Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
1.
Article in Chinese | WPRIM | ID: wpr-995333

ABSTRACT

Objective:To investigate the phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B/Victoria lineage (BV) viruses in Beijing during the 2021-2022 influenza surveillance season, and to analyze whether the circulating BV viruses match the vaccine strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) cases in the 2021-2022 influenza surveillance season were collected from surveillance network labs in Beijing and cultured in MDCK cells and chicken embryo to isolate BV viruses. Nucleic acids of the viruses were extracted, and the HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity of the HA gene was analyzed using MEGA5.0 software. A phylogenetic tree of HA gene was constructed using the maximum likelihood method. The N-glycosylation sites in HA were predicted online. Three-dimensional structure of HA was constructed using SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) test was performed to analyze the antigenicity of BV viruses.Results:A total of 402 BV viruses were collected and 58 strains with full-length HA gene sequences were chosen for further analysis. Compared with the HA gene of this year′s vaccine strain (B/Washington/02/2019), there were 27 amino acid mutations, 11 of which were located in four different antigenic determinants. The phylogenetic analysis revealed that three subgroups of 1A.3, 1A.3a1, and 1A.3a2 co-circulated in Beijing with 54 strains (54/58, 93.10%) clustered to the Clade 1A.3a2, two strains (2/58, 3.45%) clustered to the Clade 1A.3a1, and two strains (2/58, 3.45%) in the same subgroup (Clade 1A.3) as the vaccine component BV strain in 2021-2022. Compared with the vaccine strain (B/Washington/02/2019), two BV strains had an additional N-glycosylation site at residue 197, while the other 56 strains showed no change in N-glycosylation sites. Antigenic analysis showed that 35 BV strains (35/58, 60.34%) were antigenically similar to the vaccine strain and 23 strains (23/58, 39.66%) were low-response strains.Conclusions:Three subgroups of BV viruses co-circulated in Beijing during the 2021-2022 influenza surveillance season. The predominant subgroup was Clade 1A.3a2 (93.10%), showing a certain genetic distance with the vaccine strain (B/Washington/02/2019). Nearly 40% (39.66%) of the viruses were low-response strains. This study indicated that continuous monitoring of the variations of influenza epidemic strains and timely providing laboratory basis for screening vaccine component strains were the basic technical guarantee for coping with influenza pandemic.

2.
Article in Chinese | WPRIM | ID: wpr-954807

ABSTRACT

Objective:To clarify the M protein ( emm gene) types and drug susceptibility characteristic variations of Group A Streptococcus (GAS) in children in Beijing. Methods:The GAS strains isolated from throat swab samples of children diagnosed with scarlet fever and pharyngeal infection in scarlet fever etiology surveillance sentinel hospitals in 16 districts of Beijing in 2018, 2019 and 2021 were analyzed retrospectively.PCR amplification and sequencing were used for emm genotyping, and the minimum inhibitory concentrations (MIC) of 10 antibiotics were determined by the broth microdilution method.The data were analyzed using χ2 test and Fisher′ s exact method between groups. Results:A total of 557 GAS strains were collected, and 11 emm genotypes ( emm1, emm3, emm4, emm6, emm11, emm12, emm22, emm75, emm89, emm128, and emm212) were detected.Of 557 strains, 238 trains were of emm1 type (42.73%), 271 strains were of emm12 type (48.65%) and 48 strains were of other emm types (8.62%). The detection rates of emm1, emm12 and other emm type genes in 2018, 2019, and 2021 were [37.50% (105/280 strains), 57.14% (160/280 strains), 5.36% (15/280 strains)], [49.05% (129/263 strains), 39.54% (104/263 strains), 11.41% (30/263 strains)], and [28.57% (4/14 strains), 50.00% (7/14 strains), 21.43% (3/14 strains)], respectively.In children infected with emm12 in 2018 and 2019, there were more children under 6 years old than children over 6 years old (62.50% vs.46.88%, 46.36% vs.30.36%) (χ 2=7.182, 6.973; all P<0.05). Drug susceptibility testing results suggested that 225 randomly selected GAS strains were all 100.00% sensitive to 7 antibiotics including Penicillin, Levofloxacin, Meropenem, Linezolid, Cefotaxime, Cefepime and Vancomycin.The rates of resistance to Erythromycin, Tetracycline and Clindamycin were [88.57% (93/105 strains), 87.62% (92/105 strains), 86.67% (91/105 strains)], and [94.34% (100/106 strains), 94.34% (100/106 strains), 87.74% (93/106 strains)] in 2018 and 2019, respectively.The test strains were 100.00% (14/14 strains) resistant to the above 3 antibiotics in 2021.MIC 50 and MIC 90 values of Penicillin in 2018, 2019, and 2021 were (0.03 mg/L, 0.03 mg/L), (0.03 mg/L, 0.06 mg/L), and (0.06 mg/L, 0.06 mg/L), respectively.Among 225 GAS strains, 207 strains had drug resistance and were resistant to more than one drug.Specifically, 94.69% (196/207 strains) were resistant to Erythromycin, Tetracycline and Clindamycin.About 4.35% (9/207 strains) were resistant to both Erythromycin and Clindamycin.A total of 0.97% (2/207 strains) were resistant to Erythromycin and Tetracycline. Conclusions:The emm genotypes of GAS in children in Beijing are diverse in 2018, 2019 and 2021.The dominant genotypes are emm12 and emm1, and emm12 is the main epidemiological type.GAS strains maintain highly resistant to Erythromycin, Clindamycin and Tetracycline, and sensitive to Penicillin and other antibiotics.However, MIC 50 and MIC 90 of Penicillin shows an ascending trend.

