A Moter - Academia.edu (original) (raw)

Papers by A Moter

FEMS Microbiology Letters, 2000

A new technique is presented for analyzing subgingival bacterial plaque. Different materials (pol... more A new technique is presented for analyzing subgingival bacterial plaque. Different materials (polytetrafluoroethylene, gold, dentin) kept for several days in periodontal pockets of patients suffering from periodontitis were analyzed by electron microscopy and fluorescence in situ hybridization (FISH). Those parts of the carriers extending into the deepest zone of the pockets were predominantly colonized by spirochetes and Gram-negative bacteria whereas those segments in contact with a shallower region were colonized by streptococci. Independent of the material used, the bacterial colonization of the carriers appears to be similar. FISH using eubacteria-and species-specific oligonucleotides on semi-thin cross-sections of the carriers in combination with confocal laser scanning microscopy allowed detailed analysis of the architecture of biofilms and identification of putative periodontal pathogens with single cell resolution.

Commercially available nucleic acid probe-and amplification-based systems for detection and diffe... more Commercially available nucleic acid probe-and amplification-based systems for detection and differentiation of mycobacteria are widely used in clinical microbiology laboratories. Here we report two cases of human leprosy in which the COBAS AMPLICOR Mycobacterium intracellulare test led to false-positive results. Correct identification of Mycobacterium leprae was possible only by amplification and comparative sequence analysis of the 16S rRNA gene.

Journal of Bone and Joint Surgery-british Volume, 2015

The aim of the present study was to assess the antibiofilm activity of daptomycin- and vancomycin... more The aim of the present study was to assess the antibiofilm activity of daptomycin- and vancomycin-loaded poly(methyl methacrylate) (PMMA) and PMMA-Eudragit RL100 (EUD) microparticles against mature biofilms of polysaccharide intercellular adhesin-positive S. epidermidis. The effect of plain, daptomycin- and vancomycin-loaded PMMA and PMMA-EUD microparticles on S. epidermidis biofilms was assessed by isothermal microcalorimetry (IMC) and fluorescence in situ hybridization (FISH). Biofilms were grown for 48h onto poly-urethane pieces of fixed dimensions. Each sample was washed with PBS in order to remove planktonic bacteria and incubated for 24h with different concentrations of acrylic microparticles (20–1.25 mg/mL). The minimal biofilm inhibitory concentration (MBIC) of the antibiotic-loaded particles was defined as the lowest concentration of particles that was able to prevent heat flow associated to the recovery of the biofilms. After incubation with the microparticles, sessile coc...

Clinical Microbiology and Infection, 2017

Objectives: Aim of this study was to detect microorganisms in fetal membranes and placental tissu... more Objectives: Aim of this study was to detect microorganisms in fetal membranes and placental tissue in preterm chorioamnionitis by combining fluorescence in situ hybridization (FISH) with broad range PCR. The combination of the two molecular techniques enables identification and localization of the microorganisms within the tissue, confirming their clinical relevance. Methods: In a prospective cohort study, we compared 31 women with preterm premature rupture of membranes or preterm labour and preterm delivery by caesarean section with a control group of 26 women undergoing elective caesarean section at term. Fetal membranes and placental tissue were analysed by FISH and broad range 16S rRNA-gene PCR and sequencing. Results: For 20 women in the preterm group, caesarean section was performed because of a clinical diagnosis of chorioamnionitis. Microorganisms were detected in the tissues by both molecular techniques in 11 out of 20 women. Among those, Ureaplasma spp. was most abundant, with five cases that remained culture-negative and would have been missed by routine diagnostic procedures. Other infections were caused by Staphylococcus aureus, Streptococcus mitis or Escherichia coli. FISH and PCR were negative for all women without suspected chorioamnionitis and for the control group. Conclusions: Combination of FISH with broad-range PCR and sequencing permitted unambiguous identification of the causative microorganisms in chorioamnionitis. The high prevalence of Ureaplasma spp. should lead to a re-evaluation of its clinical significance and possible therapeutic consequences.

