Candida colonization in intensive care unit patients' urine

Catheter-associated urinary tract infections in adult intensive care units at a selected tertiary hospital, Addis Ababa, Ethiopia

Background

Catheter-associated urinary tract infection is the leading cause of hospital-acquired infections. They remain the second most common healthcare-associated infection in critically sick patients.

Objective

To determine the prevalence of catheter-associated urinary tract infection, the spectrum of etiological agents, antibiotic sensitivity profile of bacterial pathogens among adult patients admitted to intensive care units.

Materials and methods

Patients admitted to the intensive care unit of hospitals in Addis Ababa who were on urethral indwelling catheters for >48 hours from October 2020 to September 2021 were included in the study. Urine specimens were aseptically collected and processed as per standard protocols. Microorganisms were isolated, identified, and subjected to antibiotic susceptibility testing.

Results

In all 220 pateints included in the study development of significant bacteriuria/candiduria was not affected by sex, age, and prior antibiotic therapy. However, the length of stay in the intensive care unit was significantly associated with bacteriuria /candiduria (P-value < 0.001). The overall prevalence of bacteriuria/candiduria was 51.4% among which 21.0%, 19.1%, and 11.4% were bacteriuria, candiduria, and polymicrobial infections, respectively. About 138 organisms were recovered of which 79 (57.25%) were bacteria and 59 (42.75%) were yeast isolates. Acinetobacter species, Pseudomonas species, Klebsiella species E. coli, and Enterococcus species were the dominant bacterial isolates. Candida. albicans, Candida. krusei and Candida. tropicalis were the commonest yeasts. Many gram-negative bacterial isolates were resistant to ceftriaxone 36(94.7%), ampicillin 21(91.3%) followed by cefotaxime34(89.5%), amikacin (16.0%), nitrofurantoin (17.4%), meropenem (20.0%) and imipenem (20.0%). Out of 79 bacterial pathogens, 52(65.8%) were multiple antibiotic resistant of which 37(71.0%) were Gram-negative bacteria and 15(29%%) were Gram-positive bacteria. About 13(86.7%) isolates of Acinetobacter, all isolates of Klebsiella species (100%) and E. coli (100%) were multiple antibiotic-resistant. Out Of 18,10(55.56%), isolates of Enterococcus were multiple antibiotic-resistant.

Conclusions

A very high prevalence of bacteriuria/ candiduria was demonstrated in this study. This warrants the establishment of multidimensional infection control approach on catheter associated urinary tract infection in ICU. In addition to high prevalence of candiduria, recovery of non-albicans candida species almost in equal proportion with candida albicans in the present study was an important finding as non-albicans candida species distinct to C. albicans are intrinsically resistant to the commonly used azole antifungal drugs in Ethiopia. The prevalence of rate MDR bacteria in our ICU particularly of E. coli, Klebsiella spp, Pseudomonas and Acetobacter spp was very high. In order to combat this problem, proper antibiotic policies should be formulated.

Characterisation of Candida parapsilosis CYP51 as a Drug Target Using Saccharomyces cerevisiae as Host

The fungal cytochrome P450 lanosterol 14α-demethylase (CYP51) is required for the biosynthesis of fungal-specific ergosterol and is the target of azole antifungal drugs. Despite proven success as a clinical target for azole antifungals, there is an urgent need to develop next-generation antifungals that target CYP51 to overcome the resistance of pathogenic fungi to existing azole drugs, toxic adverse reactions and drug interactions due to human drug-metabolizing CYPs. Candida parapsilosis is a readily transmitted opportunistic fungal pathogen that causes candidiasis in health care environments. In this study, we have characterised wild type C. parapsilosis CYP51 and its clinically significant, resistance-causing point mutation Y132F by expressing these enzymes in a Saccharomyces cerevisiae host system. In some cases, the enzymes were co-expressed with their cognate NADPH-cytochrome P450 reductase (CPR). Constitutive expression of CpCYP51 Y132F conferred a 10- to 12-fold resistance to fluconazole and voriconazole, reduced to ~6-fold resistance for the tetrazoles VT-1161 and VT-1129, but did not confer resistance to the long-tailed triazoles. Susceptibilities were unchanged in the case of CpCPR co-expression. Type II binding spectra showed tight triazole and tetrazole binding by affinity-purified recombinant CpCYP51. We report the X-ray crystal structure of ScCYP51 in complex with VT-1129 obtained at a resolution of 2.1 Å. Structural analysis of azole—enzyme interactions and functional studies of recombinant CYP51 from C. parapsilosis have improved understanding of their susceptibility to azole drugs and will help advance structure-directed antifungal discovery.

