Read by QxMD icon Read

International Journal of Medical Microbiology: IJMM

Mathilde Phillips-Houlbracq, Jean-Damien Ricard, Arnaud Foucrier, Deborah Yoder-Himes, Stéphane Gaudry, Julie Bex, Jonathan Messika, Dimitri Margetis, Jérémie Chatel, Ulrich Dobrindt, Erick Denamur, Damien Roux
Ventilator-associated pneumonia (VAP) remains the most frequent life-threatening nosocomial infection. Enterobacteriaceae including Escherichia coli are increasingly involved. If a cumulative effect of pathogenicity islands (PAIs) has been shown for E. coli virulence in urinary tract or systemic infections, very little is known regarding pathophysiology of E. coli pneumonia. This study aimed to determine the role of each of the 7 PAIs present in pathogenic E. coli strain 536 in pneumonia pathophysiology. We used mutant strains to screen pathophysiological role of PAI in a rat pneumonia model...
January 5, 2018: International Journal of Medical Microbiology: IJMM
Balaji Pathakumari, Santhi Devasundaram, Prabhavathi Maddineni, Alamelu Raja
High global prevalence of latent TB infection (LTBI) is a key challenge in distinguishing patients with active pulmonary TB (PTB) from those with LTBI. The functional profile of CD4+ and CD8+ T cell cytokines produced as a response to Mycobacterium tuberculosis antigens vary during the course of tuberculosis (TB) infection. We evaluated antigen-specific CD4+ and CD8+ T cell cytokine response after overnight in vitro stimulation of peripheral blood with mycobacterial antigens ESAT-6, CFP-10, Rv2204c, Rv0753c and Rv0009 by flow cytometry...
December 6, 2017: International Journal of Medical Microbiology: IJMM
Minh-Thu Nguyen, Arif Luqman, Katharina Bitschar, Tobias Hertlein, Johannes Dick, Knut Ohlsen, Barbara Bröker, Birgit Schittek, Friedrich Götz
Most Staphylococcus aureus strains secrete two lipases SAL1 and SAL2 encoded by gehA and gehB. These two lipases differ with respect to their substrate specificity. Staphylococcus hyicus secretes another lipase, SHL, which is in contrast to S. aureus lipases Ca2+-dependent and has a broad-spectrum lipase and phospholipase activity. The aim of this study was to investigate the role of staphylococcal (phospho) lipases in virulence. For this we constructed a gehA-gehB double deletion mutant in S. aureus USA300 and expressed SHL in agr-positive (accessory gene regulator) and agr-negative S...
November 29, 2017: International Journal of Medical Microbiology: IJMM
Bhavani V Peddayelachagiri, Soumya Paul, Madhurjya Gogoi, Murali H Sripathy, Harsh V Batra
Assays for the rapid detection and accurate differentiation of Burkholderia pseudomallei from near-neighbor species are urgently needed in melioidosis endemic regions due to the high associated mortality and biowarfare importance of the pathogen. PCR-based methods have revolutionized this field due to the accuracy, sensitivity, and specificity that are achievable in a rapid way. In this study, a compound molecular detection system, consisting of a duplex PCR assay, was developed for the specific identification of Burkholderia pseudomallei and differentiation from other Burkholderia species...
November 28, 2017: International Journal of Medical Microbiology: IJMM
Alejandro Gómez-Mejia, Gustavo Gámez, Sven Hammerschmidt
Streptococcus pneumoniae is a human pathobiont possessing a diverse array of multifunctional proteins essential for bacterial fitness and virulence. Gene expression is tightly controlled by regulatory components and among the pneumococcal sensorial tools, two‑component regulatory systems (TCS) are the most widespread and conserved. This review aims to provide a comprehensive analysis of original studies on pneumococcal TCS on a functional level. Despite a rather chaotic nomenclature, the current available information on pneumococcal regulation by these systems can be conveniently addressed, according to the regulation of pathophysiological cell processes and the responses to detectable environmental signals...
November 26, 2017: International Journal of Medical Microbiology: IJMM
Jessica Horn, Kathrin Stelzner, Thomas Rudel, Martin Fraunholz
Staphylococcus aureus is a notorious opportunistic pathogen causing a plethora of diseases. Recent research established that once phagocytosed by neutrophils and macrophages, a certain percentage of S. aureus is able to survive within these phagocytes which thereby even may contribute to dissemination of the pathogen. S. aureus further induces its uptake by otherwise non-phagocytic cells and the ensuing intracellular cytotoxicity is suggested to lead to tissue destruction, whereas bacterial persistence within cells is thought to lead to immune evasion and chronicity of infections...
