Occurrence of middle ear pathogens in the nasopharynx of young individuals. A quantitative study in four age groups

Colonization of middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis), potential pathogens (S. aureus and coagulase-negative staphylococci) and non-pathogens was determined quantitatively on the posterior wall of the nasopharynx (NPH) of children (four age groups: under 2 years, 2-5 years, 6-10 years and 11-15 years). None of the 90 individuals examined was suffering at the time of bacterial sampling from acute otitis media (AOM), sinusitis, or tonsillitis. All individuals under 2 years of age harboured middle ear pathogens in the NPH, but only 40% of the individuals of the oldest age group (p less than 0.001). Furthermore, in the youngest group, 57% of the cases had pathogens in the NPH, which completely dominated the bacterial flora, i.e. constituted more than 90% of the total bacterial count when calculated as CFU/cm2. The corresponding count in the oldest age group was only 20% (p less than 0.01). One important reason for the high incidence of AOM among young children in particular seems to be the noticeable accumulation of middle ear pathogens in huge quantities in the NPH in this age group.     

Quantitative analysis of the bacterial findings in otitis media

Qualitative and quantitative bacterial analysis of 200 samples of middle ear effusions collected from patients with current otitis media was performed. When middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis) were found during current acute otitis media or otitis media with effusion infection, the quantity of these bacteria was of the magnitude 10(6)-10(8)/ml and 0-5 x 10(5)/ml effusion material, respectively. Mucopurulent effusion material contained 6 x 10(5)-10(8) bacteria per ml whereas effusion from chronically discharging ears exceeded 10(9) bacteria per ml. Serous effusions did not harbour middle ear pathogens. The appearance of the effusion material was dependent on the number of bacteria involved. Quantification of bacteria in various middle ear effusions offers opportunities to make the diagnosis of various otitis media infections more accurate and readily comparable.     

Quantity of aerobic bacteria in the bony portion of the external auditory canal of children

OBJECTIVE: the human external auditory canal (EAC) hosts a commensal bacterial flora of mainly non-pathogens, but bacterial pathogens may also be present. The latter are important in the aetiopathogenesis of external otitis and middle ear cholesteatoma with discharge. The purpose of this study was to quantify the bacteria normally harboured in the healthy EAC and on a well-defined region of the cavum conchae (CC) of children. METHODS: bacterial samples were collected from the CC and bony portion of the EAC of 32 children (18 boys, 14 girls; median age 5 years). Prior to sampling, the EACs were either left untreated, anaesthetized with Bonain's solution, or washed with 70% alcoholic solution. The samples were incubated at 37 degrees C and evaluated regarding bacterial species and number. RESULTS: the predominant bacterial non-pathogens were coagulase-negative Staphylococci and coryneforms (diphtheroids) and pathogens Staphylococcus aureus and Pseudomonas aeruginosa. Total bacterial counts of the CC ranged between 2 x 10(3) and 4.6 x 10(4) CFU/cm(2) (median value 7 x 10(3); n = 14). Total bacterial counts from the bony portion of the EAC ranged between 0 and 5.7 x 10(7) CFU/EAC (median value 8 x 10(3); n = 32). Pre-treatment of the EACs with Bonain's solution containing the highly bactericidal substance phenol or with 70% alcoholic solution did not sterilize the EAC. CONCLUSIONS: small numbers of bacterial non-pathogens (and sometimes pathogens) are found in the EAC of children. Neither phenol nor 70% alcoholic solution can inhibit or eradicate all these microorganisms.     

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.     

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.     

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.     

How long do middle ear pathogens survive in mucoid effusion material?

Middle ear pathogens (S. pneumoniae, H. influenzae, B. catarrhalis, S. aureus and coagulase-negative staphylococci) were injected into 28 samples of mucoid effusion materials taken from 17 patients suffering from secretory otitis media. In every case the effusion material was sticky, hydrophilic and thick and contained no bacteria. S. pneumoniae and H. influenzae survived for only 1-2 days in mucoid effusion material incubated at 37 degrees C, while B. catarrhalis and staphylococci survived for at least 18-36 days when incubated in this medium. It seems that mucoid effusion material filling the middle ear cavity during secretory otitis media has a dual function in providing protection against middle ear infections. Thanks to its physical properties the effusion material hinders bacteria from ascending from the nasopharynx and is a poor substrate for some microorganisms. In contrast, mucoid effusion material is a superior medium for B. catarrhalis and staphylococci.     

