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Biomedical subjects

Rabih O Darouiche

Publications and source records attributed to Rabih O Darouiche.

At least 19 recordsLinked to original sources

Combination of tigecycline and N-acetylcysteine reduces biofilm-embedded bacteria on vascular catheters.

To assess the efficacy of an antibiofilm/antimicrobial agent combination, we incubated catheter segments colonized with one of six studied bacterial organisms in N-acetylcysteine, tigecycline, N-acetylcysteine-tigecycline, or saline. Segments were washed, sonicated, and cultured. N-acetylcysteine-tigecycline significantly decreased all viable biofilm-associated bacteria and was synergistic for methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis.

Acetylcysteine↗

Vancomycin-induced elevation of liver enzyme levels.

OBJECTIVE: To report a case of oral vancomycin-induced elevation of liver enzyme levels. CASE SUMMARY: A 57-year-old man with multiple medical conditions requiring systemic antibiotic therapy developed numerous Clostridium difficile-associated enterocolitis episodes. The patient did not respond adequately to oral metronidazole, as evidenced by his continuing diarrhea. He was treated with oral vancomycin on 5 separate occasions (with doses from 125 to 500 mg/day), each of which resulted in significant elevations in alanine aminotransferase (to 371 U/L) and aspartate aminotransferase (to 203 U/L) levels. The elevations resolved on each occasion with discontinuation of vancomycin. DISCUSSION: Vancomycin, a glycopeptide antibiotic, has primary activity against gram-positive bacteria. Oral vancomycin can be used for the treatment of C. difficile-associated enterocolitis in patients who fail to respond to or are intolerant to metronidazole therapy. Oral vancomycin has very poor bioavailability and, as of May 4, 2006, has not been associated with hepatic toxicity. Inflammatory bowel disease processes can result in increased absorption of oral vancomycin. CONCLUSIONS: This is the first reported case of oral vancomycin-induced elevation of hepatic enzyme levels. Use of the Naranjo probability scale indicated that this was a probable adverse drug-associated event.

Alanine Transaminase↗

Impact of StatLock securing device on symptomatic catheter-related urinary tract infection: a prospective, randomized, multicenter clinical trial.

BACKGROUND: The objective of this study was to assess the impact of using the StatLock securing device on symptomatic catheter-related urinary tract infection (UTI). METHODS: In this prospective, randomized, multicenter clinical trial, adult patients with spinal cord injury or dysfunction because of multiple sclerosis were randomized to have their indwelling bladder catheters secured in place by using the StatLock device (experimental group) versus preexisting methods (control group that included tape, Velcro strap, CathSecure, or none). Patients were monitored for the development of symptomatic UTI within the subsequent period of 8 weeks. RESULTS: Of a total of 127 enrolled patients, 118 (60 in the experimental group and 58 in the control group) were evaluable. The 2 groups of evaluable patients were comparable in terms of clinical characteristics and risk factors for infection. Symptomatic UTI was diagnosed in 8 of 60 (13.3%) patients in the experimental group versus 14 of 58 (24.1%) patients in the control group (P = .16; RR = 0.55, 95% confidence interval: 0.25-1.22). CONCLUSION: Although the trial size precluded the demonstration of statistically significant differences, the finding of a 45% reduction in the rate of symptomatic UTI in patients who received the StatLock securing device is clinically relevant and prompts further investigations.

Adolescent↗

Bacterial interference for prevention of urinary tract infection: a prospective, randomized, placebo-controlled, double-blind pilot trial.

This prospective, randomized, placebo-controlled, double-blind pilot trial examined the efficacy of bacterial interference in preventing urinary tract infection (UTI) in 27 patients with spinal cord injury. Patients whose bladders became colonized with Escherichia coli 83972 were half as likely (P=.01) than noncolonized patients to develop UTI during the subsequent year.

Adult↗

Colicins prevent colonization of urinary catheters.

OBJECTIVES: Natural microbial defence systems, such as bacteriocins, may be a novel means to prevent catheter-associated urinary tract infection. We investigated in vitro whether a colicin-expressing strain of Escherichia coli could prevent urinary catheter colonization by a colicin-susceptible, uropathgenic strain of E. coli. METHODS: Segments of urinary catheter were inoculated with colicin-producing E. coli K-12 and then exposed to either colicin-susceptible E. coli (a uropathogenic clinical isolate) or colicin-resistant E. coli (derived from the susceptible clinical isolate). Catheters were then incubated overnight, rinsed and sonicated. RESULTS: The presence of colicin-producing E. coli K-12 on the catheter surface completely prevented catheter colonization by colicin-susceptible E. coli but not by resistant E. coli. The colicin-susceptible strain but not the colicin-resistant strain also disappeared from broth cultures in the presence of colicin-producing E. coli K-12. CONCLUSIONS: The observed inhibition of catheter colonization by the uropathogenic clinical isolate of E. coli can be attributed to the presence of a colicin-producing strain of E. coli on the catheter surface. Bacteriocin production by a non-pathogenic organism may have clinical applicability as a means to prevent catheter-associated urinary tract infection.

Catheters, Indwelling↗

Ventriculoperitoneal shunt infection due to Serratia marcescens.

