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Biomedical subjects

E B Shotts

Publications and source records attributed to E B Shotts.

At least 19 recordsLinked to original sources
PubMed1992

Salmonellosis in gerbils induced by nonrelated experimental procedure.

An outbreak of salmonellosis in a gerbil colony was investigated. The clinical, bacteriologic, and pathologic findings are reported. Clinical signs included an occasional sudden death, depression, emaciation, dehydration, rough hair coat, and testicular enlargement. Not every sign was observed in every infected gerbil. At necropsy, 11 animals had lesions consistent with salmonellosis. Histopathologic lesions consisted of interstitial pneumonia, hepatic and splenic necrosis, meningitis, and suppurative orchitis. Splenic and intestinal amyloidosis were also noted. Salmonella, group D, was recovered from gerbil feces, a container in which adult mosquitos were reared, filarial inoculum, and a cockroach. An epizootiologic investigation led to salmonella-infected cockroaches as the possible source of animal contamination via mosquitos and the subsequent filarial inoculum.

Animals↗
PubMed1991

Comparison of cortical bone and serum concentrations of clindamycin achievable by direct local infusion and intravenous administration.

Tibial cortical bone and serum concentrations of clindamycin were compared using two drug delivery methods in dogs. An implantable drug pump, used to continuously infuse clindamycin directly into the cortical bone, was compared with clindamycin administered i.v. Dosage for the direct continuous infusion was 4 mg/kg/day, and 44 mg/kg/day for the i.v. bolus regimen. Serum concentrations of clindamycin were significantly higher during i.v. bolus administration when compared with those achieved during pump infusion (p less than 0.05). However, tibial cortical bone concentrations were significantly higher during pump infusion than were those achieved by i.v. bolus. When examining serum and bone clindamycin concentrations over 21 days of direct local infusion, there was no significant difference in concentrations between sampling days within each tissue (p greater than 0.05). Furthermore, there were significantly greater concentrations of clindamycin in the cortical bone than in the serum at each sampling period (p less than 0.05). Results indicate that delivery of clindamycin to canine bone by implantable drug pump achieve significantly higher bone concentrations than i.v. bolus administration of the drug at higher dosages. Direct infusion also can sustain high concentrations in cortical bone without increasing systemic concentrations of clindamycin.

Animals↗
PubMed1991

Effects of cytochalasin D and methylamine on intracellular growth of Legionella pneumophila in amoebae and human monocyte-like cells.

A cloned and axenically cultured strain of Hartmannella vermiformis was used as a model to study intracellular multiplication of Legionella pneumophila in amoebae. The growth of L. pneumophilia in both H. vermiformis and a human monocyte-like cell line (U937) was investigated with cytoskeletal and metabolic inhibitors. L. pneumophila replicated only intracellularly in these cellular models, and electron microscopy showed ultrastructural similarities in the initial phase of multiplication. Treatment of amoebae with an inhibitor of microfilament-dependent phagocytosis (cytochalasin D, 0.5 or 1.0 micrograms/ml) did not inhibit intracellular growth of L. pneumophila; however, intracellular multiplication was inhibited by treatment of U937 monocytes with the same concentrations of cytochalasin D. Methylamine (10 to 100 mM), an inhibitor of adsorptive pinocytosis, inhibited the replication of L. pneumophila in amoebae in a dose-dependent manner. All doses of methylamine tested (10 to 50 mM) inhibited growth of L. pneumophila in U937 monocytes. Cytochalasin D and methylamine had no effect on the multiplication of L. pneumophila in culture medium or on the viability of amoebae or U937 monocytes. Intracellular replication of L. pneumophila in H. vermiformis may be accomplished by a cytochalasin D-independent mechanism, such as adsorptive pinocytosis. In contrast, both cytochalasin D- and methylamine-sensitive mechanisms may be essential for the intracellular multiplication of L. pneumophila in U937 monocytes.

Analysis of Variance↗
PubMed1990

Stability of antibiotics under growth conditions for thermophilic anaerobes.

It was shown that the inhibitory effect of kanamycin and streptomycin in a growing culture of Clostridium thermohydrosulfuricum JW 102 is of limited duration. To screen a large number of antibiotics, their stability during incubation under the growth conditions of thermophilic clostridia was determined at 72 and 50 degrees C by using a 0.2% yeast extract-amended prereduced mineral medium with a pH of 7.3 or 5.0. Half-lives were determined in a modified MIC test with Escherichia coli, Staphylococcus aureus, and Bacillus megaterium as indicator strains. All compounds tested were similar at the two temperatures or more stable at 50 than at 72 degrees C. The half-life (t1/2) at pH 7.3 and 72 degrees C ranged from 3.3 h (k = 7.26 day-1, where k [degradation constant] = 1/t1/2) for ampicillin to no detectable loss of activity for kanamycin, neomycin, and other antibiotics. Apparently some compounds (e.g., lasalocid and neomycin) became more potent during incubation (k greater than 0). A change to pH 5.0 caused some compounds to become more labile (e.g., kanamycin) and others (e.g., streptomycin) to become more stable than at pH 7.3.

