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Laurance Johnston, Ph.D.

Sponsor: Institute of Spinal Cord Injury, Iceland



1) Antibiotics

2) Urinary Antiseptics

3) Bacterial Interference

4) Nutritional

5) Alternative

Urinary-tract infections (UTIs) are an aggravating, recurring health problem for individuals with SCI. According to the US Agency for Health Care Policy and Research, 80% of those with SCI will experience UTIs within 16 years of injury. UTIs are the most frequent secondary medical complication during acute care and rehabilitation, and urinary-system disorders are the fifth most common primary or secondary cause of death. Waites and colleagues (Alabama, USA) estimated that the incidence of UTIs with fever and chills in people with SCI was 1.82 episodes annually.

In the general population, most UTIs are caused by Escherichia coli bacteria, which, although a normal part of our intestinal miroflora, do not belong in our urinary system.  In the case of SCI, a diversity of bacteria can cause UTIs, including, in addition to E. Coli, Klebsiella, Pseudomonas, Proteus, Serratia, Providencia, Enterococcus, and Staphylococcus.


For more than 60 years, people with SCI have relied on antibiotics to control UTIs. The development of these drugs stems back to 1928 when British microbiologist and eventual Nobel Laureate Alexander Fleming observed that bacterial growth was inhibited by a penicillin-producing mold. Although infection-fighting molds have been a part of mankind’s healing armamentarium since antiquity and noted by scientists before Fleming, penicillin became the first antibiotic isolated from one. The exigencies of World War II resulted in penicillin’s production in sufficient quantities for general use. Since then, scientists have developed many potent antibiotics.

Although greatly increasing life expectancy for people with SCI, the growth of antibiotic-resistant bacteria is of great concern for this population that relies on their use. For example, studies have shown every year two-million hospital patients acquire infections that that they did not have when they entered the hospital; of these, 80,000 die. Statistics such as these are especially relevant to infection- and hospitalization-prone individuals with SCI and clearly indicate the need to maintain antibiotic effectiveness.

In spite of commonly held assumptions that bacteria are the bad guys, optimal health requires that we maintain a symbiotic, health-enhancing partnership with them.  For example, many different bacteria living within our digestive system are essential for proper digestion, nutrition, and long-term health.  Every time we use an antibiotic, we undercut this bacterial partnership. By constantly killing off the good guys as collateral damage, we create a void that may be filled by health-compromising pathogens or antibiotic-resistant bacteria that now have no competition for growth.

In spite of their clear importance, every time you use antibiotics you short-circuit your body’s inherent healing potential, cumulatively compromising your long-term health. You may be winning the immediate health-care battle, but you are setting yourself up to lose the war.

In general, experts believe that antibiotics should be reserved for the treatment of symptomatic UTIs and not prophylactically used for prevention or treating asymptomatic bacteriuria (i.e., bacteria in the urine without symptoms). To minimize some of the antibiotic problems, the chosen antibiotic should be tailored to the patient’s specific UTI bacterial profile as determined by culture, and preferably a single antibiotic should be used.  Many antibiotics have been used to treat SCI-associated UTIs, including cotrimoxazole, trimethroprim, mecillinam, amoxicillin, norfloxacin, ciprofloxacin, cephalosporins, fosfomycin, ceftazidine, meropenem, and piperacillin.

Urinary Antiseptics - Methenamine

Used by many with SCI to combat UTIs, methenamine derivatives (e.g., Hiprex®) are urinary antiseptics that kill bacteria. Because methenamine is not an antibiotic, bacterial resistance is not an issue. If the urine is sufficiently acidic, the methenamine splits into ammonia and bacteriostatic formaldehyde. Differences in acidification procedures and, in turn, the amount of bacteria-killing formaldehyde that is produced might explain some of the disparity in study results.

