Microbiology

Transposon mutagenesis screen in Klebsiella pneumoniae identifies genetic determinants required for growth in human urine and serum

1. Jessica Gray
2. Von Vergel L Torres
3. Emily Goodall
4. Samantha A McKeand
5. Danielle Scales
6. Christy Collins
7. Laura Wetherall
8. Zheng Jie Lian
9. Jack A Bryant
10. Matthew T Milner
11. Karl A Dunne
12. Christopher Icke
13. Jessica L Rooke
14. Thamarai Schneiders
15. Peter A Lund
16. Adam F Cunningham
17. Jeff A Cole
18. Ian R Henderson

• Curated by eLife

  eLife assessment

  This valuable study is of relevance for those interested in the mechanism required for infections of humans by Klebsiella pneumoniae. The authors apply TraDIS (high-density TnSeq) to K. pneumoniae with the goal of identifying genes required for survival under various infection-relevant conditions and the gene sets identified, together with the raw sequence data, will be resources for the Klebsiella research community. The evidence to support the lists of essential and conditionally-essential genes is convincing. The study provides strong evidence that some genes are conditionally essential in urine because of iron limitation, but there is less mechanistic insight for genes that are conditionally essential in serum.

Reviewed by eLife

Secreted antigen A peptidoglycan hydrolase is essential for Enterococcus faecium cell separation and priming of immune checkpoint inhibitor therapy

1. Steven Klupt
2. Kyong Tkhe Fam
3. Xing Zhang
4. Pavan Kumar Chodisetti
5. Abeera Mehmood
6. Tumara Boyd
7. Danielle Grotjahn
8. Donghyun Park
9. Howard C Hang

• Curated by eLife

  eLife assessment

  The authors build upon prior data implicating the secreted peptidoglycan hydrolase SagA produced by Enterococcus faecium in immunotherapy. Leveraging new strains with sagA deletion/complementation constructs, the investigators reveal that sagA is non-essential, with sagA deletion leading to a marked growth defect due to impaired cell division, and sagA being necessary for the immunogenic and anti-tumor effects of E. faecium. In aggregate, the study utilizes compelling methods to provide both fundamental new insights into E. faecium biology and host interactions and a proof-of-concept for identifying the bacterial effectors of immunotherapy response.

Reviewed by eLife

Modular small RNA drives pathogen emergence

1. Deepak Balasubramanian
2. Salvador Almagro-Moreno

Reviewed by PREreview

CoCoNuTs are a diverse subclass of Type IV restriction systems predicted to target RNA

1. Ryan T Bell
2. Harutyun Sahakyan
3. Kira S Makarova
4. Yuri I Wolf
5. Eugene V Koonin

• Curated by eLife

  eLife assessment

  This paper marks a fundamental advance in our understanding of prokaryotic Type IV restriction systems. The authors provide an encyclopedic overview of a hitherto uncharacterized branch of these systems, which they name CoCoNuTs, for coiled-coil nuclease tandems. They provide compelling evidence that these nucleases target RNA and are part of an echeloned defense response following viral infection. This article will be of great interest to scientists studying prokaryotic immunity mechanisms, as well as broadly to protein scientists engaged in the analysis, classification, and functional annotation of the proteome of life.

Reviewed by eLife

A weaponized phage suppresses competitors in historical and modern metapopulations of pathogenic bacteria

1. Talia Backman
2. Sergio M. Latorre
3. Efthymia Symeonidi
4. Artur Muszyński
5. Ella Bleak
6. Lauren Eads
7. Paulina I. Martinez-Koury
8. Sarita Som
9. Aubrey Hawks
10. Andrew D. Gloss
11. David M. Belnap
12. Allison M. Manuel
13. Adam M. Deutschbauer
14. Joy Bergelson
15. Parastoo Azadi
16. Hernán A. Burbano
17. Talia L. Karasov

Reviewed by Rapid Reviews Infectious Diseases

Reducing the Bacterial Lag Phase Through Methylated Compounds: Insights from Algal-Bacterial Interactions

1. Martin Sperfeld
2. Delia A. Narváez-Barragán
3. Sergey Malitsky
4. Veronica Frydman
5. Lilach Yuda
6. Jorge Rocha
7. Einat Segev

Reviewed by Arcadia Science

Bacterial vampirism mediated through taxis to serum

1. Siena J Glenn
2. Zealon Gentry-Lear
3. Michael Shavlik
4. Michael J Harms
5. Thomas J Asaki
6. Arden Baylink

• Curated by eLife

  eLife assessment

  This work uses an interdisciplinary approach combining microfluidics, structural biology, and genetic analyses to provide important findings that show that pathogenic enteric bacteria exhibit taxis toward human serum. The data are compelling and show that the behavior utilizes the bacterial chemotaxis system and the chemoreceptor Tsr, which senses the amino acid L-serine. The work provides an ecological context for the role of serine as a bacterial chemoattractant and could have clinical implications for bacterial bloodstream invasion during episodes of gastrointestinal bleeding.

Reviewed by eLife

RNA polymerase III is involved in regulating Plasmodium falciparum virulence

1. Gretchen Diffendall
2. Aurelie Claes
3. Anna Barcons-Simon
4. Prince Nyarko
5. Florent Dingli
6. Miguel M Santos
7. Damarys Loew
8. Antoine Claessens
9. Artur Scherf

• Curated by eLife

  eLife assessment

  This important study links the activity of polymerase III to the regulation of virulence gene expression in the deadliest malaria parasite, Plasmodium falciparum. It identifies Maf1 as a Pol III inhibitor that enables the parasite to respond to external stimuli such as magnesium chloride plasma levels by downregulating Pol III-transcribed ruf6 genes and subsequently regulated var genes. While the evidence presented is generally convincing, some of the results are incomplete, and the mechanistic link between external signals and Maf1 activation remains unknown.

Reviewed by eLife

Stratification of viral shedding patterns in saliva of COVID-19 patients

1. Hyeongki Park
2. Raiki Yoshimura
3. Shoya Iwanami
4. Kwang Su Kim
5. Keisuke Ejima
6. Naotoshi Nakamura
7. Kazuyuki Aihara
8. Yoshitsugu Miyazaki
9. Takashi Umeyama
10. Ken Miyazawa
11. Takeshi Morita
12. Koichi Watashi
13. Christopher B. Brooke
14. Ruian Ke
15. Shingo Iwami
16. Taiga Miyazaki

• Curated by eLife

  eLife assessment

  This useful work by Park attempts to use machine learning algorithms to identify correlates of different observed shedding patterns in two COVID-19 cohorts. The evidence supporting the study conclusions is incomplete due to the lack of uniformity in assays between the 2 cohorts, relevant metadata (previous infection/vaccination status, viral variant), early viral load data in the cohorts, and incomplete statistical analyses. With a strengthened analysis, the work may be of interest to virologists, clinicians, and public health scientists.

Reviewed by eLife

Release of P-TEFb from the Super Elongation Complex promotes HIV-1 latency reversal

1. William J. Cisneros
2. Shimaa H. A. Soliman
3. Miriam Walter
4. Lacy M. Simons
5. Daphne Cornish
6. Simone De Fabritiis
7. Ariel W. Halle
8. Eun-Young Kim
9. Steven M. Wolinsky
10. Ramon Lorenzo-Redondo
11. Ali Shilatifard
12. Judd F. Hultquist

Reviewed by Rapid Reviews Infectious Diseases