Gastrointestinal Parasites of Stabled and Grazing Horses in Central and Northern Greece

The aim of this investigation was to compare parasites found in feces from stabled and grazing horses in Greece. For this, a total of 223 fecal samples were collected from horses from various parts of Central and Northern Greece. One hundred fifty were stabled and 73 were grazing horses, used for riding, working, or breeding. One hundred came from seven riding clubs, 73 from one breeding farm, and 50 were work horses from five farms. Parasitologic investigation was performed by applying three fecal examination techniques (Teleman's, zinc flotation, and stained smears) to detect ova, larvae, and oocysts of parasites. It was found that 77 the 223 horses (34.5%) in the study were infected with one or more parasite species. In the stabled horses, the most common parasites detected were eggs of strongyles, Strongyloides spp, Anoplocephala spp, Habronema spp, and Parascaris equorum and oocysts of Eimeria spp and Cryptosporidium spp; in the grazing horses, Anoplocephala spp. Strongyles were significantly more prevalent in the group of stabled horses than in the other group (P < .05). The results of the current study demonstrate that parasite infection is highly prevalent in horses in Greece.     

Clinical, biochemical, and hygiene assessment of stabled horses provided continuous or intermittent access to drinking water

OBJECTIVE: To compare health, hydration status, and management of stabled pregnant mares provided drinking water continuously or via 1 of 3 intermittent delivery systems. ANIMALS: 22 Quarter Horse (QH) or QH-crossbred mares and 18 Belgian or Belgian-crossbred mares (study 1); 24 QH or QH-crossbred mares and 18 Belgian or Belgian-crossbred mares (study 2). PROCEDURE: Stabled horses were provided water continuously or via 1 of 3 intermittent water delivery systems in 2 study periods during a 2-year period. Body temperature, attitude, appetite, water intake, and urine output were recorded daily. Hygiene of each horse and the stable were assessed weekly. Clinical and biochemical measures of hydration were determined 3 times during each study. Clinical measures of hydration included skin turgor, gum moisture, capillary refill time, and fecal consistency. Biochemical measures of hydration included PCV, plasma total protein concentration, serum osmolality, plasma vasopressin concentration, urine specific gravity, and urine osmolality. RESULTS: All horses remained healthy. Stable hygiene was worse when horses had continuous access to water. Clinical and biochemical measures of hydration did not differ among water delivery systems. CONCLUSIONS AND CLINICAL RELEVANCE: Various continuous and intermittent water delivery systems provided adequate amounts of water to stabled horses to maintain health and hydration status. Providing intermittent access to water may be preferable on the basis of stable hygiene.     

Impact of Dietary Cellobiose on the Fecal Microbiota of Horses

Cellobiose is a disaccharide with potential prebiotic effects, as demonstrated in different animal species, but not yet in horses. It was, therefore, the aim of the present study to evaluate the impact of dietary cellobiose on the fecal microbiota of horses. Eight healthy adult horses and two ponies were included in this study. The animals received a diet without or with 10 g and 20 g cellobiose per day for 14 days each. At the end of the feeding periods, fresh fecal samples were collected to measure bacterial metabolites and the microbial composition. For the microbiota analysis, 16S rRNA gene sequencing was used. Cellobiose was well accepted and tolerated by the animals. The lowest fecal concentrations of D-lactate, propionic acid, i-valeric acid, and total short-chain fatty acids were measured at the dose 10 g cellobiose per horse per day (quadratic effect: P < .05). A dose-dependent increase of the relative abundance of Firmicutes (P = .049), Coriobacteriales (P < .001), and Clostridium (P = .031) could be detected. In addition, a dose-dependent decrease of the relative abundance of Bacteroidetes (P = .035) was observed. In conclusion, the increase of Coriobacteriales and Clostridium indicates a bacterial fermentation of cellobiose in the equine intestine, as members of both groups exert saccharolytic activity. As clostridia have previously been assumed to be a key component of the intestinal microbiota in horses, the observed increase of Clostridium in the feces might indicate beneficial and potentially prebiotic effects of cellobiose in horses. However, this finding requires further investigation, particularly with regard to the Clostridium species that have been promoted by dietary cellobiose.     

