Antibiofilm and intraosteoblastic activities of rifamycins against Staphylococcus aureus: promising in vitro profile of rifabutin

2020 ◽  
Vol 75 (6) ◽  
pp. 1466-1473 ◽  
Author(s):  
Lélia Abad ◽  
Jérôme Josse ◽  
Jason Tasse ◽  
Sébastien Lustig ◽  
Tristan Ferry ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Therapeutic Potential ◽  
Joint Infection ◽  
Small Colony Variant ◽  
Resistance Selection ◽  
Low Concentrations ◽  
Infection Models ◽  
Small Colony

Abstract Background Targeting biofilm-embedded and intraosteoblastic Staphylococcus aureus, rifampicin gained a pivotal role in bone and joint infection (BJI) treatment. Two other rifamycins, rifabutin and rifapentine, may represent better-tolerated alternatives, but their activity against bacterial reservoirs associated with BJI chronicity has never been evaluated. Objectives To evaluate the activities of rifampicin, rifabutin and rifapentine in osteoblast infection models. Methods Using three S. aureus isolates, rifamycins were compared regarding: (i) their intracellular activity in ‘acute’ (24 h) and ‘chronic’ (7 days) osteoblast infection models at 0.1× MIC, 1× MIC, 10× MIC and 100× MIC, while impacting infection-induced cytotoxicity (MTT assay), intracellular phenol-soluble modulin (PSM) secretion (RT–PCR), resistance selection and small colony variant (SCV) emergence; and (ii) their minimal biofilm eradication concentration (MBEC) and their MIC to prevent biofilm formation (bMIC). Results At 0.1× MIC, only rifabutin significantly reduced intracellular inoculum and PSM secretion. All rifamycins allowed a 50% reduction of intraosteoblastic inoculum at higher concentrations, with no difference between acute and chronic infection models, while reducing infection-induced cytotoxicity and PSM secretion. Dose-dependent emergence of intracellular SCVs was observed for all molecules. No intracellular emergence of resistance was detected. bMICs were equivalent for all molecules, but MBEC90s of rifapentine and rifabutin were 10- to 100-fold lower than those of rifampicin, respectively. Conclusions All rifamycins are efficient in reducing the S. aureus intraosteoblastic reservoir while limiting infection-induced cytotoxicity, with a higher activity of rifabutin at low concentrations. All molecules prevent biofilm formation, but only rifapentine and rifabutin consistently reduce formed biofilm-embedded bacteria for all isolates. The activity of rifabutin at lower doses highlights its therapeutic potential.

Phage Activity Against Planktonic and Biofilm Staphylococcus aureus Periprosthetic Joint Infection Isolates

2021 ◽  
Author(s):  
Katherine M. Caflisch ◽  
Robin Patel
Keyword(s):  
Staphylococcus Aureus ◽  
Successful Treatment ◽  
Periprosthetic Joint Infection ◽  
Joint Infection ◽  
Bacterial Isolates ◽  
Small Colony Variant ◽  
Small Colony ◽  
Planktonic State ◽  
Phage Activity

We recently reported the successful treatment of a case of periprosthetic joint infection (PJI) with phage. Phage activity against bacteria causing PJI has not been systematically evaluated. Here we examined the in vitro activity of seven lytic phages against 122 clinical isolates of Staphylococcus aureus recovered between April 1999 and February 2018 from subjects with PJI. Phages were assessed against planktonic and biofilm phenotypes. Activity of individual phages was demonstrated against up to 73% of bacterial isolates in the planktonic state and up to 100% of biofilms formed by isolates that were planktonically phage-susceptible. Susceptibility to phage was not correlated with small colony variant status. These results demonstrate that phages can infect S. aureus causing PJI in both planktonic and biofilm phenotypes, and thus are worthy of investigation as an alternative or addition to antibiotics in this setting.

scholarly journals Attenuated Virulence and Biofilm Formation in Staphylococcus aureus following Sublethal Exposure to Triclosan

2012 ◽  
Vol 56 (6) ◽  
pp. 3092-3100 ◽  
Author(s):  
Joe Latimer ◽  
Sarah Forbes ◽  
Andrew J. McBain
Keyword(s):  
Staphylococcus Aureus ◽  
Growth Rate ◽  
Growth Rates ◽  
Biofilm Formation ◽  
Galleria Mellonella ◽  
Concentration Gradients ◽  
Content Type ◽  
Small Colony Variant ◽  
Small Colony ◽  
Repeated Passage