Infection and Immunity, 2014

The recent finding that high numbers of strict anaerobes are present in the respiratory tract of ... more The recent finding that high numbers of strict anaerobes are present in the respiratory tract of cystic fibrosis (CF) patients has drawn attention to the pathogenic contribution of the CF microbiome to airway disease. In this study, we investigated the specific interactions of the most dominant bacterial CF pathogen, Pseudomonas aeruginosa , with the anaerobic bacterium Veillonella parvula , which has been recovered at comparable cell numbers from the respiratory tract of CF patients. In addition to growth competition experiments, transcriptional profiling, and analyses of biofilm formation by in vitro studies, we used our recently established in vivo murine tumor model to investigate mutual influences of the two pathogens during a biofilm-associated infection process. We found that P. aeruginosa and V. parvula colonized distinct niches within the tumor. Interestingly, significantly higher cell numbers of P. aeruginosa could be recovered from the tumor tissue when mice were coinfect...

To evaluate the association of oral Treponema (T.) spp. with severity of canine periodontitis, su... more To evaluate the association of oral Treponema (T.) spp. with severity of canine periodontitis, subgingival plaque samples of dogs of various breeds undergoing surgery were investigated. A wide range of oral Treponema spp. was analysed by a molecular and culture-independent approach applying DNA-DNA dot blot hybridization analysis and fluorescence in situ hybridization using Treponema specific oligonucleotide probes specific for phylogenetic groups I-VII of oral treponemes as well as probes specific for T. socranskii and T. denticola. To assess the periodontal status of affected dogs clinical parameters were measured and the periodontal status was classified from grade 0 (physiological periodont) to 3 (severe periodontitis). The periodontal status correlated significantly with an increasing concentration of volatile sulfur compounds (VSC, r=0.854) determined with a Halimeter, indicating a positive correlation between the presence of VSC-producing bacteria and periodontitis. In this study Treponema spp. of phylogenetic groups III, V-VII were not detected in any sample, whereas T. denticola-like treponemes were found only in 2 of 51 animals. However, treponemes belonging to phylogenetic groups I, II and IV of oral treponemes or T. socranskii were found in up to 64.84% of the dogs. The detection rate of Treponema spp. was significantly associated with an increased periodontal status. Treponemes present in periodontal lesions were also visualized by fluorescence in situ hybridization of gingival biopsies showing Treponema spp. not only in the microbial biofilm but also within the gingival tissue. The data presented here indicate that oral Treponema spp. are associated with canine periodontitis. Similar to human periodontitis, treponemes of groups I, II and IV and T. socranskii were found more frequently the higher the degree of periodontitis was.

Antimicrobial Agents and Chemotherapy, 2012

In a patient with mitral-aortic native-valve Streptococcus oralis endocarditis, daptomycin concen... more In a patient with mitral-aortic native-valve Streptococcus oralis endocarditis, daptomycin concentrations in aortic and mitral valves were 8.6 and 30.8 μg/g, respectively, and 26 μg/g in the mitral vegetation. In the case of porcine-aortic-valve Staphylococcus epidermidis endocarditis, the daptomycin concentrations were 53.1 μg/g in the valve and 18.1 μg/g in perivalvular tissues. Daptomycin achieved apparently adequate tissue concentrations. S. epidermidis was eradicated, whereas Streptococcus oralis persisted, and its daptomycin MIC displayed a 4-fold increase.

Journal of Clinical Microbiology, 1998

Periodontitis, a disease responsible for tooth loss worldwide, is characterized by chronic inflam... more Periodontitis, a disease responsible for tooth loss worldwide, is characterized by chronic inflammation of the periodontium, eventually leading to destruction of periodontal ligaments and supporting alveolar bone. Spirochetes, identified by dark-field microscopy as being the most predominant bacteria in advanced lesions, are thought to play a causative role. Various spirochetal morphotypes were observed, but most of these morphotypes are as yet uncultivable. To assess the role of these organisms we designed oligonucleotide probes for the identification of both cultivable and so far uncultivable spirochetes in periodontitis patients. Subgingival plaque specimens taken from diseased sites ( n = 200) and healthy control sites ( n = 44) from 53 patients with rapidly progressive periodontitis (RPP) were submitted to direct in situ hybridization or dot blot hybridization after prior amplification with eubacterial primers. Spirochetes were found in all patients, but their distributions var...

Annals of oncology : official journal of the European Society for Medical Oncology, 1992

The Thoracic and Cardiovascular Surgeon

Chemotaxis is an important feature of motile organisms that allows navigation through various env... more Chemotaxis is an important feature of motile organisms that allows navigation through various environments. It enables them to detect nutrients and to avoid unfavorable or dangerous conditions. Motility and chemotaxis are widely acknowledged as important virulence factors for pathogenic bacteria. In this review, we try to explore the role of chemotaxis in the pathogenesis of spirochetes. Chemotaxis might be involved in tissue identification and penetration, and represents a possible mechanism for evasion of the host's immune defense. The recent development of genetic tools for pathogenic spirochetes and "tracking" techniques, employing fluorescent in situ hybridization (FISH), could revolutionize our understanding of the importance of chemotaxis for infection and persistence of these bacteria in their host.

