E coli urine infection

Urinary Tract Infections

Urinary tract infections (UTIs) are a common medical complaint. It is estimated that up to 40 percent of women will have a UTI at some time in their lives. Also called bladder infections or cystitis, a UTI occurs when bacteria enter the bladder, usually through the urethra (urine tube), and begin to multiply.

Urine contains fluids, salts and waste products but is sterile or free of bacteria, viruses and other disease-causing organisms. A UTI occurs when bacteria from another source, such as the nearby anus, gets into the urethra. The most common bacteria found to cause UTIs is Escherichia coli (E. coli). Other bacteria can cause UTI, but E. coli is the culprit about 90 percent of the time.

E. coli normally lives harmlessly in the human intestinal tract, but it can cause serious infections if it gets into the urinary tract. In women, the trip from the anus to the urethra is a short one. This is the reason why “wiping front to back” after using the toilet is helpful in preventing UTI.

An untreated UTI can move up to the kidneys and cause an even more serious infection, so prompt diagnosis and treatment is important. Sexually active women, pregnant women and older women all may be at increased risk for UTI.

Our Approach to Urinary Tract Infections

UCSF offers personalized, sensitive care for common women’s health problems, including urinary tract infections. Our mission is to provide every woman who comes to us with the highest quality care and the information she needs to make informed decisions about her health.

When urinary tract infections keep coming back

Why some women get recurrent UTIs

The infections are usually caused by Escherichia coli, a bacterium that lives in the intestinal system. If E. coli are carried from the rectum to the vagina, they can enter the urethra (the tube that carries urine from the bladder) and infect the bladder.

Risk factors for UTI vary with age. Before menopause, the most common risk factors are sexual intercourse and use of spermicides. It’s thought that sex increases the number of bacteria in the bladder, and many experts advise women to urinate after sex to flush them out. Spermicides may kill off Lactobacilli, beneficial bacteria in the vagina, making it easier for E. coli to move in.

After menopause, certain physical changes help set the stage for UTIs. The numbers of Lactobacilli in the vagina naturally decline. The bladder also contracts less strongly than it once did, making it more difficult to empty it completely.

In both premenopausal and postmenopausal women, genes play a role as well. Having a mother or sister who has frequent UTIs is also a risk factor.

Preventing UTIs

These approaches have some evidence to support them:

  • Drink plenty of fluids every day. Aim for about 2 to 3 liters.
  • Use alternative contraception that does not include a spermicide.
  • Empty your bladder immediately following sexual intercourse.
  • Consider vaginal estrogen therapy for post-menopausal women.
  • Wipe front to back, although this has not been scientifically proven to make a difference.


Taking a low dose of one of the antibiotics used to treat UTI—nitrofurantoin (Furadantin, Macrobid), trimethoprim-sulfamethoxazole or TMP-SMX (Septra, Bactrim), and cephalexin (Keflex, Ceporex)—is the most reliable way of dealing with recurrences. However, bacteria may become resistant to an antibiotic over time and it may not be effective in treating subsequent infections. “This is an area in which women can experiment and find which solution works for them,” Dr. Gupta says. There are several options if you have a prescription on hand:

  • taking a low dose daily for six months or longer
  • using only after you have sex
  • waiting until you have UTI symptoms.

If you have recurrent UTIs, talk to your clinician. The two of you can come up with a plan that is likely to be effective for you.

… and it won’t hurt to try these

Like many women, you may have memorized the following age-old advice for preventing UTIs:

  • Wipe from front to back.

  • Urinate before and after sex.

  • Drink lots of water.

  • Avoid tight underpants and jeans.

These suggestions are directed at flushing the bladder and keeping E. coli from spreading into the urinary tract. Although studies have failed to show that they prevent either primary or recurrent UTIs, there’s no harm in trying them, Dr. Gupta says. “They can’t hurt, and if they help, you’re ahead of the game.”

As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review on all articles. No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.

How E. coli bacteria can harm your kidneys

Author(s): Urooj Fatima
Topics: Dialysis , News , Kidney disease prevention

An E. coli outbreak linked to romaine lettuce has generated a lot of news headlines. According to the Centers for Disease Control and Prevention (CDC), 32 people have been infected with the outbreak strain of Shiga toxin-producing E. coli.

Every few years we hear about E. coli outbreaks, and are advised to stop using certain food products. But what is E. coli, where does it come from, and how can it cause kidney failure?

