Diagnostic Yield of Pneumococcal Antigen Detection in Cerebrospinal Fluid for Diagnosis of Pneumococcal Meningitis Among Children in China

Objective: To determine the diagnostic accuracy of pneumococcal antigen detection indiagnosis of pneumococcal meningitis in children. Methods: Purulent meningitis wasdiagnosed according to European Society for Clinical Microbiology and Infectious Diseases(ESCMID) guideline between July 2014 and June 2016. Along with a cerebrospinal fluid(CSF) culture, pneumococcal antigen detection in cerebrospinal fluid (CSF) was performed,and further identification of pathogens was done with 16S rDNA-PCR and high-throughputsequencing. Results: CSF samples collected from 184 children (median age of 1.92 mo).CSF culture was used as the gold standard. 46 (25%) had positive results for culture and 10(5.4%) were pneumococci; 34 (18.5%) were pneumococcal antigen positive. The sensitivityand specificity of pneumococcal antigen detection were 100% (95% CI: 89.4%–100%) and86.2% (95% CI: 96.4%–99.9%), respectively. 92.3% (12/13) were confirmed by nucleic aciddetection to be pneumococci. Conclusions: Pneumococcal antigen detection in CSF hasadequate sensitivity and specificity in diagnosing pneumococcal meningitis.

Serotypes and ampicillin resistance of Haemophilus influenzae isolates from children with respiratory infection in Hangzhou / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To investigate the serotypes distribution and ampicillin resistance of Haemophilus influenzae isolates from children with respiratory infection in Hangzhou.</p><p><b>METHODS</b>Haemophilus influenzae strains were identified with V factor and X factor tests. Serotypes were determined with the slide agglutination method. Nitrocefin test was used to detect beta-lactamase. The sensitivities of ampicillin to Haemophilus influenzae were determined with the Kirby-Bauer diffusion method and the E-test method.</p><p><b>RESULTS</b>One hundred and fifty-two Haemophilus influenzae isolates, 108 from boys and 44 from girls, were identified between December 2006 and July 2007. Of the 152 isolates, 148 (97.4%) were untypable, only 4 (2.6%) were typable, including type a, type d, type e and type f (n=1 each type). Haemophilus influenzae type b and c strain was not found. Thirty-four isolates (22.4%) were beta-lactamase-positive. One hundred and thirteen isolates (74.3%) were susceptible to ampicillin, while 34 isolates (22.4%) were resistant to ampicillin.</p><p><b>CONCLUSIONS</b>Untypable strains were the most common in Haemophilus influenzae isolates from children with respiratory infection in Hangzhou. The isolates of Haemophilus influenzae kept susceptibity to ampicillin to a certain extent.</p>

Drug-resistance of staphylococcus aureus and detection of mecA gene in all strains isolated from children in Hangzhou / 中华儿科杂志

<p><b>OBJECTIVE</b>To study the resistance of staphylococcus aureus (S. aureus) isolated from children in Hangzhou to antibiotics and analyze the clinical value of mecA-PCR in determining oxacillin-resistant isolates.</p><p><b>METHODS</b>S. aureus isolates were screened by using latex agglutination test and identified with GPI card of Vitek system. Antibiotics sensitivity tests were performed using disk diffusion methods and tests for sensitivity to oxacillin and vancomycin were performed with a further E-test method. The mecA gene was detected with polymerase-chain reaction (PCR).</p><p><b>RESULTS</b>Of all 259 S. aureus strains, 185 from clinical specimens in inpatients and 74 from pharyngeal swabs in healthy children, 247 strains (95.8%) were beta-lactamase-positive and resistant to penicillin, while 91.1% of all strains were sensitive to oxacillin. All the strains were sensitive to vacomycin and 91.9% of all the strains were susceptible to cefotaxime and ceftriaxone. Resistance to erythromycin, tetracycline, clindamycin, trimethoprim-sulfamethoxazole, chloramphenicol, ofloxacin and rifampin were 48.3%, 30.9%, 21.6%, 11.2%, 10.0%, 2.3% and 1.5%, respectively. The resistance rate to oxacillin, cefotaxime, and ceftriaxone in clinical strains were significantly higher than that in carried strains (P < 0.05), while erythromycin-resistance rate was significantly higher in carried strains than that in clinical isolates (P < 0.05). The mecA-PCR showed that the control strain ATCC25923 and all oxacillin-sensitive S. aureus were mecA-negative, while all oxacillin-resistant strains were mecA-positive instead. Only one strain was mecA-positive in 7 oxacillin-intermediate S. aureus strains.</p><p><b>CONCLUSION</b>Oxacillin-resistance in S. aureus isolates was low, and mecA-PCR method is a good choice for rapid examination oxacillin-resistant strains.</p>

