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1.
Chinese Journal of Schistosomiasis Control ; (6): 583-589, 2023.
Article in Chinese | WPRIM | ID: wpr-1011416

ABSTRACT

Objective To investigate the HIV-1 genotype and distribution of newly diagnosed HIV-1 cases in Fujian Province in 2020, so as to provide insights into formulation of the precise AIDS control strategy in the province. Methods Newly diagnosed HIV-1 cases without antiretroviral therapy (excluding AIDS patients) were randomly sampled from each city of Fujian Province in 2020 at a proportion of 50% of the mean number of HIV-infected cases reported across 9 cities of Fujian Province during the past three years. Subjects’ demographic and epidemiological data were collected and blood samples were collected. The HIV-1 pol gene was amplified using nested reverse-transcription PCR assay, and the gene sequences were used for HIV-1 genotyping and phylogenetic analysis. The gene sequences were uploaded to the HIV Drug Resistance Database (http://hivdb.stanford.edu) for genotypic drug resistance assays, and the scores and level of HIV drug resistance were estimated using the HIVDB Algorithm version 9.5. Results A total of 1 043 newly diagnosed HIV-1 cases were reported in Fujian Province in 2020, and 936 gene sequences were successfully obtained following sequencing of blood samples. There were 9 HIV-1 genotypes characterized in blood samples from 936 newly diagnosed HIV-1 cases, with CRF07_BC (52.1%) and CRF01_AE (30.4%) as predominant subtypes, followed by CRF08_BC (4.9%), CRF55_01B (3.0%), subtype C (2.5%), subtype B (2.1%), CRF85_BC (1.7%), CRF59_01B (0.3%) and CRF65_CPX (0.1%), and unidentified subtypes were found in 26 blood samples. HIV-1 drug resistance was detected in 43 out of the 936 newly diagnosed HIV-1 cases, with 4.6% prevalence of HIV-1 drug resistance prior to therapy, and the highest drug resistance was found in the HIV CRF59_01B subtype, followed by in CRF08_BC, B, C, CRF01_AE, CRF07_BC and other subtypes, with a significant difference in the genotype-specific prevalence of HIV-1 drug resistance (χ2 = 45.002, P < 0.05). Conclusions There was a HIV-1 genotype diversity in Fujian Province in 2020, and emerging recombinant and drug-resistant HIV-1 strains were detected and spread across patients and regions. Monitoring of HIV-1 genotypes is recommended to be reinforced for timely understanding of the transmission and spread of novel recombinant and drug-resistant HIV-1 strains.

2.
Chinese Journal of Contemporary Pediatrics ; (12): 1161-1169, 2023.
Article in Chinese | WPRIM | ID: wpr-1009864

ABSTRACT

OBJECTIVES@#To explore the molecular characteristics of Staphylococcus aureus (S. aureus) in children, and to compare the molecular characteristics of different types of strains (infection and colonization strains) so as to reveal pathogenic molecular markers of S. aureus.@*METHODS@#A cross-sectional study design was used to conduct nasopharyngeal swab sampling from healthy children in the community and clinical samples from infected children in the hospital. Whole genome sequencing was used to detect antibiotic resistance genes and virulence genes. A random forest method to used to screen pathogenic markers.@*RESULTS@#A total of 512 S. aureus strains were detected, including 272 infection strains and 240 colonization strains. For virulence genes, the carrying rates of enterotoxin genes (seb and sep), extracellular enzyme coding genes (splA, splB, splE and edinC), leukocytotoxin genes (lukD, lukE, lukF-PV and lukS-PV) and epidermal exfoliating genes (eta and etb) in infection strains were higher than those in colonization strains. But the carrying rates of enterotoxin genes (sec, sec3, seg, seh, sei, sel, sem, sen, seo and seu) were lower in infection strains than in colonization strains (P<0.05). For antibiotic resistance genes, the carrying rates of lnuA, lnuG, aadD, tetK and dfrG were significantly higher in infection strains than in colonization strains (P<0.05). The accuracy of cross-validation of the random forest model for screening pathogenic markers of S. aureus before and after screening was 69% and 68%, respectively, and the area under the curve was 0.75 and 0.70, respectively. The random forest model finally screened out 16 pathogenic markers (sem, etb, splE, sep, ser, mecA, lnuA, sea, blaZ, cat(pC233), blaTEm-1A, aph(3')-III, ermB, ermA, ant(9)-Ia and ant(6)-Ia). The top five variables in the variable importance ranking were sem (OR=0.40), etb (OR=3.95), splE (OR=1.68), sep (OR=3.97), and ser (OR=1.68).@*CONCLUSIONS@#The random forest model can screen out pathogenic markers of S. aureus and exhibits a superior predictive performance, providing genetic evidence for tracing highly pathogenic S. aureus and conducting precise targeted interventions.


