Colonization and infection

Ureteral stenting (the insertion of the Double-J catheter) is and in the near future will remain one of the most common urological interventions. Consequently , bacterial and fungal complication of this stenting are in the focus of many controversial discussions [1]. These discussions are related not only to differences between patient selections, but also to differences in interpretation of basic definitions, such as coloniza-tion and infection. For most authors, colonization means infection and is the first stage of microbial infection by the establishment of the pathogen at the appropriate portal of entry. For a reduced number of authors, coloni-zation and infection remain two different processes. All multicellular organisms are colonized to some degree by extrinsic organisms, and the vast majority of these exist in either a mutualistic or commensal relationship with the host. The difference between an infection and colonization is often only a matter of circumstance. Non-pathogenic organisms can become pathogenic given specific conditions, and even the most virulent organism requires certain circumstances to cause a compromising infection. According to " Gale Encyclopedia of Medicine " [2], colonization is the presence of bacteria on a body surface (like on the skin, mouth, intestines or airway) without causing disease in the person. Infection is the invasion of a host organism's bodily tissues by disease-causing organisms. Infection also results from the interplay between pathogens and the defenses of the hosts they infect. The article " Rate of positive urine culture and double –J catheters colonization on the basis of microorganism DNA analysis " [3] states that " these results point a rule that stent insertion practically means its colonization " , and the underlying inconsistency between urine infection and stent coloni-zation confirms the presumption that colonization of the stents and urine infections are two different entities. Though they are related to one another, in a urinary infection, other risk factor such as age, comorbidities, basic urinary illness and the reason for stenting have the determinant role. It is worth mentioning here, that the problem of col-onization-infection occurs in other circumstances, interestingly all implantable medical devices, such as central venous catheters [4], pacemakers and TEP-s [5]. In biological conditions, where there are approximately ten times as many bacterial cells in the human flora as there are human cells in the body, and where it is a " rule that stent insertion practically means its colonization " may we say that " coloniza-tion …