Postnatal development of gut microbial activity and their importance for jejunal motility in piglets

Despite their anti-inflammatory properties, role in barrier function, absorption and microbial balance in the gut, knowledge on maturational and dietary effects on intestinal short-chain fatty acids (SCFA) in neonatal piglets is scarce. Moreover, little information exists whether SCFA and lactic acid (LA) modulates gut motility at this age. The present study aimed (1) to investigate the maturational changes in the SCFA profile with and without creep feeding of piglets in the first 3 wk of life; and (2) to examine the effects of SCFA and LA on muscle contractibility in jejunal tissue from neonatal piglets ex vivo. SCFA concentrations were measured in fecal samples of 52 piglets from 10 litters collected on days 2, 6, 13, and 20 of life using gas chromatography. Half of the litters were fed a commercial creep feed from day 10 of life. The organ bath system was used to test the effect of SCFA (acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, and caproate) as well as of LA and the combination of LA and SCFA on muscle contractibility in piglet’s jejunum. Average daily gain of piglets was similar between groups before and after introduction of creep feed. SCFA were detectable in feces in relevant concentrations from day 2 of life and increased on day 6 in males by 3.0-fold and on day 13 in females by 1.6-fold but decreased again on day 20 in both sexes compared with day 2 (P < 0.05). Creep feeding reduced fecal SCFA by 0.6-fold on day 13 without largely modifying molar proportions, whereas it increased fecal SCFA by 0.8-fold on day 20 of life compared with the sow-reared only piglets (P < 0.05). Applying SCFA ex vivo increased the muscle contraction of the jejunum by 30% (P < 0.05). Likewise, addition of LA and the combination of LA and SCFA increased the jejunal muscle contractibility by 34.9% and 32.2%, respectively, compared with the muscle tension preaddition (P < 0.05). In conclusion, the present results for fecal SCFA in first days of life suggest high bacterial activity on milk components and emphasize the importance of SCFA for intestinal development and function. After a lag phase, creep feeding promotes fermentation in the distal colon, which may be beneficial for the gut homeostasis. Results further demonstrate the stimulating effect of SCFA and LA for jejunal motility, suggesting a role for mixing of digesta (segmentation) and digestion and absorption of nutrients as well as passage in the jejunum of neonatal piglets.     

Isomaltooligosaccharide and Bacillus regulate the duration of farrowing and weaning-estrous interval in sows during the perinatal period by changing the gut microbiota of sows

This study investigated the effects of isomaltooligosaccharide (IMO) and Bacillus in perinatal diets on the duration of farrowing and post-weaning estrus, serum reproductive hormone concentrations, and gut microbiota and its metabolites of sows. Multiparous sows (n = 130) were fed diets without IMO (control, CON group), or diets containing only IMO (IMO group), IMO and Bacillus subtilis (IMOS group), IMO and Bacillus licheniformis (IMOL group), and IMO and B. subtilis and B. licheniformis (IMOSL group), respectively. The results indicate that the duration of farrowing and post-weaning estrus was shorter in sows in the IMOS, IMOL, and IMOSL groups, and the weaning-estrous interval was lower in sows in the IMOL greoup. In addition, the lowest fecal score was observed in the IMOL group during d 106 to 112 of gestation. Sows in most of the treatment groups had a higher concentration of serum prolactin and prostaglandin at farrowing, but a lower serum concentration of estradiol, oxytocin, and progesterone on d 18 of lactation than sows in the CON group. The treatment groups had a higher abundance of Candidatus Methanoplasma and Bacillus and a lower abundance of Escherichia-Shigella in their feces at farrowing. Furthermore, the treatment groups had higher concentrations of total short-chain fatty acids (SCFA) in feces at farrowing and a higher concentration of branched fatty acids in feces on d 18 of lactation. Furthermore, the abundance of Bacillus in feces was positively correlated with serum prostaglandin concentrations and fecal total SCFA of sows at farrowing, but was negatively correlated with the duration of farrowing. Overall, dietary IMO and Bacillus supplementation affected the concentration of serum reproductive hormones and the duration of farrowing and post-weaning estrus, and the gut microbiota is a key factor.     