Subject(s)
Child , Humans , Staphylococcus aureus/genetics , Cross-Sectional Studies , Enterotoxins/genetics , Staphylococcal Infections , Whole Genome Sequencing
3.
Journal of Xi'an Jiaotong University(Medical Sciences) ; (6): 691-696, 2022.
Article in Chinese | WPRIM | ID: wpr-1006662

ABSTRACT

【Objective】 To compare the macrolide resistance, molecular characteristics and multilocus antigen sequence typing (MAST) of Bordetella pertussis (Bp) collected from Xi’an and Shanghai so as to provide reference for prevention of pertussis and optimize vaccination strategies. 【Methods】 Erythromycin, azithromycin and clarithromycin susceptibility of clinical isolates collected from Xi’an and Shanghai during 2018 and 2019 were determined by E-test. PCR was used to detect the drug-resistant genes and mutation sites. MAST was employed to do molecular typing for the strains. The differences in macrolide resistance and MAST types between Xi’an and Shanghai were compared. 【Results】 Totally 34 strains from Xi’an and 26 strains from Shanghai were isolated. There were differences between Xi’an and Shanghai in the macrolide resistance (χ2=13.650, P<0.001). The composition ratio of MAST types of pertussis strains was also different between Xi’an and Shanghai (χ2=18.642, P<0.001) in that the prn1/ptxP1/ptxA1/fim3-1/fim2-1 strains dominated in Xi’an, while the prn1/ptxP1/ptxA1/fim3-1/fim2-1 and prn2/ptxP3/ptxA1/fim3-1/fim2-1 were almost half and half in Shanghai. A2047G site mutation was detected in all the macrolide-resistant strains, but not in all sensitive strains. Methylase genes ermA and ermB were detected in some macrolide-resistant strains. No other macrolide-resistant genes were found in resistant strains and no mutation or drug resistance gene was found in all the susceptible strains. 【Conclusion】 Differences existed between Xi’an and Shanghai in the macrolide resistance and MAST types of Bordetella pertussis strains. Further monitoring of Bordetella pertussis in China is required to better understand the resistance and evolution of the pathogen.

