Microbiological characteristics of yeasts isolated from urinary tracts of intensive care unit patients undergoing urinary catheterization

Isolation and identification of Candida species from catheter-associated urinary tract infection in Thamar city hospitals, Yemen

BACKGROUND

The incidence of urinary tract infections associated with Candida is increasing in Yemeni public hospitals.

OBJECTIVES

The primary objective of this research was to isolate specific Candida species responsible for catheter-associated urinary tract infections (UTIs) and to examine the antifungal sensitivity of these Candida isolates.

PATIENTS AND METHODS

A total of 200 samples were collected from patients with catheters admitted to multiple hospitals of Thamar city (Yemen). There were 50 positive samples with Candida out of 200 samples. We conducted the primary identification process using the established protocols. Before isolation and identification, all yeast isolates underwent sub-culturing on Sabouraud dextrose agar. We employed the standard microbiological procedures such as Gram staining, colonial morphology analysis, lactophenol cotton blue assay, germ tube formation assessment, colony staining on chrom agar Candida medium, and incubation at 37 °C for 48 h. The assessment of cultures was conducted by evaluating their predominant species. All Candida isolates were tested for antifungal susceptibility using the disk diffusion technique, as indicated by the Clinical and Laboratory Standards Institute (CLSI) M44-A document recommendations.

RESULTS

In this study, the prevalence of Candida species obtained from catheter-associated UTIs was shown to be the highest among individuals aged 51-60 years (28.0%) and the lowest was among those aged 10-20 years (8.0%). Males exhibit higher rates than females, with males accounting for 56.0 and females for 44.0%, respectively. The predominant strain from catheters linked to urinary tract infections was Candida albicans. The Candida isolates had the highest susceptibility to itraconazole, with fluconazole and nystatin at sensitivity rates of 64, 60, and 50%, respectively. Amphotericin B and ketoconazole exhibited the most elevated concentrations. The p value of duration of catheterization < 5 was significant (p = 0.01), as well as significant in anti-fungal susceptibility testing of itraconazole, ketoconazole, and nystatin which are (p = 0.03), (p = 0.04), and (p = 0.03) respectively.

CONCLUSION

Urinary tract infection due to candiduria was more common in patients with indwelling urinary catheter. The catheter-associated urinary tract infection caused by Candida species occurred mainly in old male patients. Candia albicans was the predominant Candida species isolated from urinary tract infection associated with urinary catheter at Thamar city hospitals. This study determined that diabetes and antibiotic use are significant predisposing factors associated with isolation of Candida in specimens submitted by patients at Thamar city hospitals.

Hand Carriage of Yeast in Student of Medicine, Nursing, and Medical Laboratory Science: Impact of Infection Control Measures

We studied yeast hand carriage of 260 healthcare students. We isolated yeasts in 27 students (10.4%), without differences between medicine, nursing, and medical laboratory science programs and gender. A significant lower prevalence of carriage was shown in the clinical cycle (2.7%) compared to the basic cycle (13.5%) (p = 0.022) and the preclinical cycle (13.5%) (p = 0.014). Increased handwashing frequency and the use of alcohol gel and antiseptic soap decreased yeast carriage. Students who applied moisturizing hand cream two or more times a day had a lower frequency of yeast carriage (3.4%) than those who did not use it or used it once a day (16.5%), showing a significant difference (p = 0.016). The most prevalent species was C. parapsilosis sensu stricto (81.5%), followed by Meyerozyma guilliermondii (C. guillermondii) (7.4%), Trichosporon mucoides (7.4%), and R. mucilagenosa (3.7%). One case showed mixed carriage of C. parapsilosis and C. albicans. All strains were sensitive to voriconazole, caspofungin, and anidulafungin. This study shows hand carriage of yeast in health students, mainly by C. parapsilosis, and the frequency of infection control measures and moisturizing hand cream is associated with colonization control.

Epidemiological profile of patients hospitalized with candiduria in the Central-Western region of Brazil

BACKGROUND

Candida yeasts are considered the main agents of nosocomial fungal infections.

AIMS

This study aimed to establish the epidemiological profile of patients with candiduria hospitalized in the capital of the State of Mato Grosso, in the Central-Western region of Brazil.

METHODS

Patients from three private hospitals and a public hospital participated in the study. This was an observational and cross-sectional study including analysis of patients mortality. It was carried out from March to August 2015.

RESULTS

A total of 93 patients with candiduria were evaluated. Candida tropicalis was found most commonly (37.6%; n=35), followed by Candida albicans (36.6%; n=34), Candida glabrata (19.3%; n=18), psilosis complex (4.3%; n=4), Candida lusitaniae (1.1%; n=1) and Candida krusei (1.1%; n=1). Antibiotic therapy (100%) and the use of an indwelling urinary catheter (89.2%; n=83) were the most frequent predisposing factors. Antifungal treatment was given to 65.6% of the patients, and anidulafungin was the most used antifungal. Mortality rates were 48% higher among patients with candiduria who had renal failure. Micafungin was the antifungal most prescribed among the patients who died. Candidemia concomitant with candiduria occurred in eight (8.6%; n=8) cases. Considering the species recovered in the blood and urine, only one patient had genetically distinct clinical isolates.

