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.     

Antibiotic resistance in pathogens causing acute otitis media in Finnish children

IntroductionMicrobiology and susceptibility of middle ear pathogens in children change over time and antibiotic resistance is increasing globally. For the clinicians it is important to be up to date about the resistance situation when considering antibiotic treatment in acute otitis media (AOM). In this study we analysed the resistance profile of AOM pathogens in out-patient children in Finland.Methods and materialsA total of 41 culture positive middle ear fluid (MEF) samples were analysed for bacteria and the presence of antibiotic resistant strains. The samples were obtained from children aged six – 39 months who participated in the otitis media trial during one year period.ResultsThe most common pathogen was Haemophilus influenzae 17 (40%), followed by Streptococcus pneumoniae in 15 (35%) and Moraxella catarrhalis in 8 (19%). Other pathogens were detected in 3 (7%) of cases. Antibiotic resistance or diminished sensitivity was seen in 63% of the detected bacteria and 28% of pathogens produced beta-lactamase.ConclusionsAntibiotic resistant bacterial strains causing AOM have increased in Finland. Nevertheless, most of the pathogens (72%) were sensitive to amoxicillin, which is still recommended as the first line antibiotic in the treatment of AOM.     

Individual-level effects of antibiotics on colonizing otitis pathogens in the nasopharynx

BackgroundAlthough there is evidence of an association between antibiotic consumption and resistant bacteria on a population level, the relationship on an individual level has been less well studied, particularly in terms of nasopharyngeal colonization. We have therefore analysed this association, using data from a closely followed cohort of children taking part in a vaccination trial.Methods109 children with early onset of acute otitis media (AOM) were randomised to heptavalent pneumococcal conjugate vaccine (PCV7) or no vaccination. They were followed for three years with scheduled appointments as well as sick visits. Nasopharyngeal cultures were obtained at all visits. Antibiotic treatments were recorded, as were risk factors for AOM, including siblings, short breast-feeding and parental smoking. Data were entered into a Cox regression model, and the findings of Streptococcus pneumoniae and Haemophilus influenzae with reduced susceptibility to the penicillin group were related to the number of previous courses of antibiotics.ResultsThere was evidence of an association between the amount of previously consumed betalactams and colonization with beta-lactamasenegative ampicillin-resistant (BLNAR) H. influenzae (RR 1.21; 95% CI 1.03–1.43; p = 0.03), and also with the most commonly prescribed drug; amoxicillin (RR 1.39; 95% CI 1.09–1.76; p = 0.01). There was no evidence for an association between antibiotic consumption and betalactamase producing H. influenzae or S. pneumoniae with reduced susceptibility to penicillin. Furthermore, there was no evidence of an association between resistant bacteria and AOM risk factors or PCV7.ConclusionIn this subgroup of children, most of whom were given several courses of antibiotics in early childhood, there was evidence of an association between betalactam/amoxicillin consumption and nasopharyngeal colonization with BLNAR strains, bacteria that have increased in prevalence during the last 10–15 years, and that are notoriously difficult to treat with oral antibiotics.     

Single dose amoxicillin treatment of acute otitis media

A double blind study comparing a single dose of amoxicillin versus a 10-day course of amoxicillin in the treatment of acute otitis media (AOM) was undertaken. All children diagnosed with AOM in a pediatric clinic were requested to participate. After tympanocentesis was performed, patients were randomly assigned to receive either amoxicillin (100 mg/kg) followed by placebo every 8 hours for 10 days or placebo followed by amoxicillin (40 mg/kg/D) for 10 days. Patients returned to clinic on days 3 and 10 post-treatment. Seventeen patients were enrolled: 7 received single dose therapy and 10 received 10 days of therapy. There were no failures in the control group and 3 failures in the single dose group (day 5, day 6, and 11) (p = 0.05). Middle ear isolates included: S. pneumoniae 7, H. influenzae 4, B. catarrhalis 1, and no pathogen in 5. Due to the significant number of failures in the treatment group, the study was prematurely terminated.     

