Comparative analysis of the gut microbiota of the blue fox (Alopex lagopus) and raccoon dog (Nyctereutes procyonoides)

Exploring the Gastrointestinal Microbiome of Eurasian Griffon Vultures (Gyps fulvus) Under Rehabilitation in Portugal and Their Potential Role as Reservoirs of Human and Animal Pathogens

The Eurasian griffon vulture (Gyps fulvus), a widely distributed scavenger, plays a crucial role in ecosystem health by consuming decomposing carcasses. Scavengers have adapted to avoid disease from the rotting carrion they feed on, probably through a specialized gut microbiome. This study aimed to characterize the gut microbiome of G. fulvus (n = 8) present in two rehabilitation centers in mainland Portugal and evaluate their potential as reservoirs of pathogens. Samples were studied through high-throughput 16S rDNA amplicon sequencing of the hypervariable V3-V4 regions and further analyzed using the Qiime2 bioinformatics platform. Our results showed that factors such as sex, location, and time of sampling did not significantly affect the gut microbiome of the griffon vulture. Its composition was highly similar to that of phylogenetically closed animals. However, several potential human and veterinary pathogens were identified. In conclusion, the gut microbiome of Gyps fulvus in rehabilitation centers is not significantly altered by stress associated with captivity. Its composition is similar to that of other vultures and scavengers due to their identic diet and needs, suggesting a well-conserved functional gut microbiome, which seems to be influenced by season. The potential risks posed by the identified pathogens to humans and other animals should be further investigated.

Suitability of red fox (Vulpes vulpes) and golden jackal (Canis aureus) as hosts of Echinococcus multilocularis based on egg production characteristics and literature data on the intestinal ecosystems of carnivores

Echinococcus multilocularis is the most important food-borne parasite in Europe. Its natural definitive host is the red fox (Vulpes vulpes) while other canid species play a secondary role in the maintenance of its endemics. However, recent studies call attention to the potential of golden jackal (Canis aureus) as a suitable definitive host for E. multilocularis. Our study aimed to evaluate the quantitative and qualitative egg production traits of adult E. multilocularis in different hosts as an indicator of reproductive success. Investigation of 111 and 82 parasites from 33 red foxes and 29 golden jackals, respectively, we ascertained that the proportion of worms with mature eggs was significantly lower in golden jackals than in red foxes. Those worms, which produced mature eggs in golden jackal hosts, originated from less crowded infrapopulations than their fox-originated counterparts. Other characteristics of the parasite's reproductive ability, such as the proportion of fertile worms, and mean egg production were similar in the two hosts. Comparing these findings to evolutionary data on different canid taxa, we hypothesised that the mutual presence of red fox and a differently evolved host of E. multilocularis might contribute to the formation of stable parasite circulation in these multi-host systems.

Thymol improves the growth performance of blue foxes by regulating the gut microbiota

Introduction

The drawbacks of using antibiotics as feed additives for blue foxes have gradually become apparent; moreover, thymol has wide-spectrum antimicrobial activity and has the potential to replace antibiotics in various animals. However, there are few reports on the effects of thymol on blue foxes.

Methods

This study aimed to investigate the effects of different concentrations of thymol on the growth performance, apparent nutrient digestibility, serum biochemical indicators, intestinal morphology, and gut microbiota of blue foxes. Twenty-four male blue foxes (120 ± 5 d) of similar weight (6.05 ± 0.16 kg) were randomly divided into 4 groups. 0, 100, 200, and 300 mg/kg thymol were added to the basal diets of groups C, L, M, and H, respectively.

Results

Compared with those in the C group, the addition of 100 mg/kg thymol to the diet significantly increased organic matter (OM) digestibility, crude protein (CP) digestibility, immunoglobulin (Ig) A, IgM, the VH of the duodenum, the CD of the jejunum, the VH of the ileum, and the VH/CD of the ileum (P < 0.05) and strongly significantly increased IgG (P < 0.01). The addition of 200 mg/kg thymol to the diet increased the VH/CD of the duodenum (P < 0.05). The addition of 300 mg/kg thymol to the diet significantly increased the VH and CD of the jejunum (P < 0.05). The addition of 200 mg/kg and 300 mg/kg thymol to the diets increased the final weight (FW) (P < 0.05). Adding 100 mg/kg thymol significantly increased the levels of interleukin-4 (IL-4) and catalase (CAT) compared with those in the other groups (P < 0.05). 16S rRNA gene detection revealed that thymol can change the abundances of Bifidobacterium, Fusobacterium, Allobaculum, Streptococcus, Megasphaera, and Lactobacillus in the gut.

