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Nina Molin Høyland-Kroghsbo, Katrina Arcelia Muñoz, Bonnie L Bassler
Clustered regularly interspaced short palindromic repeat (CRISPR)-associated (CRISPR-Cas) systems are adaptive defense systems that protect bacteria and archaea from invading genetic elements. In Pseudomonas aeruginosa , quorum sensing (QS) induces the CRISPR-Cas defense system at high cell density when the risk of bacteriophage infection is high. Here, we show that another cue, temperature, modulates P. aeruginosa CRISPR-Cas. Increased CRISPR adaptation occurs at environmental (i.e., low) temperatures compared to that at body (i...
November 13, 2018: MBio
Ambra Sarracino, Lavina Gharu, Anna Kula, Alexander O Pasternak, Veronique Avettand-Fenoel, Christine Rouzioux, Maryana Bardina, Stéphane De Wit, Monsef Benkirane, Ben Berkhout, Carine Van Lint, Alessandro Marcello
Posttranscriptional regulation of HIV-1 replication is finely controlled by viral and host factors. Among the former, Rev controls the export of partially spliced and unspliced viral RNAs from the nucleus and their translation in the cytoplasm or incorporation into new virions as genomic viral RNA. To investigate the functional role of the Rev cofactor MATR3 in the context of HIV infection, we modulated its expression in Jurkat cells and primary peripheral blood lymphocytes (PBLs). We confirmed that MATR3 is a positive regulator of HIV-1 acting at a posttranscriptional level...
November 13, 2018: MBio
Raphael N Sieber, Robert L Skov, Jens Nielsen, Jana Schulz, Lance B Price, Frank M Aarestrup, Anders R Larsen, Marc Stegger, Jesper Larsen
The spread of livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398 (LA-MRSA CC398) within the Danish pig production system has been linked to an increased number of human infections. Yet, the population structure and transmission dynamics of this important pathogen remain poorly understood. In this study, whole-genome sequences from 371 LA-MRSA CC398 isolates collected between 2004 and 2015 were subjected to bioinformatic analyses. The isolates originated from Danish pig farms ( n = 209) and people having livestock contact ( n = 79)...
November 13, 2018: MBio
Youbao Zhao, Srijana Upadhyay, Xiaorong Lin
Switching between different morphotypes is an adaptive cellular response in many microbes. In Cryptococcus neoformans , the yeast-to-hypha transition confers resistance to microbial predation in the soil and is an integral part of its life cycle. Morphogenesis is also known to be associated with virulence, with the filamentous form being immune-stimulatory and protective in mammalian models of cryptococcosis. Previous studies identified the transcription factor Znf2 as a master regulator of cryptococcal filamentation...
November 13, 2018: MBio
Arif M Tanmoy, Emilie Westeel, Katrien De Bruyne, Johan Goris, Alain Rajoharison, Mohammad S I Sajib, Alex van Belkum, Samir K Saha, Florence Komurian-Pradel, Hubert P Endtz
Typhoid fever, caused by Salmonella enterica serovar Typhi, is a global public health concern due to increasing antimicrobial resistance (AMR). Characterization of S Typhi genomes for AMR and the evolution of different lineages, especially in countries where typhoid fever is endemic such as Bangladesh, will help public health professionals to better design and implement appropriate preventive measures. We studied whole-genome sequences (WGS) of 536 S Typhi isolates collected in Bangladesh during 1999 to 2013 and compared those sequences with data from a recent outbreak in Pakistan reported previously by E...
November 13, 2018: MBio
Matthew A Campbell, Piotr Łukasik, Mariah C Meyer, Mark Buckner, Chris Simon, Claudio Veloso, Anna Michalik, John P McCutcheon
For insects that depend on one or more bacterial endosymbionts for survival, it is critical that these bacteria are faithfully transmitted between insect generations. Cicadas harbor two essential bacterial endosymbionts, " Candidatus Sulcia muelleri" and " Candidatus Hodgkinia cicadicola." In some cicada species, Hodgkinia has fragmented into multiple distinct but interdependent cellular and genomic lineages that can differ in abundance by more than two orders of magnitude. This complexity presents a potential problem for the host cicada, because low-abundance but essential Hodgkinia lineages risk being lost during the symbiont transmission bottleneck from mother to egg...
November 13, 2018: MBio
Jessica Borgmann, Sina Schäkermann, Julia Elisabeth Bandow, Franz Narberhaus
Small regulatory RNAs play an important role in the adaptation to changing conditions. Here, we describe a differentially expressed small regulatory RNA (sRNA) that affects various cellular processes in the plant pathogen Agrobacterium tumefaciens Using a combination of bioinformatic predictions and comparative proteomics, we identified nine targets, most of which are positively regulated by the sRNA. According to these targets, we named the sRNA PmaR for peptidoglycan biosynthesis, motility, and ampicillin resistance regulator...
