551
|
Kovsca Janjatović A, Lacković G, Bozić F, Kezić D, Popović M, Valpotić H, Harapin I, Pavicić Z, Njari B, Valpotić I. Histomorphometric evaluation of intestinal cellular immune responses in pigs immunized with live oral F4ac+ non-enterotoxigenic E. coli vaccine against postweaning colibacillosis. Eur J Histochem 2010; 54:e4. [PMID: 20353911 PMCID: PMC3167290 DOI: 10.4081/ejh.2010.e4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Accepted: 12/17/2009] [Indexed: 11/23/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) infection is the most common type of porcine postweaning colibacillosis (PWC). Among fimbriae of porcine ETEC strains the best studied family of fimbriae are the members of F4 adhesins, existing in at least three variants: ab, ac, ad. Active immunization against porcine PWC is difficult due to: i) ETEC strains are only one of the essential predisposing factors, ii) the success of vaccinal antigen uptake depends on the presence of enterocyte receptors for F4 adhesins, iii) the intestinal immune system may react with tolerance or hypersensitivity to the same antigens depending on the dose and form of the vaccinal immunogen, and iv) kinetics of the specific immune responses may be different in the case of F4 (earlier) and the other ETEC adhesins, particularly F18 (later). The aim of this study was to test the effectiveness of a live attenuated F4ac+ non-ETEC vaccine against porcine PWC by analyzing quantitative differences in the small intestinal lymphoid and myeloid cell subsets of immunized (with or without levamisole given as an adjuvant) vs control non-immunized pigs. Four week-old pigs were intragastrically immunized with a vaccine candidate F4ac+ non-ETEC strain 2407 at day 0, challenged 7 days later with a virulent F4ac+ strain ETEC 11-800/1/94, euthanatized at day 13 and sampled for immunohistology. Non-immunized pigs received saline at day 0 and were processed as the principals. Immuno-phenotypes of lymphoid and myeloid cell subsets were demonstrated within jejunal and ileal mucosa by immunohistochemical avidin-biotin complex method and corresponding morphometric data were analyzed using software program Lucia G for digital image analyses. Monoclonal antibodies reactive with surface molecules on porcine immune cells such as CD3, CD45RA, CD45RC, CD21 and SWC3 enabled clear insight into distribution patterns and amount of these cells within the gut-associated lymphoid tissues (GALT) examined. The numbers of jejunal and ileal cell subsets tested were significantly increased (at P<0.5 or lower) in both principal groups (vaccinated or levamisole primed-vaccinated) of pigs, compared to those recorded in the control non-vaccinated pigs. Based on the histomorphometric quantification of porcine intestinal immune cells from the GALT compartments tested, it is possible to differentiate the responses of pigs immunized by an experimental mucosal vaccine from those of non-immunized pigs.
Collapse
|
552
|
Ruiz R, García MP, Lara A, Rubio LA. Garlic derivatives (PTS and PTS-O) differently affect the ecology of swine faecal microbiota in vitro. Vet Microbiol 2009; 144:110-7. [PMID: 20080364 DOI: 10.1016/j.vetmic.2009.12.025] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 12/14/2009] [Accepted: 12/18/2009] [Indexed: 11/25/2022]
Abstract
A number of in vitro experiments were designed to evaluate the effects of two different industrial products, namely PROALLIUM-S-DMC and PROALLIUM-SO-DMC (DMC Research Center, Granada, Spain), obtained from garlic (Allium sativum) on the faecal microbiota of pigs. The effects of three different concentrations (50, 200 and 400 ppm) of the active compounds (PTS and PTS-O, respectively) from both industrial products on the gastrointestinal microbiota of pigs were tested. Growth medium without any additive (0 ppm) was used as control. Predominant bacterial groups (total aerobes, total anaerobes, lactobacilli, bifidobacteria, coliforms, enterobacteria, bacteroides and clostridia) were studied. Results showed that both PTS and PTS-O have significant (P<0.01) antimicrobial activity against every group studied, although enterobacteria and coliforms were the most affected populations (P<0.01). Time kill curves for Escherichia coli and Salmonella typhimurium, two common pathogens of pigs, showed that both compounds had a bactericidal effect against these strains. For the bacterial groups here studied, the antimicrobial effect of PTS-O was significantly (P<0.001) stronger than that of PTS. Trials in vivo are in course to study the potential use of these products as alternatives to antibiotics in pig feeds.
Collapse
Affiliation(s)
- Raquel Ruiz
- Dpto de Fisiología y Bioquímica de la Nutrición Animal IFNA, EEZ, CSIC, Profesor Albareda 1, 18008 Granada, Spain
| | | | | | | |
Collapse
|
553
|
Administration of loperamide and addition of wheat bran to the diets of weaner pigs decrease the incidence of diarrhoea and enhance their gut maturation. Br J Nutr 2009; 103:879-85. [DOI: 10.1017/s0007114509992637] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The influence of fibre inclusion and transit time regulation on the performance, health status, microbial activity and population, physico-chemical characteristics of the hindgut digesta and intestinal morphology in early weaned pigs were examined. For these experiments, wheat bran (WB) was used as fibre source and loperamide as a drug (LOP) to increase the digesta transit time. In Expt 1, a total of 128 early weaned pigs were randomly distributed in a 2 × 2 factorial combination of WB inclusion (0v.40 g/kg) and LOP administration (0v.0·07 mg/kg body weight) during 13 d. For Expt 2, a total of twenty-four piglets were allotted to three dietary treatments for 15 d with the same basal diet (control diet) as Expt 1; a diet with 80 g/kg of WB and the combination of WB and LOP. In Expt 1, LOP improved the average daily feed intake and average daily gain of the animals (P = 0·001 and 0·007, respectively). The same result was obtained when WB was combined with LOP. The WB–LOP group also showed a higher concentration of SCFA (P = 0·013), acetic acid (P = 0·004) and propionic acid (P = 0·093). On the other hand, WB inclusion reduced the organic matter and crude protein digestibility (P = 0·001) and tended to decrease the enterobacteria population (P = 0·089). In Expt 2, WB increased the butyric acid concentration (P = 0·086). We concluded that the inclusion of WB to modify the intestinal microbiota activity combined with LOP may be beneficial to animal health and performance.
