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Antibiotic resistance is a global problem and bacterial biofilms contribute to its development. In this context, this study aimed to perform the synthesis and characterization of seven materials based on silica mesoporous nanoparticles functionalized with three types of fluoroquinolones, along with Cu2+ or Ag+ species to evaluate the antibacterial properties against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa, including clinical and multi-drug-resistant strains of S. aureus and P. aeruginosa. In addition, in order to obtain an effective material to promote wound healing, a well-known proliferative agent, phenytoin sodium, was adsorbed onto one of the silver-functionalized materials. Furthermore, biofilm studies and the generation of reactive oxygen species (ROS) were also carried out to determine the antibacterial potential of the synthesized materials. In this sense, the Cu2+ materials showed antibacterial activity against S. aureus and E. coli, potentially due to increased ROS generation (up to 3 times), whereas the Ag+ materials exhibited a broader spectrum of activity, even inhibiting clinical strains of MRSA and P. aeruginosa. In particular, the Ag+ material with phenytoin sodium showed the ability to reduce biofilm development by up to 55% and inhibit bacterial growth in a “wound-like medium” by up to 89.33%.

Prosthetic joint infection is an uncommon entity, but it supposes high costs, both from the economic side to the health systems and from the emotional side of the patient. The evaluation of the bacterial adherence to different materials frequently involved in joint prostheses allows us to better understand the mechanisms underlying this and provide information for the future development of prevention strategies. This study evaluated the bacterial adherence of four different species (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli and Pseudomonas aeruginosa) on Ti6Al4V and CoCrMo. The topography, surface contact angles, and linear average roughness were measured in the samples from both alloys. The interaction with the surface of both alloys was significantly different, with the CoCrMo showing an aggregating effect on all the species, with additional anti-adherent activity in the case of Pseudomonas aeruginosa. The viability also changes, with a significant decrease (p < 0.05) in the CoCrMo alloy. In the case of S. epidermidis, the viability in the supernatant from the samples was different, too, with a decrease in the colony-forming units in the Ti6Al4V, which could be related to cation release from the surface. Beyond adhesion is a multifactorial and complex process, and considering that topography and wettability were similar, the chemical composition could play a main role in the different properties observed.

This study is the first one to analyze a high number of isolates of Gram-negative bacilli that are the cause of prosthetic joint infection. The analysis includes biofilm development and antimicrobial susceptibility testing of both planktonic and sessile bacteria. The obtained results support the clinical knowledge about the treatment of these bacteria when biofilms are involved.

This study aimed to characterize 79Isolates were phylotyped according to the single-locus sequence typing (SLST) scheme. We evaluated the ability of the biofilm formation ofMost of the isolates from PJIs belonged to the SLST class H/phylotype IB (34.2%), followed by class D/phylotype IA

Prosthetic joint infections (PJIs) are typically caused by microorganisms that grow in biofilms. Traditional antimicrobial susceptibility tests are based on the study of planktonic bacteria that might lead to missing the biofilm behavior and to a treatment failure. This study was designed to analyze the antimicrobial susceptibility of clinical Gram-negative bacilli (GNB) isolates from PJIs in planktonic and sessile states and the possible relationship between antimicrobial resistance and biofilm formation. A total of 46 clinical isolates from patients with PJIs (mainly hip and knee prostheses) plus three GNB ATCC isolates were studied. The Minimal Inhibitory Concentration (MIC), minimal bactericidal concentration (MBC), minimal biofilm inhibitory concentration (MBIC), and minimal biofilm eradication concentration (MBEC) were assessed using a previously published methodology. Almost all of the GNB clinical isolates tested were biofilm forming. Pseudomonas aeruginosa was the largest biofilm-forming species. A comparison of MBIC

