Candidemia due to Candida tropicalis: clinical, epidemiologic, and microbiologic characteristics of 188 episodes occurring in tertiary care hospitals

Comparative Evaluation of Candida Species-Specific T-Cell Immune Response in Human Peripheral Blood Mononuclear Cells

Non-albicans Candida (NAC) species are increasingly recognized as significant contributors to candidemia infections; however, relatively less is known about the immune responses induced by these species. In this study, we compared the cytokine production ability of human peripheral blood mononuclear cells (PBMCs) upon stimulation with different Candida species (Candida spp.). We measured secreted cytokines using ELISA and checked the functional profiles of T-cell responses using multicolor flow cytometry. Although there was a differential expression of cytokines against Candida spp., significant difference were observed in the levels of IFN-γ, TNF-α, IL-10, IL-12p40, and IL-23 (p < 0.05) between Candida spp. A significant difference was observed between C. albicans and C. glabrata (p = 0.026) in the levels of TNF-α. C. glabrata showed significant differences compared to C. albicans, C. parapsilosis, and C. krusei in the levels of IL-10 (p values of 0.02, 0.04, and 0.01, respectively). Despite the percentages of CD4+ and CD8+ expressing Th1, Th2, and Th17 cytokines being higher in stimulated PBMCs, none of the Candida spp. showed significant differences. The levels of secreted IL-17A and IL-23 were consistently lower in Candida spp. regardless of the stimulus used. Here, we showed the differential regulation of Th1, Th2, and Th17 during Candida spp. stimulation of the immune system ex vivo. Additionally, our findings suggest that C. albicans elicits an IFN-γ response, whereas C. glabrata promotes IL-10 cellular responses, but this warrants additional studies to conclude this association. This investigation holds the potential to advance our comprehension of the distinct immune responses induced by Candida spp., with probable implications in designing antifungal immunotherapeutics.

Oral candida lesions and Candida tropicalis: Potential prognostic markers in end-of-life cancer patients

AIMS

Oral candidosis is common in patients with end-of-life cancer; however, its prognosis is unclear. We aimed to assess oral candidosis and Candida species as prognostic indicators in palliative care for these patients.

METHODS

We consecutively included palliative care patients, assessed for candidosis via microbiological techniques, and classified into three groups by the extent of oral lesions. The association between oral candidosis and overall survival was assessed using a Cox proportional hazards model adjusted by performance status (PS).

RESULTS

We studied 142 patients (median age 77; 52.8% women) with a 76.1% oral candidosis prevalence. Candida albicans (80.6%) was the most common species. Oral lesions were classified as none, grade 1 (28.7%), or ≥ grade 2 (14.8%). During follow-up, Cox models identified ≥grade 2 lesions (aHR = 2.04; 95% CI: 1.18-3.54; p = .011) and Candida tropicalis (aHR = 2.38; 95% CI: 1.03-5.55; p = .044) as predictors.

CONCLUSION

The extent of oral candidosis lesions or the presence of C. tropicalis may serve as prognostic indicator in patients with end-of-life cancer. Therefore, solely concentrating on the prevalence and frequency of fungal species may be insufficient for predicting life prognosis; it is advisable to assess these parameters through both visual examination and culture.

Unveiling the inverse antimicrobial impact of a hetero-chitooligosaccharide on Candida tropicalis growth and biofilm formation

Chitosan and chitooligosaccharide (COS) are renowned for their potent antimicrobial prowess, yet the precise antimicrobial efficacy of COS remains elusive due to scant structural information about the utilized saccharides. This study delves into the antimicrobial potential of COS, spotlighting a distinct hetero-chitooligosaccharide dubbed DACOS. In contrast to other COS, DACOS remarkably fosters the growth of Candida tropicalis planktonic cells and fungal biofilms. Employing gradient alcohol precipitation, DACOS was fractionated, unveiling diverse structural characteristics and differential impacts on C. tropicalis. Notably, in a murine model of systemic candidiasis, DACOS, particularly its 70 % alcohol precipitates, manifests a promotive effect on Candida infection. This research unveils a new pathway for exploring the intricate nexus between the structural attributes of chitosan oligosaccharides and their physiological repercussions, underscoring the imperative of crafting chitosan and COS with meticulously defined structural configurations.

Two Cases of Superficial Fungal Infection Caused by Non-Albicans Candida Species Manifest Greenish-black Discoloration

The clinical manifestation of superficial candidiasis varies depending on the infectious sites and causative Candida species that brings a great challenge to diagnose or treat without mycological or pathological evidence in clinical settings. Oral mucosal candidiasis and onychomycosis are most common types of superficial candidiasis. Typically, oral mucosal candidiasis manifests as white or erythematous thrush coated on the tongue and other interior oral cavity; and onychomycosis caused by Candida spp. presents with thick, fragile, or cracked fingernails or toenails in yellow or white discoloration. Here, we report one case of patient with a black hairy tongue caused by Candida tropicalis and one case of greenish discolored onychomycosis caused by Candida parapsilosis. The cases of superficial candidiasis with the same discolored lesions were searched in literature and compared with our cases in clinical manifestation, causative pathogen and treatment. These cases highlight the importance of mycological diagnosis for identifying non-Candida albicans Candida species (NCAC) in superficial infections to guide an effective therapy.

The emerging threat antifungal-resistant Candida tropicalis in humans, animals, and environment

Antifungal resistance in humans, animals, and the environment is an emerging problem. Among the different fungal species that can develop resistance, Candida tropicalis is ubiquitous and causes infections in animals and humans. In Asia and some Latin American countries, C. tropicalis is among the most common species related to candidemia, and mortality rates are usually above 40%. Fluconazole resistance is especially reported in Asian countries and clonal spread in humans and the environment has been investigated in some studies. In Brazil, high rates of azole resistance have been found in animals and the environment. Multidrug resistance is still rare, but recent reports of clinical multidrug-resistant isolates are worrisome. The molecular apparatus of antifungal resistance has been majorly investigated in clinical C. tropicalis isolates, revealing that this species can develop resistance through the conjunction of different adaptative mechanisms. In this review article, we summarize the main findings regarding antifungal resistance and Candida tropicalis through an "One Health" approach.

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.

