Unilateral auditory neuropathy spectrum disorder

A polymerase chain reaction (PCR)-based genotyping of the penicillin-binding protein (PBP) genes pbp1a , pbp2x and pbp2b was used to characterize Streptococcus pneumoniae isolated from the nasopharynx of children with acute otitis media (AOM). Mutations were observed in pbp1a , pbp2x and pbp2b genes in 36.5% of the strains. Decreased susceptibility to &;#103 -lactam antibiotics was closely associated with the frequency of mutations in the three PBP genes. Of penicillin-intermediately-resistant S. pneumoniae strains, 54.5% appeared to be genetically similar to penicillin-resistant S. pneumoniae strains. Of penicillin-susceptible S. pneumoniae strains, 33.3% had mutations in the pbp2x gene and showed relatively high MICs to cephalosporins. Strains with mutations in the three PBP genes were often isolated from children &;#104 2 years old. Evaluation of mutations in PBP genes using PCR will prove useful for studying the epidemiology of antibiotic resistance.     

High prevalence of Streptococcus pneumoniae with mutations in pbp1a, pbp2x, and pbp2b genes of penicillin-binding proteins in the nasopharynx in children in Japan

OBJECTIVE: To evaluate the resistances of Streptococcus pneumoniae to beta-lactams developed by stepwise alterations in high-molecular-weight penicillin-binding proteins (PBPs) with a reduced binding affinity of beta-lactams. Among the numerous mutations in pbp genes that alter the affinity for beta-lactams, the decreased affinity of PBP1A, 2X and 2B is especially important in the development of resistances to beta-lactams. STUDY DESIGN: Retrospective review. METHODS: In this study, we investigated the mutations in pbp1a, pbp2x, and pbp2b genes evaluated by polymerase chain reaction (PCR) in 866 pneumococcal isolates collected from the nasopharynx of Japanese children with acute otitis media. RESULTS: 210 strains (24.3%) exhibited no mutations in the three pbp genes. 333 strains (38.5%) had mutations in the three pbp genes, 78 (9.0%) in two pbp genes, whereas 245 (28.3%) displayed mutations in only one pbp gene. Among the 656 strains with mutations in pbp genes, 620 (94.5%) strains had mutations in pbp2x. The annual prevalence of antimicrobial-resistant S. pneumoniae showed a gradual increase in strains with mutations in the three pbp genes and a parallel decrease in strains without mutations. CONCLUSIONS: PCR-based genotyping can characterize the antimicrobial resistances in pneumococci along with minimal inhibitory concentrations (MICs). Physicians should pay attention to the recent increase in antimicrobial-resistant S. pneumoniae when treating pediatric acute otitis media.     

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.     

Genotyping of Streptococcus pneumoniae and Haemophilus influenzae isolated from paired middle ear fluid and nasopharynx by pulsed-field gel electrophoresis

Twenty-eight isolates of Streptococcus pneumoniae and 30 isolates of Haemophilus influenzae from paired nasopharynx and middle ear fluids of 21 children with acute otitis media (AOM) were evaluated to determine genotypes by polymerase chain reaction and pulsed-field gel electrophoresis (PFGE). Among the 28 isolates of S. pneumonaie, 21 isolates (75.0%) possessed mutations in the pbp1a,pbp2x, and pbp2b genes, and 7 isolates (25%) had mutations in the pbp2x gene. Nineteen isolates (67.9%) expressed the mefE gene, and 5 isolates (17.9%) possessed the ermB gene. Among the 30 isolates of H. influenzae, 5 isolates (16.7%) had mutations in pbp3 genes, 3 isolates (10.0%) produced beta-lactamase, and 2 (6.7%) isolates possessed mutations both in the pbp3 gene and the beta-lactamase gene. Ten out of the 14 pairs (71.4%) of the restriction fragment patterns of S. pneumoniae from paired nasopharynx and middle ear fluids were indistinguishable following PFGE analysis. The same patterns were identified among 5 children of unrelated families. The restriction fragment patterns of H. influenzae isolated by PFGE were also indistinguishable in 13 out of the 15 pairs (86.7%) of nasopharynx and middle ear fluids. The genetic similarity between nasopharyngeal and middle ear isolates suggests that the causative bacteria migrate from the nasopharynx into the middle ear cavity via the Eustachian tube. Some resistant strains might be prevalent. In children with AOM, the nasopharynx could have been colonized by a virulent strain of bacteria that replaced the benign, commensal bacteria and then progressed to the middle ear, where they caused AOM.     

