PCR-RFLP detection and species identification of fungal pathogens in patients with febrile neutropenia

Rapid sourdough yeast identification using panfungal PCR combined with high resolution melting analysis

The microbial composition of the sourdough starter affects the sourdough bread properties. Therefore, it is crucial to find a tool for rapid, time-saving, and economical identification of the sourdough microbiota. We focused on the rapid identification of sourdough yeasts. We designed a panfungal real time-PCR targeting the ITS2 region (ITS-amplicon) and a fragment of D1/D2 region of 26S rRNA gene (U-amplicon) and used high resolution melting analysis (HRM) for subsequent species identification. The sensitivity and specificity of our method were tested on the reference yeast cultures. We obtained divergent melting peaks (Tm). The further analysis of melt curves suggests the possibility to discriminate yeasts on the genus- and some on species-specific level in the mixed sample. The applicability of this method in routine practice was evaluated on nine sourdough samples. Revealed melt curves of U-amplicons were predominantly characteristic of the sourdough. The evaluation of the Tm and the shape of the melt curve was used to assess the sourdough yeasts. Additionally, using the HRM-PCR method the contamination with the ergot fungus DNA was revealed. Our data showed HRM-PCR is a simple, rapid, and inexpensive tool useful in identifying sourdough yeasts.

Long-Reads-Based Metagenomics in Clinical Diagnosis With a Special Focus on Fungal Infections

Identification of the causative infectious agent is essential in the management of infectious diseases, with the ideal diagnostic method being rapid, accurate, and informative, while remaining cost-effective. Traditional diagnostic techniques rely on culturing and cell propagation to isolate and identify the causative pathogen. These techniques are limited by the ability and the time required to grow or propagate an agent in vitro and the facts that identification based on morphological traits are non-specific, insensitive, and reliant on technical expertise. The evolution of next-generation sequencing has revolutionized genomic studies to generate more data at a cheaper cost. These are divided into short- and long-read sequencing technologies, depending on the length of reads generated during sequencing runs. Long-read sequencing also called third-generation sequencing emerged commercially through the instruments released by Pacific Biosciences and Oxford Nanopore Technologies, although relying on different sequencing chemistries, with the first one being more accurate both platforms can generate ultra-long sequence reads. Long-read sequencing is capable of entirely spanning previously established genomic identification regions or potentially small whole genomes, drastically improving the accuracy of the identification of pathogens directly from clinical samples. Long-read sequencing may also provide additional important clinical information, such as antimicrobial resistance profiles and epidemiological data from a single sequencing run. While initial applications of long-read sequencing in clinical diagnosis showed that it could be a promising diagnostic technique, it also has highlighted the need for further optimization. In this review, we show the potential long-read sequencing has in clinical diagnosis of fungal infections and discuss the pros and cons of its implementation.

Molecular analysis of edible bird's nest and rapid authentication of Aerodramus fuciphagus from its subspecies by PCR-RFLP based on the cytb gene

Edible bird's nest (EBN), for its great nutritional value, is widely used around the world, especially in China and Singapore. EBNs of different origins and types may vary in price and quality. Nowadays, birds' nests are difficult to identify morphologically, except for some whole bird's nests of which origins can be roughly identified. In this study, forty-two samples were collected from different regions for sequencing analysis and phylogenetic classification to initially determine their origins. Two stable enzyme digestion sites were found in the analysis of restriction maps of the species. Then, a quick and specific PCR-RFLP method was established to identify the EBN samples' origins. The genetic identification results indicated that the forty-two samples were from five origins. With the Af/g-486bp-F/R primer and restriction enzyme Taq I, Aerodramus fuciphagus (A. fuciphagus) was efficiently differentiated from the other species. Furthermore, the cytb-592bp-F/R primer and the BamH I enzyme were found to be useful in distinguishing Aerodramus fuciphagus (A. fuciphagus) from its subspecies (Aerodramus germani, A. germani). The PCR-RFLP method provides a potential tool for the rapid discrimination of A. fuciphagus at the species and even the subspecies levels to ensure the quality of the EBN products.