Comparison of risk factors and outcomes of Candida auris candidemia with non-Candida auris candidemia: A retrospective study from Pakistan

Candida auris has emerged as a nosocomial multi-drug resistant pathogen. This study aimed to compare the risk factors and outcomes of C. auris candidemia patients with non-C. auris candidemia, at a single center in Pakistan. A retrospective study compared 38 C. auris with 101 non-C. auris (36 C. albicans, 38 C. tropicalis, and 27 C. parapsilosis) candidemia patients between September 2014 and March 2017 at the Aga Khan University Hospital, Pakistan. Demographics, clinical history, management and outcomes were studied. Prior history of surgery (adjusted odds ratio [aOR] 4.9, 95% confidence interval [CI]: 1.4-17.5), antifungals exposure (aOR 38.3, 95% CI: 4.1-356) and prior MDR bacteria isolation (aOR 5.09, 95% CI: 1.6-15.9) were associated with C. auris candidemia. On survival analysis both groups of patients had similar outcome in terms of mortality (62.6% vs. 52.54%, hazard ratio [HR] 1.45, 95% CI: 0.84-2.4, P-value = .17) and microbiological failure rates (42.3% vs. 32.2%, HR 0.65, 95% CI: 0.35-1.2, P-value = .17) however, C. auris patients had a higher mean hospital stay (36.32 days vs. 14.8 days, P-value = <.001) and higher >15-day in-hospital stay from positive culture (HR 2.68, 95% CI: 1.1-6.3, P-value = .025). Antifungal susceptibility was different, with C. auris more often resistant to voriconazole (29.6% vs. 0%) and amphotericin (3.7 vs. 0%); though no echinocandin resistance was detected in either group. As opposed to other Candida species, C. auris candidemia occurred after nosocomial exposure, and its source was most commonly an indwelling line. Although these patients had a higher in-hospital stay, but there was no excess mortality when compared to other Candida species.

Internalization and membrane activity of the antimicrobial peptide CGA-N12

Antimicrobial peptides (AMPs) are conventional antibiotic alternatives due to their broad-spectrum antimicrobial activities and special mechanisms of action against pathogens. The antifungal peptide CGA-N12 was originally derived from human chromogranin A (CGA) and consists of the 65th to 76th amino acids of the CGA N-terminal region. In the present study, we found that CGA-N12 had fungicidal activity and exhibited time-dependent inhibition activity against Candida tropicalis. CGA-N12 entered the cells to exert its antagonist activity. The internalization of CGA-N12 was energy-dependent and accompanied by actin cytoskeleton-, clathrin-, sulfate proteoglycan-, endosome-, and lipid-depleting agent-mediated endocytosis. Moreover, the CGA-N12 internalization pathway was related to the peptide concentration. The effects of CGA-N12 on the cell membrane were investigated. CGA-N12 at a low concentration less than 4 × MIC100 did not destroy the cell membrane. While with increasing concentration, the damage to the cell membrane caused by CGA-N12 became more serious. At concentrations greater than 4 × MIC100, CGA-N12 destroyed the cell membrane integrity. Therefore, the membrane activity of CGA-N12 is concentration dependant.

Trends towards lower azole susceptibility among 200 Candida tropicalis bloodstream isolates from Brazilian medical centres

OBJECTIVES

Candida tropicalis is one of the three most frequent species causing candidaemia in Latin America. Despite the high prevalence of C. tropicalis in candidaemia cases in Brazil, little is known about the trends in fluconazole susceptibility over time. The objective of this study was to evaluate temporal trends in azole resistance rates among C. tropicalis bloodstream isolates from patients treated in six Brazilian medical centres over a 12-year period.

METHODS

We selected 200 C. tropicalis bloodstream isolates from six medical centres in Brazil collected between 2007 and 2018. Species identification was confirmed by MALDI-TOF/MS. Antifungal susceptibility testing for four antifungal agents was performed by the Clinical and Laboratory Standards Institute (CLSI) microbroth method.

RESULTS

Overall, rates of non-susceptibility were 4% and 3.5% to fluconazole and voriconazole, respectively. All isolates were susceptible to amphotericin B and only one isolate was resistant to echinocandins.

CONCLUSION

Although we failed to demonstrate statistical differences in the rates of azole resistance documented during the period of analysis, trends towards lower susceptibility to fluconazole and voriconazole were shown.

Clinical and epidemiological aspects of Candidemia in eight medical centers in the state of Parana, Brazil: Parana Candidemia Network

Objectives

Candida spp. has been reported as one of the common agents of nosocomial bloodstream infections and is associated with a high mortality. Therefore, this study evaluated the clinical findings, local epidemiology, and microbiological aspects of candidemia in eight tertiary medical centers in the state of Parana, South of Brazil.

Methods

In this study, we reported 100 episodes of candidemia in patients admitted to eight different hospitals in five cities of the state of Parana, Brazil, using data collected locally (2016 and 2017) and tabulated online.

Results

The incidence was found to be 2.7 / 1000 patients / day and 1.2 / 1000 admissions. C. albicans was responsible for 49% of all candidemia episodes. Cancer and surgery were the two most common underlying conditions associated with candidemia. The mortality rate within 30 days was 48%, and removal of the central venous catheter (p = 0.029) as well as empirical or prophylactic exposure to antifungals were both related to improved survival (p = 0.033).

Conclusions

This study highlights the high burden and mortality rates of candidemia in hospitals from Parana as well as the need to enhance antifungal stewardship program in the enrolled medical centers.

Antifungal Properties of Nerolidol-Containing Liposomes in Association with Fluconazole

(1) Background: Infections by Candida species represent a serious threat to the health of immunocompromised individuals. Evidence has indicated that nerolidol has significant antifungal properties. Nonetheless, its use is restricted due to a low water solubility and high photosensitivity. The incorporation into liposomes may represent an efficient alternative to improve the physicochemical and biopharmaceutical properties of this compound. The present study aimed to characterize the antifungal properties of liposomal nerolidol, alone or in combination with fluconazole. Of note, this is the first study reporting the antifungal activity of liposomal nerolidol and its potentiating effect in association with fluconazole. (2) Methods: The Inhibitory Concentration 50%-IC₅₀ and minimum fungicide concentrations (MFC) of the substances against Candida albicans (CA), Candida tropicalis (CT), and Candida krusei (CK) were established by subculture in a solid medium. To evaluate the antifungal-enhancing effect, the MFC of fluconazole was determined in the presence or absence of subinhibitory concentrations of nerolidol (free or liposomal). The analysis of fungal dimorphism was performed through optical microscopy and the characterization of liposomes was carried out considering the vesicular size, polydispersion index, and zeta medium potential, in addition to a scanning electron microscopy analysis. (3) Results: The physicochemical characterization revealed that liposomes were obtained as homogenous populations of spherical vesicles. The data obtained in the present study indicate that nerolidol acts as an antifungal agent against Candida albicans and Candida tropicalis, in addition to potentiating (only in the liposomal form) the effect of fluconazole. However, the compound had little inhibitory effect on fungal dimorphism. (4) Conclusions: The incorporation of nerolidol into liposomes improved its antifungal-modulating properties.

