amirhossein davari

Given the high mortality rate of invasive candidiasis inhospitalized pediatric patients, it is crucial to establish a predictive system to achieveearly diagnosis and treatment of patients who are likely to benefit from early antifungal treatment. This study aimed to assess the Candida colonization index, species distribution, and antifungal susceptibility pattern of Candida strains isolated frompediatric patients with high Candida colonization index (CI)

This study was carried out at the Children’s Medical Center inTehran-Iran. In total, 661 samples were collected from 83 patients. The Candida CI wascalculated according to the descriptions of previous studies. The isolates were identified using polymerase chain reaction-based techniques. The Clinical and Laboratory Standard Institute protocol M60 was used to conduct the antifungal susceptibility test.

A colonization index greater than 0.5 was confirmed in 29 cases (58% ofpositive samples) with two children developing candidemia. Candida albicans (n=53,49.5%) was the most common Candida species in patients with CI > 0.5. Except foracute lymphoblastic leukemia, no risk factors were linked to a high index in colonizedchildren (P > 0.05). Twelve isolates (7.01%) were multi-azole resistant with high MICsagainst both isavuconazole and ravuconazole and seven strains (4.09%) wereechinocandins resistant.

In pediatric intensive care units, patients are at risk of fungal infection,particularly candidemia. In this study, more than half of the children with positive yeastcultures had CI > 0.5, and 6.8% developed candidemia.

This study aimed to evaluate the species distribution and susceptibility pattern of the strains isolated from Candida colonization in pediatric patients staying at pediatric intensive care unit (ICU) and infant ICU of Children’s Medical Center in Tehran, Iran.

This study was conducted in the Children’s Medical Center in Tehran, Iran. In total, 440 samples from 56 patients with oral cavity, skin surrounded catheters, and ear, throat, nasal, and urine cultures were collected. All patients were evaluated in terms of Candida colonization on the admission day as well as the days 7, 14, and 28 according to the previous studies. CHROMagar Candida medium was applied for primary/multiple species identification and the isolates were identified by using polymerase chain reaction-based methods to the species-specific complex level. The antifungal susceptibility test was performed according to the Clinical and Laboratory Standards protocol published as M27-A3 and M60 documents.

In total, 136 yeast samples from 26 individuals (30.9%) out of 440 samples were considered colonization. The most prevalent species in IICU was C. albicans (27%,n=20) followed by C. krusei (24 %, n=18) and C. parapsilosis (16%, n=12). In PICU, the predominant species was C. krusei (40%, n=24) followed by C. parapsilosis (18%, n=11) and C. dubliniensis (16%, n=10). Among the 40 tested isolates from both units, fluconazole-resistant isolates (n=11, 8.15%) were determined according to the new breakpoints. In the case of echinocandins, 2 isolates, including C. albicans (n=1) and C. krusei (n=1) were resistant against both caspofungin and anidulafungin (totally 1.48%).

In the present study, since C. krusei is intrinsically-resistance against fluconazole, emphasizing the importance of species-level identification of Candida isolates is outstanding. However, according to the antifungal susceptibility testingresults, only 7.2% of the strains were resistant to fluconazole. It would be beneficial tomonitor the ICU patients who are at high risk of invasive Candida infection.

Encapsulation can lead to improved efficacy and safety of antifungal compounds. The attention of scientists has recently turned to biocompatible lipids as the carriers for the delivery of antifungal drugs, such as fluconazole. Although several research reports have already been published on fluconazole loaded solid lipid nanoparticles (FLZ-SLNs) and fluconazole loaded nanostructured lipid carriers (FLZ-NLCs), the possible advantages of NLCs over SLNs have not yet been fully established. Studies performed so far have given several contradictory results.

Both formulations of fluconazole were synthesized using probe ultrasonication method and the characteristics were analyzed. Antifungal susceptibility testing (AFST) was performed with FLZ, FLZ-SLNs, and FLZ-NLCs using CLSI document M60 against some common fluconazole-resistant Candida species.

A significant decrease was observed in minimum inhibitory concentration values when both formulations were applied. Nonetheless, FLZ-NLCs were significantly more effective (P<0.05). However, three species groups were not statistically different in terms of the activity of FLZ-NLCs.

Based on the obtained results, FLZ-NLCs could reverse the azole-resistance phenomenon in the most common Candida species more effectively, as compared to FLZ-SLNs.

Recently, there is an increasing trend in the diversity of pathogenic yeasts isolated from clinical samples. However, Candida albicans is even now the major cause of yeast infections. Candida albicans is one of the members of the mucosal microbiota which can cause cutaneous, mucosal, and disseminated invasive infections in susceptible individuals. For persistence in the host, the yeast must have the ability to adhere to both biotic and abiotic surfaces following host tissue invasion, and obtain iron. One of the important properties of this pathogenic yeast is dimorphism which is its ability to switch from a unicellular to a hyphal mode of growth. Dimorphism is triggered in response to certain environmental conditions, such as pH alternation, temperature, or serum availability. These changes which allow the yeast to invade are associated with the expression of several genes involving in its pathogenesis, including SAP genes family encoding the secreted aspartic proteinases (Saps), the agglutinin-like sequence (ALS) family encoding the adhessive proteins, and phenotypic and morphologic switching systems. This review aimed at summarizing recent data on the regulation and relevant signal transduction of some important essential genes associated with virulence factors in Candid albicans. Surely, understanding the genetic of the virulence factors would be of great benefit in effective combating the yeast and also in designing new antifungal agents.

Candida parapsilosis isolates usually have a low minimum inhibitory concentration (MIC) against azoles. Although Candida parapsilosis isolates usually have low MICs against azoles, recent studies candida invasive infections due to azole resistant-C. parapsilosis isolates . Regarding this, the main aim of this study was to determine the susceptibility pattern of Iranian clinical C. parapsilosis against available azole antifungal drugs.

This study was conducted on 105 previously-identified isolates of C. parapsilosis sensu stricto. For the purpose of the study, the isolates were subjected to antifungal susceptibility testing against fluconazole (FLZ), itraconazole (ITZ), voriconazole (VRZ), and two new azole drugs, namely luliconazole (LUZU) and lanoconazole (LZN). The broth microdilution reference method adopted in this study was according to the Clinical & Laboratory Standards Institute M27-A3 and M27-S4 documents.

According to the results, 89% (n=94) of C. parapsilosis isolates showed a MIC of ≥ 1 µg/ml, indicating resistance against ITZ. Multi-azole resistance was observed in 3.8% of the isolates. In addition, LUZU and LZN demonstrated the highest efficacy with the MIC50 values of 0.5 and 1 µg/ml, respectively.

The majority of the isolates showed high MIC values against ITZ. This may have been associated with the long-term ITZ prophylaxis/therapy in patients infected with candidiasis. Hence, the adoption of an appropriate antifungal agent is a crucial step for starting the treatment.