Collapse
|
554
|
Opapeju FO, Rademacher M, Nyachoti CM. Effect of dietary crude protein level on jejunal brush border enzyme activities in weaned pigs. Arch Anim Nutr 2009; 63:455-66. [DOI: 10.1080/17450390903299133] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
555
|
Kuhn L, Aldrovandi GM. Clean water helps but is not enough: challenges for safe replacement feeding of infants exposed to HIV. J Infect Dis 2009; 200:1183-5. [PMID: 19758096 DOI: 10.1086/605842] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
|
556
|
Halas D, Hansen CF, Hampson DJ, Mullan BP, Wilson RH, Pluske JR. Effect of dietary supplementation with inulin and/or benzoic acid on the incidence and severity of post-weaning diarrhoea in weaner pigs after experimental challenge with enterotoxigenicEscherichia coli. Arch Anim Nutr 2009; 63:267-80. [DOI: 10.1080/17450390903020414] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
557
|
Setia A, Bhandari SK, House JD, Nyachoti CM, Krause DO. Development and in vitro evaluation of an Escherichia coli probiotic able to inhibit the growth of pathogenic Escherichia coli K881. J Anim Sci 2009; 87:2005-12. [DOI: 10.2527/jas.2008-1400] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
558
|
Putative adhesins of enteropathogenic and enterohemorrhagic Escherichia coli of serogroup O26 isolated from humans and cattle. J Clin Microbiol 2009; 47:2090-6. [PMID: 19403767 DOI: 10.1128/jcm.02048-08] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) strains are responsible for food poisoning in developed countries via consumption of vegetal and animal food sources contaminated by ruminant feces, and some strains (O26, O111, and O118 serogroups) are also responsible for diarrhea in young calves. The prevalence of 27 putative adhesins of EHEC and of bovine necrotoxigenic E. coli (NTEC) was studied with a collection of 43 bovine and 29 human enteropathogenic (EPEC) and EHEC strains and 5 non-EPEC/non-EHEC (1 bovine and 4 human) O26 strains, using specific PCRs. Four "groups" of adhesins exist, including adhesins present in all O26 strains, adhesins present in most O26 strains, adhesins present in a few O26 strains, and adhesins not present in O26 strains. The common profile of EHEC/EPEC strains was characterized by the presence of loc3, loc5, loc7, loc11, loc14, paa, efa1, iha, lpfA(O26), and lpfA(O113) genes and the absence of loc1, loc2, loc6, loc12, loc13, saa, and eibG genes. Except for the lpfA(O26) gene, which was marginally associated with bovine EHEC/EPEC strains in comparison with human strains (P = 0.012), none of the results significantly differentiated bovine strains from human strains. One adhesin gene (ldaE) was statistically (P < 0.01) associated with O26 EHEC/EPEC strains isolated from diarrheic calves in comparison with strains isolated from healthy calves. ldaE-positive strains could therefore represent a subgroup possessing the specific property of producing diarrhea in young calves. This is the first time that the distribution of putative adhesins has been described for such a large collection of EHEC/EPEC O26 strains isolated from both humans and cattle.
Collapse
|
559
|
Jamalludeen N, Johnson RP, Shewen PE, Gyles CL. Evaluation of bacteriophages for prevention and treatment of diarrhea due to experimental enterotoxigenic Escherichia coli O149 infection of pigs. Vet Microbiol 2009; 136:135-41. [DOI: 10.1016/j.vetmic.2008.10.021] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2008] [Revised: 10/16/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
|
560
|
Sarabia-Sainz AI, Ramos-Clamont G, Candia-Plata MMDC, Vázquez-Moreno L. Biorecognition of Escherichia coli K88 adhesin for glycated porcine albumin. Int J Biol Macromol 2009; 44:175-81. [DOI: 10.1016/j.ijbiomac.2008.11.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Revised: 11/22/2008] [Accepted: 11/27/2008] [Indexed: 11/16/2022]
|
561
|
Kiarie E, Slominski B, Nyachoti C. Tissue fatty acid profiles, plasma biochemical characteristics and cecal biogenic amines in piglets fed diets containing flaxseed and carbohydrase enzymes. Livest Sci 2009. [DOI: 10.1016/j.livsci.2008.05.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|
562
|
Lessard M, Dupuis M, Gagnon N, Nadeau E, Matte JJ, Goulet J, Fairbrother JM. Administration of Pediococcus acidilactici or Saccharomyces cerevisiae boulardii modulates development of porcine mucosal immunity and reduces intestinal bacterial translocation after Escherichia coli challenge1,2. J Anim Sci 2009; 87:922-34. [DOI: 10.2527/jas.2008-0919] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
563
|
Coddens A, Diswall M, Angström J, Breimer ME, Goddeeris B, Cox E, Teneberg S. Recognition of blood group ABH type 1 determinants by the FedF adhesin of F18-fimbriated Escherichia coli. J Biol Chem 2009; 284:9713-26. [PMID: 19208633 DOI: 10.1074/jbc.m807866200] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
F18-fimbriated Escherichia coli are associated with porcine postweaning diarrhea and edema disease. Adhesion of F18-fimbriated bacteria to the small intestine of susceptible pigs is mediated by the minor fimbrial subunit FedF. However, the target cell receptor for FedF has remained unidentified. Here we report that F18-fimbriated E. coli selectively interact with glycosphingolipids having blood group ABH determinants on type 1 core, and blood group A type 4 heptaglycosylceramide. The minimal binding epitope was identified as the blood group H type 1 determinant (Fucalpha2Galbeta3GlcNAc), while an optimal binding epitope was created by addition of the terminal alpha3-linked galactose or N-acetylgalactosamine of the blood group B type 1 determinant (Galalpha3(Fucalpha2)Galbeta3GlcNAc) and the blood group A type 1 determinant (GalNAcalpha3(Fucalpha2)-Galbeta3GlcNAc). To assess the role of glycosphingolipid recognition by F18-fimbriated E. coli in target tissue adherence, F18-binding glycosphingolipids were isolated from the small intestinal epithelium of blood group O and A pigs and characterized by mass spectrometry and proton NMR. The only glycosphingolipid with F18-binding activity of the blood group O pig was an H type 1 pentaglycosylceramide (Fucalpha2Galbeta3GlcNAc-beta3Galbeta4Glcbeta1Cer). In contrast, the blood group A pig had a number of F18-binding glycosphingolipids, characterized as A type 1 hexaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer), A type 4 heptaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GalNAcbeta3Galalpha4Galbeta4Glcbeta1Cer), A type 1 octaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer), and repetitive A type 1 nonaglycosylceramide (GalNAcalpha3(Fucalpha2)Galbeta3GalNAcalpha3-(Fucalpha2)Galbeta3GlcNAcbeta3Galbeta4Glcbeta1Cer). No blood group antigen-carrying glycosphingolipids were recognized by a mutant E. coli strain with deletion of the FedF adhesin, demonstrating that FedF is the structural element mediating binding of F18-fimbriated bacteria to blood group ABH determinants.
