Pathogenicity Factors of Staphylococcus Pettenkoferi in Foot Wounds and Osteitis in Diabetic Patients
- Conditions
- Diabetic Foot Ulcer
- Registration Number
- NCT06688084
- Lead Sponsor
- Centre Hospitalier Universitaire de Nīmes
- Brief Summary
Gram-positive cocci, particularly Staphylococcus aureus and coagulase-negative staphylococci (SCoN), are the bacteria most frequently isolated from diabetic foot ulcers. Although studies have been carried out on the role of S. aureus in the unfavorable evolution of these wounds, no studies have focused on the role of SCoN. Of the fifty or so SCoN species, not all have the same virulence potential. The role of Staphylococcus pettenkoferi is unknown, yet this bacterium is the 7th most frequently identified in diabetic foot ulcers, suggesting that it may also be involved in the pathophysiology of these infections. At Nîmes University Hospital, this bacterium is mainly identified in samples from diabetic foot ulcers or osteitis in our laboratory and 80% of the bacteria present are in biofilms.It is essential to understand the mechanisms governing these bacterial interactions and establish the true pathogenic potential of these bacteria. Recently, the Nîmes team showed that a strain of S. pettenkoferi (SP165) isolated from foot osteitis in a diabetic patient had real virulence potential. SP165 could not only produce biofilm, but could also survive in human blood, human keratinocytes and murine and human macrophages. It also caused significant embryonic mortality in a zebrafish model. A second study of 29 isolates from Nîmes University Hospital subsequently demonstrated that there were two predominant clones with different virulences. Three biofilm production profiles (rapidly and highly biofilm-producing, slowly biofilm-producing and non-biofilm-producing) and two zebrafish profiles (highly and moderately lethal) were reported by phenotypic and genomic analyses on this panel of strains. Genes for resistance, virulence and biofilm production were also found on their genomes.
- Detailed Description
Gram-positive cocci, in particular Staphylococcus aureus and coagulase-negative staphylococci (SCoN), are the bacteria most frequently isolated from diabetic foot ulcers. While studies have been carried out on the role of S. aureus in the unfavorable evolution of these wounds, no study has focused on the role of SCoN. Of the fifty or so SCoN species, not all have the same virulence potential. The role of Staphylococcus pettenkoferi is not known. Yet this bacterium is the 7th most frequently identified in diabetic foot ulcers, suggesting that it may also be involved in the pathophysiology of these infections. In the work of Loetsche et al. a study of the microbiome of 349 diabetic foot ulcer samples by targeted 16S rDNA sequencing showed that the genus Staphylococcus was the most abundant, with a relative abundance of 22.8%, including 13.3% S. aureus and 5.3% S. pettenkoferi.
At Nîmes University Hospital, this bacterium is mainly identified in samples from diabetic foot ulcers or osteitis in our laboratory (89 isolations of S. pettenkoferi from diabetic foot ulcer samples out of 167 isolations made of this bacterium between 2018 and 2022).The difficulty of managing chronic wounds also lies in the fact that almost 80% of the bacteria present are in biofilms. It has also been established that the environment in which bacteria are found, and in particular the interactions they establish between themselves, play a significant role in delayed wound healing. It is therefore essential to understand the mechanisms governing these bacterial interactions and to establish the true pathogenic potential of these bacteria.
Recently, our team demonstrated that a strain of S. pettenkoferi (SP165) isolated from foot osteitis in a diabetic patient had real virulence potential. As well as being able to produce biofilm, SP165 was able to survive in human blood, human keratinocytes and murine and human macrophages. It also demonstrated its virulence by causing significant embryonic mortality in the zebrafish model.
A second study of 29 isolates from Nîmes University Hospital subsequently demonstrated the existence of two predominant clones with different virulences.
Three biofilm production profiles (rapidly and highly biofilm-producing, slowly biofilm-producing and non-biofilm-producing) and two zebrafish virulence profiles (highly and moderately lethal) were reported by phenotypic and genomic analyses on this panel of strains. Genes for resistance, virulence and biofilm production were also found on their genomes.
Recruitment & Eligibility
- Status
- ACTIVE_NOT_RECRUITING
- Sex
- All
- Target Recruitment
- 230
- Not applicable for this research on a ready-constituted collection of strains of Staphylococcus pettenkoferi
- Not applicable for this research on a ready-constituted collection of strains of Staphylococcus pettenkoferi
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method Genetic diversity of Staphyloccocus pettenkoferi strains isolated from osteitis and non-diabetic wounds, blood cultures and nasal carriage. Day 0 to 3 months Number of clades estimated via typing by complete sequencing of the bacterial genomes of all S. pettenkoferi strains and analysis of phylogenetic distances (whole genome and core genome single nucleotide polymorphisms).
