In vitro bacterial interference in the nasopharynx of otitis media-prone and non-otitis media-prone children

OBJECTIVE: To compare the frequency of recovery of potential pathogens and aerobic- and anaerobic-interfering bacteria in the nasopharynx of otitis media-prone (OMP) with that in non-OMP (N-OMP) children. PATIENTS AND METHODS: Nasopharyngeal cultures were obtained from 20 OMP and 20 N-OMP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. RESULTS: Eighteen potential pathogens were isolated from 12 of the 20 OMP children, and 9 were recovered from 5 of the 20 N-OMP children (P<.05). Fifty-eight aerobic and anaerobic isolates with interfering capability against 4 potential pathogens were recovered from 5 of the OMP group, and 139 from 17 of the N-OMP group (P<.05). These interfering organisms included alphahemolytic streptococci, nonhemolytic streptococci, Prevotella species, and Peptostreptococcus species. CONCLUSION: The nasopharyngeal flora of N-OMP children contains more aerobic and anaerobic organisms with interfering capability and less potential pathogens than that of OMP children.     

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.     

Recovery of potential pathogens and interfering bacteria in the nasopharynx of otitis media-prone children and their smoking and nonsmoking parents

OBJECTIVE: To study the frequency of isolation of potential pathogens and interfering bacteria in the posterior nasopharynx of otitis media-prone (OMP) children and their smoking and nonsmoking parents to possibly explain why active and passive exposure to smoking is associated with carriage of potentially pathogenic bacteria and an increased risk of respiratory tract infection in both adults and children. SETTING: Outpatient clinic. PARTICIPANTS: Twenty OMP children and their smoking parents (smoking group) and 20 OMP children and their nonsmoking parents (nonsmoking group). INTERVENTIONS: Posterior nasopharynx cultures were taken from 20 OMP children and their smoking parents and 20 OMP children and their nonsmoking parents. MAIN OUTCOME MEASURE: Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. RESULTS: Fourteen potential pathogens were isolated from smoking parents, and 17 were recovered from their children. Concordance in isolation of a pathogen between a parent and child was noted in 11 instances. Three potential pathogens were isolated from nonsmoking parents (P<.001 compared with the parents and children in the smoking group and children in the nonsmoking group), and 16 were recovered from their children. Bacterial interference by normal flora isolates against potential pathogens was noted in 58 instances in smoking parents and in 55 instances in their children (P<.05). Bacterial interference was noted in 129 instances in nonsmoking parents (P<.05 compared with the parents and children in the smoking group and children in the nonsmoking group) and in 55 instances in their children. CONCLUSIONS: A high recovery rate of potential pathogens and a low number of interfering organisms were observed in OMP children. This was not related to their parents' smoking habits. The posterior nasopharynx flora of smoking parents contained more potential pathogens similar to the ones recovered from OMP children and fewer interfering organisms than nonsmoking parents.     

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.     

Rate of eradication of group A beta-hemolytic streptococci in children with pharyngo-tonsillitis by amoxicillin and cefdinir

Background

Cephalosporins were found to be more effective than penicillins in the eradication of group A β-hemolytic streptococcal (GABHS) from tonsillar tissues. This study investigated the effect of amoxicillin and cefdinir therapies on the rate of eradication of GABHS from the tonsils of children with acute pharyngo-tonsillitis (PT).

Patients and methods

Of 50 children suffering from PT 25 were treated with amoxicillin (40 mg/(kg d) or 250 mg every 8 h) and 25 with cefdinir (14 mg/(kg d) or 600 mg once a day) for 10 days. Pharyngo-tonsillar cultures were obtained from all children before treatment and on the 1st, 2nd, 3rd, 4th, 7th, and 12th days.

Results

GABHS was eradicated more rapidly from children treated with cefdinir as compared to those receiving amoxicillin. A smaller number of patients with GABHS were found in those treated with cefdinir as compared to amoxicillin throughout the treatment period. Eradication of GABHS from 68% (8 of 25 patients) was noted in those treated with cefdinir after 2 days and those treated with amoxicillin after 4 days. The differences between the number of patients who had a bacteriological cure between those receiving cefdinir to those getting amoxicillin was statistical significant at day 4 (32% vs. 8%). At the end of therapy GABHS was recovered from 5 (20%) and 2 (8%) of the patients. The group that received cefdinir, had a more rapid reduction in fever on the first after initiation of therapy as compared to those receiving amoxicillin. The fever reduction in those receiving cefdinir occurred a day earlier than in those getting amoxicillin.

