Intestinal changes associated with rotavirus and enterotoxigenic Escherichia coli infection in calves

Newborn calves inoculated with rotavirus, enterotoxigenic Escherichia coli (ETEC) serotype 020:K' x 106':K99:HNM, either alone or in combination, became depressed, anorectic, diarrhoeic and dehydrated. ETEC did not adhere to the intestine although there was extensive proliferation in the lumen. Only slight mucosal changes were induced by ETEC and the activity of membrane bound lactase remained normal. More severe mucosal damage and a decrease in lactase activity were found in newborn calves inoculated with either rotavirus or rotavirus and ETEC in combination. The most severe clinical illness was found in calves inoculated with both rotavirus and ETEC. Calves inoculated at 1 week of age with either rotavirus or ETEC remained clinically normal. Rotavirus infection produced slight mucosal changes and a reduction of lactase activity. In contrast, colostrum-fed or suckling calves up to 2 weeks old inoculated with both rotavirus and ETEC became clinically affected, showed severe mucosal damage and decreased lactase activity. There was no bacterial adhesion to the intestinal mucosa as observed by immunofluorescent labelling and light microscopy.     

Prevalence of enteric pathogens in the feces of healthy beef calves

Fecal specimens from 136 healthy beef calves (1 day to 12 weeks of age) were examined for the presence of infectious agents known to cause enteric disease in calves. The calves were selected from 22 herds in which all calves were free of clinically apparent enteric disease. Salmonella sp, enterotoxigenic Escherichia coli, Cryptosporidium, and coronavirus were not detected in any of the calves. Three calves were infected with rotavirus and 1 calf was infected with Yersinia enterocolitica. Campylobacter-like bacteria were isolated from 50 of 130 calves, with 36 of the calves positive for C jejuni. Seemingly, clinically normal calves may be infected more often with enterotoxigenic E coli, Cryptosporidium, coronavirus, or rotavirus in herds in which some calves have enteric disease than in herds free of major enteric disease. Campylobacter jejuni was well adapted to the bovine host and was of similar prevalence in diarrheal and nondiarrheal calves. The K99 positive, nonenterotoxigenic E coli was isolated from the feces of 16 healthy calves. Information in addition to the presence of K99 antigen is useful when diagnosing enterotoxic colibacillosis in calves.     

Ileal Peyer's patches in experimental infections of calves with rotaviruses and enterotoxigenic Escherichia coli: a light and electron microscopic and enzyme histochemical study

The effect of rotaviruses and enterotoxigenic Escherichia coli administered in various sequences to cesarean-derived, colostrum-deprived calves was studied using light and electron microscopy. The structure of the lymphoid tissue in the ileum, the number of mitoses in the crypts, number of intraepithelial lymphocytes, and enzyme histochemistry (alkaline phosphatase, acid phosphatase, succinic dehydrogenase, beta-galactosidase, and leucinaminopeptidase) of the ileal dome epithelium were evaluated. The area of lymphoid follicles in Peyer's patches of the ileum was investigated morphometrically. Monoinfections with either rotavirus or enterotoxigenic E. coli induced a significant increase in lymphoid follicle area, but did not affect dome epithelial cells. Dual infections did not consistently affect the follicle area, but the number of intraepithelial lymphocytes and the mitotic indices exceeded those of comparable monoinfections. Changes in activity of enzymes in the ileal dome epithelial area were minor.     

Effect of experimentally-induced villus atrophy on adhesion of K88ac-positive Escherichia coli in just-weaned piglets

Three- to four-week-old, just-weaned piglets were infected with transmissible gastroenteritis (TGE) virus and the next day with K88ac+ enterotoxigenic Escherichia coli (ETEC). Histological examination of caudal jejunum and ileum of piglets killed 2-3 days after virus challenge (1-2 days after ETEC infection) revealed severe villus atrophy especially in the jejunum compared with controls (P less than 0.05). Four-5 days after TGE virus infection villus length increased and after 7 days it was near normal. Villi scraped from jejunal and ileal mucosa of the piglets were incubated in vitro with K88ac+ E. coli and the number of bacteria adhering to 250 micron villus brush border was counted. Attachment of bacteria to villi of piglets killed 2-3 days after TGE virus infection was significantly decreased in comparison with adhesion to villi of non-infected piglets or of piglets killed 7 days after the virus infection. Correlation between in vitro adhesion and villus height was 0.6649 (P less than 0.001). The results suggest that the experimentally-induced villus atrophy was attended with a temporarily diminished susceptibility of villus enterocytes to adhesion of K88ac+ E. coli.     

Pathological changes in the small intestine of neonatal calves naturally infected with reo-like virus (rotavirus).

