A Novel Bacteriophage Infecting Multi-Drug- and Extended-Drug-Resistant Pseudomonas aeruginosa Strains.

The prevalence of carbapenem-resistant P. aeruginosa has dramatically increased over the last decade, and antibiotics alone are not enough to eradicate infections caused by this opportunistic pathogen. Phage therapy is a fresh treatment that can be administered under compassionate use, particularly against chronic cases. However, it is necessary to thoroughly characterize the virus before therapeutic application. Our work describes the discovery of the novel sequenced bacteriophage, vB_PaeP-F1Pa, containing an integrase, performs a phylogenetical analysis, describes its stability at a physiological pH and temperature, latent period (40 min), and burst size (394 ± 166 particles per bacterial cell), and demonstrates its ability to infect MDR and XDR P. aeruginosa strains. Moreover, this novel bacteriophage was able to inhibit the growth of bacteria inside preformed biofilms. The present study offers a road map to analyze essential areas for successful phage therapy against MDR and XDR P. aeruginosa infections, and shows that a phage containing an integrase is also able to show good in vitro results, indicating that it is very important to perform a genomic analysis before any clinical use, in order to prevent adverse effects in patients.

Risk Factors for Therapeutic Failure and One-Year Mortality in Patients with Intramedullary Nail-Associated Infection after Trochanteric and Subtrochanteric Hip Fracture Repair.

Despite the implications of trochanteric and subtrochanteric intramedullary (IM) nail infection for patients with hip fracture, little is known about risk factors for therapeutic failure and mortality in this population. We performed a retrospective observational analysis including patients diagnosed with trochanteric and subtrochanteric IM nail infection at a Spanish academic hospital during a 10-year period, with a minimum follow-up of 22 months. Of 4044 trochanteric and subtrochanteric IM nail implants, we identified 35 cases of infection during the study period (0.87%), 17 of which were chronic infections. Patients with therapeutic failure (n = 10) presented a higher average Charlson Comorbidity Index (CCI) (5.40 vs. 4.21, p 0.015, CI 0.26-2.13) and higher rates of polymicrobial (OR 5.70, p 0.033, CI 1.14-28.33) and multidrug-resistant (OR 7.00, p 0.027, CI 1.24-39.57) infections. Upon multivariate analysis, polymicrobial infection and the presence of multidrug-resistant pathogens were identified as independent risk factors for therapeutic failure. Implant retention was associated with an increased risk of failure in chronic infection and was found to be an independent risk factor for overall one-year mortality in the multivariate analysis. Our study highlights the importance of broad-spectrum empirical antibiotics as initial treatment of trochanteric and subtrochanteric IM nail-associated infection while awaiting microbiological results. It also provides initial evidence for the importance of implant removal in chronic IM-nail infection.

Prosthetic Joint Infections Caused by Mycobacterium tuberculosis Complex-An ESGIAI-ESGMYC Multicenter, Retrospective Study and Literature Review.

PURPOSE: While tuberculosis remains a significant global health concern, prosthetic joint infections (PJIs) caused by members of the Mycobacterium tuberculosis complex are exceptionally rare. Our objective is to perform a retrospective search of new cases of this disease and analyze all cases available in the literature of tuberculous PJIs, aiming to detect factors that may influence patient outcomes. METHODS: The ESGIAI and ESGMYC study groups were used to collect information on non-published cases of tuberculous prosthetic joint infections (PJIs). Additionally, a literature review of all published cases of tuberculous PJIs was conducted. All identified cases in the retrospective study and in the literature review were merged and included in the statistical analysis, involving both univariate and multivariate analyses. RESULTS: Fifteen previously unreported cases of tuberculous prosthetic joint infections (PJIs) from four countries were detailed. Among them, ten patients were female, with a median age of 76 years. The hip was affected in 13 cases. Seven patients experienced co-infection with another microorganism. Treatment approaches varied, with 13 patients undergoing implant removal, one treated with DAIR (debridement, antibiotics, and implant retention), and one case was treated with an unknown treatment method. All patients received antibiotic therapy and achieved a cure. The literature review that was conducted detected 155 published cases. Univariate analysis revealed a statistical significance for previous tuberculosis, joint, and no importance of surgery for cure. CONCLUSIONS: Tuberculous prosthetic joint infection (PJI) is a rare condition, typically presenting as a localized chronic infection. Antibiotic treatment is essential for the management of these patients, but neither surgical treatment nor duration of treatment seems to have importance in the outcome.

