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Biomedical subjects

J G Songer

Publications and source records attributed to J G Songer.

At least 55 records · Page 3Linked to original sources
PubMed1986

Characterization of lectin-binding lymphocytes in goats with caseous lymphadenitis.

Numbers of lymphoid cells bearing markers for peanut agglutinin, wheat germ agglutinin, and anti-immunoglobulin G in healthy goats and in goats with caseous lymphadenitis were determined by use of immunofluorescent techniques. Results indicated that, when compared with healthy goats, diseased goats had normal numbers of anti-immunoglobulin G-positive cells (B cells), had significantly reduced numbers of peanut agglutinin-positive cells (T cells), and had fewer cells with receptor sites for Lens culinaris agglutinin and concanavalin A. Compared with healthy goats, numbers of peanut agglutinin-positive cells in goats with caseous lymphadenitis indicated that the goats may have had a compromised cell-mediated immunity.

Animals↗
PubMed1985

Experimentally induced pneumonic pasteurellosis: dose-response relationships and protection against natural reinfection in calves.

Calves were inoculated intranasally with 2 X 10(6.2) tissue culture infective doses of infectious bovine rhinotracheitis virus, followed in 7 days by intratracheal inoculations with 1 of 4 challenge doses of pathogenic Pasteurella haemolytica. Severity and duration of the ensuing clinical signs of respiratory tract disease were correlated with the challenge dose of bacteria. Calves given 1 X 10(6) colony-forming units (CFU) of bacteria did not develop reliable clinical evidence of disease, whereas those given 1 X 10(8) CFU or 1 X 10(10) CFU of bacteria developed clinical signs of pneumonic pasteurellosis within 12 to 24 hours of bacterial challenge. Severity of clinical signs was equal at the 10(8) and 10(10) doses of bacteria, but duration of clinical signs was greater in calves given the 10(10) dose. Calves given 1 X 10(12) CFU of bacteria developed relatively severe respiratory tract disease in excess of what was necessary for positive clinical detection. Positive correlations were found between the bacterial challenge dose and the height and duration of increased rectal temperature, amount and duration of increases in ocular and nasal discharges, and the subjective evaluation of depressed attitude and appetite. Correlations were not found between challenge dose and respiratory rate or character, or between challenge dose and complete blood cell count. Convalescent calves were resistant to naturally occurring pneumonic pasteurellosis, which caused severe disease in nontreated calves. Adverse effects of P haemolytica were not observed after the first 4 to 15 days after bacterial administration; however, the bacteria were isolated from nasal secretions of convalescent calves 89 to 116 days after bacterial inoculation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

In vitro interaction of Mycobacterium avium with intestinal epithelial cells.

Human intestinal epithelial cell monolayers were inoculated with cultures of Mycobacterium avium serotype 2, 8, or 10 that were viable, autoclaved, Formalin killed, exposed to UV light, or suspended in anti-M. avium serotype 2 serum. The effects of four reagents known to block phagocytosis or endocytosis (cytochalasin B, dibutyryl cyclic adenosine monophosphate, iodoacetate, and 2,4-dinitrophenol) on the bacteria-cell interaction were also studied. The maximum uptake of pathogenic M. avium by human intestinal epithelial cells occurred after 2 to 3 h of incubation. Serotype 2 was taken up in greater quantity than serotype 8 or 10. Saprophytic mycobacteria did not attach to or penetrate the host cells. The data showed that viable mycobacteria are ingested by host cells, whereas dead organisms are not. Components of the bacterial cells are partially, but not solely, responsible for the phagocytosis of M. avium serotype 2 by human intestinal epithelial cells. Furthermore, uptake of M. avium by human intestinal epithelial cells was suppressed by reagents which inhibit uptake by known phagocytic cells, suggesting that the mechanism of uptake is an endocytic process induced by virulent mycobacteria.

2,4-Dinitrophenol↗
PubMed1983

Isolations of aerobic bacteria from wild desert bighorn sheep (Ovis canadensis nelsoni and O. c. mexicana) in Arizona.