Kevorkian and colleagues (Minnesota, USA) evaluated methenamine’s UTI-preventing potential in 39 patients with a neurogenic bladder (i.e., a malfunctioning bladder due to neurologic dysfunction) who were in a program of intermittent catheterization and bladder retraining. Twenty-two were male and 17 female, and age ranged from 17 to 78 (average 30) years. Subjects received six 1-gram doses of methenamine daily or placebo for 21 days. Compared to an 86% infection rate in placebo subjects, only 53% of the methenamine-treated patients became infected.

Krebs and associates (Texas, USA) randomized 40 men injured within the preceding half year to either methenamine-treated (four 2-gram doses daily) or control groups. After approximately 70 days, UTI incidence was significantly less in the methenamine group. Specifically, the methenamine and control subjects had 4 and 11 symptomatic UTIs, respectively.

Recently, Lee et al (Australia) looked at methenamine’s UTI-fighting potential in 75 patients with SCI (Spinal Cord 2007; 45). Ranging in age from 16 to 82 (average 43.5) years, 83% were men and 55% had cervical injuries. The average time since injury was 12 years. Subjects consumed a daily one-gram methenamine dose for six months and were compared to those who consumed a placebo or methenamine together with cranberry (discussed below). No UTI-preventative effect could be statistically documented for this treatment regimen. However, this study used a much lower methenamine dosage than the previously discussed investigations and did not ensure the urinary acidity supposedly required for formaldehyde bacteriostatic release.

Bacterial Interference

With the bacterial interference UTI-fighting approach, innocuous bacteria are allowed to colonize the bladder, which, in turn, inhibits colonization by the bad bacteria. Of course, any antibiotic treatment during colonization would kill off the protective bacteria. Studies focused on this topic have been carried out by investigators, including Dr. Rabih Darouiche,  at research institutions in Houston, Texas (USA).

As reported in 2000, these investigators studied the UTI-preventing potential of bacterial interference in 22 subjects with SCI. All but three were men, age ranged from 32 to 55 years, and the time lapsing from injury varied from 5 to 24 months. Subjects were inoculated in the bladder using a catheter with a benign E. coli strain. Long-term bladder colonization with this strain - lasting from 2 to 40 months - was achieved in 13 subjects. Although these subjects had averaged 3.1 symptomatic UTIs annually before colonization, no infections were observed after colonization as long as the colonization remained in place. In contrast, infections were observed in patients who were not successfully colonized and also in those who lost colonization.

The next year, the investigators reported the results of a larger study involving 44 subjects with SCI. Of the 44 inoculated with the same E. coli strain mentioned above, 30 became colonized and experienced while colonized a 63-fold reduction in symptomatic-UTI incidence compared to their pre-study infection rate.

In 2005, the investigative team reported the results of a rigorously designed prospective, randomized placebo-controlled, double-blind pilot trial . Of the 21 patients whose bladders were inoculated with the benign E. coli strain, all were men, average age was 52, and 10 and 11 had quadriplegia and paraplegia, respectively. Control subjects were inoculated with a sterile saline solution. The investigators concluded that colonized subjects were half as likely as non-colonized patients to acquire a UTI during the following year.

In a much larger randomized, double-blind, placebo-controlled study scheduled for completion in 2008, 160 patients with SCI or spina bifida will be recruited from five medical centers in Texas, Georgia, and Illinois. Because only about 1/3rd of colonized subjects are expected to remain colonized for the 12-month study period, subjects will be randomized in a 3:1 ratio. All subjects will be treated with antibiotics before inoculation to eliminate preexisting bacteria, and several days afterwards will be inoculated with the protective E. coli strain or placebo.

The investigators have also studied bacterial interference’s potential to reduce catheter-associated UTIs. Bacterial biofilm that grows on implanted catheters can seed infections on an on-going basis. The investigators concluded that pre-exposure of the catheter to benign E. coli significantly reduced catheter colonization by UTI-causing bacteria.

A 2009 study evaluated 13 individuals with SCI who underwent 19 insertions of urinary catheters that had been pre-inoculated with the benign E. coli strain. The catheter was left in for three days and then removed. Of these individuals, eight became successfully colonized with the benign strain. Before this intervention, these individuals averaged 2.27 UTIs per year, afterwards only 0.77 UTIs per year.