ABSTRACTSubeffective exposure ofStaphylococcus aureusto the biocide triclosan can reportedly induce a small-colony variant (SCV) phenotype.S. aureusSCVs are characterized by low growth rates, reduced pigmentation, and lowered antimicrobial susceptibility. While they may exhibit enhanced intracellular survival, there are conflicting reports regarding their pathogenicity. The current study reports the characteristics of an SCV-like strain ofS. aureuscreated by repeated passage on sublethal triclosan concentrations.S. aureusATCC 6538 (the passage 0 [P0] strain) was serially exposed 10 times to concentration gradients of triclosan to generate strain P10. This strain was then further passaged 10 times on triclosan-free medium (designated strain ×10). The MICs and minimum bactericidal concentrations of triclosan for P0, P10, and ×10 were determined, and growth rates in biofilm and planktonic cultures were measured. Hemolysin, DNase, and coagulase activities were measured, and virulence was determined using aGalleria mellonellapathogenicity model. Strain P10 exhibited decreased susceptibility to triclosan and characteristics of an SCV phenotype, including a considerably reduced growth rate and the formation of pinpoint colonies. However, this strain also had delayed coagulase production, had impaired hemolysis (P< 0.01), was defective in biofilm formation and DNase activity, and displayed significantly attenuated virulence. Colony size, hemolysis, coagulase activity, and virulence were only partially restored in strain ×10, whereas the planktonic growth rate was fully restored. However, ×10 was at least as defective in biofilm formation and DNase production as P10. These data suggest that although repeated exposure to triclosan may result in an SCV-like phenotype, this is not necessarily associated with increased virulence and adapted bacteria may exhibit other functional deficiencies.

scholarly journals Attenuated Vancomycin Bactericidal Activity against Staphylococcus aureus hemB Mutants Expressing the Small-Colony-Variant Phenotype

2008 ◽  
Vol 52 (4) ◽  
pp. 1533-1537 ◽  
Author(s):  
Brian T. Tsuji ◽  
Christof von Eiff ◽  
Pamela A. Kelchlin ◽  
Alan Forrest ◽  
Patrick F. Smith
Keyword(s):  
Staphylococcus Aureus ◽  
Bactericidal Activity ◽  
Pharmacodynamic Model ◽  
Small Colony Variant ◽  
Variant Phenotype ◽  
Small Colony ◽  
Bactericidal Activities

ABSTRACT The in vitro bactericidal activities of vancomycin against Staphylococcus aureus hemB mutants displaying the small-colony-variant phenotype and their parental strains were evaluated. Vancomycin killing activities against hemB mutants were markedly attenuated, demonstrating approximately 50% less effect, a result which was well described by a Hill-type pharmacodynamic model.

scholarly journals In Vitro Activity of Vancapticin MCC5145 against Methicillin-Resistant Staphylococcus aureus from Periprosthetic Joint Infection

2021 ◽  
Author(s):  
Hye-Kyung Cho ◽  
Melissa J. Karau ◽  
Kerryl E. Greenwood-Quaintance ◽  
Karl A. Hansford ◽  
Matthew A. Cooper ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Periprosthetic Joint Infection ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Joint Infection ◽  
Vitro Activity ◽  
In Vitro Activity ◽  
Methicillin Resistant

MRSA periprosthetic 1 joint infection (PJI) can be challenging to treat due to biofilm formation, alongside sometimes limited vancomycin activity (1-3).…

scholarly journals Investigation of a Staphylococcus argenteus Strain Involved in a Chronic Prosthetic-Joint Infection

2020 ◽  
Vol 21 (17) ◽  
pp. 6245
Author(s):  
Alan Diot ◽  
Virginie Dyon-Tafani ◽  
Marine Bergot ◽  
Jason Tasse ◽  
Patricia Martins-Simões ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Young Woman ◽  
Cell Invasion ◽  
Prosthetic Joint Infection ◽  
Biofilm Formation ◽  
Joint Infection ◽  
Bone Cell ◽  
Persistent Infections ◽  
Prosthetic Joint

Staphylococcus argenteus is an emerging species responsible for infections comparable to those induced by Staphylococcus aureus. It has been involved in few chronic or persistent infections so far. In this study, we described a case of a persistent prosthetic-joint infection (PJI) affecting a young woman. We investigated in vitro the virulence traits of the incriminated S. argenteus strain (bone cell invasion, biofilm formation and induction of inflammation) and analyzed its genome, in comparison with two other strains of S. argenteus and two S. aureus isolates. It appeared that this S. argenteus PJI strain combined biofilm formation, osteoblast invasion and intracellular persistence abilities together with genes potentially involved in the escape of the host immune defenses, which might explain the chronicization of the infection.

