D349 - Helicobacter spp.

Description:

Helicobacter is a genus of gram-negative, microaerophilic, curved to spiral-shaped bacteria isolated from gastric mucosa of humans and animals. To date, the genus Helicobacter includes 14 formally named species as well as other unnamed closely related organisms. Species known to cause infection in canines and/or felines include H. pylori, H. felis, and H. bizzozeronii. Helicobacter are tolerant of low pH, allowing them to colonize the stomach. In most dogs and cats, Helicobacter lives quietly and causes either no symptoms or only mild disease, but the symptoms vary between species and the extent of the infection. The most common symptom in dogs and cats is mild, intermittent vomiting. Some dogs may develop ulcers of the stomach lining, while cats may develop inflammatory bowel disease, a condition in which the intestinal and stomach lining becomes thickened and prevents proper absorption of nutrients. Vomiting in dogs with chronic superficial gastritis attributed to Helicobacter spp. has been characterized as intermittent, consisting of mucus or gastric secretions, sometimes containing bile. Pica, belching, anorexia, and weight loss also are occasionally noted. In ferrets, Helicobacter often causes severe, sometimes fatal diarrhea. Humans develop a range of symptoms from mild gastric reflux (heartburn) to severe bleeding ulcers. Signs attributed to gastric helicobacteriosis have been based on finding these organisms in gastric biopsy samples from animals with GI illness. Because these organisms can be present in clinically healthy animals, the direct cause-and-effect relationship to clinical illness cannot always be ascertained.
The mechanisms of Helicobacter transmission are poorly understood. Gastric helicobacters are specific for enteric tissue and colonize only gastric and not intestinal epithelium. Fecal-oral transmission has been suggested, but helicobacters have rarely been isolated from feces of animals or humans using conventional methods of detection. Oral-oral transmission is more likely and is supported by the fact that H. pylori was cultured from feline salivary secreations in 50% of infected cats and from gastric fluid samples in 91% of infected cats .

Diagnosis:

Previously, diagnosis of Helicobacter spp. required culturing and isolation of the specific strain thought to be associated with an infection. Unfortunately, H. bizzozeronii, one of most common spiral organisms in dogs and cats, has been extremely difficult to culture on artificial media, and H. felis has been very difficult to isolate. A diagnosis of chronic gastritis in animals, as in humans, cannot be made by gross visual examination of the gastric mucosa by endoscopy. Histologic evaluation of gastric biopsy samples has been used successfully, however, this method requires the use of a special silver stain or modified Giemasa stain to reveal the presence of gastric Helicobacter-like organisms. Serologic assays are being employed to diagnose H. pylori in humans. Still, these assays do not provide a reliable, non-invasive diagnostic test for gastric Helicobacter infection in dogs and cats. Recently, a PCR-based test for the presence of Helicobacter spp. became available. PCR is an excellent diagnostic test for Helicobacter infections because it is specific, sensitive, and rapid. Using this assay, it is possible to definitively confirm the presence of Helicobacter spp. in a sample, since the test relies on detecting and amplifying genetic sequences that are unique to the organism.

Sample:

1. Feces in a sterile container.
2. Tissue biopsy of affected organ.
3. Salivary fluid / oral swab in a sterile container.

Special Handling:

Store samples at 4°C until pick up or shipment.

Test Code:

D349