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Biomedical subjects

C M Scanlan

Publications and source records attributed to C M Scanlan.

At least 37 records · Page 2Linked to original sources
PubMed1990

Bacteriologic and pathologic studies of hepatic lesions in sheep.

At an abattoir, lesion specimens from 140 condemned sheep livers were collected for bacteriologic culture and for pathologic examination. Grossly, 23 lesions were abscesses; from 9 of which, Fusobacterium necrophorum biovar A (3 in pure culture and 6 in mixed culture) was isolated and from 14 of which, biovar B (6 in pure culture and 8 in mixed culture) was isolated. Escherichia coli was the predominant facultative anaerobic bacterium and Clostridium perfringens was the predominant obligate anaerobic bacterium isolated from the 14 lesions with mixed bacterial infection. Histologically, these lesions had a core of coagulation necrosis, encircled by a zone of necrotic phagocytic cells and bacteria with cellular characteristics of F necrophorum biovars A or B, and a connective tissue capsule. Of the 117 lesions without F necrophorum, 49 were culture-positive (for other organisms) and 69 were culture-negative. These 117 lesions were fibrous and were smaller than the 23 abscesses. A variety of gram-positive and gram-negative facultative anaerobic and obligate anaerobic bacteria was isolated from the culture-positive lesions, but always in low numbers. Eleven culture-negative and 18 culture-positive lesions were examined and had histologic characteristics of parasite-induced granulomas, with numerous eosinophils and epithelioid giant cells. Results of the study indicated that the histologic appearance of ovine hepatic lesions with F necrophorum was similar to bovine liver abscesses caused by F necrophorum, but unlike bovine liver abscesses, F necrophorum biovar B was isolated more frequently than was biovar A and often in pure culture. Most of the lesions in the condemned livers were parasite-induced granulomas.

Animals↗
PubMed1989

A bacteriologic study of scabby-hip lesions from broiler chickens in Texas.

Broilers from commercial flocks experiencing a 10-60% incidence of scabby-hip lesions at processing were examined, and selected skin lesions were cultured. Over 70% of the lesions were associated with traumatic excoriations, particularly on the caudal dorsal convexity of the birds. Most lesions were observed on birds that were 5 weeks of age or older. From the 27 specimens cultured, Clostridium perfringens was isolated in pure culture from 4 lesions and Staphylococcus species from 10 lesions. Pure cultures of staphylococci were recovered from 4 lesions, and 2-5 different staphylococci were isolated from 6 lesions. Eight staphylococci were identified as S. sciuri, 8 as S. simulans, 2 as S. epidermidis, 2 as S. lentus, 2 as S. warneri, 1 as S. cohnii, and 1 as S. intermedius. Fifty cutaneous specimens from 10 5-week-old normal broilers were cultured. A total of 197 isolates were identified including 65 S. sciuri, 52 S. lentus, 24 S. simulans, 12 S. hyicus, 11 S. warneri, 9 S. cohnii, 9 S. gallinarium, 8 S. xylosus, and 7 S. epidermidis.

Animals↗
PubMed1989

Cultural and biochemical characterization of Actinobacillus and Actinobacillus-like species from ram lambs with epididymitis.

Cellular, colonial, cultural, and biochemical characteristics of 25 field strains of gram-negative pleomorphic bacilli from rams with epididymitis were compared with Actinobacillus actinomycetemcomitans American Type Culture Collection (ATCC) strain 29522 and Actinobacillus seminis ATCC strain 15768. Three field strains were identified as A. actinomycetemcomitans, 15 as A. seminis, and 2 as Haemophilus agni; however, 5 strains (3 in group A and 2 in group B) were not identified as species in the genera Actinobacillus, Haemophilus, or Pasteurella based on the taxonomic criteria in Bergey's manual of systematic bacteriology. The 5 Actinobacillus-like organisms in groups A and B were predominantly gram-negative coccobacilli and exhibited less pleomorphism than the 2 Actinobacillus species. The colonial morphologies of groups A and B were similar to the 2 Actinobacillus species but were smaller in diameter and had a pale yellow color. Groups A and B, like the actinobacilli, were facultative anaerobic and capnophilic, did not grow on MacConkey agar, and were catalase-positive and oxidase-positive. Group A reduced nitrate but group B did not. The A. seminis strains utilized ornithine, and group A utilized arginine; but group B did not utilize either ornithine or arginine. All strains failed to utilize lysine or tryptophane. All strains produced acid but no gas from glucose, and the utilization of other carbohydrates varied markedly both between and within the 5 groups of bacteria.(ABSTRACT TRUNCATED AT 250 WORDS)

