Microbiology

Molecular Basis for Interferon-mediated Pathogen Restriction in Human Cells

1. Sumit K. Matta
2. Hinissan P. Kohio
3. Pallavi Chandra
4. Adam Brown
5. John G. Doench
6. Jennifer A. Philips
7. Siyuan Ding
8. L. David Sibley

Reviewed by Review Commons

Initiation of HIV-1 Gag lattice assembly is required for recognition of the viral genome packaging signal

1. Xiao Lei
2. Daniel Gonçalves-Carneiro
3. Trinity M Zang
4. Paul D Bieniasz

• Curated by eLife

  eLife assessment

  This work presents valuable findings that advance our understanding of the roles of the CA domain in specific binding of HIV-1 Gag to the viral genomic RNA. The compelling evidence obtained using the modified CLIP-seq and chemical crosslinking approaches support the authors' conclusion that the initial Gag lattice formation mediated by CA is essential for Gag recognition of the 5' Ψ sequence. This work will be of interest to virologists working on gRNA packaging of not only HIV-1 but also other RNA viruses.

Reviewed by eLife

GWAS and functional studies suggest a role for altered DNA repair in the evolution of drug resistance in Mycobacterium tuberculosis

1. Saba Naz
2. Kumar Paritosh
3. Priyadarshini Sanyal
4. Sidra Khan
5. Yogendra Singh
6. Umesh Varshney
7. Vinay Kumar Nandicoori

• Curated by eLife

  eLife assessment

  Drug-resistant tuberculosis (TB) is a growing threat to global public health. By analysing a large database of clinical Mycobacterium tuberculosis isolates, the authors of this study identify previously unrecognized genetic mutations that might be implicated in improved mycobacterial survival under antibiotic treatment. Using laboratory and experimental infection models, they present evidence that these mutations should be considered potential genetic markers of reduced antibiotic efficacy and accelerated acquisition of TB drug resistance.

Reviewed by eLife

A human-specific motif facilitates CARD8 inflammasome activation after HIV-1 infection

1. Jessie Kulsuptrakul
2. Elizabeth A Turcotte
3. Michael Emerman
4. Patrick S Mitchell

• Curated by eLife

  eLife assessment

  The study shows that human inflammasome-forming sensor CARD8 contains a specific motif that allows cleavage by the proteases of HIV-1 and its direct precursor infecting chimpanzees. In comparison, CARD8 proteins from non-human primates contain changes in this motif and seem largely resistant to proteolytic activation. The results are important, and the data on the cleavage of CARD8 in HEK293T cells are convincing, while effects on inflammasome stimulation and cell death in primary viral target cells are insufficiently supported.

Reviewed by eLife, PREreview

A glycine zipper motif governs translocation of type VI secretion toxic effectors across the cytoplasmic membrane of target cells

1. Jemal Ali
2. Manda Yu
3. Li-Kang Sung
4. Yee-Wai Cheung
5. Erh-Min Lai

Reviewed by Review Commons

Competitive interactions between culturable bacteria are highly non-additive

1. Amichai Baichman-Kass
2. Tingting Song
3. Jonathan Friedman

• Curated by eLife

  eLife assessment

  This important study presents an interesting example of how complexities of communities may be reduced by showing that the joint effects of two or more species on a focal species are generally not additive, but rather dominated by the strongest single effect. The evidence, enabled by over 14,000 measurements using nanodroplet-based microfluidics, is compelling, although the generality of the conclusion awaits further studies. This paper is of interest to microbial ecologists.

Reviewed by eLife

Fitness advantage of Bacteroides thetaiotaomicron capsular polysaccharide in the mouse gut depends on the resident microbiota

1. Daniel Hoces
2. Giorgia Greter
3. Markus Arnoldini
4. Melanie L Stäubli
5. Claudia Moresi
6. Anna Sintsova
7. Sara Berent
8. Isabel Kolinko
9. Florence Bansept
10. Aurore Woller
11. Janine Häfliger
12. Eric Martens
13. Wolf-Dietrich Hardt
14. Shinichi Sunagawa
15. Claude Loverdo
16. Emma Slack

• Curated by eLife

  eLife assessment

  This study addresses whether the composition of the microbiota influences the intestinal colonization of encapsulated vs unencapsulated Bacteroides thetaiotaomicron, a resident micro-organism of the colon. This is an important question because factors determining the colonization of gut bacteria remain a critical barrier in translating microbiome research into new bacterial cell-based therapies. To answer the question, the authors develop an innovative method to quantify B. theta population bottlenecks during intestinal colonization in the setting of different microbiota. Their main finding that the colonization defect of an acapsular mutant is dependent on the composition of the microbiota is valuable and this observation suggests that interactions between gut bacteria explains why the mutant has a colonization defect. The evidence supporting this claim is currently insufficient. Additionally, some of the analyses and claims are compromised because the authors do not fully explain their data and the number of animals is sometimes very small.

Reviewed by eLife

A frameshift in Yersinia pestis rcsD alters canonical Rcs signalling to preserve flea-mammal plague transmission cycles

1. Xiao-Peng Guo
2. Hai-Qin Yan
3. Wenhui Yang
4. Zhe Yin
5. Viveka Vadyvaloo
6. Dongsheng Zhou
7. Yi-Cheng Sun

• Curated by eLife

  eLife assessment

  This valuable study substantially advances our understanding of the phenotypic divergence of the plague-causing bacterium, Yersinia pestis, from a closely related species, Yersinia pseudotuberculosis, which causes much milder disease. The authors provide convincing evidence that a frameshift mutation in the Y. pestis rcsD gene changes a signaling pathway that contributes to the flea-mammal transmission of plague. The work shows how small genetic differences can alter pathogenicity and stress survival.

Reviewed by eLife

Interactions between metabolism and growth can determine the co-existence of Staphylococcus aureus and Pseudomonas aeruginosa

1. Camryn Pajon
2. Marla C Fortoul
3. Gabriela Diaz-Tang
4. Estefania Marin Meneses
5. Ariane R Kalifa
6. Elinor Sevy
7. Taniya Mariah
8. Brandon Toscan
9. Maili Marcelin
10. Daniella M Hernandez
11. Melissa M Marzouk
12. Allison J Lopatkin
13. Omar Tonsi Eldakar
14. Robert P Smith

• Curated by eLife

  eLife assessment

  How the pathogens Pseudomonas aeruginosa and Staphylococcus aureus compete and co-occur within opportunistic infections is a topic of broad significance, but the major drivers of these interactions remain unclear. Here the authors defined parameters that predict the coexistence of these microbes using their absolute growth in certain nutritional conditions, leading to questions about how other nutrients lead to the dominance of one or the other during infections. Within a confined context, this valuable study provides solid support for a novel framework in which to evaluate this clinically important species interaction.

Reviewed by eLife

The sphingolipids ceramide and inositol phosphorylceramide protect the Leishmania major membrane from sterol-specific toxins

1. Chaitanya S. Haram
2. Samrat Moitra
3. Rilee Keane
4. F. Matthew Kuhlmann
5. Cheryl Frankfater
6. Fong-Fu Hsu
7. Stephen M. Beverley
8. Kai Zhang
9. Peter A. Keyel

Reviewed by Review Commons