[Ureaplasma urealyticum, Ureaplasma parvum, and Mycoplasma hominis: commensals or pathogens?]

Mycoplasma hominis, Ureaplasma urealyticum, and Ureaplasma parvum are bacteria commonly found in the urogenital tract. However, their pathogenicity in sexually active or obstetrical patients remains controversial. Therefore, determining the significance of screening and treatment for these organisms is challenging, unlike Mycoplasma genitalium which now has well-defined management guidelines. We conducted a review of the literature to clarify the clinical significance of detecting these micro-organisms. It is crucial to carefully select the few cases that warrant further investigations, in order to mitigate the risks of overdiagnosis and overtreatment.

[Myases from here and elsewhere : pseudo-furonculosis and Ignatzschineria larvae bacteremia]

Myiasis is an infestation by maggots. In humans, it predominates in regions with low socio-economic development. We report on two cases of myiasis acquired during a tropical travel and in Switzerland, respectively. The first one presented as a furunculous-like disease due to the invasion of subcutaneous tissues by Cordylobia sp. larvae. The second corresponded to a chronic wound infestation that resulted in a rarely reported bacteremia due to Ignatzschineria larvae, a commensal bacteria of maggots' digestive tract. Surgery was necessary in both cases, mainly for psychological reasons in the first case. Both the entomologist and molecular biology were instrumental for treatment decisions.

[Common causes of infectious mononucleosis]

Most cases of infectious mononucleosis are caused by Epstein-Barr virus (EBV). However, other rare but potentially serious etiologies need to be considered. Cytomegalovirus (CMV) and Toxoplasma gondii infections, although generally benign, can cause severe congenital infections. An acute infection by the human immunodeficiency virus (HIV) can also mimic infectious mononucleosis. Laboratory diagnostic of those infections relies primarily on the detection of specific antibodies and antigens. The interpretation of laboratory results can be impeded by cross-reactions or persistence over several months of markers of acute infection. This article reviews the most common causes of infectious mononucleosis and their diagnosis.

[Periprosthetic joint infections: a practical overview for family physicians]

Periprosthetic joint infection is a rare but serious complication. Its management requires the collaboration between general practitioner, orthopaedic surgeon and infectious disease specialist. A delay in the diagnosis can result in complications, requiring complex surgical procedures. Identification of the causative pathogen and its susceptibility pattern is crucial, because it guides both the choice of antimicrobial treatment and the surgical strategy. Antimicrobial treatment without proper micro- biological sampling must be avoided. Swabs from open wounds are not helpful, because microorganisms belonging to the skin flora will grow. The target audience of this review article on periprosthetic joint infections is the general practitioner.

CBFB-SMMHC is correlated with increased calreticulin expression and suppresses the granulocytic differentiation factor CEBPA in AML with inv(16)

The pericentric inversion of chromosome 16, inv(16)(p13q22), is associated with acute myeloid leukemia (AML) subtype M4Eo that is characterized by the presence of myelomonocytic blasts and atypical eosinophils. This rearrangement fuses the CBFB and MYH11 genes, with the latter encoding the smooth muscle myosin heavy chain (SMMHC). The myeloid transcription factor CCAAT/enhancer-binding protein alpha (CEBPA) is crucial for normal granulopoiesis. Alterations of structure and expression of CEBPA have been implicated in particular subtypes of AML. Here, we found that conditional expression of core-binding factor beta (CBFB)-SMMHC in U937 cells suppresses CEBPA protein expression and binding activity. However, CEBPA mRNA levels remained unchanged. No differences were detected in CEBPA mRNA levels in patients with inv(16) AML-M4Eo (n = 12) compared to patients with AML with a normal karyotype and M4 subtype (n = 6), whereas CEBPA protein and binding activity were significantly reduced in patients with CBFB-SMMHC. Furthermore, calreticulin, an inhibitor of CEBPA translation, was induced on mRNA and protein level in CBFB-SMMHC patients with AML and after expression of CBFB-SMMHC in the U937-cell system. Inhibition of calreticulin by siRNA restored CEBPA levels. Our results suggest that modulation of CEBPA by calreticulin represents a novel mechanism involved in the differentiation block in CBFB-SMMHC AML.