A prebiotic, Celmanax™, decreases Escherichia coli O157:H7 colonization of bovine cells and feed-associated cytotoxicity in vitro

<p>Abstract</p> <p>Background</p> <p><it>Escherichia coli </it>O157:H7 is the most common serovar of enterohemorrhagic <it>E. coli </it>associated with serious human disease outbreaks. Cattle are the main reservoir with <it>E. coli </it>O157:H7 inducing hemorrhagic enteritis in persistent shedding beef cattle, however little is known about how this pathogen affects cattle health. Jejunal Hemorrhage Syndrome (JHS) has unclear etiology but the pathology is similar to that described for <it>E. coli </it>O157:H7 challenged beef cattle suggestive that <it>E. coli </it>O157:H7 could be involved. There are no effective treatments for JHS however new approaches to managing pathogen issues in livestock using prebiotics and probiotics are gaining support. The first objective of the current study was to characterize pathogen colonization in hemorrhaged jejunum of dairy cattle during natural JHS outbreaks. The second objective was to confirm the association of mycotoxigenic fungi in feeds with the development of JHS and also to identify the presence of potential mycotoxins. The third objective was to determine the impact of a prebiotic, Celmanax™, or probiotic, Dairyman's Choice™ paste, on the cytotoxicity associated with feed extracts <it>in vitro</it>. The fourth objective was to determine the impact of a prebiotic or a probiotic on <it>E. coli </it>O157:H7 colonization of mucosal explants and a bovine colonic cell line <it>in vitro</it>. The final objective was to determine if prebiotic and probiotic feed additives could modify the symptoms that preceded JHS losses and the development of new JHS cases.</p> <p>Findings</p> <p>Dairy cattle developed JHS after consuming feed containing several types of mycotoxigenic fungi including <it>Fusarium culmorum</it>, <it>F. poae</it>, <it>F. verticillioides</it>, <it>F. sporotrichioides</it>, <it>Aspergillus</it><it>flavus</it>, <it>Penicillium roqueforti, P. crustosum, P. paneum </it>and <it>P. citrinum</it>. Mixtures of Shiga toxin - producing <it>Escherichia coli </it>(STEC) colonized the mucosa in the hemorrhaged tissues of the cattle and no other pathogen was identified. The STECs expressed Stx1 and Stx2, but more significantly, Stxs were also present in the blood clot blocking the jejunum. Mycotoxin analysis of the corn crop confirmed the presence of fumonisin, NIV, ZEAR, DON, 15-ADON, 3-ADON, NEO, DAS, HT-2 and T-2. Feed extracts were toxic to enterocytes and 0.1% Celmanax™ removed the cytotoxicity <it>in vitro</it>. There was no effect of Dairyman's Choice™ paste on feed-extract activity <it>in vitro</it>. Fumonisin, T-2, ZEAR and DON were toxic to bovine cells and 0.1% Celmanax™ removed the cytotoxicity <it>in vitro</it>. Celmanax™ also directly decreased <it>E. coli </it>O157:H7 colonization of mucosal explants and a colonic cell line in a dose-dependent manner. There was no effect of Dairyman's Choice™ paste on <it>E. coli </it>O157:H7 colonization <it>in vitro</it>. The inclusion of the prebiotic and probiotic in the feed was associated with a decline in disease.</p> <p>Conclusion</p> <p>The current study confirmed an association between mycotoxigenic fungi in the feed and the development of JHS in cattle. This association was further expanded to include mycotoxins in the feed and mixtures of STECs colonizing the severely hemorrhaged tissues. Future studies should examine the extent of involvement of the different STEC in the infection process. The prebiotic, Celmanax™, acted as an anti-adhesive for STEC colonization and a mycotoxin binder <it>in vitro</it>. Future studies should determine the extent of involvement of the prebiotic in altering disease.</p

Heavy metal concentration in plerocercoids of Triaenophorus nodulosus [Pallas, 1781] [Cestoda: Triaenophoridae] and in different organs of their host - perch Perca fluviatilis [L.]

Background. Heavy metals are at present classified among the most important and dangerous water pollutants. Since over 15 years parasites have been used as a bioindicators of water pollution, e.g. using their ability to accumulate heavy metals. Concentration of four elements (Zn, Cd, Ni, Cu) in selected organs of the perch (Perca fluviatilis) and in the tissues of its parasite, plerocercoid of the tapeworm Triaenophorus nodulosus, was analysed. Material and methods. The fish were subject to full helminthological section, resulting in 66 tapeworm larvae isolated from cysts, located in the liver. Plerocecroids, gills, liver and intestine with duodenum were removed and frozen. Content of heavy metals was determined with atomic absorption spectroscopy method. Results. The distribution of the content of Ni, Cd and Zn was similar. In all cases, among all the examined fish organs, the highest mean concentration of the metals was found in the liver, followed by the intestine; it was the lowest in the gills. The mean concentration of the metals in the tapeworm tissues was from 6 to 74 x higher than in the gills, 5−37 x higher than in the intestine and 2.5−28 x higher than in the liver. The concentration of Cu was also the highest in the tapeworm tissues, but its concentration in the fish intestine and liver was nearly the same; it was the lowest in the gills

EFFECT OF ADAPTATION STRESS ON BLOOD INDICES OF LIMOUSINE COWS**

Abstract: The aim of research was to assess glucose (Glu), fibrinogen (Fb) and hematocrit (Ht) in the whole blood samples, while cortisol (Cort), haptoglobin (Hp), serum amyloid A (SAA), total protein (TPt) and concentrations of protein fractions (albumins, globulins) in blood serum to monitor adaptation stress in beef cows of Limousine breed. Three groups of cows, each consisting of 8 animals shortly after parturition, were studied simultaneously after different time of adaptation to the new herd (Group I- 1 week, Group II- 3 weeks, Group III- 1 year). Group III animals were perceived as already adapted to the herd environment. Limousine cows with the shortest time of stay in the new herd characterised with elevated concentrations of Glu (P&lt;0.01), Cort, SAA and β-globulin fraction while concentration of γ-globulins was significantly lowered (P≤0.05). These indices may be related to adaptation stress lasting ca 1 week. The most sensitive response of animals to adaptation stress lasting 1 week was exhibited in elevated Glu values. Cows with 3 weeks elapsed time from relocation exhibited only elevated Ht and SAA values. Key words: beef cattle, adaptation stress, blood indice