A study on candiduria in neonates and infants from a tertiary care center, North India

PURPOSE

Candida albicans is the major cause of fungal UTI in neonates and infants but nowadays non albicans Candida is also increasing and these are mostly multidrug resistant. So it's important to know the species of candidal UTI for the proper management. This study was undertaken to determine the Candida species distribution in UTI along with their susceptibility pattern and outcome in infants and neonates admitted in different wards and ICU of our hospital. We also assess the incidence rate of candiduria in ICUs.

METHOD

Urine samples were collected from infants and neonates presented in pediatrics and neonatal ICU (intensive care units) and clinical wards with a clinical suspicion of candiduria and infants at risk of invasive candidiasis were also included in the study. Identification of Candida sp. was done by Gram's staining, germ tube test, chlamydospore formation on corn meal agar, color appearance on CHROM agar and also confirmed by MALDI-TOF Assay. Antifungal susceptibility was performed by using broth microdilution method as per the CLSI M27-A3/M27-S4.

RESULT

Urine samples were received from 219 infants, and Candida was isolated from samples from 52 infants (isolation rate 23.75%), of which 30 were admitted in pediatric or neonatal ICU and 22 in the wards. The incidence rate of candiduria in ICU was 3.25%. Candida albicans was the most frequently isolated species from the samples of infants in the wards (13/22 i.e. 59%), while Candida tropicalis was most frequently isolated from samples of infants in the ICUs (13/30 i.e. 43.34%). Candida glabrata was the least commonly isolated species and was only encopuntered in the ICU. There was no discrepancy between the results of conventional methods of identification and MALDI-TOF. Antifungal susceptibility was performed for 18 randomly selected isolates. All were found to be susceptible to caspofungin, micafungin, itraconazole, voriconazole, fluconazole, amphotericin B.

CONCLUSION

High suspicion of candiduria is needed especially in ICU admitted infants and identification of candida at species level along with the susceptibility pattern is important for the better management of patients.

Characterization of the Urinary Metagenome and Virome in Healthy Children

Recent advances in next-generation sequencing and metagenomic studies have provided insights into the microbial profile of different body sites. However, research on the microbial composition of urine is limited, particularly in children. The goal of this study was to optimize and develop reproducible metagenome and virome protocols using a small volume of urine samples collected from healthy children. We collected midstream urine specimens from 40 healthy children. Using the metagenomics shotgun approach, we tested various protocols. Different microbial roots such as Archaea, Bacteria, Eukaryota, and Viruses were successfully identified using our optimized urine protocol. Our data reflected much variation in the microbial fingerprints of children. Girls had significantly higher levels of Firmicutes, whereas boys had significantly higher levels of Actinobacteria. The genus Anaerococcus dominated the urinary bacteriome of healthy girls, with a significant increase in Anaerococcus prevotii, Anaerococcus vaginalis, and Veillonella parvula (p-value < 0.001) when compared with that of boys. An increased relative abundance of Xylanimonas and Arthrobacter, with a significantly high abundance of Arthrobacter sp. FB24 (p-value 0.0028) and Arthrobacter aurescences (p-value 0.015), was observed in boys. The urinary mycobiome showed a significant rise in the genus Malassezia and Malassezia globose fungus (p-value 0.009) in girls, whereas genus Saccharomyces (p-value 0.009) was significantly high in boys. The beta diversity of the urinary mycobiome was found to differ between different age groups. Boys had significantly more Mastadenovirus and Human mastadenovirus-A in their urinary virome than girls. With increasing age, we noticed an increase in the relative abundance of the order Caudovirales. Our optimized protocols allowed us to identify the unique microbes for each sex by using an adequate volume of urine (3−10 mL) to screen for the bacteriome, mycobiome, and virome profiles in the urine of healthy children. To the best of our knowledge, this is the first study to characterize the metagenomics profiles of urine in a healthy pediatric population.

Ultrasonographic evaluation of the children with candiduria for the fungal ball: Is It necessary?

