Clostridium perfringens alpha-toxin and NetB toxin antibodies and their possible role in protection against necrotic enteritis and gangrenous dermatitis in broiler chickens

Necrotic enteritis (NE) and gangrenous dermatitis (GD) are important infectious diseases of poultry. Although NE and GD share a common pathogen, Clostridium perfringens, they differ in other important aspects such as clinical signs, pathologic symptoms, and age of onset. The primary virulence factors of C perfringens are its four major toxins (alpha, beta, epsilon, iota) and the newly described NE B-like (NetB) toxin. While neutralizing antibodies against some C perfingens toxins are associated with protection against infection in mammals, the serologic responses of NE- and GD-afflicted birds to these toxins have not been evaluated. Therefore, we measured serum antibody levels to C perfringens alpha-toxin and NetB toxin in commercial birds from field outbreaks of NE and GD using recombinant toxin-based enzyme-linked immunosorbent assay (ELISA). Initially, we used this ELISA system to detect antibody titers against C perfringens alpha-toxin and NetB toxin that were increased in birds experimentally coinfected with Eimeria maxima and C perfringens compared with uninfected controls. Next, we applied this ELISA to field serum samples from flock-mated birds with or without clinical signs of NE or GD. The results showed that the levels of antibodies against both toxins were significantly higher in apparently healthy chickens compared to birds with clinical signs of NE or GD, suggesting that these antitoxin antibodies may play a role in protection against NE and GD.     

Evaluation of novel adjuvant Eimeria profilin complex on intestinal host immune responses against live E. acervulina challenge infection

The effects against avian coccidiosis of two novel adjuvants, Quil A/cholesterol/dimethyl dioctadecyl ammonium bromide/Carbopol (QCDC) and QCDC/Bay R1005 (R)/cytosine-phosphate-guanosine (CpG) oligodeoxynucleotides (CpG ODN [T]) (QCDCRT) emulsified with profilin, a conserved Eimeria recombinant protein, were determined in broiler chickens. Chickens were subcutaneously immunized with isotonic saline (control group), profilin (P), profilin emulsified with QCDC (P-Q), or profilin with QCDCRT (P-QR) at 2 and 9 days post-hatch and orally challenged with 1.0 x 10(4) sporulated oocysts of Eimeria acervulina (EA) at 7 days postimmunization. All profilin-immunized groups showed increased body weight gain when compared to the control group, and the P-QR group had significantly higher body weight gain than did those of the P and P-Q groups following EA challenge infection. All groups immunized with profilin showed significantly decreased intestinal lesions compared with the control group, with the P-QR group showing the lowest intestinal lesions among the profilin-treated groups. Finally, the P-QR group showed greater CD4+/CD8+ and TCR1+/TCR2+ splenocytes and higher antiprofilin serum antibody titers compared with the P and P-Q (or both) groups following EA challenge infection. These results further suggest that vaccination of chickens with profilin, in combination with the QCDCRT adjuvant, may provide a novel control strategy against EA infection in commercial flocks.     

Expression of estrogen receptor alpha and beta in the uterus and vagina of immature rats treated with 17-ethinyl estradiol

The action of estrogen on target organs has been actively studied with the discovery of estrogen receptor (ER) beta. This study was carried out to examine the expression of ERalpha and ERbeta in the uterus and the vagina of immature Sprague-Dawley rats treated with 17-ethinyl estradiol (EE). Twenty days old rats were subcutaneously treated with EE at the doses of 0 (vehicle control), 0.03, 0.3, 1.0, 3.0, and 10.0 microg/kg/day for three consecutive days. The treatment of EE at the doses of 0.3, 1.0, 3.0 and 10.0 microg/kg/day significantly increased the weights of the uterus and vagina of rats (p<0.01) and retained fluid in the uterus of rats. At the high doses of 3.0 and 10.0 microg/kg/day, the treatment of EE caused an increase in the uterine height, hypertrophy, and a decrease in the expression of ERalpha and ERbeta in the uterine luminal and glandular epithelium. The treatment of EE at the doses of 3.0 and 10.0 microg/kg/day also caused cornification and a decrease in the expression of ERalpha and ERbeta in the vaginal epithelium. These results suggest that the EE treatment decrease the expression of ERalpha and ERbeta in the uterus and vagina of immature rats and that may be associated with the morphological changes such as increase in the uterine height, hypertrophy of the uterine epithelium, and cornification of the vagina.     

