Types and what are the dangers of bacteria in urine?

Today, we increasingly hear the question of whether bacteria in urine are dangerous. Should they be found there? It turns out that urine is considered a conditionally sterile biological fluid, so normally there should be no bacteria in it. However, in fact, bacteria are often found in urine. And this is already a sign of pathology, which can serve as an important diagnostic criterion, on the basis of which one or another diagnosis can be made.

Why are bacteria in urine dangerous?

Patients often ask the question: "What is the danger of bacteria in urine?" The main thing a patient needs to know is that normally there are no bacteria in urine. Therefore, their presence indicates inflammation and the development of an infectious process. This is dangerous because the infection progresses and causes serious damage to the kidneys and the genitourinary system as a whole. Chronic inflammation is dangerous, as well as possible consequences and complications, such as the formation of new foci of infection, or the penetration of infection into the reproductive system, the development of gynecological and urological diseases, which often lead to infertility, or problems during pregnancy and childbirth in women. [ 1 ]

Cylinders in urine and bacteria

If cylinders and bacteria are found in a patient's urine sample, this may indicate the development of a pathology in the urinary system and kidneys. So, first of all, you need to know exactly how many bacteria have been detected, and which ones (species and genus). It is also important to determine the type of cylinders, since different types of cylinders indicate different types of pathology. Normally, cylinders are absent; in case of pathology, they are detected during a microscopic examination of the urinary sediment. Most often, cylinders are derivatives of cellular or protein structures of the body, and appear in the urine as a result of the destruction of these structures.

For example, the detection of hyaluronic cylinders may indicate kidney pathology, the decomposition of protein components as a result of intoxication, exposure to high temperatures (prolonged fever, a sharp jump in body temperature). Often observed against the background of pregnancy, poisoning, severe infectious diseases, nephropathy and renal failure. [ 2 ]

Waxy casts are mainly represented by red blood cell mass and appear when blood elements enter a person's urine. For example, they can be a sign of kidney rejection, anemia, red blood cell damage, amyloidosis, in many chronic kidney pathologies and renal circulation disorders.

The appearance of red blood cell casts indicates open renal bleeding. Waxy and red blood cell casts are similar to each other, it is important to differentiate them accurately.

Epithelial and leukocyte cylinders indicate the development of an inflammatory process, powerful epithelialization, and are less often a sign of poisoning with heavy metal salts.

Granular casts are an unfavorable phenomenon. They can be a sign of nephrotic syndrome, the disintegration of cellular and tissue structures, indicate severe degenerative processes, renal failure. Often indicate the irreversibility of processes. [ 3 ]

Bacteria and urates in urine

The detection of bacteria and urates in human urine may indicate acidification of urine, that is, urine acquires an acidic environment. This means that it contains a large number of acidic salts. This is often observed at high temperatures or prolonged fever, with a temperature drop from critically low to high values, with various infectious diseases that affect the kidneys, and are also accompanied by hyperthermia. Urate often appears with gout, hypovolemia, which is accompanied by diarrhea and vomiting. Can be a sign of dehydration, severe dehydration of the body. Also, urates are no less often detected with extensive thermal burns, in situations in which thermoregulation is significantly impaired, the protective and excretory function of the skin is reduced. Urate can be diagnosed in urine after intensive radiation or cytostatic therapy, which takes place in the treatment of leukemia, malignant neoplasms. [ 4 ]

Urate is a small pigmented grain, which most often acquires a red, brick shade, and colors urine in the corresponding color. In this case, an acidic environment is formed. Accordingly, the microflora changes dramatically - representatives of the normal environment die, the number of acidophilic bacteria increases sharply, that is, bacteria that live in an acidic environment and consume acids as a nutrient substrate. This contributes to the additional development of inflammatory processes, irritation of the mucous membranes, dysbacteriosis appears.

Types of bacteria in urine

First of all, it is important to understand that normally there is not a single type of bacteria that could be found in urine. If we are talking about pathology, a fairly large variety of bacterial species can be found in urine.

