Hyperimmune Colostrum Research Articles

Diagnosis and control of cryptosporidiosis in farm animals.

Cryptosporidium is a pathogenic protozoan parasite infecting the gastrointestinal epithelium of human and animal hosts. In farm animals, cryptosporidiosis causes significant economic losses including deaths in newborn animals, retarded growth, increased labor involved and high cost of drugs. The detection of Cryptosporidium oocysts in fecal samples is traditionally dependent on examination of stained slides by light microscope or by advanced microscopical tools such as: electron microscopy and phase contrast microscopy. Immunological diagnosis using either antibody or antigen detection could offer high sensitivity and specificity. Examples for these tests are Enzyme Linked Immunosorbent Assay (ELISA), Immunochromatographic tests, Immunochromatographic lateral flow (ICLF), Immunofluorescence assays (IFA) and Flow cytometry coupled with cell sorting. Molecular methods could differentiate species and genotypes of Cryptosporidium and help in studying the epidemiological features of this parasite with rapid, simple and sensitive procedures. Nanotechnology-based platforms could improve the sensitivity and specificity of other detection methods like: ELISA, ICLF, IFA and polymerase chain reaction. As the available prophylactic and therapeutic drugs or natural products treatments are insufficient and no approved vaccines are available, the best approach to control this parasite is by following firm hygienic measures. Many vaccine attempts were performed using hyperimmune colostrum, live or attenuated vaccines, recombinant and Deoxyribonucleic acid vaccines. Also, Clustered Regularly Interspaced Short Palindromic Repeats/Cas9 technology could help in Cryptosporidium genome editing to improve drug and vaccine discovery. Another approach that could be useful for assigning drug targets is metabolomics. Probiotics were also used successfully in the treatment of acute diarrhea and they proved a limiting effect on cryptosporidiosis in animal models. In addition, nanotherapy-based approaches could provide a good strategy for improving the potency of any type of drugs against Cryptosporidium and give good anti-cryptosporidial effects. In conclusion, accurate diagnosis using advanced techniques is the key to the control and prevention of cryptosporidiosis.

Diagnosing and Mitigating the Risks of Lambs’ Mortality in the Sheep Farms of Kuwait

A survey was carried out to diagnose the rates of mortality of lambs in the sheep farms of Kuwait. The survey results helped determine that the cause of high mortality rate in Kuwait of newborn lambs (≈35%) during the first three weeks of age is the certain infectious diseases affecting the sheep. Following the survey, a field experiment was carried out using a modified vaccination protocol (vaccination during pregnancy) to improve the immune status of the secreted colostrum. This new protocol has improved the immunity of newborn lambs after suckling the hyperimmune colostrum, and reduced mortality rate significantly, compared to the conventional protocol (vaccination before pregnancy). The results have proved the efficiency of the modified vaccination protocol. The experiment concluded that the vaccination during pregnancy has shown great promise to reduce the mortality rate of newborn lambs in sheep farms of Kuwait. Upscaling the tested vaccination protocol may set the scene for the betterment of sheep industry of Kuwait.

Preservation of protective capacity of hyperimmune anti-Stx2 bovine colostrum against enterohemorrhagic Escherichia coli O157:H7 pathogenicity after pasteurization and spray-drying processes

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major etiologic agent that causes bloody diarrhea, hemorrhagic colitis, and hemolytic uremic syndrome (HUS). Shiga toxin (Stx) is the main virulence factor of EHEC responsible for the progression to HUS. Although many laboratories have made efforts to develop an effective treatment for Stx-mediated HUS, a specific therapy has not been found yet. Human consumption of bovine colostrum is known to have therapeutic effects against several gastrointestinal infections because of the peptide and proteins (including antibodies) with direct antimicrobial and endotoxin-neutralizing effects contained in this fluid. We have previously demonstrated that colostrum from Stx type 2 (Stx2)-immunized pregnant cows effectively prevents Stx2 cytotoxicity and EHEC O157:H7 pathogenicity. In this study we evaluated the preservation of the protective properties of hyperimmune colostrum against Stx2 (HIC-Stx2) after pasteurization and spray-drying processes by performing in vitro and in vivo assays. Our results showed that reconstituted HIC-Stx2 colostrum after pasteurization at 60°C for 60 min and spray-dried under optimized conditions preserved specific IgG that successfully neutralized Stx2 cytotoxicity on Vero cells. Furthermore, this pasteurized/dehydrated and reconstituted HIC-Stx2 preserved the protective capacity against EHEC infection in a weaned mice model. The consumption of hyperimmune HIC-Stx2 bovine colostrum could be effective for HUS prevention in humans as well as in EHEC control in calves. However, further studies need to be done to consider its use for controlling EHEC infections.

