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https://www.readbyqxmd.com/read/28813461/epidemiology-of-clostridium-difficile-in-infants-in-oxfordshire-uk-risk-factors-for-colonization-and-carriage-and-genetic-overlap-with-regional-c-difficile-infection-strains
#1
Nicole Stoesser, David W Eyre, T Phuong Quan, Heather Godwin, Gemma Pill, Emily Mbuvi, Alison Vaughan, David Griffiths, Jessica Martin, Warren Fawley, Kate E Dingle, Sarah Oakley, Kazimierz Wanelik, John M Finney, Melina Kachrimanidou, Catrin E Moore, Sherwood Gorbach, Thomas V Riley, Derrick W Crook, Tim E A Peto, Mark H Wilcox, A Sarah Walker
BACKGROUND: Approximately 30-40% of children <1 year of age are Clostridium difficile colonized, and may represent a reservoir for adult C. difficile infections (CDI). Risk factors for colonization with toxigenic versus non-toxigenic C. difficile strains and longitudinal acquisition dynamics in infants remain incompletely characterized. METHODS: Predominantly healthy infants (≤2 years) were recruited in Oxfordshire, UK, and provided ≥1 fecal samples. Independent risk factors for toxigenic/non-toxigenic C...
2017: PloS One
https://www.readbyqxmd.com/read/28809435/first-case-report-of-non-human-primates-alouatta-clamitans-with-the-hypervirulent-klebsiella-pneumoniae-serotype-k1-strain-st-23-a-possible-emerging-wildlife-pathogen
#2
Eleine Kuroki Anzai, Júlio César de Souza Júnior, Amanda Rezende Peruchi, Juliana Mello Fonseca, Elke Kreuscher Gumpl, Antônio Carlos Campos Pignatari, Zelinda Maria Braga Hirano, Alessandro Conrado de Oliveira Silveira
BACKGROUND: Hypervirulent strain of Klebsiella pneumoniae genotype K1 isolates have recently emerged, causing severe pyogenic liver abscess complicated by devastating metastatic infections in humans. METHODS: We describe a short outbreak of the non-human primate (NHP) research center, associated with a hypervirulent K. pneumoniae. The genetic similarity of the strains was evaluated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) techniques, and virulence encoding genes were detected by polymerase chain reaction (PCR)...
August 15, 2017: Journal of Medical Primatology
https://www.readbyqxmd.com/read/28776043/amino-acid-differences-in-the-1753-to-1851-region-of-tcdb-influence-variations-in-tcdb1-and-tcdb2-cell-entry
#3
Jonathan J Hunt, Jason L Larabee, Jimmy D Ballard
Clostridium difficile TcdB2 enters cells with a higher efficiency than TcdB1 and exhibits an overall higher level of toxicity. However, the TcdB2-specific sequences that account for more efficient cell entry have not been reported. In this study, we examined the contribution of carboxy-terminal sequence differences to TcdB activity by comparing the binding, uptake, and endosomal localization of TcdB1 and TcdB2 or selected recombinant fragments of these proteins. Our findings suggest that sequence differences in the amino acid 1753 to 1851 region proximal to the combined repetitive oligopeptide domain (CROP) support enhanced uptake of TcdB2 and localization of toxin in acidified endosomes...
July 2017: MSphere
https://www.readbyqxmd.com/read/28769806/a-red-blood-cell-membrane-camouflaged-nanoparticle-counteracts-streptolysin-o-mediated-virulence-phenotypes-of-invasive-group-a-streptococcus
#4
Tamara Escajadillo, Joshua Olson, Brian T Luk, Liangfang Zhang, Victor Nizet
Group A Streptococcus (GAS), an important human-specific Gram-positive bacterial pathogen, is associated with a broad spectrum of disease, ranging from mild superficial infections such as pharyngitis and impetigo, to serious invasive infections including necrotizing fasciitis and streptococcal toxic shock syndrome. The GAS pore-forming streptolysin O (SLO) is a well characterized virulence factor produced by nearly all GAS clinical isolates. High level expression of SLO is epidemiologically linked to intercontinental dissemination of hypervirulent clonotypes and poor clinical outcomes...
