Methods to monitor bacterial growth and replicative rates at the single-cell level.

The heterogeneity of bacterial growth and replicative rates within a population was proposed a century ago notably to explain the presence of bacterial persisters. The term "growth rate" at the single-cell level corresponds to the increase in size or mass of an individual bacterium while the "replicative rate" refers to its division capacity within a defined temporality. After a decades long hiatus, recent technical innovative approaches allow population growth and replicative rates heterogeneity monitoring at the single-cell level resuming in earnest.

Evaluation of CHROMagar™ LIN-R for the Screening of Linezolid Resistant Staphylococci from Positive Blood Cultures and Nasal Swab Screening Samples.

The increasing number of nosocomial pathogens with resistances towards last resort antibiotics, like linezolid for gram positive bacteria, leads to a pressing need for screening and, consequently, suitable screening media. Some national guidelines on infection prevention (e.g.

Sub-Inhibitory Concentrations of Oxacillin, but Not Clindamycin, Linezolid, or Tigecycline, Decrease Staphylococcal Phenol-Soluble Modulin Expression in Community-Acquired Methicillin-Resistant Staphylococcus aureus.

Staphylococcus aureus (SA) is a major human pathogen producing virulence factors, such as Panton-Valentine-leucocidin (PVL), alpha-hemolysin (Hla), and phenol-soluble-modulins alpha (PSMα), including delta-hemolysin (Hld). Unlike oxacillin, clindamycin and linezolid subinhibitory concentrations (sub-MIC) display an anti-toxin effect on PVL and Hla expression. Few studies have investigated PSMα and Hld expression modulation by antibiotics.

Evaluation of the MRSA/SA ELITe MGB Assay for the Detection of in Bone and Joint Infections.

Bone and joint infections represent a potentially devastating complication of prosthetic orthopedic joint replacement, thus requiring both rapid and appropriate antibiotic treatment. Staphylococcus aureus is one of the most common pathogens involved in this pathology. Being able to assert its presence is the first step of efficient patient management.

In vitro antibiotic activity against intraosteoblastic Staphylococcus aureus: a narrative review of the literature.

Staphylococcus aureus - a major aetiological agent of bone and joint infection (BJI) - is associated with a high risk of relapse and chronicity, in part due to its ability to invade and persist in non-professional phagocytic bone cells such as osteoblasts. This intracellular reservoir protects S. aureus from the action of the immune system and most antibiotics.

Presence of the neonatal Staphylococcus capitis outbreak clone (NRCS-A) in prosthetic joint infections.

Staphylococcus capitis is a coagulase-negative staphylococcus that has been described primarily as causing bloodstream infections in neonatal intensive care units (NICUs), but has also recently been described in prosthetic joint infections (PJIs). The multidrug-resistant S. capitis subsp.

Risk factors and outcomes associated with the carriage of tigecycline- and vancomycin-resistant Enterococcus faecium.

Objectives: Vancomycin-resistant E. faecium (VRE) is a common cause of healthcare-associated infections. The emergence of VRE with tigecycline resistance (TVRE) is increasing but its impact on patient outcome is still not well defined.

Staphylococcal Panton-Valentine Leucocidin and Gamma Haemolysin Target and Lyse Mature Bone Marrow Leucocytes.

is a major human pathogen, inducing several infections ranging from the benign to the life-threatening, such as necrotising pneumonia. is capable of producing a great variety of virulence factors, such as bicomponent pore-forming leucocidin, which take part in the physiopathology of staphylococcal infection. In necrotising pneumonia, Panton-Valentine leucocidin (PVL) induces not only lung injury and necrosis, but also leukopenia, regarded as a major factor of a poor prognosis.

Investigation of a Strain Involved in a Chronic Prosthetic-Joint Infection.

is an emerging species responsible for infections comparable to those induced by . 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.

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

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.

Small Colony Variants (SCVs): News From a Chronic Prosthetic Joint Infection.

Small colony variants (SCV) of have been reported as implicated in chronic infections. Here, we investigated the genomic and transcriptomic changes involved in the evolution from a wild-type to a SCV from in a patient with prosthetic joint infection relapse. The SCV presented a stable phenotype with no classical auxotrophy and the emergence of rifampicin resistance.

[Spider bite or infection caused by Panton Valentine leucocidin-producing Staphylococcusaureus?].

Introduction: Spiders, especially those of the genus Loxoceles such as L. rufescens, endemic in Mediterranean regions, are frequently reported as causes of venom poisoning in humans in the south of France. The most common signs consist of cutaneous necrosis presenting initially as inflammatory cellulitis and progressing towards the emergence of a necrotic centre.

Successful implementation of infection control measure in a neonatal intensive care unit to combat the spread of pathogenic multidrug resistant .