CONCLUSIONS

Non-C. albicans Candida species were predominant, with C. tropicalis being the most responsible for most cases of candiduria.

Candiduria in Hospitalized Patients and Identification of Isolated Candida Species by Morphological and Molecular Methods in Ilam, Iran

BACKGROUND

Candiduria in hospitalized patients may represent contamination, colonization, or urinary tract infections. On the other hand, candidemia and upper urinary tract infection could be the complications of candiduria. The aim of this study was to determine candiduria in hospitalized patients and identify isolated Candida species by conventional and molecular methods.

METHODS

This cross-sectional study was conducted on hospitalized patients in Imam Khomeini and Mostafa Khomeini hospitals in Ilam, western Iran from Jan to Dec 2016. Urine samples of hospitalized patients were collected during a period of 4 months for diagnosis of candiduria. Primary identification was done by conventional methods. PCR profile was carried out using phenol-chloroform method and confirmed using restriction fragment length polymorphism (PCR-RFLP) technique by MspI restriction enzyme.

RESULTS

Candiduria was diagnosed in 18 (9.2%) cases from a total of 195 patients. Isolated yeasts were identified as C. albicans (n: 13), C. glabrata (n: 5), and C. parapsilosis (n: 1) in the one case both C. albicans and C. glabrata were isolated from a urine sample.

CONCLUSION

Candida urinary tract infection is becoming increasingly common in hospitalized patients but, differentiation fungal colonization from infection and identification of etiologic agents for optimal treatment is necessary.

Candiduria: Evidence-based approach to management, are we there yet?

Candiduria is considered one of the most controversial issues in patient management. Neither the diagnosis nor the optimal treatment options are standardized. This is further complicated by lack of defined laboratory criteria for diagnosis as most of the studies were set for bacterial rather than fungal urinary tract infection (UTI). Furthermore, since Candida species is a known commensal of the genitourinary tract its presence in the urine sample adds ambiguity to making a definitive diagnosis of candidal UTI. Guidelines for diagnosis and management of candiduria have changed considerably over the past decades. In 1960s, the condition was believed to be benign with no intervention required. However, over the years new dimensions were added to address the issues associated with candiduria until the latest Infectious Diseases Association of America (IDSA) guidelines were published in 2009, which indicated that there was an increase in the incidence of candiduria caused by more resistant non-Candida albicans species. Further complicating the issue is the observation that candiduria may be the only indicator of a more serious invasive candidiasis, especially in immunocompromised patients. Long-term urinary catheterization is considered to be the most significant risk factor for candiduria followed by antibiotic use and diabetes. Strategies for management are based on the evaluation of candiduria in the context of the clinical setting to determine its relevance and make an appropriate decision about the need for antifungal therapy. Fluconazole is the main drug used for its efficacy and least complications. Other options include bladder irrigation with amphotericin B, flucytosine or parenteral amphotericin B. Since azoles other than fluconazole and all echinocandins are poorly excreted in urine they have been found to be less effective in candiduric patients.

Urinary tract infections due to Trichosporon spp. in severely ill patients in an intensive care unit

Objective

To evaluate the incidence of urinary tract infections due to Trichosporon spp. in an intensive care unit.

Methods

This descriptive observational study was conducted in an intensive care unit between 2007 and 2009. All consecutive patients admitted to the intensive care unit with a confirmed diagnosis were evaluated.

Results

Twenty patients presented with urinary tract infections due to Trichosporon spp. The prevalence was higher among men (65%) and among individuals > 70 years of age (55%). The mortality rate was 20%. The average intensive care unit stay was 19.8 days. The onset of infection was associated with prior use of antibiotics and was more frequent in the fall and winter.

Conclusion

Infection due to Trichosporon spp. was more common in men and among those > 70 years of age and was associated with the use of an indwelling urinary catheter for more than 20 days and with the use of broadspectrum antibiotics for more than 14 days. In addition, patients with urinary infection due to Trichosporon spp. were most often hospitalized in intensive care units in the fall and winter periods.

Fungal profile of funguria cases at a tertiary care hospital in southern India

BACKGROUND & OBJECTIVES

Candida albicans is the most common aetiological agent in funguria cases commonly observed in hospitalized patients. But a few reports are available from India where non-albicans Candida species have accounted for >50 per cent of urinary Candida isolates. We undertook this study to know the fungal profile amongst funguria cases.

