The endemic treponematoses

The agents of human treponematoses include four closely related members of the genus Treponema: three subspecies of Treponema pallidum plus Treponema carateum. T. pallidum subsp. pallidum causes venereal syphilis, while T. pallidum subsp. pertenue, T. pallidum subsp. endemicum, and T. carateum are the agents of the endemic treponematoses yaws, bejel (or endemic syphilis), and pinta, respectively. All human treponematoses share remarkable similarities in pathogenesis and clinical manifestations, consistent with the high genetic and antigenic relatedness of their etiological agents. Distinctive features have been identified in terms of age of acquisition, most common mode of transmission, and capacity for invasion of the central nervous system and fetus, although the accuracy of these purported differences is debated among investigators and no biological basis for these differences has been identified to date. In 2012, the World Health Organization (WHO) officially set a goal for yaws eradication by 2020. This challenging but potentially feasible endeavor is favored by the adoption of oral azithromycin for mass treatment and the currently focused distribution of yaws and endemic treponematoses and has revived global interest in these fascinating diseases and their causative agents.

Endemic treponematosis: review and update

Despite major efforts to eradicate these disorders, yaws, bejel, and pinta (endemic treponematosis) remain serious health issues in many regions of the world. Aside from prominent skin manifestations, these diseases may also lead to significant osseous, neurologic, and ophthalmologic complications. Although progress has been made in differentiating the causative species in a research setting, a simple, specific, and sensitive diagnostic test remains elusive. Parenteral penicillin, in appropriate dosage, is the treatment of choice; alternative antibiotics such as tetracycline and erythromycin may also be effective.

[Overview of endemic treponematoses]

Endemic treponematoses including yaws, bejel, pinta are distinguished from venereal syphilis on the basis of epidemiological characteristics and clinical manifestations. They cannot be differentiated by morphological and serological methods. A few minor genetic differences have been identified among the subspecies (Treponema pallidum sp. pallidum, pertenue, endemicum, carateum). Although penicillin therapy is effective, these infectious diseases have yet to be eliminated.

[Rare cause of cholestatic hepatitis]

When bile duct obstruction is ruled out newly developed icterus is mainly caused by infection with hepatotropic viruses, autoimmune hepatitis or drug induced hepatopathy. We report on a 30 year old previously healthy patient with cholestatic hepatitis which was caused by infection with Treponema pallidum. Cholestatic hepatitis resolved after administration of penicillin without recurrence.

Clinical features and rapid plasma reagin antibody titers in spontaneous and experimental rabbit syphilis

Rapid plasma reagin (RPR) titers were periodically examined during and after treatment in three rabbits clinically diagnosed with rabbit syphilis. RPR titers remained positive after clinical recovery and then gradually declined. Of the two rabbits inoculated experimentally, one showed clinical signs of the disease, while the other did not. RPR titers were also periodically evaluated before and after inoculation in these two rabbits. The trends in RPR titers reflected the course of infection, both in the spontaneous and in the experimental cases. An inapparent case and cases without clinical signs after clinical recovery showed low titers for long period of time. Useful information for interpretation of RPR titers measured clinically was obtained by this survey.

Acute bacterial suppurative parotitis: microbiology and management

The parotid gland is the salivary gland most commonly affected by inflammation. The most common pathogens associated with acute bacterial parotitis are Staphylococcus aureus and anaerobic bacteria. The predominant anaerobes include gram-negative bacilli (including pigmented Prevotella and Porphyromonas spp.), Fusobacterium spp., and Peptostreptococcus spp. Streptococcus spp. (including S. pneumoniae) and gram-negative bacilli (including Escherichia coli) have also been reported. Gram-negative organisms are often seen in hospitalized patients. Organisms less frequently found are Arachnia, Haemophilus influenzae, Klebsiella pneumoniae, Salmonella spp., Pseudomonas aeruginosa, Treponema pallidum, cat-scratch bacillus, and Eikenella corrodens. Mycobacterium tuberculosis and atypical mycobacteria are rare causes of parotitis. Therapy includes maintenance of hydration and administration of parenteral antimicrobial therapy. Once an abscess has formed surgical drainage is required. The choice of antimicrobial depends on the etiologic agent. Maintenance of good oral hygiene, adequate hydration, and early and proper therapy of bacterial infection of the oropharynx may reduce the occurrence of suppurative parotitis.

