Neylan A. Vedros

San Miguel Sea Lion Virus Isolation, Preliminary Characterization and Relationship to Vesicular Exanthema of Swine Virus

BETWEEN 1932 and 1954 there were repeated outbreaks of vesicular exanthema of swine (VES) in Californian swine herds, but since 1956 no cases have occurred in the United States and this has been attributed to a federal law which prohibited the feeding of raw garbage to swine1. The continuing importance of vesicular diseases of swine, however, is suggested by reports from Italy2, Hong Kong3, Austria, Poland and Britain (personal communication from A. H. Dariri, Plum Island Animal Disease Laboratory, 1973) of a vesicular syndrome in swine that could not be ascribed to foot and mouth disease virus (FMDV).

Leptospirosis Epizootic among California Sea Lions

A Leptospira species is suspected of being the etiological agenit in a recent epizootic among California sea lions. The disease was confined to subadult males of the species Zalophus c. californianus.

Taxonomy of the Neisseriae: Deoxyribonucleic Acid Base Composition, Interspecific Transformation, and Deoxyribonucleic Acid Hybridization

Deoxyribonucleic acid (DNA) base composition, intergenic transformation efficiency, and DNA hybridization were used to determine the relatedness of a variety of established or proposed species of Neisseria and Branhamella. These studies indicated that these bacteria form three genetic groupings. Group I, comprised of N. meningitidis, N. gonorrhoeae, N. subflava, N. flava, N. perflava, N. sicca, N. mucosa, N. cinerea, N. flavescens, N. lactamica, N. elongata, N. canis, and N. denitrificans, was characterized by DNA base compositions ranging between 49.3 and 55.6 mol% guanine plus cytosine. Group II, comprised of N. cuniculi, N. caviae, and N. ovis, was characterized by DNA base compositions ranging between 45.3 and 47.3 mol% guanine plus cytosine. Group III, comprised of one species, B. catarrhalis, was characterized by DNA base compositions between 41 and 42 mol% guanine plus cytosine. Transformation and DNA hybridization results revealed that members of each group, with few exceptions, exhibited high DNA homology with other members of the same group but most often distinctly lower levels of homology with members of a different group. These data suggest that N. ovis, N. caviae, and N. cuniculi may be significantly different from other neisseriae and from branhamellae to warrant their separation in a distinct genus.

Neisseria macacae sp. nov., a new Neisseria Species Isolated from the Oropharynges of Rhesus Monkeys (Macaca mulatta)

Three gram-negative, oxidase-positive diplococcal strains were isolated from the oropharynges of healthy monkeys. These three strains closely resembled Neisseria perflava in their physiological and biochemical characteristics, were more similar to Neisseria canis in their cellular fatty acid profiles, and were moderately related to Neisseria mucosa (51.9%) as determined by deoxyribonucleic acid-deoxyribonucleic acid hybridization. An analysis of 11 enzymes indicated clustering closest to Neisseria sicca, followed by N. mucosa. We propose the name Neisseria macacae for this new species, and the type strain of this species is strain M-740 (= ATCC 33926).

Taxonomy of the Neisseriae: Fatty Acid Analysis, Aminopeptidase Activity, and Pigment Extraction

The cellular fatty acids of reference strains of most of the currently recognized species of Neisseria and Branhamella species were examined. Analysis of fatty acids with chain lengths of over 12 carbons supported the division of the species into two groups. Group I, comprised of N. meningitidis, N. gonorrhoeae, N. flava, N. subflava, N. perflava, N. sicca, N. mucosa, N. lactamica, and N. cinerea, contains methyl laurate, methyl palmitoleate, methyl palmitate, methyl oleate, and, often, methyl myristate as principal fatty acids. Group II, represented oy N. caviae, N. cuniculi, N. ovis, and B. catarrhalis, contains large amounts of a 17-carbon fatty acid with a retention time similar to those of methyl-14, methyl hexadecanoate, methyl heptadecanoate, and, often, methyl stearate in addition to those fatty acids found in group I organisms. The greatest distinction between the two groups was the percentage of major fatty acids with chain lengths greater than 16 carbons. Aminopeptidase activity was most useful in differentiating N. meningitidis from N. gonorrhoeae. N. cuniculi, N. ovis, N. caviae, and B. catarrhalis had similar aminopeptidase reactions. Pigment profiles were of limited taxonomic value but were useful in differentiating between selected pigmented species.

