Invasive Candidiasis in Brescia, Italy: Analysis of Species Distribution and Antifungal Susceptibilities During Seven Years

Genotyping of oral Candida albicans and Candida tropicalis strains in patients with orofacial clefts undergoing surgical rehabilitation by MALDI-TOF MS: Case-series study

Patients with orofacial clefts are more likely to develop oral fungal diseases due to anatomo-physiological changes and surgical rehabilitation treatment. This case-series study evaluated the genetic diversity and dynamics of oral colonization and spread of C. albicans and C. tropicalis in four patients with orofacial clefts, from the time of hospital admission, perioperative and outpatient follow-up, with specialized physician. Candida biotypes previously identified by CHROMagar Candida and PCR methods were studied by MALDI-TOF MS assays and clustering analyses. Possible correlations with pathogenicity characteristics were observed, including production of hydrolytic exoenzymes and the antifungal sensitivity profiles. Amphotericin B-sensitive and fluconazole-resistant (low frequency) C. tropicalis and C. albicans, including clinically compatible MIC of nystatin, were found in the oral cavity of these patients. Clusters of isolates revealed phenomena of (i) elimination in the operative phase, (ii) maintenance or (iii) acquisition of oral C. tropicalis in the perioperative period and specialized outpatient and medical follow-up. For C. albicans, these phenomena included (i) elimination in the operative phase, (ii) acquisition in the operative phase and propagation from the hospital environment, and (iii) maintenance during hospitalization and operative phase. Amphotericin B and nystatin were shown to be effective in cases of clinical treatment and/or prophylaxis, especially considering the pre-existence of fluconazole-resistant strains. This study confirmed the phenomena of septic maintenance, septic neocolonization and septic elimination involving the opportunistic pathogens. MALDI-TOF MS associated with clustering analysis may assist the monitoring of clinical isolates or groups of epidemiologically important microbial strains in the hospital setting.

Role of lizards as reservoirs of pathogenic yeasts of zoonotic concern

Reptiles have become popular exotic pets and in some parts of the world, they are used as important source of food, medicines, and materials. Synanthropic lizards are recognized as reservoirs of viruses, bacteria, and parasites but their role in dissemination of zoonotic pathogenic yeasts in the environment was never investigated. Therefore, fecal samples (n=177) from Podarcis siculus (Italian wall lizard), Chalcides ocellatus (Ocellated skink) and Tarentola mauritanica (Moorish gecko) were collected and yeasts were isolated and identified biochemically and molecularly by sequencing the rDNA internal transcribed spacer region (ITS). The phylogenetical relationship of isolated yeast species and their antifungal susceptibility profiles to ten antifungal agents were also assessed. Sixty samples (n=60/177; 33.9%) scored positive for yeasts, with the highest occurrence in C. ocellatus (n=11/17; 64.7%) and the highest variety of species in P. siculus (n=11/12; 91.6%). A total of 364 isolates belonging to Candida, Trichosporon, Saccharomyces and Geotrichum genera were molecularly identified. In particular, Candida albicans (n=160; 44%) followed by Trichosporon coremiiforme (n=44; 12.1%), Pichia kudriavzevii (n=32; 8.8%) and Trichosporon asahii (n=28; 7.7%) were the most frequently isolated species. The phylogenetic tree grouped all representative sequence types within the clade including Candida spp. strains from different geographical areas and from animal species, including human. All tested strains showed high susceptibility to the assayed antifungal drugs. This study suggests the role of lizards as reservoirs and spreaders of zoonotic pathogenic yeasts in the environment. The absence of resistance phenomena in the isolated yeasts might reflect an environment free of azole antifungal pollution or chemicals, suggesting the usefulness of these animals as bio indicators of environment quality.

Molecular Identification and Antifungal Susceptibility Patterns of Candida Species Isolated from Candidemia Patients in Yasuj, Southwestern Iran

