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Transmissibility of Mycoplasma Dispar under Experimental Conditions
Mycoplasma dispars smittbarhet under experimentella förhållanden
Acta Veterinaria Scandinavica volume 28, pages 227–240 (1987)
Abstract
Twenty three 1- to 18-week old Ayrshire calves were exposed to infection by Mycoplasma dispar, 1 or 2 at a time, in a series of consecutive experiments. Exposure took place either at direct contact, i. e. with the possibility of physical contact between susceptible and infected calves (type I), or through separation of susceptibles from the nearest infected calf at a distance of 0.8 m (type II) or 1.3 m (type III). Frequent nasal swabbing was used for the detection of the infection and the measurement of the level of colonisation. Ten, 4, and 9 calves were subjected to type I, II, and III exposures, respectively. When the first positive nasal specimen preceding a rise in titres in the following specimens was used to signify an establishment of infection of a susceptible calf, the medians (ranges) of the times for the transmission of infection (including the latent period of early colonisation undetectable by nasal swabbing) in the 3 exposure groups were: 4.5 (1-27), 8.5 (7-9), and 17 (6-32), respectively. The difference between groups I and III was significant (p < 0.05). The last figures for type III of exposures represent the results of only 5 calves succesfully exposed; the remaining 4 of the 9 calves of this exposure type were not found to pick up the infection within the periods of 2 to 3 weeks of exposure. The results indicate a transmission mode via droplets.
Four calves exposed only for 4 h by direct contact were found to be infected on days 0, 4, 4, and 7, respectively. This indicated variability in the length of the latency as regards the detection by nasal swabbing.
Four of the 7 calves in the type I experiments sampled at hour 4 showed low titers for M. dispar. Only in 1 of these calves was this early finding of transfer followed by positivity and a rise in titers through subsequent specimens. The other 3 calves became positive anew, with subsequent developing colonisation, first on days 4, 4, and 12, respectively.
Sammendrag
Tjugotre 1- til 18-veckor gamla Ayrshire kalvar utsattes för infektion med Mycoplasma dispar en eller två åt gången i en serie av på varandra följande experiment. Djuren utsattes för smittan antingen genom direkt kontakt d.v.s. möjlighet till fysisk kontakt mellan mottagliga och infekterade kalvar (typ I) eller genom separering av mottagliga djur från det närmaste infekterade med ett avstånd på 0.8 m (typ II) eller 1.3 m (typ III). För att påvisa infektion och för att mäta kolonisationsnivån togs talrika nässe kretsprov.
Tio, 4, och 9 kalvar utsattes för typ I, II, och III smitta i nämd ordning. Om det första provet som föregick en höjning av titern i de påföljande proven användes som ett tecken på att infektionen etablerat sig i en mottaglig kalv är medianerna (variationsvidderna) av tiderna för infektionens utbredning (inklusive latensperioden för den tidiga kolonisationen som inte kan påvisas genom nässekretprov) i de 3 utsatta grupperna: 4.5 (1-27), 8.5 (7–9) och 17 (6–32) i nämnd ordning. Skillnaden mellan grupperna 1 och III är signifikant (P < 0.05). De sista värden för typ III:s experiment motsvarar endast 5 kalvars framgångsrika medsmittning; de återstående 4 kalvarna av 9 i denna experimentgrupp förvärvade inte infektionen inom 2 eller 3 veckors perioderna som försöket pågick. Resultaten motsvarar en smittoväg via droppar.
Fyra kalvar som utsattes för smitta under 4 timmars tid genom direkt kontakt visade sig vara infekterade på dagarna 0, 4, 4, och 7. En variabilitet av latensperioden, med referens till nässekretprov, var häntydd.
Proven tagna på timme 4 av fyra av de 7 kalvarna inom experiment I hade låga titrar för M. dispar. Endast hos en av dessa kalvar åtföljdes denna upptäckt av tidig mykoplasma överföring av en positivitet och av en höjning av litrarna bland de följande proven. De övriga 3 kalvarna blev positiva på nytt, med senare utveckling av kolonisation, först på dagarna 4, 4, och 12.
References
Bell DP, Wheeler SM: Susceptibility of caesarian- derived rats to natural infection with chronic respiratory disease. Lab. Anim. 1970, 4, 45–53.
Bitsch V, Friis NF, Krogh HV: A microbiological study of pneumonic calf lungs. Acta vet. scand. 1976, 17, 32–42.
Brownlie J, Howard CJ, Gourlay RN: Pathogenicity of certain mycoplasma species in the bovine mammary gland. Res. Vet. Sei. 1976, 20, 261–266.