Der Internist

Eine 24-jährige Patientin aus Sierra Leone wurde nach unklaren intrazerebralen Blutungsereignisse... more Eine 24-jährige Patientin aus Sierra Leone wurde nach unklaren intrazerebralen Blutungsereignissen und einer echoreichen Auflagerung an der Aortenklappe vorstellig. Die Patientin war bei paroxysmalem Vorhofflimmern und Non-compaction-Kardiomyopathie antikoaguliert. In der weiteren Diagnostik gelang durch Fluoreszenz-in-situ-Hybridisierung in Kombination mit Polymerase-Kettenreaktion und Sequenzierung der Nachweis einer durch Bartonellaquintana verursachten Mitral- und Aortenklappenendokarditis. Retrospektiv waren die intrazerebralen Hämorrhagien als septische Embolien mit sekundärer Einblutung unter neuen oralen Antikoagulanzien zu werten. Nach biologischem Mitral- und Aortenklappenersatz sowie mehrwöchiger Doxycyclin- und Gentamicingabe zeigte sich die Patientin in ihren Beschwerden deutlich gebessert und ohne weitere Blutungsereignisse.

The Thoracic and Cardiovascular Surgeon, 2018

PLOS ONE

Colonization of in-dwelling catheters by microbial biofilms is a major concern in patient health ... more Colonization of in-dwelling catheters by microbial biofilms is a major concern in patient health eventually leading to catheter-related blood stream infections. Biofilms are less susceptible to standard antibiotic therapies that are effective against planktonic bacteria. Standard procedure for the detection of microorganisms on the catheter tip is culture. However, viable but non-culturable cells (VBNCs) may be missed. The aim of this study was to evaluate the use of fluorescence in situ hybridization (FISH) as an indicator to visualize and quantify the effect of the antibiotics daptomycin and vancomycin on biofilms in situ. We established an in vitro catheter biofilm model of Staphylococcus epidermidis biofilms on polyurethane catheters. Biofilm activity was measured by FISH and correlated to colony forming units (CFU) data. Digital image analysis was used for quantification of total biofilm mass and the area of the FISH positive biofilm cells. FISH showed a pronounced effect of both antibiotics on the biofilms, with daptomycin having a significantly stronger effect in terms of both reduction of biofilm mass and number of FISH-positive cells. This supports the anti-biofilm capacity of daptomycin. Interestingly, neither antibiotic was able to eradicate all of the FISH-positive cells. In summary, FISH succeeded in visualization, quantification, and localization of antibiotic activity on biofilms. This technique adds a new tool to the arsenal of test systems for anti-biofilm compounds. FISH is a valuable complementary technique to CFU since it can be highly standardized and provides information on biofilm architecture and quantity and localization of survivor cells.