Acute otitis media-diagnosis and treatment in the era of antibiotic resistant organisms: updated clinical practice guidelines

The treatment of children with AOM has to rely on an accurate diagnosis and a clear discrimination between AOM and serous otitis media. The last decade has seen major changes in the epidemiology of AOM with an earlier onset of disease and a greater proportion of children with recurrent/complicated AOM. The processes of changing susceptibility of bacterial pathogens added a major problem in treatment selection. Tastier, more efficient, safe and conveniently-dosing as well as cost effective drugs are required to achieve adherence to therapy. The recent published guidelines for the treatment of AOM in the present era of pneumoccocal resistance represent a major step forward in the approach to the management of this disease by establishing a clear hierarchy among the various therapeutic agents. A 48-72 h observation option without use of antibacterial therapy in selected children with uncomplicated AOM should be promoted. Immunization against S. pneumoniae with the heptavalent pneumococcal conjugated vaccines was showed to result in a decrease in the frequency of AOM caused by this pathogen, including AOM caused by antibiotic-resistant S. pneumoniae.     

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.     

Prevalence and antimicrobial-resistance of S. pneumoniae and S. pyogenes in healthy children in the region of Madrid

Streptococcus pneumoniae and Streptococcus pyogenes are common agents of respiratory or ORL pathology. Pneumococcus sensitivity has progressively decreased to penicillin and other antimicrobial agents, mainly in south of Europe, but this resistance report can be erroneous by a selection bias, because they sampled only hospital cases. OBJECTIVES: To determine the prevalence, antimicrobial susceptibility and risk factors of S. pneumoniae and S. pyogenes in healthy children under 5 years of age who go to infant school. SUBJECT AND METHODS: Cross sectional study in six infant schools. An epidemiological inquiry (risk factors of carrier state) was filled out and a nasopharyngeal specimen was taken from each child, S. pneumoniae and S. pyogenes were identified and antimicrobial tests were performed. RESULTS: We have studied 156 children with a mean age of 2.24 (standard deviation (S.D.), 0.85) and 58% have been treated with antibiotic in the last 3 months. The prevalence of S. pneumoniae or S. pyogenes were 12.2 and 5.1%, respectively. S. pyogenes only was isolated in two schools. Age was associated with S. pyogenes carrier but the rest of studied factors have no statistical significance with both microorganisms. All the S. pneumoniae showed resistance to one or more antibiotic (mainly to clavunate-amoxycillin: 94.7%), while S. pyogenes only was resistant to clavunate-amoxycillin. CONCLUSION: Healthy children (0-4 years) with antibiotherapy in last 3 months have a great frequency of resistant S. pneumoniae. It is necessary to reduce the antibiotic use at home (Medical education).     

Acute otitis media in infants less than three months of age: clinical presentation, etiology and concomitant diseases

OBJECTIVE: Acute otitis media (AOM) in the neonatal period can be difficult to diagnose. This infection can be isolated and localized, or it may be associated with serious bacterial infections or other illnesses. The objectives of this study were to determine the clinical presentation, etiology, susceptibility pattern, and frequency of bacteremia, meningitis and other serious bacterial infections associated with the first episode of AOM in young infants. METHODS: From July 2002 to August 2004, infants less than 12 weeks of age with confirmed AOM underwent tympanocentesis with culture of the middle ear fluid. Sepsis work-up was performed in all infants, and they were admitted to the pediatric department. Parenteral antibiotic therapy with a combination of ampicillin and gentamicin was initiated. RESULTS: Sixty-eight infants were diagnosed with AOM. The median age was 43+/-17 days, 17 infants (25%) were less than 4 weeks of age. Fever was present in 45 (66%) of the patients. Meningitis or bacteremia was not diagnosed in any of the cases. Concomitant urinary tract infection was diagnosed in six (8.8%) cases and broncholitis in seven (10.4%). Forty-seven bacterial pathogens were isolated from the middle-ear fluid. Streptococcus pneumoniae was the leading pathogen with 18 isolates (38%), followed by non-typable Haemophilus influenzae with nine (19%). Fourteen of the S. pneumoniae (78%) isolates were susceptible to penicillin and the other four (22%) were intermediately resistant. Three (33%) of the nine H. influenzae isolates were beta-lactamase producers. CONCLUSIONS: In our study, AOM in infants less than 3 months of age is a localized infection and it is not associated with severe bacterial infections. S. pneumoniae and H. influenzae are the leading pathogens. In our region, most of S. pneumoniae strains are still susceptible to penicillin. Although only small number of patients were under 4 weeks of age, the results of the present study raise the question of whether the current policy of a full sepsis work-up in neonates with AOM is relevant.     

