[What to expect from whitening toothpaste?] / Wat kun je van whitening tandpasta verwachten?

To assess the whitening effect of whitening toothpastes, their ingredients were studied. These toothpastes turned out to have an influence articularly on the extrinsic discoloration of teeth caused by staining. To a large extent, the effectiveness of the whitening toothpastes relies on removing these extrinsic stains, preventing new stains from developing and on certain optical effects. The intrinsic colour of the teeth themselves is not, however, effected.

Detection of Giardia lamblia, Cryptosporidium spp. and Entamoeba histolytica in clinical stool samples by using multiplex real-time PCR after automated DNA isolation.

Diagnosis of intestinal parasites in stool samples is generally still carried out by microscopy; however, this technique is known to suffer from a low sensitivity and is unable to discriminate between certain protozoa. In order to overcome these limitations, a real-time multiplex PCR was evaluated as an alternative approach for diagnosing Giardia lamblia, Cryptosporidium spp. and Entamoeba histolytica in stool samples.Therefore, a total of 631 faecal samples were analysed both by microscopy as well as by real-time PCR following automated DNA extraction. Results showed that real-time PCR exhibited sensitivity and specificity of both 100%, whereas traditional microscopy exhibited sensitivity and specificity of 37.5% and 99.8% respectively. As real-time PCR provides simple, sensitive and specific detection of these three important pathogenic protozoan parasites, this technique, rather than microscopy, has become our diagnostic method of choice for the detection of enteric protozoan parasites for the majority of patients.

Azole resistance in Aspergillus: an emerging problem?

Reports of Aspergillus' azole resistance are emerging, and resistance is now recognised as a cause of treatment failure. The scope of this article is to describe the problem of resistance in Aspergillus: the epidemiology, clinical impact and the underlying molecular mechanisms. In patients with acute invasive aspergillosis, the probability that the patient harbours a resistant strain depends on the emergence of resistant strains in the environment (acquired resistance due to CYP51A mutations and/or natural resistant Aspergillus species). As environmental pan-azole resistance of Aspergillus fumigatus is reported in increasing numbers in the Netherlands, surveillance is warranted. Voriconazole currently remains the first line therapeutic agent for invasive aspergillosis in Belgium. In chronic (and chronically treated) Aspergillus infections,"in-patient" resistance development is possible, especially in the setting of aspergilloma. Culturing an isolate during therapy should therefore be a trigger to test susceptibility.

Invasive pulmonary aspergillosis due to a multi-azole resistant Aspergillus fumigatus.

A patient with invasive pulmonary aspergillosis due to an azole-resistant Aspergillus fumigatus is described. Despite treatment change from voriconazole to amphotericin B as soon as the resistance data were available, the patient died. Azole resistance is an emerging problem, which significantly complicates the management of A. fumigatus infections. It should be considered in every patient with an invasive A. fumigatus infection who is not responding to voriconazole therapy.

First case of anti-ganglioside GM1-positive Guillain-Barré syndrome due to hepatitis E virus infection.

A 51-year-old previously healthy woman presented with Guillain-Barré syndrome (GBS) and elevated liver enzymes. Further diagnostic investigations showed the presence of an acute hepatitis E infection associated with anti-ganglioside GM1 antibodies. After treatment with intravenous immunoglobulins, the patient made a rapid recovery. Here, we report the first case of GBS due to acute hepatitis E virus (HEV) infection associated with the presence of anti-ganglioside GM1 antibodies. We also review available literature on the association between acute HEV infection and GBS.

A case of aseptic meningitis due to Japanese encephalitis virus in a traveller returning from the Philippines.

We here report the case of Japanese encephalitis virus (JEV) meningitis in a previously healthy young women returning from a trip to the Philippines. JEV is a mosquito-borne encephalitic flavivirus pathogen, which is endemic in South East and Eastern Asia. Our patient presented with aseptic meningitis and recovered well under supportive therapy. Although the chance of a traveller getting symptomatic JEV infection is extremely low, clinicians and microbiologist should be aware of patients contracting this emerging infectious disease, especially in the light of the increasing international travel.

False positive Lyme serology due to syphilis: report of 6 cases and review of the literature.

A 44-year-old man presented with visual field defects. Ophthalmoscopy revealed papilloedema of the left eye. Neuroborreliosis was suspected and serum was positively being tested using VIDAS* Lyme screen II (bioMerieux Vitek Inc). However, confirmatory testing using the Borrelia VlsE C6 titre was negative. Western Blotting on serum and cerebrospinal fluid could not confirm the possible diagnosis of neuroborreliosis. VDRL and TPPA testing was positive, and finally, the diagnosis of neurosyphilis was established. We subsequently screened our database on patients with positive VIDAS Lyme screening and negative confirmatory testing by Western blot, and found another 5 cases in which Lyme screening was false positive due to cross-reactivity with Treponema pallidum antibodies. Our data show that in patients with positive Lyme screening and negative confirmatory testing, performance of lues serology should be considered.