The Flo Adhesin Family

The first step in the infection of fungal pathogens in humans is the adhesion of the pathogen to host tissue cells or abiotic surfaces such as catheters and implants. One of the main players involved in this are the expressed cell wall adhesins. Here, we review the Flo adhesin family and their involvement in the adhesion of these yeasts during human infections. Firstly, we redefined the Flo adhesin family based on the domain architectures that are present in the Flo adhesins and their functions, and set up a new classification of Flo adhesins. Next, the structure, function, and adhesion mechanisms of the Flo adhesins whose structure has been solved are discussed in detail. Finally, we identified from Pfam database datamining yeasts that could express Flo adhesins and are encountered in human infections and their adhesin architectures. These yeasts are discussed in relation to their adhesion characteristics and involvement in infections.

Candiduria-Study of Virulence Factors and Its Antifungal Susceptibility Pattern in Tertiary Care Hospital

Background The increased incidence of candiduria in hospitalized patients is due to the use of indwelling devices, long-term antibiotics, parenteral nutrition, and immunocompromised status of the patient. In this study, an attempt was made to speciate, characterize, and determine the antifungal susceptibility pattern of Candida isolated from urinary tract infections (UTIs).

Materials and Methods A total of 70 Candida isolates were obtained from urine samples. The isolated Candida species were studied for the production of virulence factors like phospholipase, protease activities, hemolysin, and biofilm production. Antifungal susceptibility testing of the isolated yeasts was done using Mueller-Hinton agar supplemented with 0.5 mg/mL methylene blue by E-test method for amphotericin B, fluconazole, caspofungin, and voriconazole.

Results Out of 70 isolates, Candida tropicalis was the most frequently isolated species (65.7%), followed by Candida albicans (14.3%), Candida glabrata (7.1%), Candida krusei (5.7%), Candida parapsilosis (4.3%), and Candida dubliniensis (2.9%). A total of 37.1% were biofilm producers, 62.9% showed proteinase activity, 38.6% were phospholipase positive, and 58.6% isolates showed hemolytic activity. Antifungal susceptibility profile of Candida species showed 38.6, 25.7, 15.7, and 12.9% resistance to amphotericin B, fluconazole, caspofungin, and voriconazole, respectively.

Conclusion A rising trend in isolation of non-albicans Candida from urinary isolates was noticed, which was statistically significant when comparing catheterized and noncatheterized urinary isolates from our study. However, there was no statistically significant difference when different virulence factor expressions were compared among Candida spp. isolated from catheterized and noncatheterized urinary samples. Due to this rise in non-albicans Candida species causing UTI that are intrinsically resistant to certain antifungal agents like azoles and increasing incidence of antifungal resistance, it is essential to monitor the antifungal susceptibility profile of Candida species causing candiduria.

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.

Identification and antifungal susceptibility of Candida species isolated from the urine of patients in a university hospital in Brazil

The aim of this study was to identify Candida spp. isolated from candiduria episodes at a tertiary hospital in the Midwest region of Brazil, and to determine their susceptibility profiles to antifungal compounds. From May 2011 to April 2012, Candida spp. isolated from 106 adult patients with candiduria admitted to the University Hospital of the Federal University of Mato Grosso do Sul were evaluated. Both, species identification and susceptibility testing with fluconazole-FLC, voriconazole-VRC, and amphotericin B-AmB were carried out using the Vitek 2. To discriminate species of the C. parapsilosis complex, a RAPD-PCR technique using the RPO2 primer was performed. From the total of 106 isolates, 42 (39.6%) C. albicans and 64 (60.4%) Candida non-albicans (CNA) - 33 C. tropicalis, 18 C. glabrata, 5 C. krusei, 4 C. parapsilosis sensu stricto, 2 C. kefyr, 1 C. lusitaniae, and 1 C. guilliermondii were identified. All isolates were susceptible to AmB and VRC, whereas all C. glabrata isolates presented either resistance (5.6%) or dose-dependent susceptibility (94.4%) to FLC. The study of Candida spp. and their resistance profiles may help in tailoring more efficient therapeutic strategies for candiduria.