Collapse
Affiliation(s)
- Annelies Coddens
- Laboratory of Veterinary Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke 9820, Belgium
| | | | | | | | | | | | | |
Collapse
|
564
|
The polymeric stability of the Escherichia coli F4 (K88) fimbriae enhances its mucosal immunogenicity following oral immunization. Vaccine 2008; 26:5728-35. [DOI: 10.1016/j.vaccine.2008.08.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2008] [Revised: 08/09/2008] [Accepted: 08/11/2008] [Indexed: 11/23/2022]
|
565
|
Taillon C, Nadeau E, Mourez M, Dubreuil JD. Heterogeneity of Escherichia coli STb enterotoxin isolated from diseased pigs. J Med Microbiol 2008; 57:887-890. [PMID: 18566148 DOI: 10.1099/jmm.0.2008/000281-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To investigate the presence and frequency of estB variant(s), a collection of 100 STb-positive enterotoxigenic Escherichia coli (ETEC) strains isolated from 1980 to 2007 inclusively and randomly selected from diseased pigs in Québec, Canada, was analysed. A wide diversity of virulence gene profiles (virotypes) was detected in the strain collection. The estB gene was amplified by PCR using primers designed from the signal sequence and the C-terminal end, and the amplified fragment was sequenced using the forward primer. The translated DNA sequence revealed a His(12)-->Asn change in 23 of the 100 ETEC isolates tested. The STb-variant strains were observed throughout the sampling period covered in the study. No other STb-variant type was found in this study. All 23 variant strains were also positive for the STa enterotoxin and were resistant to tetracycline, as for strain 2173. The STb variant was associated with Stx2-positive strains (5/6) and STa : STb strains that did not harbour any of the tested porcine fimbrial adhesins (13/17). The remaining variant strains were associated with fimbriae F4 (1/40), F5 (1/6), F6 (1/1) and F18 (2/7; excluding F18 : Stx2 strains).
Collapse
Affiliation(s)
- Christine Taillon
- Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada
| | - Eric Nadeau
- Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada
| | - Michaël Mourez
- Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada
| | - J Daniel Dubreuil
- Centre de Recherche en Infectiologie Porcine (CRIP), Faculté de Médecine Vétérinaire, Université de Montréal, Saint-Hyacinthe, QC J2S 7C6, Canada
| |
Collapse
|
566
|
JANJATOVI AK, LACKOVI G, BOI F, POPOVI M, VALPOTI I. Levamisole synergizes proliferation of intestinal IgA+cells in weaned pigs immunized with vaccine candidate F4ac+nonenterotoxigenicEscherichia colistrain. J Vet Pharmacol Ther 2008; 31:328-33. [DOI: 10.1111/j.1365-2885.2008.00961.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
567
|
Comparison of the contributions of heat-labile enterotoxin and heat-stable enterotoxin b to the virulence of enterotoxigenic Escherichia coli in F4ac receptor-positive young pigs. Infect Immun 2008; 76:3141-9. [PMID: 18426880 DOI: 10.1128/iai.01743-07] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In swine, the most common and severe enterotoxigenic Escherichia coli (ETEC) infections are caused by strains that express K88 (F4)(+) fimbriae, heat-labile enterotoxin (LT), heat-stable enterotoxin b (STb), and enteroaggregative E. coli heat-stable toxin 1. Previous studies based on a design that involved enterotoxin genes cloned into a nontoxigenic fimbriated strain have suggested that LT but not STb plays an important role in dehydrating diarrheal disease in piglets <1 week old and also enhances bacterial colonization of the intestine. In the present study, we compared these two toxins in terms of importance for piglets >1 week old with a study design that involved construction of isogenic single- and double-deletion mutants and inoculation of 9-day-old F4ac receptor-positive gnotobiotic piglets. Based on the postinoculation percent weight change per h and serum bicarbonate concentrations, the virulence of the STb(-) mutant (Delta estB) did not significantly differ from that of the parent. However, deletion of the LT genes (Delta eltAB) in the STb(-) mutant resulted in a complete abrogation of weight loss, dehydration, and metabolic acidosis in inoculated pigs, and LT complementation restored the virulence of this strain. These results support the hypothesis that LT is a more significant contributor than STb to the virulence of F4(+) ETEC infections in young F4ac receptor-positive pigs less than 2 weeks old. However, in contrast to previous studies with gnotobiotic piglets, there was no evidence that the expression of LT enhanced the ability of the F4(+) ETEC strain to colonize the small intestine.