November 26, 2017: International Journal of Medical Microbiology: IJMM
Stephan Fuchs, Henry Mehlan, Jörg Bernhardt, André Hennig, Stephan Michalik, Kristin Surmann, Jan Pané-Farré, Anne Giese, Stefan Weiss, Linus Backert, Alexander Herbig, Kay Nieselt, Michael Hecker, Uwe Völker, Ulrike Mäder
In light of continuously accumulating data and knowledge on major human pathogens, comprehensive and up-to-date sources of easily accessible information are urgently required. The AureoWiki database ( provides detailed information on the genes and proteins of clinically and experimentally relevant S. aureus strains, currently covering NCTC 8325, COL, Newman, USA300_FPR3757, and N315. By implementing a pan-genome approach, AureoWiki facilitates the transfer of knowledge gained in studies with different S...
November 24, 2017: International Journal of Medical Microbiology: IJMM
Shrilakshmi Hegde, Martina Zimmermann, Renate Rosengarten, Rohini Chopra-Dewasthaly
Mycoplasma agalactiae exhibits antigenic variation by switching the expression of multiple surface lipoproteins called Vpmas. Although implicated to have a significant influence on the pathogenicity, their exact role in pathogen-host interactions has not been investigated so far. Initial attachment to host cells is regarded as one of the most important steps for colonization but this pathogen lacks the typical mycoplasma attachment organelle. The aim of this study was to determine the role of Vpmas in adhesion of M...
November 22, 2017: International Journal of Medical Microbiology: IJMM
F Abdouchakour, F Aujoulat, P Licznar-Fajardo, H Marchandin, M Toubiana, S Parer, A Lotthé, E Jumas-Bilak
Most multidrug-resistant (MDR) and extensively drug-resistant (XDR) P. aeruginosa strains belonged to epidemic high-risk (EHR) clones that succeeded worldwide in the context of hospital outbreaks. In order to study the intraclonal diversity in EHR P. aeruginosa, we selected clinical and environmental strains of the EHR clone ST308 that caused outbreak clusters over five years in a hospital and then persisted in the hospital environment during four additional years, causing sporadic infections. Unexpectedly, resistance phenotype was very diverse within the population, independently of the origin (environmental or human) and the period of isolation (during or after outbreaks)...
November 21, 2017: International Journal of Medical Microbiology: IJMM
Daniel M Mrochen, Dorothee Grumann, Daniel Schulz, Janine Gumz, Patricia Trübe, Kathleen Pritchett-Corning, Sarah Johnson, Werner Nicklas, Petra Kirsch, Karine Martelet, Jens van den Brandt, Sabine Berg, Barbara M Bröker, Siouxsie Wiles, Silva Holtfreter
We previously reported that laboratory mice from all global vendors are frequently colonized with Staphylococcus aureus (S. aureus). Genotyping of a snap sample of murine S. aureus isolates from Charles River, US, showed that mice were predominantly colonized with methicillin-sensitive CC88 strains. Here, we expanded our view and investigated whether laboratory mice from other global animal facilities are colonized with similar strains or novel S. aureus lineages, and whether the murine S. aureus isolates show features of host adaptation...
November 20, 2017: International Journal of Medical Microbiology: IJMM
Stefan Schille, Peter Crauwels, Rebecca Bohn, Katrin Bagola, Ger van Zandbergen
Phagocytosis is essential for uptake and elimination of pathogenic microorganisms. Autophagy is a highly conserved mechanism for incorporation of cellular constituents to replenish nutrients by degradation. Recently, parts of the autophagy machinery - above all microtubule-associated protein 1 light chain 3 (LC3) - were found to be specifically recruited to phagosomal membranes resulting in phagosome-lysosome fusion and efficient degradation of internalized cargo in a process termed LC3-associated phagocytosis (LAP)...
November 20, 2017: International Journal of Medical Microbiology: IJMM
Stephen A Clark, Ronan Doyle, Jay Lucidarme, Ray Borrow, Judith Breuer
In England and Wales, approximately one half of all laboratory-confirmed meningococcal disease cases fail to yield a viable invasive isolate, primarily due to the use of antibiotics. Characterisation of non-culture meningococci has been restricted to the detection or sequencing of specific gene targets within clinical specimens. In this study we investigated the ability of the Agilent SureSelectXT kit to facilitate DNA enrichment and genome sequencing of meningococcal DNA within a small panel of blood and CSF specimens...
November 13, 2017: International Journal of Medical Microbiology: IJMM
Brendan Dolan, Lucy Burkitt-Gray, Stephen Shovelin, Billy Bourke, Brendan Drumm, Marion Rowland, Marguerite Clyne
Helicobacter pylori infection occurs within families but the transmission route is unknown. The use of stool specimens to genotype strains facilitates inclusion of complete families in transmission studies. Therefore, we aimed to use DNA from stools to analyze strain diversity in H. pylori infected families. We genotyped H. pylori strains using specific biprobe qPCR analysis of glmM, recA and hspA. Concentration of H. pylori organisms before DNA isolation enhanced subsequent DNA amplification. We isolated H...