Carbapenem-resistant Klesiella pneumoniae (CR-KP) infection rates depict an almost pre-antibiotic scenario since the pipeline for effective antibiotics against this pathogen has been almost entirely depleted. This study aims to evaluate the antibacterial effect of gold nanostars (GNS) alone or associated with some of the most widely used antibiotics for the treatment of CR-KP strains, i.e., meropenem or amikacin, on both planktonic and sessile forms. Additionally, we measured the effect of GNS on cell proliferation and biocompatibility in invertebrate in vivo models. (2) Materials and methods: GNS were made from gold seeds grown using a seeded-growth surfactant-free method assisted by silver ions and functionalized with mercapto-poly(ethylene glycol)amino by ligand exchange. The antimicrobial capacity, effect on cell proliferation, and biocom-patibility of the most effective combination was evaluated in a Galleria mellonella model. (3) Results: The minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) were 80 and 160 µM of GNS for all strains, respectively. The minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were >320 µM of GNS for both. A synergy was found between GNS and amikacin. Larvae administered GNS plus amikacin were found to tolerate the treatment well, which prevented infection. (4) Conclusions: GNS are a promising anti-CR-KP nanomaterial, This research was funded by the European Research Council through ERC-2015-AdG694160 (VERDI) grant. AM is funded by grants from Instituto de Salud Carlos III through the “Miguel Servet” program (CP15/00053)

Staphylococcus aureus is the most common cause of surgical site infections and its treatment is challenging due to the emergence of multi-drug resistant strains such as methicillin-resistant S. aureus (MRSA). Natural berry-derived compounds have shown antimicrobial potential, e.g., ellagitannins such as sanguiin H-6 and lambertianin C, the main phenolic compounds in Rubus seeds, have shown antimicrobial activity. The aim of this study was to evaluate the effect of sanguiin H-6 and lambertianin C fractionated from cloudberry seeds, on the MRSA growth, and as treatment of a MRSA biofilm development in different growth media in vitro and in vivo by using a murine wound infection model where sanguiin H-6 and lambertianin C were used to prevent the MRSA infection. Sanguiin H-6 and lambertianin C inhibited the in vitro biofilm development and growth of MRSA. Furthermore, sanguiin H-6 showed significant anti-MRSA effect in the in vivo wound model. Our study shows the possible use of sanguiin H-6 as a preventive measure in surgical sites to avoid postoperative infections, whilst lambertianin C showed no anti-MRSA activity.

(1) Background: Carbapenem-resistant

Cutibacterium acnes is a common cause of prosthetic joint infections (PJIs). The C. acnes population can be divided into six main phylotypes (IA1, IA2, IB, IC, II and III) that are associated with different clinical conditions and normal skin. A single-locus sequence typing (SLST) scheme can distinguish ten main SLST types: A-E (all IA1), F (IA2), G (IC), H (IB), K (II), L (III). We genome-sequenced and compared 16 strains of C. acnes isolated from healthy skin (n = 4) and PJIs (n = 12), including six PJI cases with a good outcome (four shoulder PJIs, one hip PJI, one knee PJI) and six with infection relapse (three shoulder PJIs, three hip PJIs). The sequenced strains belonged to four different phylotypes (IA1, IA2, IB and II) and seven different SLST types. All five type IB strains (all SLST type H1) were PJI isolates (three hip PJIs, two shoulder PJIs), and four of these caused infection relapse (three hip PJIs, one shoulder PJI). Isolates from PJI cases with a good outcome belonged to three different phylotypes (IA, IB, II). Interestingly, four strains (three strains from PJI cases with good outcome and one strain from healthy skin) contained a linear plasmid, these strains belonged to different SLST types (A1, C1, F4, H1) and were isolated in three different hospitals. This study suggests that type IB strains have the potential to cause infection relapse, in particular regarding hip PJIs. Moreover, our study revealed that strains belonging to the same SLST type can differ in their accessory genome in different geographic locations, indicative of microevolution.