Detection of spirochetes by polymerase chain reaction and its relation to the course of digital dermatitis after local antibiotic treatment in dairy cattle

The aim of the study was to monitor the course of digital dermatitis after local antibiotic treatment in an experimental group (treated on diagnosis) and a control group (treated 5 days later). The present study was carried out on 2 farms involving 18 animals. Monitoring was performed by means of clinical findings and detection of spirochetes on the surface of the lesions, using a polymerase chain reaction. Superficial wound smears were taken before and after treatment. Twelve animals on both farms followed the classical healing process, but six animals responded poorly to treatment. We observed that without treatment, there was no self-cure in the control group within 5 days. There was a significant improvement in the clinical condition of all animals after treatment on both farms, during the follow-up period. The time until reappearance of new digital dermatitis lesions was not significantly different between the experimental and control group, but it was different between the two farms which could be due to the influence of farm factors. Using primers specific for Treponema denticola and Treponema vincentii, all the disease stages had at least one positive polymerase chain reaction result indicating the presence of spirochetes in samples of all the disease stages during the healing process. This implies that the spirochetes are not completely eradicated from the surface of the lesions after treatment. It was also observed that the classical ulcerative disease stage (M2) had relatively more positive polymerase chain reaction results compared to any other disease stage, showing a possible link between the presence of spirochetes and clinical disease.

Bejel in Malatya, Turkey

Bejel is a form of endemic syphilis which is transmitted by non-venereal route. According to our knowledge, no cases of bejel have been reported from Turkey for more than 30 years. In this report, three children and their father who suffer from bejel are presented. The history, physical findings, laboratory investigations, treatment and results of the cases are reviewed, and the related literature is discussed.

[Provision and measures for sanitation in piglet breeding operations with latent swine dysentery]

The eradication and control of swine dysentery in breeding or farrow-to-finish herds require comprehensive knowledge about the epidemiology, pathogenesis and immunology of this typical multifactorial disease. Based upon this background information, the characteristics of chemotherapy, immunoprophylaxis and other necessary concomitant measures are described. The objectives of the eradication and control schemes should be the production of Treponema-free weaner pigs and a long-term prevention of reinfections.

Role of intestinal excretion in the effect of subcutaneously administered sedecamycin on cecal infection caused by Treponema hyodysenteriae in mice

The therapeutic effects of subcutaneously administered sedecamycin on experimental Treponema hyodysenteriae infection in mice were evaluated. Sedecamycin was more active than tiamulin and lincomycin. The efficacy of sedecamycin upon subcutaneous administration was similar to that upon oral administration. Sedecamycin given subcutaneously provided similar degrees of protection in bile duct-ligated and intact mice. Pharmacokinetic studies utilizing a liquid chromatographic technique were carried out to determine the concentration of sedecamycin in the cecum, the site of T. hyodysenteriae infection in mice. Little sedecamycin was found; however, lankacidinol, a major metabolite of sedecamycin, was found in the cecal contents of intact mice after subcutaneous or oral administration of sedecamycin. Lankacidinol was also found in the cecal contents of bile duct-ligated mice, although the concentration found after subcutaneous administration of sedecamycin was much lower than that found after subcutaneous or oral administration to intact mice. These results indicate that sedecamycin is excreted directly into the intestinal tract as an active metabolite by a route other than the bile duct. It is suggested that this intestinal excretion plays an important role in the efficacy of subcutaneously administered sedecamycin against cecal infection of mice by T. hyodysenteriae.

