Clostridium difficile in faeces from healthy dogs and dogs with diarrhea

Background

This study was conducted to evaluate the faecal occurrence and characterization of Clostridium difficile in clinically healthy dogs (N = 50) and in dogs with diarrhea (N = 20) in the Stockholm-Uppsala region of Sweden.

Findings

Clostridium difficile was isolated from 2/50 healthy dogs and from 2/20 diarrheic dogs. Isolates from healthy dogs were negative for toxin A and B and for the tcdA and tcdB genes. Both isolates from diarrheic dogs were positive for toxin B and for the tcdA and tcdB genes. The C. difficile isolates from healthy dogs had PCR ribotype 009 (SE-type 6) and 010 (SE-type 3) whereas both isolates from dogs with diarrhoea had the toxigenic ribotype 014 (SE-type 21). One of the isolates from healthy dogs was initially resistant to metronidazole.

Conclusions

This study revealed presence of toxigenic C. difficile in faecal samples of diarrheic dogs and low number of non- toxigenic isolates in healthy dogs from Uppsala-Stockholm region in Sweden. However, more comprehensive studies are warranted to investigate the role of C. difficile in gastrointestinal disease in dogs.     

Occurrence of antimicrobial resistant bacteria in healthy dogs and cats presented to private veterinary hospitals in southern Ontario: A preliminary study

The prevalence and patterns of antimicrobial susceptibility of fecal Escherichia coli, Salmonella spp., extended β-lactamase producing E. coli (ESBL-E. coli), methicillin-resistant Staphylococcus aureus (MRSA), and methicillin-resistant Staphylococcus pseudintermedius (MRSP) were determined for healthy dogs (n = 188) and cats (n = 39) from veterinary hospitals in southern Ontario that had not had recent exposure to antimicrobials. The prevalence of antimicrobial resistance in E. coli was as follows: streptomycin (dogs — 17%, cats — 2%), ampicillin (dogs — 13%, cats — 4%), cephalothin (dogs — 13%, cats — < 1%), and tetracycline (dogs — 11%, cats — 2%). Eleven percent of dogs and 15% of cats had isolates that were resistant to at least 2 antimicrobials. Cephamycinase (CMY)-2 producing E. coli was cultured from 2 dogs. No Salmonella spp., ESBL-E. coli, MRSA, or MRSP isolates were recovered. The observed prevalence of resistance in commensal E. coli from this population was lower than that previously reported in companion animals, but a small percentage of dogs may be a reservoir for CMY-2 E. coli.     

Exposure to maternal feces in lactation influences piglet enteric microbiota,growth, and survival preweaning

It is known that gilt progeny performance is reduced compared with sow progeny. Previous research suggests that the presence of maternal feces in early life improves the health and survival of offspring. Therefore, we aimed to determine whether contact with feces from multiparous (MP) sows would improve the growth and survival of piglets born and reared on primiparous (P1) sows and if so, whether these differences are associated with the gut microbiota. Four treatments were applied for 10 days: Donor (n = 29) piglets had limited access to maternal feces as, each morning, sow feces were removed and placed in the crate of a P1 sow (P1-FT; n = 30 piglets) and P1-Con (n = 29) and MP-Con (n = 33) piglets had access to their own mothers’ feces. All piglets were weighed on days 1, 3, 10, and 18. Fecal samples were collected from a subset of sows (n = 10/treatment) 3 days post farrow and from two female piglets/litter on days 10 and 18 (n = 20/treatment) and subject to 16S rRNA amplicon analysis. Escherichia, Clostridium, Campylobacter, and Treponema were more abundant in MP sows, while P1 sows had a higher abundance of Lactobacillus and Prevotella. At 10 days, P1 progeny fecal microbiota differed, and growth and survival were reduced when compared with MP progeny. No treatment effect was observed for P1-FT piglets (P > 0.05). Donor piglets had a different fecal microbiota and improved weight and survival then all other treatments (P < 0.05). Overall, the removal of sow feces from the farrowing crate improved piglet microbiota development, growth, and survival.     

