Biomedical subjects

U Reischl

Publications and source records attributed to U Reischl.

At least 37 records · Page 2Linked to original sources

PubMed2000

[Disciform keratatis caused by Bartonella henselae infection: detection of a rare ocular complication of cat-scratch disease with PCR].

BACKGROUND: Cat scratch disease (CSD) is a common infectious disease, however its association with a disciforme keratitis is to our knowledge a previously unreported ocular complication. PATIENT: A 65-year old female was treated unsuccessfully with topical antibiotics, acyclovir and corticosteroids for several weeks because of a disciforme keratitis. Repeatedly, microbiological investigations (microscopy and culture) were negative. 16S rDNA-PCR with subsequent DNA-sequencing on material obtained by corneal scrape identified Bartonella henselae. Based on this result we have initiated a treatment with topical cephotaxim and within a short period of time the cornea healed with a paracentral scar. CONCLUSION: 16S rDNA-PCR was very helpful in identifying the intracellular sited bacterium Bartonella henselae as the causative pathogen of an unusual form of disciforme keratitis.

Aged↗

PubMed2000

[Polymerase chain reaction (PCR) for microbiological diagnosis in refractory infectious keratitis: a clinical study in 16 patients].

BACKGROUND: The identification of the causative pathogen in infectious keratitis is possible in only 60% of the cases. The aim of this study was to show if this number increases by the use of PCR. PATIENTS AND METHODS: In a series of 16 eyes with infectious keratitis corneal specimens were collected for culture and PCR. Serology (HSV, VZV, and Borrelia) was performed in all eyes, with exception of the 4 eyes presenting an acute form of keratitis, which obviously was bacterial origin. RESULTS: In all 4 cases of acute keratitis the causative pathogen (Pseudomonas aeruginosa) was detected by both culture and PCR. Of the remaining 12 eyes PCR was capable to identify the causative pathogen in 11 eyes. In 3 eyes herpes simplex virus was detected, in 3 eyes Moraxella catharalis, in 2 eyes Borrelia burgdorferii, in 2 eyes varizella zoster virus, and in 1 eye Bartonella henselae. Culture was positive in only 2 eyes, infected by Moraxella catharalis. CONCLUSIONS: PCR is a useful supplement in the microbiological diagnostic of infectious keratitis, in particular if only a small amount of pathogens are available (non-acute form) or if the eye has been treated by antibiotics prior to the microbiological diagnostic.

Chronic Disease↗

PubMed2000

Mycobacterium heckeshornense sp. nov., A new pathogenic slowly growing Mycobacterium sp. Causing cavitary lung disease in an immunocompetent patient.

A pathogenic scotochromogenic Mycobacterium xenopi-like organism was isolated from the lung of an immunocompetent young woman. This pathogen caused severe bilateral cavitary lung disease, making two surgical interventions necessary after years of chronic disease. This case prompted us to characterize this mycobacterium by a polyphasic taxonomic approach. The isolate contained chemotaxonomic markers which were typical for the genus Mycobacterium, i.e., the meso isomer of 2,6-diaminopimelic acid, arabinose, and galactose as diagnostic whole-cell sugars, MK-9(H(2)) as the principal isoprenoid quinone, a mycolic acid pattern of alpha-mycolates, ketomycolates, and wax ester mycolates, unbranched saturated and unsaturated fatty acids plus a significant amount of tuberculostearic acid, and small amounts of a C(20:0) secondary alcohol. On the basis of its unique 16S rRNA and 16S-23S spacer gene sequences, we propose that the isolate should be assigned to a new species, Mycobacterium heckeshornense. This novel species is phylogenetically closely related to M. xenopi. The type strain of M. heckeshornense is strain S369 (DSM 44428(T)). The GenBank accession number of the 16S rRNA gene of M. heckeshornense is AF174290.

Adult↗

PubMed2000

Novel diagnostic algorithm for identification of mycobacteria using genus-specific amplification of the 16S-23S rRNA gene spacer and restriction endonucleases.