Biofilm on total joint replacement materials can be reduced through electromagnetic induction heating using a portable device.

BACKGROUND: Periprosthetic joint infection is a serious complication following joint replacement. The development of bacterial biofilms bestows antibiotic resistance and restricts treatment via implant retention surgery. Electromagnetic induction heating is a novel technique for antibacterial treatment of metallic surfaces that has demonstrated in-vitro efficacy. Previous studies have always employed stationary, non-portable devices. This study aims to assess the in-vitro efficacy of induction-heating disinfection of metallic surfaces using a new Portable Disinfection System based on Induction Heating. METHODS: Mature biofilms of three bacterial species: S. epidermidis ATCC 35,984, S. aureus ATCC 25,923, E. coli ATCC 25,922, were grown on 18 × 2 mm cylindrical coupons of Titanium-Aluminium-Vanadium (Ti6Al4V) or Cobalt-chromium-molybdenum (CoCrMo) alloys. Study intervention was induction-heating of the coupon surface up to 70ºC for 210s, performed using the Portable Disinfection System (PDSIH). Temperature was monitored using thermographic imaging. For each bacterial strain and each metallic alloy, experiments and controls were conducted in triplicate. Bacterial load was quantified through scraping and drop plate techniques. Data were evaluated using non-parametric Mann-Whitney U test for 2 group comparison. Statistical significance was fixed at p ≤ 0.05. RESULTS: All bacterial strains showed a statistically significant reduction of CFU per surface area in both materials. Bacterial load reduction amounted to 0.507 and 0.602 Log10 CFU/mL for S. aureus on Ti6Al4V and CoCrMo respectively, 5.937 and 3.500 Log10 CFU/mL for E. coli, and 1.222 and 0.372 Log10 CFU/mL for S. epidermidis. CONCLUSIONS: Electromagnetic induction heating using PDSIH is efficacious to reduce mature biofilms of S aureus, E coli and S epidermidis growing on metallic surfaces of Ti6Al4V and CoCrMo alloys.

Synergism between remdesivir and ribavirin leads to SARS-CoV-2 extinction in cell culture.

BACKGROUND AND PURPOSE: There is a need for effective anti-COVID-19 treatments, mainly for individuals at risk of severe disease such as the elderly and the immunosuppressed. Drug repositioning has proved effective in identifying drugs that can find a new application for the control of coronavirus disease, in particular COVID-19. The purpose of the present study was to find synergistic antiviral combinations for COVID-19 based on lethal mutagenesis. EXPERIMENTAL APPROACH: The effect of combinations of remdesivir and ribavirin on the infectivity of SARS-CoV-2 in cell culture has been tested. Viral populations were monitored by ultra-deep sequencing, and the decrease of infectivity as a result of the treatment was measured. KEY RESULTS: Remdesivir and ribavirin exerted a synergistic inhibitory activity against SARS-CoV-2, quantified both by CompuSyn (Chou-Talalay method) and Synergy Finder (ZIP-score model). In serial passage experiments, virus extinction was readily achieved with remdesivir-ribavirin combinations at concentrations well below their cytotoxic 50 value, but not with the drugs used individually. Deep sequencing of treated viral populations showed that remdesivir, ribavirin, and their combinations evoked significant increases of the number of viral mutations and haplotypes, as well as modification of diversity indices that characterize viral quasi-species. CONCLUSION AND IMPLICATIONS: SARS-CoV-2 extinction can be achieved by synergistic combination treatments based on lethal mutagenesis. In addition, the results offer prospects of triple drug treatments for effective SARS-CoV-2 suppression.

