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Biomedical subjects

U Reischl

Publications and source records attributed to U Reischl.

At least 19 recordsLinked to original sources

Use of partial 16S rRNA gene sequencing for identification of Legionella pneumophila and non-pneumophila Legionella spp.

We examined 49 Legionella species, 26 L. pneumophila and 23 non-pneumophila Legionella spp., using partial 16S rRNA gene sequencing. This approach accurately identified all the L. pneumophila isolates, characterized all non-pneumophila Legionella isolates as such within this genus, and classified most (20/23; 87%) of the non-pneumophila Legionella isolates to the species level.

Bacterial Typing Techniques↗

[Control of methicillin-resistant S. aureus by active surveillance. Results of a workshop held by the Deutsche Gesellschaft für Hygiene und Mikrobiologie].

In Germany, methicillin-resistant S. aureus (MRSA) is increasing continuously. To control the spread of MRSA, active surveillance and admission screening are recommended. In most cases, screening cultures of patients at risk for MRSA will be sufficient. Screening of all patients admitted to an ICU is cost-effective when the incidence of MRSA and nosocomial MRSA infections is high (>2 cases/100 patients and 0.3 MRSA infections/100 patients, respectively): Under these circumstances, a decrease in the incidence of nosocomial MRSA infections of 50% leads to cost-effectiveness at costs of 16 Euro/sample (including subsequent costs). If the incidence of nosocomial MRSA infections decreases by 75%, costs of 24 Euro/sample (including subsequent costs) are cost-effective. If the incidence of MRSA is high, screening by PCR may be cost-effective for patients at high risk for MRSA, especially if they are isolated prophylactically. Recently, PCR methods have been developed which allow the specific identification of MRSA even from nasal swabs.

Cost-Benefit Analysis↗

Sterile abscess: a surprise diagnosis?

We present the case of an otherwise healthy female hairdresser of Brazilian origin who started to have pain and swelling in her left arm. An antecubital abscess was surgically treated at another institution and there was good initial wound healing. Swelling then recurred and fistulae appeared in the scar. Our diagnostic workup revealed an isolated intramuscular tuberculous abscess, which was successfully treated by an antituberculous drug regimen.

Abscess↗

Healthcare-associated outbreaks and community-acquired infections due to MRSA carrying the Panton-Valentine leucocidin gene in southeastern Germany.

In response to several isolations of methicillin-resistant Staphylococcus aureus carrying the Panton-Valentine leucocidin gene (PVL-MRSA), the present study was conducted to document the spread of infection in a small region of southeastern Germany. During a 9-month period, two healthcare-associated outbreaks with PVL-MRSA occurred, affecting 83 patients, personnel and contacts of personnel, and 34 additional cases were detected in the community. The clinical spectrum ranged from colonization to skin infection and necrotizing pneumonia. The findings represent the largest number of PVL-MRSA cases detected in Germany so far, and demonstrate the potential of this emerging pathogen to spread within the community and in healthcare institutions.

Adolescent↗

An ospA-polymerase chain reaction/restriction fragment length polymorphism-based method for sensitive detection and reliable differentiation of all European Borrelia burgdorferi sensu lato species and OspA types.

We describe a sensitive and reliable method for detection and differentiation of the five relevant European Borrelia burgdorferi sensu lato species ( B. burgdorferi sensu stricto, B. afzelii, B. garinii, B. valaisiana, and B. lusitaniae), based on a heminested ospA-PCR followed by restriction enzyme analysis. Sensitivity was one borrelia per PCR except for B. afzelii, where it was five per PCR. None of seven relapsing fever borreliae, eight Leptospira serovars or two Treponema species were amplified. Except B. garinii, each of the five B. burgdorferi s.l. species is represented by one or two characteristic restriction fragment length polymorphism (RFLP) patterns. Analysis of the heterogeneous group of B. garinii resulted in five different RFLP patterns, corresponding to the OspA types 3-7 associated with this species. In a pilot study on 529 Ixodes ricinus ticks from three different regions in Southern Germany, all species and OspA types were found except B. lusitaniae and B. garinii OspA type 7, arguing for a broad distribution of almost all OspA types. A further notable finding was the focal prevalence of OspA type 4, which has rarely been detected in ticks previously. Thus, the developed method provides a fast and simple tool for epidemiological studies on the heterogeneity of species and OspA types in Europe which has important implications for the development of vaccines and (microbiological) test systems for Europe.

Animals↗

Rapid and standardized detection of Chlamydia pneumoniae using LightCycler real-time fluorescence PCR.