Nasal, pharyngeal, cervical and vaginal swab specimens were obtained from 74 desert bighorn sheep for the purpose of investigating the normal aerobic bacterial flora of wild sheep. A total of 281 isolates was obtained and identified by standard microbiologic tests. One hundred seven of these isolates were gram positive and included Bacillus sp. (36%), Staphylococcus epidermidis (8%), S. aureus (4%), Corynebacterium sp. (diphtheroids, 4%), and Streptococcus sp. (48%). gram negative isolates totaled 174 and included Neisseria sp. (18%), Citrobacter sp. (3%), Enterobacter sp. (2%), Escherichia coli (2%), Proteus sp. (2%) and non-fermentative bacilli (NFB) (73%). Of the NFB isolates, Pseudomonas sp. (25%), Acinetobacter sp. (18%), Moraxella sp. (15%) were identified.

Aerobiosis↗
PubMed1983

Serologic survey for leptospirosis in Arizona beef cattle in 1981.

Sera from 1,215 beef cattle in Arizona were evaluated by leptospiral microscopic agglutination test in 1981. Over 25% had agglutinins to greater than or equal to 1 of 5 serovars of Leptospira interrogans used as antigens (canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona) at a titer of greater than or equal to 1:100, and 8.2% had titers of greater than or equal to 1:400 to greater than or equal to 1 serovars. The most common serovar to which reactions were detected was hardjo; agglutinins were detected at titers of greater than or equal to 1:100 in 14.3% and of greater than or equal to 1:400 in 5.5%. Cross reactions were rare at serum dilutions greater than or equal to 1:100 (2%) and extremely rare at greater than or equal to 1:400 (0.7%). Because vaccination with leptospiral bacterins is seldom practiced in Arizona beef cattle, a titer of greater than or equal to 1:100 may be useful in estimating incidence and prevalence of the disease and as an aid to diagnosis of leptospirosis.

Animals↗
PubMed1983

Leptospirosis in rodents from an arid environment.

Rodents (n = 358) were trapped from 6 locations in Arizona, including 2 dairies, 2 swine raising operations, and 2 areas where domestic animal access was limited. Isolates of Leptospira interrogans serovar ballum were obtained from 3 house mice (Mus musculus) trapped in dairies. Leptospira were seen in silver-stained kidney sections of 10.4% of the rodents. The usefulness of serologic data in detecting leptospiral infection in these rodents was uncertain because so few animals yielded isolates that valid comparisons of culture positives to serologic positives were not possible. Titers greater than or equal to 1:160 were obtained to serovars autumnalis, ballum, bratislava, canicola, grippotyphosa, hardjo, icterohaemorrhagiae, and pomona. Nearly 60% of the rodents had microscopic lesions in kidneys, including 20 of 34 (59%) of those in which leptospira were seen.

Animals↗
PubMed1980

Epidemiological investigation of swine tuberculosis in Arizona.

Swine tuberculosis occurred in thirteen herds of swine in Arizona. Mycobacterium avium serotypes 1, 2, 4, 5 and 8 were isolated from tissues of affected animals. These serotypes are responsible for approximately 85% of the mycobacterial infections found in swine in the United States. Based on tuberculin skin test responses and examinations of tissues collected at slaughter, the source of infection in at least one of these herds, Herd A, was found to be infected sawdust and wood shavings used as bedding. This finding concurs with the reports of others. Tuberculin skin tests performed on slaughter pigs in Herd A showed a 97.1% correlation between the number of pigs responding to tuberculin and the number found to have tuberculous lesions at slaughter. No correlation of skin test response and presence of lesions was possible for individual pigs, but these results imply that the test may have value when used to determine prevalence of the disease in a herd of pigs.

Animals↗
PubMed1979

Comparison of selective culture and serologic agglutination of Treponema hyodysenteriae for diagnosis of swine dysentery.