Conclusion

The addition of thymol to diets can increase the abundance of Bifidobacterium, Fusobacterium, and Allobaculum, which may contribute to improving the growth performance of blue foxes.

Effects of Dietary Alfalfa Meal Supplementation on the Growth Performance, Nutrient Apparent Digestibility, Serum Parameters, and Intestinal Microbiota of Raccoon Dogs (Nyctereutes procyonoides)

The raccoon dog (Nyctereutes procyonoides) is a typical omnivore possessing wide dietary adaptability and tolerance to rough feeding, which may be attributed to its intestinal microbiota. The study aimed to investigate the effect of dietary alfalfa meal levels on the growth performance, nutrient apparent digestibility, serum parameters, and intestinal microbiota of raccoon dogs. Sixty raccoon dogs were randomly divided into four dietary treatments containing 0% (AM0), 5% (AM5), 10% (AM10), and 15% (AM15) alfalfa meal for a 60-day experiment. The results showed that compared to raccoon dogs fed the AM0 diet, those fed the AM5 and AM10 diets had no significant difference in growth performance, while those fed the AM15 diet experienced a significant decrease. Raccoon dogs fed the AM5 diet had no significant effect on the nutrient apparent digestibility. Dietary supplementation with alfalfa meal significantly decreased serum urea levels and increased the antioxidant capacity of raccoon dogs. The intestinal microbiome analysis showed that the richness and diversity of colonic microbiota significantly increased in the AM15 group. With the increase in dietary alfalfa meal levels, the relative abundance of fiber-degrading bacteria in the colon of raccoon dogs, such as Treponema, Phascolarctobacterium, and Christensenellaceae R-7 group, increased. However, the relative abundance of pathogenic bacteria, including Anaerobiospirillum, decreased. In conclusion, the inclusion of 5% alfalfa meal in the raccoon dogs' diet had no effect on growth performance, but it exhibited the potential to improve serum antioxidant capacity and intestinal microbiota. This indicates that raccoon dogs have a certain tolerance to the addition of alfalfa meal in their diet.

Dietary change influences the composition of the fecal microbiota in two rescued wild raccoon dogs (Nyctereutes procyonoides)

The gut microbiota of wild animals, influenced by various factors including diet, nutrition, gender, and age, plays a critical role in their health and disease status. This study focuses on raccoon dogs (Nyctereutes procyonoides), a commonly found wild animal, and its gut microbiota composition in response to dietary shifts. The study aimed to compare the fecal bacterial communities and diversity of rescued raccoon dogs fed three different diet types (fish and amphibians, mixed protein with maize, and solely maize) using high-throughput sequencing. Results indicated that the dietary composition significantly influenced the gut microbiota, with notable differences in the abundance of several key phyla and genera. The study identified Firmicutes as the dominant phylum in all diet groups, with notable variations in the relative abundances of Bacteroidota, Proteobacteria, and Verrucomicrobiota. Notably, the group solely fed maize exhibited a significant increase in Proteobacteria, potentially linked to dietary fiber and lignin degradation. The genus-level analysis highlighted significant differences, with Lactobacillus and Bifidobacterium responding to dietary shifts. The genus Akkermansia in Verrucomicrobiota can be identified as a marker for assessing the health of the gut and deserves further investigation. Gender-specific differences in the gut microbiota were observed, highlighting the influence of individual variation. Furthermore, the analysis of bacterial functions suggested a connection between diet and host metabolism, emphasizing the need for further research to understand the complex mechanisms underlying the relationship between dietary composition and gut microbiota in wild animals. These findings provide crucial insights into conservation and rescue efforts for wild animals.