Actinobacillus↗
PubMed1989

Experimental infection of dogs with Brucella abortus: effect of exposure dose on serologic responses and comparison of culture methods.

Two studies of experimentally induced Brucella abortus infections in dogs are reported. Twenty dogs in experiment 1 were fed approximately 4.8 X 10(10) colony forming units of B. abortus strain 2308 (BA 2308), and 11 dogs in experiment 2 were fed approximately 3.4 X 10(14) BA 2308. Serum samples from each infected dog and noninfected control were tested on the day of infection and at weekly and biweekly intervals post-infection (PI) for antibodies to B. abortus. The standard tube agglutination (STA) and rivanol (RIV) mean log-titers of the infected dogs in the 2 experiments were compared statistically on the day of infection and on PI days 7, 14, 21, 35, 42 and 49. The STA and RIV titers of the infected dogs in experiment 2 were significantly higher than were those of the dogs in experiment 1. Brucella abortus was isolated from 29 infected dogs in experiments 1 and 2 including 10 dogs, which were seronegative when cultured.

Animals↗
PubMed1988

Bovine brucellosis: an investigation of latency in progeny of culture-positive cows.

Calves (n = 150) born to cows infected with field strains of Brucella abortus were weaned within 24 hours after birth or allowed to nurse until weaned (age at weaning ranged from 10 to 43 weeks). After weaning, female calves were placed in small groups in special pens constructed to prevent further direct and environmental exposure to brucellae. At weaning, male calves were moved to an isolated pasture and were kept as a single group. Later, first-generation heifers were bred and placed in individual isolation pens until termination of pregnancy. Two of the first-generation heifers (that were culture-negative) developed persistent serologic responses (to B abortus) of unexplained origin. Brucellae were not isolated from progeny of infected cows (105) or from progeny offspring (95 fetuses and neonates), indicating that latency may be infrequent.

Animals↗
PubMed1988

Septic arthritis and osteomyelitis in a bovine digit: a mixed infection of Actinomyces pyogenes and Fusobacterium necrophorum.

A 4-year-old beefmaster cow was examined for a left hind leg lateral claw lameness due to septic arthritis of the distal interphalangeal joint and associated osteomyelitis of the second and third phalanges. Actinomyces pyogenes and Fusobacterium necrophorum, which have been demonstrated previously to act synergistically in ovine heel abscesses, were isolated from the affected digit. A claw amputation was performed because of the advanced destructive nature of the lesion.

Actinomyces↗
PubMed1987

Experimental infection of dogs with Brucella abortus.

Thirteen female dogs, which included eight principals that were fed approximately 4.4 X 10(10) colony forming units (cfu) of Brucella abortus strain 2308 and five sentinels that were housed with the principals, were examined for serologic responses, blood culture, tissue distribution of the organisms and pathologic lesions. Serum samples from each dog were tested on the day of exposure and on post exposure days 5, 7, 10, 14, 21, 28, 35, 42 and 49 for antibodies to B. abortus, using the brucellosis card (BC), standard tube agglutination (STA), 2-mercaptoethanol (ME) and rivanol (RIV) tests. Antibodies were detected in the principals by day 5 and increased through day 21. The STA test was the first to become positive, followed by the BC, ME and RIV tests. After 28 days, the serologic titers receded. From day 14 through day 42, all principals had greater than or equal to 1:50 STA titers. On day 49, seven principals had greater than or equal to 1:50 STA titers and one had a 1:25 STA titer. The sentinels were negative for all tests, except sentinel number 9 which had STA titers ranging from 1:25 to 1:50 on day 14 through day 35. Blood cultures that were obtained from each principal at intervals from one hour after exposure through 49 days were negative. Brucella abortus was isolated from various lymph nodes of the eight principals and from sentinel number 9, which was apparently infected by ingesting brucellae contaminated feces from the principals. Microscopic lesions were not observed in the culture-positive tissues examined.