Production of hyperimmune colostrum in the bovine against cariogenic streptococci and assess its impact on growth and biofilm formation of bacteria

Production of hyperimmune colostrum in the bovine against cariogenic streptococci and assess its impact on growth and biofilm formation of bacteria

Immunization of pregnant cows with Shiga toxin-2 induces high levels of specific colostral antibodies and lactoferrin able to neutralize E. coli O157:H7 pathogenicity

E. coli O157:H7 is a foodborne pathogen responsible for bloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). The objective of the present work was to evaluate the ability of colostral IgG obtained from Stx2-immunized cows to prevent against E. coli O157:H7 infection and Stx2 cytotoxicity. Hyperimmune colostrum (HC) was obtained from cows intramuscularly immunized with inactivated Stx2 or vehicle for controls. Colostral IgG was purified by affinity chromatography. Specific IgG antibodies against Stx2 and bovine lactoferrin (bLF) levels in HC and the corresponding IgG (HC-IgG/bLF) were determined by ELISA. The protective effects of HC-IgG/bLF against Stx2 cytotoxicity and adhesion of E. coli O157:H7 and its Stx2-negative mutant were analyzed in HCT-8 cells. HC-IgG/bLF prevention against E. coli O157:H7 was studied in human colon and rat colon loops. Protection against a lethal dose of E. coli O157:H7 was evaluated in a weaned mice model. HC-IgG/bLF showed high anti-Stx2 titers and high bLF levels that were able to neutralize the cytotoxic effects of Stx2 in vitro and in vivo. Furthermore, HC-IgG/bLF avoided the inhibition of water absorption induced by E. coli O157:H7 in human colon and also the pathogenicity of E. coli O157:H7 and E. coli O157:H7Δstx2 in rat colon loops. Finally, HC-IgG/bLF prevented in a 100% the lethality caused by E. coli O157:H7 in a weaned mice model. Our study suggests that HC-IgG/bLF have protective effects against E. coli O157:H7 infection. These beneficial effects may be due to specific anti-Stx2 neutralizing antibodies in combination with high bLF levels. These results allow us to consider HC-IgG/bLF as a nutraceutical tool which could be used in combination with balanced supportive diets to prevent HUS. However further studies are required before recommendations can be made for therapeutic and clinical applications.

Evaluation of recombinant P23 protein as a vaccine for passive immunization of newborn calves against Cryptosporidium parvum.

Cryptosporidiosis is a zoonotic protozoan disease that affects the gastrointestinal tract of animals and humans. Diarrhoea as the most important indication of the infection leads to high economic losses in livestock industries and is a life threatening infection in immunocompromised individuals. In the absence of the effective drugs, vaccine has an effective role in the prevention of infection. For this purpose we developed a vaccine utilizing recombinant P23 protein and immunized pregnant cows four times from 70days to parturition every 2weeks. After parturition, each calf received his dam colostrum and challenged with 1×10(7) Cryptosporidium parvum oocysts at 12h of age. Results showed that in contrast with the control group, the antibody titre in the sera and first milking colostra of the immunized cows significantly increased and calves fed hyperimmune colostrum did not show cryptosporidiosis signs. Moreover, enriched colostrum not only reduced significantly the amount of oocyst excretion but also delayed its onset. Our study showed that recombinant P23 protein could be used for passive immunization of newborn calves against Cryptosporidium parvum.

The gut microbiome as a target for regulatory T cell-based immunotherapy: induction of regulatory lymphocytes by oral administration of anti-LPS enriched colostrum alleviates immune mediated colitis.