A novel genus-specific PCR for mycobacteria with simple identification to the species level by restriction fragment length polymorphism (RFLP) was established using the 16S-23S ribosomal RNA gene (rDNA) spacer as a target. Panspecificity of primers was demonstrated on the genus level by testing 811 bacterial strains (122 species in 37 genera from 286 reference strains and 525 clinical isolates). All mycobacterial isolates (678 strains among 48 defined species and 5 indeterminate taxons) were amplified by the new primers. Among nonmycobacterial isolates, only Gordonia terrae was amplified. The RFLP scheme devised involves estimation of variable PCR product sizes together with HaeIII and CfoI restriction analysis. It yielded 58 HaeIII patterns, of which 49 (84%) were unique on the species level. Hence, HaeIII digestion together with CfoI results was sufficient for correct identification of 39 of 54 mycobacterial taxons and one of three or four of seven RFLP genotypes found in Mycobacterium intracellulare and Mycobacterium kansasii, respectively. Following a clearly laid out diagnostic algorithm, the remaining unidentified organisms fell into five clusters of closely related species (i.e., the Mycobacterium avium complex or Mycobacterium chelonae-Mycobacterium abscessus) that were successfully separated using additional enzymes (TaqI, MspI, DdeI, or AvaII). Thus, next to slowly growing mycobacteria, all rapidly growing species studied, including M. abscessus, M. chelonae, Mycobacterium farcinogenes, Mycobacterium fortuitum, Mycobacterium peregrinum, and Mycobacterium senegalense (with a very high 16S rDNA sequence similarity) were correctly identified. A high intraspecies sequence stability and the good discriminative power of patterns indicate that this method is very suitable for rapid and cost-effective identification of a wide variety of mycobacterial species without the need for sequencing. Phylogenetically, spacer sequence data stand in good agreement with 16S rDNA sequencing results, as was shown by including strains with unsettled taxonomy. Since this approach recognized significant subspecific genotypes while identification of a broad spectrum of mycobacteria rested on identification of one specific RFLP pattern within a species, this method can be used by both reference (or research) and routine laboratories.

Algorithms↗

PubMed2000

Rapid identification of methicillin-resistant Staphylococcus aureus and simultaneous species confirmation using real-time fluorescence PCR.

A duplex LightCycler PCR assay targeting the mecA gene and a Staphylococcus aureus-specific marker was used to test 165 S. aureus strains and 80 strains of other bacterial species. Within an assay time of 60 min plus 10 min for sample preparation, S. aureus as well as the presence or absence of the mecA gene was correctly identified.

Bacterial Proteins↗

PubMed2000

Molecular evidence of bacteremia by gastrointestinal pathogenic bacteria in an infant mummy from ancient Egypt.

In this study, we describe an infant mummy from ancient Egypt that showed macromorphologic signs of chronic anemia and vitamin C deficiency. From this infant, we have obtained a sterile sample from a metatarsal bone to extract ancient bacterial DNA. Following polymerase chain reaction amplification and subcloning of the amplicons, the sequence of the 16S ribosomal DNA was determined in several resulting clones. The presence of pathogenic and apathogenic bacteria, such as Escherichia coli, are indicated by our result, providing evidence of bacteremia, which probably contributed to death due to septicemia. These findings suggest that the infant, who already had chronic anemia and vitamin C deficiency, acquired a gastrointestinal infection, which finally led to a systemic spread. To our knowledge, this is the first case identifying potentially septicemic bacterial dissemination in an ancient Egyptian mummy. Using our approach, we hope to investigate distinct paleomicrobiological aspects of ancient populations, which will potentially enlighten our understanding of the development and evolution of pathogenic bacteria.

Bacteremia↗

PubMed1999

Regression and epithelial hyperplasia after myopic photorefractive keratectomy in a human cornea.

We present the histology of a cornea of a woman who had excimer laser photorefractive keratectomy (PRK) for myopia 6 months before she died in an accident. Preoperative spherical refraction was -6.00 diopters (D) with an astigmatism of -0.50 D. Six months postoperatively, refraction was -4.50 D. Slight corneal haze was noted at 1 and 3 months. The corneal histology showed marked epithelial hyperplasia in the center of the ablation zone without subepithelial deposition of newly synthesized collagen, proteoglycans, or both. The epithelial thickness was 38 microns in the untreated area and 93 microns in the center of the ablation. In conclusion, postoperative epithelial hyperplasia was responsible for regression after PRK in this eye.

Adult↗

PubMed1999

Variations in the 16S rRNA gene sequence of Yersinia enterocolitica isolates influence the specificity of molecular identification systems.