Phylogenetic analysis of hindgut microbiota in Hokkaido native horses compared to light horses

The analysis of 16S rDNA sequence of bacteria in feces of Hokkaido native horses and light horses were performed to compare the hindgut microbiota between the two breeds. One hundred and four bacterial 16S rDNA clones (57 clones from four native horses and 47 clones from two light horses) were obtained. Only four sequences (3.8% of total sequences) showed 97% or more similarity to known species. The sequences were mainly affiliated with Cytophaga–Flavobacter–Bacteroides and low GC Gram‐positive bacteria (LGCGP). Proportion of LGCGP was higher in light horses. Other phyla including Verrucomicrobia, Spirochaetes and Archaea were detected only for native horses, suggesting high diversity of microbiota in native horses. In LGCGP, clusters related to known cellulolytic species were found only for native horses, while a cluster related to soluble sugar‐utilizing species was detected only for light horses. The library composition‐comparing software LIBSHUFF showed significant (P < 0.05) difference of fecal microbiota between the horse breeds. The number of Fibrobacter succinogenes‐related sequence and the frequency of detection of novel groups were found to be higher in native horses by selective amplification analysis. The results suggest that genetic diversity and population size of the F. succinogenes group are higher in the hindgut of native horses.     

Evaluation of changes in microbiota after fecal microbiota transplantation in 6 diarrheic horses

The purpose of this study was to characterize the fecal microbiota of horses with acute and chronic diarrhea before and after fecal microbiota transplantation (FMT). Six client-owned horses with acute and chronic diarrhea received FMT from 2 healthy donor horses. Microbiota analysis using next-generation sequencing was performed on fecal samples collected before and 2 and 7 d after FMT. Signs of diarrhea improved in 4 horses, whereas the remaining 2 horses did not survive. There was a significant difference in the number of bacterial species between donors and recipients (P < 0.05). The Order Lactobacillales and the genera Lactobacillus, Intestinimonas, and Streptococcus were increased in the microbiota of diarrheic horses, and Saccharofermentans genus increased in healthy donors. The results suggest that FMT from the healthy donors was not effective over a 7-day period as it did not change the fecal microbiota of the diarrheic horses. Further research to improve the efficacy of FMT in horses is needed.     

Evaluation of a novel animal milk oligosaccharide biosimilar: macronutrient digestibility and gastrointestinal tolerance,fecal metabolites,and fecal microbiota of healthy adult dogs and in vitro genotoxicity assays

Milk oligosaccharides (MO) are bioactive compounds in mammalian milk that provide health benefits to neonates beyond essential nutrients. GNU100, a novel animal MO biosimilar, was recently tested in vitro, with results showing beneficial shifts in microbiota and increased short-chain fatty acid (SCFA) production, but other effects of GNU100 were unknown. Three studies were conducted to evaluate the safety, palatability, and gastrointestinal (GI) tolerance of GNU100. In study 1, the mutagenic potential of GNU100 was tested using a bacterial reverse mutation assay and a mammalian cell micronucleus test. In study 2, palatability was assessed by comparing diets containing 0% vs. 1% GNU100 in 20 adult dogs. In study 3, 32 adult dogs were used in a completely randomized design to assess the safety and GI tolerance of GNU100 and explore utility. Following a 2-wk baseline, dogs were assigned to one of four treatments and fed for 26 wk: 0%, 0.5%, 1%, and 1.5% GNU100. On weeks 2, 4, and 26, fresh fecal samples were collected to measure stool quality, immunoglobulin A, and calprotectin, and blood samples were collected to measure serum chemistry, inflammatory markers, and hematology. On weeks 2 and 4, fresh fecal samples were collected to measure metabolites and microbiota. On week 4, total feces were collected to assess apparent total tract macronutrient digestibility. Although revertant numbers were greater compared with the solvent control in tester strain WP2uvrA(pKM101) in the presence of metabolic activation (S9) in the initial experiment, they remained below the threshold for a positive mutagenic response in follow-up confirmatory tests, supporting that GNU100 is not mutagenic. Similarly, no cytotoxicity or chromosome damage was observed in the cell micronucleus test. The palatability test showed that 1% GNU100 was strongly preferred (P < 0.05; 3.6:1 consumption ratio) over the control. In study 3, all dogs were healthy and had no signs of GI intolerance or illness. All diets were well accepted, and food intake, fecal characteristics, metabolite concentrations, and macronutrient digestibilities were not altered. GNU100 modulated fecal microbiota, increasing evenness and Catenibacterium, Megamonas, and Prevotella (SCFA producers) and reducing Collinsella. Overall, the results suggest that GNU100 is palatable and well-tolerated, causes no genotoxicity or adverse effects on health, and beneficially shifts the fecal microbiota, supporting the safety of GNU100 for the inclusion in canine diets.     