Collapse
|
568
|
Bhandari SK, Xu B, Nyachoti CM, Giesting DW, Krause DO. Evaluation of alternatives to antibiotics using an Escherichia coli K88+ model of piglet diarrhea: Effects on gut microbial ecology1. J Anim Sci 2008; 86:836-47. [DOI: 10.2527/jas.2006-822] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
569
|
Kiarie EG, Slominski BA, Krause DO, Nyachoti CM. Nonstarch polysaccharide hydrolysis products of soybean and canola meal protect against enterotoxigenic Escherichia coli in piglets. J Nutr 2008; 138:502-8. [PMID: 18287357 DOI: 10.1093/jn/138.3.502] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Infectious diarrhea is a major problem in both children and piglets. Enterotoxigenic Escherichia coli (ETEC) infection results in fluid and electrolyte losses in the small intestine. We investigated the effect of nonstarch polysaccharide (NSP) hydrolysis products of soybean meal (SBM) and canola meal (CM) on net absorption of fluid and solutes during ETEC infection. Products were generated by incubating SBM and CM with a blend of carbohydrase enzymes. Following incubation, slurries were centrifuged and the supernatants mixed with absolute ethanol to produce 2 product types: 80% ethanol-soluble (ES) and 80% ethanol-insoluble (EI). Products from SBM and CM were studied in 2 independent experiments in which 2 factors were investigated: product type (EI vs. ES) and time of ETEC infection (before vs. after perfusion). Pairs of small intestine segments, one noninfected and the other ETEC infected, were perfused simultaneously with different products for 7.5 h. Net absorption of fluid and solutes were determined. In both experiments, ETEC-infected segments perfused with saline control had lower (P < or = 0.05) net fluid and solute absorption compared with SBM and CM products. The interaction (P < or = 0.05) between product type and time of infection on fluid absorption was only evident for SBM, in which case perfusing ES products before infection resulted in higher fluid absorption (735 +/- 22 microL/cm2) compared with ETEC infection before perfusion (428 +/- 34 microL/cm2). In conclusion, NSP hydrolysis products of SBM and CM, particularly ES from SBM, were beneficial in maintaining fluid balance during ETEC infection, suggesting potential for controlling ETEC-induced diarrhea in piglets.
Collapse
Affiliation(s)
- Elijah G Kiarie
- Department of Animal Science, University of Manitoba, Winnipeg, Manitoba, R3T 2N2, Canada
| | | | | | | |
Collapse
|
570
|
Koh SY, George S, Brözel V, Moxley R, Francis D, Kaushik RS. Porcine intestinal epithelial cell lines as a new in vitro model for studying adherence and pathogenesis of enterotoxigenic Escherichia coli. Vet Microbiol 2008; 130:191-7. [PMID: 18261863 DOI: 10.1016/j.vetmic.2007.12.018] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 12/08/2007] [Accepted: 12/10/2007] [Indexed: 11/18/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) infections result in large economic losses in the swine industry worldwide. The organism causes diarrhea by adhering to and colonizing enterocytes in the small intestines. While much progress has been made in understanding the pathogenesis of ETEC, no homologous intestinal epithelial cultures suitable for studying porcine ETEC pathogenesis have been described prior to this report. In the current study, we investigated the adherence of various porcine ETEC strains to two porcine (IPEC-1 and IPEC-J2) and one human (INT-407) small intestinal epithelial cell lines. Each cell line was assessed for its ability to support the adherence of E. coli expressing fimbrial adhesins K88ab, K88ac, K88ad, K99, F41, 987P, and F18. Wild-type ETEC expressing K88ab, K88ac, and K88ad efficiently bound to both IPEC-1 and IPEC-J2 cells. An ETEC strain expressing both K99 and F41 bound heavily to both porcine cell lines but an E. coli strain expressing only K99 bound very poorly to these cells. E. coli expressing F18 adhesin strongly bound to IPEC-1 cells but did not adhere to IPEC-J2 cells. The E. coli strains G58-1 and 711 which express no fimbrial adhesins and those that express 987P fimbriae failed to bind to either porcine cell line. Only strains B41 and K12:K99 bound in abundance to INT-407 cells. The binding of porcine ETEC to IPEC-J2, IPEC-1 and INT-407 with varying affinities, together with lack of binding of 987P ETEC and non-fimbriated E. coli strains, suggests strain-specific E. coli binding to these cell lines. These findings suggest the potential usefulness of porcine intestinal cell lines for studying ETEC pathogenesis.
Collapse
Affiliation(s)
- Seung Y Koh
- Department of Veterinary Science, South Dakota State University, Brookings, SD 57007, USA
| | | | | | | | | | | |
Collapse
|
571
|
Schierack P, Walk N, Reiter K, Weyrauch KD, Wieler LH. Composition of intestinal Enterobacteriaceae populations of healthy domestic pigs. MICROBIOLOGY-SGM 2008; 153:3830-3837. [PMID: 17975092 DOI: 10.1099/mic.0.2007/010173-0] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
In this study, the Enterobacteriaceae microbiota, including their diversity as well as the distribution of haemolytic and virulence gene-harbouring Escherichia coli of 56-day-old healthy piglets, was characterized. Both the composition and the diversity of Enterobacteriaceae populations varied considerably between individual pigs and intestinal sections. E. coli, Enterobacter cloacae, Citrobacter freundii and Klebsiella pneumoniae dominated the Enterobacteriaceae microbiota. However, mucosa-associated Enterobacteriaceae were scarce or in some cases undetectable. The majority of E. coli clones from the jejunum were also found in the colon, with up to 10 different E. coli clones in one intestinal section. Other Enterobacteriaceae species were represented by only one clone localized to one intestinal section. While several piglets did not harbour virulence gene-positive or haemolytic E. coli, such strains dominated intestinal sections of other animals. This study reveals that the diversity of intestinal Enterobacteriaceae is clearly individual. In general, Enterobacteriaceae do not appear to be a consistent fraction of the microbiota of the jejunum. High numbers of adherent bacteria do not appear to be essential for successful intestinal colonization, and E. coli clones do not necessarily colonize distinct intestinal sections based on the particular phylogenetic affiliation. Furthermore, dominance of haemolytic or virulence gene-positive E. coli does not correlate with disease. Finally, probiotic Enterococcus faecium feed supplementation does not affect the Enterobacteriaceae microbiota.