Four identification systems were used to type Yersinia enterocolitica strain Y11 and Yersinia enterocolitica sensu strictoT. Two systems based on biochemical reaction patterns identified both strains as Yersinia enterocolitica. Two molecular assays targeting the 16S rRNA gene failed to identify either strain Y11 or the type strain. Therefore, both strains were typed by the classical taxonomical approach requiring a determination of the overall base composition and the base sequence similarity using hybridization. Again both strains were classified as Yersinia enterocolitica isolates. Consequently, the sequences of the 16S rRNA gene of both strains were determined and compared. The strains differed in a region where nucleotide changes between species of the genus Yersinia had been described earlier. These differences may explain the failure of the molecular assays to identify the strains. They also demonstrate an independent evolution of the 16S rRNA genes in the species Yersinia enterocolitica sensu stricto suggesting an amendment to the nomenclature to be used in the future.

DNA, Ribosomal↗

PubMed1999

A case of severe chronic active infection with Epstein-Barr virus: immunologic deficiencies associated with a lytic virus strain.

Infectious mononucleosis (IM) is a self-limiting, lymphoproliferative disease induced by primary infection with the Epstein-Barr virus (EBV). Infection with EBV leads in general to lifelong asymptomatic persistence of the virus. We report the case of a woman who acquired IM at the age of 15 years and then suffered from recurrent high fever, fatigue, and signs of immunologic disorder for more than 12 years until she died of liver failure. In an attempt to describe and to define the course of chronic active infection with EBV, we performed immunologic and molecular assays that demonstrated lytic replication of EBV in the B and T cells of the peripheral blood. In addition to signs of humoral and cellular immune deficiency, we detected an EBV strain with an impaired capability to immortalize B cells and a tendency to lytic replication, thus contributing to the pathogenesis of this chronic active infection.

Adult↗

PubMed1999

Optimal detection and identification of Mycobacterium haemophilum in specimens from pediatric patients with cervical lymphadenopathy.

Acid-fast bacilli from pediatric patients with lymphadenopathy were detected in the BACTEC radiometric system and in MB Redox broth, but not on Löwenstein Jensen medium. PCR amplification identified the isolates as Mycobacterium haemophilum, which has special nutrition requirements (iron supplements) for growth. Suitable culture medium ensures optimal recovery of this microorganism, avoiding underdiagnosis.

Base Sequence↗

PubMed1999

Light on population health status.

A new approach to illustrating and analysing health status is presented which allows comparisons of various aspects of health in a population at different times and in different populations during given periods. Both quantitative and qualitative elements can be represented, the impact of interventions can be monitored, and the extent to which objectives are achieved can be assessed. The practical application of the approach is demonstrated with reference to the health profiles to Tunisia in 1966 and 1994.

Adult↗

PubMed1998

[Epidermal growth factor (EGF) in tears in excimer laser photorefractive keratectomy. Responsible for postoperative refraction and "haze"?].

BACKGROUND: Corneal wound healing is of critical importance for the postoperative outcome of excimer laser PRK. Wound healing is a complex biological process that is well characterised at the microscopic level, but its regulation is poorly understood at the molecular level. Among various cytokines, epidermal growth factor (EGF) plays an important role in superficial wound healing. The synthesis of EGF varies individually; therefore, by determining the EGF concentration in the tear fluid, patients with increased wound healing activity might be traced. METHODS: In this study we measured the EGF concentration pre- and postoperatively in the tear fluid of 50 eyes using a ELISA test. The preoperative refraction was between -2.00 and -10.00 dioptres. The maximum follow-up was 6 months. RESULTS: Preoperatively, in all eyes the EGF concentration in the tear fluid was between 0.2 and 1.7 ng/ml. In contrast, 1 week postoperatively, these values increased (0.21-22.50 ng/ml); 4 weeks postoperatively, the EGF concentration was in all eyes back to preoperative levels. In eyes with high EGF tear fluid concentration 1 week after surgery, refraction at 6 months was outside the intended correction of +/- 1.0 D. We could not find any correlation between EGF concentration and "corneal haze". CONCLUSIONS: EGF may play an important role in postoperative wound healing after excimer laser PRK. Investigations concerning a pharmaceutical control of EGF should be undertaken.

Adult↗

PubMed1998

Chronic gastritis in tigers associated with Helicobacter acinonyx.

Helicobacter pylori-like organisms (HPLOs) were isolated from the gastric mucosa of two Sumatran tigers and identified by polymerase chain reaction analysis as Helicobacter acinonyx. At histological examination, both tigers revealed a chronic gastritis associated with HPLOs as demonstrated by immunolabelling and electron microscopy. This is the first isolation of H. acinonyx from tigers, in which, as previously reported in cheetahs, it may be a cause of gastritis.

Animals↗

PubMed1998

Specific detection of monkeypox virus by polymerase chain reaction.

