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Objectives:To study the molecular characteristics, virulence gene and resistance profiles of Staphylococcus aureus ( S. aureus, SA) isolates from bloodstream infections (BSI), so as to further understand the molecular characteristics of S. aureus in pediatric patients. Methods:A total of 53 S. aureus strains in bloodstream infections from Shanghai Children′s Hospital between 2016 and 2021 were collected. Antimicrobial susceptibility test were adopted by instrumental and disk diffusion method. Thirty-two kinds of virulence genes were detected by PCR and underwent multi-locus sequence typing (MLST), Staphylococcus protein A (spa) typing and staphylococcal chromosome cassette (staphylococcal cassette chromosome mec, SCCmec) typing characterizing methicillin-resistant Staphylococcus aureus (MRSA). Statistical analysis was performed using χ 2 test or Fisher exact test. Results:MRSA isolates accounted for 50.94% of the total(27/53), with ST398-t034-SCCmecV (6/53, 11.32%) and ST59-t437-SCCmecIV (4/53, 7.55%) as the most common MRSA clones. Methicillin-sensitive Staphylococcus aureus (MSSA) isolates occupied 49.06% (26/53), among which typing ST22-t309 (3/53, 5.66%) and ST7-t091/t1685 (2/53, 3.77% each) were prevalent. Of the 53 strains, all carried ≥6 virulence genes, 33 strains (62.26%) carried ≥10 virulence genes, including 18 strains of MSSA (69.23%) and 15 strains of MRSA (55.56%). The carriage rate of pvl gene in MSSA was higher than that of MRSA isolates (12/26, 33.33% vs. 6/27, 22.22%), and sasX was only detected in MRSA isolates (4/53, 7.55%). The resistant rates of BSI-SA isolates to penicillin, erythromycin and clindamycin were 98.11%, 49.06% and 41.51%, respectively. MRSA were more resistant to clinical antimicrobial agents than MSSA. Conclusions:MRSA strains cover a high proportion in S. aureus bloodstream infection of children, with ST398-t034 and ST59-t437 being the most common clones. The virulence gene carrying rate for BSI-SA was high with a greater pvl gene carrying rate in MSSA isolates while sasX was only detected in MRSA isolates. More clinical attention should be paid to the high resistance status and virulence genes characteristics of BSI-SA.
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Objective:To investigate the tendency of bacterial distribution and drug resistance of clinically isolated pathogens in the pediatric intensive care unit (PICU), which provided references for the reasonable application of antibiotics.Methods:The distribution characteristics of all clinical isolates from PICU of Children′s Hospital of Shanghai Jiaotong University from January 2010 to December 2018 and their trend of drug resistance were retrospectively analyzed.Results:A total of 2 749 strains of bacteria were isolated, including 1 912 strains (69.6%) Gram-negative bacteria and 837 strains (30.4%) Gram-positive bacteria.The top 6 detected bacteria were Acinetobacter baumannii (749 stains, 27.2%), Klebsiella pneumoniae (289 stains, 10.5%), Staphylococcus aureus (214 stains, 7.8%), Stenotrophomonas maltophilia (207 stains, 7.5%), Escherichia coli (204 stains, 7.4%) and Pseudomonas aeruginosa (189 stains, 6.9%). Among them, the detective rate of Maltophilia Stenotrophomonasannually increased from 6 strains (2.8%) in 2010 to 39 strains (9.5%) in 2018.The resistance rates of Acinetobacter baumannii and Klebsiella pneumoniae to carbapenems increased year by year, which was up to 96.0% and 71.4% to Meropenem by 2018.Their resistance rates to the third-generation cephalosporins, aminoglycosides and sulfonamides were higher than 70.0%.The sensitivity rate to Tigecycline and Polymyxin was 100.0%.The detection rate of Methicillin-resistant Staphylococcus aureus (MRSA) significantly increased from 18.2% in 2010 to 50.0% in 2018 ( χ2=19.38, P=0.013). No Vancomycin-resistant strains were found. Conclusions:Gram-negative bacteria are the main clinical isolates of PICU.Acinetobacter baumannii, Klebsiella pneumoniae, and especially Pseudomonas maltophilus, have a significant growth trend in the detection rate. Acinetobacter baumannii and Klebsiella pneumoniae are highly resistant to carbapenems.MRSA annually grows, but it still maintains a high degree of sensitivity to Vancomycin.