Probiotic Bacillus subtilis C-3102 Improves Eggshell Quality after Forced Molting in Aged Laying Hens

This study was carried out to evaluate the effects of probiotic Bacillus subtilis C-3102 feed additive on quality characteristics including strength, thickness, and weight of eggshells of Boris Brown laying hens. The control group (n=64) was fed a basal diet comprised of maize and feed rice, whereas the experimental group (n=64) was fed a basal diet supplemented with B. subtilis C-3102 (3×10⁵ CFU/g) starting at 49 weeks of age. From 67 to 69 weeks, all hens were induced to molt using an anorexic program; then, the birds in both groups returned to their respective diets (from 69 to 82 weeks). Eggshell strength, measured six times with 60 eggs selected before the molting treatment, was significantly greater in the C-3102 group than in the control group at 51, 59, 63, and 66 weeks (3.45, 3.44, 3.28, and 3.13 kg/cm²; P<0.05, 0.05, 0.01, and 0.01, respectively). Moreover, eggshell strength—measured three times after the molting treatment—was significantly greater in the C-3102 group than in the control group at 73 and 77 weeks (3.79 and 3.65 kg/cm²; P<0.01 and 0.01, respectively). Eggshell thickness was also significantly greater in the C-3102 group than in the control group at 73 and 77 weeks (0.400 and 0.390 mm; P<0.01 and 0.01, respectively). Fecal samples collected from eight hens of each group at 70 weeks of age after forced molting, showed a significantly higher proportion of Lactobacillus spp. in the C-3102 group (8.94 log CFU/g) (P<0.05) than in the control group (8.63 log CFU/g). Clostridium spp. abundance was significantly lower in the C-3102 group (2.92 log CFU/g) than in the control group (4.3 log CFU/g). These results suggest that C-3102 supplementation improves eggshell quality in aged laying hens, particularly after forced molting.     

An investigation into the association between cpb2-encoding Clostridium perfringens type A and diarrhea in neonatal piglets

To investigate the possible role of cpb2-positive type A Clostridium perfringens in neonatal diarrheal illness in pigs, the jejunum and colon of matched normal and diarrheic piglets from 10 farms with a history of neonatal diarrhea were examined grossly and by histopathology, and tested for C. perfringens, for C. perfringens beta2 (CPB2) toxin, as well as for Clostridium difficile toxins, Salmonella, enterotoxigenic Escherichia coli, rotavirus, transmissible gastroenteritis (TGE) virus, and coccidia. Clostridium perfringens isolates were tested using a multiplex real-time polymerase chain reaction (PCR) to determine the presence of cpa, consensus and atypical cpb2, and other virulence-associated genes. The numbers of C. perfringens in the intestinal contents were lower in diarrheic piglets (log₁₀ 5.4 CFU/g) compared with normal piglets (log₁₀ 6.5 CFU/g) (P < 0.05). The consensus cpb2 was present in 93% of isolates in each group, but atypical cpb2 was less common (56% healthy, 32% diarrheic piglets isolates, respectively, P < 0.05). The presence of CPB2 toxin in the intestinal contents of normal and diarrheic piglets did not differ significantly. Clostridium difficile toxins and rotavirus were each detected in 7 of the 21 (33%) diarrheic piglets. Rotavirus, C. difficile toxins, Salmonella, or enterotoxigenic E. coli were concurrently recovered in different combinations in 4 diarrheic piglets. The cause of diarrhea in 8 of the 21 (38%) piglets on 6 farms remained unknown. The etiological diagnosis of diarrhea could not be determined in any of the piglets on 2 of the farms. This study demonstrated that the number of cpb2-positive type A C. perfringens in the intestinal contents was not a useful approach for making a diagnosis of type A C. perfringens enteritis in piglets. Further work is required to confirm whether cpb2-carrying type A C. perfringens have a pathogenic role in enteric infection in neonatal swine.     

Association of intrauterine presence of Lactobacillus spp. with inflammation and pathogenic bacteria in the uterus in postpartum dairy cows

The aim of this study was to clarify the influence of Lactobacillus spp. on the degree of endometrial inflammation in the postpartum period and the relationship between Lactobacillus spp. and pathogenic bacteria in the endometrium of postpartum dairy cows. Endometrial samples were collected from 41 Holstein-Friesian cows at 4 and 8 weeks postpartum using cytobrushes for polymorphonuclear neutrophil (PMN) count and bacterial culture to isolate Lactobacillus spp., Escherichiacoli, and Trueperella pyogenes. The 4-week samples were divided into four groups (E+L+), (E+L−), (E−L+), (E−L−) according to whether endometritis was diagnosed (E+) and Lactobacillus spp. was isolated (L+). The diagnostic criterion for cytological endometritis was > 18% PMN. The average PMN% in the E+L+ group was lower than that in the E+L-group (P < 0.05) at 8 weeks postpartum. There were no significant correlations between the number of colonies of Lactobacillus spp. and E. coli or between that of Lactobacillus spp. and T. pyogenes. Lactobacillus spp. could reduce PMN% in dairy cows with endometritis during the puerperal period. In conclusion, the intrauterine presence of Lactobacillus spp. may have a positive effect on uterine involution in postpartum dairy cows.     