The open reading frame coding for the A-type inclusion body protein (ATI) of monkeypox virus (MPV) was identified and sequenced for two strains. Nucleotide sequence comparison revealed 72-95.3% homology with the reported open reading frame sequences of the ATIs of other orthopoxvirus species, such as variola, vaccinia, cowpox, ectromelia, and camelpox viruses. Each MPV strain contained an 8-bp deletion, which caused a frameshift that introduced a premature stop in the open reading frame at base 2091 relative to the ATI open reading frame of cowpox virus strain Brighton. The sequences enabled a primer pair to be designed that flanked the deletion and specifically amplified a 601-bp fragment that identified and differentiated 19 MPV strains examined from five other Old World orthopoxvirus species examined. The specificity was confirmed by cleavage of the 19 MPV strain amplicons with BglII, which produced three subfragments of expected sized, based on the determined MPV sequences.

Animals↗

PubMed1998

Characterization of an isolate belonging to the newly described species Mycobacterium hassiacum.

The isolation, from a urine sample, of a rapidly growing acid-fast mycobacterium assigned to the thermophilic species Mycobacterium hassiacum led to further insight into present knowledge of this newly described organism. Already known phenotypic traits of M. hassiacum were extended and its susceptibility to additional antimicrobials was investigated. The high-performance liquid chromatography pattern of mycolic acids is, for the first time, presented. So far, no clinical relevance was proved for our isolate; likewise for the one which led to the species' original description.

Female↗

PubMed1998

Diagnosis of infectious endophthalmitis after cataract surgery by polymerase chain reaction.

PURPOSE: To ascertain whether the use of the polymerase chain reaction (PCR) technique leads to more rapid diagnosis of infectious endophthalmitis after cataract surgery. SETTING: University Eye Clinic Regensburg, Germany. METHODS: The aqueous humor and vitreous of 16 eyes with infectious endophthalmitis (10 acute, 6 delayed) were evaluated by microscopy, diagnostic culture, and PCR to detect the infectious agent. RESULTS: Microscopy of the vitreous was positive in 3 eyes and the culture media results were positive in 7 eyes, all with acute endophthalmitis. Significantly fewer positive results were obtained in the aqueous humor. Using PCR, an infectious agent was detected in the aqueous humor of all 16 eyes and in the vitreous of 14. The vitreous sample was negative in 2 eyes with delayed endophthalmitis. CONCLUSIONS: Detection of the infectious agent was more successful using PCR than using conventional microbiological tests, especially in the diagnosis of delayed endophthalmitis where the pathogen was detected in the aqueous humor in all eyes.

Acute Disease↗

PubMed1998

[Listeria monocytogenes-induced endogenous endophthalmitis in an otherwise healthy patient: PCR-assisted rapid diagnosis as the basis for successful therapy].

BACKGROUND: Listeria monocytogenes is a rare cause of endogenous endophthalmitis. Only 14 cases are published in the literature so far. All eyes showed similar clinical features and profound visual loss. PATIENTS AND METHODS: We report on a case of an otherwise healthy 73-year-old male. He was referred to our hospital because of acute hypopyoniritis with secondary glaucoma. Within a few hours the severity of the intraocular infection increased dramatically resulting in the clinical picture of an acute endophthalmitis. RESULTS AND CONCLUSION: Early identification of the causative pathogen in the aqueous humor after anterior chamber paracenthesis using polymerase chain reaction (PCR) and the initiation of a specific, systemic antibiotic medication resulted in a complete recovery of visual acuity.

Acute Disease↗

PubMed1998

Mycobacterium bohemicum sp. nov., a new slow-growing scotochromogenic mycobacterium.

A new, slow-growing, scotochromogenic mycobacterium was isolated from sputum of a 53-year-old patient with Down's syndrome suffering from tuberculosis. Growth occurred at temperatures between 25 and 40 degrees C with an optimum at 37 degrees C. This strain had surprisingly few enzymic activities (only positive for 68 degrees C heat-stable catalase and weakly positive for urease) and was sensitive to prothionamide, cycloserine, clarithromycin, gentamicin and amikacin but showed resistance to isoniazid, streptomycin, ethambutol, rifampin and ciprofloxacin. These characteristics assign this organism to a novel mycobacterial species characterized by a unique 16S rDNA nucleotide sequence. The name Mycobacterium bohemicum sp. nov. is proposed for this new, slow-growing, scotochromogenic mycobacterium. The type strain is DSM 44277T.

Base Composition↗