Although S. Glomerulonephritis can also occur in patients with bacterial endocarditis infection and inflammation of heart tissue ; however, it is currently unknown whether glomerulonephritis associated with endocarditis is also immune-mediated.
Leptospira are generally harmless spirochetes that are commonly found in the soil. However, some pathogenic species can cause an infection called leptospirosis in the kidneys and other organs Figure 2. Leptospirosis can produce fever, headache, chills, vomiting, diarrhea, and rash with severe muscular pain. If the disease continues to progress, infection of the kidney, meninges, or liver may occur and may lead to organ failure or meningitis.
Pulmonary hemorrhagic syndrome can also develop in the lungs, and jaundice may occur. Leptospira spp. Humans generally become infected by coming in contact with contaminated soil or water, often while swimming or during flooding; infection can also occur through contact with body fluids containing the bacteria. The bacteria may enter the body through mucous membranes, skin injuries, or by ingestion.
The mechanism of pathogenicity is not well understood. The bacteria can also be cultivated in specialized media, with growth observed in broth in a few days to four weeks; however, diagnosis of leptospirosis is generally made using faster methods, such as detection of antibodies to Leptospira spp. Polymerase chain reaction PCR , enzyme-linked immunosorbent assay ELISA , slide agglutination, and indirect immunofluorescence tests may all be used for diagnosis.
Treatment for leptospirosis involves broad-spectrum antibiotics such as penicillin and doxycycline. For more serious cases of leptospirosis, antibiotics may be given intravenously.
Figure 2. There are two main categories of bacterial urethritis: gonorrheal and nongonococcal. Gonorrheal urethritis is caused by Neisseria gonorrhoeae and is associated with gonorrhea, a common STI. This cause of urethritis will be discussed in Bacterial Infections of the Reproductive System. The term nongonococcal urethritis NGU refers to inflammation of the urethra that is unrelated to N. In women, NGU is often asymptomatic.
In men, NGU is typically a mild disease, but can lead to purulent discharge and dysuria. Because the symptoms are often mild or nonexistent, most infected individuals do not know that they are infected, yet they are carriers of the disease. Asymptomatic patients also have no reason to seek treatment, and although not common, untreated NGU can spread to the reproductive organs, causing pelvic inflammatory disease and salpingitis in women and epididymitis and prostatitis in men.
Important bacterial pathogens that cause nongonococcal urethritis include Chlamydia trachomatis , Mycoplasma genitalium , Ureaplasma urealyticum , and Mycoplasma hominis. An intracellular pathogen, C. Although most persons infected with C. The life cycle of C. These include polymorphic outer-membrane autotransporter proteins , stress response proteins , and type III secretion effectors.
The type III secretion effectors have been identified in gram-negative pathogens, including C. This virulence factor is an assembly of more than 20 proteins that form what is called an injectisome for the transfer of other effector proteins that target the infected host cells. The outer-membrane autotransporter proteins are also an effective mechanism of delivering virulence factors involved in colonization, disease progression, and immune system evasion.
These bacteria are commonly found in the normal microbiota of healthy individuals, who may acquire them during birth or through sexual contact, but they can sometimes cause infections leading to urethritis in males and females or vaginitis and cervicitis in females.
It has lipid-associated membrane proteins that are involved in causing inflammation. Figure 3. The black arrow indicates cellular debris. Several possible virulence factors have been implicated in the pathogenesis of U. The phospholipases are virulence factors that damage the cytoplasmic membrane of target cells. It can generate hydrogen peroxide, which may adversely affect host cell membranes through the production of reactive oxygen species.
Treatments differ for gonorrheal and nongonococcal urethritis. However, N. NGU is most commonly treated using tetracyclines such as doxycycline and azithromycin ; erythromycin is an alternative option.
Tetracyclines and fluoroquinolones are most commonly used to treat U. A simple test with a violet color dye called gram stain is used to determine the type of the bacteria when looked at under a microscope. The bacteria with a membrane repel the gram stain and remain pink, and therefore are called gram-negative.