METHODS

A total of 123 consecutive fungal isolates obtained from clinically suspected cases of urinary tract infection from April to September, 2013, were included. Yeast species was identified by standard phenotypic methods. Antifungal susceptibility testing of yeast was performed for fluconazole (25 μg) by disc diffusion method as per Clinical and Laboratory Standards Institute (CLSI) guidelines.

RESULTS

The male to female ratio was 0.92. The mean age of patients was 42.7 ± 18.9 yr. C. tropicalis (58.5%) was the most common fungal agent followed by C. albicans (30.1%). Only one isolate of C. tropicalis was resistant to fluconazole.

INTERPRETATION & CONCLUSIONS

C. tropicalis and C. albicans were the predominant fungal pathogens responsible for urinary tract infection. Less resistance to fluconazole observed in the study may be due to restricted use of fluconazole in this area.

Candiduria in children: a first report from an Iranian referral pediatric hospital

Candida spp. especially Candida albicans is considered as one of the most common cause of fungal infections. The aim of our study was to determine epidemiology of candiduria in children who were referred to an Iranian referral hospital. During May 2011 to February 2013, among 4813 urine culture positive, 209 candida spp. isolates (4.3%) was found. Forty-one percent of cadiduria infection was seen in patients between 1 month and 1 year, 24% in neonatant and 24% in patients 1 to 5 years. Cadiduria was mainly found in patients who had received more than 2 or 3 antibiotic during their hospitalization (37% and 24%, respectively). In our study, the highest frequency of cadiduria was seen in patients who had received more than 2 antibiotics and more than 3 antibiotics during their hospitalization; therefore, the strategic goals to optimize antimicrobial use including optimizing choice and duration of empiric therapy as well as monitoring and providing feedback regarding antibiotic resistance are recommended.

Sexual biofilm formation in Candida tropicalis opaque cells

Candida albicans and Candida tropicalis are opportunistic fungal pathogens that can transition between white and opaque phenotypic states. White and opaque cells differ both morphologically and in their responses to environmental signals. In C. albicans, opaque cells respond to sexual pheromones by undergoing conjugation, while white cells are induced by pheromones to form sexual biofilms. Here, we show that sexual biofilm formation also occurs in C. tropicalis but, unlike C. albicans, biofilms are formed exclusively by opaque cells. C. tropicalis biofilm formation was dependent on the pheromone receptors Ste2 and Ste3, confirming the role of pheromone signalling in sexual biofilm development. Structural analysis of C. tropicalis sexual biofilms revealed stratified communities consisting of a basal layer of yeast cells and an upper layer of filamentous cells, together with an extracellular matrix. Transcriptional profiling showed that genes involved in pheromone signalling and conjugation were upregulated in sexual biofilms. Furthermore, FGR23, which encodes an agglutinin-like protein, was found to enhance both mating and sexual biofilm formation. Together, these studies reveal that C. tropicalis opaque cells form sexual biofilms with a complex architecture, and suggest a conserved role for sexual agglutinins in mediating mating, cell cohesion and biofilm formation.

Profile of yeasts isolated from urinary tracts of catheterized patients

PURPOSE

Nosocomial fungal infections are important cause of morbidity and mortality in hospital patients. Urinary catheters have been held responsible to cause a large number of hospital acquired Urinary Tract Infections (UTIs). This study was undertaken to determine the incidence of nosocomial Candiduria associated with in dwelling urinary catheters, to characterize the species and assess their resistance to antifungal agents.

MATERIALS & METHODS

Urine specimens from 510 catheterized patients were inoculated on Sabauraud Dextrose Agar; the species identification of Candida isolates was done by biochemical tests and antifungal susceptibility testing was done by disc diffusion method.

RESULTS

Candida was isolated in 112 (21.96%) specimens. Of these, Candida albicans was commonly isolated in 50.89% followed by C. tropicalis, C. glabrata, C. krusei, C. parapsilosis, C. guillermondi and C. pseudotropicalis. Fluconazole resistance was encountered in some isolates. All C. glabrata and C. krusei were uniformly resistant to fluconazole and 8 of 16 C. tropicalis were also resistant to it. But only 7 of 57 isolates of C. albicans were resistant to it. Resistance to Nystatin was seen in 34 isolates. Similarly, emergence of resistance was also seen to Ketoconazole and Itraconazole in 24 of 112 isolates. Amphoterecin B resistance was exhibited by 3 C. albicans, 2 C. tropicalis, 1 C. glabrata and 1 C. krusei strain. C. albicans is an important nosocomial pathogen causing UTI in catheterized patients, nevertheless role of other species of Candida as emergent pathogens and resistance to antifungal drugs needs to be emphasized.

Yeasts isolated from nosocomial urinary infections: antifungal susceptibility and biofilm production

BACKGROUND

Urinary Candida infections in the hospital environment are frequent and need to be better understood.