A retrospective study on the etiological diagnoses of diarrhea in neonatal piglets in Ontario,Canada, between 2001 and 2010

Laboratory surveillance data from the Animal Health Laboratory, University of Guelph, on the etiological diagnoses of neonatal diarrhea in piglets were analyzed to determine the relative importance and trends of different enteric pathogens in Ontario. A total of 237 cases, including live and dead 1- to 7-day-old piglets, were submitted for diagnosis of gastrointestinal illness between 2001 and 2010. The combined frequencies for cases of gastrointestinal illness involving Escherichia coli, Clostridium perfringens type A, rotavirus, and Clostridium difficile, either as single pathogens or a complex of pathogens, accounted for 56% of the total cases. In a total of 33% of cases of gastrointestinal illness, an etiological agent was not identified. The frequency of cases diagnosed with enterotoxigenic E. coli was decreased from 2007. Cases submitted in 2010 were more likely to be diagnosed with C. perfringens type A compared to cases submitted in 2002 to 2007 (P < 0.05). There was a significant trend for cases submitted in the winter to be diagnosed with C. perfringens type A, enterotoxigenic E. coli, rotavirus, and Cystoisospora suis (formerly Isospora suis) (P < 0.05). Enterotoxigenic E. coli was less likely diagnosed if C. difficile, C. perfringens, or rotavirus were detected (P < 0.05). Younger piglets were more likely to be diagnosed with C. perfringens type A (P < 0.05) and C. difficile (P < 0.05) than older piglets. This study shows that E. coli, C. perfringens type A, rotavirus, and C. difficile are enteric pathogens of concern for Ontario swine farrowing operations and further research is required to understand the reasons for the cases that are not diagnosed.     

Clostridium difficile shedding by healthy dogs in Nigeria and Malawi

The objectives of this study were to determine the prevalence and characteristics of Clostridium difficile shedding in owned dogs in Nigeria and Malawi. Clostridium difficile was isolated from 31/120 (26%) dogs in Nigeria and 11/92 (12%) dogs in Malawi (p = 0.012). Overall, 22/42 (52%) isolates were toxigenic; 17/31 (55%) from Nigeria and 5/11 (45%) from Malawi. All toxigenic isolates possessing tcdA and tcdB, and only one also possessed cdtA/B. Sixteen different ribotypes were found, ten (63%) of which were non‐toxigenic. Most isolates corresponded to ribotypes that have been previously identified in humans or livestock. The role of dogs in transmission of C. difficile and the clinical implications of C. difficile shedding in dogs remain unclear. These data indicate that dogs could act as a source of C. difficile for exposure of other species, including humans; however, the true risk is unknown. Further study of the ecology of C. difficile and the role of dogs in disease of humans and other domestic animals is indicated.     

Prevalence and risk factor investigation of Campylobacter species in beef cattle feces from seven large commercial feedlots in Alberta,Canada

This fecal prevalence study targeted cattle from 7 large (10 000 to > 40 000 head) commercial feedlots in Alberta as a means of establishing Campylobacter levels in cattle just prior to animals entering the food chain. Overall, 87% [95% confidence interval (CI) = 86–88] of 2776 fresh pen-floor fecal samples were culture positive for Campylobacter species, with prevalences ranging from 76% to 95% among the 7 feedlots. Campylobacter spp. prevalence was 88% (95% CI = 86–90) in the summer (n = 1376) and 86% (95% CI = 85–88) in the winter (n = 1400). In addition, 69% (95% CI = 66–71) of 1486 Campylobacter spp. positive samples were identified as Campylobacter jejuni using hippurate hydrolysis testing. Of those, 64% (95% CI = 58–70) of 277 and 70% (95% CI = 67–72) of 1209 Campylobacter isolates were identified as C. jejuni in winter and summer, respectively. After accounting for clustering within pen and feedlot, feedlot size and the number of days on feed were associated with Campylobacter spp. isolation rates. The high isolation rates of Campylobacter spp. and C. jejuni in feedlot cattle feces in this study suggest a potential role for feedlot cattle in the complex epidemiology of campylobacters in Alberta.     

