Middle Ear Fluid Of Children Research Articles

Real-time quantitative PCR for the detection of Streptococcus pneumoniae in the middle ear fluid of children with acute otitis media

PCR based on the amplification of pneumolysin gene fragments has previously been applied to demonstrateStreptococcus pneumoniae in clinical specimens. Here, a real-time PCR method for the detection and quantification of pneumococci by amplifying a 206-bp fragment of the pneumolysin-encoding gene is described. The amplified fragments were detected simultaneously using fluorescent-labeled sequence-specific hybridization probes. The applicability of the assay to clinical samples was evaluated by studying 50 middle ear fluid (MEF) specimens from children with acute otitis media. Twenty-six of the MEF samples were positive by real-time PCR and the numbers of genome equivalents detected varied from 90 to 88,000/μl in 17 culture-positive samples and from 1 to 1200/μl in 9 culture-negative samples. The results were compared to culture findings and to results obtained by using agarose gel electrophoresis or Europium-labeled hybridization probes for the detection of amplification products of conventional PCR. The sensitivity and specificity of the real-time PCR assay developed in the present study compared to culture were 100 and 73%, and to conventional PCR with agarose gel and/or TRF detection 93 and 96%, respectively. The real-time PCR assay was found to be rapid, easy to use, and sensitive in detecting and quantifying pneumococci.

Biofilm formation by nontypeable Haemophilus influenzae: strain variability, outer membrane antigen expression and role of pili

BackgroundNontypeable Haemophilus influenzae is an important cause of otitis media in children and lower respiratory tract infection in adults with chronic obstructive pulmonary disease (COPD). Several lines of evidence suggest that the bacterium grows as a biofilm in the human respiratory tract.ResultsFifteen clinical isolates from middle ear fluid of children with otitis media and 15 isolates from sputum of adults with COPD were studied in an in vitro assay of biofilm formation. Striking variability among isolates was observed in their ability to form biofilms. Analysis of cell envelopes revealed minimal differences in banding patterns in polyacrylamide gels, alteration of expression of an epitope on lipooligosaccharide, and preservation of expression of selected epitopes on outer membrane proteins P2, P5 and P6 in biofilms compared to planktonically grown cells. A pilus-deficient variant showed a marked impairment in biofilm formation compared to its isogenic parent.ConclusionsNontypeable H. influenzae forms biofilms in vitro. Clinical isolates show substantial variability in their ability to grow as biofilms. Three major outer membrane proteins (P2, P5 and P6) are expressed during growth as a biofilm. Expression of lipooligosaccharide is altered during growth as a biofilm compared to planktonic growth. Pili are important in biofilm formation. As the role of biofilms in human infection becomes better defined, characterization of biofilms may be important in understanding the pathogenesis of infection and immune response to nontypeable H. influenzae in children with otitis media and adults with COPD.

Bacterial etiology of acute myringitis in children less than two years of age.

Acute myringitis is an inflammation of the tympanic membrane that occurs alone or in association with external otitis or otitis media. The two clinical entities, based on physical examination, are bullous myringitis and hemorrhagic myringitis. To investigate the association of concomitant middle ear disease with acute myringitis and to analyze the bacteriologic findings of the middle ear fluid in children with acute myringitis. A prospective longitudinal cohort study of 2028 children age 7 to 24 months at primary care level in the Finnish Otitis Media Vaccine Trial. Matched case-control design for analysis of bacterial pathogen distribution. There were 82 children in whom 92 ears were diagnosed with acute bullous myringitis and 37 children in whom 40 ears were diagnosed with hemorrhagic myringitis during the follow-up. Middle ear disease was associated with bullous myringitis in 97% of ears and with hemorrhagic myringitis in 82% of ears. Bacterial pathogen distribution was similar to that of acute otitis media, although a higher proportion of Streptococcus pneumoniae was detected in both bullous and hemorrhagic acute myringitis. Middle ear fluid was present in vast majority of ears with acute myringitis in young children. The same etiologic bacteria were found in acute myringitis as in acute otitis media, but S. pneumoniae was the major pathogen. Acute bullous myringitis should be treated as acute otitis media in children <2 years of age.

