The microbial biofilm composition on peripherally inserted central catheters: A comparison of polyurethane and hydrophobic catheters collected from paediatric patients

Antimicrobial Resistance and Biofilms Underlying Catheter-Related Bloodstream Coinfection by Enterobacter cloacae Complex and Candida parapsilosis

Biofilm-associated infections are a public health concern especially in the context of healthcare-associated infections such as catheter-related bloodstream infections (CRBSIs). We evaluated the biofilm formation and antimicrobials resistance (AMR) of Enterobacter cloacae complex and Candida parapsilosis co-isolated from a CRBSI patient. Antimicrobial susceptibility of central venous catheters (CVCs) and hemoculture (HC) isolates was evaluated, including whole genome sequencing (WGS) resistome analysis and evaluation of gene expression to obtain insight into their AMR determinants. Crystal violet assay was used to assess dual biofilm biomass and microscopy was used to elucidate a microorganism’s distribution within biofilms assembled on different materials. Bacteria were multidrug-resistant including resistance to colistin and beta-lactams, likely linked to the mcr-9-like phosphoethanolamine transferase and to an ACT family cephalosporin-hydrolyzing class C beta-lactamase, respectively. The R398I and Y132F mutations in the ERG11 gene and its differential expression might account for C. parapsilosis resistance to fluconazole. The phenotype of dual biofilms assembled on glass, polystyrene and polyurethane depends on the material and how biofilms were initiated by one or both pathogens. Biofilms assembled on polyurethane were denser and richer in the extracellular polymeric matrix, and microorganisms were differently distributed on the inner/outer surface of the CVC.

Stability of vancomycin hydrochloride employed in antimicrobial seal solutions of central intravenous catheters

OBJECTIVE

to verify the stability of vancomycin hydrochloride in antimicrobial seal solutions with and without association of heparin sodium according to temperature and association time.

METHOD

an experimental study designed for the analysis of hydrogenionic potential and concentration by means of high-efficiency liquid chromatography of vancomycin hydrochloride (n=06) and vancomycin hydrochloride and heparin sodium (n=06). The solutions studied were submitted to absence of light, as well as to 22°C and 37°C. Analyses in triplicate (n=192) were performed at the initial moment (T0) and three (T3), eight (T8) and 24 hours (T24) after preparation. The data were submitted to analysis of variance (p≤0.05).

RESULTS

concentration of the antimicrobial at 22°C presented a reduction (T0-T8) and a subsequent increase (T24); hydrogenionic potential decreased significantly over time. At 37°C, the concentration increased up to T3 and decreased at T24, with a reduction of hydrogenionic potential up to 24 hours. Concentration of the vancomycin hydrochloride and heparin sodium solutions varied with a reduction at 22°C, accompanied by increased hydrogenionic potential. Precipitate formation was observed by visual inspection of the vancomycin hydrochloride-heparin sodium association (T3).

CONCLUSION

pharmacological stability of vancomycin hydrochloride (5 mg/mL) and physical incompatibility with heparin sodium (100 IU/mL) were evidenced after three hours of association in the antimicrobial seal solutions studied.

Estabilidad del clorhidrato de vancomicina utilizado en soluciones de sellado antimicrobiano para catéteres intravenosos centrales