Effects of dietary Forsythia suspensa extract supplementation to lactating sows and nursery pigs on post-weaning performance,antioxidant capacity,nutrient digestibility,immunoglobulins, and intestinal health

The aim of this study was to determine the effect of dietary Forsythia suspensa extract (FSE) supplementation to lactating sows and nursery pigs on post-weaning performance, antioxidant capacity, immunoglobulins, and intestinal health. Based on backfat, body weight (BW), and parity, 24 gestating sows (Landrace × Yorkshire) with average parity of 3.38 ± 0.61 and BW of 234 ± 6.81 kg were allotted into two dietary treatments (control vs. 100 mg/kg FSE) with 12 sows per treatment from day 107 of gestation to day 21 of lactation. After weaning, based on the initial BW and source litter, 192 nursery pigs (Duroc × [Landrace × Yorkshire], average BW of 6.98 ± 0.32 kg, weaned at day 21) were allotted into four dietary treatments with eight replicate pens per treatment, six pigs per pen for a 4-wk study. The treatments included the following: 1) CC (sows and their piglets both fed control diet); 2) CF (sows fed control diet and their piglets fed FSE diet [containing 100 mg/kg FSE]); 3) FC (sows fed FSE diet and their piglets fed control diet); and 4) FF (sows and their piglets both fed FSE diet). The MIXED procedures of SAS for a split-plot arrangement with sow diet as the whole plot and nursery diet as split plot were used to analyze the data. After weaning, piglets from FSE-fed sows had improved (P < 0.05) average daily gain and feed efficiency, and lower (P < 0.05) diarrhea rate in overall (day 1 to 28) compared with those from sows fed control diet. Piglets from FSE-fed sows also had higher (P < 0.05) contents of immunoglobulin G (IgG), growth hormone, superoxide dismutase (SOD), total antioxidant capacity in serum, villus height in ileum, and villus height to crypt depth ratio in jejunum, as well as lower (P < 0.05) content of malondialdehyde (MDA) in serum and crypt depth in ileum compared with those from sows fed control diet. Piglets fed FSE during nursery had increased (P < 0.05) concentrations of IgG, SOD, and catalase, and decreased (P < 0.05) MDA and tumor nuclear factor-α levels in serum compared with those fed control diet during nursery. Piglets from FC group had increased (P < 0.05) protein expression of occludin in jejunal mucosa and relative abundance of Lactobacillus on genus level in colon compared with those from CC group. In conclusion, for the performance and intestinal health, diets supplemented with FSE during lactation phase seemed more efficient to alleviate weaning stress than the nursery phase. In terms of the antioxidant status and immunoglobulins, FSE supplemented in both phases were efficient for nursery pigs.     

Early supplementation with Lactobacillus plantarum in liquid diet modulates intestinal innate immunity through toll-like receptor 4-mediated mitogen-activated protein kinase signaling pathways in young piglets challenged with Escherichia coli K88

