A study of the skin flora of spinal cord injured patients

Proteeae Groin Skin Carriage in Ambulatory Geriatric Outpatients

Aerobic gram-negative bacillus (AGNB) groin skin carriage was prospectively studied in ambulatory geriatric outpatients: 42 from three nursing homes and 44 from private homes. Initially, 12 (28.6%) Proteeae carriers were in the former group and 3 (6.8%) were in the latter (P =0.01). At one year, 6 of 7 surviving nursing home carriers remained Proteeae carriers while none from private homes remained carriers (P =0.007). The annual prevalence of Proteeae carriage was 14 (33.3%) in nursing homes and 4 (9.1%) in private homes (P =0.008); of non-Proteeae AGNB carriage, the annual prevalence was 2 (4.8%) and 4 (11.4%), respectively. Nursing home subjects had similar initial health characteristics; however, by one year, 5 of 12 carriers in contrast to 3 of 30 noncarriers were dead of chronic disease (P =0.03). These nursing homes included persons with chronic diseases that apparently facilitated Proteeae carriage. Urethral catheters, skin ulcers, and recent antibiotics were not factors.

Proteeae Groin Skin Carriage Among Nursing Home Resident—Resistance to Antiseptics

Proteeae carriage was evaluated in groin skin carriers following vigorous antiseptic application. Three Proteus mirabilis carriers were treated with 60% isopropyl alcohol or 4% chlorhexidine, observed to prevent skin contact, and then recultured; at four and eight hours P mirabilis numbers remained undiminished. Ten Proteeae carriers received a series of nine body baths with soap, chlorhexidine, and 0.75% povidone-iodine plus three cefazolin injections over 16 to 34 days; cumulative treatments failed to clear seven carriers. Within three months, all were again carriers. Proteeae carriers also had affinity for groin carriage of various aerobic gram-negative bacilli (AGNB) including cefazolin-resistant strains. In seven subjects, more than one AGNB species were recovered shortly after applying an antiseptic. Proteeae groin skin carriage appears to reflect a major change in the nature of resident bacteria on intact groin skin.

Nerve-derived transmitters including peptides influence cutaneous immunology

Clinical observations suggest that the nervous and immune systems are closely related. For example, inflammatory skin disorders; such as psoriasis, atopic dermatitis, rosacea and acne; are widely believed to be exacerbated by stress. A growing body of research now suggests that neuropeptides and neurotransmitters serve as a link between these two systems. Neuropeptides and neurotransmitters are released by nerves innervating the skin to influence important actors of the immune system, such as Langerhans cells and mast cells, which are located within close anatomic proximity. Catecholamines and other sympathetic transmitters that are released in response to activation of the sympathetic nervous system are also able to reach the skin and affect immune cells. Neuropeptides appear to direct the outcome of Langerhans cell antigen presentation with regard to the subtypes of Th cells generated and neuropeptides induce the degranulation of mast cells, among other effects. Additionally, endothelial cells, which release many inflammatory mediators and express cell surface molecules that allow leukocytes to exit the bloodstream, appear to be regulated by certain neuropeptides and transmitters. This review focuses on the evidence that products of nerves have important regulatory activities on antigen presentation, mast cell function and endothelial cell biology. These activities are highly likely to have clinical and therapeutic relevance.

Pathogenesis of urinary tract infections: a review

Pathogenesis of urinary tract infections (UTIs) is not well-understood. In this paper, we review the current understanding of UTIs, particularly in relationship to individuals using intermittent catheterization. Relationships exist between the human host, infectious agent and the environment. In the human host, the urethra connects the bladder to potential infectious agents on the perineum. A high-pressure zone exists within the urethra at a point where the urethra passes through the urogenital diaphragm. This zone creates a natural barrier to ascent of organisms colonized in the distal urethra and the bladder itself has natural defences against invading organisms. The interaction of host defences with bacteria (infectious agent) determines whether or not the bacteria persist. A small number of bacteria and some types of bacteria are controlled more effectively by natural bladder defence mechanisms and frequent bladder emptying than a large number of bacteria. Escherichia coli, coliforms and enterococci are considered common bacterial causes of UTIs and are found in high numbers on the perineum. Intermittent catheterization is an effective way of bladder emptying but as an invasive procedure it remains a risk factor in the development of UTI.