November 13, 2018: MBio
Xiaoquan Su, Gongchao Jing, Daniel McDonald, Honglei Wang, Zengbin Wang, Antonio Gonzalez, Zheng Sun, Shi Huang, Jose Navas, Rob Knight, Jian Xu
With the expansion of microbiome sequencing globally, a key challenge is to relate new microbiome samples to the existing space of microbiome samples. Here, we present Microbiome Search Engine (MSE), which enables the rapid search of query microbiome samples against a large, well-curated reference microbiome database organized by taxonomic similarity at the whole-microbiome level. Tracking the microbiome novelty score (MNS) over 8 years of microbiome depositions based on searching in more than 100,000 global 16S rRNA gene amplicon samples, we detected that the structural novelty of human microbiomes is approaching saturation and likely bounded, whereas that in environmental habitats remains 5 times higher...
November 13, 2018: MBio
Andrés Corral-Lugo, Miguel A Matilla, David Martín-Mora, Hortencia Silva Jiménez, Noel Mesa Torres, Junichi Kato, Akiko Hida, Shota Oku, Mayte Conejero-Muriel, Jose A Gavira, Tino Krell
Histamine is a key biological signaling molecule. It acts as a neurotransmitter in the central and peripheral nervous systems and coordinates local inflammatory responses by modulating the activity of different immune cells. During inflammatory processes, including bacterial infections, neutrophils stimulate the production and release of histamine. Here, we report that the opportunistic human pathogen Pseudomonas aeruginosa exhibits chemotaxis toward histamine. This chemotactic response is mediated by the concerted action of the TlpQ, PctA, and PctC chemoreceptors, which display differing sensitivities to histamine...
November 13, 2018: MBio
Jeremy C Jones, Gyanendra Kumar, Subrata Barman, Isabel Najera, Stephen W White, Richard J Webby, Elena A Govorkova
No abstract text is available yet for this article.
November 13, 2018: MBio
Muniyandi Selvaraj, Kavestri Yegambaram, Eleanor J A A Todd, Charles-Adrien Richard, Rachel L Dods, Georgia M Pangratiou, Chi H Trinh, Sophie L Moul, James C Murphy, Jamel Mankouri, Jean-François Éléouët, John N Barr, Thomas A Edwards
Human respiratory syncytial virus (HRSV) is a negative-stranded RNA virus that causes a globally prevalent respiratory infection, which can cause life-threatening illness, particularly in the young, elderly, and immunocompromised. HRSV multiplication depends on replication and transcription of the HRSV genes by the virus-encoded RNA-dependent RNA polymerase (RdRp). For replication, this complex comprises the phosphoprotein (P) and the large protein (L), whereas for transcription, the M2-1 protein is also required...
November 13, 2018: MBio
Ann M Guggisberg, Philip M Frasse, Andrew J Jezewski, Natasha M Kafai, Aakash Y Gandhi, Samuel J Erlinger, Audrey R Odom John
In the malaria parasite Plasmodium falciparum , synthesis of isoprenoids from glycolytic intermediates is essential for survival. The antimalarial fosmidomycin (FSM) inhibits isoprenoid synthesis. In P. falciparum , we identified a loss-of-function mutation in HAD2 ( P. falciparum 3D7_1226300 [PF3D7_1226300]) as necessary for FSM resistance. Enzymatic characterization revealed that HAD2, a member of the haloacid dehalogenase-like hydrolase (HAD) superfamily, is a phosphatase. Harnessing a growth defect in resistant parasites, we selected for suppression of HAD2-mediated FSM resistance and uncovered hypomorphic suppressor mutations in the locus encoding the glycolytic enzyme phosphofructokinase 9 (PFK9)...
November 13, 2018: MBio
Colin S Maxwell
The role of phenotypic plasticity in the evolution of new traits is controversial due to a lack of direct evidence. Phage host range becomes plastic in the presence of restriction-modification (R-M) systems in their hosts. I modeled the evolution of phage host range in the presence of R-M systems. The model makes two main predictions. The first prediction is that the offspring of the first phage to gain a new methylation pattern by infecting a new host make up a disproportionate fraction of the subsequent specialist population, indicating that the plastically produced phenotype is highly predictive of evolutionary outcome...