Anti-Bacterial Agents↗
PubMed1990

The presence of Yersinia enterocolitica and other Yersinia species on the carcasses of market broilers.

Sixty ready-to-cook broiler carcasses obtained from several local supermarkets were tested for the presence of Yersinia enterocolitica and other Yersinia species. In the present study, the authors used two enrichment broths, yeast-extract/rosebengal-bile oxalate sorbose (YER-BOS) and phosphate-buffered saline with a postenrichment KOH treatment (PBS-KOH), and two plating media, cefsulodin-irgasan-novobiocin (CIN) and pectin agar. Yersinia organisms were found on 34 of 60 carcasses (56.7%) and Y. enterocolitica, on 16 of 60 carcasses (26.7%). There was no significant difference between CIN and pectin agar; however, PBS-KOH yielded a significantly higher (P less than or equal to .05) detection rate than YER-BOS, regardless of the plating media used. In addition to Y. enterocolitica, Y. frederiksenii and Y. intermedia were also isolated from the market broilers. None of the Y. enterocolitica isolates were found to be presumptively virulent.

Animals↗
PubMed1990

Comparison of enrichment and plating media for isolation of Yersinia.

Yersinia enterocolitica (Serotypes 0:3 or 0:8), Yersinia frederiksenii, Yersinia kristensenii, or Yersinia intermedia along with 10(8) cells of each of three extraneous organisms (Escherichia coli, Enterobacter aerogenes, Pseudomonas fragi), all commonly found on market poultry, were inoculated into five enrichment media followed by streaking onto 11 plating media to determine the most-efficacious combinations for future surveys or assessment studies. For Yersinia enterocolitica (0:8), infrequent recoveries were made using yeast extract-rosebengal-bile oxalate sorbose broth and phosphate-buffered saline (4 C) followed by plating onto pectin, DNase-Tween 80 (polyoxyethylene sorbitan monooleate)-sorbitol, MacConkey-Tween 80, or cefsulodin-irgasan-novobiocin (CIN) agars. With Y. enterocolitica (0:3), recoveries were most frequently made using phosphate-buffered saline, sorbitol bile (incubated for 17 days) and yeast extract-rosebengal-bile oxalate sorbose broth followed by plating onto pectin, CIN, bismuth sulfite (Difco Laboratories, Detroit, MI), or modified Rimler-Shotts agar. For Y. frederiksenii, Y. kristensenii, and Y. intermedia, incubation in sorbitol bile for 17 days or in yeast extract-rosebengal-bile oxalate sorbose broth, followed by plating onto CIN, pectin, DNase-Tween/80-sorbitol, cellobiose-arginine-lysine agar, or MacConkey-Tween 80 agar yielded the most-frequent recoveries. Overall, the CIN and pectin agars performed best for the recovery of the Yersinia bacterium; the modified selenite broth and the bismuth-sulfite plating agars were unsatisfactory in the present study.

Animals↗
PubMed1990

A medium for the selective isolation of Edwardsiella ictaluri.

A selective medium, called Edwardsiella ictaluri medium (EIM), has been formulated for the isolation of Edwardsiella ictaluri. The medium inhibits the growth of most gram-negative bacteria, except Proteus sp., Serratia marcescens and some isolates of Aeromonas hydrophila and Yersinia ruckeri. The bacteria that grow on the EIM are easily differentiated from E. ictaluri based on colony morphology. The EIM inhibits gram-positive bacteria with the exception of enterococci. The addition of fungizone to EIM suppressed the growth of most fungi. The EIM allows the evaluation of environmental reservoirs, levels of contamination and carrier states of E. ictaluri.

Animals↗
PubMed1990

Microflora associated with the skin of the bowhead whale (Balaena mysticetus).

