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Biomedical subjects

J F Timoney

Publications and source records attributed to J F Timoney.

At least 91 records · Page 5Linked to original sources
PubMed1985

Immunologically reactive proteins of Streptococcus equi.

Immunologically reactive proteins in acid extracts and culture supernatants of Streptococcus equi were recognized through a combination of chromatographic and immunologic procedures. Both high- and low-molecular-weight components of each of these protein preparations were protective for mice and were, therefore, presumed to contain a variety of hydrolytic products or fragments of the M protein of S. equi. Convalescent horse sera that exhibited strong bactericidal activity for S. equi always reacted with polypeptides in the molecular weight range of 24,000 to 29,000, whereas preinfection sera did not. Rabbit antisera to affinity-purified S. equi protein also reacted with these polypeptides, as well as with a polypeptide of about 36,000 to 37,000 molecular weight. M protein in acid extract and culture supernatant did not cross-react in immunodiffusion, but rabbit antiserum to affinity-purified M protein from an acid extract of S. equi reacted strongly with culture supernatant proteins of approximate molecular weights of 67,000, 58,000, and 43,000. We suggest, therefore, that the M protein in culture supernatant is masked by other sequences that are removed by hot acid during preparation of acid extracts. Polypeptides common to acid extracts of S. equi and Streptococcus zooepidemicus were also identified. These polypeptides had molecular weights of about 55,000 and 31,000.

Animals↗
PubMed1985

The frequency of salmonellae on duck eggs.

Total plate counts on washed duck eggs from a breeder farm on Long Island were less than 30/shell during the winter (January to February) of 1982. Clean unwashed eggs had counts less than 9 X 10(1)/shell, whereas dirty unwashed eggs had counts as high as 9 X 10(5)/shell. Our results showed that washing with a chlorine sanitizer (under commercial conditions) was highly effective in reducing surface bacterial counts on egg shells. Prolonged storage reduced bacterial counts on clean eggs, but it did not significantly affect loads on dirty eggs. No salmonellae could be detected on shells or in the magma of all eggs examined. In a second trial (March 1982) bacterial loads on washed and clean duck eggs from six different breeder farms were low, ranging from too few to count to 10(2)/shell. A higher proportion of dirty eggs were heavily contaminated with counts ranging from 10(5) to 10(6)/shell, but no salmonellae were detected either on shells or in magma. In the third trial (May 1982) bacterial determinations on eggs from breeder ducks that were not confined followed the pattern of the second trial. However, in this trial Salmonella enteritidis was detected on dirty egg shells in four of six farms. In a fourth trial (May 1983), bacterial loads on washed and nest-clean eggs from the same breeder farms (not confined) ranged between 10(2) to 10(3)/shell and 10(2) to 10(4)/shell, respectively. S. enteritidis and S. badar were recovered from washed, nest clean, and dirty eggs in two of six farms. We conclude that proper egg washing and confinement of duck breeders should minimize the problem of salmonellosis in ducklings.

Animals↗
PubMed1985

Immune complexes in purpura hemorrhagica of the horse contain IgA and M antigen of Streptococcus equi.

Purpura hemorrhagica is an acute disease of the horse characterized by edema of the head and limbs, leucocytoclastic vasculitis, petechial hemorrhages in mucosae, musculature and viscera, and sometimes glomerulonephritis. It is usually associated with strangles, an upper respiratory tract disease of the horse caused by Streptococcus equi. We have detected and characterized immune complexes in the sera of horses with poststrangles purpura hemorrhagica by using PEG precipitation and Western blot analysis. The immune complexes contained IgA and S. equi-specific antigens similar to those found in acid extracts. We propose that purpura hemorrhagica is an immune complex-mediated disease.

Animals↗
PubMed1984

Accumulation and elimination of Escherichia coli and Salmonella typhimurium by hard clams in an in vitro system.

A simple, in vitro protocol was devised to study contamination by and subsequent elimination of Escherichia coli and Salmonella typhimurium in the hard clam, Mercenaria mercenaria. The test bacteria were eliminated rapidly at similar rates for 8 h after exposure and less rapidly thereafter. At 24 h, numbers of E. coli had declined more than S. typhimurium. Bacteria were cleared in the form of rapidly sedimenting fecal and pseudofecal particulates with which the bacteria were stably associated. Ionic bonding was apparently not involved in this association. Degradation of substantial numbers of bacteria occurred in feces at between 6 and 24 h.