2017: Frontiers in Pharmacology
https://www.readbyqxmd.com/read/28753640/mycobacterium-tuberculosis-universal-stress-protein-rv2623-interacts-with-the-putative-atp-binding-cassette-abc-transporter-rv1747-to-regulate-mycobacterial-growth
#5
Lisa N Glass, Ganduri Swapna, Sivagami Sundaram Chavadi, JoAnn M Tufariello, Kaixia Mi, Joshua E Drumm, TuKiet T Lam, Guofeng Zhu, Chenyang Zhan, Catherine Vilchéze, Jesus Arcos, Yong Chen, Lijun Bi, Simren Mehta, Steven A Porcelli, Steve C Almo, Syun-Ru Yeh, William R Jacobs, Jordi B Torrelles, John Chan
We have previously shown that the Mycobacterium tuberculosis universal stress protein Rv2623 regulates mycobacterial growth and may be required for the establishment of tuberculous persistence. Here, yeast two-hybrid and affinity chromatography experiments have demonstrated that Rv2623 interacts with one of the two forkhead-associated domains (FHA I) of Rv1747, a putative ATP-binding cassette transporter annotated to export lipooligosaccharides. FHA domains are signaling protein modules that mediate protein-protein interactions to modulate a wide variety of biological processes via binding to conserved phosphorylated threonine (pT)-containing oligopeptides of the interactors...
July 2017: PLoS Pathogens
https://www.readbyqxmd.com/read/28729708/new-mycobacterium-tuberculosis-beijing-clonal-complexes-in-china-revealed-by-phylogenetic-and-bayesian-population-structure-analyses-of-24-loci-miru-vntrs
#6
Chao Zheng, Yann Reynaud, Changsong Zhao, Thierry Zozio, Song Li, Dongxia Luo, Qun Sun, Nalin Rastogi
Beijing lineage of Mycobacterium tuberculosis constitutes the most predominant lineage in East Asia. Beijing epidemiology, evolutionary history, genetics are studied in details for years revealing probable origin from China followed by worldwide expansion, partially linked to higher mutation rate, hypervirulence, drug-resistance, and association with cases of mixed infections. Considering huge amount of data available for 24-loci Mycobacterial Interspersed Repetitive Units-Variable Number of Tandem Repeats, we performed detailed phylogenetic and Bayesian population structure analyses of Beijing lineage strains in mainland China and Taiwan using available 24-loci MIRU-VNTR data extracted from publications or the SITVIT2 database (n = 1490)...
July 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28729207/first-two-cases-of-severe-multifocal-infections-caused-by-klebsiella-pneumoniae-in-switzerland-characterization-of-an-atypical-non-k1-k2-serotype-strain-causing-liver-abscess-and-endocarditis
#7
Baharak Babouee Flury, Valentina Donà, Niccolò Buetti, Hansjakob Furrer, Andrea Endimiani
BACKGROUND: We describe the first two multifocal invasive infections due to Klebsiella pneumoniae recently observed in Switzerland. METHODS: Phenotypic (MIC assays and string test) and molecular analyses (PCR/Sequencing for bla, virulence factor genes and whole genome sequencing for one strain) were performed to characterize the causative K. pneumoniae isolates. RESULTS: Both K. pneumoniae isolates (Kp1 and Kp2) were pan-susceptible to antibiotics and produced narrow-spectrum SHV β-lactamases...
July 17, 2017: Journal of Global Antimicrobial Resistance
https://www.readbyqxmd.com/read/28728202/-pyogenic-liver-abscess-changes-of-organisms-and-consequences-for-diagnosis-and-therapy
#8
REVIEW
Alexander Mischnik, Winfried Vincenz Kern, Robert Thimme
Liver abscess is a rare but potentially fatal disease with mortality rates of 2 - 12 %. The spectrum of causative microorganisms varies across the world and is changing due to increasing worldwide travel activity. As a result, previously less frequent pathogens must increasingly be considered in the differential diagnosis. The most common pathogens of liver abscess are so-called abscess streptococci, anaerobes and Gram-negative bacteria such as Escherichia coli and Klebsiella pneumoniae. Certain clones among the Gram-negatives, typically among Klebsiella spp...
July 2017: Deutsche Medizinische Wochenschrift
https://www.readbyqxmd.com/read/28717029/the-metabolite-transporter-peg344-is-required-for-the-full-virulence-of-the-hypervirulent-klebsiella-pneumoniae-strain-hvkp1-after-pulmonary-but-not-subcutaneous-challenge
#9
Jeffrey Bulger, Ulrike MacDonald, Ruth Olson, Janet Beanan, Thomas A Russo
Hypervirulent Klebsiella pneumoniae (hvKP) is an emerging pathotype that is capable of causing tissue-invasive, organ and life threatening infections in healthy individuals from the community. Knowledge on the virulence factors specific to hvKP is limited. In this report we describe a new factor (PEG344) that increases the virulence of the hvKP strain hvKP1. peg344 is present on the hvKP1 virulence plasmid, is broadly prevalent among hvKP strains, and has increased RNA abundance when grown in human ascites...