UK-69,753, a novel member of the efrotomycin family of antibiotics. II. Structure determination and biological activity

A novel antibiotic, UK-69,753, has been isolated from a submerged fermentation of Amycolatopsis orientalis strain N731-15. UK-69,753 has been assigned the structure 1 using spectroscopic means, primarily by NMR analysis. UK-69,753 is a glycoside of factumycin (A40A), a previously reported member of a small group of antibiotics related to aurodox and efrotomycin. UK-69,753 was shown to have potent activity both in vitro and in vivo against the swine pathogen Treponema hyodysenteriae.

In vitro and in vivo activities of sedecamycin against Treponema hyodysenteriae

Sedecamycin (lankacidin A), one of the lankacidin-group antibiotics, showed potent activity against Treponema hyodysenteriae. The MICs of sedecamycin against 79 field isolates of T. hyodysenteriae ranged from 0.78 to 12.5 micrograms/ml, the MIC for 90% of the strains tested (MIC90) being 3.13 micrograms/ml. The protective and therapeutic effects of sedecamycin were compared with those of carbadox, tiamulin, and lincomycin against experimental infection with T. hyodysenteriae in mice. The protective effect of sedecamycin was similar to that of carbadox, two times more potent than that of tiamulin, and three times greater than that of lincomycin. In the therapeutic test, sedecamycin showed activity similar to that of carbadox and was two times more active than both tiamulin and lincomycin. At doses of 10 mg or more of sedecamycin per kg, the recurrence of shedding of T. hyodysenteriae into the feces of mice was not detected for at least 8 weeks postmedication.

Hygromycin A, an antitreponemal substance. II. Therapeutic effect for swine dysentery

This study was conducted to evaluate hygromycin A fed to growing swine at 1, 5, 10 or 20 g/ton feed for the control of Treponema hyodysenteriae-caused dysentery. Pigs provided carbadox at 50 g/ton feed served as an infected treatment control group. All pigs were orally, via stomach intubation, administered 100 ml of a T. hyodysenteriae broth culture. During the in vivo test, rectal swabs were taken for T. hyodysenteriae isolation, body weights of all pigs and the feed consumption was determined. All pigs were euthanized and necropsied at study end; the large intestine was cultured for T. hyodysenteriae and gross intestinal lesions were noted. T. hyodysenteriae-caused swine dysentery was successfully controlled by feeding hygromycin A at 5 g/ton. Hygromycin A medicated pigs performed as well as or better than carbadox-medicated pigs.

Hygromycin A, an antitreponemal substance. I. Screening method and therapeutic effect for Treponema hyodysenteriae-caused infection in CF-1 mice

In vitro and in vivo screening methods were established for the discovery of new active substances against Treponema hyodysenteriae. During the screening methods, hygromycin A produced by Streptomyces hygroscopicus KA-355 was found to be active against T. hyodysenteriae. Hygromycin A did not show high antitreponemal activity in in vitro test using the paper disc method on the agar plate inoculated with T. hyodysenteriae. However, the antibiotic exhibited highly therapeutic effect in CF-1 mice, compared with of lincomycin, tiamulin, lankacidin C or olaquindox drinking water. The effective dose (ED50) of hygromycin A was 1.1 micrograms/ml.

