Microbiological cultures of heart valves and valve tags are not valuable for patients without infective endocarditis who are undergoing valve replacement

We evaluated the significance of the results of microbiological cultures of heart valves and identification tags from newly inserted prosthetic valves that were removed from patients with valvular heart disease; none of these patients had a preoperative diagnosis of endocarditis. We reviewed the charts of patients with positive cultures for evidence of infections before or after surgery. Cultures were positive for 11.9% of 219 valves (206 native valves and 13 prosthetic or bioprosthetic valves) and 11.6% of 224 tags. The most common isolates were coagulase-negative staphylococci. Typical agents of endocarditis--viridans streptococcus, Enterococcus faecalis, and Staphylococcus aureus--were cultured from five specimens, and Mycobacterium avium complex was identified in six valves. None of the patients with positive valve or tag cultures developed postsurgical endocarditis or wound infection. Findings on histopathologic examination of the valves were not consistent with endocarditis. We conclude that the results of cultures of valves from patients without preoperative diagnoses of endocarditis lack clinical significance, and positive tag cultures are not predictive of postsurgical infection. Positive cultures are most likely a result of contamination during surgery or thereafter.     

Lack of clinical utility of bronchoalveolar lavage cultures for cytomegalovirus in HIV infection

This study assessed the presence of cytomegalovirus (CMV) in bronchoalveolar lavage (BAL) in three subpopulations of HIV-infected patients and correlated its presence with clinical status during 3 mo of follow-up. Nineteen asymptomatic volunteers, six patients with CMV retinitis, and 46 patients with acute pulmonary symptoms underwent BAL and were assessed for CMV by cytopathology, conventional shell vial cultures, and antigen detection. Transbronchial biopsies were also obtained when possible and evaluated for histopathologic changes of CMV. All patients were followed for approximately 3 mo. Cytomegalovirus was detected in BAL in nine of 19 (47%) asymptomatic volunteers, in all six patients with CMV retinitis, and in 33 of 46 (72%) patients with pulmonary symptoms. Only one symptomatic patient with a positive CMV BAL culture developed clinically significant CMV pulmonary disease; this patient developed disseminated CMV and died. The only other death occurred in a patient with CMV retinitis who developed staphylococcal bacteremia. None of the asymptomatic volunteers or patients with CMV retinitis developed evidence of CMV pneumonia or any other organ disease with CMV. Cytomegalovirus is frequently detected in BAL from HIV-infected patients regardless of their pulmonary symptoms and its presence does not clinically predict significant pulmonary morbidity or mortality in 3 mo of follow-up.     

The effects of detergents on t-butyl hydroperoxide-induced chemiluminescence

Subcutaneous central venous infusion reservoirs (central venous catheters) are one of the primary devices for administration of intravenous chemotherapy. Usually these devices have few problems, and they provide dependable long term central venous access. Infection of these catheters is a significant problem that usually requires removal. When infection is suspected, it is often difficult to make this determination without actually removing the catheter. Thorough preoperative evaluation may help the surgeon decide which catheters are infected and should be removed. A total of 817 subcutaneous infusion reservoirs were placed at our institution from January 1, 1990 through November 1, 1994. During the same time period, 143 catheters were removed, 63 for suspected infection. The charts of these 63 patients were reviewed to determine to what extent available preoperative information could be used to predict which catheters were infected, thus avoiding unnecessary removal. Twenty-three preoperative parameters were assessed, including physical exam, body temperature, leukocyte count, platelet count, blood cultures from the catheter and peripheral blood, time from placement to removal, whether or not the catheter was functional, and whether it was currently in use. Forty catheters (65%) removed for suspected infection were infected, as demonstrated by a positive culture from the catheter or the wound. Staphylococcus was the most common microorganism. Physical exam (local erythema, tenderness, or swelling) correlated significantly with catheter infection (P = 0.0238). In contrast, blood culture data and the other clinical and laboratory parameters showed no significant association with catheter infection. We conclude that physical exam is the best indicator of catheter infection. Commonly used parameters such as fever, leukocytosis, and positive blood cultures are nonspecific, may not be due to catheter infection, and were not significant in our study. Removal and subsequent restoration of long term intravenous access is associated with significant morbidity and expense. Clinical decision making should not be based on isolated laboratory findings, but must be individualized in each patient with suspected catheter infection.     