AIMS

To compare the results of antifungal susceptibility profiles of yeasts isolated from patients with urinary infections obtained by broth microdilution method (BM) and by disk diffusion (DD), and also evaluate the capacity of these yeasts to form biofilms.

METHODS

Only yeasts obtained from pure urine cultures with counts higher than 10(5) colony-forming units per milliliter, without bacteria development, of symptomatic patients were included. The isolates were identified by classical methods and the antifungal susceptibility tests were performed with the following drugs: amphotericin B, ketoconazole, fluconazole, itraconazole, voriconazole and caspofungin. The biofilm studies were carried out in polystyrene microtitration plates.

RESULTS

Ninety-five yeasts isolates were analyzed, including 40 Candida albicans, 31 Candida glabrata, 24 Candida tropicalis. In general, the majority of the isolates were susceptible to the tested drugs but some resistance was observed, especially against fluconazole. Great variability in the antifungal susceptibility results was observed with the different tested drugs and a few discrepancies were observed between both methods. We suggest that in case of DD resistance this result should be confirmed by BM, the standard method. C. tropicalis isolates showed high biofilm production (91.7%) compared to C. albicans (82.5%) and C. glabrata (61.3%), with statistical significance (p=0.0129).

CONCLUSIONS

Candiduria in critical patients requires major attention and a better control. The different susceptibility results obtained in this study showed the need to identify yeasts up to the species level, especially in patients with urinary tract infection. The development of techniques of antifungal susceptibility tests can help the clinicians in the empiric treatment of candiduria.

Candida colonization in urine samples of ICU patients: determination of etiology, antifungal susceptibility testing and evaluation of associated risk factors

The presence of Candida in urine presents a therapeutic challenge for the physician as it is often asymptomatic, and management guidelines have not been clearly laid down on this issue. The presence of Candida in urine may represent contamination of clinical sample, actual colonization of the lower urinary tract or may be a true indicator of invasive infection of lower and/or upper urinary tract. In a clinical setting like the ICU, multiple risk factors for Candida colonization may be present in the same patient, thereby increasing the chances of candiduria, manifold. In the present study on 80 patients in ICU, high rate of Candida colonization (57.5%) was found in urine samples of ICU patients with C. tropicalis (57.3%) being the predominant species. We also isolated 8 strains of Trichosporon species, all of these presented as a mixed infection along with Candida species. Among the various risk factors studied, urinary catheterization and previous antibiotic therapy were identified as statistically significant (P value <0.05). The minimum inhibitory concentration of the isolates was determined for amphotericin B, fluconazole and itraconazole by E-test. Most of the isolates were susceptible to amphotericin B. The C. parapsilosis strains did not show any drug resistance; however, resistance to fluconazole was observed 18.6, 27.27, 50 and 25% in C. tropicalis, C. albicans, C. glabrata and Trichosporon species, respectively.

Current knowledge of Trichosporon spp. and Trichosporonosis

Trichosporon spp. are basidiomycetous yeast-like fungi found widely in nature. Clinical isolates are generally related to superficial infections. However, this fungus has been recognized as an opportunistic agent of invasive infections, mostly in cancer patients and those exposed to invasive medical procedures. It is possible that the ability of Trichosporon strains to form biofilms on implanted devices, the presence of glucuronoxylomannan in their cell walls, and the ability to produce proteases and lipases are all factors likely related to the virulence of this genus and therefore may account for the progress of invasive trichosporonosis. Disseminated trichosporonosis has been increasingly reported worldwide and represents a challenge for both diagnosis and species identification. Phenotypic identification methods are useful for Trichosporon sp. screening, but only molecular methods, such as IGS region sequencing, allow the complete identification of Trichosporon isolates at the species level. Methods for the diagnosis of invasive trichosporonosis include PCR-based methods, Luminex xMAP technology, and, more recently, proteomics. Treating patients with trichosporonosis remains a challenge because of limited data on the in vitro and in vivo activities of antifungal drugs against clinically relevant species of the genus. Despite the mentioned limitations, the use of antifungal regimens containing triazoles appears to be the best therapeutic approach.

Susceptibilities to amphotericin B, fluconazole and voriconazole of Trichosporon clinical isolates

A total of 35 Trichosporon isolates were collected from the Taiwan Surveillance of Antimicrobial Resistance of Yeasts (TSARY) project from 1999 to 2006, and their identifications as well as drug susceptibilities were determined. The most frequently isolated species was T. asahii (62.9%), and the most common clinical sample that yielded Trichosporon isolates was urine (37.1%). The etiology of all seven invasive trichosporonosis was T. asahii. For the 22 T. asahii isolates, the MIC(50) and MIC(90) for amphotericin B were 0.25 and 1 μg/mL, respectively. Those for fluconazole were 2 and 4 μg/mL, respectively, and for voriconazole 0.031 and 0.063 μg/mL, respectively. When the intraclass correlation coefficients (ICCs) and agreements were calculated, we found that the MICs of fluconazole obtained from different methods were similar and the inter-method discrepancies were low. Nevertheless, no unanimous MIC of amphotericin B and voriconazole was obtained among different methods.

