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Objective:To investigate the distribution of fungal species and their sensitivity to antifungal drugs in children with invasive fungal infections.Methods:All the fungal strains primarily isolated from the sterile parts of children in Beijing Children′s Hospital, Capital Medical University from January 2010 to December 2016 were analyzed.The sensitivity of strains to 5-Fluorocytosine, Fluconazole, Amphotericin B, Itraconazole and Voriconazole was tested using ATB-FUNGUS 3 yeast drug sensitivity test strip in accordance with the standards of Clinical and Laboratory Standards Institute M27-A2.Statistical analysis of data was performed using WHONET 5.6 software.Results:Among 236 fungi isolated from aseptic samples, 64.0% (151 strains) were from blood, 22.9%(54 strains) from cerebrospinal fluid, 3.8%(9 strains) from bone marrow, 3.8%(9 strains) from ascites, 3.4%(8 strains) from pleural effusion and 2.1%(5 strains) from tissues.The top 3 dominant species detected in the 236 strains of fungi were Candida spp.(175 strains, 74.2%), Cryptococcus neoformans (31 strains, 13.1%), and Saccharomyces spp.(9 strains, 3.8%). Among the Candida spp., the main isolates were Candida albicans (107 strains, 61.1%), Candida parapsilosis (33 isolates, 18.9%), and Candida tropicalis (13 isolates, 7.4%). Rare fungi of Penicillium marneffei, Exophiala spp.and Rhizopys spp.were also detected. Candida spp.was 100% sensitive to Amphotericin B. Cryptococcus neoformans was 100% sensitive to Fluconazole, Voliconazole and Amphotericin B. Conclusions:The most common strain isolated from pediatric patients with invasive fungal infections is Candida spp., especially Candida albicans. Cryptococcus neoformans causes central nervous system and systemic disseminated infections that can′t be ignored.Amphotericin B has higher antibacterial activity against Candida spp.and Cryptococcus neoformans.Separation of species of invasive fungal infections and monitoring of drug resistance in children should be strengthened to effectively control invasive fungal infections and facilitate rational use of antifungal drugs.
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Objective@#To investigate the prevalence and resistance changes of carbapenem-resistant Enterobacteriaceae (CRE) strains isolated from children patients of Chinese Bacterial Resistance Surveillance Network (CHINET) from 2005 to 2017.@*Methods@#Antimicrobial susceptibility testing was carried out by disk diffusion method (KB method) and automated systems. Results were analyzed according to the Clinical and Laboratory Standards Institute (CLSI) 2017 edition standards.@*Results@#Among the 4 481 CRE clinical strains, the overall prevalence of CRE in children was 6.4%, including 8.8% in neonatal period, 7.3% in infancy, 3.8% in early childhood, 4.0% in preschool, 4.7% at school age and 7.4% of puberty. The CRE prevalence of citrobacter spp. remained stable in 2005-2017, whereas other bacteria showed an upward trend, which was higher than that of the adult group (P<0.01). Among the 4 481 CRE strains, there were 2 905 strains of Klebsiella spp. (64.8%), 813 strains of Escherichia coli (18.1%), 549 strains of Enterobacter spp.(12.3%), and 65 strains of Citrobacter spp.(1.5%). Among the 4 481 CRE strains, 20.7%, 13.3%, and 11.8% were from the intensive care unit (ICU), neonatal department and internal medicine wards, respectively. Specimens were distributed as respiratory (42.8%), urine (26.3%), and blood (14.9%). The results of antimicrobial susceptibility testing exhibited that the CRE strains were highly resistant to most commonly used antimicrobial agents in clinical practice, such as imipenem, meropenem and ertapenem, as well as penicillins and cephalosporins, etc.@*Conclusion@#The prevalence of CRE strains in children is increasing year by year, and their antimicrobial resistance to common antibacterial agents in clinical practice is extremely serious, to which serious attention needs to be paid. According to the results of antimicrobial susceptibility testings, the antibacterial agents should be rationally selected to effectively control the spread of CRE.
