OBJECTIVETo investigate the prevalence of Moraxella catarrhalis in the nasopharyngeal region of children with respiratory infection and the sensitivity of Moraxella catarrhalis isolates to common antimicrobial drugs.

METHODSNasopharyngeal swabs were collected from 1 082 children with respiratory infection, and Moraxella catarrhalis strains were isolated. The E-test method and disc diffusion test were used to determine the sensitivity of these strains to 11 common antimicrobial drugs. The test results were interpreted with reference to the standards of European Committee on Antimicrobial Susceptibility Testing (EUCAST), Clinical and Laboratory Standards Institute (CLSI), and British Society for Antimicrobial Chemotherapy (BSAC). The nitrocefin disc method was used to detect whether the isolated strains produced β-lactamase.

RESULTSAmong the 1 082 children with respiratory infection, 77 (77/1 082, 7.12%) carried Moraxella catarrhalis in the nasopharyngeal region. All the strains produced β-lactamase. With reference to all the three standards, all the strains were sensitive to amoxycillin-clavulanate and had a susceptibility rate of >95% towards ciprofloxacin and tetracycline. According to the EUCAST and CLSI standards, the susceptibility rate of the strains towards sulfamethoxazole-trimethoprim was as high as 98.7%, and more than 80% of all strains were sensitive to the three cephalosporins detected; however, with reference to the BSAC standard, only 2.6% of the strains were sensitive to cefuroxime, with an intermediate rate of 44.2% and a drug resistance rate of 53.2%. The rate of resistance to ampicillin was 81.8%. According to the CLSI standard, the non-susceptibility rate of the strains to erythromycin was 79.2%, and according to the EUCAST or BSAC standards, their non-susceptibility rate reached 90.9%; more than one third of the strains (27/77, 35.1%) had a minimal inhibitory concentration of >256 mg/L.

CONCLUSIONSAll of the Moraxella catarrhalis isolates in the nasopharyngeal region of children with respiratory infection produce β-lactamase and are sensitive to amoxycillin-clavulanate. These isolates have high susceptibility rates to the third- and fourth-generation cephalosporins and sulfamethoxazole-trimethoprim, but most of the isolates are resistant to ampicillin, cefuroxime, and erythromycin.

Adolescent ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Moraxella (Branhamella) catarrhalis ; drug effects ; isolation & purification ; Nasopharynx ; microbiology ; Respiratory Tract Infections ; microbiology

BACKGROUND AND OBJECTIVES: Acute otitis media (AOM) is one of the most common forms of bacterial infection in children. The aim of this study was to investigate the clinical characteristics and the common pathogens of AOM children who visited three different centers. SUBJECTS AND METHOD: We have conducted a retrospective study of 133 children under 15 years with the diagnosis of AOM that had been seen between January 2010 and January 2011. We examined of AOM children's symptoms, signs and culture results. RESULTS: The most common symptoms were in the order of crying or irritability, otalgia and fever. Otorrhea was significantly higher under 2 years old and drum injection was over 2 years old. The most common pathogens were Streptococcus pneumoniae (26.6%), followed by Moraxella catarrhalis (19.0%), Haemophilus influenzae (11.4%) and Staphylococcus aureus (11.4%). Among the total pathogens, about 71% of pathogens were resistant to amoxicillin, 78% to macroride, and 55.2% to clindamycin. About 58.3% of H. influenza and M. catarrhalis were positive to beta-lactamase. CONCLUSION: More than half of pathogens were resistant to standard dose amoxicillin. For the appropriate treatment of AOM, decisions were made based on the common symptoms, signs and antibiotic resistances of pathogens.
Acute Disease ; Amoxicillin ; Bacterial Infections ; beta-Lactamases ; Child* ; Clindamycin ; Crying ; Diagnosis ; Earache ; Fever ; Haemophilus influenzae ; Humans ; Influenza, Human ; Moraxella (Branhamella) catarrhalis ; Otitis Media* ; Otitis* ; Retrospective Studies ; Staphylococcus aureus ; Streptococcus pneumoniae