Silicone colonization by non-Candida albicans Candida species in the presence of urine

Urinary tract infections (UTIs) are the most common nosocomial infections and 80 % are related to the use of urinary catheters. Furthermore, Candida species are responsible for around 15 % of UTIs and an increasing involvement of non-Candida albicans Candida (NCAC) species (e.g. Candida glabrata, Candida tropicalis and Candida parapsilosis) has been recognized. Given the fact that silicone is frequently used in the manufacture of urinary catheters, the aim of this work was to compare both the adhesion and biofilm formation on silicone of different urinary clinical isolates of NCAC species (i.e. C. glabrata, C. tropicalis and C. parapsilosis) in the presence of urine. Several clinical isolates of NCAC species recovered from patients with UTIs, together with reference strains of each species, were examined. Adhesion and biofilm formation were performed in artificial urine and the biofilm biomass was assessed by crystal violet staining. Hydrophobicity and surface charge of cells was determined by measuring contact angles and zeta potential, respectively. The number of viable cells in biofilms was determined by enumeration of c.f.u. after appropriate culture. The biofilm structure was also examined by confocal laser scanning microscopy (CLSM). The results showed that all isolates adhered to silicone in a species- and strain-dependent manner with C. parapsilosis showing the lowest and C. glabrata the highest levels of adhesion. However, these differences in adhesion abilities cannot be correlated with surface properties since all strains examined were hydrophilic and exhibited a similar zeta potential. Despite a higher number of cultivable cells being recovered after 72 h of incubation, stronger biofilm formation was not observed and CLSM showed an absence of extracellular polymeric material for all isolates examined. In summary, this work demonstrated that all tested NCAC species were able to adhere to and survive on silicone in the presence of urine. Furthermore, C. glabrata strains presented higher colonization abilities than C. tropicalis and C. parapsilosis strains, a fact that might explain the larger role of C. glabrata colonization and disseminated infections in hospitalized and catheterized patients.

Candida infections of the genitourinary tract

All humans are colonized with Candida species, mostly Candida albicans, yet some develop diseases due to Candida, among which genitourinary manifestations are extremely common. The forms of genitourinary candidiasis are distinct from each other and affect different populations. While vulvovaginal candidiasis affects mostly healthy women, candiduria occurs typically in elderly, hospitalized, or immunocompromised patients and in neonates. Despite its high incidence and clinical relevance, genitourinary candidiasis is understudied, and therefore, important questions about pathogenesis and treatment guidelines remain to be resolved. In this review, we summarize the current knowledge about genitourinary candidiasis.

To treat or not to treat--critically ill patients with candiduria

The prevalence of candiduria has increased in patients admitted to intensive care units (ICUs) and it has emerged as a common nosocomial infection among critically ill patients. Generally, urinary candidiasis should be regarded as a risk factor for invasive candidiasis, but not as a disease that needs to be treated on its own. However, decision-making in critically ill patients with candiduria may become a balancing act, because candiduria may be the only indication for invasive candidaemia with significant morbidity and mortality. Of further concern, there is a worldwide increase in the incidence of non-albicans spp. isolated from urine with highly variable susceptibility to fluconazole, which has been the first-line therapy for Candida infections during the last decades. This article discusses everyday problems with urinary candidiasis in interdisciplinary ICUs.

[Candiduria: a clinical and therapeutic approach]

Candiduria remains a controversial issue for clinicians once that it may represent a broad variety of possibilities including colonization, local or systemic infection. We will discuss the epidemiology, diagnosis and treatment of candiduria in different settings of patients, including renal transplant recipients. Definitions on therapy are mostly based on epidemiological and clinical data. Once antifungal therapy is required the following antifungal treatment may be used: intravenous amphotericin B, bladder irrigation with amphotericin B or fluconazole. Blood cultures may be required in patients with candiduria and high risk for developing hematogenous infection. Removal of the urinary catheter must be considered in order to avoid persistent candiduria and recurrence.

Candiduria in intensive care units: association with heavy colonization and candidaemia

Candiduria is increasingly detected in intensive care unit (ICU) patients and often coexists with candidal colonization at other anatomical sites. Studies involving surgical and medical ICU patients have consistently reported a relationship between candiduria and heavy colonization. This suggests that candiduria could be considered as a marker for heavy colonization. Risk factors that predispose to heavy colonization are generally similar to those predisposing to candidaemia. Candiduria in ICU patients is characterized by a high mortality, largely through a significant relationship with candidaemia, which in some patients may reach 50%. Therapeutic interventions should be strongly considered in the critically ill patient who presents with candiduria and concurrent clinical risk factors predisposing to dissemination.