Fecal Sand Clearance Is Enhanced with a Product Combining Probiotics, Prebiotics, and Psyllium in Clinically Normal Horses

Consumption of sand and dirt by horses can cause chronic diarrhea, weight loss, and colic caused by irritation and obstruction of the gastrointestinal tract. Prevention has been primarily focused on changes in management to reduce the intake of sand resulting from feeding on the ground. Studies regarding the use of psyllium for the prevention of sand accumulation in clinically normal horses have not been published. A nutritional supplement combining probiotics, prebiotics, and psyllium was hypothesized to increase fecal sand output in clinically normal horses in a natural environment. A measured volume of feces was collected daily from eight clinically normal horses and screened for sand 1 week before and during 35 days of treatment with a supplement combining probiotics, prebiotics, and psyllium. Sand was isolated from feces using a flotation decanting method and was expressed in milligrams sand per gram of feces. Fecal sand output increased significantly (P < .01) by day 4 of supplementation and remained significantly increased through day 31 of the feeding trial. Daily supplementation with a probiotic, prebiotic, and psyllium supplement demonstrated enhanced fecal sand clearance in clinically normal horses. These results suggest that this product may be an effective prophylactic treatment for sand enteropathy and sand colic in which management alone is not sufficient to prevent intestinal sand accumulation. Further studies are needed to confirm the utility of this product in clearing sand from horses with naturally occurring sand impactions and enteropathy.     

Apparent total tract energy and macronutrient digestibility and fecal fermentative end-product concentrations of domestic cats fed extruded, raw beef-based, and cooked beef-based diets

The objectives of this study were to determine differences in apparent total tract energy and macronutrient digestibility, fecal and urine characteristics, and serum chemistry of domestic cats fed raw and cooked meat-based diets and extruded diet. Nine adult female domestic shorthair cats were utilized in a replicated 3 × 3 Latin square design. Dietary treatments included a high-protein extruded diet (EX; 57% CP), a raw beef-based diet (RB; 53% CP), and a cooked beef-based diet (CB; 52% CP). Cats were housed individually in metabolic cages and fed to maintain BW. The study consisted of three 21-d periods. Each period included diet adaptation during d 0 to 16; fecal and urine sample collections during d 17 to 20; and blood sample collection at d 21. Food intake was measured daily. Total feces and urine were collected for determination of nutrient digestibility. In addition, a fresh urine sample was collected from each cat for urinalysis, and a fresh fecal sample was collected from each cat for determination of DM percentage and ammonia, short-chain fatty acid (SCFA), and branched-chain fatty acid (BCFA) concentrations. All feces were scored after collection using a scale ranging from 1 (hard, dry pellets) to 5 (watery, liquid that can be poured). Blood was analyzed for serum metabolites. Apparent total tract DM, OM, CP, fat, and GE digestibilities were greater (P ≤ 0.05) in cats fed RB and CB than those fed EX. Total fecal SCFA concentrations did not differ among dietary treatments; however, molar ratios of SCFA were modified by diet, with cats fed RB and CB having an increased (P ≤ 0.05) proportion of fecal propionate and decreased (P ≤ 0.05) proportion of fecal butyrate compared with cats fed EX. Fecal concentrations of ammonia, isobutyrate, valerate, isovalerate, and total BCFA were greater (P ≤ 0.05) in cats fed EX compared with cats fed RB and CB. Our results indicated that cooking a raw meat diet does not alter apparent total tract energy and macronutrient digestibility and may also minimize risk of microbial contamination. Given the increasing popularity of feeding raw diets and the metabolic differences noted in this experiment, further research focused on the adequacy and safety of raw beef-based diets in domestic cats is justified.     