Nosocomial Candiduria in the Elderly: Microbiological Diagnosis

Candiduria is associated with high morbidity, mortality, and long hospitalization, involving high costs for the healthcare system. The use of increasingly aggressive treatments has prolonged the lives of patients susceptible to candiduria, namely the immunosuppressed, the premature, and the elderly. Our objective was to evaluate the incidence of nosocomial candiduria and the implicated species in hospitalized patients aged over 80 years old from three Spanish centers during 2012 and 2013. Urine samples received from these patients were cultured and analyzed by flow cytometry in search of leukocyturia, hematuria, proteinuria, and microbial nitrate reductase activity. The isolated yeast species were identified microscopically, by germ tube formation in serum, colony morphology after subculture onto CHROMagar Candida (Becton-Dickinson, UK), assimilation of carbon compounds ID32C (bioMérieux, France), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDITOF) (Bruker Daltonics, Germany) and, in case of inconsistency, by sequencing of the ITS regions of ribosomal DNA (ITS1-5, 8S-ITS2). Susceptibility tests were also performed. The incidence of candiduria in the elderly population was 10.3%. A total of 155 strains of yeasts were isolated. The predominant species was Candida albicans, followed by Candida glabrata and then Candida tropicalis. Several infrequent species were found; among them, the first isolate of candiduria-producing Candida pulcherrima described in the literature. Our finding should raise concerns about the elderly population, which is probably the most important risk group for candiduria in the present moment, and the emergence of unusual yeast species producing candiduria, which are resistant against the commonly used antifungal agents.

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.

Isolation, characterization and mechanism of action of an antimicrobial peptide from Lecythis pisonis seeds with inhibitory activity against Candida albicans

Antimicrobial peptides (AMPs) are produced by a range of organisms as a first line of defense against invaders or competitors. Owing to their broad antimicrobial activity, AMPs have attracted attention as a potential source of chemotherapeutic drugs. The increasing prevalence of infections caused by Candida species as opportunistic pathogens in immunocompromised patients requires new drugs. Lecythis pisonis is a Lecythydaceae tree that grows in Brazil. The AMPs produced by this tree have not been described previously. We describe the isolation of 12 fractions enriched in peptides from L. pisonis seeds. Of the 12 fractions, at 10 μg/ml, the F4 fraction had the strongest growth inhibitory effect (53.7%) in Candida albicans, in addition to a loss of viability of 94.9%. The F4 fraction was separated into seven sub-fractions by reversed-phase chromatography. The F4.7' fraction had the strongest activity at 10 μg/ml, inhibiting C. albicans growth by 38.5% and a 69.3% loss of viability. The peptide in F4.7' was sequenced and was found to be similar to plant defensins. For this reason, the peptide was named L. pisonis defensin 1 (Lp-Def1). The mechanism of action that is responsible for C. albicans inhibition by Lp-Def1 includes a slight increase of reactive oxygen species induction and a significant loss of mitochondrial function. The results described here support the future development of plant defensins, specifically Lp-Def1, as new therapeutic substances against fungi, especially C. albicans.

Candidemia: incidence rates, type of species, and risk factors at a tertiary care academic hospital in China

OBJECTIVES

To investigate the incidence rates of candidemia in hospitalized patients and to identify differences in risk factors of patients with Candida albicans and non-C. albicans and with Candida guilliermondii and non-C. guilliermondii candidemia.

METHODS

Non-immunosuppressed, non-neutropenic inpatients with candidemia diagnosed after admission were included in this retrospective observational study at a tertiary academic hospital in China.

RESULTS

During the study period (January 2009 to December 2011), 238 eligible patients had candidemia episodes with an incidence rate 5.4%. Of these patients, 29.8% had candidemia due to C. albicans, 27.7% due to C. parapsilosis, and 16.4% due to C. guilliermondii. Diabetes was a significant risk factor for patients with candidemia due to C. albicans (35.2%, 25/71) compared to candidemia due to non-C. albicans spp (13.2%, 22/167) (odds ratio (OR) 0.2792, 95% confidence interval (CI) 0.144-0.5412; p < 0.001). Compared to patients with candidemia due to non-C. guilliermondii spp, preterm birth with low birth weight (OR 0.0887, 95% CI 0.0398-0.1977; p < 0.001), intravenous nutrition (OR 0.0662, 95% CI 0.0226-0.1938), and surgery (OR 0.0662, 95% CI 0.0226-0.1938; p < 0.001) were significant risk factors for candidemia due to C. guilliermondii. Furthermore, compared to patients with candidemia due to C. albicans, patients with candidemia due to C. guilliermondii had markedly higher rates of central venous catheterization (85.9%, 61/71 vs. C. guilliermondii: 100%, 39/39; p = 0.013) and intravenous nutrition (89.7%, 35/39 vs. C. albicans: 42.2%, 30/71; p < 0.001).