Age-dependent changes in bacterial adherence to epithelial cells of nasopharynx in vivo

Epithelial cells were scraped from the posterior wall of the nasopharynx (NPH) of 20 consecutive patients (age range 1 to 52 years, 9 males, 11 females) undergoing ENT surgery under general anaesthesia. The cellular mixture was immediately homogenized, filtrated through a 5 microns pore filters and centrifuged (10 min, 1,500 rpm). Non-ciliated, squamous epithelial cells caught by the filter were harvested and stained with acridine orange. Epithelial cells with bacteria attached were evaluated when specimens were examined under a fluorescence microscope. A distinct difference was noted between young individuals and adult patients regarding bacterial adherence to nasopharyngeal epithelial cells, adherence in young patients being especially remarkable. Bacteria appeared not to attach to ciliated epithelial cells. The high incidence of otitis media infections among young individuals may be due to the remarkable bacterial adherence to nasopharyngeal non-ciliated epithelial cells in this age group.     

Nasopharyngeal bacterial flora in otitis prone children treated with immunoglobulin.

The present study was undertaken to evaluate possible beneficial effects of regularly given, long term immunoglobulin prophylaxis of children below 2 years of age with recurrent acute otitis media (RAOM). The nasopharyngeal bacterial flora and the frequency of acute otitis media (AOM) and secretory otitis media SOM were studied. Every second of 44 children with 3 or more periods of AOM during the last year received immunoglobulin intramuscularly (Gammaglobulin Kabi 165 mg/l, 0.45 ml/kg b.w.) every third week for 6 months, while the other 22 children served as controls. All children were followed for 12 months. Immunoglobulin prophylaxis neither influenced the nasopharyngeal flora, nor the frequency of AOM or SOM periods. Children with AOM or SOM more often harbored bacterial pathogens in their nasopharynx than children with normal middle ear status. Also, the immunoglobulin prophylaxis did not influence the increased frequency of bacterial pathogens in the nasopharynx of children attending public day care or family day care as compared to those taken care of at home.     

In vivo attachment of Streptococcus pneumoniae and Haemophilus influenzae to nasopharyngeal epithelium in children.

Attachment of Streptococcus pneumoniae and Haemophilus influenzae to epithelial cells on the posterior wall of the nasopharynx (NPH) was determined in 10 healthy children, culture-positive for either of these microorganisms. By using immunofluorescence technique and specific fluorescein-labelled antisera against these microorganisms, it was shown that in only 2 of the children studied were these pathogens firmly attached to the non-ciliated cells of the NPH. Attachment of S. pneumoniae and H. influenzae to the epithelial cells close to the nasopharyngeal opening of the Eustachian tube is of the utmost importance for the development of invasive disease, especially acute otitis media. Attachment of these pathogens to the epithelial cells covering the adenoid tissue may naturally be of significance for the induction of specific antibody body production against these microorganisms.     

Bacterial quantification--a necessary complement for the comprehension of middle ear inflammations.

Quantification of bacteria in various types of middle ear effusion (MEE) obtained during current acute otitis media (AOM), otitis media with effusion (OME) and chronic suppurative otitis media (COM) was performed. The bacteria were stained with acridine orange and their number per ml effusion evaluated under the fluorescence microscope according to a method described in detail elsewhere. During AOM, 53% of the MEE samples were culture-positive and contained 10(6)-10(8) bacteria per ml (median value 10(7) per ml). During OME, serous effusion and 78% of the mucoid effusions contained no bacteria whatsoever, whereas the remaining mucoid effusions contained 10(4)-5 x 10(5) bacteria per ml (median value 10(4) per ml). Mucopurulent effusions contained 6 x 10(5)-10(8) bacteria per ml (median value 5 x 10(6) per ml). During COM, purulent MEE had 6 x 10(6)-10(9) bacteria per ml (median value 10(8) per ml). Quantification of bacteria involved in middle ear diseases provides further information about the etiopathogenesis and appropriate management of various pathological conditions of the middle ear.     

Occurrence of Streptococcus pneumoniae and Haemophilus influenzae in otitis media with effusion.

Eighty mucoid effusion samples obtained from 56 patients with otitis media with effusion (OME) were subjected to quantitative and qualitative bacteriological analysis using standard culturing methods, direct microscopy and immunofluorescent assay. 30% of the samples contained culture-positive pathogens (H. influenzae, S. pneumoniae, B. catarrhalis), with counts never exceeding 5 x 10(5) per ml. In addition, 19% of the samples had dormant H. influenzae and S. pneumoniae, which did not grow on standard agar plates. Viable and dormant bacteria, as well as bacterial remnants, play a crucial role in the pathogenesis of OME and similarities between OME and reactive arthritis, i.e. Lyme arthritis, Reiter's syndrome and rheumatic fever, are evident.     