Background: Candidemia is the most common systemic infection in hospitalized patients causing high mortality. Hence, the diagnosis of this infection in the early stage with appropriate antifungal therapy is paramount. Objectives: The study aimed at molecular identification of Candida species isolated from candidemia patients and evaluation of the in vitro antifungal susceptibility patterns of these strains to fluconazole, amphotericin B, and caspofungin. Methods: In the present study, 800 hospitalized patients who were suspected to have candidemia were sampled. Candida species were isolated and identified based on morphological characteristics and PCR-sequencing of the ITS1-5.8S-ITS2 region. Antifungal susceptibility tests for fluconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute protocol M27-A3. Also, clinical data were recorded from the patients' records. Results: Twenty-seven patients among the sample of hospitalized patients were found to have candidemia. A total of 33.3% of candidemia patients were treated with amphotericin B, in which case the mortality rate was 14.8%. The majority of patients (59%) were from the neonatal intensive care unit, and premature birth was the most common underlying condition. Candida albicans (n = 18; 66.6%) was the most common species isolated from blood cultures, followed by C. parapsilosis (n = 7; 25.9%), C. pelliculosa (n = 1; 3.7%), and C. tropicalis (n = 1; 3.7%). Only one C. albicans isolate resistant to fluconazole (minimum inhibitory concentration = 32 µg/mL). Conclusions: Generally, C. albicans has been the most frequent causative agent of candidemia. Resistance to antifungal drugs among candidemia agents was rare. Also, the identification of Candida isolates at the species level with in vitro antifungal susceptibility tests helps manage candidemia patients better and decrease the mortality rate among them.

Molecular epidemiology, antifungal susceptibility and virulence factors of Candida glabrata complex strains in Kayseri/Turkey

BACKGROUND

Candida nivariensis and Candida bracarensis are included in Candida glabrata complex, which are usually misidentified as C. glabrata based on phenotypic identification methods. It was aimed to identify C. glabrata complex isolated from various clinical samples in Kayseri/Turkey to the species level and to determine antifungal susceptibilities, virulence factors, and molecular epidemiology.

METHODS

Eighty three C. glabrata complex strains were studied in this study. Strains were phenotypically and molecularly identified. Phylogenetic analysis was done by the neighbor-joining method. Proteinase, phospholipase, esterase enzyme activity, and biofilm formation of strains were determined phenotypically. Antifungal susceptibility of strains were determined according to M60-Ed2 recommendations.

RESULTS

All the 83 strains identified as C. glabrata complex by phenotypic tests were confirmed as C. glabrata sensu stricto (C. glabrata) by PCR amplification and sequence analysis, but other complex members C. nivariensis and C. bracarensis were not detected. Phylogenetic analysis results revealed 19 different genotypes. No clonal relationship was detected among the strains. Biofilm formation in 75.9% of strains and esterase activity in 7.2% were found positive. Antifungal resistance rates of strains were determined as 9.2% for fluconazole and 45.8% for itraconazole; 43.4% of the strains for voriconazole were determined as non-wild type.

CONCLUSION

It was determined that biofilm and esterase activity might play an active role in the virulence of C. glabrata. In addition, high resistance rates to azoles in C. glabrata strains isolated in our hospital at Kayseri/Turkey emphasized the significance of epidemiological studies.

[Laparostoma-Avoidance and treatment of complications]

The open abdomen (OA) is an established concept for treating severe abdominal diseases. The most frequent reasons for placement of an open abdomen are abdominal sepsis (e.g. from intestinal perforation or anastomotic leakage), severe abdominal organ injury and abdominal compartment syndrome. The pathophysiology is much more complex than the surgeon's eye can see in an OA. The temporary closure of the abdominal wall ensures sufficient drainage of infected ascites, protection of the intestinal loops and conditioning of the abdominal wall in order to be able carry out definitive closure of the abdominal wall at the end of the surgical treatment. Negative peritoneal pressure therapy combined with fascia traction (with or without mesh) is well-established in the management of an open abdomen.

Accuracy of matrix-assisted LASER desorption ionization-time of flight mass spectrometry for identification of Candida

Background: Candida is a fungus that causes various types of candidemia, which is the fourth major infectious disease of the blood system. MALDI-TOF-MS is a simple and rapid detection instrument. The aim of the present study was to verify the accuracy of MALDI-TOF-MS in detecting Candida.

Method: A pooled analysis of articles on MALDI-TOF-MS for diagnosis of candidemia was performed. The quality of original research was assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) guidelines. Stata 12.0 software was used to merge the correct identification rates of Candida and Candida subspecies and obtain pooled sensitivity and specificity of the diagnostic methods. Heterogeneity was found in the subgroup analysis of the included articles. Hence, we explored the factors causing the heterogeneity and its impact on the overall situation. Sensitivity analysis was used to examine the effect of Candida level on total response. Egger’s test was used to evaluate the publication bias of the included articles.

Results: A total of 16 articles in Pubmed, 79 articles in Embase, 1 article in Cochrane Library, 30 articles in Web of Science and 3 from other sources were identified, of which 10 articles were included based on the inclusion and exclusion criteria. The overall identification accuracy was 100%.

