Abstract
Enterococcal clinical isolates were investigated for the ability to form biofilm on inert surfaces, as a measure of slime production, in an attempt to find new possible virulence factors for these microorganisms. This property was commonly found among Enterococcus faecalis. Also E. faecium isolates were able to form biofilm, although to a lesser extent; for this species, however, biofilm formation seemed more frequently associated with isolates from infection rather than with environmental strains or isolates from healthy individuals. Biofilm formation was strongly affected by the presence of an additional carbohydrate source in the medium, or by iron deprivation, indicating a role of slime for survival in stressful conditions. Slime-producing E. faecalis were able to survive inside peritoneal macrophages for extended periods compared to slimenegative strains or to slime-positive bacteria grown in conditions depressing slime production. In particular, slime-producing and slime-negative cells showed a decrease of 1 and 2 log units, respectively, at 1 h after infection; slime-negative cells were then rapidly killed, with clearance of bacterial cells at 24 h. Slime-producing bacteria persisted up to 48 h, which was the last time point examined as after that time viability of both infected and non-infected macrophages started to decline. Scanning electron microscopy observations showed the presence of abundant amorphous extracellular material, of possible polysaccharide nature, embedding bacterial cells to form a multilayered biofilm. Even in conditions not supporting biofilm formation, bacterial cells appeared capsulated, suggesting that capsule and slime might represent different structures. Genes belonging to the epa locus or to a putative icaA homolog did not seem to be involved in synthesis and export of slime.
| Original language | English |
|---|---|
| Pages (from-to) | 113-120 |
| Number of pages | 8 |
| Journal | Medical Microbiology and Immunology |
| Volume | 190 |
| Issue number | 3 |
| Publication status | Published - 2001 |
Fingerprint
Keywords
- Colonization
- Slime
- Survival in macrophages
ASJC Scopus subject areas
- Immunology and Allergy
- Microbiology (medical)
- Immunology
Cite this
Enterococcus spp. produces slime and survives in rat peritoneal macrophages. / Baldassarri, Lucilla; Cecchini, Roberto; Bertuccini, Lucia; Ammendolia, Maria G.; Iosi, F.; Arciola, Carla R.; Montanaro, Lucio; Di Rosa, Roberta; Gherardi, Giovanni; Dicuonzo, Giordano; Orefici, Graziella; Creti, Roberta.
In: Medical Microbiology and Immunology, Vol. 190, No. 3, 2001, p. 113-120.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Enterococcus spp. produces slime and survives in rat peritoneal macrophages
AU - Baldassarri, Lucilla
AU - Cecchini, Roberto
AU - Bertuccini, Lucia
AU - Ammendolia, Maria G.
AU - Iosi, F.
AU - Arciola, Carla R.
AU - Montanaro, Lucio
AU - Di Rosa, Roberta
AU - Gherardi, Giovanni
AU - Dicuonzo, Giordano
AU - Orefici, Graziella
AU - Creti, Roberta
PY - 2001
Y1 - 2001
N2 - Enterococcal clinical isolates were investigated for the ability to form biofilm on inert surfaces, as a measure of slime production, in an attempt to find new possible virulence factors for these microorganisms. This property was commonly found among Enterococcus faecalis. Also E. faecium isolates were able to form biofilm, although to a lesser extent; for this species, however, biofilm formation seemed more frequently associated with isolates from infection rather than with environmental strains or isolates from healthy individuals. Biofilm formation was strongly affected by the presence of an additional carbohydrate source in the medium, or by iron deprivation, indicating a role of slime for survival in stressful conditions. Slime-producing E. faecalis were able to survive inside peritoneal macrophages for extended periods compared to slimenegative strains or to slime-positive bacteria grown in conditions depressing slime production. In particular, slime-producing and slime-negative cells showed a decrease of 1 and 2 log units, respectively, at 1 h after infection; slime-negative cells were then rapidly killed, with clearance of bacterial cells at 24 h. Slime-producing bacteria persisted up to 48 h, which was the last time point examined as after that time viability of both infected and non-infected macrophages started to decline. Scanning electron microscopy observations showed the presence of abundant amorphous extracellular material, of possible polysaccharide nature, embedding bacterial cells to form a multilayered biofilm. Even in conditions not supporting biofilm formation, bacterial cells appeared capsulated, suggesting that capsule and slime might represent different structures. Genes belonging to the epa locus or to a putative icaA homolog did not seem to be involved in synthesis and export of slime.
AB - Enterococcal clinical isolates were investigated for the ability to form biofilm on inert surfaces, as a measure of slime production, in an attempt to find new possible virulence factors for these microorganisms. This property was commonly found among Enterococcus faecalis. Also E. faecium isolates were able to form biofilm, although to a lesser extent; for this species, however, biofilm formation seemed more frequently associated with isolates from infection rather than with environmental strains or isolates from healthy individuals. Biofilm formation was strongly affected by the presence of an additional carbohydrate source in the medium, or by iron deprivation, indicating a role of slime for survival in stressful conditions. Slime-producing E. faecalis were able to survive inside peritoneal macrophages for extended periods compared to slimenegative strains or to slime-positive bacteria grown in conditions depressing slime production. In particular, slime-producing and slime-negative cells showed a decrease of 1 and 2 log units, respectively, at 1 h after infection; slime-negative cells were then rapidly killed, with clearance of bacterial cells at 24 h. Slime-producing bacteria persisted up to 48 h, which was the last time point examined as after that time viability of both infected and non-infected macrophages started to decline. Scanning electron microscopy observations showed the presence of abundant amorphous extracellular material, of possible polysaccharide nature, embedding bacterial cells to form a multilayered biofilm. Even in conditions not supporting biofilm formation, bacterial cells appeared capsulated, suggesting that capsule and slime might represent different structures. Genes belonging to the epa locus or to a putative icaA homolog did not seem to be involved in synthesis and export of slime.
KW - Colonization
KW - Slime
KW - Survival in macrophages
UR - http://www.scopus.com/inward/record.url?scp=0035211711&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0035211711&partnerID=8YFLogxK
M3 - Article
C2 - 11827199
AN - SCOPUS:0035211711
VL - 190
SP - 113
EP - 120
JO - Medical Microbiology and Immunology
JF - Medical Microbiology and Immunology
SN - 0300-8584
IS - 3
ER -