Mario Bonadio

Current Microbiological and Clinical Aspects of Urinary Tract Infections

Objectives: To evaluate some risk factors which could affect the isolation rates of various uropathogens and their in vitro susceptibility to antibiotics in ambulatory and hospitalized patients. Patients and Methods: A prospective study was conducted in a microbiological laboratory at Pisa Hospital. Nine–hundred and seventy–two consecutive patients with documented urinary tract infection were enrolled from April 1996 to October 1999. Data on age, sex, current or previous bladder catheterization, some underlying diseases as diabetes mellitus, and previous antibiotic therapy were recorded. The distribution of bacteria isolates and their in vitro susceptibility to antibiotics was evaluated. Results: Escherichia coli was responsible for 54.7% of urinary tract infections. Isolation of E. coli is decreasing in comparison to previous observations, especially in males and in patients with indwelling bladder catheters who instead show higher Pseudomonas spp. and Enterococcus spp. isolation rates than females and non–catheterized patients. Diabetes mellitus does not affect the isolation rate of uropathogens and their patterns of susceptibility. Multivariate analysis of multiresistant uropathogens showed a positive significant correlation with indewelling bladder catheter and age. An upward trend in the resistance of E. coli to cotrimoxazole, ampicillin and fluoroquinolones was observed from 1996 to 1999; more than 50% of Pseudomonas spp. strains were resistant to fluoroquinolones and gentamicin. Conclusions: The empirical antibiotic therapy of patients with urinary tract infection should be guided by an accurate anamnesis evaluating not only age and sex but also the presence of a bladder catheter at the moment of urine collection or a history of recent bladder catheterization and previous courses of antimicrobial drugs.

Measurement of Glomerular Filtration Rate in Man Using DTP A-99mTc

The aim of this study was the evaluation of the mechanism of renal excretion of DTPA-99mTc in man. For this purpose the renal clearances of DTPA-99mTc and diatrizoate-131

Asymptomatic Bacteriuria in Women with Diabetes: Influence of Metabolic Control

We screened 228 women with diabetes for bacteriuria during the period of January 1997 through December 2000 at Pisa General Hospital (Pisa, Italy). A control group of 146 women without diabetes was also evaluated. The frequency of significant bacteriuria was 17.5% (40 of 228) among women with diabetes and 18.5% (27 of 146) among women in the control group. Seven (13.5%) of 52 and 33 (18.8%) of 176 women with type 1 and in type 2 diabetes, respectively, had significant bacteriuria. The presence of higher glycated hemoglobin levels was the only significant risk factor for significant bacteriuria in women with type 2 diabetes. A similar frequency of bacteriuria in women with and women without diabetes was found. Severe impairment of metabolic control of type 2 diabetes increases the risk of acquiring asymptomatic bacteriuria.

Urinary tract infection in diabetic patients

Aim: The aim of the study was to compare the epidemiological, microbiological and clinical features of diabetic patients with urinary tract infection (UTI) to those of nondiabetic ones. Methods: A prospective study was performed on 490 consecutive patients with proven UTI. The patients were studied on the basis of a specific questionnaire and hospital records. Results: Of 490 enrolled patients, 89 (18.1%) had diabetes mellitus. The mean age of diabetics and nondiabetics was respectively 64.9 ± 13.2 (SD) and 54.4 ± 23.3 years. Most diabetics had asymptomatic bacteriuria and had undergone bladder catheterization more frequently than the nondiabetics. The most frequent causative agents of UTI in diabetics and nondiabetics were: E. coli (respectively, 56.1 vs. 56.8%), Proteus sp. (7.9% vs. 7.2%), Pseudomonas sp. (6.7 vs. 8.2%), Enterococcus sp. (6.7 vs. 7.2%). More than 50% of the isolated Pseudonomas sp. strains in both groups were resistant to gentamicin, piperacillin and norfloxacin. Both diabetics (52.8%) and nondiabetics (42.2%) had recurrent UTI during the follow-up period; the difference in the incidences did not reach statistical significance. Conclusion: No significant differences in epidemiological, clinical and microbiological evaluated features of diabetics and nondiabetics were pointed out, except for the higher frequency of bladder catheterization of diabetics than nondiabetics. However, the eradication of UTI seemed to be more difficult in diabetics than in nondiabetics.

Influence of Postural Changes on the Glomerular Filtration Rate in Nephroptosis

The influence of postural changes on renal function was determined in 13 patients with nephroptosis and in 5 normal subjects by measuring GFR in the erect and supine positions. The results indicate that GFR was reduced in the erect position in 10 of 13 patients with either unilateral or bilateral nephroptosis whereas GFR was increased in the erect position in 4 of 5 patients without renal disease. One patient with bilateral nephroptosis and renovascular hypertension was studied before and after surgical correction of his disease. These observations indicate that patients with nephroptosis may have significant reductions in renal function when they assume an upright position, and suggest that GFR measurements in the supine and erect position in patients with nephroptosis can be helpful in evaluating this disease.

Dip-Slide in Patients at High Risk of Urinary Tract Infection

146 initial and follow-up urine specimens of a urinary tract infection clinic were processed simultaneously by a dip-slide and by a standard pour plate method to evaluate the reliability of this simplified urine culture technique in a population with a high incidence of urinary tract infections. The dip-slide method gave false-negative results in only 8.7% of infected urines (greater than 10(5) cfu/ml urine), as determined by pour plate method. 1.3% false-positives were recorded. The false-negative rate rose to 22.2% when the dip-slide was used on the urines from patients on antimicrobial therapy. Our findings suggest that this simplified urine culture method is a useful tool even in populations with high incidence of urinary infections, although more careful evaluation of these test results is necessary when antimicrobial drugs are present in the urine specimens.

Experimental Infection in Uremic Rats: Preliminary Observations

To verify if uremia per se influences the eventual outcome of bacterial challenge, we have set up an experimental model of infection in rats with surgically induced uremia and controls. Our preliminary results indicate that both uremic and control rats die at the same rate when challenged intraperitoneally with LD50 of a Pseudomonas strain. These observations would suggest that uremia per se is not a major determinant of the increased incidence of infectious complications as has been noted in this condition.

Indapamide: Antihypertensive Activity and Renal Effects

Indapamide is a sulphonamide derivative with definite antihypertensive activity. The aim of this study is the evaluation of the antihypertensive efficacy and the effect on renal function of Indapamide in hypertensive patients with different degrees of renal function.