Search

The paper reports the case of a 12-year-old female affected by ulcerative colitis and treated with double immunosuppressant therapy (methotrexate and infliximab). The patient presented with 7 day-lasting fever associated with pharyngotonsillar hyperaemia, cheilitis, vesicular-bollous lesions on labial mucosa and rash on malar regions, chest and upper extremities. Since full blood count showed lymphocytosis and inflammatory markers were negative, a viral infection was suspected. Virological tests identified the presence of IgM against Cytomegalovirus (CMV), Herpes and Mumps viruses, but Real-Time PCR was negative for the DNA detection of any of those viruses. Despite hospital admission and different investigations, fever persisted for more than 7 days without any explanation. Therefore, it was considered as Fever of unknown origin (FUO). FUO is often an unusual manifestation of a common disease but so far there is not a single validated diagnostic protocol. In the presented case only did the repetition of the Real-Time PCR test after a few days enable CMV DNA to be identified in the patient's blood and urine and CMV infection to be diagnosed.

The number of pathogens involved in community-acquired pneumonia, with varying susceptibilities to antimicrobials, is numerous constituting an enormous challenge for diagnostic microbiology. Differentiation of infections due to Streptococcus pneumoniae and those due to Mycoplasma pneumoniae, Chlamydophila pneumoniae, or L. pneumophila as well as those due to viruses is essential to allow correct decisions concerning the antibiotics to be administered. The sensitivity and specificity of real-time simplex and multiplex nucleic acid sequence-based amplification (NASBA), and simplex PCR were compared for the detection of M. pneumoniae, C. pneumoniae and Legionella spp. in respiratory specimens from hospitalized and outpatients with community-acquired pneumonia (CAP). Two hundred fifty one respiratory specimens were collected from 147 patients with CAP. NASBA was done using the NucliSens Basic Kit (bioMérieux). PCR for M. pneumoniae and C. pneumoniae was done as described earlier [Ieven, M., Ursi, D., Van Bever, H., Quint, W., Niesters, H. G. M., and Goossens, H. 1996. Detection of Mycoplasma pneumoniae by two polymerase chain reactions and role of M. pneumoniae in acute respiratory tract infections in pediatric patients. J. Infect. Dis. 173, 144514452.; Ursi, D., Ieven, M., Van Bever, H. P., and Goossens, H. 1998. Construction of an internal control for the detection of Chlamydia pneumoniae by PCR. Mol. Cellul. Probes. 12, 235238.]. A real-time PCR was developed to detect L. pneumophila whereas a real-time NASBA was designed to detect Legionella spp. All samples with discordant results were re-analysed. Compared to an expanded gold standard the sensitivities of the different techniques, were 77.8%, 100%, and 100% for detection of M. pneumoniae; and 50%, 100%, and 50% for detection of L. pneumophila by PCR, real-time simplex NASBA, and real-time multiplex NASBA, respectively. C. pneumoniae was detected in two samples only. Simplex real-time NASBA proved to be more sensitive than simplex PCR and was also more sensitive than real-time multiplex NASBA, as previously found with spiked clinical specimens. It's practical attractiveness pleads for further optimalisation of the multiplex approach.

A woman with systemic lupus erythematosus (SLE) presented with a zoster eruption. Transverse myelitis developed at the site of the dermatomal distribution of the rash. SLE and varicella zoster virus (VZV) can both cause myelitis, and are difficult to differentiate. The topographic association between the cutaneous and the neurological involvement suggesting VZV myelitis was confirmed by polymerase chain reaction (PCR) for VZV in the cerebrospinal fluid. This case illustrates the potential role of the selective amplification of VZV DNA in cerebrospinal fluid to diagnose central neurological complications associated with VZV. The value of magnetic resonance imaging of the spinal cord in the evaluation of patients with myelitis is emphasized.

A woman with systemic lupus erythematosus (SLE) presented with a tester eruption, Transverse myelitis developed at the site of the dermatomal distribution of the rash, SLE and varicella tester virus (VZV) can both cause myelitis, and are difficult to differentiate, The topographic association between the cutaneous and the neurological involvement suggesting VZV myelitis was confirmed by polymerase chain reaction (PCR) for VZV in the cerebrospinal fluid. This case illustrates the potential role of the selective amplification of VZV DNA in cerebrospinal fluid to diagnose central neurological complications associated with VZV. The value of magnetic resonance imaging of the spinal cord in the evaluation of patients with myelitis is emphasized.

The sensitivity of the polymerase chain reaction (PCR) on the DNA coding for the species-specific fragment of 16S rRNA of Mycobacterium leprae studied on mouse foot pad harvests and human skin biopsies varies widely between 1 and 3 x 10(4) organisms. This is probably the result of variations in the proportions of organisms with sufficiently intact DNA suitable for PCR. Preserving human skin biopsies for 3 weeks at an ambient temperature even after boiling for 6 minutes gives rise to a 10-fold decrease in sensitivity. Fixation of tissues in formol 10% or Lowy fixative or preserving in Dubos OAA broth is very harmful to the PCR, mainly due to the enhancement of an inhibitory effect on the PCR reaction. For preservation, the best choice at the moment seems to be alcohol 70%. Sample preparation of five cycles of freeze-boiling is simple and generally more efficient than proteinase K treatment and DNA extraction.