Rapid identification of the Candida glabrata species complex by high-resolution melting curve analysis

Background

Candida glabrata is a common pathogen that causes invasive candidiasis. Among non‐albicans Candida infections, C glabrata infections are associated with the highest fatality rates. Candida glabrata sensu stricto, Candida nivariensis, and Candida bracarensis have been identified and together form the C glabrata species complex. It is difficult to detect the two rare species by traditional laboratory methods. This study established a method for the rapid identification of members of the C glabrata species complex based on high‐resolution melting curve (HRM) analysis and evaluated its practical application.

Methods

The internal transcribed spacer (ITS) region was used as target gene region to design specific primers. HRM analysis was performed with three subspecies of the C glabrata species complex and negative controls to test its specificity and sensitivity. To evaluate its practical application, the HRM technique was tested with clinical isolates, and the results were compared with the DNA sequencing results.

Results

Differences were detected among the melting profiles of the members of the C glabrata species complex. The negative controls were not amplified, indicating the high specificity of the method. The minimum detection limits of C glabrata sensu stricto, C nivariensis, and C bracarensis were approximately 1 × 10¹ copies/µL or less. The results of the HRM analysis of the clinical isolates were consistent with the DNA sequencing results.

Conclusions

The HRM method is sensitive and can be used to rapidly identify the members of the C glabrata species complex. The method can allow early and targeted treatment of patients with invasive candidiasis.

Diagnosis of invasive fungal disease in children: a narrative review

Introduction: Invasive fungal diseases (IFD) represent important causes of morbidity and mortality in pediatrics. Early diagnosis and treatment of IFD is associated with better outcome and this entails the need to use fast and highly sensitive and specific methods that can support clinicians in the management of IFD.Areas covered: A narrative review was performed on conventional diagnostic methods such as culture, microscopy and histopathology are still gold standard but are burdened by a lack of sensitivity and specificity; on the other hand, imaging and noninvasive antigen-based such as beta-D-glucan, galactomannan and molecular biomarkers are the most convenient nonculture methods for diagnosis and monitoring effects of therapy. Aim of the present review is to summarize what is available in these fields at end of the second decade of the third millennium and look for future perspectives.Expert opinion: Promising and useful diagnostic methods have been applied in infectious disease diagnosis in clinical practice or in designing platforms. Unfortunately, most of them are not standardized or validated in pediatric population. However, clinicians should be aware of all innovative diagnostic tools to use in combination with conventional diagnostic methods for a better management of pathology and patient.

Aspergillus diversity in the environments of nosocomial infection cases at a university hospital

Aspergillus species (sp.) that causes opportunistic infections have been increasingly found in human mainly immunosuppressive patients around the world every year. The main objective was to use a rapid and cheap molecular method for monitoring Aspergillus infections and epidemiological approaches. In order to identity Aspergilli species (spp.), a number of molecular methods including restriction fragment length polymorphism (RFLP) have been employed in accordance with ribosomal RNA amplification. The focus of this study — a group of hospitalized patients with clinical and subclinical signs of infection. All of the collected clinical specimens were transported to the medical mycology lab and examined for Aspergillus identification. The environmental specimens were collected from air and surfaces inspected for the Aspergillus within the hospital sources. At first, growth characteristics and microscopic features on mycological media for the identification of Aspergillus sp. were performed. For the confirmation of Aspergillus isolates which similarly found in clinical and environmental sources, molecular method polymerase chain reaction/restriction fragment length polymorphism was carried out. From the mentioned specimens, 102 fungal isolates included Candida spp., Aspergillus spp. and other fungi. Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.5%) all were found as the most common clinical isolates. In addition, Aspergillus isolates from environmental were Aspergillus niger (43.7%), Aspergillus flavus (41.7%), Aspergillus fumigatus (14.6%). Therefore, polymerase chain reaction-restriction fragment length polymorphism with a single restriction enzyme can be very useful in the identification of Aspergillus spp., because of its facility in use, speed, robust, and high sensitivity of diagnosis.

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.