4.
Chinese Journal of Infectious Diseases ; (12): 32-37, 2019.
Article in Chinese | WPRIM | ID: wpr-745013

ABSTRACT

Objective To understand the genetic variations of neuraminidase (NA) genes of avian influenza virus H9N2 in Weining,Guizhou Province,and to provide the scientific evidence for the prevention and control of avian influenza virus.Methods Ribonucleic acids (RNA) were extracted and NA genes were amplified and sequenced from 13 randomly selected H9N2 positive samples from the live poultry market (LPM)environments in north of Weining Yi and Hui and Miao autonomous county (Weining),Guizhou Province during 2015 to 2017.Then the homology,genetic evolution,and sites of stalk deletion areas,potential N-glycosylation,receptor binding regions and drug resistance of H9N2 subtype avian influenza viruses were analyzed by a series of bioinformation software.Results Homology analysis revealed that there were 93.0%-100.0% and 92.1%-100.0% similarity among 13 strains H9N2 avian influenza viruses in nucleotide and amino acid of the NA gene,respectively.All strains belonged to DK/HK/Y280/97 sub-lineage,but their genetic sources were complex and diverse.Thirteen strains had a stalk deletion of 3 amino acid residues TEI at positions 63-65 and 3 isolates had mutation QN to QK at positions 39-40.The potential N-glycosylation sites at amino acid residues 86,146,200,and 234 of the NA protein of all strains were highly conserved,while other N-glycosylation sites had quantity and site mutations.There were different mutation types at the three sialic acid binding site areas,especially at 399-404 area.All NA protease activity sites and key sites of the 13 strains had no mutations associated with resistance to the neuraminidase inhibitor drugs.Conclusions All 13 strains H9N2 viruses belongs to DK/HK/Y280/97 sub-lineage in Weining,Guizhou Province during 2015-2017,and their genetic sources are complex and diverse.The mutations on sites of stalk areas,potential N-glycosylation and sialic acid binding site areas are presented at different degrees.Hence,enhancing surveillance and controlling H9N2 avian influenza virus is necessary.

5.
Chinese Journal of Preventive Medicine ; (12): 153-158, 2019.
Article in Chinese | WPRIM | ID: wpr-810473

ABSTRACT

Objective@#To investigate the molecular characteristics of serogroup B neisseria meningitidis in China.@*Methods@#Total of 485 (100 strains isolated from cerebrospinal fluid or blood samples of encephalomyelitis cases, and 385 strains isolated from nasopharynx of healthy carriers) Meningococcal serogroup B (MenB) strains, isolated from 29 provinces of China between 1968 and 2016, were analyzed by multilocus sequence typing (MLST) and PorA typing methods. Further, the genetic diversity of three MenB vaccine proteins, FHbp, NadA and NHBA, were analyzed.@*Results@#The 485 study strains belonged to 270 sequence types (STs), 107 of which (representing 211 strains) could be grouped into ten clonal complexes (CC). CC4821 has been the predominant lineage in China since 2005 (28.7%, n=139). The most common PorA types of MenB strains from invasive meningococcal cases were P1.5-2,2-2 (10.0%, n=10), P1.5-1,2-2 (9.0%, n=9) and P1.5-1,10-4 (9.0%, n=9). Four hundred and twenty one strains had intact fhbp gene; variant 1, 2 and 3 accounted for 12.8% (54 strains), 85.0% (358 strains) and 2.2% (9 strains) respevtively. Ten out of 432 strains (2.3%) contained complete nadA gene. All the 172 strains for which the nhba gene was sequenced had intact gene sequence which corresponded to 68 peptide types.@*Conclusion@#CC4821 was the predominant CC of MenB strains in China; the vaccine proteins were diverse about the sequences. The vaccine proteins should be carefully selected when developing MenB vaccines in China.

6.
Chinese Journal of Microbiology and Immunology ; (12): 848-854, 2018.
Article in Chinese | WPRIM | ID: wpr-711464

ABSTRACT

Objective To investigate the molecular characteristics of H5 subtype avian influenza viruses (AIV) in Weining, Guizhou Province. Methods Nine representative strains were randomly select-ed from H5 subtype AIV that were identified by real-time PCR in Weining, Guizhou Province from 2015 to 2017. Nucleic acid was extracted from each sample and hemagglutinin (HA) genes were amplified and then sequenced. Homology, genetic evolution and the sites related to pathogenicity, receptor binding regions as well as potential glycosylation of H5 AIV were analyzed by bioinformation software. Results Homology analysis revealed that there was 96. 1%-99. 9% and 95. 7%-100% similarity among the nine strains in nu-cleotide and amino acid of HA gene, respectively. These strains belonged to two branches, H5-1 and H5-2. The cleavage site motifs were PLREKRRKR↓GLF for five strains in H5-1 branch and PQRERRRKR↓GLF for four strains in H5-2 branch, which made them high pathogenic. QSG and QRG at the key receptor bind-ing sites were found in H5-1 and H5-2 branch strains, respectively. They were responsible for receptor bind-ing specificity of AIV. Mutations of 138Q, 139G and 53K were all detected in the nine strains. 129K, 189T, 140K and 282V mutations were discovered in the five strains of H5-1 branch, while 189N, 140M and 282I mutations were found in the four strains of H5-2 branch. Results of the glycosylation motif analysis showed that six sites were conservative, but there was an addition of 124NHT site in two strains of H5-2 branch isolated in 2017. Conclusion Two high pathogenic H5 subtypes of AIV could be epidemic in Wein-ing, Guizhou Province during 2015 to 2017. Although H5 subtype AIV did not possess specific receptor binding regions like human influenza viruses, they were in continuous variation with an increase in glycosyla-tion motifs, which might enhance their virulence and pathogenicity to human beings. Hence, surveillance and study on the molecular properties of H5 subtype AIV should be strengthened.

