Comparison of real-time PCR, nested PCR, and galactomannan antigen detection by enzyme-linked immunosorbent assay in sera for diagnosis of invasive aspergillosis.

Conventional methods for diagnosis of invasive aspergillosis (IA) lack sensitivity and specificity. Serological methods still have many cases of cross-reactivity. However, molecular techniques seem to arise as a rapid approach, specific and direct that could be used in the diagnosis of IA. In this study, we analyzed 88 serum samples from patients of having IA using GM-ELISA test, nested PCR with primers for the rRNA 18S of Aspergillus genus and real time PCR specific for A. fumigatus. Among the 88 samples, 64 of them had positive GM titers and 23 had positive nested PCRs; 18 of the 23 PCR-positive samples were also GM-positive. On the other hand, 18 samples were detected positive by reel time PCR; 13 positive samples were also detecting positive by nested PCR. QPCR revealed 26 % of the patients with IA, while nested PCR and galactomannan ELISA revealed respectively 34 % and 94 % of the patients with IA. Probable IA was diagnosed in 18 and possible IA was diagnosed in 6 episodes. Forty-four episodes were defined as not having IA. The positive and negative predictive values were respectively 100 %, and 88 % for QPCR, 100 % and 97 % for nested PCR, and 28 % and 60 % for GM test. These results suggesting that combined use of methods might improve the diagnosis of IA.

[Contribution of the chromogenic medium CHROMagar(®)Candida in mycological diagnosis of yeasts]. / Apport du milieu chromogène CHROMagar(®)Candida dans le diagnostic mycologique des levures.

The incidence of invasive candidiasis has increased dramatically over the last decades due to a larger number of patients at risk. The diagnosis remains difficult as the clinical presentation is not specific and the biological diagnosis usually takes several days to become positive. We propose in this work through a prospective study to evaluate the contribution of a chromogenic medium CHROMagar(®) (Becton-Dickinson) in the mycological diagnosis of Candida. We selected 680 samples from patients hospitalized in the intensive care unit for epidemiological surveillance over a period of 11 weeks. We treated samples by culture on Sabouraud and on CHROMagar(®). The species identification was performed by chlamydosporulation test and carbohydrate assimilation tests. We found that the CHROMagar(®)Candida evaluated in our work was a valuable tool in the primary culture in differentiating the most frequently isolated yeast species and in better detection of mixed cultures.

[Procalcitonin in invasive candidosis]. / Procalcitonine et candidoses invasives en milieu de réanimation.

The use of reliable and specific diagnosis tools in patients of intensive care unit constitutes the best way to follow up these patients and to take charge of severe infections. It is in the context that the measuring of procalcitonin should be considered in order to prove its role in invasive candidosis. This prospective study included 52 patients from an intensive care unit. Blood samples for serum procalcitonin were drawn on days 1, 3, 5. Our results showed that on the one hand, procalcitonin levels have significantly increased in cases of confirmed and probable candidosis. On the other hand, this parameter has a certain prognosis value. In conclusion, an increase in procalcitonin level does not only imply a bacterial infection but it should also evoke a case of invasive candidosis especially in intensive care units.

[Pneumocystis pneumonia in 3 non HIV patients]. / Pneumocystose pulmonaire chez les patients non VIH: à propos de trois cas.

We report 3 cases of pneumocystis pneumonia (PCP) in 2 female and 1 male patients (mean age=50 years) free of human immunodeficiency virus (HIV) infection. One female patient presented with breast neoplasm the other with Wegener's granulomatosis, the male patient with lymphoma. All patients were taking immunosuppressive treatment at the time of infection. Persistent cough, dyspnea, and severe hypoxemia were the most characteristic clinical signs. All patients presented with lymphopenia (average CD4-cell count=275/mm3), two with hypoalbuminemia, and one with renal failure. In all cases, the microscopic analysis of bronchoalveolar lavage was used to establish the diagnosis. All patients were treated with trimethoprim and sulfamethoxazole and a tapering dose of corticosteroids. Outcome was favorable for 1 patient, 1 was transferred to the intensive care unit for acute respiratory failure, and 1 died.

[Cutaneous mucormycosis and diabetes: about one observation]. / Mucormycose cutanée primitive et diabète: a propos d'une observation.

Mucormycosis is a rare opportunistic infection but a fulminant disease. Varying clinical forms have been described, including cutaneous localisations which are mainly observed in diabetic and burned patients. The cutaneous lesions induced by the mucormycosis affection are often atypical and gangrenous. We report a case of cutaneous mucormycosis in a Tunisian patient with diabetic ketoacidosis. He developed cutaneous necrotic lesions at the low limb. The diagnosis of mucormycosis was not initially evoked but tardily confirmed by identifying mucorale hyphae in tissue sections and Rhizopus oryzae in the sample culture. The treatment consisted of an extensive surgical debridement associated with intravenous perfusion of amphotericin B. The patient had a fatal outcome.

[Comparative study of adherence of five Candida species to polyvinyl chloride]. / Etude comparatie de l'adhérence de cinq espèces de Candida au polychlorur de vinyle.

Colonization of biomaterial by Candida species could be the first step of Candida infection. We examined the in vitro adherence capabilities of five Candida species to polyvinyl chlorure (PVC). Twenty stains were tested: C. albicans (9), C. glabrata (3), C. tropicalis (3), C. kefyr (4) and C. parapsilosis (1). The adherence to PVC was evaluated by direct microscopic examination. The results indicate that the adherence of C. albicans to PVC is similar to that of C. glabrata and C. tropicalis. Only C. kefyr adheres to a lower degree. We conclude that the adherence capabilities of non-albicans species were similar to that of C. albicans. There is a relationship between the adherence of Candida species and their abilities to colonize the biomaterial. The species, which are more adherent, are those, which are more virulent.

[Visceral and cutaneous leishmaniases in the north. Retrospective study of cases diagnosed in the Rabta Hospital of Tunis]. / Leishmanioses viscérales et cutanées du nord. Etude rétroactive des cas diagnostiqués à l'hôpital La Rabta de Tunis.

The authors report a retrospective study of 50 cases of infantile visceral Leishmaniasis (April 1994-April 1995), and 53 cases of sporadic cutaneous Leishmaniasis of north-Tunisia (August 1990-July 1994), diagnosed in parasitology laboratory of Rabta hospital. They insist on the recrudescence and the extension of the distribution geographical area of these two clinical forms of human leishmaniasis observed in Tunisia.