Methylobacterium sp. is isolated from water distribution systems and has been linked in the biofilms of the systems with a lower presence of Mycobacterium avium. In this study we aimed to determine the in vitro activity of Methylobacterium sp. in the development of rapidly growing mycobacteria (RGM) biofilms. Methylobacterium sp. CECT 7805 was added as a suspension of living bacteria (LB), an autoclaved suspension (AS), and an extract obtained after sonication (ES) at different times (24, 48, and 72 h), to preformed biofilms of Mycobacterium abscessus DSM 44196, Mycobacterium chelonae ATCC 19235, and Mycobacterium fortuitum ATCC 6841, using a 96 h control of each species. The biofilms were analyzed by confocal laser scanning microscopy and by the Calgary biofilm device using the plates MBECTM Biofilm Inoculator. A statistically significant reduction in the thickness and covered surface was observed in all mycobacterial biofilms with all forms of Methylobacterium sp. A statistically significant increase in the autofluorescence was observed in M. abscessus biofilms but not in other biofilms. The increased percentage of dead mycobacteria was statistically significant in all cases. The reduced log CFU (colony-forming units)/peg recount was statistically significant in M. chelonae biofilms after treatment with AS and ES, but in M. fortuitum biofilms the recount decreased only with AS. M. abscessus biofilms were always significantly reduced with AS at 72 h and with ES. Methylobacterium sp. could inhibit RGM biofilm formation. Living cells of Methylobacterium sp. were not necessary to inhibit the growth of a preformed biofilm. M. chelonae biofilms were the most greatly reduced.

Introduction. Candida auris is a pathogenic yeast that mainly affects immunosuppressed patients and those with implanted medical devices. This pathogen also displays elevated resistance to common antifungals and high survival and spreading capacities. Since no antifungal breakpoints have yet been defined for this pathogen, the data obtained here can be useful for further research concerning treatment or implementation of a prevention and disinfection protocol. Our aim was to study the antifungal resistance of C. auris to current antifungals in planktonic and sessile states. Using confocal laser scanning microscopy and viable biomass production, we demonstrated the ability of C. auris to develop a mature biofilm. We compared the minimal inhibitory concentration (MIC) and the minimal biofilm eradication concentration (MBEC) for the C. auris DSM 21092 strain plus two clinical isolates, and the results were compared with those obtained for Candida albicans and Candida parapsilosis, two species strongly linked to bloodstream infections and infections associated with biomaterials. We found that the clinical isolates of C. auris were resistant to fluconazole and sensitive to echinocandins and polyenes. The C. auris biofilms did not show susceptibility to any antifungal agent, showing MBECs that were up to 512-fold higher than the MICs. These findings highlight the importance of biofilm formation as a key factor underlying the resistance of this species to antifungals and suggest that the presence of implantable medical devices is one of the major risk factors in immunocompromised patients.

Ti-doped ZnO thin films were obtained with the aim of tailoring ZnO film bioadhesiveness and making the optoelectronic properties of ZnO materials transferable to biological environments. The films were prepared on silicon substrates by sol–gel spin-coating and subsequent annealing. A Ti–O segregation limits the ZnO crystallite growth and creates a buffer out-layer. Consequently, the Ti-doped ZnO presents slightly increased resistivity, which remains in the order of 10–3 Ω·cm. The strong biochemical interference of Zn2+ ions released from pure ZnO surfaces was evidenced by culturing Staphylococcus epidermidis with and without the Zn2+ coupling agent clioquinol. The Ti-doped ZnO surfaces showed a considerable increase of bacterial viability with respect to pure ZnO. Cell adhesion was assayed with human mesenchymal stem cells (hMSCs). Although hMSCs find difficulties to adhere to the pure ZnO surface, they progressively expand on the surface of ZnO when the Ti doping is increased. A preliminary microdevice has been built on the Si substrate with a ZnO film doped with 5% Ti. A one-dimensional micropattern with a zigzag structure shows the preference of hMSCs for adhesion on Ti-doped ZnO with respect to Si. The induced contrast of surface tension further induces a cell polarization effect on hMSCs. It is suggested that the presence of Ti–O covalent bonding on the doped surfaces provides a much more stable ground for bioadhesion. Such fouling behavior suggests an influence of Ti doping on film bioadhesiveness and sets the starting point for the selection of optimal materials for implantable optoelectronic devices.