Serratia marcescens is an opportunistic Gram-negative bacillus that is most often associated with infections of the respiratory tract, urinary tract, wounds, and bloodstream. Infections of the central nervous system (CNS) with this pathogen are exceedingly infrequent. Even more rare is the association of S. marcescens with infections of ventriculoperitoneal (VP) shunts. To the best of our knowledge, we describe in this report not only the first case of a VP shunt infection by S. marcescens in an adult, but also the first case of a VP shunt infection by this organism in the absence of bowel perforation.

Abdominal Abscess↗

Catheter-related vancomycin-resistant Enterococcus faecium bacteremia: clinical and molecular epidemiology.

OBJECTIVE: To study the clinical and molecular epidemiology of vancomycin-resistant Enterococcus faecium organisms causing catheter-related bacteremia in patients with cancer. DESIGN: Retrospective case-control study. SETTING: University of Texas M. D. Anderson Cancer Center, a tertiary-care hospital in Houston, Texas. PATIENTS: Case-patients were patients with cancer who had catheter-related vancomycin-resistant E. faecium bacteremia and control-patients were patients with cancer and vancomycin-resistant E. faecium gastrointestinal colonization without infection. RESULTS: Ten case-patients with catheter-related vancomycin-resistant E. faecium bacteremia were compared with 30 control-patients with gastrointestinal colonization by vancomycin-resistant E. faecium. Patients with catheter-related vancomycin-resistant E. faecium bacteremia were more likely to have required mechanical ventilation (P < .01), received total parenteral nutrition (P < .01), and had polyurethane catheters (P < .01) inserted in the femoral vein (P = .01). With the use of pulsed-field gel electrophoresis, 4 of the 10 catheter-related vancomycin-resistant E. faecium bacteremia isolates were genetically indistinguishable, whereas only 2 of the 30 control vancomycin-resistant E. faecium isolates displayed this same DNA pattern (P = .03). CONCLUSION: This study suggests that catheter-related vancomycin-resistant E. faecium bacteremia occurs more frequently in patients who receive total parenteral nutrition, mechanical ventilation, and femoral catheters.

Adult↗

Prevention of catheter-associated urinary tract infection.

PURPOSE OF REVIEW: The underlying cause of catheter-associated urinary tract infection is biofilm formation by uropathogens on the urinary catheter. Biofilm is a relatively new concept in medicine, and current measures to prevent biofilm formation are inadequate. Considerable work is being done in this area, but little clinical progress has been made. The purpose of this review is to analyze recent publications concerning prevention of catheter-associated urinary tract infection. RECENT FINDINGS: Several recent studies have elucidated aspects of biofilm formation in catheter-associated urinary tract infection. Other researchers are working on methods to disrupt biofilm formation on catheter surfaces. At the same time, the magnitude of the problem of catheter-associated urinary tract infection has increased awareness of the effectiveness of basic infection control measures. A modern approach to infection control may include computerized ordering systems that minimize unnecessary days of catheterization. Finally, consumption of cranberry juice products and bacterial interference are two novel approaches to urinary tract infection prevention. SUMMARY: Biofilm-disrupting strategies offer promise for the future but have little immediate applicability. Implementation of infection control measures to improve catheter function and remove unnecessary catheters can be done at the present time. In general, prevention of catheter-associated urinary tract infection remains an elusive goal. More basic research at the level of pathogenesis is needed so that novel strategies can be designed.

Biofilms↗

Comparison of antimicrobial impregnation with tunneling of long-term central venous catheters: a randomized controlled trial.

OBJECTIVE: We sought to compare the impact of antimicrobial impregnation to that of tunneling of long-term central venous catheters on the rates of catheter colonization and catheter-related bloodstream infection. SUMMARY BACKGROUND DATA: Tunneling of catheters constitutes a standard of care for preventing infections associated with long-term vascular access. Although antimicrobial coating of short-term central venous catheters has been demonstrated to protect against catheter-related bloodstream infection, the applicability of this preventive approach to long-term vascular access has not been established. METHODS: A prospective, randomized clinical trial in 7 university-affiliated hospitals of adult patients who required a vascular access for > or = 2 weeks. Patients were randomized to receive a silicone central venous catheter that was either impregnated with minocycline and rifampin or tunneled. The occurrence of catheter colonization and catheter-related bloodstream infection was determined. RESULTS: Of a total of 351 inserted catheters, 346 (186 antimicrobial-impregnated and 160 tunneled) were analyzed for catheter-related bloodstream infection. Clinical characteristics were comparable in the 2 study groups, but the antimicrobial-impregnated catheters remained in place for a shorter period of time (mean, 30.2 versus 43.8 days). Antimicrobial-impregnated catheters were as likely to be colonized as tunneled catheters (7.9 versus 6.3 per 1000 catheter-days). Bloodstream infection was 4 times less likely to originate from antimicrobial-impregnated than from tunneled catheters (0.36 versus 1.43 per 1000 catheter-days). CONCLUSIONS: Antimicrobial impregnation of long-term central venous catheters may help obviate the need for tunneling of catheters.