7.
Chinese Journal of Epidemiology ; (12): 1465-1471, 2018.
Article in Chinese | WPRIM | ID: wpr-738169

ABSTRACT

Objective To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province.Methods RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017.Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package.Results Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8%-99.2% and 99.2% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO,respectively.Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2%-99.3% and 97.6%-98.8% similarities with vaccine strain A/Hunan/02650/2016,respectively.Other 6 stains detected in 2017 shared 99.1%-99.4% and 98.9%-99.3% similarities with strain A/Guangdong/17SF003/2016,respectively.Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch,but they were derived from different small branch.PEVPKRKRTAR ↓ GLF was found in 6 of 24 strains cleavage site sequences of HA protein,indicating the characteristic of highly pathogenic avian influenza virus.Mutations A134V,G186V and Q226L at the receptor binding sites were found in the HA.All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein,and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/ 18980/2017.In addition,potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains.Condusions HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017.The mutations of key sites might enhance the virulence of the virus,human beings are more susceptible to it.Hence,the risk of infection is increasing.

8.
Chinese Journal of Epidemiology ; (12): 1465-1471, 2018.
Article in Chinese | WPRIM | ID: wpr-736701

ABSTRACT

Objective To understand the molecular characteristics of hemagglutinin (HA) and neuraminidase (NA) as well as the disease risk of influenza virus A H7N9 in Guizhou province.Methods RNAs were extracted and sequenced from HA and NA genes of H7N9 virus strains obtained from 18 cases of human infection with H7N9 virus and 6 environmental swabs in Guizhou province during 2014-2017.Then the variation and the genetic evolution of the virus were analyzed by using a series of bioinformatics software package.Results Homology analysis of HA and NA genes revealed that 2 strains detected during 2014-2015 shared 98.8%-99.2% and 99.2% similarities with vaccine strains A/Shanghai/2/2013 and A/Anhui/1/2013 recommended by WHO,respectively.Two strains detected in 2016 and 14 strains detected in 2017 shared 98.2%-99.3% and 97.6%-98.8% similarities with vaccine strain A/Hunan/02650/2016,respectively.Other 6 stains detected in 2017 shared 99.1%-99.4% and 98.9%-99.3% similarities with strain A/Guangdong/17SF003/2016,respectively.Phylogenetic analysis showed that all the strains were directly evolved in the Yangtze River Delta evolution branch,but they were derived from different small branch.PEVPKRKRTAR ↓ GLF was found in 6 of 24 strains cleavage site sequences of HA protein,indicating the characteristic of highly pathogenic avian influenza virus.Mutations A134V,G186V and Q226L at the receptor binding sites were found in the HA.All the strains had a stalk deletion of 5 amino acid residue "QISNT" in NA protein,and drug resistance mutation R294K occurred in strain A/Guizhou-Danzhai/ 18980/2017.In addition,potential glycosylation motifs mutations NCS42NCT were found in the NA of 9 of 24 strains.Condusions HA and NA genes of avian influenza A (H7N9) virus showed genetic divergence in Guizhou province during 2014-2017.The mutations of key sites might enhance the virulence of the virus,human beings are more susceptible to it.Hence,the risk of infection is increasing.