Acute otitis media: bacteriology and bacterial resistance in 205 pediatric patients

Acute otitis media (AOM) is one of the most frequent diagnoses in children below the age of 2 years. Treatment is usually based on information included in the literature concerning bacteriology. The purpose of this work was to define the most frequent germs in the etiology of AOM within our community, in order to optimize therapeutics for this pathology. Cultures in middle ear secretions obtained through tympanocentesis were performed to this end, ensuring careful sample taking and processing. The results obtained are similar to those published in previous papers for which Streptococcus pneumoniae and Haemophilus influenzae proved to be the predominant germs. However, there are certain discrepancies concerning the incidence of Moraxella catarrhalis and this has a direct impact on the total percent of resistant strains, thus modifying therapeutic approaches for treatment of AOM. The antibiotic sensitivity profiles of the most frequent etiologic agents were studied in accordance with the principles established by the 'National Committee for Clinical Laboratory Standards' (NCCLS).     

Comparison of amoxicillin and azithromycin in the prevention of recurrent acute otitis media

OBJECTIVE: To compare the outcome of patients with recurrent acute otitis media (AOM) treated either with amoxicillin or with azithromycin. METHODS: This prospective, controlled, and randomized study, compares the outcome of 71 patients with recurrent AOM treated with azithromycin (31 patients) or amoxicillin (40 patients) for the prevention of AOM. azithromycin was given at a dose of 10 mg/kg once a week, whereas amoxicillin was administered daily as a single intake of one third of the therapeutic dosage (20 mg/kg per day). All treatments were prescribed for 3 months. Both groups were homogeneous with regard to the currently accepted predisposing factors of recurrent AOM. Mean age of children was 35.3 months, and average follow-up was 11.5 months. The treatment was considered effective when the number of episodes of AOM dropped to less than 50% after the prophylaxis. RESULTS: Patients in the azithromycin group had a clinical response to prophylaxis (80.6%) comparable to those treated with amoxicillin (89.5%) (P=0.300). The incidence of adverse effects was similar in both groups. CONCLUSION: According to these results, a prophylaxis with azithromycin is as useful as amoxicillin to prevent recurrent AOM.     

Effects of amoxicillin and cefdinir on nasopharyngeal bacterial flora

OBJECTIVE: To compare the effects of cefdinir (14 mg/kg per day) and amoxicillin (90 mg/kg per day) antimicrobial therapy on the nasopharyngeal flora of children with acute otitis media. DESIGN: Nasopharyngeal cultures for aerobic and facultative bacteria were obtained before therapy and 2 to 4 days after completion of therapy. SETTING: Outpatient clinic. PATIENTS: Fifty children, aged 7 months to 5 years 4 months. MAIN OUTCOME MEASURES: After completion of therapy, 22 (88%) of the 25 patients treated with cefdinir and 16 (64%) of the 25 patients treated with amoxicillin were considered clinically cured (P<.05). A significant reduction in the number of all isolates occurred following therapy in those treated with cefdinir (36 vs 71, P<.01) or with amoxicillin (56 vs 73, P<.05). However, the total number of isolates recovered after therapy was significantly lower in those treated with cefdinir (36) compared with those treated with amoxicillin (56) (P<.01). RESULTS: The recovery of potential pathogenic organisms (eg, Streptococcus pneumoniae, Staphylococcus aureus, beta-hemolytic streptococci, Haemophilus species, and Moraxella catarrhalis), as well as penicillin-resistant bacteria, was lower following completion of therapy in the cefdinir group (6 pathogens, including 5 that were penicillin resistant), compared with the amoxicillin group (27 pathogens, including 16 that were penicillin resistant) (P<.01). CONCLUSION: This study illustrates the greater ability of cefdinir compared with amoxicillin to reduce the number of potential nasopharyngeal pathogens as well as penicillin-resistant bacteria in children with acute otitis media.     