This study was conducted to investigate the effects of early supplementation during 4 to 18 d of age with Lactobacillus plantarum (LP) in liquid diets on intestinal innate immune response in young piglets infected with enterotoxigenic Escherichia coli (ETEC) K88. Seventy-two barrow piglets at 4 d old were assigned to basal or LP-supplemented liquid diet (5 × 10¹⁰ CFU·kg⁻¹). On day 15, piglets from each group were orally challenged with either ETEC K88 (1 × 10⁸ CFU·kg⁻¹) or the same amount of phosphate-buffered saline. The intestinal mucosa, mesenteric lymph node (MLN), and spleen samples were collected on day 18. Here, we found that LP pretreatment significantly decreased the mRNA relative expression of inflammatory cytokines (interleukin [IL]-1β, IL-8, and tumor necrosis factor-α), porcine β-defensin 2 (pBD-2), and mucins (MUC1 and MUC4) in the jejunal mucosa in piglets challenged with ETEC K88 (P < 0.05). Moreover, LP significantly decreased the ileal mucosa mRNA relative expression of IL-8 and MUC4 in young piglets challenged with ETEC K88 (P < 0.05). Furthermore, the piglets of the LP + ETEC K88 group had lower protein levels of IL-8, secretory immunoglobulin A, pBD-2, and MUC4 in the jejunal mucosa than those challenged with ETEC K88 (P < 0.05). Besides, LP supplementation reduced the percentage of gamma/delta T cells receptor (γδTCR) and CD172a⁺ (SWC3⁺) cells in MLN and the percentage of γδTCR cells in the spleen of young piglets after the ETEC K88 challenge. Supplementation with LP in liquid diets prevented the upregulated protein abundance of toll-like receptor (TLR) 4, phosphorylation-p38, and phosphorylation-extracellular signal-regulated protein kinases in the jejunal mucosa induced by ETEC K88 (P < 0.05). In conclusion, LP supplementation in liquid diet possesses anti-inflammatory activity and modulates the intestinal innate immunity during the early life of young piglets challenged with ETEC K88, which might be attributed to the suppression of TLR4-mediated mitogen-activated protein kinase signaling pathways. Early supplementation with LP in liquid diets regulates the innate immune response, representing a promising immunoregulation strategy for maintaining intestinal health in weaned piglets.     

Experimental Enteric Colibacillosis in Piglets

Eleven of 20 piglets inoculated orally with Escherichia coli:0101:KU460(A):NM and one of 18 piglets inoculated orally with E. coli:08:K87, K88a, b:H19 developed enteric colibacillosis. Successful reproduction of the disease was associated with recovery of a dense growth in a nearly pure culture of the inoculated strain from the feces. Piglets which remained clinically normal had none, or very few, of the inoculated strain in their feces. Seventeen control piglets inoculated orally with the non-enteropathogenic E. coli:043:K —:H28 remained normal.     

Effect of dietary folate level on organ weight,digesta pH,short-chain fatty acid concentration,and intestinal microbiota of weaned piglets

Folate is increasingly thought to promote gastrointestinal health and regulate the diversity of gut microbiota to alleviate weaning stress in piglets. The present study was conducted to investigate the effects of folate on organ weight, digesta pH, short-chain fatty acids (SCFAs) concentration, and intestinal microbiota in weaned piglets. A total of 28 piglets (6.73 ± 0.62 kg) were allocated to four dietary treatments consisting of a control group, 3, 9, and 18 mg/kg of folate supplementation in a 14-d feeding trial. The results showed that piglets fed with 9 and 18 mg/kg of folate supplementation had greater (P < 0.05) average liver and spleen weight than the control group. Folate supplementation (9 and 18 mg/kg) can significantly increase (P < 0.05) the stomach pH and tend (P < 0.10) to decrease the cecum pH. Folate treatment (9 and 18 mg/kg) had a positive effect on the metabolism of SCFAs in piglets, in particular, compared with the control group, and the content of acetic acid (AA) and valeric acid was markedly increased (P < 0.05) in the cecum and colon, respectively. Moreover, isobutyric acid, butyric acid, and isovaleric acid were tended (P < 0.10) to increase in the colon. Cecum contents samples were used to determine bacterial community diversity by 16S rRNA gene amplicon sequencing. At the genus level, in the cecum, there was a higher (P < 0.05) relative abundance of Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus mucosae in the 9 mg/kg folate supplementation group. The functional pathways analysis predicted that folate may modify nutrient metabolism by changing the gut microbiota function of weaned piglets. Furthermore, the data showed that Lactobacillus was positively correlated with AA in the cecum. Overall, these findings suggested that folate treatment could increase the organ weight and the stomach pH of weaned piglets and had beneficial effects on gut health, which might be attributed to the alteration in intestinal microbiota induced by folate and the interaction of the intestinal microbiota with SCFAs.     

