Olson L D
Department of Veterinary Pathology, College of Veterinary Medicine, University of Missouri, Columbia 65211, USA.
J Am Vet Med Assoc. 1995 Dec 1;207(11):1470-2.
To determine the survival of Serpulina hyodysenteriae in an infected lagoon that received effluent from a confinement building housing swine dysentery-infected swine.
Prospective controlled trial.
48 shedder swine inoculated with S hyodysenteriae and housed in the building drained by the lagoon; 18 clinically normal detector swine confined in a separate building.
Shedder swine were inoculated with S hyodysenteriae by oral administration of 20 g of diced colon from swine infected with swine dysentery. The lagoon that received effluent from the building housing the shedder swine was assayed for S hyodysenteriae by providing lagoon effluent twice daily for 2 or 4 days to detector swine as their sole source of drinking water and by subsequently examining these swine for signs of swine dysentery. Smears from rectal swab specimens and sometimes fecal specimens were stained for detection of large spirochetes. Fecal and rectal swab specimens and colonic scraping specimens were examined for S hyodysenteriae by anaerobic microbial culture on blood agar containing 400 micrograms of spectinomycin/ml. All shedder swine were necropsied after removal from the confinement building, as were detector swine after developing diarrhea or after 42 days of monitoring.
For the first 5 to 6 days after removal of swine dysentery-infected shedder swine from the confinement building, lagoon effluent from the building remained infective. Detector swine, given lagoon effluent as their drinking water for a 2-day period, developed clinical swine dysentery, and S hyodysenteriae was cultured from specimens from these swine. Swine dysentery did not develop in each group of 2 detector pigs given lagoon effluent as their sole source of drinking water on days 7 and 8, 9 and 10, 11 through 14, or 15 through 18 after removal of the infected shedder swine. Large spirochetes were not observed on microscopy of stained colonic scraping specimens, and S hyodysenteriae and Salmonella spp were not cultured from specimens from these detector swine after being monitored for 42 days. Serpulina hyodysenteriae or Salmonella spp were not cultured from samples of the lagoon effluent.
Although many factors could influence the survivability of S hyodysenteriae in a lagoon, results suggested that a facility with an open gutter-flush system that housed swine dysentery-infected swine should remain idle for more than 5 to 6 days before repopulating with unexposed swine.
确定猪痢疾蛇形螺旋体在一个受感染的泻湖中的存活情况，该泻湖接收来自饲养感染猪痢疾猪的封闭猪舍的废水。
前瞻性对照试验。
48头接种猪痢疾蛇形螺旋体并饲养在由该泻湖排水的猪舍中的排菌猪；18头临床正常的检测猪饲养在单独一栋猪舍中。
给排菌猪口服20克来自感染猪痢疾猪的切碎结肠，以接种猪痢疾蛇形螺旋体。通过每天两次向检测猪提供泻湖废水，持续2天或4天作为其唯一饮用水源，并随后检查这些猪是否有猪痢疾迹象，来检测接收排菌猪舍废水的泻湖中的猪痢疾蛇形螺旋体。对直肠拭子标本涂片，有时也对粪便标本涂片进行染色，以检测大型螺旋体。通过在含400微克壮观霉素/毫升的血琼脂上进行厌氧微生物培养，检查粪便、直肠拭子标本和结肠刮取标本中是否存在猪痢疾蛇形螺旋体。所有排菌猪从封闭猪舍移出后进行剖检，检测猪在出现腹泻后或监测42天后进行剖检。
在将感染猪痢疾的排菌猪从封闭猪舍移出后的最初5至6天内，该猪舍的泻湖废水仍具传染性。给检测猪饮用泻湖废水2天，它们出现了临床猪痢疾，并且从这些猪的标本中培养出了猪痢疾蛇形螺旋体。在感染的排菌猪移出后的第7和8天、第9和10天、第11至14天或第15至18天，每组2头饮用泻湖废水作为唯一饮用水源的检测猪均未出现猪痢疾。对染色的结肠刮取标本进行显微镜检查未观察到大型螺旋体，在对这些检测猪监测42天后，从它们的标本中未培养出猪痢疾蛇形螺旋体和沙门氏菌属。从泻湖废水样本中未培养出猪痢疾蛇形螺旋体或沙门氏菌属。
尽管许多因素可能影响猪痢疾蛇形螺旋体在泻湖中的存活能力，但结果表明，一个采用开放式水槽冲洗系统且曾饲养感染猪痢疾猪的设施，在重新饲养未接触过病原体的猪之前，应闲置5至6天以上。