Identification of bacterial strain at each episode of recurrent acute otitis media

This study was undertaken to investigate whether each episode of recurrent acute otitis media (rAOM) is caused by the same strain of bacteria or different strains at each episode. Seventy infants less than 3-years of age, having experienced rAOM for a period shorter than 8 weeks, were selected and included in the present study. The total number of AOM episodes experienced by this group was 282. At each subsequent episode of AOM, otorrhea and nasopharyngeal swabs were taken for bacterial culture and determination of the MIC for antibiotics. When S. pneumoniae was identified, its serotype, and its pbp, ermAM, and mefE genes were also investigated to determine the bacterial species and strains. S. pneumoniae was the most frequently cultured bacteria with 26 penicillin-sensitive S. pneumoniae (PSSP), 65 penicillin-insensitive S. pneumoniae (PISP), and 50 penicillin-resistant S. pneumoniae (PRSP). H. influenzae was the next most frequently cultured bacteria of which 65 were sensitive to penicillin, 27 were found to be beta-bactamase-negative-ampicillin-resistant (BLNAR) and 17 were found to be beta-bactamase positive. Bacteria cultured from each pair of two successive episodes of AOM were compared as to the identity of the bacteria during the two episodes. In 150 out of 202 pairs (74%), the cultured pathogen was different. In 22 cases in which either PISP or PRSP was the pathogen detected in two consecutive AOM episodes, 15 cases (68%) were found in which the involved strain differed between the two episodes. This study indicates that the pathogen involved in rAOM is likely to differ at each episode of AOM, not only in cases caused by PSSP, but also in those caused by PRSP.     

Etiology of acute otitis media in childhood and evaluation of two different protocols of antibiotic therapy: 10 days cefaclor vs. 3 days azitromycin

BACKGROUNDS: Acute otitis media (AOM) is a common childhood infection that is frequently treated by antibiotics. There are no prospective and comprehensive trials evaluating childhood AOM for etiologic pathogens and resistance pattern in Turkey. The aims of the study were to determine the bacterial etiologies and resistance patterns, and identify the efficacy and the relapse rates of 3 days of azitromycin and 10 days of cefaclor therapy in AOM. METHODS: This prospective, randomized, single-blind, open study was carried out in 78 cases of AOM. Mean age was 30.7+/-27 months. Tympanocentesis and aspiration of middle ear fluid (MEF) were used to obtain purulent material from the middle ear. Group 1 consisted of the cases (n=41) on azitromycin therapy and Group 2 (n=37) on cefaclor. Dosage of azitromycin was 10 mg/kg per day for 3 days and cefaclor 40 mg/kg per day for 10 days. The patients were evaluated on days 3-5 (second visit), day 10 (third visit), and day 30 (fourth visit) during follow-up. RESULTS: A total of 50 species were isolated from 44 of 78 cases from which materials were obtained (44/78; 56.4%). Most frequently isolated microorganism was Streptococcus pneumoniae (n=18; 36%), followed by Haemophilus influenzae (n=11; 22%), S. aureus (n=9; 18%), Moraxella catarrhalis (n=4; 8%), and group A beta-hemolytic streptococcus (GAS, n=4; 8%). Enterococcus faecalis was isolated from three cases and H. parainfluenzae from one. Penicillin and amoxicillin resistances of bacteria were found to be 40 and 36%, respectively. The frequency of penicillin and amoxicillin resistance in 相似文献   

Acute otitis media develops in the rat after intranasal challenge of Streptococcus pneumoniae

OBJECTIVES/HYPOTHESIS: The rat is a frequently used animal model for middle ear research. To date, acute otitis media (AOM) has been evoked after instillation of bacteria directly into the middle ear cavity or after traumatizing the tympanic membrane. The purpose of the study was to examine whether, with an intact tympanic membrane and middle ear cavity, intranasally deposited bacteria cause AOM and how tympanic membrane stimulation influences this procedure. STUDY DESIGN: In vivo, murine model. METHODS: In a rat model, Streptococcus pneumoniae, type 3, was intranasally inoculated for 5 consecutive days. The tympanic membrane was treated with saline or with compound 48/80 or was left untreated. The development of AOM was evaluated by otomicroscopy, light microscopy, and middle ear culture. RESULTS: Ninety percent of the ears developed AOM. However, when the tympanic membranes were treated with saline or compound 48/80, only 40% and 57%, respectively, developed AOM. In all, 23 of 40 ears developed AOM and 20 ears showed growth of bacteria. CONCLUSION: Repeated intranasal deposition of S. pneumoniae, type 3, causes AOM in the rat. The development of AOM can be influenced by tympanic membrane stimulation.     

