[Second-degree atrioventricular block caused by Lyme disease]. / Tweedegraads atrioventriculair blok door lymeziekte.

BACKGROUND: Tick-borne diseases, including Lyme disease, are becoming increasingly common in Europe. Lyme disease has a wide variety of clinical manifestations, as a result of which physicians of diverse disciplines are coming into contact with such patients. CASE DESCRIPTION: A 58-year-old man was seen at the emergency room with a symptomatic Wenckebach-type second-degree atrioventricular (AV) block and periods of 2:1 AV block. Four weeks previously the patient had noticed a red skin lesion on his left lower leg. Under the working diagnosis of early disseminated Lyme disease with cardiac involvement, treatment with ceftriaxone was started. This diagnosis was supported by a positive Borrelia PCR and culture of a skin biopsy and positive Borreliaserology. The AV conduction disorders resolved completely after 2 weeks of treatment with antibiotics and it was not necessary to implant a pacemaker. CONCLUSION: A Borrelia infection is a reversible but rare cause of AV conduction disorders. In the event of sudden onset of symptoms or a severe or progressive AV conduction disorder, Lyme carditis should be considered, especially if the medical history or physical examination provides clues for Lyme disease.

Low prevalence of Blastocystis sp. in active ulcerative colitis patients.

Ulcerative colitis (UC) is thought to originate from a disbalance in the interplay between the gut microbiota and the innate and adaptive immune system. Apart from the bacterial microbiota, there might be other organisms, such as parasites or viruses, that could play a role in the aetiology of UC. The primary objective of this study was to compare the prevalence of Blastocystis sp. in a cohort of patients with active UC and compare that to the prevalence in healthy controls. We studied patients with active UC confirmed by endoscopy included in a randomised prospective trial on the faecal transplantation for UC. A cohort of healthy subjects who served as donors in randomised trials on faecal transplantation were controls. Healthy subjects did not have gastrointestinal symptoms and were extensively screened for infectious diseases by a screenings questionnaire, extensive serologic assessment for viruses and stool analysis. Potential parasitic infections such as Blastocystis were diagnosed with the triple faeces test (TFT). The prevalence of Blastocystis sp. were compared between groups by Chi-square testing. A total of 168 subjects were included, of whom 45 had active UC [median age 39.0 years, interquartile range (IQR) 32.5-49.0, 49 % male] and 123 were healthy subjects (median age 27 years, IQR 22.0-37.0, 54 % male). Blastocystis sp. was present in the faeces of 40/123 (32.5 %) healthy subjects and 6/45 (13.3 %) UC patients (p = 0.014). Infection with Blastocystis is significantly less frequent in UC patients as compared to healthy controls.

Subtype determination of Blastocystis isolates by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS).

The pathogenic role of the enteric parasite Blastocystis remains controversial. Recent studies have suggested that various subtypes (STs) found in human samples could be correlated to the presence or absence and variability of clinical manifestations, and that STs can differ with respect to drug sensitivity. Polymerase chain reaction (PCR) techniques used to determine these STs are expensive and are usually restricted to research laboratory settings. This study evaluates the potential application of the inexpensive matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) technique to discriminate Blastocystis STs. A database of parasitic protein signatures was constructed for five Blastocystis STs, and the reference spectra were challenged with those from 19 axenic cultures of ST1, ST2, ST3, ST4 and ST8 and those from nine xenic liquid cultures of ST3 and ST4. Samples from axenic cultures were prepared using standard formic acid extraction and direct deposition procedures. The reference spectra revealed five distinct spectral profiles, and the database library allowed for discrimination between all of the cultures with reliability indices ranging from 2.038 to greater than 2.8 when an extraction was performed. The direct deposition procedure resulted in greater variability in the discrimination and direct MALDI-TOF MS identification from xenic liquid cultures was effective in 3 out of 9 samples. MALDI-TOF MS proved to be an effective technology for efficiently discriminating Blastocystis STs in axenic cultures.