Effect of soybean husk supplementation on the fecal fermentation metabolites and microbiota of dogs

In vitro fermentation and in vivo feeding experiments were conducted to characterize the effects of soybean (Glycine max) husk on the fecal fermentation metabolites and microbiota of dogs. An in vitro fermentation study using feces from three Toy Poodle dogs (6.5 ± 3.5 months in age and 2.9 ± 0.4 kg in body weight) revealed that the fecal inoculum was able to ferment soybean husk (supplemented at 0.01 g/mL culture) and increased levels of short chain fatty acids (SCFA) and Bifidobacterium, irrespective of pre‐digestion of the husk by pepsin and pancreatin. In a feeding experiment, four Shiba dogs (7–48 months in age and 7.5 ± 1.7 kg in body weight) fed a commercial diet supplemented with 5.6% soybean husk showed an increase in SCFA, such as acetate and butyrate, and lactate, and a decrease in indole and skatole in the feces compared to those fed a 5.6% cellulose diet. Real‐time PCR assay showed that soybean husk supplementation stimulated the growth of lactobacilli, Clostridium cluster IV including Faecalibacterium prausnitzii, Clostridium cluster XIVa, Bacteroides‐Prevotella‐Porphyromonas group but inhibited the growth of Clostridium cluster XI. Both in vitro and in vivo experiments indicated that soybean husk supplementation improves gastrointestinal health through optimization of beneficial organic acid production and increase of beneficial bacteria. Therefore, soybean husk is suggested to be applicable as a functional fiber in the formulation of canine diets.     

Effect of liquid whey feeding on fecal microbiota of mature and growing pigs

The effect of liquid whey feeding on fecal bacteria and their metabolites was assessed in five pregnant sows and 66 growing pigs. Sows were fed a control diet for 4 weeks (control period) followed by the same diet but with whey feeding (5 L/day/pig) for 4 weeks (whey period). One group of growing pigs was given 267 L of whey per pig (whey group), while the other group was not (control group). In both cases, liquid whey was given separately from control diet. Sows in the whey period had feces showing lower pH, lower ammonia concentration, and larger population sizes of total bacteria, lactobacilli and bifidobacteria. The bacterial gene library analysis indicated that Mitsuokella and Megasphaera were more frequently detected, while Clostridium disporicum were detected less frequently in the whey period. Feces from whey‐fed growing pigs showed lower pH than that from control pigs in the early stage of growing. Also, larger populations of total bacteria, lactobacilli and bifidobacteria were recorded in the whey group. From the bacterial gene library analysis, the detection frequency of Lactobacillus reuteri tended to be higher in the whey group. These results indicate that whey feeding influences the hindgut microbiota of pigs, possibly leading to a fermentation shift that is favorable for animal health.     

A dose-response experiment evaluating the effects of oligofructose and inulin on nutrient digestibility, stool quality, and fecal protein catabolites in healthy adult dogs