Conclusion: The accuracy of MALDI-TOF-MS for the identification of Candida was 100%. Further research is necessary to determine whether MALDI-TOF-MS can be used as a clinical diagnostic standard for the identification of Candida.

Candidemia in solid organ transplant recipients in Spain: Epidemiological trends and determinants of outcome

BACKGROUND

Despite being considered a high-risk population for invasive fungal disease, specific features of candidemia among solid organ transplant (SOT) recipients remain poorly characterized.

METHODS

We compiled prospective data from two multicenter studies on candidemia performed over two consecutive periods in Spain: the CANDIPOP Study (2010-2011) and the CANDI-Bundle Study (2016-2018). Episodes diagnosed in adult SOT recipients in 10 participating centers were included. Risk factors for clinical failure (all-cause 7-day mortality and/or persistent candidemia for ≥72 hours) and 30-day mortality were investigated by univariate analysis.

RESULTS

We included 55 episodes of post-transplant candidemia (32 and 23 of which occurred during the first and second periods). Kidney (38.2%) and liver recipients (30.9%) were the most common populations. Candida albicans accounted for 27.3% of episodes. The proportion of C glabrata increased over time (18.8% vs 30.4% for the first and second periods). There were no differences in the rate of fluconazole non-susceptible isolates (50.0% vs 60.0%, respectively). Clinical failure and 30-day mortality occurred in 25.5% and 27.3% of episodes and were associated with the severity of candidemia (Pitt score and severe sepsis/septic shock). Kidney transplantation (unadjusted odds ratio [uOR]: 0.17; 95% confidence interval [CI]: 0.03-0.85; P-value = .020), early catheter removal (uOR: 0.15; 95% CI: 0.03-0.76; P-value = .013), and appropriate early antifungal therapy (uOR: 0.14; 95% CI: 0.02-0.89; P-value = .041) were protective for 30-day mortality.

CONCLUSIONS

High rates of non-albicans species and fluconazole non-susceptibility must be taken into account to optimize therapeutic management and outcomes in SOT recipients with candidemia.

Adherence and Cytotoxicity of Candida spp. to HaCaT and A549 cells

Candida species are opportunistic fungal pathogens that cause superficial or invasive infections. Recently, the incidence of infection by non-Candida albicans species, especially Candida glabrata, has increased. In this study, we analyzed the adhesion and cytotoxicity of various Candida spp. that are part of the normal human microbiota. C. albicans adheres well to cell culture plates and to cultured cells. C. glabrata selectively adheres to epithelial cells rather than to cell culture plates. Candida parapsilosis insufficiently adheres to confluent monolayers of human lung epithelial A549 and keratinocyte HaCaT cells. We then analyzed the cytotoxicity of C. albicans and C. glabrata, which adhered well to epithelial cells. C. glabrata has been found to cause more damage to A549 cells than to HaCaT cells, suggesting that resident Candida spp. have distinct cytotoxic effects in different tissues. It is important to clarify the properties of Candida spp. as there is evidence that normal microbiota can cause infections. Our data suggest that it is necessary to use appropriate cell lines for characterizing the adherence and cytotoxicity of Candida spp.

Changing Epidemiology of Invasive Candidiasis in Children during a 10-Year Period

Candida species are a common cause of invasive infection in neonates and children. The aim of our study was to evaluate the epidemiology and microbiology of invasive candidiasis (IC) in the largest tertiary Greek pediatric hospital during a 10-year period. A retrospective cohort study was performed from January 2008 to December 2017. Identification of species and antifungal susceptibility testing was performed according to the Clinical and Laboratory Standards Institute (CLSI) methodology. During the study period, 178 cases of IC were recorded. The tissue distribution included blood (87.1%), cerebrospinal (7.9%), peritoneal (3.9%) and pleural fluids (1.1%). Candida albicans and Candida parapsilosis (sensu lato) were the most frequently isolated species (47.8% and 28.7% respectively). From period 2008⁻2012 to period 2013⁻2017, a significant decrease in IC rates was detected (0.21 cases/1000 hospitalization days VS 0.11 cases/1000 hospitalization days, P = 0.040), while median minimum inhibitory concentrations (MICs) of amphotericin B were significantly increased for both C. albicans and C. parapsilosis (sl) (P = 0.037 and P = 0.004 respectively). The decrease in IC rates may reflect the increased awareness as well as the effective infection control initiatives and antifungal interventions. However, the significant increase in the MICs for amphotericin B and echinocandins such as caspofungin, raises concerns about their common use as first-line treatment. Epidemiologic monitoring is, therefore, critically important in order to evaluate and optimize therapeutic protocols for IC in pediatric populations.

