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Objective:To explore the epidemiological characteristics of Streptococcus pyogenes, namely β-hemolytic Group A Streptococcus (GAS) in children in Shenzhen. Methods:Multilocus sequence typing (MLST) data on the epidemic clonal population of GAS infection in children in Shenzhen Children′s Hospital from January 2016 to December 2018 were retrospectively analyzed.In the present study, 32 GAS strains belonging to 7 different emm types were from 32 children′s with impetigo, cellulitis, scarlet fever, sepsis, pneumonia, obstructive sleep apnea hypopnea syndrome, bronchitis, allergy with rhinitis, buttock abscess, allergic purpura or pharyngeal tonsillitis, which were isolated from 23 throat swabs, 5 sputum samples, 3 pus and 1 blood.Using polymerase chain reaction technology, 7 pairs of allelic housekeeping genes ( gki, gtr, murI, mutS, recP, xpt and yqiL) of 32 GAS isolates were analyzed, and the target gene products were subjected to sequencing.Then the obtained gene sequences of each allele were submitted to the MLST database to obtain the allele profile.Finally, the allele profiles were introduced in the MLST database again to confirm the sequence typing (ST). Results:The GAS clone groups of emm 1.00 and its subtypes, emm 4.00, emm 12.00 and its subtypes, emm 22.00, emm 28.00, emm 75.00, and emm 89.00 belonged to the sequence typing ST28, ST39, ST36, ST46, ST52, ST49, and ST921, respectively. Conclusions:From 2016 to 2018, the MLST clone populations of GAS isolates causing infections in children in Shenzhen are classified as ST28, ST39, ST36, ST46, ST52, ST49 and ST921.
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Objective To investigate the distribution and drug resistance of carbapenem-resistant Enterobacteriaceae ( CRE) isolated from children in China. Methods CRE strains were collected in 10 ter-tiary children's hospitals of China from January 1, 2016 to December 31, 2017. Antimicrobial susceptibility of the clinical strains was detected with disk diffusion method ( KB method) and automated method. The re-sults were analyzed according to the Clinical and Laboratory Standards Institute ( CLSI) Standards published in 2017. WHONET 5. 6 software was used to retrospectively analyze the distribution characteristics and drug resistance of these strains. Results A total of 3065 CRE clinical strains were isolated from children with an overall prevalence of 7. 7％ and among them, 13. 5％ were isolated in neonatal group and 5. 8％ in non-neo-natal group. The detection rate of CRE in 2017 was higher than that in 2016 (9. 7％ vs 5. 7％). Among the 3065 CRE strains, there were 1912 strains of Klebsiella pneumoniae (62. 0％), 667 strains of Escherichia coli (22. 0％), 206 strains of Enterobacter cloacae (7. 0％), 56 strains of Klebsiella aerogenes (1. 8％) and 47 strains of Serratia marcescens (1. 5％). Most of the strains were isolate in neonatology departments including neonatal intensive care units (NICU) and intensive care units (ICU), accounting for 44. 8％ and 19. 7％, respectively. Respiratory tract (61. 8％), urine (19. 4％) and blood (5. 7％) specimens were the main sources of CRE isolates. Results of antimicrobial susceptibility test showed that the CRE strains were highly resistant to carbapenem antibiotics such as imipenem, meropenem and ertapenem, as well as penicillins and most cephalosporins (79. 6％-100％), especially those isolated in the neonatal group (P<0. 05). Children had relatively low resistance rates to aminoglycosides such as amikacin (19. 7％) and fos-fomycin (11. 9％), fluoroquinolones such as levofloxacin (37. 7％) and ciprofloxacin (43. 3％), and tige-cycline (3. 8％). Currently, no polymyxin B-resistant strains were isolated. Conclusions The prevalence of common CRE strains in children in 2017 was higher than that in 2016, especially in newborns. Drug re-sistance in CRE strains isolated from neonates to common antibiotics was more severe, suggesting that great attention should be paid to it and timely measures should also be taken.