Impact of antibiotics on pathogens associated with otitis media with effusion

OBJECTIVE: To further understand the roles of bacteria and antibiotics in the development of otitis media with effusion (OME). METHODS: Samples of middle-ear effusion (MEE) were collected during the placement of ventilation tubes to treat chronic OME. Children with acute otitis media within the past three months were excluded from this study. We used polymerase chain reaction (PCR) to detect pathogens and to test the susceptibility of Streptococcus pneumoniae to penicillin. RESULTS: Among MEE samples from 52 children, PCR detected bacterial DNA in 32 per cent (24/75) of them. S. pneumoniae was detected more frequently in middle ears that required ventilation tube insertion at least twice compared with those requiring ventilation tube insertion only once (5/15 versus 4/60; p = 0.013). Higher levels of S. pneumoniae were detected in MEE from children with, than without, a long history of antibiotic administration (7/10 versus 2/14; p = 0.0187). The pbp genes of all isolated S. pneumoniae contained mutations. CONCLUSIONS: Long exposure to antibiotics might significantly influence the bacterial genome in MEE.     

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.     

Evaluation of mutations in penicillin binding protein-3 gene of non-typeable Haemophilus influenzae isolated from the nasopharynx of children with acute otitis media

CONCLUSION: Younger children tend to harbor more resistant strains because they are exposed to these pathogens more often through contacts with siblings or attendance at day-care centers and are frequently treated with antibiotics. The high prevalence of BLNAR strains should be taken into account in the treatment of AOM in young children. OBJECTIVE: Non-beta-lactamase-producing ampicillin-resistant (BLNAR) strains with mutations in penicillin-binding protein (PBP) genes of Haemophilus influenzae have been prevalent recently among younger children. MATERIAL AND METHODS: We investigated mutations in the ftsI gene encoding PBP-3 of H. influenzae isolated from the nasopharynx of children with acute otitis media (AOM) using polymerase chain reaction (PCR). RESULTS: Strains containing the bla gene (beta-lactamase-producing ampicillin-resistant) were identified in 4.7% of cases. Strains with mutations in the ftsI gene (BLNAR) were identified in 23.3% of cases. Strains without mutations in the ftsI gene and that did not contain the bla gene (non-beta-lactamase-producing ampicillin-susceptible) were identified in 70.7% of cases. Strains with both expression of the bla gene and mutations in the ftsI gene (beta-lactamase-producing amoxicillin clavulanate-resistant) were identified in 1.3% of cases. The MICs of ampicillin against the strains evaluated in this study were 0.5-2.0 microg/ml. Cefditoren-pivoxil had the lowest MIC90 against the strains (0.06 microg/ml). Strains with mutations in the ftsI gene (BLNAR) were broadly identified among young children.     

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.     

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

CONCLUSION: A high prevalence of penicillin-binding protein gene-mutated (PGM) strains of Haemophilus influenzae should be taken into account when treating otitis media in children. OBJECTIVE: To evaluate the prevalence of beta-lactamase-non-producing ampicillin-resistant strains of H. influenzae with mutations in the ftsI gene encoding penicillin-binding protein 3 (PBP3) among children with otitis media. MATERIAL AND METHODS: A total of 644 nasopharyngeal isolates of H. influenzae were collected from pediatric acute otitis media patients with or without otitis media with effusion at the clinics of the Department of Otolaryngology-Head and Neck Surgery, Wakayama Medical University Hospital and 6 affiliated hospitals in Wakayama Prefecture between January 1999 and December 2003. MICs to ampicillin (AMP), cefdinir (CFD), cefaclor (CCL), cefpodoxime (CPD) and cefcapene (CFPN) were determined by a microbroth dilution method according to the recommendations of the National Committee for Clinical Laboratory Standards. Types of mutations in the PBP3 gene (ftsI) were evaluated by means of a polymerase chain reaction (PCR)-based genotyping method. The beta-lactamase gene (bla) was also identified by means of PCR. RESULTS: Beta-lactamase-producing (BLP) strains having the bla gene were identified in 16 isolates (2.5%). PGM strains were identified in 279 isolates (43.3%). There were 242 PGM1-non-BLP strains (37.6%) with mutations in the variable mutated locus of ftsI, 35 PGM2-non-BLP strains (5.4%) with mutations in the highly mutated locus of ftsI and 2 BLP-PGM strains (0.3%) with mutations in ftsI that produced beta-lactamase. BLP-non-PGM strains producing beta-lactamase without mutations in ftsI were identified in 14 isolates (2.2%). MICs of PGM1-non-BLP strains to AMP were 0.5-2.0 microg/ml. The MIC90 of CDN to the PGM1-non-BLP strains was the lowest (0.06 microg/ml). The proportion of PGM1-non-BLP strains increased rapidly during 1999-2002 and then decreased in 2003. In contrast, the proportion of PGM2-non-BLP strains increased in 2003.     

