Clinical manifestations of candidemia caused by uncommon Candida species and antifungal susceptibility of the isolates in a regional hospital in Taiwan, 2007-2014

Six-Year Retrospective Analysis of Epidemiology, Risk Factors, and Antifungal Susceptibilities of Candidiasis from a Tertiary Care Hospital in South China

Candidiasis is a life-threatening disease that increases mortality in critically ill patients. However, such epidemiological data are still lacking in underdeveloped regions of China. A retrospective analysis (2016 to 2021) was conducted in Meizhou People's Hospital, China to study the burden of candidiasis, particularly candidemia, and antifungal susceptibilities of the species among hospitalized patients. Of the 7,864 candidiasis cases, 461 (5.86%) were candidemia cases. Candida albicans (64.25%) was the most identified species, followed by C. tropicalis (12.61%), C. glabrata (10.79%), and C. parapsilosis (9.79%). In non-C. albicans (NCA) candidemia cases, the number of C. glabrata cases was higher (102/461, 22.37%) than C. tropicalis (64/461, 14.04%). Gastrointestinal pathology, respiratory dysfunctions, septic shock, and malignancies were common underlying comorbidities, respectively. A central venous catheter was an independent risk factor for both C. albicans and NCA candidemia. The mortality rate was not statistically significant for either C. albicans or NCA. Amphotericin B and 5-flucytosine were highly effective (98 to 100%), while azoles were least effective (67.74 to 95.66%). Candidemia cases caused by C. tropicalis and C. glabrata had significantly lower azole susceptibility than non-candidemia-causing isolates. This study provides valuable information for prescribers to choose the right empirical therapy, for researchers to explore different resistance mechanisms, and for health care managers to control candidiasis better. IMPORTANCE This study provides important information on the burden of candidiasis, particularly candidemia, and the antifungal susceptibility of Candida species among hospitalized patients in an underdeveloped region of China. First, the finding that azoles were least effective against Candida species causing candidemia is particularly noteworthy, as it suggests the possibility of resistance to this class of antifungal agents. This information can guide the choice of empirical therapy and help in the selection of appropriate antifungal agents for the treatment of candidemia, thereby reducing the risk of resistance development. Second, the study provides important information for researchers to explore different resistance mechanisms in Candida species. Finally, the study has important implications for health care managers in controlling the spread of candidiasis. The high prevalence of candidemia cases in the study highlights the need for appropriate infection control measures to prevent the spread of the disease.

Meyerozyma guilliermondii species complex: review of current epidemiology, antifungal resistance, and mechanisms

Meyerozyma guilliermondii has been accepted as a complex composed of Meyerozyma guilliermondii, Meyerozyma carpophila, and Meyerozyma caribbica. M. guilliermondii is a saprophyte detected on human mucosa and skin. It can lead to serious infections in patients with risk factors like chemotherapy, immunodeficiency, gastrointestinal or cardiovascular surgery, and oncology disorders. Most deaths related to M. guilliermondii infections occur in individuals with malignancy. In recent decades, incidence of M. guilliermondii infections is increased. Sensitivity of this microorganism to conventional antifungals (e.g., amphotericin B, fluconazole, micafungin and anidulafungin) was reduced. Prophylactic and empirical uses of these drugs are linked to elevated minimal inhibitory concentrations (MICs) of M. guilliermondii. Drug resistance has concerned many researchers across the world. They are attempting to discover appropriate solution to combat this challenge. This study reviews the most important mechanisms of resistance to antifungals developed by in M. guilliermondii species complex.

Prevalence and species distribution of Candida bloodstream infection in children and adults in two teaching university hospitals in Egypt: first report of Candida kefyr

BACKGROUND

Candidemia is a pervasive problem associated with significant morbidity and mortality in health care settings. This study aimed to determine the changing distribution of Candida species and the emergence of uncommon species.

