Isolation Frequency Characteristics of Candida Species from Clinical Specimens

Distribution Analysis of Candida albicans according to Sex and Age in Clinical Specimen Testing for Sexually Transmitted Diseases

The prevalence of candidiasis, a contagious disease with high morbidity and mortality, has sharply increased globally over the last two decades. Candida albicans can cause serious infections in patients with weak immunity and in recipients of prolonged antibiotic treatment. Consequently, rapid and accurate identification of species can play an important role in the treatment of candidiasis. Here, we investigated the positive rate and infection trend of Candida albicans according to age, specimen type, and sex using multiplex real-time polymerase chain reactionbased testing of samples collected for the diagnosis of sexually transmitted diseases in Korea between 2018 and 2020. When the type of specimen collected was a swab, the positive rate of Candida albicans was higher among younger women, and tended to decrease with age. Analysis of swab samples revealed higher positive rates than urinalysis. The reduction trend in positive rates by age was comparable between the overall samples and urine specimens. Among male patients, the positive rate did not differ substantially across the various types of specimens collected. Previous studies have shown a higher prevalence of non-albicans Candida species than Candida albicans in clinical specimens, and exclusion of the former from our analysis may be a limitation of this study. However, our findings contribute significantly to the literature because globally, there is a paucity of epidemiological studies using molecular techniques to detect Candida albicans in sexually transmitted disease test samples.

So Many Diagnostic Tests, So Little Time: Review and Preview of Candida auris Testing in Clinical and Public Health Laboratories

The recognition of a new yeast, Candida auris, in 2009 in East Asia, and its rapid global spread, was a reminder of the threats posed by multidrug-resistant fungal pathogens. C. auris had likely remained unrecognized for a long time as accurate tests were not available. The laboratory community responded to the C. auris challenge by publishing 35 new or revised diagnostic methods between 2014 and early 2021. The commercial sector also modified existing diagnostic devices. These C. auris diagnostic tests run the gamut from traditional culture-based differential and selective media, biochemical assimilations, and rapid protein profiles, as well as culture-independent DNA-based diagnostics. We provide an overview of these developments, especially the tests with validation data that were subsequently adopted for common use. We share a workflow developed in our laboratory to process over 37,000 C. auris surveillance samples and 5,000 C. auris isolates from the outbreak in the New York metropolitan area. Our preview covers new devices and diagnostic approaches on the horizon based on microfluidics, optics, and nanotechnology. Frontline laboratories need rapid, cheap, stable, and easy-to-implement tests to improve C. auris diagnosis, surveillance, patient isolation, admission screening, and environmental control. Among the urgent needs is a lateral flow assay or similar device for presumptive C. auris identification. All laboratories will benefit from devices that allow rapid antifungal susceptibility testing, including detection of mutations conferring drug resistance. Hopefully, multiplex test panels are on the horizon for synergy of C. auris testing with ongoing surveillance of other healthcare-associated infections. C. auris genome analysis has a proven role for outbreak investigations, and diagnostic laboratories need quick access to regional and national genome analysis networks.

In vitro anticandidal activity and gas chromatography-mass spectrometry (GC-MS) screening of Vitex agnus-castus leaf extracts

Background

Candida infections are becoming more drug resistant; it is necessary to search for alternative medications to treat them. Therefore, the present study estimates the anticandidal activity of Vitex agnus-castus (VA-C) leaf extracts.

Methods

We used the agar well diffusion method to assess the anticandidal activity of three different VA-C leaf extracts (ethanol, methanol, and water) against three Candida species (Candida tropicalis, Candida albicans, and Candida ciferrii). The minimum inhibitory concentration (MIC) was estimated using the two-fold dilution method and the minimum fungicidal concentration (MFC) was determined using the classic pour plate technique. The MFC/MIC ratio was calculated to estimate the microbicidal or microbiostatic activity. A gas chromatography mass spectrometer was used to screen the phytochemicals of the VA-C leaf extracts (ethanol, methanol, and water).

Results

All VA-C extracts ethanol, methanol, and water were significantly inhibited the growth of the test Candida species and the inhibition activity depended on the solvent used and the Candida species. The results showed that C. tropicalis was the most highly inhibited by all extracts followed by C. albicans and C. ciferrii. The MIC values were 12.5–25 µg/ml, and MFC values were 25–100 µg/ml. The ratios of MFC/MIC were two-fold to four-fold which was considered candidacidal activity. Ninety-five phytochemical compounds were identified by the GC-MS assay for the VA-C leaf extracts. The total number of compounds per extract differed. Methanol had 43 compounds, ethanol had 47 compounds, and water had 52 compounds. The highest compound concentrations were: 4,5-Dichloro-1,3-dioxolan-2-one in ethanol and methanol, 1H-Indene, 2,3-dihydro-1,1,2,3,3-pentamethyl in ethanol, Isobutyl 4-hydroxybenzoate in methanol, and Benzoic acid and 4-hydroxy- in water. These phytochemical compounds belong to different bioactive chemical group such as polyphenols, fatty acids, terpenes, terpenoids, steroids, aldehydes, alcohols, and esters, and most of which have anticandidal activity.