3-Acetyl-4''-isovaleryl tylosin for prevention of swine dysentery

The 21 field isolates of Treponema hyodysenteriae which were tested were sensitive to 3-acetyl-4''-isovaleryl tylosin (AIV); the minimal inhibitory concentration was 0.25 to 16 micrograms/ml. 3-Acetyl-4''-isovaleryl tylosin administered prophylactically to pigs at concentrations of 5 to 100 mg/kg of feed and tylosin at 110 mg/kg of feed for 28 or 31 days prevented swine dysentery induced by tylosin-sensitive T hyodysenteriae strain SQ2; 15 nonmedicated, inoculated control pigs had bloody diarrhea, and 9 pigs died. In 2 additional trials, AIV administered prophylactically for 28 days at 55 or 110 mg/kg of feed prevented swine dysentery induced by tylosin-insensitive T hyodysenteriae strain B204. All of the inoculated principal pigs medicated with AIV at 55 or 110 mg/kg of feed or carbadox at 55 mg/kg of feed and the noninoculated sentinel pigs for each group had solid feces throughout the 56-day trial. In the nonmedicated, inoculated control groups, bloody diarrhea began at 4 to 5 days after inoculation was done, and 9 of 10 principal pigs and 6 of 9 sentinel pigs had dysentery; 2 pigs died. In the groups medicated with AIV at 27.5 or 5.5 mg/kg of feed, all 5 principal pigs and 3 or 4 sentinel pigs in each group had dysentery; 3 or 4 pigs in each group died. In the group medicated with tylosin at 110 mg/kg of feed, 7 of 10 principal pigs and all 9 sentinel pigs had dysentery; 1 pig died.(ABSTRACT TRUNCATED AT 250 WORDS)

Tiamulin in drinking water for treatment and development of immunity to swine dysentery

The diarrhea of swine dysentery receded in swine treated with 60 or 45 mg of tiamulin/L of drinking water (60 or 45 ppm). However, within 2 to 10 days (average 4.1 days) after drug withdrawal, diarrhea recurred. Tiamulin (22.5 mg/L in drinking water) did not markedly reduce the diarrhea during medication, and tylosin (66 mg/L in the drinking water) was not effective. In swine treated with 120 mg of dimetridazole/L of drinking water, there was no recurrence of diarrhea. After the recurrence of diarrhea in swine, repeated medication with tiamulin in drinking water reduced the severity of diarrhea and prevented deaths. After 1 to 3 retreatments, swine were immune to exposure with swine dysentery inoculum, and there was a significant (P less than 0.05) increase in their serum anti-Treponema hyodysenteriae antibodies. Seemingly, drug withdrawal permitted the occurrence and recurrence of diarrhea that was necessary to stimulate immunity.

Eliminating organisms against Treponema hyodysenteriae in the gut of mice

Ta:CF#1 mice lost their high susceptibility to Treponema hyodysenteriae infection after being mingled with Slc:ICR mice which had no susceptibility to the infection. Ta:CF#1 mice also lost susceptibility to the infection after being treated orally with fecal suspensions from Slc:ICR mice; treatment with heated (70 degrees C, 15 min) or filtered (pore size 0.2 micron) fecal suspensions did not cause a loss of susceptibility. Furthermore, even after the infection had established, Ta:CF#1 mice became free from T. hyodysenteriae and cecal lesions by oral treatment with the fecal suspensions. When Slc:ICR mice were treated with spectinomycin throughout the experiment, they became susceptible to the infection. These studies indicate that there exist eliminating organisms against T. hyodysenteriae in the gut of mice.

Mass treatment campaigns against the endemic treponematoses

In pre-antibiotic times, mass campaigns against the endemic treponematoses required multiple injections of arsenicals and bismuth. The essentiality of a population census, an examination of the total population, and the treatment of clinical and latent cases were all appreciated, as was the value of a multipurpose approach. It was also recognized that, in combination with the anticipated slow correction of economic circumstances and attitudes, chemotherapy was the chief weapon against disease but that this weapon, even if successful in a particular area, could not prevent later reintroduction of infection. With the introduction of single-dose penicillin therapy and the impetus of worldwide, internationally assisted mass campaigns came a dramatic reduction in incidence. However, in some areas continued surveillance by the local health services did not materialize. Thus, there has been not just a low-level continuum of disease but a resurgence, particularly in Africa, where a return to mass therapy has once again proved necessary--this time combined with multipurpose immunization.