Study of suspected plague cases for isolation and identification of Yersinia pestis

A total of 62 suspected patients of plague were investigated for evidence of Yersinia pestis, by blood culture, lymph node aspirate culture, sputum culture, animal inoculation and serology for f1 antibodies against f1 antigen of Yersinia pestis. None of the samples was positive by direct smear examination and culture for Yersinia pestis, as well as for serology. The non positivity of the cultures is discussed.     

Stimulation by leptin of 3H GDP binding to brown adipose tissue of fasted but not fed rats

We conducted a retrospective review of 125 patients undergoing high-dose therapy and stem cell rescue in order to evaluate the incidence of documented infection and the utility of the administration of vancomycin empirically. All patients received prophylactic oral quinolone therapy. Because neutropenia in this setting is relatively brief, 21 patients never manifested fever, and no patient died of infection. Of the remaining 104 patients, positive blood cultures were obtained in only 10, nine with a gram stain positive and one with a gram stain negative organism. Sixty-two patients without any evidence of gram positive infection received vancomycin according to the existing algorithm for care of neutropenic fevers. In this population of patients, empiric administration of vancomycin for neutropenic fevers without culture documentation appears to be unnecessary, could be discontinued safely and at substantial cost savings, and might slow the appearance of vancomycin-resistant organisms.     

Medical cuneiform fracture-dislocation associated with medial and intermediate cuneiform fractures

We report the microbiological characteristics of two Rahnella aquatilis strains isolated in the faeces of two patients with acute gastroenteritis, one of whom is an AIDS patient. The biochemical behaviour was studied with different automated identification systems, and the few clinical cases to be found in the literature were reviewed. Of the nine strains isolated in clinical samples, two were obtained from blood cultures, two from respiratory samples, one from urine, one from a burn wound, one from a surgical wound, and two (our strains) from faeces. In almost all cases the patient presented an underlying condition facilitating infection by opportunistic microorganisms. The majority of strains are characterized by their resistance to ampicillin, cephalothin and cefoxitin. Due to the rarity of the isolation of R. aquatilis in human samples it is not yet possible to establish, with any degree of certainty, its true pathogenic capacity.     

The influence of biliary infection on the postoperative course after biliary tract surgery

A prospective clinicobacteriological study was undertaken in 167 patients undergoing biliary surgery so as to assess the possible influence of the endogenous preoperative biliary infection on postoperative morbidity. Bile cultures were positive in 33% (55 patients); in those undergoing cholecystectomy alone this finding was present in 23% while in those in whom a choledochotomy was also performed cultures were positive in 65%. The incidence of wound infection was found to be twice as high in those undergoin choledochotomy as in those undergoing cholecystectomy alone--37.8% vs. 18.5%. There was no appreciable difference in the rate of wound infection when a routine appendectomy was performed during biliary tract surgery. Among the 38 patients with wound infection, bile cultures were positive in 16. In 13 cases the offending organism in the wound was identical with that recovered from the bile coulture. This finding suggests an endogenous source for the wound infection. This study further indicated that wound infection is most likely to be encountered in patients with pathogenic organisms in the bile, in the aged and in those whose resistance to infection has been lowered by concomitant disease.     

Human and rodent hantavirus infection in New York State: public health significance of an emerging infectious disease

BACKGROUND: A case of hantavirus pulmonary syndrome with possible exposure in New York and/or Rhode Island was confirmed in February 1994. OBJECTIVE: To conduct four studies to determine the historical and geographic distribution of human and small-mammal infection with hantaviruses in New York State. METHODS: Enzyme-linked immunosorbent assays were performed on serum samples obtained from 130 humans during a 1978 babesiosis survey, 907 small mammals collected in New York State since 1984, 12 rodents collected in 1994 near the residences of the patients with hantavirus pulmonary syndrome, and 76 New York patients with acute respiratory distress syndrome-like illness (as suspected cases of hantavirus pulmonary syndrome). RESULTS: None of the human serum samples from the 1978 serosurvey showed evidence of hantavirus exposure by enzyme-linked immunosorbent assay. Statewide historical serum samples from white-footed mice showed evidence of Sin Nombre virus infection in 12.0% (97/809) and Seoul-like virus infection in 9.6% (78/809). Site-specific seropositivity rates were as high as 48.5% with Sin Nombre virus during 1 year (1984). Two of 12 mice captured near the residences of a human patient were positive for Sin Nombre virus by enzyme-linked immunosorbent assay, yet were negative for viral RNA by polymerase chain reaction. None of the patients with suspected hantavirus pulmonary syndrome was serologically reactive for Sin Nombre virus. CONCLUSIONS: We provide serologic evidence of small-mammal infection with hantaviruses in New York State as long ago as 1984. Human cases of hantavirus pulmonary syndrome are rare in New York, and data indicate that transmission to humans is probably infrequent. A unique set of host, agent, and environmental factors may be necessary to cause hantavirus pulmonary syndrome in humans.     