Samples of faeces and of serum were collected from pigs of various ages on 21 farms. Faecal samples were cultured on trypticase soy agar containing 5 per cent citrated bovine blood and 400 micrograms per ml spectinomycin, incubated at 42 degrees C in Gaspak jars under an atmosphere of 80 per cent hydrogen: 20 per cent carbon dioxide. Antibody titres to Treponema hyodysenteriae were determined by a microtitration agglutination method using merthiolate-inactivated whole cell antigen prepared from a beta-haemolytic isolate. Results indicated that mean titres in pigs from which beta-haemolytic T hyodysenteriae was isolated were significantly higher than in pigs which yielded isolates of weak beta-haemolytic T innocens or in culturally negative pigs (P less than 0.0225). Mean titres of herds where beta-haemolytic T hyodysenteriae was isolated were significantly higher (P less than 0.005) than the mean titres of either of the other two groups. However, mean titres of herds where no isolates were obtained were not significantly different from mean titres of herds where weak beta-haemolytic T innocens was isolated.

Agglutination Tests↗
PubMed1978

Isolation of Treponema hyodysenteriae from sources other than swine.

Fecal samples were collected from animals and environments on 3 swine farms and cultured for Treponema hyodysenteriae. Each farm was a farrow-to-finish operation and, at the time of sampling, swine dysentery was enzootic among 8- to 22-week-old pigs. Pathogenic T hyodysenteriae was isolated from pigs on all 3 farms. On farm A, nonpathogenic T hyodysenteriae was isolated from a sample of lagoon water. On farm B, pathogenic T hyodysenteriae was isolated from a waste-holding pit. On farm C, a dog was observed to be eating feces of pigs that had swine dysentery. The dog was diarrheic and a fecal sample yielded a pathogenic isolant of T hyodysenteriae. Further isolation attempts were unsuccessful after the dog was removed from the infected premises. Isolation of pathogenic and nonpathogenic organisms from waste-holding systems emphasizes the need for cultural techniques in detecting pathogenic T hyodysenteriae.

Animals↗
PubMed1978

Experimental infection with Treponema hyodysenteriae in guinea pigs.

Outbred and inbred (Hartley strain) guinea pigs (GP) were inoculated intragastrically with pathogenic and nonpathogenic Treponema hyodysenteriae. GP 3 to 16 weeks old received T. hyodysenteriae after a fasting period of 36 to 72 h. Infected GP with pathogenic T. hyodysenteriae developed a diarrheal and/or depressive condition, with mucus but not blood in the feces. Of 88 GP, 40 had gross lesions resembling those of swine dysentery. Lesions were limited mainly to the large intestine. TP used as controls or inoculated with nonpathogenic T. hyodysenteriae did not develop these lesions in the large intestine. These studies suggest that the GP may be used as an animal model for swine dysentery.

Animals↗
PubMed1978

Transmission of swine dysentery by carrier pigs.

Swine dysentery (SD) was transmitted to healthy pigs by contact with experimentally-induced carrier pigs. Carrier pigs were produced by exposure of specific pathogen-free (SPF) swine to swine acutely affected with SD. When carrier pigs became acutely affected with SD, they were allowed to recover naturally or were treated with dimetridazole or ronidazole. Recovery was based on disappearance of clinical signs of SD. At a given time after recovery, normal SPF swine were housed with the carriers in a disinfected isolation unit to determine the ability of carriers to transmit SD. In each of 3 experiments, carriers that had recovered and remained asymptomatic for 11 to 25 days transmitted SD to contacts in 14 to 51 days. In 2 experiments, pathogenic Treponema hyodysenteriae was isolated from carriers 12 days before clinical SD was observed in contacts. Carriers which had recovered and remained asymptomatic for 70 and 90 days transmitted SD to contacts in 1 of 3 experiments. Treponema hyodysenteriae was isolated only from contacts with clinical signs of SD. In 4 experiments, carriers that had been treated with nitroimidazole compounds and subsequently recovered for 19 to 44 days failed to transmit SD. Culture of fecal samples on trypticase soy agar with 5% bovine blood and 400 microgram of spectinomycin/ml was helpful in predicting the carrier state, but phase contact contact microscopy of wet fecal smears was not.

