Prostatitis is a condition in which the prostate gland, found only in males, is swollen due to inflammation. The prostate gland produces the fluid that makes up semen in which sperm are suspended and secretes it directly into the urethra. The majority of prostatitis diagnoses are due to inflammation unrelated to infection, usually associated with stress and immune dysfunction. However, when bacteria pass the defenses of the urethra, they can reach the prostate and cause serious disease.
Acute bacterial prostatitis is an emergency medical condition in which bacteria such as Escherichia coli, Klebsiella, Proteus, Enterobacter, Pseudomonas, Serratia, Enterococcus, and Staphylococcus aureus infect the prostate gland. This occurs when bacteria in urine leak into the prostate gland. Symptoms of prostatitis are fever, chills, back pain, and painful urination. It can be diagnosed through the detection of leukocytes, a type of white blood cell, and bacteria in the urine. Treatment involves the use of intravenous administration of ciprofloxacin or tetracycline antibiotics. If left untreated, bacteria can escape the prostate gland into the bloodstream, causing sepsis, a condition in which an infection results in a system-wide inflammatory response. Sepsis causes severe damage to the tissues and can result in death if not treated immediately.
Chronic bacterial prostatitis is not as dangerous and is much rarer than acute prostatitis but can still be troublesome. Symptoms of chronic prostatitis are similar to that of typical urinary tract infections, causing inflammation of the urethra and pain during urination. However, while treatment with antibiotics will ease symptoms, the organism frequently returns to cause disease again. Detection of chronic prostatitis usually involves culturing bacteria from semen, which is typically considered sterile because the species present in semen from healthy males are not culturable. Treatment of chronic prostatitis involves use of tetracyclines, ciprofloxacin, or fluoroquinolones, which penetrate the blood-prostate barrier.
Epidemiology is a science that investigates the cause, transmission, timing, and distribution of infectious disease episodes, with a focus on recognizing outbreaks, controlling those outbreaks, and treating the infected. The epidemiological study of urinary tract infections has revealed three primary routes by which urinary tract infections are most commonly spread: community-acquired, catheter-acquired, or through imbalanced microbiota.
The first route of infection is called community-acquired, where the pathogen is transferred to the urinary tract from another organ system. As the most common causative agent of urinary tract infections is Escherichia coli, the most common source of community-acquired UTIs is the gastrointestinal tract. Contamination of the urinary tract by gut microbes generally occurs when the genitals come into contact with fecal matter, which contains many of the same bacteria (E. coli) that live in the gut. This contamination can be prevented with regular hygiene and safe sex practices. For example, women wipe themselves from front to back, urethra before the anus, in order to prevent fecal bacteria from getting into the urethra. Women are also encouraged to urinate before and after sexual intercourse to clear the urethra of potential contaminants.
The second route of infection is via catheter, a medical instrument that is inserted into the urethra in order to drain the bladder artificially. Because the catheter travels all the way to the bladder and prevents urine flow through the urethra, bacteria attached to the surface of the catheter, or located in the urinary tract, may be transferred to the bladder. Some bacteria, such as E. faecalis, E. coli, S. epidermidis, and S. aureus, are uniquely adapted to colonize the interface between the catheter and the epithelial wall, building structures called biofilms that reduce the efficacy of antibiotic treatment. These infections can be prevented through frequent replacement and cleaning of the catheter to remove bacterial growth.The third route of infection is through infection by organisms that are a part of the healthy microbiota. These normal microbes that inhabit the body change their behavior to cause infection under certain circumstances. The second most common causative agent of urinary tract infections is Staphylococcus saprophyticus, a gram-positive bacterium that is a common member of the microbial communities that naturally colonize parts of the urinary tract. S. saprophyticus shifts to pathogenesis when cells evade the natural defenses of the urinary tract and reach more vulnerable organs, such as the bladder. Streptococcus agalactiae is a gram-positive coccus-shaped bacterium that is commonly found colonizing both the large and small intestines and the genitourinary tract in healthy humans. Before the development of PCR amplification and DNA sequencing technologies, bacteria from similar species were differentiated based on other biochemical characteristics. One system designed to distinguish between streptococci was called the Lancefield system, which grouped them based on the content of their cell walls. S. agalactiae produces a rhamnose-glucosamine capsule surrounding its cells and so was designated a Group B streptococcus, which is how it is commonly referred to in research. This capsule is known as a virulence factor, a feature enabling a pathogen to cause disease by releasing toxins, invading host cells and tissues, suppressing the host's immune responses, or otherwise damaging the host. S. agalactiae also produces an enzyme called beta-hemolysin, which forms pores in the cell membranes of red blood cells, causing them to lyse, or break open.
Group B streptococcus is found colonizing as much as 30% of the human population, though it does not cause disease in most people. Group B streptococcus infections can be passed from pregnant mothers that to infants, in whom it can cause serious illness. A newborn is inoculated by bacteria in the vagina during birth or during the rupture of the membrane surrounding the infant prior to birth. However, the infant's immune system is not yet equipped to fight the infection. S. agalactiae is, therefore, the leading cause of infections in newborns and can be very dangerous. Group B streptococcus can quickly spread to the blood, causing sepsis.Additionally, Group B streptococcal infections of the urinary tract of pregnant women can induce labor and cause preterm birth. Newborns are at higher levels of risk of developing infection if their mothers are colonized or infected, if they experience a period of labor longer than 18 hours, or if they are born prematurely. One common means of preventing infections is to screen pregnant mothers to see if they are naturally colonized by S. agalactiae. If the mother has the bacteria in their normal microbiota, it can be treated with antibiotics during labor.
Bacterial Urinary System Pathogens
|Enterococcus faecalis (Gram-positive coccus native to the alimentary canal)||Poor hygiene, opportunistic||Commonly requires antibiotic mixtures; beta-lactam and multidrug resistance common|
|Escherichia coli (Gram-negative rod native to the alimentary canal)||Poor hygiene, opportunistic||Nitrofurantoin and ciprofloxacin antibiotics; ampicillin resistance common|
|Klebsiella pneumoniae (Gram-negative rod native to the alimentary canal and skin, found in soil)||Poor hygiene, opportunistic, long-term catheterization||Quinolone antibiotics; commonly resistant to beta-lactams|
|Leptospira (Spirochete from soil and nonsaline aquatic environments)||Indirect contact with urine from infected animals, water contaminated with animal excrement||Use of polymerase chain reaction suggests the use of Beta-lactam antibiotics|
|Proteus vulgaris (Gram-negative rod native to the alimentary canal)||Poor hygiene, opportunistic||Beta-lactam antibiotics, often in combination with beta-lactamase inhibitors|
|Pseudomonas aeruginosa (Widely distributed gram-negative rod)||Catheters, opportunistic, contact with standing water||Aminoglycoside, cephalosporin, polymyxin, or quinolone antibiotics; many multidrug-resistant strains|
|Staphylococcus saprophyticus (Gram-positive coccus, native to the alimentary canal and female genital tract)||Poor hygiene, opportunistic||Nitrofurantoin and trimethoprim-sulfamethoxazole antibiotics|
|Streptococcus agalactiae (Gram-positive coccus, native to the alimentary canal and genitourinary system)||Poor hygiene, opportunistic||Beta-lactam antibiotics, typically penicillin|