Search

In routine hematological instruments, blood cells are counted and sized by monitoring the impedance signals induced during their passage through a Coulter orifice. However, only signals associated with centered paths in the aperture are considered for analysis, while the rejected measurements, caused by near-wall trajectories, can provide additional information on red blood cells (RBC), as recent publications suggest. To assess usefulness of two new parameters in describing alterations in RBC properties, we performed a pilot study to compare blood samples from patients with diabetes mellitus (DM), frequent pathological condition associated with impairment in RBC deformability, versus controls. A total of 345 blood samples were analyzed: 225 in the DM group and 120 in the control group. A diagram of [Formula: see text] and [Formula: see text], the two new parameters derived from the analysis of impedancemetry pulses, was used to compare distribution of RBC subpopulations between groups. To discriminate RBC from DM and control individuals, based on our multiparametric analysis, we built a score from variables derived from [Formula: see text] matrix which showed good performances: area under the receiving operating characteristic curve 0.948 (0.920-0.970), p

Introduction The pathophysiology of Charcot neuroarthropathy (CN) remains unclear. There are a number of hypotheses but these are not exclusive. In its clinical presentation, this complication intersects with the semiology of diabetic-induced neuropathy, such as peripheral hypervascularization and the appearance of arteriovenous shunt. The EPICHAR study is as yet an unpublished cohort of people living with diabetes complicated by CN (in active or chronic phase). Based on the findings of the EPICHAR study, this study aimed to investigate whether a reduction in the rate of hyperglycemia accompanies the onset of an active phase of CN.Research design and methods Hemoglobin A1c (HbA1c) levels were assessed 3 months (M3) and 6 months (M6) before the diagnosis of active CN (M0).Results 103 patients living with diabetes and presenting active CN were included between January and December 2019 from the 31 centers participating in this study (30 in France and 1 in Belgium). The mean age of the participants was 60.2±12.2 years; the vast majority were men (71.8%) living with type 2 diabetes (75.5%). Mean HbA1c levels significantly declined between M6 (median 7.70; Q1, Q3: 7.00, 8.55) and M3 (median 7.65; Q1, Q3: 6.90, 8.50) (p=0.012), as well as between M6 and M0 (median 7.40; Q1, Q3: 6.50, 8.50) (p=0.014). No significant difference was found between M3 and M0 (p=0.072).Conclusions A significant reduction in HbA1c levels seems to accompany the onset of the active phase of CN.Trial registration number NCM03744039.

Diabetic foot ulcers (DFU) represent a growing public health problem. The emergence of multidrug-resistant (MDR) bacteria is a complication due to the difficulties in distinguishing between infection and colonization in DFU. Another problem lies in biofilm formation on the skin surface of DFU. Biofilm is an important pathophysiology step in DFU and may contribute to healing delays. Both MDR bacteria and biofilm producing microorganism create hostile conditions to antibiotic action that lead to chronicity of the wound, followed by infection and, in the worst scenario, lower limb amputation. In this context, alternative approaches to antibiotics for the management of DFU would be very welcome. In this review, we discuss current knowledge on biofilm in DFU and we focus on some new alternative solutions for the management of these wounds, such as antibiofilm approaches that could prevent the establishment of microbial biofilms and wound chronicity. These innovative therapeutic strategies could replace or complement the classical strategy for the management of DFU to improve the healing process.

Staphylococcus aureus is one of the main pathogens isolated from diabetic foot infections (DFI). The purpose of this study was to evaluate the importance of the persistence of S. aureus in this environment and the possible modifications of the bacterial genome content over time. Molecular typing of S. aureus isolates cultured from patients with the same DFI over a 7-year study revealed a 25% rate of persistence of this species in 48 patients, with a short median persistence time of 12weeks (range: 4–52weeks). Non-specific clonal complexes were linked to this persistence. During the follow-up, bla genes were acquired in three cases, whereas some virulence markers were lost in all cases after a long period of colonization (21.5weeks). Only one patient (2%) had a long-term persistence of 48weeks. The genome sequencing of a clonal pair of early/late strains isolated in this patient showed mutations in genes encoding bacterial defence and two-component signal transduction systems. Although, this study suggests that the long-term persistence of S. aureus in DFI is a rare event, genomic evolution is observed, highlighting the low adaptive ability of S. aureus to the specific environment and stressful conditions of diabetic foot ulcers. These results provide the basis for better understanding of S. aureus dynamics during persistent colonization in chronic wounds.

BackgroundBone and joint infections (BJIs) due to Streptococcus agalactiae are rare but has been described to increase in the past few years. The objective of this study was to describe clinical features and outcomes of cases of S. BJIs.MethodsWe conducted a retrospective analysis of adult cases of S. agalactiae BJIs that occurred between January 2009 and June 2015 in a French university hospital. The treatment success was assessed until 24 months after the end of antibiotic treatment.ResultsAmong the 26 patients included, 20 (77%) were male, mean age was 62 years ± 13 and mean Charlson comorbidity index score was 4.9 ± 3.2. Diabetes mellitus was the most common comorbidity (n = 14, 54%). Six had PJI (Prosthetic Joint Infections), five osteosynthesis-associated infections, 11 osteomyelitis and four native septic arthritis. Eleven patients had a delayed or late infection: six with a prosthetic joint infection and five with an internal fixation device infection. Sixteen patients (62%) had a polymicrobial BJI, most commonly with Gram-positive cocci (75%) notably Staphylococcus aureus (44%). Polymicrobial infections were more frequently found in foot infections (90% vs 44%, p = 0.0184). During the two-year follow-up, three patients died (3/25, 12%) and seven (7/25, 28%) had treatment failure.ConclusionDiabetes mellitus was the most common comorbidity. We observed an heterogenous management and a high rate of relapse.