3.
Article in Chinese | WPRIM | ID: wpr-907858

ABSTRACT

Objective:To investigate the clinical features of patients with Langerhans cell histiocytosis (LCH), and analyze the association between BRAF V600E mutation status and clinical features. Methods:A retrospective analysis was carried out for the clinical data of 60 patients with LCH at the Department of Pediatric Oncology, Sun Yat-sen Memorial Hospital between April 2013 and December 2019.Among them, 39 patients undertook BRAF V600E mutation testing, which in paraffin-embedded tissue samples were detected by quantitative real-time PCR (qRT-PCR), and in peripheral blood and/or bone marrow were tested by high-throughput sequencing, for analyzing the correlation between BRAF V600E mutation and clinical characteristics of LCH. Results:(1)Clinical characteristics: the age of 60 LCH patients was (4.08±0.45) years, with 43 male cases and 17 female cases.Patients at young age (≤2 years) and with risk organ (RO+ ) and central nervous system (CNS) risk lesions involvement were concentrated in the multisystem involvement (MS) group ( P<0.05). (2)Therapeutic response after induction therapy: the response to induction therapy was achieved in 28 of 60 treated patients (41.7%) and 32 (53.3%) did not.After excluding stratification factors of treatment regimen, MS ( OR=6.855, 95% CI: 2.077-22.622, P=0.002) and the age≤2 years ( OR=4.944; 95% CI: 1.601-15.275; P=0.005) were risk factors in poor chemotherapy response.RO+ ( OR=8.250, 95% CI: 1.617-42.090, P=0.005) was a significant risk factor for a poor chemotherapy response in JLSG-02 treatment group.Differently, RO+ had no dramatic effect on chemotherapy response in CCHG-LCH-2019 treatment group.(3) BRAF V600E mutation: 39 patients were determined BRAF V600E status, with the positive rate of BRAF V600E mutation in paraffin-embedded tissue samples reaching 70.3%(26 cases). BRAF V600E mutation was not associated with early treatment response, age, sex, MS and RO+ ( P>0.05). However, the positive rate of BRAF V600E in children with MS and CNS risk lesions was higher than the controls, with 76.0% (19 cases) vs.57.1% (8 cases) and 74.1% (20 cases) vs.58.3% (7 cases), respectively.Totally, 3 of 8 cases were positive in bone marrow, with 2 cases of MS, and 1 case of multiple bone invasions, and 1 of 5 cases was positive in peripheral blood, with liver and spleen being involved. Conclusions:LCH patients with age≤2 years, MS and RO+ exhibited a poor response to initial treatment, required for more aggressive treatment strategy.Lesion with activating BRAF V600E mutations suggests that LCH is a clonal disorder.There may be great variability between BRAF V600E mutations and MS as well as CNS risk lesions.In the mutation dataset, part of patients had positive BRAF V600E mutations in bone marrow/peripheral blood.This might suggest a different pathogenesis in such patients, has a certain clinical sense in some aspect.