Acute otitis media caused by Streptococcus pneumoniae in children's hospitals between 1994 and 1997.

To determine patterns of resistance for isolates of Streptococcus pneumoniae recovered from middle ear fluids of children from eight children's hospitals between September, 1994, and August, 1997. Data were extracted retrospectively from the medical records of eight children's hospitals. A standardized data form was completed for each episode of pneumococcal infection. Systemic isolates (blood and pleural, synovial and spinal fluids) of S. pneumoniae were collected during the same period. All isolates of S. pneumoniae from each center were sent to a central laboratory. Susceptibility to penicillin and ceftriaxone was determined by microbroth dilution. Organisms were considered nonsusceptible to penicillin if the minimum inhibitory concentration was > or = 0.1 microg/ml and nonsusceptible to ceftriaxone if the minimum inhibitory concentration was > or = 1.0 microg/ml. S. pneumoniae was recovered from the middle ear fluids of 707 children from all centers during the study period. Thirty-nine (5.5%) were infections recorded at 4 centers which evaluated middle ear fluid only sporadically and were not included in this analysis. The remaining 668 infections reported by the 4 remaining participating hospitals reflect the experience of 608 children. There were 54% boys; 440 (73%) were Caucasian, 111 (18%) were African-American, 38 (6%) were Hispanic and for 19 (3%) the race was not recorded. The children ranged in age from 16 days to 13.8 years with a mean (+/-sD) of 26.0 (+/- 26.1) months. Children who received antibiotics in the 30 days before the middle ear isolate was recovered were more likely to harbor a resistant strain of S. pneumoniae than children who had not recently received an antibiotic (P < 0.001). Isolates recovered from children with spontaneous otorrhea were more likely to be susceptible to penicillin than isolates recovered during myringotomy, with or without the insertion of tympanostomy tubes (P < 0.01). There was wide variation in the susceptibility of middle ear isolates to penicillin and ceftriaxone according to geographic location; however, in every locale the middle ear isolates were less likely to be susceptible to penicillin and ceftriaxone than systemic isolates of S. pneumoniae. The prevalence of penicillin-resistant and cephalosporin-resistant S. pneumoniae in middle ear isolates derived from children cared for at four different children's hospitals was quite variable. In some locations the prevalence of resistance is still increasing, whereas in other areas the rate of resistance was at a plateau during the period of surveillance. The prevalence of isolates of S. pneumoniae susceptible to penicillin and ceftriaxone was always less common among middle ear isolates than among systemic isolates. Previous antibiotic use remains the most predictive factor for the recovery of isolates resistant to penicillin and ceftriaxone.

Interleukin‐8 Secretion of Human Epithelial and Monocytic Cell Lines Induced by Middle Ear Pathogens

Otitis media with effusion (OME) is one of the most common diseases in children. Alloiococcus otitidis, a new gram-positive bacterial species, was isolated from the middle ear fluid of children with OME; however, the pathogenic role of this bacteria is yet unknown. In this study, the ability of cultured epithelial cell lines (Hep-2 and Hela) and monocytic cell lines (THP-1 and U 937) to secrete chemokine interleukin-8 (IL-8) in response to the A. otitidis organism and three bacterial organisms mainly detected from middle ear fluid in OME, and bacterial cell components was investigated. When stimulated with four viable bacterial cells, epithelial cells and monocytes secreted IL-8 in a time-dependent manner. The monocytes produced significantly higher levels of IL-8 than the epithelial cells. Compared with that by viable bacterial cells, IL-8 secretion by stimulated epithelial cells and monocytes was reduced when the bacteria were heated and treated with glutaraldehyde. With bacterial stimulations, cell treatment of interferon-gamma caused monocytes to increase the induction of IL-8 production, however, the induction of monocyte differentiation caused monocytes to reduce the induction of IL-8 production. Furthermore, epithelial cells and monocytes stimulated by four viable bacterial organisms physically separated from cultured cells reduced the induction of IL-8 compared with directly stimulated cells, and monocytes stimulated with soluble extracts prepared from A. otitidis organisms produced IL-8 in a dose-dependent manner. These results suggest that part of the IL-8 stimulation of the A. otitidis organism may exist in a diffusable factor released by the bacteria or soluble components of the bacteria itself.