Intellectual level (IQ) in heterozygotes for phenylketonuria (PKU). Is the PKU gene also acting by means other than phenylalanine-blood level elevation?

Wound infection in 239 patients who underwent cholecystectomy were analyzed retrospectively. Seventeen per cent of the patients with acute cholecystitis had wound infection compared with 8.9 per cent of patients with chronic cholecystitis. Bacteriology of wound infections revealed Staphylococcus aureus in 76.4 per cent of the chronic cholecystitis group and in 12.5 per cent of the acute cholecystitis group. Wound infection in the acute cholecystitis group involved gram-negative rods predominantly. Organisms were isolated from bile culture in 71.4 per cent of acute cholecystitis patients compared with 59.6 per cent of chronic cholecystitis patients. Of patients with positive bile cultures 11.3 per cent had wound infections compared with 6.8 per cent of patients with negative bile cultures. The most common organisms isolated from bile cultures with resultant wound infections were S epidermis, S aureus, and Klebsiella sp. Wound infection after cholecystectomy for chronic cholecystitis arises from external sources and not contaminated bile. Antibiotic therapy should be directed accordingly.     

Diagnosis of cytomegalovirus infections by shell vial assay and conventional cell culture during antiviral prophylaxis

A total of 3,552 specimens for conventional cytomegalovirus (CMV) culture and shell vial assay for CMV immediate-early antigen were obtained during a prospective randomized trial for prophylaxis of CMV disease after liver transplantation. Prophylaxis with ganciclovir for 2 weeks and then high-dose acyclovir for 2.5 months was compared with high-dose acyclovir alone for 3 months. During the first 12 weeks after transplantation, when the patients were on prophylaxis, there were significantly more clinical samples positive by the shell vial assay and negative by standard culture in comparison with the number of samples obtained from weeks 13 to 24, after prophylaxis was discontinued, that were positive by the shell vial assay and negative by standard culture. In contrast, significantly fewer samples were positive by both the shell vial assay and standard culture during the first 12 weeks compared with the number obtained 13 to 24 weeks after transplantation that were positive by both methods. Samples positive by the shell vial assay only were obtained significantly more frequently from patients with asymptomatic than symptomatic CMV infections, while samples positive by both methods were obtained significantly more often from patients with symptomatic CMV infection. It was concluded that antiviral prophylaxis with high-dose acyclovir or ganciclovir and then high-dose acyclovir and asymptomatic CMV infection are associated with a decrease in the level of CMV isolation by standard cell culture in comparison with that by the shell vial assay.     

Methicillin-resistant Staphylococcus aureus: a four-year experience in a spinal cord injury unit in Spain

Methicillin-Resistant Staphylococcus aureus (MRSA) infection poses a problem for both acute and long-term-care facilities, Spinal Cord Injury units included. This paper describes the 4-year evolution of MRSA outbreaks in a SCI unit in a university hospital where control measures were implemented from the first case detected. The protocol procedure was as follows: contact isolation, washing with antiseptic soap both those infected and those sharing the same room, contacts study and monitoring of MRSA patients up to the time when three consecutive negative cultures (sampled at time lapses of over 48 h) were obtained, antiseptic soap for the health-care personnel to wash their hands, and cultures of the nares done on the personnel in the event of an outbreak. Twenty-one (3.4%) MRSA positive cases were detected out of 550 admissions registered during the study period (November 1990 through October 1994). The evolution occurred in three outbreaks and six isolated MRSA positive patients without secondary cases. 71.5% of the cases were nosocomial. Seven (33%) were colonizated and 14 (67%) infected. The 14 patients infected presented 15 infections: nine with urinary tract infections, three surgical wound infections, two tracheostomy wound infections, and one patient with a decubitus ulcer infection. Two of those with urinary tract infections presented with secondary sepsis. No carriers were detected amongst the personnel. Urinary tract colonizations responded to treatment with cotrimoxazol except in two cases in which combined treatment was required (cotrimoxazol plus rifampicin). The patients with a MRSA positive tracheal aspirate were negative after combined treatment. Wounds and cultures of the nares responded favorably to initial treatment. One of the patients with a urinary tract infection and sepsis died the infection being a contributing cause. The prospective follow-up of the patients with MRSA positive cultures and the precocious implementation of isolation measures allow for the limitation of transmission, even although complete eradication is not possible.     