Prevalence of Pentatrichomonas hominis in foxes and raccoon dogs and changes in the gut microbiota of infected female foxes in the Hebei and Henan Provinces in China

Pentatrichomonas hominis (P. hominis) is a zoonotic parasite that affects a wide range of hosts, causing gastrointestinal diseases. The present study aimed to evaluate the prevalence of P. hominis among caged foxes and raccoon dogs and the effect of P. hominis on the gut microbiota in female foxes. A total of 893 fresh fecal samples were collected from the Hebei and Henan Provinces in China. P. hominis was screened based on 18S rRNA gene expression via nested PCR. The difference in the gut microbiota between nine P. hominis-positive and nine P. hominis-negative samples was investigated by 16S rRNA gene sequencing. The total prevalence of P. hominis infection in foxes and raccoon dogs was 31.7% (283/893). The prevalence rates of P. hominis infection were 28.2% (88/312) and 33.6% (195/581) in foxes and raccoon dogs, respectively. Phylogenetic analysis revealed that all P. hominis strains detected in foxes and raccoon dogs in the present study were the zoonotic genotype CC1. Moreover, compared with those in the P. hominis-negative group, the diversity of the gut microbiota in the P. hominis-positive group was lower, and the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidetes (F/B) in the P. hominis-positive group were lower than those in the P. hominis-negative group. We speculate that these differences may be due to indigestion and diarrhea in infected female foxes. Overall, the present study evaluated the prevalence of P. hominis in foxes and raccoon dogs in the Henan and Hebei Provinces and revealed that P. hominis infection interrupted the diversity of the gut microbiota in female foxes.

Mannan oligosaccharides improve the fur quality of raccoon dogs by regulating the gut microbiota

Introduction

Adding antibiotics to animal basal diets can improve growth and production performance. However, the use of antibiotics poses a potential threat to public health safety.

Methods

The study was conducted to investigate the effects of different levels of mannan oligosaccharides (MOS) on the fur quality, nutrient apparent digestibility, serum immunity, antioxidant status, intestinal morphology, and gut microbiota of fur-growing raccoon dogs. Divide 24 male raccoon dogs (120 ± 5 d) of similar weight (5.01 ± 0.52 kg) into 4 groups randomly. Add 0, 0.05, 0.1, and 0.2% MOS to the basal diets of groups C, L, M, and H, respectively.

Results

Compared to the C group, the addition of 0.05% and 0.1% MOS in the diet increased the apparent digestibility of crude protein (CP), Underfur length (UL), Guard hair length (GL), immunoglobulin A (IgA), immunoglobulin G (IgG), and immunoglobulin M (IgM) levels in the serum (p < 0.05); Under the dosage of 0.05 % MOS, the activities of Superoxide Dismutase (SOD) and catalase (CAT) increased (p < 0.05). Compared to the C group, adding 0.05% MOS significantly increased the VH/CD of the duodenum and ileum, while also increasing the VH and CD of the jejunum (p < 0.05). Through Spearman correlation analysis of the gut microbiota, it was found that MOS can improve fur quality by reducing the abundance of Dorea while improving the immune response of raccoon dogs by reducing the abundance of Blautia and Gemmiger.

Discussion

In conclusion, MOS can improve the fur quality, serum immunity, antioxidant capacity, and gut microbiota of raccoon dogs. Therefore, MOS has the potential to replace antibiotics.

Multi-Omics Analysis Reveals the Pathogenesis of Growth-Disordered Raccoon Dog

Microorganisms of the genus Eperythrozoon are a zoonotic chronic infectious disease with wide distribution. We found that raccoons infected with Eperythrozoon showed obvious stunting, which seriously affected the economic benefits of raccoon dogs. To investigate the pathogenesis of the raccoon dog, we used transcriptome and proteome sequencing to analyze the changes in mRNA, miRNA, and protein expression in raccoon dogs infected with Eperythrozoon and normal raccoons. The results showed that the expression levels of genes related to immunity, metabolism, and enzyme activity were significantly changed. Among these, ERLIN1, IGF1R, CREB3L1, TNS1, TENC1, and mTOR play key roles. Additionally, the miR-1268, miR-125b, miR-10-5p, and miR-10 as central miRNAs regulate the expression of these genes. Integrated transcriptomic and proteomic analyses revealed consistent trends in mRNA and protein changes in MYH9, FKBP1A, PRKCA, and CYP11B2. These results suggest that Eperythrozoon may contribute to the slow development of raccoons by affecting the expression of mRNAs and miRNAs, reducing their immunity and causing metabolic abnormalities.

