A survey on the occurrence of Brachyspira pilosicoli and Brachyspira hyodysenteriae in growing-finishing pigs

Background: The major pathogenic intestinal spirochetes affecting pigs during the growing- finishing stage of production include Brachyspira hyodysenteriae and Brachyspira pilosicoli. The aim of this study was to assess the current occurrence of B. hyodysenteriae and B. pilosicoli in Polish pig herds. Moreover, associations between the presence of diarrhea or other intestinal pathogens and occurrence of B. hyodysenteriae and B. pilosicoli in pigs were investigated. Methods: Between January 2017 and August 2019, a total of 401 samples of pig feces from 95 different herds were submitted to the National Veterinary Research Institute of Poland. These samples were obtained from pigs older than 7 weeks. All the received fecal samples were examined for the presence of B. hyodysenteriae, B. pilosicoli and Lawsonia intracellularis by real-time PCR. Results: B. pilosicoli was detected in 4.5% (95% CI, 2.5–7.0%) (18/401) of pig fecal samples. At the herd level 13.7% (95% CI, 7.5–22.3%) (13/95) of herds were positive for B. pilosicoli. B. hyodysenteriae was detected in 7.0% (95% CI, 4.7–9.9%) (28/401) of pig fecal samples and 18.9% (95% CI, 11.6–28.3%) (18/95) of pig herds were positive. Out of 18 B. pilosicoli positive samples, this pathogen was detected alone in 5 samples; simultaneously with L. intracellularis in 9 samples; simultaneously with B. hyodysenteriae in 1 sample and in 3 samples was detected simultaneously with both of these bacteria. The presence of B. hyodysenteriae in fecal samples was associated with the presence of diarrhea in pigs. Conclusions: This study confirmed that B. pilosicoli infections occur in Polish pig herds, but the prevalence is at a low level and the presence of B. pilosicoli is not associated with the development of diarrhea in pigs. B. hyodysenteriae is still a common cause of diarrhea among pigs from Polish herds.

Identification and distribution of Brachyspira species in feces from finishing pigs in Argentina

Background and Aim: Brachyspira are Gram-negative, aerotolerant spirochetes that colonize the large intestine of various species of domestic animals and humans. The aim of this study was to determine the presence and distribution of different species of Brachyspira presents in feces from finishing pigs in Argentina. Materials and Methods: Fecal samples (n=1550) were collected from finishing pigs in 53 farms of the most important swine production areas of Argentina, and Brachyspiras species were identified by bacteriological and molecular methods. Results: The regional prevalence of Brachyspira spp. was at the level of 75.5% (confidence interval 95%, 62.9-87.9), and it was lower among those farms with >1001 sows. One hundred and twenty-eight isolates of Brachyspira were properly identified and the species found were: Brachyspira hyodysenteriae, Brachyspira pilosicoli, Brachyspira innocens, and Brachyspira murdochii. B. hyodysenteriae and B. pilosicoli had low prevalence (1.9% and 7.5%, respectively), B. innocens was isolated from 34% of the farms and B. murdochii was found in 39.6%. Conclusion: The present study provides epidemiological data about herd prevalence of the different Brachyspira species in Argentina, showing that the prevalence figure seems to be higher than that reported in other countries.

Evidence of homologous recombination as a driver of diversity in Brachyspira pilosicoli

The enteric, pathogenic spirochaete Brachyspira pilosicoli colonizes and infects a variety of birds and mammals, including humans. However, there is a paucity of genomic data available for this organism. This study introduces 12 newly sequenced draft genome assemblies, boosting the cohort of examined isolates by fourfold and cataloguing the intraspecific genomic diversity of the organism more comprehensively. We used several in silico techniques to define a core genome of 1751 genes and qualitatively and quantitatively examined the intraspecific species boundary using phylogenetic analysis and average nucleotide identity, before contextualizing this diversity against other members of the genus Brachyspira . Our study revealed that an additional isolate that was unable to be species typed against any other Brachyspira lacked putative virulence factors present in all other isolates. Finally, we quantified that homologous recombination has as great an effect on the evolution of the core genome of the B. pilosicoli as random mutation (r/m=1.02). Comparative genomics has informed Brachyspira diversity, population structure, host specificity and virulence. The data presented here can be used to contribute to developing advanced screening methods, diagnostic assays and prophylactic vaccines against this zoonotic pathogen.