9.
Chinese Journal of Infectious Diseases ; (12): 280-285, 2018.
Article in Chinese | WPRIM | ID: wpr-806476

ABSTRACT

Objective@#To investigate the molecular characteristics and tracing of the hemagglutinin (HA) gene, and to analyze the risk of human infection with influenza virus A (H7N9) in Guizhou Province, so that to provide evidence for the prevention and control of highly pathogenic avian influenza A (H7N9).@*Methods@#Nucleic acids of 5 strains of H7N9 including 1 sample of the patient′s nasopharyngeal swab and 4 samples of the live poultry market (LPM) environment were extracted and HA genes were amplified and sequenced. Then the homology, genetic evolution and the pivotal sites related to receptor binding regions, pathogenicity and potential glycosylation of the avian influenza A (H7N9) viruses were analyzed by a series of bioinformatics softwares.@*Results@#Homology analysis revealed that the homologies of nucleotide and amino-acid of the HA gene of H7N9 strains from the patient and LPM in Weining County, Guizhou Province were 99.8% and 99.6%, respectively, while those of 4 strains from LPM were both 100%. The homologies of nucleotide and amino-acid of the HA gene of H7N9 strains were the highest with the strain of A/Guangxi/5/2017 isolated from a Guangxi infected patient (99.7%-99.9% and 99.4%-99.8%, respectively), while those with the strain isolated from LPMs environment at the end of 2016 (A/Environment/Guangdong/C16283222/2016) were 99.0%-99.2% and 98.9%-99.2%, respectively. However, the homologies of nucleotide and amino-acid of the HA gene of H7N9 strains with A/Shanghai/2/2013 recommended by world health organization and the candidate vaccine strain A/Anhui/1/2013 were 96.8%-97.0% and 95.8%-96.2%, respectively. Phylogenetic analysis showed that the 5 strains had the nearest genetic distance to the strain A/Guangxi/5/2017. All the 5 strains cleavage site sequences of HA protein showed mutation of PEVPKRKRTAR↓GLF, and they were highly pathogenic avian influenza viruses mutant strains, which all had mutation of G186V at the receptor binding sites of HA gene, while no Q226L mutation was found. All 5 strains had new mutation of A363S, and new mutations of R56K and I297V were only found in the strain isolated from the patient. Among the five potential glycosylation motifs in the HA, only 421NWT and 493NNT had variation of the position post shift.@*Conclusions@#All the 5 H7N9 strains isolated in Weining County, Guizhou Province are highly pathogenic avian influenza mutative viruses. The current candidate vaccine may not provide a very good protection. The mutations of cleavage site of HA protein, G186V as well as other new mutation sites of HA may enhance the susceptibility and pathogenicity to human beings.

10.
Chinese Journal of Zoonoses ; (12): 805-808,813, 2017.
Article in Chinese | WPRIM | ID: wpr-659520

ABSTRACT

We delineated the molecular characteristic of recombinant strain GⅡ.P16/GⅡ.2 of norovirus associated with acute viral gastroenteritis outbreaks in Fujian Province in winter of 2016.Norovirus were detected in specimens of patients collected from the gastroenteritis outbreaks by real time reverse transcription-PCR and reverse transcription-PCR (RT-PCR).The PCR products of the positive samples were purified,and partial RNA dependent RNA polymerase (RdRp) gene and partial capsid gene were sequenced.The sequences were analyzed using bioinformatics software and online database,and phylogenetic tree were also constructed.Norovirus were detected in all 18 stools.Analysis of 9 positive sequences indicated an emergence of norovirus GⅡ.P16/ GⅡ.2 and confirmed being the cause of gastroenteritis outbreaks.All the strains shared homology of 98% with strains of Kawasaki 194 of Japan detected in 2016 and 97.7%-98.8% with IPH2161-08VG06 of Belgium detected in 2008,RdRp and capsid separately.These outbreak strains showed some degree of differences from the predominant strain,2012 Sydney GⅡ.4 variant.This is the first time to have found norovirus GⅡ.P16/ GⅡ.2 causing viral gastroenteritis outbreaks in Fujian.More in-depth analysis of the Norovirus GⅡ.P16/ GⅡ.2 could be useful to optimize preventative strategies and develop new and more effective therapeutic measure.