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Carbapenem resistant Klebsiella pneumoniae (CRKP) has been a global public health problem. Recently the detection rate of CRKP in children is increasing and children with CRKP infection may result in treatment failure and high mortality. The diverse carbapenemase genes of CRKP isolated from children are always located in transportable plasmids and easily spread, which should be paid more attention. Strength on control of CRKP infection needs multidisciplinary team. In order to avoid the abuse of broad-spectrum antibiotics, let clinicians make a right decision of effective and target antimicrobial agents selection according to the result of antimicrobial susceptibility provided by microbiologists, infection and control measures should be applied to reduce the infection rate of CRKP.
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Objective:To investigate the genetic characteristics of norovirus (NoV) in children with acute gastroenteritis in Shanghai.Methods:A total of 709 stool specimens were collected from outpatients with acute gastroenteritis in Children′s Hospital of Shanghai from October 2018 to September 2019. Real-time RT-PCR was used for qualitative detection of NoV, and RT-PCR was used to identify the genotypes of NoV with the primers of VP1 gene, RdRp region and RdRp-VP1 region. SPSS20.0 statistical software was used for data processing and bioinformatics software was used for homology, phylogenetic and recombination analysis of NoV gene sequences.Results:NoV was detected in 265 out of the 709 stool specimens with a positive rate of 37.4%. Sequence analysis of RdRp region and VP1 gene showed that seven different genotypes including GⅡ.P16-GⅡ.2, GⅡ.P12-GⅡ.3, GⅡ.Pe-GⅡ.4_Sydney 2012, GⅡ.P7-GⅡ.6, GⅡ.P8-GⅡ.8, GⅡ.P21-GⅡ.13 and GⅡ.P17-GⅡ.17 were detected from 111 NoV-positive specimens. The predominated genotype was GⅡ.P16-GⅡ.2 (30.6%, 34/111), followed by GⅡ.Pe-GⅡ.4_Sydney 2012 (27.0%, 30/111) and GⅡ.P12-GⅡ.3 (24.3%, 27/111). Two new NoV recombinant strains belonging to GⅡ.P21-GⅡ.13 genotype were identified and the recombination site was in the junction region of ORF1 and ORF2. NoV infection occurred every month, but the predominant genotype was different. No significant difference in the positive rates of NoV was found between male and female patients ( P=0.329). However, there were significant differences between different age groups ( P=0.011) and the children in the age groups of >11-12 years old and >2-3 years old had higher rates of NoV infection. Conclusions:The predominated recombinant NoV strains belonged to GⅡ.P16-GⅡ.2, GⅡ.Pe-GⅡ.4_Sydney 2012 and GⅡ.P12-GⅡ.3 genotypes, and two new recombinant NoV strains (GⅡ.P21-GⅡ.13) were found in Shanghai during October 2018 to September 2019. Gene sequencing across ORF1 and ORF2 was conducive to better understanding the NoV genotypes and recombination.
