Identification of the five human Plasmodium species including P. knowlesi by real-time polymerase chain reaction.

Recently, Plasmodium knowlesi has been recognised as the fifth Plasmodium species causing malaria in humans. Hundreds of human cases infected with this originally simian Plasmodium species have been described in Asian countries and increasing numbers are reported in Europe from travellers. The growing impact of tourism and economic development in South and Southeast Asia are expected to subsequently lead to a further increase in cases both among locals and among travellers. P. knowlesi is easily misidentified in microscopy as P. malariae or P. falciparum. We developed new primers for the rapid and specific detection of this species by low-cost real-time polymerase chain reaction (PCR) and added this method to an already existing panel of primers used for the molecular identification of the other four species in one reaction. Reference laboratories should now be able to identify undisputably and rapidly P. knowlesi, as it is a potentially fatal pathogen.

[Pneumocystis jiroveci: epidemiological, pathophysiological and biological update]. / Pneumocystis jiroveci : mise à jour épidémiologique, physiopathologique et biologique.

One century after its discovery, Pneumocystis jiroveci is an infectious agent still responsible of a high mortality rate among immunocompromised patients. Molecular biology advances have authorized some important progress mainly concerning epidemiology, pathophysiology and biological diagnosis. It has also brought a lot of publication on the subject. They describe a large panel of different biological diagnosis method. The purpose of this article is to synthesize these knowledges and to update the laboratory diagnosis strategy.

Molecular diagnosis of disseminated adiaspiromycosis due to Emmonsia crescens.

Emmonsia crescens is a saprophytic fungus that is distributed worldwide, causing diseases mostly in rodents. It has also been described, though rarely, as an etiologic agent of pulmonary pathology in humans, potentially leading to death. A case of pulmonary adiaspiromycosis is reported in a 30-year-old immunocompetent man. The patient presented with a history of several weeks of weakness, cough, fever, and weight loss of 10 kg. Clinical and radiographic findings showed pulmonary lesions consistent with tuberculosis or histoplasmosis, but no pathogen was found with classical microbiological procedures. The diagnosis of adiaspiromycosis due to Emmonsia crescens was initially made using molecular biology techniques. Histological observations subsequently confirmed the presence of adiaspores in granulomas. To our knowledge, this is the first case of adiaspiromycosis diagnosed by PCR and sequencing. The patient was treated with itraconazole and was seen at 1 month with symptomatic improvement. Here we will discuss this rare fungal infection and its difficult treatment and diagnosis. As represented in this case, molecular biology is a powerful method to optimize diagnostic tests and therefore improve the care of the infected patient.

[Bacterial meningitis in HIV patient: think about co-infections!]. / Méningite bactérienne chez le patient VIH positif: pensez aux co-infections!

The authors report the case of an African 34-year-old patient who was admitted to the intensive care unit for bacterial meningitis due to Streptococcus pneumoniae. A meningeal co-infection due to Cryptococcal neoformans was found the 3rd day in an HIV infection context. Cryptococcus neoformans detection in cerebrospinal fluid, using the India-ink stain, has a low sensibility which imposes the search of cryptococcal antigen and the culture of cerebrospinal fluid. These last two exams have a sensibility of at least 90%.

[Inter-laboratory reproducibility of pulsed-field electrophoresis for the study of 12 types of Pseudomonas aeruginosa]. / Reproductibilité inter-laboratoire de l'électrophorèse en champ pulsé dans l'étude de 12 souches de Pseudomonas aeruginosa.

The increasing hospital-to-hospital transmission of multiple drug-resistant bacteria is a major concern for bacteriology laboratories involved in nosocomial infection control. The interlaboratory reproducibility of pulsed-field gel electrophoresis (PFGE) for Pseudomonas aeruginosa typing was evaluated by asking four hospital laboratories (two in Lyon, one in Brest, and one in Marseille) to study 11 P. aeruginosa isolates, some of which were epidemiologically related, and the reference strain ATCC 27853. Two laboratories used the Genepath system, one the Chef DR II, system, and one the Chef Mapper system, Bio-Rad, restriction/Spe I. Profiles were read visually and by computerized comparison of restriction band molecular weights (Taxotron, software, PAD Grimont, Pasteur Institute, Paris, France). These two methods led to similar epidemiological conclusions. However, centralization of the data showed poor center-to-center reproducibility due to inadequate standardization of the procedure.

[Histamine food poisoning]. / Les intoxications alimentaires histaminiques.

The authors describe a collective histamine related food-poisoning epidemic that occurred in the Navy due to the consumption of imported smoked swordfish (Xyphias gladius). Twenty cases were detected. The relative risk among consumers of swordfish is at 7.44 (C.I. of 95%: 2.57-21.59) and the doses of histamine were from 2.030 to 4.750 ppm in 9 samples of tested fish (N < 200 ppm). The interest in using a high-resolution chromatographic liquid to ensure a diagnosis, and in using the community norms in force are shown. A recent review of the literature serves to show the variety of fish responsible for this type of accident, to insist on the mildness, elusiveness, variability, and lack of specificity of clinical signs and therefore risks error in diagnoses, treatment and under-reporting of this type of collective food-poisoning.