E. coli is a type of bacteria found in the intestines of humans and animals. There are different kinds of E. coli; most are harmless, but some can be harmful. The types of E. coli that can cause illness are most often spread through contaminated food or water.

Shiga toxin-producing E. coli (STEC) is a harmful type of E. coli that is most often involved in outbreaks. It can cause stomach cramps, fever, diarrhea and vomiting. STEC infection can be mild and resolve itself after 5-7 days. It can also be severe for some people, and can lead to kidney failure.

Infection with STEC can cause a condition called hemolytic uremic syndrome (HUS), which is a type of kidney failure. Around 5-10 percent of people who get a STEC infection develop HUS. In HUS, STEC bacteria destroy your red blood cells, which can block your kidneys’ filters and damage them, leading to kidney failure.

Early symptoms of HUS include vomiting or diarrhea, blood in stool, fever or feeling extremely tired. Later symptoms can include urinating less, unexplained bruises, pale complexion, and bleeding from your nose and mouth. There are ways to treat the symptoms of HUS, and you should visit the hospital right away if you think you could have it. Depending on the damage from HUS, you may need to be on dialysis temporarily, or have a blood transfusion. Fortunately, most people will fully recover from HUS after a few weeks. However, damage to your kidneys can lead to chronic kidney disease or even kidney failure later in life.

Young children under 5 and adults over 65 are more likely to get severe E. coli infections like STEC. In fact, HUS caused by STEC is the biggest cause of acute kidney failure in children. People with HIV, diabetes and cancer are also more at risk for STEC. There is no medicine to treat E. coli infection. The treatment involves resting and drinking a lot of water, or getting IV fluid if the infection is more severe.

You can take steps to prevent getting E. coli, and therefore HUS. Listen to warnings made by the CDC about contaminated food products, like the recent warning for romaine lettuce. To prevent getting E. coli at any time, here are things you can do to reduce your chances of exposure:

  • Make sure your meat is fully cooked before eating, and do not let raw meat touch the things you eat.
  • Avoid drinking unpasteurized milk, juice, and cider.
  • Try not to swallow water when swimming in any type of lake, pond, stream, or pool because water could be contaminated by E. coli from runoff from the ground.
  • Finally, make sure to wash your hands thoroughly after handling raw meat, changing diapers, or visiting a petting zoo.

If one member of your family is diagnosed with an E. coli infection, other members of your family should be on alert because they may have been in contact with the same contaminated source. Clean all surfaces and utensils in the kitchen if you suspect the infection came from food. To prevent spreading E. coli to someone else if you have it, wash your hands properly after using the restroom, and before preparing food. You cannot get E. coli from contact like hugging or kissing.

Although bigger outbreaks bring E. coli into the spotlight for a short time every year, E. coli infections are not uncommon. Every year in the U.S. there are around 94,000 reported cases of E. coli infections; of these about 3,600 people are hospitalized and about 30 people die. It is important to take precaution year-round to prevent E. coli infection, HUS, and to keep your kidneys healthy.

To learn more about E. coli, visit these sources:

  • Centers for Disease Control and Infection (CDC) – E. coli
  • National Organization for Rare Disease (NORD) – STEC Hemolytic Uremic Syndrome
  • CDC – E. coli Factsheet
  • CDC – E. coli Q&A
  • CDC – Outbreak Investigations
  • Posted: May 18, 2018

    About the Author(s)

    Urooj Fatima

    Urooj Fatima is the the American Kidney Fund’s Public Education Coordinator.

Website access code


Thanks to antibiotics, we tend to think of urinary tract infections as no big deal. Pop some cipro, and you’re done. A good thing, too—if the E. coli that usually cause UTIs crawl up the urinary tract, they can cause kidney failure and fatal blood poisoning.

But antibiotics may not be saving us from UTIs for very much longer. Scientists tracking UTIs from 2000 to 2010 found a dramatic uptick in cases caused by E. coli that do not respond to the drugs that are our first line of defense. In examining more than 12 million urine analyses from that period, they found that cases caused by E. coli resistant to ciprofloxacin grew five-fold, from 3% to 17.1% of cases. And E. coli resistant to the drug trimethoprim-sulfame-thoxazole jumped from 17.9% to 24.2%. These are two of the most commonly prescribed antibiotics used to treat UTIs. When they are not effective, doctors must turn to more toxic drugs, and the more those drugs are used, the less effective they in turn become. When those drugs stop working, doctors will be left with a drastically reduced toolkit with which to fight infection.