儿童急性中耳炎金黄色葡萄球菌抗生素耐药性与分子遗传背景特征分析

目的 分析儿童急性中耳炎分泌物中分离的金黄色葡萄球菌(staphylococcus aureus,SA)菌株抗生素药物敏感性和分子特征.方法 收集150例临床诊断为急性中耳炎儿童中耳腔脓液或耳分泌物进行细菌培养鉴定,进一步进行菌株的抗菌药物敏感性试验,检测菌株的耐药基因、毒力基因和多序列基因分型(MLST)分析.结果 ...     

Evolution of the bacteriologic features of persistent acute otitis media compared with acute otitis media: a 15-year study.

OBJECTIVES: To define the epidemiologic features of persistent acute otitis media (PAOM) and modifications of these features during the past 15 years and to investigate for possible differences in bacterial resistance between acute otitis media (AOM) and PAOM. DESIGN: Retrospective patient series. SETTING: Academic tertiary care center. PATIENTS AND METHODS: Persistent acute otitis media was defined as AOM lasting longer than 3 weeks despite 1 or several courses of antibiotic therapy, with the persistence of clinical and otoscopic signs of AOM. From 1982 to 1997, 475 children with PAOM were seen in our department. Every patient had 1 or several specimens of aspirations or swabs of spontaneous otorrhea (or both). Microbiologic characteristics of the isolated strains (including antibiotic susceptibility) were analyzed. Four successive series of specimens were analyzed-group 1: from October 1, 1982, to June 30, 1986 (136 patients); group 2: from January 1, 1987, to December 31, 1989 (165 patients); group 3: from January 1, 1992, to April 30, 1993 (73 patients); and group 4: from January 1, 1994, to January 31, 1997 (101 patients). During the same study periods, the bacteriologic results of patients with AOM in the same geographic region were recorded. MAIN OUTCOME MEASURES: A longitudinal comparison between the groups of patients with PAOM and a cross-comparison within each group between patients with PAOM and those with AOM. RESULTS: Obtaining repeated and multiple specimens from patients with PAOM led to a progressive decrease in the rate of sterile specimens, from 35.3% (group 1, 48 patients) to 14.9% (group 4, 15 patients) (P<.01). During this period, the prevalence of Streptococcus pneumoniae increased in patients with positive culture results, from 18.2% (group 1, 16 of 88 patients) to 44.2% (group 4, 38 of 86 patients) (P<.001). These strains rapidly and dramatically became resistant to penicillin (amoxicillin) (0% through 1989, 76.2% [16 of 21 patients] in 1993, and 97.4% [37 of 38 patients] in 1996) (P = .01). The overall prevalence of Haemophilus influenzae remained stable (between 31.4% [27 of 86 patients] and 45.4% [40 of 88 patients]), but the proportion of beta-lactamase-producing strains increased from 30.0% (group 1, 12 patients) to 55.6% (group 4, 15 patients) (P=.04). The prevalences of Pseudomonas aeruginosa and Staphylococcus aureus did not vary significantly (from 23.1% [group 2, 30 patients] to 10.7% [group 3, 6 patients] and from 10.2% [group 1, 9 patients] to 4.6% [group 4, 4 patients], respectively). Comparing data from patients with PAOM with those with AOM revealed that the increased resistance of H influenzae and, in particular, of S pneumoniae was more rapid and more marked in patients with PAOM than in those with AOM (highest rate of resistance in AOM: 36.0% [271 of 753 specimens] and 50.6% [398 of 787 specimens] for H influenzae and S pneumoniae, respectively; P<.001 for S pneumoniae). CONCLUSIONS: The increase in bacterial resistance frequently encountered during otitis media is even more marked in patients with PAOM. The identification of the organism is essential when the otitis does not resolve, especially in patients with PAOM. Obtaining repeated specimens helps to decrease the rate of sterile cultures.     

