Candida species distribution in bloodstream cultures in Lyon, France, 1998–2001

Candidaemia: A 9-Year Retrospective Analysis of Epidemiology and Antimicrobial Susceptibility in Tertiary Care Hospitals in Western China

Purpose

This investigation endeavors to scrutinize the resistance profiles to antifungal agents, alongside the clinical distribution of Candida isolates that yielded positive results in blood cultures at Suining Central Hospital spanning the years 2015 to 2023. The objective is to provide crucial epidemiological insights that may aid in early clinical intervention and judicious deployment of antifungal therapies.

Methods

This retrospective analysis analyses data on 182 different Candida strains with positive clinical blood cultures obtained from the Microbiology Laboratory of Suining Central Hospital over a period of nine consecutive years. The study involved identification of Candida species and assessment of resistance patterns to fungal drugs.

Results

Our analysis revealed that the median age of patients diagnosed with Candidaemia from the 182 strains was 62 years, with a distribution of 63.7% females and 36.3% males. Within the cohort of 182 Candida strains, Candida albicans constituted 32.4%, while non-albicans Candida species comprised 67.6% of the cases. Specifically, Candida tropicalis represented 37.4%, Candida glabrata 12.1%, Candida parapsilosis 11.0%,Candida guilliermondii 3.8%, and both Candida krusei and Candida Dublin accounted for 1.6% each. These Candida species were predominantly identified in intensive care units (ICU), hematology, gastroenterology, neurology centers, and endocrine metabolism units.

Conclusion

The findings of this investigation suggest a shift in the prevalence of non-Candida albicans species, notably C. tropicalis, as the predominant cause of Candidaemia at Suining Central Hospital, surpassing C. albicans. Although instances of antifungal resistance are infrequent, there has been a notable rise in resistance to azoles. This study provides important insights into the local epidemiology, which will be essential for informing the selection of empirical antifungal therapy and contributing to the global surveillance of antifungal resistance.

Oropharyngeal Candida Colonization in Patients with Acute Myeloid Leukemia

Objectives:

Oral candidiasis has increased in recent years because of the increasing number of high-risk populations. The prevalence of Candida species is different worldwide because of the difference between population characteristics, sampling protocols, and geographic regions. Therefore, determining the more prevalent Candida species in different geographic regions seems essential. This study aimed to determine the more prevalent Candida species in acute myeloid leukemia (AML) patients in comparison with healthy individuals in Iran in 2016.

Materials and Methods:

Fifty-one patients with AML and 62 healthy controls participated in this cross-sectional study. Samples were collected using a swab rubbed softly on the dorsal surface of the tongue and the oropharynx. The samples were cultured on CHROMagar Candida for 2 to 4 days. For differentiation between albicans and non-albicans species, positive samples were linearly inoculated on Corn Meal Agar with Tween-80. Candida species were identified using a microscope. Data were analyzed using chi-square and Fisher’s exact tests.

Results:

Candida colonization was more frequent in AML patients (41.2%) in comparison with healthy participants (38.7%). Candida glabrata (C. glabrata; 27.5%) and Candida albicans (C. albicans; 32.3%) were the most common isolated species in the AML patients and the controls, respectively. There was a significant decrease in the frequency of C. albicans (P=0.022) and a significant increase in the frequency of C. glabrata (P=0.002) in the AML patients in comparison with the controls.

Conclusion:

AML patients are more susceptible to candidiasis. C. glabrata is the dominant Candida species in AML patients.

Rapid identification of medically important Candida isolates using high resolution melting analysis

An increasing trend in non albicans infections and various susceptibility patterns to antifungal agents implies a requirement for the quick and reliable identification of a number of medically important Candida species. Real-time PCR followed by high resolution melting analysis (HRMA) was developed, tested on 25 reference Candida collection strains and validated on an additional 143 clinical isolates in this study. All reference strains and clinical isolates inconclusive when using phenotypic methods and/or HRMA were analysed using ITS2 sequencing. Considering reference and clinical strains together, 23 out of 27 Candida species could be clearly distinguished by HRMA, while the remaining 4 species were grouped in 2 pairs, when applying the mean Tm ± 3 SD values, the shape of the derivative melting curve (dMelt curve) and, in some cases, the normalized and temperature—shifted difference plot against C. krusei. HRMA as a simple, rapid and inexpensive tool was shown to be useful in identifying a wide spectrum of clinically important Candida species. It may complement the current clinical diagnostic approach based on commercially available biochemical kits.