It is important to distinguish the nature of the microbiocenosis. All types of bacteria in urine can be divided into three subgroups - transient, resident and obligate microflora. Transient microflora is bacteria that have entered the urine by chance and are not permanent inhabitants of the urinary tract. This may be microflora that was accidentally introduced from other foci of infection, which entered from other biotopes. The latter is especially common in women. For example, cases of vaginal microflora entering the urine due to the anatomical proximity of the genitourinary and reproductive systems. This also includes cases of infection from the external genitalia due to poor toileting, cases of collecting urine in non-sterile containers. [ 5 ]

Usually, two factors indicate transient microflora:

1. Bacterial species not typical for the genitourinary system were detected in the urine.
2. the number of microorganisms is insignificant (it may be one or several single colonies).

If transient microflora is detected or suspected, it is recommended to conduct a repeat study to confirm or refute the diagnosis.

Transient microflora most often includes various types of fungal infections, including yeast-like fungi of the genus Candida. These include Proteus vulgarus, Lactobacillus spp., Bifidobacterium spp., various representatives of vaginal, cervical, urethral microflora, pathogens of sexually transmitted diseases, less often - pathogens of tetanus, soil microorganisms, various types of anaerobic infection.

Resident microflora is represented by those microorganisms that normally inhabit the urogenital tract. These are various representatives of normal human microflora. It is appropriate to talk about opportunistic microorganisms, since normally (at an optimal quantity that does not exceed the norm), these microorganisms perform protective functions, preventing the development of urogenital tract diseases. This is achieved due to the colonization resistance of the mucous membranes, which occurs as a result of the functioning of opportunistic microflora. The presence of normal microflora does not allow the penetration of pathogenic microflora, and accordingly, protects against various diseases.

However, under certain conditions, opportunistic and normal microflora itself can cause disease, since its numbers increase sharply. Such a situation can arise with reduced immunity, after recent antibiotic therapy, after chemotherapy, radiation therapy, against the background of immunodeficiencies of varying severity, with dysbiosis and dysbacteriosis. Resident microflora includes various types of staphylococci, streptococci, E. coli, enterococci, Klebsiella, various types of bacilli, vibrios. Most often, this is gram-positive aerobic microflora. When identifying transient microflora, the diagnostic value is not so much its qualitative characteristics as its quantitative indicators. [ 6 ]

Obligate microflora is represented by pathogenic microorganisms that should not normally be in the human body, and primarily in the genitourinary system. These are all pathogens of inflammatory and infectious diseases, bacteremia, sepsis. This includes a wide variety of gram-negative and gram-positive microorganisms, which can be both aerobes and anaerobes. Acidophilic microorganisms that live in urine with increased acidity are also common. These can be various types of genitourinary, venereal infections, representatives of the intestinal group, mycobacteria, urobacteria, chlamydia, rickettsia, prions, spitochetes, and even tuberculosis bacteria.

E. coli bacteria in urine

E. Coli bacteria are not normally found in urine. Escherichia coli is nothing more than intestinal stick, which is normally a representative of the normal intestinal microflora. It can occur in urine during some inflammatory and infectious processes. Penetration of intestinal stick into biotopes that are not typical for it, for example, into the genitourinary tract, causes an inflammatory process in it. Therefore, it is important to determine quantitative indicators. The higher the degree of bacterial contamination, the more severe the inflammatory process. If more than 10 ⁴ CFU/ml is detected, antibiotic therapy is required. [ 7 ]

E. Coli bacteria can also get into urine accidentally, for example, when using a poor toilet and feces get into the urine, or when collecting urine in a dirty container (transient microflora). But in this case, single microorganisms are detected. A large number of these bacteria often indicates a pathological process and requires treatment. If single colonies of microorganisms are detected, the analysis must be repeated. [ 8 ], [ 9 ]

Klebsiella bacteria in urine

Depending on the exact type of Klebsiella bacteria detected in the urine, the exact source of penetration of the said bacteria into the body can be determined. Klebsiella is often a representative of the normal microflora of the urogenital tract, intestines or respiratory system. Detection of over 10 ⁴ CFU/ml indicates the development of an intense inflammatory and infectious process. The risk of developing bacteremia and sepsis increases sharply. In most cases, antibiotic therapy is required.