4.
Article in Chinese | WPRIM | ID: wpr-885573

ABSTRACT

Objective:To investigate the clinical and genetic features of 3-methylglutaconic aciduria, dystonia-deafness, hepatopathy, encephalopathy, Leigh-like syndrome(MEGDHEL syndrome) caused by SERAC1 gene variation. Methods:This study retrospectively described the clinical and molecular features and prognosis of a baby boy who was transferred to Children's Hospital of Fudan University and later diagnosed with MEGDHEL syndrome in August 2016. A summary of the clinical and genetic manifestations of MEGDHEL syndrome cases reported in China and foreign areas was conducted through a literature review.Results:(1) Case report: The 2-day-old patient was transferred to Children's Hospital of Fudan University due to hyperlactic acidemia after birth. Physical examination revealed scattered petechiae and ecchymoses of the skin. Laboratory examination showed coagulation disorders and cranial MRI revealed abnormal signals in both basal ganglia. A homozygous variation of c.442C>T(p.Arg148*) in the SERAC1 gene was detected in the patient, which is a pathogenic variant included in the Human Gene Mutation Database. Both of his parents were heterozygous carriers, thereby the diagnosis of MEGDHEL syndrome was confirmed. Followed up to the age of three years and 11 months, he was found to have psychomotor retardation, spasticity, dystonia, deafness, and loss of language ability. (2)Literature review: Together with the case reported in this study, a total of 88 cases were retrieved, involving 57 different variants. The clinical features were homogenous, with onset mostly in the neonatal period (72%, 62/86), and severe reversible liver dysfunction (49%, 38/77) and neonatal hypoglycemia (44%, 35/80) were the main features. Nervous system was affected since infancy and common symptoms, included hypotonia (86%, 68/79), progressive spasticity (82%, 67/82), dystonia (80%, 66/82), intellectual disability (88%, 58/66) and sensorineural hearing impairment (74%, 59/80). Furthermore, bilateral basal ganglia involvement on cranial MRI (93%,70/75) and 3-methylglutaconic aciduria (98%,80/82) were also seen. Supportive care is currently the main management, however, the prognosis is extremely poor. Conclusions:MEGDHEL syndrome should be highly suspected when reversible neonatal liver dysfunction or hypoglycemia of unknown reasons in neonatal period, followed by progressive deafness-dystonia syndrome in infancy. As the prognosis of these patients is usually poor, genetic testing may provide an early diagnosis in neonatal period.

5.
Article in Chinese | WPRIM | ID: wpr-804951

ABSTRACT

Objective@#To understand the antigenicity and genetic characterization of influenza B virus HA gene in B/Victoria-lineage virus (BV) in Beijing during 2017-2018.@*Methods@#Thirty BV virus strains isolated from MDCK cell culture by 17 laboratories in Beijing were collected. The antigenicity was analyzed by comparing with the vaccine strain recommended by WHO. The total viral nucleic acid was extracted and HA gene was amplified by RT-PCR and sequenced. The phylogenetic tree was constructed by HA and mutant sites were analyzed.@*Results@#Among 30 strains of BV, 23 strains (76.7%) were low-reactive strains, other 7 strains (23.3%) were related to the vaccine. The phylogenetic analysis showed that the HA gene of all 30 strains located in Clade 1A branch. In addition, amino acid mutations occurred in 8 sites, and 6 of them located in the antigen determining region.@*Conclusions@#There was a correlation between the high proportion of low-reactive antigenicity and 6 aa variation in antigenic determinants involved in HA region of BV influenza virus between 2017-2018, which provides an important laboratory basis for the recommendation of BV influenza vaccine.

