ABSTRACT
We report here a PCR-based assay using a single primer pair targeting the RPL31 gene that allows discrimination between Candida glabrata, Candida bracarensis, and Candida nivariensis according to the size of the generated amplicon.
Subject(s)
Candida/classification , Candida/isolation & purification , Candidiasis/microbiology , Microbiological Techniques/methods , Polymerase Chain Reaction/methods , Base Sequence , Candida/genetics , DNA Primers/genetics , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Ribosomal Spacer/chemistry , DNA, Ribosomal Spacer/genetics , Humans , Molecular Sequence Data , Sequence Alignment , Sequence Analysis, DNAABSTRACT
Candida glabrata has emerged as the second most common etiologic agent, after Candida albicans, of superficial and invasive candidiasis in adults. Strain typing is essential for epidemiological investigation, but easy-to-use and reliable typing methods are still lacking. We report the use of a multilocus microsatellite typing method with a set of eight markers on a panel of 180 strains, including 136 blood isolates from hospitalized patients and 34 digestive tract isolates from nonhospitalized patients. A total of 44 different alleles were observed, generating 87 distinct genotypes. In addition to perfect reproducibility, typing ability, and stability, the method had a discriminatory power calculated at 0.97 when all 8 markers were associated, making it suitable for tracing strains. In addition, it is shown that digestive tract isolates differed from blood culture isolates by exhibiting a higher genotypic diversity associated with different allelic frequencies and preferentially did not group in clonal complexes (CCs). The demonstration of the occurrence of microevolution in digestive strains supports the idea that C. glabrata can be a persistent commensal of the human gut.
Subject(s)
Candida glabrata/classification , Candida glabrata/genetics , Candidiasis/microbiology , Digestive System/microbiology , Fungemia/microbiology , Microsatellite Repeats , Mycological Typing Techniques/methods , Adult , DNA, Fungal/genetics , Genetic Variation , Genotype , Humans , Molecular Epidemiology/methods , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
In the Democratic Republic of Congo (DRC), as in many African countries, AIDS and its procession of opportunistic infections are a major cause of morbidity and mortality. In Kinshasa, the estimated prevalence rate of HIV-infected persons is between 4 and 5%, corresponding to more than 200,000 people. Due to the lack of trained laboratory personnel and appropriate diagnostic equipment, no local investigation has been carried out to determine the prevalence of the opportunistic digestive parasitic infection in HIV-infected persons. As a step to obtaining this information that is needed for implementation of an adequate care policy, a preliminary investigation was carried out in Paris, France on 50 stool samples from 50 AIDS-patients hospitalized in 3 reference hospitals in Kinshasa. Eleven patients (22%) had digestive symptoms with a diarrhea syndrome. Further study using specialized techniques demonstrated 2 cases of digestive infection related to opportunistic parasites (4%). The first involved a Cryptosporidium sp. The second represented the first case of Enterocytozoon bieneusi infection reported in the literature from the DRC.
Subject(s)
AIDS-Related Opportunistic Infections/epidemiology , Intestinal Diseases, Parasitic/epidemiology , AIDS-Related Opportunistic Infections/parasitology , Adult , Democratic Republic of the Congo/epidemiology , Diarrhea/parasitology , Female , Humans , Intestinal Diseases, Parasitic/parasitology , Male , Middle Aged , PrevalenceABSTRACT
Cryptococcus neoformans is a fungal pathogen that causes life-threatening infections primarily in immunocompromised hosts. Based on the genetic characteristics and serologic properties of capsular polysaccharides, three varieties and five serotypes have been defined: C. neoformans var. neoformans (serotype D), C. neoformans var. grubii (serotype A), hybrid serotype AD, and C. neoformans var. gattii (serotypes B and C). Epidemiologic features, such as geographic distribution and ecologic niche, and clinical characteristics have been shown to be associated with serotypes. At the present time, serotyping is based on agglutination tests with either commercial or "homemade" antisera or on immunofluorescence assays using a monoclonal antibody directed against the capsule polysaccharide. In this paper, we describe two molecular methods (PCR-restriction enzyme analysis and length polymorphism analysis) for C. neoformans serotype identification. Both are based on the sequence characteristics of a fragment of the CAP59 gene required for capsule biosynthesis. Testing of 72 C. neoformans strains including representatives of the five serotypes demonstrated the reliability of these methods.