On the other hand, gram-positive bacteria are lacking the membrane, and therefore easily accumulate the dye under the microscope, and appear violet. This membrane is what makes it harder to treat infections caused by gram-negative bacteria. On top of it, the gram-negative bacteria also share an increased resistance to antibiotics and are more toxic to the host than gram-positive bacteria. A subgroup of gram-negative bacteria that produce extended-spectrum beta-lactamases ESBL enzymes deserves special mention.
This enzyme allows the bacteria to resist most beta-lactam antibiotics, including penicillins, cephalosporins, and the monobactam aztreonam. Unfortunately, infections with ESBL-producing organisms are very hard to treat. Patients in hospitals or nursing home settings are at an increased risk to contract an ESBL-producing bacteria. When examining UTI bacteria types, we need to keep in mind that different patients kids, young women, pregnant females, males, or the elderly are unequally susceptible to different bacteria types.
Also, depending on how you acquired your UTI for example due to bladder stones or a catheter in a hospital setting will determine which bacteria are most likely to be at fault. Moreover, some bacteria might colonize a bladder without even causing a UTI. This is a gram-negative bacterium prone to developing resistance to antibiotics. While E. Opportunistic bacteria take advantage of an opportunity that is not normally available, such as a host with a weakened immune system or an altered microbiota for example, a disrupted gut or vaginal microbiota and rapidly grow in those circumstances.
Proteus mirabilis is a gram-negative bacterium and favors patients with long-term catheters. Catheter-associated urinary tract infections CAUTI caused by Proteus mirabilis are very difficult to treat due to their ability to form biofilms and develop drug resistance.
When a catheter is inserted, it could damage the mucosal layer of the urethra, which disrupts the natural barrier and allows bacterial colonization. Moreover, the catheter tube is like a highway for bacteria that makes it easier for them to enter the bladder as well as establish their biofilm colonies on its surface.
Besides typical UTI, this bacteria could also cause a dangerous, symptom-less bacteriuria, especially in the elderly and in patients with type-2 diabetes, which could lead to life-threatening urosepsis. Additionally, P. It is also not clear if P. In fact, some clinical studies point out that this infection could be transmitted from person-to-person, especially in a hospital setting.
This is supported by evidence that some patients with P. At the same time, P. Unfortunately, P. Not only does this bacterium possess a variety of virulent mechanisms helping it to spread and withstand antibiotics, but it also quickly forms biofilms on the surface of catheters further avoiding antibiotic attacks. Klebsiella pneumoniae K. This gram-negative bacterium is also notorious for developing antibiotic resistance, including to carbapenem antibiotics.
For example, carrier rates of K. Women are at greater risk of developing a UTI than are men. Infection limited to your bladder can be painful and annoying. However, serious consequences can occur if a UTI spreads to your kidneys. Doctors typically treat urinary tract infections with antibiotics.
But you can take steps to reduce your chances of getting a UTI in the first place. Urinary tract infections don't always cause signs and symptoms, but when they do they may include:. UTIs may be overlooked or mistaken for other conditions in older adults. Each type of UTI may result in more-specific signs and symptoms, depending on which part of your urinary tract is infected. Contact your doctor if you have signs and symptoms of a UTI. Urinary tract infections typically occur when bacteria enter the urinary tract through the urethra and begin to multiply in the bladder.
Although the urinary system is designed to keep out such microscopic invaders, these defenses sometimes fail. When that happens, bacteria may take hold and grow into a full-blown infection in the urinary tract. The most common UTIs occur mainly in women and affect the bladder and urethra. Infection of the bladder cystitis. However, sometimes other bacteria are responsible. Sexual intercourse may lead to cystitis, but you don't have to be sexually active to develop it. All women are at risk of cystitis because of their anatomy — specifically, the short distance from the urethra to the anus and the urethral opening to the bladder.
Urinary tract infections are common in women, and many women experience more than one infection during their lifetimes. Risk factors specific to women for UTIs include:.
When treated promptly and properly, lower urinary tract infections rarely lead to complications. But left untreated, a urinary tract infection can have serious consequences. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. This content does not have an English version.
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