Collapse
Affiliation(s)
- Peter Schierack
- Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Nicole Walk
- Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, Philippstr. 13, 10115 Berlin, Germany
| | - Katja Reiter
- Institut für Veterinär-Anatomie, Freie Universität Berlin, Koserstr. 20, 14195 Berlin, Germany
| | - Karl D Weyrauch
- Institut für Veterinär-Anatomie, Freie Universität Berlin, Koserstr. 20, 14195 Berlin, Germany
| | - Lothar H Wieler
- Institut für Mikrobiologie und Tierseuchen, Freie Universität Berlin, Philippstr. 13, 10115 Berlin, Germany
| |
Collapse
|
572
|
Complete genomic sequence of bacteriophage phiEcoM-GJ1, a novel phage that has myovirus morphology and a podovirus-like RNA polymerase. Appl Environ Microbiol 2007; 74:516-25. [PMID: 18039824 DOI: 10.1128/aem.00990-07] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The complete genome of phiEcoM-GJ1, a lytic phage that attacks porcine enterotoxigenic Escherichia coli of serotype O149:H10:F4, was sequenced and analyzed. The morphology of the phage and the identity of the structural proteins were also determined. The genome consisted of 52,975 bp with a G+C content of 44% and was terminally redundant and circularly permuted. Seventy-five potential open reading frames (ORFs) were identified and annotated, but only 29 possessed homologs. The proteins of five ORFs showed homology with proteins of phages of the family Myoviridae, nine with proteins of phages of the family Podoviridae, and six with proteins of phages of the family Siphoviridae. ORF 1 encoded a T7-like single-subunit RNA polymerase and was preceded by a putative E. coli sigma(70)-like promoter. Nine putative phage promoters were detected throughout the genome. The genome included a tRNA gene of 95 bp that had a putative 18-bp intron. The phage morphology was typical of phages of the family Myoviridae, with an icosahedral head, a neck, and a long contractile tail with tail fibers. The analysis shows that phiEcoM-GJ1 is unique, having the morphology of the Myoviridae, a gene for RNA polymerase, which is characteristic of phages of the T7 group of the Podoviridae, and several genes that encode proteins with homology to proteins of phages of the family Siphoviridae.
Collapse
|
573
|
Abstract
Salmonellosis is an important disease in humans and is associated with contaminated food, including pork products. Salmonella infection is invasive in humans, but it usually remains latent within the swine population, creating reservoirs for carcass contamination. Although abattoirs implement stringent procedures during carcass processing, some raw pork products still have Salmonella contamination. To reduce the presence of Salmonella, a dynamic picture of the pork production chain is needed that includes management practices aimed at health and welfare of swine and practices within swine operations that affect the environment and community health. Swine practices indirectly influence the spread of zoonotic enteric pathogens. Pathogens in food animals can escape detection, and critical control points often are missed. Preharvest growth of swine by enhancement of normal gut flora and targeting intestinal pathogens through nonantibiotic approaches might improve food safety and reduce antibiotic residues. In light of the threat posed by multidrug-resistant pathogens, old dogma is being revisited with optimism for potential utility in promoting pre- and postharvest pork safety. This review includes possible approaches that can be implemented in swine operations and postslaughter during pork processing with simultaneous omission of subtherapeutic antibiotics to control Salmonella. We emphasize the vital roles of the veterinarians, pig producers, industry, food research scientists, and government guidelines for the strategic implementation of approaches to Salmonella control across the pork production and processing chains.
Collapse
Affiliation(s)
- Shivani Ojha
- Agriculture and Agri-Food Canada, Food Research Program, 93 Stone Road West, Guelph, Ontario, Canada N1G 5C9
| | | |
Collapse
|
574
|
Animal health and welfare aspects of different housing and husbandry systems for adult breeding boars, pregnant, farrowing sows and unweaned piglets - Scientific Opinion of the Panel on Animal Health and Welfare. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.572] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
|
575
|
Opinion of the Scientific Panel on Animal Health and Welfare on a request from the Commission related to animal health and welfare in fattening pigs in relation to housing and husbandry. EFSA J 2007. [DOI: 10.2903/j.efsa.2007.564] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
|
576
|
Cutler SA, Lonergan SM, Cornick N, Johnson AK, Stahl CH. Dietary inclusion of colicin e1 is effective in preventing postweaning diarrhea caused by F18-positive Escherichia coli in pigs. Antimicrob Agents Chemother 2007; 51:3830-5. [PMID: 17724148 PMCID: PMC2151407 DOI: 10.1128/aac.00360-07] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
With worldwide concern over the use of antibiotics in animal agriculture and their contribution to the spread of antibiotic resistance, alternatives to conventional antibiotics are needed. Previous research in our laboratories has shown that colicin E1 is effective against some Escherichia coli strains responsible for postweaning diarrhea (PWD) in vitro. In this study we examined the efficacy of the dietary inclusion of colicin E1 in preventing experimentally induced PWD caused by F18-positive enterotoxigenic E. coli in young pigs. Twenty-four weaned pigs (23 days of age), identified by genotyping to be susceptible to F18-positive E. coli infections, were individually housed and fed diets containing 0, 11, or 16.5 mg colicin E1/kg diet. Two days after the start of the trial, all animals were orally inoculated with 1 x 10(9) CFU of each of two F18-positive E. coli strains isolated from pigs with PWD. The dietary inclusion of colicin E1 decreased the incidence and severity of PWD caused by F18-positive enterotoxigenic E. coli and improved the growth performance of the piglets. Additionally, the reduced incidence of PWD due to dietary colicin E1, lowered the levels of expression of the genes for interleukin 1beta and tumor necrosis factor beta in ileal tissues from these animals. The dietary inclusion of colicin E1 may be an effective alternative to conventional antibiotics in the diets of weaning pigs for the prevention of PWD caused by F18-positive enterotoxigenic E. coli.