Conclusions

Fever was reduced and GABHS was eradicated more rapidly from children treated with cefdinir as compared to amoxicillin.     

Emergence and persistence of beta-lactamase-producing bacteria in the oropharynx following penicillin treatment

The emergence and persistence of aerobic and anaerobic beta-lactamase-producing bacteria (BLPB) were investigated in 26 children treated with penicillin for otitis media or pharyngitis and in 28 nontreated control children. beta-Lactamase-producers were isolated in three (12%) of the treated children before therapy, in 12 (46%) seven to ten days after completion of therapy, in nine (35%) 40 to 45 days after therapy, and in seven (27%) 85 to 90 days after therapy. These organisms were present in three (11%) of the nontreated children, and the number of patients harboring BLPB stayed constant throughout the three-month follow-up. The predominant BLPB were Bacteroides species (Bacteroides melaninogenicus group, Bacteroides oralis, and Bacteroides oris-buccae), Staphylococcus aureus, Haemophilus influenzae, and Branhamella catarrhalis. The emergence and persistence of BLPB after penicillin therapy may have important implications for the antimicrobial management of infections of the upper respiratory tract.     

Increase of macrolide-resistant Streptococcus pneumoniae-expressing mefE or ermB gene in the nasopharynx among children with otitis media

OBJECTIVE: To evaluate prevalence of macrolide resistant strains and the genotypes of the resistance among Streptococcus pneumoniae isolated from the nasopharynx of children with otitis media. STUDY DESIGN: Retrospective review. METHODS: A total of 858 S. pneumoniae isolates were collected from the nasopharynx of pediatric patients with acute otitis media at the clinics of Otolaryngology-Head and Neck Surgery, Wakayama Medical University Hospital and six affiliated hospitals in Wakayama prefecture between January 1998 and December 2002. The antibiotic susceptibility patterns were analyzed for penicillin, erythromycin, and clindamycin according to the National Committee for Clinical Laboratory Standards. Macrolide resistance genes of mefE and ermB were determined by polymerase chain reaction of all S. pneumoniae. RESULTS: Of 858 clinical isolates, 259 (30.1%) were strains without ermB or mefE gene, 279 (32.5%) carrying mefE, 292 (34.0%) carrying ermB, and 28 (3.4%) carrying both genes. There was a strong correlation between phenotypes and the presence of macrolide resistance genes. The macrolide resistance genes were especially frequently identified among penicillin-resistant S. pneumoniae. Strains carrying ermB gene gradually increased from 25% in 1998 to 45% in 2002, with a concurrent decrease in strains carrying mefE from 36% in 1998 to 1999 to 19% in 2002. Strains having mefE were frequently identified among children younger than 2 years old. The current finding suggested that high-level ermB-mediated macrolide resistance in S. pneumoniae is increasing at an alarming rate in pediatric patients with otitis media, especially among young children. Physicians should pay close attention to such macrolide-resistant bacterial pathogens in the antimicrobial treatment of pediatric patients with otitis media.     

Efficacy/safety of amoxicillin/clavulanate in adults with bacterial rhinosinusitis

PURPOSE: Acute bacterial rhinosinusitis (ABRS) is a common and uncomfortable condition, frequently caused by Streptococcus pneumoniae or Haemophilus influenzae. Antibacterial resistance among these and other common respiratory pathogens is now widespread and of concern. Pharmacokinetically enhanced amoxicillin/clavulanate 2000/125 mg was developed to be effective against the common respiratory pathogens, including many resistant strains. MATERIALS AND METHODS: This open-label, noncomparative study assessed the bacteriologic and clinical efficacy of amoxicillin/clavulanate 2000/125 mg in adult patients with ABRS. Requirements for study entry included a clinical diagnosis of ABRS supported by radiologic findings. In addition, sinus puncture for bacteriologic assessment was required at study entry. RESULTS: Overall, bacteriologic success (eradication or clinical evidence of eradication) at the follow-up visit (days 17-28) was achieved in 87.8% (722/822) of patients with 1 or more pathogen isolated at screening, in 93.2% (246/264) of patients with S pneumoniae, in 96.7% (29/30) of those with penicillin-resistant S pneumoniae (penicillin minimum inhibitory concentrations >or=2 microg/mL), and in 88.7% (110/124) of patients with beta-lactamase-positive pathogens. Bacteriologic success was achieved against 6 of 7 S pneumoniae isolates with amoxicillin/clavulanic acid minimum inhibitory concentrations of 4/2 microg/mL or higher. CONCLUSIONS: Amoxicillin/clavulanate 2000/125 mg was generally well tolerated. This new amoxicillin/clavulanate formulation provides a suitable option for empiric therapy for ABRS in adults.     