Efficacy of phage therapy in pigs: systematic review and meta-analysis

Limits on the use and efficacy of various antibiotics coupled with negative consumer perception of the practice have together spurred substantial research into compounds that could reduce the use antibiotics to control bacterial diseases in pigs. Bacteriophages are often among such potential compounds, and various groups have examined the efficacy of bacteriophages or bacteriophage products in limiting transmission or colonization of targeted bacteria. The study presented here provides a systematic review of such studies followed by a meta-analysis of aggregated data produced by each study. The data set was limited to inputs (n = 19; 576 total observations) from studies where: 1) live pigs were inoculated with a known quantity of challenge bacteria; 2) challenged animals were treated with a known quantity of phages; 3) concentrations of the challenge bacteria were measured in different tissues/fluids following phage treatment; and 4) SD (or SE to allow calculation of SD) was reported. Concentrations of challenge bacteria were significantly lower in phage-treated pigs versus challenged but untreated pigs (P < 0.0001; effect size = −1.06 1log₁₀ colony-forming units [CFU]/g). The effect size of phage treatment was significantly greater (P < 0.05) in samples collected 48 to 96 h following phage treatment versus those collected ≤ 24 h following phage treatment. Likewise, effect size of phage treatment was significantly greater in piglets versus market-weight pigs. Across observations, phage treatment effect sizes were greatest (P < 0.01) in fecal samples versus ileal or cecal samples. Taken together, these data indicate that phage treatment can significantly reduce the concentrations of targeted bacteria in pigs; scenarios exist, however, where phage treatment could predictably be more or less effective.     

Effect of maternal organic selenium supplementation during pregnancy on sow reproductive performance and long-term effect on their progeny

Selenium (Se) is an essential trace element for animals and exists in nature in both inorganic and organic forms. Although organic Se is more bioavailable than inorganic Se, there are inconsistent reports on the effect of organic Se on the reproductive performance of sows. This study was conducted to investigate the effect of maternal organic Se (2-hydroxy-4-methylselenobutanoic [HMSeBA]) supplementation on reproductive performance and antioxidant capacity of sows, and the long-term effect on the growth performance and antioxidant capacity of their offspring with or without lipopolysaccharide (LPS) challenge. The experimental design used in this study was a completely randomized design; 45 Landrace × Yorkshire sows were randomly allocated to receive one of the following three diets during gestation: control diet (Control, basal diet, n = 15), sodium selenite (Na₂SeO₃)-supplemented diet (Na₂SeO₃, basal diet + 0.3 mg Se/kg Na₂SeO₃, n = 15), and HMSeBA-supplemented diet (HMSeBA, basal diet + 0.3 mg Se/kg HMSeBA, n = 15). On day 21 of age, male offspring from each group were injected with LPS or saline (n = 6). As compared with the control group, maternal HMSeBA supplementation increased the number of total born piglets, while decreased birth weight (P < 0.05). In the first week of lactation, maternal HMSeBA supplementation increased litter weight gain compared with the Na₂SeO₃ group (P < 0.05) and increased the average daily gain of piglets compared with the control group and Na₂SeO₃ group (P < 0.05). Meanwhile, maternal HMSeBA supplementation decreased piglet birth interval as compared with the control group and Na₂SeO₃ group (P < 0.05). Besides, plasma glutathione peroxidase (GSH-Px) activity was higher in the HMSeBA group on farrowing 0 min and 90 min, while malondialdehyde (MDA) concentration was lower on farrowing 0, 90, and 135 min than those in the control group (P < 0.05). In addition, maternal HMSeBA supplementation increased the concentration of selenoprotein P (SELENOP) in colostrum compared with the control group (P < 0.05). Further study revealed that the LPS-challenged HMSeBA group had higher GSH-Px and total antioxidant capacity and lower MDA in weaning piglets compared with the LPS-challenged control group (P < 0.05). Taken together, maternal HMSeBA supplementation increased the number of total born piglets, shortened the duration of farrowing, improved the antioxidant capacities of sows and their offspring, and improved the growth performance of suckling pigs at the first week of lactation. Thus, HMSeBA supplementation during gestation has the potentiality to produce more kilogram of meat.     

Effect of trehalose supplementation in milk replacer on the incidence of diarrhea and fecal microbiota in preweaned calves