Conjugate pneumococcal vaccine and antibiotic-resistant Streptococcus pneumoniae: herd immunity and reduction of otitis morbidity.

Conjugate pneumococcal vaccine and antibiotic-resistant Streptococcus pneumoniae: herd immunity and reduction of otitis morbidity.

The Role of Chlamydia in Upper Respiratory Tract Infections.

Although Chlamydia pneumoniae and Chlamydia psittaci are well-established causes of community-acquired pneumonia, little is known about the role of Chlamydia species in upper respiratory tract infections. C. pneumoniae may play a role in the pathogenesis of acute otitis media. Although C. pneumoniae has been isolated from the middle-ear fluid of children with otitis, children in whom the organism was isolated from middle-ear fluid improved despite being treated with antibiotics that are not active against C. pneumoniae. Although many patients with community-acquired pneumonia caused by C. pneumoniae have symptoms suggestive of sinusitis, there is only one report of isolation of the organism from the maxillary sinus of a patient with sinusitis. Studies of the association with pharyngitis are all based on serology, which often has a poor correlation with isolation of the organism by culture.

Interleukin 8 in middle ear fluid during acute otitis media: correlation with aetiology and bacterial eradication

OBJECTIVESTo study the concentration of interleukin 8 (IL-8) in the middle ear fluid of children with acute otitis media and the association between IL-8 concentrations, aetiology of acute otitis media,...

Resistant bacteria in middle ear fluid at the time of tympanotomy tube surgery.

This study was performed to determine the prevalence of resistant Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis isolated from middle ear fluid of children undergoing placement of ventilation tubes. The extent of resistance to commonly prescribed antibiotics and the risk factors associated with this resistance were also examined. Children who had fluid present in their middle ears at the time of ventilation tube placement from May 1996 to May 1997 were included in the study. Middle ear fluid was plated onto culture media in the operating room, and antimicrobial resistance of cultured organisms was ascertained. Risk factors for this resistance were determined from the medical history and analyzed. Cultures of 244 patients (355 ears) were positive for organisms in 29.6%. Penicillin resistance was found in 38.2% of S pneumoniae cultures. Beta-lactamase production was found in 65.1% and 100% of H influenzae and M catarrhalis specimens, respectively. Risk factor analysis revealed young age, day care attendance, and number of antibiotic courses to most reliably predict the presence of resistant microorganisms.

Penetration of ceftazidime into middle ear fluid in children with effusion: Begue P, Garabedian EN, Bertrand C, et al. Laryngoscope 108:662, 1998

Penetration of ceftazidime into middle ear fluid in children with effusion: Begue P, Garabedian EN, Bertrand C, et al. Laryngoscope 108:662, 1998

Penetration of ceftazidime into middle ear fluid in children with otitis media with effusion.

Twenty-five children with otitis media with effusion received ceftazidime 50 mg/kg intravenously before bilateral myringotomy with insertion of tympanostomy tubes. Concentrations of ceftazidime measured in serum and middle ear fluid exceeded 4 mg/L (i.e., largely above the minimal inhibitory concentrations for the gram-negative pathogens commonly recovered from children with otitis media) for at least 4 hours. Mean peak concentrations occurred 30 to 90 minutes after the injection and reached 11 to 14 mg/L. These results are in keeping with the clinical efficacy of ceftazidime in the treatment of chronic middle ear infections in children.

Penetration of ceftriaxone into the middle ear fluid of children.

Penetration of ceftriaxone into the middle ear fluid of children.