BackgroundGut-derived bacterial endotoxin is an important cofactor in the pathogenesis of IBD. Regulatory T cells (Tregs) are essential for maintenance of peripheral tolerance and can prevent and alleviate IBD. To determine the immune modulatory effect of anti-LPS enriched hyperimmune colostrum, its ability to induce Tregs and alleviate immune mediated colitis.MethodsImmune-mediated colitis was induced in mice by intra-colonic instillation of Trinitrobenzene Sulfonate (TNBS). Four groups of mice were orally administered with two dosages of IgG-enriched colostrum fractions. The fractions were harvested from cows immunized against LPS derived from intestinal Escherichia coli bacteria (Imm124E). Control mice received non-immunized colostrum or vehicle (PBS). Treatment was administered one day following sensitization and four additional days following the administration of TNBS. The following parameters in the mice were tracked: body weight, bowel histology, serum cytokine levels and regulatory T cells.ResultsOral administration of Imm124E hyperimmune colostrum ameliorated immune-mediated colitis. Significant amelioration of weight reduction was noted in treated mice. Oral administration of Imm124E improved bowel histology. Both the extent of the disease, inflammation score, and colitis damage and regeneration scores decreased in Imm-124E treated animals. These effects were associated with an increase in serum IL10 anti inflammatory cytokine levels, and an increase in CD4 + CD25+ and CD4 + Foxp3+ Tregs.ConclusionsOral administration of Imm124E promoted Tregs and alleviated bowel inflammation in immune mediated colitis. The present data suggests that the microbiome may serve as a target for Tregs-based immunotherapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12876-015-0388-x) contains supplementary material, which is available to authorized users.

Vaccination of pregnant cows with EspA, EspB, γ-intimin, and Shiga toxin 2 proteins from Escherichia coli O157:H7 induces high levels of specific colostral antibodies that are transferred to newborn calves

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is a major cause of intestinal disease and hemolytic uremic syndrome, a serious systemic complication that particularly affects children. Cattle are primary reservoirs for EHEC O157:H7 and the main source of infection for humans. Vaccination of cattle with different combinations of bacterial virulence factors has shown efficacy in decreasing EHEC O157:H7 shedding. It is, therefore, important to demonstrate whether vaccination of pregnant cows with EHEC O157:H7 induces high titers of transferable antibodies to avoid early colonization of calves by the bacteria. In this study we evaluated the ability of EspA, EspB, the C-terminal fragment of 280 amino acids of γ-intimin (γ-intimin C280) and inactivated Shiga toxin (Stx) 2 proteins to induce specific antibodies in colostrum and their passive transference to colostrum-fed calves. Friesian pregnant cows immunized by the intramuscular route mounted significantly high serum and colostrum IgG responses against EspB and γ-intimin C280 that were efficiently transferred to their calves. Antibodies to EspB and γ-intimin C280 were detected in milk samples of vaccinated cows at d 40 postparturition. Significant Stx2-neutralizing titers were also observed in colostrum from Stx2-vaccinated cows and sera from colostrum-fed calves. The results presented showed that bovine colostrum with increased levels of antibodies against EHEC O157:H7 may be obtained by systemic immunization of pregnant cows, and that these specific antibodies are efficiently transferred to newborn calves by feeding colostrum. Hyperimmune colostrum and milk may be an alternative to protect calves from early colonization by EHEC O157:H7 and a possible key source of antibodies to block colonization and toxic activity of this bacterium

Oral administration of immunoglobulin G-enhanced colostrum alleviates insulin resistance and liver injury and is associated with alterations in natural killer T cells

Insulin resistance and metabolic syndrome are chronic inflammatory conditions that lead to hepatic injury and non-alcoholic steatohepatitis (NASH). Bovine colostrum has therapeutic effects in a variety of chronic infections. However its effectiveness in NASH was never studied. Natural killer T (NKT) cells have been shown to be associated with some of the pathological and metabolic abnormalities accompanying NASH in leptin-deficient (ob/ob) mice. In the present study, we used hyperimmune bovine colostrum to treat hepatic injury and insulin resistance and we also assessed the effects on NKT cells. We used ob/ob mice that were fed for 6 weeks with either 0·1 mg bovine colostrum prepared from non-immunized cows, 0·1 mg hyperimmune colostrum raised against a bacterial lipopolysaccharide (LPS) extract or 0·001, 0·1 or 1 mg of immunoglobulin (Ig)G purified from hyperimmune colostrum (IgG-LPS). NKT cells were phenotyped by flow cytometry, and hepatic injury and insulin resistance were assessed by measuring fasting glucose levels, glucose tolerance tests and liver enzymes. Fat accumulation was measured in the liver and plasma. Oral administration of hyperimmune colostrums decreased alanine aminotransferase (ALT) serum levels and serum triglycerides compared to controls. Glucose intolerance was also improved by the hyperimmune colostrum preparations. These results were accompanied by a decrease in serum tumour necrosis factor (TNF)-α levels following oral treatment with 0·1 or 1 mg of IgG-LPS. The beneficial effects of hyperimmune colostrums were associated with an increase in the number of splenic NKT cells. These data suggest that oral administration of hyperimmune colostrum preparations can alleviate chronic inflammation, liver injury and insulin resistance associated with NASH.

