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Chia-Yen Dai, Yi-Shan Tsai, Wen-Wen Chou, Tawei Liu, Chung-Feng Huang, Shu-Chi Wang, Pei-Chien Tsai, Ming-Lun Yeh, Ming-Yen Hsieh, Ching-I Huang, Shang-Yin Vanson Liu, Jee-Fu Huang, Wan-Long Chuang, Ming-Lung Yu
Background/Aims: MicroRNA-125b (miR-125b) has been found to regulate inflammation and acts as an oncogene in many cancers. The mechanisms of miR-125b expression during hepatitis C virus (HCV) infection remain to be clarified. The present study aims to identify the factors that might regulate miR-125b expression in HCV infection. Results: High expression of miR-125b was found to correlate with HCV infection in replicon cells and in sera from HCV-infected patients, whereas the miR-125b inhibitor reduced HCV gene expression...
February 16, 2018: Oncotarget
Flemming G Hansen, Tove Atlung
More than 50 years have passed since the presentation of the Replicon Model which states that a positively acting initiator interacts with a specific site on a circular chromosome molecule to initiate DNA replication. Since then, the origin of chromosome replication, oriC , has been determined as a specific region that carries sequences required for binding of positively acting initiator proteins, DnaA-boxes and DnaA proteins, respectively. In this review we will give a historical overview of significant findings which have led to the very detailed knowledge we now possess about the initiation process in bacteria using Escherichia coli as the model organism, but emphasizing that virtually all bacteria have DnaA proteins that interacts with DnaA boxes to initiate chromosome replication...
2018: Frontiers in Microbiology
Bangari Haldipur, Prudhvi Lal Bhukya, Vidya Arankalle, Kavita Lole
Molecular mechanisms of liver pathology and clinical disease in HEV infection remain unclear. MicroRNAs are known to modulate viral pathogenesis either by directly altering viral gene expression or by enhancing cellular antiviral responses. Given the importance of microRNA-122 (miR-122) in liver pathobiology, we investigated possible role of miR-122 in HEV infection. In silico predictions using genotype 1, 2, 3 and 4 HEV sequences showed that majority of genomes (203/222) harbor at least one miR-122/miR-122* target site...
March 14, 2018: Journal of Virology
Sudhakar Agnihothram, Vineet D Menachery, Boyd L Yount, Lisa C Lindesmith, Trevor Scobey, Alan Whitmore, Alexandra Schäfer, Mark T Heise, Ralph S Baric
Zoonotic viruses circulate as swarms in animal reservoirs and can emerge into human populations causing epidemics that adversely affect public health. Portable, safe, and effective vaccine platforms are needed in the context of these outbreak and emergence situations. In this manuscript, we report the generation and characterization of an alphavirus replicon vaccine platform based on a non-select agent, attenuated Venezuelan equine encephalitis (VEE) virus vaccine strain 3526 (VRP 3526). Using both noroviruses and coronaviruses as model systems, we demonstrate utility of the VRP 3526 platform in generation of recombinant proteins, production of virus like particles, and in vivo efficacy as a vaccine against emergent viruses...
March 14, 2018: Journal of Virology
Cecilia M Lotufo, Maximiliano Wilda, Adrian N Giraldez, Pablo R Grigera, Nora M Mattion
A foot-and-mouth disease virus (FMDV) DNA-launched reporter replicon containing a luciferase gene was used to assess the impact of non-structural (NS) protein 3A on viral replication. Independent deletions within the N-terminal region (amino acid [aa] residues 6 to 24) and the central hydrophobic region (HR, aa 59 to 76) of FMDV NS protein 3A were engineered, and luciferase activity in lysates of control and mutated replicon-transfected cells was measured. Triple alanine replacements of the N-terminal triplet Arg 18- His 19 -Glu 20 and a single alanine substitution of the highly charged Glu 20 residue both resulted in a 70-80% reduction in luciferase activity when compared with wild-type controls...
March 13, 2018: Archives of Virology
Mitsutaka Kitano, Myra Hosmillo, Edward Emmott, Jia Lu, Ian Goodfellow
Human norovirus (HuNoV) is a major cause of nonbacterial gastroenteritis worldwide yet, despite their impact on society, vaccines and antivirals are currently lacking. A HuNoV replicon system has been widely applied to the evaluation of antiviral compounds and has thus accelerated the process of drug discovery against HuNoV infection. Rupintrivir, an irreversible inhibitor of the human rhinovirus 3C protease, has been reported to inhibit the replication of the Norwalk virus replicon via the inhibition of the norovirus protease...
March 12, 2018: Antimicrobial Agents and Chemotherapy
Daniel Enosi Tuipulotu, Natalie E Netzler, Jennifer H Lun, Jason M Mackenzie, Peter A White
Norovirus infections are a significant health and economic burden globally, accounting for hundreds of millions of cases of acute gastroenteritis every year. In the absence of an approved norovirus vaccine, there is an urgent need to develop antivirals to treat chronic infections, and provide prophylactic therapy to limit viral spread during epidemics and pandemics. Toll-like receptor (TLR) agonists have been explored widely for their antiviral potential and several are progressing through clinical trials for the treatment of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and as adjuvants for norovirus virus-like particle (VLP) vaccines...