Collapse
Affiliation(s)
- S A Cutler
- Department of Animal Science, Iowa State University, Ames, USA
| | | | | | | | | |
Collapse
|
577
|
Mucosal immunization of piglets with purified F18 fimbriae does not protect against F18+ Escherichia coli infection. Vet Immunol Immunopathol 2007; 120:69-79. [PMID: 17686530 DOI: 10.1016/j.vetimm.2007.06.018] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2006] [Revised: 06/01/2007] [Accepted: 06/13/2007] [Indexed: 10/23/2022]
Abstract
Post-weaning diarrhoea and oedema disease in weaned piglets are caused by infection with F4+ or F18+ Escherichia coli strains. There is no commercial vaccine available, but it is shown that oral immunization of weaned piglets with purified F4 fimbriae induces a protective mucosal immune response. In the present study, piglets were orally and nasally immunized with purified F18 fimbriae in the presence of the mucosal adjuvant LT(R192G) or CTA1-DD, respectively. This immunization could not lead to protection against F18+ E. coli infection. The induced F18-specific immune response was directed towards the major subunit FedA and weakly towards the adhesive subunit FedF. The results of these experiments demonstrate that it is difficult to induce protective immunity against F18+ E. coli using the whole fimbriae due to the low response against the adhesin.
Collapse
|
578
|
Hogenkamp A, Herías MV, Tooten PCJ, Veldhuizen EJA, Haagsman HP. Effects of surfactant protein D on growth, adhesion and epithelial invasion of intestinal Gram-negative bacteria. Mol Immunol 2007; 44:3517-27. [PMID: 17477970 DOI: 10.1016/j.molimm.2007.03.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 03/09/2007] [Accepted: 03/14/2007] [Indexed: 11/21/2022]
Abstract
Surfactant protein D (SP-D) interacts with various different microorganisms and plays an important role in pulmonary innate immunity. SP-D expression has also been detected in extrapulmonary tissues, including the gastro-intestinal tract. However, its function in the intestine is unknown and may differ considerably from SP-D functions in the lung. Therefore, the effects of porcine SP-D (pSP-D) on several strains of intestinal bacteria were studied by means of bacterial growth assays, colony-count assays, radial diffusion assays and differential fluorescent staining. Furthermore, the effect of pSP-D on the adhesion- and invasion-characteristics was investigated. All bacterial strains tested in this study were aggregated by pSP-D, but only Escherichia coli K12 was susceptible to pSP-D-mediated growth inhibition. Bacterial membrane integrity of E. coli K12 was affected by pSP-D, but this did not lead to a reduced bacterial viability. Therefore, it is unlikely that pSP-D has a direct antimicrobial effect, and the observed effects are most likely due to pSP-D-mediated bacterial aggregation. The effects of pSP-D on bacterial adhesion and invasion were studied with the porcine intestinal epithelial cell line IPI-2I. Preincubation with pSP-D results in a several-fold increase in adhesion (E. coli and Salmonella) and invasion (Salmonella), but did not affect the IL-8 production induced by the bacteria. Results obtained in this study suggest that pSP-D promotes uptake of pathogenic bacteria by epithelial cells. This may reflect a scavenger function for pSP-D in the intestine, which enables the host to generate a more rapid response to infectious bacteria.
Collapse
Affiliation(s)
- Astrid Hogenkamp
- Department of Infectious Diseases and Immunology, Division Molecular Host Defence, Graduate School of Animal Health, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands
| | | | | | | | | |
Collapse
|
579
|
Jamalludeen N, Johnson RP, Friendship R, Kropinski AM, Lingohr EJ, Gyles CL. Isolation and characterization of nine bacteriophages that lyse O149 enterotoxigenic Escherichia coli. Vet Microbiol 2007; 124:47-57. [PMID: 17560053 DOI: 10.1016/j.vetmic.2007.03.028] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 03/09/2007] [Accepted: 03/22/2007] [Indexed: 11/20/2022]
Abstract
The goal of this study was to isolate and characterize phages that might be used in prevention and treatment of porcine post-weaning diarrhea due to O149 enterotoxigenic E. coli (ETEC). Serotype O149:H10:F4 was especially targeted because this is the dominant ETEC serotype. Mixtures of 10 strains of O149:H10:F4 ETEC and of 10 O149:H43:F4 ETEC were used as hosts for isolation of phages in sewage from 38 Ontario pig farms. Six phages (GJ1-GJ6) that lysed O149:H10:F4 ETEC and three (GJ7-GJ9) that lysed O149:H43:F4 ETEC were isolated. All phages produced large, clear plaques. All nine phages had necks and contractile tails and therefore belonged to the Myoviridae. Their estimated genome sizes were 48.3-50.7kb and their restriction enzyme fragments suggested that they were closely related. Phages GJ1-GJ6 lysed 99-100% of 85 O149:H10:F4 ETEC, 0-12% of 42 O149:H43:F4 ETEC, 3-35% of 37 non-O149 porcine ETEC, and 6-68% of the 72 strains of the ECOR collection. Phages GJ7-GJ9 lysed 86-98% of the O149:H43:F4 ETEC, 2-53% of the O149:H10:F4 ETEC, and 24-41% of the non-O149 porcine ETEC. Titres of the nine phages were unaffected by exposure for 16h to pH 5-9. Among phages GJ1-GJ6, resistance of O149:H10:F4 ETEC to one phage was generally not accompanied by resistance to other phages. It is concluded that the nine phages are suitable candidates for prophylaxis and therapy of porcine post-weaning diarrhea due to O149 ETEC.