Paecilomycosis in dogs and horses and a review of the literature

We reviewed 14 cases of paecilomycosis in a tertiary care veterinary hospital and all reports of the disease in the veterinary literature. Paecilomycosis is a rare disease primarily of dogs, horses, reptiles, and humans. Clinical manifestations in veterinary patients vary but include disseminated disease and diskospondylitis, particularly in dogs: pneumonia in dogs, horses, and reptiles; keratitis in horses; and miscellaneous local infections. It is important to have an appropriate index of suspicion because the diagnosis can be difficult, particularly in localized disease where it is difficult to determine whether a positive culture represents an etiology or a contamination with an environmental saprophyte. Spinal radiographs, transtracheal washes, histopathology, and fungal culture have proven to be valuable diagnostic tools. The prognosis for paecilomycosis is poor, although some treatment success has been reported, and success rates could improve if additional information were available regarding fungal species occurring in veterinary patients and drugs to which these fungi are susceptible.     

Effects of dietary administration of Macsumsuk® on growth and stress to low salinity and low dissolved oxygen in whiteleg shrimp,Litopenaeus vannamei (Boone, 1931) juveniles

An 8‐week study was conducted to explore the results of Macsumsuk^® as a feed additive on the stress tolerance and growth of Litopenaeus vannamei in 15 culture tanks of 36 L each. Three hundred shrimp averaging 0.1 ± 0.01 g were fed with five isonitrogenous (48.38 ± 0.38% CP) diets (in triplicate groups) containing kaolinite (Macsumsuk^®) at 0%, 0.3%, 0.6%, 1.2% and 2.4%, namely Mk₀, Mk_0.3, Mk_0.6, Mk_1.2 and Mk_2.4. Specific growth rate (SGR) and weight gain (WG) of shrimp fed diets Mk_1.2 and Mk_2.4 were significantly better than those of shrimp fed diet Mk₀ (p < .05). However, SGR and WG of shrimp fed diets Mk_0.6, Mk_1.2 and Mk_2.4 were not significantly different. Protein efficiency ratio (PER) and feed efficiency (FE) of shrimp fed diets Mk_1.2 and Mk_2.4 were significantly better than those of shrimp fed diets Mk₀, Mk₀.₃ and Mk_0.6. Furthermore, the survival of shrimp fed diet Mk_2.4 was significantly lower than that of shrimp fed diet Mk_0.6 (p < .05). Cumulative mortality of shrimp fed diet Mk_1.2 was significantly lower than that of shrimp fed diet Mk₀ at 1–1.5 hr post‐stress to low dissolved oxygen (from 6.1 mg/L to 2.9 mg/L) and 4–5 hr post‐stress to low salinity (from 32‰ to 1‰) (p < .05). The optimum dietary Macsumsuk^® level for juvenile L. vannamei was determined as 1.97% by the polynomial regression analysis of weight gain.     

Detection of Salmonella dublin mammary gland infection in carrier cows, using an enzyme-linked immunosorbent assay for antibody in milk or serum

An ELISA has been developed for measurement of milk and serum IgG concentrations directed against Salmonella dublin. Four groups of cows were studied: group A--7 experimentally challenge-exposed cows (infected, recovered group); group B--6 normal uninfected randomly selected control cows; group C--7 naturally occurring S dublin carrier cows; and group D--6 normal uninfected S dublin negative cows from the same herd as group C. Group-A cows were inoculated orally, or inoculated orally and then IV, but none became a S dublin carrier. As expected, all 7 group-A cows responded with a marked increase in ELISA titer after oral exposure to virulent S dublin, starting with a mean serum titer of 17.7% and reaching a peak mean serum titer of 79.3% approximately 76 days after initial exposure. As determined by necropsy and organ culturing of the remaining cows, none of the group-A cows became carriers. The mean serum ELISA titer for group-B uninfected control cows was 14.1% (SD +/- 12.8%). The mean milk ELISA titer was -1.0% (SD +/- 5.5%). Colostrum and then milk gave false-positive results for up to 2 weeks after onset of lactation. Group-B cows were culture negative for S dublin in feces and milk during lactation, and when tissues were cultured after euthanasia. Milk and serum samples for ELISA, and milk and fecal samples for culturing were taken from all group-A and -B cows twice a week for 6 months. Statistical correlation (P less than 0.05) was found between serum and milk ELISA titers.(ABSTRACT TRUNCATED AT 250 WORDS)     