Nine calves, of which six had been challenged with an enteropathogenic strain of Escherichia coli, were found to be naturally infected with rotavirus. Rotavirus was recovered from the faeces of six calves and rotavirus antigen was detected in the intestinal mucosa of all calves. Stunting and fusion of villi were seen principally in the proximal and middle small intestine, where rotavirus antigen was detected by immunofluorescence. Typical lesions of enteric colibacillosis were found in the distal ileum of the challenged calves, associated with adhesion of the challenge strain of E coli to the mucosa. All samples were removed from the intestine under general anaesthesia and denudation of villi was not observed. However, following exsanguination and resampling at the same site in the small intestine of one calf, denudation was a constant feature.     

Effect of combined rotavirus and Escherichia coli in neonatal gnotobiotic calves

Gnotobiotic calves (24 hours old) were monoinfected with calf rotavirus (CRV) strain NCDV, an enterotoxigenic Escherichia coli (ETEC) strain B44 (K99+), or a nonenterotoxigenic E coli (NETEC) strain 123 (K99-). Calves also were dually infected with CRV and either ETEC or NETEC. Eighteen calves equally allotted between 6 treatment groups were used in these studies: Noninfected controls--group A; CRV--group B; ETEC--group C; NETEC--group D; CRV + ETEC--group E; and CRV + NETEC--group F. Severe diarrhea and villous atrophy were observed in calves of treatment groups B, C, E, and F. Mortality was present only in treatment groups C and E as result of ETEC infection. There were no significant differences in the clinical responses or enteric lesions between treatments B and F, although a significant increase in the concentrations of NETEC was demonstrated in calves dually infected with CRV + NETEC (group F) as compared with calves monoinfected with NETEC (group D). Calves inoculated with ETEC (group C) had severe villous atrophy, neutrophilic infiltration of intestinal lumen, and moderate enterocyte necrosis. Calves dually inoculated with CRV + ETEC (group E) had the most extensive and severe lesions, similar to those in group C, plus a pronounced necrotic fibrino-hemorrhagic enteritis. Infection of enterocytes by CRV did not affect in any way the adherence of ETEC to the intestinal mucosa. Dual viral and bacterial infections of the same enterocytes were evident.     

FACTORS CONTRIBUTING TO POSTWEANING DIARRHOEA IN A LARGE INTENSIVE PIGGERY

Some aspects of postweaning diarrhoea (PWD) in a piggery during the first week after early weaning were investigated. A haemolytic enterotoxigenic strain of E. coli (0149: K88: H10) was regularly recovered from piglets with PWD while rotavirus was demonstrated on a number of occasions. Prior to weaning piglets were either free of, or shed very few, haemolytic E. coli in their faeces. However, all piglets were excreting haemolytic E. coli between 5 and 7 days after weaning. The role of rotavirus in PWD was unclear. There appeared to be a direct relationship between serum antibodies to rotavirus in the sow at farrowing and those of the piglets soon after birth. The decline of maternal neutralising antibody to rotavirus coincided with the immediate postweaning period (3 to 5 weeks after birth). This was followed by an increase in antibody levels, 5 to 8 weeks after birth. There was no significant difference in the growth rate between affected and unaffected piglets over a period of 120 days. Medication of water during the first week after weaning had no significant effect on the incidence of PWD in the herd. A change in both the weaner diet and the weaning procedure reduced piglet mortality associated with PWD by more than half.     

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.     

Aetiology of diarrhoea in young calves

Faeces samples were collected from 302 untreated calves on the day of onset of diarrhoea and from 49 healthy calves at 32 farms experiencing outbreaks of diarrhoea. At least four diarrhoeic calves were sampled on each farm, and samples were examined for rotavirus, coronavirus, cryptosporidium, enterotoxigenic Escherichia coli and Salmonella species. Although all these enteropathogens were excreted more frequently by the diarrhoeic than by the healthy calves, the difference was significant overall only for rotavirus. Rotavirus was excreted by 18 per cent of healthy calves, coronavirus by 4 per cent, cryptosporidium by 14 per cent, and no enterotoxigenic E coli or Salmonella species were detected. The most common enteropathogen in diarrhoeic calves was rotavirus, which was excreted by more than half the diarrhoeic calves on 18 farms. Coronavirus was excreted at a similar high prevalence on one farm, cryptosporidium on five farms and enterotoxigenic E coli on three farms. Concurrent infection with two or more microorganisms occurred in 15 per cent of diarrhoeic calves. There was no difference in the isolation rate of campylobacters between diarrhoeic and healthy calves.     