Effect of Limosilactobacillus reuteri ZJF036 on Growth Performance and Gut Microbiota in Juvenile Beagle Dogs

This experiment investigated the effects of Limosilactobacillus reuteri ZJF036 on growth performance, serum biochemical parameters, and gut microbiota in beagle dogs. Sixteen 75 ± 5-day-old healthy male beagles (4.51 ± 1.37 kg) were randomly divided into two groups; the experimental group (L1) and the control group (L0), and then fed with or without a basal diet containing L. reuteri ZJF036 (10⁹ CFU/g), respectively. The results showed that there was no significant difference in daily weight gain between the two groups (P > 0.05). However, we found that L. reuteri ZJF036 decreased Chao1 index and ACE index and increased the relative abundance of Firmicutes and Fusobacteria (P < 0.05) compared to the L0 group. In addition, we also found that the ratio of Firmicutes to Bacteroidetes was decreased in L1 group. Furthermore, the relative abundance of Lactobacillus increased, while that of Turicibacter and Blautia decreased in L1 group (P < 0.05). In conclusion, L. reuteri ZJF036 appeared to regulate the intestinal microbiota of beagle dogs. This study revealed the potential use of L. reuteri ZJBF036 as a probiotic supplement for beagle dogs.

Dietary supplementation with Cyberlindnera jadinii improved growth performance, serum biochemical Indices, antioxidant status, and intestinal health in growing raccoon dogs (Nyctereutes procyonoides)

This study was conducted to investigate whether different dietary Cyberlindnera jadinii levels affect growth performance, serum immunity, antioxidant capacity, and intestinal microbiota in growing raccoon dogs. Forty-five healthy male raccoon dogs were randomly assigned to three treatment groups, with 15 raccoon dogs per group. Each raccoon dog was housed in an individual cage. The raccoon dogs in the three groups were fed diets supplemented with Cyberlindnera jadinii at dosages of 0 (N group), 1 × 10⁹ (L group) and 5 × 10⁹ CFU/g (H group). A 7-day pretest period preceded a formal test period of 30 days. The results showed that Cyberlindnera jadinii in the L and H groups improved average daily gain (ADG) (P < 0.05) and decreased the ratio of feed to weight (F/G) (P < 0.05). Serum immunoglobulins A and G levels were increased in the L and H groups compared to the N group (P < 0.05). Cyberlindnera jadinii in the L and H groups increased serum superoxide dismutase activity (P < 0.05), and serum glutathione peroxidase activity was increased in the L group compared to the N group (P < 0.05). The relative abundance of Firmicutes and Actinobacteriota were increased, and the relative abundance of Bacteroidota was decreased in the L and H groups compared to the N group (P < 0.05). The relative abundance of Proteobacteria and Cyanobacteria was increased in the H group compared to the other two groups (P < 0.05). The ratio of Firmicutes to Bacteroidetes in the Cyberlindnera jadinii supplementation groups increased compared with the N group (P < 0.05). The relative abundance of Megasphaera and Bifidobacterium were increased, and the relative abundance of Prevotella was decreased in the L and H groups compared to the N group (P < 0.05). The relative abundance of Dialister was increased, while the relative abundance of Blautia was decreased in the H group compared to the other two groups (P < 0.05). The relative abundance of Agathobacter was decreased in the H group compared to the N group (P < 0.05). In conclusion, dietary supplementation with Cyberlindnera jadinii increased growth performance, serum immunity, antioxidant capacity, and improved intestinal microbiota in growing raccoon dogs. Cyberlindnera jadinii can therefore be used as a growth promoter in raccoon dogs.