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Objective To investigate the distribution and resistance profile of bacterial isolates in Shanghai Children's Hospital. Methods Antimicrobial susceptibility of all isolates was determined by Kirby-Bauer disk diffusion method according to 2016 CLSI standard. The data were analyzed by WHONET 5.6 software. Results A total of 23 259 non-duplicate strains were isolated from 2011 to 2016, including 10 885(46.8％)gram-postive cocci and 12 374(53.2％)gram-negative bacilli. The average prevalence of methicillin-resistant S. aureus(MRSA)and coagulase-negative Staphylococcus(MRCNS)was 35.8％ and 82.2％, respectively. The prevalence of MRSA rose from 27.4％ in 2011 to 42.9％ in 2016. The resistance rate of MRSA and MRCNS strains were significantly higher than methicillin sensitive strains. The resistance rate of Enterococcus faecium strains was significant higher than Enterococcus faecalis. The prevalence of non-susceptible Streptococcus pneumoniae was 31.2％(908). No gram-positive strain was resistant to vancomycin or linezolid. The prevalence of carbapenem resistance increased in gram-negative strains. The resistance rate of Klebsiella pneumoniae to imipenem and meropenem rose from 3.1％ and 4.8 ％ in 2011 to 28.7％ and 37.4％ in 2016, respectively.The rate of Pseudomonas aeruginosa resistance to imipenem and meropenem rose from 13.8％ and 16.5％ in 2011 to 18.8％ and 19.4％ in 2016, respectively, while Acinetobacter baumannii showed resistance rate of 38.3％ and 39.9 ％ in 2011 to 68.4％ and 69.7％ in 2016. Conclusions Increasing prevalence of MRSA, carbapenem-resistant K. pneumoniae, extensively drug-resistant A.baumannii has become a concern in clinical practice. Therefore, antimicrobial resistance surveillance should be highly strengthened in children's hospital.
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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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The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.
Subject(s)
Animals , Mice , Angiotensin II , Pharmacology , Angiotensin II Type 1 Receptor Blockers , Pharmacology , Animals, Newborn , Catalase , Genetics , Metabolism , Cell Proliferation , Cells, Cultured , Extracellular Signal-Regulated MAP Kinases , Metabolism , Fibroblasts , Gene Expression Regulation , Heart , Hydrogen Peroxide , Metabolism , Pharmacology , Isoflavones , Pharmacology , Myocardium , Cell Biology , Metabolism , NADPH Oxidases , Metabolism , Neuropeptides , Metabolism , Signal Transduction , Transcription Factor AP-1 , Metabolism , Transcriptional Activation , rac1 GTP-Binding Protein , MetabolismABSTRACT
The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.
Subject(s)
Animals , Mice , Angiotensin II , Pharmacology , Angiotensin II Type 1 Receptor Blockers , Pharmacology , Animals, Newborn , Catalase , Genetics , Metabolism , Cell Proliferation , Cells, Cultured , Extracellular Signal-Regulated MAP Kinases , Metabolism , Fibroblasts , Gene Expression Regulation , Heart , Hydrogen Peroxide , Metabolism , Pharmacology , Isoflavones , Pharmacology , Myocardium , Cell Biology , Metabolism , NADPH Oxidases , Metabolism , Neuropeptides , Metabolism , Signal Transduction , Transcription Factor AP-1 , Metabolism , Transcriptional Activation , rac1 GTP-Binding Protein , MetabolismABSTRACT
Objective To investigate the factors affecting the isolation of fastidious bacteria such as Streptococcus pneumoniae and Haemophilus influenzae from lower respiratory tract specimens in children.Methods A total of 210 lower respiratory tract specimens from children were collected and inoculated on both blood agar plate and chocolate agar plate 0.5 h,2 h,6 h,12 h,and 24 h after collection.The effect of specimen turnaround time,transport medium,and inoculation medium on the isolation of fastidious bacteria was studied.Results The results of 200 qualified specimens showed that the isolation of S.pneumoniae and H.influenzae significantly decreased with the increasing of specimen turnaround time (P＜0.05),but no significant difference was observed between 0.5 h and 2 h timepoints.The isolation of fastidious bacteria in semi-solid medium was non-significantly higher than the other two transport medium (P＞0.05).No significant difference was found in the isolation and growth ofS.pneumoniae and H.influenzae on different inoculation media (P＞0.05).Conclusions The appropriate specimen turnaround time,transport medium,and inoculation medium are important for improving the isolation of fastidious bacteria from lower respiratory tract in children.