OBJECTIVE: To research the prevalences of four kinds of bacteria including Alloiococcus otitidis, Streptococcus pneumonia, Haemophilus influenzae, and Moraxella catarrhalis in children with chronic otitis media with effusion (SOM) of the middle ear effusion, and the reproduction of the nasopharynx, so as to explore their meaning for the children with SOM. METHOD: Alloiococcus otitidis, Streptococcus pneumonia, Haemophilus influenza, and Moraxella catarrhal were investigated in the samples obtained from middle ear effusion and nasopharyn- geal swabs, using PCR and conventional bacterial culture methods. RESULT: By bacterial culture, the pathogen detection rate from middle ear effusion was 3.6%,while the nasopharynx was 54.0%, the detection rate of Streptococcus pneumonia, Haemophilus influenza, Moraxella catarrhalis was 10.8%, 27.0%, 4.5%, respectively, the drug susceptibility results for 51 samples of bacterial culture positive showed that 39 cases was sensitivite to the β-lactam antibiotic; By PCR, the number of detecting various kinds of bacteria simultaneously in middle ear effusion or in the nasopharynx were 6 and 34. The bacteria prevalences of S. pneumoniae, H. influenzae, M. catarrhalis, and A. otitidis are 5.4%, 5.4%, 3.6%, and 42.3% in the middle ear effusion, are 25.2%, 27.0%,13.5% and 34.2% in nasopharyngeal, respectively. CONCLUSION (1) PCR method is more sensitively detecting the bacteria than conventional bacterial culture methods. (2) The chronic SOM of children may be a combination of mixed bacterial infection, A. otitidis may be the most common pathogen of children SOM. (3) For children of SOM, if antibiotics are chosen to be used early in the disease, we suggest using the β-lactam antibiotics.
Bacteria ; Bacterial Infections ; complications ; Child ; Haemophilus influenzae ; isolation & purification ; Humans ; Moraxella (Branhamella) catarrhalis ; isolation & purification ; Nasopharynx ; Otitis Media with Effusion ; complications ; microbiology ; Polymerase Chain Reaction ; Prevalence ; Streptococcus pneumoniae ; isolation & purification

OBJECTIVES: To detect the prevalences of Alloiococcus otitidis, as well as Haemophilus influenzae, Streptococcus pneumoniae, and Moraxella catarrhalis in children with chronic otitis media with effusion (OME) and to simultaneously investigate the colonization of these bacteria in the nasopharynx and palatine tonsils of these patients. METHODS: The study included 34 pediatric patients with OME, and 15 controls without OME. In the study group, A. otitidis, H. influenzae, S. pneumoniae, and M. catarrhalis were investigated in the samples obtained from middle ear effusions (MEE), nasopharyngeal swabs (NPS) and tonsillar swabs (TS), using multiplex polymerase chain reaction (PCR) and conventional culture methods. Only the samples obtained from NPS and TS were studied with the same techniques in the control group. RESULTS: A. otitidis was isolated only in MEE and only with multiplex PCR method. A. otitidis, S. pneumoniae, M. catarrhalis, H. influenzae were identified in 35%, 8.8%, 8.8%, and 2.9%, respectively, in 34 MEE. A. otitidis was not isolated in NPS or TS of the study and the control groups. CONCLUSION: The prevalence of A.otitidis is high in children with OME and A.otitidis doesn't colonize in the nasopharynx or tonsil.
Bacteria ; Child ; Colon ; Ear, Middle ; Haemophilus influenzae ; Humans ; Influenza, Human ; Moraxella (Branhamella) catarrhalis ; Multiplex Polymerase Chain Reaction ; Nasopharynx ; Otitis ; Otitis Media ; Otitis Media with Effusion ; Palatine Tonsil ; Pneumonia ; Polymerase Chain Reaction ; Prevalence ; Streptococcus pneumoniae