scholarly journals Staphylococcus aureus Aggregates on Orthopedic Materials under Varying Levels of Shear Stress

2020 ◽  
Vol 86 (19) ◽  
Author(s):  
Tripti Thapa Gupta ◽  
Niraj K. Gupta ◽  
Matthew J. Pestrak ◽  
Devendra H. Dusane ◽  
Janette M. Harro ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Joint Infection ◽  
Implant Surface ◽  
Clinical Issue ◽  
Content Type ◽  
Artificial Joint Replacement ◽  
Orthopedic Materials ◽  
Kinetics Of

ABSTRACT Periprosthetic joint infection (PJI) occurring after artificial joint replacement is a major clinical issue requiring multiple surgeries and antibiotic interventions. Staphylococcus aureus is the bacterium most commonly responsible for PJI. Recent in vitro research has shown that staphylococcal strains rapidly form aggregates in the presence of synovial fluid (SF). We hypothesize that these aggregates provide early protection to bacteria entering the wound site, allowing them time to attach to the implant surface, leading to biofilm formation. Thus, understanding the attachment kinetics of these aggregates is critical in understanding their adhesion to various biomaterial surfaces. In this study, the number, size, and surface area coverage of aggregates as well as of single cells of S. aureus were quantified under various conditions on different orthopedic materials relevant to orthopedic surgery: stainless steel (316L), titanium (Ti), hydroxyapatite (HA), and polyethylene (PE). It was observed that, regardless of the material type, SF-induced aggregation resulted in reduced aggregate surface attachment and greater aggregate size than the single-cell populations under various shear stresses. Additionally, the surface area coverage of bacterial aggregates on PE was relatively high compared to that on other materials, which could potentially be due to the rougher surface of PE. Furthermore, increasing shear stress to 78 mPa decreased aggregate attachment to Ti and HA while increasing the aggregates’ average size. Therefore, this study demonstrates that SF induced inhibition of aggregate attachment to all materials, suggesting that biofilm formation is initiated by lodging of aggregates on the surface features of implants and host tissues. IMPORTANCE Periprosthetic joint infection occurring after artificial joint replacement is a major clinical issue that require repeated surgeries and antibiotic interventions. Unfortunately, 26% of patients die within 5 years of developing these infections. Staphylococcus aureus is the bacterium most commonly responsible for this problem and can form biofilms to provide protection from antibiotics as well as the immune system. Although biofilms are evident on the infected implants, it is unclear how these are attached to the surface in the first place. Recent in vitro investigations have shown that staphylococcal strains rapidly form aggregates in the presence of synovial fluid and provide protection to bacteria, thus allowing them time to attach to the implant surface, leading to biofilm formation. In this study, we investigated the attachment kinetics of Staphylococcus aureus aggregates on different orthopedic materials. The information presented in this article will be useful in surgical management and implant design.

scholarly journals Time-dependent efficacy of combination of silver-containing hydroxyapatite coating and vancomycin on methicillin-resistant Staphylococcus aureus biofilm formation in vitro

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Akira Hashimoto ◽  
Hiroshi Miyamoto ◽  
Sakumo Kii ◽  
Tomoki Kobatake ◽  
Takeo Shobuike ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Laser Scanning ◽  
Joint Infection ◽  
Microscopic Analysis ◽  
Time Dependent ◽  
Confocal Laser ◽  
Methicillin Resistant ◽  
Ha Coating

Abstract Objective We developed a silver-containing hydroxyapatite (Ag-HA) coating to prevent periprosthetic joint infection (PJI). Methicillin-resistant Staphylococcus aureus (MRSA) is the main PJI-causing bacteria. Previously, we had reported the combined effect of Ag-HA coating and vancomycin (VCM) on MRSA biofilm formation 24 h after MRSA inoculation. In this study, we investigated the time-dependent efficacy of Ag-HA coating and VCM on MRSA biofilm formation on Ti discs in vitro by three-dimensional confocal laser scanning microscopic analysis. Results For the Ti VCM and HA VCM groups, the total biofilm volumes per area at 96 h after MRSA inoculation were significantly larger than those at 48 h after MRSA inoculation, respectively (p < 0.001). In contrast, for the Ag-HA VCM group, the total biofilm volume per area at 96 h was significantly smaller than that at 48 h (p < 0.0001). Moreover, 96 h after MRSA inoculation, the total biofilm volume per area of the Ag-HA VCM groups was significantly smaller than those of the Ti VCM and HA VCM groups (p < 0.0001). Thus, the combination of Ag-HA and VCM might be useful for the prevention of MRSA-associated PJI.

