemolytic Streptococci (AHS) in vitro on the three commonest otitis media pathogens, Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, was previously investigated. The aim of this study was to determine the mechanism of this inhibitory activity. MATERIAL AND METHODS/RESULTS: When fractions of AHS filtrate were assayed to determine their inhibitory activity after size-exclusion chromatography, the inhibitory activity was found in the fractions with a low molecular weight. The inhibitory effect was completely reversed when catalase was added to the cell-free filtrate of AHS. A quantitative method also revealed high production (approximately 3 mmol/l) of hydrogen peroxide in the AHS filtrate with the best inhibitory activity. Electron microscopy of bacteria exposed to AHS filtrate with an inhibitory effect showed changes similar to bacteria exposed to hydrogen peroxide. CONCLUSIONS: We conclude that the inhibitory effect of AHS is most likely due to the production of hydrogen peroxide. The significance of hydrogen peroxide production of AHS is discussed in relation to the non-specific and specific mucosal defence systems.     

Interventions for prevention of otitis media may be most effective if implemented in the first weeks of life

OBJECTIVE: For Indigenous Australian children living in remote communities, onset of otitis media commences within weeks of birth and is associated with early nasopharyngeal colonisation with multiple respiratory bacterial pathogens: Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The high prevalence of eardrum perforation and the failure of standard therapies to cure or prevent OM in this population require urgent attention. The objective of this study was to measure the changes in nasopharyngeal bacterial flora between birth and first episode of otitis media. METHODS: For 10 randomly selected Indigenous children with early onset otitis media, S. pneumoniae, H. influenzae, M. catarrhalis, S. aureus, and total bacterial load were enumerated in serial nasopharyngeal swabs using real-time quantitative PCR. RESULTS: Between 0 and 3 weeks of age, all 10 infants had bilaterally normal ears. At 3-6 weeks of age, seven of eight infants examined had otitis media. By 6-13 weeks of age, all 10 infants had otitis media. The relative density of respiratory pathogens among total nasopharyngeal flora increased significantly with onset of otitis media, and the majority of children became colonised with the three respiratory pathogens. There was no association between OM onset and S. aureus load. CONCLUSIONS: Onset of otitis media between 3 and 6 weeks of life was associated with a significant increase in all major bacterial OM pathogens (S. pneumoniae, H. influenzae, M. catarrhalis), as well as total bacterial load in the nasopharynx. Interventions to prevent acquisition of multiple OM pathogens in the first weeks of life are needed.     

A nasal spray with alpha-haemolytic streptococci as long term prophylaxis against recurrent otitis media.

Previous studies have shown that children with recurrent acute otitis media (rAOM) have significantly lower quantities of alpha-haemolytic streptococci (AHS) in the nasopharynx than healthy children. Furthermore children with otitis media have AHS with lower inhibitory activity in vitro on Streptococcus pneumoniae and non-typable Haemophilus influenzae compared with healthy children. A randomised, placebo controlled and double blind clinical study among children with rAOM was designed to determine whether or not a nasal spray, containing AHS with very good inhibitory activity on the three most common OM pathogens, could be an alternative to tympanostomy tube insertion. Forty three children under 4 years of age were included in the study. The children sprayed once daily for 4 months and were monitored for 6 months. Sixteen children in the active group and 20 children in the placebo group were evaluated. The result showed no significant differences regarding the number of episodes of AOM, with seven recurrences in the active group and eight in the placebo group. No significant changes of the nasopharyngeal flora could be detected during the study period regarding the OM pathogens. Nasal spray according to the performed schedule is not yet an alternative to tympanostomy tubes in children with rAOM. The possibility of increasing the efficacy of this ecological treatment, by using pre-treatment antibiotics, more adhesive bacteria and alternative treatment schedules is discussed.     

Interference of nontypeable Haemophilus influenzae and Moraxella catarrhalis by Streptococcus oralis in adenoid organ culture: a possible strategy for the treatment of the otitis-prone child

The role of viridans group streptococci (Streptococcus oralis) in the prevention of colonization with nontypeable Haemophilus influenzae and Moraxella catarrhalis was investigated in an adenoid organ culture system. The adenoids from 100 patients who were undergoing adenoidectomy for either hypertrophy or recurrent otitis media were used. Streptococcus oralis Parker uniformly inhibited colonization with nontypeable H. influenzae or M. catarrhalis over a 24-hour period of incubation in adenoid organ culture. Streptococcus oralis Booth, a noninhibitory strain, did not significantly reduce colonization with nontypeable H. influenzae and M. catarrhalis. The results indicate that some strains of S. oralis may inhibit colonization with potential pathogens in the nasopharynx. It is therefore possible that colonization with inhibitory strains of viridans streptococci may be used in the nasopharynx as a relatively safe and inexpensive approach to prevention of recurrent otitis media in some children.     