Pathogenesis of bacteriuria and infection in the spinal cord injured patient

Spinal cord injury (SCI) produces profound alterations in lower urinary tract function. Incontinence, elevated intravesical pressure, reflux, stones, and neurological obstruction, commonly found in the spinal cord-injured population, increase the risk of urinary infection. The overall rate of urinary infection in SCI patient is about 2.5 episodes per patient per year. Despite improved methods of treatment, urinary tract morbidity still ranks as the second leading cause of death in the SCI patient.SCI removes the ability of the pontine micturition center and higher centers in the brain to inhibit, control, or coordinate the activity of the vesicourethral unit. As a result, a patient with complete quadriplegia is typically unaware of bladder activity. Bladder contraction is accompanied by vesicosphincter dyssynergia instead of sphincter relaxation. It is widely accepted that intermittent catheterization, when compared with indwelling catheters, reduces the risk of urinary tract infection (UTI) in SCI patients and is the preferred method of bladder drainage in this patient population. Attempts at eliminating bacteriuria associated with indwelling or intermittent catheters have generally been unsuccessful. There is now appreciation of the fact that a creeping adherent biofilm of bacteria frequently ascends through the luminal and external surfaces of an indwelling catheter, often within 8 to 24 hours, leading to bacterial adherence to the bladder surface and correlating with symptomatic infection. The use of antimicrobial agents to clear or prevent bacteriuria in patients on indwelling or intermittent catheterization has had mixed success. Treatment for asymptomatic bacteriuria in SCI patients remains controversial. SCI patients with symptomatic urinary infections should be treated with the most specific, narrowest spectrum antibiotics available for the shortest possible time. Guidelines for selecting antimicrobial agents in SCI patients are similar to guidelines for the treatment of complicated urinary infections in the general population. Characteristics of the quinolones make them well suited to treating UTI in the SCI patient.

Catheter-associated urinary infection in kidney post-transplant patients

CONTEXT

There is still controversy as to the use and dosage of antimicrobial prophylaxis of the urinary infection associated with urethral catheterization in the post renal transplant period.

OBJECTIVE

To determine whether patients develop urinary infection during short-term urethral catheterization after renal transplant without routine antimicrobial prophylaxis.

DESIGN

Prospective study.

SETTING

Kidney Transplantation Unit.

SAMPLE

20 patients submitted to non-complicated kidney transplant, with a normal urinary tract and no risk factors present regarding urinary infection. Aged 15 to 65 years.

MAIN MEASUREMENTS

Before the transplant, material from the urethral meatus and urine were collected for culture. After the transplant, in the period during which the patient was with short-term urethral catheterization (4 to 5 days), material from the urethral meatus and urine from the bladder and the collecting bag were taken daily from all recipients for culture.

RESULTS

There was a predominance of coagulase-negative Staphylococcus and S. viridans in the normal urethral meatus flora and in the first two days of urethral catheterization. After the second day, there was a predominance of E. coli and E. faecalis. Urinary infection did not occur during the period of urethral catheterization. In the follow up only one female patient (7%) had asymptomatic bacteriuria caused by E.coli after the withdrawal of the urethral catheter.

CONCLUSIONS

Infection urinary does not occur during the period of urethral catheterization in kidney post-transplant patients. Thus, antimicrobial prophylaxis is not recommended for these patients to prevent urinary infection.

Prospective surveillance for antibiotic-resistant organisms in patients with spinal cord injury admitted to an acute rehabilitation unit

BACKGROUND

The objective of this study was to evaluate the epidemiology of antibiotic-resistant organisms among patients with spinal cord injury admitted to an acute rehabilitation unit for the first time.

METHODS

After informed consent, 63 patients with spinal cord injury admitted to an acute rehabilitation unit between January 1997 and July 1998 had surveillance cultures (nares, urine, wounds or ulcers, and perineum) done on admission and every 2 weeks thereafter until discharge or as long as 6 weeks after admission.