Attaching and effacing and enterotoxigenic Escherichia coli associated with enteric colibacillosis in the dog.

The objective of this study was to describe observations from cases of enteric colibacillosis in the dog. Thirteen cases of canine enteric colibacillosis were diagnosed from routine necropsy submissions to our diagnostic laboratory from 1980 to 1992. In all cases there was a clinical history of gastrointestinal disease associated with histological and bacteriological evidence of either attaching and effacing Escherichia coli (AEEC) or enterotoxigenic Escherichia coli (ETEC) infection. Of these 13 cases of enteric colibacillosis, 12 were associated with AEEC and one with ETEC. Eight of the 12 AEEC isolates were available for study. They were of various serogroups, non-hemolytic, and negative for the genes coding for fimbrial antigens F4, F5, F6, F41 and F165; enterotoxins STap, STb and LT; and verotoxins VT1 and VT2. These eight isolates were EAE-positive (E. coli attaching and effacing) by colony hybridization; six of these were also EAF-positive (EPEC adherence factor), and six were BFP-positive (bundle-forming pilus). The ETEC isolate was negative for the EAE, EAF and BFP determinants and for the fimbrial antigens tested but was positive for the STap and STb genes. Most of the dogs affected with enteric colibacillosis originated from kennels and pet shops and were aged between 1.5 and 3 months. Coinfection with other enteric pathogens was identified in eight of these 13 cases. This study showed that Escherichia coli should be considered of causal significance when investigating diarrheal disease in dogs, particularly in puppies.     

大麦糠麸饲粮中添加复合酶制剂对畜禽消化性能的影响

研究了猪鸡不同类型饲粮中添加复合酶制剂对其消化性能的影响。结果表明 ,加酶后使畜禽肠道食糜粘度、粪中大肠杆菌数和腹泻频率都显著下降 ,复合酶制剂还提高了猪空肠粘膜绒毛高度和肉鸡十二指肠粘膜绒毛宽度 ,猪鸡饲粮养分的表观消化率也得到显著改善     

ENTERITIS IN FOALS INDUCED BY ROTAVIRUS AND ENTEROTOXIGENIC ESCHERICHIA COLI

Colostrum-deprived, colostrum-fed or suckling foals were orally inoculated with foal rotavirus and enterotoxigenic Escherichia coli derived from a calf. Neither agent given alone caused diarrhoea in foals aged 1 or 2 days, although with rotavirus, 2 of the 3 inoculated foals became depressed 3 days after inoculation and all 3 were excreting rotavirus in the faeces. Inoculation of both agents induced diarrhoea in colostrum-deprived, colostrum-fed or suckling foals aged up to 16 days. There was an apparent age-related resistance to diarrhoea which developed between 2 and 3 weeks of age. It was related to failure of rotavirus to establish apparent infection in older foals and was independent of preinoculation maternal antibody.     

Chicken egg yolk antibodies(IgY) as non-antibiotic production enhancers for use in swine production:a review

In recent years,the use of in-feed antibiotics for growth and disease prevention in livestock production has been under severe scrutiny.The use and misuse of in-feed antibiotics has led to problems with drug residues in animal products and increased bacterial resistance.Chicken egg yolk antibodies(IgY) have attracted considerable attention as an alternative to antibiotics to maintain swine health and performance.Oral administration of IgY possesses many advantages over mammalian IgG such as cost-effectiveness,convenience and high yield.This review presents an overview of the potential to use IgY immunotherapy for the prevention and treatment of swine diarrhea diseases and speculates on the future of IgY technology.Included are a review of the potential applications of IgY in the control of enteric infections of either bacterial or viral origin such as enterotoxigenic Escherichia coli,Salmonella spp.,rotavirus,porcine transmissible gastroenteritis virus,and porcine epidemic diarrhea virus.Some potential obstacles to the adoption of IgY technology are also discussed.     

Attaching and effacing Escherichia coli infection as a cause of diarrhea in young calves

A form of enteric Escherichia coli infection was identified in 60 calves from 59 farming operations. The E coli responsible for these infections principally colonized the colon, inducing a distinctive lesion described as attaching and effacing. Hemorrhagic enterocolitis or blood in the feces was observed on 40% of the farms. Of affected calves, 86.6% were dairy calves (average age, 11.8 days). Forty-four calves were infected concurrently with other enteropathogens (cryptosporidia, rotavirus, coronavirus, enterotoxigenic E coli, bovine viral diarrhea virus, coccidia). Verotoxin-producing E coli was recovered from 31 calves; 8 were serotype O111:NM isolates, 3 were serotype O5:NM, and 1 was serotype O26:NM.     