Bacteria of the genus Klebsiella can be found in urine mainly in pathologies of the kidneys, bladder, cystitis, pyelonephritis, and other inflammatory processes, as well as in cases of reduced immunity, after antibiotic therapy, treatment with uroseptics, after operations on the genitourinary system, after many infectious diseases, and even colds.

Proteus bacteria in urine

Detection of Proteus bacteria in urine may indicate inflammatory processes. Proteus is a normal representative of the urogenital microflora. Normally, no more than 10 ³ CFU/ml are found in the genitourinary system (on the mucous membranes). Exceeding these parameters indicates the development of inflammation, as well as a decrease in the protective and compensatory mechanisms of the mucous membranes. A similar situation is often observed with dysbacteriosis, as well as in women with gynecological diseases. Failure to observe personal hygiene, especially in women during menstruation, can lead to an increase in the number of these microorganisms. Exceeding the norm requires antibiotic therapy. [ 10 ], [ 11 ]

P. mirabilis is capable of causing symptomatic urinary tract infections, including cystitis and pyelonephritis, and is present in cases of asymptomatic bacteriuria, particularly in the elderly and patients with type 2 diabetes.[ 12 ],[ 13 ] These infections can also lead to bacteremia and progress to potentially life-threatening urosepsis. In addition, P. mirabilis infections can cause the formation of urinary stones (urolithiasis).

P. mirabilis is frequently isolated from the gastrointestinal tract, although whether it is a commensal, pathogen, or transient organism is somewhat controversial. Most P. mirabilis urinary tract infections (UTIs) are thought to result from shedding of the bacteria from the gastrointestinal tract, while others result from person-to-person transmission, particularly in health care settings.[ 14 ] This is supported by evidence that some patients with P. mirabilis UTIs have the same strain of P. mirabilis in their stool, while others do not have P. mirabilis in their stools.[ 15 ] In addition to urinary tract infection, this species can also cause infection of the respiratory tract, eyes, ears, nose, skin, throat, burns, and wounds, and has been associated with neonatal meningoencephalitis, empyema, and osteomyelitis. [ 16 ] Several studies have linked P. mirabilis to rheumatoid arthritis, although others have failed to find a link (see reviews in [ 17 ] and [ 18 ]). It is thought that antibodies against the enzymes hemolysin and urease are subsequently able to recognize autoantigens targeted in patients with rheumatoid arthritis.

Cocci bacteria in urine

Cocci bacteria may be detected in urine, which is considered a sign of pathology, since urine should normally be sterile. Cocci are any bacteria that have a round shape (staphylococci, streptococci, enterococci, pneumococci, and others). The appearance of cocci, like any other bacteria in urine, means only one thing - the development of a pathological process in the body. First of all, this means an inflammatory process, which is accompanied by the development of a bacterial infection. [ 19 ]

When cocci are detected, it is important to identify them (determine the exact name of the microorganism species) and determine quantitative indicators. Knowing how many cocci are found in the urine, one can judge the severity of the infectious process, draw conclusions and forecasts, and select appropriate treatment. [ 20 ]

It is impossible to give a definitive answer to the question of what caused the appearance of cocci bacteria in urine (at least without an accurate comprehensive diagnosis). This is due to the fact that there is a fairly wide variety of these reasons. [ 21 ]

Enterococcus bacteria in urine

Enterococcus bacteria may be detected in urine. To be more precise, it should be said that representatives of the genus Enterococcus have been detected, since this generic name unites a large number of similar related bacteria. Normally, they are representatives of the normal intestinal microflora, and when they enter the genitourinary system, they lead to the development of an infectious process. There may be several ways for enterococci to enter urine. Most often, this is autoinfection or infection from external sources. Autoinfection should be understood as a source of infection located in the body. From it, an inflammatory and infectious process subsequently develops. This may be a chronic infection of the urinary tract, kidneys, reproductive system, latent, active or chronic genitourinary infections, venereal diseases. [ 22 ]