The role of Haemophilus influenzae in pyoinflammatory diseases of the ear and paranasal sinuses

We studied the role of Haemophilus influenzae in ENT inflammation in children, in purulent otitis and rhinosinusitis in particular, basing on the results of microbiological investigations of microflora. Examination of 59 patients aged 3 months to 17 years (39 patients with otitis media purulenta and 20 patients with chronic rhinosinusitis) has established that main pathogens in these diseases are streptococci, H. influenzae (HI) and M. catarrhalis. HI is a frequent associated microorganism in children of Uzbekistan. It occurs in 22% patients with acute otitis media purulenta and in 25% patients with chronic rhinosinusitis.     

The bacterial flora of the nasopharynx, with special reference to middle ear pathogens. A quantitative study in twenty children

Quantification of middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis) and potential pathogens (S. aureus and coagulase-negative staphylococci) adhering to the posterior wall of the nasopharynx was performed in 20 patients of whom 5 were suffering from secretory otitis media (SOM), 5 from recurrent attacks of acute otitis media (rAOM), 5 from attacks of upper respiratory infection (URI) and 5 from blocked nose (BN). While the patients were under general anesthesia a glass cylinder (diameter 1.3 cm) was pressed against the posterior wall of the nasopharynx and swabs were taken from the mucosa delineated by the glass tube. Quantification of the bacteria was performed using blood and chocolate agar plates. Total bacterial counts ranged between 2.6 x 10(4)CFU/cm2 and 4.0 x 10(8)CFU/cm2. In the rAOM group, 4 out of 5 children had bacterial counts in the nasopharynx which constituted of 95% pathogens. Coagulase-negative staphylococci never exceeded 1.9 x 10(5)CFU/cm2.     

Epidemiology of otitis media

Although otitis media (OM) incidence and prevalence estimates from around the world vary widely, it is clear that OM is a very common childhood disease. It is especially prevalent in children younger than 2 years of age. Furthermore, the earlier the first episode of OM, the greater the risk of subsequent recurrent OM and chronic otitis media with effusion. In addition, a number of other host, agent, and environmental factors have been associated with increased risk of otitis media. Environmental factors that favor the transmission of upper respiratory pathogens increase the risk of OM, recurrent OM, and chronic OME with effusion. Several factors suggest a genetic role in OM susceptibility, which needs further exploration.     

Acute mastoiditis caused by Moraxella catarrhalis

Acute mastoiditis is the most frequent intratemporal complication of otitis media. The bacteriology of acute otitis media is changing continuously and it differs markedly from the bacteriology of acute mastoiditis. Moraxella catarrhalis (M. catarrhalis) is the third most common bacteria found in acute otitis media, and in recent years its importance as an etiological factor of acute otitis media has markedly increased in certain geographic areas. However, there are no reports of acute mastoiditis caused solely by M. catarrhalis. This report describes a case of a 2-year-old girl with acute mastoiditis and M. catarrhalis in the bacterial culture of middle ear effusion.     

Bacterial interference of penicillin-sensitive and -resistant Streptococcus pneumoniae by Streptococcus oralis in an adenoid organ culture: implications for the treatment of recurrent upper respiratory tract infections in children and adults

OBJECTIVES: The role of the viridans group of streptococci (Streptococcus oralis) in the prevention of colonization with Streptococcus pneumoniae was investigated in an adenoid organ culture system. METHODS: The adenoids from 10 patients who were undergoing adenoidectomy for either hypertrophy or recurrent otitis media were used. RESULTS: Streptococcus oralis Parker and S. oralis Booth (two organisms isolated from the nasopharynges of patients undergoing adenoidectomy only and patients undergoing adenoidectomy and bilateral tympanostomy with tubes, respectively) uniformly inhibited both penicillin-sensitive and penicillin-resistant S. pneumoniae. Although both strains of S. oralis inhibited the growth of both S. pneumoniae strains, strain Parker provided more complete inhibition than did strain Booth. CONCLUSIONS: The results indicate that some strains of S. oralis may inhibit the growth of the most serious pathogens in the nasopharynx. It is therefore possible that colonization of inhibitory strains of viridans streptococci may be used in the nasopharynx as a relatively safe and inexpensive approach to prevention of recurrent otitis media in some children and of recurrent suppurative sinusitis in both children and adults.     