This article belongs to the Special Issue Prosthetic Joint Infection: The Challenges of Prevention, Diagnosis and Treatment and Opportunities for Future Research. Fungal PJI is one of the most feared complications after arthroplasty. Although a rare finding, its high associated morbidity and mortality makes it an important object of study. The most frequent species causing fungal PJI is C. albicans. New technology to treat this type of PJI involves organic–inorganic sol-gels loaded with antifungals, as proposed in this study, in which anidulafungin is associated with organophosphates. This study aimed to evaluate the efficacy of an anidulafungin-loaded organic–inorganic sol-gel in preventing prosthetic joint infection (PJI), caused by Candida albicans using an in vivo murine model that evaluates many different variables. Fifty percent (3/6) of mice in the C. albicans-infected, non-coated, chemical-polished (CP)-implant group had positive culture and 100% of the animals in the C. albicans-infected, anidulafungin-loaded, sol-gel coated (CP + A)-implant group had a negative culture (0/6) (p = 0.023). Taking the microbiology and pathology results into account, 54.5% (6/11) of C. albicans-infected CP-implant mice were diagnosed with a PJI, whilst only 9.1% (1/11) of C. albicans-infected CP + A-implant mice were PJI-positive (p = 0.011). No differences were observed between the bone mineral content and bone mineral density of noninfected CP and noninfected CP + A (p = 0.835, and p = 0.181, respectively). No histological or histochemical differences were found in the tissue area occupied by the implant among CP and CP + A. Only 2 of the 6 behavioural variables evaluated exhibited changes during the study: limping and piloerection. In conclusion, the anidulafungin-loaded sol-gel coating showed an excellent antifungal response in vivo and can prevent PJI due to C. albicans in this experimental model. This research received financial support from the Mutua Madrileña Foundation (04078/001).

Candida auris is a multiresistant pathogenic yeast commonly isolated from bloodstream infections in immunocompromised patients. In this work, we infected Galleria mellonella larvae with 105 CFU of a reference strains and two clinical isolates of C. albicans and C. auris and we compared the outcomes of infection between both species. Larvae were evaluated every 24 h for a total of 120 h following the G. mellonella Health Index Scoring System, and survival, activity, melanization and cocoon formation were monitored. Our results showed that clinical isolates were significantly more pathogenic than reference strains independently of the tested species, producing lower survival and activity scores and higher melanization scores and being C. albicans strains more virulent than C. auris strains. We did not find differences in mortality between aggregative and non-aggregative C. auris strains, although non-aggregative strains produced significantly lower activity scores and higher melanization scores than aggregative ones. Survival assays using Galleria mellonella have been previously employed to examine and classify strains of this and other microbial species based on their virulence before scaling the experiments to a mammal model. Taken together, these results show how a more complete evaluation of the model can improve the study of C. auris isolates.

The aim of this study was to evaluate the effectiveness of a moxifloxacin-loaded organic-inorganic sol-gel (A50) by locally preventing the catheter-related bloodstream infection (CRBSI) provoked by Staphylococcus epidermidis (S. epidermidis) and the effect resulting from its hydrolytic degradation on coagulation by using a rabbit in-vivo model. A50 coating can completely inhibit growth and would locally prevent CRBSI provoked by S. epidermidis. None of the coagulation blood parameters showed a significant difference constant over time between the control catheter group and the A50-coated catheter group, despite the visible silica release resulting from physiological A50 sol-gel degradation detected in serum at least during the first week. At pathological level, foreign body reaction was present in both of types of catheter, and it was characterized by the presence of macrophages and foreign body giant cell. However, this reaction was different in each group: the A50-coated catheter group showed a higher inflammation with histiocytes, which were forming granuloma-like aggregates with an amorphous crystalline material inside, accompanied by other inflammatory cells such as plasma cells, lymphocytes and mast cells. In conclusion, A50 coating a venous catheter showed excellent bactericidal anti-biofilm response since it completely inhibited S. epidermidis biofilm development and, far from showing procoagulant effects, showed slightly anticoagulant effects., This research received financial support from the Mutua Madrileña Foundation (04078/001). J.J.A.-C. was funded by an FPI grant from the Spanish Ministry of Economics and Competitiveness (BES-2014-069007).

