From cantaloupe to cattle: Pseudomonas alabamensis sp. nov. described from diseased cantaloupe (Cucumis melo) foliage and a bovine (Bos taurus) nasopharynx

Authors: FULLEM, KIERSTEN - University Of Florida; MACLELLAN, MICHELLE - University Of Georgia; IRIARTE, FANNY - University Of Florida; POUDEL, MOUSAMI - University Of Florida; CAPIK, SARAH - Tumbleweed Veterinary Services, Pllc; DEDONDER, KEITH - Latham Biopharm Group; Bono, James; Harhay, Dayna; Harhay, Gregory; GOSS, ERICA - University Of Florida; POTNIS, NEHA - Auburn University; MINSAVAGE, GERALD - University Of Florida; JONES, JEFFREY - University Of Florida; PARET, MATHEWS - University Of Florida

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2025
Publication Date: 7/14/2025
Citation: Fullem, K.R., MacLellan, M.P., Iriarte, F.B., Poudel, M., Capik, S., DeDonder, K., Bono, J.L., Harhay, D.M., Harhay, G.P., Goss, E.M., Potnis, N., Minsavage, G.V., Jones, J.B., Paret, M.L. 2025. From cantaloupe to cattle: Pseudomonas alabamensis sp. nov. described from diseased cantaloupe (Cucumis melo) foliage and a bovine (Bos taurus) nasopharynx. International Journal of Systematic and Evolutionary Microbiology. 75(7). Article 006848. https://doi.org/10.1099/ijsem.0.006848.
DOI: https://doi.org/10.1099/ijsem.0.006848

Interpretive Summary: Researchers have discovered a new bacterial species, Pseudomonas alabamensis, found in both diseased cantaloupe plants in Alabama and a healthy calf in Kansas. This discovery is significant because while some bacteria in the Pseudomonas group are known to infect both plants and animals, it's uncommon. This new species was identified through extensive testing, including genetic sequencing and analysis, which confirmed that the bacteria from the cantaloupe and the calf were the same unique species, different from all other known Pseudomonas species. Despite being found in a diseased plant, experiments showed this bacterium doesn't cause disease in common crops like cantaloupe, watermelon or squash. This finding highlights the adaptability of Pseudomonas bacteria and suggests more research could uncover other species capable of living in diverse environments, including both plants and animals. The study underscores the importance of monitoring bacterial populations for potential agricultural and health implications.

Technical Abstract: In 2022, a fluorescent bacterial isolate, designated 22-AL-CL-001, was isolated from diseased cantaloupe (Cucumis melo) foliage collected in Alabama, USA, displaying marginal necrosis and general blighting. Whole-genome sequencing and subsequent comparisons to publicly available bacterial genomes identified Pseudomonas isolate USDA-ARS-USMARC-56711, isolated from a clinically healthy calf (Bos taurus) in Kansas, USA, as genetically similar to isolate 22-AL-CL-001. The two isolates were then characterized using phenotypic and genetic analyses, including fluorescence on King's medium B; LOPAT reactions; pathogenicity assays on cantaloupe, watermelon and squash plants; 16S rRNA gene sequence analysis; phylogeny based on multi-locus sequence analysis (MLSA) of four housekeeping genes; average nucleotide identity based on blast (ANIb); in silico DNA-DNA hybridization (isDDH) including comparison to the Type Genome Server and biochemical profiling using the Biolog Gen III microplate system. MLSA phylogeny placed both isolates into a single clade within the genus Pseudomonas, distant from all included reference strains. ANIb and isDDH analyses definitively identified the isolates as members of the same species (ANIb, 97.25; isDDH, 78.5%), though comparison scores to reference strains were all below the accepted thresholds for species determination. Biolog biochemical profiling, as well as MALDI-TOF mass spectrometry of isolate 22-AL-CL-001, was also unable to identify the isolate as a member of any existing bacterial species. Using a combination of genetic and phenotypic data, we conclude that the two isolates belong to a new species of Pseudomonas, for which we propose the name Pseudomonas alabamensis. The specific epithet, alabamensis, was chosen to represent the location where the type strain 22-AL-CL-001T (NCPPB 4760T=LMG 33363T) was isolated, Alabama, USA. Taxonomic classification of the two isolates by the Genome Taxonomy Database revealed other previously sequenced bacterial strains that, according to ANI and isDDH results, also belong to P. alabamensis.