Detection and identification of fungi in bronchoalveolar lavage fluid from immunocompromised patients using panfungal PCR

Rapid diagnostics of fungal pneumonia and initiation of appropriate therapy are still challenging. In this study, we used two panfungal assays to test bronchoalveolar lavage fluid (BALF) samples to prove their ability to confirm invasive fungal disease diagnosis and identify causative agents. Two methods targeting different fungal rDNA regions were used, and the obtained PCR products were sequenced directly or after cloning. In total, 106 BALF samples from 104 patients were tested. After sequencing, we obtained 578 sequences. Four hundred thirty-seven sequences were excluded from further analysis due to duplication (n = 335) or similarity with sequences detected in the extraction control sample (n = 102); 141 unique sequences were analyzed. Altogether, 23/141 (16%) of the fungi detected belonged to pathogenic species, and 63/141 (45%) were identified as various yeasts; a variety of environmental or very rare fungal human pathogens represented 29/141 (21%) of the total and 26/141 (18%) were described as uncultured fungus. Panfungal PCR detected fungal species that would be missed by specific methods in only one case (probable cryptococcosis). Panfungal PCR followed by sequencing has limited use for testing BALF samples due to frequent commensal or environmental fungal species pickup.

Database establishment for the secondary fungal DNA barcode translational elongation factor 1α (TEF1α) 1

With new or emerging fungal infections, human and animal fungal pathogens are a growing threat worldwide. Current diagnostic tools are slow, non-specific at the species and subspecies levels, and require specific morphological expertise to accurately identify pathogens from pure cultures. DNA barcodes are easily amplified, universal, short species-specific DNA sequences, which enable rapid identification by comparison with a well-curated reference sequence collection. The primary fungal DNA barcode, ITS region, was introduced in 2012 and is now routinely used in diagnostic laboratories. However, the ITS region only accurately identifies around 75% of all medically relevant fungal species, which has prompted the development of a secondary barcode to increase the resolution power and suitability of DNA barcoding for fungal disease diagnostics. The translational elongation factor 1α (TEF1α) was selected in 2015 as a secondary fungal DNA barcode, but it has not been implemented into practice, due to the absence of a reference database. Here, we have established a quality-controlled reference database for the secondary barcode that together with the ISHAM-ITS database, forms the ISHAM barcode database, available online at http://its.mycologylab.org/ . We encourage the mycology community for active contributions.

Galactomannan, β-D-Glucan, and Polymerase Chain Reaction-Based Assays for the Diagnosis of Invasive Fungal Disease in Pediatric Cancer and Hematopoietic Stem Cell Transplantation: A Systematic Review and Meta-Analysis

We systematically reviewed and analyzed the available data for galactomannan (GM), β-D-glucan (BG), and polymerase chain reaction (PCR)-based assays to detect invasive fungal disease (IFD) in patients with pediatric cancer or undergoing hematopoietic stem cell transplantation when used as screening tools during immunosuppression or as diagnostic tests in patients presenting with symptoms such as fever during neutropenia (FN). Of 1532 studies screened, 25 studies reported on GM (n = 19), BG (n = 3), and PCR (n = 11). All fungal biomarkers demonstrated highly variable sensitivity, specificity, and positive predictive values, and these were generally poor in both clinical settings. GM negative predictive values were high, ranging from 85% to 100% for screening and 70% to 100% in the diagnostic setting, but failure to identify non-Aspergillus molds limits its usefulness. Future work could focus on the usefulness of combinations of fungal biomarkers in pediatric cancer and HSCT.

Development of Candida-Specific Real-Time PCR Assays for the Detection and Identification of Eight Medically Important Candida Species

Culture-based identification methods have been the gold standard for the diagnosis of fungal infection. Currently, molecular technologies such as real-time PCR assays with short turnaround time can provide desirable alternatives for the rapid detection of Candida microbes. However, most of the published PCR primer sets are not Candida specific and likely to amplify DNA from common environmental contaminants, such as Aspergillus microbes. In this study, we designed pan-Candida primer sets based on the ribosomal DNA-coding regions conserved within Candida but distinct from those of Aspergillus and Penicillium. We demonstrate that the final two selected pan-Candida primer sets would not amplify Aspergillus DNA and could be used to differentiate eight medically important Candida pathogens in real-time PCR assays based on their melting profiles, with a sensitivity of detection as low as 10 fg of Candida genomic DNA. Moreover, we further evaluated and selected species-specific primer sets covering Candida albicans, Candida glabrata, Candida tropicalis, and Candida dubliniensis and show that they had high sensitivity and specificity. These real-time PCR primer sets could potentially be assembled into a single PCR array for the rapid detection of Candida species in various clinical settings, such as corneal transplantation.