Acute otitis media and age at onset among children in Greenland

This survey examines the age at onset of acute otitis media (AOM) in 591 unselected Greenlandic children aged 3, 4, 5 and 8 years from the two largest towns in Greenland. The attendance rate was 86%. Parental information about episodes of AOM was cross-checked in medical records, which were available for 95% of the children. AOM was defined as episodes with earache, otorrhoea or previous treatment for AOM, with written otoscopic evidence of AOM resulting in treatment with weak analgetics or antibiotics. Recurrent AOM (rAOM) was defined as > or = 5 AOM episodes since birth. In total, 66% of the children had experienced AOM at least once. Of all children, 40% had AOM during the first year of life. Median age of the first episode was 10 months (range: 1-84 months), and there was no sex difference. Children between 7 and 12 months of age were at highest risk of AOM. Children with rAOM had their first AOM episode at a significantly younger age than children with < 5 AOM episodes (median: 7 months, range: 2-48 months). In addition, 83% of children with rAOM had their first AOM episode before 12 months of age compared with 53% of children with < 5 episodes (p < 0.0001). The relative risk of rAOM was eight times greater if the first episode of AOM occurred before six months of age compared to more than 24 months of age. Thirty-five percent of children with rAOM had chronic otitis media as well, compared to only 4% of children with < 5 AOM episodes. We conclude that early onset of AOM (before one year of age) occurs frequently in Greenlandic children compared to others, and a high proportion of these children develop rAOM.     

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.     

Middle ear fluid bacteriology of acute otitis media in neonates and very young infants

The middle ear fluid (MEF) bacteriology of 107 attacks of acute otitis media (AOM) in 101 infants less than 3 months old was analyzed. A total of 108 bacteria were isolated from 85 attacks. Major AOM-pathogens, S. pneumoniae (19%), H. influenzae (9%) or B. catarrhalis (7%) were cultured in approximately one-third of all the attacks. S. aureus (17%) and coagulase-negative staphylococci (22%) without the above pathogens were commonly found, whereas gram-negative enteric bacteria were culturable from only 5 attacks. Only 8% of the MEFs were polymicrobial. More than half of all the bacterial strains produced beta-lactamase. The bacteriology of those younger than one month was not different from that of the others. The same was true with attacks of out-patients and in-patients, except for a larger proportion of beta-lactamase producing strains in in-patients. Nasal-nasopharyngeal and MEF samples showed the same bacteriology in only 20% of cases. Two-thirds of AOM attacks were present in infants with perinatal or other concomitant morbidity, but their bacteriology was not different from those without other morbidity. In addition to the examination of ears in infants presenting with any illness before the age of 3 months, the study stresses the importance of bacteriological analysis of MEF in all cases of AOM at this age.     

Colonization of middle ear pathogens in the nasopharyngeal opening of the Eustachian tube during secretory otitis media

Colonization of middle ear pathogens (S. pneumoniae, H. influenzae and B. catarrhalis) in the nasopharyngeal opening of the Eustachian tube (NO) was charted in 94 patients (170 ears) suffering from secretory otitis media (SOM). Subsequent determination of microorganisms in the middle ear effusion was performed. 76% of the patients had colonization of pathogens in the NO, while pathogens colonized the middle ear cavity (MEC) in 30% of the cases. Predominant pathogen was S. pneumoniae, followed by B. catarrhalis and H. influenzae. When colonizing the MEC, there was a 100% correlation to NO regarding B. catarrhalis, 81% correlation for S. pneumoniae and 57% for H. influenzae. S. aureus and/or coagulase-negative staphylococci were only occasionally found in the NO. Accumulation of a sticky glue effusion material in the middle ear cavity may serve as a barrier against ascending pathogens from the nasopharynx.     

The effect of intravenous immunoglobulin treatment in recurrent acute otitis media

The effect of serial intravenous infusion of human immunoglobulin on the frequency of acute otitis media (AOM) episodes and on other upper respiratory tract infections was prospectively studied in a group of 22 otitis-prone children, 1-4 years old. After pair-matching, the children were allocated to immunoglobulin treatment or to a control group. Increased specific IgG antibody activities against pneumococcal types associated with recurrent AOM (rAOM) were generally achieved, but no significant difference was noted in the frequency of AOM attacks or other respiratory tract infections between the immunoglobulin-treated children and their pair-matched untreated controls. The results indicate that, although serum antibody activities against bacteria associated with AOM are increased by immunoglobulin infusions, this does not prevent the development of AOM in children suffering from rAOM.     