Animals↗
PubMed1980

A sudden decline in ampicillin resistance in Salmonella typhimurium.

Starting in 1975, an abrupt decline in ampicillin resistance of Salmonella typhimurium (the most common and antibiotic-resistant serotype) occurred in New York City. The present lower rate of 5% to 7.9% at our hospitals represents a return to the 1965 level. At the same time, the ampicillin resistance in S typhimurium from calves and other farm animals from upper New York State, which has been rising since 1972, has reached 75%. Substantial differences between levels of resistance in Escherichia coli from animals and humans were also noted. The divergence of the trends in S typhimurium from these two sources in New York State suggests a substantial degree of separation of the respective reservoirs of Salmonella and of antibiotic resistance.

Ampicillin↗
PubMed1980

pJT2: unusual H1 plasmid in a highly virulent lactose-positive and chloramphenicol-resistant Salmonella typhimurium strain from calves.

A lactose-positive and chloramphenicol-resistant strain of Salmonella typhimurium of high virulence was isolated from an outbreak of enteric and septicemic salmonellosis in veal calves. the lactose-positive marker was located on an H1 plasmid, pJT2, together with resistance to chloramphenicol, streptomycin, sulfonamides, and tetracycline, pJT2 was unusually large and had a molecular weight of about 150 X 10(6). A similar plasmid was also present in a third of the Escherichia coli strains isolated from the intestines of septicemic calves during the outbreak. Spontaneously derived Lac- derivatives of pJT2 had an approximate molecular weight of 140 X 10(6).

Animals↗
PubMed1980

Prevalence of salmonellae on eggs from poultry farms in New York State.

The purpose of this study was to determine the prevalence of salmonellae on egg shells. One hundred eggs from each of 14 Central New York poultry farms were tested for salmonella contamination of the shell. The egg magma was examined in those eggs that were positive on shell culture. Only .21% or three of the egg shells yielded salmonellae, all three of which were identified as S. typhimurium. No salmonellae were found in the magma of these eggs. Feed samples from 12 farms were also negative for salmonellae. From this study it would appear that the incidence of salmonellae on eggs from Central New York poultry farms is very low.

Animals↗
PubMed1979

Neuritis of the cauda equina, a chronic idiopathic polyradiculoneuritis in the horse.

Four cases of neuritis of the cauda equina (NCE) were studied by light and electron microscopy. Examination of sacral intradural rootlets revealed inflammatory cell infiltrates and an array of myelinated fiber changes which included myelin stripping by invading mononuclear cells and macrophages, as well as splitting and vesiculation of myelin lamellae without obvious participation by leukocytes. More distally in the extradural roots, there was marked granulomatous inflammation, and demyelinative changes were overshadowed by widespread evidence of irreversible axon damage. In all cases, unusual crystalline inclusions appeared in the endoneurium and sheaths of the rootlets and fascicles. The changes in NCE were compared and contrasted with those observed in acute and chronic inflammatory demyelinative neuropathies.

Animals↗
PubMed1979

Vivo clearance of enteric bacteria from the hemolymph of the hard clam and the American oyster.

American oysters, Crassostrea virginica, and hard clams, Mercenaria mercenaria, were experimentally contaminated with Escherichia coli, Salmonella typhimurium, and Shigella flexneri either by intracardial injection or via the natural route of ingestion. Bacterial inactivation in the hemolymph was monitored for 72 h after exposure to these enteric pathogens at 20 and 6 degrees C. At 6 degrees C, both mean bacterial uptake by ingestion and subsequent clearance was singificantly lower that at 20 degrees C. However, substantial bacterial clearance from the hemolymph occurred for both shellfish at each temperature. At 20 degrees C, viable bacteria were no longer detectable after 24 h in hemolymph of either clams or oysters after exposure to contaminated water containing 4 x 10(3) bacteria per ml.

Animals↗
PubMed1978

The epidemiology and genetics of antibiotic resistance of Salmonella typhimurium isolated from diseases animals in New York.