11.
Chinese Journal of Zoonoses ; (12): 805-808,813, 2017.
Article in Chinese | WPRIM | ID: wpr-657443

ABSTRACT

We delineated the molecular characteristic of recombinant strain GⅡ.P16/GⅡ.2 of norovirus associated with acute viral gastroenteritis outbreaks in Fujian Province in winter of 2016.Norovirus were detected in specimens of patients collected from the gastroenteritis outbreaks by real time reverse transcription-PCR and reverse transcription-PCR (RT-PCR).The PCR products of the positive samples were purified,and partial RNA dependent RNA polymerase (RdRp) gene and partial capsid gene were sequenced.The sequences were analyzed using bioinformatics software and online database,and phylogenetic tree were also constructed.Norovirus were detected in all 18 stools.Analysis of 9 positive sequences indicated an emergence of norovirus GⅡ.P16/ GⅡ.2 and confirmed being the cause of gastroenteritis outbreaks.All the strains shared homology of 98% with strains of Kawasaki 194 of Japan detected in 2016 and 97.7%-98.8% with IPH2161-08VG06 of Belgium detected in 2008,RdRp and capsid separately.These outbreak strains showed some degree of differences from the predominant strain,2012 Sydney GⅡ.4 variant.This is the first time to have found norovirus GⅡ.P16/ GⅡ.2 causing viral gastroenteritis outbreaks in Fujian.More in-depth analysis of the Norovirus GⅡ.P16/ GⅡ.2 could be useful to optimize preventative strategies and develop new and more effective therapeutic measure.

12.
Chinese Pharmaceutical Journal ; (24): 346-352, 2016.
Article in Chinese | WPRIM | ID: wpr-859184

ABSTRACT

Klebsiella pneumoniae, an important nosocomial infection pathogen, has high rate of clinical isolates. Carbapenems agents is stable for the majority β-lactamase initially, but with the broadly use of carbapenems agents, carbapenem resistant Klebsiella pneumoniae(CRKP) appear in hospital as a results, which result in the antibactic invalidation. With the CRKP rapiding growth in some area, the contents of the relevant literature review, in this article, the related literature content of the CRKP mechanism of drug resistance, molecular epidemiology and clinical antibiotic selection is reviewed, aims to explain the interaction between CRKP molecular characteristics and antimicrobial activity, also to provide theoretical basis for the more rational use of antimicrobial agents in the treatment of CRKP infection, and to investigate the CRKP different molecular mechanisms and antimicrobial activity relationship studies lay the theoretical foundation.