Fabry disease is characterized by lyso-Gb3 accumulation, gastrointestinal symptoms and severe nephropathy and myocardiopathy. Clinically relevant lyso-Gb3 concentrations disrupt the gut microbiota homeostasis. Biofilm formation by enteric bacteria is modulated, favoring Bacteroides fragilis growth. In complex gut bacterial communities, lyso-Gb3 reduced bacteria associated with a healthy microbiota (Bifidobacterium, Akkermansia, Lactobacillus, and butyrate-producing Blautia coccoides-Eubacterium rectale, and Clostridium leptum) and butyrate production. We now discuss the clinical and pathophysiological implications of these findings as butyrate has anti-inflammatory properties through epigenetic regulation of histone acetylation that may protect against nephropathy and myocardiopathy. Lyso-Gb3 modulation of the gut microbiota may directly contribute to the gastrointestinal symptoms and indirectly to systemic manifestations of Fabry disease through modulation of the epigenetic regulation of inflammation., JJAC is funded by an FPI grant from Spanish Ministry of Economics and Competitiveness (BES-2014-069007). The authors were further supported by FIS PI15/00298, PI16/02057, PI18/01366, PI19/00815, DTS18/00032, ERA-PerMed-JTC2018 (KIDNEY ATTACK AC18/00064), ISCIII-RETIC REDinREN RD016/0009 Fondos FEDER, Sociedad Española de Nefrología, Comunidad de Madrid B2017/BMD-3686 CIFRA2-CM, Miguel Servet MS14/00133 to MDSN and AGL2016-75951-R.

Fabry disease is a rare X-linked lysosomal storage disorder resulting from deficient activity of α-galactosidase A, leading to the accumulation of glycosphingolipids such as globotriaosylsphingosine (lyso-Gb3). The gastrointestinal symptoms of this disease may be disabling, and the life expectancy of affected patients is shortened by kidney and heart disease. Our hypothesis was that lyso-Gb3 may modify the gut microbiota. The impact of a clinically relevant concentration of lyso-Gb3 on mono- or multispecies bacterial biofilms were evaluated. A complex bacterial community from the simulated transverse colon microbiota was studied using quantitative PCR to estimate different bacterial group concentrations and a HPLC was used to estimate short-chain fatty acids concentrations. We found that lyso-Gb3 increased the biofilm-forming capacity of several individual bacteria, including Bacteroides fragilis and significantly increased the growth of B. fragilis in a multispecies biofilm. Lyso-Gb3 also modified the bacterial composition of the human colon microbiota suspension, increasing bacterial counts of B. fragilis, among others. Finally, lyso-Gb3 modified the formation of short-chain fatty acids, leading to a striking decrease in butyrate concentration. Lyso-Gb3 modifies the biology of gut bacteria, favoring the production of biofilms and altering the composition and short-chain fatty-acid profile of the gut microbiota.

The aim of this study was to evaluate the effect of a moxifloxacin-loaded organicinorganic sol-gel with different antibiotic concentration in the in vitro biofilm development and treatment against Staphylococcus aureus, S. epidermidis, and Escherichia coli, cytotoxicity and cell proliferation of MC3T3-E1 osteoblasts; and its efficacy in preventing the prosthetic joint infection (PJI) caused by clinical strains of S. aureus and E. coli using an in vivo murine model. Three bacterial strains, S. epidermidis ATCC 35984, S. aureus 15981, and, E. coli ATCC 25922, were used for microbiological studies. Biofilm formation was induced using tryptic-soy supplemented with glucose for 24 h, and then, adhered and planktonic bacteria were estimated using drop plate method and absorbance, respectively. A 24-h-mature biofilm of each species growth in a 96- well plate was treated for 24 h using a MBECTM biofilm Incubator lid with pegs coated with the different types of sol-gel, after incubation, biofilm viability was estimated using alamrBlue. MC3T3-E1 cellular cytotoxicity and proliferation were evaluated using CytoTox 96 Non-Radioactive Cytotoxicity Assay and alamarBlue, respectively. The microbiological studies showed that sol-gel coatings inhibited the biofilm development and treated to a mature biofilm of three evaluated bacterial species. The cell studies showed that the sol-gel both with and without moxifloxacin were non-cytotoxic and that cell proliferation was inversely proportional to the antibiotic concentration containing by sol-gel. In the in vivo study, mice weight increased over time, except in the E. coliinfected group without coating. The most frequent symptoms associated with infection were limping and piloerection; these symptoms were more frequent in infected groups with non-coated implants than infected groups with coated implants. The response of moxifloxacin-loaded sol-gel to infection was either total or completely absent. No differences in bone mineral density were observed between groups with coated and non-coated implants and macrophage presence lightly increased in the bone grown directly in contact with the antibiotic-loaded sol-gel. In conclusion, moxifloxacinloaded sol-gel coating is capable of preventing PJI caused by both Gram-positive and Gram-negative species The authors acknowledge the financial support from the Regional Government of Madrid through the program MULTIMAT-CHALLENGE (S2013/MIT-2862), and from the Mutua Madrileña Foundation (04078/001). JA-C was funded by an FPI grant from the Spanish Ministry of Economics and Competitiveness (BES-2014-069007). AM was funded by grants from Instituto de Salud Carlos III through the “Miguel Servet” program (CP15/00053). DR was funded by a grant from the Fundación Conchita Rábago