6.
Chinese Journal of Epidemiology ; (12): 1375-1380, 2018.
Article in Chinese | WPRIM | ID: wpr-738155

ABSTRACT

Objective: To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS), isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. Methods: Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS. Eleven currently known SAg genes including SpeA, speC, speG, speH, speI, speJ, speK, speL, speM, smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR. Results: A total of 377 GAS were isolated from 6 801 throat swab specimens, with the positive rate as 5.5%. There were obvious changes noticed among speC, speG, speH and speK in three years. A total of 45 SAg genes profiles were observed, according to the SAgs inclusion. There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emm1 and emm12 strains (χ(2)=38.196, P<0.001; χ(2)=72.310, P<0.001). There also appeared significant differences in the frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (χ(2)=146.154, P<0.001; χ(2)=52.31, P<0.001; χ(2)=58.43, P<0.001; χ(2)=144.70, P<0.001). Conclusions: Obvious changes were noticed among SAg genes including speC, speG, speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017. SAg genes including speA, speH, speI and speJ appeared to be associated with the emm 1 and emm 12 strains. More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles, during the epidemic period.


Subject(s)
Female , Humans , Pregnancy , Antigens, Bacterial/genetics , Bacterial Outer Membrane Proteins , Bacterial Proteins , Beijing/epidemiology , China/epidemiology , Exotoxins , Membrane Proteins , Pharyngitis/microbiology , Pharynx/microbiology , Pregnancy Complications, Infectious/microbiology , Real-Time Polymerase Chain Reaction , Scarlet Fever/microbiology , Streptococcal Infections , Streptococcus pyogenes/isolation & purification , Superantigens/genetics
7.
Chinese Journal of Epidemiology ; (12): 1375-1380, 2018.
Article in Chinese | WPRIM | ID: wpr-736687

ABSTRACT

Objective To analyze the characteristics of super-antigen (SAg) of group A Streptococcus pyogenes (GAS),isolated from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017.Methods Throat swab specimens from patients with scarlet fever or pharyngeal infections were collected and tested for GAS.Eleven currently known SAg genes including SpeA,speC,speG,speH,speI,speJ,speK,speL,speM,smeZ and ssa were tested by real-time PCR while M protein genes (emm genes) were amplified and sequenced by PCR.Results A total of 377 GAS were isolated from 6 801 throat swab specimens,with the positive rate as 5.5%.There were obvious changes noticed among speC,speG,speH and speK in three years.A total of 45 SAg genes profiles were observed,according to the SAgs inclusion.There were significant differences appeared in the frequencies among two of the highest SAg genes profiles between emml and emml2 strains (x2=38.196,P<0.001;x 2=72.310,P<0.001).There also appeared significant differences in the frequencies of speA,speH,speI and speJ between emm 1 and emm 12 strains (x2 =146.154,P< 0.001;x2=52.31,P<0.001;x2=58.43,P<0.001;x2=144.70,P<0.001).Conclusions Obvious changes were noticed among SAg genes including speC,speG,speH and speK from patients with scarlet fever or pharyngeal infections in Beijing between 2015-2017.SAg genes including speA,speH,speI and speJ appeared to be associated with the emm 1 and emm 12 strains.More kinds of SAg genes profiles were isolated form GAS but with no significant differences seen in the main SAg genes profiles,during the epidemic period.

8.
Article in Chinese | WPRIM | ID: wpr-664868

ABSTRACT

Objective To reveal the genetic distribution of group A streptococcus progeny(GAS)isolated from children with re-spiratory tract infection in Beijing in 2015.Methods The throat swabs were collected from children with clinical diagnosis of scarlet fever and pharyngeal infection during May to July,2015.16 pediatric outpatient departments or pediatric emergency department of hospitals located in 16 districts of Beijing were enrolled in this study.PCR amplification and gene sequencing were employed.The encoding mature M protein gene(emm)distribution in different condition was compared and analyzed.Results A total of 247 GAS were isolated,including 73(29.6%,73/247)isolates from cases with scarlet fever and 174(70.4%,174/247)isolates from cases with pharyngeal infection.Among all isolates,six genotypes of emm were identified,including emm12(53.4%,132/247),emm1(44. 1%,109/247)and others(emm22,emm75,emm131 and emm241,2.5%,6/247).The significant difference of emm distribution with age was observed in this study:emm1 isolates were dominant in children aged 6-12,whereas emm12 isolates were dominant in chil-dren aged 1-5(P<0.05).While the emm distribution showed no significant difference in groups with different location,gender,and disease pattern(P>0.05).Conclusion Emm1 and emm12 were the circulating genotype of GAS in Beijing children,2015.Moreo-ver,the difference of distribution between emm1 and emm12 was proved in this study.