Diagnostic Criteria for Otitis media in Children

Objectives: To determine the accuracy of various symptoms in predicting acute otitis media and the accuracy of pneumo-otoscopy and minitympanometry in identifying middle ear fluid in children. Patients: Symptoms were recorded and compared to pneumo-otoscopic findings in 354 children suffering from acute illness, to analyze the validity of various symptoms in predicting acute otitis media. Pneumo-otoscopic findings were recorded in 76 children and minitympanometric findings in 162 children referred for surgery due to recurrent or chronic otitis media and compared to the myringotomy finding to assess the validity of various pneumo-otoscopic signs and type B minitympanogram in identifying middle ear effusion. Results and Conclusions: The ear-related symptoms were specific, but too unsensitive, and the general symptoms too unsensitive and unspecific to be used alone as criteria for acute otitis media. The abnormal position and impaired mobility of the tympanic membrane in pneumatic otoscopy were very specific signs of middle ear effusion but only the latter had a moderately high sensitivity. When combined by an experienced otoscopist into an overall subjective judgement, however, they afforded an acceptably high sensitivity (81%) and specificity (86%). Type B minitympanogram was reasonably sensitive (79%) and had a high specificity, but only in cooperative children (93%), the specificity in uncooperative children being very low (38%). All in all, penumatic otoscopy and minitympanometry, the latter in cooperative children, are acceptably accurate methods to be used in the diagnosis of both acute otitis media and chronic otitis media with effusion.

Chlamydia pneumoniae in acute otitis media.

Aerobic bacterial pathogens are recovered from 65 to 85% of patients with acute otitis media (AOM). Although Chlamydia pneumoniae is a common pathogen of pediatric pneumonia, it has rarely been cultured from children with chronic otitis media and its role in AOM is unknown. We cultured for C. pneumoniae in tympanocentesis aspirates and nasopharyngeal swabs from 101 consecutive, otherwise healthy children with AOM or refractory AOM. A control group of 50 similarly aged, healthy children was evaluated for nasopharyngeal carriage of C. pneumoniae. Specimens were also evaluated by PCR for C. pneumoniae. C. pneumoniae was recovered by tympanocentesis in 8 (8%) of 101 children with AOM. Among the 8 children with C. pneumoniae-positive-AOM, 5 had C. pneumoniae detected by PCR in middle ear fluid, none had C. pneumoniae recovered by nasopharyngeal culture or PCR and 5 were younger than 16 months. C. pneumoniae was the sole pathogen isolated in 2 patients. Copathogens included beta-lactamase-positive positive Haemophilus influenzae (2), beta-lactamase positive Moraxella catarrhalis (1), penicillin-resistant Streptococcus pneumoniae (2) and penicillin-susceptible S. pneumoniae (1). C. pneumoniae was recovered from nasopharyngeal culture in 2 additional patients with C. pneumoniae-negative AOM and in none of 50 healthy control children, although 2 controls were positive by PCR from the nasopharynx. This is the first study to report the isolation of C. pneumoniae in middle ear fluid of children with AOM.

Middle ear fluid concentrations of amoxicillin after large dosages in children with acute otitis media.

Middle ear fluid concentrations of amoxicillin after large dosages in children with acute otitis media.

Penetration of cefpodoxime into middle ear fluid in pediatric patients with acute otitis media.

Penetration of cefpodoxime into middle ear fluid in pediatric patients with acute otitis media.

Development of beta-lactamase-mediated resistance to penicillin in middle-ear isolates of Moraxella catarrhalis in Finnish children, 1978-1993.

The frequency of beta-lactamase production was analyzed in a study of 1,452 strains of Moraxella catarrhalis and 2,738 strains of Haemophilus influenzae isolated from middle-ear fluid of children < 6 years of age at Tampere University Hospital in Tampere, Finland, between 1978 and 1993. In addition, 401 isolates of M. catarrhalis from similar samples collected in different parts of Finland in 1988-1990 were tested for beta-lactamase production; minimal inhibitory concentrations of ampicillin, cefaclor, cephalothin, erythromycin, tetracycline, and trimethoprim-sulfamethoxazole for these strains were determined. These data were compared with figures for the annual consumption of beta-lactam antimicrobials in the community in 1978-1993. A bimodal increase in the proportion of strains of M. catarrhalis producing beta-lactamase was detected: from 0 to 60% in 1978-1983 and from 60% to 80% in 1988-1990. Concurrently with the second increase, the consumption of cephalosporins increased substantially in the community. The frequency of beta-lactamase-producing strains of H. influenzae did not increase between 1978 and 1993.

