Bacterial Phenotype Variants in Group B Streptococcal Toxic Shock Syndrome1
| Autor: | Jan Sjölin, Linda Johansson, Samira Dahesh, Jessica Darenberg, Anna Norrby-Teglund, Parham Sendi, Nina M Van-Sorge, Mari Norgren, Victor Nizet |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Microbiology (medical) Bacterial capsule medicine.medical_specialty Neutrophils Epidemiology Biology medicine.disease_cause Hemolysis Streptococcus agalactiae Microbiology Mice 03 medical and health sciences Bacterial Proteins Phagocytosis Streptococcal Infections Molecular genetics medicine Animals Humans Fasciitis Necrotizing Bacterial Capsules 030304 developmental biology beta-hemolysin 0303 health sciences 030306 microbiology Research fungi food and beverages Genetic Variation Toxic shock syndrome Middle Aged Opsonin Proteins Haemolysis medicine.disease Shock Septic Phenotype In vitro toxic shock syndrome 3. Good health Repressor Proteins carotenoid pigment Infectious Diseases Group B streptococci |
| Zdroj: | Emerging Infectious Diseases |
| ISSN: | 1080-6059 1080-6040 |
| Popis: | Variants with markedly different expression of virulence factors can arise in invasive infection in humans. We conducted genetic and functional analyses of isolates from a patient with group B streptococcal (GBS) necrotizing fasciitis and toxic shock syndrome. Tissue cultures simultaneously showed colonies with high hemolysis (HH) and low hemolysis (LH). Conversely, the HH and LH variants exhibited low capsule (LC) and high capsule (HC) expression, respectively. Molecular analysis demonstrated that the 2 GBS variants were of the same clonal origin. Genetic analysis found a 3-bp deletion in the covR gene of the HH/LC variant. Functionally, this isolate was associated with an increased growth rate in vitro and with higher interleukin-8 induction. However, in whole blood, opsonophagocytic and intracellular killing assays, the LH/HC phenotype demonstrated higher resistance to host phagocytic killing. In a murine model, LH/HC resulted in higher levels of bacteremia and increased host mortality rate. These findings demonstrate differences in GBS isolates of the same clonal origin but varying phenotypes. |
| Databáze: | OpenAIRE |
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