Research output: Contribution to journal › Article › Academic › peer-review
Three-Dimensional In Vitro Staphylococcus aureus Abscess Communities Display Antibiotic Tolerance and Protection from Neutrophil Clearance. / Hofstee, Marloes I.; Riool, Martijn; Terjajevs, Igors et al.
In: Infection and immunity, Vol. 88, No. 11, e00293, 11.2020.Research output: Contribution to journal › Article › Academic › peer-review
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TY - JOUR
T1 - Three-Dimensional In Vitro Staphylococcus aureus Abscess Communities Display Antibiotic Tolerance and Protection from Neutrophil Clearance
AU - Hofstee, Marloes I.
AU - Riool, Martijn
AU - Terjajevs, Igors
AU - Thompson, Keith
AU - Stoddart, Martin J.
AU - Richards, R. Geoff
AU - Zaat, Sebastian A. J.
AU - Moriarty, T. Fintan
PY - 2020/11
Y1 - 2020/11
N2 - Staphylococcus aureus is a prominent human pathogen in bone and soft-tissue infections. Pathophysiology involves abscess formation, which consists of central staphylococcal abscess communities (SACs), surrounded by a fibrin pseudocapsule and infiltrating immune cells. Protection against the ingress of immune cells such as neutrophils, or tolerance to antibiotics, remains largely unknown for SACs and is limited by the lack of availability of in vitro models. We describe a three-dimensional in vitro model of SACs grown in a human plasma-supplemented collagen gel. The in vitro SACs reached their maximum size by 24 h and elaborated a fibrin pseudocapsule, as confirmed by electron and immunofluorescence microscopy. The in vitro SACs tolerated 100× the MIC of gentamicin alone and in combination with rifampin, while planktonic controls and mechanically dispersed SACs were efficiently killed. To simulate a host response, SACs were exposed to differentiated PLB-985 neutrophil-like (dPLB) cells and to primary human neutrophils at an early stage of SAC formation or after maturation at 24 h. Both cell types were unable to clear mature in vitro SACs, but dPLB cells prevented SAC growth upon early exposure before pseudocapsule maturation. Neutrophil exposure after plasmin pretreatment of the SACs resulted in a significant decrease in the number of bacteria within the SACs. The in vitro SAC model mimics key in vivo features, offers a new tool to study host-pathogen interactions and drug efficacy assessment, and has revealed the functionality of the S. aureus pseudocapsule in protecting the bacteria from host phagocytic responses and antibiotics.
AB - Staphylococcus aureus is a prominent human pathogen in bone and soft-tissue infections. Pathophysiology involves abscess formation, which consists of central staphylococcal abscess communities (SACs), surrounded by a fibrin pseudocapsule and infiltrating immune cells. Protection against the ingress of immune cells such as neutrophils, or tolerance to antibiotics, remains largely unknown for SACs and is limited by the lack of availability of in vitro models. We describe a three-dimensional in vitro model of SACs grown in a human plasma-supplemented collagen gel. The in vitro SACs reached their maximum size by 24 h and elaborated a fibrin pseudocapsule, as confirmed by electron and immunofluorescence microscopy. The in vitro SACs tolerated 100× the MIC of gentamicin alone and in combination with rifampin, while planktonic controls and mechanically dispersed SACs were efficiently killed. To simulate a host response, SACs were exposed to differentiated PLB-985 neutrophil-like (dPLB) cells and to primary human neutrophils at an early stage of SAC formation or after maturation at 24 h. Both cell types were unable to clear mature in vitro SACs, but dPLB cells prevented SAC growth upon early exposure before pseudocapsule maturation. Neutrophil exposure after plasmin pretreatment of the SACs resulted in a significant decrease in the number of bacteria within the SACs. The in vitro SAC model mimics key in vivo features, offers a new tool to study host-pathogen interactions and drug efficacy assessment, and has revealed the functionality of the S. aureus pseudocapsule in protecting the bacteria from host phagocytic responses and antibiotics.
KW - 3-dimensional
KW - Antibiotic tolerance
KW - Bacterium-host cell interactions
KW - Fibrin pseudocapsule
KW - In vitro model
KW - Staphylococcal abscess communities
KW - Staphylococcus aureus
UR - http://www.scopus.com/inward/record.url?scp=85093889948&partnerID=8YFLogxK
U2 - 10.1128/IAI.00293-20
DO - 10.1128/IAI.00293-20
M3 - Article
C2 - 32817328
VL - 88
JO - Infection and immunity
JF - Infection and immunity
SN - 0019-9567
IS - 11
M1 - e00293
ER -
ID: 13974859