Animals↗
PubMed1978

Enteropathogenicity testing of Treponema hyodysenteriae in ligated colonic loops of swine.

Multiple, ligated loops of swine colon were used as an in vivo model in which to test enteropathogenicity of isolates of Treponema hyodysenteriae. Gross and microscopic lesions observed in 21 of 22 colonic loops in pigs killed 48 to 72 hours after inoculation with isolates known to be enteropathogenic were characteristic of swine dysentery. These lesions were not observed in 12 loops exposed to uninoculated media or in 12 loops inoculated with nonpathogenic isolates of T hyodysenteriae. The swine-loop technique provides a relatively rapid, economical, reliable model in which to test enteropathogenicity of T hyodysenteriae isolates.

Animals↗
PubMed1976

Selective medium for isolation of Treponema hyodysenteriae.

Pure cultures of six pathogenic isolates of Treponema hyodysenteriae, the colonic mucosal scrapings of seven pigs with acute swine dysentery, and feces from seven unaffected pigs were diluted in phosphate-buffered saline and plated on Trypticase soy agar with 5% citrated bovine blood (TSA) and TSA with various levels of spectinomycin (TSA-S). The plates were incubated at 42 degrees C in a vented GasPak jar with a cold palladium catalyst and either 80:20 H2-CO2 by evacuation and refilling or a H2-CO2 generator envelope. Viable cell counts of the six pathogenic isolates were not altered by plating on TSA-S with 400 mug of spectinomycin per ml (TSA-S400) as compared with TSA alone. Dilutions of colonic mucosal scrapings from seven pigs with acute swine dysentery showed numbers of T. hyodysenteriae to be unchanged when plated on TSA-S400. Flora other than T. hyodysenteriae present in acute swine dysentery was inhibited, on the average, by 99.99%. Plating of dilutions of feces of unaffected pigs on TSA-S400 showed inhibition of flora that averaged more than 99.9%. Pathogenicity of T. hyodysenteriae was not altered by isolation or serial passage on TSA-S400.

Animals↗
PubMed1974

Sewage treatment by controlled eutrophication: bacterial study.

Several groups of bacteria were isolated and identified in an evaluation of the microbiological properties of a sewage treatment system involving the process of controlled eutrophication in a marine setting (J. G. Songer, N. M. Trieff, R. F. Smith, and D. Grajcer, 1974). Fecal coliforms, enterococci, Salmonellae, Shigellae, Vibrio parahaemolyticus, and Vibrio alginolyticus were studied at three stages of the treatment process. Significant reductions in fecal coliforms (P < 0.01) and enterococci (P < 0.01) were noted from raw sewage to effluent. Salmonellae and Shigellae were not detected at any stage, nor was V. parahaemolyticus. V. alginolyticus was isolated from the effluent only, reflecting the halophilic nature of the organism; low concentrations in raw sewage increased in the more saline effluent. Brine shrimp (Artemia salina), the herbivores in this system, were tested and found to have extremely low numbers of the organisms under study associated with them. Findings point further toward the use of this system as a combined mariculture-sewage treatment facility.

Analysis of Variance↗
PubMedDate not supplied

Enteritis as a cause of mortality in the western bluebird (Sialia mexicana).

Increased mortalities in adult western bluebirds utilizing nestboxes were noted in western Oregon during 1998 and 1999. A necrohemorrhagic enteritis was found in 8 of 10 birds submitted for necropsy. Acanthocephalan parasites were present in four of eight birds with enteritis. Microscopic changes consistent with necrotic or ulcerative enteritis were commonly present. Anaerobic culture of the intestine yielded Clostridium perfringens in three of three birds. Genotype analysis of two of these isolates revealed them to be C. perfringens type A. Bacterial enteritis is believed to be the cause of the increased mortality rate, but further investigation is required to prove a definitive link to a clostridial agent.

Acanthocephala↗