1,721,043 research outputs found
Phenotypic and genotypic analysis of antimicrobial resistance in multiple drug-resistant Klebsiella pneumoniae isolates from humans
No full textMolekulare Epidemiologie von Brucellose in Ägypten, Diagnoseverfahren, Proteomik und Untersuchungen zur Pathogenese
No full textBrucellosis is a zoonotic disease occurring worldwide in animals as well as in humans leading to huge economic losses. The infection is caused by Gram-negative bacteria of the genus Brucella. The disease is a very common in developing countries, but is often neglected. In Egypt, brucellosis was reported in a scientific report for the first time in 1939. Since then the disease emerged and remained endemic at high levels among ruminants, particularly in newly established large intensive breeding farms. The disease is prevalence nationwide in all farm animal species, in carrier hosts e.g. rats and in the environment. Serological investigations within the national surveillance program give indirect proof for the presence of brucellosis in cattle, buffaloes, sheep, goats and camels. Even though serologic assays for brucellosis are a well-established procedure but most of the corresponding studies still miss scientific standards. B. melitensis bv 3 and B. abortus bv 1 are the predominant isolates in Egypt and have been isolated from farm animals and Nile catfish. The epidemiologic situation of brucellosis in Egypt is complicated and needs clarification (Chapter 1). The disease is characterized by high morbidity but low mortality. However, the disease mainly transmitted via direct contact with infected animals, the most common way of infection is ingestion of contaminated milk or milk products and meat. DNA of B. melitensis was detected in milk samples that collected from apparently healthy animals’ produces milk for human consumption by molecular assays. The shedding of Brucella spp. especially the highly pathogenic species B. melitensis in milk poses an increasing threat to consumers and this is of obvious concern (Chapter 2). In endemic countries like Egypt, transmission of host specific Brucella spp. to nonpreferred hosts may occur due to the mixed rearing of farm animals. The interspecies transmission of B. melitensis from small ruminants to cattle and buffalo was reported. It is worth mentioning that, B. abortus DNA was identified in serum samples collected from aborted ewe and goats by real time PCR. This study is the first record on brucellosis caused by B. abortus in small ruminants in Egypt. Interestingly that, both B. abortus and B .melitensis. DNA was detected in one ovine serum. These results should be taken in consideration during implementation of control measures (Chapter 3). Among the 11 known Brucella spp., B. melitensis is the most virulent one and is the major causes of abortions in small ruminants. It causes also the severe form of human brucellosis. While, B. abortus infectious occurs in cattle preferably among cows. These two species having similar genomes, while are differences in host specificity and display different proteomes. A comprehensive identification of immunodominant proteins of these two species using antibodies present in the serum of naturally infected ruminants provided insight on the mechanism of their infection in different hosts. A number of heat shock proteins, binding proteins, enzymes, and hypothetical proteins were identified using western immunoblotting and MALDI-TOF MS/MS in both B. abortus and B. melitensis. Brucellae appear to express these proteins mainly for their survival in the host system during infection (Chapter 4). Diagnosis of brucellosis is still challenging in animals and humans and is based mainly on serology and isolation of Brucella. All serological tests have limitations concerning specificity and sensitivity. Cross-reactivity with other Gram-negative bacteria and within the species of the genus is the major hindrance for the specific serological diagnosis of brucellosis. The present study suggest a number of new immunogenic protein candidates of B. abortus and B. melitensis that had immunoreactivity against only sera collected from cattles, buffaloes, sheep and goats, respectively. Among of them five proteins, (Dihydrodipicolinate synthase, glyceraldehyde-3-phosphate dehydrogenase, lactate malate dehydrogenase, amino acid ABC transporter substrate-binding proteins, and fumarylacetoacetate hydrolase domaincontaining protein 2) have prominent immunogenic features. They may be cloned, purified and expressed in recombinant form to be used as specific antigen in serodiagnosis of brucellosis in the future. These proteins can be used to replace the classical LPS antigen preparation in Brucella serodiagnosis, will help to specify the causative species and will reduce false positive reactions resulting from cross-reaction with other Gram-negative bacteria (Chapter 5). Brucellae are intracellular stealthy pathogens causing disease in humans and in a wide range of domestic and wild animals. Rapid multiplication and cytoarchitectural damages induced in liver, kidney, lung, spleen, gastrointestinal tract, spinal meninges, yolk sac and chorioallantoic membrane after egg inoculation of B. microti in chicken embryos demonstrated the proliferation and pathogenicity of B. microti. This study provides the first results on the multiplication of the mouse pathogenic B. microti in chicken embryos and describes gross and histopathology associated with the infection. Our results suggest that, even though chicken are no mammals, they are useful tools to study the pathogenesis, pathogen interactions and immunopathology of brucellae (Chapter 6)
