In situ detection of urease-positive Helicobacter pylori-like organisms on swine gastric mucosa.

The objective of this study was to improve the visual localization of urease activity of Helicobacter pylori-like organisms (HPLO) on swine gastric mucosa by in vitro optimization of the urea concentration and pH indicator of a urease test reagent. Five 21-day-old conventional pigs were infected orally with HPLO (3 pigs) or Brucella broth alone (2 pigs). At 17 d after infection the pigs were euthanized and their stomachs excised and tested for HPLO by a modified urease test formulation sprayed onto the gastric mucosa, as well as confirmatory culture and isolation of HPLO from urease-positive sites.

In utero transmission of porcine torque teno viruses.

Sera and selected tissue homogenates collected from gnotobiotic swine never exposed to the environment or other swine tissues were tested for the presence of porcine torque teno virus (TTV) DNAs by nested and non-nested polymerase chain reactions (PCR) using primers specific for the untranslated region of porcine genogroups (g) 1 and 2. Twenty-three of 105 (21.9%) gnotobiotic piglets were g1- and/or g2-TTV DNA positive.

Evaluation of Mycoplasma hyopneumoniae bacterins for porcine torque teno virus DNAs.

Objective: To determine whether commercial Mycoplasma hyopneumoniae bacterins sold for use in swine contain porcine torque teno virus (TTV).

Sample Population: 22 commercially available M hyopneumoniae bacterins.

Procedures: Direct and nested PCR assays for genogroup-specific TTV DNAs were performed on serials of M hyopneumoniae bacterins by use of published and custom-designed primer pairs at 3 laboratories in North America and Europe.

A novel method for the detection of porcine circovirus type 2 replicative double stranded viral DNA and nonreplicative single stranded viral DNA in tissue sections.

Porcine circovirus type 2 (PCV2), an economically important pathogen of swine, is the necessary cause of post weaning multisystemic wasting disease (PMWS); PCV2 infection is associated with porcine dermatitis and nephritis syndrome (PDNS). Current immunohistochemical (IHC) methodologies identify PCV2 antigens but are not capable of differentiating replicating virus from nonreplicating virion particles in tissue sections. In this paper, a combination of IHC using commercial monoclonal antibodies specific for single stranded (ss) and double stranded (ds) DNA and PCV2 specific in situ hybridization (ISH) was used to show the specificity of the former for PCV2 DNA in tissue sections from PCV2-infected gnotobiotic pigs.

Age-dependent seroprevalence of antibodies against a Helicobacter pylori-like organism and Helicobacter pylori in commercially reared swine.

Objective: To determine the prevalence of antibodies against a swine-origin Helicobacter pylori-like organism (HPLO) and H pylori in conventionally reared swine.

Animals: 640 conventionally reared swine of various ages from 16 high-health farms in Canada, 20 sows from Ohio, and 35 gnotobiotic swine.

Procedures: Blood was collected from the cranial vena cava.

Isolation and preliminary characterization of a novel Helicobacter species from swine.

Objective: To determine whether a Helicobacter sp similar to Helicobacter pylori in the stomachs of humans could be isolated from the stomachs of pigs.

Animals: 4 young conventionally reared and 21 gnotobiotic pigs.

Procedure: Gastric mucosal homogenates (10% wt/vol) from 4 young conventionally reared pigs were cultured on Skirrow medium under microaerophilic conditions to assess the presence of Helicobacter spp.