苹果矮化砧崂山柰子的特性和利用的研究

对苹果矮化砧崂山柰子特性的研究表明,砧木的根皮率高;压条繁殖较易生根;用作中间砧嫁接的1年生果苗及成龄树的根系发达,且分布广而深;其中间砧嫁接的苹果幼树,矿质元素的吸收水平较高。选出了嫁接亲和良好、树体半矮化,早果、丰产性好的崂山柰子优系N29、N32。砧穗组合的研究表明,崂山柰子自根砧嫁接的红星、倭锦等品种大树,表现矮化、早果、稳产;作中间砧,与印度、乔纳金和红富士组合表现较好。     

In vitro susceptibilities of canine urinary bacteria to selected antimicrobial agents

Antimicrobial susceptibility tests were conducted on bacteria that were isolated from urine specimens collected by antepubic cystocentesis from dogs with urinary tract infections. Antimicrobics to which greater than or equal to 90% of these urinary bacteria were susceptible in vitro included trimethoprim-sulfamethoxazole (TMP-SMZ), nitrofurantoin, cephalexin, nalidixic acid, and gentamicin for isolates of Escherichia coli; ampicillin, TMP-SMZ, cephalexin, nalidixic acid, and gentamicin for isolates of Proteus mirabilis; ampicillin chloramphenicol, TMP-SMZ, nitrofurantoin, cephalexin, kanamycin, and gentamicin for isolates of coagulase-positive staphylococci; cephalexin, nalidixic acid, and gentamicin for isolates of Klebsiella pneumoniae; ampicillin, TMP-SMZ, and gentamicin for isolates of Streptococcus faecalis, Str faecium, and Str zymogenes; ampicillin, chloramphenicol, TMP-SMZ, and gentamicin for isolates of Str viridans; and ampicillin, chloramphenicol, TMP-SMZ, nitrofurantoin, cephalexin, kanamycin, and gentamicin for isolates of Str canis. No antimicrobial agent tested was effective in vitro at the 90% level for isolates of Pseudomonas aeruginosa, but gentamicin was closest, at 89%.     

The effect of antibody to caseous lymphadenitis in ewes on the efficacy of vaccination in lambs

The effect of maternal antibody to the toxin of Corynebacterium pseudotuberculosis, produced by caseous lymphadenitis (CLA) in ewes or by vaccinating ewes before lambing, on the efficacy of vaccination against CLA in their lambs was examined. Lambs were allocated to treatments according to either the vaccination history of their dam or level of CLA toxin antibody of their dam. They were vaccinated twice using 2 different inoculation regimes and then artificially infected with CLA organisms. The number of lambs with CLA lesions was assessed at slaughter. In one experiment high levels of CLA toxin antibody activity in ewes were associated with decreased efficacy of CLA vaccination in their lambs, when lambs were vaccinated at 2 and 8 weeks or 8 and 14 weeks of age. In a second experiment the efficacy of lamb vaccination at 8 and 12 weeks, but not at 14 and 18 weeks of age, was decreased. In sheep flocks with a high prevalence of CLA, vaccinating lambs against CLA at less than 10 weeks of age may not produce optimum protection against CLA in lambs. There was no difference in infection rate between lambs from vaccinated and unvaccinated ewes. However, vaccination of lambs at 2 and 8 wks was less effective that vaccination at 8 and 14 weeks, probably due to reduced immunocompetence in young lambs. In sheep flocks where significant numbers of lambs receive their primary vaccination at less than 3 weeks of age vaccination programmes to control CLA in lambs may be less effective.