The use of culture, pooled samples and PCR for identification of herds infected with Brachyspira hyodysenteriae.

Department of Large Animal Clinical Sciences, Swedish University of Agricultural Sciences, Faculty of Veterinary Medicine, Uppsala.
Animal Health Research Reviews 07/2001; 2(1):37-43. DOI: 10.1079/AHRR200120
Source: PubMed

ABSTRACT The sensitivity of culturing Brachyspira hyodysenteriae was determined after sampling with swabs from porcine fecal specimens inoculated with tenfold dilutions of a field strain of these microbes. After storage of swabs, Brachyspira hyodysenteriae was recovered throughout the first 3 weeks after inoculation from feces with more than 140 cells/g. Viable spirochetes could still be recovered after up to 83 days of storage from feces, with 1.4 x 10(6) cells or more per gram. Culture for Brachyspira spp. was performed on 285 rectal swabs, which were pooled in batches of five. The number of pooled samples positive for B. hyodysenteriae corresponded with the sum results of individual analysis of the corresponding collections of five samples. A PCR system based on the tlyA gene of B. hyodysenteriae was developed and tested on primary cultures of pooled samples. The results of the PCR assay showed a 97% correlation with the culture results. The prevalence of Brachyspira spp. was determined in five swine herds and found to be highest among breeding gilts and boars aged 13-16 weeks and among 6-12-week-old weaned pigs. In contrast, Brachyspira spp. were only rarely found in sows, which may reflect the development of immunity by adult pigs to all species of the genus.

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    ABSTRACT: The fastidious, anaerobic spirochaete Brachyspira is capable of causing enteric disease in avian, porcine and human hosts, amongst others, with a potential for zoonotic transmission. Avian intestinal spirochaetosis (AIS), the resulting disease from colonisation of the caeca and colon of poultry by Brachyspira leads to production losses, with an estimated annual cost of circa £18 million to the commercial layer industry in the United Kingdom. Of seven known and several proposed species of Brachyspira, three are currently considered pathogenic to poultry; B. alvinipulli, B. intermedia and B. pilosicoli. Currently, AIS is primarily prevented by strict biosecurity controls and is treated using antimicrobials, including tiamulin. Other treatment strategies have been explored, including vaccination and probiotics, but such developments have been hindered by a limited understanding of the pathobiology of Brachyspira. A lack of knowledge of the metabolic capabilities and little genomic information for Brachyspira has resulted in a limited understanding of the pathobiology. In addition to an emergence of antibiotic resistance amongst Brachyspira, bans on the prophylactic use of antimicrobials in livestock are driving an urgent requirement for alternative treatment strategies for Brachyspira-related diseases, such as AIS. Advances in the molecular biology and genomics of Brachyspira heralds the potential for the development of tools for genetic manipulation to gain an improved understanding of the pathogenesis of Brachyspira.
    Veterinary Microbiology 11/2013; 168(2-4). DOI:10.1016/j.vetmic.2013.11.019 · 2.73 Impact Factor
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    ABSTRACT: BACKGROUND:Avian intestinal spirochetosis (AIS) is caused by spiral-shaped Gram-negative Brachyspira spp. in poultry and is known as a cause of diarrhea, low egg production, and increased occurrence of dirty eggs in layer hens. OBJECTIVES: In this study, the presence of some Brachyspira spp. was investigated in laying hens. METHODS: A total of 100 cloacal swab samples were individually collected from 20 laying hen flocks showing fecal egg staining in northeastern Iran. RESULTS: Using culture and morphologic examination, 41 samples (41%) from 20 flocks were positive; however, by using genus-specific PCR, only 37 (37%) samples were confirmed as Brachyspira spp. Using speciesspecific primers, single colonization was identified in 18 samples associated with B. pilosicoli (48.6%), while single colonization with B. intermedia was found in only two samples (5.4%). Simultaneous colonization by B. intermedia and B. murdochii was detected in 3 samples (8.1%). B. pilosicoli was the most prevalent species in concurrent colonization in 11 cases (29.7%). Finally, cocolonization by B. intermedia and B. innocens was identified in 3 samples (8.1%). CONCLUSIONS: The results of this study showed the colonization of different species of Brachyspira with dominance of B. pilosicoli in layer hens.
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    ABSTRACT: The general aim of this thesis was to study enteric diseases in growing pigs, with special reference to diseases caused by Brachyspira hyodysenteriae and Lawsonia intracellularis. The occurrence of enteric diseases in “growers” is a problem of increasing importance in Sweden and an understanding of the mechanisms by which the microorganisms causes enteric diseases is essential to develop good prophylactic measures. The most important microorganisms involved in enteric diseases in grower pigs were identified as Lawsonia intracellularis and Brachyspira pilosicoli, as determined by necropsy, microbiological and histopathological examinations performed on representative growing pigs from good and poor performing herds. Diagnostic methods based on polymerase chain reaction for L. intracellularis in tissue or faecal samples were established and the results related to those obtained by necropsy and serology. An internal control, a mimic, was constructed to demonstrate inhibition of the PCR reactions and to evaluate different preparation methods. The methods for the demonstration of L. intracellularis in tissue samples were sensitive and specific, and the bacteria were reliably identified in faeces from pigs with overt disease. A number of factors interacting in the clinical expression of swine dysentery were evaluated. In this work, group-housing of pigs and the addition of 50% soybean meal in feed was shown to predispose for infection. A model was developed that enabled the sequential monitoring of disease in single animals by repeated endoscopy and biopsy sampling through a caecal cannula. This reduced the number of experimental animals required and increased the accuracy of the study. The general condition of the animal was not affected. The model was used to study the development of experimentally induced swine dysentery and the sequential development of lesions was characterised by histopathology and immunohistochemistry. An increase in the acute phase proteins serum amyloid A and haptoglobin and in monocytes was seen when haemorrhagic dysentery occurred.