Development of an anti-infective urinary catheter composed of polyvinyl alcohol/sodium alginate/methylcellulose/polyethylene glycol by using a pressure-assisted 3D-printing technique.

Catheter-associated urinary tract infections (CAUTI) are a common complication associated with catheterization, leading to urosepsis, bacteriuria, and septicaemia. The present work focuses on 3D printing a urinary catheter with anti-infective properties using various concentrations of polyvinyl alcohol (PVA, e.g., 6-8 %), sodium alginate (NaAlg, e.g. 1-4 %), methylcellulose (MC, 5 %), polyethylene glycol (PEG, 5 %) impregnated with secnidazole, an antibiotic acting against Gram-negative bacteria. To produce suitable polymer ink for Pressure Assisted Microsyringe (PAM) 3D printing, the cross-linked between NaAlg and calcium chloride is necessary to prepare the catheter. The optimised catheter was found to have an outer diameter of 5 mm, an inner diameter of 3.5 mm, and a length of the catheter of 50 mm. The analysis by various methods confirms the successful incorporation of secnidazole in the 3D-printed catheter. A drug-loaded/coated catheter showed an initial drug release of 79 % following a sustained release to reach 100 % within 5 h. Weibull model fits well with the drug release data. The release models suggest the Quasi-Fickian diffusion mechanism from the system. Moreover, the secnidazole 3D printed catheter disrupted biofilms and suppressed all the Quorum sensing mediated virulence factors of two important keystone pathogens causing urinary tract infections.

Biofilm-forming fluconazole-resistant Candida auris causing vulvovaginal candidiasis in an immunocompetent patient: A case report

Rationale: Candida auris is a potential emerging pathogen among Candida and causes serious health threats globally. Patient concerns: We reported a case of vulvovaginal candidiasis caused by Candida auris. A 26-year-old female presented with complaints of vaginal discharge, itching and low back pain. Diagnosis: High vaginal swab culture yielded Candida. The strain was confirmed as Candida auris by amplification and sequencing the internal transcribed spacer region. Antifungal susceptibility testing revealed that the isolate was resistant to fluconazole, amphotericin B and clotrimazole and susceptible to ketoconazole and nystatin. The isolate also exhibited biofilm forming ability. Interventions: Her symptoms did not subside with initial management with fluconazole and clotrimazole. Later, she was started on ketoconazole therapy. The patient responded well to ketoconazole. Outcome and lessons: To the best of our knowledge, this is the first report about the presence of a drug resistant biofilm forming Candida auris strain isolated from a vaginal swab sample from Chennai area. Biofilm forming ability might contribute to its drug resistance. Nucleic acid analysis helps in rapid and accurate identification of such rare species.

Suppressing the phenotypic virulence factors of Uropathogenic Escherichia coli using marine polysaccharide.

Uropathogenic Escherichia coli (UPEC) is one of the keystone pathogen that cause 80-90% of community acquired urinary tract infections (UTIs) and Catheter associated urinary tract infections (CAUTIs). Pathogenicity and ability of UPEC to colonize the bladder majorly relies on the expression of phenotypic virulence factors like flagella, pili, curli, and non pilus adhesion. Pathogens that colonize on the indwelling medical devices are able to communicate using quorum sensing (QS) signals. QS Plays a vital role in coordinating biofilm formation which results in the bacterial cells encased inside an extracellular polymeric substance (EPS). Chitosan is a marine polysaccharide which is known for its antibacterial activity. In the present study we investigated the ability of chitosan extracted from marine biowaste to mitigate the QS mediated biofilm formation in UPEC. Extracted chitosan (EC) and Commercial chitosan (CC) showed percentage inhibition of 80-85% and 60-75% respectively on young biofilm inhibition and preformed biofilm disruption. EC and CC were assessed for its ability to suppress QS mediated virulence in UPEC. Hemolysis assay showed a percentage inhibition of 79% against EC. Both chitosan showed profound activity to suppress the phenotypic virulence factors like swarming motility which is mediated by type I pili and colony morphology assay showed repression in cellulose production in UPEC. Furthermore, Real-Time PCR confirmed the ability of EC to down regulate the virulent genes which are responsible for invasion in UPEC. Accordingly, the current study foresees the quorum sensing inhibiting (QSI) potential of chitosan extracted from marine biowaste which offers an antibiotic free approach to combat UTI caused by UPEC.