- Secondary Outcome Measures
Name Time Method Genetic diversity of Staphyloccocus pettenkoferi strains isolated from osteitis and non-diabetic wounds, blood cultures and nasal carriage. 3 - 6 months Number of clades estimated via typing by complete sequencing of the bacterial genomes of all Staphylococcus pettenkoferi strains and analysis of phylogenetic distances.
Resistome in the strain population according to sample origin:osteitis 3 - 6 months The presence of antibiotic resistance genes (resistome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Resistome in the strain population according to sample origin: non-diabetic wounds 3 - 6 months The presence of antibiotic resistance genes (resistome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Resistome in the strain population according to sample origin: diabetic wounds 3 - 6 months The presence of antibiotic resistance genes (resistome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Resistome in the strain population according to sample origin: blood cultures 3 - 6 months The presence of antibiotic resistance genes (resistome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Resistome in the strain population according to sample origin: nasal carriage 3 - 6 months The presence of antibiotic resistance genes (resistome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Virulome in the strain population according to sample origin: osteitis 3 - 6 months The presence of virulence genes (virulome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Virulome in the strain population according to sample origin: non-diabetic wounds 3 - 6 months The presence of virulence genes (virulome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Virulome in the strain population according to sample origin: diabetic wounds 3 - 6 months The presence of virulence genes (virulome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Virulome in the strain population according to sample origin: blood cultures 3 - 6 months The presence of virulence genes (virulome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Virulome in the strain population according to sample origin: nasal carriage 3 - 6 months The presence of virulence genes (virulome) will be identified by bioinformatics analysis of sequenced bacterial genomes.
Plasmids inthe strain population and according to sample origin: osteitis 3 - 6 months The presence of plasmids will be identified by bioinformatics analysis of sequenced bacterial genomes.
Plasmids inthe strain population and according to sample origin: non-diabetic wounds 3 - 6 months The presence of plasmids will be identified by bioinformatics analysis of sequenced bacterial genomes.
Plasmids inthe strain population and according to sample origin: diabetic wounds 3 - 6 months The presence of plasmids will be identified by bioinformatics analysis of sequenced bacterial genomes.
Plasmids inthe strain population and according to sample origin: blood cultures 3 - 6 months The presence of plasmids will be identified by bioinformatics analysis of sequenced bacterial genomes.
Plasmids inthe strain population and according to sample origin: nasal carriage 3 - 6 months The presence of plasmids will be identified by bioinformatics analysis of sequenced bacterial genomes.
Phenotypic resistance profiles in the population in a subsample of 85 strains 6 - 14 months The minimum inhibitory concentration for a series of antibiotics will be recorded (antibiograms of isolates).These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Phenotypic resistance profiles in the population and according to sample origin: osteitis 6 - 14 months Minimum inhibitory concentration for a series of antibiotics (antibiograms of isolates). These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Phenotypic resistance profiles in the population and according to sample origin: non-diabetic wounds 6 - 14 months Minimum inhibitory concentration for a series of antibiotics (antibiograms of isolates). These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Phenotypic resistance profiles in the population and according to sample origin: diabetic wounds 6 - 14 months Minimum inhibitory concentration for a series of antibiotics (antibiograms of isolates). These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Phenotypic resistance profiles in the population and according to sample origin: blood cultures 6 - 14 months Minimum inhibitory concentration for a series of antibiotics (antibiograms of isolates). These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Phenotypic resistance profiles in the population and according to sample origin: nasal carriage 6 - 14 months Minimum inhibitory concentration for a series of antibiotics (antibiograms of isolates). These antibiograms will be established on newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin.
Amount of biofilm formation in the absence and presence of antibiotics in a selection (85 sub-samples) of S. pettenkoferi strains according to sample origine: osteitis 6 - 14 months Biofilm formation index in the presence/absence of a series of antibiotics (antibiograms of isolates). These antibiotics will be newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin. Results recorded on a scale ranging from 0 = biofilm and 12 = no biofilm
Amount of biofilm formation in the absence and presence of antibiotics in a selection (85 sub-samples) of S. pettenkoferi strains according to sample origine: non-diabetic wounds 6 - 14 months Biofilm formation index in the presence/absence of a series of antibiotics (antibiograms of isolates). These antibiotics will be newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin. Results recorded on a scale ranging from 0 = biofilm and 12 = no biofilm
Amount of biofilm formation in the absence and presence of antibiotics in a selection (85 sub-samples) of S. pettenkoferi strains according to sample origine: diabetic wounds 6 - 14 months Biofilm formation index in the presence/absence of a series of antibiotics (antibiograms of isolates). These antibiotics will be newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin. Results recorded on a scale ranging from 0 = biofilm and 12 = no biofilm
Amount of biofilm formation in the absence and presence of antibiotics in a selection (85 sub-samples) of S. pettenkoferi strains according to sample origine: blood cultures 6 - 14 months Biofilm formation index in the presence/absence of a series of antibiotics (antibiograms of isolates). These antibiotics will be newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin. Results recorded on a scale ranging from 0 = biofilm and 12 = no biofilm
Amount of biofilm formation in the absence and presence of antibiotics in a selection (85 sub-samples) of S. pettenkoferi strains according to sample origine: nasal carriage 6 - 14 months Biofilm formation index in the presence/absence of a series of antibiotics (antibiograms of isolates). These antibiotics will be newly-marketed or current molecules such as Ceftarolin, Ceftobiprol, Dalbavancin, Delafloxacin, Tedizolid and Oritavancin. Results recorded on a scale ranging from 0 = biofilm and 12 = no biofilm
Bacterial growth rate according to sample origin in a sub-sample of 20 strains: osteitis 6 - 14 months Bacterial growth curve by measuring absorbance on bacterial culture over time.
