Bronchiolitis ; diagnosis ; microbiology ; pathology ; Female ; Humans ; Infant ; Leukotriene D4 ; analysis ; Male ; Nasopharynx ; chemistry ; microbiology ; pathology

OBJECTIVETo clarify the diagnosis of one suspected case of diphtheria in Guangdong province by epidemiological analysis and etiologic detection.

METHODSOn July 6th 2010, the corynebacterium diphtheria was detected from the nasal secretions of one nasopharyngeal carcinoma patient in a college-town hospital in Guangzhou City, Guangdong Province. The patient and the close contacts were asked to participate in the epidemiological survey; and their nasopharyngeal swabs (3 samples) and the nasal secretions of the patient (1 sample) were collected. The bacteria of the samples were isolated and cultured by blood plate and agar loefflera. The smears of positive strains were dyed and identified by BioMerieux API Coryne biochemical card. Gene tox of β-Corynebacteriophage, Corynebacterium diphtheriae was tested by PCR method, the aliphatic acid was analyzed by gas chromatography method and the Corynebacterium diphtheriae (CMCC 38009) was selected as positive control.

RESULTSThe patient had not gone out, neither had been visited. The patient denied history of vaccines or the immunizations. From the survey on patient's family members and close contacts, no similar symptoms had been found. One strain of Corynebacterium diphtheriae was isolated from the patient's nasal secretions, Gram positive and shape diversified. After cultured by agar loefflera and Gram-dyed and Neisser-dyed, one end or both two ends of the strain showed typical metachromatic granule. API Coryne was identified to Corynebacterium diphtheriae mitis/belfanti (99.4%). The result of gas chromatography method also indicated Corynebacterium diphtheriae. No Corynebacterium diphtheriae was isolated from the nasopharyngeal swabs, neither of the patient nor of the close contacts. The gene tox of β-Corynebacteriophage, Corynebacterium diphtheriae was negative according to the PCR test.

CONCLUSIONThe isolated Corynebacterium diphtheriae did not produce toxin as there was no biological structure gene of toxin. The patient was a health carrier of nontoxic Corynebacterium diphtheriae.

China ; epidemiology ; Corynebacterium diphtheriae ; isolation & purification ; Diphtheria ; epidemiology ; microbiology ; Female ; Humans ; Middle Aged ; Nasopharynx ; microbiology ; Polymerase Chain Reaction ; methods

OBJECTIVETo compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia.

METHODSA total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA.

RESULTSThe positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05).

CONCLUSIONSMP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.

Adolescent ; Bronchoalveolar Lavage Fluid ; microbiology ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Female ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Pneumonia, Mycoplasma ; diagnosis

Acute Disease ; Bacteria ; isolation & purification ; Child, Preschool ; Haemophilus influenzae ; isolation & purification ; Humans ; Infant ; Infant, Newborn ; Nasopharynx ; microbiology ; Respiratory Tract Infections ; diagnosis ; microbiology ; Streptococcus pneumoniae ; isolation & purification ; Trachea ; microbiology

OBJECTIVEThe P1 protein of Mycoplasma pneumoniae (MP) plays an important role in the pathogenesis of MP pneumonia. It mediates the attachment of the pathogen to host cells and elicits a strong humoral immune response during infection. In early studies, only two types of MP P1 genes were assumed to exist. Later, eight subtypes of MP P1 genes and some variations of P1 gene were reported. However, there are no related reports in China until now. This study aimed to understand epidemiology of MP subtype in Zhejiang province, China, as well as the relationship between MP subtype and clinical severity of MP pneumonia.

METHODClinical samples were collected by nasopharyngeal aspiration from children with MP pneumonia hospitalized in the Children's Hospital of Zhejiang University School of Medicine from February to December in 2009. P1 gene fragment was amplified by using PCR method (with primers of ADH1/ADH2 and ADH3/ADH4, respectively). Then ADH1/ADH2-generated fragments were digested with HaeIII, HpaII, Sau3A, and the ADH3/ADH4-generated fragments digested with HaeIII, Sau3A, HhaI, RsaI. The MP P1 subtypes were determined based on resulting fragments. Part of samples were selected for sequencing. The clinical data of different MP subtype pneumonia were compared.

RESULTA total of 300 hospitalized children with MP pneumonia were enrolled in this study. All the samples produced specific bands for MP P1 gene after PCR with primers of ADH1/ADH2 and ADH3/ADH4 respectively. By restrictive fragment length polymorphism analysis, 297 clinical specimens showed the characteristic band patterns for P1 type 1 identical to Mp129, and only 3 clinical specimens showed the characteristic band pattern for P1 type 2 identical to MP-FH. All P1 type 1 and P1 type 2 showed the same subtype bands respectively, as subtype 1b and 2a. After sequencing, one synonymous point mutation in P1 type 1 was identified relative to the MP129 P1 sequence at nucleotide position (nt) 208(G→A). Three cases with P1 type 2 MP pneumonia were found to have liver damage, and longer hospital stay and fever duration than P1 type 1, but no statistically significant difference was found.

CONCLUSIONClinical samples can be used directly for genotyping of MP. The dominating type of MP in Zhejiang Province was P1 type 1 subtype 1b. But whether there was any relationship between MP subtype and clinical severity remains to be clarified.

Adhesins, Bacterial ; genetics ; Child ; China ; DNA, Bacterial ; genetics ; Genotype ; Humans ; Mycoplasma pneumoniae ; genetics ; isolation & purification ; Nasopharynx ; microbiology ; Pneumonia, Mycoplasma ; microbiology ; Polymorphism, Restriction Fragment Length

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

OBJECTIVETo investigate the distribution and the antibiotic susceptibility of pathogenic bacteria in children from Guiyang with lower respiratory infection (LRI).

