First report of interaction of nematophagous fungi onLibyostrongylus douglassii (Nematoda: Trichostrongylidae)

Assessing the efficacy of the ovicidal fungus Mucor circinelloides in reducing coccidia parasitism in peacocks

The biological control of gastrointestinal (GI) parasites using predatory fungi has been recently proposed as an accurate and sustainable approach in birds. The current study aimed to assess for the first time the efficacy of using the native ovicidal fungus Mucor circinelloides (FMV-FR1) in reducing coccidia parasitism in peacocks. For this purpose, an in vivo trial was designed in the resident peacock collection (n = 58 birds) of the São Jorge Castle, at Lisbon, Portugal. These animals presented an initial severe infection by coccidia of the genus Eimeria (20106 ± 8034 oocysts per gram of feces, OPG), and thus received commercial feed enriched with a M. circinelloides suspension (1.01 × 108 spores/kg feed), thrice-weekly. Fresh feces were collected every 15 days to calculate the coccidia shedding, using the Mini-FLOTAC technique. The same bird flock served simultaneously as control (t0 days) and test groups (t15-t90 days). The average Eimeria sp. shedding in peacocks decreased up to 92% following fungal administrations, with significant reduction efficacies of 78% (p = 0.004) and 92% (p = 0.012) after 45 and 60 days, respectively. Results from this study suggest that the administration of M. circinelloides spores to birds is an accurate solution to reduce their coccidia parasitism.

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

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 Mucor circinelloides (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 in vivo trial was developed based on feeding M. circinelloides 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 M. circinelloides 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 M. circinelloides administrations (P = 0.62 and P = 0.15, respectively). Although findings from this research suggest the lack of virulence of this M. circinelloides parasiticide isolate, more complementary in vitro and in vivo 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 Mucor circinelloides 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 M. circinelloides 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 M. circinelloides isolate, more complementary research is needed to conclude about the safety of its administration to birds in the scope of parasite biocontrol programs.

Germination capacity of the Pochonia chlamydosporia fungus after its passage through the gastrointestinal tract of domestic chickens (Gallus gallus domesticus)

This study evaluated the germination capacity of Pochonia chlamydosporia (VC4) fungus after its passage through the gastrointestinal tract of domestic chickens and its interaction with Ascaridia galli and Heterakis gallinarum eggs. Twenty-two domestic chickens were divided in two groups: control group (G1) received shredded corn substrate without VC4; and treatment group (G2) received a single dose of 29 g corn substrate containing 3.3 × 10⁶ conidia/chlamydospores (VC4). Subsequently, chicken fecal samples were collected at intervals of 0, 6, 8, 10, 12, 18 and 24 h. Petri dishes from fecal samples of the treated group (G2) were subdivided (G2a and G2b), and then replicated in 2% agar-water medium for the microbiological test. After VC4 growth, approximately 200 eggs of A. galli (G2a) and H. gallinarum (G2b) were added to each subgroup to evaluation of ovicidal activity. There was fungal viability after passage through chicken gastrointestinal tract and egg predation of 59.9% and 43.2% for A. galli and H. gallinarum, respectively. The present work demonstrates the ability of the fungus P. chlamydosporia to survive after passing through the gastrointestinal tract of domestic chickens, an extreme environment (low pH, enzymes, microbiota and mechanical action), and still germinate after being excreted with feces.

Association and predatory capacity of fungi Pochonia chlamydosporia and Arthrobotrys cladodes in the biological control of parasitic helminths of bovines

Nematophagous fungi are used in the biological control of the parasitic helminths of animals and plants. The association of ovicidal and predator nematophagous fungi may present a complementary and increased action on the biological control of helminths. Joint growth compatibility and predation tests were carried out on infective larvae of nematode parasites of bovines with the nematophagous fungus ovicide Pochonia chlamydosporia and the nematophagous fungus predator Arthrobotrys cladodes. The tests of antagonism in direct confrontation, antibiosis and the effect of volatile metabolites between the isolates of P. chlamydosporia and A. cladodes indicated the viability of joint growth of these fungi. The association of the fungi P. chlamydosporia and A. cladodes presented a higher predatory capacity of infective larvae of the parasitic nematodes of bovines when compared to the predation of the fungi used alone. Therefore, under laboratory conditions, the fungi studied presented growth compatibility and the association of these increased the nematicidal activity against parasitic helminths of cattle.

First report of Libyostrongylus douglassii (Strongylida: Trichostrongylidae) in ostriches (Struthio camelus) from Mexico

Nematodes of the Libyostrongylus genus are hematophagous parasites found under the ostrich's proventriculus membrane: they are frequent and can cause 50% of mortality in chicks and occasionally death in adults. With the aim of determining the presence of the Libyostrongylus genus in two private collections, one located in Ayapango, State of Mexico and the other in Amacuzac, Morelos, a total of 27 fecal samples were collected between August and December of 2016. Samples were analyzed using the flotation technique. The eggs were quantified using the McMaster technique. Positive samples were cultured to obtain infective larvae and to be identified by their morphometric characteristics. Only 18 samples collected in Ayapango were positive to Libyostrongylus douglassii. This is the first time that L. douglassii is reported in Mexico.

Nematicide activity of microfungi (Orbiliales, Orbiliaceae) after transit through gastrointenstinal tract of “Gallus gallus domesticus”

SUMMARY Parasites are common in intensive or organics systems destined for chickens, which is more conducive to the emergence of gastrointestinal parasites, favored by direct contact with soil and other organisms. The growing demand for animal protein stimulates an expansion of production systems, increasing the stocking density. Outdoor poultry breeding systems (organic or not) that enable lower population density and higher animal welfare does not exclude these animals the presence of environmental pathogens. The control of gastrointestinal helminthosis in non-organic intensive and extensive systems is accomplished by administering anthelmintics with high cost and results unsatisfactory due to the misuse of drugs with consequent selection parasite strains resistant to chemical bases. This problem stimulate research into alternative control measures. Nematophagous fungi are used by its enzymatic action in controlled conditions and how environmental biocontrolers of larvae of gastrointestinal nematodes of livestock. This study evaluated the capacity of conidia/chlamydospores of nematophagous fungi as Duddingtonia flagrans (AC001 and CG722) and Monacrosporium thaumasium (NF34A) for cross the gastrointestinal tract of domestic chickens (Gallus gallus domesticus), and yours germination after traffic and predatory activity “in vitro” on larvae of Panagrellus spp. Fungi conidia/chlamydospores was identified in feces of chickens at times of 6, 12 and 24 hours after administration and spores viability was found after observing the germination, mycelial growth, followed by production of traps, capture and death of Panagrellus spp larvae in feces. Fungi Nematophagous are alternative control measures, efficient and innovative technology for the biological control of helminth parasites of chickens.