Collapse
Affiliation(s)
- Nidham Jamalludeen
- Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
| | | | | | | | | | | |
Collapse
|
580
|
Leclerc S, Boerlin P, Gyles C, Dubreuil JD, Mourez M, Fairbrother JM, Harel J. paa, originally identified in attaching and effacing Escherichia coli, is also associated with enterotoxigenic E. coli. Res Microbiol 2006; 158:97-104. [PMID: 17125971 DOI: 10.1016/j.resmic.2006.09.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2006] [Revised: 09/07/2006] [Accepted: 09/14/2006] [Indexed: 10/24/2022]
Abstract
Previous studies on virotypes and antimicrobial resistance in a collection of porcine enterotoxigenic Escherichia coli (ETEC) O149 strains from Quebec revealed an increase in the number of multiresistant strains (in particular to tetracycline) and the appearance of new virulence factors with time. Among these factors is paa (for porcine attaching- and effacing-associated), originally identified in a porcine enteropathogenic strain, but also present in enterohemorrhagic E. coli O157:H7. In the present study, the association of paa with other ETEC virulence genes, its conservation and expression were investigated in the O149 ETEC collection. All 37 paa-positive strains possessed estB, elt, astA and faeG, and more than half also carried the estA gene, defining two main virotypes, estA(+) and estA(-). Most strains were tetA- or tetB-positive, or both. paa is carried on high molecular weight plasmids. On tetA plasmids, paa is mostly found with enterotoxin gene estA and autotransporter gene sepA. Paa, a 30 kDa protein, is highly conserved and expressed in these strains. Moreover, paaETEC and porcine EPEC/EHEC contain IS signatures, suggesting that paa could be derived from a common ancestor. All these observations suggest a broader role than previously assessed in virulence for paa.
Collapse
Affiliation(s)
- Sebastien Leclerc
- Département de Pathologie et Microbiologie, Faculté de Médecine Vétérinaire, Université de Montréal, 3200, rue Sicotte, C. P. 5000, Saint-Hyacinthe, Québec, J2S 7C6 Canada
| | | | | | | | | | | | | |
Collapse
|
581
|
Helgerson AF, Sharma V, Dow AM, Schroeder R, Post K, Cornick NA. Edema disease caused by a clone of Escherichia coli O147. J Clin Microbiol 2006; 44:3074-7. [PMID: 16954229 PMCID: PMC1594711 DOI: 10.1128/jcm.00617-06] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Edema disease is a systemic disease of weaned pigs caused by host-adapted strains of Escherichia coli, most commonly belonging to serogroup O138, O139, or O141. In the late 1990s, E. coli O147 strains containing the virulence genes f18, sta, stb, and stx(2) were recovered from outbreaks of edema disease in the United States. Pulsed-field gel electrophoresis (PFGE) was used to determine that the majority of these strains (34/43) were closely related to one another. Subsequent analysis by multilocus restriction typing confirmed the PFGE results and indicated that the cluster of edema disease strains were only distantly related to other E. coli O147 strains. Serogrouping of edema disease isolates from the Iowa State University Veterinary Diagnostic laboratory recovered between 1996 and 2000 indicated that 42% belonged to serogroup O147. Our data suggest that these strains may be a common serotype of edema disease-causing E. coli in the United States.
Collapse
Affiliation(s)
- Amy F Helgerson
- Department of Veterinary Microbiology, Iowa State University, 2130 Vet. Med. Bldg., National Animal Disease Center, Ames, 50011-1250, USA
| | | | | | | | | | | |
Collapse
|
582
|
Turner SM, Chaudhuri RR, Jiang ZD, DuPont H, Gyles C, Penn CW, Pallen MJ, Henderson IR. Phylogenetic comparisons reveal multiple acquisitions of the toxin genes by enterotoxigenic Escherichia coli strains of different evolutionary lineages. J Clin Microbiol 2006; 44:4528-36. [PMID: 17050815 PMCID: PMC1698409 DOI: 10.1128/jcm.01474-06] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Escherichia coli is a diverse bacterial species which is widely distributed in the environment but also exists as a commensal and pathogen of different host species. Human intestinal pathogenic E. coli causes over 160 million cases of diarrhea and an estimated 1 million deaths per year. The majority of deaths are attributable to one pathovar of E. coli, namely, enterotoxigenic E. coli. The pathogenesis of enterotoxigenic E. coli is dependent on the production of a colonization factor to promote adhesion to the intestinal epithelium and the elaboration of heat-labile or heat-stable toxins which induce a secretory diarrhea. Despite the high morbidity and mortality associated with enterotoxigenic E. coli infection, little is known of the genetic background of this global pathogen. Here we demonstrate by multilocus sequence typing that enterotoxigenic E. coli isolates are present in all phylogenetic lineages of E. coli, indicating that acquisition of the toxin genes may be sufficient to generate an enterotoxigenic E. coli strain. In addition, screening of diarrheal isolates for the presence of additional genes previously associated with the virulence of enterotoxigenic E. coli revealed that they were not abundant. These observations have significant implications for disease epidemiology and for the design of effective vaccines.