Nasopharyngeal Streptococcus pneumoniae carriage in Japanese children attending day-care centers

Objectives

We conducted a prospective bacteriological survey to investigate antibiotic resistance-related genetic characteristics and the turnover of nasopharyngeal Streptococcus pneumoniae carriage in healthy children in day-care centers (DCCs).

Methods

A total of 363 nasopharyngeal mucus samples were collected from children aged 0 to 6 years attending two DCCs in the summer of 2004 (n = 181) and the following winter (n = 182). We obtained 157 S. pneumoniae isolates and analyzed them by antibiotic susceptibility testing, PCR assay for the penicillin-binding protein (PBP) genes and macrolide-resistance gene, and pulsed-field gel electrophoresis (PFGE).

Results

The overall carriage rate was 43.3% (157/363). The percentages of penicillin-intermediately resistant S. pneumoniae (PISP) strains, penicillin-resistant S. pneumoniae (PRSP) strains, erythromycin-intermediately resistant S. pneumoniae strains and erythromycin-resistant S. pneumoniae strains were 35.7% (56/157), 0.6% (1/157), 1.9% (3/157), and 69.4% (109/157), respectively. The percentages of S. pneumoniae strains with the pbp mutation(s) and mefA and/or ermB gene(s) were 92.4% (145/157) and 71.3% (112/157), respectively. Fifty strains with different PFGE patterns were obtained from among the 157 isolates. Thirteen strains were observed in both seasons, but only one of these strains was isolated from the same carrier. Twenty-one strains (42.0%) were isolated from two or more children, and 17 of these were each isolated from children attending the same DCC.

Conclusions

These results indicate the spread of S. pneumoniae, particularly those with antibiotic-resistance genes, and the vigorous genetic turnover and substantial horizontal transmission of this pathogen in healthy children attending DCCs in Japan.     

Evaluation of mutations in penicillin binding protein-3 gene of non-typeable Haemophilus influenzae isolated from the nasopharynx of children with acute otitis media

Conclusion Younger children tend to harbor more resistant strains because they are exposed to these pathogens more often through contacts with siblings or attendance at day-care centers and are frequently treated with antibiotics. The high prevalence of BLNAR strains should be taken into account in the treatment of AOM in young children. Objective Non-β-lactamase-producing ampicillin-resistant (BLNAR) strains with mutations in penicillin-binding protein (PBP) genes of Haemophilus influenzae have been prevalent recently among younger children. Material and methods We investigated mutations in the ftsI gene encoding PBP-3 of H. influenzae isolated from the nasopharynx of children with acute otitis media (AOM) using polymerase chain reaction (PCR). Results Strains containing the bla gene (β-lactamase-producing ampicillin-resistant) were identified in 4.7% of cases. Strains with mutations in the ftsI gene (BLNAR) were identified in 23.3% of cases. Strains without mutations in the ftsI gene and that did not contain the bla gene (non-β-lactamase-producing ampicillin-susceptible) were identified in 70.7% of cases. Strains with both expression of the bla gene and mutations in the ftsI gene (β-lactamase-producing amoxicillin–clavulanate-resistant) were identified in 1.3% of cases. The MICs of ampicillin against the strains evaluated in this study were 0.5–2.0 μg/ml. Cefditoren-pivoxil had the lowest MIC₉₀ against the strains (0.06 μg/ml). Strains with mutations in the ftsI gene (BLNAR) were broadly identified among young children.     