Animals↗
PubMed1986

Biochemical characterization of the leukotoxins of three bovine strains of Fusobacterium necrophorum.

The biochemical characteristics of the leukotoxins of 3 bovine isolates of Fusobacterium necrophorum which represent biotypes A, AB, and B were compared. Two methods were used for the production of the leukotoxins: medium M-1 continuous dialysis sac cultures and brain-heart infusion agar plate cultures. The supernatant cultural fluids were fractionated sequentially by membrane-partition chromatography, using ultrafilters with approximate molecular weight (mol wt) exclusion limits of 100,000, 10,000, 2,000, and 500. The ultrafiltrates (less than 500 mol wt) were fractionated by gel-permeation chromatography, using G-10 Sephadex. The leukotoxins of the 3 F necrophorum strains were estimated to have a molecular weight between 350 and 450. The leukotoxins in the ultrafiltrates (less than 500 mol wt) were stable at 60 C for 4 hours and at 100 C for 30 minutes, stable to extremes of pH (3 to 11), and stable to degradative enzymes including trypsin, protease, alpha-amylase, lipase, deoxyribonuclease, and ribonuclease. Significant differences were not observed in the biochemical characteristics of the leukotoxins produced in vitro by the 3 F necrophorum biotypes. These assays were done, using monolayers of mouse peritoneal macrophages. The monolayers were exposed to the 4 ultrafiltrates of both the continuous dialysis sac and brain-heart infusion agar cultures (pH 7.2) for 4 hours at 4 C, 25 C, and 37 C. Maximal cytotoxic activity in the assays was at 37 C.

Animals↗
PubMed1986

Comparative changes in a rat liver abscess model induced with three Fusobacterium necrophorum strains.

Viable cultures of 3 bovine Fusobacterium necrophorum strains were inoculated into the hepatic portal veins of rats. The experimentally produced hepatic necrobacillosis lesions were examined beginning at 15 minutes after inoculation was done and continuing for 4 weeks. Fusobacterium necrophorum 2101 (FN 2101), a biotype A, was the most virulent; F necrophorum 2030 (FN 2030), a biotype AB, was of intermediate virulence; and F necrophorum 2035 (FN 2035), a biotype B, was the least virulent. Gross lesions were first observed at 2, 8, and 18 hours after inoculation in the FN 2101-, FN 2030-, and FN 2035-inoculated rats, respectively. Gross and histopathologic descriptions of the FN 2101 and FN 2030 hepatic necrobacillosis lesions were similar, but were markedly different from those of the FN 2035 lesions. Abscesses produced by FN 2101 and FN 2030 attained maximal diameter (1 cm) in the hepatic parenchyma. Subcapsular abscesses were produced by FN 2035 and attained a diameter of 2 to 3 mm (maximal).

Animals↗
PubMed1985

Ranitidine prophylaxis before anaesthesia in early pregnancy.

Forty patients presenting for vaginal termination of pregnancy, divided randomly into four groups, received either no medication, sodium citrate 30 ml orally, ranitidine 150 mg orally or ranitidine 50 mg intravenously. During the procedure, gastric contents were removed by orogastric tube for volume and pH measurements. Ranitidine, orally and intravenously, significantly increased gastric pH and reduced gastric volume. In the control group only one pH was greater than 2.5. Sodium citrate raised the pH above 2.5 in 6 out of 10 patients. Fasting patients in the first months of pregnancy may be at risk of developing Mendelson's syndrome. Ranitidine is very effective in increasing gastric pH and at the same time reducing gastric volume in such patients.

Abortion, Induced↗
PubMed1985

Brucella abortus in wildlife on selected cattle farms in Alabama.

