- Email: [email protected]
Isolation of Mycoplasma Agalactiae Varias Bovis from the Respiratory Tract
Br. vet.
J. (1971),
127, ix
ISOLATION OF MYCOPLASMA AGALACTIAE VARIAS BOVIS FROM THE RESPIRATORY TRACT. Bv 0.
KARST AND
0.
ONOVIRAN
Federal Department of Veterinary Research, Vom, Benue-Plateau State, Nigeria
During in-contact challenge trials for assessing contagious bovine pleuropneumonia (CBPP) vac:cine, post-mortem examination is carried out on all the cattle taking part in the trial. Isolation of mycoplasma is attempted from lung and trachea and also from mediastinal, bronchial, prescapular, mandibular, parotid and suprapharyngeal lymph glands. Any mycoplasma from these sites isolated on agar is subjected to identification by immunofluorescence, differentiating between Mycoplasma mycoides varias mycoides and other mycoplasma only. A mycoplasma which could not be identified as M. mycoides v. myc. was isolated from lungs and mandibular lymph glands of a bull which had been vaccinated against CBPP with T 1-strain vaccine a month before it entered a challenge trial. During the fourteen weeks in which the bull was exposed to CBPP by close contact with cattle suffering from CBPP, it was serologically negative (tests once a week) to CBPP throughout. Post-mortem examination revealed a slightly swollen right apical lobe with haemorrhagic areas, and no other macroscopical lesions. Agar gel diffusion test on lung tissue for precipitating CBPP antigen was negative. The unidentified mycoplasma strain was grown in pure culture and lyophilized. A number of ampoules were sent to the FAOJWHO International Reference Centre for Animal Mycoplasma, Aarhus, Denmark, where Dr H. Ernoe identified the strain as Mycoplasma agalactiae varias bovis using biological and serological techniques. On receipt of this information, 40 ml of broth culture containing 2·2 x 108 colony-forming units per ml was inoculated into the right front teat of a cow which was on the point of being milked dry. Within two days the infected quarter became warm and swollen, but not hard. There was a rise in rectal temperature to 103° F for two days. After four days the discharge from the infected quarter consisted of pus followed by a whey-like fluid. Within twelve days all four quarters were affected and mycoplasma in big numbers were isolated from the discharge. Mycoplasma agalactiae varias bovis has been isolated several times in the U.S.A. (Hale, Helmboldt, Plastridge & Stuala, 1962; Jasper, Jain & Brazil, 1966; Jain, Jasper & Dellinger, 1968) and found to be the cause of mastitis in big industrialized dairy herds. It is of interest that the present isolation was from a Zebu bull, purchased from a nomadic cattle owner. From the day of purchase to the day of slaughter (approximately five months) the
X
BRITISH VETERINARY JO URNAL, 127, 5
bull was in contact with other Zebu bulls of similar origin only. Cottew & Leach ( r g6g ) write th a t there is no evidence of respiratory infec tions due to Mycoplasma galactiae varias bovis strains, but that the respiratory tract could conceivably be a reservoir for infec tion between outbreaks of mastitis. The presen t findings seem to substantiate this point of view, and they indicate th at .~1ycoplasma agalactiae varias bovis may be found not only in industrialized da iry herds in the U.S.A., but a lso in nomadic, low-yielding herds in Nigeria. REFERENCES
G. S. & LEA CH, R. H. ( rg6g). The MycojJ!asrn atales and the Lcfihase of Bacteria, cd. Hayflick, page .549· HALE, H . H. , HELMBOLDT, C. F. , PLASTRIDGE , \\'. N . & STUALA , E. F. ( rg62 ). Cornell Vet. 5 2, 5 82. j.<~.IN , N. c., j ASPE R , D. E. & DELLINGER , ] . D. ( rg6g). Cornell Vet. 59· ! 0. j ASPER, D. E., jAI N, N. C. & BRAZIL , L. H . ( rg66) ]. A111. vet. med. Ass. 148, 101 7· CoTTEW,
J. (1971),
127, ix
ISOLATION OF MYCOPLASMA AGALACTIAE VARIAS BOVIS FROM THE RESPIRATORY TRACT. Bv 0.