The effect of biomaterials and antifungals on biofilm formation by Candida species: a review

Candida albicans, C. glabrata, C. parapsilosis, and C. tropicalis are able to form biofilms on virtually any biomaterial implanted in a human host. Biofilms are a primary cause of mortality in immunocompromised and hospitalized patients, as they cause recurrent and invasive candidiasis, which is difficult to eradicate. This is due to the fact that the biofilm cells show high resistance to antifungal treatments and the host defense mechanisms, and exhibit an excellent ability to adhere to biomaterials. Elucidation of the mechanisms of antifungal resistance in Candida biofilms is of unquestionable importance; therefore, this review analyzes both the chemical composition of biomaterials used to fabricate the medical devices, as well as the Candida genes and proteins that confer drug resistance.

Species distribution and in vitro antifungal susceptibility of clinical Candida isolates from a university hospital in Turkey over a 5-year period

We retrospectively evaluated the distribution of clinical Candida spp. isolated over a 5-year period in our hospital relative to year, specimen types, hospital departments and their antifungal susceptibility patterns. Overall 3,756 Candida spp. were recovered from 10,857 specimens. In vitro antifungal susceptibility tests were conducted with 2,068 isolates against amphotericin B, fluconazole and itraconazole using the Etest method. C. albicans was isolated frequently from non-sterile body specimens while non-C. albicans Candida spp. were commonly recovered from sterile body specimens. Isolation rates of C. albicans were 83%, 61.2% and 49% in non-sterile body specimens, sterile body specimens and blood-sterile body fluids, respectively. C. krusei was an important isolate from specimens of patients in the Haematology and Bone Marrow Transplantation units and its rate of recovery increased in these departments. Amphotericin B resistance was detected in only seven C. krusei isolates, whereas 80% (n = 1,653), 76% (n = 1,572) and 99% (n = 2,061) of all isolates were susceptible to fluconazole, itraconazole and amphotericin B, respectively. In conclusion, the distribution of Candida species was variable among hospital departments and among body sites. These results may be useful in predicting potential fungal pathogens and the choice of antifungal treatment.

Canadian clinical practice guidelines for invasive candidiasis in adults

Candidemia and invasive candidiasis (C/IC) are life-threatening opportunistic infections that add excess morbidity, mortality and cost to the management of patients with a range of potentially curable underlying conditions. The Association of Medical Microbiology and Infectious Disease Canada developed evidence-based guidelines for the approach to the diagnosis and management of these infections in the ever-increasing population of at-risk adult patients in the health care system. Over the past few years, a new and broader understanding of the epidemiology and pathogenesis of C/IC has emerged and has been coupled with the availability of new antifungal agents and defined strategies for targeting groups at risk including, but not limited to, acute leukemia patients, hematopoietic stem cell transplants and solid organ transplants, and critical care unit patients. Accordingly, these guidelines have focused on patients at risk for C/IC, and on approaches of prevention, early therapy for suspected but unproven infection, and targeted therapy for probable and proven infection.

The changing face of epidemiology of invasive fungal disease in Europe

Invasive fungal diseases (IFDs) are an increasingly common complication in critically ill patients in Europe and are frequently fatal. Because of changes in treatment strategies and the increased use of antifungal prophylaxis, the epidemiology of IFDs has changed substantially in recent years and infections due to Candida species are no longer the majority in many institutions. In contrast, the emergence of non-Candida IFDs such as aspergillosis, zygomycosis and fusariosis has increased. European surveys indicate that Candida albicans is responsible for more than half the cases of invasive candidaemia; however, the occurrence of non-albicans-related IFDs appears to be increasing. Rates of IFD-related mortality in Europe depend on the pathogen, geographical location and underlying patient characteristics, with rates ranging from 28 to 59% for Candida infections and from 38 to 80% for invasive aspergillosis. Early initiation of antifungal therapy is critical for improving outcomes; however, this is complicated by the difficulty in diagnosing IFDs rapidly and accurately. The introduction of new extended-spectrum azole antifungal agents (e.g. voriconazole, posaconazole) and echinocandins (e.g. micafungin, caspofungin, anidulafungin) has increased the number of therapeutic options for early therapy. Choice between agents should be based on a variety of factors, including spectrum of activity, adverse events, drug interactions, route of administration, clinical efficacy of individual agents and local epidemiology.

[Epidemiology of candidemia: a one-year prospective observational study in the west of France]

OBJECTIVE

A one-year prospective, observational study was conducted in the west of France, to evaluate the epidemiology of candidemia.

METHOD

During the year 2004, each patient with at least one blood culture yielding Candida sp. was included. For each episode of candidemia, mycological, demographical, clinical, and therapeutic data, as well as outcome, were collected.