A study of the microbiological flora isolated from cultures of normal and lesional skin tissue samples collected from 19 bowhead whales (Balaena mysticetus) over a 4 yr period is presented. These cultures were obtained from 30 tissue samples (17 normal, 13 lesion) and 248 swab samples (157 normal, 91 lesion). Seven hundred-thirty bacterial and yeast isolations were made (285 normal, 445 lesion). Distribution revealed that 56% of the gram positive bacterial isolates, 75% of the gram negative bacterial isolates and 64% of the yeast isolates recovered were associated with lesional skin. It was found that 80% of one group of Corynebacterium sp. isolates, 90% of the Acinetobacter sp. isolates and 94% of the Moraxella sp. isolates were associated with lesional skin. Although the primary yeasts recovered were Candida spp., they were found on both normal and lesional skin. Enzymatic assays of isolates from normal and lesional skin demonstrated production of enzymes capable of causing necrosis. The majority of the microorganisms recovered were facultative anaerobes and many of them could be considered potential pathogens of mammalian hosts.

Animals↗
PubMed1989

Automated biochemical identification of bacterial fish pathogens using the Abbott Quantum II.

The Quantum II, originally designed by Abbott Diagnostics for automated rapid identification of members of Enterobacteriaceae, was adapted for the identification of bacterial fish pathogens. The instrument operates as a spectrophotometer at a wavelength of 492.600 nm. A sample cartridge containing 20 inoculated biochemical chambers is inserted in the path of the analyzing beam. Reactions are converted into a 7-digit octal biocode, relayed via a sensor to the memory module, and compared to biocodes preprogrammed in the memory. An identification is then printed. Presently, the Quantum II is capable of identifying human strains of Aeromonas hydrophila and Edwardsiella tarda. This study was initiated to determine the feasibility of expanding the use of the Quantum II to include identification of bacterial fish pathogens. Ten to 50 isolates of Edwardsiella ictaluri, Serratia liquefaciens, Yersinia ruckeri, Aeromonas hydrophila, typical Aeromonas salmonicida, and atypical Aeromonas salmonicida were utilized to determine optimal incubation conditions, relative stability of the biochemicals, and ability to obtain consistent biocode numbers. After sorting the octal biocodes from the 169 isolates into groupings using a cluster analysis technique, it was shown by a Chi-square goodness of fit test that isolates of a given species were sorted into the same cluster group at a frequency of at least 99%. Results of this study illustrate the usefulness of the Quantum II BID system for the identification of bacterial fish pathogens not contained within the system's memory module.

Animals↗
PubMed1989

Feather damage due to mycotic infections in wild turkeys.

Wild turkeys (Meleagris gallopavo) from Pearl River Wildlife Management Area, St. Tammany Parish and from adjacent St. Helena Parish, Louisiana (USA) were observed to have broken and frayed rectrices. The condition was noted in 21% of 90 wild turkeys harvested by hunters during the springs of 1985 through 1988 from the Pearl River Wildlife Management Area. Damage to feathers ranged from mild to severe. Histologic and microbiologic study of five birds disclosed colonization and invasion of the rachis sheath and pulp by fungi of the genera Aspergillus, Curvularia, Cladosporium, Dactylella, Exophiala, Helminthosporium and Trichophyton and by Streptomyces. Sterilized normal rectrices from wild turkeys were inoculated with these organisms and subsequently developed damage that was histologically compatible with field cases. The condition was diagnosed as a multiple etiology mycosis. Successful colonization and invasion of experimentally inoculated feathers required addition of moisture and elevation of relative humidity within the cultures. The apparent high moisture requirements of the fungi suggest that late winter and early spring flooding may be a probable predisposing factor for this condition.

Animals↗
PubMed1988

Tropical fish medicine. Bacterial culture and evaluation of diseases of fish.

Bacteria are ubiquitous in nature. Fish are constantly exposed to bacteria, and usually only succumb to an infection after having been exposed to prolonged periods of stress. Before making a diagnosis of a bacterial disease, it is necessary to eliminate the possibility of environmental or parasitic problems. Environmental factors may act as stressors and can predispose a fish to bacterial disease while affecting the fish simultaneously. Clinical signs caused by the various bacterial pathogens are very similar. Therefore, to make a definitive bacterial diagnosis, it is necessary to culture and identify the organisms involved.

Animals↗
PubMed1988

Survival of coliforms and bacterial pathogens within protozoa during chlorination.