Nickel and gold in skin lesions of pierced earlobes with contact dermatitis. A study using scanning electron microscopy and x-ray microanalysis

OBJECTIVE: To make an analysis of fungemia in HIV-infected patients in our hospital. PATIENTS AND METHODS: We retrospectively (1989-1997) studied all HIV-infected patients with positive blood cultures for Candida sp., Cryptococcus neoformans or any other fungal infection. RESULTS: C. neoformans was isolated in 11 patients (10 men and 1 woman): Six were treated with amphotericin B and 5 with fluconazole. 2 patients died during the acute phase and the infection relapsed in 3. Blood culture for Candida sp. were positive in 9 (8 men and 1 woman): only a case was nosocomial. Seven patients were intravenous drug users and the presenting manifestations were autolimited candidemia in 3, aortic and tricuspid endocarditis in 1 and 2 cases respectively and pneumonia in another one. Six C. albicans, 2 C. krusei and 1 C. glabrata were isolated. 3 patients received amphotericin B and 3 received fluconazole. 2 patients suffering from endocarditis died and so did the patient with C. glabrata infection. A patient, who denied having travelled to endemic areas, developed histoplasmosis; blood culture was positive for H. capsulatum. He initially had a good response to amphotericin B and itraconazole. CONCLUSIONS: Fungemia is not frequent in HIV-infected patients. Cryptococcosis and histoplasmosis occur in advanced HIV-patients and candidemia is fundamentally associated with intravenous drug use.     

Clinical evaluation in organ transplant patients of a polymerase chain reaction test for CMV DNA applied on white blood cells and serum

A polymerase chain reaction (PCR) test for CMV DNA was evaluated for clinical usefulness. Leukocytes and serum were sampled from 36 patients who had recently undergone organ transplantation. Clinical symptoms, virus culture, and IgG and IgM antibodies were used to identify, in retrospect, patients with CMV disease certified beyond all doubt, with probable disease, with asymptomatic infection, or without infection. PCR tests for CMV DNA in leukocytes (BC-PCR) and serum (SE-PCR) were then evaluated. BC-PCR was positive in all patients with certified CMV disease but also in 31% of the samples from patients without infection. SE-PCR was positive in 11/13 patients with certified disease and was concordant with CMV culture in 192/231 tests. Of the 39 discordant cases, 27 had a positive SE-PCR with a negative culture. The effect of ganciclovir treatment could not be predicted by any test. In conclusion, a negative BC-PCR is strong evidence against CMV disease and a positive SE-PCR strongly suggests CMV disease, but the opposite results are of little clinical help.     

Is epidural anesthesia in labor associated with chronic low back pain? A prospective cohort study

The aim of this prospective study was to compare differential blood cultures and quantitative catheter tip cultures for the diagnosis of catheter-related sepsis. Over a period of 2 years, 283 central venous catheters were inserted in 190 adult patients. Catheters were removed when they were no longer needed or when infection was suspected. Immediately before removal of the central venous catheters, blood cultures were performed, with blood drawn simultaneously from the catheter and the peripheral vein. After removal, quantitative catheter culture was performed according to the Brun-Buisson modified Cleri technique. Fifty-five quantitative catheter cultures were positive. They were classified as contaminated (n = 18), colonized (n = 23), or infected (n = 14). Differential blood cultures correctly identified 13 infections. With a catheter/peripheral cfu ratio of 8, differential blood cultures had a sensitivity of 92.8% and a specificity of 98.8%. When the catheters were removed because of suspected infection, differential blood cultures had a sensitivity of 92.8% and a specificity of 100%. Differential blood culture, a technique that does not necessitate catheter removal, seems effective in the diagnosis of catheter-related sepsis in patients in the intensive care unit.     