METHODS

This was a cross-sectional study performed in two Cairo University hospitals between 2019 and 2020. All Candida species isolates recovered from blood cultures of adults and pediatrics patients admitted to the hospitals were included. Candida isolates were identified by chromogenic Candida agar and Vitek2 YST identification card. Candida kefyr was confirmed by chip array.

RESULTS

Candida species were responsible for 1.6% of bloodstream infections in adults and 10.8% in pediatric patients. C. albicans was the most prevalent species representing 27.8% in adults and 48.3% in pediatrics. Non-albicans species (NAC) represented the most isolated Candida species among adults and pediatrics (72.2% and 51.6%, respectively) with the predominance of C. tropicalis (27.8% and 22.5%, respectively) followed by C. parapsilosis (16.7% and 10.8%, respectively). The uncommon Candida, which is Candida species other than C. albicans, C. parapsilosis, C. tropicalis, C. glabrata, and C. krusei, represents 16.6% and 14% of all candidemia in adults and pediatrics, respectively. Only one of each of C. lusitaniae, C. utilis, and C. kefyr were detected in adults. C. lusitaniae was the most frequently recovered uncommon Candida among pediatrics resulting in 6.4% of candidemia followed by C. famata (4.3%), C. utilis (2.2%), and C. kefyr (1.1%).

CONCLUSIONS

C. albicans is still the primary species isolated from pediatrics and adults with candidemia despite the considerable shift to the non-albicans species. C. tropicalis and C. parapsilosis are the most prevalent NAC. The increased prevalence of uncommon Candida species is alarming and necessitates a prompt stewardship program.

The Role of Biofilm in Central Venous Catheter Related Bloodstream Infections: Evidence-based Nursing and Review of the Literature

BACKGROUND

Biofilm is a fundamental component in the pathogenesis of infections related to the use of the central venous catheter (CVC,) which can represent an important health issue in everyday practice of nursing and medical staff.

OBJECTIVE

The objective of the following review is to analyze the components of biofilm and their role in catheter-related infection determinism in an evidencebased nursing perspective in such a way as to give health professionals useful suggestions in the prevention and management of these complications.

METHODS

The following databases were consulted for the bibliographic search: Medline, Scopus, Science Direct. Biofilm can be the cause of CVC extraction and can lead to serious haematogenic infectious complications that can increase the morbidity and mortality of affected patients.

RESULTS

Updated pathophysiologic knowledge of biofilm formation and appropriate diagnostic methodology are pivotal in understanding and detecting CVC-related infections. Lock therapy appears to be a useful, preventive, and therapeutic aid in the management of CVCrelated infections. New therapies attempting to stop bacterial adhesion on the materials used could represent new frontiers for the prevention of CVC-related infections.

CONCLUSION

The correct evidence-based nursing methods, based on the use of guidelines, provides the opportunity to minimize the risks of infection through the implementation of a series of preventive measures both during the CVC positioning phase and in the subsequent phase, for example, during device management which is performed by medical and nursing staff.

Species identification and antifungal susceptibility of uncommon blood yeast isolates

BACKGROUND/PURPOSE

Accurate identification of Candida species is increasingly important in the era of emergence of Candida auris. We aimed to compare the identification performance of two matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems (Vitek MS and Bruker biotyper MS) and an oligonucleotide array for uncommon blood yeast isolates and demonstrate the susceptibilities among those isolates.

METHOD

Candida species isolates from blood culture other than Candida albicans, Candida parapsilosis, Candida tropicalis, Candida glabrata, and Candida krusei identified by biochemical methods were collected from multiple hospitals and further identified by an oligonucleotide array based on the internal transcribed spacer-1 (ITS-1) and ITS-2 sequences of the rRNA genes, Vitek MS and Bruker biotyper MS. The minimal inhibitory concentrations (MICs) of these clinical isolates were determined by the Sensititre YeastOne (SYO) system.