9.
Article in Chinese | WPRIM | ID: wpr-613119

ABSTRACT

Objective To investigate the genetic characteristic of whole-genome of influenza A/H3N2 viruses in severe acute respiratory infection cases in Beijing area.Methods From 2014 to 2016,the viral RNA was extracted from 32 strains isolated from SARI cases,then sequenced by Ion Torrent PGM Sequencer.The phylogeny and molecular features of whole-genome were analyzed by Mega and Consurf software.Results The HA gene of tested strains isolated in 2014-2015 influenza season belonged to lineage 3C.3a and 3C.2a,while those isolated in 2015-2016 influenza season belonged to cluster 3C.2a.Moreover,compared with the vaccine strains,7 variant amino acids of protein of HA1 were identified,and two of them were located in antigenic sites.All isolates were sensitive to neuraminidase inhibitors while showed resistance to blockers for M2 ion channel.Conclusion The phylogenetic features of isolates studied in this study are similar with that of current circulating strains.However,the difference between isolates and vaccines should not be overlooked.

10.
Chinese Journal of Epidemiology ; (12): 514-517, 2017.
Article in Chinese | WPRIM | ID: wpr-736206

ABSTRACT

Objective This study aimed to explore the incidence trends and onset features of scarlet fever during the years of epidemic,from 2006 to 2015,in Beijing.Methods Spatial,temporal and population distributions,prognosis of the reported cases and surveillance data on scarlet fever and other streptococcal infections (including the patients of streptococcal infection,tonsillitis and isthmitis) were analyzed by the descriptive epidemiological methods.Results A total of 27 987 scarlet fever cases were reported from 2006 to 2015,with the incidence rates as 7.04 to 18.53 per 100 000 persons during these years,except for 2011.A total of 6 152 cases were reported in 2011,with the incidence of 31.37 per 100 000 persons,significantly higher than the average levels of the other years.There were more cases reported in rural-urban continuum,in summer and winter,with most of the cases were children in primary schools and infant-institutes.From May to December in 2011,4 332 cases were interviewed three weeks after the disease onset,and their conditions improved or recovered,with no death or complication appeared at the follow-up period.There were 2 725 cases of scarlet fever and 104 013 clinical cases of streptococcal infections reported in 36 surveillance hospitals during the same period.The ratio between numbers of scarlet fever cases and streptococcal infection was 1 ∶ 38.17.The weekly numbers of scarlet fever were remarkably correlated to the streptococcal infections,with a Pearson's correlation coefficient as 0.729 (P<0.001).Accordingly,we estimated that about 21.4 thousand clinical cases of streptococcal infections that were caused by Group A streptococcus in 2011,in Beijing.Conclusions Incidence of scarlet fever in 2011 was significantly higher than the average levels of other years in Beijing,but characteristics on spatial,temporal and population distributions of scarlet fever remained the same,with good prognosis of the reported cases.A large number of culture-positive Group A streptococcus infections among all the clinical cases of streptococcal infection might have been served as important source on septic infection,of scarlet fever.