INTRODUCTION

Imaging of the urinary tract by ultrasonography (USG) or computerized tomography scanning is recommended for detecting structural abnormalities, hydronephrosis, abscesses, emphysematous pyelonephritis, or fungus ball formation. Limited studies on the epidemiology and the imaging results of candiduria were present in the children.

AIM

This study aimed to evaluate the results of renal ultrasonography imaging in hospitalized pediatric patients with candiduria.

STUDY DESIGN

In this descriptive study, we reviewed our ultrasonography findings with hospitalized children and infants who with candiduria. The study included the period between January 2012 and December 2019. Demographic data, the previous medical history, the clinical features of the patients, ultrasonographic findings of the urinary tract system, presence of an indwelling urinary catheter, type of urinary samplings, type of candida species were retrospectively recorded. The study was approved by Institutional Review Board with the registration number 2019/366.

RESULTS

During the study period, 220 children with nosocomial candiduria were evaluated. The most common isolated candida species was Candida albicans (68.2%) and followed by C. tropicalis (9.1%). Among all patients, 2 (0.9%) had renal fungal balls associated with C. Albicans. Twenty-five patients (11.4%) had findings including internal echogenicity in the bladder (n = 12), uroepithelial thickening of the kidney (n = 10), and sediments in the renal pelvis (n = 3).

DISCUSSION

Candida albicans was the most prominent candida isolated from the patients. The fungal ball is an uncommon infection especially in children and predominantly caused by Candida species. Fungal ball in the kidney was reported as case reports especially in neonates, in immunosupressed patients, and in patients who had undergone surgical procedures. In our study, none of the patients with the fungal ball were in the neonatal period, however, the patients with fungus ball had underlying disease or condition. Our study has several limitations including a retrospective study, and the USG were not performed by a single radiologist. Besides these limitations, our findings are important to give information about the place of USG for diagnosis of the renal fungal ball in children adding valuable information to a topic in which data came from mainly case reports.

CONCLUSIONS

Despite the low incidence of fungal balls reported, considering the high consequences of missing a fungal ball and elimination of it, a non-invasive method such as the renal bladder USG is still necessary for detection of fungal ball especially. More prospective studies are required for high risk groups to establish the diagnostic value of renal USG.

Pediatric candiduria, epidemiology, genotype distribution and virulence factors of Candida albicans

The presence of Candida species in urine may be due to colonization of this species in the bladder, urinary catheter, and perineum. Candida albicans has been the most commonly isolated from urine samples in patients with candiduria. Several virulence factors include adhesion to host cells, secreted extracellular enzymes, phenotype switching, and biofilm formation are contributing to the pathogenicity of C. albicans. ABC genotyping is the method based on the determination of 25s rDNA and C. albicans is divided into four genotypes include A, B, C, and E. We aimed to identify Candida species from pediatrics and evaluate extracellular enzyme activities, phenotype switching, biofilm formation, and genotyping in isolates. Urine samples collected, cultured, and yielded yeasts were identified. Phenotype switching, biofilm formation, enzymatic patterns, and genotyping of 50 isolates of C. albicans were evaluated. The Genotyping pattern was compared with extracellular enzymes, biofilm formation, and phenotype switching pattern. 16.2% of urine cultures were positive for the different Candida species. The most common species was C. albicans, followed by C. glabrata. Out of 50 isolates of C. albicans, 72% and 28% isolates were recognized as genotypes A and C. All isolates were produced extracellular enzymes and biofilm formation. In conclusion, candiduria with high colony counts is still a challenge in Iranian pediatrics. Genotype A was the predominant genotype among C. albicans strains. There is a statistical difference between esterase and genotypes of C and A C. albicans.

Genotypic diversity and antifungal susceptibility pattern of Candida albicans species isolated from hospitalized paediatric patients with urinary tract infection in Iran

AIMS

The present study aimed to determine the microsatellite length polymorphism (MLP) genotypic patterns and antifungal susceptibility profiles of Candida albicans isolated from patients with candiduria.