RESULTS

Among 136 isolates, Candida guilliermondii was most common (52, 38.2%), followed by C. lusitaniae (13, 9.6%) and C. haemulonii (12, 8.8%). The oligonucleotide array, Vitek MS and Bruker biotyper MS correctly identified 89.7% (122), 90.4% (123), and 92.6% (126) of these isolates, respectively. Elevated minimal inhibitory concentrations (MICs) of fluconazole were observed for C. haemulonii (MIC₉₀: 256 mg/L), and C. guilliermondii (MIC₉₀: 16 mg/L) with 28.4% of uncommon Candida isolates with MIC ≧ 8 mg/L.

CONCLUSIONS

For uncommon Candida species, the unmet need for current databases of two commercial MALDI-TOF MS systems is highlighted, and the oligonucleotide array may serve as a supplement.

Expect the unexpected: fungemia caused by uncommon Candida species in a Turkish University Hospital

Fungemia caused by uncommon Candida species (UCS) (other than C.albicans, C.glabrata, C.parapsilosis, C.tropicalis, C.krusei) is a rare but emerging threat with their potential to exhibit reduced susceptibility or resistance to antifungal agents. We identified 25 patients with UCS fungemia (9 C.kefyr, 8 C.lusitaniae, 4 C.dubliniensis, 2 C.guilliermondii, 1 C.pelliculosa, 1 C.rugosa) through January 2011 and August 2018. Echinocandins were the most common administered agents, followed by fluconazole. Overall mortality was 44%. Echinocandins and voriconazole showed sufficient activity against all tested isolates. High fluconazole MICs among C.guilliermondii, C.pelliculosa, and C.rugosa were determined. MIC value of C.pelliculosa was above the epidemiological cut-off proposed for fluconazole.

Species Distribution and Antifungal Susceptibility of Invasive Candidiasis: A 2016-2017 Multicenter Surveillance Study in Beijing, China

OBJECTIVE

Invasive candidiasis (IC), a life-threatening fungal infection prevalent among hospitalized patients, has highly variable regional epidemiology. We conducted a multicenter surveillance study to investigate recent trends in species distribution and antifungal susceptibility patterns among IC-associated Candida spp. in Beijing, China, from 2016 to 2017.

MATERIALS AND METHODS

A total of 1496 non-duplicate Candida isolates, recovered from blood and other sterile body fluids of IC patients, were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry combined with ribosomal DNA internal transcribed spacer (ITS) region sequencing. Broth microdilution-based susceptibility testing using six antifungal agents was also conducted.

RESULTS

Candida albicans was the most frequently isolated species (49.9%), followed by Candida tropicalis (15.5%), Candida glabrata (14.7%) and Candida parapsilosis (14.2%). No significant differences in species distribution were observed when compared with a 2012-2013 dataset. Overall, the rates of susceptibility to fluconazole and voriconazole were high among C. albicans (98% and 97.2%, respectively) and C. parapsilosis species complex (91.1% and 92%, respectively) isolates but low among C. tropicalis (81.5% and 81.1%, respectively) isolates. In addition, the rate of azole resistance among C. tropicalis isolates increased significantly (1.8-fold, P<0.05) compared with that observed in 2012-2013, while micafungin resistance rates were <5% for all tested Candida species.

CONCLUSION

Our results suggest that species distribution has remained stable among IC-associated Candida isolates in Beijing. Resistance to micafungin was rare, but increased azole resistance among C. tropicalis isolates was noted. Our study provides information on local epidemiology that will be important for the selection of empirical antifungal agents and contributes to global assessments of antifungal resistance.

