Perturbations of the ileal mycobiota by necrotic enteritis in broiler chickens

Background:Intestinal microbiota is critical for maintaining animal health and homeostasis.However,involvement of the fungal community,also known as the mycobiota,in animal health and disease is poorly understood.This study was aimed to examine the association between the intestinal mycobiota and the severity of necrotic enteritis(NE),an economically significant poultry disease.Methods:A total of 90 day-of-hatch Cobb broilers were infected with Eimeria maxima on d 10,followed by an oral challenge with C.perfringens on d 14 to induce NE,while another 10 broilers were served as mock-infected controls.On d 17,the lesions in the jejunum were scored,and the ileal digesta were subjected to DNA isolation and real-time PCR quantification of total bacterial and fungi populations.Internal transcribed spacer 2(ITS2)amplicon sequencing was also performed to profile the ileal mycobiota composition.Changes in the ileal mycobiota in response to NE were investigated.Spearman correlation analysis was further conducted to identify the correlations between relative abundances of individual ileal fungi and the severity of NE.Results:While the total bacterial population in the ileum was increased by 2-to 3-fold in NE chickens,the total fungal population was progressively declined in more exacerbated NE,with the most severely infected chickens showing a nearly 50-fold reduction relative to mock-infected controls.Richness of the ileal mycobiota also tended to reduce in chickens with NE(P=0.06).Compositionally,among 30 most abundant fungal amplicon sequence variants(ASVs),11 were diminished and 7 were enriched(P<0.05),while 12 remained largely unchanged in NEafflicted chickens(P>0.05).Multiple Wallemia and Aspergillus species were markedly diminished in NE(P<0.05)and also showed a significant negative correlation with NE severity(P<0.05).Conclusions:Dysbiosis of the ileal mycobiota is induced evidently by NE and the extent of the dysbiosis is positively correlated with disease severity.These findings suggest a possible role of the intestinal mycobiota in NE pathogenesis and highlight the mycobiota as a new potential target for NE mitigation in poultry.

Reniforma rhynchophori sp.nov.(Basidiomycota,Microbotryales)from guts of red palm weevil

During a survey of mycobiota inhabiting guts of red palm weevil(Rhynchophorus ferrugineus)in Assiut area of Egypt,two interesting yeast isolates were obtained from 2 different gut samples(out of 11 gut samples investigated).Two isolates were identified phenotypically and genotypically with 87%ITS sequencing similarities with the type strain Reniforma strues.The name Reniforma rhynchophori was assigned for the new species.The two strains were deposited in Assiut University Mycological Centre Culture Collection and AUMC numbers 10263^(T)(as the type strain)and AUMC 10264 were given.The ITS gene sequences for AUMC 10263^(T)&AUMC 10264 were also deposited at the National Center for Biotechnological Information(NCBI)and accession numbers are given as KX011609 and KX015891 respectively.Full description and photos of the new species are presented.This new species was recorded as the second species of the genus Reniforma.