RESULTS

Of the 4 surveillance sites, perineal cultures most commonly grew one or more potential pathogens; however, antibiotic-resistant organisms were most often isolated from wounds or ulcers and least often in urine cultures. Staphylococcus aureus (methicillin-sensitive plus methicillin-resistant) and enterococci represented 44% of all organisms isolated in surveillance cultures. Methicillin-resistant S aureus was the most common resistant organism isolated. Less than 30% of the gram-negative bacilli isolated were considered antibiotic-resistant strains. Nosocomial infection as a result of any resistant organism was infrequent. After adjusting for various confounding factors in a logistic regression model, only the presence of a pressure ulcer predicted carriage of any resistant organism on admission to the rehabilitation unit. Acquisition of a resistant organism after admission to the unit at one or more surveillance sites occurred in 8 (22%) of 36 patients not colonized on admission.

CONCLUSIONS

Methicillin-resistant S aureus was the most common resistant organism colonizing patients with spinal cord injury at the time of admission to an acute rehabilitation unit and throughout their stay. However, acquisition of any resistant organism after admission was uncommon on this unit, which used Standard Precautions in the routine care of patients. These findings have implications for the type of isolation procedures on acute rehabilitation units. The low rate of acquisition and infection with MRSA after admission argues against attempts at eradication as a method of control.

Antimicrobial resistance in gram-negative bacteria isolated from the urinary tract in community-residing persons with spinal cord injury

OBJECTIVE

To assess the epidemiology of antimicrobial resistance among community-residing persons with spinal cord injury (SCI).

DESIGN

Retrospective analysis of existing data.

SETTING

Data were obtained from persons with SCI attending clinic for annual examinations.

PARTICIPANTS

Two hundred eighty-seven SCI outpatients.

INTERVENTION

None.

MAIN OUTCOME MEASURE

Occurrence of bacteriuria with gram-negative organisms demonstrating resistance to antimicrobial agents in 2 or more classes.

RESULTS

There were 706 gram-negative isolates from 444 urine specimens. Resistance to drugs in 2 or more classes occurred in 33% of bacterial isolates, but did not significantly increase in frequency among those injured for longer periods or more severely. Significantly higher rates of multidrug-resistant bacteria occurred in specimens from males, younger age group (< or =45 yrs), and persons with indwelling and condom catheters.

CONCLUSIONS

Antimicrobial resistance in outpatients with SCI is common and is related to widespread use of specific drugs, type of bladder management, and other host factors.

Eradication of urinary tract infection following spinal cord injury

A prospective study to evaluate the microbiological efficacy of antimicrobial treatment for urinary tract infection (UTI) was performed in 64 catheter-free spinal cord injured (SCI) patients who were visited monthly by a public health nurse who collected urine for culture and urinalysis. Patients also mailed urine dip slides for weekly bacterial counts. UTI was defined as a culture yielding > or = 100,000 colonies/ml. Treatment was given to asymptomatic patients only if pyuria (> or = 10 urinary leukocytes/high powered microscopic field) was present. Initial treatment was for 7-14 days (group 1). When it became apparent during the study that eradication was difficult and relapse or reinfection frequently occurred within a short time after cessation of antibiotic, a second treatment course of > or = 28 days (group 2) was given. By the end of the study, in which all patients were followed for a minimum of 30 days post treatment, 39/42 (93%) cases in group 1 and 11/13 (85%) in group 2 who had initial eradication, had relapsed or become reinfected. The median number of days and standard error for group 1 to relapse or become reinfected was 16 +/- 2.5, and for group 2 it was 27 +/- 6. Development of drug resistance was documented when bacteria isolated prior to any treatment were compared with strains isolated after > or = 28 days of antibiotics. In this study, urine sterility was achieved in a minority of treated UTIs and was relatively short lived.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology and risk factors for urinary tract infection following spinal cord injury