Trehalose, a nonreducing disaccharide consisting of d-glucose with α,α-1,1 linkage, was evaluated as a functional material to improve the gut environment in preweaned calves. In experiment 1, 173 calves were divided into two groups; the trehalose group was fed trehalose at 30 g/animal/d with milk replacer during the suckling period, and the control group was fed nonsupplemented milk replacer. Medication frequency was lower in the trehalose group (P < 0.05). In experiment 2, calves (n = 20) were divided into two groups (control group [n = 10] and trehalose group [n = 10]) based on their body weight and reared under the same feeding regimens as in experiment 1. Fresh feces were collected from individual animals at the beginning of the trial (average age 11 d), 3 wk after trehalose feeding (experimental day 22), and 1 d before weaning, and the fecal score was recorded daily. Fecal samples were analyzed for fermentation parameters and microbiota. The fecal score was significantly lower in the trehalose group than in the control group in the early stage (at an age of 14 to 18 d; P < 0.05) of the suckling period. Calves fed trehalose tended to have a higher proportion of fecal butyrate on day 22 than calves in the control group (P = 0.08). Population sizes of Clostridium spp. were significantly lower (P = 0.036), whereas those of Dialister spp. and Eubacterium spp. tended to be higher in the feces of calves in the trehalose group on day 22 (P = 0.060 and P = 0.083). These observations indicate that trehalose feeding modulated the gut environment and partially contributed to the reduction in medication frequency observed in experiment 1.     

Full-fat field cricket (Gryllus bimaculatus) as a substitute for fish meal and soybean meal for weaning piglets: effects on growth performance,intestinal health,and redox status

Full-fat field cricket meal (FCP) is an alternative protein ingredient in livestock production; however, the effects of replacing conventional protein sources with FCP in nursery diets have not been determined. In this study, the effects of the partial replacement of either fish meal or soybean meal with FCP on weaning pigs were evaluated, including the analyses of growth performance, nutrient utilization, intestinal morphology,
immunity, oxidative stress, and fecal microbial counts. A total of 100 crossbred weaning pigs [(Landrace × Large White) × Duroc] were allotted to one of the following five treatments with five replicates (four pigs/pen) and fed for 28 d postweaning. Treatments were 1) a corn-soybean meal (SBM)-based diet with 5% fish meal (Positive control; PC), 2) a corn-SBM-based diet without fish meal (Negative control; NC), 3) field crickets replacing fishmeal on a total Lys basis (FCP1), 4) field crickets replacing fishmeal on a kg/kg basis (FCP2), and 5) field crickets replacing fish meal and soybean meal (FCP3). The piglets on FCP1 had a higher body weight on days 14 and 28, and an increased average daily gain over the experimental period than NC (P < 0.05); FCP2 and FCP3 were similar to the FCP1 treatment. The incidence of diarrhea was lower under an FCP-supplemented diet than under the NC diet throughout the study (P < 0.05). Pigs fed FCP1 and FCP2 had a higher digestibility of crude
protein (P = 0.041), and all FCP groups increased crude fat digestibility (P = 0.024). FCP1 and FCP2 also increased jejunal villus height
(P = 0.009), whereas the increase in jejunal villus-to-crypt ratios (P = 0.019) was greater in pigs fed the FCP2 diet than those fed the NC diet. Furthermore, FCP2 supplementation increased serum immunoglobulin A levels on days 14 and 28, including reduced serum interleukin-6 and tumor necrosis factor alpha levels (P < 0.05). Pigs fed an FCP2 diet had reduced malondialdehyde levels than those fed a PC diet, while pigs fed an FCP2 diet had higher superoxide dismutase and glutathione peroxidase levels, and more fecal Lactobacillus spp. than those fed an NC diet (P < 0.05). These results support the use of FCP as an alternative protein ingredient with beneficial effects on growth performance, intestinal morphology, antioxidant capacity, and intestinal microbiota. In particular, FCP can be used as a partial substitute for fish meal and soybean meal without detrimental effects on weaning pigs.     

Preliminary molecular analysis of Clostridium difficile isolates from healthy horses in northern Italy

Clostridium difficile, associated with a wide spectrum of diseases in humans, as well as in several animal species, is an important cause of colitis in adult horses and foals. The aim of this study was to investigate by toxin gene profile and PCR-ribotyping the molecular characteristics of 14 C. difficile strains isolated from 42 faeces of healthy horses. Both toxin genes, tcdA and tcdB, were present in only 1 isolate (7.1%). Six isolates (42.9%) demonstrated tcdA−/tcdB+ genotype, and seven isolates (50.0%) were tcdA−/tcdB−. All strains were binary toxin genes negative (cdtA−/cdtB−). The PCR-positive strains, except for the tcdA+/tcdB+ isolate, tested negative for, in vitro, A and/or B toxins production by EIA. Eleven distinct ribotypes were observed.In conclusion, C. difficile can be present in the normal intestinal flora of healthy adult horses, in addition to foals. These animals could therefore play an important role as potential reservoirs of toxigenic strains.     