In order to meet the need of many microbiological laboratories for a standardized system for detecting Chlamydia pneumoniae in respiratory specimens, a hybridization probe-based LightCycler (Roche Diagnostics, Germany) PCR assay was developed. The assay's analytical sensitivity and specificity were evaluated according to the recommendations of the Centers for Disease Control and Prevention (USA) and Laboratory Centre for Disease Control (Canada). Seventy-four bacterial species other than Chlamydia pneumoniae, including strains of Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pecorum, tested negative. Six of six representative Chlamydia pneumoniae strains tested positive. An analytical sensitivity of 1 inclusion forming unit per ml of bronchoalveolar lavage fluid, corresponding to 0.02 inclusion forming units per PCR reaction, was observed. The assay showed 100% specificity and sensitivity for Chlamydia pneumoniae when testing DNA preparations from 12 specimens of patients with known pulmonary Chlamydia pneumoniae infection and from 78 specimens of patients with respiratory tract disease of other origin. The newly developed LightCycler assay may contribute to the urgently needed standardization of laboratory diagnosis of Chlamydia pneumoniae.

Bacteriological Techniques↗

Molecular study on human tuberculosis in three geographically distinct and time delineated populations from ancient Egypt.

We describe the molecular identification of human tuberculosis (TB) from vertebral bone tissue samples from three different populations of ancient Egypt. The specimens were obtained from the predynastic to early dynastic necropolis of Abydos (7 individuals, c. 3500-2650 B.C.), from a Middle Kingdom to Second Intermediate Period tomb of the necropolis of Thebes-West (37. c. 2100-1550 B.C.) and from five further Theban tombs used in the New Kingdom and the Late Period (39, c. 1450-500 B.C.). A total of 18 cases tested positive for the presence of ancient DNA (aDNA) of the M. tuberculosis complex. Out of the 9 cases with typical macromorphological signs of tuberculous spondylitis, 6 were positive for mycobacterial aDNA (66.7%). Of 24 cases with non-specific pathological alterations, 5 provided a positive result (20.8%). In 50 cases of normally appearing vertebral bones 7 tested positive (14.0%). There were only minor differences in the frequencies between the three populations. These data strongly support the notion that tuberculosis was present and prevalent in ancient Egypt since very early periods of this civilization. The unexpectedly high rate of mycobacterial aDNA in normal bone samples is presumably due to a pre- to perimortal systemic spread of the bacteria and indicates a generalized infection by M. tuberculosis.

Bone and Bones↗

Evaluation of a commercial line probe assay for identification of mycobacterium species from liquid and solid culture.

The performance of a commercial line probe assay (LiPA) (Inno-LiPA Mycobacteria; Innogenetics, Belgium) for the detection and identification of Mycobacterium species from liquid and solid culture was evaluated at five routine clinical laboratories. The LiPA method is based on the reverse hybridization principle, in which the mycobacterial 16S-23S ribosomal RNA (rRNA) spacer region is amplified by polymerase chain reaction (PCR). Amplicons are subsequently hybridized with oligonucleotide probes arranged on a membrane strip and detected by a colorimetric system. The test detects the presence of Mycobacterium species and specifically identifies Mycobacterium tuberculosis complex, Mycobacterium kansasii, Mycobacterium xenopi, Mycobacterium gordonae, Mycobacterium avium complex, Mycobacterium avium, Mycobacterium intracellulare, Mycobacterium scrofulaceum, and Mycobacterium chelonae - Mycobacterium abscessus complex. The results of LiPA were compared with the results obtained using traditional biochemical and molecular tests (DNA probe-based techniques, PCR restriction enzyme analysis of the 65 kDa heat-shock protein gene, and sequencing of the 16S rDNA). A total of 669 isolates, 642 of which were identified as Mycobacterium species and 27 as non- Mycobacterium species, were tested by LiPA. After analysis of 14 initially discordant results and exclusion of one isolate, concordant results were obtained for 636 of 641 Mycobacterium isolates (99.2% accuracy). All Mycobacterium species reacted with the MYC ( Mycobacterium species) probe (100% sensitivity), and all non- Mycobacterium species were identified as such (100% specificity).

Bacterial Typing Techniques↗

[Corneal haze after photorefractive keratectomy. Role of individual collagen type IV synthesis on postoperative corneal opacity].