Conclusions

VA-C leaf extracts may be useful alternatives to anticandidal drugs, based on their effectiveness against all test Candida species at low concentrations. However, appropriate toxicology screening should be conducted before use.

Association between gastric Candida colonization and surgical site infections after high-level hepatobiliary pancreatic surgeries: the results of prospective observational study

AIM

High-level hepatobiliary pancreatic (HBP) surgeries are highly associated with surgical site infections (SSIs), in which microorganisms have a significant role. In the present study, we investigated whether gastric Candida colonization had a significant role in SSIs after high-level HBP surgeries.

METHODS

Between May 2016 and February 2017, the 66 patients who underwent high-level HBP surgeries were enrolled in the present study. The gastric juice was prospectively collected through nasogastric tube after general anesthesia induction and was incubated onto the CHROMagar Candida plate for the cultivation of various Candida species. First of all, we compared the incidence of SSIs according to the presence or absence of Candida species in gastric juice. Secondly, we evaluated the variables contributing to the development of SSIs by multivariate analysis. The protocol was approved by the medical ethics committee of Mie University Hospital (No.2987).

RESULTS

Gastric Candida colonization was identified in 21 patients (group GC) and was not identified in the other 45 patients (group NGC). There were no differences in preoperative variables including compromised status, such as age, nutritional markers, complications of diabetes mellitus, and types of primary disease between the two groups. SSIs occurred in 57.1% (12/21) of group GC and in 17.8% (8/45) of group NGC, showing a significant difference (p = 0.001). Multivariate analysis revealed gastric Candida colonization as a significant risk factor of SSIs (OR 6.17, p = 0.002).

CONCLUSION

Gastric Candida colonization, which is not a result of immunocompromised status, is highly associated with SSIs after high-level HBP surgeries.

TRIAL REGISTRATION

Japan Primary Registries Network; UMIN-CTR ID: UMIN000040486 (retrospectively registered on 22nd May, 2020).

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.

Prevalence of Candida bloodstream isolates from patients in two hospitals in Vietnam

BACKGROUND AND OBJECTIVES

Identification of yeasts provides helpful information for appropriate administration of anti-fungal treatments; however, few reports from the Vietnam have been published. This study has been performed to find the prevalence of Candida blood stream isolates from patients in two hospitals in Vietnam.

MATERIALS AND METHODS

Candida spp. were isolated from blood cultures in two hospitals, Vietnam between May 2013 and May 2015. Participating hospitals were 103 Military Hospital, Ha Noi city (550 beds) and Cho Ray Hospital, Ho Chi Minh city (1800 beds). All the bloodstream isolates were identified to species level by the germ tube test and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In addition, unknown isolates were subjected to PCR sequencing.

RESULTS

A total of 93 Candida isolates were isolated from blood cultures during the study period. The results of this study showed that C. tropicalis (n = 47, 50.54%) was the most common agent, followed by Candida albicans/dubliniensis (n = 18, 19.35%), C. parapsilosis (n = 16, 17.20%), C. glabrata (n = 6, 6.45%), C. mesorugosa (n = 5, 5.38%) and C. krusei (n = 1, 1.08%), respectively.

CONCLUSION

The frequency of the non-albicans Candida species in blood is increasing, especially C. tropicalis. Additional investigations should be made to clarify the epidemiological profile of invasive Candida bloodstream in Vietnam.

A performance evaluation of an immuno-latex chromatography card for the rapid detection of Candida spp

This report evaluates the performance and species specificity of an immuno-latex chromatography card (ICC) for rapid detection of Candida spp. Double-manipulator single-blind Gram staining smear examination (GSSE) and ICC were used to analyze 354 vaginal discharge specimens (VDS) (including 98 tested as positive by GSSE) from women with suspected candidal vaginitis, simulated specimens with a concentration gradient, and vaginitis causing organism suspensions (0.9% NaCl) of 22 species from nine genera. Limit of detection, semi-quantitative detection performance, total detection performance and species specificity were determined for ICC, and the results were compared with those of the GSSE method. The limits of detection of ICC for Candida spp. in organism suspensions with 0.9% NaCl and simulated specimens were 7 × 10⁶ cells/L and 7 × 10⁸ cells/L respectively. For species specificity, the results were positive for six Candida spp. (C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei and C. guilliermondii) and negative for the remaining 16 species (C. lusitaniae, Saccharomyces cerevisiae; three Gram-positive coccus species, four Gram-negative bacillus species, three Gram-negative coccus species and four common microbes causing vaginal infection) from eight genera. The overall sensitivity, specificity, accuracy, positive predictive value and negative predictive value of ICC for VDS were 93.81%, 99.10%, 97.31, 98.14% and 96.90%, respectively. The above indicators in the 98 VDS evaluated as positive were 84.39%, 92.86%, 86.74%, 96.72% and 70.27%, respectively. In summary, ICC offered better specificity, sensitivity, positive predictive value and negative predictive value for the detection of Candida spp. in VDS.