Bacterial Flora of Foot Rot: Report of Findings in 100 Cattle

Abstract

One hundred and eight specimens were obtained for bacteriological study from 100 head of cattle affected with foot rot on 10 cattle farms located in Hato Rey, Bayamón, Dorado, Carolina, and Canóvanas. Smears were made on sterile slides and stained by Gram's method. Aerobic and anaerobic cultures were also made with the specimens. Gram-negative bacilli morphologically resembling S. necrophorus were encountered in about 10 percent of the smears, yet the organism itself was cultured from only half of the specimens having positive smears. Bacillus cereus, Streptococci, and Clostridia were found in many specimens. Corynebacterium pyogenes and Bacteroides melaninogenicus each had an incidence of 10 percent of the total number of specimens. Pseudomonas aeruginosa was cultured from only 3 percent of all specimens. It was concluded from limited in vitro tests that wide-spectrum antibiotics were most active against these organisms. However, Ps. aeruginosa was resistant to all the antibiotics tested.