Resumen Objetivo: verificar la estabilidad del clorhidrato de vancomicina en soluciones de sellado antimicrobiano solo y combinado con heparina sódica según la temperatura y el tiempo de combinación. Método: estudio experimental diseñado para analizar el potencial de hidrógeno y la concentración por cromatografía líquida de alta resolución de soluciones de clorhidrato de vancomicina (n=06) y de clorhidrato de vancomicina y heparina sódica (n=06). Las soluciones estudiadas fueron sometidas a ausencia de luz, 22°C y 37°C. Se realizaron análisis por triplicado (n=192) en el momento inicial (T0), a las tres (T3), ocho (T8) y 24 horas (T24) después de la preparación. Los datos fueron sometidos a análisis de varianza (p≤0,05). Resultados: la concentración de antimicrobiano a 22°C mostró una reducción (T0-T8) y un posterior aumento (T24); el potencial de hidrógeno disminuyó significativamente con el tiempo. A 37°C, la concentración aumentó hasta T3 y disminuyó en T24, el potencial de hidrógeno disminuyó hasta las 24 horas. La concentración de las soluciones de clorhidrato de vancomicina y heparina sódica mostró variación con la reducción a 22°C acompañada de un aumento del potencial de hidrógeno. Mediante inspección visual se observó la formación de un precipitado al combinar clorhidrato de vancomicina y heparina sódica (T3). Conclusión: el clorhidrato de vancomicina (5 mg/ml) presentó evidencia de estabilidad farmacológica e incompatibilidad física con la heparina sódica (100 UI/ml) después de las tres horas de haberse realizado la combinación en las soluciones de sellado antimicrobiano estudiadas.

Stability of vancomycin hydrochloride employed in antimicrobial seal solutions of central intravenous catheters

Abstract Objective: to verify the stability of vancomycin hydrochloride in antimicrobial seal solutions with and without association of heparin sodium according to temperature and association time. Method: an experimental study designed for the analysis of hydrogenionic potential and concentration by means of high-efficiency liquid chromatography of vancomycin hydrochloride (n=06) and vancomycin hydrochloride and heparin sodium (n=06). The solutions studied were submitted to absence of light, as well as to 22°C and 37°C. Analyses in triplicate (n=192) were performed at the initial moment (T0) and three (T3), eight (T8) and 24 hours (T24) after preparation. The data were submitted to analysis of variance (p≤0.05). Results: concentration of the antimicrobial at 22°C presented a reduction (T0-T8) and a subsequent increase (T24); hydrogenionic potential decreased significantly over time. At 37°C, the concentration increased up to T3 and decreased at T24, with a reduction of hydrogenionic potential up to 24 hours. Concentration of the vancomycin hydrochloride and heparin sodium solutions varied with a reduction at 22°C, accompanied by increased hydrogenionic potential. Precipitate formation was observed by visual inspection of the vancomycin hydrochloride-heparin sodium association (T3). Conclusion: pharmacological stability of vancomycin hydrochloride (5 mg/mL) and physical incompatibility with heparin sodium (100 IU/mL) were evidenced after three hours of association in the antimicrobial seal solutions studied.

Biofilm reduction potential of 0.02% polyhexanide irrigation solution in several types of urethral catheters

Background

Long-term use of urethral catheters is associated with high risk of urinary tract infection (UTI) and blockage. Microbial biofilms are a common cause of catheter blockage, reducing their lifetime and significantly increasing morbidity of UTIs. A 0.02% polyhexanide irrigation solution developed for routine mechanical rinsing shows potential for bacterial decolonization of urethral catheters and has the potential to reduce or prevent biofilm formation.

Methods

Using an in vitro assay with standard market-leading types of catheters artificially contaminated with clinically relevant bacteria, assays were carried out to evaluate the biofilm reduction and prevention potential of a 0.02% polyhexanide solution versus no intervention (standard approach) and irrigation with saline solution (NaCl 0.9%). The efficiency of decolonization was measured through microbial plate count and membrane filtration.

Results

Irrigation using a 0.02% polyhexanide solution is suitable for the decolonization of a variety of transurethral catheters. The effect observed is significant compared to irrigation with 0.9% saline solution (p = 0.002) or no treatment (p = 0.011). No significant difference was found between irrigation with 0.9% saline solution and no treatment (p = 0.74).

Conclusions

A 0.02% polyhexanide solution is able to reduce bacterial biofilm from catheters artificially contaminated with clinically relevant bacteria in vitro. The data shows a reduction of the viability of thick bacterial biofilms in a variety of commercially available urinary catheters made from silicone, latex-free silicone, hydrogel-coated silicone and PVC. Further research is required to evaluate the long-term tolerability and efficacy of polyhexanide in clinical practice.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12894-021-00826-3.