Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype
Staphylococcus aureus is a common pathogen causing both hospital and community-acquired infections. Hemolysin is one of the important virulence factors for S. aureus and causes the typical β-hemolytic phenotype which is called complete hemolytic phenotype as well. Recently, Staphylococcus aureus wit...
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Frontiers Media S.A.
2016-11-01
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| Series: | Frontiers in Cellular and Infection Microbiology |
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| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fcimb.2016.00146/full |
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| author | Haifang Zhang Yi Zheng Huasheng Gao Min Wang Aiqing Li Minhui Miao Xiaofang Xie Yimai Deng Huiqin Zhou Hong Du |
| author_facet | Haifang Zhang Yi Zheng Huasheng Gao Min Wang Aiqing Li Minhui Miao Xiaofang Xie Yimai Deng Huiqin Zhou Hong Du |
| author_sort | Haifang Zhang |
| collection | DOAJ |
| description | Staphylococcus aureus is a common pathogen causing both hospital and community-acquired infections. Hemolysin is one of the important virulence factors for S. aureus and causes the typical β-hemolytic phenotype which is called complete hemolytic phenotype as well. Recently, Staphylococcus aureus with an incomplete hemolytic phenotype (SIHP) was isolated from clinical samples. To study the microbiologic characteristics of SIHP, SIHP was inoculated on the sheep blood agar plates supplied by different manufacturers to compare their hemolytic phenotype. Expression of hemolysin genes hla, hlb, hlgC and hld of SIHP was detected by qRT-PCR. In addition, the alpha-hemolysin encoded by gene hla was analyzed by western blot. At the same time, the antimicrobial susceptibility of SIHP was tested using the broth dilution method. The main antibiotic resistance gene mecA and virulence genes tst were detected by PCR in SIHP strains. Furthermore, the virulence of SIHP strains was detected through comparing their intracellular survival in macrophage. The cytokines and chemokines secreted by macrophage were measured by flow cytometry. Finally, the genotyping of SIHP was performed by multilocus sequence typing (MLST) analysis. The results showed that the incomplete hemolytic phenotype of SIHP could be observed on the sheep blood agar plates from different suppliers. The relative mRNA expression of hlb in SIHP was obviously increased compared to the control Staphylococcus aureus strains, while the expression of hla, hlgC and hld in SIHP was significantly decreased. In addition, it was shown that the alpha-hemolysin of SIHP was less than that of control strains as well. All sixty SIHP strains were identified to be the methicillin resistant Staphylococcus aureus (MRSA), and moreover these SIHP strains all contains mecA gene. The virulence gene tst were all present in SIHP, and the intracellular survival ability of SIHP was much greater than that of the gene tst negative Staphylococcus aureus. We also found that IL-2, IL-6 and IL-17A secreted in the supernatant of SIHP infected macrophages increased significantly compared to tst negative control strains infected ones. MLST analysis showed that all of SIHP strains were classified into ST5 clone. To our knowledge, this study firstly showed that SIHP strains are |
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| spelling | doaj.art-d9cd91377f66408f8ae4ac7e5e8369e32022-12-22T01:48:27ZengFrontiers Media S.A.Frontiers in Cellular and Infection Microbiology2235-29882016-11-01610.3389/fcimb.2016.00146225314Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic PhenotypeHaifang Zhang0Yi Zheng1Huasheng Gao2Min Wang3Aiqing Li4Minhui Miao5Xiaofang Xie6Yimai Deng7Huiqin Zhou8Hong Du9The Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityThe Second Affiliated Hospital of Soochow UniversityStaphylococcus aureus is a common pathogen causing both hospital and community-acquired infections. Hemolysin is one of the important virulence factors for S. aureus and causes the typical β-hemolytic phenotype which is called complete hemolytic phenotype as well. Recently, Staphylococcus aureus with an incomplete hemolytic phenotype (SIHP) was isolated from clinical samples. To study the microbiologic characteristics of SIHP, SIHP was inoculated on the sheep blood agar plates supplied by different manufacturers to compare their hemolytic phenotype. Expression of hemolysin genes hla, hlb, hlgC and hld of SIHP was detected by qRT-PCR. In addition, the alpha-hemolysin encoded by gene hla was analyzed by western blot. At the same time, the antimicrobial susceptibility of SIHP was tested using the broth dilution method. The main antibiotic resistance gene mecA and virulence genes tst were detected by PCR in SIHP strains. Furthermore, the virulence of SIHP strains was detected through comparing their intracellular survival in macrophage. The cytokines and chemokines secreted by macrophage were measured by flow cytometry. Finally, the genotyping of SIHP was performed by multilocus sequence typing (MLST) analysis. The results showed that the incomplete hemolytic phenotype of SIHP could be observed on the sheep blood agar plates from different suppliers. The relative mRNA expression of hlb in SIHP was obviously increased compared to the control Staphylococcus aureus strains, while the expression of hla, hlgC and hld in SIHP was significantly decreased. In addition, it was shown that the alpha-hemolysin of SIHP was less than that of control strains as well. All sixty SIHP strains were identified to be the methicillin resistant Staphylococcus aureus (MRSA), and moreover these SIHP strains all contains mecA gene. The virulence gene tst were all present in SIHP, and the intracellular survival ability of SIHP was much greater than that of the gene tst negative Staphylococcus aureus. We also found that IL-2, IL-6 and IL-17A secreted in the supernatant of SIHP infected macrophages increased significantly compared to tst negative control strains infected ones. MLST analysis showed that all of SIHP strains were classified into ST5 clone. To our knowledge, this study firstly showed that SIHP strains arehttp://journal.frontiersin.org/Journal/10.3389/fcimb.2016.00146/fullDrug ResistanceStaphylococcus aureusVirulencehemolysinincomplete hemolytic phenotype |
| spellingShingle | Haifang Zhang Yi Zheng Huasheng Gao Min Wang Aiqing Li Minhui Miao Xiaofang Xie Yimai Deng Huiqin Zhou Hong Du Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype Frontiers in Cellular and Infection Microbiology Drug Resistance Staphylococcus aureus Virulence hemolysin incomplete hemolytic phenotype |
| title | Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype |
| title_full | Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype |
| title_fullStr | Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype |
| title_full_unstemmed | Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype |
| title_short | Identification and Characterization of Staphylococcus aureus Strains with an Incomplete Hemolytic Phenotype |
| title_sort | identification and characterization of staphylococcus aureus strains with an incomplete hemolytic phenotype |
| topic | Drug Resistance Staphylococcus aureus Virulence hemolysin incomplete hemolytic phenotype |
| url | http://journal.frontiersin.org/Journal/10.3389/fcimb.2016.00146/full |
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