Some of this growing resistance in E. coli and other bacteria is due to the fact that antibiotics are being overprescribed, handed out to patients who have no bacterial infections. There is also evidence that the genes that give bacteria resistance to drugs are being spread in livestock farming operations, where antibiotics are a common ingredient in animal feed. Ciprofloxacin is one of those antibiotics, and researchers have found that E. coli resistant to it are thriving in poultry farms. Very closely related strains of drug-resistant E. coli have been found in people, suggesting that the bugs spread from the birds to humans.

E. Coli That Cause Urinary Tract Infections

In this chart from the report, the trends in resistance are clear.

People suffered from UTIs long before antibiotics were discovered in the early twentieth century, of course. Should these drugs cease to be effective, we’ll have to go back to what we were doing before. The truth is, though, before antibiotics we had no real treatment. Sicknesses resembling UTIs have been described in medical texts for thousands of years, by everyone from the ancient Greeks and Chinese to the pioneers of evidence-based medicine in the early 1900s. Some of these doctors prescribed various tinctures, ointments, and special diets to deal with the symptoms, but in cases in which the infection spread to the bladder and kidneys and beyond, they were fairly helpless. As a last-ditch effort, they operated to drain puss from the infected kidneys and hoped the patient would survive. Treatment did not fundamentally change until antibiotics arrived on the scene.

In a world without antibiotics, many peoples’ UTIs would doubtless subside under attack from the immune system. But some fraction of them would not, and those people would find themselves in dire straits. And about the common idea that cranberry juice can prevent or treat UTIs: evidence is pretty spotty. Better to try to reduce the irresponsible use of antibiotics than rely on juice.

Image courtesy of somegeekintn / Flickr

Kidney Infection (Pyelonephritis)

What is kidney infection (pyelonephritis)?

Infection in the urinary tract can involve the lower tract especially the bladder (cystitis), prostate (prostatitis) or the upper tract and kidney (pyelonephritis). It is usually a bacterial infection. The disease occurs in roughly three to seven of every 10,000 people in the United States. The occurrence in pregnant women is about 2 percent. It is readily treatable if diagnosed early.

A bacteria called Escherichia Coli (E Coli) causes about 90 percent of kidney infections. The bacteria migrate from the genitals through the urethra (the tube that removes urine from the body) into the bladder and up the tubes (ureters) that connect the bladder to the kidneys.

Some bacteria, such as staphylococcus infections, can enter the kidneys from the bloodstream.

What are the causes of kidney infections (pyelonephritis)?

Normally, bacteria are flushed out by the flow of urine. However, several problems can increase the risk of a kidney infection. These problems can include:

  • Structural abnormalities (strictures, stents, stones, surgery) blocking urine flow.
  • An enlarged prostate gland (benign prostatic hyperplasia) compressing the urethra.
  • Backflow (reflux) of urine from the bladder to the kidneys.
  • If your immune system is affected (low white blood cell count, use of certain medications, HIV, cancer, an organ transplant).
  • Pregnancy, during which time the enlarging uterus can squeeze the ureters and reduce the flow of urine, allowing the bacteria to migrate to the kidneys.
  • Uncontrolled diabetes mellitus.

What are the symptoms of kidney infection?

A number of symptoms can indicate to your doctor that you may have a kidney infection. The more severe the symptoms, the more likely the infection involves the kidney. Symptoms of a kidney infection include:

  • Sudden onset of chills
  • Fever over 100 degrees Fahrenheit
  • Pain in the groin, lower back or side
  • Nausea
  • Vomiting
  • Abdominal muscle spasm

More general symptoms of upper kidney infection include:

  • Flushed or reddened skin
  • Painful urination
  • Increased urination
  • Unproductive attempts to urinate despite feelings of urgency
  • General ill feelings
  • Cloudy urine
  • Abnormally colored urine
  • Blood in the urine
  • Foul smelling urine

If you experience any of these sudden onset symptoms, please seek medical attention.

Share Facebook Twitter LinkedIn Email Get useful, helpful and relevant health + wellness information enews

Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy

About the author

Leave a Reply

Your email address will not be published. Required fields are marked *