PURPOSE: Histological studies on human corneas have shown that collagen type IV plays a major role in the development of haze after photoreactive keratectomy (PRK). Currently, there is no clinically available pharmaceutical agent which can inhibit the synthesis of collagen IV. The aim of this study was to determine if there are individual differences in the expression of collagen IV and if there is a correlation between the amount of collagen IV and haze. This would give new options to prevent haze after PRK. PATIENTS AND METHODS: PRK was carried out on 26 eyes (26 patients) with a myopia ranging between -1.50 to -6.00 D. Prior to the surgery a small sample of epithelium was taken from the cornea and the individual concentration of collagen IV alpha 3 mRNA was quantitatively determined by a newly developed PCR test. RESULTS: In all samples collagen IV alpha 3 mRNA was measured with levels between 0.11 and 6.42 (mean: 1.68; SD: 1.64). There was a correlation between haze and the amount of collagen IV alpha 3 mRNA. (r = 0.92). CONCLUSIONS: With this quantitative PCR-based test we were able to measure the individual collagen IV mRNA concentration in corneal epithelial cells. Further development of this test could establish a screening test which identifies patients with a pronounced synthesis of collagen IV as high risk individuals in terms of haze.

Adult↗

Semiquantitative PCR analysis of Epstein-Barr virus DNA in clinical samples of patients with EBV-associated diseases.

The laboratory diagnosis of primary and reactivated Epstein-Barr virus (EBV) infection is based on serologic methods in immunocompetent patients. However, in immunocompromised patients, serologic data are difficult to interpret and do not often correlate with clinical data. In order to find a useful and practical marker for diagnosis of EBV-related diseases, a polymerase chain reaction (PCR) assay was established for semiquantitative detection of EBV sequences. The method was based on a nested PCR, using primers of the virus capsid antigen p23 region and an endpoint dilution. This method was carried out on 68 plasma samples, 68 samples of peripheral blood mononuclear cells and 5 cerebrospinal fluid samples of 39 patients with various diseases to evaluate the EBV-genome copy number. Samples from patients suffering from infectious mononucleosis served as positive controls for active EBV infection. In 5 patients with infectious mononucleosis, high copy numbers of EBV genomes in peripheral blood mononuclear cells were detected within a range of 1,000-40,000 copies in 10(5) peripheral blood mononuclear cells. In contrast, samples from 19 latently infected persons either showed low copy numbers (10-100 in 10(5) peripheral blood mononuclear cells) or were EBV PCR negative. Comparable results were observed in seven renal transplant patients without any symptoms. The practical value of the semiquantitative detection of EBV DNA was demonstrated in three bone marrow transplant recipients. Two developed a lymphoproliferative disease associated with extremely high amounts of EBV DNA in plasma (16,000 and 50,000 copies/ml, respectively) and peripheral blood mononuclear cells (100,000 and 6.5 million copies in 10(5) peripheral blood mononuclear cells, respectively). The high EBV load in plasma and peripheral blood mononuclear cells was reduced dramatically after successful antiviral therapy in one case. The third bone marrow transplant recipient developed an EBV-induced transverse myelitis with an increased number of EBV-genome copies in peripheral blood mononuclear cells and EBV-positive cerebrospinal fluid samples. After combined antiviral and immune therapy, the EBV-genome copy numbers decreased and the patient recovered completely. These data demonstrate a good correlation between semiquantitative detection of EBV genomes and clinical findings. The method is recommended for the diagnosis of EBV-associated diseases in patients after transplantation, as well as for monitoring the response to therapy.

Acute Disease↗

[Screening of myopic LASIK patients with increased epithelial wound healing].

BACKGROUND: Wound healing of the cornea is critical for the refractive outcome of myopic laser-assisted in situ keratomileusis (LASIK). As epidermal growth factor (EGF) is important for the origin of epithelial hyperplasia, this study examined preoperative EGF mRNA concentrations in the corneal epithelial cells to detect patients with increased epithelial wound healing response. PATIENTS AND METHODS: The epithelium was biopsied before LASIK in 35 eyes with myopia of -10.0 D. The EGF mRNA concentration in the epithelial cells was quantified by polymerase chain reaction and enzyme-linked oligosorbent assay, and the correlation with postoperative refraction at 6 months was assessed. RESULTS: All eyes were around emmetropia 3 weeks after the surgery. At 6 months postoperatively 27 eyes were within +/- 1.0 D of emmetropia while 8 showed regression of 2.0-4.0 D. Higher EGF mRNA levels were found in eyes with regression than in eyes with postoperative emmetropia. CONCLUSIONS: Preoperative EGF mRNA concentration in the corneal epithelial cells may be an indicator of postoperative refractive outcome of myopic LASIK and offers a new possibility for pharmaceutical manipulation.

Adult↗

Mycobacterium doricum sp. nov.

