39 research outputs found

    EXPERIMENTAL PYELONEPHRITIS : I. EFFECT OF URETERAL LIGATION ON THE COURSE OF BACTERIAL INFECTION IN THE KIDNEY OF THE RAT

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    A study has been made of the effect of ureteral ligation on the susceptibility of the kidney to pyogenic infection. In most experiments a strain of E. coli was employed as the test organism, being injected intravenously in varying quantity either before or after ureteral ligation. A few experiments were also carried out with S. marcescens. Preliminary observations were made on the distribution and persistence of E. coli following its inoculation into the blood stream of normal rats. Rapid reduction in number of bacteria in the circulation occurred during the first 30 minutes, but bacteriemia persisted at a comparatively low level for at least 48 hours. Large proportions of the inoculated bacteria were arrested and apparently destroyed in the liver, spleen, and lungs. Comparatively small numbers were deposited in the kidneys; nevertheless, these continued to be demonstrable during the 1st week, without notable tendency to increase or decrease, then disappeared during the 2nd week. There was no acceleration in rate of disposal of the bacteria in the kidney when a second injection was made 1 week after the first. In rats with one ureter ligated the number of bacteria lodging in the kidneys after intravenous inoculation did not differ from that found in normal animals. It appears, therefore, that the increased susceptibility of the obstructed kidney to infection via the blood stream is not attributable to an increased trapping of circulating bacteria. 4 to 6 hours after the intravenous injection, however, an increased number of bacteria could be demonstrated in the obstructed kidney, apparently due to local multiplication, and by the end of 24 hours purulent infection was usually obvious. A comparatively large number of bacteria was required to cause infection, even in the kidney with obstruction. This appeared to be related to the small proportion of the intravenous inoculum which lodged in the kidney initially. Although bacteria could be demonstrated in the normal kidney for a week or more following intravenous injection it was not possible to induce active infection with equal regularity by ligating the ureter throughout this time. During the first 3 days the majority of obstructed kidneys developed infection, but after 5 or more days this occurred in only a small proportion of animals so treated. The reason for the difference, in relation to interval between intravenous injection and time of ligation, is not apparent. When the ureter was ligated but no intravenous injection of bacteria was given, staphylococcal infection developed in the obstructed kidney within 2 weeks in about one-third of the animals. Reasons are given for the belief that this was blood-borne infection, and not the result of contamination at the time of operation. Staphylococci were not recovered from the normal rat kidney. These "spontaneous" staphylococcal infections seldom developed when E. coli was injected intravenously at the time of ureteral ligation

    Pyelonephritis XV. Long-term study of ascending Escherichia coli pyelonephritis in mice.

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    Keane and Freedman (1) demonstrated that diuresis produced by feeding 5% glucose rendered mice susceptible to acute ascending pyelonephritis with Escherichia coli. We reported the use of this model in therapeutic studies of E. coli (2) and Proteus mirabilis (3) pyelonephritis. The present investigation, a bacteriologic, immunologic, and pathologic study of long-term infection with E. coli shows that pyelonephritis persisted and progressed for the duration of the study (32 wk). MATERIALS AND METHODS Animals. Random-bred male Swiss-Webster mice weighing 20-25 g were obtained from local commerical sources. Bacteria. Escherichia coli strain Yale, originally isolated from a patient with urinary tract infection, was used. Media. Brain-heart infusion broth and agar (Difco) were used. Blood agar base (BBL) with 5 % defibrinated sheep erythrocytes was used to grow the E. coli directly from infected kidneys during mouse passage to maintain virulence. Production of diuresis. Experimental animals were fed 5 % glucose in water a

    FUNGUS INFECTIONS OF THE URINARY TRACT,

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    Although bacterial infections of the urinary tract have received considerable attention in recent years, diseases of this system due to fungi have only been sporadically mentioned in the literature. The majority of cases reported have been instances of renal involvement secondary to dissemination of the fungi by the circulation. Only a few instances of primary diseases have been noted. With the increase in number of fungal infections observed in recent years, " it would be expected that a similar rise might occur in the incidence of primary urinary tract infections due to fungi. Since the clinical appearance of fungal and bacterial infections of the kidney and bladder are often indistinguishable, the diagnosis must be made from information obtained by urine culture. Fungi frequently appear in the urine in small numbers and are usually discarded as contaminants by laboratory personnel. However, with the use of quantitative methods of culture, it is possible to distinguish a significant bacteriuria (or "funguria"). ' This report describes observations made on 15 patients whose urines contained large numbers of fungi. MATERIALS AND METHODS Urine specimens were obtained in male and female patients by "clean voided" technique. Previous observations have demonstrated that this is a satisfactory method of collection when quantitative bacteriological procedures are employed.28 8 Urine was diluted serially in nutrient broth and 1 ml. of a 1: 100 dilution incorporated into an agar pour plate. (Earlier in the work an additional plate was made with an aliquot of a 1: 10,000 dilution.) Additional samples of undiluted urine were inoculated into blood and desoxycholate agar plates and thioglycollate broth. Cultures were examined after incubation for 48 hours at 37 ° C. In this manner an estimate of the type and quantity of organisms was obtained and further identification performed by appropriate methods

    The Rhinoviruses of Man

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    Rhinoviruses, prominent agents of the common cold syndrome in man, are small ribonucleic acid (rna) viruses resembling enteroviruses in their physicochemical properties except for high density and lability to acid pH. Rhinoviruses are propagated in human and monkey cells. Highest titers of virus are obtained in HeLa cell cultures. Rhinoviruses produce characteristic cytopathic effect in diploid fibroblasts. A plaque assay in HeLa cells is useful for their titration. The rhinovirus group includes many serotypes. Although rhinoviruses cause predominantly upper respiratory tract symptoms, they may on occasion infect the lower respiratory tract. Volunteers with specific antibody, when challenged with homotypic rhinovirus, are protected against the common cold

    Susceptibility of Herpesviruses to Cytosine Arabinoside: Standardization of Susceptibility Test Procedure and Relative Resistance of Herpes Simplex Type 2 Strains

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    Susceptibility testing of herpes simplex type 1 (HSV-1) and type 2 (HSV-2) viruses to cytosine arabinoside (Ara-C) has been standardized under conditions of optimal reproducibility, susceptibility, and simplicity. Standard conditions were defined as virus inoculum of 10(1.5) to 10(2.5) TCID(50), WI-38 strain of lung fibroblasts, 2-day incubation, and observation of virus cytopathic effect after staining by the May-Greenwald-Giemsa method. The variability of minimum inhibitory concentration (MIC) of cytopathic effect was fourfold within each test and sixfold in successive assays. MIC values of all seven tested HSV-1 strains were in the range of 0.25 to 0.75 μg per ml, whereas four of nine HSV-2 strains had MIC values of 0.9 μg per ml and greater. A similar method can be used for assay of virus inhibitory titers of body fluids
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