慢性化脓性中耳炎中的肺炎克雷伯菌对氟喹诺酮类药物的耐药机制

目的 研究慢性化脓性中耳炎病例中分离肺炎克雷伯菌Ⅱ型拓扑异构酶基因突变与耐氟喹诺酮类药物的关系.方法 用二倍琼脂稀释法检测6种氟喹诺酮类药物对40株肺炎克雷伯菌临床分离株的最低抑菌浓度,PCR 扩增 gyrA、parC 基因的喹诺酮耐药决定区(QPDR),产物测序后分析.结果 有26株Ⅱ型拓扑异构酶基因发生突变,突变发...     

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

Conclusion. A high prevalence of penicillin-binding protein gene-mutated (PGM) strains of Haemophilus influenzae should be taken into account when treating otitis media in children. Objective. To evaluate the prevalence of β-lactamase-non-producing ampicillin-resistant strains of H. influenzae with mutations in the ftsI gene encoding penicillin-binding protein 3 (PBP3) among children with otitis media. Material and methods. A total of 644 nasopharyngeal isolates of H. influenzae were collected from pediatric acute otitis media patients with or without otitis media with effusion at the clinics of the Department of Otolaryngology—Head and Neck Surgery, Wakayama Medical University Hospital and 6 affiliated hospitals in Wakayama Prefecture between January 1999 and December 2003. MICs to ampicillin (AMP), cefdinir (CFD), cefaclor (CCL), cefpodoxime (CPD) and cefcapene (CFPN) were determined by a microbroth dilution method according to the recommendations of the National Committee for Clinical Laboratory Standards. Types of mutations in the PBP3 gene (ftsI) were evaluated by means of a polymerase chain reaction (PCR)-based genotyping method. The β-lactamase gene (bla) was also identified by means of PCR. Results. β-lactamase-producing (BLP) strains having the bla gene were identified in 16 isolates (2.5%). PGM strains were identified in 279 isolates (43.3%). There were 242 PGM1-non-BLP strains (37.6%) with mutations in the variable mutated locus of ftsI, 35 PGM2-non-BLP strains (5.4%) with mutations in the highly mutated locus of ftsI and 2 BLP-PGM strains (0.3%) with mutations in ftsI that produced β-lactamase. BLP-non-PGM strains producing β-lactamase without mutations in ftsI were identified in 14 isolates (2.2%). MICs of PGM1-non-BLP strains to AMP were 0.5–2.0?µg/ml. The MIC₉₀ of CDN to the PGM1-non-BLP strains was the lowest (0.06?µg/ml). The proportion of PGM1-non-BLP strains increased rapidly during 1999–2002 and then decreased in 2003. In contrast, the proportion of PGM2-non-BLP strains increased in 2003.     

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.     

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 pharyngitis in adults: the presence of viruses and bacteria

Pharyngeal swabs from patients with acute pharyngitis were evaluated for viruses and bacterial organisms from December 2000 through June 2001. Viral genomes were detected by PCR. Of 56 patients, potentially pathogenic bacteria were isolated in 34 (60.7%), viruses in 19 (33.9%), and no etiological pathogens in 16 patients (28.6%). Both viral and bacterial infections were found in 13 (23.2%). Of 56 patients, beta streptococci were found in 10 (6 with group A streptococci, 4 with other groups), H. influenzae in 13, S. pneumoniae in 8, and S. aureus in 7. Two bacterial organisms were isolated in 4 and 3 in 1. Virus infection was found in 19 (29.7%): Adenovirus was most frequently recovered (11 cases; 57.9%), followed by Influenza A and B virus (4 cases; 21.0%), Parainfluenza 1 virus (4 cases; 21.0%) and RS virus (2 cases; 10.5%). Two cases had 2 viruses infections. On the basis of our results, viral and bacterial coinfections are observed in early illness.     