A new polyvalent vaccine against enteral infections in newborn calves

The most frequent microbial causative agents of massive diarrheas in new-born calves kept on large cattle farms in the CSSR are rotaviruses, coronaviruses and enterotoxigenic strains of E. coli, manifesting themselves as complicated virus-bacterial infections. An inactivated polyvalent adjuvant vaccine has been developed for the prevention and specific prophylaxis of these enteral infections; the vaccine contains bovine rotavirus, bovine coronavirus and three enterotoxigenic serotypes of E. coli with protective antigen K 99. The rotavirus and coronavirus are propagated on the stable cellular line MDBK and inactivated with 0.2% formalin, the Escherichia strains are submersed in the MINCA culture medium during their cultivation and inactivated with 0.5% formalin. The vaccine was prepared as a blend of the same amounts of rotavirus and coronavirus and of such an amount of bacterin so that 1 ml of the vaccine will contain 10(9) bacteria. One part of oil adjuvant was added to five parts of the virus-bacterial blend and the blend was homogenized in the Ultraturax apparatus. The vaccine is to be used for immunization of pregnant cows and heifers; in these animals it induces the production of specific antibodies to all antigens contained in the vaccine. Its immunogenic effects were checked in 32 calves and 38 cows in the herds with the occurrence of diarrheas caused by both enteropathogenic viruses and enterotoxigenic escherichia. It was demonstrated that the inactivation did not influence in either of the viruses the process of inducing the production of specific antibodies, and the antibody response of the calves and heifers after application of 2 ml of complete inactivated vaccine was equally strong as after application of live vaccine containing only rotavirus and coronavirus. The level of the rotavirus antibodies increased on the average 30 times and 200 times, coronavirus antibodies twice and four times. The antibody response to coronavirus was negatively influenced by the relatively high levels of antibodies before vaccination. The antibody response to antigen K 99 was expressive in all cases.     

Evaluation of a combined rotavirus and enterotoxigenic Escherichia coli vaccine in cattle

A vaccine of rotavirus and K99 antigen from enterotoxigenic Escherichia coli was emulsified in oil adjuvant and administered intramuscularly to pregnant cows. Calves born to and reared on vaccinated dams were protected against experimental rotavirus infection at five days old when compared with calves from unvaccinated control cows. Field trials of the vaccine were carried out in 40 commercial herds, in which half the cows in each herd were selected at random for vaccination and half were left unvaccinated. In 31 herds (2641 cows) there was no significant diarrhoea problem (less than 10 per cent morbidity); these herds were excluded from further analysis. The nine remaining herds did experience a calf diarrhoea problem of greater than 10 per cent morbidity, but on four farms the disease was associated with cryptosporidiosis and on a fifth no enteropathogens were detected; these five farms (461 cows) were also excluded from further analysis. Of the remaining four herds, two beef suckler herds (105 cows) had concurrent rotavirus and cryptosporidial infections, and vaccination was associated with a decreased excretion of rotavirus but not with a decreased incidence of diarrhoea. In the other two dairy herds (68 cows) with prevaccination rotavirus problems, there was a significantly decreased incidence of diarrhoea in calves born to vaccinated cows. No natural field challenge of enterotoxigenic E coli was encountered on any of the trial farms.     

Effect of infection with bovine viral diarrhea virus alone,bovine rotavirus alone,or concurrent infection with both on enteric disease in gnotobiotic neonatal calves

OBJECTIVE: To compare experimentally induced concurrent infection with bovine viral diarrhea virus (BVDV) and bovine rotavirus (BRV) with infection of either virus alone in calves. ANIMALS: Seventeen 1-day-old gnotobiotic calves. PROCEDURE: Calves were allotted to 8 treatments as follows: group 1, mock-infected control calves (n = 2); group 2, inoculated with BVDV on day 1 (2); groups 3, 5, and 7, inoculated with BRV on days 1 (2), 4 (1), or 7 (2), respectively; and groups 4, 6, and 8, inoculated with BVDV on day 1 and with BRV on days 1 (2), 4 (2), or 7 (4), respectively. Concentrations of BVDV in serum and ileal tissues were measured, and BRV shedding in feces was determined. Histologic examination and immunohistochemical analysis were conducted to detect lesions and viral antigens. RESULTS: Neonatal calves inoculated with BVDV alone or with BVDV on day 1 and BRV on day 7 developed villus atrophy and submucosal inflammation of the intestines. Concurrent BVDV and BRV infections acted synergistically in the intestinal tract, causing more severe enteric disease than infection with either virus alone. Severe lymphoid depletion was associated with BVDV infection in calves regardlesss of concurrent BRV infection. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with BVDV played direct and indirect roles in enteritis in neonatal calves, causing villus atrophy in the duodenum and submucosal inflammation of the intestines. Also, BVDV potentiated effects of BRV. Concurrent infection with BVDV and BRV resulted in more severe enteric disease in neonatal calves than infection with BRV or BVDV alone.     