With an external source of infection, the infection enters the body from the external environment. It can enter the urine accidentally, for example, with feces, with insufficient toilet before collecting urine for analysis. In women, the cause of infection is often the penetration of infection from the genitals (from the external genitalia, the infection rises up to the genitourinary system, forming the main source of infection). In some cases, the detection of representatives of the intestinal microflora in the urine may indicate proctological diseases, and also be a sign of a rectovaginal fistula in women, in which the contents of the intestine enter the vagina and genitourinary system. With a fistula, there is an opening (through fistula) in the rectovaginal septum, which separates the intestine (rectum) from the vagina and urinary system. [ 23 ]

In urine bacteria +, ++, +++

In the analysis results, it is necessary to determine not only the presence of bacteria in the urine, but also to indicate their approximate quantity. The exact quantity (a specific numerical value expressed in CFU/ml) can only be determined during a special bacteriological study, during which urine is sown on special nutrient media, then the pathogen is isolated and identified. In a regular general (clinical) analysis, only the conditional degree of bacteremia is indicated. Thus, bacteria in urine are designated by the signs +, ++, +++. The + sign indicates an insignificant amount of bacteria in the urine. These may be single bacteria. The ++ sign indicates a moderate amount that exceeds the normal values and may be a sign of infection. The +++ sign may indicate an intense inflammatory and infectious process in the genitourinary system, and requires additional diagnostics and mandatory treatment. Also, in some classifications, the ++++ sign is distinguished, which indicates a severe infectious process, bacteremia, sepsis. [ 24 ]

Bacteria in urine in moderate amounts

Despite the fact that the test results may indicate the ++ sign, which indicates the presence of bacteria in the urine in moderate quantities, such a formulation is incorrect and uninformative. This can only indicate the need for detailed diagnostics. It is necessary to conduct a bacteriological study, check the urine for sterility. During these laboratory tests, the exact quantitative content of microorganisms in the urine will be revealed. It is also important to identify the microorganisms and determine the exact species of the pathogen. This will allow you to choose the appropriate treatment.

Significant amount of bacteria in urine

If a significant number of bacteria are detected in the urine (designation +++ or ++++ in the OAM results), additional diagnostics must be performed. During additional diagnostics, it is necessary to determine the type of microorganism and its exact quantity, expressed in CFU / ml. This is the basis for making an accurate diagnosis and prescribing appropriate treatment. It is also important to take into account the patient's current condition, the clinical picture of the pathology, and the symptoms. If a significant number of bacteria are detected in the urine, the latent course of the pathology is almost completely excluded. The person will have pronounced symptoms of an inflammatory and infectious process. In more detail, the symptoms depend on which bacteria are detected in the urine (different bacteria cause different pictures of the pathology).

Symptoms such as urinary dysfunction, frequent or false urge to urinate, pain, stinging, burning, discomfort are often present. The pain increases at night. The pain may increase sharply with movement.

Complications and consequences

The consequences, complications, can be very unfavorable. Bacteria in the urine always indicate the development of inflammation, an infectious process. The infection requires treatment, it never goes away on its own. Without treatment, there is a fairly high risk of sepsis and bacteremia, as well as kidney failure, insufficiency, cirrhosis, necrosis. Less dangerous consequences are the development of a chronic infection, which will be accompanied by periodic exacerbations, relapses, and can also cause various inflammations of the genitourinary system - from cystitis to nephritis, pyelonephritis, glomerulonephritis, nephropathy. [ 25 ]

No less dangerous is a latent infection, foci of infection that can migrate to other biotopes, like metastases in cancerous tumors. An infection in the urine that is not completely cured can cause reproductive pathologies, including infertility, the inability to conceive and bear a child. In women, an infection in the urine can cause abortions and miscarriages, premature births and even intrauterine infection of the fetus. Therefore, mandatory treatment is required, often even hospitalization in a specialized department. The sooner it is started, the more effective and faster the result will be. It is important to start treatment in a timely manner.