Prevention and Treatment of Influenza with Hyperimmune Bovine Colostrum Antibody

BackgroundDespite the availability of specific vaccines and antiviral drugs, influenza continues to impose a heavy toll on human health worldwide. Passive transfer of specific antibody (Ab) may provide a useful means of preventing or treating disease in unvaccinated individuals or those failing to adequately seroconvert, especially now that resistance to antiviral drugs is on the rise. However, preparation of appropriate Ab in large scale, quickly and on a yearly basis is viewed as a significant logistical hurdle for this approach to control seasonal influenza.Methodology/Principal FindingsIn this study, bovine colostrum, which contains approximately 500 g of IgG per milking per animal, has been investigated as a source of polyclonal antibody for delivery to the respiratory tract. IgG and F(ab')2 were purified from the hyperimmune colostrum of cows vaccinated with influenza A/Puerto Rico/8/34 (PR8) vaccine and were shown to have high hemagglutination-inhibitory and virus-neutralizing titers. In BALB/c mice, a single administration of either IgG or F(ab')2 could prevent the establishment of infection with a sublethal dose of PR8 virus when given as early as 7 days prior to exposure to virus. Pre-treated mice also survived an otherwise lethal dose of virus, the IgG- but not the F(ab')2-treated mice showing no weight loss. Successful reduction of established infection with this highly virulent virus was also observed with a single treatment 24 hr after virus exposure.Conclusions/SignificanceThese data suggest that a novel and commercially-scalable technique for preparing Ab from hyperimmune bovine colostrum could allow production of a valuable substitute for antiviral drugs to control influenza with the advantage of eliminating the need for daily administration.

Preventive effect of ordinary and hyperimmune bovine colostrums on mice diabetes induced by alloxan

In the present study, the anti-diabetic effect of ordinary and hyperimmune bovine colostrum were evaluated in diabetic mice induced by alloxan. The results indicated that blood glucose levels were significantly decreased after administration of colostrum for 30 d, and the glucose tolerance was strengthened in a dose-dependent manner. In addition, the hyperimmune colostrum was more efficient than ordinary colostrum in decreasing the blood glucose level and improving glucose tolerance in diabetic mice (P<0.05). Furthermore, total levels of serum cholesterol (TC) and triglycerides (TG) were significantly decreased, and serum high density lipoprotein cholesterol (HDL-c) was significantly increased in a dose-dependent manner compared with the control; the hyperimmune colostrum was also more efficient than ordinary colostrum in reducing the serum levels of TC and TG, and increasing the serum levels of HDL-c in diabetic mice (P<0.05). These results suggest that bovine colostrum could modify the diabetic phenotype of mice induced by alloxan.