716. A Case of Symptomatic Intestinal Spirochetosis

Background Intestinal spirochetosis (IS) is a condition caused by Brachyspira aalborgi and Brachyspira Pilosicoli. Its clinical significance has long been a point of contention with some debating that these spirochetes are simply colonic commensals. It is a condition that is more prevalent in developing nations as well as patients with HIV and the homosexual population. The epidemiology and prevalence of IS has not been studied in the local context. Methods We reviewed a case of a 37-year-old man who presented with a two month history of persistent lower abdominal pain, hematochezia, and increase in mucous discharge per rectum. He is sexually active with multiple male partners, and was previously treated for gonorrhea, chlamydia, and syphilis. His basic laboratory investigations were unremarkable, Venereal Disease Research Laboratory (VDRL) antibody and human immunodeficiency virus (HIV) screen were both non-reactive. Computed tomography of the abdomen was unremarkable. Endoscopic evaluation revealed multiple discrete ulcers measuring 1-2mm seen only in the rectum. Random biopsies of the cecum, ascending colon, transverse colon and descending colon showed mild acute colitis with IS. There was also mild to moderate acute proctitis in the rectum with spirochetes seen. 16s RNA gene sequencing of the biopsy specimen were confirmatory for Brachyspira aalborgi. Investigation findings. A: Discrete Ulcers found in rectum, B: Hemotoxylin and Eosin stained specimen showing proctitis, C: False brush Border appearance D: Spirochetes on Warthin Starry stain Results The patient received a 10 day course of metronidazole with complete resolution of his symptoms. Conclusion This case demonstrates the existence of a treatable condition that can be diagnosed with current available investigations for patients with similar symptoms. Recognising at risk populations can also raise clinical suspicion for this condition. Some studies have found associations between IS with development of colonic polyps and also certain colorectal cancers. Further studies on this treatable condition and its disease burden in the local context should be further explored. Disclosures All Authors: No reported disclosures

A survey on the occurrence of Brachyspira pilosicoli and Brachyspira hyodysenteriae in growing-finishing pigs

Background: The major pathogenic intestinal spirochetes affecting pigs during the growing- finishing stage of production include Brachyspira hyodysenteriae and Brachyspira pilosicoli. The aim of this study was to assess the current occurrence of B. hyodysenteriae and B. pilosicoli in Polish pig herds. Moreover, associations between the presence of diarrhea or other intestinal pathogens and occurrence of B. hyodysenteriae and B. pilosicoli in pigs were investigated. Methods: Between January 2017 and August 2019, a total of 401 samples of pig feces from 95 different herds were submitted to the National Veterinary Research Institute of Poland. These samples were obtained from pigs older than 7 weeks. All the received fecal samples were examined for the presence of B. hyodysenteriae, B. pilosicoli and Lawsonia intracellularis by real-time PCR. Results: B. pilosicoli was detected in 4.5% (95% CI, 2.5–7.0%) (18/401) of pig fecal samples. At the herd level 13.7% (95% CI, 7.5–22.3%) (13/95) of herds were positive for B. pilosicoli. B. hyodysenteriae was detected in 7.0% (95% CI, 4.7–9.9%) (28/401) of pig fecal samples and 18.9% (95% CI, 11.6–28.3%) (18/95) of pig herds were positive. Out of 18 B. pilosicoli positive samples, this pathogen was detected alone in 5 samples; simultaneously with L. intracellularis in 9 samples; simultaneously with B. hyodysenteriae in 1 sample and in 3 samples was detected simultaneously with both of these bacteria. The presence of B. hyodysenteriae in fecal samples was associated with the presence of diarrhea in pigs. Conclusions: This study confirmed that B. pilosicoli infections occur in Polish pig herds, but the prevalence is at a low level and the presence of B. pilosicoli is not associated with the development of diarrhea in pigs. B. hyodysenteriae is still a common cause of diarrhea among pigs from Polish herds.