METHODSThe nasopharyngeal aspirate samples were obtained from 893 hospitalized children with LRI between August 2006 and June 2008. An antibiotic susceptibility test was performed using the VITEK system and the Kirby-Bauer diffuse method after bacteria were identified.

RESULTSFive hundred and forty-three patients (60.8%) were bacteria-positive. A total of 598 strains (30 kinds of bacteria) were obtained from the sputum samples. Of them, 533 strains (89.1%) were gram-negative and 57 were gram-positive (9.8%). Escherichia coli (E. coli) and Kleb-siella pneumoniae (K. pneumoniae) were common in gram-negative strains. They were susceptive to piperacillin/tazobactam, amikacin, ciprofloxacin, and levofloxacin, especially to imipenem. Streptococcus pneumoniae (S. pneumoniae) and Stapthylococcus aureus (S. aureus) were common in gram-positive strains. S. pneumoniae was susceptive to penicillin and cefazolin sodium, but S. aureus was resistant. Both were high susceptive to vancomycin, and resistant to roxithromycin.

CONCLUSIONSGram-negative bacteria are the main pathogens in children from Guiyang with LRI, and E. coli and K. pneumoniae are common. The antibiotic susceptibility of pathogenic bacteria varies with different strains of bacteria. A reasonable selection of antibiotics should be based on the antibiotic susceptibility test.

Adolescent ; Bacteria ; drug effects ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Microbial Sensitivity Tests ; Nasopharynx ; microbiology ; Respiratory Tract Infections ; microbiology

Streptococcus (S.) dysgalactiae subsp. equisimilis is responsible for severe diseases in humans, including primary bacteraemia, pneumonia, endocarditis, and toxic shock syndrome. Infection in some animal species can also occur, although a few studies have looked into cross-species infectivity. In horses, S. equisimilis is generally considered infrequent or opportunistic, but has recently been isolated from cases of strangles-like disease. Rapid and sensitive diagnostic techniques could enable epidemiological studies and effective investigation of outbreaks involving these bacteria. In this study, PCR protocols previously described in cattle and in humans to detect the species S. dysgalactiae and the subspecies equisimilis were evaluated to detect specific sequences in equine samples. For this purpose, 99 monolateral nasal swabs were collected from horses from stud farms with a history of S. equisimilis infection and were tested blindly by bacteriological isolation and by single and duplex PCR. DNA for PCR was extracted both from the colonies grown on agar media and from enrichment broth aliquots after incubation with nasal swab samples. S. equisimilis was identified by bacteriological isolation in 23 out of 99 swab samples, and PCR assays on these colonies were fully concordant with bacteriological identification (kappa statistic = 1.00). In addition, PCR of the enrichment broth aliquots confirmed the bacteriological results and detected S. equisimilis in 6 samples more than the bacteriological examination (kappa statistic = 0.84). The PCR protocols appeared to be reliable for the rapid identification of S. equisimilis in equine nasal swab samples, and could be useful for microbiological diagnosis.
Animals ; NA, Bacterial/chemistry/genetics ; Horse Diseases/diagnosis/*microbiology ; Horses ; Limit of Detection ; Male ; Nasopharynx/microbiology ; Polymerase Chain Reaction/methods/*veterinary ; Respiratory Tract Infections/diagnosis/microbiology/*veterinary ; Sensitivity and Specificity ; Streptococcal Infections/diagnosis/microbiology/*veterinary ; Streptococcus/genetics/*isolation & purification

OBJECTIVETo investigate nasopharyngeal carriage rate, antimicrobial resistance and serotype distribution of Streptococcus pneumoniae among children with upper respiratory infection.

METHODSNasopharygeal swabs were collected from children with upper respiratory infection visiting the outpatient department of Beijing Children′s Hospital between March 2013 and February 2014. The antibiotic susceptibility was tested by Etest method, and the serotype was determined by Quellung reaction.

RESULTSThe nasopharyngeal carriage rate for Streptococcus pneumoniae was 23.8% (699/2 941). One hundred isolates were randomly chosen for antimicrobial susceptiblity test and serotyping. Up to 98.0% isolates were susceptible to parenteral penicillin. The susceptible rate against oral penicillin, however, was 33.0%. The non-susceptible rate to erythromycin and azithromycin was 97.0%. The multi-drug resistance rate was up to 86.0%. The common serotypes were 6A(12.0%), 19F(12.0%), 6B(10.0%), 23F(9.0%) and 14(8.0%). The coverage rates of 7-, 10- and 13-valent pneumococcal conjugate vaccine were 41.0%, 42.0% and 59.0% respectively.

CONCLUSIONSAbout 25% of children with upper respiratory infection are nasopharyngeal colonized by Streptococcus pneumoniae. The isolates show a high antimicrobial resistance. The 13-valent pneumococcal conjugate vaccine covers about 60.0% of the isolates.

Adolescent ; Carrier State ; epidemiology ; microbiology ; Child ; Child, Preschool ; Drug Resistance, Bacterial ; Female ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Pneumococcal Vaccines ; immunology ; Respiratory Tract Infections ; microbiology ; Serotyping ; Streptococcus pneumoniae ; classification ; drug effects ; isolation & purification

Adolescent ; Adult ; Aged ; Female ; Humans ; Male ; Middle Aged ; Mycoses ; diagnosis ; drug therapy ; Nasopharyngitis ; diagnosis ; drug therapy ; Nasopharynx ; microbiology ; Retrospective Studies ; Young Adult