Potential value of a rapid syndromic multiplex PCR for the diagnosis of native and prosthetic joint infections: a real-world evidence study.

Introduction: The BIOFIRE Joint Infection (JI) Panel is a diagnostic tool that uses multiplex-PCR testing to detect microorganisms in synovial fluid specimens from patients suspected of having septic arthritis (SA) on native joints or prosthetic joint infections (PJIs). Methods: A study was conducted across 34 clinical sites in 19 European and Middle Eastern countries from March 2021 to June 2022 to assess the effectiveness of the BIOFIRE JI Panel. Results: A total of 1527 samples were collected from patients suspected of SA or PJI, with an overall agreement of 88.4 % and 85 % respectively between the JI Panel and synovial fluid cultures (SFCs). The JI Panel detected more positive samples and microorganisms than SFC, with a notable difference on Staphylococcus aureus, Streptococcus species, Enterococcus faecalis, Kingella kingae, Neisseria gonorrhoeae, and anaerobic bacteria. The study found that the BIOFIRE JI Panel has a high utility in the real-world clinical setting for suspected SA and PJI, providing diagnostic results in approximately 1 h. The user experience was positive, implying a potential benefit of rapidity of results' turnover in optimising patient management strategies. Conclusion: The study suggests that the BIOFIRE JI Panel could potentially optimise patient management and antimicrobial therapy, thus highlighting its importance in the clinical setting.

SARS-CoV-2 mutant spectra as variant of concern nurseries: endless variation?

Introduction: SARS-CoV-2 isolates of a given clade may contain low frequency genomes that encode amino acids or deletions which are typical of a different clade. Methods: Here we use high resolution ultra-deep sequencing to analyze SARS-CoV-2 mutant spectra. Results: In 6 out of 11 SARS-CoV-2 isolates from COVID-19 patients, the mutant spectrum of the spike (S)-coding region included two or more amino acids or deletions, that correspond to discordant viral clades. A similar observation is reported for laboratory populations of SARS-CoV-2 USA-WA1/2020, following a cell culture infection in the presence of remdesivir, ribavirin or their combinations. Moreover, some of the clade-discordant genome residues are found in the same haplotype within an amplicon. Discussion: We evaluate possible interpretations of these findings, and reviewed precedents for rapid selection of genomes with multiple mutations in RNA viruses. These considerations suggest that intra-host evolution may be sufficient to generate minority sequences which are closely related to sequences typical of other clades. The results provide a model for the origin of variants of concern during epidemic spread─in particular Omicron lineages─that does not require prolonged infection, involvement of immunocompromised individuals, or participation of intermediate, non-human hosts.

Comparative Efficacy of Continuous Ceftazidime Infusion vs. Intermittent Bolus against In Vitro Ceftazidime-Susceptible and -Resistant Pseudomonas aeruginosa Biofilm.

Background: As the anti-biofilm pharmacokinetic/pharmacodynamic (PK/PD) properties of antibiotics are not well-defined, we have evaluated the PK/PD indices for different regimens of ceftazidime (CAZ; with/without colistin) against Pseudomonas aeruginosa biofilm. Methods: We have used the Center for Disease Control and Prevention Biofilm Reactor with two susceptible (PAO1 and HUB-PAS) and one resistant (HUB-XDR) strains of P. aeruginosa. The regimens were CAZ monotherapies (mimicking a human dose of 2 g/8 h, CAZ-IB; 6 g/daily as continuous infusion at 50 mg/L, CAZ-CI50; and 9 g/daily at 70 mg/L, CAZ-CI70) and CAZ-colistin combinations. Efficacy was correlated with the CAZ PK/PD parameters. Results: CAZ-CI70 was the most effective monotherapy against CAZ-susceptible strains (Δlog CFU/mL 54-0 h = -4.15 ± 0.59 and -3.05 ± 0.5 for HUB-PAS and PAO1, respectively; p ≤ 0.007 vs. other monotherapies), and adding colistin improved the efficacy over CAZ monotherapy. CAZ monotherapies were ineffective against the HUB-XDR strain, and CAZ-CI50 plus colistin achieved higher efficacy than CAZ-IB with colistin. The PK/PD index that correlated best with anti-biofilm efficacy was fAUC0-24h/MIC (r2 = 0.78). Conclusions: CAZ exhibited dose-dependent anti-biofilm killing against P. aeruginosa, which was better explained by the fAUC0-24h/MIC index. CAZ-CI provided benefits compared to CAZ-IB, particularly when using higher doses and together with colistin. CAZ monotherapies were ineffective against the CAZ-resistant strain, independently of the optimized strategy and only CAZ-CI plus colistin appeared useful for clinical practice.

