Publications

4786

AbstractBACKGROUNDAlthough it is known that Candidatus Liberibacter asiaticus (CLas), the agent of citrus Huanglongbing, circulates and multiplies within the insect vector Diaphorina citri, the specific factors enabling CLas transmission remain unclear. Previous studies have shown that ATPSyn‐β facilitates phytoplasma movement in vector insects, and functions as a transport protein in D. citri. In this study, the role of ATPSyn‐β was expected to be unveiled in CLas transmission in D. citri.RESULTSThe interaction between ATPSyn‐β of D. citri and the outer membrane protein A (OmpA) of CLas was identified using glutathione S‐transferase pull‐down and yeast two‐hybrid assays. No interactions existed between OmpA and vitellogenin (Vg). Bioinformatics analysis revealed that ATPSyn‐β contained two conserved domains, ATP‐synt_ab_N and ATP‐synt_ab. Notably, ATP‐synt_ab_N interacted with both OmpA and Vg, indicating a competitive relationship between Vg and OmpA for binding to ATPSyn‐β. After silencing ATPSyn‐β expression using RNAi, the feeding behavior of D. citri decreased, resulting in a lower acquisition of CLas. Subsequently, this inhibited CLas movement within D. citri and reduced the inoculation of CLas to healthy citrus plants.CONCLUSIONATPSyn‐β was involved in the acquisition, movement in vivo, and inoculation of CLas by interacting with OmpA, thus offering a novel target to prevent the spread of citrus Huanglongbing. © 2025 Society of Chemical Industry.

Abstract Aim Candidatus Methanoperedens-related archaea have recently been identified as anaerobic methane oxidizers in paddy soils. Fertilization practices, including the application of inorganic and organic fertilizers (e.g. chicken manure), may significantly influence their community dynamics and the associated methane cycling processes. However, the comparative effects of inorganic and chicken manure fertilization on these archaeal community in paddy fields remain unclear. This study aimed to examine the diversity, community composition, and abundance of Methanoperedens-related archaea at three representative soil layers of 0–10, 20–30, and 40–50 cm under three fertilization treatments (no fertilizer, inorganic fertilizer, chicken manure fertilizer). Methods and results High-throughput sequencing revealed significant differences in community composition among treatments, while overall diversity showed minimal changes. Quantitative Polymerase Chain Reaction indicated that archaeal abundance under inorganic (2.3 × 106 copies g−1) and chicken manure fertilization (2.2 × 106 copies g−1) treatments was significantly greater than that under no fertilization (1.8 × 106 copies g−1) in upper 30 cm soils, with no significant difference at 40–50 cm depth. Inorganic fertilization more strongly promoted archaeal abundance, whereas chicken manure had a greater effect on community structure. Soil ammonium, nitrate, and organic carbon contents were significantly correlated with archaeal community patterns. Conclusion Both inorganic and organic fertilization can substantially influence the community structure and abundance of Methanoperedens-related archaea in paddy soils.

Ticks spread pathogens that affect both human and animal health and often cause significant economic losses to the livestock industry. However, there is limited data on the distribution of ticks and tick-borne pathogens, particularly those affecting cattle in Cameroon. In this study, ticks were collected from cattle in Buea, the capital of the South West Region of Cameroon, to determine their diversity and identify tick-borne pathogens through PCR and sequencing. The tick samples were screened for pathogens using assays that target the rOmpA gene (ompA) of Rickettsia, the ssrRNA gene of Babesia and Theileria and the Ehrlichia genus 16SrRNA gene. A total of 458 ticks were collected with Rhipicephalus annulatus (65.6%) as the predominant species. From 68 tick pools screened, 26 (38.2%) were positive for pathogen/ symbiont DNA. The pathogen identified was Rickettsia africae (22.1%). This study reports the first molecular detection of the symbiont Candidatus Midichloria mitochondrii (22.1%) in the sampled tick species. It was observed that male ticks were significantly more likely to test positive for R. africae (OR = 208, 95% CI = 28.6 - 4553, p<0.001). Animal handlers may face the risk of these zoonotic infections and as such, there is a need to employ protective measures to prevent or reduce pathogen spread.

The genus Moraxella (Moraxellaceae, Pseudomonadales) comprises a diverse group of bacteria inhabiting human and animal mucosa, as well as environmental niches such as water, soil and food. While some species are clinically significant pathogens, others play ecological or biotechnological roles. Despite previous taxonomic revisions, Moraxella remains polyphyletic, necessitating a refined classification. In this study, we conducted comprehensive taxogenomic analyses integrating core protein phylogeny, average amino acid identity and the percentage of conserved proteins, along with 16S rRNA similarities and inferred phylogeny. Our results revealed three distinct phylogenetic clusters within Moraxella. The core group, comprising Moraxella lacunata NBRC 102154T and closely related species, exhibited strong genomic cohesion. A second cluster, consisting of Moraxella boevrei DSM 14165T, Moraxella osloensis CCUG 350T and Moraxella atlantae NBRC 14588T, showed greater genetic affinity to Faucicola mancuniensis GVCNT2T, supporting their reassignment to the genus Faucicola. The third group, represented by Moraxella lincolnii CCUG 9405T, was phylogenetically distinct, occupying a basal position relative to Psychrobacter, indicating the need for its classification within a novel genus within the family Moraxellaceae, for which we propose the name Lwoffella lincolnii gen. nov., comb. nov. Phenotypic data compiled from the original published descriptions of the respective species, including fatty acid composition and enzymatic profiles, further corroborated these genomic findings. This study refines Moraxella taxonomy by clarifying genus boundaries and evolutionary relationships, with implications for ecology and clinical microbiology.

Despite their large environmental impact and multiple independent emergences, the processes leading to the evolution of anaerobic methanotrophic archaea (ANME) remain unclear. This work uses comparative metagenomics of a recently evolved but understudied ANME group, “ Candidatus Methanovorans” (ANME-3), to identify evolutionary processes and innovations at work in ANME, which may be obscured in earlier evolved lineages. We identified horizontal transfer of hdrA homologs and convergent evolution in carbon and energy metabolic genes as potential early steps in Methanovorans evolution. We also identified the erosion of genes required for methylotrophic methanogenesis along with horizontal acquisition of multiheme cytochromes and other loci uniquely associated with ANME. The assembly and comparative analysis of multiple Methanovorans genomes offers important functional context for understanding the niche-defining metabolic differences between methane-oxidizing ANME and their methanogen relatives. Furthermore, this work illustrates the multiple evolutionary modes at play in the transition to a globally important metabolic niche.