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Biomedical subjects

D F Birch

Publications and source records attributed to D F Birch.

33 records · Page 2Linked to original sources

Comparison of mid catheter collection and suprapubic aspiration of urine for diagnosing bacteriuria due to fastidious micro-organisms.

We examined 40 female patients for the presence of fastidious bacteria in the bladder by culture of mid catheter and suprapubic aspiration urine specimens. Gardnerella vaginalis and Ureaplasma urealyticum were the most frequently isolated fastidious species. The suprapubic aspirate was positive in 3 patients with more than 10(5) colony-forming units per ml. Gardnerella vaginalis and 7 with more than 10(2) colony-forming units per ml. Ureaplasma urealyticum in the mid catheter urine specimen, while it was negative for bacteria in 6 patients with less than 10(4) colony-forming units per ml. coryneform bacilli or lactobacilli in the mid catheter urine specimen. The results show that culture of mid catheter urine samples provides a reasonable guide to the presence of bacteriuria owing to fastidious micro-organisms and can be used when a suprapubic aspiration specimen cannot be obtained easily.

Bacteriological Techniques↗

Unconventional bacteria in urinary tract disease: Gardnerella vaginalis.

Bladder aspirate urine samples (N = 190) were cultured for the presence of fastidious microorganisms. These samples were obtained from patients with urinary tract disease in whom standard bacteriologic investigation had failed to indicate infection. Gardnerella vaginalis was recovered alone, or in association with Ureaplasma urealyticum from the bladder urine of 33% of patients with reflux scarring. G. vaginalis was localized to the upper urinary tract in 75% of these patients with bladder counts greater than 10(3) colony-forming units per milliliter. The results show that two fastidious microbial species, not conventionally associated with urinary tract infection, are recoverable from the upper urinary tracts of patients with so-called sterile pyelonephritis.

Bacterial Infections↗

Urinary erythrocyte morphology in the diagnosis of glomerular hematuria.

Urine samples from 141 consecutive patients referred for investigation of microscopic hematuria were examined by phase-contrast microscopy to determine the probable site of bleeding into the urinary tract. Dysmorphic (i.e. morphologically variable) erythrocytes, suggestive of glomerular bleeding, were present in 86 of 87 patients with significant hematuria who were later shown to have glomerulonephritis. In contrast, all of 30 patients with non-glomerular lesions had isomorphic (i.e. morphologically uniform) erythrocytes in the urine. Ten patients yielded a mixed morphologic pattern suggestive of dual pathology which was confirmed in four patients. Urine erythrocyte counts from 376 healthy individuals showed that 95% yielded less than 8,000 cells/ml and in each case erythrocytes exhibited a dysmorphic pattern suggesting that erythrocytes enter the urine of healthy subjects via the glomerulus. Electron microscopy of urinary erythrocytes from 36 patients with glomerulonephritis demonstrated the range of dysmorphic changes characteristic of glomerular bleeding, presumably resulting from environmental changes suffered by the erythrocytes within renal tubules.

Adolescent↗

Urinary red-cell morphology during exercise.

Midstream urine samples were examined by phase-contrast microscopy before and immediately after 48 subjects participated in a long-distance run. Minor abnormalities were found in six samples before exercise. Eighteen subjects developed proteinuria and five haematuria on dipstick testing after exercise. Forty-four subjects had increased urinary red-cell counts after exercise; of these, 33 had counts above the normal range (800/ml). In all subjects urinary red cells were dysmorphic both before and after exercise, indicating a glomerular source. Ten subjects developed red-cell casts and 42 showed an increase in hyaline and hyaline-granular casts after exercise. There were modest increases in urinary white-cell counts in 35 subjects but little change in urine pH or osmolality with exercise. This study confirms that urinary red-cell counts commonly increase appreciably after exercise. The dysmorphic appearance of the red cells together with the presence of red-cell casts indicates a glomerular source for this common form of exercise haematuria.

Adolescent↗

Haematuria associated with ureaplasma infection in sickle-cell trait.

Phase-contrast microscopy of the urine of a young Greek woman with macroscopic haematuria showed sickling of the red blood cells. The diagnosis of sickle-cell trait was confirmed with haemoglobin electrophoresis, and an intravenous pyelogram demonstrated the typical medullary cavities seen in this disease. Urine collected from the left ureter, from which the haematuria originated, grew 10(6) Ureaplasma urealyticum/ml. With Doxycycline therapy the macroscopic haematuria and the sickled cells in the urine resolved, but red cell casts and an excessive number of glomerular red blood cells persisted in the urine, confirming the presence of glomerulonephritis. Ureaplasma urealyticum has not previously been described in association with a sickling episode nor with the scarring of a sickle cell kidney. The possible role of this infection is discussed.

Adult↗

Unconventional bacteria in urinary tract disease: Ureaplasma urealyticum.

Bladder-aspirate urine samples (N = 428) were cultured for the presence of fastidious microorganisms. These samples were obtained from 190 patients with urinary tract disease or symptoms suggesting infection of the urinary tract in whom standard bacteriologic investigation had failed to indicate bacterial infection. Ureaplasma urealyticum was recovered alone or in association with other microorganisms from the bladder urine of 75% of patients with reflux scarring and abnormal renal function. Ureaplasma organisms were localized to the upper urinary tract in 80% of patients with bladder counts greater than 10(3) colony-forming units per ml. The results indicate that microorganisms not conventionally associated with urinary tract infection are recoverable from the bladder urine of a high percentage of patients with so-called "sterile pyelonephritis," in which group of patients these microorganisms may contribute to progressive renal disease.

Female↗

Ureaplasma urealyticum in the upper urinary tracts of renal allograft recipients.

Urine samples from 123 renal transplant recipients were cultured for the presence of Ureaplasma urealyticum and other fastidious microorganisms. Ureaplasmas were recovered alone or in association with other microbial species from the bladder urine of 13 (11%) of the 123 patients, and evidence of involvement of the upper urinary tract was present in nine patients. Colonization of the upper urinary tract by U. urealyticum was not associated with a decline in function of the grafted kidney and was found only in patients with a primary diagnosis of reflux nephropathy (50% of such patients were positive for ureaplasmas) or glomerulonephritis (10% were positive) who had their own kidneys. The next most common isolate was Gardnerella vaginalis, recovered from 7% of patients, the majority of whom harbored the organism in the bladder only. The results confirm that U. urealyticum may colonize the upper urinary tracts of patients with proven renal disease.

Female↗

Persistent bacteriuria in the rat after reflux challenge with Pseudomonas aeruginosa.

An experiment based upon reflux of culture suspensions of Pseudomonas aeruginosa into the rat kidney was set up to examine possible factors of importance in the development of ascending renal infection. We monitored the persistence of challenge bacteria in the rat urinary tract by quantitative culture of urine collected by spontaneous micturition, despite heavy contamination with commensal microflora. In most animals challenged, pseudomonads gave rise to bacteriuria of only limited duration. During bacterial persistence in urine, colony counts fluctuated widely from day to day.

Animals↗

Renal infection in the rat after reflux challenge with Pseudomonas aeruginosa.

A rat-pseudomonad reflux model was employed to examine the effect of the size of inoculum on the emergence of renal infection. Widely varying degrees of renal disease observed in challenged animals indicated that a number of variables influenced the outcome of the host-parasite interaction. In this regard, animals in which there was a reduction of the colony counts below a threshold figure rarely gave evidence of renal infection when examined at autopsy on the eighth day following reflux. These results suggest that a threshold level of bacteriuria may also have to be exceeded if renal infection is to become established in patients with vesico-ureteric reflux.

Animals↗