Bacterial growth rate according to sample origin in a sub-sample of 20 strains: non-diabetic wounds 6 - 14 months Bacterial growth curve by measuring absorbance on bacterial culture over time.
Bacterial growth rate according to sample origin in a sub-sample of 20 strains: diabetic wounds 6 - 14 months Bacterial growth curve by measuring absorbance on bacterial culture over time.
Bacterial growth rate according to sample origin in a sub-sample of 20 strains: blood cultures 6 - 14 months Bacterial growth curve by measuring absorbance on bacterial culture over time.
Bacterial growth rate according to sample origin in a sub-sample of 20 strains: nasal carriage 6 - 14 months Bacterial growth curve by measuring absorbance on bacterial culture over time.
Virulence profiles according to sample origin in a sub-sample of 3 strains: osteitis 6 - 14 months The rate of internalisation and release of LDH (a sign of cellular toxicity of the bacterial isolate) in an in vitro osteoblast cell culture model (MC3T3-E1)
Virulence profiles according to sample origin in a sub-sample of 3 strains: intracellular bacterial multiplication of S. pettenkoferi strains from osteitis 6 - 14 months The amount of intracellular bacterial multiplication will be assessed in an in vitro macrophage cell culture model (RAW 264.7).
Virulence profiles according to sample origin in a sub-sample of 3 strains: diabetic wounds 6 - 14 months The rate of internalisation and release of LDH (a sign of cellular toxicity of the bacterial isolate) in an in vitro osteoblast cell culture model (MC3T3-E1)
Virulence profiles according to sample origin in a sub-sample of 3 strains: intracellular bacterial multiplication of S. pettenkoferi strains from diabetic wounds 6 - 14 months The amount of intracellular bacterial multiplication will be assessed in an in vitro macrophage cell culture model (RAW 264.7).
Virulence profiles according to sample origin in a sub-sample of 3 strains: blood cultures 6 - 14 months The rate of internalisation and release of LDH (a sign of cellular toxicity of the bacterial isolate) in an in vitro osteoblast cell culture model (MC3T3-E1)
Virulence profiles according to sample origin in a sub-sample of 3 strains:intracellular bacterial multiplication of S. pettenkoferi strains from blood cultures 6 - 14 months The amount of intracellular bacterial multiplication will be assessed in an in vitro macrophage cell culture model (RAW 264.7).
Virulence profiles according to sample origin in a sub-sample of 3 strains: nasal carriage 6 - 14 months The rate of internalisation and release of LDH (a sign of cellular toxicity of the bacterial isolate) in an in vitro osteoblast cell culture model (MC3T3-E1)
Virulence profiles according to sample origin in a sub-sample of 3 strains:intracellular bacterial multiplication of S. pettenkoferi strains from nasal carriage 6 - 14 months The amount of intracellular bacterial multiplication will be assessed in an in vitro macrophage cell culture model (RAW 264.7).
Virulence profiles according to sample origin in a sub-sample of 3 strains: survival time of diabetic zebrafish immersed in S. pettenkoferi strains from osteitis Up to 48 hours Survival curve at 48 hours
Virulence profiles according to sample origin in a sub-sample of 3 strains: survival time of diabetic zebrafish immersed in S. pettenkoferi strains from non-diabetic wounds Up to 48 hours Survival curve at 48 hours
Virulence profiles according to sample origin in a sub-sample of 3 strains: survival time of diabetic zebrafish immersed in S. pettenkoferi strains from diabetic wounds Up to 48 hours Survival curve at 48 hours
Virulence profiles according to sample origin in a sub-sample of 3 strains: survival time of diabetic zebrafish immersed in S. pettenkoferi strains from blood cultures Up to 48 hours Survival curve at 48 hours
Virulence profiles according to sample origin in a sub-sample of 3 strains: survival time of diabetic zebrafish immersed in S. pettenkoferi strains from nasal carriage Up to 48 hours Survival curve at 48 hours
Trial Locations
- Locations (1)
Nîmes University Hospital
🇫🇷Nîmes, Gard, France