Routine synovial fluid culture: is it necessary? Lessons from an audit

An estimated third of rheumatologists send aspirated synovial fluid samples for culture routinely during the course of management of their patients irrespective of the underlying diagnosis. This is done apparently even when sepsis is not suspected. This audit of 507 synovial fluid culture requests revealed that positive bacterial growth was rare even when sepsis was queried on the request forms but none was positive in any of the routine samples. Our findings throw doubt on the value of routine synovial fluid culture. We recommend that such cultures are undertaken when infection is a possibility and in immuno-compromised patients. An average health district would save pounds 3000 per annum if such a policy was adopted, but across the National Health Service as a whole the total expenditure saved on this unnecessary investigation would be considerable.     

Postcesarean endometritis. Clinical risk factors predictive of positive blood cultures

OBJECTIVE: To identify peripartum risk factors that are predictive of positive blood cultures in patients with postcesarean endometritis. STUDY DESIGN: A retrospective review of 179 patients diagnosed with postcesarean endometritis was conducted. Patients with positive and negative blood cultures obtained at the time of diagnosis were compared. Patient's charts were reviewed for intrapartum, intraoperative and postpartum factors. Chi-square and nonpaired Student's tests were used when appropriate, with P < .05 considered significant. RESULTS: During this period, 179 (20%) postcesarean patients developed endometritis. One hundred sixty-eight (94%) of those patients had blood cultures. Eleven (6.5%) were positive; however, one of these grew a skin contaminant and was disregarded. When patients with positive blood cultures were compared to those with negative blood cultures, length of labor, number of vaginal examinations, postoperative day when the diagnosis was established, estimated blood loss at the time of cesarean delivery, presence of intrapartum chorioamnionitis, number of hours of ruptured membranes, white blood cell count at the time of diagnosis, use of prophylactic antibiotics, development of wound infection or other infectious etiologies were not shown to be predictive. There were no positive blood cultures among patients with a temperature < 38.5 degrees C. At a temperature < 38.8 degrees C, 1/126 (0.79%) had a positive blood culture. At a temperature > or = 38.8 degrees C, 9/42 (21.4%) had a positive blood culture (P < .001). Approximately $5,890 was spent on obtaining positive blood cultures in patients with temperatures < 38.8 degrees C. In contrast, $218 was spent per positive blood culture obtained from patients with a temperature > or = 38.8 degrees C. CONCLUSION: The traditional practice of obtaining blood cultures at a temperature > or = 38.0 degrees C is not justified but elevating the threshold to 38.8 degrees C is equally effective and less costly.     

Controlled clinical evaluation of BACTEC Plus Aerobic/F and BacT/Alert Aerobic FAN bottles for detection of bloodstream infections

A total of 7,190 blood culture sets were obtained from adult patients with a suspected bloodstream infection. A 20-ml sample of blood was distributed equally between the aerobic FAN bottle which was monitored in the BacT/Alert system and a Plus Aerobic/F bottle which was monitored in the BACTEC 9240 system. A total of 988 positive cultures were obtained from 483 patients; however, only 453 positive cultures from 173 patients met the criteria for volume ( > or = ml per bottle) and clinical significance on the basis of concurrent case review required for data analysis. There were 25 and 68 false positives from the FAN and Plus Aerobic/F bottles, respectively. There were no statistically significant differences between systems in the number of positive cultures or septic episodes by species; however, the total number of Enterobacteriaceae and Pseudomonas aeruginosa isolates combined was significantly greater in the FAN bottle (P = 0.04). Detection times did not differ significantly between systems for positive cultures; however, episodes of Staphylococcus aureus bacteremia were detected significantly more rapidly from the FAN bottle (P = 0.005). There was no significant difference between systems in the detection of bloodstream infections in patients receiving antibiotics at the time of blood culture.     