Anti-Bacterial Agents↗

Catheter-associated infections: pathogenesis affects prevention.

Intravascular catheters and urinary catheters are the 2 most commonly inserted medical devices in the United States, and they are likewise the two most common causes of nosocomially acquired bloodstream infection. Biofilm formation on the surfaces of indwelling catheters is central to the pathogenesis of infection of both types of catheters. The cornerstone to any preventive strategy of intravascular catheter infections is strict attention to infection control practices. Antimicrobial-impregnated intravascular catheters are a useful adjunction to infection control measures. Prevention of urinary catheter-associated infection is hindered by the numbers and types of organisms present in the periurethral area as well as by the typically longer duration of catheter placement. Antimicrobial agents in general have not been effective in preventing catheter-associated urinary tract infection in persons with long-term, indwelling urethral catheters. Preventive strategies that avoid the use of antimicrobial agents may be necessary in this population.

Anti-Infective Agents, Local↗

In vitro activity and in vivo efficacy of antimicrobial-coated vascular grafts.

The serious medical consequences and costly management of infections associated with vascular grafts have prompted an expanding interest in examining the preventive efficacy of antimicrobial-coated vascular grafts. The purpose of antimicrobial coating of vascular grafts is to reduce bacterial colonization of the device and, hopefully, the occurrence of clinical infection. In this study we demonstrated that expanded-polytetrafluoroethylene vascular grafts coated with minocycline and rifampin provide broad-spectrum antimicrobial activity in vitro, as reflected by zones of inhibition, against Staphylococcus epidermidis, S. aureus, Enterococcus faecium, and Pseudomonas aeruginosa. We also showed in a rabbit model that subcutaneously placed minocycline/rifampin-coated vascular grafts have lower rates of staphylococcal device colonization (1/24 = 4% vs. 8/30 = 27%, p = 0.033) and device-related infection (0/24 = 0% vs. 6/30 = 20%, p = 0.028) than uncoated grafts. These promising results encourage the clinical evaluation of vascular grafts coated with minocycline and rifampin.

Animals↗

Role of biofilm in catheter-associated urinary tract infection.

The predominant form of life for the majority of microorganisms in any hydrated biologic system is a cooperative community termed a "biofilm." A biofilm on an indwelling urinary catheter consists of adherent microorganisms, their extracellular products, and host components deposited on the catheter. The biofilm mode of life conveys a survival advantage to the microorganisms associated with it and, thus, biofilm on urinary catheters results in persistent infections that are resistant to antimicrobial therapy. Because chronic catheterization leads almost inevitably to bacteriuria, routine treatment of asymptomatic bacteriuria in persons who are catheterized is not recommended. When symptoms of a urinary tract infection develop in a person who is catheterized, changing the catheter before collecting urine improves the accuracy of urine culture results. Changing the catheter may also improve the response to antibiotic therapy by removing the biofilm that probably contains the infecting organisms and that can serve as a nidus for reinfection. Currently, no proven effective strategies exist for prevention of catheter-associated urinary tract infection in persons who are chronically catheterized.

Biofilms↗

Inactivated influenza vaccination for people with spinal cord injury.

OBJECTIVE: To examine the antibody responses of people with spinal cord injury (SCI) to the commercially available trivalent influenza vaccine. DESIGN: Prospective trial of patients and controls. SETTING: Veterans Affairs medical center. PARTICIPANTS: Forty people with SCI and 40 able-bodied subjects. INTERVENTION: Intramuscular administration of inactivated influenza vaccine. MAIN OUTCOME MEASURES: Antibody responses were determined by using the standard hemagglutination-inhibition test before and 4 weeks after vaccination. Serum antibody responses were assessed as follows: (1) percentage of each cohort achieving a 4-fold or greater rise in antibody titer, (2) percentage of each cohort achieving a postvaccination antibody titer of 32 or more, and (3) postvaccination geometric mean antibody titers. RESULTS: The serum antibody responses to each vaccine antigen were similar for the SCI and the control cohorts for the 3 outcomes. Neither the time since injury (</=1 y vs >1 y) nor the level of injury (paraplegia vs quadriplegia) affected the vaccine antibody responses in the SCI cohort. Subjects older than 65 years had lower postvaccination serum antibody levels than those younger than 65 years ( P <.05). CONCLUSIONS: People with SCI responded to influenza vaccination in a manner similar to able-bodied subjects and would be expected to benefit from vaccination.

Adult↗

Spinal epidural abscess presenting as intra-abdominal pathology: a case report and literature review.

Spinal epidural abscess is a rare infectious disease. However, if left unrecognized and untreated, the clinical outcome of spinal epidural abscess can be devastating. Correctly diagnosing a spinal epidural abscess in a timely fashion is often difficult, particularly if the clinician does not actively consider the diagnosis. The most common presenting symptoms of spinal epidural abscess include backache, radicular pain, weakness, and sensory deficits. However, early in its course, spinal epidural abscess can also present with vague and nondescript manifestations. In this report, we describe a case of spinal epidural abscess presenting as abdominal pain, and review the literature describing other cases of spinal epidural abscess presenting as intra-abdominal pathology.

Abdomen, Acute↗