Microbiology

Staphylococcus aureus counters organic acid anion-mediated inhibition of peptidoglycan cross-linking through robust alanine racemase activity

1. Sasmita Panda
2. Yahani P Jayasinghe
3. Dhananjay D Shinde
4. Emilio Bueno
5. Amanda Stastny
6. Blake P Bertrand
7. Sujata S Chaudhari
8. Tammy Kielian
9. Felipe Cava
10. Donald R Ronning
11. Vinai C Thomas

• Curated by eLife

  eLife Assessment

  In this useful study, the authors present convincing evidence linking the enzyme D-alanine-D-alanine ligase (Ddl), crucial for cell wall fortification, to organic acid exposure in Staphylococcus aureus. While it's established that organic acids impede bacterial growth, the researchers reveal a novel coping mechanism where S. aureus maintains elevated levels of D-alanine, the substrate for Ddl, to counteract this inhibition. This discovery illuminates a bacterial strategy for organic acid tolerance, offering new insights for microbiologists and potentially informing future antimicrobial approaches.

Reviewed by eLife, Arcadia Science

Characterization of vaginal microbiomes in clinician-collected bacterial vaginosis diagnosed samples

1. Hayden N. Brochu
2. Qimin Zhang
3. Kuncheng Song
4. Ling Wang
5. Emily A. Deare
6. Jonathan D. Williams
7. Crystal R. Icenhour
8. Lakshmanan K. Iyer

Reviewed by PREreview

Establishing the green algae Chlamydomonas incerta as a platform for recombinant protein production

1. Kalisa Kang
2. Évellin do Espirito Santo
3. Crisandra Jade Diaz
4. Aaron Oliver
5. Lisa Saxton
6. Lauren May
7. Stephen Mayfield
8. João Vitor Dutra Molino

Reviewed by Arcadia Science

RNase III in Salmonella Enteritidis enhances bacterial virulence by reducing host immune responses

1. Bill Kwan-wai Chan
2. Yingxue Li
3. Hongyuhang Ni
4. Edward Wai-chi Chan
5. Xin Deng
6. Linfeng Huang
7. Sheng Chen

• Curated by eLife

  eLife Assessment

  This useful study examines the function of the rnc gene, which encodes the RNase III ribonuclease, as it relates to virulence of Salmonella Enteritidis. The authors demonstrate that the rnc gene is markedly upregulated in strains proposed to exhibit high virulence and that the product of the rnc gene promotes the expression of SodA, which contributes to the survival of Salmonella Enteritidis in the face of oxidative stress. The study also suggests that elevated levels of rnc gene expression assist Salmonella Enteritidis in evading immune responses by diminishing the presence of accumulated double-stranded RNA (dsRNA), although the evidence substantiating this and the above assertions remains incomplete.

Reviewed by eLife

Lipid discovery enabled by sequence statistics and machine learning

1. Priya M Christensen
2. Jonathan Martin
3. Aparna Uppuluri
4. Luke R Joyce
5. Yahan Wei
6. Ziqiang Guan
7. Faruck Morcos
8. Kelli L Palmer

• Curated by eLife

  eLife Assessment

  This study reports important findings on identifying sequence motifs that predict substrate specificity in a class of lipid synthesis enzymes. It sheds light on a mechanism used by bacteria to modify the lipids in their membrane to develop antibiotic resistance. The evidence is compelling, with a careful application of machine learning methods, validated by mass spectrometry-based lipid analysis experiments. This interdisciplinary study will be of interest to computational biologists and to the community working on lipids and on enzymes involved in lipid synthesis or modification.

Reviewed by eLife

Reversion to sensitivity explains limited transmission of resistance in a hospital pathogen

1. Kevin C Tracy
2. Jordan McKaig
3. Clare Kinnear
4. Jess Millar
5. Aaron A King
6. Andrew F Read
7. Robert J Woods

• Curated by eLife

  eLife Assessment

  This important study, which will be of interest to those studying the evolution and maintenance of antibiotic resistance, addresses the hypothesis that antibiotic resistance arising de novo during treatment will carry a higher fitness cost and will revert to susceptibility more readily than resistance that has been transmitted between hosts. There are, however, concerns that the 'putatively transmitted isolates' in this study do not necessarily represent resistant isolates that have been transmitted between hosts. The support for the central claim of different patterns of reversion between isolates with de novo resistance and putatively transmitted resistant isolates is currently incomplete.

Reviewed by eLife

Trim7 does not have a role in the restriction of murine norovirus infection in vivo

1. Mridula Annaswamy Srinivas
2. Linley R. Pierce
3. Mikayla C. Olson
4. Shelly J. Roberston
5. Gail L. Sturdevant
6. Sonja M. Best
7. Robert C. Orchard

Reviewed by Arcadia Science

Salmonella-induced SIRT1 and SIRT3 are crucial for maintaining the metabolic switch in bacteria and host for successful pathogenesis

1. Dipasree Hajra
2. Raju S Rajmani
3. Ayushi Devendrasingh Chaudhary
4. Shashi Kumar Gupta
5. Dipshikha Chakravortty

• Curated by eLife

  eLife Assessment

  This auhors present findings on the role of the sirtuins SIRT1 and SIRT3 during Salmonella Typhimurium infection. This valuable study increases our understanding of the mechanisms used by this pathogen to interact with its host and may have implications for other intracellular pathogens. The reviewers disagreed on the strength of the evidence to support the claims. Although one reviewer found the strength of the evidence convincing, the other found that it was incomplete, and that the main claims are only partially supported, as can be seen from the public reviews.

Reviewed by eLife

PfMORC protein regulates chromatin accessibility and transcriptional repression in the human malaria parasite, Plasmodium falciparum

1. Zeinab M Chahine
2. Mohit Gupta
3. Todd Lenz
4. Thomas Hollin
5. Steven Abel
6. Charles Banks
7. Anita Saraf
8. Jacques Prudhomme
9. Suhani Bhanvadia
10. Laurence A Florens
11. Karine G Le Roch

• Curated by eLife

  eLife Assessment

  This important study examines the role of Microrchidia (MORC) proteins in the human malaria parasite Plasmodium falciparum. Solid experimental results, including genome editing and chromatin profiling methods (ChIP-seq and Hi-C), provide a comprehensive picture of the critical role MORC plays in shaping parasite chromatin. Depletion of MORC results in a lethal collapse of heterochromatin and parasite death, nominating the factor as a new target of antimalarial therapies.

Reviewed by eLife

Bacillus velezensis HBXN2020 alleviates Salmonella Typhimurium infection in mice by improving intestinal barrier integrity and reducing inflammation

1. Linkang Wang
2. Haiyan Wang
3. Xinxin Li
4. Mengyuan Zhu
5. Dongyang Gao
6. Dayue Hu
7. Zhixuan Xiong
8. Xiangmin Li
9. Ping Qian

• Curated by eLife

  eLife Assessment

  In this useful study, Wang and colleagues investigate the potential probiotic effects of Bacillus velezensis in a murine model. They provide convincing evidence that B. velezensis limits the growth of Salmonella typhimurium in lab culture and in mice, together with beneficial effects on the microbiota. The overall presentation of the manuscript has improved and the work will be of interest to infectious disease researchers.

Reviewed by eLife