In Vivo Detection of Staphylococcus aureus Infections Using Radiolabeled Antibodies Specific for Bacterial Toxins.

Purpose: The Gram-positive Staphylococcus aureus bacterium is one of the leading causes of infection in humans. The lack of specific noninvasive techniques for diagnosis of staphylococcal infection together with the severity of its associated complications support the need for new specific and selective diagnostic tools. This work presents the successful synthesis of an immunotracer that targets the α-toxin released by S. aureus. Methods: [89Zr]Zr-DFO-ToxAb was synthesized based on radiolabeling an anti-α-toxin antibody with zirconium-89. The physicochemical characterization of the immunotracer was performed by high-performance liquid chromatography (HPLC), radio-thin layer chromatography (radio-TLC), and electrophoretic analysis. Its diagnostic ability was evaluated in vivo by positron emission tomography/computed tomography (PET/CT) imaging in an animal model of local infection-inflammation (active S. aureus vs. heat-killed S. aureus) and infective osteoarthritis. Results: Chemical characterization of the tracer established the high radiochemical yield and purity of the tracer while maintaining antibody integrity. In vivo PET/CT image confirmed the ability of the tracer to detect active foci of S. aureus. Those results were supported by ex vivo biodistribution studies, autoradiography, and histology, which confirmed the ability of [89Zr]Zr-DFO-ToxAb to detect staphylococcal infectious foci, avoiding false-positives derived from inflammatory processes. Conclusions: We have developed an immuno-PET tracer capable of detecting S. aureus infections based on a radiolabeled antibody specific for the staphylococcal alpha toxins. The in vivo assessment of [89Zr]Zr-DFO-ToxAb confirmed its ability to selectively detect staphylococcal infectious foci, allowing us to discern between infectious and inflammatory processes.

Microevolution, reinfection and highly complex genomic diversity in patients with sequential isolates of Mycobacterium abscessus.

Mycobacterium abscessus is an opportunistic, extensively drug-resistant non-tuberculous mycobacterium. Few genomic studies consider its diversity in persistent infections. Our aim was to characterize microevolution/reinfection events in persistent infections. Fifty-three sequential isolates from 14 patients were sequenced to determine SNV-based distances, assign resistance mutations and characterize plasmids. Genomic analysis revealed 12 persistent cases (0-13 differential SNVs), one reinfection (15,956 SNVs) and one very complex case (23 sequential isolates over 192 months), in which a first period of persistence (58 months) involving the same genotype 1 was followed by identification of a genotype 2 (76 SNVs) in 6 additional alternating isolates; additionally, ten transient genotypes (88-243 SNVs) were found. A macrolide resistance mutation was identified from the second isolate. Despite high diversity, the genotypes shared a common phylogenetic ancestor and some coexisted in the same specimens. Genomic analysis is required to access the true intra-patient complexity behind persistent infections involving M. abscessus.

Biofilm Development by Mycobacterium avium Complex Clinical Isolates: Effect of Clarithromycin in Ultrastructure.