11.
Chinese Journal of Epidemiology ; (12): 514-517, 2017.
Article in Chinese | WPRIM | ID: wpr-737674

ABSTRACT

Objective This study aimed to explore the incidence trends and onset features of scarlet fever during the years of epidemic,from 2006 to 2015,in Beijing.Methods Spatial,temporal and population distributions,prognosis of the reported cases and surveillance data on scarlet fever and other streptococcal infections (including the patients of streptococcal infection,tonsillitis and isthmitis) were analyzed by the descriptive epidemiological methods.Results A total of 27 987 scarlet fever cases were reported from 2006 to 2015,with the incidence rates as 7.04 to 18.53 per 100 000 persons during these years,except for 2011.A total of 6 152 cases were reported in 2011,with the incidence of 31.37 per 100 000 persons,significantly higher than the average levels of the other years.There were more cases reported in rural-urban continuum,in summer and winter,with most of the cases were children in primary schools and infant-institutes.From May to December in 2011,4 332 cases were interviewed three weeks after the disease onset,and their conditions improved or recovered,with no death or complication appeared at the follow-up period.There were 2 725 cases of scarlet fever and 104 013 clinical cases of streptococcal infections reported in 36 surveillance hospitals during the same period.The ratio between numbers of scarlet fever cases and streptococcal infection was 1 ∶ 38.17.The weekly numbers of scarlet fever were remarkably correlated to the streptococcal infections,with a Pearson's correlation coefficient as 0.729 (P<0.001).Accordingly,we estimated that about 21.4 thousand clinical cases of streptococcal infections that were caused by Group A streptococcus in 2011,in Beijing.Conclusions Incidence of scarlet fever in 2011 was significantly higher than the average levels of other years in Beijing,but characteristics on spatial,temporal and population distributions of scarlet fever remained the same,with good prognosis of the reported cases.A large number of culture-positive Group A streptococcus infections among all the clinical cases of streptococcal infection might have been served as important source on septic infection,of scarlet fever.

12.
Chinese Journal of Epidemiology ; (12): 1397-1400, 2015.
Article in Chinese | WPRIM | ID: wpr-248639

ABSTRACT

<p><b>OBJECTIVE</b>To understand the distribution of emm gene types related to group A streptococcus-caused scarlet fever among children in Beijing and to analyze the relationship between the mutation of the emm types and scarlet fever.</p><p><b>METHODS</b>Nasopharyngeal swab samples were collected from the scarlet fever cases diagnosed in 36 hospitals in Beijing to isolate the GAS strains from May to July, betgween 2011 and 2014. Genotyping of emm gene was performed with PCR and N-terminal gene fragments of M protein were sequenced. Data of all the scarlet fever cases in Beijing that reported through the National Notifiable Infectious Disease Surveillance System (NNIDSS) , were gathered and analyzed.</p><p><b>RESULTS</b>Among the collected 2 161 nasopharyngeal swabs, 762 GAS strains were identified (35.3%). In addition, 7 emm types were detected, in which emm12 accounted for 69.4% (529/762) , emm1 accounted for 29.8% (227/762) , and other five types (emm 11, 22, 75, 89, and 128) accounted for 0.8% (6/762) , respctively. Compared with the emm types detected between 2011 and 2014, emm12, emm1 and other types accounted for 82.2% (295/359) , 16.7% (60/359) and 1.1% (4/359, including emm11, 22 and 89) in 2011 respectively.emm12, emm1 and emm75 accounted for 77.3% (123/163) , 23.9% (39/163) and 0.6% (1/163) respectively in 2012. emm12 and emm1 accounted for 50.7% (38/75) and 49.3% (37/75) in 2013 while emm12, emm1 and emm128 accounted for 44.2% (73/165) , 55.2% (91/165) and 0.6% (1/165) respectively in 2014. The differences of the constitution of emm types from 2011 to 2014 appeared statistically significant (P<0.001). In 2011 and 2012, major type appeared as emm12, but in 2014, emm1 became predominant. A total of 6 152 cases were reported in 2011, while 2 908, 2 048 and 3 918 cases were reported in 2012, 2013 and 2014 respectively. Age specific differences were noticed in the distribution of emm types GAS strains in 2011, with the number of emm12 strains detected higher in 1-5 year olds than in age group > 5 years (P<0.05). There were area specific differences in distribution of emm types of GAS strains seen in 2011 and 2013. In 2011, the number of emm1 strains detected in urban area was higher than in suburb area (P<0.05). However, in 2013, the number of emm1 strains detected in suburb area was seen higher than in urban area (P< 0.05).</p><p><b>CONCLUSION</b>GAS with emm12 and GAS emm1 appeared interchangeably predominant in Beijing from 2011 to 2014. Changes in predominant emm types seemed also related to the trends of incidence rates on scarlet fever.</p>


Subject(s)
Child , Humans , Antigens, Bacterial , Bacterial Outer Membrane Proteins , Beijing , Epidemiology , Carrier Proteins , Genotype , Mutation , Scarlet Fever , Epidemiology , Genetics , Streptococcus pyogenes , Classification , Genetics
13.
Zhonghua Yu Fang Yi Xue Za Zhi ; (12): 988-992, 2015.
Article in Chinese | WPRIM | ID: wpr-296649