Nutritional Approaches

Cranberries:  Cranberry products are a traditional UTI-fighting folk remedy embraced by the SCI community. In addition to supposedly acidifying the urine, cranberries contain substances that inhibit bacteria from attaching to the bladder lining and, as such, flush out bacteria with the urine stream.

Pilot-study results involving 15 subjects with SCI carried out by Dr. Gregor Reid and colleagues (Canada) suggested that drinking cranberry juice greatly reduced bacterial attachment to cells lining the bladder. Promisingly, this was a broad-spectrum, anti-bacterial effect not limited to merely E. coli, the UTI-causing culprit in the general population.

In 2008, Dr. Marika Hess and colleagues (USA) reported the results of randomizing 47 subjects with SCI to receive either cranberry extract tablets or placebo. After six months, the treatments were reversed; i.e., the placebo-treated subjects now received cranberry tablets, and the cranberry-treated subjects now received placebo. On average, the cranberry-treated subjects had only 0.3 UTIs per year compared to 1.0 UTIs of placebo-treated subjects. The investigators concluded that “cranberry extract tablets should be considered for the prevention of UTI in SCI patients with neurogenic bladder.”

However, the UTI-fighting properties of cranberry-containing supplements (i.e., extracts not juice) could not be demonstrated in several other studies.

For example, Dr. Todd Linsenmeyer et al (USA) randomized 21 subjects to receive either a cranberry tablet or inactive placebo for four weeks. After a one-week washout period, the subjects who had received the cranberry supplement were now given the placebo and vice versa. No statistical difference was noted between the placebo and cranberry groups as measured by several UTI-indicative criteria. Furthermore, urinary acidity did not differ between the treatment groups.

In another example, Dr. K. B. Waites and colleagues (USA) compared 26 subjects with SCI who received a two-gram daily dose of cranberry extract in capsule form for six months with 22 placebo-treated subjects. The investigators concluded that the cranberry extract did not reduce UTIs.

Dr. B. B. Lee and associates (Australia) evaluated the effects of cranberry tablets in preventing UTIs in 78 subjects with SCI. Subjects consumed an 800-milligram dose of cranberry twice daily for six months. No difference in UTI incidence was noted between cranberry and placebo-treated groups.

D-Mannose: Evidence indicates that D-mannose is effective in dislodging E. coli bacteria from the bladder wall, and, as can ameliorate many of the UTIs caused by this bacteria, including in individuals with SCI. D-mannose is a naturally occurring sugar similar in structure to glucose (a component of table sugar). Because the body metabolizes only small amounts of D-mannose and excretes the rest in the urine, it doesn’t interfere with blood-sugar regulation, even in diabetics.

The cell wall of the UTI-causing E. coli has tiny finger-like projections that contain complex molecules called lectins on their surfaces. These lectins are cellular glue that binds the bacteria to the bladder wall so they cannot be readily rinsed out by urination.  However, because D-mannose molecules will glom on to these lectins and fill up all of the bacterial anchoring sites, the bacteria can no longer attach to the bladder wall and are, therefore, flushed away. In other words, unlike antibiotics, D-mannose does not kill any bacteria, whether they are good or bad, but simply helps to displace them.

Vitamin C: Dietary supplementation with vitamin C is believed by many to inhibit UTIs by increasing urine acidity. Based on this belief, Dr. Nils Hjeltnes and colleagues (Norway) have initiated a study that will evaluate vitamin-C’s UTI-fighting potential for SCI.  Forty individuals with SCI, who have had three or more UTIs over the previous two years, will be randomized to receive one gram of vitamin C daily or no vitamin C for one year, and the number of UTIs between groups will be compared.

Alternative Approaches

Herbal Medicine: Before modern medicine started emphasizing chemically synthesized drugs, herbal remedies were the cornerstone of most of the world’s healing traditions and even today, are used by 80% of the world’s population who cannot afford Western pharmaceutics. As concerns grow about drug side effects or bacterial resistance, many are once again turning to herbal remedies to treat diverse ailments, including UTIs.