July 17, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28713783/streptococcus-pyogenes-phospholipase-a2-induces-the-expression-of-adhesion-molecules-on-human-umbilical-vein-endothelial-cells-and-aorta-of-mice
#10
Masataka Oda, Hisanori Domon, Mie Kurosawa, Toshihito Isono, Tomoki Maekawa, Masaya Yamaguchi, Shigetada Kawabata, Yutaka Terao
The Streptococcus pyogenes phospholipase A2 (SlaA) gene is highly conserved in the M3 serotype of group A S. pyogenes, which often involves hypervirulent clones. However, the role of SlaA in S. pyogenes pathogenesis is unclear. Herein, we report that SlaA induces the expression of intercellular adhesion molecule 1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1) via the arachidonic acid signaling cascade. Notably, recombinant SlaA induced ICAM1 and VCAM1 expression in human umbilical vein endothelial cells (HUVECs), resulting in enhanced adhesion of human monocytic leukemia (THP-1) cells...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28698641/a-transcription-activator-like-effector-tal7-of-xanthomonas-oryzae-pv-oryzicola-activates-rice-gene-os09g29100-to-suppress-rice-immunity
#11
Lulu Cai, Yanyan Cao, Zhengyin Xu, Wenxiu Ma, Muhammad Zakria, Lifang Zou, Zaiquan Cheng, Gongyou Chen
Xanthomonas oryzae pv. oryzicola (Xoc) and X. oryzae pv. oryzae (Xoo) cause bacterial leaf streak (BLS) and bacterial leaf blight (BLB) in rice, respectively. Unlike Xoo, endogenous avirulence-resistance (avr-R) gene interactions have not been identified in the Xoc-rice pathosystem; however, both pathogens possess transcription activator-like effectors (TALEs) that are known to modulate R or S genes in rice. The transfer of individual tal genes from Xoc RS105 (hypervirulent) into Xoc YNB0-17 (hypovirulent) led to the identification of tal7, which suppressed avrXa7-Xa7 mediated defense in rice containing an Xa7 R gene...
July 11, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28673237/contribution-of-pilus-type-2b-to-invasive-disease-caused-by-a-streptococcus-agalactiae-st-17-strain
#12
Maddalena Lazzarin, Rong Mu, Monica Fabbrini, Claudia Ghezzo, C Daniela Rinaudo, Kelly S Doran, Immaculada Margarit
BACKGROUND: Group B Streptococcus (GBS) is a major cause of invasive disease especially in neonates. In GBS three structurally distinct pilus polymers have been identified as important virulence factors and promising vaccine candidates. The vast majority of Group B Streptococci belonging to the hypervirulent serotype III ST-17 lineage bear pilus types 1 and 2b. The purpose of this study was to investigate the relative contribution of these two pilus types to the pathogenesis of a ST-17 strain...
July 3, 2017: BMC Microbiology
https://www.readbyqxmd.com/read/28663824/towards-the-complete-proteinaceous-regulome-of-acinetobacter-baumannii
#13
Leila G Casella, Andy Weiss, Ernesto Pérez-Rueda, J Antonio Ibarra, Lindsey N Shaw
The emergence of Acinetobacter baumannii strains, with broad multidrug-resistance phenotypes and novel virulence factors unique to hypervirulent strains, presents a major threat to human health worldwide. Although a number of studies have described virulence-affecting entities for this organism, very few have identified regulatory elements controlling their expression. Previously, our group has documented the global identification and curation of regulatory RNAs in A. baumannii. As such, in the present study, we detail an extension of this work, the performance of an extensive bioinformatic analysis to identify regulatory proteins in the recently annotated genome of the highly virulent AB5075 strain...
March 2017: Microbial Genomics
https://www.readbyqxmd.com/read/28634474/different-dynamic-distribution-in-chickens-and-ducks-of-the-hypervirulent-novel-genotype-fowl-adenovirus-serotype-4-recently-emerged-in-china
#14
Qing Pan, Yanchao Yang, Zhibin Shi, Linlin Liu, Yulong Gao, Xiaole Qi, Changjun Liu, Yanping Zhang, Hongyu Cui, Xiaomei Wang
A hypervirulent fowl adenovirus serotype 4 (FAdV-4) has caused hepatitis-hydropericardium syndrome (HHS) with mortalities that range from 30 to 80% in outbreaks across China since 2015. The FAdV-4 strain was characterized as a novel genotype based on the specific genome characteristics. However, our understanding of the dynamic distribution, tissue tropism, and pathogenesis of the novel FAdV-4 is incomplete. In this study, a new, sensitive and FAdV-4-specific real-time PCR was developed and applied to detect the dynamic distribution of the duck origin, novel FAdV-4 strain HLJDAd15 in experimentally infected special-pathogen free (SPF) chickens and ducks...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28622015/the-first-whole-genome-sequence-and-pathogenicity-characterization-of-a-fowl-adenovirus-4-isolated-from-ducks-associated-with-inclusion-body-hepatitis-and-hydropericardium-syndrome
#15
Qing Pan, Linlin Liu, Yongqiang Wang, Yanping Zhang, Xiaole Qi, Changjun Liu, Yulong Gao, Xiaomei Wang, Hongyu Cui
In June 2015, an infectious disease with high prevalence causing severe hydropericardium syndrome (HPS) first appeared in duck farms of northeast China. The disease showed high morbidity of 35% and mortality of 15% in a commercial duck farm with 200,000 45-day-old ducks. One strain of hypervirulent fowl adenovirus serotype 4 was identified and designated as HLJDAd15. The whole genome of the duck isolate was sequenced and found to contain the same large deletions as a genotype that has become prevalent in chickens in China recently, indicating that this disease might be transmitted from chickens to ducks...