Update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA 12: suitability of taxonomic units notified to EFSA until March 2020

The qualified presumption of safety (QPS) was developed to provide a generic safety evaluation for biological agents to support EFSA's Scientific Panels. It is based on an assessment of the taxonomic identity, the body of knowledge, safety concerns and antimicrobial resistance. Safety concerns identified for a taxonomic unit (TU) are where possible to be confirmed at strain or product level, reflected by 'qualifications'. No new information was found that would change the previously recommended QPS TUs of the 39 microorganisms notified to EFSA between October 2019 and March 2020, 33 were excluded, including five filamentous fungi, five Escherichia coli, two Enterococcus faecium, two Streptomyces spp. and 19 TUs already evaluated. Six TUs were evaluated. Akkermansia muciniphila was not recommended for QPS status due to safety concerns. Clostridium butyricum was not recommended because some strains contain pathogenicity factors. This TU was excluded for further QPS evaluation. Galdieria sulphuraria and Pseudomonas chlororaphis were also rejected due to a lack of body of knowledge. The QPS status of Corynebacterium ammoniagenes (with the qualification 'for production purposes only') and of Komagataella pastoris (with the qualification 'for enzyme production') was confirmed. In relation to the taxonomic revision of the Lactobacillus genus, previously designated Lactobacillus species will be reassigned to the new species and both the old and new names will be retained in the QPS list.

Risk factors associated with mortality among patients who had candidemia in a university hospital

INTRODUCTION:

Bloodstream infection due to Candida spp. is a primary cause of morbidity and mortality in tertiary hospitals.

METHODS:

In this retrospective study, we included patients with a positive blood culture for Candida spp. after 48 h of hospitalization.

RESULTS

A total of 335 patients who had candidemia were included in this study. Risk factors associated with mortality were hospitalization in internal medicine units and surgical clinics, age >60 years, mechanical ventilation, orotracheal intubation, hemodialysis, corticosteroids use, and C. parapsilosis infection.

CONCLUSIONS:

This study highlights the importance of health care related to invasive procedures and actions to improve patient immunity.

Scientific Opinion on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA (2017-2019)

The qualified presumption of safety (QPS) was developed to provide a safety pre-assessment within EFSA for microorganisms. Strains belonging to QPS taxonomic units (TUs) still require an assessment based on a specific data package, but QPS status facilitates fast track evaluation. QPS TUs are unambiguously defined biological agents assessed for the body of knowledge, their safety and their end use. Safety concerns are, where possible, to be confirmed at strain or product level, and reflected as 'qualifications'. Qualifications need to be evaluated at strain level by the respective EFSA units. The lowest QPS TU is the species level for bacteria, yeasts and protists/algae, and the family for viruses. The QPS concept is also applicable to genetically modified microorganisms used for production purposes if the recipient strain qualifies for the QPS status, and if the genetic modification does not indicate a concern. Based on the actual body of knowledge and/or an ambiguous taxonomic position, the following TUs were excluded from the QPS assessment: filamentous fungi, oomycetes, streptomycetes, Enterococcus faecium, Escherichia coli and bacteriophages. The list of QPS-recommended biological agents was reviewed and updated in the current opinion and therefore now becomes the valid list. For this update, reports on the safety of previously assessed microorganisms, including bacteria, yeasts and viruses (the latter only when used for plant protection purposes) were reviewed, following an Extensive Literature Search strategy. All TUs previously recommended for 2016 QPS list had their status reconfirmed as well as their qualifications. The TUs related to the new notifications received since the 2016 QPS opinion was periodically evaluated for QPS status in the Statements of the BIOHAZ Panel, and the QPS list was also periodically updated. In total, 14 new TUs received a QPS status between 2017 and 2019: three yeasts, eight bacteria and three algae/protists.