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Objective To investigate the antibiotic resistance profile and ftsⅠ genotypes of Haemophilus influenzae isolates from respiratory tract in children.Methods A total of 141 consecutive nonduplicate clinical strains of H.influenzae were collected from January to March 2016.Antimicrobial susceptibility was determined using Kirby-Bauer method.Beta-lactamase production was detected by nitrocefin disk test.PCR technique was employed for ftsⅠ genotyping.Antimicrobial resistance was compared between differentfisⅠ genotypes.Results The prevalence of β-lactamases was 40.4％ (57/141) in H.influenzae isolates.More than half (53.2％,75/141) of the strains were resistant to ampicillin.Mutation offtsI gene was positive in 72.3％ (102/141) of the isolates.The dominant genotype of genomic beta-lactamase-negative ampicillin-resistant (gBLNAR) strains was type Ⅲ (72/102,70.6％).The gBLNAR strains showed higher resistance rate to ampicillin and cefuroxime than the genomic beta-lactamase-negative ampicillin susceptible (gBLNAS) strains (P＜0.05).Conclusions High prevalence offisⅠgene mutation is found in the strains ofH.influenzae isolated from respiratory tract in children.The dominant genotype of gBLNAR strains was type Ⅲ.Mutation offtsⅠ gene in H.influenzae is associated with higher resistance rate to ampicillin and cefuroxime.
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Objective To understand the mutations of macrolide resistance gene locus (23S rRNA) of Mycoplasma pneumoniae (MP) and its correlation with clinical features .Methods A total of 354 respiratory tract samples were collected from children pa-tients with pneumonia .MP and its mutations in 23S rRNA gene locus were detected by real-time PCR .The children cases of MP positive were divided into the mutation group and non-mutation group .Then the clinical data were compared between the two groups .Results Among 354 respiratory tract samples ,166 cases(46 .9% ) were MP positive ,moreover the mutation of 23S rRNA gene locus existed in 135 MP positive samples with the positive detection rate of 81 .3% ,while no 23S rRNA gene locus mutations were detected in 31 samples .Analyzing the clinical data of the mutation group and non-mutation group found that there was no sta-tistical difference in the aspects of age and gender between the two groups .The occurrence rates of severe pneumonia and extrapul-monary complications in the mutation group were higher than those in the non-mutation group (P<0 .05) ,moreover the average hospitalization time and fever duration in the mutation group were longer than those in the non-mutation group (P<0 .05) .Conclu-sion 23S rRNA gene locus mutation has higher detection rate ,prompting that MP shows high resistant rate to macrolides ,which could provide a certain basis for treatment of M P infections .
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To investigate the feasibility of application of digital images of the palatal rugae in forensic identification. One hundred patients, consisting of 50 males and 50 females, who received treatment between January 2015 and June 2015 at Shanxi Medical University Stomatological Hospital, China, were included in this study. High-resolution digital image of the palatal rugae was taken from each patient using a digital SLR camera and then processed using a digital image recognition system, including noise reduction, contrast enhancement, image segmentation, feature extraction, edge detection and information matching. Using an MATLAB software system, match results and the time taken by each operator for information matching were recorded. The digital image recognition system assisted in information matching of the palatal rugae. Three oral physicians had a 100% correction rate in information matching. Two other operators failed in formation matching in one or two cases. The time taken by oral physicians for information matching was shorter than that taken by the other two operators. Unique palatal rugae morphology has gradually become a novel marker for forensic identification. Digital images of the palatal rugae morphology contribute to rapider and more accurate forensic identification.
El objetivo fue investigar la viabilidad de la aplicación de imágenes digitales de rugas palatinas para la identificación forense. Se incluyeron 100 pacientes, 50 hombres y 50 mujeres, que recibieron tratamiento entre enero de 2015 y junio de 2015 en el Hospital Odontológico de la Universidad Médica de Shanxi, China. Se tomaron imágenes digitales de alta resolución de las rugas palatinas de cada paciente utilizando una cámara réflex digital y luego se procesaron mediante un sistema de reconocimiento de imagen digital, incluyendo reducción de sonido, mejora del contraste, segmentación de imágenes, extracción de características, detección de márgenes y coincidencia de la información. Mediante el programa MATLAB se registraron los resultados y el tiempo de cada operador para obtener información coincidente, además se utilizó el sistema de reconocimiento de imágenes digitales para hacer coincidirlas con la información de las rugas palatinas. Tres odontólogos informaron una tasa de corrección del 100 % al realizar cruces de información. Otros dos operadores fracasaron en uno o dos casos. El tiempo asignado por los odontólogos para la coincidencia de la información fue menor al de los otros operadores. La morfología especializada de las rugas palatinas se ha convertido gradualmente en un nuevo marcador para la identificación forense. Las imágenes digitales de la morfología de las rugas palatinas contribuyen a una rápida y precisa identificación forense.