Prevention and treatment of cryptosporidiosis in immunocompromised patients

Cryptosporidiosis is a disease that causes diarrhoea lasting about one to two weeks, sometimes extending up to 2.5 months among the immunocompetent and becoming a more severe life-threatening illness among immunocompromised individuals. Cryptosporidium is a common cause of gastroenteritis. Cryptosporidiosis is common in HIV-infected individuals. The objective of the review was to assess the efficacy of interventions for the treatment and prevention of cryptosporidiosis among immunocompromised individuals. We searched the following databases for randomised controlled trials up to August 2005: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, AIDSLINE, AIDSearch, EMBASE, CINAHL, Current Contents, Geobase, and the Environmental Sciences and Pollution Management. Randomised controlled trials that compared the use of any intervention to treat or prevent cryptosporidiosis in immunocompromised persons were included. The outcome measures for treatment studies included symptomatic diarrhoea and oocyst clearance. Two reviewers independently assessed the trials for quality of randomisation, blinding, withdrawals, and adequacy of allocation concealment. The relative risk for each intervention was calculated using a random effects model. Seven trials involving 169 participants were included. There were 130 adults with AIDS enrolled in five studies. Evidence of significant heterogeneity was present. There was no evidence for a reduction in the duration or frequency of diarrhoea by nitazoxanide (RR 0.83 (95% CI 0.36-1.94)) and paramomycin (RR 0.74 (95% CI 0.42-1.31)) compared with placebo. Nitazoxanide led to a significant evidence of oocyst clearance compared with placebo among all children with a relative risk of 0.52 (95% CI 0.30-0.91). The effect was not significant for HIV-seropositive participants (RR 0.71 (95% CI 0.36-1.37)). HIV-seronegative participants on nitazoxanide had a significantly higher relative risk of achieving parasitological clearance of 0.26 (95% CI 0.09-0.80) based on a single study. The single study comparing spiramycin with placebo found no significant difference in reduction of the duration of hospitalisation (mean difference -0.40 days (95% CI -6.62-5.82)) or in mortality between the two arms of the trial (RR 0.43 (95% CI 0.04-4.35)). One study assessed the role of bovine dialyzable leukocyte extract, reporting a relative risk for decreased stool frequency of 0.19 (95% CI 0.03-1.19), while another compared bovine hyperimmune colostrum with placebo and found no evidence for improvement of stool volume (RR 3.00 (95% CI 0.61-14.86)) or in oocyst concentration per ml of stool (RR 0.27 (95% CI 0.02-3.74)). No studies were found that assessed prevention. This review confirms the absence of evidence for effective agents in the management of cryptosporidiosis. The results indicate that nitaxozanide reduces the load of parasites and may be useful in immunocompetent individuals. Due to the seriousness of the potential outcomes of cryptosporidiosis, the use of nitaxozanide should be considered in immunocompromised patients. The absence of effective therapy highlights the need to ensure that infection is avoided. Unfortunately, evidence for the effectiveness and cost-effectiveness of preventive interventions is also lacking.

Present and future control of cryptosporidiosis in humans and animals

Although water treatment processes to remove Cryptosporidium are improving and detection methods for identifying the parasite in water are becoming more sensitive, outbreaks of cryptosporidiosis continue in the human population. Animals, especially dairy calves, often become infected as C. parvum oocysts are present in high numbers, remain viable for long periods of time after excretion and no disinfectants, prophylactic or therapeutic reagents exist. Vaccination against C. parvum is being attempted in ruminants for the purpose of generating hyperimmune colostrum containing antibodies that may be effective in passive immunotherapy against cryptosporidiosis in the young. A number of recombinant C. parvum surface or internal antigens have been expressed by DNA-cloning technology. Immune colostrum specific for several recombinant C. parvum proteins have demonstrated efficacy in murine and ruminant models against cryptosporidiosis. The P23 and CP15 antigens appear to be the most promising candidates for vaccine development. Recent studies have demonstrated efficacy of the drug nitazoxanide against C. parvum infection in humans. In the near future, control of this parasitic disease in humans and animals will rely on a combination of passive immunotherapy and selective drug treatment.

Avaliação da eficácia do colostro bovino hiperimune na infecção experimental de roedores com Cryptosporidium parvum

The hyperimmune bovine colostrum has a high concentration of antibodies anti-Cryptosporidium parvum. This product is considered one of the promising therapeutic strategies in the control of intestinal cryptosporidiosis in humans. With the purpose to evaluate the hyperimmune bovine colostrum efficacy in reducing the parasitism and preventing intestinal mucosa alterations, several strains of rats F344 and mice were experimentally infected with Cryptosporidium parvum oocysts. The results showed that the hyperimmune bovine colostrum had high levels of antibodies. The rats F344, treated either with hyperimmune or normal bovine colostrum, had reduction of the intestinal parasitism and presented little mucosa compromise. The mice C57BL/6 when treated either with hyperimmune or normal colostrum had slight reduction of the intestinal parasitism and evidenced no statistical significant differences in the histopathological mucosa changes. In conclusion, the use of hyperimmune bovine colostrum has a limited benefit in Cryptosporidium parvum infection.

Survival of rotavirus antibody activity derived from bovine colostrum after passage through the human gastrointestinal tract.