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Objective@#To describe the clinical characteristics of pneumococcal infections and drug resistance of Streptococcus pneumoniae isolates from children's hospitals, which would provide reference for preventing and treating pneumococcal diseases.@*Methods@#This was a prevalence survey. In this study, the age, specimen type, monthly distribution characteristics, and antimicrobial resistance of Streptococcus pneumoniae isolates from 9 children's hospitals in China were investigated between January 1, 2016 and December 31, 2016. The WHONET 5.6 software was used to analyze the antibiotic susceptibility of Streptococcus pneumoniae. The comparison of rates was performed by Chi-square test.@*Results@#A total of 6 200 isolates of streptococcus pneumoniae were obtained, namely, 95.1% (5 876/6 177) from the respiratory tract specimens, 2.2% (136/6 177) from blood specimens and 0.4% (24/6 177) from cerebrospinal fluid specimens. The isolates were mainly from children older than 1 and younger than 5 years (54.7%, 3 381/6 185) . Most of strains (33.2%, 1 184/3 563) were isolated in November, December and January. Streptococcus pneumoniae isolates were completely sensitive to vancomycin (100.0%, 6 189/6 189) , linezolid (100.0%, 6 030/6 030) , moxifloxacin (100.0%, 3 064/3 064) , highly sensitive to levofloxacin (99.8%, 5 528/5 540), ertapenem (98.8%, 3 024/3 061) and lowly sensitive to erythromycin (1.7%, 102/6 016), clindamycin (3.7%, 116/3 136), and tetracycline (5%, 244/4 877), respectively. According to the parenteral susceptibility breakpoints for non-meningitis isolates, the sensitivity of Streptocococus pneumoniae to penicillin from children's hospital of Chongqing Medical University (49.3%, 892/1 809) was significantly lower than those of other hospitals (χ2=1 268.161, P<0.05) .@*Conclusions@#Streptococcus pneumoniae is mainly isolated from respiratory tract, from children older than 1 and younger than 5 years and during November to January in tertiary children's hospital of China. The Streptococcus pneumoniae from children is highly sensitive to vancomycin, linezolid, moxifloxacin, levofloxacin. There are also significant differences in the sensitivity of penicillin for Streptococcus pneumoniae from different hospitals.
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Objective@#To analyze the antimicrobial resistance profile in Chinese children.@*Methods@#This was a prevalence survey. From January 1 through December 31, 2016, the isolates were collected from 10 tertiary children hospitals in China. Antimicrobial susceptibility testing was carried out by routine laboratory methods. The penicillin susceptibility of streptococcus pneumonia and Meropenem susceptibility of gram-negative bacteria were detected by E-test and disk diffusion method respectively. Antimicrobial susceptibility results were interpreted according to the criteria of Clinical and Laboratory Standards Institute (CLSI) Guideline 2016. The data of antimicrobial susceptibility testing of isolates from either the different patients (neonatal group and non-neonatal group) or various sources were analyzed by WHONET 5.6 software.@*Results@#A total of 56 241 isolates were collected, of which 41.5% (23 328 isolates) were gram-positive organisms and 58.5% (32 886 isolates) gram-negative organisms. The five leading pathogens were Escherichia coli (7 995/56 214, 14.2%), Straphylococcus aureus (6 468/56 214, 11.5%), Streptococcus pneumonia (6 225/56 214, 11.1%), Haemophilus influenza (5 435/56 214, 9.7%) and Klebsiella pneumonia (4 523/56 214, 8.0%). The Meropenem resistance rates of Klebsiella pneumonia, Enterobacter cloacae, Escherichia coil, Pseudomonas aeruginosa, Acinetobacter baumonia isolates were 27.4% (326/1 189) , 8.1% (29/358) , 2.0% (27/1 362) , 19.5% (34/174) , 49.7% (230/463) in neonatal group and 15.4% (512/3 327) , 4.8% (40/841) , 2.3% (151/6 564) , 13.7% (252/1 840) , and 53.4% (860/1 611) in non-neonatal group. The Methicillin-resistant Staphylococcus aureus (MRSA) rates of neonatal group and non-neonatal group were 46.2% (649/1 404) and 33.3% (1 668/5 010) . The penicillin non-susceptible rates of Streptococcus pneumonia in the two groups were 17.6% (6/34) and 18.2% (1 121/6 158) respectively. The β-lactamase positive rates of Haemophilus pneumonia isolates in the neonatal group and non-neonatal groups were 33.8% (47/139) and 44.4% (2 345/5 282) respectively.@*Conclusion@#This investigation highlights the worrisome trend of antimicrobial resistance in children, especially among neonatal patients in China.
