Isolation ofLeptospira InterrogansSerovarsBratislavaandHardjofrom Swine at Slaughter

Abstract

Brief communications 87A and B were added to each cupule, and the reactions were allowed to develop for 5 minutes at room temperature. The color intensity of the reactions was compared to the manufacturer's scheme and graded as follows: 0, no color change; trace, ≤ 5 nanomoles (nmol); 1, 5 nmol; 2, 10 nmol; 3, 20 nmol; 4, 30 nmol; and 5, ≥40 nmol. Both grade 0 and trace reactions, which produced only slight color changes, were scored as negative reactions; grade 1, as weak positive reactions; and grades 2-5 as strong positive reactions.All 42 strains were negative for alpha-galactosidase, alphaglucosidase, alpha-fucosidase, alpha-mannosidase, beta-galactosidase, beta-glucosidase, beta-glucuronidase, chymotrypsin, cystine aminopeptidase, leucine aminopeptidase, lipase (C14), N-acetyl-beta-glucosaminidase, phospholipase, trypsin, and valine aminopeptidase. Both the biovar A and the biovar B strains had negative to weak positive reactions for esterase (C4) and negative to strong positive reactions for esterase lipase (C8). The 20 biovar A strains and the biovar AB strain had strong positive acid phosphatase and alkaline phosphatase reactions, whereas the 21 biovar B strains had either negative or weak positive reactions.The commercial semiquantitative enzyme system provided a rapid and reproducible method for determining the preformed enzyme activities of the F. necrophorum strains from cattle and sheep. This method distinguished the biovar A strains that had strong positive acid phosphatase and alkaline phosphatase reactions from the biovar B strains that had either negative or weak positive acid phosphatase and alkaline phosphatase reactions. It also helped clarify the taxonomic status of the biovar AB strain, which has phenotypic and biological properties of both biovar A and biovar B. Although the F. necrophorum biovars A and B had distinct enzyme profiles, no differences were noted between the bovine and ovine strains for either the biovar A strains or the biovar B strains. The data indicate that the marked differences in the levels of acid phosphatase and alkaline phosphatase between biovars A and B may be incorporated as an adjunct method with the phenotypic characteristics and the traditional biological criteria 1,7,10 for distinguishing the pathogenic biovars.

Evidence of leptospirosis in the kidneys and serum of feral swine (Sus scrofa) in the United States

“…Based on the high titres indicating active infection, and the high frequency of seropositive animals for Bratislava and Pomona serovars, humans that come into contact with feral swine are most likely to be exposed to these serovars. It is not surprising that these serovars were commonly identified in the feral swine we tested because they have been reported previously in both domestic swine [6,8] and feral swine [15,16]. Serovars Pomona and Bratislava have also been commonly identified in feral swine not only in the United States [11][12][13]30], but also in countries around the world such as Spain [14], Italy [31], Australia [15,32], Japan [24], and Germany [16].…”

“…Pigs have been identified as reservoir hosts for the disease in humans [6], which is significant since pigs have similar anatomy, genetics and physiology to humans [7], and could serve as a source of infection to those with the potential for occupational exposure. The most common serovars infecting domestic swine in the United States are Bratislava, Grippotyphosa, and Pomona, with occasional reports of Canicola and Icterohaemorrhagiae [8]. Infection in pigs rarely causes death and is generally characterized by abortion, weakness, inability to stand, muscle spasms, and muscle rigidity [4].…”

Prevalence and Serovars of Leptospira Involved in Equine Abortions in Central Kentucky during the 1990 Foaling Season

“…The epidemiology of bratislava is not known, 6 but strains of this serovar have been recovered from dogs 14 and pig 1,8 in the United States and from horses in Northern Ireland. [5][6][7] A high prevalence of antibodies against bratislava and the isolation of bratislava from the kidney of 7 of 91 adult horses indicated that horses may be the maintenance host for serovar bratislava in Northern Ireland.…”

“…Serovar kennewicki was recovered from 5 of these 8 cases, suggesting that these mares were previously exposed to bratislava and that infection by serovar kennewicki stimulated titers against bratislava or that the mares were infected with both serovars. Serovar bratislava is extremely fastidious 1,8 and would probably not grow in the medium used in this study.…”

A review of evidence for immunosuppression due to Porcine Reproductive and Respiratory Syndrome Virus

“…Many pathogens, both viral and bacterial, were initially implicated, by virtue of their isolation from many clinical cases, yet no pathogen was able to reproduce the disease experimentally, neither alone nor in combination [2,9,12,14,16,22,34,38,46,54,62]. The lack of consistent isolation of any single agent from cases of the disease however, suggested that, rather than being the primary agents, their presence was opportunistic, causing secondary infections leading to multifactorial disease.…”