Urinary Tract Infections (Essay Sample)

URINARY TRACT INFECTIONS
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Urinary Tract Infections
Urinary Tract Infection is often described as the invasion of the tissues that make up the urinary tract system by microbial organisms. The infection of the human urinary tract is a major symptom for the contemporary experimental microbial treatment in both primary and secondary care. Additionally, the number of urine samples when compared with the other typical specimens in the field of medical microbiology laboratories is very large. In normal human condition, the urinary tract is often sterile though the urinary tract infections can result from different conditions. The infections can be simple or complicated, symptomatic or asymptomatic infections. Clinical physicians in medical microbiology have categorized urinary tract infections into upper and lower tract infections on an anatomical basis. An infection of the bladder is referred to as cystitis and in cases where the infection spreads to other areas such as the ureters and the kidneys, the infection is referred to as pyelonephritis. Cystitis is thus regarded to as a lower urinary tract infection while pyelonephritis is an upper urinary tract infection. The latter is much more severe and usually complicated. In spite of the availability of several antibacterial factors such as urea concentration, pH, salt content of the urine, osmolarity, and other urinary tract inhibitors of bacterial adherence, several bacteria are still able to invade the urinary tract system. The bacteria predispose the patients to a variety of urinary tract infections. The most common types of bacteria that have been correlated with a diverse range of urinary tract infections include the Gram negative bacteria of E. coli and the Klebsiella species. The uropathogenic bacteria have still been able to overcome the several urinary inhibitors to bacterial invasion such as the Tamm-Horsfall protein (THP), lactoferrins, low-molecular weight oligosaccharides, bladder mucopolysaccharides, and secretory IgA. Thus, the presence of bacteria inhibition factors and conditions, the bacteria are still able to adhere, grow, multiply, and resist against the host’s defense mechanisms, ultimately resulting in massive colonization and subsequent infection of the urinary tract system (Stamm 2006, 2-4). This paper is aimed at reviewing the numerous bacteria that are responsible for the various urinary tract infections. It also highlights the laboratory diagnostic routine procedures that are used in the diagnosis of these bacteria in the most prone particular population groups, as well as the infections are usually exhibited by the general populations.
Bacteria that may cause urinary tract infections
Many researchers and scholars in microbial urinary tract infections are in agreement that the Gram negative bacteria of E. coli and the bacteria associated with the Klebsiella species are the most common organism that causes urinary tract infections in both males and females. In fact, E. coli is responsible for between 70-90% of both upper and lower urinary tract infections ( HYPERLINK "/search?sa=X&tbm=bks&tbm=bks&q=inauthor:%22Angela+Kilmartin%22&ei=-SWoU8OILam47AblgYH4Aw&ved=0CCIQ9AgwAQ&biw=819&bih=506" Kilmartin 2002, 38).
The E. coli is responsible for many uncomplicated cases of cystitis in females, especially the younger women. The bacteria are usually harmless with its origin being the intestines. However, when the bacteria invade the urinary tract, it can colonize the bladder and result in an infection. Enterococci, proteus mirabilis, and Staphylococcus saprophyticus are other forms of bacteria that are responsible for between 5-15% of urinary tract infections, especially in younger females (Irwin &Rippe 2008, 6-7). Some rare bacteria that cause some forms of urinary tract infections include Mycoplasma hominis and Ureaplasma urealyticum. These are typically harmless organisms. Citrobacter has also been associated with some complicated forms of urinary tract infections that are related to structural or physical conditions.
Other forms of bacteria that can cause complicated or severe urinary tract infections include Enterobacter, aeruginosa, and the Serratia species gram-positive bacteria including the Enterococcus species.
Risk Factors and Risk groups for urinary tract infections
Some of the major risk factors that have been associated with urinary tract infections include, genetic predisposition, behavioral factors, frequency of urination, urologic structural abnormalities and the antibacterial activity of prostatic fluid (in males). Other predisposing factors include the numerous aspects of personal hygiene and use of birth control pills, diabetes, pregnancy conditions, hypertension, immune-suppression, low concentration of lactobacilli in older females, stone formation, and instrumentation such as catheterization during medical procedures.
