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Biomedical subjects

M D Mansouri

Publications and source records attributed to M D Mansouri.

7 recordsLinked to original sources

Antifungal activity of antimicrobial-impregnated devices.

The in-vitro and in-vivo efficacy against Candida albicans and Candida krusei of devices impregnated with chlorhexidine and chloroxylenol was examined. The impregnated devices produced large zones of inhibition against both organisms (mean size, 39 mm and 38 mm, respectively). In a rabbit model in which segments of silicone catheters were placed percutaneously, non-impregnated devices were twice as likely as impregnated devices to become colonised with either C. albicans or C. krusei. Impregnated devices also had significantly lower colony counts of C. albicans (58 vs. 1361 CFU; p 0.008) and C. krusei (19 vs. 764 CFU; p 0.008).

Animals↗

Dalbavancin compared with vancomycin for prevention of Staphylococcus aureus colonization of devices in vivo.

OBJECTIVES: Although active against free-floating bacteria, vancomycin displays a poor activity against organisms embedded within the biofilm surrounding implanted devices. Dalbavancin is a novel glycopeptide antibiotic with strong activity against staphylococci and a long half-life that allows for once-a-week dosing. The objective of this animal study was to examine the ability of dalbavancin and vancomycin to prevent Staphylococcus aureus colonization of devices. METHODS: Twelve rabbits were randomized, in three groups of four each, to receive intravenous injections of dalbavancin, vancomycin or normal saline (control). Eight polyurethane catheter segments were subcutaneously implanted in the back of each rabbit, then inoculated with S. aureus. Rabbits were sacrificed a week later and explanted devices were cultured. RESULTS: The rates of device colonization were comparable in the vancomycin (53%) and control (47%) groups, whereas only 28% of devices in the dalbavancin group became colonized. There was a trend (although not statistically significant) toward a lower rate of device colonization following receipt of dalbavancin vs. vancomycin (P = 0.07) or saline (P = 0.02). CONCLUSIONS: The demonstrated efficacy of dalbavancin in this animal study suggest that this novel antibiotic may have an important role in the prevention and treatment of device-related infection.

Animals↗

Antimicrobial activity of antiseptic-coated orthopaedic devices.

Antimicrobial coating of medical devices, including fracture fixation devices, has evolved as a potentially effective method for preventing device-related infections. We examined the in vitro antimicrobial activity of titanium cylinders coated with the antiseptic combination of chlorhexidine and chloroxylenol. The coated devices provided zones of inhibition against Staphylococcus epidermidis, S. aureus, Pseudomonas aeruginosa, Escherichia coli and Candida albicans, at baseline and up to 8 weeks after incubation of the coated cylinders in human serum at 37 degrees C. This durable antimicrobial activity was attributed to the relatively slow leaching of chlorhexidine and chloroxylenol from the coated cylinders as measured by high-performance liquid chromatography. These results suggest that antiseptic-coated orthopaedic devices may provide broad-spectrum and durable antimicrobial protection against device-related infection.

Anti-Infective Agents, Local↗

Identification of a Klebsiella pneumoniae strain associated with nosocomial urinary tract infection.

To differentiate between relapse of infection and reinfection of the urinary tract due to Klebsiella pneumoniae, 33 K. pneumoniae isolates collected from 20 patients with spinal cord injury (SCI) over 2 years were typed by genomic fingerprinting by repetitive-element PCR. Clinical isolates obtained from the same patients with recurrent episodes of urinary tract infection (UTI) revealed identical genomic fingerprints indicating relapse of UTI due to K. pneumoniae, despite appropriate antibiotic therapy. Seventeen isolates obtained from 8 of the 20 SCI patients shared a common genotype, termed RD6. Among non-SCI patients residing in other nursing units, the RD6 genotype was found in 5 of 10 patients with K. pneumoniae UTI but in only 1 of 20 patients with K. pneumoniae infection that did not involve the urinary tract, suggesting a strong association of this genotype with UTI. All RD6 isolates exhibited strong adherence (> or =50 adherent bacteria per cell) to HEp-2 cells, whereas other K. pneumoniae isolates generally did not adhere to or adhered very weakly to HEp-2 cells (< or =5 adherent bacteria per cell). Adherence was inhibited either by 4% D-mannose or by anti-type 1 fimbrial rabbit serum. These results suggest that the capacity of K. pneumoniae RD6 isolates to cause UTI may be mediated by its striking adherence to mammalian cells.

Antibodies, Blocking↗