Epidemiology, species distribution, and predictive factors for mortality of candidemia in adult surgical patients

Background

We evaluated the epidemiology, clinical characteristics, microbiology, outcomes, and risk factors for mortality of candidemia in adult surgical patients in Shenyang from 2012 to 2018.

Methods

We designed a retrospective observational study of adult patients with candidemia in a teaching hospital including three hospital campuses. Data regarding clinical and demographic characteristics were collected from the patient’s medical records.

Results

Of the 236 cases of candidemia, 172 (72.9%) were identified in surgical patients, including 146 (84.9%) general surgeries, 11 (6.4%) urologic surgeries, 6 (3.5%) thoracic surgeries, and others. Higher proportions of solid tumors, total parenteral nutrition, the presence of a urinary catheter, and the presence of a gastric tube were observed in surgical patients with candidemia versus non-surgical ones, whereas the percentages of hematological malignancy, diabetes mellitus, and renal replacement therapy were relatively lower in surgical patients. Renal failure, leukopenia, and thrombocytopenia were less common laboratory findings in surgical patients with candidemia than compared to non-surgical ones. Among surgical patients with candidemia, Candida parapsilosis was the predominant species (43%), followed by C. albicans (33.7%), C. glabrata (11%), C. tropicalis (8.1%), and others (4.1%). Overall susceptibility, susceptible dose dependent or intermediate susceptibility, and resistance to fluconazole were detected in 73.3, 19.8, and 3.5% Candida isolates from surgical patients, respectively, but no resistance to amphotericin B was observed. Overall, the 30-day mortality in surgical patients was 19.2%. At multivariable analysis, independent risk factors for death in surgical patients with candidemia were ICU stay, thrombocytopenia, and C. albicans infection.

Conclusions

Surgical patients account for the majority of candidemia cases. Among patients with recent surgery, risk factors for species distribution, antifungal sensitivity patterns of Candida isolates causing candidemia, and independent risk factors for mortality should be evaluated and considered for a better outcome in the antifungal treatment.

Candida spp bloodstream infections in a Latin American Pediatric Oncology Reference Center: Epidemiology and associated factors

BACKGROUND

Invasive fungal disease is a significant cause of morbidity and mortality in immunosuppressed children. The recognition of patients at risk for candidaemia is paramount to a better prognosis.

OBJECTIVES

To characterize Candida spp bloodstream infections (BSI) in a reference centre for paediatric oncology and to describe the most prevalent risk factors associated with candida infections.

PATIENTS/METHODS

This is a retrospective cohort study carried out with paediatric patients followed up with at the Institute of Pediatric Oncology, Brazil, who presented positive blood culture for Candida spp from January 2004 to December 2016.

RESULTS

Ninety episodes of candidaemia were analysed; patients had a median age of 4.5 years, and 57.8% were males, with a diagnosis of solid tumours in 54.5% of cases. The most common Candida species were C albicans (35.6%), C parapsilosis (30.0%) and C tropicalis (16.7%). C tropicalis BSI was associated with neutropenia and skin lesions. Therapy was successful in 67.1% of the episodes. Older age and thrombocytopenia were associated with therapeutic failure. Death within 30 days occurred in 24.4% of patients; predictive factors were older age and admission to an ICU C parapsilosis candidaemia was a protective factor for death when compared to C albicans.

CONCLUSION

The main species isolated were C albicans, C parapsilosis and C tropicalis. C tropicalis BSI was associated with neutropenia and skin lesions. The death rate was significant, and a worse prognosis was associated with older age, thrombocytopenia and admission to an ICU C parapsilosis infection proved to be a protective factor against mortality.

Investigation of a healthcare-associated Candida tropicalis candidiasis cluster in a haematology unit and a systematic review of nosocomial outbreaks

BACKGROUND

Non-albicans Candida spp. are an emerging cause of hospital-acquired bloodstream infections, associated with high mortality due to the challenges in diagnosis and delayed treatment.

OBJECTIVES

We aimed to investigate a cluster of healthcare-associated invasive candidiasis caused by C tropicalis and review the literature of healthcare-associated outbreaks or clusters caused by C tropicalis.

METHODS

An investigation was performed to determine clinical presentation, treatment outcomes and the factors contributing to C tropicalis candidemia occurrence. We searched the Medline database via PubMed and Ovid using the keywords of "Candida tropicalis" combined with "outbreak" or "clustering" or "clusters," and we limited the search to studies conducted from January 1989 to January 2019.

RESULTS

We report two related cases of C tropicalis candidemia among patients with AML following a period of neutropenia, who had erythematous skin rash as a first manifesting sign of candidiasis. C tropicalis was isolated from blood and skin cultures of both patients, which were identical by pulsed-field gel electrophoresis typing. Our systematic review of outbreaks caused by C tropicalis suggests that (a) most reported outbreaks have occurred in neonatal and adult ICUs; (b) patients who receive total parenteral therapy, antibiotics and those who have indwelling catheters and recent surgery are at high risk of infection; and (c) environmental and healthcare personnel surveillance suggest that cross-contamination is a major risk factor.

CONCLUSION

Control of nosocomial outbreaks caused by C tropicalis should include better infection control measures, education of healthcare professionals especially working in adult and neonatal intensive care and haematology units.

Honey as a Strategy to Fight Candida tropicalis in Mixed-Biofilms with Pseudomonas aeruginosa

Fungal contaminations with Candida species are commonly responsible for several infections, especially when associated to bacteria. The therapeutic approach commonly used is being compromised due to microbial resistances of these microorganisms to antimicrobial agents, especially in biofilm. The use of honey as an antimicrobial agent has been emerging as a valuable solution and proving its potential in planktonic and in biofilm cells. This work aims to assess the effect of different honeys on biofilms of Candida tropicalis and Pseudomonas aeruginosa. The effect of Portuguese heather (PH) and manuka honeys on planktonic growth of Candida was initially evaluated by determination of the minimum inhibitory concentrations (MIC). Then, the same effect was evaluated in mixed biofilms, by colony-forming units numeration and fluorescence microscopy. The combinations of honey plus fluconazole and gentamicin were also tested. The results showed that the honeys tested enabled a great reduction of C. tropicalis, both in planktonic (12.5% and 25% of MIC for PH and manuka) and in biofilm. In polymicrobial biofilms, the use of PH and manuka honeys was revealed to be a promising choice and an alternative treatment, since they were able to reduce cells from both species. No synergistic effect was observed in antimicrobial combinations assays against polymicrobial biofilms.