The effect of chlorhexidine and gentian violet on the adherence of Candida spp. to urinary catheters

Urinary tract infection associated with catheters is the most common infection in the hospital environment. The adherence of microorganisms to the surface is a determining factor in colonization and infection. Antiseptics such as chlorhexidine and gentian violet have been shown to be effective against yeasts, as well as having low toxicity and being low-cost. The objective of the present study was to evaluate whether prior treatment of siliconized latex urinary catheters with antiseptics reduces the adherence of yeasts. Two reference strains of C. albicans (ATCC 645448 and ATCC 90028) and six strains isolated from catheter, two each of C. albicans, C. tropicalis, and C. parapsilosis, were used. An in vitro study of adherence was carried out with previously treated catheters, in separate experiments of 1 h and 24 h of incubation under continued shaking. The relative hydrophobicity of the cell surface of the yeasts before and after 1 h of exposure to chlorhexidine was determined. The results demonstrated that both treatments were effective in controlling the adherence of yeast to the catheter (P < 0.0001), and that the hydrophobicity of the eight strains significantly increased after contact with chlorhexidine (P < 0.0001). These results suggest that the antimicrobial activity of chlorhexidine and gentian violet reduces the adherence of the microorganisms to the catheter.

Nosocomial candiduria in women undergoing urinary catheterization. Clonal relationship betweenstrains isolated from vaginal tract and urine

We determined the incidence of nosocomial candiduria associated with indwelling urinary catheters in 42 women with and without Candida spp. vaginal colonization being treated in the intensive care unit (ICU). We established a relationship between strains initially isolated from the vaginal tract and those subsequently recovered from urine samples through the use of random amplified polymorphic DNA (RAPD). The overall incidence of nosocomial candiduria in these patients was 21.4%. Vaginal colonization by Candida spp. was detected in 11 patients (26.2%) of whom 6 (54.5%) developed candiduria. In comparison, only 3 (9.7%) cases of candiduria were found in women who were not colonized by the yeast (RR: 4.4, 95% CI 1.61-86.8, P=0.005). The dendrogram obtained by RAPD using 14 primers showed that the strains isolated from vagina and urine samples in five women had high similarity values (SAB >0.9) forming independent clusters. Our study suggests that women vaginally colonized by Candida spp. in an ICU setting have a high risk of acquiring nosocomial candiduria and that strains isolated from both sites in a single patient may be genetically related.

[Candiduria in intensive care unit: significance and value of yeast numeration in urine]

JUSTIFICATION

Candiduria is increasingly frequent among patients admitted to intensive care units but its significance remains unclear.

OBJECTIVES

Search for eventual correlation between quantitative candiduria and known risk factors for invasive candidiasis.

STUDY DESIGN

Prospective.

PATIENTS AND METHODS

A four-month study was conducted in 162 patients hospitalized in the intensive care unit for more than 72 hours. All patients underwent a weekly research of candiduria added to sampling from different body sites to determine the Pittet Candida colonization index.

RESULTS

Candiduria has been proved in 56 cases (34%). It was superior or equal to 10(4) UFC/ml among 28 patients (50%). Candida tropicalis, Candida glabrata and Candida albicans has been isolated in 41, 22 and 20% respectively. All patients had at least one major and two minor risk factors for Candida infection. Six patients (10%) developed invasive candidiasis. The global mortality rate was at 52%. Pittet colonization index was significantly different between patients with candiduria and those with invasive candidiasis (p=0.01). There was a statistically significant correlation between candiduria superior or equal to 10(4) UFC/ml and Pittet colonization index superior or equal to 0.5 (p=0.01).

CONCLUSION

Candiduria superior or equal to 10(4) UFC/ml associated with risk factors may predict invasive candidiasis in critically ill patients.

Candida colonization in intensive care unit patients' urine

The objective of this study was to identify possible predisposing factors for candiduria in intensive care unit (ICU) patients from Hospital das Clínicas, Universidade Federal de Goiás, Goiânia, Brazil, during one year. Urine samples from 153 ICU patients were obtained by catheterization on admission day and every seven days. Data such as sex, age, antifungal therapy, and variables as antibiotics, underlying diseases or comorbid conditions and stay in the hospital, were collected from patients who had at least one urine culture that yielded > 10(3) yeast colonies/ml. Candiduria was recovered in 68 patients and the commonest predisposing factors were antibiotic therapy (100%) and indwelling urinary catheter (92.6%). The percentage of Candida spp. isolation increased during the extended periods in which patients remained in the ICU. C. albicans was isolated in 69.1%, and the other species non-albicans as C. glabrata, C. kefyr, C. parapsilosis, C. famata, C. guilliermondii, C. krusei, and C. tropicalis were isolated in lower percentage. The high frequency of candiduria and the possible predisposing factors found in ICU patients show that candiduria surveillance should be performed to help reducing nosocomial infections.