June 16, 2017: Avian Pathology: Journal of the W.V.P.A
https://www.readbyqxmd.com/read/28607468/clostridium-difficile-flagella-induce-a-pro-inflammatory-response-in-intestinal-epithelium-of-mice-in-cooperation-with-toxins
#16
Jameel Batah, Hussein Kobeissy, Phuong Trang Bui Pham, Cécile Denève-Larrazet, Sarah Kuehne, Anne Collignon, Claire Janoir-Jouveshomme, Jean-Christophe Marvaud, Imad Kansau
Clostridium difficile is the most important enteropathogen involved in gut nosocomial post-antibiotic infections. The emergence of hypervirulent strains has contributed to increased mortality and morbidity of CDI. The C. difficile toxins contribute directly to CDI-associated lesions of the gut, but other bacterial factors are needed for the bacteria to adhere and colonize the intestinal epithelium. The C. difficile flagella, which confer motility and chemotaxis for successful intestinal colonization, could play an additional role in bacterial pathogenesis by contributing to the inflammatory response of the host and mucosal injury...
June 12, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28596600/detection-of-dna-amplicons-of-polymerase-chain-reaction-using-litmus-test
#17
Dingran Chang, Kha Tram, Ben Li, Qian Feng, Zhifa Shen, Christine H Lee, Bruno J Salena, Yingfu Li
We report on a new colorimetric DNA detection method that takes advantage of the power of polymerase chain reaction (PCR) and the simplicity of the classic litmus test. The strategy makes use of a modified set of primers for PCR to facilitate ensuing manipulations of resultant DNA amplicons: their tagging with urease and immobilization onto magnetic beads. The amplicon/urease-laden beads are then used to hydrolyze urea, resulting in the increase of pH that can be conveniently reported by a pH-sensitive dye...
June 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28581267/characterization-of-oropharyngeal-carriage-isolates-of-neisseria-meningitidis-in-healthy-korean-adolescents-in-2015
#18
Han Wool Kim, Soyoung Lee, Daeho Kwon, Jihei Cha, Jong Gyun Ahn, Kyung Hyo Kim
The meningococcus carriage rate is age-dependent, with a high prevalence in adolescents and young adults. This cross-sectional study aimed to estimate the oropharyngeal carriage rate of meningococcus among healthy Korean adolescents and its relationship with several population characteristics. The survey was conducted from April to May 2015 among 1,460 first-year high-school students in 9 high schools located in Gyeonggi province, Korea. Each student answered a short questionnaire assessing risk factors for carriage, and posterior pharyngeal wall swab samples were obtained...
July 2017: Journal of Korean Medical Science
https://www.readbyqxmd.com/read/28577357/assessing-the-effect-of-patient-screening-and-isolation-on-curtailing-clostridium-difficile-infection-in-hospital-settings
#19
Sara Maghdoori, Seyed M Moghadas
BACKGROUND: Patient screening at the time of hospital admission is not recommended as a routine practice, but may be an important strategy for containment of Clostridium difficile infection (CDI) in hospital settings. We sought to investigate the effect of patient screening in the presence of asymptomatic carriers and in the context of imperfect patient isolation. METHODS: We developed and parameterized a stochastic simulation model for the transmission dynamics of CDI in a hospital ward...
June 2, 2017: BMC Infectious Diseases
https://www.readbyqxmd.com/read/28573471/emergence-of-clostridium-difficile-tcdc-variant-078-in-marseille-france
#20
N Cassir, N Fahsi, G Durand, J-C Lagier, D Raoult, P-E Fournier
The purpose of this investigation was to evaluate the epidemiology of hypervirulent Clostridium difficile ribotypes from January 2013 to February 2017 in the Marseille area of southern France. By using the Xpert Clostridium difficile Epi polymerase chain reaction (PCR) assay and sequencing the tcdC gene, we characterised C. difficile isolates from symptomatic patients diagnosed with C. difficile infection (CDI) in Marseille university hospitals. We first tested retrospectively 278 C. difficile samples isolated from January 2013 to December 2014 and observed a high prevalence of isolates with tcdC mutations and deletions previously described in both hypervirulent ribotypes RT027 and RT078 (16...
June 1, 2017: European Journal of Clinical Microbiology & Infectious Diseases
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