Rapamycin administration during an acute heat stress challenge in growing pigs

Study objectives were to determine the effects of rapamycin (Rapa) on biomarkers of metabolism and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n = 32; 63.5 ± 7.2 kg body weight [BW]) were blocked by initial BW and randomly assigned to 1 of 4 environmental-therapeutic treatments: 1) thermoneutral (TN) control (n = 8; TNCon), 2) TN and Rapa (n = 8; TNRapa), 3) HS control (n = 8; HSCon), or 4) HS and Rapa (n = 8; HSRapa). Following 6 d of acclimation to individual pens, pigs were enrolled in two experimental periods (P). During P1 (10 d), pigs were fed ad libitum and housed in TN conditions (21.3 ± 0.2°C). During P2 (24 h), HSCon and HSRapa pigs were exposed to constant HS (35.5 ± 0.4°C), while TNCon and TNRapa pigs remained in TN conditions. Rapamycin (0.15 mg/kg BW) was orally administered twice daily (0700 and 1800 hours) during both P1 and P2. HS increased rectal temperature and respiration rate compared to TN treatments (1.3°C and 87 breaths/min, respectively; P < 0.01). Feed intake (FI) markedly decreased in HS relative to TN treatments (64%; P < 0.01). Additionally, pigs exposed to HS lost BW (4 kg; P < 0.01), while TN pigs gained BW (0.7 kg; P < 0.01). Despite marked changes in phenotypic parameters caused by HS, circulating glucose and blood urea nitrogen did not differ among treatments (P > 0.10). However, the insulin:FI increased in HS relative to TN treatments (P = 0.04). Plasma nonesterified fatty acids (NEFA) increased in HS relative to TN treatments; although this difference was driven by increased NEFA in HSCon compared to TN and HSRapa pigs (P < 0.01). Overall, circulating white blood cells, lymphocytes, and monocytes decreased in HS compared to TN pigs (19%, 23%, and 33%, respectively; P ≤ 0.05). However, circulating neutrophils were similar across treatments (P > 0.31). The neutrophil-to-lymphocyte ratio (NLR) was increased in HS relative to TN pigs (P = 0.02); however, a tendency for reduced NLR was observed in HSRapa compared to HSCon pigs (21%; P = 0.06). Plasma C-reactive protein tended to differ across treatments (P = 0.06) and was increased in HSRapa relative to HSCon pigs (46%; P = 0.03). Circulating haptoglobin was similar between groups. In summary, pigs exposed to HS had altered phenotypic, metabolic, and leukocyte responses; however, Rapa administration had limited impact on outcomes measured herein.     

Efficacy of a novel virulence gene-deleted Salmonella Typhimurium vaccine for protection against Salmonella infections in growing piglets

We have previously developed a novel attenuated Salmonella Typhimurium (S. Typhimurium) ΔcpxR Δlon vaccine. This study was carried out to examine whether this vaccine could effectively protect growing piglets against Salmonella infection. Attenuated S. Typhimurium secreting the B subunit of Escherichia coli heat-labile enterotoxin was also used as a mucosal adjuvant. Pregnant sows in groups A and B were primed and boosted with the vaccine and mucosal adjuvant, whereas sows in groups C, D and E received PBS. Piglets in groups A and C were intramuscularly primed with formalin-inactivated vaccine and orally boosted with live vaccine, while piglets in groups B, D and E received PBS. Piglets in groups A, B, C, and D were challenged with a wild type virulent S. Typhimurium at the 11th weeks of age. Colostrum sIgA and IgG titers in vaccinated groups A and B sows were approximately 50 and 40 times higher than those of non-vaccinated groups C, D and E sows (P < 0.001). Serum IgG titers of group A piglets were also significantly higher than those of groups D and E piglets during the study (P < 0.001). Furthermore, no clinical signs were observed in group A piglets during the entire experimental period after the challenge, while diarrhea was observed in many of the piglets in groups B, C, and D. No Salmonella was isolated from fecal samples of the groups A and C piglets on day 14 after challenge, whereas the challenge strain was isolated from several piglets in groups B and D. These results indicate that vaccination of the piglets with the vaccine and mucosal adjuvant in addition to vaccination of their sows induced effective protection against Salmonella infections in the growing piglets.