Collapse
Affiliation(s)
- Sue M Turner
- Division of Immunity and Infection, The Medical School, The University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom, and St. Luke's Episcopal Hospital, Houston, TX 77083, USA
| | | | | | | | | | | | | | | |
Collapse
|
583
|
Kiers JL, Hoogendoorn A, Nout RMJ, Rombouts FM, Nabuurs MJA, van der Meulen J. Effect of osmolality on net fluid absorption in non-infected and ETEC-infected piglet small intestinal segments. Res Vet Sci 2006; 81:274-9. [PMID: 16969915 DOI: 10.1016/j.rvsc.2005.12.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
In the small intestinal segment perfusion model the effect of osmolality on net fluid absorption in enterotoxigenic Escherichia coli (ETEC)-infected and non-infected small intestinal segments of piglets was investigated. In ETEC-infected segments net fluid absorption was reduced. Lowering the osmolality from 375 to 150 mOsmol/l by reducing sodium chloride concentrations increased net fluid absorption. There was a linear relationship between osmolality and net fluid absorption for both non-infected and ETEC-infected segments. Below 150 mOsmol/l the inverse relationship between osmolality and net fluid absorption disappeared. Substitution of sodium chloride with mannitol decreased net fluid absorption since mannitol cannot be actively absorbed. In ETEC-infected segments perfused with oral rehydration solution net fluid absorption significantly increased compared to a sodium chloride solution of similar osmolality, probably because of the high glucose concentration. Supplying hypotonic sodium chloride fluids to piglets can be beneficial in replenishing water and electrolyte losses in case of infectious diarrhoea.
Collapse
Affiliation(s)
- J L Kiers
- Agrotechnology and Food Sciences Group of Wageningen UR, Laboratory of Food Microbiology, P.O. Box 8129, 6700 EV Wageningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
584
|
Herren CD, Mitra A, Palaniyandi SK, Coleman A, Elankumaran S, Mukhopadhyay S. The BarA-UvrY two-component system regulates virulence in avian pathogenic Escherichia coli O78:K80:H9. Infect Immun 2006; 74:4900-9. [PMID: 16861679 PMCID: PMC1539585 DOI: 10.1128/iai.00412-06] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The BarA-UvrY two-component system (TCS) in Escherichia coli is known to regulate a number of phenotypic traits. Both in vitro and in vivo assays, including the chicken embryo lethality assay, showed that this TCS regulates virulence in avian pathogenic E. coli (APEC) serotype O78:K80:H9. A number of virulence determinants, such as the abilities to adhere, invade, persist within tissues, survive within macrophages, and resist bactericidal effects of serum complement, were compromised in mutants lacking either the barA or uvrY gene. The reduced virulence was attributed to down regulation of type 1 and Pap fimbriae, reduced exopolysaccharide production, and increased susceptibility to oxidative stress. Our results indicate that BarA-UvrY regulates virulence properties in APEC and that the chicken embryo lethality assay can be used as a surrogate model to determine virulence determinants and their regulation in APEC strains.
Collapse
Affiliation(s)
- Christopher D Herren
- Virginia-Maryland Regional College of Veterinary Medicine, University of Maryland at College Park, 8075 Greenmead Drive, College Park, Maryland 20742-3711, USA
| | | | | | | | | | | |
Collapse
|
585
|
Guo X, Li D, Lu W, Piao X, Chen X. Screening of Bacillus strains as potential probiotics and subsequent confirmation of the in vivo effectiveness of Bacillus subtilis MA139 in pigs. Antonie Van Leeuwenhoek 2006; 90:139-46. [PMID: 16820971 DOI: 10.1007/s10482-006-9067-9] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2005] [Accepted: 03/03/2006] [Indexed: 10/24/2022]
Abstract
A total of 124 samples were collected from the intestine of broiler chickens, piglet faeces, fermented foods, soils and Chinese herbs. More than 750 strains of aerobic, spore-forming bacteria were isolated from these samples. The inhibitory activity of these spore-forming strains against Escherichia coli K88, E. coli K99, Salmonella typhimurium and Staphylococcus aureus was assessed using a disc plate diffusion assay. The six bacilli with the largest inhibition zones against the four indicator bacteria were chosen and assessed for their resistance to unfavorable conditions within simulated gut environments. The strain Bacillus subtilis MA139 showed full resistance to pH 2, 0.3% bile salts and exhibited the highest antimicrobial activity. Based on these results, B. subtilis MA139 was selected as a potential probiotic and fed to piglets at concentrations of 2.2 x 10(5), 2.2 x 10(6) or 2.2 x 10(7) CFU/g of feed during a 28-day feeding trial. A negative control consisting of the basal diet with no additives and a positive control consisting of the basal diet supplemented with 16 g/ton flavomycin were also included. Ninety piglets between 35 and 40 days old were used in the in vivo animal trials. B. subtilis MA139 enhanced daily gain (P = 0.10) and feed conversion (P = 0.03) compared with the negative control. The performance of pigs fed B. subtilis MA139 supplemented diets did not differ from that of pigs fed the antibiotic diet. There was a significant increase in Lactobacilli cell counts (P = 0.02) and a numerical decrease in E. coli counts (P = 0.05) in the faecal samples of pigs fed B. subtilis MA139 with 2.2 x 10(5) CFU/g of feed. The overall results of this study show that the use of initial co-culture with indicator pathogens, a disc plate diffusion assay and simulated gut environment tolerance tests is one of effective methods of screening Bacillus for probiotic use and that B. subtilis MA139 is a promising alternative to antibiotics for use as a feed additive in piglet diets.
Collapse
Affiliation(s)
- Xiaohua Guo
- National Key Laboratory on Animal Nutrition, China Agricultural University, No. 2. West Road Yuanmingyuan, Beijing 100094, PR China
| | | | | | | | | |
Collapse
|