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.
BACKGROUND: Cytomegalovirus (CMV) infection is a life-threatening complication after solid organ transplantation. It usually appears in the first months after transplantation as a consequence of immunosuppression. The goal of this study was to evaluate the clinical significance of CD38(high)/CD3(+)8(+) percentages in the detection of CMV infection in patients after kidney transplantation. METHODS: In this retrospective study, 269 patients were monitored 2-3 months after renal transplantation for the percentage of CD38(high)/CD3(+)8(+) lymphocytes estimated by flow cytometry and for the number of CMV DNA copies in peripheral blood using a real-time polymerase chain reaction. RESULTS: CMV infection was diagnosed in 12 (4.5%) patients between the 31st and 63rd days after transplantation, and all of them had percentages of CD38(high)/CD3(+)8(+) T lymphocytes above 20%. In 4 of them, CMV DNAemia in peripheral blood was not detected, and 2 of these suffered from tissue-invasive CMV disease. In 7 patients with CMV DNAemia, the CD38(high)/CD3(+)8(+) T lymphocyte percentage did not exceed 20%, and these patients did not develop CMV infection requiring antiviral treatment. In 23 additional patients, a CD38(high)/CD3(+)CD8(+) percentage above 20% was recorded without CMV DNAemia. All of the remaining 234 patients never exceeded the arbitrary limit of 20%. The estimated sensitivity and specificity were 100% and 91% using clinical decision on the presence of CMV infection as a reference value, respectively. The estimated negative predictive value was 100%; however, the estimated positive predictive value was quite low (34%). CONCLUSIONS: The CD38(high)/CD3(+)8(+) lymphocyte percentage seems to be a useful additional diagnostic marker for CMV infection in patients after kidney transplantation, especially when patients are in the risk of a tissue-invasive disease when CMV DNA copies may not be detectable in peripheral blood.
- MeSH
- antigeny CD38 biosyntéza MeSH
- biologické markery metabolismus MeSH
- CD8-pozitivní T-lymfocyty imunologie metabolismus patologie MeSH
- cytomegalovirové infekce komplikace diagnóza imunologie MeSH
- Cytomegalovirus patogenita fyziologie MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- monitorování fyziologických funkcí metody MeSH
- prediktivní hodnota testů MeSH
- rejekce štěpu komplikace diagnóza imunologie MeSH
- retrospektivní studie MeSH
- senzitivita a specificita MeSH
- transplantace ledvin MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
High-resolution melting analysis (HRMA) is a fast (post-PCR) high-throughput method to scan for sequence variations in a target gene. The aim of this study was to test the potential of HRMA to distinguish particular bacterial species of the Staphylococcus genus even when using a broad-range PCR within the 16S rRNA gene where sequence differences are minimal. Genomic DNA samples isolated from 12 reference staphylococcal strains (Staphylococcus aureus, Staphylococcus capitis, Staphylococcus caprae, Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis, Staphylococcus intermedius, Staphylococcus saprophyticus, Staphylococcus sciuri, Staphylococcus simulans, Staphylococcus warneri, and Staphylococcus xylosus) were subjected to a real-time PCR amplification of the 16S rRNA gene in the presence of fluorescent dye EvaGreen™, followed by HRMA. Melting profiles were used as molecular fingerprints for bacterial species differentiation. HRMA of S. saprophyticus and S. xylosus resulted in undistinguishable profiles because of their identical sequences in the analyzed 16S rRNA region. The remaining reference strains were fully differentiated either directly or via high-resolution plots obtained by heteroduplex formation between coamplified PCR products of the tested staphylococcal strain and phylogenetically unrelated strain.
- MeSH
- DNA bakterií chemie MeSH
- DNA fingerprinting metody MeSH
- druhová specificita MeSH
- heteroduplexní analýza MeSH
- molekulární sekvence - údaje MeSH
- ribozomální DNA chemie genetika MeSH
- RNA ribozomální 16S chemie genetika MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza DNA MeSH
- sekvenční seřazení MeSH
- senzitivita a specificita MeSH
- Staphylococcus klasifikace genetika MeSH
- tranzitní teplota MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cardiobacterium valvarum, a fastidious Gram-negative bacterium, was detected in the aortic valve of a previously healthy 63-year-old man by broad-range PCR and 16S rRNA gene sequencing. In contrast to the patients in five previously published cases, our patient had neither a congenital bicuspid nor a prosthetic aortic valve. Here, we present a case of C. valvarum native tricuspid aortic valve infective endocarditis and a review of the literature.
- MeSH
- antibakteriální látky aplikace a dávkování terapeutické užití MeSH
- aortální chlopeň parazitologie patologie MeSH
- bakteriální endokarditida farmakoterapie chirurgie mikrobiologie MeSH
- Cardiobacterium izolace a purifikace MeSH
- cefotaxim aplikace a dávkování terapeutické užití MeSH
- gentamiciny aplikace a dávkování terapeutické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- nemoci srdečních chlopní mikrobiologie patologie MeSH
- polymerázová řetězová reakce MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