Septic arthritis and prosthetic joint infection (PJI) are conditions commonly associated with Gram-positive cocci, however, a drastic increase in cases derived from enterobacterial species has recently been observed. Recently it has been reported by multiple groups that staphylococci rapidly form free-floating aggregates in the presence of synovial fluid. These aggregates are comparatively more resistant to antimicrobial challenge than their planktonic counterparts, and thus may play a role in the pathogenesis of joint infection. While staphylococcal aggregates have been the primary focus of interest in the field, it is unclear just how widespread synovial fluid mediated aggregation (SFMA) is in Gram negative enterobacteria (GNE). Through this work we have evaluated SFMA in clinical GNE isolated from PJIs. Two PJI clinical strains each of Enterobacter cloacae, Escherichia coli, Klebsiella pneumonia and Proteus mirabilis strains representing a range of antibiotic susceptibilities were exposed to 10% bovine synovial fluid supernatant (BSF) using a relatively simple, quick semi-quantitative method using an imaging plate reader. BSF stimulated aggregation within 0.5 hr both strains of E. cloacae and P. mirabilis and one strain of E.coli. In one strain of P. mirabilis and E.coli, the size of the aggregates significantly increased from 0.5 to 2 hr exposure. In contrast, neither K. pneumoniae strain aggregated in BSF. These preliminary findings show that aggregation can occur quickly in GNE, but the extent appears strain and species specific. Further work is required to assess the impact of SFMA on antibiotic tolerance, host innate immunity and the establishment of biofilms.

Fluorine, an essential element present in bone and dental tissues, promotes mineralization and is directly involved in the bone formation process. The antibacterial effects of fluorine on oral bacteria are also well known. In this study, metallic implants were coated with a thin layer of calcium phosphate enriched with fluorine to improve osteointegration and protect against infections. These coatings were obtained by pulsed laser deposition (PLD) using, as a target, a bioceramic of marine origin, mainly composed of fluorapatite from the enameloid of shark teeth. The compositional dependence of coatings on H2O vapor pressures applied during PLD was analyzed in order to optimize physicochemical properties. Physicochemical characterization to evaluate morphology (SEM), thickness (interferometric profilometry), structure (XRD) and composition (FTIR, XPS) was performed. To evaluate the biological response, both MC3T3-E1 pre-osteoblasts and bacterial strains Staphylococcus aureus and Staphylococcus epidermidis, most responsible for 77% of infections associated with prosthetic implants, were tested. Proper cell proliferation (MTT assay) and ALP synthesis up to 21 days were confirmed. Antibacterial properties were also demonstrated: compared to synthetic hydroxyapatite coatings, there was a significant reduction in colony-forming units (CFUs) for both strains.