Penicillin resistance is not extrapolable to amoxicillin resistance in Streptococcus pneumoniae isolated from middle ear fluid in children with acute otitis media

OBJECTIVES: We evaluated the in vitro antibacterial activity of amoxicillin against penicillin-susceptible and -nonsusceptible Streptococcus pneumoniae strains isolated from children with acute otitis media (AOM). METHODS: Children more than 3 months of age with AOM who were seen in the Dr Sótero del Rio and Luis Calvo Mackenna Hospitals in Santiago, Chile, between July 1998 and December 2002 were subjected to tympanic puncture for middle ear fluid culture. The penicillin and amoxicillin susceptibilities of the S pneumoniae isolates were determined by epsilometer test (E test). RESULTS: A bacterial pathogen was isolated in 432 of 543 children (80%) as follows: S pneumoniae, 40%; Haemophilus influenzae, 29%; Moraxella catarrhalis, 7%; and Streptococcus pyogenes, 4%. Penicillin-susceptible S pneumoniae strains were less common than amoxicillin-susceptible strains (60% versus 95%; odds ratio [OR], 0.08; 95% confidence interval [CI], 0.04 to 0.18). Both intermediate- and high-resistance strains were more common for penicillin (22% versus 4.5%; OR, 5.6; 95% CI, 2.5 to 12.7) than for amoxicillin (18% versus 0.5%; OR, 41.3; 95% CI, 6.0 to 821). CONCLUSIONS: Penicillin resistance is not extrapolable to amoxicillin among S pneumoniae strains isolated from middle ear fluid of children with AOM. Our results support the recommendation to evaluate the minimal inhibitory concentrations of penicillin-nonsusceptible S pneumoniae for amoxicillin and to continue use of this antimicrobial as a first-line antimicrobial choice for children with AOM.     

Factors associated with clinical outcomes in acute otitis media

Acute otitis media (AOM) is a common disease in childhood. If predictors of outcome in AOM were known, it would be possible to individualize therapy. Our aim was to identify factors that predict the outcome in AOM. We enrolled 368 children with AOM (ages, 10 to 86 months). The severity of symptoms and the severity of tympanic membrane changes were graded with a scoring system. Nasopharyngeal colonization with middle ear pathogens was determined on day 1. Three outcomes were assessed: persistence of symptoms at day 5, persistence of tympanic membrane changes at day 28, and recurrence of acute symptoms prior to day 28. Persistence of symptoms at day 5 was associated with younger age (35 versus 44 months; p < .001), higher symptom score on day 1 (3.5 versus 2.9; p < .05), and colonization with Streptococcus pneumoniae (61% versus 41%; p < .05). Persistence of tympanic membrane changes at day 28 was associated with younger age (39 versus 45 months; p < .01), higher tympanic membrane score on day 1 (4.1 versus 3.6; p < .01), and nasopharyngeal colonization with S. pneumoniae, especially drug-resistant S. pneumoniae (33% versus 13%; p < .05). Recurrence of acute symptoms prior to day 28 occurred in 14% of the children. Streptococcus pneumoniae was the only pathogen associated with an increased recurrence rate (23%) as compared to the group without pathogens (7%; p < .05). Age, severity of disease at presentation, and nasopharyngeal colonization patterns were proven to be important determinants of outcome in AOM.     

Effect of smoking cessation on the microbial flora

OBJECTIVE: To determine the effect of smoking cessation on the frequency of recovery of potential pathogens and aerobic and anaerobic interfering bacteria in the nasopharynges of smokers. DESIGN: Nasopharyngeal cultures were taken from 20 smokers before and 12 to 15 months after cessation of smoking. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. RESULTS: Eleven potential pathogens (0.92 pathogens per subject) were isolated from nasopharyngeal cultures obtained from 9 individuals before smoking cessation, and 2 (0.17 per subject) were recovered from 2 individuals after smoking cessation (P < .05). Bacterial interference between 2 aerobic (alpha and nonhemolytic streptococci) and 2 anaerobic species (Prevotella and Peptostreptococcus species) and 4 potential pathogens (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pyogenes) was observed. Bacterial interference was noted in 35 instances against the 4 potential pathogens by 14 normal flora isolates that were recovered from the smokers before cessation and in 116 instances by 42 isolates after cessation (P < .01). CONCLUSION: To our knowledge, these findings illustrate for the first time that the high number of pathogens and low number of interfering organisms found in the nasopharynx of smokers revert to normal levels after complete cessation of smoking.     