Rapid identification of clinical common invasive fungi via a multi-channel real-time fluorescent polymerase chain reaction melting curve analysis

The incidence of invasive fungal infections (IFIs) has recently increased, and early and accurate diagnosis of IFIs is important for the rational selection of antifungal drugs with high efficacy. We developed a method for rapid and accurate clinical diagnosis of IFIs and provide a reference for personalized drug treatment.We designed and screened fungal internal transcribed spacer regions with universal primers and designed 8 TaqMan detection probes to establish a multi-channel real-time fluorescent polymerase chain reaction (PCR) melting curve analysis (MCA) method. The sensitivity, specificity, and reproducibility of this method were investigated using standard fungal strains and clinical isolates. Candidemia was detected using the MCA method.The limit of detection and assay cut-off (melting temperature [Tm]) for Candida albicans were 0.05 pg/μL and 66.50 °C; Candida glabrata were 0.1 pg/μL and 66.25 °C; Candida tropicalis were 0.1 pg/μL and 60.15 °C; Candida krusei were 0.1 pg/μL and 72.15 °C; Candida parapsilosis were 0.2 pg/μL and 63.10 °C; Candida guilliermondii were 0.1 pg/μL and 61.84 °C; Cryptococcus neoformans were 0.1 pg/μL and 65.50 °C; Aspergillus flavus were 0.05 pg/μL and 71.50 °C; Aspergillus terreus, Aspergillus fumigatus, and Aspergillus niger were 0.05 pg/μL and 76.80 °C. Analytical specificity was evaluated using 13 clinical pathogens including Streptococcus pneumoniae, Staphylococcus aureus, and Haemophilus influenzae, etc. No false-positive results were obtained for any of these samples. The MCA method can detect and identify different candidemia simulations. The limit detection concentration of C albicans was 44 cfu/mL, C glabrata was 73 cfu/mL, C tropicalis was 29 cfu/mL, C parapsilosis was 21 cfu/mL, C krusei was 71 cfu/mL, and C guilliermondii was 53 cfu/mL.The multi-channel real-time fluorescence PCR melting curve analysis displayed high sensitivity and specificity in detecting various clinically invasive fungi. Furthermore, it simultaneously detected the genera Candida, Cryptococcus, and Aspergillus and identified Candida at the species level. Our method can facilitate early and accurate clinical diagnosis and personalized medication regimens.

The analysis of nanomechanical properties of Candida spp. by atomic force microscopy (AFM) method

The aim of the study was to analyze the selected nanomechanical properties of Candida spp: Candida albicans (standard strain ATCC 10231), Candida albicans (clinical strain, cultured from an oral swab), Candida lipolytica (clinical strain, cultured from a nosal swab) in atomic force microscopy (AFM). The culture Candida spp. was performed of Tryptone Soya Broth (BioMaxima). The topography and sample properties were analysed in AFM (Ntegra Spectra C from NT) and the results were carried out using NOVA 1.1.0.1824 software. C. albicans ATCC 10231 cells were significantly higher 1.81 μm (p = 0.001) from clinical strains: C. albicans (1.30 μm) and C. lipolytica (1.23 μm). C. albicans ATCC 10231 cells, and C. albicans cells of the clinical strain were softer, especially in the top parts of cells, than C. lipolytica cells. Adhesion force measured for C. albicans ATCC 10231 was 62.83 nN, and was significantly higher compared to the values obtained for C. albicans (41.93 nN, p = 0.0002 ) and C. lipolytica (41.78 nN, p = 0.0002 ). The stiffness of the Candida spp. cell surface was comparable and was in the range of 5–6 nA. The differences in height may result from different conditions in which clinical strains grow. Adhesion force can be helpful in the analysis of the degree of destruction of the cell wall by various substances. The conducted analyses showed morphological differences and the differences in mechanical properties of the researched Candida spp. This data may be important in assessing their susceptibility to the effects of various substances of a lytic nature.

Epidemiology, species distribution, antifungal susceptibility and mortality risk factors of candidemia among critically ill patients: a retrospective study from 2011 to 2017 in a teaching hospital in China

Background

Candidemia is still a common life-threatening disease and causes significant morbidity and mortality, especially in critically ill patients. We conducted this study to analyze the epidemiology, clinical characteristics, species distribution, antifungal susceptibility and mortality risk factors of candidemia in an intensive care unit.