Caenorhabditis elegans as a model animal for investigating fungal pathogenesis

The morbidity and mortality associated with systemic fungal infections in humans cannot be underestimated. The nematode Caenorhabditis elegans has become popular for the in vivo study of the pathogenesis of human fungal pathogens and as an antifungal drug-screening tool. C. elegans offers many advantages as a model organism for the study of human fungal diseases, including lack of ethics requirements, easy maintenance in the laboratory, fully sequenced genome, availability of genetic mutants, and the possibility of liquid assays for high-throughput antifungal screening. Its major drawbacks include the inability to grow at 37 °C and absence of an adaptive immune response. However, several virulence factors involved in the pathogenesis of medically important fungal pathogens have been identified using the C. elegans model, consequently providing new leads for drug discovery and potential drug targets. We review the use of C. elegans as a model animal to understand the pathogenesis of medically important human fungal pathogens and the discovery of novel antifungal compounds. The review makes a case for C. elegans as a suitable invertebrate model for a plethora of practical applications in the investigation of fungal pathogenesis as well as its amenability for liquid-based high-throughput screening of potential antifungal compounds.

The general transcriptional repressor Tup1 governs filamentous development in Candida tropicalis

Filamentous development is associated with the ability to cause infections and colonize the host in pathogenic Candida species. Candida tropicalis is one of the major fungal pathogens of humans. The conserved transcriptional repressor Tup1 plays a critical role in the regulation of transcription and filamentation in yeast species. Despite its central role, the full coding sequence of TUP1 has not been found in the reported genome sequence of C. tropicalis to date. In this study, we report the identification of Tup1 and characterize its role in filamentous growth in C. tropicalis. As expected, C. tropicalis Tup1 exhibits general conserved features to the orthologs of other fungi in terms of its structure and function. Deletion of TUP1 in C. tropicalis leads to increased filamentation under several culture conditions. However, Tup1 indeed exhibits species-specific roles in the regulation of filamentous development in C. tropicalis. For example, unlike the tup1/tup1 mutant of Candida albicans, the tup1/tup1 mutant of C. tropicalis is able to exist in the yeast form at low temperatures or in the presence of N-acetylglucosamine (GlcNAc). Acidic pH conditions also favor the yeast form of the tup1/tup1 mutant of C. tropicalis. Quantitative real-time PCR (qRT-PCR) assays indicate that Tup1 may regulate filamentous development through the transcriptional control of key filamentation regulators in C. tropicalis, such as Ume6, Brg1, Wor1, Sfl2, Ahr1, and Zcf3. Taken together, our findings demonstrate both conserved and species-specific roles of Tup1 in the regulation of filamentation and provide novel insights into the biology of C. tropicalis.

Protein kinase A governs growth and virulence in Candida tropicalis

Candida tropicalis is one of the most important human fungal pathogens causing superficial infections in locations such as the oral mucosa and genital tract, as well as systemic infections with high mortality. In its sister species Candida albicans, the cyclic AMP/protein kinase A (cAMP/PKA) pathway regulates fungal adhesion and dimorphism, both of which correlate closely with virulence. CaTpk1 and CaTpk2, the catalytic subunits of PKA, not only share redundant functions in hyphal growth, adhesion, and biofilm formation, but also have distinct roles in stress responses and pathogenesis, respectively. However, studies on PKA in the emerging fungal pathogen C. tropicalis are limited. Our results suggest that Tpk1 is involved in cell wall integrity and drug tolerance. The tpk2/tpk2 mutants, which have no protein kinase A activity, have reduced hyphal growth and adhesion. In addition, the tpk1/tpk1 tpk2/tpk2 double deletion mutant demonstrated delayed growth and impaired hyphal formation. In a murine model of systemic infection, both TPK1 and TPK2 were required for full virulence. We further found that EFG1 and HWP1 expression is regulated by PKA, while BCR1, FLO8, GAL4, and RIM101 are upregulated in the tpk1/tpk1 tpk2/tpk2 mutant. This study demonstrates that Tpk1 is involved in drug tolerance and cell wall integrity, while Tpk2 serves as a key regulator in dimorphism and adhesion. Both Tpk1 and Tpk2 are required for growth and full virulence in C. tropicalis.

Conserved and Divergent Functions of the cAMP/PKA Signaling Pathway in Candida albicans and Candida tropicalis

Fungal species undergo many morphological transitions to adapt to changing environments, an important quality especially in fungal pathogens. For decades, Candida albicans has been one of the most prevalent human fungal pathogens, and recently, the prevalence of Candida tropicalis as a causative agent of candidiasis has increased. In C. albicans, the ability to switch between yeast and hyphal forms is thought to be a key virulence factor and is regulated by multiple signaling cascades—including the cyclic adenosine monophosphate/protein kinase A (cAMP/PKA), calcineurin, high-osmolarity glycerol (HOG), and mitogen-activated protein kinases (MAPK) signaling pathways—upon receiving environmental cues. The cAMP/PKA signaling pathway also triggers white-opaque switching in C. albicans. However, studies on C. tropicalis morphogenesis are limited. In this minireview, we discuss the regulation of the yeast-hypha transition, virulence, and white-opaque switching through the cAMP/PKA pathway in the closely related species C. albicans and C. tropicalis.

The Elusive Anti-Candida Vaccine: Lessons From the Past and Opportunities for the Future

Candidemia is a bloodstream fungal infection caused by Candida species and is most commonly observed in hospitalized patients. Even with proper antifungal drug treatment, mortality rates remain high at 40–50%. Therefore, prophylactic or preemptive antifungal medications are currently recommended in order to prevent infections in high-risk patients. Moreover, the majority of women experience at least one episode of vulvovaginal candidiasis (VVC) throughout their lifetime and many of them suffer from recurrent VVC (RVVC) with frequent relapses for the rest of their lives. While there currently exists no definitive cure, the only available treatment for RVVC is again represented by antifungal drug therapy. However, due to the limited number of existing antifungal drugs, their associated side effects and the increasing occurrence of drug resistance, other approaches are greatly needed. An obvious prevention measure for candidemia or RVVC relapse would be to immunize at-risk patients with a vaccine effective against Candida infections. In spite of the advanced and proven techniques successfully applied to the development of antibacterial or antiviral vaccines, however, no antifungal vaccine is still available on the market. In this review, we first summarize various efforts to date in the development of anti-Candida vaccines, highlighting advantages and disadvantages of each strategy. We next unfold and discuss general hurdles encountered along these efforts, such as the existence of large genomic variation and phenotypic plasticity across Candida strains and species, and the difficulty in mounting protective immune responses in immunocompromised or immunosuppressed patients. Lastly, we review the concept of “trained immunity” and discuss how induction of this rapid and nonspecific immune response may potentially open new and alternative preventive strategies against opportunistic infections by Candida species and potentially other pathogens.