A prospective study was performed to quantitate frequency and evaluate risk factors for urinary tract infection (UTI) in 64 catheter-free spinal cord injury (SCI) patients who were visited monthly in their homes for up to 1 year by a public health nurse who performed a physical examination and collected urine for culture and urinalysis. Patients also mailed in urine dip slides weekly. UTI was defined as > or = 100,000 CFU/mL. Of 406 UTIs evaluated, 111 (27%) were asymptomatic, whereas 295 (73%) evidenced some sign or symptom possibly referable to the urinary tract. Fever and chills occurred in 43 (11%) episodes. Incidence of UTI overall was 18.4 episodes per person-year at risk whereas the rate for those associated with fever and chills was 1.82 episodes per person-year at risk. Prevalence of UTI was 57.4%. Pyuria was significantly associated with the occurrence of fever and chills (p < 0.0001), with gram-negative bacterial species being relatively more pyogenic than gram-positive species. Demographic and behavioral factors shown to correlate with risk for UTI by rate ratios and 95% confidence intervals were: black ethnicity, poor personal hygiene, and less-than-daily condom catheter changes. Racial difference was observed independently of the other two variables. Bladder drainage method, age, years since injury, income, education, sex, neurologic level, and administration of prophylactic antibiotics were not correlated with increased risk of UTI. This study provides new data regarding characteristics and frequency of UTI following SCI as well as risk factors that influence its development.

Virulence factors in Escherichia coli from urinary tract infections in patients with spinal injuries

A collection of 70 strains of Escherichia coli from urinary tract infections in spine-injured patients undergoing long-term bladder catheterization were tested for characteristics that have been associated with the ability to produce pyelonephritis. The incidence of the virulence factors were: mannose-resistant haemagglutinins (30%), P-fimbriae (17%), haemolysin (27%), K-antigens (28%) and aerobactin (by bioassay 33%, by gene probe 39%). Only 54% of the strains belonged to the O-serotypes usually associated with urinary tract infections. E. coli carrying the full complement of virulence factors were rare in the urinary tract of the spinal patients and were not associated with episodes of symptomatic pyelonephritis. It is clear that the neuropathic bladder and the presence of the catheter permits a wide variety of bacterial types to colonize the urinary tract and cause infection of the kidney. The identification of host markers rather than bacterial factors is suggested as a more fruitful approach to the early detection of cases likely to progress to pyelonephritis in this group of patients.

Correlation of bacteriological flora of the urethra, glans and perineum with organisms causing urinary tract infection in the spinal injured male patient

Positive urine cultures are common and often asymptomatic in the male spinal injured patient performing self clean intermittent catheterisation. It is possible that the positive urine cultures result from contamination from the colonised urethra at the time of catheterisation. This contamination could result in true infection of the bladder urine or yield false positive results, explaining the frequently seen asymptomatic cases. In a prospective study positive urine cultures were found on 58 occasions (74%) in 10 asymptomatic patients studied. In 19% of screenings, with positive urine cultures, an identical organism was cultured from the catheter specimen of urine, the perineum and the urethra. The flora of the anterior urethra is strongly correlated to that of the perineum (37.1%), as well as that of the bladder (52.6%). In 4 patients a correlation also existed between the urethra and fingers, and the perineum and fingers. This was associated with an increased incidence of positive urine culture in these patients. Suprapubic aspirates of urine before and after catheterisation cultured the same organisms. However, quantitative culture revealed colony counts that approached a 10-fold increase following catheterisation in one patient. This suggests that catheterisation is at least partially responsible for ascending infection in this group of patients. Catheter specimens were found to be a good representation of the bladder urine, with an 87.5% correlation.