Cytokine gene polymorphism in recurrent acute otitis media.

BACKGROUND: There is increasing evidence that a strong genetic component is involved in the predisposition to recurrent acute otitis media (rAOM). Cytokines play a key role in the pathogenesis of otitis media. Constitutional polymorphisms in cytokine genes may lead to individual variations in cytokine secretion. OBJECTIVE: To elucidate the role of cytokine gene polymorphisms in rAOM. SETTING: University hospital. PARTICIPANTS AND METHODS: Blood samples for genetic analysis were obtained from 63 individuals with rAOM from 20 different families and from 400 healthy blood donors. The medical history of the rAOM group was based on medical records and interview data. We studied the polymorphisms of tumor necrosis factor alpha, interleukin (IL) 1 alpha, IL-1 beta, and IL-1 receptor antagonist genes. RESULTS: The distribution of cytokine alleles in the rAOM group did not differ significantly from that of the control group. However, in patients with rAOM without a history of allergic disorders, allele frequencies of IL-1 alpha-889 differed significantly from those of controls (P =.03). CONCLUSIONS: There is no clear association between the polymorphism of studied cytokine genes and rAOM. However, the IL-1 alpha gene polymorphism may be associated with recurrent middle ear infections in a subgroup of patients without allergic disorders.     

Children with recurrent episodes of acute otitis media: the effect of local administration of immunoglobulin G on acute otitis media, colonization and turnover of non-encapsulated Haemophilus influenzae in the nasopharynx

In most children with recurrent episodes of acute otitis media (AOM), tube treatment is successful, but there are those who nevertheless suffer from middle ear infections. The aim of the present study was to ascertain whether local administration of immunoglobulin could reduce the number of episodes of otorrhoea in otitis-prone infants <2 years old who were treated with tubes, or whether it could affect the nasopharyngeal colonization and turnover of bacterial pathogens in the nasopharynx. IgG or placebo were also administered intranasally daily for 6 months to 50 infants, randomized in a double-blind study. An arbitrarily primed polymerase chain reaction (AP-PCR) was used to characterize the different isolates of NTHI (non-encapsulated, non-typable Haemophilus influenzae). Three infants in the IgG group and six infants in the control group suffered from > or =3 episodes of acute otitis media. No effect on the nasopharyngeal colonization or the turnover of non-encapsulated H. influenzae in the nasopharynx could be detected in either group.     

Nasopharyngeal and middle ear flora in children with acute otitis media

Nasopharyngeal flora can be a reservoir of bacteria caused acute otitis media in children. The aim of the study was to identify microorganisms and antimicrobial susceptibilities of pathogens from the nasopharynx and middle ear of children with acute otitis media. The study comprised 128 children ages 1 year to 14 years with diagnosed of acute otitis media with purulent discharge. The nasopharyngeal and middle ear samples were collected at the same time. Agar, chocolate, blood and Chapman plates were inoculated for isolation of bacteria. The plates were incubated at 37 degrees C and examined at 24 hours. The susceptibility of bacteria was determined by disk diffusion technique containing concentration gradients for following antibiotics: penicillin, amoxicillin/clavulanate, ampicillin/sulbactam, cefaclor, cefprozil, cefuroxime, erythromycin, azithromycin, clindamycin and trimethoprim/sulfamethoxazole. 196 organisms from nasopharynx and 325 organisms from middle ear were isolated. Most frequent cultured bacteria were: Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis--75.6% in nasopharynx and 77.8% in middle ear. We observed statistically significant (p < 0.01) increased of Moraxella catarrhalis in specimens from the middle ear than from nasopharynx. Most of the organisms were susceptible to amoxicillin/clavulanate--83.2% of bacteria from nasopharynx and 81.8% of bacteria from middle ear. Most organisms were resistant to trimethoprim/sulfamethoxazole--60.7% of bacteria from nasopharynx and 62.6% of bacteria from middle ear. Penicillin resistance was observed in 25.0% of bacteria from nasopharynx and 25.6% of bacteria from middle ear. The correlation in resistance of bacteria between trimethoprim/sulfamethoxazole and erythromycin (r = 0.4886) and between trimethoprim/sulfamethoxazole and penicillin (r = 0.5027) was observed. Nasopharyngeal and middle ear flora in children with acute otitis media is similar. In that case susceptibility of bacteria from the nasopharynx can be useful for empirical treatment of acute otitis media in children.