In this experiment, three concentrations (0.3, 0.6, and 0.9% of diet, as-fed basis) of two fructans, oligofructose (OF) and inulin, were tested against a 0% supplemental fructan control. Seven ileal-cannulated adult female dogs were fed a meat-based, kibbled diet and assigned to treatments in a 7 x 7 Latin square design. Dietary supplementation of fructans had no effect on nutrient intakes or ileal digestibilities. Total-tract digestibilities of DM, OM, and CP decreased (P < 0.05) as a result of dietary OF and inulin supplementation. Dogs fed the control diet had a DM total-tract digestibility of 83.0%. The percentages of fecal DM for dogs fed the control and 0.3, 0.6, and 0.9% OF were 36.6, 33.3, 32.8, and 31.7%, respectively. When compared with the control, OF (P < 0.01) and inulin (P < 0.01) supplementation increased fecal ammonia concentrations. Higher fecal short-chain fatty acid (SCFA; P < 0.10) and isovalerate concentrations (P < 0.01) were noted for dogs fed both fructans. Total fecal SCFA for dogs fed the control diet and 0.3, 0.6, and 0.9% OF were 406.4, 529.9, 538.3, and 568.8 micromol/g of feces (DM basis), respectively. Dogs fed 0.3, 0.6, and 0.9% inulin had total fecal SCFA of 472.2, 468.8, and 471.5 micromol/g of feces (DM basis), respectively. Linear increases were observed in putrescine (P < 0.11), cadaverine (P < 0.07), spermidine (P < 0.12), and total amines (P < 0.05) in feces of dogs fed OF. Lower fecal phenol (P < 0.08) and total phenol (P < 0.04) concentrations occurred in dogs fed inulin, along with a linear decrease (P < 0.08) in total phenols with OF supplementation. Total fecal phenols for dogs fed the control, 0.3, 0.6, and 0.9% inulin were 3.03, 1.86, 1.97, and 2.23 micromol/g of feces (DM basis), respectively. Low-level dietary inclusion of inulin and OF positively affected indices known to be associated with gut health of the dog without seriously compromising nutrient digestibility or stool quality. Overall, the 0.9% OF treatment resulted in the best responses, including no adverse effect on nutrient intakes, ileal digestibilities, or stool quality, as well as increased fecal SCFA and decreased fecal phenols. The biological responses due to inulin were more variable.     

Feeding cashew nut shell liquid decreases methane production from feces by altering fecal bacterial and archaeal communities in Thai local ruminants

The effect of feeding cashew nut shell liquid (CNSL) on fecal fermentation products and microbiota was investigated in Thai native cattle and swamp buffaloes. Four of each animal were fed rice straw and concentrate diet with control pellets without CNSL for 4 weeks, followed by the same diet with pellets containing CNSL for another 4 weeks, so that CNSL was administered at a level of 4 g/100 kg body weight. Feces were collected the last 2 days in each feeding period. CNSL alkyl phenols were recovered from feces (16%–28%) in a similar proportion to those in the diet, indicating that most functional anacardic acid was not selectively removed throughout the digestive tract. In vitro production of gas from feces, particularly methane, decreased with CNSL feeding. The proportion of acetate in feces decreased with CNSL feeding, whereas that of propionate increased, without affecting total short-chain fatty acid concentration. CNSL feeding changed fecal microbial community, particularly in swamp buffaloes, which exhibited decreases in the frequencies of Treponema, unclassified Ruminococcaceae, and Methanomassiliicoccaceae. These results suggest that CNSL feeding alters not only rumen fermentation but also hindgut fermentation via modulation of the microbial community, thereby potentially attenuating methane emission from the feces of ruminant animals.     