scholarly journals A novel hemA mutation is responsible for small colony variant phenotype in Escherichia coli

2020 ◽  
Author(s):  
Alasdair T. M. Hubbard ◽  
Adam P. Roberts
Keyword(s):  
Escherichia Coli ◽  
Biofilm Formation ◽  
Mammalian Cells ◽  
Initial Step ◽  
Fitness Cost ◽  
Small Colony Variant ◽  
Small Colony ◽  
Tract Infections ◽  
Novel Drug

AbstractWe identified a small colony variant (SCV) of a clinical isolate of Escherichia coli from Malawi following sequential in vitro selection in sub-inhibitory concentrations of amoxicillin-clavulanic acid and gentamicin. The SCV was auxotrophic for hemin and had impaired biofilm formation compared to the ancestral isolates. A single novel nucleotide polymorphism (SNP) in hemA, which encodes a glutamyl-tRNA reductase responsible for the initial step of porphyrin biosynthesis leading to the production of haem, was responsible for the SCV phenotype. We showed this phenotype was stable over multiple generations and the SNP in hemA resulted in a significant fitness cost to the isolate which persisted even in the presence of hemin. As hemA is not found in mammalian cells, and disruption of the gene results in impaired biofilm formation and a significant fitness cost, it represents a potential target for novel drug development specifically for the treatment of catheter-associated urinary tract infections caused by biofilm-producing E. coli.

scholarly journals In VitroSusceptibility of ClinicalStaphylococcus aureusSmall-Colony Variants to β-Lactam and Non-β-Lactam Antibiotics

2018 ◽  
Vol 62 (4) ◽  
Author(s):  
Evgeny A. Idelevich ◽  
André Kriegeskorte ◽  
Nina Schleimer ◽  
Georg Peters ◽  
Christof von Eiff ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Prolonged Incubation ◽  
Content Type ◽  
Small Colony Variant ◽  
Normal Phenotype ◽  
Gradient Diffusion ◽  
Small Colony ◽  
Inhibition Zones

ABSTRACTTheStaphylococcus aureussmall-colony variant (SCV) phenotype has been associated with relapsing and antibiotic-refractory infections. However, little is known about the activities of antibiotics on clinical SCVs. Here, we demonstrated that SCVs without detectable auxotrophies were at least as susceptible to most β-lactam and non-β-lactam antibioticsin vitroas their corresponding clonally identical strains with a normal phenotype. After prolonged incubation, a regrowth phenomenon has been observed in gradient diffusion inhibition zones irrespective of the strains' phenotype.

scholarly journals Involvement of Small Colony Variant-Related Heme Biosynthesis Genes in Staphylococcus aureus Persister Formation in vitro

2021 ◽  
Vol 12 ◽  
Author(s):  
Xuyang Wang ◽  
Weizheng Li ◽  
Wenjie Wang ◽  
Shiyong Wang ◽  
Tao Xu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Acid Stress ◽  
Heme Biosynthesis ◽  
Rna Seq ◽  
Small Colony Variant ◽  
Persistent Infections ◽  
Allelic Replacement ◽  
Small Colony ◽  
The Relationship

Background: Persisters are important reasons for persistent infections, and they can lead to antibiotic treatment failure in patients and consequently chronic infection. Staphylococcus aureus small colony variants (SCVs) have been shown to be related to persistent infection. Mutations in the genes of the heme biosynthesis pathway lead to the formation of SCVs. However, the relationship between heme production genes and persister has not been tested.Methods:HemA and hemB were knocked out by allelic replacement from S. aureus strain USA500 separately, and then, the heme deficiency was complemented by overexpression of related genes and the addition of hemin. The stress-related persister assay was conducted. RNA-sequencing was performed to find genes and pathways involved in heme-related persister formation, and relative genes and operons were further knocked out and overexpressed to confirm their role in each process.Results: We found that heme biosynthesis deficiency can lead to decreased persister. After complementing the corresponding genes or hemin, the persister levels could be restored. RNA-seq on knockout strains showed that various metabolic pathways were influenced, such as energy metabolism, amino acid metabolism, carbohydrate metabolism, and membrane transport. Overexpression of epiF and operon asp23 could restore USA500∆hemA persister formation under acid stress. Knocking out operon arc in USA500∆hemA could further reduce USA500∆hemA persister formation under acid and oxidative stress.Conclusion: Heme synthesis has a role in S. aureus persister formation.

Sign in / Sign up

Export Citation Format

Share Document