Invasive Fungal Infection in Romania: Changing Incidence and Epidemiology During Six Years of Surveillance in a Tertiary Hospital

The present study aimed to evaluate the incidence of candidemia, the trend of species distribution and the antifungal susceptibility patterns of all invasive strains of Candida spp. isolated over a 6-year period in an Eastern European University hospital. A total number of 156 isolates were reidentified by MALDI-TOF and tested for susceptibility by Sensititre^TM YeastOne™. Isolates were assigned as non-susceptible or belonging to the wild type according to the new CLSI (2017, 2018) break points and epidemiological cut-off values. C. parapsilosis (37.82%) was the most frequently isolated yeast, followed by C. albicans (26.28%). The general tendency of the species distribution during the surveyed period shifted towards an increase in C. parapsilosis and C. lusitaniae isolates. Fluconazole resistance was present in 23.52% of C. glabrata, 5.08% of C. parapsilosis and in none of the C. albicans, C. tropicalis and C. lusitaniae isolates. Echinocandin resistance was present only in 1(5.88%) C. glabrata isolate. The study emphasises the importance of monitoring local epidemiologic data and antifungal susceptibility trends due to the diversity of affected patient groups in our hospital.

Evaluation of candidemia and antifungal consumption in a large tertiary care Italian hospital over a 12-year period

PURPOSE

An early adequate antifungal therapy based on the knowledge of local epidemiology can reduce the candidemia-attributable mortality and the length of hospitalization. We performed a retrospective study to analyze the epidemiology of candidemia and the antifungal consumption in our hospital.

METHODS

We analyzed Candida spp. isolated from the blood, and their susceptibility profile from 2005 to 2016 in Careggi University Hospital, Florence, Italy. We also performed a stratified analysis by clinical setting where Candida spp. were isolated (Medical Wards, Surgery, Intensive Care Unit-ICU). Then, we retrospectively reviewed the annual consumption of antifungal agents and calculated the defined daily dosing for 10,000 hospital days.

RESULTS

The rate of candidemia was higher in ICU than other settings and Candida albicans was the first cause of candidemia (61.2%). After adjustment for hospital days, the rate of C. albicans showed a statistically significant parabolic trend (p < 0.001), with a peak of incidence in 2010. After 2010, we observed a reduction of candidemia due to both C. albicans and non-albicans species. Between 2005 and 2015, we reported an increasing increased use of echinocandins. As far as resistance profile is concerned, only one Candida glabrata isolate was resistant to caspofungin (1.9%) and 30% of C. glabrata were resistant to fluconazole.

CONCLUSIONS

Our data describe C. albicans as the first cause of candidemia in all the studied settings and the low rate of echinocandin resistance, despite their increased use over the study period. ICU was confirmed as the setting with the highest incidence of candidemia.

Multilocus Sequence Typing Reveals a New Cluster of Closely Related Candida tropicalis Genotypes in Italian Patients With Neurological Disorders

Candida tropicalis is a pathogenic yeast that has emerged as an important cause of candidemia especially in elderly patients with hematological malignancies. Infections caused by this species are mainly reported from Latin America and Asian-Pacific countries although recent epidemiological data revealed that C. tropicalis accounts for 6-16.4% of the Candida bloodstream infections (BSIs) in Italy by representing a relevant issue especially for patients receiving long-term hospital care. The aim of this study was to describe the genetic diversity of C. tropicalis isolates contaminating the hands of healthcare workers (HCWs) and hospital environments and/or associated with BSIs occurring in patients with different neurological disorders and without hematological disease. A total of 28 C. tropicalis isolates were genotyped using multilocus sequence typing analysis of six housekeeping (ICL1, MDR1, SAPT2, SAPT4, XYR1, and ZWF1) genes and data revealed the presence of only eight diploid sequence types (DSTs) of which 6 (75%) were completely new. Four eBURST clonal complexes (CC2, CC10, CC11, and CC33) contained all DSTs found in this study and the CC33 resulted in an exclusive, well-defined, clonal cluster from Italy. In conclusion, C. tropicalis could represent an important cause of BSIs in long-term hospitalized patients with no underlying hematological disease. The findings of this study also suggest a potential horizontal transmission of a specific C. tropicalis clone through hands of HCWs and expand our understanding of the molecular epidemiology of this pathogen whose population structure is still far from being fully elucidated as its complexity increases as different categories of patients and geographic areas are examined.