Antifungal susceptibility of 50 Candida isolates from invasive mycoses in Chile

We determined the antifungal susceptibility of 50 Candida isolates from invasive mycoses in intensive care unit patients in Chile. Candida albicans (27 isolates) and C. parapsilosis (12 isolates) were the most common etiologic species. Candida glabrata (five isolates) was isolated only from children. Our data are consistent with those of recent Brazilian and Argentinean studies but differ from those of some US, Canadian and Norwegian studies, in which the relatively azole-resistant C. glabrata was the predominant non-C. albicans species seen. All isolates in this study were susceptible to amphotericin B. Itraconazole and fluconazole resistance were observed in 6 and 4% of the isolates, respectively.

Application of control measures for infections caused by multi-resistant gram-negative bacteria in intensive care unit patients

Multi-resistant gram-negative rods are important pathogens in intensive care units (ICU), cause high rates of mortality, and need infection control measures to avoid spread to another patients. This study was undertaken prospectively with all of the patients hospitalized at ICU, Anesthesiology of the Hospital São Paulo, using the ICU component of the National Nosocomial Infection Surveillance System (NNIS) methodology, between March 1, 1997 and June 30, 1998. Hospital infections occurring during the first three months after the establishment of prevention and control measures (3/1/97 to 5/31/97) were compared to those of the last three months (3/1/98 to 5/31/98). In this period, 933 NNIS patients were studied, with 139 during the first period and 211 in the second period. The overall rates of infection by multi-resistant microorganisms in the first and second periods were, respectively, urinary tract infection: 3.28/1000 patients/day; 2.5/1000 patients/day; pneumonia: 2.10/1000 patients/day; 5.0/1000 patients/day; bloodstream infection: 1.09/1000 patients/day; 2.5/1000 patients/day. A comparison between overall infection rates of both periods (Wilcoxon test) showed no statistical significance (p = 0.067). The use of intervention measures effectively decreased the hospital bloodstream infection rate (p < 0.001), which shows that control measures in ICU can contribute to preventing hospital infections.

Efficacy of a single intravenous dose of amphotericin B for Candida urinary tract infections: further favorable experience

Studies in experimental animals and humans have shown that Amphotericin B (AmB) persists in urine for days to weeks after a single IV dose in levels that should inhibit candidal organisms and thereby obviate the need for frequent dosing. Including data from four previously described patients, we have now treated a total of 11 patients (12 episodes) with Candida urinary tract infections with single-dose AmB (six, Candida albicans; two, C. tropicalis; four, other nonalbicans Candida). The duration of candiduria prior to entry ranged from 18 to 180 days. Predisposing conditions included renal transplantation (1), diabetes mellitus (8), genitourinary stones (1) or anomalies (4), catheterization (2), and antibacterial therapy (11). A single patient was intolerant of AmB. Out of 11 evaluable candiduric episodes, eight resolved. Failure occurred in one patient with a chronic indwelling bladder catheter and in the allograft recipient. The data suggest that the sustained urinary excretion of AmB may permit successful single- or paucidose therapy of Candida urinary tract infections in some patients with a minimum of toxicity.

Trichosporon loubieri infection in a patient with adult polycystic kidney disease

A 45-year-old man from Nepal with a 13-year history of polycystic kidney disease was diagnosed as suffering from chronic renal failure with end-stage renal disease. After receiving empirical antituberculosis treatment, he was treated with broad-spectrum antibiotics. A left nephrectomy was performed, and after 4 months, he received a kidney transplant. The left kidney was grossly enlarged, with multiple cystic spaces filled with blackish material. Histologic examination of the excised left kidney tissue stained with hematoxylin and eosin and Gomori's methenamine silver stains showed numerous hyaline, septate, fungal hyphae of various lengths, many broken into rectangular arthroconidia in the cystic spaces. Culture of the kidney tissue yielded white, glabrous, yeast-like colonies. Based on its micromorphology, growth at 42 degrees C, and ribosomal DNA (rDNA) sequence analysis, and also sequence analysis of the internal-transcribed-spacer and D1/D2 rDNA regions, the yeast was identified as Trichosporon loubieri. Postsurgically, the patient was treated with amphotericin B and oral itraconazole, followed by maintenance therapy with fluconazole. He remained afebrile and asymptomatic. At the final follow-up, all parameters were found normal and the patient was doing well, with normal renal function reports. This paper presents the first known case of human infection caused by T. loubieri.

Mucosal candidiasis

This article examines the ecology and epidemiology of gastrointestinal candidiasis, esophageal candidiasis, chronic mucocutaneous candidiasis, urinary tract candidiasis, and vulvovaginal candidiasis. Such issues as pathogenesis and host defenses, clinical manifestations, diagnosis, and treatment are discussed.

