Comparison of Staphylococcus epidermidis isolated from prosthetic joint infections and commensal isolates in regard to antibiotic susceptibility, agr type, biofilm production, and epidemiology

Hellmark, Bengt; Söderquist, Bo; Unemo, Magnus; Nilsdotter-Augustinsson, Åsa

doi:10.1016/j.ijmm.2012.11.001

Cited by 77 publications

(87 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…5). In some studies, the type I strains were the most frequently identified in S. epidermidis infections (19,21,22), and perhaps these interference properties give these strains a competitive advantage. However, the high prevalence of agr type I strains is not universal, as a recent large study of 200 S. epidermidis isolates from hospitalized patients in Germany found over two-thirds to be agr type II and III (23).…”

Section: Discussionmentioning

confidence: 99%

“…Following the initial description of the locus (16,17), it was several years before sequencing studies revealed three different classes of S. epidermidis agr systems in clinical isolates (18), which are referred to here as agr types I, II, and III. Although there has been some effort to correlate these classes with S. epidermidis disease (19)(20)(21)(22)(23), the presence of different agr classes, and their unique AIP signals, has remained largely overlooked. Of these, only the AIP-I structure has been characterized (16).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Staphylococcus epidermidis agr Quorum-Sensing System: Signal Identification, Cross Talk, and Importance in Colonization

et al. 2014

View full text Add to dashboard Cite

e Staphylococcus epidermidis is an opportunistic pathogen that is one of the leading causes of medical device infections. Global regulators like the agr quorum-sensing system in this pathogen have received a limited amount of attention, leaving important questions unanswered. There are three agr types in S. epidermidis strains, but only one of the autoinducing peptide (AIP) signals has been identified (AIP-I), and cross talk between agr systems has not been tested. We structurally characterized all three AIP types using mass spectrometry and discovered that the AIP-II and AIP-III signals are 12 residues in length, making them the largest staphylococcal AIPs identified to date. S. epidermidis agr reporter strains were developed for each system, and we determined that cross-inhibitory interactions occur between the agr type I and II systems and between the agr type I and III systems. In contrast, no cross talk was observed between the type II and III systems. To further understand the outputs of the S. epidermidis agr system, an RNAIII mutant was constructed, and microarray studies revealed that exoenzymes (Ecp protease and Geh lipase) and low-molecular-weight toxins were downregulated in the mutant. Follow-up analysis of Ecp confirmed the RNAIII is required to induce protease activity and that agr cross talk modulates Ecp activity in a manner that mirrors the agr reporter results. Finally, we demonstrated that the agr system enhances skin colonization by S. epidermidis using a porcine model. This work expands our knowledge of S. epidermidis agr system function and will aid future studies on cell-cell communication in this important opportunistic pathogen.

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

Staphylococcus epidermidis agr Quorum-Sensing System: Signal Identification, Cross Talk, and Importance in Colonization

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Based on the high prevalence of strains encoding aap (12,28,42,(78)(79)(80)(81)(82) and the ability of ica-negative strains to cause infection (12,32,39,81,(83)(84)(85)(86), we hypothesized that Aap contributed to S. epidermidis virulence. To address this question, we compared the infectivity of our isogenic strain set in our validated model of rat central venous catheter (CVC) infection.…”

Section: Figmentioning

confidence: 99%

Accumulation-Associated Protein Enhances Staphylococcus epidermidis Biofilm Formation under Dynamic Conditions and Is Required for Infection in a Rat Catheter Model

et al. 2015

View full text Add to dashboard Cite

Biofilm formation is the primary virulence factor of Staphylococcus epidermidis. S. epidermidis biofilms preferentially form on abiotic surfaces and may contain multiple matrix components, including proteins such as accumulation-associated protein (Aap). Following proteolytic cleavage of the A domain, which has been shown to enhance binding to host cells, B domain homotypic interactions support cell accumulation and biofilm formation. To further define the contribution of Aap to biofilm formation and infection, we constructed an aap allelic replacement mutant and an icaADBC aap double mutant. When subjected to fluid shear, strains deficient in Aap production produced significantly less biofilm than Aap-positive strains. To examine the in vivo relevance of our findings, we modified our previously described rat jugular catheter model and validated the importance of immunosuppression and the presence of a foreign body to the establishment of infection. The use of our allelic replacement mutants in the model revealed a significant decrease in bacterial recovery from the catheter and the blood in the absence of Aap, regardless of the production of polysaccharide intercellular adhesin (PIA), a well-characterized, robust matrix molecule. Complementation of the aap mutant with full-length Aap (containing the A domain), but not the B domain alone, increased initial attachment to microtiter plates, as did in trans expression of the A domain in adhesion-deficient Staphylococcus carnosus. These results demonstrate Aap contributes to S. epidermidis infection, which may in part be due to A domain-mediated attachment to abiotic surfaces.