Effect of telithromycin and azithromycin on nasopharyngeal bacterial flora in patients with acute maxillary sinusitis

OBJECTIVE: To explore the efficacy of the ketolide telithromycin compared with azithromycin in eradicating S pneumoniae from the nasopharynx of adults with acute maxillary sinusitis. The growing resistance of Streptococcus pneumoniae to penicillin and macrolides brought about the development of a new class of antibiotics-the ketolides-that are effective against resistant pneumococci. SETTING: Otolaryngology clinic. PATIENTS: One-hundred five patients with acute maxillary sinusitis. INTERVENTIONS: Nasopharyngeal cultures were obtained before therapy and 10 to 12 days after initiation of treatment. Fifty-nine patients were treated with 500 mg of azithromycin daily for 3 days and 46 were treated with 800 mg of telithromycin daily for 5 days. RESULTS: Sixty-seven potential pathogens were recovered prior to initiation of therapy in 57 patients, 32 treated with telithromycin and 25 treated with azithromycin: S pneumoniae (31 isolates), Haemophilus influenzae (non-type b) (13), Staphylococcus aureus (8), Streptococcus pyogenes (8), and Moraxella catarrhalis (7). The distribution of the pathogens was similar in both groups. The number of S pneumoniae isolates in the azithromycin group was reduced following treatment from 14 to 8 (43% reduction), and 5 of these 8 isolates were resistant to azithromycin. In contrast, the number of S pneumoniae isolates in the telithromycin group was reduced following treatment from 17 to 1 (94% reduction) (P < .01). This isolate was susceptible to azithromycin and telithromycin. No differences were noted in the eradication rate of all of the other potential pathogens, which were all susceptible to both azithromycin and telithromycin. Development of resistance to the antimicrobial agents used (defined as increase in the minimal inhibitory concentration by at least 2 tubes) was found only in 5 isolates (4 S pneumoniae and 1 H influenzae) recovered only from patients who received azithromycin (P < .05). CONCLUSION: These data illustrate the superiority of telithromycin to azithromycin in the eradication of S pneumoniae from the nasopharynx.     

Molecular analysis of pathogens of upper respiratory tract infections in children--a study of nasopharyngeal S. pneumoniae and PBP genes in acute otitis media

We have recently been confronted with refractory upper respiratory infections with an increasing prevalence of penicillin (Pc)-resistant S. pneumoniae. There has been a broad consensus that acute otitis media (AOM) is caused by migration of pathogens from nasopharynx and proliferation in the middle ear space, and thus it is, very important to study the bacterial environment in the nasopharynx as the source of middle ear infections. Eighty pneumococcal isolates from the nasopharynx of children with acute otitis media were evaluated by polymerase chain reaction (PCR) for mutation of Pc-binding protein (PBP) genes. The results showed mutation of all three PBP genes, pbp 1a, pbp 2x, and pbp 2b, in 30% of the isolates, while 74% were found to possess various PBP gene mutations, mostly in one-year-old children. Of the 46 isolates whose minimum inhibitory concentration (MIC) of Pc was < or = 0.06 microgram/mL, 43% were found to possess a pbp 2x mutaion, which affects cefem resistance. We genotyped each pneumococcal isolate from the nasopharynx of children with recurrent AOM by pulsed-field gel electrophoresis (PFGE). In 9 of 11 pairs (82%) of consecutive AOM episodes, the nasopharyngeal isolate in the second episode was different. In addition, discrimination of each isolate based upon the mutation profile of its PBP genes in 8 pairs (72%) of consecutive AOM episodes showed that the isolates were different, and there was little difference between the results of PBP gene mutation and PFGE analysis. These findings suggest that most nasopharyngeal isolates from children with AOM possess PBP mutations and that children with increased numbers of drug-resistant bacteria in their nasopharynx during AOM has been colonized or recolonized by different strains during each episode. We therefore emphasize that clinicians should assess the antibiotic susceptibility of nasopharyngeal isolates from children during each episode. PBP gene mutation analysis of S. pneumoniae is useful not only in providing valuable information on the antibiotic susceptibility of each strain but for assessing changes in causative strains in the sequential episodes of pneumococcal infection.     

Myringotomy in the treatment of acute otitis media in children.

