Some strains of enteric Gram-negative bacilli have factors of virulence which produce urinary infections. Within these factors, adhesion and hemolysis are related with the localization of urinary tract infection (U.T.I.). Adhesion comes from a specific link between a bacterial phili, called adhesin and a human urothelium membrane receptor. Some of these receptors are identified, e.g., the mannose receptor and the D-galactosyl receptor. Strains with adhesion to the mannose receptor are called mannose-sensitive (M.S.), the M.S. strains do not have hemolysis properties (H -). Strains with adhesion to D-galactosyl receptor, are called mannose-resistant (M.R.) because they are not adhesive to the mannose receptor. These strains have hemolysis properties (H +). This work correlates strains of enteric Gram-negative bacilli mannose-resistant and (H +) with upper U.T.I., and mannose-sensitive (H -) strains with lower U.T.I. 16 patients with clinical evidence and a bacteriologic diagnosis of U.T.I. were followed. Patients were divided into two groups: first Group; having lower U.T.I. and the second Group: having upper U.T.I. The following determinations were made: a fresh exam of the urinary samples, culture in lactose-agar, quantification of total colonies, Gram-negative bacilli typing, hemoagluttination test with or without mannose and hemolysis in sheep's blood agar. 16 stains of enteric Gram-negative bacilli were studied (figure 1), 6 of these strains corresponded to lower U.T.I. and 10 of them to upper U.T.I. The lower U.T.I. strains were E. coli. Within these groups, 5 M.S and (H -) strains (83,3 %), and 1 M. R. and (H +) strain (16.7 %) were found. The upper U.T.I. producing strains were 8 E. coli, 1 Pseudomonas and 1 Proteus. 9 mannose- resistant and (H +) strains (90.0 %) and only 1 mannose-sensitive and (H -) were found that corresponded to an E. coli pregnant woman (figure 2). There is a relationship between the bacterial adhesion and U.T.I. localization. Adhesion constitutes a prerequisite for the start of an infection, and the receptor localization determines the position within urinary tract. Through immunohistochemistry techniques, the distribution within the urothelium of two membrane receptors are particularly thick around the introitus. Additionally, the mannose receptors spreads uniformly throughout the urinary tree and the D-galactosyl only appears in the collecting tube. Therefore, strains with adhesive quality constantly colonize the vagina and from this point they begins to ascend (figure 3). Those with adhesins to mannose will be attached progressively to the lower sectors. Those lacking adhesin keep on ascending to the kidney where they will become attached due to the adhesins to D-galactosyl. This study demonstrate the relationship between the lower U.T.I. with mannosesensitive and nonhemolytic strains (83.3 %) and the upper U.T.I. with mannoseresistant and (H +) strains (90.0 %). Knowledge of this pathological factor will allow to study new methods of prevention and treatment of recurrent U.T.I., such as the use of antibiotics in subinhibitory concentrations, or vaccine testing, and the use of substances that inhibit adhesins or membrane receptors. This investigative field open future expectatives for the control of recurrent urinary tract infections.