BACKGROUND: Nasopharyngeal bacterial flora can cause respiratory tract diseases as well as invasive bacterial diseases. Moraxella catarrhalis colonizing in the nasopharynx is considered an important potential pathogen with an increasing production of beta-lactamase. This study examined the nasopharyngeal colonization rate of M. catarrhalis and the antibiotic susceptibility of M. catarrhalis. MATERIALS AND METHODS: Healthy children who visited one of the three University hospitals in the Republic of Korea or attended a day-care center around the participating hospitals were enrolled in this study. The nasopharyngeal samples were obtained by nasopharyngeal washing with normal saline and M. catarrhalis was isolated. The nasopharyngeal colonization rate of M. catarrhalis was investigated and the minimal inhibitory concentrations (MICs) were measured for commonly used oral antibiotics (amoxicillin, amoxicillin/clavulanate, cefaclor, cefixime, cefdinir, cefditoren, erythromycin and trimethoprim). RESULTS: Three hundred and seventy-nine children aged between 6 months and 5 years were enrolled, and the nasopharyngeal colonization rate of M. catarrhalis was 33% (124 children). All isolated M. catarrhalis produced beta-lactamase. The MIC90 of the antibiotics were as follows: amoxicillin, >16 mg/L; amoxicillin/clavulanate, 0.5 mg/L; cefaclor, 8 mg/L ; cefixime, 0.125 mg/L; cefdinir, 0.25 mg/L; cefditoren, 0.25 mg/L; erythromycin, 0.5 mg/L; and trimethoprim, >16 mg/L. CONCLUSIONS: M. catarrhalis was colonized in 33% of the children aged 6 months to 5 years, and showed low MICs for amoxicillin/clavulanate and oral 2nd and 3rd generation cephalosporins.
Aged ; Amoxicillin ; Anti-Bacterial Agents ; beta-Lactamases ; Cefaclor ; Cefixime ; Cephalosporins ; Child ; Colon ; Drug Resistance ; Erythromycin ; Hospitals, University ; Humans ; Moraxella ; Moraxella (Branhamella) catarrhalis ; Nasopharynx ; Republic of Korea ; Respiratory Tract Diseases ; Trimethoprim

BACKGROUND: beta-lactam antibiotics are one of the most common antimicrobial agents. However, the increasing of beta-lactamase-producing bacteria makes these agents less useful. Therefore, agents stable for beta-lactamase have been developed. This study was conducted to determine the activities of the combination agent ceftriaxone-sulbactam and to compare its activities with other agents. METHODS: A total of 437 clinical isolates of aerobic and anaerobic bacteria were collected in Severance Hospital from 2007 to 2011. Using 23 antimicrobial agents, antimicrobial susceptibility tests were performed using the Clinical and Laboratory Standards Institute (CLSI) agar dilution method. RESULTS: The minimal inhibitory concentrations (MICs) of ceftriaxone and ceftriaxone-sulbactam were similar to or lower than those of other beta-lactam antibiotics for methicillin-susceptible Staphylococcus aureus (MSSA), Streptococcus pneumoniae, S. pyogenes, and viridans group streptococci. For Moraxella catarrhalis, Neisseria gonorrhoeae, Haemophilus influenzae, and H. parainfluenzae, ceftriaxone and the ceftriaxone-sulbactam combination also show low MIC50 and MIC90. For extended-spectrum beta-lactamase (ESBL)-producing E. coli, the MICs of ceftriaxone-sulbactam were lower than those of other cephalosporins. Among the anaerobes, ceftriaxone-sulbactam showed good activity compared to ceftriaxone alone for the Bacteroides fragilis group, B. thetaiotaomicron, other Bacteroides sp., Prevotella sp., and Porphyromonas sp. CONCLUSIONS: Ceftriaxone-sulbactam showed good antimicrobial activity and thus is useful for the treatment of infections by MSSA, S. pneumoniae, S. pyogenes, viridans group streptococci, M. catarrhalis, N. gonorrhoeae, H. influenzae, H. parainfluenzae, E. coli, and K. pneumoniae, B. fragilis group, B. thetaiotaomicron, other Bacteroides sp., Prevotella sp., and Porphyromonas sp.
Agar ; Anti-Bacterial Agents ; Anti-Infective Agents ; Bacteria ; Bacteria, Anaerobic ; Bacteroides ; Bacteroides fragilis ; beta-Lactamases ; Ceftriaxone ; Cephalosporins ; Haemophilus influenzae ; Influenza, Human ; Moraxella (Branhamella) catarrhalis ; Neisseria gonorrhoeae ; Paramyxoviridae Infections ; Pneumonia ; Porphyromonas ; Prevotella ; Staphylococcus aureus ; Streptococcus pneumoniae ; Sulbactam