The treatment of acute otitis media was studied in 158 children. All children (mean age 4 years) received penicillin orally 80 000--100 000 IU per day for 10 days. Myringotomy was performed on 68 children at the time of the diagnosis. The other 90 children were treated with penicillin and ear drops. The bacteriological findings from the nasopharynx at the time of diagnosis were equivalent in both groups. After 2 weeks, 42% of the children without myringotomy and 71% of the children with myringotomy were cured. The children who were not cured were treated with amoxicillin for 10 days. Four weeks after diagnosis 71% and 90% of the children respectively were cured. The differences between the two groups are significant. The observations indicate that myringotomy clearly accelerates the recovery from acute otitis media.     

Bacterial interference in the nasopharynx and nasal cavity of sinusitis prone and non-sinusitis prone children

The aim of this study was to compare the frequency of recovery of potential pathogens and aerobic and anaerobic interfering bacteria in the nasopharynx and nasal cavity of sinusitis prone (SP) children, with their recovery in non-sinusitis prone (N-SP) children. Nasopharyngeal and nasal cultures were taken from 20 SP and 20 N-SP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these micro-organisms were identified. Twenty-one potential pathogens (1.05 patient) were isolated from nasopharyngeal cultures from 14 of the 20 SP children, and 10 (0.5 patient) were recovered from 6 of the 20 NSP (p < 0.05). Bacterial interference between two aerobic (alpha and non-haemolytic streptococci) and two anaerobic species (Prevotella and Peptostreptococcus species) and four potential pathogens was observed. Bacterial interference was noted in 64 instances against 4 potential pathogens by 24 normal flora isolates that were recovered from 7 of the SP group and in 144 instances by 47 isolates from 18 of the NSP group (p < 0.05). Nineteen potential pathogens (0.95/patient) were isolated from nasal cultures of 13 of the 20 SP children and 8 (0.4/patient) were recovered from 5 of the 20 NSP (p < 0.05). Bacterial interference by similar micro-organisms was noted in 21 instances by 9 normal flora isolates that were recovered from 5 of the SP group, and in 63 instances by 26 isolates from 15 of the NSP group (p < 0.05). Our findings illustrate for the first time that the nasopharyngeal and nasal flora of NSP children contains more aerobic and anaerobic micro-organisms with interfering capability and less potential pathogens than that of SP children.     

Effect of antimicrobial therapy with amoxicillin and cefprozil on bacterial interference and beta-lactamase production in the adenoids

To compare the effects on the bacterial flora of the adenoids of antimicrobial therapy with amoxicillin or cefprozil, we enrolled in a prospective randomized study 60 children scheduled for elective adenoidectomy because of recurrent otitis media. They were randomized before surgery into 3 groups of 20 patients each: a no-therapy group, and groups with 10 days of either amoxicillin or cefprozil therapy. Core adenoid materials were quantitatively cultured for aerobic and facultative bacteria. The in vitro ability of alpha-hemolytic streptococci (AHS) to inhibit the growth of non-type B Haemophilus influenzae and Streptococcus pneumoniae was determined. The number of organisms in adenoids obtained from patients treated with either antibiotic was reduced as compared to that in adenoids from controls. However, in patients treated with amoxicillin, a significant decline in the number of AHS, and an increase (in Staphylococcus aureus) or no change in the number of other beta-lactamase-producing bacteria (BLPB) was noted. In contrast, in those treated with cefprozil, no change was noted in the frequency of recovery of AHS, and the number of BLPB decreased. Interfering AHS were more often recovered in patients treated with cefprozil. We conclude that the adenoids contain more interfering AHS after therapy with a second-generation oral cephalosporin (cefprozil) than after amoxicillin therapy. This study suggests a potential beneficial effect of using an antimicrobial that selectively spares interfering AHS while inhibiting BLPB.     

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.     

Failure of antibiotic therapy in acute otitis media

The aim of this retrospective study was to determine the possible causes of failure of antibiotic therapy in children with acute otitis media (AOM). Thirty-nine samples of middle-ear fluid were obtained by myringotomy from 31 children suffering from AOM, unrelieved by antibiotic therapy administered for over 48 hours. The samples were analysed by the usual microbiological techniques, including cultures, tests for beta-lactamase producing strains and the determination of the minimal inhibitory concentration of penicillin for Streptococcus pneumoniae. In 14 samples, no bacterial strains were detected in the cultures of middle-ear fluid; and in two samples the cultures revealed two strains of bacteria. The bacteria most frequently identified were Haemophilus influenzae, found in 11 samples, and Streptococcus pneumoniae, found in seven samples, of which four produced strains with reduced susceptibility to penicillin. The failure of antibiotic therapy in AOM appears to be related to the increased resistance of Haemophilus influenzae and to the reduced susceptibility of Streptococcus pneumoniae to penicillin. Other factors contributing to the failure of antibiotic therapy in AOM may be the viruses or the bacteria that produce multiple pathogens in the middle ear.     