Serum and colostrum immunoglobulin levels in the Northern Fur Seal Callorhinus ursinus

Abstract IgG, IgM, and IgA were measured in the serum and colostrum of adult and immature Northern Fur Seals ( Callorhinus ursinus ). Levels of these immunoglobulin classes in adults were comparable to those in terrestrial mammals. However, maternal transfer of immunoglobulin to neonatal pups either transplacentally or via the colostrum was low. The rate of appearance of IgG and IgA in the serum of pups from 3 days to 4 months was less than in most terrestrial mammals. IgM was present at 19% of the adult average in full term pups and rapidly rose to 70% of the adult value by 5 weeks of age. The significance of these results in regard to rookery mortality of fur seal pups is discussed.

BACTERIAL AND FUNGAL FLORA OF WILD NORTHERN FUR SEALS (CALLORHINUS URSINUS)

Tissues from healthy subadult and moribund newborn northern fur seals (Callorhinus ursinus) on St. Paul Island, Pribilof Islands, Alaska, and from healthy pups and yearlings on San Miguel Island, California, were sampled for bacteria and fungi. Corynebacterium spp. and Staphylococcus spp. were more frequently present in tissues from animals on St. Paul Island whereas Pseudomonas spp. were frequently isolated on San Miguel Island. Approximately half of the blood samples were positive for bacteria. Salmonella spp. were isolated from rectal swabs of animals only on San Miguel Island. Fungi were isolated from the hair and skin of subadult males.

Immunochemical analysis and possible biological role of an Aeromonas hydrophila surface array protein in septicaemia

The biochemical, immunological, and biological properties of an S layer purified from an Aeromonas hydrophila strain (AH-342) involved in a case of bacteraemia were investigated. The S layer selectively removed from the cell surface was composed of a single acidic (pI 4.56) protein subunit (surface array protein, SAP) with a molecular mass of approximately 52 kDa. Amino acid analysis of this 52 kDa protein indicated a molecule composed of 498 amino acids with 46% hydrophobic residues. No cysteine residues were detected. The first 35 residues of the N-terminus were sequenced by Edman degradation; only 4-24% homology was noted between this sequence and those previously published for SAPs of Aeromonas salmonicida (A450) and a strain of A. hydrophila (TF7) originally isolated from a moribund fish. Polyclonal antibodies raised against AH-342 SAP were genospecific, reacting only against S layers produced by A. hydrophila strains and not those from Aeromonas veronii. Acute serum from the bacteraemic patient from whom AH-342 was isolated reacted strongly with the SAP of AH-342 in immunoblot studies. Purified SAP, when intraperitoneally co-inoculated with SAP- strains of A. hydrophila into Swiss-Webster mice, could reduce the 50% lethal dose by approximately 30-70 fold. The results suggest that the SAP of A. hydrophila strains may play an important role in systemic dissemination after invasion through the gastrointestinal mucosa.

Genetic Relationships among Neisseria Species Assessed by Comparative Enzyme Electrophoresis

The electrophoretic mobilities of 12 enzymes from 19 Neisseria species (including 6 strains of N. perflava), Gemella haemolysans, Escherichia coli and Branhamella catarrhalis were characterized by polyacrylamide slab gel electrophoresis. All strains and species tested exhibited qualitatively different zymogram patterns. Species and strain relationships were quantified by pairwise comparisons of all 12 enzyme systems to obtain similarity indices; these data were subjected to numerical clustering methods to obtain groups and a phenogram. The electrophoretic classification compared favourably with those obtained by other criteria. In addition, the quantitative clustering data indicated that N. ovis and N. caviae are sufficiently different from the other Neisseria species to warrant their separation into a distinct group. These two species also lacked the characteristic NADPH-diaphorase zymogram pattern found in all the other Neisseria species. Intra-species similarity indices were generally greater than the inter-species index values. However, certain species such as N. meningitidis and N. gonorrhoeae had similarity index values in the range of inter-strain index values.

Identification and characterization of three immunoglobulin classes in the northern fur seal Callorhinus ursinus.

Abstract Three immunoglobulin classes were isolated and identified from serum pools and throat mucus of the Northern Fur Seal, Callorhinus ursinus . These classes were shown to cross-react with antigenic determinants of human IgM and IgA and porcine IgG. Data obtained from gel filtration, ultracentrifugation, and reduction experiments indicate that these immunoglobulin classes have physiochemical properties similar to those in terrestrial mammals. Fractionation of serum on DEAE anion exchangers demonstrated two distinct peaks of IgG, the first of which (designated IgG-fp) possessed an antigenic determinant not found on the second peak (IgG-sp). On this basis, we conclude that the two peaks represent subclasses of IgG.