KARST AND
0.
ONOVIRAN
Federal Department of Veterinary Research, Vom, Benue-Plateau State, Nigeria
During in-contact challenge trials for assessing contagious bovine pleuropneumonia (CBPP) vac:cine, post-mortem examination is carried out on all the cattle taking part in the trial. Isolation of mycoplasma is attempted from lung and trachea and also from mediastinal, bronchial, prescapular, mandibular, parotid and suprapharyngeal lymph glands. Any mycoplasma from these sites isolated on agar is subjected to identification by immunofluorescence, differentiating between Mycoplasma mycoides varias mycoides and other mycoplasma only. A mycoplasma which could not be identified as M. mycoides v. myc. was isolated from lungs and mandibular lymph glands of a bull which had been vaccinated against CBPP with T 1-strain vaccine a month before it entered a challenge trial. During the fourteen weeks in which the bull was exposed to CBPP by close contact with cattle suffering from CBPP, it was serologically negative (tests once a week) to CBPP throughout. Post-mortem examination revealed a slightly swollen right apical lobe with haemorrhagic areas, and no other macroscopical lesions. Agar gel diffusion test on lung tissue for precipitating CBPP antigen was negative. The unidentified mycoplasma strain was grown in pure culture and lyophilized. A number of ampoules were sent to the FAOJWHO International Reference Centre for Animal Mycoplasma, Aarhus, Denmark, where Dr H. Ernoe identified the strain as Mycoplasma agalactiae varias bovis using biological and serological techniques. On receipt of this information, 40 ml of broth culture containing 2·2 x 108 colony-forming units per ml was inoculated into the right front teat of a cow which was on the point of being milked dry. Within two days the infected quarter became warm and swollen, but not hard. There was a rise in rectal temperature to 103° F for two days. After four days the discharge from the infected quarter consisted of pus followed by a whey-like fluid. Within twelve days all four quarters were affected and mycoplasma in big numbers were isolated from the discharge. Mycoplasma agalactiae varias bovis has been isolated several times in the U.S.A. (Hale, Helmboldt, Plastridge & Stuala, 1962; Jasper, Jain & Brazil, 1966; Jain, Jasper & Dellinger, 1968) and found to be the cause of mastitis in big industrialized dairy herds. It is of interest that the present isolation was from a Zebu bull, purchased from a nomadic cattle owner. From the day of purchase to the day of slaughter (approximately five months) the
X
BRITISH VETERINARY JO URNAL, 127, 5
bull was in contact with other Zebu bulls of similar origin only. Cottew & Leach ( r g6g ) write th a t there is no evidence of respiratory infec tions due to Mycoplasma galactiae varias bovis strains, but that the respiratory tract could conceivably be a reservoir for infec tion between outbreaks of mastitis. The presen t findings seem to substantiate this point of view, and they indicate th at .~1ycoplasma agalactiae varias bovis may be found not only in industrialized da iry herds in the U.S.A., but a lso in nomadic, low-yielding herds in Nigeria. REFERENCES
G. S. & LEA CH, R. H. ( rg6g). The MycojJ!asrn atales and the Lcfihase of Bacteria, cd. Hayflick, page .549· HALE, H . H. , HELMBOLDT, C. F. , PLASTRIDGE , \\'. N . & STUALA , E. F. ( rg62 ). Cornell Vet. 5 2, 5 82. j.<~.IN , N. c., j ASPE R , D. E. & DELLINGER , ] . D. ( rg6g). Cornell Vet. 59· ! 0. j ASPER, D. E., jAI N, N. C. & BRAZIL , L. H . ( rg66) ]. A111. vet. med. Ass. 148, 101 7· CoTTEW,