Pathogenic bacteria of childhood lower respiratory tract infection / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the pathogenic bacteria of lower respiratory tract infection (LRTI), and age and gender distribution and drug resistance of the pathogenic bacteria in children.</p><p><b>METHODS</b>Sputum specimens for bacterial cultures were collected in sterile tubes from all of the children with LRTI who had been admitted to the Children's Hospital of Zhejiang University between August 2001 and July 2002. Antibiotic susceptibility tests were performed using the Vitek system, the Kirby-Bauer diffuse method and the Etest method after bacteria were identified.</p><p><b>RESULTS</b>Among the 4,238 patients with LRTI during the study period, 1,181 patients were bacteria-positive, with a positive rate of 27.9%. Streptococcus pneumoniae (S. pneumoniae) was the most common (222 strains), followed by Haemophilus influenzae (H. influenzae) (216 strains), Klebsiella pneumoniae (K. pneumoniae) (216 strains), Escherichia coil (E. coli) (169 strains) and Staphylococcus aureus (S. aureus) (89 strains). The isolation rate of S. pneumoniae in females was significantly higher than in males (6.2% vs 4.7%; P < 0.05). However, the isolation rates of K. pneumoniae and S. aureus in males were higher than in females (5.1% vs 4.1% and 2.5% vs 1.5%, respectively; P < 0.05). A higher incidence of LRTI due to S. pneumoniae and H. influenzae was found in the 1-3 years group, while the incidence of LRTI due to K. pneumoniae, E. coli, S. aureus and E. cloacae was higher in patients under 1 year of age. Antibiotic susceptibility tests showed that rates of penicillin non-susceptible S. pneumoniae, ampicillin resistant H. influenzae, oxacillin-resistant S. aureus and ESBL-positive K. pneumoniae and E. coli were 55.0%, 16.5%, 41.2%, 42.6% and 4.5%, respectively.</p><p><b>CONCLUSIONS</b>S. pneumoniae, H. influenzae, K. pneumoniae, E. coli and S. aureus were common pathogens of LRTI in children. The infection rate varied with age and gender. Antibiotics for treating LRTI should be selected based on the drug susceptibility test.</p>

Serotypes and antibiotics-resistance patterns of 247 strains of Haemophilus Influenzae isolated from children in Hangzhou / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the serotypes and antibiotics-resistance patterns of Haemophilus influenzae isolated from children in Hangzhou.</p><p><b>METHODS</b>Isolates were identified with api-NH card. Serotypes were determined with slide agglutination method. The sensitivities of 13 antibiotics against 247 strains of Haemophilus influenzae were determined in vitro with Kirby-Bauer diffusion methods and MICs of ampicillin were determined with E-test. Nitrocefin test was used to detect beta-lactamase.</p><p><b>RESULTS</b>Of the 247 strains isolated from children during the period from August 2001 to July 2002, 153 strains were non-typable, while 94 strains (38.1%) were typable and 90.4% and 1.1% of them belonged to type d and type b, respectively. Higher incidence of typable Haemophilus influenzae was found in male than in female children and the difference was significant (chi(2) = 5.30, P < 0.05), while between upper and lower respiratory tract infected children the difference was not statistically significant (chi(2) = 3.60, P > 0.05). Forty-one isolates (16.6%) were beta-lactamase-positive and 14 strains could not grow on medium in antibiotics sensitivity test. Of all 233 isolates tested successfully, 85.4% were susceptible to ampicillin, and the sensitivity rate to cefaclor, ceftriaxone, cefotaxime, imipenem, rifampin, clarithromycin, and chloramphenicol were as high as 98.7%, 99.6%, 99.6%, 99.6%, 98.7%, 91.0%, and 90.6%, respectively. All strains were sensitive to amoxicillin/clavulanic acid, ampicillin/sulbactan and ofloxacin, while 107 strains (45.9%) were resistant to trimethoprim-sulfamethoxazole, followed by that of tetracycline (14.6%). Resistance to ampicillin and trimethoprim-sulfamethoxazole in typable isolates was statistically significantly higher than in non-typable strains. Twenty-six strains (10.5%) were multi-resistant isolates and the multi-resistance rate in beta-lactamase-positive strains were significantly higher than that in beta-lactamase-negative strains (chi(c)(2) = 146.8, P < 0.001).</p><p><b>CONCLUSION</b>Non-typable Haemophilus influenzae was the most common type in clinical strains isolated from children in Hangzhou, while type d was the overwhelming type and type b was uncommon in typable isolates. Incidence of typable isolates was higher in male than in female children, and it was apt to intergrow with other species of pathogenic bacteria. The proportion of beta-lactamase-positive strains was not high and ampicillin or other beta-lactam actibiotics were still the treatment of choice for infections with Haemophilus influenzae.</p>

Antibiotics-resistance pattern and genetic type of Streptococcus pneumoniae isolated from children in Hangzhou / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the antibiotics-resistance type and molecular epidemiology of Streptococcus pneumoniae isolated from children in Hangzhou.</p><p><b>METHODS</b>The sensitivities of 323 strains of Streptococcus pneumoniae to 9 antibiotics were determined in vitro by Kirby-Bauer diffuse methods, and MICs of penicillin and cefotaxime were determined by E-test methods.</p><p><b>RESULTS</b>Among all 323 strains isolated from children during the period from August 2001 to July 2002, 136 strains (42.1%) were sensitive to penicillin, while 57 strains (17.7%) were penicillin-resistant. Penicillin MICs ranged from 0.012 microg/ml to 4.0 microg/ml. All the strains were sensitive to cefotaxime and its MICs ranged from 0.012 microg/ml to 4.0 microg/ml. The most resistant antibiotic was erythromycin and it's resistant-rate was as high as 90.7%, followed by tetracycline (87.6%), trimethoprim-sulfamethoxazole (48.6%) and chloromycetin (14.9%). Totally 197 strains (61.0%) were multi-drug-resistant pneumococci and most of them were resistant to trimethoprim-sulfamethoxazole, erythromycin and tetracycline at the same time. Two strains (0.6%) were resistant to rifampin and none was resistant to vancomycin and ofloxacin. BOX PCR typing was carried out and no overwhelming fingerprinting pattern was found among penicillin resistant Streptococcus pneumoniae strains which were isolated from patients, while the banding patterns were always similar or identical among the strains isolated from the same specimen or from the same patient at different time, respectively.</p><p><b>CONCLUSION</b>The antibiotics-resistant rate of pneumococci was high in Hangzhou, but the third-generation cephalosporins were still the best antibiotics against Streptococcus pneumoniae. One child could be infected or colonized by more than one pneumococci clone at the same or different time.</p>