Many urinary-system herbal remedies have a long history of use by both Western and indigenous (e.g., Native American) cultures; have been listed in numerous official medical resources before our focus on synthesized drugs pushed them to the sidelines; and even today, have been often sanctioned by European governments in efforts to reconcile and integrate herbal and modern medicine perspectives.

Although little focus has been on the use of these herbal remedies to treat SCI-specific UTIs, many of these remedies act against E. coli bacteria, the primary UTI culprit in the general and SCI population. Several UTI-fighting herbal remedies or medicinal foods are listed below:

bulletUva Ursi or bearberry, isolated from a small shrub related to blueberry and cranberry plants, contains a urinary antiseptic called arbutin;
bulletHorsetail, isolated from a prehistoric-looking plant that resembles a horse’s tail, supports general urinary tract health;
bulletJuniper berries contains volatile oils that serve as urinary antiseptics;
bulletBuchu, an indigenous South African remedy often combined with cranberries in commercial products, contains volatile oils that are urinary tract antiseptics;
bulletAsparagus, especially the wild type, is a traditional remedy for promoting urinary tract health;
bulletParsley, the familiar garnish, provides urinary-system nutritional support and contains apiol, a volatile oil urinary tract antiseptic;
bulletCelery Seed possesses antibacterial agents, including apiol;
bulletGarlic, an herbal heavyweight in many respects, has significant antibacterial activity;
bulletGolden Seal Root, isolated from a North American woodland plant, contains an anti-bacterial compound called berberine.
bulletMarshmallow root, isolated from a plant that grows in wet, marshy areas, possesses a high mucilage content that sooths mucus membranes;
bulletCorn Silk, prepared from the stigmas of corn plant female flowers, is valued for urinary system support.
bulletBirch, the deciduous tree, possesses many antibacterial substances.
bulletCleavers (also goosegrass), a common succulent plant, is beneficial for treating diverse urinary-system problems;
bulletHydrangea Root, isolated from the elegant shrub, contains substances that nutritionally support the urinary system.

Essential Oils: Often the antibacterial agents in herbs, volatile essential oils are extracted from plants using steam distillation. These highly concentrated oils are often complex mixtures of chemicals possessing wide-ranging properties.

Essential oils can fight diverse infections, including the UTI-causing E. coli bacteria. UTIs can be treated with baths and massages using, for example, sandalwood, pine, chamomile, cedarwood, juniper, bergamot, fennel oils, tea tree, and niaouli, and cajeput .  For example, a massage oil containing sandalwood, niaouli or cajeput can be rubbed directly over your lower abdomen above your pubic bone and lower back kidney region. These concentrated essential oils are usually diluted with some sort of vegetable oil or lotion before being applied to the skin.

Homeopathy: Homeopathy is a popular alternative healing tradition developed by Dr. Samuel Hahnemann in the early 19th century. He discovered that substances causing illness symptoms in a healthy person could be used in exceedingly low doses to cure similar symptoms when they result from illness.

Although homeopathic remedies are often confused with herbal products that bear similar names, the remedies are based on fundamentally different principles. Specifically, prepared by a process of a successive cycle of dilution and shaking, homeopathic (unlike herbal or essential oil), remedies are virtually bereft of physiologically active molecules. Homeopathy’s healing effects are mediated through a retained energy imprint of the original, pre-dilution substance. Because this runs counter to molecule-dependant pharmaceutical principles, conventional medicine has shunned homeopathy in spite of a long-history of often very effective use and documentation through some rigorously designed clinical studies.

Many homeopathic remedies are indicated for UTIs, including Aconitum napellus, Apis, Berberis, Belladonna, Cantharis, Equisetum, Eupatorium purpureum, Mercurius vivus, Nitric acid, Nux vomica, Pulsatilla, and Sarsaparilla.