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equine assay data sheet Clostridium
species B0037 is included in P0015 - equine GI/diarrhea panel Test code: B0042 - Ultrasensitive qualitative detection of Clostridium perfringens alpha toxin and enterotoxin by real time PCR Test code: B0043 - Ultrasensitive qualitative detection of Clostridium piliforme (Tyzzer's disease) bacteria by real time PCR Test code: B0061 - Qualitative detection but not differentiation of several common Clostridium species, including C. difficile, C. piliforme and C. perfringens, by polymerase chain reaction. Assay DOES NOT detect Clostridium botulinum.
Clostridium difficile The organism is an important cause of enteric disease in laboratory rodents and horses. Hamsters, guinea pigs and mice may be affected by pseudomembranous colitis induced by antimicrobial therapy. In neonatal foals, C. difficile has been associated with hemorrhagic necrotizing enterocolitis and diarrhea. The lack of an established intestinal microflora may make foals more susceptible to colonization by this bacterium. Adult horses may develop typhlocolitis and outbreaks of nosocomially acquired diarrhea have been reported (Donaldson and Palmer, 1999; Madewell et al., 1995; Perrin et al., 1993). C. difficile has also recently been implicated as a cause of typhlocolitis in nursing piglets, chronic diarrhea in dogs and enterotoxemia in ostriches. In clinically normal patients, an established intestinal microflora is thought to competitively prevent proliferation of C. difficile and subsequent toxin attachment. Alteration of intestinal microbial balance with antibiotic use and increased exposure to the organism in a hospital setting allows C. difficile to colonize the gut in susceptible individuals. Bacterial culture of C. difficile is not highly sensitive and does not differentiate the pathogenic and non-pathogenic strains. Specific tests for C. difficile toxins used in the diagnostic laboratory include cell culture, which relies on the presence of biologically active toxin, and an ELISA assay which detects immunologically active toxin that may or may not be biologically active. PCR detection of C. difficile is highly sensitive and can discriminate between toxigenic and nontoxigenic strains of the organism by detecting its toxin producing genes.
Clostridium perfringens Infections due to C. perfringens can result in tissue necrosis, bacteremia, emphysematous cholecystitis and gas gangrene. The bacteria can secrete α-toxin which results in gangrene formation. If patients ingest the bacteria, colic, diarrhea and sometimes nausea can result. Food poisoning due to C. perfringens bacteria is one of the common causes of food-borne illness. Poorly prepared meat and poultry are commonly the sources of food poisoning. The enterotoxin (CPE) secreted by the bacteria, which mediates the food poisoning, is heat-resistant and cannot be destroyed easily. Furthermore, the bacteria themselves form spores that can withstand cooking temperatures. If these spores are then left at room temperature, germination may begin and infective bacterial colonies develop. Generally, the incubation time of these spores is 6 to 24 (commonly 10 to 12) hours after ingestion of contaminated food. Since meat and poultry are often prepared in advance of consumption, this allows good opportunities for the spores to germinate. People ingesting these bacteria can develop abdominal cramping and diarrhea. Vomiting and fever are unusual. Illness usually resolves within 24 hours. It is also possible that many cases of C. perfringens food poisoning remain subclinical, as antibodies to the toxin are common among humans. This has led to the conclusion that most of the population has experienced food poisoning due to C. perfringens. Detection of C. perfringens by culture is slow and not very sensitive. PCR detection is the method of choice for rapid, sensitive and specific detection of this pathogen (Abubakar, 2007).
Clostridium piliforme The organism is an obligate gram-negative bacteria found in necrotic foci in spore forms. Transmission is mainly through the fecal-oral route. Although Tyzzer’s is a severe disease in many animal species, infected mice often do not exhibit clinical symptoms. These mice become carriers of the disease and spread the pathogen to other mice and other animal species. Interestingly, different mouse strains differ in their susceptibility to the pathogen (Waggie et al., 1981). Clostridium piliforme cannot be cultivated in artificial media, so diagnosis may be based on microscopic examination of tissues, serological assays or steroid challenge tests; these methods all require blood or necropsy samples. When steroid challenge assays are performed, extreme care must be taken to avoid spreading the pathogen. Moreover, microscopic examination, serology and steroid challenge all suffer from a lack of sensitivity and are labor intensive. Detection of this pathogen by polymerase chain reaction is highly sensitive and specific. The test can be performed on fecal specimens rather than blood or tissue, resulting in less trauma and risk to animals. Utilities:
References: Specimen requirements: Rectal swab, or 0.2 ml feces, or food swab, or lesion swab, or environmental surface swab. Contact Zoologix if advice is needed to determine an appropriate specimen type for a specific diagnostic application. For specimen types not listed here, please contact Zoologix to confirm specimen acceptability and shipping instructions. For all specimen types, if there will be a delay in shipping, or during very warm weather, refrigerate specimens until shipped and ship with a cold pack unless more stringent shipping requirements are specified. Frozen specimens should be shipped so as to remain frozen in transit. See shipping instructions for more information. Turnaround time: 2 business days Methodology: Qualitative PCR Normal range: Nondetected |
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