March 12, 2018: Antimicrobial Agents and Chemotherapy
Shanshan Fu, Xiangning Bai, Ruyue Fan, Hui Sun, Yanmei Xu, Yanwen Xiong
Non-O157 Shiga toxin-producing Escherichia coli (STEC) is increasingly recognized as an important enteric foodborne pathogen. The hallmark of the disease is the production of Shiga toxins; however, there are other virulence factors that contribute to the pathogenesis of STEC. This study aimed to investigate the prevalence and genetic diversity of the enterohaemolysin gene, ehxA, among non-O157 STEC strains from human, animal, and food sources. The ehxA gene was amplified from 138 (31.8%) of 434 non-O157 STEC strains, among which 36 unique ehxA sequences were identified...
March 9, 2018: Scientific Reports
Giulia Niero, Valeria Bortolaia, Michele Vanni, Luigi Intorre, Luca Guardabassi, Alessandra Piccirillo
The aim was to investigate occurrence and diversity of plasmid-mediated resistance to third-generation cephalosporins (3GC) and quinolones in clinical Escherichia coli from 200 industrial poultry farms across Italy. E. coli was isolated from colibacillosis lesions in turkeys (n = 109), broilers (n = 98) and layers (n = 22) between 2008 and 2012. 3GC-resistant isolates were screened for extended-spectrum and AmpC β-lactamase (ESBL/AmpC), while all isolates were tested for plasmid-mediated quinolone resistance (PMQR) genes...
March 2018: Veterinary Microbiology
Hamid Solgi, Farzad Badmasti, Christian G Giske, Shadi Aghamohammad, Fereshteh Shahcheraghi
Objectives: Despite the fact that the blaOXA-48 and blaNDM-1 genes have successfully disseminated among Klebsiella pneumoniae isolates worldwide, outbreaks remain unidentified in Iran. Here we examined the molecular epidemiology of 96 carbapenem-resistant K. pneumoniae recovered from an Iranian hospital. Methods: A total of 96 non-replicate carbapenem-resistant K. pneumoniae were recovered from clinical specimens in a university hospital. Detection of ESBLs and carbapenemases produced by studied strains was performed using PCR and DNA sequencing...
March 6, 2018: Journal of Antimicrobial Chemotherapy
Sabrina Ribeiro de Almeida Queiroz, José Valter Joaquim Silva Júnior, Andréa Nazaré Monteiro Rangel da Silva, Amanda Gomes de Oliveira Carvalho, Jefferson José da Silva Santos, Laura Helena Vega Gonzales Gil
INTRODUCTION: Pseudo-infectious yellow fever viral particles (YFV-PIVs) have been used to study vaccines and viral packaging. Here, we report the development of a packaging cell line, which expresses the YFV prM/E proteins. METHODS: HEK293 cells were transfected with YFV prM/E and C (84 nt) genes to generate HEK293-YFV-PrM/E-opt. The cells were evaluated for their ability to express the heterologous proteins and to package the replicon repYFV-17D-LucIRES, generating YFV-PIVs...
January 2018: Revista da Sociedade Brasileira de Medicina Tropical
Ekaterina G Viktorova, Sunil Khattar, Siba Samal, George A Belov
Poliovirus is a prototype member of the Enterovirus genus of the Picornaviridae family of small positive strand RNA viruses, which include important human and animal pathogens. Quantitative assessment of viral replication is very important for investigation of the virus biology and the development of anti-viral strategies. The poliovirus genome structure allows replacement of structural genes with a reporter protein, such as a luciferase or a fluorescent protein, whose signals can be detected and quantified in vivo, thus permitting observation of replication kinetics in live cells...
February 22, 2018: Current Protocols in Microbiology
Guillaume Méric, Leonardos Mageiros, Ben Pascoe, Dan J Woodcock, Evangelos Mourkas, Sarah Lamble, Rory Bowden, Keith A Jolley, Ben Raymond, Samuel K Sheppard
Bacterial plasmids can vary from small selfish genetic elements to large autonomous replicons that constitute a significant proportion of total cellular DNA. By conferring novel function to the cell, plasmids may facilitate evolution but their mobility may be opposed by co-evolutionary relationships with chromosomes or encouraged via the infectious sharing of genes encoding public goods. Here, we explore these hypotheses through large-scale examination of the association between plasmids and genomes in the phenotypically diverse Bacillus cereus group...
March 6, 2018: Molecular Ecology
Torunn Pedersen, John Osei Sekyere, Usha Govinden, Krishnee Moodley, Audun Sivertsen, Ørjan Samuelsen, Sabiha Yusuf Essack, Arnfinn Sundsfjord
Whole-genome sequence analyses revealed the presence of bla NDM-1 ( n =31), bla GES-5 ( n =8), bla OXA-232 ( n =1), or bla NDM-5 ( n =1) in extensively drug-resistant and pandrug-resistant Enterobacteriaceae isolated from in-patients in 10 private hospitals (2012-2013) in Durban, South Africa. Two novel NDM-1 encoding plasmids from Klebsiella pneumoniae were closed by PacBio sequencing. In p19-10_01 (IncFIB(K), 223.434 bp) bla NDM-1 was part of a Tn 1548 -like structure (16.276 bp) delineated by IS 26 The multireplicon plasmid p18-43_01 (IncR_1/IncFIB(pB171)/IncFII(Yp); 212...