First identification and characterisation of Brachyspira hyodysenteriae in pigs in Hong Kong

Swine dysentery (SD) is an important endemic disease of pigs throughout the world. The most common aetiological agent is the anaerobic intestinal spirochaete Brachyspira hyodysenteriae. The related spirochaete Brachyspira pilosicoli causes a milder form of colitis. We report the first isolation of B. hyodysenteriae and B. pilosicoli from a pig farm in Hong Kong. Faecal samples containing mucus or fresh blood were collected from the ground where finisher pigs had just been loaded into a truck for transport to the abattoir. The samples were subjected to selective anaerobic culture and PCR for B. hyodysenteriae and B. pilosicoli, and two isolates of both species were obtained. The B. hyodysenteriae isolates showed clinical resistance to tylosin and lincomycin, whilst the B. pilosicoli isolates were resistant to tylosin and showed intermediate susceptibility to lincomycin. The B. hyodysenteriae isolates were subjected to multilocus sequence typing and a single previously undescribed sequence type (ST250) was identified. Disease was not recorded in other pigs on the farm, but it may have been masked by the use of antimicrobials. Further work is required to examine the distribution of these two pathogens in this and other farms in Hong Kong and in adjoining mainland China.

Correction to: The pathogenic intestinal spirochaete Brachyspira pilosicoli forms a diverse recombinant species demonstrating some local clustering of related strains and potential for zoonotic spread

The article published in 2013 [1] described the use of the available Brachyspira multilocus sequence typing (MLST) scheme [2] to characterize the population structure of the intestinal spirochete Brachyspira pilosicoli. It used sequences of seven loci that were amplified from 131 strains that had been isolated from different geographical origins and species.

A survey on the occurrence of Brachyspira pilosicoli and Brachyspira hyodysenteriae in growing-finishing pigs

Background: The major pathogenic intestinal spirochetes affecting pigs during the growing- finishing stage of production include Brachyspira hyodysenteriae and Brachyspira pilosicoli. Infections by these pathogens, which affect the economics of pig production, can result in mortality, growth rate losses and substantial antibiotic costs. The aim of this study was to assess the current occurrence of B. hyodysenteriae and B. pilosicoli in Polish pig herds. Moreover, associations between the presence of diarrhea or other intestinal pathogens and occurrence of B. hyodysenteriae and B. pilosicoli in pigs were investigated. Methods: Between January 2017 and August 2019, a total of 401 samples of pig feces from 95 different herds were submitted to the National Veterinary Research Institute of Poland. These samples were obtained from pigs older than 7 weeks. All the received fecal samples were examined for the presence of B. hyodysenteriae, B. pilosicoli and Lawsonia intracellularis by real-time PCR. Results: For B. pilosicoli, 4.5% (95% CI, 2.5–7.0%) of samples and 13.7% (95% CI, 7.5–22.3%) of herds were positive. Out of 12 samples, B. pilosicoli was detected simultaneously with L. intracellularis, B. hyodysenteriae and B. pilosicoli were detected alone in two samples each. In terms of B. hyodysenteriae, 7.0% of samples (95% CI, 4.7–9.9%) from 18.9% of herds (95% CI, 11.6–28.3%) were positive in real time PCR. The presence of B. hyodysenteriae in fecal samples was associated with the presence of diarrhea in pigs. Conclusions: This study confirmed that B. pilosicoli infections occur in Polish pig herds, but the prevalence is at a low level and the presence of B. pilosicoli is not associated with the development of diarrhea in pigs. B. hyodysenteriae is still a common cause of diarrhea among pigs from Polish herds.