Rotavirus and enterotoxigenic Escherichia coli infections of calves on a closed Finnish dairy farm

Rotavirus and enterotoxigenic Escherichia coli infections of calves were surveyed during 2 successive years on a closed Finnish dairy farm consisting of 90–105 milking cows. From a clinical standpoint, diarrhoea was of moderate to high severity during the first year, compared to the milder disease in the second year of the study. Diarrhoea or abnormal faeces were found only in calves less than 8 weeks old, with the peak occurring during the first 2 weeks of life.In the first year, rotavirus was detected throughout the calving season in diarrhoeic or abnormal faeces of calves aged 1 day to 7 weeks. In the second calving season, rotavirus was detected only during the 4 autumn months and in calves aged 11 days to 8 weeks. Rotavirus was detected in only 1 sample of normal faeces in both years. Electron microscopy revealed no enteropathogenic viruses other than rotaviruses. Enterotoxigenic K99 E. coli was found in about half of diarrhoeic or abnormal faeces in both years and throughout the calving seasons. K99 E. coli was also found in 5–10 % of normal faeces.In the second year of the study, 45 of 101 pregnant dams were vaccinated with 2 doses of E. coli antigen. The vaccination trial did not prevent or reduce altered faeces in calves whose dams had been vaccinated compared with calves whose dams had not been vaccinated in the same year. Comparing the 2 years, the earlier uptake of colostrum together with better cleaning and disinfection of the calf house, contributed to the later and rarer occurrence of rotavirus infection in the second year of the study. The earlier uptake of colostrum together with better cleaning and disinfection of the salf house, in the second year, could not prevent enterotoxigenic E. coli infections in calves but partly prevented and modified the disease.     

犊牛轮状病毒和大肠杆菌混合感染检测

黑龙江省某规模化奶牛场部分新生犊牛发生了严重腹泻且犊牛病死率较高。为了确诊,无菌采集病料,通过病毒检测、细菌分离、生化试验、细菌和病毒特异性基因PCR扩增、动物致病性试验及药敏试验等方法进行了病毒抗原和微生物检测。结果显示,病毒检测中牛轮状病毒（BRV）呈阳性,PCR扩增得到400 bp的特异性片段;从病料中分离到1株含K99和F41兼性菌毛抗原的高致病性产肠毒素大肠杆菌（ETEC）,该分离菌株对恩诺沙星、头孢唑啉、氯霉素敏感,对其他抗生素有一定的耐药性。流行情况调查结合病原学检查确诊该牛场新生犊牛严重腹泻是由BRV和大肠杆菌混合感染造成的,根据诊断结果进行了针对性地防制,取得了良好的防控效果。     

Antimicrobial alternatives for calf diarrhea: enteric responses to Escherichia coli, deferoxamine, or gallium in neonatal calves

Intestinal malabsorption or transferable resistance in enteric bacteria are potentially serious complications of routine oral administrations of antibiotics. On the basis of reports on antimicrobial effects of host iron sequestration and on synthetic iron chelators or competitors in vitro, 2 iron antagonists were studied for their potential as alternative antimicrobials for Escherichia coli diarrhea. Deferoxamine, a fungal iron chelator used to treat acute iron intoxication, and elemental gallium, a competitive inhibitor of iron activity in metabolic enzyme systems, were examined for their effects on enteric morphology and function in neonatal calves. Twelve male calves were allotted to 4 groups: (1) given nonpathogenic E coli (control); (2) given enterotoxigenic B44 E coli; (3) given deferoxamine (50 mg/kg, twice a day); and (4) given gallium (4 mg/kg, twice a day). Calves were studied for 8 days, including the conduct of oral glucose and lactose tolerance tests on days 1, 3, and 7. By day 7, according to oral glucose and lactose tolerance tests, peak plasma glucose concentrations in all calves of groups 2, 3, and 4 were lower than those values in controls. The frequency of diarrhea was significant in all treated calves, and disease was most severe in the deferoxamine-treated calves. Quantitative cultural examination on day 8 showed significant numerical increases of jejunal and ileal E coli and ileal lactobacilli in deferoxamine-treated calves (group 3) and of ileal streptococci in gallium-treated calves (group 4) and showed jejunal and ileal overgrowths of Saccharomyces yeast in deferoxamine-treated calves.(ABSTRACT TRUNCATED AT 250 WORDS)