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Humans , Male , Female , Forensic Anthropology/methods , Forensic Dentistry/methods , Palate, Hard/anatomy & histologyABSTRACT
Objective To establish a digital system for forensic identiifcation of the palatal rugae and evaluate its application effects. Methods High-resolution digital images of the palatal rugae were harvested under the standard condition and processed including data collection, noise reduction, contrast enhancement, image segmentation, feature extraction, edge detection, and information matching. Apply an MATLAB software system to develop a digital system for forensic identiifcation of the palatal rugae ,and its application effects were evaluated. Results A digital system for forensic identification of the palatal rugae was successfully established. The digital system had an accuracy rate of 100%. Conclusion Establishing a digital system for forensic identiifcation of the palatal rugae provides a novel method for forensic identiifcation.
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Objective To investigate the distribution,epidemiologic features and antibiotic resistance of the enteric pathogens i-solated from children with diarrhea.Methods Enteric pathogens were isolated from children’s stool samples.The children with diarrhea were treated in the outpatient and inpatient of Shanghai Children’s Hospital between 2008 and 2013.Antimicrobial susceptibility testing was conducted by disk diffusion method for Salmonella and Shigella with 6 antimicrobial agents.Results A total of 545 enteric pathogens were collected.Salmonella was the dominant pathogen,accounting for 67.2%,followed by Shigella (20.7%),S.aureus (4.6%),C.jejuni (3.7%),Aeromonas (2.4%),and enteropathogenic E.coli (0.9%).The main serotypes of Salmonella were S.typhimurium and S.enteritidis.Approximately 56.3% of the patients were boys.A-bout 72.7% of the patients were infants under 2 years.The prevalence of diarrhea peaked in summer and autumn (72.9%). The susceptibility of these isolates was only tested with seven antibiotics.Shigella showed higher level of resistance to ampicil-lin and trimethoprim-sulfamethoxazole than Salmonella (P<0.05).Significantly higher percentage of S.flexneri isolates were resistant to sulbactam-ampicillin,ceftriaxone,ciprofloxacin,and chloramphenicol than S.sonnei (P<0.001).Further-more,the prevalence of multidrug resistant strains in Shigella (68.3%)was much higher than that in Salmonella (44.7%,P<0.001).Conclusions A variety of diarrhea-causing enteric pathogens are isolated from the children in Shanghai Children’s Hospital.The isolates are predominantly Salmonella and Shigella species.The epidemiological features of Salmonella and Shigella species are different in terms of gender,age,season and geographical distribution.The resistance to antibiotics is a serious problem and varies with different types of pathogens. Intensive and ongoing surveillance of enteric pathogens and their changing resistant pattern is required to control diar-rhea in children.
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Objective To investigate the infiltration of inflammatory cells and the pathogenesis of nasal polyps. Methods the nasal polyps were obtained from 42 patients undergoing nasal operations. The tissues from each patient were stained with HE and Toluidine Blue for eosiophils, lymphocyte, plasma cell and mast cell and observed under the light microscope. A mean number of the above cells were counted. All data were analyzed with the Ttest. Results Eosinophils were found predominantly in 12 polyps(28.57％). Lymphocyte infiltration was shown in the other 30 polyps (71.43％). Furthermore, many mast cells with only a few eosinophils were found in the lymphocyte infiltration polyps; the number of mast cells in these polyps were much more than those in eosinophil accumulation polyps with a very significant difference(P＜0.01). Conclusion The accumulation of eosinophils in the nasal polyps does not appear to be related to the presence of mast cells and allergy. The disorder of immunity may play an important role in the formation of nasal polyps.