[Nocardia farcinica as the causative agent of a brain abscess in a patient with interstitial lung disease]. / Nocardia farcinica jako puvodce abscesu mozku u pacienta s intersticiálním onemocnením plic.

This case report describes a two-step protocol for the identification of the causative agent of nocardiosis in a patient with brain abscess, antibiotic susceptibility testing and etiological treatment after neurosurgery. The patient treated with corticosteroids for pulmonary fibrosis and presenting with multiple neurological manifestations was admitted to a neurosurgery clinic. CT and contrast MRI revealed an expansive multilocular lesion 45 x 35 mm in size in the left parietal lobe, differentially diagnosed as malignant glioma. The lesion was biopsied and the histology showed a brain abscess containing white blood cells and dead tissue. The aspirated pus culture yielded bacteria of the genus Nocardia that were further identified, in the first step, by phenotypic methods (Gram positivity, partial acidoresistance, airborne mycelium detection, growth at 45 degrees C, lysozyme resistance and antibiotic resistance phenotype) as belonging to resistance phenotype V., v.s. N. farcinica (resistance to aminoglycosides except amikacin and to third-generation cephalosporins). In the second step of the polyphasic identification, rDNA was isolated and a 1000 bp part of the 16S rRNA gene was sequenced. Sequence comparison with the GenBank database using BLAST software identified the agent as N. farcinica (100%). The isolate was tested for susceptibility by the NCCLS /CLSI dilution method and showed good susceptibility to co-trimoxazole, amikacin and imipenem. The patient was treated with long-term intravenous cotrimoxazole acid in combination with amikacin and his clinical condition and laboratory parameters of inflammation improved. N. farcinica is among the three most frequently isolated Nocardia species in Europe as well as in the Czech Republic where it was repeatedly recovered from the lungs and respiratory tract of immunocompromised patients with systemic nocardiosis.

[The use of molecular genetics techniques in clinical microbiology--final report from the workshop of the Molecular Microbiology Working Group TIDE]. / Aplikace metod molekulární genetiky v klinické mikrobiologii: zpráva z jednání Pracovní skupiny molekulárni mikrobiologie--TIDE.

In the last decade, there has been a rapid development in the use of molecular genetics methods in clinical microbiology. Novel technologies bring new knowledge and approaches to various disciplines of microbiology--taxonomy, identification of microbes, clinical diagnosis, epidemiology of infectious diseases and antibiotic resistance. This article summarizes the conclusions from the workshop of the Molecular Microbiology Working Group TIDE held during the Second Annual Meeting of the Society for Medical Microbiology of the J. E. Purkyne Czech Medical Association.

[Filamentous "contaminants" in the mycobacteriology laboratory; their culture, identification and clinical significance]. / Vlálmoté "kontaminanty" v mykobakteriologické laboratori, jejich kultivace, identifikace a klinický význam.

Frequent "contaminants" detected during mycobacterial culture of decontaminated samples are bacteria of the order Actinomycetales. These are usually bacteria classified as the family Corynebacterineae, genera Corynebacterium, Dietzia, Gordonia, Nocardia, Rhodococcus and Tsukamurella. These bacteria frequently colonize the airways and, under certain circumstances, they may cause life-threatening diseases. In severely immunocompromised patients, they regularly cause life-threatening infections with bacteria of the genus Nocardia. These filamentous bacteria, developing aerial mycelium in the culture, are partly acid-resistant and resistant to lysozyme. They cause nocardiosis, a rare but serious disease in patients with various types of immune deficiency. Differential diagnosis must distinguish between the genera Streptomyces, Actinomadura and Nocardiopsis and other soil saprophytes that are not acid-resistant, sensitive to lysozyme and faster growing. They frequently colonize the airways of patients with lung disease but very rarely cause diseases. The diagnosis of aerobic actinomycetes and determination of their sensitivity to antibiotics are problematic since they grow longer, are difficult to stain and are involved in atypical biochemical reactions. Precise identification of the genera and species requires polyphasic identification of isolates using molecular microbiology methods. If diagnosed early, infections caused by aerobic actinomycetes are easy to treat with targeted antibiotic therapy.