November 13, 2017: International Journal of Medical Microbiology: IJMM
Marcel Sprenger, Lydia Kasper, Michael Hensel, Bernhard Hube
The mature phagosome of macrophages is a hostile environment for the vast majority of phagocytosed microbes. In addition to active destruction of the engulfed microbes by antimicrobial compounds, restriction of essential nutrients in the phagosomal compartment contributes to microbial growth inhibition and killing. However, some pathogenic microorganisms have not only developed various strategies to efficiently withstand or counteract antimicrobial activities, but also to acquire nutrients within macrophages for intracellular replication...
November 7, 2017: International Journal of Medical Microbiology: IJMM
Esther von Stebut, Stefan Tenzer
Leishmaniasis is transmitted by sand flies leading to parasite inoculation into skin. In the mammalian host, the parasite primarily resides in skin macrophages (MΦ) and dendritic cells (DC). MΦ are silently invaded by the parasite eliciting a stress response, whereas DC become activated, release IL-12, and prime antigen-specific T cells. Here we review the basics of the immune response against this human pathogen and elucidate the role and function DC and MΦ for establishment of protective immunity against leishmaniasis...
November 6, 2017: International Journal of Medical Microbiology: IJMM
Lina Herhaus, Ivan Dikic
Salmonella infections cause acute intestinal inflammatory responses through the action of bacterial effector proteins secreted into the host cytosol. These proteins promote Salmonella survival, amongst others, by deregulating the host innate immune system and interfering with host cell ubiquitylation signaling. This review describes the recent findings of dynamic changes of the host ubiquitinome during pathogen infection, how bacterial effector proteins modulate the host ubiquitin system and how the host innate immune system counteracts Salmonella invasion by using these pathogens as signaling platforms to initiate immune responses...
November 6, 2017: International Journal of Medical Microbiology: IJMM
Stefan Czurda, Shivanand Manjunath Hegde, Renate Rosengarten, Rohini Chopra-Dewasthaly
Despite their small genomes mycoplasmas maintain large multigene families devoted to surface antigenic variation. Although implicated as important factors for mycoplasma pathogenicity and persistence, the role of these antigenic switches in host immune evasion has never been unequivocally proven in these minimalist microbes. Mycoplasma agalactiae exhibits antigenic variation due to Xer1-mediated site-specific DNA inversions of vpma genes encoding abundant multiple surface lipoproteins. To evaluate the biological significance of Vpma oscillations the xer1 recombinase gene has been disrupted in earlier studies to abolish Vpma switching and to generate stable phase-locked mutants (PLMs) steadily expressing a single Vpma product...
November 6, 2017: International Journal of Medical Microbiology: IJMM
Gerrit J K Praefcke
Guanylate-binding proteins (GBP) are a family of dynamin-related large GTPases which are expressed in response to interferons and other pro-inflammatory cytokines. GBPs mediate a broad spectrum of innate immune functions against intracellular pathogens ranging from viruses to bacteria and protozoa. Several binding partners for individual GBPs have been identified and several different mechanisms of action have been proposed depending on the organisms, the cell type and the pathogen used. Many of these anti-pathogenic functions of GBPs involve the recruitment to and the subsequent destruction of pathogen containing vacuolar compartments, the assembly of large oligomeric innate immune complexes such as the inflammasome, or the induction of autophagy...
November 2, 2017: International Journal of Medical Microbiology: IJMM
Nadine Radomski, Annica Rebbig, Ralf M Leonhardt, Michael R Knittler
Autophagy is an evolutionarily ancient and highly conserved eukaryotic mechanism that targets cytoplasmic material for degradation. Autophagic flux involves the formation of autophagosomes and their degradation by lysosomes. The process plays a crucial role in maintaining cellular homeostasis and responds to various environmental conditions. While autophagy had previously been thought to be a non-selective process, it is now clear that it can also selectively target cellular organelles, such as mitochondria (referred to as mitophagy) and/or invading pathogens (referred to as xenophagy)...
November 2, 2017: International Journal of Medical Microbiology: IJMM
Miriam Hiller, Christina Lang, Wiebke Michel, Antje Flieger
Legionella pneumophila is an intracellular pathogen and the main causative agent of Legionnaires' disease, a potentially fatal pneumonia. The bacteria infect both mammalian cells and environmental hosts, such as amoeba. Inside host cells, the bacteria withstand the multifaceted defenses of the phagocyte and replicate within a unique membrane-bound compartment, the Legionella-containing vacuole (LCV). For establishment and maintenance of the infection, L. pneumophila secretes many proteins including effector proteins by means of different secretion systems and outer membrane vesicles...
October 28, 2017: International Journal of Medical Microbiology: IJMM
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"