Evaluation of Fluorescent Capillary Electrophoresis for Rapid Identification of Candida Fungal Infections

Early diagnosis of fungal infection is critical for initiating antifungal therapy and reducing the high mortality rate in immunocompromised patients. In this study, we focused on rapid and sensitive identification of clinically important Candida species, utilizing the variability in the length of the ITS2 rRNA gene and fluorescent capillary electrophoresis (f-ITS2-PCR-CE). The method was developed and optimized on 29 various Candida reference strains from which 26 Candida species were clearly identified, while Candida guilliermondii, C. fermentati, and C. carpophila, which are closely related, could not be distinguished. The method was subsequently validated on 143 blinded monofungal clinical isolates (comprising 26 species) and was able to identify 88% of species unambiguously. This indicated a higher resolution power than the classical phenotypic approach which correctly identified 73%. Finally, the culture-independent potential of this technique was addressed by the analysis of 55 retrospective DNA samples extracted directly from clinical material. The method showed 100% sensitivity and specificity compared to those of the combined results of cultivation and panfungal PCR followed by sequencing used as a gold standard. In conclusion, this newly developed f-ITS2-PCR-CE analytical approach was shown to be a fast, sensitive, and highly reproducible tool for both culture-dependent and culture-independent identification of clinically important Candida strains, including species of the "psilosis" complex.

High frequency of Candida fabianii among clinical isolates biochemically identified as Candida pelliculosa and Candida utilis

Clinical yeast isolates belonging to Candida pelliculosa, Candida utilis and Candida fabianii are difficult to distinguish in a routine mycology laboratory using common biochemical tests. The aims of this study were to determine the prevalence of C. pelliculosa, C. utilis and C. fabianii in clinical samples and to compare their minimum inhibitory concentrations (MICs) to systemic antifungals. Two hundred and forty-eight clinical yeast isolates obtained from eight large hospitals in the Czech Republic were included in this study. Identification was performed biochemically using ID 32C kit and by MALDI-TOF MS. MICs were determined using colorimetric broth dilution Sensititre YeastOne panels. From a total number of 248 isolates, 175 were identified as C. pelliculosa and 73 as C. utilis using the biochemical kit. In contrast, MALDI-TOF MS identified 222 isolates as C. fabianii, 20 as C. pelliculosa and 6 as C. utilis. The highest mean MICs were found in C. fabianii and, regardless of the studied species, in isolates from blood cultures and central venous catheters. MALDI-TOF MS revealed C. fabianii to be most prevalent in clinical samples as compared with the other studied species. Higher MIC values in C. fabianii support the importance of correct identification of this species.

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.

Aspergillus monitoring project in a large educational hospital using molecular assay

BACKGROUND

It is important to find reliable and accessible methods for the diagnosis and identification of fungal species causing hospital acquired infections. Our main objective was using a rapid and accessible molecular method for the monitoring of Aspergillus infections and identification of causing agents in the level of species.

MATERIAL AND METHODS

The study subjects were primarily clinical specimens collected from suspected HAI patients with clinical symptoms after hospitalization. Also some environmental specimens were collected from air and instruments of health care facilities for the investigation of Aspergillus sources in a university hospital of UMSU, Urmia. All specimens were transported to Medical Mycology Center for the detection and identification of Aspergillus species using morphological methods. Also molecular method, PCR-RFLP using single restriction enzyme as a rapid and available method was performed to investigate environmental sources of Aspergillus infections.