Rotavirus is a major cause of infectious diarrhea in infants and young children. Several studies have shown that hyperimmune bovine colostrum, derived from cows immunized with rotavirus, can prevent rotavirus diarrhea when given passively. The objective of this study was to determine whether colostral antibody activity survived transit through the gut by measuring the level of rotavirus antibody activity in the feces. Hyperimmune colostrum containing different levels of rotavirus antibody was administered to 105 children attending nine Adelaide childcare centres. Subjects were asked to drink 100 ml of whole milk supplemented with colostrum 3 times a day, for a period of 6 days. Stool samples were collected from the subjects before, during, and after consumption of the study product. Rotavirus activity was determined using a novel virus reduction enzyme-linked immunosorbent assay (ELISA) and a virus neutralization assay. Rotavirus antibody activity was detected in 521 (86%) of 602 fecal specimens obtained during the study using the virus reduction ELISA. The antibody activity was detected as early as 8 hours after ingestion of hyperimmune colostrum and up to 72 hours after consumption had ceased. There was a strong relation (r = 0.81) between the titer of rotavirus antibody administered to subjects and the level of antibody activity detected in the feces. The results show that antirotavirus activity survived passage through the gut. Therefore, passive immunotherapy may be used to prevent or treat infectious diseases that affect the entire length of the gastrointestinal tract.

Survival of Rotavirus Antibody Activity Derived From Bovine Colostrum After Passage Through the Human Gastrointestinal Tract

ABSTRACTBackgroundRotavirus is a major cause of infectious diarrhea in infants and young children. Several studies have shown that hyperimmune bovine colostrum, derived from cows immunized with rotavirus, can prevent rotavirus diarrhea when given passively. The objective of this study was to determine whether colostral antibody activity survived transit through the gut by measuring the level of rotavirus antibody activity in the feces.MethodsHyperimmune colostrum containing different levels of rotavirus antibody was administered to 105 children attending nine Adelaide childcare centres. Subjects were asked to drink 100 ml of whole milk supplemented with colostrum 3 times a day, for a period of 6 days. Stool samples were collected from the subjects before, during , and after consumption of the study product. Rotavirus activity was determined using a novel virus reduction enzyme‐linked immunosorbent assay (ELISA) and a virus neutralization assay.ResultsRotavirus antibody activity was detected in 521 (86%) of 602 fecal specimens obtained during the study using the virus reduction ELISA. The antibody activity was detected as early as 8 hours after ingestion of hyperimmune colostrum and up to 72 hours after consumption had ceased. There was a strong relation (r = 0.81) between the titer of rotavirus antibody administered to subjects and the level of antibody activity detected in the feces.ConclusionsThe results show that antirotavirus activity survived passage through the gut. Therefore, passive immunotherapy may be used to prevent or treat infectious diseases that affect the entire length of the gastrointestinal tract.

Bovine milk antibodies for health.

The immunoglobulins of bovine colostrum provide the major antimicrobial protection against microbial infections and confer a passive immunity to the newborn calf until its own immune system matures. The concentration in colostrum of specific antibodies against pathogens can be raised by immunising cows with these pathogens or their antigens. Immune milk products are preparations made of such hyperimmune colostrum or antibodies enriched from it. These preparations can be used to give effective specific protection against different enteric diseases in calves and suckling pigs. Colostral immunoglobulin supplements designed for farm animals are commercially available in many countries. Also, some immune milk products containing specific antibodies against certain pathogens have been launched on the market. A number of clinical studies are currently in progress to evaluate the efficacy of immune milks in the prevention and treatment of various human infections, including those caused by antibiotic resistant bacteria. Bovine colostrum-based immune milk products have proven effective in prophylaxis against various infectious diseases in humans. Good results have been obtained with products targeted against rotavirus, Shigella flexneri, Escherichia coli, Clostridium difficile, Streptococcus mutans, Cryptosporidium parvum and Helicobacter pylori. Some successful attempts have been made to use immune milk in balancing gastrointestinal microbial flora. Immune milk products are promising examples of health-promoting functional foods, or nutraceuticals. This review summarises the recent progress in the development of these products and evaluates their potential as dietary supplements and in clinical nutrition.