Development of Echinocandin Resistance in Candida tropicalis following Short-Term Exposure to Caspofungin for Empiric Therapy

Isolation of two echinocandin-resistant Candida tropicalis strains from endotracheal secretions of a patient following short-term exposure to caspofungin is described. Both strains exhibited resistance to echinocandins by Etest and reference broth microdilution, showing a homozygous S645P mutation within the hot spot 1 (HS-1) region of FKS1 and belonging to a unique multilocus sequence type. Other C. tropicalis isolates collected from patients in the same intensive care unit within a 60-day period were susceptible to echinocandins and contained wild-type FKS1 sequences.

Oral mycoses and other opportunistic infections in HIV: therapy and emerging problems - a workshop report

Oral mycoses and other opportunistic infections are recognized features of HIV infection even after four decades of the epidemic. The therapeutic options, challenges of therapy, and evolving patterns of opportunistic infections were evaluated by the workshop. It was observed that high Candida counts and infection are still more prevalent in HIV-positive individuals even in the era of antiretroviral therapy. Furthermore, one or more non-Candida albicans are present in some HIV-positive individuals. While Candida species are more virulent in HIV infection, similar virulence may be present in other states of immunosuppression. Consequently, the interplay between host factors and virulence ultimately determines the clinical outcomes. Adverse clinical outcomes such as candidemia and other deep fungal infections are on the increase in HIV infection. Disseminated histoplasmosis and penicilliosis have been reported, especially with low CD4 counts. Even with advances in antifungal therapy, mortality and morbidity from deep fungal infections have not changed significantly. In addition, long-term exposure to common antifungal drugs such as fluconazole has led to the development of antifungal resistance in 6% to 36%. Development of new antifungal therapeutic agents and the use of alternative therapies may offer breakthrough. In addition, effective strategies to enhance the host immune status are being explored.

Candidemia in the elderly: What does it change?

BACKGROUND

Candidemia is a life-threatening fungal infection and it can affect patients of all ages. Characterization of candidemia in the elderly is lacking.

METHODS

We performed a retrospective study of adults (≥ 18 years) with candidemia diagnosed in our center in 2010-2015. Demographics, comorbidities, clinical and microbiologic characteristics, antifungal treatment and outcome were compared between older (≤65 years) and younger (>65 years) patients.

RESULTS

Among 302 patients with candidemia identified during the study period, 188 (62%) belonged to the elderly group. Comorbidities were significantly more frequent in older patients and included chronic pulmonary diseases, cardiovascular diseases, diabetes mellitus, and chronic renal failure (p ranging from <0.0001 to 0.017). A significantly higher proportion of older patients had septic shock (p = 0.040) at the time of candidemia. Candida albicans accounted for 53% of isolates and there were no significant differences between patients' age and Candida species. Thirty-day mortality was significantly higher in older (45%) than in younger (28%) patients (p = 0.003). Factors associated with a significant higher proportion of death in the elderly included older age (i.e.: old-old), being hospitalized in ICU rather than in other wards, suffering from chronic pulmonary diseases, the presence of septic shock, multiple organ failure, dialysis and being infected with C. glabrata (p ranging from <0.0001 to 0.034). On multivariate analysis septic shock (HR 1.744 [CI95% 1.049-2.898], p = 0.032) and multiple organ failure (HR 2.242 [CI95% 1.070-4.698], p = 0.032) were independently associated with a higher risk of death. The probability of 30-days survival of older patients was significantly reduced when compared to that of younger patients (p = 0.005) who did not receive any treatment. In the elderly, there was a trend toward higher MICs for fluconazole/C. albicans, fluconazole/C. glabrata, amphotericin B/C. albicans, and caspofungin/C. glabrata.

CONCLUSIONS

In our study, we found that elderly patients with Candida bloodstream infections are characterized by a high mortality rate. In particular, the lack of any antifungal therapy as well as the occurrence of septic shock increased significantly the overall mortality. Additionally, we found that there was a trend of higher MIC for specific drug/Candida combination.

Prevalence of fungemia in a tertiary hospital: Analysis of the last decade

INTRODUCTION

The prevalence of nosocomial fungemia has increased worldwide, and mortality caused by this disease is high.

OBJECTIVE

To assess progress in the last decade, and the prevalence and profile of fungal agents isolated in blood cultures performed in a tertiary university hospital.

METHOD

All the results of blood cultures processed at Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG), in the time intervals 2001-2003 and 2011-2013 were analyzed retrospectively. For each three-year period, the number of collected blood cultures, the overall positivity rate and the percentage of fungemia were recorded. In addition, all identified fungal species were cataloged. All blood samples were incubated in the BacT/ALERT® (bioMérieux) automation system.

RESULTS

In 2001-2003, 34,822 samples were evaluated, with 5,510 (15.8%) positive results. In 2011-2013, the number of blood cultures processed increased to 55,052 samples, with 4,873 (8.9%) positive results. There was an increase in the number of positive cultures for fungi in the analyzed period (2001-2003: 4.16%; 2011-2013: 5.95%; p<0.001). Among the agents, candidemias were predominant, especially those caused by non-albicans Candida species (2001-2003: 57.64%; 2011-2013: 65.17%; p<0.05). There was also an increase in fungemia caused by other genera (2001-2003: 2.62%; 2011-2013: 4.48%; p<0.01).

CONCLUSION

There was an increase in the prevalence of fungemia in the last decade at HC-UFMG. Although candidemias have been responsible for most of the cases, there has been an increase in fungemias caused by other species.