Efficacy and tolerance of norfloxacin in treatment of complicated urinary tract infection in outpatients with neurogenic bladder secondary to spinal cord injury

We studied the efficacy of a fourteen-day course of the fluoroquinolone, norfloxacin, in a group of 69 catheter-free spinal cord injury (SCI) outpatients who experienced a total of seventy-nine urinary tract infection (UTI) episodes. A total of 114 bacterial strains representing twenty species, including sixteen Pseudomonas aeruginosa, all susceptible to norfloxacin, were isolated from initial urine cultures. Mid-treatment cultures in 58/79 (73%) cases were negative. Cultures taken five to seven days after completing treatment in 42 cases (53%) were negative. In the remaining 37 there was persistence of initial or superinfecting pathogen(s), or early reinfection with new organisms. Cultures eight to twelve weeks later in 32 cases with initial eradication showed that 27 (84%) had either relapsed and/or become reinfected. Clinical cure occurred in 4/6 (67%) symptomatic episodes. Side effects occurred in 6 of 73 (8%) patients who received norfloxacin, 4 of whom required withdrawal from the study. Twenty of one hundred twenty-two (16%) bacterial strains isolated during or after treatment were resistant to norfloxacin. Given the limited oral treatment options and the constant risk of reinfection in the SCI population, norfloxacin appears to be a reasonable choice in many patients. However, as with other antimicrobials, when using norfloxacin in SCI patients, the emergence of resistant bacteria must be carefully monitored.

Proteeae groin skin carriage among nursing home residents--resistance to antiseptics

Proteeae carriage was evaluated in groin skin carriers following vigorous antiseptic application. Three Proteus mirabilis carriers were treated with 60% isopropyl alcohol or 4% chlorhexidine, observed to prevent skin contact, and then recultured; at four and eight hours P mirabilis numbers remained undiminished. Ten Proteeae carriers received a series of nine body baths with soap, chlorhexidine, and 0.75% povidone-iodine plus three cefazolin injections over 16 to 34 days; cumulative treatments failed to clear seven carriers. Within three months, all were again carriers. Proteeae carriers also had affinity for groin carriage of various aerobic gram-negative bacilli (AGNB) including cefazolin-resistant strains. In seven subjects, more than one AGNB species were recovered shortly after applying an antiseptic. Proteeae groin skin carriage appears to reflect a major change in the nature of resident bacteria on intact groin skin.

Proteeae groin skin carriage in ambulatory geriatric outpatients

Aerobic gram-negative bacillus (AGNB) groin skin carriage was prospectively studied in ambulatory geriatric outpatients: 42 from three nursing homes and 44 from private homes. Initially, 12 (28.6%) Proteeae carriers were in the former group and 3 (6.8%) were in the latter (P = 0.01). At one year, 6 of 7 surviving nursing home carriers remained Proteeae carriers while none from private homes remained carriers (P = 0.007). The annual prevalence of Proteeae carriage was 14 (33.3%) in nursing homes and 4 (9.1%) in private homes (P = 0.008); of non-Proteeae AGNB carriage, the annuyal prevalence was 2 (4.8%) and 4 (11.4%), respectively. Nursing home subjects had similar initial health characteristics; however, by one year, 5 of 12 carriers in contrast to 3 of 30 noncarriers were dead of chronic disease (P = 0.03). These nursing homes included persons with chronic diseases that apparently facilitated Proteeae carriage. Urethral catheters, skin ulcers, and recent antibiotics were not factors.

Contamination of the environment of spinal cord injured patients by organisms causing urinary-tract infection

Various environmental sites closely associated with spinally-injured patients were examined for contamination by organisms concurrently causing urinary infection. Of 30 episodes studied, the same organism was recovered from bedding on 20 occasions, from nine of 20 bath towels and less frequently from face cloths, clothing, wheelchairs and bedside units. The results indicate that contact with the immediate environment of spinal patients with urinary infection may lead to contamination of hands, and confirm and expand the need for handwashing by patients and staff.

Colonization of patients with spinal cord injury with Pseudomonas aeruginosa and Klebsiella pneumoniae at different institutions

Colonization of patients with Pseudomonas aeruginosa and Klebsiella pneumoniae was studied in patients with spinal cord injury at two institutions in Los Angeles County. The method of care of patients was similar at both institutions. A high prevalence of perineal colonization with P. aeruginosa and K. pneumoniae and similar serotypes of Pseudomonas were seen at both institutions. This colonization probably reflects the type of bladder management in patients with spinal cord injury. It would be of interest to examine other facilities to determine if colonization is influenced by techniques or local factors.