March 5, 2018: Antimicrobial Agents and Chemotherapy
Birson Ingti, Pranjit Saikia, Deepjyoti Paul, Anand Prakash Maurya, Debadatta Dhar Chanda, Atanu Chakravarty, Chandrayee Deshamukhya, Amitabha Bhattacharjee
OBJECTIVES: Plasmids of different replicon types are believed to be associated with the carriage and transmission of antibiotic resistance genes. Thus present study was undertaken to check the association of CIT with particular plasmid types and to identify the E. coli strains involve in the maintenance of this determinant within the plasmid. METHODS: Screening of AmpC β-lactamase phenotypically by Modified Three Dimensional Extract Method followed by Antimicrobial Susceptibility and MIC determination...
March 2, 2018: Journal of Global Antimicrobial Resistance
Maria Giufrè, Giulia Errico, Marisa Accogli, Monica Monaco, Laura Villa, Maria Antonietta Distasi, Tito Del Gaudio, Annalisa Pantosti, Alessandra Carattoli, Marina Cerquetti
The emergence of carbapenemase-producing Enterobacteriaceae (CPE) is a critical concern worldwide. In Italy, CPE isolates are very frequent with the KPC types strongly predominant whereas the New Delhi metallo-β-lactamase (NDM) enzymes are extremely rare. In this study, we report the first detection of NDM-5-producing Escherichia coli sequence type (ST) 167 isolates from two patients with urinary tract infection (Ec001and Ec002 from urines) including one with colonization (Ec003 from faeces) admitted to the same hospital in 2017 two months apart...
February 28, 2018: International Journal of Antimicrobial Agents
Robert F Potter, Meghan A Wallace, Allison R McMullen, Jerome Prusa, Christina L Stallings, Carey-Ann D Burnham, Gautam Dantas
OBJECTIVES: A carbapenem resistant Providencia rettgeri (PR1) isolate was recovered from a wound infection in Missouri, USA. This isolate possessed an EDTA inhibitable carbapenemase that was unidentified using the Xpert CARBA-R assay. Our objective was to elucidate the molecular determinant of carbapenem resistance in this isolate. We then sought to test the transmissibility of blaIMP-27 loci in clinical P. rettgeri and Proteus mirabilis isolates. METHODS: In October 2016 the novel ambler Class B carbapenemase blaIMP-27 , was reported in two different Proteus mirablis (PM185 and PM187) isolates...
February 26, 2018: Clinical Microbiology and Infection
Tomoki Yoshikawa, Hikaru Fujii, Akiko Okutani, Miho Shibamura, Natsumi Omura, Kazutaka Egawa, Hirofumi Kato, Takuya Inagaki, Shizuko Harada, Souichi Yamada, Shigeru Morikawa, Masayuki Saijo
LC16m8 (m8), a highly attenuated vaccinia virus (VAC) strain, was developed as a smallpox vaccine, and its safety and immunogenicity have been confirmed. Here, we aimed to develop a system that recovers infectious m8 from a bacterial artificial chromosome (BAC) that retains the full-length viral genomic DNA (m8-BAC system). The infectious virus was successfully recovered from a VAC-BAC plasmid, named pLC16m8-BAC. Furthermore, the bacterial replicon-free virus was generated by intramolecular homologous recombination and was successfully recovered from a modified VAC-BAC plasmid, named pLC16m8...
2018: PloS One
Shengwei Zhang, Qi Cheng, Chenxi Luo, Lei Yin, Yali Qin, Mingzhou Chen
The phosphoprotein (P) of human parainfluenza virus type 3 (HPIV3) plays a pivotal role in viral RNA synthesis, which interacts with the nucleoprotein (N) to form a soluble N0 -P complex (N0 , free of RNAs) to prevent the nonspecific RNA binding and illegitimate aggregation of N. Functional regions within P have been studied intensively. However, the precise site (s) within P directly involved in N0 -P interaction still remains unclear. In this study, using a series of deleted and truncated mutants of P of HPIV3, we demonstrate that amino-terminal 40 amino acids (aa) of P restrict and regulate N0 -P interaction...
February 15, 2018: Virology
Ramona Iseppi, Simona de Niederhäusern, Moreno Bondi, Patrizia Messi, Carla Sabia
We investigated the occurrence of extended-spectrum β-lactamase (ESBL), AmpC, and carbapenemase-producing Gram-negative bacteria isolated from 160 samples of fresh vegetables (n = 80) and ready-to-eat (RTE) prepacked salads (n = 80). Phenotypic and genotypic analyses were carried out on the isolates in terms of the species present and relative resistance. Resistance to β-lactam antibiotics was found in only 44 (24 from fresh vegetables and 20 from RTE salads) of a total of 312 Gram-negative strains (14...
February 16, 2018: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
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