A higher dose of vancomycin in continuous infusion is needed in critically ill patients.

Compared with intermittent infusion, continuous infusion of vancomycin is cheaper and logistically more convenient, achieves target concentrations faster, results in less variability in serum vancomycin concentrations, requires less therapeutic drug monitoring and causes less nephrotoxicity. Given that critically ill patients may develop very large volumes of distribution as well as supranormal drug clearance, in this study it was shown, despite the limited number of patients studied, that to achieve a target plateau concentration of 25mg/L a daily dose of 3000 mg of vancomycin in continuous infusion is needed following an appropriate loading dose.

Breakthrough Saprochaete capitata infections in patients receiving echinocandins: case report and review of the literature.

We report a rare case of a fatal Saprochaete capitata breakthrough infection in a patient with acute myeloid leukemia receiving empirical caspofungin therapy. S. capitata is an uncommon, yet emerging cause of invasive infections, especially in patients with haematological malignancies. Blood cultures from our patient yielded S. capitata which was found to be resistant, in vitro, to caspofungin. We consecutively reviewed all published cases of breakthrough infections caused by S. capitata in patients receiving echinocandins. S. capitata should be considered in those patients who remain febrile or who develop invasive mould infections while under echinocandin therapy.

Bacteraemia caused by Leptotrichia trevisanii in a neutropenic patient.

We describe an episode of Leptotrichia trevisanii bacteraemia in a neutropenic hemato-oncology patient receiving chemotherapy for Refractory Anemia with Excess Blasts-2 (RAEB-2). Although Leptotrichia spp. colonize the oral cavity and genitourinary tract, serious episodes of bacteraemia might occur in immunocompromised patients, particularly in those with severe neutropenia. Therefore, microbiologists should consider the possibility of Leptotrichia spp. septicemia in patients with blood cultures positive for gram negative bacilli, when routine microbiology tests fail to reveal a correct identification of the organism.

In vitro activity of tigecycline against multidrug-resistant Enterobacteriaceae isolates from a Belgian hospital.

Bacterial resistance among Gram-negative pathogens is a challenging clinical problem. Tigecycline has been developed specifically to overcome resistance. The aim of this study was to assess the in vitro activity of tigecycline against ESBL-producing Escherichia coli, ESBL-producing Klebsiella spp., and multidrug-resistant Enterobacter spp. Between May 2007 and March 2008, 26 strains of ESBL-producing Escherichia coli, 10 strains of ESBL-producing Klebsiella spp., and 27 strains of multidrug-resistant Enterobacter spp. were isolated consecutively from inpatients with a documented infection in which the collected isolate was identified as the probable causative organism. The in vitro susceptibility against tigecycline was measured by the E-test method. MIC(50) values were 1 microg/ml, 2 microg/ml, and 3 microg/ml respectively. MIC(90) values were respectively 1.5 microg/ml, 4 microg/ml, and 12 microg/ml. Nonsusceptibility rates of 35%, 100%, and 96% respectively were found using EUCAST breakpoints. Despite the limited number of strains tested, our in vitro data suggest that tigecycline is unsuitable for the treatment of infections with multidrug-resistant Enterobacteriaceae in our setting. Therefore, we suggest that larger multicenter studies should be conducted to reconsider the value of tigecycline for the treatment of infections with multidrug-resistant, Gram-negative bacteria.

Pelvic inflammatory disease due to Streptococcus pneumoniae: a usual pathogen at an unusual place.

We report three cases of pelvic inflammatory disease (PID) due to Streptococcus pneumoniae in previously healthy young women. S. pneumoniae frequently causes bacteremia, meningitis and respiratory infections, but it very rarely infects the genital tract. All our patients presented with an acute onset of severe abdominal pain and had an intrauterine device (IUD) present. No abnormal sexual behavior was noticed. Although the relation between PID due to S. pneumoniae and the use of an IUD has been a topic for discussions, culture of IUD in all our patients and blood culture in 2 of 3 of our patients revealed S. pneumoniae. All patients recovered well with intravenous antibiotic treatment and removal of the IUD.

Severe infective endocarditis due to Neisseria sicca: case report and review of literature.

We report a case of infective endocarditis (IE) caused by an unusual micro-organism in a previously healthy young man. Our patient presented with meningo-encephalitis and embolic signs due to IE caused by Neisseria sicca. Risk factors for IE due to Neisseria sicca, such as intravenous drug use and pre-existing heart disease were absent. The patient recovered well after mitral valve surgery and antimicrobial therapy. IE due to Neisseria spp. is associated with embolic manifestations and valve destruction. However, no deaths have been reported in patients who are treated with appropriate antimicrobial and surgical therapy.