Rapid Species Diagnosis for Invasive Candidiasis Using Mass Spectrometry

BACKGROUND: Matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI TOF-MS) allows the identification of most bacteria and an increasing number of fungi. The potential for the highest clinical benefit of such methods would be in severe acute infections that require prompt treatment adapted to the infecting species. Our objective was to determine whether yeasts could be identified directly from a positive blood culture, avoiding the 1-3 days subculture step currently required before any therapeutic adjustments can be made. METHODOLOGY/PRINCIPAL FINDINGS: Using human blood spiked with Candida albicans to simulate blood cultures, we optimized protocols to obtain MALDI TOF-MS fingerprints where signals from blood proteins are reduced. Simulated cultures elaborated using a set of 12 strains belonging to 6 different species were then tested. Quantifiable spectral differences in the 5000-7400 Da mass range allowed to discriminate between these species and to build a reference database. The validation of the method and the statistical approach to spectral analysis were conducted using individual simulated blood cultures of 36 additional strains (six for each species). Correct identification of the species of these strains was obtained. CONCLUSIONS/SIGNIFICANCE: Direct MALDI TOF-MS analysis of aliquots from positive blood cultures allowed rapid and accurate identification of the main Candida species, thus obviating the need for sub-culturing on specific media. Subsequent to this proof-of-principle demonstration, the method can be extended to other clinically relevant yeast species, and applied to an adequate number of clinical samples in order to establish its potential to improve antimicrobial management of patients with fungemia

Fatal Disseminated Acanthamoeba lenticulata Acanthamebiasis in a Heart Transplant Patient

We report a fatal case of disseminated acanthamebiasis caused by Acanthamoeba lenticulata (genotype T5) in a 39-year-old heart transplant recipient. The diagnosis was based on skin histopathologic results and confirmed by isolation of the ameba from involved skin and molecular analysis of a partial 18S rRNA gene sequence (DF3)

Invasive pulmonary aspergillosis in patients with decompensated cirrhosis: case series

BACKGROUND: Opportunistic invasive fungal infections are increasingly frequent in intensive care patients. Their clinical spectrum goes beyond the patients with malignancies, and for example invasive pulmonary aspergillosis has recently been described in critically ill patients without such condition. Liver failure has been suspected to be a risk factor for aspergillosis. CASE PRESENTATION: We describe three cases of adult respiratory distress syndrome with sepsis, shock and multiple organ failure in patients with severe liver failure among whom two had positive Aspergillus antigenemia and one had a positive Aspergillus serology. In all cases bronchoalveolar lavage fluid was positive for Aspergillus fumigatus. Outcome was fatal in all cases despite treatment with voriconazole and agressive symptomatic treatment. CONCLUSION: Invasive aspergillosis should be among rapidly raised hypothesis in cirrhotic patients developing acute respiratory symptoms and alveolar opacities

EVALUATION DE NOUVEAUX OUTILS DIAGNOSTIQUES DANS LES CANDIDOSES PROFONDES (DES BIOLOGIE MEDICALE)

PARIS-BIUM (751062103) / SudocCentre Technique Livre Ens. Sup. (774682301) / SudocSudocFranceF

Evaluation d'une "polymerase chain reaction" (PCR) en temps réel pour le diagnostic d'aspergillose invasive dans un modèle murin

PARIS-BIUP (751062107) / SudocSudocFranceF

Cas de diarrhée du voyageur chez un patient immunocométent de retour du Guatemala

Microsporidia are spore forming protozoan parasites who cause a variety of diseases among immunodeficiency patients. Only a few cases are reported among immunocompetent patients. We report a case of intestinal microsporidial infection in a 22-year-old student, coming back from Guatemala, after one month travel. Clinical aspects: The young boy was admitted to the hospital for napache with stiffness, backache and fever at 39°C. He reported nonbloody diarrhea 5 days before hospitalization, without nausea or vomiting. During his travel he also presented a few days of self-limited diarrhea, with watery stools without fever. At the end of the trip he had lost 10 kg. Before his travel he was vaccinated against A hepatitis, poliomyelitis, typhoid fever and he receved a malaria prophylaxis by Nivaquine. The clinical examination pointed out a discreet pain at the left iliac fossa, napache and fever. Diagnosis: The biology schows an inflammatory syndrome, hyperleucocytosis, and impairing of the hepatic tests with cholestasis. Routine cultures for bacterial pathogens were negative. Stool examination for parasites with use of direct examination or after diphasic concentration didn't reveal the presence of pathogens. The search of cryptosporidia was also negative. All the serologies even against the HIV for the search of a viral etiology were negative. By the use of a modified trichrome stain, some bright pink-red organism mesuring 1-2µ were detected by light microscopy in three consecutive stools. We concluded to the presence of protozoa of the phylum Microspora. Treatment: The patient receved first ciprofloxacine then albendazole, as specifically treatment. All the symptoms disappeared one month after hospitalization. The low charge of parasites didn't allow electron microscopy nor polymerase chain reaction for the determination of the species

Aspergillus flavus brain abscesses associated with hepatic amebiasis in a non-neutropenic man in Senegal

A non-neutropenic man living in Senegal was repatriated to France for liver amebic abscesses associated with brain abscesses presumed to be of amebic origin. Surprisingly, the post-mortem examinations of brain abscesses showed Aspergillus flavus. The route of infection by A. flavus in this particular context is discussed