13.
Braz. j. infect. dis ; 19(6): 614-622, Nov.-Dec. 2015. tab
Article in English | LILACS | ID: lil-769633

ABSTRACT

ABSTRACT A better understanding of the antimicrobial susceptibility, carriage of virulence determinants and molecular characteristics of Staphylococcus aureus isolates associated with skin and soft tissue infections (SSTIs) may provide further insights related to clinical outcomes with these infections. From January 2012 to September 2013, a total of 128 non-duplicateS. aureus isolates were recovered from patients with SSTIs. All 128 S. aureus SSTI isolates carried at least five virulence genes tested. Virulence genes detected among at least 70% of all tested isolates included hld (100%), hla (95.3%),icaA (96.9%), clf (99.2%),sdrC (79.7%), sdrD (70.3%), andsdrE (72.7%). The prevalence of MRSA isolates with 10 virulence genes tested (54.4%, 31/56) was significantly higher than that among MSSA isolates (35.2%, 25/71) (p < 0.05). The positive rates of seb, sen, sem, sdrE and pvl among MRSA isolates were significantly higher than among MSSA isolates (p< 0.05). ST7 and ST630 accounting for 10.9% were found to be the predominant STs. The most prevalent spa type was t091 (8.6%). MRSA-ST59-SCCmec IV was the most common clone (12.3%) among MRSA isolates whereas among MSSA isolates the dominant clone was MSSA-ST7 (15.5%). Six main clonal complexes (CCs) were found, including CC5 (52.3%), CC7 (11.7%), CC59 (8.6%), CC88 (6.3%), CC398 (4.7%), and CC121 (3.1%). A higher carriage of seb and sec was found among CC59 isolates. In comparison to CC5 and CC7 isolates, those with the highest carriage rates (>80.0%) of sdrC and sdrD, CC59 isolates had lower prevalence of these two virulence genes. All CC59 isolates were susceptible to gentamicin and trimethoprim/sulfamethoxazole, while CC5 and CC7 isolates had resistance rates to these two antimicrobials of 25.4% and 20.9%, and 40.0% and 40.0%, respectively. The resistance rates for tetracycline, clindamycin, and erythromycin among CC5 isolates were lower than among CC7 and CC59 isolates. In conclusion, the molecular typing of S. aureusSSTI isolates in the present study showed considerable heterogeneity. ST7 and ST630 became prevailing clones. Different S. aureus clones causing SSTIs were associated with specific antimicrobial resistance and virulence gene profiles.


Subject(s)
Humans , Anti-Bacterial Agents/pharmacology , Soft Tissue Infections/microbiology , Staphylococcal Skin Infections/microbiology , Staphylococcus aureus/drug effects , Staphylococcus aureus/pathogenicity , Virulence Factors/genetics , Bacterial Typing Techniques , Microbial Sensitivity Tests , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Methicillin-Resistant Staphylococcus aureus/pathogenicity , Staphylococcus aureus/genetics
14.
Chinese Journal of Microbiology and Immunology ; (12): 660-665, 2015.
Article in Chinese | WPRIM | ID: wpr-481499

ABSTRACT

Objective To investigate the correlation between the mutation of pncA gene and the susceptibility to pyrazinamide ( PZA) in Mycobacterium tuberculosis complex ( MTBC) strains and to analyze the mutation of panD and rpsA genes in wild type isolates without pncA gene mutation.Methods The sus-ceptibilities of 108 MTBC strains to first-line drugs including PZA were detected by using the MGIT 960 TB system.PCR was performed to amplify the 16S rDNA and pncA, panD and rpsA genes.The PCR products were analyzed by DNA sequencing analysis .Results Among the 78 multidrug-resistant MTBC strains , 47 isolates (60%) were resistant to PZA.Four out of 30 (13%) strains that were sensitive to ethambutol , iso-niazid, rifampicin and streptomycin (EIRS) were resistant to PZA.The drug-resistant MTBC strains showed higher resistance rate to PZA than that of the EIRS sensitive strains .There were 49 ( 96%) PZA-resistant isolates and 4 (7%) PZA-sensitive isolates occurred pncA gene mutation.Most of the pncA gene mutations in the genomes of PZA-resistant strains were base substitution mutation , especially the His57Asp substitu-tion.The pncA gene mutations centralized in the regions of 160-169, 203-289, 309-396 and 413-467.Seven novel mutation sites of pncA gene were observed including T175C, C188A, G insertion at 68, AGC insertion at 235, C insertion at 339, CC insertion at 392 and GT deletion at 395.The mutation sites founded in the genomes of PZA-sensitive strains were different from those of the PZA-resistant strains .No mutation of the pncA gene and the upstream regulatory sequence was found in two PZA-resistant strains , NJ44 and NJ108 . The sequence analysis of panD and rpsA gene showed that the NJ 108 strain had panD gene mutation at G419A, but no mutation was detected in the NJ 44 strain.Conclusion The multidrug-resistant MTBC strains showed higher resistance rate to PZA .The pncA gene mutation was common in PZA-resistant MTB strains and the panD gene mutation was also worthy of attention .

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