Response-shift bias and parent-reported quality of life in children with otitis media

OBJECTIVES: To validate the 6-item quality-of-life survey (OM-6) and to investigate response-shift bias regarding children with otitis media. SETTING: Otorhinolaryngology department of a university hospital that serves the southernmost part of the Netherlands. PATIENTS: Seventy-seven children (age range, 12-38 months) experiencing persistent otitis media with effusion and scheduled for placement of tympanostomy tubes. SURVEY: The OM-6 measures health-related quality of life in 6 domains: physical suffering, hearing loss, speech impairment, emotional distress, activity limitations, and caregiver concerns. INTERVENTION: Parents completed the OM-6 before surgery (pretest) and 6 weeks after surgery (posttest). At the posttest, parents also completed a retrospective version of the pretest (retrospective pretest). RESULTS: For most items, the test-retest reliability was good (R>0.8). The internal consistency of the OM-6 was satisfactory (alpha =.79). The construct validity, determined by correlating the ear-related global quality-of-life measure and the OM-6 summary score, was fair (R = -0.77, P<.01). Prospective change in quality of life on the OM-6 ranged from moderate (standardized response mean >/=0.5) to large (standardized response mean >/=0.8). Response-shift bias was present at the group level (t = -3.3, P<.01). Retrospective change was significant for hearing loss (z = -3.3, P<.05) and ear-related global quality of life (z = -3.6, P<.05). CONCLUSIONS: The validity of the OM-6 has been proved in a Dutch population. The data suggest that parents underestimate the seriousness of hearing loss and overestimate the quality of life of their child before surgery, indicating a response shift. Treatment results could lead parents to realize that the situation before surgery had been worse than they thought.     

Antimicrobial resistance in Haemophilus influenzae isolated from the nasopharynx among Japanese children with acute otitis media

CONCLUSION: High prevalence of penicillin-binding protein (PBP) gene mutated (PGM) strains of H. influenzae should be taken into account when treating otitis media in children. OBJECTIVE: To evaluate prevalence of ss-lactamase nonproducing ampicillin-resistant (BLNAR) strains of Haemophilus influenzae with mutations in ftsI gene encoding penicillin-binding protein 3 (PBP3) among children with otitis media. METHODS: A total of 644 nasopharyngeal isolates of H. influenzae was collected from pediatric acute otitis media (AOM) patients with or without otitis media with effusions (OME) at the clinics of Otolaryngology-Head and Neck Surgery, Wakayama Medical University Hospital and six affiliated hospitals in Wakayama prefecture between January 1999 and December 2003. Minimal inhibitory concentrations (MICs) of ampicillin (AMP), cefditoren (CDN), cefdinir (CFD), cefaclor (CCL), cefpodoxime (CPD), and cefcapene (CFPN) were determined by the microbroth dilution method according to the recommendations of the National Committee for Clinical Laboratory Standards (NCCLS). Types of mutations in PBP3 gene (ftsI) were evaluated by a polymerase chain reaction (PCR)-based genotyping method. ss-Lactamase gene (bla) was also identified by PCR. RESULTS: ss-Lactamase-producing (BLP) strains with the bla gene were identified in 16 (2.5%) of isolates. PGM strains were identified in 279 (43.3%) isolates. There were 242 (37.6%) PGM1-nonBLP strains with mutations in variable mutated locus of ftsI, 35 (5.4%) PGM2-nonBLP strains with mutations in highly mutated locus of ftsI, 2 (0.3%) BLP-PGM strains with mutations in ftsI and producing ss-lactamase. BLP-nonPGM strains producing ss-lactamase without mutations in ftsI were identified in 14 (2.2%) isolates. MICs of PGM1-nonBLP strains to AMP were 0.5-2.0 microg/ml. The MIC(90) of CDN to the PGM1-nonBLP strains was lowest (0.06 microg/ml). Proportions of PGM1-nonBLP strains rapidly increased during 1999 to 2002 and then decreased in 2003. In contrast, PGM2-nonBLP strains increased in 2003.