CONCLUSIONS

Candidemia due to C. albicans ranks first in incidence, and candidemia due to C. guilliermondii occurs in a significant proportion of our hospitalized patients.

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.

Brazilian guidelines for the management of candidiasis - a joint meeting report of three medical societies: Sociedade Brasileira de Infectologia, Sociedade Paulista de Infectologia and Sociedade Brasileira de Medicina Tropical

Candida infections account for 80% of all fungal infections in the hospital environment, including bloodstream, urinary tract and surgical site infections. Bloodstream infections are now a major challenge for tertiary hospitals worldwide due to their high prevalence and mortality rates. The incidence of candidemia in tertiary public hospitals in Brazil is approximately 2.5 cases per 1000 hospital admissions. Due to the importance of this infection, the authors provide a review of the diversity of the genus Candida and its clinical relevance, the therapeutic options and discuss the treatment of major infections caused by Candida. Each topography is discussed with regard to epidemiological, clinical and laboratory diagnostic and therapeutic recommendations based on levels of evidence.

Candida albicans and non-C. albicans Candida species: comparison of biofilm production and metabolic activity in biofilms, and putative virulence properties of isolates from hospital environments and infections

Candida albicans and, more recently, non-C. albicans Candida spp. are considered the most frequent fungi in hospitals. This study analyzed Candida spp. isolates and compared the frequency of different species, that is, C. albicans and non-C. albicans Candida spp., and the origins of isolates, that is, from hospital environments or infections. Yeast virulence factors were evaluated based on biofilm production and metabolic activity. Hemolysin production and the antifungal susceptibility profiles of isolates were also evaluated. Candida spp. were highly prevalent in samples collected from hospital environments, which may provide a reservoir for continuous infections with these yeasts. There were no differences in the biofilm productivity levels and metabolic activities of the environmental and clinical isolates, although the metabolic activities of non-C. albicans Candida spp. biofilms were greater than those of the C. albicans biofilms (p < 0.05). Clinical samples had higher hemolysin production (p < 0.05) and lower susceptibility to fluconazole (p < 0.05). Non-C. albicans Candida spp. predominated in samples collected from hospital environments and infections (p < 0.05). These species had a lower susceptibility to fluconazole and amphotericin B, and their biofilms had higher metabolic activities than those produced by C. albicans, which may explain the increased incidence of fungal infections with these yeasts during recent years.

Chateter-associated Urinary Tract Infections in Adults

INTRODUCTION

Hospital-acquired Urinary tract infections make 35% of all the hospital-acquired infections, and about 80% of them are related to the catheterization of the urinary bladder.

PURPOSE

To determine clinical characteristics and dominant etiologic factors of Urinary Tract Infections associated with urinary catheter (C-UTIs).

METHODS

Determined clinical characteristics of C-UTIs were prospectively analyzed on 38 hospitalized patients in the Clinic for Infectious Diseases at the University Clinical Centre Tuzla, from January 1(st) 2011 to December 31(st) 2011. The control group constituted of 200 patients with community-acquired Urinary Tract Infections (Co-UTIs) hospitalized in the same period.

RESULTS

It was registered on 22 (57.89%) of symptomatic infections, 14 (36.84%) asymptomatic bacteriuria and 2 (5.26%) other C-UTIs. Dominant etiologic factors were: E. coli, caused 14 (36.84%), Extended-Spectrum Beta-lactamase producing (ESBL) Klebsiella pneumoniae 7 (18.42%), Enterococcus faecium and Candida spp. 3 (7.89%) of C-UTIs. E. coli was significantly most common etiologic factor of C-UTIs in younger women (p=0.04). E. coli from C-UTIS showed significantly higher resistance to antimicrobial drugs. Inadequate antimicrobial therapy was significantly more common prescribed to patients from C-UTIs. Lethal outcome was significantly most common associated with certain clinical and laboratory findings.