BACKGROUND: The Mycobacterium avium complex includes the commonest non-tuberculous mycobacteria associated with human infections. These infections have been associated with the production of biofilms in many cases, but there are only a few studies about biofilms produced by the species included in this group. METHODS: Three collection strains (M. avium ATCC25291, M. intracellulare ATCC13950, and M. chimaera DSM756), three clinically significant strains (647, 657, and 655), and three clinically non-significant ones (717, 505, and 575) of each species were included. The clinical significance of the clinical isolates was established according to the internationally accepted criteria. The biofilm ultrastructure was studied by Confocal-Laser Scanning Microscopy by using BacLight Live-Dead and Nile Red stains. The viability, covered surface, height, and relative autofluorescence were measured in several images/strain. The effect of clarithromycin was studied by using the technique described by Muñoz-Egea et al. with modifications regarding incubation time. The study included clarithromycin in the culture medium at a concentration achievable in the lungs (11.3 mg/L), using one row of wells as the control without antibiotics. The bacterial viability inside the biofilm is expressed as a percentage of viable cells. The differences between the different parameters of the biofilm ultrastructure were analyzed by using the Kruskal-Wallis test. The correlation between bacterial viability in the biofilm and treatment time was evaluated by using Spearman's rank correlation coefficient (ρ). RESULTS: The strains showed differences between them with all the studied parameters, but neither a species-specific pattern nor a clinical-significance-specific pattern were detected. For the effect of clarithromycin, the viability of the bacteria contained in the biofilm was inversely proportional to the exposure time of the biofilm (ρ > -0.3; p-value < 0.05), excluding two M. chimaera strains (M. chimaera DSM756 and 575), which showed a weak positive correlation with treatment time (0.2 < ρ < 0.39; p-value < 0.05). Curiously, despite a clarithromycin treatment of 216 h, the percentage of the biofilm viability of the strains evaluated here was not less than 40% at best (M. avium 717). CONCLUSIONS: All the M. avium complex strains studied can form biofilm in vitro, but the ultrastructural characteristics between them suggest that these are strain-specific characteristics unrelated to the species or the clinical significance. The clarithromycin effect on MAC species is biofilm-age/time-of-treatment-dependent and appears to be strain-specific while being independent of the clinical significance of the strain.

Fluoride anodic films on stainless-steel fomites to reduce transmission infections.

The growing concern arising from viruses with pandemic potential and multi-resistant bacteria responsible for hospital-acquired infections and outbreaks of food poisoning has led to an increased awareness of indirect contact transmission. This has resulted in a renewed interest to confer antimicrobial properties to commonly used metallic materials. The present work provides a full characterization of optimized fluoride anodic films grown in stainless steel 304L as well as their antimicrobial properties. Antibacterial tests show that the anodic film, composed mainly of chromium and iron fluorides, reduces the count and the percentage of the area covered by 50% and 87.7% for Pseudomonas aeruginosa and Stenotrophomonas maltophilia, respectively. Virologic tests show that the same treatment reduces the infectivity of the coronavirus HCoV-229E-GFP, in comparison with the non-anodized stainless steel 304L.IMPORTANCEThe importance of environmental surfaces as a source of infection is a topic of particular interest today, as many microorganisms can survive on these surfaces and infect humans through direct contact. Modification of these surfaces by anodizing has been shown to be useful for some alloys of medical interest. This work evaluates the effect of anodizing on stainless steel, a metal widely used in a variety of applications. According to the study, the fluoride anodic layers reduce the colonization of the surfaces by both bacteria and viruses, thus reducing the risk of acquiring infections from these sources.

An unusual case of endotipsitis: persistent infection and migration to the right atrium of a transjugular intrahepatic portosystemic shunt (TIPS).

Endotipsitis is an underdiagnosed entity mainly because it requires a high initial level of suspicion. It should be considered in the differential diagnosis of persistent bacteremia in the cirrhotic patient with TIPS. Most cases are treated conservatively with a long-term antibiotherapy, due to the impossibility of surgical removal of the TIPS, except in a liver transplant or autopsy. The patient we present had endotipsitis that manifested as persistent bacteremia with thrombosis of the TIPS. Initially, conservative management with intravenous antibiotherapy was performed; however, due to mechanical complications caused by migration of the original endoprosthesis, it was decided to perform surgery.

