Speciation and densities of yeasts in human urine specimens

Abstract

Urine specimens from 1013 patients were selectively and quantitatively cultured for yeasts. The presence of yeasts was correlated with the age, sex, and physical condition of the individual. Yeasts occurred at an incidence of 17-6% with approximately 6% of the patients demonstrating urine populations of at least 105 yeast cells/ml. Candida albicans, Torulopsis glabrata, and C. tropicalis were the most common species isolated. These taxa occurred in high densities most frequently among diabetics and terminal patients. Torulopsis glabrata was the most common species occurring in high numbers in urine specimens from diabetics with urinary tract pathologies; one diabetic patient died of a fungemia due to T. glabrata. The physiological and morphological characteristics employed for the identification of yeasts from urine specimens were critically examined and reviewed.The incidence of yeasts in urine specimens from hospital patients has been reported to range to 8% (Mackenzie, 1961; Stenderup & Pedersen, 1962), however true infections of the urinary tract by yeasts are considered to be infrequent (Hildick-Smith, Blank & Sarkany, 1964). In contrast to the established correlation between bacteriuria and urinary tract infections (MacDonald, Levitin, Mallory & Kass, 1957;Kass, 1959), a valid relationship between the population of urine by yeasts and the existence of actual infection is in question (Guze & Haley, 1958;Haley, 1965). Preliminary results obtained in our laboratories suggested that a quantitative urine culture for yeasts can be of value in ascertaining the probability of infection. To evaluate this observation, 1051 urine specimens submitted to the Clinical Laboratory of the Jackson Memorial Hospital, Miami, Florida for quantitative bacterial cultures were selectively examined for yeasts. The species and densities of yeasts in urine were correlated with the age, sex, clinical history, and physical condition of the patient. MATERIALS AND METHODSClean-voided midstream and catheterized urine samples were obtained with aseptic precautions from 1013 patients. Using individual pipettes, 1 ml. was diluted serially to 1:105 or greater in a diluent composed of 2-00//0 dextrose, 1 "0% peptone, 0.1% yeast extract, and 0.05% chloramphenicol; a second 1 ml. sample was similarly diluted in thioglycollate broth. The broths were incubated at 37 ° C. and those showing growth at 48 hr. were plated on appropriate solid media. Microbial growth from the broth with chloramphenicol was swab-streaked on to an agar medium of similar composition. Bacteria developing in the thioglycollate broth were isolated on blood and MacConkey agars and identified by conventional procedures. Yeast colonies on

Torulopsis glabrataurinary tract infection treated with 5-fluorocytosine

“…In this department T. glabrata was found in 82 of 234 midstream and catheter urines yielding 104 or more colonies per ml of yeasts (Speller and Davies, 1973) and it is likely that infection by this organism is commoner than has been thought. Ahearn, Jannach, and Roth (1966) isolated T. glabrata from 45 of 1013 urine specimens and noted that nine of the patients had diabetes mellitus. The association with diabetes has been noted by others (Guze and Haley, 1958;Edebo and Spetz, 1965;Marks et al, 1970) and Hasenclever and Mitchell (1962) showed increased multiplication of T. glabrata in the kidneys of mice when they were made diabetic with alloxan.…”

Germ-tube production by Candida albicans in minimal liquid culture media

“…Germ-tube production by Candida albicans occurs in mammalian serum and serum substitutes (7,11,13), plasma (3), egg white (4), human saliva (2), and a complex tissue culture medium (1). This morphological characteristic of C. albicans has also been used as an aid in the laboratory identification of C. albicans.…”

Serological diagnosis of infection of the urinary tract by yeasts.

“…The yeasts isolated in this investigation were those commonly encountered in such specimens (Ahearn et al, 1966;Speller and Davies, 1973). The funguria series and the control bacteriuria series differed in several important clinical features.…”

“…As with bacteriuria, quantitative criteria can be applied (Ahearn et al, 1966), and in fresh specimens a count of 105 or more colonyforming units per millilitre almost certainly implies that the yeast is not a contaminant but is genuinely colonizing the bladder urine. Most of the patients with significant funguria, however, appear to suffer no ill effects from this, often persistent, colonization (Schonebeck, 1972) and it is only the occasional patient in whom dramatic complications develop-blood stream or tissue invasion, urinary obstruction, etc.…”