The susceptibility of coliform bacteria and bacterial pathogens to free chlorine residuals was determined before and after incubation with amoebae and ciliate protozoa. Viability of bacteria was quantified to determine their resistance to free chlorine residuals when ingested by laboratory strains of Acanthamoeba castellanii and Tetrahymena pyriformis. Cocultures of bacteria and protozoa were incubated to facilitate ingestion of the bacteria and then were chlorinated, neutralized, and sonicated to release intracellular bacteria. Qualitative susceptibility of protozoan strains to free chlorine was also assessed. Protozoa were shown to survive and grow after exposure to levels of free chlorine residuals that killed free-living bacteria. Ingested coliforms Escherichia coli, Citrobacter freundii, Enterobacter agglomerans, Enterobacter cloacae, Klebsiella pneumoniae, and Klebsiella oxytoca and bacterial pathogens Salmonella typhimurium, Yersinia enterocolitica, Shigella sonnei, Legionella gormanii, and Campylobacter jejuni had increased resistance to free chlorine residuals. Bacteria could be cultured from within treated protozoans well after the time required for 99% inactivation of free-living cells. All bacterial pathogens were greater than 50-fold more resistant to free chlorine when ingested by T. pyriformis. Escherichia coli ingested by a Cyclidium sp., a ciliate isolated from a drinking water reservoir, were also shown to be more resistant to free chlorine. The mechanism that increased resistance appeared to be survival within protozoan cells. This study indicates that bacteria can survive ingestion by protozoa. This bacterium-protozoan association provides bacteria with increased resistance to free chlorine residuals which can lead to persistence of bacteria in chlorine-treated water. We propose that resistance to digestion by predatory protozoa was an evolutionary precursor of pathogenicity in bacteria and that today it is a mechanism for survival of fastidious bacteria in dilute and inhospitable aquatic environments.

Animals↗
PubMed1988

Lidocaine treatment of dogs with Escherichia coli septicemia.

Effects of lidocaine on organ localization of neutrophils and bacteria and on hemodynamic and metabolic variables were determined during septic shock in dogs. Twelve anesthetized dogs were infused with 10(10) Escherichia coli/kg of body weight through a portal vein catheter over a 1-hour period. Six of these 12 dogs were treated with 2 mg of lidocaine HCl/kg (6 mg/kg/h) 15 minutes after the bacterial infusion had begun. Six dogs not given E coli (surgical controls) were given saline solution at the same rate as the bacterial and lidocaine infusions. Over 4 hours, nontreated dogs with septicemia developed systemic hypotension, decreased cardiac output, increased portal pressure, increased serum alanine transaminase activity, increased liver extravascular water, increased liver glycogen depletion, and decreased PaO2, compared with control dogs. Accumulations of polymorphonuclear leukocytes and E coli were found in the liver and lungs of dogs with septicemia. Lidocaine treatment did not alter the hemodynamic measurements and resulted in metabolic acidosis and hypoalbuminemia. Decreased numbers of E coli were recovered from the liver of lidocaine-treated dogs, whereas increased numbers of organisms were recovered from the blood. Neutrophil sequestration was increased in the liver, but not the lungs of lidocaine-treated dogs.

Animals↗
PubMed1987

Bacterial diseases of fish associated with human health.

As this country continues to increase its food fish output without increasing the water acreage, and environmental wastes continue to plague fish production, we can expect to encounter more zoonotic organisms, especially enteric-like organisms. Since 1972, the number of enteric genera has doubled and the species have tripled. The veterinarian engaged in aquatic animal medicine should be aware that aquatic pets or food fish can be associated with human disease and respond accordingly. In such cases, the veterinarian plays a major role in maintaining human health.

Animals↗
PubMed1987

Escherichia coli-induced lung and liver dysfunction in dogs: effects of flunixin meglumine treatment.

Twelve dogs were infused with 10(10) Escherichia coli/kg of body weight through a portal vein catheter over a 1-hour period; 6 dogs were treated with flunixin meglumine (1 mg/kg) 15 minutes after the infusion had begun. Six dogs (controls) were infused with a comparable volume of sterile saline solution over the same period. Over a 4-hour monitoring period, nontreated septicemic dogs developed systemic hypotension, decreased cardiac output, increased portal pressure, increased serum alanine transaminase values, increased extravascular liver water, increased liver glycogen depletion, and decreased arterial oxygen tension compared with control dogs. Accumulations of polymorphonuclear leukocytes and E coli were found in the livers and lungs of septicemic dogs. Flunixin meglumine treatment prevented systemic hypotension and hypoxemia, reversed the early but not the late stages of portal hypertension, and decreased E coli concentrations in the lungs. Other effects of treatment were not noticed.

Animals↗
PubMed1986

Effect of EDTA-tris on an Escherichia coli isolate containing R plasmids.

Solutions of ethylenediaminetetraacetate (EDTA)-tris combined with antibiotics have been shown to be effective in treating selected cases of persistent bacterial infections. Basic techniques in microbial genetics, including mating frequencies, chemical elimination of R plasmids, isolation of plasmid DNA and agarose gel electrophoresis, were used to determine if EDTA-tris has a curing effect on an R plasmid as part of its clinical action. Results of this study indicated that EDTA-tris by itself eliminated an antibiotic resistance marker from a clinical isolate of Escherichia coli and when combined with another chemical curing agent altered the isolate's mating frequency.

Conjugation, Genetic↗