Zeitschrift für Herz-,Thorax- und Gefäßchirurgie

ZusammenfassungTrotz der Fortschritte in Diagnostik und Therapie ist die infektiöse Endokarditis ... more ZusammenfassungTrotz der Fortschritte in Diagnostik und Therapie ist die infektiöse Endokarditis (IE) noch immer eine vital bedrohliche Erkrankung mit hoher Komplikations- und Mortalitätsrate. Aufgrund der vergleichsweise niedrigen Inzidenz und fehlender randomisierter Studien basierten die Empfehlungen zum Management lange Zeit weitestgehend auf Expertenmeinungen. In den Leitlinien der European Society of Cardiology (ESC) wurden 2009 zum ersten Mal innovative therapeutische und präventive Konzepte vorgestellt, die 2015 erneut aktualisiert und überarbeitet wurden. Die aktuellen Leitlinien können nun durch erste randomisierte Studien zu chirurgischer Behandlung sowie modernen bildgebenden Verfahren der verbesserten Diagnostik, insbesondere aus dem Bereich der Nuklearmedizin, gestützt werden. Die Endokarditis sollte heute als multidisziplinäre Erkrankung verstanden und therapiert werden, sodass Behandlung und Betreuung der betroffenen Patienten an Zentren und durch spezialisierte Teams der beteiligten Fachdisziplinen erfolgen sollten. In dieser Übersichtsarbeit werden die aktuellen Empfehlungen der ESC und Deutschen Gesellschaft für Kardiologe (DGK) zu Diagnostik, Prävention und Therapie der IE zusammengefasst – mit besonderem Augenmerk auf die kürzlich veröffentlichen Studien zur chirurgischen Behandlung und zur modernen bildgebenden Diagnostik.AbstractDespite the advances in diagnostics and treatment, infective endocarditis (IE) is still a life-threatening disease with high complication and mortality rates. Due to the comparatively low incidence and lack of randomized studies, recommendations on the management were for a long time mostly based on expert opinions. In the guidelines of the European Society of Cardiology (ESC) from 2009, innovative therapeutic and preventive concepts were presented for the first time, which were updated and revised in 2015. The current guidelines can now be supported by first randomized studies on surgical treatment and modern imaging procedures for improved diagnostics, especially in the field of nuclear medicine. Endocarditis should nowadays be considered and treated as a multidisciplinary disease so that the treatment and care of affected patients should be carried out in centers and by specialized teams from the specialist disciplines involved. This review article summarizes the current recommendations of the ESC and the German Society for Cardiology on diagnostics, prevention and treatment of IE, paying special attention to recently published studies on surgical treatment and modern imaging diagnostics.

Der Unfallchirurg

The increase in endoprosthetic and osteosynthetic surgical treatment is associated with a simulta... more The increase in endoprosthetic and osteosynthetic surgical treatment is associated with a simultaneous increase in implant-associated infections (surgical site infections, SSI). Biofilms appear to play a significant role in the diagnosis and treatment of these infections and heavily contaminated wounds. This article aims to provide a current overview of biofilm and its relevance in orthopedic surgery. A computer-assisted literature search of MedLine (PubMed) was performed using key word combinations with "biofilm" (as of March 2017). Biofilm, a polymicrobial organization and life form surrounded by a polysaccharide matrix, refers to an adaptation strategy of bacteria in unfavorable living conditions (e. g. under antibiotic therapy). Biofilms can develop after 6 h in highly contaminated wounds. In acute and chronic infections, biofilms can occur in 30-80 % of the cases. Only planktonic bacteria (high metabolic activity, cultivable) can be detected in standard microbiological cultures, biofilms, however, cannot. Molecular microscopic methods, such as fluorescence in situ hybridization (FISH), enable the detection of bacteria in biofilms. The core concepts of anti-biofilm therapy include the prevention of biofilm and early surgical debridement, followed by the local and/or systemic administration of antibiotics as well as the local application of antiseptics. The development of biofilm should be anticipated in strongly contaminated wounds as well as in acute and chronic infection sites. The best strategy to combat biofilms is to prevent their development. Standard microbiological culture methods do not enable the detection of biofilm. Therefore, the implementation of molecular biological detection methods (z. B. FISH) is important. Further anti-biofilm strategies are being investigated experimentally, but there are no real options for clinical use as of yet.

Cellular Microbiology, 2016

The human restricted pathogen Moraxella catarrhalis is an important causal agent for exacerbation... more The human restricted pathogen Moraxella catarrhalis is an important causal agent for exacerbations in chronic obstructive lung disease in adults. In such patients, increased numbers of granulocytes are present in the airways, which correlate with bacteriainduced exacerbations and severity of the disease. Our study investigated whether the interaction of M. catarrhalis with the human granulocyte-specific carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-3 is linked to NF-κB activation, resulting in chemokine production. Granulocytes from healthy donors and NB4 cells were infected with M. catarrhalis in the presence of different inhibitors, blocking antibodies and siRNA. The supernatants were analysed by enzyme-linked immunosorbent assay for chemokines. NF-κB activation was determined using a luciferase reporter gene assay and chromatin-immunoprecipitation. We found evidence that the specific engagement of CEACAM3 by M. catarrhalis ubiquitous surface protein A1 (UspA1) results in the activation of pro-inflammatory events, such as degranulation of neutrophils, ROS production and chemokine secretion. The interaction of UspA1 with CEACAM3 induced the activation of the NF-κB pathway via Syk and the CARD9 pathway and was dependent on the phosphorylation of the CEACAM3 ITAM-like motif. These findings suggest that the CEACAM3 signalling in neutrophils is able to specifically modulate airway inflammation caused by infection with M. catarrhalis.