The aim of this study was to use a commercially available kit (GenoType® HelicoDR; Hain Life Science, Germany) to detect Helicobacter pylori infection and clarithromycin resistance genotype in biopsies obtained from symptomatic children. Results : 111 out of 136 (81.6%) biopsies were H. pylori positive by genotype: 47 (42.3%) showed wild-type genotype, 53 resistant genotype (47.7%) and 11 heterogeneous genotype (9.9%). Culture was negative in 27 out of the 111 genotyped biopsies. Mutation A2143G (87.5%), followed by A2142G (7.5%) and double mutant A2142C-A2143G (5%) were found. The 11 heterogeneous genotype biopsies showed wild-type plus A2143G in 9 and plus A2142G in 2. Conclusions : This kit is a rapid, culture-independent method for routine application in biopsies from the pediatric population that allows detection of clarithromycin resistance and heterogeneous genotypes. It is important to know the clinical impact of infection with this type of strains as well as the role in treatment success.

The use of prosthetic meshes is a common practice in hernia repair surgery. However, infection can appear as an important complication where antibiotic selection must be directed by the etiology of the infection. In recent years, sonication has appeared as an important tool for the diagnosis of many biomaterial-associated infections. Here, we evaluated our experience with this methodology for the diagnosis of mesh infection. We retrospectively reviewed the microbiological records between 2015 and 2019 looking for sonicated meshes in the microbiology laboratory. All samples were processed according to the sonication protocol described by Esteban J et al. (J Clin Microbiol. 2008 Feb; 46 (2): 488–92). 26 samples were processed during the study period. 21 of them gave a positive result for culture (11 polymicrobial and 10 monomicrobial ones). Staphylococcus aureus and Candida albicans were the commonest monomicrobial isolates (4 cases each). There were five cases of mixed gut microbiota. The median (interquartile range) UFC count was > 100,000 (50,000- > 100,000) CFU/mL. Sonication is a useful technique for the diagnosis of mesh infection.

The physiological factors that contribute to Mycobacterium abscessus lung infections remain unclear. We determined whether antibiotic treatment targeting a major cystic fibrosis pathogen (i.e., Pseudomonas aeruginosa ) could provide the ideal conditions for the establishment of M. abscessus infection. Our data showed that P. aeruginosa inhibited M. abscessus biofilm formation under control conditions and that antimicrobial therapy selectively targeting P. aeruginosa diminished this competitive interaction, thereby increasing M. abscessus survival.

Non-pigmented rapidly growing mycobacteria (NPRGM) are widely distributed in water, soil and animals. It has been observed an increasing importance of NPRGM related-infections, particularly due to the high antimicrobial resistance. NPRGM have rough and smooth colony phenotypes, and several studies have showed that rough colony variants are more virulent than smooth ones. However, other studies have failed to validate this observation. In this study, we have performed two models, invitro and in vivo, in order to assess the different pathogenicity of these two phenotypes. We used collection and clinical strains of Mycobacteriumabscessus, Mycobacterium fortuitum and Mycobacteriumchelonae. On the invitro model (macrophages), phagocytosis was higher for M. abscessus and M. fortuitum rough colony variant strains when compared to smooth colony variants. However, we did not find differences with colonial variants of M. chelonae. Survival of Galleriamellonella larvae in the experimental model was lower for M. abscessus and M. fortuitum rough colony variants when compared with larvae infected with smooth colony variants. We did not find differences in larvae infected with M. chelonae.Results of our in vivo study correlated well with the experimental model. This fact could have implications on the interpretation of the clinical significance of the NPRGM isolate colonial variants.

