Analyzing the safety of the parasiticide fungus Mucor circinelloides : first insights on its virulence profile and interactions with the avian gut microbial community

• Published in: Microbiology spectrum Vol. 12; no. 5; p. e0407823
• Main Authors: Lozano, João, Cunha, Eva, Almeida, Cristina, Nunes, Mónica, Dias, Ricardo, Vicente, Eduardo, Sebastião, Daniela, Henriques, Sérgio, Madeira de Carvalho, Luís, Paz-Silva, Adolfo, Oliveira, Manuela
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 02-05-2024
• Subjects: Animals; avian parasitology; Chickens - microbiology; Feces - microbiology; Female; Gastrointestinal Microbiome; microbiome; Mucor - genetics; Mucor - pathogenicity; mycobiome; parasiticide fungi; Parasitology; Research Article; Virulence; virulence factors; Virulence Factors - genetics; Virulence Factors - metabolism; mycobiome; avian parasitology; parasiticide fungi; microbiome; virulence factors
• ISSN: 2165-0497; 2165-0497
• DOI: 10.1128/spectrum.04078-23

Parasiticide fungi are considered an accurate, sustainable, and safe solution for the biocontrol of animal gastrointestinal (GI) parasites. This research provides an initial characterization of the virulence of the native parasiticide fungus
(FMV-FR1) and an assessment of its impact on birds' gut microbes. The genome of this fungus was sequenced to identify the genes coding for virulence factors. Also, this fungus was checked for the phenotypic expression of proteinase, lecithinase, DNase, gelatinase, hemolysin, and biofilm production. Finally, an
trial was developed based on feeding
spores to laying hens and peacocks three times a week. Bird feces were collected for 3 months, with total genomic DNA being extracted and subjected to long-read 16S and 25S-28S sequencing. Genes coding for an iron permease (FTR1), iron receptors (FOB1 and FOB2), ADP-ribosylation factors (ARFs) (ARF2 and ARF6), and a GTPase (CDC42) were identified in this
genome. Also, this fungus was positive only for lecithinase activity. The field trial revealed a fecal microbiome dominated by Firmicutes and Proteobacteria in laying hens, and Firmicutes and Bacteroidetes in peacocks, whereas the fecal mycobiome of both bird species was mainly composed of Ascomycetes and Basidiomycetes fungi. Bacterial and fungal alpha-diversities did not differ between sampling time points after
administrations (
= 0.62 and
= 0.15, respectively). Although findings from this research suggest the lack of virulence of this
parasiticide isolate, more complementary
and
research is needed to conclude about the safety of its administration to birds, aiming at controlling their GI parasites.IMPORTANCEA previous study revealed that the native
isolate (FMV-FR1) can develop parasiticide activity toward coccidia oocysts, one of the most pathogenic GI parasites in birds. However, ensuring its safety for birds is of utmost importance, namely by studying its virulence profile and potential effect on commensal gut microbes. This initial study revealed that although this
isolate had genes coding for four types of virulence factors-iron permease, iron receptors, ADP-ribosylation factors, and GTPase-and only expressed phenotypically the enzyme lecithinase, the administration of its spores to laying hens and peacocks did not interfere with the abundances and diversities of their gut commensal bacteria and fungi. Although overall results suggest the lack of virulence of this
isolate, more complementary research is needed to conclude about the safety of its administration to birds in the scope of parasite biocontrol programs.