Therapy for nonvenereal treponematoses: review of the efficacy of penicillin and consideration of alternatives

Penicillin therapy has been a crucial element in public health programs for control of nonvenereal treponematoses. The recommendations made by the World Health Organization on penicillin therapy and the literature substantiating the effectiveness of penicillin therapy are reviewed. In mass public health programs, the recommended penicillin regimen can confidently be used. Although penicillin is the drug of choice for all treponemal infections, some individuals will be allergic to this drug. For these persons tetracyclines are the most thoroughly evaluated alternative antimicrobial agent and seem highly effective. However, further comparative evaluations of various tetracycline regimens are needed if tetracyclines are required by more than the occasional individual. The long-acting tetracyclines may be particularly appropriate in minimizing problems of compliance.

Swine dysentery in a sow herd. I. Clinical manifestation and elimination of the disease with a combination of lincomycin and spectinomycin

An acute outbreak of swine dysentery (Doyle) on a farrowing farm is described. Besides clinical signs of enteritis a general loss of condition was seen throughout the herd. This resulted in a decreased fertility and breeding performance among sows and an increase in piglet mortality. Several dehydrated sows aborted. The outbreak was stopped by oral treatment with lincomycin/spectinomycin 1:1. In the course of the treatment all animals and buildings were washed and disinfected. The use of pharmacotherapeutics in treating swine dysentery is discussed with emphasis on the involuntary induction of carriers.

Clinical course and treatment of venereal spirochaetosis in New Zealand white rabbits

Ten sporadic cases of venereal spirochaetosis, caused by Treponema paraluis-cuniculi, were seen in New Zealand white rabbits in two years. An equal number of males and females were affected. Females tended to have milder clinical signs than males. Lesions were usually found on the prepuce in males and the vulva in females, although the anus and skin of the perineum were also affected. Facial lesions were rare. Lesions healed in seven to 28 days in rabbits treated with penicillin. Eight rabbits had antibodies reactive in the Venereal Disease Research Laboratory (VDRL), rapid plasma reagin (RPR), and fluorescent treponemal antibody absorbed (FTA-ABS) tests when the disease was first diagnosed. In several rabbits followed longitudinally, RPR test results became negative two to four months after antimicrobial treatment, VDRL antibody titres diminished but usually persisted at low levels, while FTA-ABS antibodies declined slowly and were still evident 12 months after treatment.

Detecting anti-Treponema hyodysenteriae antibodies in swine serum using immunofluorometry

An indirect fluorescent antibody test was adapted for measuring serum anti-Treponema hyodysenteriae antibodies with a fluorometer. The immunofluorescence was recorded as fluorescent signal units. Cultures of T. hyodysenteriae and Treponema innocens were used as antigen. There was a significant (P less than 0.01) correlation between the immunofluorescence recorded with the fluorometer and that evaluated visually with a microscope. The swine exposed orally to swine dysentery infective inoculum and subsequently hyperimmunized by the intravenous inoculation of live cultures of T. hyodysenteriae had the highest average fluorescent signal unit, which was 104.5. There was a significant (P less than 0.01) correlation between the level of anti-T. hyodysenteriae antibody and the interval length between the last day of diarrhea and the day of bleeding. However, in measuring fluorescent signal units in serum from swine infected with nonpathogenic large spirochetes, (T. innocens), there was also a significant (P less than 0.01) correlation between T. hyodysenteriae and T. innocens as antigen. The coefficient of variation of the average fluorescent signal unit for a highly positive serum and a highly negative serum between 16 runs of assays were 5.7% and 19% respectively; the coefficient of variation of the average fluorescent signal unit for duplicate samples on 358 serum samples tested was 5.8%.