Reliability, validity and responsiveness of a Norwegian version of the Chronic Sinusitis Survey

Background

Nasal colonisation with otitis media (OM) pathogens, particularly Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis, is a precursor to the onset of OM. Many children experience asymptomatic nasal carriage of these pathogens whereas others will progress to otitis media with effusion (OME) or suppurative OM. We observed a disparity in the prevalence of suppurative OM between Aboriginal children living in remote communities and non-Aboriginal children attending child-care centres; up to 60% and <1%, respectively. This could not be explained by the less dramatic difference in rates of carriage of respiratory bacterial pathogens (80% vs 50%, respectively). In this study, we measured nasal bacterial load to help explain the different propensity for suppurative OM in these two populations.

Methods

Quantitative measures (colony counts and real-time quantitative PCR) of the respiratory pathogens S. pneumoniae, H. influenzae and M. catarrhalis, and total bacterial load were analysed in nasal swabs from Aboriginal children from remote communities, and non-Aboriginal children attending urban child-care centres.

Results

In both populations nearly all swabs were positive for at least one of these respiratory pathogens. Using either quantification method, positive correlations between bacterial load and ear state (no OM, OME, or suppurative OM) were observed. This relationship held for single and combined bacterial respiratory pathogens, total bacterial load, and the proportion of respiratory pathogens to total bacterial load. Comparison of Aboriginal and non-Aboriginal children, all with a diagnosis of OME, demonstrated significantly higher loads of S. pneumoniae and M. catarrhalis in the Aboriginal group. The increased bacterial load despite similar clinical condition may predict persistence of middle ear effusions and progression to suppurative OM in the Aboriginal population. Our data also demonstrated the presence of PCR-detectable non-cultivable respiratory pathogens in 36% of nasal swabs. This may have implications for the pathogenesis of OM including persistence of infection despite aggressive therapies.

Conclusion

Nasal bacterial load was significantly higher among Aboriginal children and may explain their increased risk of suppurative OM. It was also positively correlated with ear state. We believe that a reduction in bacterial load in high-risk populations may be required before dramatic reductions in OM can be achieved.     

Recurrent and penicillin V-resistant otitis media. A treatment study with amoxycillin/clavulanate and cefaclor

Clinical and bacteriological studies were performed in 122 children, aged 1-10 years, with recurrent otitis media or failed therapy with phenoxymethyl penicillin. A specimen for bacteriological culture was taken from the nasopharynx in all patients, and in our material Haemophilus influenzae, Branhamella catarrhalis and Streptococcus pneumoniae were equally distributed, each forming one-third of the total bacterial count. Thus, H. influenzae and B. catarrhalis (as well as their betalactamase-producing strains) were found more frequently than is generally reported for acute otitis media. Treatment with amoxycillin/clavulanate (Spektramox) gave a high and satisfactory effect comparable to the treatment result of cefaclor (Kefolor). The eradication of the initial pathogens was achieved to a significantly higher extent with Spektramox than with Kefolor. Both drugs were well tolerated.     

Nasopharyngeal pathogens in children with acute otitis media in a low-antibiotic use country

OBJECTIVE: Acute otitis media (AOM) is one of the most common diseases of childhood. Knowledge, of which bacteria are the most common pathogens in AOM and their susceptibilities towards antibiotics, is essential for the reasonable empiric treatment. With rapidly increasing frequencies of antibiotic resistance surveillance of the common etiologic pathogens has become pertinent. The purpose of this paper is to present the bacteriological findings and antibiotic susceptibilities, in cultures from nasopharyngeal swabs, in Danish children with AOM. METHODS: Children aged up to 10 years who had AOM diagnosed in general practice in Denmark were swabbed in nasopharynx, cultures were incubated and susceptibility testing was performed as tablet diffusion and minimal inhibitory concentrations (MICs) were determined by E-test. RESULTS: We included 331 patients, in 257 bacteria were found, which could be classified as commonly ear pathogenic. The most frequent bacteria found was Streptococcus pneumoniae followed by Haemophilus influenzae and Moraxella catarrhalis. Ninety-six percent of the tested S. pneumoniae were susceptible towards penicillin and 99% towards erythromycin. Eighty-nine percent of the H. influenzae were susceptible to ampicillin and all tested M. catarrhalis were susceptible towards erythromycin. In more than 30% of H. influenzae MIC of phenoxymethylpenicillin were above the level that could be achieved in middle ear fluid. CONCLUSION: Antimicrobial resistance is still infrequent in pathogens that might cause AOM in children in Denmark; this is probably due to minimal use of antibiotics as well as the use of phenoxymethylpenicillin as primary drug for treatment of AOM. Phenoxymethylpenicillin and azithromycin are not efficient for treating the majority of infections due to H. influenzae.     