3～6月龄伊犁马肠道微生物群落多样性的研究

本试验旨在研究3~6月龄伊犁马肠道微生物群落的多样性,揭示断奶前马驹肠道菌群演替的规律,从微生物学角度为此阶段马驹生长发育及肠道健康研究提供理论依据。试验选取平均体重为(89.75±8.81)kg、出生日期相同的3月龄伊犁马5匹,进行为期90 d的饲养试验。分别在试验的第0天(即试验开始的前1天)、第30天、第60天、第90天采集马驹粪便样品,从每份样品中提取微生物基因组总DNA,采用Illumina HiSeq测序技术检测样品微生物群落多样性。结果显示:1)对5匹马驹的20份粪样进行测序,共获得有效序列数157 665条,获得平均操作分类单元(OTUs)1 117个。2)马驹粪便中微生物群落α多样性指数(ACE、Chao1、Shannon和Simpson指数)随着马驹月龄的增加呈波动性变化,但各时间点之间均无显著性变化(P0.05)。3)在门水平上,马驹粪便中10大优势菌分别为厚壁菌门(Firmicutes)、拟杆菌门(Bacteroidetes)、变形菌门(Proteobacteria)、疣微菌门(Verrucomicrobia)、螺旋体菌门(Spirochaetes)、梭杆菌门(Fusobacteria)、无壁菌门(Tenericutes)、放线菌门(Actinobacteria)、TM7、广古菌门(Euryarchaeota),其中以厚壁菌门、拟杆菌门、变形菌门及疣微菌门的丰度较高;在科水平上,马驹粪便中10大优势菌分别为芽孢杆菌科(Bacillaceae)、莫拉氏菌科(Moraxellaceae)、动球菌科(Planococcaceae)、肉杆菌科(Carnobacteriaceae)、BS11、RFP12、乳杆菌科(Lactobacillaceae)、瘤胃球菌科(Ruminococcaceae)、毛螺旋菌科(Lachnospiraceae)、紫单胞菌科(Porphyromonadaceae);在属水平上,马驹粪便中10大优势菌分别为不动杆菌属(Acinetobacter)、德库菌属(Desemzia)、乳杆菌属(Lactobacillus)、Ureibacillus、Paludibacter、芽孢杆菌属(Bacillus)、埃希式杆菌属(Escherichia)、肉食杆菌属(Carnobacterium)、密螺旋体属(Treponema)、艰难杆菌属(Mogibacterium)。由此得出,采用Illumina HiSeq测序技术能够准确地对3~6月龄伊犁马肠道微生物群落进行分类研究;厚壁菌门、拟杆菌门、变形菌门、疣微菌门是3~6月龄伊犁马肠道内的优势菌门。     

Fecal shedding of Salmonella spp by horses in the United States during 1998 and 1999 and detection of Salmonella spp in grain and concentrate sources on equine operations

OBJECTIVE: To estimate prevalence of fecal shedding of Salmonella spp among horses in the US horse population and prevalence of Salmonella spp in grain or other concentrate used as horse feed on equine operations in the United States. DESIGN: Cross-sectional survey. SAMPLE POPULATION: Horses on 972 operations in 28 states. PROCEDURE: Fecal samples were collected from horses resident at each operation. Only a single sample was collected from any individual horse; number of horses from which samples were collected on each operation was determined on the basis of number of horses on the operation. A single sample of grain or concentrate was also collected from each operation. All samples were tested for Salmonella spp by means of bacterial culture. RESULTS: Overall, 0.8% (SE, 0.5) of resident horses shed Salmonella spp in their feces. The overall prevalence of operations positive for fecal shedding of Salmonella spp (i.e., operations with > or = 1 horse shedding Salmonella spp in its feces) was 1.8% (SE, 0.7). Prevalence of grain or other concentrate samples positive for Salmonella spp was 0.4%. Serotypes of Salmonella spp that were identified in grain or other concentrate were not those typically associated with clinical disease in horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the national prevalence of fecal shedding of Salmonella spp by horses in the United States was 0.8%, and that prevalence of Salmonella spp in grain or other concentrate used for horse feed was 0.4%.     

Evaluation of a PCR to detect Salmonella in fecal samples of horses admitted to a veterinary teaching hospital.

The diagnostic accuracy of a PCR used to identify horses shedding Salmonella spp. in their feces during hospitalization was estimated, relative to bacterial culture of serially collected fecal samples, using longitudinal data. Five or more fecal samples were collected from each of 116 horses admitted as inpatients, for reasons other than gastrointestinal disease, between July 26, 2001 and October 25, 2002. All 873 fecal samples collected were tested with a PCR based on oligonucleotide primers defining a highly conserved segment of the histidine transport operon gene of Salmonella typhimurium, and each sample was cultured for Salmonella spp. One or more samples from 87 (75%) horses were PCR positive, and Salmonella was cultured from 1 or more samples from 11 (9.5%) horses. All culture-positive horses had at least 1 PCR-positive result, whereas only 29 (28%) culture-negative horses were PCR negative on all fecal samples tested. The PCR was most specific, relative to bacterial culture of serially collected fecal samples, when used to test samples from Quarterhorse or breeds other than Thoroughbred or Standardbred, or from clinical (vs. healthy, accompanying horses) cases. Overall, the PCR had the greatest agreement (70%), compared with bacterial culture of serially collected fecal samples, using a cutoff of 2 or more positive PCR test results to define a Salmonella-positive horse. The reasons why some fecal samples, from which Salmonella organisms cannot be isolated, are PCR positive need to be determined before the PCR can be incorporated into Salmonella surveillance programs for hospitalized equine populations.     