The polymicrobial nature of biofilms and bacterial interactions inside chronic wounds are keys for the understanding of bacterial cooperation. The aim of this present study was to develop a technique to study and visualize biofilm in live imaging under flow conditions (Bioflux™ 200, Fluxion Biosciences). The BiofluxTM system was adapted using an in vitro chronic wound-like medium (CWM) that mimics the environment encountered in ulcers. Two reference strains of Staphylococcus aureus (Newman) and Pseudomonas aeruginosa (PAO1) were injected in the BiofluxTM during 24 h to 72 h in mono and coculture (ratio 1:1, bacteria added simultaneously) in the CWM vs. a control medium (BHI). The quantification of biofilm formation at each time was evaluated by inverted microscopy. After 72 h, different antibiotics (ceftazidime, imipenem, linezolid, oxacillin and vancomycin) at 1x MIC, 10x MIC and 100x MIC were administrated to the system after an automatic increase of the flow that mimicked a debridement of the wound surface. Biofilm studies highlighted that the two species, alone or associated, constituted a faster and thicker biofilm in the CWM compared to the BHI medium. The effect of antibiotics on mature or “debrided” biofilm indicated that some of the most clinically used antibiotic such as vancomycin or imipenem were not able to disrupt and reduce the biofilm biomass. The use of a life cell imaging with an in vitro CWM represents a promising tool to study bacterial biofilm and investigate microbial cooperation in a chronic wound context.

This study assessed the clonal diversity, the resistance profile and the virulence potential of Escherichia coli strains isolated from diabetic foot infection (DFI) and diabetic foot osteomyelitis (DFOM). A retrospective single-centre study was conducted on patients diagnosed with E. coli isolated from deep DFI and DFOM at Clinique du Pied Diabétique Gard-Occitanie (France) over a two-year period. Phylogenetic backgrounds, virulence factors (VFs) and antibiotic resistance profiles were determined. Whole-genome analysis of E. coli strains isolated from same patients at different periods were performed. From the two-years study period, 35 E. coli strains isolated from 33 patients were analysed; 73% were isolated from DFOM. The majority of the strains belonged to the virulent B2 and D phylogenetic groups (82%). These isolates exhibited a significant higher average of VFs number than strains belonging to other groups (p < 0.001). papG2 gene was significantly more detected in strains belonging to B2 phylogroup isolated from DFI compared to DFOM (p = 0.003). The most prevalent antibiotic resistance pattern was observed for ampicillin (82%), cotrimoxazole (45%), and ciprofloxacin (33%). The genome analysis of strains isolated at two periods in DFOM showed a decrease of the genome size, and this decrease was more important for the strain isolated at nine months (vs. four months). A shared mutation on the putative acyl-CoA dehydrogenase-encoding gene aidB was observed on both strains. E. coli isolates from DFOM were highly genetically diverse with different pathogenicity traits. Their adaptation in the bone structure could require genome reduction and some important modifications in the balance virulence/resistance of the bacteria.

Foot infections are the main disabling complication in patients with diabetes mellitus. These infections can lead to lower-limb amputation, increasing mortality and decreasing the quality of life. Biofilm formation is an important pathophysiology step in diabetic foot ulcers (DFU)—it plays a main role in the disease progression and chronicity of the lesion, the development of antibiotic resistance, and makes wound healing difficult to treat. The main problem is the difficulty in distinguishing between infection and colonization in DFU. The bacteria present in DFU are organized into functionally equivalent pathogroups that allow for close interactions between the bacteria within the biofilm. Consequently, some bacterial species that alone would be considered non-pathogenic, or incapable of maintaining a chronic infection, could co-aggregate symbiotically in a pathogenic biofilm and act synergistically to cause a chronic infection. In this review, we discuss current knowledge on biofilm formation, its presence in DFU, how the diabetic environment affects biofilm formation and its regulation, and the clinical implications.

The purpose of this prospective observational study was to evaluate the richness and diversity of bacteria in samples from diabetic foot infections using a culturomics approach. Bacterial culture findings from wound samples were analyzed together with clinical characteristics and treatment outcomes. We included 43 patients admitted to a French referral center with a moderate to severe diabetic foot infection. The 30,000 colonies identified yielded 53 different bacterial species. The global α-Shannon diversity was 3.34 and the bacterial richness per patient was 4 ± 2. Of all the identified bacterial species, 19 (35.8%) had never been previously cultured or identified by molecular methods from diabetic foot ulcers. Most of the samples were polymicrobial (N = 38; 88.3%). Of all the isolated species, the most prevalent were Staphylococcus aureus (N = 28; 52.8%), Enterococcus faecalis (N = 24; 45.2%), Enterobacter cloacae (N = 12; 22.6%), Staphylococcus lugdunensis (N = 10; 18.7%), Staphylococcus epidermidis (N = 6; 11.3%), Proteus mirabilis (N = 6; 11.3%), and Finegoldia magna (N = 5; 9.4%). The only factor associated with wound improvement after a 1-month follow-up was the presence of E. faecalis (p = 0.012) when compared with patients without wound improvement. This study confirms the complementary role of culturomics in the exploration of complex microbiota. Further studies on a larger scale are needed to fully understand the clinical importance of the microbiota of diabetic foot infections.