MiniBioReactor Array (MBRA) in vitro gut model: a reliable system to study microbiota-dependent response to antibiotic treatment.

Background: Antimicrobial drugs are mostly studied for their impact on emergence of bacterial antibiotic resistance, but their impact on the gut microbiota is also of tremendous interest. In vitro gut models are important tools to study such complex drug-microbiota interactions in humans. Methods: The MiniBioReactor Array (MBRA) in vitro microbiota system; a single-stage continuous flow culture model, hosted in an anaerobic chamber; was used to evaluate the impact of three concentrations of a third-generation cephalosporin (ceftriaxone) on faecal microbiota from two healthy donors (treatment versus control: three replicates per condition). We conducted 16S microbiome profiling and analysed microbial richness, diversity and taxonomic changes. ß-Lactamase activities were evaluated and correlated with the effects observed in the MBRA in vitro system. Results: The MBRA preserved each donor's specificities, and differences between the donors were maintained through time. Before treatment, all faecal cultures belonging to the same donor were comparable in composition, richness, and diversity. Treatment with ceftriaxone was associated with a decrease in α-diversity, and an increase in ß-diversity index, in a concentration-dependent manner. The maximum effect on diversity was observed after 72 h of treatment. Importantly, one donor had a stronger microbiota ß-lactamase activity that was associated with a reduced impact of ceftriaxone on microbiota composition. Conclusions: MBRA can reliably mimic the intestinal microbiota and its modifications under antibiotic selective pressure. The impact of the treatment was donor- and concentration-dependent. We hypothesize these results could be explained, at least in part, by the differences in ß-lactamase activity of the microbiota itself. Our results support the relevance and promise of the MBRA system to study drug-microbiota interactions.

Suction drainage fluid culture during septic orthopaedic surgery, a retrospective study.

We evaluated the usefulness of suction drainage fluid culture after septic orthopaedic surgery to predict early surgical reintervention. We conducted a retrospective observational study, at the Groupe Hospitalier Paris Saint-Joseph between 2014 and 2019. All the patients undergoing septic orthopaedic surgery, with perioperative samples and a postoperative suction drainage device, were enrolled. We compared the group with positive or negative postoperative drainage fluid cultures, respectively, on surgical outcome. We included 246 patients. The drainage fluid culture was positive in 42.3% of the cases. Early surgical reintervention concerned 14.6% of the cases (n = 36), including 61.1% of patients with positive drainage fluid culture (n = 22/36). The risk factors associated with positive drainage fluid cultures were the debridement of the infected site (without orthopaedic device removal), an infection located at the spine, perioperative positive cultures to Staphylococcus aureus. The complete change of the orthopaedic device, and coagulase-negative staphylococci on the preoperative samples, was associated with negative drainage fluid cultures. Positive drainage fluid culture was predictive of early surgical reintervention, and coagulase-negative staphylococci in the preoperative samples and knee infection were predictive of surgical success. Postoperative drainage fluid cultures were predictive of early surgical reintervention. Randomized multicentric studies should be further conducted.

Measurement of body surface topography using an automated imaging system.

An automatic computer imaging system for recording body surface topography has been developed on a microcomputer-based image processing system. The computer processes fringe patterns generated on the surface of the trunk and reconstructs the complete 3-dimensional form of the surface. From the topographic reconstruction, clinical parameters of scoliotic deformity such as Angle of Trunk Inclination are calculated at a number of levels from the upper thoracic to the sacral region. These multiple level measurements illustrate the change in deformity over the trunk and correspond to measurements obtained using conventional tactile devices on patients.