Amoxicillin-sulbactam versus amoxicillin-clavulanic acid for the treatment of non-recurrent-acute otitis media in Argentinean children

Streptococcus pneumoniae (Sp) and Haemophilus influenzae (Hi) are the leading bacterial cause of acute otitis media (AOM), having the nasopharynx (NP) as their reservoir. In October 2001 we began a prospective, multicenter, randomized, evaluator blind study, comparing the efficacy of amoxicillin-sulbactam (Ax/S) and amoxicillin-clavulanic acid (Ax/C) for the treatment of non-recurrent AOM (nr-AOM). Both antimicrobial susceptibility (AS) to Ax/S and Ax/C from Sp and Hi carried by study children (aged 6-48 months with nr-AOM) and, clinical outcome after treatment with high dose of either Ax/C (7:1) or Ax/S (4:1) (amoxicillin dose: 80 mg/(kg day), b.i.d. for 10 days) were assessed. Nasal cultures (NCs) were taken at Day 0. Follow-up NCs, were done only for Sp carriers. On final analysis 247/289 pts (85.5%) were fully evaluable (120 Ax/S and 127 Ax/C). NP carriage rate of Hi and Sp at Day 0 was 32.2% (93/289 pts) and 28.7% (83/289 pts), respectively. Persistent Sp carriage was detected only in 2 pts. Hi betalactamase positive rate was 13% (12/93). MICs for Ax/S and Ax/C were identical when tested against Sp and Hi isolates (range < or = 0.016-1.0 and < or = 0.016-0.25 mg/L, respectively). Clinical efficacy at Days 12-14 and 28-42 were 98.3% (115/117) and 94.2% (97/103) for Ax/S; and 98.3% (115/117) and 95.1% (98/103) for Ax/C, respectively (pNS). We conclude, that Sp and Hi isolated from NCs of nr-AOM pts were highly sensitive to both drugs and correlated with high clinical efficacy rate.     

Clinical effects of clarithromycin on persistent inflammation following Haemophilus influenzae-positive acute otitis media

Conclusion: Additional treatment with clarithromycin (CAM) reduced persistent middle ear inflammation after acute otitis media (AOM) caused by Haemophilus influenzae in children. CAM is a treatment option for persistent inflammation following AOM and to prevent continuing otitis media with effusion. Objective: We conducted a clinical study to evaluate a new method of treatment for persistent inflammation after AOM in children. Methods: H. influenzae-infected children with AOM were treated acutely with antimicrobial agents, after which those still demonstrating effusion of the middle ear cavity received additional treatment with carbocysteine (S-CMC) alone or S-CMC combined with clarithromycin (CAM) for 1 week. The two regimens were compared in terms of clinical effects. Results: After the initial acute treatment, many patients still showed abnormal otoscopic findings. At the completion of additional treatment, there were no significant differences between the two treatment groups. However, 1 week after completion of additional treatment, the prevalence of a diminished light reflex was significantly lower in the CAM + S-CMC group than in the S-CMC group (p = 0.017). The prevalence of redness of the tympanic membrane also tended to be lower in the combined treatment group than in those receiving a single drug (p = 0.097).     

Suppurative complications of acute otitis media in the era of antibiotic resistance

OBJECTIVE: To review our experience with suppurative complications of acute otitis media (AOM) in the era of antibiotic resistance, given a perceived increase in the number of such cases in recent years requiring surgical intervention. DESIGN: Retrospective review of pediatric patients presenting with suppurative complications of AOM from January 1993 to June 2000. SETTING: Academic tertiary care children's medical center. PATIENTS: A total of 90 pediatric patients, ranging in age from 3 months to 16 years (mean age, 45 months). RESULTS: A total of 104 suppurative complications of AOM occurred in 90 patients over the 7.5-year study period. The incidence of noncoalescent, coalescent, and total cases of mastoiditis and total number of suppurative complications all increased over the study period, with coalescent outpacing noncoalescent disease during the last 3 years of the study. A trend toward an increasing number of cases requiring surgical intervention was noted during the study period, corresponding to an increasing number of resistant Streptococcus pneumoniae isolates. Ten of 16 S pneumoniae isolates were resistant, primarily collected from younger children ranging in age from 4 to 24 months (mean age, 11.9 months). CONCLUSION: The rising incidence of resistant S pneumoniae corresponded to the increasing number of suppurative complications of AOM during the study period and seemed to contribute to more aggressive infectious processes requiring surgical intervention.     

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.