Serum and colostrum antibody responses induced by jet-injection of sheep with DNA encoding a Cryptosporidium parvum antigen

In an effort to generate high titer colostrum for immunotherapy of cryptosporidiosis, a study was conducted to test the efficacy of immunizing sheep with recombinant plasmid DNA (pCMV-CP15/60) encoding epitopes of 15 and 60 kDa surface antigens of Cryptosporidium parvum sporozoites. The plasmid DNA was used to immunize preparturient ewes at three dose levels by jet-injection into either hind limb muscle (IM) or mammary tissue (IMAM). Regardless of route of injection, a dose-dependent anti- CP15 60 immunoglobulin response was observed in sera and colostrum from sheep immunized with pCMV-CP15/60 plasmid DNA. High titer antibody responses were observed in one of three animals per group receiving an IM injection of 100 or 1000 μg pCMV-CP15/60. IMAM immunization with 100 or 1000 μg pCMV-CP15/60 plasmid DNA elicited higher titer colostrum responses and more consistent serum responses compared to IM injections. A negligible serum and colostrum anti- CP15 60 response was observed in ewes injected IM with 10 μg pCMV-CP15/60 or 1000 μg control plasmid DNA. Immunoblotting of native C. parvum sporozoiteloocyst protein with hyperimmune serum and colostrum corroborated the increased titers against CP15 60 antigen. Serum and colostrum antibodies from pCMV-CP15/60-immunized sheep were eluted from native CP15 protein and bound a surface antigen of C. parvum sporozoites as indicated by indirect immunofluorescence staining.

Treatment of experimental ovine cryptosporidiosis with ovine or bovine hyperimmune colostrum

Ovine or bovine colostrums with different antibody titers were tested for their ability to prevent cryptosporidiosis in five groups of neonatal lambs experimentally infected with 10(6) Cryptosporidium parvum oocysts 2 days after birth (Day 0). In a control group (Group 1), six lambs were deprived of ewe colostrum and exclusively fed with milk replacer. Two groups of six lambs were allowed to suckle their non-hyperimmunized (Group 2) or hyperimmunized (Group 3) dams throughout the experiment. Two groups of seven lambs were separated from their dams at birth before suckling and fed with non-hyperimmune (Group 4) or hyperimmune (Group 5) bovine colostrum; for 7 days they received 50 ml of colostrum completed by milk replacer twice a day, then they were fed with milk replacer exclusively. Control lambs became infected and developed clinical cryptosporidiosis with diarrhea on Days 4-9 post inoculation, oocyst shedding and mortality (2/6). In all the treated groups, the colostrum prevented mortality and clinical cryptosporidiosis. The mortality (5/7) observed in Group 5 was not due to cryptosporidiosis but anemia. In treated groups, specific antibodies were detected on Day 0 after 2 days of colostrum intake and varied little in time for IgM and IgG in spite of the parasite development, whereas they appeared later in the control group, on Day 4 for IgM, Day 11 for IgA and Day 14 for IgG. In all groups, the response which was the most consistent was the IgA response which evolved from Days 11 to 18 in association with the decline of oocyst shedding. Our results show that whatever the serum antibody titers were, the specific C. parvum circulating antibodies have no influence on the control of cryptosporidiosis. The prophylaxis or the treatment of cryptosporidiosis require high titers of specific C. parvum antibodies in the gut lumen during a sufficiently long period.

Cloning and expression of a cDNA encoding epitopes shared by 15- and 60-kilodalton proteins of Cryptosporidium parvum sporozoites.

A cDNA (CP15/60) encoding epitopes of Cryptosporidium parvum 15- and 60-kDa sporozoite proteins was isolated and expressed in Escherichia coli toward the goal of developing an immunogen for producing high-titer anticryptosporidial colostrum. Antisera prepared in rats to native C. parvum 15-kDa protein and used to identify the CP15/60 bacteriophage clone recognized both 15- and 60-kDa in vitro translation products derived from sporozoite RNA. Antisera specific for recombinant CP15/60 antigen recognized native 15- and 60-kDa C. parvum sporozoite proteins by immunoblotting and identified both surface and internal antigens on C. parvum sporozoites by immunofluorescence staining. Northern (RNA) and Southern blot hybridization experiments using sporozoite RNA and DNA indicated that CP15/60 DNA is transcribed as a single 1.4-kb RNA species from a single-copy gene. Recombinant CP15/60 antigen was recognized by hyperimmune colostrum from cows immunized with C. parvum oocyst-sporozoite protein and by convalescent-phase sera from C. parvum-infected calves.