A European perspective on nosocomial urinary tract infections I. Report on the microbiology workload, etiology and antimicrobial susceptibility (ESGNI-003 study). European Study Group on Nosocomial Infections

OBJECTIVES

To obtain information on the microbiology workload, etiology and antimicrobial susceptibility of urinary tract infection (UTI) pathogens isolated in European hospitals.

MATERIALS AND METHODS

We collected data available in the microbiology units of a large sample of European hospitals regarding the laboratory workload, diagnostic criteria, and etiology and antimicrobial resistance of the urinary isolates collected on one day (the study day).

RESULTS

Data were received from a total of 228 hospitals from 29 European countries. The average rate of urine samples cultured per 1000 admissions in 1999 was 324. The criteria to consider a positive urine culture as significant were quite variable; > or =10(4) colony-forming units (CFU)/mL for bacteria or > or =10(3) CFU/mL in the case of yeasts were the most used cut-off points. On the study day, a total of 607 micro-organisms from 522 patients with nosocomial UTI were isolated. The six most commonly isolated micro-organisms were, in decreasing order: Escherichia coli (35.6%), Enterococci (15.8%), Candida (9.4%), Klebsiella (8.3%), Proteus (7.9%) and Pseudomonas aeruginosa (6.9%). Pseudomonas was isolated more frequently in non-EU countries. The study data reveal high rates of antimicrobial resistance in UTI pathogens, especially in non-EU countries, where Pseudomonas aeruginosa presented rates of aminoglycoside resistance as high as 72% to gentamicin, 69.2% to tobramycin and 40% to amikacin.

CONCLUSIONS

Nosocomial UTI accounts for an important proportion of the workload in microbiology laboratories. A consensus on the practice and interpretation of urine cultures in Europe is needed. The levels and patterns of resistance of UTI pathogens must be a serious cause for concern and a clear reason for stricter guidelines and regulations in antimicrobial policy.

Management of candiduria

The distinction between Candida colonization of the urinary tract and infection is often blurred. Asymptomatic candiduria is particularly common in catheterized intensive care unit patients. To date, few studies have addressed the appropriate treatment regimens for candiduria. Fluconazole has become a mainstay of therapy; however, when to treat, whom to treat, and how long to treat are still largely unanswered questions. Asymptomatic nosocomial candiduria infrequently requires treatment intervention because morbidity is low and ascending infection and candidemia are rare complications. An understanding of the anatomic site of infection drives treatment decisions. More research is needed to define diagnostic criteria and therapeutic pathways. This review attempts to summarize the diagnosis and management of candiduria.

Nosocomial candiduria: a review

Fungal infections of the urinary tract, especially those caused by Candida species, are becoming increasingly common. Often the line between Candida colonization and infection is blurred. Diagnosis typically depends on the discovery of pyuria with high colony Candida counts in the urine. To date, there have been few studies to have addressed treatment regimens for patients with candiduria. Fluconazole has become a mainstay of therapy; however, questions regarding when to treat, whom to treat, and how long to treat are still largely unanswered. Asymptomatic nosocomial candiduria does not frequently require treatment intervention, because morbidity is low and ascending infection and candidemia are rare complications. Treatment decisions are driven by an understanding of the anatomic site of infection. For Candida cystitis, the first-line treatment is fluconazole, given orally. Ascending pyelonephritis usually requires the administration of a systemic antifungal agent and often requires correction of the obstruction or surgical drainage. More research is needed to define diagnostic criteria and therapeutic pathways. This review will attempt to summarize the state of the art of diagnosis and management of candiduria.

Candiduria: When and How to Treat It

The clinical finding of candiduria is often an enigmatic problem for the evaluating physician. The significance of yeast in the urine can range from procurement contamination to a sign of a life-threatening, opportunistic fungal infection. Proper evaluation requires validation of funguria, consideration of the setting in which it occurs, and the status of the patient. Provided that the patient is clinically stable, asymptomatic candiduria usually need not be treated with an antifungal agent. Rather, management should be directed at the elimination of predisposing factors, if feasible. When treatment is required, appropriate agents include amphotericin B (AmB), various lipid preparations of AmB (L-AmB), azoles, and flucytosine. Parenteral AmB is most useful against life-threatening infections in which the urinary tract is but one component of a widespread infection, or when resistant Candida are causative. Shorter courses of therapy may be preferable in certain cases. L-AmB treatment has been less sucessful. Intravesical AmB is a time-honored approach, but is best employed diagnostically rather than therapeutically. Fluconazole is presently the agent of first choice for susceptible fungi, but dosage and duration of therapy have not been established. Flucytosine is a useful alternative, especially for resistant Candida, but its toxicity must be closely monitored.