Mitogenic responses of hamsters infected with Treponema pertenue Lack of correlation with passive transfer of resistance

Infection of the CB/Ss Lak hamster with Treponema pertenue is characterised by chronic cutaneous lesions and lymph nodes teeming with treponemes. Throughout the course of infection lymph node and spleen cells responded poorly to the mitogens concanavalin A, phytohaemagglutinin, and lipopolysaccharide. This impairment preceded clinical signs of infection and correlated well with the chronicity of framboesial infection. High concentrations of antigen from T pertenue, but not from the non-pathogenic Treponema phagedenis, depressed the mitogenic response of normal lymphoid cells. After framboesial hamsters were treated with penicillin the mitogenic activities of their lymph node and spleen cells were similar to or slightly raised above those of controls. No significant differences were detected among recipients of framboesial immune cells with or without mitogenic activity. Recipients of immune lymph node and spleen cells from penicillin-treated or non-penicillin-treated animals had no cutaneous lesions 21 days after infection and had significantly lower lymph node weights and fewer treponemes per node than recipients of cells from normal penicillin-treated or non-penicillin-treated animals. Since lymphocyte transformation in vitro does not correlate with in-vivo treponemicidal activity, it is not a valid approach to assess the protective immune capacity of the framboesial host.

Tiamulin water medication in the treatment of swine dysentery under farm conditions

The clinical efficacy of tiamulin given in the drinking water at levels of 0.0045 per cent for five days and 0.006 per cent for three days was evaluated for the treatment of swine dysentery in six clinical studies and compared with positive controls using tylosin at 0.02 per cent in the drinking water for five days and untreated controls. Efficacy was evaluated by assessment of the pigs' general appearance; the extent of diarrhoea and dehydration; performance, as measured by average daily gains and feed conversion efficiency; the presence or absence of Treponema hyodysenteriae in the faeces and mortality. As a result of statistical analysis of these parameters tiamulin medication was found to be an efficacious therapeutic regimen for naturally occurring swine dysentery when given at either level in the drinking water.

Tiamulin feed premix in the prevention and control of swine dysentery under farm conditions in the UK

Three field trials were carried out to evaluate the efficacy of tiamulin hydrogen fumarate at levels of 20 and 30 ppm in the feed for the prevention and control of swine dysentery. Tiamulin at 30 ppm was shown to be highly effective in preventing the clinical signs of dysentery. Treponema hyodysenteriae was not isolated from these pigs. Tiamulin at 20 ppm was effective in two out of three trials. The trials were performed on pigs either on or from farms with swine dysentery problems which had proven resistant to medication with other products.

Therapeutic effects of various concentrations of lincomycin in drinking water on experimentally transmitted swine dysentery

Three experimental studies were conducted in 232 growing pigs (8 to 12 weeks old) to evaluate the therapeutic effects of various concentrations of lincomycin in drinking water, against swine dysentery experimentally transmitted, by oral inoculation or by contact-commingling exposure. Four or 5 concentrations of lincomycin were used in each experiment (132, 66, 33, 16.5 or 0.0 mg/L of drinking water). Medication was initiated 7 to days after exposure and was continued for 6 to 10 days. Both methods of exposure were capable of transmitting the disease successfully. A more marked dose response was noticed in pigs inoculated orally than in pigs that were exposed by contact. All concentrations of lincomycin were effective for the treatment of swine dysentery by oral or by contact exposure. At the smaller concentration of 16.5 mg/L of drinking water, lincomycin was less effective for treating the disease than it was at greater concentrations. The suggested optimal concentration was 33 mg of lincomycin/L of drinking water for the treatment of swine dysentery.

Ronidazole in the treatment and prophylaxis of experimental swine dysentery

Experimental swine dysentery was produced in groups of susceptible pigs by feeding pure cultures of two isolates of T hyodysenteriae. These infected groups of pigs were then used to assess the efficacy of ronidazole medication of the drinking water and of the feed in the treatment and prophylaxis of the experimental disease. Ronidazole was found to be effective in the treatment of swine dysentery and appeared to eliminate the causal agent, T hyodysenteriae, from treated affected pigs when given in the drinking water at 30 and 60 ppm for three days and in the feed at 120 ppm for four days. The inclusion of ronidazole in the feed for 14 days at 30, 60 and 90 ppm was found to suppress the development of the disease but 90 ppm was the only level found to prevent the development of infection.