Imaging of transfection and intracellular release of intact, non-labeled DNA using fluorescent nanodiamonds.

Efficient delivery of stabilized nucleic acids (NAs) into cells and release of the NA payload are crucial points in the transfection process. Here we report on the fabrication of a nanoscopic cellular delivery carrier that is additionally combined with a label-free intracellular sensor device, based on biocompatible fluorescent nanodiamond particles. The sensing function is engineered into nanodiamonds by using nitrogen-vacancy color centers, providing stable non-blinking luminescence. The device is used for monitoring NA transfection and the payload release in cells. The unpacking of NAs from a poly(ethyleneimine)-terminated nanodiamond surface is monitored using the color shift of nitrogen-vacancy centers in the diamond, which serve as a nanoscopic electric charge sensor. The proposed device innovates the strategies for NA imaging and delivery, by providing detection of the intracellular release of non-labeled NAs without affecting cellular processing of the NAs. Our system highlights the potential of nanodiamonds to act not merely as labels but also as non-toxic and non-photobleachable fluorescent biosensors reporting complex molecular events.

Transcriptome temporal and functional analysis of liver regeneration termination.

Decades of liver regeneration studies still left the termination phase least elucidated. However regeneration ending mechanisms are clinicaly relevant. We aimed to analyse the timing and transcriptional control of the latest phase of liver regeneration, both controversial. Male Wistar rats were subjected to 2/3 partial hepatectomy with recovery lasting from 1 to 14 days. Time-series microarray data were assessed by innovative combination of hierarchical clustering and principal component analysis and validated by real-time RT-PCR. Hierarchical clustering and principal component analysis in agreement distinguished three temporal phases of liver regeneration. We found 359 genes specifically altered during late phase regeneration. Gene enrichment analysis and manual review of microarray data suggested five pathways worth further study: PPAR signalling pathway; lipid metabolism; complement, coagulation and fibrinolytic cascades; ECM remodelling and xenobiotic biotransformation. Microarray findings pertinent for termination phase were substantiated by real-time RT-PCR. In conclusion, transcriptional profiling mapped late phase of liver regeneration beyond 5(th) day of recovery and revealed 5 pathways specifically acting at this time. Inclusion of longer post-surgery intervals brought improved coverage of regeneration time dynamics and is advisable for further works. Investigation into the workings of suggested pathways might prove helpful in preventing and managing liver tumours.

Unusual chromatographic behavior of oligonucleotide sequence isomers on two different anion exchange HPLC columns.

The retention behavior of the unmodified phosphodiester oligonucleotide sequence isomers was investigated on two different anion exchange columns: Biospher GMB 1000Q (based on DEAE-modified glycidyl methacrylate) and PolyWAX LP (based on silica with a crosslinked coating of linear polyethyleneimine). There was a notable difference in retention of oligonucleotides of the same composition but differing in the position of a single base. The most pronounced difference was observed between the oligonucleotides with the variable base in the end and in the center of the sequence. The use of either acetonitrile or 2-propanol as a mobile phase organic modifier did not markedly affect the retention time patterns. Prediction of the retention times of oligonucleotides must take into account the base position as well as identity. This is the first report of such a "same composition different sequence" effect, described for the short peptides, for synthetic oligonucleotides.

Familial hypertrophic cardiomyopathy owing to double heterozygosity for a 403Arg--> Trp mutation in exon 13 of the MYH7 gene and a novel mutation, 453Arg--> His, in exon 14 of the MYH7 gene: A case report.

An unusual clinical history of a 23-year-old male proband with obstructive hypertrophic cardiomyopathy associated with a rare genotype is presented. Genetic analysis of the proband found evidence for two distinct mutations of the MYH7 gene (the gene coding for the beta-myosin heavy chain): 403Arg--> Trp in exon 13 and a novel mutation, 453Arg--> His, in exon 14. A heterozygous site mutation was identified in exon 13 in the proband's father but no mutation site was found in his mother. Thus, the novel mutation in exon 14 is a de novo mutation.