ABSTRACT
Growth of 3 reference bovine C. fetus strains in media with and without antibiotics and bacteriostats active against the most common contaminant bacteria in the bovine genital tract was evaluated. In addition, 2 regional bovine C. fetus strains and 1 reference C. sputorum biovar bubulus strain were used in some experiments. Reference strain C. fetus subsp. venerealis was completely inhibited by polymyxin (> or = 0.25 IU/ml) whereas the other C. fetus strains were not inhibited. In Sheplers medium supplemented with rifampicin (10 micrograms/ml) subsp. fetus, was the only one to grow. When rifampicin was used at 5 micrograms/ml together with a reduced dose of the other Sheplers antibiotics, especially polymyxin B (0.85 IU/ml), subsp. venerealis was able to grow; nevertheless even at such a reduced dose, rifampicin was inhibitory for the biotype intermedius. It was demonstrated that triclosan (Irgasan) could be very useful at or = 50 micrograms/ml. C. sputorum biovar. bubulus was less inhibited than C. fetus with triclosan grew up to more than 100 micrograms/ml, with 5-fluorouracil up to 100 micrograms/ml and with fosfomycin up to 50 micrograms/ml. Growth of C. fetus subspp. was compared in different microaerophilic atmospheres contained in anaerobic jars (Oxoid HP 11) without palladium catalyzer. Growth with nitrogen or hydrogen was similar. When jars were replaced by 15 x 13 cm cylindrical cans without valves or gas measurement devices only pure hydrogen supported satisfactory growth of all C. fetus subspp. and C. sputorum biovar. bubulus strains. The candle system, a commercial nitrogen rich gas mixture and pure carbonic anhydride prepared in these cans failed to enable these strains to grow. C. fetus subsp. fetus was more aero-tolerant than subsp. venerealis and its biotype intermedius and was able to grow, although very weakly, with only carbonic anhydride added to an aerobic atmosphere. The growth obtained using a commercial gas generating microaerophilic kit (Oxoid BR-56) was comparable to the one achieved with the hydrogen rich atmosphere prepared in our laboratory.
ABSTRACT
Growth of 3 reference bovine C. fetus strains in media with and without antibiotics and bacteriostats active against the most common contaminant bacteria in the bovine genital tract was evaluated. In addition, 2 regional bovine C. fetus strains and 1 reference C. sputorum biovar bubulus strain were used in some experiments. Reference strain C. fetus subsp. venerealis was completely inhibited by polymyxin (> or = 0.25 IU/ml) whereas the other C. fetus strains were not inhibited. In Sheplers medium supplemented with rifampicin (10 micrograms/ml) subsp. fetus, was the only one to grow. When rifampicin was used at 5 micrograms/ml together with a reduced dose of the other Sheplers antibiotics, especially polymyxin B (0.85 IU/ml), subsp. venerealis was able to grow; nevertheless even at such a reduced dose, rifampicin was inhibitory for the biotype intermedius. It was demonstrated that triclosan (Irgasan) could be very useful at or = 50 micrograms/ml. C. sputorum biovar. bubulus was less inhibited than C. fetus with triclosan grew up to more than 100 micrograms/ml, with 5-fluorouracil up to 100 micrograms/ml and with fosfomycin up to 50 micrograms/ml. Growth of C. fetus subspp. was compared in different microaerophilic atmospheres contained in anaerobic jars (Oxoid HP 11) without palladium catalyzer. Growth with nitrogen or hydrogen was similar. When jars were replaced by 15 x 13 cm cylindrical cans without valves or gas measurement devices only pure hydrogen supported satisfactory growth of all C. fetus subspp. and C. sputorum biovar. bubulus strains. The candle system, a commercial nitrogen rich gas mixture and pure carbonic anhydride prepared in these cans failed to enable these strains to grow. C. fetus subsp. fetus was more aero-tolerant than subsp. venerealis and its biotype intermedius and was able to grow, although very weakly, with only carbonic anhydride added to an aerobic atmosphere. The growth obtained using a commercial gas generating microaerophilic kit (Oxoid BR-56) was comparable to the one achieved with the hydrogen rich atmosphere prepared in our laboratory.
ABSTRACT
This paper describes a case of poisoning by blue-green algae growing in a fresh water pond in Goyena, Provincia de Buenos Aires. The predominating algae were identified as Microcystis aeruginosa. They show an intense growth when certain meteorologic condition prevail, in coincidence with certain chemical characteristics of the water. Once this growth has occurred, the direction of the wind has a decisive role, because it determines the accumulation on the shore, increasing their concentration and consequently, the risk of poisonous action. From a total of 170 cows, 72 died after ingestion of algae in a lapse of 24 hours. Death was very sudden so that symptoms could be observed in only 10 animals: diarrhea, incoordination, excitability, dyspnea and death. The gross lesions observed were: full stomachs showing the presence of algae; a serum-blood collection in the abdominal cavity and congestive intestines. Histopathology showed nephrosis and probable hepatic centrolobular necrosis. Water toxicity was tested on laboratory animals and gave positive results. The gross lesions, the histological changes and the laboratory tests, confirm the toxicity of the water in the pond. Toxin detection in the digestive content of the poisoned animals has not been previously mentioned in the literature; it is a very valuable diagnostic method.