Background: Once present in a neonatal intensive care unit (NICU), multidrug resistant NRCS-A is able to settle and diffuse.

Objective: The objective of this study was to evaluate the impact of infection control (IC) interventions to reduce the spread of NRCS-A in a NICU.

Methods: Between December 2012 and December 2017, all patients presenting positive sampling (blood, skin or catheter) to were included, and clinical data were recorded from electronic clinical charts.

Novel staphylococcal cassette chromosome composite island (SCC-CI) with a new subtype of SCCmecVI cassette found in ST5 methicillin-resistant Staphylococcus aureus in France.

An emergent kanamycin-susceptible ST5 methicillin-resistant Staphylococcus aureus (MRSA) lineage has been identified in France. Whole-genome sequencing revealed a 40-kb staphylococcal cassette chromosome (SCC) composite island with a mosaic structure including three SCC elements: a ΨSCC, a SCC with a ccrC recombinase, and a novel subtype of SCCmec type VI (VIb). This mosaic structure suggests a high recombination rate of SCC elements from distinct staphylococci species.

Clindamycin suppresses virulence expression in inducible clindamycin-resistant Staphylococcus aureus strains.

Clindamycin is a protein synthesis inhibitory agent that has the ability to suppress the expression of virulence factors in Staphylococcus aureus. Recent guidelines recommend the use of clindamycin for the treatment of toxin-mediated infections. Clindamycin modulates virulence expression at sub-inhibitory concentrations (sub-MICs) in clindamycin-susceptible S.

Susceptibility of Methicillin-Resistant and -Susceptible Staphylococcus aureus Isolates of Various Clonal Lineages from Germany to Eight Biocides.

Few studies have been conducted on the susceptibility of bacteria to biocides. A total of 182 methicillin-resistant and -susceptible isolates collected from healthy or diseased humans and animals in Germany were included in the present study. Sixty-three isolates of animal origin and 119 human isolates were tested for their MICs to eight biocides or heavy metals by the broth microdilution method.

Pressure ulcer-related pelvic osteomyelitis: evaluation of a two-stage surgical strategy (debridement, negative pressure therapy and flap coverage) with prolonged antimicrobial therapy.

Background: A two-stage surgical strategy (debridement-negative pressure therapy (NPT) and flap coverage) with prolonged antimicrobial therapy is usually proposed in pressure ulcer-related pelvic osteomyelitis but has not been widely evaluated.

Methods: Adult patients with pressure ulcer-related pelvic osteomyelitis treated by a two-stage surgical strategy were included in a retrospective cohort study. Determinants of superinfection (i.

Processing and antibacterial properties of chitosan-coated alginate fibers.

The preparation of chitosan-coated alginate fibers by a wet spin process is presented and the characterization of the antibacterial activities of these fibers is discussed. Preformed calcium alginate fibers were passed in chitosan acetate solutions. The coagulation method of the coating consisted in the immersion of fibers in a bath of calcium dihydroxide solution (0.

Routine Whole-Genome Sequencing for Outbreak Investigations of in a National Reference Center.

The French National Reference Center for Staphylococci currently uses DNA arrays and typing for the initial epidemiological characterization of strains. We here describe the use of whole-genome sequencing (WGS) to investigate retrospectively four distinct and virulent lineages [clonal complexes (CCs): CC1, CC5, CC8, CC30] involved in hospital and community outbreaks or sporadic infections in France. We used a WGS bioinformatics pipeline based on assembly (reference-free approach), single nucleotide polymorphism analysis, and on the inclusion of epidemiological markers.

Origin, evolution, and global transmission of community-acquired ST8.

USA300 is a pandemic clonal lineage of hypervirulent, community-acquired, methicillin-resistant (CA-MRSA) with specific molecular characteristics. Despite its high clinical relevance, the evolutionary origin of USA300 remained unclear. We used comparative genomics of 224 temporal and spatial diverse isolates of multilocus sequence type (ST) 8 to reconstruct the molecular evolution and global dissemination of ST8, including USA300.

Vancomycin treatment is a risk factor for vancomycin-nonsusceptible Staphylococcus capitis sepsis in preterm neonates.

Objectives: Multidrug-resistant, vancomycin-nonsusceptible Staphylococcus capitis is an emerging cause worldwide of late-onset sepsis (LOS) in preterm neonates. The pathophysiology and risk factors for S. capitis-related LOS are poorly understood, but we hypothesized that S.

Human Adaptive Immunity Rescues an Inborn Error of Innate Immunity.

The molecular basis of the incomplete penetrance of monogenic disorders is unclear. We describe here eight related individuals with autosomal recessive TIRAP deficiency. Life-threatening staphylococcal disease occurred during childhood in the proband, but not in the other seven homozygotes.