RESULTS

Total of 110 clinical fungal isolates included Candida and Aspergillus species and some other opportunistic fungi. Among the clinical Aspergillus findings, Aspergillus flavus (47%), Aspergillus fumigatus (29.4%) and Aspergillus niger (23.6%) were the most frequent species respectively and also Aspergillus niger (43.7%), Aspergillus flavus (41.8%), Aspergillus fumigatus (14.7%) were isolated as the most frequent species from environmental sources.

CONCLUSION

Because of accessibility, speed and high sensitivity of diagnosis, the PCR-RFLP was very useful for the identification of medically important Aspergillus species and epidemiological approaches.

Polymerase chain reaction-based assays for the diagnosis of invasive fungal infections

Currently accepted fungal diagnostic techniques, such as culture, biopsy, and serology, lack rapidity and efficiency. Newer diagnostic methods, such as polymerase chain reaction (PCR)-based assays, have the potential to improve fungal diagnostics in a faster, more sensitive, and specific manner. Preliminary data indicate that, when PCR-based fungal diagnostic assays guide antifungal therapy, they may lower patient mortality and decrease unnecessary antifungal treatment, improving treatment-associated costs and avoiding toxicity. Moreover, newer PCR techniques can identify antifungal resistance DNA loci, but the clinical correlation between those loci and clinical failure has to be studied further. In addition, future studies need to focus on the implementation of PCR techniques in clinical decision making and on combining them with other diagnostic tests. A consensus on the standardization of PCR techniques, along with validation from large prospective studies, is necessary to allow widespread adoption of these assays.

Bacterial and fungal microflora in surgically removed lung cancer samples

Background

Clinical and experimental data suggest an association between the presence of bacterial and/or fungal infection and the development of different types of cancer, independently of chemotherapy-induced leukopenia. This has also been postulated for the development of lung cancer, however the prevalence and the exact species of the bacteria and fungi implicated, have not yet been described.

Aim

To determine the presence of bacterial and fungal microflora in surgically extracted samples of patients with lung cancer.

Materials and methods

In this single-center prospective, observational study, tissue samples were surgically extracted from 32 consecutive patients with lung cancer, and reverse-transcription polymerase chain reaction (RT-PCR) was used to identify the presence of bacteria and fungi strains.

Results

The analysis of the electrophoresis data pointed out diversity between the samples and the strains that were identified. Mycoplasma strains were identified in all samples. Strains that appeared more often were Staphylococcus epidermidis, Streptococcus mitis and Bacillus strains, followed in descending frequency by Chlamydia, Candida, Listeria, and Haemophilus influenza. In individual patients Legionella pneumophila and Candida tropicalis were detected.

Conclusions

A diversity of pathogens could be identified in surgically extracted tissue samples of patients with lung cancer, with mycoplasma strains being present in all samples. These results point to an etiologic role for chronic infection in lung carcinogenesis. Confirmation of these observations and additional studies are needed to further characterize the etiologic role of inflammation in lung carcinogenesis.

PCR diagnosis of invasive candidiasis: systematic review and meta-analysis

Invasive candidiasis (IC) is a significant cause of morbidity and mortality. Diagnosis relies on culture-based methods, which lack sensitivity and delay diagnosis. We conducted a systematic review assessing the diagnostic accuracy of PCR-based methods to detect Candida spp. directly in blood samples. We searched electronic databases for prospective or retrospective cohort and case-control studies. Two reviewers abstracted data independently. Meta-analysis was performed using a hierarchical logistic regression model. Random-effects metaregression was performed to assess the effects of study methods and infection characteristics on sensitivity or specificity values. We included 54 studies with 4,694 patients, 963 of whom had proven/probable or possible IC. Perfect (100%) sensitivity and specificity for PCR in whole-blood samples was observed when patients with cases had candidemia and controls were healthy people. When PCR was performed to evaluate patients with suspected invasive candidiasis, the pooled sensitivity for the diagnosis of candidemia was 0.95 (confidence interval, 0.88 to 0.98) and the pooled specificity was 0.92 (0.88 to 0.95). A specificity of >90% was maintained in several analyses considering different control groups. The use of whole-blood samples, rRNA, or P450 gene targets and a PCR detection limit of ≤ 10 CFU/ml were associated with improved test performance. PCR positivity rates among patients with proven or probable IC were 85% (78 to 91%), while blood cultures were positive for 38% (29 to 46%). We conclude that direct PCR using blood samples had good sensitivity and specificity for the diagnosis of IC and offers an attractive method for early diagnosis of specific Candida spp. Its effects on clinical outcomes should be investigated.