Programs to improve body image in adolescents: A systematic review / Programas para mejorar la imagen corporal en adolescentes: una revisión sistemática

Abstract Objective: To examine the intervention programs that have been conducted on body image in adolescents. Materials and methods: The PRISMA statement was used in this review. The search for studies was conducted in PubMed, Web of Science, MEDLINE-ProQuest, and EBSCO databases from January 1, 2017, to January 25, 2022. Methodological quality was assessed using the Quality Assessment Tool for Quantitative Studies, developed by the Effective Public Health Practice Project. Results: Eight studies were included, most of which had a strong methodological quality. The results obtained after the implementation of the programs reflected favorable changes in body image and body satisfaction for adolescents between 11 and 18 years old, only for five studies. Additionally, five studies maintained the same changes at follow-up. Conclusions: Findings from this review allow us to conclude that intervention programs are a safe and effective way to influence adolescent body image.

Resumen Objetivo: Examinar los programas de intervención que se han realizado sobre imagen corporal en adolescentes. Materiales y métodos: En esta revisión se utilizó la declaración PRISMA. La búsqueda de los estudios se realizó en las bases de datos PubMed, Web of Science, MEDLINE-ProQuest y EBSCO, a partir del 1 enero de 2017 hasta el 25 de enero de 2022. La calidad metodológica se evaluó a través de la Quality Assessment Tool for Quantitative Studies, desarrollada por el Effective Public Health Practice Project. Resultados: Se incluyeron ocho estudios, de los cuales la mayoría tuvo una calidad metodológica fuerte. Los resultados obtenidos después de la implementación de los programas reflejaron cambios favorables en la imagen corporal y en satisfacción corporal para los adolescentes de entre 11 y 18 años, solo para cinco estudios. Adicionalmente, cinco estudios mantuvieron en el seguimiento los mismos cambios. Conclusiones: Los hallazgos de esta revisión nos permiten concluir que los programas de intervención, constituyen una forma segura y eficaz de incidir en la imagen corporal de los adolescentes.

Multicenter evaluation of BioFire JI panel related to improved microbiological diagnostics on acute osteoarticular infections.

Microbiological diagnosis of osteoarticular infections (OI) is crucial for a successful treatment. A prospective multicenter study including 262 synovial fluids with suspicion of acute OI was performed between July 2021 and October of 2022. BioFire Joint Infection Panel multiplex-PCR test was performed and results were compared with conventional cultures of synovial fluid specimens. In total, 136 microorganisms were detected, and fourteen samples were positive for more than one microorganism. In monomicrobial infections (n = 87) agreement with culture was 69%. In 26 samples, the multiplex PCR yield an additional positive result when culture result was negative. It helped in the detection of fastidious microorganisms as K. kingae and N. gonorrhoeae. This multiplex PCR has proven to be a useful technique that can be used for patients with high suspicion of acute OI in a rapid and automated manner.

Multicenter evaluation of the BIOFIRE Joint Infection Panel for the detection of bacteria, yeast, and AMR genes in synovial fluid samples.

The bioMérieux BIOFIRE Joint Infection (JI) Panel is a multiplex in vitro diagnostic test for the simultaneous and rapid (~1 h) detection of 39 potential pathogens and antimicrobial resistance (AMR) genes directly from synovial fluid (SF) samples. Thirty-one species or groups of microorganisms are included in the kit, as well as several AMR genes. This study, performed to evaluate the BIOFIRE JI Panel for regulatory clearance, provides data from a multicenter evaluation of 1,544 prospectively collected residual SF samples with performance compared to standard-of-care (SOC) culture for organisms or polymerase chain reaction (PCR) and sequencing for AMR genes. The BIOFIRE JI Panel demonstrated a sensitivity of 90.9% or greater for all but six organisms and a positive percent agreement (PPA) of 100% for all AMR genes. The BIOFIRE JI Panel demonstrated a specificity of 98.5% or greater for detection of all organisms and a negative percent agreement (NPA) of 95.7% or greater for all AMR genes. The BIOFIRE JI Panel provides an improvement over SOC culture, with a substantially shorter time to result for both organisms and AMR genes with excellent sensitivity/PPA and specificity/NPA, and is anticipated to provide timely and actionable diagnostic information for joint infections in a variety of clinical scenarios.