Bacterial zoonose : molecular characterization of antimicrobial resistance and pathogenicity from one-health perspective
No full textThe extensive use of broad-spectrum antibiotics in human medicine, farm animals, and the food industry has led to multidrug-resistant bacteria. The studies carried out within the scope of this Habilitation work aimed at resistance profiling and better understanding the mechanisms of resistance development and pathogenicity in the leading multiple drug resistance (MDR) bacterial pathogens known to cause nosocomial infections, such as ESKAPE pathogens, i.e. Acinetobacter baumannii, Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA), as well as bacteria causing neglected zoonoses such as Brucella. Combined in-vitro phenotyping with in-silico molecular analysis using Illumina MiSeq Next-Generation-Sequencing (NGS) technology and BioIT pipelines on a large number of clinical and non-clinical strains collected from Europe, Asia, and Africa were applied to achieve the goal of the One-Health approach. Antimicrobial resistance is a growing concern in veterinary medicine, the food chain, and the environment as in human medicine. However, data on animals, foods and environmental sources are still scarce. The emergence and dissemination of certain ESKAPE pathogens such as A. baumannii and K. pneumonia were reported since the late 20th century and increased over time in developed and developing countries. Whole-genome sequencing (WGS) is a powerful tool for rapidly identifying antimicrobial resistance (AMR) genes and can define resistance-associated determinants with much greater precision compared to conventional phenotypic tools. Continuous susceptibility testing, updating breakpoints, and assessing mutations that lead to resistance are needed for fastidious bacteria
Bacterial zoonose: molecular characterization of antimicrobial resistance and pathogenicity from one-health perspective
Full text linkThe extensive use of broad-spectrum antibiotics in human medicine, farm animals, and the food industry has led to multidrug-resistant bacteria. The studies carried out within the scope of this Habilitation work aimed at resistance profiling and better understanding the mechanisms of resistance development and pathogenicity in the leading multiple drug resistance (MDR) bacterial pathogens known to cause nosocomial infections, such as ESKAPE pathogens, i.e. Acinetobacter baumannii, Klebsiella pneumoniae and methicillin-resistant Staphylococcus aureus (MRSA), as well as bacteria causing neglected zoonoses such as Brucella. Combined in-vitro phenotyping with in-silico molecular analysis using Illumina MiSeq Next-Generation-Sequencing (NGS) technology and BioIT pipelines on a large number of clinical and non-clinical strains collected from Europe, Asia, and Africa were applied to achieve the goal of the One-Health approach. Antimicrobial resistance is a growing concern in veterinary medicine, the food chain, and the environment as in human medicine. However, data on animals, foods and environmental sources are still scarce. The emergence and dissemination of certain ESKAPE pathogens such as A. baumannii and K. pneumonia were reported since the late 20th century and increased over time in developed and developing countries. Whole-genome sequencing (WGS) is a powerful tool for rapidly identifying antimicrobial resistance (AMR) genes and can define resistance-associated determinants with much greater precision compared to conventional phenotypic tools. Continuous susceptibility testing, updating breakpoints, and assessing mutations that lead to resistance are needed for fastidious bacteria
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
The striking incidence of animal listeriosis in Germany (2014–2024) indicates a persistent but neglected risk for One Health
Full text linkListeriosis is a serious zoonotic disease caused by the genus Listeria, with Listeria monocytogenes being the most pathogenic species for humans and various animal species. This bacterium is commonly found in the environment and poses significant health risks. We analysed official surveillance data detailing animal listeriosis in Germany over the last decade to unravel its host diversity and spatiotemporal distribution. Altogether, 1.629 notifications involving 3.326 various animal species were reported. Listeriosis has a broad host range in farm animals and wildlife, with a consistently striking incidence reported nationwide. Addressing this issue is crucial for public health and the safety of our food supply
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