Results of a Preliminary Trial with Sphaerophorus necrophorus Toxoids to Control Liver Abscesses in Feedlot Cattle

A preliminary field experiment was undertaken to evaluate the efficacy of alum precipitated toxoids of Sphaerophorus necrophorus prepared from sonicated whole cells and cell fractions to reduce the incidence of bovine abscesses. A total of 108 calves were divided into five groups and treated as follows: I. uninoculated control, II. adjuvant inoculated control, III. 15.5 mg protein of sonicated (fragmented cells) toxoid, IV. 10.5 mg protein of cytoplasmic toxoid. V. 15.5 mg protein of cytoplasmic toxoid. All animals were maintained under similar conditions to those prevailing in feedlots in Alberta. Livers were examined at slaughter. The most promising result was achieved with the injection of 15.5 mg protein of cytoplasmic toxoid. In this treatment group, no scars (healed lesions) were found in the liver and the incidence of liver abscesses was reduced to 10% from the average 35% liver abscesses and scars found in the uninoculated and adjuvant inoculated groups. The toxoid from sonicated whole cells did not reduce liver abscess incidence. These data suggest that the incidence of liver abscesses in cattle fattened in feedlots may be reduced by immunization.     

Sphaerophorus necrophorus. A study of 23 strains

Twenty-three strains of Sphaerophorus necrophorus, isolated from animal pathological processes, were characterized. The two biotypes of Fievez (1963) were recognized, differing in colony morphology, cell morphology, degree of hemolysis, growth modus in broth, and hemagglutination. The following characters were shared by all strains: Gram-negative, anaerobic, nonsporeforming, immotile rods, producing acid from fructose, glucose, mannose, maltose, and (variably) from galactose, but not from arabinose, xylose, lactose, saccharose, cellobiose, melezitose, adonitole, sorbitole, mannitole, and salicine. Terminal pH in glucose medium was 5.77 ± 0.17. Growth was not inhibited by 0.008 % brilliant green, but was partially inhibited by 10 % ox bile. Indole was produced. Nitrate was not reduced. A lecitinase was present. Proteolytic properties were present. Threonine was deaminated. The fatty acids: acetic, propionic, and butyric acid were produced in medium both with and without glucose.     

A simple method for rapid identification of Sphaerophorus necrophorus isolates.

A hemagglutination inhibition test for the rapid identification of Sphaerophorus necrophorus is described. Erythrocytes from six species of animals were tested and human cells were found to be the best agglutination indicators. Antiserum prepared in rabbits was found to be specific for S. necrophorus hemagglutinins when tested against 20 isolates of S. necrophorus and 117 other bacteria belonging to 22 genera. The possibility of using a hemagglutination inhibition test for the detection of bovine necrobacillosis was explored.     

Isolation ofSphaerophorus necrophorus from bovine liver abscesses in the Sudan

Conclusion The isolation ofS. necrophorus from 84 of 100 bovine livers strongly suggests that it is the principal bacterial agent responsible for bovine liver abscesses in the Sudan. Pure cultures of the organism were isolated from 57 per cent of the abscesses compared with the range of 67 to 85 per cent recorded by Simon and Stovell (1971) and Newsom (1938). The difference between the results obtained in this study and previous ones elsewhere is the lack of variety of organisms isolated from bovine liver abscesses. Madin (1949) and Simon and Stovell (1971) found a wide spectrum of organisms, including members of the generaEscherichia, Corynebacterium, Staphylococcus, Streptococcus and others, present in association withS. necrophorus in 30 per cent of the bovine liver abscesses examined. In this study only in 26 per cent of the abscesses were there associated organisms and these were coagulase-negative staphylococci and diphtheroids.     

Cultivation and Maintenance of Sphaerophorus necrophorus Part I: An Anaerobic Medium for Aerobic Incubation

Out of 185 media formulated and studied for the growth of Sphaerophorus necrophorus, ten were selected for intensive investigation. Their ability to promote growth was compared photometrically. Medium 156 made up of Brewer's thioglycollate broth, yeast extract, L-cystine, and ascorbic acid, was found to yield a very heavy growth. The viability of S. necrophorus was maintained indefinitely by weekly subcultures. When not subcultured, all isolates remained viable for fifteen weeks and some isolates for 30 weeks at 37°C.

Twenty-nine isolates were tested. No variation in maximum growth was noticed.

Medium 156 is an optimum medium for S. necrophorus. It can be incubated aerobically without interfering with maximum growth. The medium does not deteriorate when stored for at least 12 weeks at room temperature.

     

Hepatic Abscesses Associated With Diabetes Mellitus in Two Dogs

Two diabetic dogs were presented for anorexia, persistent fever, and poor control of hyperglycemia. Both had neutrophilia with left shift, hypoalbuminemia, and increased serum alkaline phosphatase (SAP) activity. Radiography indicated intrahepatic gas densities in 1 dog and a hepatic mass in the other. Abdominal sonography demonstrated multiple well-demarcated hypoechoic hepatic lesions consistent with abscesses. Both dogs were successfully treated by surgical resection of the abscessed liver lobes inconjunction with antibiotics and supportive therapy. Good control of hyperglycemia was achieved in both dogs after recovery. Intracellular and extracellular Gram-negative rod-shaped bacteria were abundant in the abscesses from both dogs. These cases suggest an association between diabetes mellitus and hepatic abscessation.     

Cultivation and maintenance of Sphaerophorus necrophorus. Part II: Influence of pH on maximum growth and acid production in Medium 156.

Sphaerophorus necrophorus was grown in Medium 156 at 40 pH values ranging from 4.93 to 9.46. Growth occurred between pH 5.30 and 9.28. The optimum pH for maximum growth was 6.84 while the optimum pH for acid production was 7.70. At pH 7.70 acid production was more than double that at pH 6.84 during a 12 hour incubation period. Thus, maximum growth occurs at one pH and maximum acid producation at another. Since the two optima are different, acid production should be evaluated only when: 1. an optimum medium is employed, 2. the optimum pH for acid production is employed. 3. the incubation period necessary for maximum acid production has elapsed before the test is conducted.