Gram-Negative Bacteria Are Internalized Into Osteocyte-Like Cells

Evaluation of Different Activity of Lactobacillus spp. against Two Proteus mirabilis Isolated Clinical Strains in Different Anatomical Sites In Vitro: An Explorative Study to Improve the Therapeutic Approach

Urinary tract infections (UTIs) and catheter-associated UTIs (CAUTIs) are the principal hospital-acquired infections. Between these, bacterial prostatitis is believed to be the leading cause of recurrent UTIs in men under 50 years of age and is often unresponsive to antibiotic treatment. Proteus mirabilis is more commonly associated with UTIs in these abnormalities, especially in patients undergoing catheterization. Lactobacillus spp. are an important component of the human microbiota and occur in large quantities in foods. Probiotics are proposed as an alternative to antibiotic therapy in the treatment of urinary tract infections. In addition to their ability to produce antimicrobial metabolites, they have immunomodulatory activity and do not cause side effects. For this reason, the combination of probiotic microorganisms and conventional drugs was considered. The aim of this work was to select the most active Lactobacillus strains against two clinical isolates of P. mirabilis on bladder and prostatic epithelium, potentially exploitable to improve the clinical management of UTIs.

Silver carboxylate and titanium dioxide-polydimethylsiloxane coating decreases adherence of multi-drug resistant Serratia marcescens on spinal implant materials

PURPOSE

The opportunistic multi-drug resistant nosocomial gram negative bacilli Serratia marcescens (S. marcescens) is a rising contributor to spinal implant infections (Iguchi et al., Genome Biol Evol 6:2096-2110, 2014; Teresa et al., J Clin Microbiol 55:2334-2347; Dante et al., J Clin Microbiol 54:120-126). This study investigates the most effective matrix ratio of an antibiotic-independent, silver carboxylate-doped titanium dioxide (TiO₂)-polydimethylsiloxane (PDMS) coating in preventing adherence of multidrug resistant pathogen S. marcescens to spinal implant materials.

METHODS

This project examined an antibiotic-independent, silver carboxylate-doped titanium dioxide (TiO₂)-polydimethylsiloxane (PDMS) coating on three common spinal implant materials, polyetheretherketone (PEEK), stainless steel (SS), and titanium (Ti), which previously were found to be prone to bacterial adhesion (Garcia et al., Spine Deform 8:351-359). After generation of dose response curves to find the optimal silver carboxylate concentration, 95% TiO₂-5% PDMS was combined with 10× silver carboxylate and compared to 100% silver carboxylate and uncoated implants. Implants were imaged using scanning electron microscopy and confocal laser scanning microscopy to detect adherent S. marcescens.

RESULTS

Ninety-five percent TiO₂-5% PDMS and 10× silver carboxylate coating decreased adherence of S. marcescens on PEEK by 99.61% (p = 0.001), on titanium by 98.77% (p = 0.001), and on stainless steel by 88.10% (p = 0.001) after 24 h. The average decrease in bacterial adherence was 95.49% compared to uncoated implants.

CONCLUSION

A coating composition comprised of 95% TiO₂-5% PDMS matrix and 10× silver carboxylate most effectively decreases adherence of S. marcescens on spinal implants. These results suggest that the application of a non-antibiotic, bactericidal coating prior to spinal surgery may prevent the adherence and proliferation of MDR S. marcescens and decrease the incidence of spinal SSI.

Non-elective and revision arthroplasty are independently associated with hip and knee prosthetic joint infection caused by Acinetobacter baumannii: a Brazilian single center observational cohort study of 98 patients

BACKGROUND

Prosthetic joint infection (PJI) caused by Acinetobacter baumannii (Ab) has become a growing concern due to its overwhelming ability to express resistance to antibiotics and produce biofilm.

AIM

This study aimed to identify independent risk factors (RFs) associated with Ab-associated PJI and their role in the treatment outcome.

METHODS

This was a single-centre, retrospective cohort study of PJI patients diagnosed between January 2014 and July 2018. A PJI diagnosis was made based upon the MSIS 2018 criteria. To estimate RFs associated with Ab-associated PJI, multivariate analyses with a level of significance of p < 0.05 were performed. To evaluate treatment failure, Kaplan-Meier analysis and log-rank test were performed.

RESULTS

Overall, 98 PJI cases were assessed, including 33 with Ab-associated PJI and 65 with PJI involving other microorganisms (non-Ab-associated PJI). Independent RFs associated with Ab-associated PJI were revision arthroplasty [odds ratio (OR) = 3.01; 95% confidence interval (CI) = 1.15-7.90; p = 0.025] and nonelective arthroplasty (OR = 2.65; 95% CI = 1.01-7.01; p = 0.049). Ab-associated PJI was also more likely than non-Ab-associated PJI to be classified as a chronic late infection (OR = 5.81; 95% CI = 2.1-16.07; p = 0.001). Ab-associated PJI was not associated with treatment failure (p = 0.557).

CONCLUSIONS

Late chronic infections, surgical revision and nonelective arthroplasty are well-known predictors of PJI but were also independently associated with Ab-associated PJI. Infections caused by Ab and surgical treatment with debridement, antibiotics and implant retention were not associated with PJI treatment failure.

TRIAL REGISTRATION

Study data supporting our results were registered with the Brazilian Registry of Clinical Trials ( https://www.ensaiosclinicos.gov.br/rg/RBR-6ft5yb/ ), an open-access virtual platform for the registration of studies on humans performed in Brazil. Registration no. RBR-6ft5yb .