Azole Antifungal Resistance in Candida albicans and Emerging Non-albicans Candida Species

Within the limited antifungal armamentarium, the azole antifungals are the most frequent class used to treat Candida infections. Azole antifungals such as fluconazole are often preferred treatment for many Candida infections as they are inexpensive, exhibit limited toxicity, and are available for oral administration. There is, however, extensive documentation of intrinsic and developed resistance to azole antifungals among several Candida species. As the frequency of azole resistant Candida isolates in the clinical setting increases, it is essential to elucidate the mechanisms of such resistance in order to both preserve and improve upon the azole class of antifungals for the treatment of Candida infections. This review examines azole resistance in infections caused by C. albicans as well as the emerging non-albicans Candida species C. parapsilosis, C. tropicalis, C. krusei, and C. glabrata and in particular, describes the current understanding of molecular basis of azole resistance in these fungal species.

The Correlation Between Biofilm Production and Catheter-Related Bloodstream Infections Sustained by Candida. A Case Control Study

Biofilm forming capacity of yeasts colonizing the intravenous devices is considered a key factor involved in the pathogenesis of Candida catheter-related bloodstream infections (CCRBSI). The biofilm production of strains of Candida spp. isolated both from the CVC and from the blood of patients with CCRBSI was compared to that of strains isolated from patients not having CCRBSI. Results, expressed in terms of Biofilm Index (BI), revealed that biofilm-producing strains were isolated in the CCRBSI group with a frequency significantly higher than in the non-CCRBSI group (χ² = 4.25, p = 0.03). The species more frequently cultured was C. parapsilosis complex (including C. parapsilosis sensu stricto, C. orthopsilosis and C. metapsilosis). When this species was isolated from the CVC tip cultures of the CCRBSI group it showed BIs significantly (p = 0.05) higher than those found in the non-CCRBSI group. All the strains of C. tropicalis isolated from the CCRBSI group produced biofilm. Instead most of the isolates of C. glabrata were non-producers. The cumulative BI of non-albicans Candida strains isolated from CCRBSI patients was significantly higher than that of non-albicans strains cultured from patients non-CCRBSI (χ² = 6.91; p = 0.008). C. albicans was a biofilm producer both in the CCRBSI and in the non-CCRBSI group. When isolated from the blood it showed enhanced biofilm production in the CCRBSI group only, while when colonizing the CVC it displayed high BIs both in the CCRBSI group and in non-CCRBSI group. Our data seem to indicate that the biofilm production capacity should be considered in the clinical management of CCRBSI.

Pathogenic factors in Candida biofilm-related infectious diseases

Candida albicans is a commonly found member of the human microflora and is a major human opportunistic fungal pathogen. A perturbation of the microbiome can lead to infectious diseases caused by various micro-organisms, including C. albicans. Moreover, the interactions between C. albicans and bacteria are considered to play critical roles in human health. The major biological feature of C. albicans, which impacts human health, resides in its ability to form biofilms. In particular, the extracellular matrix (ECM) of Candida biofilm plays a multifaceted role and therefore may be considered as a highly attractive target to combat biofilm-related infectious diseases. In addition, extracellular DNA (eDNA) also plays a crucial role in Candida biofilm formation and its structural integrity and induces the morphological transition from yeast to the hyphal growth form during C. albicans biofilm development. This review focuses on pathogenic factors such as eDNA in Candida biofilm formation and its ECM production and provides meaningful information for future studies to develop a novel strategy to battle infectious diseases elicited by Candida-formed biofilm.

Pathogenic Candida species differ in the ability to grow at limiting potassium concentrations

A high intracellular concentration of potassium (200–300 mmol/L) is essential for many yeast cell functions, such as the regulation of cell volume and pH, maintenance of membrane potential, and enzyme activation. Thus, cells use high-affinity specific transporters and expend a lot of energy to acquire the necessary amount of potassium from their environment. In Candida genomes, genes encoding 3 types of putative potassium uptake systems were identified: Trk uniporters, Hak symporters, and Acu ATPases. Tests of the tolerance and sensitivity of C. albicans, C. dubliniensis, C. glabrata, C. krusei, C. parapsilosis, and C. tropicalis to various concentrations of potassium showed significant differences among the species, and these differences were partly dependent on external pH. The species most tolerant to potassium-limiting conditions were C. albicans and C. krusei, while C. parapsilosis tolerated the highest KCl concentrations. Also, the morphology of cells changed with the amount of potassium available, with C. krusei and C. tropicalis being the most influenced. Taken together, our results confirm potassium uptake and accumulation as important factors for Candida cell growth and suggest that the sole (and thus probably indispensable) Trk1 potassium uptake system in C. krusei and C. glabrata may serve as a target for the development of new antifungal drugs.

Antibiofilm activity of carboxymethyl chitosan on the biofilms of non-Candida albicans Candida species

Although most cases of candidiasis have been attributed to Candida albicans, non-C. albicans Candida species have been isolated in increasing numbers in patients. In this study, we determined the inhibition of carboxymethyl chitosan (CM-chitosan) on single and mixed species biofilm of non-albicans Candida species, including Candida tropicalis, Candida parapsilosis, Candida krusei and Candida glabrata. Biofilm by all tested species in microtiter plates were inhibited nearly 70%. CM-chitosan inhibited mixed species biofilm in microtiter plates and also on medical materials surfaces. To investigate the mechanism, the effect of CM-chitosan on cell viability and biofilm growth was employed. CM-chitosan inhibited Candida planktonic growth as well as adhesion. Further biofilm formation was inhibited with CM-chitosan added at 90min, 12h or 24h after biofilm initiation. CM-chitosan was not only able to inhibit the metabolic activity of Candida cells, but was also active upon the establishment and the development of biofilms.

Novel point mutations in the ERG11 gene in clinical isolates of azole resistant Candida species

The azoles are the class of medications most commonly used to fight infections caused by Candida sp. Typically, resistance can be attributed to mutations in ERG11 gene (CYP51) which encodes the cytochrome P450 14α-demethylase, the primary target for the activity of azoles. The objective of this study was to identify mutations in the coding region of theERG11 gene in clinical isolates of Candidaspecies known to be resistant to azoles. We identified three new synonymous mutations in the ERG11 gene in the isolates of Candida glabrata (C108G, C423T and A1581G) and two new nonsynonymous mutations in the isolates of Candida krusei - A497C (Y166S) and G1570A (G524R). The functional consequence of these nonsynonymous mutations was predicted using evolutionary conservation scores. The G524R mutation did not have effect on 14α-demethylase functionality, while the Y166S mutation was found to affect the enzyme. This observation suggests a possible link between the mutation and dose-dependent sensitivity to voriconazole in the clinical isolate of C. krusei. Although the presence of the Y166S in phenotype of reduced azole sensitivity observed in isolate C. kruseidemands investigation, it might contribute to the search of new therapeutic agents against resistant Candida isolates.