Several research studies have shown that females are more susceptible to these infections than their male counterparts. Indeed, re-infections tend to occur more in women than in men. This is because the urethra is longer in men and shorter in women. The use of contraceptive spermicides and diaphragm are other risk factors that make women more susceptible to urinary tract infections than men (Foxman 2005, pp. 5). Numerous research studies have highlighted that urinary tract infections in women are much common such that one in five women suffers a form of urinary tract infection in their lifetime. On a clinical perspective, the issue of urinary tract infection in women is a recognized global problem.
When women attain the menopause age, there is a substantial decrease in estrogen that protects the inner lining of the urinary tract, and this increases their susceptibility to bacterial urinary tract infections. Although pregnancy has not been shown to exacerbate the development of urinary tract infections, evidence suggests that it exacerbates the risk of developing some serious infections that can potentially harm both the mother and the fetus. Therefore, pregnant women are advised to report to any symptoms of urinary tract infections to their medical supervisors for timely screening for asymptomatic bacteriuria (Clarridge, Johnson & Pezzlo 2001, 18).
Individuals who suffer from spinal cord injuries or severe nerve damage around the bladder area have difficulties in emptying their bladder completely. Consequently, bacteria get a precise chance to grow and multiply within the urine that over-stays within the bladder. Furthermore, any individual who has an abnormality of the urinary tract, such as a kidney stone or an enlarged prostate, has a higher risk of developing some form of urinary tract infection. Individuals suffering from diabetes or those with issues in their body’s natural defense mechanisms are more susceptible to urinary tract infections.
Another primary cause of infections along the urinary tract stems from the use of tubes or catheters that are placed in the bladder or urethra. These devices interfere with the body’s ability to remove microbes from the urinary tract. As a result, bacteria are able to travel around or through the instruments until they establish an area where they are able to grow and thrive. It is plausible to note that people who are unconscious or critically ill cannot regularly urinate, and this necessitates the need for use of catheters in order to aid the process of emptying the bladder. Therefore, medical scholars emphasize that the use of such devices should be limited to the minimum time possible (Carroll, Hale, Von Boerum, Reich, Hamilton & Matse 2004, 102).
The various methods used in microbiology laboratories for the identification and characterization of the several bacteria involved in the causation of urinary tract infections include Gram stain followed by motility testing, biochemical test and microscopic examinations. The Enteric bacteria, particularly the E. coli remains the commonest cause of urinary tract infections, accounting for a great percentage of the workload in clinical microbiology laboratories. Although the E. coli bacteria are the most frequent causes of urinary tract infections, the distribution of the pathogens that are responsible for the urinary tract infections is changing significantly. Of great importance is the increase in resistance to several antimicrobial agents, especially the resistance to trimethoprim-sulfamethoxazole as is the case with E. coli (Andriole 2005, 94). Clinical physicians have been to distinguish urinary tract infections from other infections that bear similar clinical signs through the utilization of a small number of combined clinical tests. This is because none of the several tests, when used individually has the potential to offer adequate specificity and sensitivity. In the category of the diagnostic tests, urinalysis remains broadly useful especially for the exclusion of bacteriuria. The urine culture is not always necessary as part of clinical evaluation of out-patients who show uncomplicated urinary tract infections. However, it is still necessary for the out-patients who demonstrate to have recurrent cases of urinary tract infections, or those patients who exhibit complicated cases of urinary tract infections. The urine culture is also necessary for the evaluation of in-patients who develop urinary tract infections within the clinical set-up. Urinary tract infections pose serious challenges for clinical practitioners, not only due to the large number of cases that are reported every year, but also because the diagnosis of urinary tract infections is not often a straightforward undertaking. This means that physicians have to differentiate urinary tract infections from other types of infections that have similar clinical manifestations. For example, some urinary t...