Two studies of brucellosis in wildlife on farms where the brucellosis infection prevalence in cattle was known are reported. On a research farm, 233 feral animals of 22 mammalian species and 12 of seven avian species were trapped during three time periods. Sixty were studied before cattle were introduced, 128 were studied while 501 cattle infected with Brucella abortus were calving and aborting, and 60 specimens were collected 20 mo after the last infected cow calved. Selected tissues from 229 wild animals were cultured and sera from 138 were examined using the brucellosis card, standard tube agglutination (STA), 2-mercaptoethanol (2-ME) and rivanol (RIV) tests. Brucella abortus was not recovered from any animals sampled prior to cattle being introduced and all sera collected were negative. Brucella abortus was isolated from four opossums (Didelphis virginiana) and one raccoon (Procyon lotor) in the group of animals trapped during the calving period. Three serums were tested and had STA titers ranging from 1:100 to 1:200. Of 68 sera only one had antibodies. Brucella were not isolated from 59 animals trapped after the calving period and only one of 42 serums had antibodies. On regional cattle farms, 243 wild animals were trapped. Brucellae were not isolated from 223 animals which were cultured. No serums had significant titers. The data from this study suggest opossums and raccoons can be infected from cattle but are unlikely to maintain the infection.

Alabama↗
PubMed1984

Experimental infection of gray foxes (Urocyon cinereoargenteus) with Brucella abortus.

Ten gray foxes, eight principals that were fed approximately 4.4 X 10(10) colony forming units of Brucella abortus strain 2308 and two controls, were examined for serologic responses and tissue distribution of the organisms. Blood sera from each fox were tested on the day of exposure and at seven weekly intervals for antibodies to B. abortus, using the brucellosis card, standard tube agglutination, 2-mercaptoethanol and rivanol tests. Control foxes were serologically negative for all tests throughout the study and the principals were negative prior to exposure. On days 14, 21 and 28, the eight principals had positive card reactions and greater than or equal to 1:100 tube agglutination titers. After 28 days, the titers receded; and by day 49, three principals had negative card reactions and one of these was negative for all tests. Brucella abortus was isolated from one or more lymph nodes from seven of eight principals including the one which was seronegative. The bacterium was not isolated from lungs, livers, spleens, kidneys, uteri or testicles.

Agglutination Tests↗
PubMed1983

Bovine rumenitis - liver abscess complex: a bacteriological review.

Fusobacterium necrophorum is considered to be a member of the normal rumen flora and is the primary etiologic agent of bovine liver abscesses. Of the three biotypes of F. necrophorum, A, B, and C, only biotypes A and B have been implicated in the disease. Type B is the predominant biotype isolated from ruminal lesions and type A is the predominate biotype isolated from liver abscesses. Type A is usually found in pure culture in the liver abscesses; whereas, type B is usually found in mixed culture with either type A or with other bacterial species. Corynebacterium pyogenes, Streptococcus spp., Staphylococcus spp., and Bacteroides spp. are the most prevalent bacteria recovered from mixed cultures. Corynebacterium pyogenes is the most common species isolated and can cause disease synergistically with type B isolates.

Animals↗
PubMed1983

Comparative biological features of a rat liver abscess model induced with three Fusobacterium necrophorum strains.

Several biological features were compared in a rat liver abscess model, using intraportal inoculations with 3 bovine strains of Fusobacterium necrophorum which varied in virulence. Serum alanine aminotransferase activities were increased significantly (P less than 0.05) in rats inoculated with F necrophorum 2101 by postinoculation hours 6, 12, and 24. Thereafter, alanine aminotransferase values returned to base line for the remainder of the experiment. Also, rats inoculated with F necrophorum 2101 had a significantly greater (P less than 0.05) weight loss than did the control rats during the first 5 postinoculation days and developed leukocytosis characterized by a neutrophilia with a left shift. The duration of the bacteremia was related directly to the virulence of the F necrophorum strain. Fusobacterium necrophorum 2101, a biotype A which was the most virulent, induced the most persistent bacteremia; F necrophorum 2035, a biotype B which was the least virulent, produced the shortest bacteremia; and F necrophorum 2030, a biotype AB which was of intermediate virulence, led to bacteremia of intermediate duration. Plasma endotoxin was demonstrated intermittently during the first 24 hours, but did not correlate with the bacteremia.