Biocompatible succinic acid-based polyesters for potential biomedical applications: fungal biofilm inhibition and mesenchymal stem cell growth

Poly(alkene succinates) are promising materials for specialized medical devices and tissue engineering, presenting intrinsic properties, such as; fungal biofilm inhibition, biocompatibility and stem cells controlled growth promotion.

Antibiofilm activity of tert-BuOH functionalized ionic liquids with methylsulfonate counteranions

Thetert-BuOH functionalized and dodecyl alkyl chain bearing imidazolium ionic liquid [C₁₂-^tOHim][OMs] significantly prevented biofilm formation ofS. epidermidisand showed potential antimicrobial activity.

Imidazolium salts as antifungal agents: strong antibiofilm activity against multidrug-resistant Candida tropicalis isolates

The in vitro activity of the imidazolium salt C16 MImCl against planktonic and biofilm cells of multidrug-resistant isolates of Candida tropicalis was evaluated, both in solution and applied on a commercial catheter surface. This was determined by inhibition and susceptibility assays of biofilm and planktonic cells. In both cases, C16 MImCl prevented in vitro biofilm formation of C. tropicalis strains, including multidrug-resistant ones. Outstanding performances were observed, even at extremely low concentrations. Furthermore, this is the first report of the antifungal lock property of C16 MImCl, using a tracheal catheter as the test specimen to mimic a clinical in vivo condition. As such, C16 MImCl has been identified as a promising antimicotic pharmaceutical candidate for the treatment of candidiasis infections.

SIGNIFICANCE AND IMPACT OF THE STUDY

The imidazolium salt 1-n-hexadecyl-3-methylimidazolium chloride (C16 MImCl) strongly prevents, in concentrations as low as 0·028 μg ml(-1) , the biofilm formation of multidrug-resistant Candida tropicalis isolates, either in solution or applied on the surface of commercial catheters. This presents an effective antimicotic candidate and alternative for invasive clinical procedure toolset asepsis.

The First Reported Case of Colonic Infection Caused by Candida tropicalis and a Review of the Literature

Lower gastrointestinal tract infections caused by Candida species are rarely reported, and Candida albicans is the only pathogen that has been identified. The author reports a first case of colonic candidiasis caused by Candida tropicalis in a 55-year-old female with diabetes mellitus type 2, diffuse large B-cell lymphoma and neutropenia induced by chemotherapy. Diarrhea and fever were the presenting symptoms. Diagnosis was made based on deep tissue involvement on colonoscopy with biopsy and positive hemoculture. This alerted the physician to be aware of Candida non-albicans as a cause of colonic infection. Fungal culture should always be done to identify specific Candida species, leading to appropriate antifungal therapy. A review of the literature on colonic candidiasis is also presented here.

In vitro evaluation of the enzymatic activity profile of non-albicans Candida species isolated from patients with oral candidiasis with or without diabetes

OBJECTIVE

To evaluate the expression of phospholipase (PL) and secreted aspartyl proteinase (SAP) by Candida glabrata and C tropicalis obtained from the denture biofilms of healthy participants (16 isolates), patients with oral candidiasis with diabetes (10 isolates), and patients with oral candidiasis without diabetes (25 isolates).

STUDY DESIGN

After incubation, the supernatants and pellets of the isolates were used for the enzymatic assays and quantification of colony-forming units (CFU), respectively. Colorimetric tests were used with phosphatidylcholine as a substrate for PL and azocasein as a substrate for SAP, and the absorbances of the samples were measured. Enzymatic rates were calculated, and values were normalized by CFU. Results were analyzed with factorial analyses of variance (α = .05).

RESULTS

C tropicalis and C glabrata were proteolytic and phospholipolytic. The clinical sources of isolates had no significant effect on the enzymatic activities (P > .05). C tropicalis had significantly higher enzymatic activity for both PL and SAP (P < .001) than did C glabrata.

CONCLUSIONS

C tropicalis isolates produced significantly higher amounts of both enzymes than did the C glabrata isolates.

Synergistic effect of the flavonoid catechin, quercetin, or epigallocatechin gallate with fluconazole induces apoptosis in Candida tropicalis resistant to fluconazole

Flavonoids are a class of phenolic compounds commonly found in fruits, vegetables, grains, flowers, tea, and wine. They differ in their chemical structures and characteristics. Such compounds show various biological functions and have antioxidant, antimicrobial, anti-inflammatory, and antiapoptotic properties. The aim of this study was to evaluate the in vitro interactions of flavonoids with fluconazole against Candida tropicalis strains resistant to fluconazole, investigating the mechanism of synergism. Three combinations formed by the flavonoids (+)-catechin hydrated, hydrated quercetin, and (-)-epigallocatechin gallate at a fixed concentration with fluconazole were tested. Flavonoids alone had no antifungal activity within the concentration range tested, but when they were used as a cotreatment with fluconazole, there was significant synergistic activity. From this result, we set out to evaluate the possible mechanisms of cell death involved in this synergism. Isolated flavonoids did not induce morphological changes or changes in membrane integrity in the strains tested, but when they were used as a cotreatment with fluconazole, these changes were quite significant. When evaluating mitochondrial damage and the production of reactive oxygen species (ROS) only in the cotreatment, changes were observed. Flavonoids combined with fluconazole were shown to cause a significant increase in the rate of damage and the frequency of DNA damage in the tested strains. The cotreatment also induced an increase in the externalization of phosphatidylserine, an important marker of early apoptosis. It is concluded that flavonoids, when combined with fluconazole, show activity against strains of C. tropicalis resistant to fluconazole, promoting apoptosis by exposure of phosphatidylserine in the plasma membrane and morphological changes, mitochondrial depolarization, intracellular accumulation of ROS, condensation, and DNA fragmentation.

Six-year trend analysis of nosocomial candidemia and risk factors in two intensive care hospitals in Mato Grosso, midwest region of Brazil

We conducted this cross-sectional retrospective study using clinical and laboratory data from two tertiary hospitals in Cuiabá, Mato Grosso, Brazil, in order to explore the risk factors and estimate mortality, prevalence and lethality of candidemia between 2006 and 2011. A total of 130 episodes of candidemia were identified. The prevalence of candidemia was 1.8 per 1,000 admissions, the mortality rate was 0.9 per 1,000 admissions, and the lethality was 49.2 %. The main agent in this population was Candida parapsilosis (n = 50), followed by C. albicans (n = 45). Comparison between the numbers of episodes in the two triennia revealed that the non-albicans group grew by 48.2 %. The distribution of yeast species of Candida per hospital unit revealed that C. albicans was more prevalent than C. parapsilosis in the adult ICU and C. parapsilosis was more prevalent than C. albicans in the neonatal ICU. Patients remained hospitalized for an average of 53.5 days. Central venous catheters, parenteral nutrition and age were the variables that proved to be independent in the multivariate analysis and that maintained a statistically significant association with the incidence of death in patients with candidemia. The annual prevalence of candidemia showed a significant increase in the second triennium (2009-2011) compared with the first (2006-2008) probably due to increased exposure to risk factors: central venous catheter, H2 blockers, nutrition parenteral corticosteroids and mean hospital duration.