November 13, 2018: MBio
Krystal A Fontaine, Kristoffer E Leon, Mir M Khalid, Sakshi Tomar, David Jimenez-Morales, Mariah Dunlap, Julia A Kaye, Priya S Shah, Steve Finkbeiner, Nevan J Krogan, Melanie Ott
Zika virus (ZIKV) infection of neural progenitor cells (NPCs) in utero is associated with neurological disorders, such as microcephaly, but a detailed molecular understanding of ZIKV-induced pathogenesis is lacking. Here we show that in vitro ZIKV infection of human cells, including NPCs, causes disruption of the nonsense-mediated mRNA decay (NMD) pathway. NMD is a cellular mRNA surveillance mechanism that is required for normal brain size in mice. Using affinity purification-mass spectrometry, we identified multiple cellular NMD factors that bind to the viral capsid protein, including the central NMD regulator up-frameshift protein 1 (UPF1)...
November 6, 2018: MBio
José Pedro Lopes, Marios Stylianou, Emelie Backman, Sandra Holmberg, Jana Jass, Rolf Claesson, Constantin F Urban
Microbial colonizers of humans have evolved to adapt to environmental cues and to sense nutrient availability. Oxygen is a constantly changing environmental parameter in different host tissues and in different types of infection. We describe how Candida albicans , an opportunistic fungal pathogen, can modulate the host response under hypoxia and anoxia. We found that high infiltration of polymorphonuclear leukocytes (PMNs) to the site of infection contributes to a low oxygen milieu in a murine subdermal abscess...
November 6, 2018: MBio
Ada K Hagan, Yael M Plotnick, Ryan E Dingle, Zachary I Mendel, Stephen R Cendrowski, David H Sherman, Ashootosh Tripathi, Philip C Hanna
Bacillus anthracis is a Gram-positive bacillus that under conditions of environmental stress, such as low nutrients, can convert from a vegetative bacillus to a highly durable spore that enables long-term survival. The sporulation process is regulated by a sequential cascade of dedicated transcription factors but requires key nutrients to complete, one of which is iron. Iron acquisition by the iron-scavenging siderophore petrobactin is required for vegetative growth of B. anthracis under iron-depleted conditions and in the host...
November 6, 2018: MBio
Jennifer R Bratburd, Caitlin Keller, Eugenio Vivas, Erin Gemperline, Lingjun Li, Federico E Rey, Cameron R Currie
The gut microbiota confers resistance to pathogens of the intestinal ecosystem, yet the dynamics of pathogen-microbiome interactions and the metabolites involved in this process remain largely unknown. Here, we use gnotobiotic mice infected with the virulent pathogen Salmonella enterica serovar Typhimurium or the opportunistic pathogen Candida albicans in combination with metagenomics and discovery metabolomics to identify changes in the community and metabolome during infection. To isolate the role of the microbiota in response to pathogens, we compared mice monocolonized with the pathogen, uninfected mice "humanized" with a synthetic human microbiome, or infected humanized mice...
November 6, 2018: MBio
Theodore Gouliouris, Kathy E Raven, Catherine Ludden, Beth Blane, Jukka Corander, Carolyne S Horner, Juan Hernandez-Garcia, Paul Wood, Nazreen F Hadjirin, Milorad Radakovic, Mark A Holmes, Marcus de Goffau, Nicholas M Brown, Julian Parkhill, Sharon J Peacock
Vancomycin-resistant Enterococcus faecium (VREfm) is a major cause of nosocomial infection and is categorized as high priority by the World Health Organization global priority list of antibiotic-resistant bacteria. In the past, livestock have been proposed as a putative reservoir for drug-resistant E. faecium strains that infect humans, and isolates of the same lineage have been found in both reservoirs. We undertook cross-sectional surveys to isolate E. faecium (including VREfm) from livestock farms, retail meat, and wastewater treatment plants in the United Kingdom...
November 6, 2018: MBio
Yang Mi, Rajendra Kumar Gurumurthy, Piotr K Zadora, Thomas F Meyer, Cindrilla Chumduri
Cervical and ovarian cancers exhibit characteristic mutational signatures that are reminiscent of mutational processes, including defective homologous recombination (HR) repair. How these mutational processes are initiated during carcinogenesis is largely unclear. Chlamydia trachomatis infections are epidemiologically associated with cervical and ovarian cancers. Previously, we showed that C. trachomatis induces DNA double-strand breaks (DSBs) but suppresses Ataxia-telangiectasia mutated (ATM) activation and cell cycle checkpoints...
November 6, 2018: MBio
George B Kyei, Shanshan Meng, Rashmi Ramani, Austin Niu, Chandraiah Lagisetti, Thomas R Webb, Lee Ratner
The main obstacle to an HIV cure is the transcriptionally inert proviruses that persist in resting CD4 T cells and other reservoirs. None of the current approaches has significantly reduced the size of the viral reservoir. Hence, alternative approaches, such as permanent blocking of viral transcription, to achieve a sustained remission, need urgent attention. To identify cellular factors that may be important for this approach, we sought for host targets that when altered could block HIV transcription and reactivation...
November 6, 2018: MBio
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