show abstract

“…S. aureus is a commonly described microorganism in different hospital-acquired infections (16), probably because of its abundance on the skin, as in the case of S. epidermidis (17). Several authors have concluded that the pathogenicity of these microorganisms in implant-related infections lies in their ability to form biofilms (2,18,19), as these structures protect the bacteria from the immune system and also make them less susceptible to antibiotics (2,7,(19)(20)(21)(22). We must also not forget other species of staphylococci, such as S. lugdunensis, which is being increasingly recognized as the cause of severe infections (2,23).…”

Section: Discussionmentioning

confidence: 99%

“…We must also not forget other species of staphylococci, such as S. lugdunensis, which is being increasingly recognized as the cause of severe infections (2,23). The emergence of these organisms may be related to the presence of a gene complex with a similar order and sequence in all of the 3 aforementioned species (20). Other species studied in this work, such as P. aeruginosa, E. cloacae, S. paucimobilis, and K. pneumoniae, have also been reported to cause PJI, although less frequently than staphylococci (2,24,25).…”

Section: Discussionmentioning

confidence: 99%

Detection of Polyclonality among Clinical Isolates from Prosthetic Joint Infections

et al. 2015

View full text Add to dashboard Cite

Prosthetic joint infection (PJI) is an increasingly important health concern in the Western world due to the rising number of joint arthroplasties. Although most infections are considered to be monomicrobial, the introduction of sonication procedures has led to an increase in the detection of polymicrobial infections. To date, no published studies have investigated the presence of different clones of the same species in the infected patient. The objective of this study was to analyze whether the phenomenon of polyclonality, or the appearance of different clones in the same sample, occurs in PJI. Bacteria isolated by sonication of the retrieved implant from patients with theoretically monomicrobial PJI were included in the study. Two techniques (random amplified polymorphic DNA [RAPD] and matrix-assisted laser desorption ionization-time of flight [MALDI-TOF] mass spectrometry) were used to determine the presence of several clones in the same sample. Results were analyzed to determine bacterial species and infection type (acute versus chronic). RAPD showed a predominance of polyclonal cases (16 of 19). However, when performing the analysis with MALDI-TOF, all cases were shown to be polyclonal. We were unable to establish any relationship between the two methodologies. Polyclonality is a common phenomenon in acute and chronic PJI. Further studies are needed to establish the potential implications of this phenomenon on patient outcomes. P rosthetic joint replacement, or arthroplasty, is a surgical procedure that has improved the quality of life for many people around the world, providing pain relief and improved functionality to limbs (1-3). However, 10% of all patients who undergo this operation develop complications at some point in their lives; although it is not the most common, infection is one of the most significant of these complications, having an incidence of 1% to 3% (1, 3, 4). The microorganisms that cause most cases of prosthetic joint infection (PJI) are those belonging to the genus Staphylococcus (60% of cases), of which infections caused by Staphylococcus aureus constitute 25%. Gram-negative organisms (Enterobacteriaceae, Pseudomonas aeruginosa, and other species) represent a smaller proportion of cases (10%) (1, 2, 5). Notably, up to 20% to 25% of PJIs are polymicrobial infections (1-3).When the growth conditions of the bacteria causing PJI become hostile, as may occur during antibiotic therapy, a coping mechanism known as spontaneous random hypermutation occurs as the bacteria attempt to overcome the unfavorable environment (6). This results in the development of polyclonality or the appearance of different clones in the same sample or environment (6). Polyclonality can also occur when the patient is infected with different clones from the same section of skin, which may occur either during surgery or afterwards and is likely a more common phenomenon (7). Several reports have found polyclonality in monomicrobial infections among isolates of small-colony variant staphylococci, which present phenotyp...

show abstract

Comparison of Staphylococcus epidermidis isolated from prosthetic joint infections and commensal isolates in regard to antibiotic susceptibility, agr type, biofilm production, and epidemiology

Cited by 77 publications

References 39 publications

Staphylococcus epidermidis agr Quorum-Sensing System: Signal Identification, Cross Talk, and Importance in Colonization

Staphylococcus epidermidis agr Quorum-Sensing System: Signal Identification, Cross Talk, and Importance in Colonization

Accumulation-Associated Protein Enhances Staphylococcus epidermidis Biofilm Formation under Dynamic Conditions and Is Required for Infection in a Rat Catheter Model

Detection of Polyclonality among Clinical Isolates from Prosthetic Joint Infections

Contact Info

Product

Resources

About