RESULTS

One hundred and ninety-three strains of Candida sp. were isolated in 186 patients, Candida albicans accounting for 54.9%, Candida glabrata for 18.7%, Candida parapsilosis for 12.9%, Candida tropicalis for 4.7% and Candida krusei for 4.1% of these isolates. A percentage of 84% of the Candida isolates were fully susceptible to fluconazole in vitro. Dose-dependent susceptibility or resistance to fluconazole was detected in more than one third of the Candida glabrata strains, of which 36% were also resistant to voriconazole. Two-thirds of the patients were males, and the mean age was 61.5 years. A percentage of 37% of patients were hospitalized in intensive care units. The main predisposing factors for candidemia were broad-spectrum antibiotics (75.8%), central venous catheter (72.6%), cancer or hematologic malignancy (47.3%), recent surgery (42.5%), total parenteral nutrition (37.6%). One hundred and fifty-four patients were treated with antifungal therapy, two-thirds of whom received fluconazole as first-line agent. Mortality was 49% overall, and was significantly higher in case of septic shock, advanced age, and absence of catheter removal.

Yeast identification--past, present, and future methods

The focus of this review is the evolution of biochemical phenotypic yeast identification methods with emphasis on conventional approaches, rapid screening tests, chromogenic agars, comprehensive commercial methods, and the eventual migration to genotypic methods. As systemic yeast infections can be devastating and resistance is common in certain species, accurate identification to the species level is paramount for successful therapy and appropriate patient care.

A cluster of Candida krusei infections in a haematological unit

BACKGROUND

Candida krusei infections are associated with high mortality. In order to explore ways to prevent these infections, we investigated potential routes for nosocomial spread and possible clonality of C. krusei in a haematological unit which had experienced an unusually high incidence of cases.

METHODS

We searched for C. krusei contamination of the hospital environment and determined the level of colonization in patients and health care workers. We also analyzed the possible association between exposure to prophylactic antifungals or chemotherapeutic agents and occurrence of C. krusei. The C. krusei isolates found were genotyped by pulsed-field electrophoresis method in order to determine possible relatedness of the cases.

RESULTS

Twelve patients with invasive C. krusei infection and ten patients with potentially significant infection or mucosal colonization were documented within nine months. We were unable to identify any exogenic source of infection or colonization. Genetic analysis of the isolates showed little evidence of clonal transmission of C. krusei strains between the patients. Instead, each patient was colonized or infected by several different closely related genotypes. No association between medications and occurrence of C. krusei was found.

CONCLUSION

Little evidence of nosocomial spread of a single C. krusei clone was found. The outbreak may have been controlled by cessation of prophylactic antifungals and by intensifying infection control measures, e.g. hand hygiene and cohorting of the patients, although no clear association with these factors was demonstrated.

Clinical and microbiological aspects of candidemia due to Candida parapsilosis in Brazilian tertiary care hospitals

In order to characterize the epidemiology, microbiology and outcome of candidemia due to Candida parapsilosis, we examined a database of 282 episodes of candidemia prospectively collected from four tertiary care hospitals in São Paulo, Brazil between March 2002 and February 2003, and compared the characteristics of patients with candidemia due to C. parapsilosis (n=64) with those caused by Candida albicans (n=107). C. parapsilosis candidemia was associated with neutropenia (p=0.005), tunneled central venous catheter (p=0.005) and cancer chemotherapy (p=0.03). By multivariate analysis, candidemia due to C. parapsilosis was associated with the presence of a tunneled central venous catheter (relative risk 3.71, 95% confidence interval 1.28-10.70). Except for a single isolate of C. parapsilosis that exhibited MIC >1 microg/ml to amphotericin B, no resistance was observed in 166 isolates tested against fluconazole, itraconazole, 5-flucytosine and amphotericin B. The caspofungin MIC values of C. parapsilosis isolates were significantly higher than those exhibited by C. albicans isolates (p<0.001). The overall mortality of patients with candidemia due to C. parapsilosis was significantly lower (45% vs. 62%, p=0.03). The association between C. parapsilosis candidemia and a tunneled central venous catheter supports the idea that the main mode of acquisition of C. parapsilosis is from an external source.

Epidemiology of candidemia in Brazil: a nationwide sentinel surveillance of candidemia in eleven medical centers

Candidemia studies have documented geographic differences in rates and epidemiology, underscoring the need for surveillance to monitor trends. We conducted prospective candidemia surveillance in Brazil to assess the incidence, species distribution, frequency of antifungal resistance, and risk factors for fluconazole-resistant Candida species. Prospective laboratory-based surveillance was conducted from March 2003 to December 2004 in 11 medical centers located in 9 major Brazilian cities. A case of candidemia was defined as the isolation of Candida spp. from a blood culture. Incidence rates were calculated per 1,000 admissions and 1,000 patient-days. Antifungal susceptibility tests were performed by using the broth microdilution assay, according to the Clinical and Laboratory Standards Institute guidelines. We detected 712 cases, for an overall incidence of 2.49 cases per 1,000 admissions and 0.37 cases per 1,000 patient-days. The 30-day crude mortality was 54%. C. albicans was the most common species (40.9%), followed by C. tropicalis (20.9%) and C. parapsilosis (20.5%). Overall, decreased susceptibility to fluconazole occurred in 33 (5%) of incident isolates, 6 (1%) of which were resistant. There was a linear correlation between fluconazole and voriconazole MICs (r = 0.54 and P < 0.001 [Spearman's rho]). This is the largest multicenter candidemia study conducted in Latin America and shows the substantial morbidity and mortality of candidemia in Brazil. Antifungal resistance was rare, but correlation between fluconazole and voriconazole MICs suggests cross-resistance may occur.