Nasopharyngeal flora in the first three years of life in normal and otitis-prone children

Nasopharyngeal carriage of the three major middle ear pathogens (Streptococcus pneumoniae, nontypeable Hemophilus influenzae, and Moraxella catarrhalis) was evaluated prospectively in a group of 110 children followed up for the first 3 years of life. The findings suggested that nasopharyngeal carriage of middle ear pathogens increases significantly during respiratory illness among the general population of young children; however, otitis-prone children demonstrated a tendency to carry nontypeable H influenzae at an unusually high rate even during health. This propensity to carry nontypeable H influenzae might explain why nontypeable H influenzae is a major cause of recurrent or chronic otitis media.     

Antibodies specific to outer membrane antigens of Moraxella catarrhalis in sera and middle ear effusions from children with otitis media with effusion

OBJECTIVE: Recent studies have shown that bacterial DNA is present in a significant percentage of middle ear effusions, suggesting that persistent bacterial infection may be more important in pathogenesis and recurrence of otitis media with effusion (OME) than previously considered. Although Moraxella (M.) catarrhalis is one of the most common pathogens of otitis media, relatively little is known about immune response to the organism. The objective of the present study is to investigate how systemic and local immune activities against M. catarrhalis may be associated with severity of OME. METHODS: The antibody levels specific to outer membrane antigens of M. catarrhalis in sera and middle ear effusions (MEEs) from 59 children with OME were measured by enzyme-linked immunosorbent assay. Their ages ranged from 1 to 12 years with a median 5.0 years. The children were followed 1 year prospectively and classified into two groups with or without recurrent/persistent OME according to severity of OME during the follow-up 1 year. RESULTS: Serum IgG, IgM, and IgA antibodies specific to outer membrane antigens of M. catarrhalis were detected in all samples and the median levels were 35, 0.93, and 1.2 microg/ml respectively. The MEE IgG, IgM, IgA, and secretory IgA antibodies were detected in over 95% samples tested and the median levels were 371, 158, 20, and 50 ng/mg total protein respectively. A comparison between acute and subacute/chronic phases revealed that the median levels of MEE IgG and IgM antibodies were higher at the acute phase (692 vs. 340, P = 0.06; 35 vs. 10, P = 0.02, respectively); while the MEE secretory IgA antibody level was increased at the subacute/chronic phase (74 vs. 35, P = 0.02). Either serum or MEE IgG antibody level was significantly lower in recurrent/persistent OME group than that in nonrecurrent/non-persistent OME group (13 vs. 43 ,microg/ml, P = 0.009; 238 vs. 577 ng/mg protein, P = 0.006, respectively). CONCLUSIONS: These data provide additional information on the immunologic aspects of children with OME. Decreased serum and MEE IgG antibody levels specific to outer membrane antigens of M. catarrhalis may lead to failure to eliminate this organism, resulting in persistent and/or recurrent appearance of MEE.     

Presence of viral and bacterial pathogens in the nasopharynx of otitis-prone children. A prospective study

OBJECTIVE: The purpose of the present study was to examine and follow up the presence of respiratory viral and bacterial pathogens in the nasopharynx of otitis-prone children during the cold season and compare the findings with the child's respiratory symptoms. METHODS: We enrolled 121 otitis-prone children, aged 10 months to 4 years for a prospective study. The nasopharyngeal swab (NPS) were studied at the baseline and after 12 and 24 weeks for respiratory viruses and at the baseline and after 24 weeks for bacteria. Presence of picorna(rhino-entero-parecho)-, influenza-, adenoviruses and Mycoplasma pneumoniae was detected by PCR. NPS specimens were cultured for Haemophilus influenzae, Streptococcus pneumoniae and Moraxella catarrhalis. Clinical data (the rate of respiratory symptom days, otitis media, tympanometry findings, day-care attendance and the number of siblings) were compared with microbiological data. RESULTS: Rhinovirus was found in 30% of the samples at the baseline, in 8% and in 19% of the samples after 12 and 24 weeks, respectively. Enterovirus was detected in 19% of the samples, in 21% and in 12% of samples after 12 and 24 weeks, respectively. Picornavirus positivity correlated with the respiratory symptoms but not with the number of otitis media or with abnormal tympanometry. Two samples were adeno- and three samples influenzavirus positive. Parechovirus and M. pneumoniae were negative in all samples. Rhinovirus positivity correlated with that of M. catarrhalis and S. pneumonia but not with H. influenzae. Microbiological positivity was not significantly associated with the type of day-care. CONCLUSIONS: Picornaviruses as well as bacteria were commonly found in the nasopharynx of otitis-prone children during the cold season, even in the absence of clinical symptoms.