Reduction of methicillin-resistant Staphylococcus aureus biofilm growth and development using arctic berry extracts.

Introduction: Surgical site infection remains a devastating and feared complication of surgery caused mainly by Staphylococcus aureus (S. aureus). More specifically, methicillin-resistant S. aureus (MRSA) infection poses a serious threat to global health. Therefore, developing new antibacterial agents to address drug resistance are urgently needed. Compounds derived from natural berries have shown a strong antimicrobial potential. Methods: This study aimed to evaluate the effect of various extracts from two arctic berries, cloudberry (Rubus chamaemorus) and raspberry (Rubus idaeus), on the development of an MRSA biofilm and as treatment on a mature MRSA biofilm. Furthermore, we evaluated the ability of two cloudberry seed-coat fractions, hydrothermal extract and ethanol extract, and the wet-milled hydrothermal extract of a raspberry press cake to inhibit and treat biofilm development in a wound-like medium. To do so, we used a model strain and two clinical strains isolated from infected patients. Results: All berry extracts prevented biofilm development of the three MRSA strains, except the raspberry press cake hydrothermal extract, which produced a diminished anti-staphylococcal effect. Discussion: The studied arctic berry extracts can be used as a treatment for a mature MRSA biofilm, however some limitations in their use exist.

Bacteriophage-Antibiotic Combination Therapy against Pseudomonas aeruginosa.

Phage therapy is an alternative therapy that is being used as the last resource against infections caused by multidrug-resistant bacteria after the failure of standard treatments. Pseudomonas aeruginosa can cause pneumonia, septicemia, urinary tract, and surgery site infections mainly in immunocompromised people, although it can cause infections in many different patient profiles. Cystic fibrosis patients are particularly vulnerable. In vitro and in vivo studies of phage therapy against P. aeruginosa include both bacteriophages alone and combined with antibiotics. However, the former is the most promising strategy utilized in clinical infections. This review summarizes the recent studies of phage-antibiotic combinations, highlighting the synergistic effects of in vitro and in vivo experiments and successful treatments in patients.

Antibacterial Properties of Mesoporous Silica Nanoparticles Modified with Fluoroquinolones and Copper or Silver Species.

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%.

Is an isolated positive sonication fluid culture in revision arthroplasties clinically relevant?

OBJECTIVES: The aim of this study was to investigate the clinical relevance of an isolated positive sonication fluid culture (SFC) in patients who underwent revision surgery of a prosthetic joint. We hypothesized that cases with a positive SFC have a higher rate of infection during follow-up compared with controls with a negative SFC. METHODS: This retrospective multicentre observational study was performed within the European Study Group of Implant-Associated Infections. All patients who underwent revision surgery of a prosthetic joint between 2013 and 2019 and had a minimum follow-up of 1 year were included. Patients with positive tissue cultures or synovial fluid cultures were excluded from the study. RESULTS: A total of 95 cases (positive SFC) and 201 controls (negative SFC) were included. Infection during follow-up occurred in 12 of 95 cases (12.6%) versus 14 of 201 controls (7.0%) (p = 0.125). In all, 79.8% of cases were with treated with antibiotics (76/95). Of the non-treated cases, 89% (17/19) had a positive SFC with a low virulent microorganism. When solely analysing patients who were not treated with antibiotics, 16% of the cases (3/19) had an infection during follow-up versus 5% of the controls (9/173) (p = 0.08). DISCUSSION: Although not statistically significant, infections were almost twice as frequent in patients with an isolated positive SFC. These findings require further exploration in larger trials and to conclude about the potential benefit of antibiotic treatment in these cases.