Candida guilliermondii fungemia in patients with hematologic malignancies

The microbiological, clinical, and epidemiological features of most non-Candida albicans Candida species are well known, but much less is known about species such as Candida guilliermondii, an uncommon pathogen causing a variety of deep-seated infections in immunocompromised hosts. To characterize C. guilliermondii fungemia in patients with hematological malignancies and its susceptibility to antifungal drugs, all cases of C. guilliermondii fungemia diagnosed in our department between 1983 and 2005 were retrospectively analyzed and the literature was reviewed. C. guilliermondii caused 29/243 (11.7%) candidemia episodes diagnosed during the study period. Central venous catheters were the documented sources of candidemia in 19/29 episodes (65.5%), and invasive tissue infections were documented in 2 (6.9%). In the remaining eight, the catheter was not removed and the source of the fungemia remained obscure. Seven episodes ended in death, but only one could be attributed to invasive C. guilliermondii infection. Molecular typing data reveal no evidence of common infection sources. Isolates displayed high rates of in vitro susceptibility to amphotericin B (100%), voriconazole (95%), and fluconazole (90%) and lower rates of in vitro susceptibility to flucytosine (86%), itraconazole (76%), and caspofungin (33%). Our literature review confirms that C. guilliermondii is a significantly more frequent cause of candidemia among cancer patients compared with the general hospital population. It accounted for <1% of the total number of Candida bloodstream isolates reported in the articles we reviewed, with higher rates in Europe (1.4%) and Asia (1.8%) compared with North America (0.3%).

Epidemiology of Visceral Mycoses in Patients with Leukemia and MDS-Analysis of the Data in Annual of Pathological Autopsy Cases in Japan in 1989, 1993, 1997 and 2001-

To study the changes of visceral mycoses in autopsy cases, data on visceral mycosis cases with leukemia and myelodysplastic syndrome (MDS) reported in the Annual of the Pathological Autopsy Cases in Japan in 1989, 1993, 1997 and 2001 were analyzed. The frequency rate of visceral mycoses with leukemia and MDS was 27.9% (435/1,557) in 1989, 23.0% (319/1,388) in 1993, 22.3% (246/1,105) in 1997 and 25.1% (260/ 1,037) in 2001, which was clearly higher than the rate of cases without leukemia and MDS: 3.4%, 2.7%, 3.5% and 3.7%, respectively. Furthermore, in comparing the rate of mycoses in recipients of stem cell transplantation with that of non-recipients, that of recipients was about 10% higher. The predominant causative agents were Candida and Aspergillus, at approximately the same rate (Candida 33.6%, Aspergillus 33.3%) as in 1989. However, Aspergillus increased conspicuously in 1993 (Candida 22.3% Aspergillus 44.5%), and continued to increase (Candida 22.8%, Aspergillus 50.8% in 1997; Candida 16.9%, Aspergillus 54.2% in 2001). In aspergillosis and zygomycosis, the lung and bronchi comprised the most commonly infected organs: 74.7% and 75.6% of the total cases, respectively. Among a total of 1,260 cases with mycotic infections in the four years studied, acute lymphatic leukemia and acute myeloid leukemia were the major diseases (35.5% and 33.5%, respectively) followed by MDS (29.0%). Given these facts, we emphasize that a greater interest in mycoses should be taken by clinicians, and immunocompromised patients should be protected from opportunistic invasive fungal infections, especially aspergillosis.

Global trends in candidemia: Review of reports from 1995–2005

Candida species are an important cause of health care-related bloodstream infections (BSI). Understanding the current Candida BSI incidence trends, the dominant species causing disease, and the mortality associated with this infection are important to help guide therapeutic and prophylaxis measures. In this review, trends in the incidence of Candida BSI are assessed using data extracted from reports published worldwide during 1995 to 2005. The incidence trend of Candida BSI was found to be stable for most of the reports reviewed, and Candida albicans remains the most common species causing Candida BSIs. Surveillance to monitor the burden of disease and emergence of resistance, among the general patient population and among high risk patient populations, should be continued.