Only 12% of 249 strains of Salmonella typhimurium isolated during the period 1973-1976 from diseased animals were sensitive to six commonly used antibiotics. Isolates from calves exhibited the highest frequency of resistance as well as a steadily increasing frequency of resistance to ampicillin and chloramphenicol. The majority of strains from horses, dogs, and cats were also resistant to more than one antibiotic, a finding which was interpreted as primarily an effect of therapeutic rather than of growth-promoting use of antibiotics in these species. Ninety-one percent of resistant strains possessed transferable resistance. In 31% of these strains, the transfer factors were heat-sensitive and did not function at 37 C. The determinant of resistance to ampicillin was usually associated with a non-heat-sensitive transfer factor, whereas resistance to chloramphenicol, kanamycin, and tetracycline was more commonly associated with heat-sensitive transfer factors. Strains of S. typhimurium with similar patterns of resistance often contained different plasmids. There was more genetic homogeneity among determinants of resistance to tetracycline than among other determinants.

Ampicillin↗
PubMed1978

Heavy-metal and antibiotic resistance in the bacterial flora of sediments of New York Bight.

The New York Bight extends seaward some 80 to 100 miles (ca. 129 to 161 km) from the Long Island and New Jersey shorelines to the edge of the continental shelf. Over 14 x 10(6) m(3) of sewage sludge, dredge spoils, acid wastes, and cellar dirt are discharged into this area each year. Large populations of Bacillus sp. resistant to 20 mug of mercury per ml were observed in Bight sediments contaminated by these wastes. Resistant Bacillus populations were much greater in sediments containing high concentrations of Hg and other heavy metals than in sediments from areas further offshore where dumping has never been practiced and where heavy-metal concentrations were found to be low. Ampicillin resistance due mainly to beta-lactamase production was significantly (P < 0.001) more frequent in Bacillus strains from sediments near the sewage sludge dump site than in similar Bacillus populations from control sediments. Bacillus strains with combined ampicillin and Hg resistances were almost six times as frequent at the sludge dump site as in control sediments. This observation suggests that genes for Hg resistance and beta-lactamase production are simultaneously selected for in Bacillus and that heavy-metal contamination of an ecosystem can result in a selection pressure for antibiotic resistance in bacteria in that system. Also, Hg resistance was frequently linked with other heavy-metal resistances and, in a substantial proportion of Bacillus strains, involved reduction to volatile metallic Hg (Hg degrees ).

Anti-Bacterial Agents↗
PubMed1978

Feline salmonellosis. A nosocomial outbreak and experimental studies.

An outbreak of S. typhimurium gastroenteritis and septicemia is described in young cats admitted to a veterinary hospital for routine medical and surgical reasons. A morbidity of 32% and a mortality of 61% was observed in the outbreak. Affected cats exhibited oral shedding of the organism and contaminated feed and water dishes may have been the vehicle of spread of infection. Possible detrimental effects of incorrect choice of antibiotic therapy are discussed. Attempts to reproduce the disease in a group of laboratory cats were unsuccessful. Antibody production was poorly correlated with infection in these cats.

Animals↗
PubMed1977

Bacteriophages of Streptococcus equi.

Bacteriophages were isolated from twelve lysogenic strains of Streptococcus equi. Based on sensitivity data and antiserum neutralization tests, the phage isolates were divided into two distinct but related groups. All twelve phage change the colonial morphology of S. equi from mucoid to matt. Possible phage-mediated effects on S. equi virulence are discussed.

Bacteriophage Typing↗
PubMed1977

Salmonella in surface waters of central New York state.

Six tributary streams and southern Cayuga Lake in central New York state were sampled for the presence of Salmonella on swabs immersed for 4 days. Of a total of 322 swabs, 39% yielded salmonellae. Swabs were cultured in tetrathionate enrichment at 41.5 degrees C. Isolations were made from brilliant green agar. Salmonellae were isolated from many sites on the streams and from some lake sites. Twenty-five serotypes (11 somatic antigen groups) and a distinct biotype of S. typhimurium (H2S negative) were found. Most frequent isolates, in order of decreasing occurrence, were S. typhimurium, S. thompson, S. oranienburg, and S. enteritidis. Several uncommon isolates also appeared. When tested for mouse infectivity, the isolates generally showed little or no virulence. The incidence of clinical salmonellosis among humans was low in the area and the variety of serotypes had not been noted among cattle. The presence of Salmonella in waters ranging in classification from potable to agricultural and industrial indicated the existence of a low level and undefined reservoirs of the bacteria in the region.

Escherichia coli↗
PubMed1976

Toxoplasmosis.

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Animals↗