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Objective To understand the biological characteristicsand drug resistance of methicillin-resistant staphylococcus aureus (MRSA) isolated from neonatal clinic and the nose swabs of medical staff in the neonatal department.Methods Twenty-six strains of MRSA clinically isolated from the neonatal department and the nose swabs of medical staff in this department were collected and performed the multilocus sequence typing (MLST),spa typing, staphylococcus cassette chromosome mec (SCCmec) typing and pulsed-field gel electrophoresis (PFGE) typing.The Panton-Valentine leukocidin (PVL) gene was simultaneously detected.The antimicrobial susceptibility test of 14 antibacterial dugs was performed.Results Among 26 strains of MRSA,53.8% was isolated from sputum,2 strains were detected from the nase swab of medical staff.The MLST type had 5 types,ST59 accounted for 76.9%.The spa type had 8 types,t437 acoounted for 65.4%.the SCCmec type had only 2 types,20 strains were SCCmecⅣ(76.9%,20/26) and 4 strains(15.4%) were SCCmecV.In the PLV gene detection,the PVL positive rate was 15.4%.One strain of MRSA from the nose swabs of medical staff in the neonatal department was100% homologous with 1 strain from the patient by PFGE analysis.The drug susceptibility test results showed that all MRSA strains were 100% sensitive to antibacterial drugs of nitrofurantoin,quinupristin/dalfopristin,vancomycin and quinolone,while had higher resistance rates to tetracycline,erythromycin and clindamycin,which were above 50%.Conclusion In MRSA strains isolated from the neonatal department in this study,the most common clones were MRSA-ST59-SCCmecⅣ-t437.Erythromycin and clindamycin should not be preferred in the empiric treatment of newborn MRSA.
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Objective To evaluate pathogens and antimicrobial resistance of pathogens causing refractory pneumonia in children.Methods Children with refractory pneumonia who admitted to a hospital between May 2008 and December 2014 were performed bronchoscopy,and bronchoalveolar lavage fluid (BALF)were performed bacterial culture and antimicrobial resistance testing.Results 1 693 patients were recruited in the study,273 bacterial isolates were isolated from BALF speci-mens of 226 children,gram-positive bacteria accounted for 38.10% (104/273 ),the main gram-positive bacteria were Streptococcus pneumoniae (n=71)and Staphylococcus aureus (n=23);gram-negative bacteria accounted for 58.24%(159/273),including 44 isolates of Haemophilus parainfluenzae ,28 Klebsiella pneumoniae ,19 Escherichia coli ,and 17 Pseud-omonas aeruginosa ;10 isolates of fungi were also detected,8 of which were Candida albicans .The sensitivity of Streptococ-cus pneumoniae to quinolones,ceftriaxone and cefotaxime were high.Methicillin-resistant Staphylococcus aureus (MRSA) positive rate was 26.32%.ESBLs-producing rate of Haemophilus parainfluenzae and Klebsiella pneumoniae was 32.72% and 62.96% respectively.Conclusion The major pathogens causing refractory pneumonia were Streptococcus pneumoniae and Haemophilus parainfluenzae ,empirical treatment should be conducted accordingly,antimicrobial resist-ance should be considered if therapeutic effect is poor,and targeted therapy should be performed according to cultured re-sults and antimicrobial susceptibility testing result.
