Laboratory diagnosis of urinary tract infection
Definition Urinary tract infection (UTI) is the active infection in any part of urinary tract beyond distal urethra which is normally bacteriologically sterile. Causative Agents A large number of organisms gaining access to urinary tract are capable of causing UTI (Table 1). These organisms may reach the urinary tract through ascending route or by haematogenous route. Table 1 : Causative agents of UTI Factors Predisposing to UTI Various bacterial attributes and host factors favour urinary tract infections. Mechanical factors are important. Anything that disrupts normal urine flow or complete emptying of the bladder, or facilitates access of organisms to bladder, will predispose an individual to UTI. Clinical Specimen: Collection and Transportation Mid-stream sample of urine is the ideal specimen for the diagnosis of UTI. First part of the urine washes away the surface commensals from the distal urethra and hence the midstream specimen indicates actual bacteriological pi...