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Objective To analyze the distribution and antibiotic resistance profile of Haemophilus influenzae strains isolated from children for better antibiotic use.Methods The clinical and laboratory data concerning 350 strains ofH.influenzae were collected and analyzed retrospectively from 2014 to 2015 in our hospital,including pathogen source,production of beta lactamases and antimicrobial susceptibility.Antimicrobial susceptibility testing was carried out by using disk diffusion method.The results were interpreted according to the breakpoints of the Clinical and Laboratory Standards Association (CLSI) in 2014,and analyzed using WHONET 5.6 software.Results H.influenzae infection was more common in infants and young children.The prevalence of beta lactamase was 53.1％ in H.influenzae isolates.The H.influenzae isolates showed the highest resistance rate to trimethoprimsulfamethoxazole (76.9％),but relatively high susceptible rate to ciprofloxacin (99.1％),ceftizoxime (98.9％),chloramphenicol (95.4％),tetracycline (88.3％),amoxicillin-clavulanic acid (87.7％),cefuroxime (74.9％),azithromycin (65.4％),cefaclor (56.6％) and ampicillin (46.0％).All these H.influenzae strains were susceptible to ceftriaxone and meropenem.Conclusions Beta-lactamases are highly prevalent in the H.influenzae strains isolated from children,which is the main mechanism underlying ampicillin resistance in H.influenzae.Ampicillin is therefore not appropriate for first-line treatment ofH.influenzae infections.The H.influenzae strains are highly resistant to trimethoprim-sulfamethoxazole.In addition to beta-lactams,ciprofloxacin is the most active agent against H.influenzae strains,followed by chloramphenicol.
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Objective To investigate the distribution and antimicrobial resistance profile of the common pathogens isolated during the period from 2009 to 2015.Methods All the bacterial strains isolated from pediatric inpatients in Beijing Children's Hospital during the period from 2009 to 2015 were analyzed. Antimicrobial susceptibility was determined by disk diffusion method and Phoenix 100 Automated Microbiology System. Results were analyzed according to the guidelines of CLSI (2014) using WHONET 5.6 software.Results The total strains were 26630. The most common gram-positive isolates were Streptococcus pneumoniae,Staphylococcusaureusand coagulase-negative Staphylococcus (CNS), while the most frequently isolated gram-negative microorganisms were Klebsiella spp.,Pseudomonas aeruginosa and Escherichia coli. The prevalence of S. pneumoniae was up to 25.7 % (4101/15973) in all respiratory tract specimens. About 50.2 % of the S. pneumoniae isolates were not susceptible to penicillin. The prevalence of methicillin-resistant strains was 20.6 % in S. aureus (MRSA) and 87.8 % in coagulase negative Staphylococcus (MRCNS) on average. The prevalence of MRSA increased from 11.1 % in 2009 to 29.8 % in 2015. No S. pneumoniae or staphylococcal strains were found resistant to vancomycin or linezolid. The Enterococcus strains were still highly susceptible to vancomycin and linezolid. Overall 0.3 % of the Enterococcus faecium isolates were resistant to vancomycin. The extended-spectrum beta-lactamases (ESBLs) producing strains accounted for 71.4 % -78.1 % of E. coli and 65.1 % - 76.9 % of K. pneumoniae isolates. The carbapenem-resistant E. coli and K. pneumoniae were reported for the first time in 2010, but in 2014, the strains resistant to carbapenems had increased to more than 7 % in E. coli, and higher than 20 % in K. pneumoniae. In 2015, up to 27.7 % and 25.7 % of P. aeruginosa isolates were resistant to imipenem and meropenem, respectively, and 59.9 % of the A. baumannii isolates were resistant to imipenem and meropenem. Beta-lactamase was positive in 46.3 % of the H. influenzae isolates. Conclusions MRSA and the carbapenem-resistant strains of E. coli,K. pneumoniae and A. baumannii are still on the rise in pediatric inpatients, which poses a serious threat to clinical practice and implies the importance of strengthening infection control.
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Objective To obtain better insights into transmission dynamics of macrolide resistance genes between human and animal Enterococcus strains.Methods The antimicrobial susceptibility to 8 anti-bioties of 52 Enterococci isolated from animal and 55 Enterococci isolated from human was determined.PCR was used to detect the macrolide resistance genes ermB and mefA,tetracycline resistance genes tetM,and the integrase gene int of Tnl545 of the total 107 strains.Forty-nine ermB positive strains were chosen to be se-quenced.Filter mating experiments were taken.Results The resistance rate to erythromycin were 89.09% and 80.77%for isolates from human and animal:and resistance rate to tetracycline were 80.00%and 67.3l%for isolates from human and animal.respectively.All isolated Enterococci strains were found sensi-tive to vancomycin ermB was detected in 61.82% human Enterococci and 53.85% porcine ones.Identical er-mB gene sequences were found in animal and human Enterococci.Transfer of the ermB gene from porcine E.faecalis to human E.feacalis was successful.and the transfer frequency is 1.2×10-5.Conclusion En-terococci have a high resistance rate to erythromycin and some other antibio tics,especially in pediatric iso-lates:but still very sensitive to glycopeptide.ermB was the predominant genes for macrolide and tetracy-cline.Identical ermB gene sequences were present in animal and human Enterococci and that transfer of the ermB gene from porcine E.faecalis to human E.faecalis and vice versa is possible.but probably occurs at a low frequency.