Alanine Transaminase↗
PubMed1983

Experimental hepatic necrobacillosis infection in cattle.

Viable cultures of Fusobacterium necrophorum were inoculated into the hepatic portal veins of 7 cattle. The experimentally produced hepatic necrobacillosis lesions were described from 30 minutes through 36 hours. The lesions were established by 2 different host-bacterial interactions. Most frequent, microabscesses were initiated by diffusely distributed bacteria and were observed from 30 minutes through 2 hours. Gross abscesses from 3 through 8 hours had centrally located abscess cores and were encircled by leukocytes which were predominantly neutrophils. Lesions from 12 through 36 hours had abscess cores that were encircled by leukocytes which were predominantly macrophages. Less frequent, emboli of F. necrophorum initiated infections in hepatic sinusoids or telangiectatic lesions. Hepatocytes adjacent to the bacteria exhibited coagulation necrosis and few leukocytes were observed in these lesions.

Animals↗
PubMed1982

Comparative in vitro leukotoxin production of three bovine strains of Fusobacterium necrophorum.

The in vitro leukotoxic activity of 3 bovine isolates of Fusobacterium necrophorum which varied in pathogenicity were compared. Monolayers of mouse peritoneal macrophages were exposed to culture filtrates from each F necrophorum strain, and cell viability was determined, using the trypan blue dye exclusion test. Two methods were used for production of the leukotoxin: (1) medium M-1 continuous dialysis sac cultures and (2) brain-heart infusion agar plate cultures. Supernatant cultural fluids containing the leukotoxin were subjected to membrane-partition chromatography, using ultrafilters with approximate molecular weight (mol wt) exclusion limits of 100,000, 10,000, 2,000, and 500. All ultrafiltrates had a cytotoxic effect on the monolayers. Cytotoxic activity was not found in the ultrafilter residues or in the control media ultrafiltrates. Comparative study of leukotoxin production indicated that F necrophorum 2101, type A, produced the most leukotoxin; F necrophorum 2030, type AB, produced slightly less leukotoxin; and F necrophorum 2035, type B, produced small amounts of leukotoxin. Endotoxin activity, as demonstrated by the mouse lethality test, was found in the residues of the XM-100A ultrafilter (100,000 mol wt), but not in the filtrates. Culture supernatant fluids and the XM-100A ultrafiltrates were positive for endotoxin, using the limulus amebocyte lysate assay; however, the other ultrafiltrates with lower mol wt exclusion limits were negative.

Animals↗
PubMed1982

Studies of Fusobacterium necrophorum from bovine hepatic abscesses: biotypes, quantitation, virulence, and antibiotic susceptibility.

Isolates of Fusobacterium necrophorum were obtained from 124 bovine hepatic abscesses (in 119 cattle) and from the ruminal contents of 12 cattle. Three biotypes (A, AB, and B) were found. Type A isolates were most common in hepatic abscesses, and type B isolates were most common in ruminal contents. Virulence studies in mice indicated that type A isolates were more pathogenic than types AB or B isolates. The difference in virulences between types A and B isolates was not related to the toxicity of the endotoxin. Results of serotesting (passive hemagglutination) showed that a wide heterogeneity existed between isolates. Minimal inhibitory concentrations of antibiotics for 12 of the isolates (7 type A, 1 type AB, and 4 type B) were as follows: less than or equal to 0.06 IU of penicillin G/ml; less than or equal to 0.5 micrograms of cephaloridine/ml; less than or equal to 2 micrograms of chloramphenicol/ml; less than or equal to 0.06 micrograms of clindamycin/ml; less than or equal to 8 micrograms of erythromycin/ml; less than or equal to 128 micrograms of gentamicin/ml; less than or equal to 0.25 micrograms of oxytetracycline/ml; and less than or equal to 4 micrograms of tylosin/ml.

Animals↗