16S rRNA based polymerase chain reaction compared with culture and serological methods for diagnosis of Mycoplasma pneumoniae infection

The use of a 16S rRNA based polymerase chain reaction (PCR) for the detection of Mycoplasma pneumoniae infection was investigated. Sputum samples from 34 patients with respiratory illness and evidence of pneumonia as judged by chest X-ray were analyzed by PCR and microbiological culture. Throat swabs from 14 healthy individuals were used as controls. For serology, an enzyme immunoassay for the detection of immunoglobulin M antibodies and a complement fixation assay were performed. Evidence of Mycoplasma pneumoniae infection was obtained in ten patients (29%), eight of whom were found positive by both PCR and serology. Two of the sputum samples from these eight patients were negative by culture. Of the remaining two patients positive for Mycoplasma pneumoniae, one was positive by PCR and culture but negative by serology, and one was found positive by serology but negative by PCR and culture. Thirteen of the 14 controls were negative by both PCR and serology. One control, however, was negative by serology but positive by PCR, which was probably due to asymptomatic carriage of Mycoplasma pneumoniae. The results of this study indicate the suitability of the PCR for the detection of Mycoplasma pneumoniae in clinical samples as well as its potential value as an additional tool for the diagnosis of infection.     

Etiological agents of infectious diarrhea: implications for requests for microbial culture

Gastrointestinal infections remain a frequent disease worldwide. In order to increase our knowledge of the epidemiology for our patient population, we retrospectively analyzed the results obtained for stool samples received at the clinical microbiology laboratory of the University Hospital of Geneva during a 4-year period. A total of 13,965 specimens from 7,124 patients (1.96 specimens per patient) were cultured, yielding 369 (2.6%) Salmonella spp., 408 (2.9%) Campylobacter spp., and 79 (0.6%) Shigella spp. The cumulative positivity rate of 6.1% decreased to 2.7% when patients received antimicrobial agents (P < 0.001). The positivity rate for 5,912 specimens obtained from patients hospitalized for < or = 3 days was 12.6%, whereas it dropped to 1.4% for patients hospitalized for > 3 days (P < 0.001). Of 3,837 stool samples originating from pediatric patients, 8.8% were positive, and 5.1% of 10,128 samples from adults were positive (P < 0.001). The cytotoxin of Clostridium difficile was detected in 379 of 3,723 samples analyzed (10.2%), and rotaviruses were detected in 190 of 1,601 samples (11.9%). We recommend that the use of cultures for enteric bacterial pathogens be restricted to patients hospitalized for < or = 3 days, with the exceptions of follow-up samples, specimens from immunocompromised patients, and patients whose first sample was culture negative or in the rare event of nosocomial food-borne outbreaks. For patients under antimicrobial therapy, testing for cytotoxin of C. difficile should primarily be requested; this analysis should also be accepted for samples from patients not receiving antimicrobial agents at the time of specimen collection. By applying these restrictions, we could have saved at least $5,000 annually.     

Quantitative urine cultures do not reliably detect renal candidiasis in rabbits

The significance of quantitative urine cultures in patients at risk for hematogenous disseminated candidiasis is controversial. While various concentrations of Candida spp. in urine have been suggested as critical cutoff points in the diagnosis of renal candidiasis, other investigators consider quantitative cultures less critical in diagnosing upper tract infections. To determine the significance of quantitative urine cultures in renal candidiasis, we studied serial quantitative urinary cultures of Candida albicans in a rabbit model of hematogenous infection. Of 197 urine samples from 34 infected animals, 144 were culture positive, with a sensitivity of 73.1% for urine cultures and a lower limit of detection of 10 CFU/ml. The yield of urine cultures varied according to severity and duration of infection. The mean renal and urinary concentrations of C. albicans from rabbits with subacute candidiasis differed significantly from those from rabbits with acute candidiasis (P = 0.013 and P < or = 0.001, respectively). During the first 4 days of subacute renal candidiasis, more than one-half of all urine cultures were negative for C. albicans. Only 12 (8.1%) of 148 urine cultures in animals with subacute renal candidiasis had concentrations of > 10(3) CFU/ml, 2.7% had concentrations of > 10(4) CFU/ml, and none were > or = 10(5) CFU/ml. By comparison, all urine cultures from the animals with lethal acute renal candidiasis had higher concentrations of C. albicans and were positive throughout the course of infection. Urinary concentrations of C. albicans were not predictive of the amount of Candida in the kidney (r < or = 0.49) and did not correlate with survival (r = 0.0232). However, the renal concentration of C. albicans (in CFU/gram) inversely correlated with the duration of survival (in days) of rabbits with renal candidiasis (r = 0.76; P < 0.001). These findings indicate that a negative urine culture in rabbits does not preclude the presence of renal candidiasis. The interpretation of a urine culture positive at any concentration, on the other hand, must involve an analysis of the risk factors for renal candidiasis, for any urinary concentration of C. albicans may reflect kidney infection.