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Objective To analyze the epidemiological characteristics of mycoplasma pneumoniae (MP) infection among the out-patients and inpatients children in Shenzhen area during 2010-2012 and to explore the significance of the results of the laboratory routine tests in the diagnosis of MP infection .Methods The children patients with respiratory tract infection from 2010 to 2012 were selected and the MP infection and the non-MP infection were screened out .The epidemiological characteristics of gender ,age , etc .,among the children patients with MP infection during these 3 years were analyzed .The differences in the laboratory routine tests and high sensitivity C reactive protein (hsCRP) were compared between the MP infection and the non-MP infection .Results The positive detection rate of MP-DNA in males was slightly higher than that in females ,the difference had no statistical signifi-cance (P>0 .05);MP infection occurred in different age groups ,the positive detection rate of MP-DNA was lowest in the children patients aged <1 year old and highest in the children patients aged 3 - < 6 years (P< 0 .05);the routine laboratory tests and hsCRP level had no specificity in the diagnosis of MP infection .Conclusion The MP molecular epidemiology in Shenzhen area shows that MP infection has the seasonality ,the laboratory routine tests and hsCRP level can not be used as the basis of the MP la-boratory diagnosis .
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OBJECTIVE To investigate the disinfectant-sulfanilamide resistance gene(qacE△1-sul1)and integrase gene(IntⅠ1)of Acinetobacter baumannii(ABA)isolated in pediatric clinic and analyze the relationship between these genes and multidrug resistance.METHODS Twenty eight strains of A.baumannii were collected and isolated from the sputum culture in the deep trachea of children with pneumonia during 2006.Identification of bacteria and susceptibility test by VITEK-32 automicroscan using GNI and GNS cards,were undertaken,qacE△1-sul1 gene and IntⅠ1 gene were analyzed by polymerase chain reaction(PCR).RESULTS Three of 28 strains of A.baumannii showed multidrug resistance,the positive rate was 10.71%.A.baumannii 4 strains were resistant to sulfamethoxazole/trimethoprim(SXT)with the positive rate 14.29%.Eleven strains that carrying qacE△1-sul1 genes and 4 strains carrying IntⅠ1 genes were detected,the positive rate was 39.29% and 14.29%,and qacE△1-sul1 and IntⅠ1 genes positive strains of A.baumannii were resistant to SXT,the other 7 qacE△1-sul1 positive strains were sensitive to SXT.CONCLUSIONS The main drug resistance in ABA resistant to SXT is to obtain qacE△1-sul1 gene.It should be paid attention to qacE△1-suⅠ1 positive but sensitive to SXT strains.It indicates that the strain carrying integron Ⅰ may show multidrug resistance.
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OBJECTIVE To apply D-test for detection of inducible resistance of erythromycin to clindamycin in staphylococci and investigate their resistant rate to erythromycin and clindamycin. METHODS According to the standards of NCCLS to detect inducible resistance of erythromycin to clindamycin in staphylococci . RESULTS Co-resistance to erythromycin and clindamycin accounted for 50% and 22.8% in 77 strains of staphylococci (20 of S.aureus and 57 of coagulase-negative staphylococci). The rate of erythromycin resistance and clindamycin sensitivity accounted for 20% and 59.6%. D-test positive rate was 50% and 61.8% of which were erythromycin resistant and clindamycin sensitive respectively. CONCLUSIONS D-test for detection of inducible resistance of erythromycin to clindamycin in staphylococci should be checked in clinical microbiology laboratory in order to help physicians to select MLSb antimicrobial agents correctly.
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OBJECTIVE To evaluate application of cefoxitin disk diffusion method in detecting meticillin-resistant staphylococci(MRS)mediated by mecA gene.METHODS The cefoxitin disk diffusion method,oxacillin disk(diffusion) method,oxacillin agar dilution test,VITEK automicroscan as well as PCR amplification were performed and compared simultaneously for detection of MRS,and VITEK automicroscan was used in testing MIC.(RESULTS)(Among) 96 strains of Staphylococcus(16 S.aureus and 80 coagulase-negative staphylococci strains),54 strains of MRS(2 S.aureus and 52 coagulase-negative staphylococci strains) were identified by oxacillin disk(diffusion) method,oxacillin agar dilution test and VITEK automicroscan,48 mecA-genes were identified by PCR amplification(2 S.aureus and 46 coagulase-negative staphylococci strains) which was the same as by cefoxitin disk diffusion method.CONCLUSIONS The(cefoxitin) disk diffusion method is highly consistent with mecA gene method,and a reliable one of screening and(identifying) MRS mediated by mecA gene.