CONCLUSION

Initial antimicrobial therapy of those serious infections should be based on data from those research.

Nosocomial infections in a pediatric intensive care unit of a developing country: NHSN surveillance

INTRODUCTION

This study aimed to determine the epidemiology of the three most common nosocomial infections (NI), namely, sepsis, pneumonia, and urinary tract infection (UTI), in a pediatric intensive care unit (PICU) in a developing country and to define the risk factors associated with NI.

METHODS

We performed a prospective study on the incidence of NI in a single PICU, between August 2009 and August 2010. Active surveillance by National Healthcare Safety Network (NHSN) was conducted in the unit and children with NI (cases) were compared with a group (matched controls) in a case-control fashion.

RESULTS

We analyzed 172 patients; 22.1% had NI, 71.1% of whom acquired it in the unit. The incidence densities of sepsis, pneumonia, and UTI per 1,000 patients/day were 17.9, 11.4, and 4.3, respectively. The most common agents in sepsis were Enterococcus faecalis and Escherichia coli (18% each); Staphylococcus epidermidis was isolated in 13% of cases. In pneumonias Staphylococcus aureus was the most common cause (3.2%), and in UTI the most frequent agents were yeasts (33.3%). The presence of NI was associated with a long period of hospitalization, use of invasive devices (central venous catheter, nasogastric tube), and use of antibiotics. The last two were independent factors for NI.

CONCLUSIONS

The incidence of NI acquired in this unit was high and was associated with extrinsic factors.

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.

Species distribution and in vitro fluconazole susceptibility of clinical Candida isolates in a Brazilian tertiary-care hospital over a 3-year period

INTRODUCTION

In this study, we aimed at identifying Candida isolates obtained from blood, urine, tracheal secretion, and nail/skin lesions from cases attended at the Hospital Universitário de Londrina over a 3-year period and at evaluating fluconazole susceptibilities of the isolates.

METHODS

Candida isolates were identified by polymerase chain reaction (PCR) using species-specific forward primers. The in vitro fluconazole susceptibility test was performed according to EUCAST-AFST reference procedure.

RESULTS

Isolates were obtained from urine (53.4%), blood cultures (19.2%), tracheal secretion (17.8%), and nail/skin lesions (9.6%). When urine samples were considered, prevalence was similar in women (45.5%) and in men (54.5%) and was high in the age group >61 years than that in younger ones. For blood samples, prevalence was high in neonates (35%) and advanced ages (22.5%). For nail and skin samples, prevalence was higher in women (71.4%) than in men (28.6%). Candida albicans was the most frequently isolated in the hospital, but Candida species other than C. albicans accounted for 64% of isolates, including predominantly Candida tropicalis (33.2%) and Candida parapsilosis (19.2%). The trend for non-albicans Candida as the predominant species was noted from all clinical specimens, except from urine samples. All Candida isolates were considered susceptible in vitro to fluconazole with the exception of isolates belonging to the intrinsically less-susceptible species C. glabrata.

CONCLUSIONS

Non-albicans Candida species were more frequently isolated in the hospital. Fluconazole resistance was a rare finding in our study.

Molecular assay to detect nosocomial fungal infections in intensive care units

SUMMARY

The aims of this study were to determine the incidence of fungal infections in hospital intensive care units and to evaluate a molecular method to detect these infections.

MATERIAL AND METHODS

The participants in this study were patients admitted to any of the 10 intensive care units at Nemazi Hospital (Shiraz, southern Iran) between March 2009 and January 2010. Oral and rectal swabs, urine, and sputum samples from patients were checked for fungal colonization. If a nosocomial fungal infection was suspected, clinical samples were examined for fungal infection by culture, direct microscopic examination and real-time PCR. Blood samples were cultured by bedside inoculation onto BACTEC medium. Susceptibility of the isolates to antifungal agents was also determined.

RESULTS

Of 870 patients, 550 (63.2%) had Candida colonization in different body sites and 17 (1.9%) had fungal infections. The mortality rate in patients with fungal infections was 58.8% (10 cases). The etiologic agents were Candida albicans, Candida glabrata, Aspergillus flavus, Aspergillus fumigatus and Aspergillus spp. Three C. albicans were found to be resistant to amphotericin B and itraconazole, and one A. fumigatus and two A. flavus were resistant to amphotericin B, ketoconazole and itraconazole. One A. fumigatus was additionally resistant to caspofungin.