Joint prosthesis failure is mainly related to aseptic loosening and prosthetic joint infections, both of which are associated with high morbidity and substantial costs for patients and health systems. The development of a biomaterial that is capable of stimulating bone growth while minimizing bacterial adhesion would reduce the incidence of prosthetic failure. We report antibacterial and osteostimulatory effects in a novel fluorine-phosphorus (F-P)-doped TiO2 oxide film grown on Ti-6Al-4V alloy with a nanostructure of bottle-shaped nanotubes (bNT) using five bacterial species (Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia) and MCT3T3-E1 osteoblastic cells. The interaction between the bacteria and bNT Ti-6Al-4V was complex, as the adhesion of four bacterial species decreased (two staphylococcus species, E. coli, and S. maltophilia), and the viability of staphylococci and S. maltophilia also decreased because of the aluminum (Al) released by bNT Ti-6Al-4V. This released Al can be recruited by the bacteria through siderophores and was retained only by the Gram-negative bacteria tested. P. aeruginosa showed higher adhesion on bNT Ti-6Al-4V than on chemically polished (CP) samples of Ti-6Al-4V alloy and an ability to mobilize Al from bNT Ti-6Al-4V. The cell adhesion and proliferation of MCT3T3-E1 osteoblastic cells significantly increased at 48 and 168 h, as did the matrix mineralization of these cells and the gene expression levels of three of the most important markers related to bone differentiation. According to our results, the bNT Ti-6Al-4V alloy could have clinical application, preventing infection and stimulating bone growth and thus preventing the two main causes of joint prosthesis failure.IMPORTANCE This work evaluates F-P-doped bNT Ti-6Al-4V from microbiological and cellular approaches. The bacterial results highlight that the antibacterial ability of bNT Ti-6Al-4V is the result of a combination of antiadhesive and bactericidal effects exerted by Al released from the alloy. The cell results highlight that F-P bNT Ti-6Al-4V alloy increases osseointegration due to modification of the chemical composition of the alloy resulting from P incorporation and not due to the nanostructure, as reported previously. A key finding was the detection of Al release from inside the bNT Ti-6Al-4V nanostructures, a result of the nanostructure growth during the anodizing process that is in part responsible for its bactericidal effect., This work was funded by a grant from the Spanish Ministry of Economics and Competitiveness (MAT2013-48224-C2-2-R and MAT2013-48224-C2-1-R). J.-J.A.-C. is funded by an FPI grant from the same institution (BES-2014-069007). We acknowledge Oliver Shaw for his help with the English language and Isabelle Schalk for providing the P. aeruginosa ATCC 15692 ΔpchA and ΔpvdF ΔpchA mutants.

Parts of this work were previously presented at the 21st, 22nd, and 23rd Spanish Congress of Clinical Microbiology and Infectious Diseases, the 29th European Congress of Clinical Microbiology and Infectious Diseases, the 6th Update on Fabry Disease, and 15th Annual Word Symposium of Lysosomal Diseases Research & Conference., Fabry disease is a rare X-linked lysosomal storage disorder resulting from deficient activity of α-galactosidase A, leading to the accumulation of glycosphingolipids such as globotriaosylsphingosine (lyso-Gb3). The gastrointestinal symptoms of this disease may be disabling, and the life expectancy of affected patients is shortened by kidney and heart disease. Our hypothesis was that lyso-Gb3 may modify the gut microbiota. The impact of a clinically relevant concentration of lyso-Gb3 on mono- or multispecies bacterial biofilms were evaluated. A complex bacterial community from the simulated transverse colon microbiota was studied using quantitative PCR to estimate different bacterial group concentrations and a HPLC was used to estimate short-chain fatty acids concentrations. We found that lyso-Gb3 increased the biofilm-forming capacity of several individual bacteria, including Bacteroides fragilis and significantly increased the growth of B. fragilis in a multispecies biofilm. Lyso-Gb3 also modified the bacterial composition of the human colon microbiota suspension, increasing bacterial counts of B. fragilis, among others. Finally, lyso-Gb3 modified the formation of short-chain fatty acids, leading to a striking decrease in butyrate concentration. Lyso-Gb3 modifies the biology of gut bacteria, favoring the production of biofilms and altering the composition and short-chain fatty-acid profile of the gut microbiota., JJAC is funded by an FPI grant from Spanish Ministry of Economics and Competitiveness (BES-2014-069007). The authors were further supported by FIS PI16/02057, PI18/01366, ISCIII-RETIC REDinREN RD016/0009 Fondos FEDER, Sociedad Española de Nefrología, Comunidad de Madrid B2017/BMD-3686 CIFRA2-CM, Miguel Servet MS14/00133 to MDSN and AGL2016-75951-R.