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

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

A bacteriological study of the middle ear and upper respiratory tract in children with chronic secretory otitis media

Middle ear effusions and swabs from the external auditory meatus, nasopharynx and anterior nares have been collected from 100 children with chronic secretory otitis media. Isolates of Haemophilus influenzae and Streptococcus pneumoniae were typed and in vitro sensitivities to commonly used antibiotics were determined for these species and Staphylococcus aureus. Positive middle ear cultures were obtained from 21 children (27 effusions). Haemophilus influenzae and S. pneumoniae were the commonest organisms isolated, both from the middle ear and upper respiratory tract. When one or other of these species was isolated from the middle ear, the same organism was generally found in the upper respiratory tract, but not in the ear canal. The serotypes isolated from the different sites were also the same. Type 19 was the commonest Pneumococcal serotype isolated, while type e was the commonest capsulated strain of H. influenzae. Thirty-six per cent of strains of H. influenzae were resistant to penicillin and 25% of those of S. pneumoniae were resistant to trimethaprim. Eighty-one per cent of isolates of S. aureus were penicillin resistant. There was no difference in the incidence of either S. pneumoniae or H. influenzae in the post nasal spaces of children who had had their adenoids removed and those who had not.     

Clonal spread of β-lactamase-producing amoxicillin-clavulanate-resistant (BLPACR) strains of non-typeable Haemophilus influenzae among young children attending a day care in Japan

Objective

Resistant strains of non-typeable Haemophilus influenzae (NTHi) are one of the principal causes of recurrent acute otitis media (otitis prone), rhinosinusitis, and pneumonia in young children. β-Lactamase-nonproducing ampicillin-resistant (BLNAR) strains are particularly common in Japan, and β-lactamase-producing amoxicillin-clavulanate resistant (BLPACR) strains are now emerging. We investigated the nasopharyngeal carriage status of these resistant strains among children attending a same day care center during a 10-year period.

Methods

From 1999 to 2008, we obtained nasopharyngeal swab specimens from young children attending a same day care center and examined the incidence of resistant strains of NTHi. Antimicrobial resistance of NTHi was identified based on PCR analysis of mutation of the penicillin binding protein (PBP) genes. Pulsed-field gel electrophoresis (PFGE) was performed to examine the clonal relationship of each resistant strain.

Results

The prevalence of resistant strains of NTHi among the children attending this day care has significantly increased during the past 10 years and most of this day care children recently have resistant strains with PBP gene mutations in their nasopharynx. Genetically BLPACR (gBLPACR) strains have rapidly increased since 2007 and PFGE analysis demonstrated that all gBLPACR were clonally identical. This is the first report of apparent clonal dissemination of gBLPACR strains of NTHi occurring in a certain environment such as day care.

Conclusions

The rapidly increasing prevalence of resistant strains, in particular gBLPACR, in this day care center may predict a high incidence of these resistant bacteria from clinical isolates in the near future and potential serious medical problems worldwide.     

Effect of prior antibiotic treatment on middle ear disease in children.

The effect of prior antibiotic treatment on the course of otitis media was assessed in a group of 62 children who experienced 83 episodes of ear infection during 3 years of observation. Bacterial quantitation in middle ear fluids demonstrated a significantly higher colony count in symptomatic children (3.9 x 10(4) +/- 12 bacteria per milliliter) compared to asymptomatic children (6.3 x 10(3) +/- 10 bacteria per milliliter; p = .05). Bacterial counts similarly tended to be higher in children with Streptococcus pneumoniae (4.0 x 10(6) +/- 16 bacteria per milliliter) and Hemophilus influenzae (2.0 x 10(6) +/- 16 bacteria per milliliter), who were more often symptomatic (73% and 55%, respectively, versus 38%) than children with Moraxella catarrhalis (7.9 x 10(3) +/- 2). Antibiotic therapy between 3 and 30 days prior to bacterial diagnosis was associated with a reduction in symptoms from 70% to 38% (p less than .025). However, prior treatment did not statistically reduce bacterial colony counts, although S pneumoniae decreased 90% in the previously treated group. Resistance to ampicillin occurred in 0% of S pneumoniae, 39% of nontypeable H influenzae, and 80% of M catarrhalis subjects without prior treatment and in 0%, 46%, and 100%, respectively, of subjects previously treated (p less than .025). These data suggest that prior treatment has a significant impact on the subsequent course of otitis media in children.