Evaluation of Microsatellite Typing, ITS Sequencing, AFLP Fingerprinting, MALDI-TOF MS, and Fourier-Transform Infrared Spectroscopy Analysis of<i> Candida auris</i>

Candida auris is an emerging opportunistic yeast species causing nosocomial outbreaks at a global scale. A few studies have focused on the C. auris genotypic structure. Here, we compared five epidemiological typing tools using a set of 96 C. auris isolates from 14 geographical areas. Isolates were analyzed by microsatellite typing, ITS sequencing, amplified fragment length polymorphism (AFLP) fingerprint analysis, matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), and Fourier-transform infrared (FTIR) spectroscopy methods. Microsatellite typing grouped the isolates into four main clusters, corresponding to the four known clades in concordance with whole genome sequencing studies. The other investigated typing tools showed poor performance compared with microsatellite typing. A comparison between the five methods showed the highest agreement between microsatellite typing and ITS sequencing with 45% similarity, followed by microsatellite typing and the FTIR method with 33% similarity. The lowest agreement was observed between FTIR spectroscopy, MALDI-TOF MS, and ITS sequencing. This study indicates that microsatellite typing is the tool of choice for C. auris outbreak investigations. Additionally, FTIR spectroscopy requires further optimization and evaluation before it can be used as an epidemiological typing method, comparable with microsatellite typing, as a rapid method for tracing nosocomial fungal outbreaks

Recent trends in molecular diagnostics of yeast infections : from PCR to NGS

The incidence of opportunistic yeast infections in humans has been increasing over recent years. These infections are difficult to treat and diagnose, in part due to the large number and broad diversity of species that can underlie the infection. In addition, resistance to one or several antifungal drugs in infecting strains is increasingly being reported, severely limiting therapeutic options and showcasing the need for rapid detection of the infecting agent and its drug susceptibility profile. Current methods for species and resistance identification lack satisfactory sensitivity and specificity, and often require prior culturing of the infecting agent, which delays diagnosis. Recently developed high-throughput technologies such as next generation sequencing or proteomics are opening completely new avenues for more sensitive, accurate and fast diagnosis of yeast pathogens. These approaches are the focus of intensive research, but translation into the clinics requires overcoming important challenges. In this review, we provide an overview of existing and recently emerged approaches that can be used in the identification of yeast pathogens and their drug resistance profiles. Throughout the text we highlight the advantages and disadvantages of each methodology and discuss the most promising developments in their path from bench to bedside

Safety, Immunogenicity, and Protective Efficacy of Intradermal Immunization with Aseptic, Purified, Cryopreserved Plasmodium falciparum Sporozoites in Volunteers Under Chloroquine Prophylaxis

Immunization of volunteers under chloroquine prophylaxis by bites of *Plasmodium falciparum* sporozoite (PfSPZ)–infected mosquitoes induces > 90% protection against controlled human malaria infection (CHMI). We studied intradermal immunization with cryopreserved, infectious PfSPZ in volunteers taking chloroquine (PfSPZ chemoprophylaxis vaccine [CVac]). Vaccine groups 1 and 3 received 3x monthly immunizations with 7.5 x 10^4 PfSPZ. Control groups 2 and 4 received normal saline. Groups 1 and 2 underwent CHMI (#1) by mosquito bite 60 days after the third immunization. Groups 3 and 4 were boosted 168 days after the third immunization and underwent CHMI (#2) 137 days later. Vaccinees (11/20, 55%) and controls (6/10, 60%) had the same percentage of mild to moderate solicited adverse events. After CHMI #1, 8/10 vaccinees (group 1) and 5/5 controls (group 2) became parasitemic by microscopy; the two negatives were positive by quantitative real-time polymerase chain reaction (qPCR). After CHMI #2, all vaccinees in group 3 and controls in group 4 were parasitemic by qPCR. Vaccinees showed weak antibody and no detectable cellular immune responses. Intradermal immunization with up to 3 x 10^5 PfSPZ-CVac was safe, but induced only minimal immune responses and no sterile protection against Pf CHMI. INTRODUCTIO

New methods for the rapid identification and antifungal susceptibility testing of clinically important Candida species

This Ph.D. project focused on the optimization of a new method for the rapid detection of Candida species that are resistant to antifungals aiming at future use in routine clinical laboratories. The present study provides the first comprehensive assessment of MALDI-TOF MS for AFST against echinocandins. MALDI Biotyper antibiotic susceptibility test rapid assay (MBT ASTRA), a semi-quantitative method based on MALDI TOF MS, was optimized to detect C. albicans, C. glabrata, and C. auris resistant to echinocandins within 7h. This method is potential to be automated and it will be introduced to routine clinical laboratories after further optimization and automization. Accordingly, MBT ASTRA has the potential to get used for testing a broad range of microorganisms against different antibiotics and antifungals. Furthermore, if a MALDI-TOF MS is available in the lab, the price to apply MBT ASTRA per sample is affordable. In addition, a comparative study has been performed on different typing methods for C. auris, and possibilities have been explored for the use of a lactoferine peptide (hLF1-11) for the enrichment and identification of C. albicans. The findings of this study showed that MALDI-TOF MS is not only an accurate and outstanding method for the identification of microbes, but its application in AFST has also been approved. Therefore, it may open a new window for a broader application of the MALDI-TOF MS technique to be used in research and clinical laboratories in the future

Prevalence of Trichomonas vaginalis Using Parasitological Methods in Tehran

"nBackground: Trichomonas vaginalis is a parasitic protozoan with a predilection for human urogenital tract and causative agent for vaginitis, cervicitis and urethritis in females. T. vaginalis is known as a cofactor in transmission of human immunodeficiency virus and may lead to adverse outcomes in pregnant women. The goal of this study was to determine the prevalence of T. vaginalis infection in females attending Mirzakuchak Khan Hospital, Tehran, Iran. "nMethods: During May 2008 to March 2009, 500 vaginal discharges samples were obtained from women attending sexual transmitted disease (STD) clinic of Mirzakuchak Khan Hospital in Tehran, Iran. The samples were examined by Dorsse culture medium and wet-mount meth­ods. The prevalence of T. vaginalis was determined using culture based method and wet-mount examinations. "nResults: Sixteen positive (3.2%) and 484 negative (96.8%) samples for T. vaginalis were de­tected by culture based methods. The wet mount examination revealed 13 positive (2.6%) and 487 negative (97.4%) samples. In the above population, prevalence of trichomoniasis was es­timated as 3.2% based on culturing method. "nConclusion: Due to adverse outcomes of vaginal trichomoniasis and its correlation with HIV transmission, there is a great need for public education regarding implementation of personal hygienic measures and prevention of inappropriate sexual contacts