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2009. A total of 16 specimens were distributed. Eight specimens were distributed to 339 laboratories with 322 (95.0%) returns in Trial I, and another eight specimens to 337 laboratories with 327 returns (97.0%) in Trial II. Two slide specimens for mycobacterium stain (AFB) were distributed in both Trial I and II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Sterotrophomonas maltophilia, Staphylococcus aureus, Streptococcus agalactiae, Micrococcus luteus, Vibrio parahemolyticus and Candida glabrata (Trial I) were 94.4%, 98.5%, 92.1%, 62.3%, 92.1% and 71.5%, respectively. The acceptable percentages of bacterial identification on Pseudomonas aeruginosa, Enterococcus faecalis, Candida albicans, Staphylococcus epidermidis, Moraxella catarrhalis and Enterobacter cloacae (Trial II) were 98.5%, 94.1%, 89.2%, 86.2%, 79.6% and 98.5%, respectively. The acceptable percentages for antimicrobial susceptibility tests on S. maltophilia and S. aureus (Trial I), and P. aeruginosa and E. faecalis(Trial II) were relatively good compared to data of the last year, except results using disk method for S. maltophilia. The acceptable percentages for AFB stain in Trial I and II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Anti-Infective Agents ; Candida albicans ; Candida glabrata ; Enterobacter cloacae ; Enterococcus faecalis ; Korea ; Micrococcus luteus ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Staphylococcus epidermidis ; Streptococcus agalactiae ; Vibrio

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Moraxella (Branhamella) catarrhalis ; drug effects ; Prevalence ; Respiratory Tract Infections ; epidemiology ; microbiology

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Aeromonas ; Candida tropicalis ; Enterococcus ; Enterococcus faecalis ; Escherichia coli ; Klebsiella pneumoniae ; Korea ; Listeria monocytogenes ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Streptococcus pyogenes ; Yersinia enterocolitica

Two trials of external quality assessment for clinical microbiology laboratories were performed in 2007. A total of 14 specimens were distributed. Six specimens were distributed to 317 laboratories with 305 (96.2%) returns in Trial I, and 8 specimens to 320 laboratories with 309 returns (96.5%) in Trial II. For the first time, two slide specimens for mycobacterium stain (AFB) were distributed in Trial II. The acceptable percentages of Gram stain were relatively good for both stainability and morphology. The acceptable percentages of bacterial identification (correct answers to species level) on Streptococcus pyogenes, Branhamella catarrhalis, Escherichia coli, Enterococcus faecalis, Aeromonas hydrophilia and Yersinia enterocolitica (Trial I) were 83.5%, 70.8%, 98.1%, 87.0%, 89.2%, and 97.0%, respectively. The acceptable percentages of bacterial identification on Staphylococcus aureus, Pseudomonas aeruginosa, Candida tropicalis, Listeria monocytogenes, Enterococcus casseliflavus and Klebsiella pneumoniae (Trial II) were 98.1%, 97.7%, 71.6%, 77.4%, 72.4% and 96.2%, respectively. The acceptable percentages for antimicrobial susceptibility tests on E. coli and E. faecalis (Trial I), and S. aureus and P. aeruginosa (Trial II) were relatively good compared to data of recent three years. The acceptable percentages for AFB stain in Trial II were relatively high. In summary, the acceptable percentages of bacterial stain and identification were relatively good. However, it is still necessary that the quality assurance of the individual laboratories should be improved for antimicrobial susceptibility tests, and the selection of the most appropriate antimicrobial agents to test should be also considered.
Aeromonas ; Candida tropicalis ; Enterococcus ; Enterococcus faecalis ; Escherichia coli ; Klebsiella pneumoniae ; Korea ; Listeria monocytogenes ; Moraxella (Branhamella) catarrhalis ; Mycobacterium ; Pseudomonas aeruginosa ; Staphylococcus aureus ; Streptococcus pyogenes ; Yersinia enterocolitica