Current status and future perspectives on molecular and serological methods in diagnostic mycology

Invasive fungal infections are an important cause of infectious morbidity. Nonculture-based methods are increasingly used for rapid, accurate diagnosis to improve patient outcomes. New and existing DNA amplification platforms have high sensitivity and specificity for direct detection and identification of fungi in clinical specimens. Since laboratories are increasingly reliant on DNA sequencing for fungal identification, measures to improve sequence interpretation should support validation of reference isolates and quality control in public gene repositories. Novel technologies (e.g., isothermal and PNA FISH methods), platforms enabling high-throughput analyses (e.g., DNA microarrays and Luminex® xMAP™) and/or commercial PCR assays warrant further evaluation for routine diagnostic use. Notwithstanding the advantages of molecular tests, serological assays remain clinically useful for patient management. The serum Aspergillus galactomannan test has been incorporated into diagnostic algorithms of invasive aspergillosis. Both the galactomannan and the serum β-D-glucan test have value for diagnosing infection and monitoring therapeutic response.

Acremonium Vertebral Osteomyelitis: Molecular Diagnosis and Response to Voriconazole

We present a case of Acremonium vertebral osteomyelitis that relapsed despite surgical debridement and prolonged treatment with liposomal amphotericin B, but which responded to voriconazole therapy. The report highlights the role of molecular diagnosis of rare fungal osteomyelitis. The patient was successfully treated with voriconazole.

MOLECULAR-GENETIC APPROACHES TO IDENTIFICATION AND TYPING OF PATHOGENIC CANDIDA YEASTS

Currently, invasive candidal infections represent an increasing cause of morbidity and mortality in seriously ill hospitalised patients. Because the accurate diagnosis of candidiasis remains difficult, a fast and reliable assay for characterization of fungal pathogens is critical for the early initiation of adequate antifungal therapy and/or for introduction of preventive measures. As novel molecular genetic techniques are continuously introduced, their role in the management of infectious diseases has also been growing. Today, molecular strategies complement conventional methods and provide more accurate and detailed insight. It can be expected that future technical development will improve their potential furthermore. In this article, we provide a critical review on the value and limitations of molecular tools in pathogenic Candida species identification and strain typing regarding their sensitivity, discriminatory power, reproducibility, cost and ease of performance.

McRAPD as a new approach to rapid and accurate identification of pathogenic yeasts

Despite advances in antifungal prophylaxis and therapy, morbidity and mortality incurred by yeasts remain a significant burden. As pathogenic yeast species vary in their susceptibilities to antifungal agents, clinical microbiology laboratories face an important challenge to identify them rapidly and accurately. Although a vast array of phenotyping and genotyping methods has been developed, these are either unable to cover the whole spectrum of potential yeast pathogens or can do this only in a rather costly or laborious way. Random amplified polymorphic DNA (RAPD) fingerprinting was repeatedly demonstrated to be a convenient tool for species identification in pathogenic yeasts. However, its wider acceptance has been limited mainly due to special expertise and software needed for analysis and comparison of the resulting banding patterns. Based on a pilot study, we demonstrate here that a simple and rapid melting curve analysis of RAPD products can provide data for identification of five of the most medically important Candida species. We have termed this new approach melting curve of random amplified polymorphic DNA (McRAPD) to emphasize its rapidity and potential for automation, highly desirable features for a routine laboratory test.

Molecular Methods in the Diagnosis of Endocarditis

Advances in molecular microbiologic diagnostics have yielded new tools to diagnose infective endocarditis. These tools can detect microorganisms that are difficult to grow or are uncultivable, because of prior antimicrobial therapy or because of innate characteristics of the microorganisms. This paper reviews molecular microbiologic diagnostic techniques and their role in the diagnosis of infective endocarditis.