Pharmacokinetics of ceftibuten in children

The bioavailability and pharmacokinetics of ceftibuten administered as an oral suspension were characterized by several studies in young healthy male adults (19 to 39 years old) and children ranging in age from 6 months to 17 years. Ceftibuten suspension was found to be bioequivalent and thus interchangeable with a standard 400-mg capsule. As with the capsule formulation, food slightly (< 20%) affected the rate and extent of absorption of the suspension. The recommended dose of 9.0 mg/kg was found to produce comparable plasma concentrations in children of all ages (6 months to 17 years). The range of mean values of maximum plasma concentrations (Cmax) was 12 to 16 micrograms/ml at the 9.0-mg/kg dose level. Doses of 4.5, 9.0 and 13.5 mg/kg produced Cmax and area under the plasma concentration-time curve values that were dose-proportional. The half-life (t1/2) was essentially independent of age and dose, ranging from 2 to 3 hours. The apparent clearance (Cl/F), uncorrected for the fraction of drug absorbed (F), is independent of dose but appears to increase with a decrease in age. This also occurs to a lesser degree with the volume of distribution (Vd/F), uncorrected for F. Current evidence suggests that this is more likely to be caused primarily by a decrease in F than an increase in Cl. Ceftibuten rapidly and extensively reaches the middle ear fluid in children with acute otitis media. Within 4 hours concentrations in middle ear fluid are similar to plasma concentrations and can be measured for 12 hours. The ratio of area under the concentration time curve for middle ear fluid relative to plasma was about 70%.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimicrobial resistance of Streptococcus pneumoniae in Finland, 1987-1990.

A nationwide survey of the prevalence of antimicrobial resistance among Streptococcus pneumoniae isolates from the middle ear fluid of children with acute otitis media (639 strains) and from throat-swab samples of healthy children (149 strains) was conducted in Finland during 1987-1990. The MICs of penicillin, cephalothin, cefaclor, erythromycin, trimethoprim, and co-trimoxazole were determined by the agar dilution method. Low-level resistance to penicillin (MIC, 0.1-1 microgram/mL) was found in 1.7% of the otitis-related and 1.3% of the healthy-carrier strains. No highly penicillin-resistant strains (MIC, > or = 2 micrograms/mL) were found. Six multiresistant strains were detected, three of them possibly belonging to a previously identified clone present in Finland since 1985. Eighty-five percent of the resistant otitis-related strains, including 9 of the 11 moderately penicillin-resistant strains (4 of which were multiresistant), belonged to the three most common serogroups (6, 19, and 23).

Antibodies to Pneumolysin and Pneumococcal Capsular Polysaccharides in Middle Ear Fluid of Children with Acute Otitis Media

Antibodies to pneumococcal pneumolysin and capsular polysaccharides were measured by enzyme immunoassay in 169 acute phase middle ear fluid samples of 116 children with acute otitis media. Antibodies to pneumococcal pneumolysin were detected in 84% and to capsular polysaccharides in 50% of the MEF samples. The Ig class detected most often was IgA to both types of pneumococcal antigens, and it was present in MEF even with non-detectable levels of serum IgA of the same specificity. 59% of the MEF samples positive for IgA to pneumolysin were also positive for secretory component of the same specificity, and 53% of IgA to capsular polysaccharide pool (containing serotypes 6B, 14, 19F, and 23F), respectively. This suggests both leakage of specific IgA from serum to the middle ear and local production of it. In contrast, specific IgG was detected in MEF only with concomitant IgG in serum. Antibodies to pneumolysin occurred in no relation to bacterial findings in MEF. On the contrary, IgG class antibodies to capsular polysaccharides, most likely serum-derived, were detected less often in MEF samples positive for pneumococcus than for other bacteria.