ABSTRACT

<p><b>OBJECTIVE</b>To investigate superantigen gene profiles of group A Streptococcus (GAS) isolated in Beijing pediatric patients in 2014, and to explore the the relationship between superantigen gene profiles with emm types, and GAS infections with diseases.</p><p><b>METHODS</b>A total of 259 GAS strains were isolated from pediatric patients clinically who diagnosed with scarlet fever and pharyngitis from 36 hospitals in Beijing from May to July, 2014.The Superantigens genes of strains were performed by Real-time PCR (speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa). PCR amplification of GAS strain M protein N gene segments were carried ort; products after sequencing comparison were analyzed to determine the GAS types of emm. The differences in distributions of superantigen genes and emm types of GAS isolates were compared between subgroups.</p><p><b>RESULTS</b>Among the 259 GAS strains, the detection rates of 13 superantigens were as the following: speA 48.6% (126), speB 99.2% (257), speC 99.2% (257), speF 98.8% (256), speG 98.5% (255), speH 43.6% (113), speI 46.3% (120), speJ 49.0% (127), smeZ 99.2% (257) and ssa 98.5% (255), respectively, however, speK, speL, and speM were not found. Eleven superantigen gene profiles in all were observed (A-K). The percentage of emm1 strains harbored spe A and speJ were 94.2% (113/120), 95.0% (114/120), respectively, which were significantly higher than those of emm12 strains (5.6% (7/124), 5.6% (7/124), respectively; χ(2) = 191.20, 194.80, P < 0.001). The percentage of emm12 strains harbored speH and speI were 83.9% (104/124), 88.7% (110/124), respectively, which were significantly higher than those of emm1 strains (3.3% (4/120), 4.2% (5/120), respectively; χ(2) = 160.30, 174.90, P < 0.001).The superantigen genotypes of GAS strains and emm types, which were isolated from scarlet fever and pharyngitis cases, were not significant different (P > 0.05).</p><p><b>CONCLUSION</b>The GSA strains isolated in Beijing pediatric patients in 2014, the relevance ratio of speB, speC, speF, smeZ, speG, ssa were higher than others, while speK, speL, and speM were no detected in any GAS strains. The superantigen genes appeared to be associated with the emm type. Furthermore, emm type distribution and superantigen genes were not different between scalet fever and pharyngitis.</p>


Subject(s)
Child , Humans , Antigens, Bacterial , Genetics , Beijing , Genotype , Real-Time Polymerase Chain Reaction , Streptococcal Infections , Microbiology , Streptococcus pyogenes , Genetics , Allergy and Immunology , Superantigens , Genetics
14.
Article in Chinese | WPRIM | ID: wpr-484952

ABSTRACT

Objective To explore the relationship between superantigen and M protein gene (emm)-types genes of Group A Streptococcus pyogenes (GAS) isolated from patients with scarlet fever in Beijing from May 2012 to July 2013 .Methods GAS was isolated from specimens of patients with scarlet fever . Superantigen genes (speA ,speB ,speC ,speF ,speG ,speH ,speI ,speJ ,speL ,speK ,speM ,ssa ,and smeZ) ,and emm gene were amplified by polymerase chain reaction .Rate and proportion were compared by chi-square test .Results Of the 423 GAS strains isolated from patients with scarlet fever from 2012 to 2013 ,most of the isolates possessed speB (97 .6% ) ,speC (99 .8% ) ,speF (98 .3% ) ,speG (99 .8% ) , smeZ (94 .1% ) and ssa (88 .4% ) ,and some of them possessed speH (54 .6% ) ,speI (53 .4% ) ,speA (45 .2% ) and speJ (43 .5% ) ,but very few isolates possessed speK (2 .4% ) ,speL (1 .4% ) and speM (1 .7% ) .Type emm12 (59 .5% ) and type emm1 (37 .4% ) were the main types of GAS .Most of the emm12-type isolates possessed speH (84 .8% ) and speI (84 .0% ) compared with only 4 .0% of speH and 3 .4% of speI in type emm1 .Most of type emm1 possessed speA (95 .3% ) and speJ gene (94 .6% ) compared with only 17 .3% of speA and 14 .8% of speJ in type emm12 .The superantigen genes profiles were significant different between emm 1-type and emm 12-type isolates (P< 0 .05) .Conclusion Type emm1 and type emm12 are epidemic strains in patients with scarlet fever from 2012 to 2013 in Beijing ,and emm gene-types are associated with superantigen genes profiles .