A novel mycobacterial species is described in this study. The strain was isolated from the cerebrospinal fluid of a severely immunocompromised AIDS patient. It was scotochromogenic and slow-growing. Characteristic features for its differentiation from other mycobacteria are its lipid pattern and the unique gene sequences within the hypervariable regions of the 16S rDNA. The strain shows susceptibility to current antimycobacterial drugs. The pathogenicity of the novel mycobacterium and its clinical significance are not certain, as the neurological symptoms of the patient could also be due to concomitant infection with Cryptococcus neoformans. The name Mycobacterium doricum sp. nov. is proposed for the novel mycobacterium; the type strain is strain FI-13295T (= DSM 44339T = CIP 106867T).

AIDS-Related Opportunistic Infections↗

In vitro activities of six quinolones and mechanisms of resistance in Staphylococcus aureus and coagulase-negative staphylococci.

Of 94 clinical isolates of Staphylococcus aureus (n = 51) and coagulase-negative staphylococci (CNS) (n = 43), mutations in the quinolone resistance-determining region of topoisomerases GrlA, GrlB, GyrA, and GyrB together with MICs of six quinolones were analyzed. Amino acid substitutions at identical residues (GrlA residues 80 and 84; GyrA residues 84 and 88) were found in S. aureus and CNS. Active efflux, as suggested by blocking by reserpine, contributed substantially to the resistance phenotype in some strains. Among ciprofloxacin, clinafloxacin, levofloxacin, nalidixic acid, trovafloxacin, and sparfloxacin, a 0.5-microg/ml concentration of sparfloxacin discriminated best between strains with two or three mutations and those with no mutations.

4-Quinolones↗

Real-time PCR assay targeting IS481 of Bordetella pertussis and molecular basis for detecting Bordetella holmesii.

Detection of Bordetella holmesii by a real-time PCR assay targeting IS481 of Bordetella pertussis is reported. Sequencing of IS481-specific PCR products from B. pertussis and B. holmesii isolates revealed sequence homology. Restriction fragment length polymorphism demonstrated a low copy number of IS481-like sequences in B. holmesii. These results, and culture of B. holmesii from patients with cough, suggest that the specificity and predictive value of IS481-based PCR assays for pertussis may be compromised.

Bordetella↗

Molecular evidence for different stages of tuberculosis in ancient bone samples from Hungary.

This paleomicrobiologic study was conducted on osseous tissue specimens from ancient Hungarian skeletal samples from the 7-8th and the 17th centuries AD with typical macromorphologic evidence of osseous tuberculosis (n = 3), morphologic alterations probably due to tuberculosis (n = 6), or with nontypical osseous changes of vertebral bodies suggestive of inflammatory reaction (n = 5). From these bone samples, DNA was extracted and amplified by polymerase chain reaction (PCR) by using various primer pairs recognizing DNA segments of different mycobacterial species. To confirm specificity of the analysis, the amplification products of several samples were subjected to restriction enzyme digestion and/or direct sequencing. Of the analyzed 14 cases, 8 were unambiguously positive for mycobacterial DNA of the Mycobacterium tuberculosis complex, as shown by the amplification of the IS6110 sequence. In 13 cases we found a PCR product with primers specific for the 65-kDa antigen gene, including 2 cases without genomic DNA. We conclude that the application of other mycobacterial DNA primers may reveal contamination of bones with atypical saprophytic mycobacteria. A positive result for typical mycobacteria was seen in 2 of 3 cases with typical morphologic signs of tuberculosis and amplifiable DNA, in 3 of 6 probable cases, but also in 3 of 6 cases with nontypical bone changes. This indicates that minor osseous reactions of the surface of vertebral bodies may be due-at least in several cases-to infections with bacteria of the M. tuberculosis complex. In these cases the disease may have proceeded rapidly, and the morphologic osseous changes may represent "early" stages of tuberculous infection of the vertebrae.

Adult↗

Improved detection of microorganisms by polymerase chain reaction in delayed endophthalmitis after cataract surgery.

OBJECTIVE: To evaluate whether the use of polymerase chain reaction (PCR) improves the identification of the causative pathogen in eyes developing delayed endophthalmitis after cataract surgery. DESIGN: Prospective, noncomparative case series. PARTICIPANTS: Consecutive series of 25 eyes with the clinical diagnosis of delayed endophthalmitis after cataract. MAIN OUTCOME MEASURE: Presence of bacterial or fungal DNA in aqueous humor and vitreous samples. RESULTS: In the aqueous humor the causative pathogen was identified in 84% (n = 21) of the eyes by PCR compared with 0% by diagnostic culture and 0% by microscopy. In the vitreous samples the pathogen was identified in 92% (n = 23) of the eyes by PCR compared with 24% by diagnostic culture (n = 6) and 0% by microscopy. CONCLUSIONS: PCR is useful for the identification of the causative pathogen in delayed endophthalmitis and had a higher rate of positive identification of the causative organism than microscopy or diagnostic culture.

Aqueous Humor↗