METHODS AND RESULTS

DNA of 50 C. albicans isolates was used for molecular identification based on the ITS₁ -5.8s-ITS₂ region. MLP assays were performed to amplify three loci (EF3, CDC3 and HIS3), and PCR products were used for fragment analysis. Antifungal susceptibility tests were performed according to CLSI M27 4th ed guidelines. In all, 38 different genotypes were detected with the three polymorphic loci among C. albicans isolates, and only one genotype was homozygous. In comparison to other countries, our genotypes were divided into three clusters, two of which were linked to France and a third of which was linked to Austria. The genetic structures of the 50 C. albicans isolates revealed varied heterozygosity and significant Hardy-Weinberg equilibrium at the EF3 locus. Only one (2%) and four (8%) of isolates showed resistance to fluconazole and itraconazole, respectively. In C. albicans genotype G25, one (2%) of the isolates showed cross-resistance and non-wild-type resistance to posaconazole, itraconazole and fluconazole.

CONCLUSION

MLP typing is a useful tool to analyse the genetic structure of C. albicans isolates. High genetic diversity (38 genotypes) was detected in the isolates tested here. Compared to isolates in other countries, the ones from our patients had a clear relationship with French and Austrian isolates.

SIGNIFICANCE AND IMPACT OF THE STUDY

Iranian isolates of C. albicans have a distinct genotype and show similarities only with French and Austrian isolates.

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.

The patterns of colonization and antifungal susceptibility of Candida, isolated from preterm neonates in Khorramabad, South West of Iran

OBJECTIVE

Usually, 7-20% of preterm neonates colonized by Candida species present invasive candidiasis. Candida albicans, and several non-albicans species cause invasive infection with C. albicans being the most dominant agent. In the last two decades, infection due to non-albicans have been increased dramatically due to their low sensitivity to antifungal drugs such as fluconazole. The aim of present study was to evaluate Candida colonization pattern and antifungal susceptibility among preterm neonates from Khorramabad, South west of Iran.

MATERIALS AND METHODS

Samples were collected from 80 preterm neonates, cultured on CHROMagar Candida and incubated at 37°C. All recovered isolates were primarily screened based on classical methods and identified by PCR-RFLP targeting the ITS-rDNA regions. Antifungal susceptibility testing of all isolates was performed according to the CLSI method against amphotericin B, caspofungin, itraconazole, fluconazole and voriconazole.

RESULTS

Totally 23 isolates of Candida species were recovered from 20 patients (female: male, 50:50) including, C. albicans (18), C. parapsilosis (2) and C. glabrata (1). Furthermore, the blood cultures from two patients were yielded C. albicans and C. parapsilosis so that patient with C. albicans died after five days. Generally, in this study, 9 (39.1%) isolates were resistant to amphotericin B including; 7 (30.4%) C. albicans and 2 (8.7%) C. parapsilosis. In addition, 2 (8.7%) and 4 (17.4%) isolates were also resistant to itraconazole and caspofungin, respectively.

CONCLUSION

In conclusion, Candida colonization among preterm neonates is still an important issue in hospitals. In addition, in spite of a significant amphotericin B resistant Candida, voriconazole, fluconazole, and itraconazole are valuable antifungals, due to fully sensitivity to Candida.

Growth arrest and rapid capture of select pathogens following magnetic nanoparticle treatment

Thorough understanding of magnetic nanoparticle (MNP) properties is essential for developing new theranostics. In this study, we provide evidence that non-modified magnetic iron oxide nanoparticles and their functionalized derivatives may be used to restrict growth and capture different pathogens. Coprecipitation of Fe(2+) and Fe(3+) ions in an alkaline solution was used to synthesize MNPs that subsequently were functionalized by gold and aminosilane coating. Transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FT-IR) were used to assess their physicochemical properties. A significant decrease of Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans outgrown from medium after addition of MNPs or their derivatives was observed during 24h culture. Measurement of optical density revealed that using MNPs, these pathogens can be quickly captured and removed (with efficiency reaching almost 100%) from purposely infected saline buffer and body fluids such as human blood plasma, serum, abdominal fluids and cerebrospinal fluids. These effects depend on nanoparticle concentration, surface chemistry, the type of pathogen, as well as the surrounding environment.