Trafficking of phagocytic peritoneal cells in hypoinsulinemic-hyperglycemic mice with systemic candidiasis

Background

Candidemia is a severe fungal infection that primarily affects hospitalized and/or immunocompromised patients. Mononuclear phagocytes have been recognized as pivotal immune cells which act in the recognition of pathogens, phagocytosis, inflammation, polarization of adaptive immune response and tissue repair. Experimental studies have showed that the systemic candidiasis could be controlled by activated peritoneal macrophages. However, the mechanism to explain how these cells act in distant tissue during a systemic fungal infection is still to be elucidated. In the present study we investigate the in vivo trafficking of phagocytic peritoneal cells into infected organs in hypoinsulinemic-hyperglycemic (HH) mice with systemic candidiasis.

Methods

The red fluorescent vital dye PKH-26 PCL was injected into the peritoneal cavity of Swiss mice 24 hours before the intravenous inoculation with Candida albicans. After 24 and 48 hours and 7 days of infection, samples of the spleen, liver, kidneys, brain and lungs were submitted to the microbiological evaluation as well as to phagocytic peritoneal cell trafficking analyses by fluorescence microscopy.

Results

In the present study, PKH⁺ cells were observed in the peritoneum, kidney, spleen and liver samples from all groups. In infected mice, we also found PKH⁺ cells in the lung and brain. The HH condition did not affect this process.

Conclusions

In the present study we have observed that peritoneal phagocytes migrate to tissues infected by C. albicans and the HH condition did not interfere in this process.

Candidaemia in internal medicine departments: the burden of a rising problem

Although internal medicine wards (IMWs) represent a significant reservoir of patients with candidemia, few investigators have specifically addressed the epidemiological aspects of candidaemia in this population. Of all patients hospitalized during the study period with candidaemia, 133/348 (38%) were admitted to IMWs. Variables associated with IMWs included: antibiotic therapy prior to hospitalization, urinary or central venous catheter, parenteral nutrition, tumour and age >75 years. Overall, 30-day mortality in IMWs was significantly higher than that in other wards (51.1% vs. 38.2%, p <0.02). Multiple logistic regression analysis identified the administration of antifungal treatment 48 h after having the first positive BC as an independent determinant of hospital mortality. Patients with candidaemia in IMWs account for a substantial proportion of patients with candidaemia and have higher mortality compared with patients in other wards.

Multilocus sequence typing of Candida tropicalis shows the presence of different clonal clusters and fluconazole susceptibility profiles in sequential isolates from candidemia patients in Sao Paulo, Brazil

The profiles of 61 Candida tropicalis isolates from 43 patients (28 adults and 15 children) diagnosed with candidemia at two teaching hospitals in São Paulo, Brazil, were characterized by multilocus sequence typing (MLST). For the 14 patients who had bloodstream infections, 32 isolates were serially collected from their blood and/or catheters. Thirty-nine diploid sequence types (DSTs) were differentiated. According to the C. tropicalis MLST database (http://pubmlst.org/ctropicalis/), 36 DSTs and 23 genotypes identified from the 61 isolates had not previously been described. This report represents the first study to characterize sequential isolates of C. tropicalis from candidemia cases in South America. Microvariation in a single gene was found in the sequential isolates from 7 patients. The main polymorphisms occurred in the alleles of the XYR1 gene, specifically at nucleotide positions 215, 242, and 344. Macrovariation in six gene fragments was detected in the isolates from 3 patients. eBURST analysis added two new groups to this study (groups 6 and 18). Additionally, susceptibility tests indicate that 3 isolates were resistant to fluconazole. No correlation was found between the DSTs and susceptibility to fluconazole and/or selective antifungal pressure. Two patients were sequentially infected with resistant and susceptible strains. MLST is an important tool for studying the genetic diversity of multiple/sequential isolates of patients with candidemia, allowing the comparison of our data with those from other regions of the world, as well as allowing an analysis of the genetic relationship among several clones in sequential isolates from the same or different candidemia patient sites (blood or catheter).

Invasive candidiasis in Pakistan: clinical characteristics, species distribution and antifungal susceptibility

This study reports for the first time, to our knowledge, descriptive epidemiological data for 188 invasive Candida isolates from Pakistan, including species identification and antifungal susceptibility against fluconazole, itraconazole, voriconazole, caspofungin, micafungin, anidulafungin and amphotericin. Risk factors for invasive candidiasis (IC) were determined for 96 patients from Karachi, Pakistan. In adults and neonates, Candida tropicalis (38 and 36 %, respectively) was the most common species, followed in adults by Candida parapsilosis (17.8 %), Candida glabrata (15.9 %) and Candida albicans (12.3 %). C. albicans (21 %) was the second most common in neonates. In children, C. albicans (31.9 %), C. tropicalis (26.4 %) and C. parapsilosis (19.4 %) were the most common. C. albicans IC was significantly associated with paediatric age [crude odds ratio (COR) 3.46, 95 % confidence interval (CI) 1.63-7.32]. Rare species made up 17.5 % of the total isolates studied. Resistance to fluconazole was seen in C. glabrata (15 .0%) and Candida krusei (100 .0%). Only one isolate (C. glabrata) was resistant to all three echinocandins. Low MICs of fluconazole for 98 % (184/188) of isolates tested support its continued use as an empiric therapy for IC. Non-C. albicans IC was associated with the use of β-lactam inhibitor combinations (COR 3.16, 95 % CI 1.05-9.57). Use of healthcare devices was documented in 85.4 % of IC patients, whilst 75 .0% had been admitted to special care units. Surprisingly, 66.7 % of patients with IC were not obviously immunosuppressed. The high frequency of modifiable risk factors in this population indicates that candidaemia can be reduced with stringent antibiotic and infection control measures. These data will be useful for empiric selection of antifungals in Karachi, and contribute to global assessments of antifungal resistance.