Ronidazole in low concentrations in drinking water for treatment and development of immunity to swine dysentery

The addition of ronidazole to the drinking water at the concentration of 0.003% was effective for the treatment of experimentally induced swine dysentery in swine. Ronidazole at concentrations of 0.0015% and 0.00075% aided in the treatment of swine dysentery and the development of immunity to the disease. In experiment I, in which swine were given concentrations of 0.003, 0.0015, and 0.00075%, there were more survivors, fewer days of hemorrhagic diarrhea, greater feed and water consumption and body weight gain, and more favorable feed efficiency in the medicated swine than in the nonmedicated swine. With the 0.003% concentration, there were no deaths, and the diarrhea receded during or after treatment with the 0.0015% and 0.00075% concentrations, the incidence of nonhemorrhagic diarrhea was greater in medicated than in nonmedicated swine, and the diarrhea did not subside during treatment. In experimetn II, there were more survivors in the groups of swine medicated with the 0.0015% concentration than in the nonmedicated groups of swine. All surviving nonmedicated swine in experiment I were immune to reexposure 3 months after initial exposure. More swine given to the 0.0015% and 0.00075% concentrations in the same experiment were immune to reexposure 3 months after initial exposure than were the swine given the 0.003% concentration. In experiment II, neither the swine previously medicated with the 0.0015% concentration nor the nonmedicated swine were immune to reexposure 5 weeks after initial expsoure. Large spirochetes were observed in fecal smears from all exposed swine which developed either hemorrhagic or nonhemorrhagic diarrhea.

Ronidazole in high concentrations in drinking water for treatment and prevention of diarrhea in swine dysentery

Ronidazole administered in the drinking water at concentrations of 0.012, 0.006, and 0.003% was effective for the treatment of swine dysentery. All groups of medicated swine had more survivors, fewer days of hemorrhagic and nonhemorrhagic diarrhea, greater feed consumption, greater weight gain, and more favorable feed efficiency than did nonmedicated swine. The only adverse clinical sign and lesion observed in the medicated swine comprised the drug-delayed-augmented swine dysentery which affected 3 swine in a group given 0.003% ronidazole. Several of the swine given the 0.012% concentration developed nonhemorrhagic diarrhea while on medication, probably because of the high concentration of the drug. Diarrhea did not recur in swine after the withdrawal of medication in both of 2 groups given the 0.012% concentration, in 3 of 4 groups given the 0.006% concentration, or in 1 of 4 groups given the 0.003% concentration. One or more swine were susceptible to reexposure to swine dysentery in both groups given the 0.012% concentration, in 1 group given the 0.006% concentration and in 1 group given the 0.003% concentration. Large spirochetes were observed in fecal smears from all exposed swine which developed either hemorrhagic or nonhemorrhagic diarrhea.

Therapeutic effect of lincomycin and spectinomycin water medication on swine dysentery

The therapeutic effects of various water medications on swine dysentery were determined in 223 pigs under controlled conditions. Carrier pigs were mixed with test animals until the disease was established. Lincomycin (22 mg/liter), spectinomycin (44 mg/liter) alone and lincomycin and spectinomycin in combination (66 mg/liter) and sodium arsanilate (161 mg/liter) in drinking water for seven days were the drugs evaluated. Negative and positive controls were also included. The experiment was terminated 41 to 43 days after initial medication. Mortality, mean value for stool consistency, incidence of dysenteric days and gross lesions of swine dysentery were the parameters measured for each treatment group.The lincomycin-spectinomycin water medication was effective for the treatment of swine dysentery. Pigs treated with lincomycin-spectinomycin had a higher survival rate, a lower incidence of dysenteric days and fewer gross lesions of swine dysentery than pigs treated with sodium arsanilate, lincomycin or spectinomycin alone or the infected controls (P < 0.05).