Shown is a scanning electron micrograph of the fungal pathogen Magnaporthe oryzae (pink) on the surface of a rice leaf. A specialised fungal infection cell known as the appressorium uses physical force to breach the surface of the host leaf. Min He et al. find that very-long-chain fatty acids (VLCFAs) act as mediators of septin organization at membrane interfaces and that depletion of VLCFAs prevents septin assembly and host penetration by M. oryzae. They show that inhibitors of VLCFA biosynthesis prevent initiation of septin-mediated fungal infection and can be used as broad-spectrum fungicides for the prevention of rice blast disease and fungal pathogens of maize, wheat and locusts, without affecting plant hosts.

See He, M. et al.

Transcription factors that regulate Candida albicans cell fate undergo liquid–liquid demixing, which is analogous to that of oil and water (as shown in the image). Frazer et al. find that the assembly of multifactorial transcription complexes through phase separation is necessary for the regulation of cell identity in this clinically important fungal pathogen.

See Frazer, C. et al.

Saldivia et al. identify CLK1 as the target for the amidobenzimidazoles series of compounds. Inhibition of this protein kinase impairs inner kinetochore recruitment, causing cell-cycle arrest and cell death in trypanosomal pathogens such as Trypanosoma brucei.

See Saldivia, M. et al.

Das et al. report that gangliosides expressed in late endolysosomes are receptors for hepatitis A virus (HAV) entry into cells. The image shows a three-dimensional reconstruction of a UGCG (ceramide glucosyltransferase) knockout cell lacking gangliosides six hours after HAV infection. Most virions (magenta) are trapped within LAMP1+ endolysosomes (yellow), with only a few virions (green) present in other endosomes. [The credit line for the cover image was originally incorrect as ‘Stanley M. Lemon, University of North Carolina’; it has now been updated to ‘Maryna Kapustina, University of North Carolina’.]

See Das, A. et al.

Morris et al. report the discovery of a virus that is continuously produced by the ocean's most abundant bacteria, SAR11, with enhanced virus production in conditions typical of the open ocean. The image shows the virions (yellow) together with vesicle-like particles (green).

See Morris, R. M. et al.

In order to become infectious to humans and animals, Trypanosoma brucei parasites invade the ectoperitrophic space of the tsetse fly gut using a specialised organ called the proventriculus. The image shows a tsetse proventriculus (seen in black) fully infected with trypanosomes (green).

See Rose, C. et al.

Urban informal settlements are hotspots for the environmental transmission of antimicrobial resistance. Pickering et al. propose that improvements in water and waste infrastructure, as well as legal and economic incentives, could limit environmental antimicrobial resistance dissemination.

See Pickering, A. J. et al.

Using a macroecological approach and human and murine gut microbiota datasets, the authors show that these complex microbial communities display similar quantitative relationships to those observed in other systems, including the identification of specific taxa that are impacted by environmental change.

See Vitkup, D. et al.

Letko et al. describe the development of an approach to rapidly screen lineage B betacoronaviruses, such as SARS-CoV and the recently emerged SARS-CoV-2, for receptor usage and their ability to infect cell types from different species. Using it, they confirm human ACE2 as the receptor for SARS-CoV-2 and show that host protease processing during viral entry is a significant barrier for viral entry.

See Letko, M. et al.

The use of an in vitro system in which key proteins involved in cell division are attached to supported lipid bilayers reveals that membrane-bound cytosolic peptides of FtsN and FtsQ co-migrate with treadmilling FtsZ–FtsA filaments via a diffusion-and-capture mechanism, elucidating how FtsZ dynamics regulate the distribution of peptidoglycan synthases.

See Baranova, N. et al.

Reactive oxygen species produced by macrophages following infection with Staphylococcus aureus attack bacterial iron–sulfur cluster-containing proteins, thereby leading to alterations in bacterial metabolism that increase their tolerance to antibiotics.

See Rowe, S. E. et al.

Some jumbo phages lead to the formation of a nucleus-like structure of unknown function upon infection. This structure is shown by Malone and colleagues to protect a Serratia jumbo phage from DNA-targeting CRISPR–Cas defence systems, although phage RNA is still susceptible to CRISPR–Cas RNA targeting in the cytoplasm.

See Malone, L. M. et al.