CONCLUSIONS

Considering the incidence of fungal infections and their high mortality rate, early detection, prompt diagnosis and treatment are critical. Molecular assays can serve as a diagnostic tool to manage patients admitted to the intensive care unit. Antifungal susceptibility testing in different geographical regions can support the choice of prophylaxis and treatment for these patients.

A murine model for catheter-associated candiduria

Candiduria is a common finding in hospitalized patients with indwelling urine-draining devices. Animal models for candiduria are not well-developed and, despite its prevalence and associated mortality, candiduria is understudied. The presence of Candida in urine does not imply disease because it is also a commensal. Biofilm formation on catheters and the host-pathogen interaction are likely to be important factors that contribute to the pathogenesis. The objective of this study was to establish a candiduria model in mice with indwelling catheters. Our data demonstrate that biofilm formation on indwelling catheters and persistent candiduria can be established in mice. The study supports the concept that biofilm formation contributes to persistence. It also outlines differences between catheter-related candiduria in mice and humans. Specifically, mice exhibit higher levels of leukocyturia. In addition, mean daily fungal burden in urine in the murine model is 10- to 100-fold lower than that in humans. These important findings must be taken into consideration when using this model to study host-pathogen interaction in the setting of candiduria.

What do we know about Candida guilliermondii? A voyage throughout past and current literature about this emerging yeast

Candida guilliermondii is an uncommon isolate throughout most of the world, the behaviour of which as an environmental fungus, a human saprophyte and an agent of serious infections has been emphasised over the years. Notably, illnesses caused by this pathogen mostly involve compromised cancer hosts and commonly lead patients to unfavourable outcomes. It is of concern that the yeast may acquire or inherently express reduced in vitro sensitivity to all antifungal classes, although widespread resistance has not yet been described, and poor correlation exists between MICs and clinical outcome. However, the organism appears as constitutively less susceptible to polyenes and echinocandins than other yeast-like fungi, so that the emergence of such pathogen in the clinical settings is of concern and may appear as a new challenge in the context of mycoses and antifungal therapy.

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.

Pan-azole-resistant Candida guilliermondii from a leukemia patient's silent funguria

Isolation of Candida non-albicans yeasts as commensals or pathogens from hospitalised hosts is acquiring increasing importance, due to the frequent drug resistance expressed by such organisms.Particularly, the recover of antifungal resistant C. guilliermondii is of worrisome concern, even if recovered as a saprophyte, since commensal yeasts may behave as reservoirs for resistance elements;furthermore, they may enter the bloodstream after chemotherapy-related mucosal damage has developed,thus causing life-threatening and difficult-to-treat fungemias. This communication deals with the unusual isolation of a pan-azole resistant C. guilliermondii strain from a leukaemic patient with silent candiduria and emphasizes the importance of monitoring less recurring species within the nosocomial setting to better understand fungal epidemiology within the wards and face the spread of resistance determinants. Also, we highlight the controversial significance of silent candiduria, clinical relevance of which should be investigated case by case, to exclude and/or prevent candiduria as well as renal impairment.

Candida parapsilosis: a review of its epidemiology, pathogenesis, clinical aspects, typing and antimicrobial susceptibility

The Candida parapsilosis family has emerged as a major opportunistic and nosocomial pathogen. It causes multifaceted pathology in immuno-compromised and normal hosts, notably low birth weight neonates. Its emergence may relate to an ability to colonize the skin, proliferate in glucose-containing solutions, and adhere to plastic. When clusters appear, determination of genetic relatedness among strains and identification of a common source are important. Its virulence appears associated with a capacity to produce biofilm and production of phospholipase and aspartyl protease. Further investigations of the host-pathogen interactions are needed. This review summarizes basic science, clinical and experimental information about C. parapsilosis.

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.

Resistência a antifúngicos de Candida tropicalis isoladas no Estado do Ceará

Neste estudo, foi avaliada a resistência a drogas antifúngicas em 51 cepas de Candida tropicalis isoladas de amostras clínicas no Estado do Ceará, Brasil. Resistência antifúngica foi um evento raro no nosso estudo e foi restrita a 3 (5,9%) das cepas de Candida tropicalis, que exibiram resistência a fluconazol e itraconazol.

[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.