15.
Chinese Journal of Epidemiology ; (12): 299-302, 2014.
Article in Chinese | WPRIM | ID: wpr-348681

ABSTRACT

<p><b>OBJECTIVE</b>To analyze the prevalence of super-antigens (SAgs) of group A streptococcus (GAS)isolated from Beijing pediatric patients in 2011, and to explore the relationship between emm types, characteristics of patients and SAgs.</p><p><b>METHODS</b>A total of 635 isolates of GAS were collected from children in 36 hospitals in Beijing from May to July, 2011. Thirteen currently known SAg genes were tested by real-time PCR, and emm gene was performed by PCR and sequencing of N-terminal gene fragments of M protein.</p><p><b>RESULTS</b>Prevalence rates of 13 SAg genes speA, speB, speC, speF, speG, speH, speI, speJ, speK, speL, speM, smeZ, ssa were 22.4%, 100.0%, 99.4%, 99.7%, 99.7%, 76.4%, 76.2%, 21.7%,0.6%, 1.1%, 2.2%, 99.7% and 98.0%, respectively. A total of 26 SAgs profiles were observed according to the SAgs inclusion. There were significant differences in frequencies of speA, speH, speI and speJ between emm1 and emm12 strains (P < 0.05). In isolates from patients with pharyngeal infection, the prevalence rates for speK and speL were higher while the frequency for ssa was lower than that from scarlet fever cases (P < 0.05).</p><p><b>CONCLUSION</b>The frequencies of speB, speF, smeZ, speG, speC, and ssa were high among strains isolated while speM, speL and speK were relatively low from children in Beijing, 2011. SAg genes appeared to be associated with the emm types. In this study, differences of frequency for speA and speC from strains collected from patients with scarlet fever and pharyngeal infection had not been found.</p>


Subject(s)
Adolescent , Child , Child, Preschool , Humans , Antigens, Bacterial , Genetics , China , Epidemiology , Microbial Sensitivity Tests , Sequence Analysis, DNA , Streptococcal Infections , Epidemiology , Microbiology , Streptococcus pyogenes , Genetics , Allergy and Immunology
16.
Zhongguo Zhong Yao Za Zhi ; (24): 1607-1609, 2012.
Article in Chinese | WPRIM | ID: wpr-266966

ABSTRACT

<p><b>OBJECTIVE</b>To establish the method for quantitative determination of sibricose A5 and sibricose A6 in Polygalae Radix by HPLC.</p><p><b>METHOD</b>The ultrasonic extracting method was applied in sample pre-treatment. The HPLC procedure was performed on the chromatographic column of Agela Promosil C18 (4.6 mm x 250 mm, 5 microm), the mobile phase was acetonitrile-0.1% phosphoric acid water solution (10:90). The detection wavelength was 330 nm and flow velocity was 1 mL x min(-1). The column temperature was 30 degrees C.</p><p><b>RESULT</b>The method has good linearity in the ranges of 0.0087-0.0694 g x L(-1) (r = 0.9993) for sibricose A5, 0.0090-0.0723 g x L(-1) (r=0.9991) for sibricose A6. The average recoveries of sibricose A5 and sibricose A6 were 101.7%, 97.87%, with the RSD of 1.7%, 1.6%, respectively.</p><p><b>CONCLUSION</b>The method was simple, quick accurate and reliable. It is appropriate for the quantitative determination of sibricose A5 and sibricose A6 in Polygalae Radix.</p>


Subject(s)
Chromatography, High Pressure Liquid , Drugs, Chinese Herbal , Chemistry , Polygala , Chemistry , Polysaccharides , Chemistry
SELECTION OF CITATIONS
SEARCH DETAIL