Gas chromatographic analysis of shell membrane amino acids from hard-shelled, soft-shelled, and shell-less eggs.

The amino acid composition of shell membranes from hard-shelled (HS), soft-shelled (SS), and shell-less (SL) eggs produced by 62-wk-old hens was analyzed by gas chromatography using N-acetyl n-propyl ester derivatives. This technique succeeded in identifying tryptophane and ornithine as shell membrane components. There were no significant differences in the concentrations of any of the 17 amino acids analyzed among HS and SS eggs, HS and SL eggs, or SS and SL eggs. Stepwise discriminant analysis of the amino acid ratios correctly classified all of the amino acid chromatograms of shell membranes from HS/SL and SS/SL egg pairs, and 92.9% of the HS/SS and 90.0% of the HS/SS/SL amino acid chromatograms were classified correctly (F = 1.0). Higher F values reduced the percentage of correct classifications to 75.0%, 85.0%, and 67.5% (F = 2.0) for the HS/SL, SS/SL, and HS/SS/SL egg groups, respectively, and to 78.6% (F = 3.0) for the HS/SS egg group. Stepwise discriminant analysis also identified specific amino acid ratios that were most efficient at classifying the amino acid chromatograms according to shell type. This process identified three amino acid ratios for the HS/SS egg group (F = 3.0), two ratios for the HS/SL egg group, four ratios for the SS/SL egg group, and four ratios for the HS/SS/SL egg group (F = 2.0). Based on the number of times they appeared as efficient discriminating variables at higher F values, alanine, proline, and isoleucine seemed to be the most important amino acids for correctly classifying shell membranes by egg type.

Improved method for high pressure liquid chromatographic determination of chlorophacinone in mouse tissue.

A simplified method is described for the determination of chlorophacinone, 2-[(p-chlorophenyl)-phenylacetyl]-1,3-indandione, in homogenized mice. Chlorophacinone is extracted with acetonitrile. After Florisil cleanup, the extract is injected into a high pressure liquid chromatograph for reverse phase chromatography on a polar Lichrosorb NH2 (10 micron) column, with a mobile phase of acetonitrile-water (80 + 20). An injection containing 70 ng chlorophacinone produces 1/2 scale peaks at 254 nm with a full scale absorbance of 0.1 unit, an order of magnitude improvement over the sensitivity reported earlier with a 280 nm detector. Six homogenized mice samples and six spiked homogenized mice samples were quantitatively analyzed for trace levels of chlorophacinone by this method. Recoveries from spiked samples, as determined by peak height measurement, were greater than 95%. Mean retention time for the chlorophacinone peaks in all samples was 6.05 +/- 0.05 min. Chlorophacinone levels determined in homogenized whole mouse samples ranged from 0 to 63 ppm.

Antibiograms of pathogenic bacteria isolated from laboratory animals.

Study of antibiotic sensitivity patterns of 178 bacterial isolants from laboratory animals revealed that these bacteria in general were sensitive to many commonly used antibiotics; however, there were notable exceptions. This report presents current antibiotic sensitivity patterns of most gram-negative and gram-positive bacterial pathogens common to laboratory animals.

Neutropenia and salmonellosis in hospitalized horses.

Colitis due to salmonellae was diagnosed in 9 horses following hospitalization for various reasons at the University of Missouri Veterinary Teaching Hospital, from May, 1971, to April, 1972. Diarrhea, fever, and either a neutrophil count of less than or equal to 3,600/cmm or a rapid decline in neutrophil numbers were specific for salmonellosis. The value of hematologic survelillance in hospitalized Equidae was demonstrated in another group of 9 horses with neutropenia, each of which was promptly treated and did not develop colitis. Bacteriologic culturing of fecal samples from 28 clinically normal horses yielded only 2 salmonella isolations, S manhattan in each case. The serotyped salmonellae isolated from the patients with colitis were all S typhimurium, with similar antibiotic resistance patterns.

Isolation of Edwardsiella tarda from swine.

Edwardsiella tarda was isolated from the intestinal tract of a 2-month-old pig. This is the first reported isolation of Edwardsiella tarda from swine in the United States. Swine have been reported as potential carriers of Edwardsiella tarda, but pathogenicity of this organism for swine has not been determined. Although the pig had access to several farm ponds, the exact source of infection was not determined.