Prevalence and genetic diversity of Giardia duodenalis in pet dogs from Zhengzhou, central China and the association between gut microbiota and fecal characteristics during infection

As a common zoonotic intestinal parasite, Giardia duodenalis could infect humans and various mammals worldwide, including pet dogs, leading to giardiasis. This study detected the infection of G. duodenalis in asymptomatic pet dogs in Zhengzhou, and evaluated the possibility of zoonosis and the relationship between gut microbiota and fecal characteristics. We randomly collected 448 fresh fecal samples from Zhengzhou, and G. duodenalis was screened based on the beta-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. The difference of gut microbiota between five G. duodenalis-positive and five G. duodenalis-negative samples was investigated by 16S rRNA gene sequencing. The overall prevalence of G. duodenalis was 7.1% (32/448) based on bg, gdh, and tpi locus, two G. duodenalis assemblages (C = 13, D = 14) and five (15.6%) mixed infection (C + D) were identified. Moreover, compared with the G. duodenalis-negative group, the diversity of gut microbiota increased in G. duodenalis-positive group. The decrease of Lactobacillus spp. and considerable increase of Prevotella spp. were associated with the fecal characteristics. These results show that the transmission of zoonotic giardiasis between humans and pet dogs is rare in Zhengzhou, central China, and support the use of Lactobacillus spp. as a potential probiotic agent to improve intestinal health in dogs, or even humans, by treating G. duodenalis. Therefore, the public health significance of G. duodenalis to humans, companion animals, and the environment should be further evaluated from One Health perspective.

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Prevalence of G. duodenalis was 7.1% in pet dogs in Zhengzhou, central China.

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G. duodenalis assemblage D infection is associated to higher gut microbial diversity.

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The abundance of Prevotella and Lactobacillus may affect fecal characteristics.

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Lactobacillus may be used as a potential feed additive to treat giardiasis.

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Effective strategies should be taken to minimize the threat posed by G. duodenalis.

Comparative Analysis of Gut Microbiota in Captive and Wild Oriental White Storks: Implications for Conservation Biology

The oriental white stork (Ciconia boyciana) is considered an endangered species based on the International Union for Conservation of Nature (IUCN) Red List. This study presents the first evidence on comparative analysis of gut microbial diversity of C. boyciana from various breeding conditions. To determine the species composition and community structure of the gut microbiota, 24 fecal samples from Tianjin Zoo and Tianjin Qilihai Wetland were characterized by sequencing 16S rRNA gene amplicons using the Illumina MiSeq platform. Firmicutes was found to be the predominant phylum. Analysis of community structure revealed significant differences in the species diversity and richness between the populations of the two breeding conditions. The greatest α-diversity was found in wild C. boyciana, while artificial breeding storks from Tianjin Zoo had the least α-diversity. Principal coordinates analysis showed that the microbial communities were different between the two studied groups. In conclusion, this study reveals the species composition and structure of the gut microbiota of oriental white storks under two breeding conditions, and our findings could contribute to the integrative conservation of this endangered bird.

Contrasting gut microbiota in captive Eurasian otters (Lutra lutra) by age

Understanding the gut microbiota characteristics of endangered species such as the Eurasian otter (Lutra lutra), especially in their early stages of life, could be essential for improving their management and ex situ conservation strategies. Here, we analyzed the gut microbiota diversity, composition, and function of captive Eurasian otters at different ages using high-throughput 16S rRNA gene sequencing. We found that: (1) Clostridiaceae was abundant in all age stages; (2) Lactococcus in cubs is thought to predominate for digesting milk; (3) bacteria associated with amino acid metabolism increase with age, while bacteria associated with carbohydrate metabolism decrease with age, which is likely due to decrease in dietary carbohydrate content (e.g., milk) and increase in dietary protein contents (e.g., fishes) with age; and (4) fish-related bacteria were detected in feces of healthy adults and juveniles. Overall, the gut microbiota of captive Eurasian otters was taxonomically and functionally different by age, which is thought to be attributed to the difference in the diet in their life stages. This study provided baseline information regarding the gut microbiota of Eurasian otters for the first time and contributes to improvement in their management in captivity.