Subject(s)
Cryptococcus neoformans/classification , Cryptococcus neoformans/genetics , Polymerase Chain Reaction/methods , Polymorphism, Restriction Fragment Length , Cryptococcosis/microbiology , Cryptococcus neoformans/immunology , DNA, Fungal/genetics , Fungal Proteins/genetics , Humans , Sensitivity and Specificity , SerotypingABSTRACT
En Republique Democratique du Congo (RDC); comme dans de nombreux pays africains; le sida et son cortege d'infections opportunistes sont une cause majeure de morbidite et de mortalite. A Kinshasa; on estime entre 4 et 5le taux de prevalence de sujets infectes par le VIH; soit plus de 200 000 personnes (chiffres du Programme National de Lutte contre le Sida; PNLS 2005). A ce jour; faute de personnels formes et de moyens diagnostiques adaptes; aucune enquete n'a encore ete menee sur la prevalence des parasites opportunistes digestifs dans la population des patients infectes par leVIH; prealable indispensable a la mise en place d'une politique de soin adaptee. Une enquete preliminaire a ete realisee a Paris sur 50 echantillons de selles de 50 patients malades du sida; hospitalises dans 3 hopitaux de references de Kinshasa. Onze patients (22) avaient une symptomatologie digestive avec un syndrome diarrheique. La realisation des examens specialises a mis en evidence 2 cas d'infection digestive par des parasitoses opportunistes (4); une a Cryptosporidium sp. et une a Enterocytozoon bieneusi; premier cas decrit dans la litterature en RDC
Subject(s)
Humans , AIDS-Related Opportunistic Infections/epidemiology , Cryptosporidium , Enterocytozoon , Acquired Immunodeficiency Syndrome , HIV , MicrosporidiaABSTRACT
En Republique Democratique du Congo (RDC); comme dans de nombreux pays africains; le sida et son cortege d'infections opportunistes sont une cause majeure de morbidite et de mortalite. A Kinshasa; on estime entre 4 et 5le taux de prevalence de sujets infectes par le VIH; soit plus de 200 000 personnes (chiffres du Programme National de Lutte contre le Sida; PNLS 2005).A ce jour; faute de personnels formes et de moyens diagnostiques adaptes; aucune enquete n'a encore ete menee sur la prevalence des parasites opportunistes digestifs dans la population des patients infectes par leVIH; prealable indispensable a la mise en place d'une politique de soin adaptee. Une enquete preliminaire a ete realisee a Paris sur 50 echantillons de selles de 50 patients malades du sida; hospitalises dans 3 hopitaux de references de Kinshasa. Onze patients (22) avaient une symptomatologie digestive avec un syndrome diarrheique. La realisation des examens specialises a mis en evidence 2 cas d'infection digestive par des parasitoses opportunistes (4); une a Cryptosporidium sp. et une a Enterocytozoon bieneusi; premier cas decrit dans la litterature en RDC
Subject(s)
EnterocytozoonABSTRACT
A cluster of cases of Candida albicans candidaemia in a surgical intensive care unit was investigated. The probability of such a cluster during a single month was highly significant compared with the frequency of candidaemia in the previous year. A molecular typing method, based on length analysis of three (EF3, CDC3, HIS3) microsatellite-containing regions, was used to investigate isolates from patients in and outside the ward. This demonstrated the involvement of different strains, indicating the absence of cross-transmission among patients. Results of microsatellite typing can be obtained almost in real-time, which is particularly useful in an outbreak context.