Methods

We retrospectively analyzed patients with candidemia in the intensive care unit of our hospital from 2011 to 2017. The clinical characteristics, including clinical and laboratory data, antibiotic therapies, underlying conditions, and invasive procedures and outcomes, were analyzed. We also performed a logistic regression analysis to identify the independent risk factors for mortality.

Results

In this six-year retrospective study, we identified 82 patients with candidemia. The median age of the patients was 76 years (range, 26 years to 91 years), and 50 of the patients (61%) were male. Candida albicans was the most common fungal species (38/82, 46.3%), followed by Candida parapsilosis (16/82, 19.5%), Candida glabrata (13/82, 15.9%), and Candida tropicalis (12/82, 14.6%). Most isolates were susceptible to the antifungal agents. The all-cause mortality rate was 51.2%. In binary logistic regression analysis, the worst Glasgow coma score (GCS), PaO₂/FiO₂ ratio (P/F ratio), and mean arterial pressure (MAP) within three days after admission were independent risk factors for mortality.

Conclusions

Candida albicans was the most frequently isolated fungal species. Most isolates were susceptible to the antifungal agents. The worst GCS score, P/F ratio, and MAP within three days after admission were independent risk factors for mortality due to candidemia in critically ill patients.

Candidemia due to Candida guilliermondii in an immuno-compromised infant: a case report and review of literature

Background and Purpose:

Candidemia is a life-threatening fungal infection with significant mortality and morbidity in neutropenic individuals, immunosuppressive chemotherapy recipients, and broad-spectrum antibiotics consumers. The epidemiology and antifungal susceptibility testing of non-albicans Candida species have been poorly studied. These species are characterized by low susceptibility to azoles and echinocandins. Herein, we report the first pediatric case of candidemia due to C. guilliermondii in Iran and review the literature on fungemia caused by C. guilliermondii.

Case report:

We presented the first candidemia case due to C. guilliermondii in a 4-month-old male infant with neuroblastoma in Iran. This study also involves a comprehensive literature review on fungemia caused by C.guilliermondii during a period of 18 years (i.e., 2000-2018) to discuss the epidemiology, clinical features, and treatment of this disease. The literature review resulted in the identification of 501 cases of candidemia caused by C. guilliermondii. Most of the patients were adults and had multiple risk factors. However, the main risk factors were significantly related to cancer chemotherapy, followed by central venous catheter use and Intensive Care Unit admission. Mortality rate due to this disease had a range of 3.4-66.6%, in this regard, the patients with cancer had the highest mortality rate.

Conclusion:

Given the high mortality of candidemia, the early diagnosis of this infection and timely initiation of antifungal therapy significantly improve the patients’ survival rate and result in better outcomes. Consequently, it is highly recommended to monitor the local epidemiology of this life-threatening infection and raise awareness in this regard.

Are we ready for the global emergence of multidrug-resistant Candida auris in Taiwan?

Candida auris is a recently identified multi-resistant Candida species, first reported in Japan in 2009, and poses a serious global health threat. Lack of awareness of this new Candida species and difficulties with laboratory identification have impacted significantly on outbreak detection and management, and compromised patient outcome. Accordingly, there is an urgent need to raise awareness of healthcare personnel to this emerging pathogen and determine its prevalence, impact, and challenges to the Taiwan healthcare system. Enhanced laboratory testing strategies are needed to differentiate C. auris from other Candida species to provide accurate diagnosis and implement control measures early enough to prevent hospital outbreaks. In this report, we review the key epidemiological, microbiological and clinical characteristics of C. auris and provide the results of a multicenter surveillance study of C. auris in Taiwan. We also conducted a web-based survey to determine awareness of the medical community to C. auris and the capability of Taiwanese hospital laboratories to identify this microorganism. C. auris has not yet been isolated from humans in Taiwan, but the unique features of this microorganism and its ability to reach across international boundaries justify the importance of these initiatives in Taiwan.