Nasal bacterial microbiota during an outbreak of equine herpesvirus 1 at a farm in southern Ontario

The objective of this study was to investigate the nasal bacterial microbiota of healthy horses and horses infected with equine herpesvirus 1 (EHV-1). The nasal bacterial microbiota of 10 horses infected with EHV-1 and 11 control horses from a farm experiencing an outbreak was characterized using the Illumina MiSeq platform targeting the V4 region of the 16S ribosomal RNA gene. The nasal bacterial microbiota of healthy horses and EHV-1 horses was significantly different in community membership and structure. Horses shedding EHV-1 had lower bacterial richness (P = 0.002), evenness (P = 0.008), and diversity (P = 0.026) than healthy horses. Healthy horses had a higher relative abundance of Firmicutes and Bacteroidetes, but lower Proteobacteria than horses with EHV-1 (P < 0.05). This study provides the basis for generating hypotheses and investigations on the role of bacterial-viral interactions in the health and diseases of adult horses.     

Prevalence of ocular microorganisms in hospitalized and stabled horses

Microorganisms from normal eyes of hospitalized and stabled horses were identified, and the frequency of isolation was compared between the 2 groups. Using standard techniques, swab specimens from both eyes of 22 hospitalized horses and both eyes of 18 stabled horses were cultured for aerobic bacteria and fungi. Ninety-six aerobic bacteria and 57 fungi were isolated. The predominant bacterial isolates were gram-positive organisms, most of which belonged to the genera Corynebacterium, Bacillus, Staphylococcus, and Streptomyces. Gram-negative organisms comprised less than one-fourth of the bacterial isolates, with the genera Neisseria, Moraxella, and Acinetobacter being the most commonly isolated. Environmental fungi Cladosporium and Alternaria accounted for half of all fungal isolates. In only 5 horses were fungi isolated without accompanying isolation of bacteria. The frequency of isolation of fungi was higher (P less than 0.01) in stabled horses. For bacteria, the frequency of isolation was higher (P less than 0.08) in male horses. Results of susceptibility testing were recorded as the percentage of all isolates susceptible to a given antimicrobic drug. Bacterial isolates were highly susceptible (greater than or equal to 90%) to neomycin, polymixin B, gentamicin, and chloramphenicol. Overall, filamentous fungi had highest susceptibility to natamycin (97%). Miconazole was highly efficacious (100% susceptibility) against Fusarium and Aspergillus.     

Pain causes increased concentrations of glucocorticoid metabolites in horse feces

The concentration of 11,17-dioxoandrostanes (11,17-DOA), a group of cortisol metabolites, was measured using enzyme immunoassay in fecal samples of horses experiencing painful episodes. One group of horses consisted of 10 stallions castrated (samples were collected daily for 10 days); the other group was made up of 29 horses which were brought to an animal hospital because of signs of colic (samples were collected twice daily for six days). Before castration, median concentrations of 10.5 nmol/kg feces were measured. On days 1 and 2 after castration, median 11,17-DOA values increased up to 26.2 and 50.0 nmol/kg feces, respectively, and decreased thereafter to levels lower than at the beginning of the sampling period. High variations were measured between individual cases of colic. In animals with colic, all horses excreted more than 33 nmol 11,17-DOA/kg feces for various periods. The highest concentration measured was 885 nmol/kg feces. One animal out of the 29 colic horses did not show any clinical signs of pain upon arrival in the hospital. The 11,17-DOA values were below 17 nmol/kg feces in all those samples. From this data we conclude, that the concentration of 11,17-DOA in feces is a parameter for painful situations that have occurred one or two days earlier.