Goodwin RFW: Isolation of Mycoplasma suipneu- moniae from the nasal cavities and lungs of pigs affected with enzootic pneumonia or exposed to this infection. Res. Vet. Sei. 1972, 13, 262–267.
Gourlay RN, Leach RH: A new mycoplasma species isolated from pneumonic lungs of calves (Mycoplasma dispar sp. nov.). J. med. Microbiol. 1970, 3, 111–123.
Gourlay RN, Mackenzie A, Cooper JE: Studies of the microbiology and pathology of pneumonic lungs of calves. J. comp. Path. 1970, 80, 575–584.
Gourlay RN, Howard CJ, Thomas LH, Wyld SG: Pathogenicity of some Mycoplasma and Acho- leplasma species in the lungs of gnotobiotic calves. Res. Vet. Sei. 1979, 27, 233–237.
Howard CJ, Gourlay RN, Thomas LH, Scott EJ: Induction of pneumonia in gnotobiotic calves following inoculation of Mycoplasma dispar and ureaplasmas (T-mycoplasmas). Res. Vet. Sei. 1976, 21, 227–231.
Jemski JV, Hetsko CM, Helms CM, Grizzard MB, Walker JS, Chanock RM: Immunoprophylaxis of experimental Mycoplasma pneumoniae disease: Effect of aerosol particle size and site of deposition of M. pneumoniae on the pattern of respiratory infection, disease, and immunity in hamsters. Infect. Immun. 1977, 16, 93–98.
Kleven SH: Transmissibility of the F strain of Mycoplasma gallisepticum in Leghorn chickens. Avian Dis. 1981, 25, 1005–1018.
Muenster OA, Ose EE, Matsouka T: The incidence of Mycoplasma dispar, Ureaplasma and coventional Mycoplasma in the pneumonic calf lung. Canad. J. comp. Med. 1979, 43, 392–398.
Ribeiro OC: Experimental infection of calves with Mycoplasma dispar. Ph.D. Thesis. Iowa State University, Ames, 1979.
Roberts DH: Experimental infection of pigs with Mycoplasma hyopneumoniae (suipneumo- niae). Brit. vet. J. 1974, 730, 68–74.
Rosendal S, Martin SW: The association between serological evidence of mycoplasma infection and respiratory disease in feedlot calves. Canad. J. vet. Res. 1986, 50, 179–183.
Siegel S: Nonparametric Statistics for the Behavioral Sciences. McGraw-Hill Book Company, New York 1956.
Steinberg P, White RJ, Fuld SL, Gutekunst RR, Chanock RM, Senterfit LB: Ecology of Mycoplasma pneumoniae infections in Marine recruits at Parris Island, South Carolina. Amer. J. Epidemiol. 1969, 89, 62–73.
Tanskanen R: Longstanding colonisation of the respiratory tract of calves by Mycoplasma dispar. Acta vet. scand. 1983, 24, 334–336.
Tanskanen R: Colonisation pattern of the respiratory tract of calves by Mycolasma dispar. Acta vet. scand. 1984, 25, 577–592.
Tanskanen R: The prevalence and level of colonisation by Mycoplasma dispar and other mycoplasmas on calf rearing farms. Acta vet. scand. 1987a, 28, 209–226.
Tanskanen R: Transmission of Mycoplasma dispar among a succession of newborn calves on a dairy farm. Acta vet. scand. 1987b, 28, in press.
Thomas LH, Smith GS: Distribution of mycoplasmas in the nonpneumonic bovine respiratory tract. J. comp. Path. 1972, 82, 1–4.
Thomas LH, Howard CJ: Effect of Mycoplasma dispar, Mycoplasma bovirhinis, Acholeplas- ma laidlawii and T-mycoplasmas on explant cultures of bovine trachea. J. comp. Path. 1974, 34, 193–201.
Whittlestone P: Effect of climatic conditions on enzootic pneumonia of pigs. Int. J. Biometeor. 1976, 20, 42–48.
Wright DN, Bailey GD, Hatch MT: Survival of airborne mycoplasma as affected by relative humidity. J. Bact. 1968a, 95, 251–252.
Wright DN, Bailey GD, Hatch MT: Role of relative humidity in the survival of airborne Mycoplasma pneumoniae. J. Bact. 1968b, 96, 970–974.
Acknowledgements
This study received financial support from The Research Council for Medical Sciences of the Academy of Finland and The Finnish Veterinary Science Foundation.
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Tanskanen, R. Transmissibility of Mycoplasma Dispar under Experimental Conditions. Acta Vet Scand 28, 227–240 (1987). https://doi.org/10.1186/BF03548245
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DOI: https://doi.org/10.1186/BF03548245