Search PubMed⌕ Search

Biomedical subjects

E B Shotts

Publications and source records attributed to E B Shotts.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1986

Antimicrobial susceptibility of Edwardsiella tarda from the United States and Taiwan.

Edwardsiella tarda isolates from the United States and Taiwan were screened against 37 antimicrobial agents. These isolates were highly susceptible to the amino-glycosides, second and third generation cephalosporins, newer penicillins, nitrofurantoin, sulfamethoxazole/trimethoprim, and the quinolones. Source-related resistance was found for penicillin G, sulfadiazine, colistin, novobiocin, spectinomycin, ampicillin, tetracycline, and chloramphenicol. Generally, the Taiwan isolates were more resistant than the United States isolates.

Animals↗
PubMed1986

Biochemical characteristics of Edwardsiella ictaluri.

A total of 119 isolates of Edwardsiella ictaluri collected over the last 7 years from several states were biochemically characterized. Although not very reactive biochemically, this bacterium shows a high degree of homogeneity. Differences were found only in the production of gas from formate or from glucose at 37 degrees C and in the production of hydrogen sulfide as detected by lead acetate paper. Analysis of E. ictaluri by year of geographic area indicated that some differences existed, but no clear-cut biotypic variations were found. All isolates studied were capable of degrading chondroitin sulfate, a major component of cartilage, which may be an important virulence factor in the formation of the hole-in-the-head lesion characteristic of infected fish.

Enterobacteriaceae↗
PubMed1986

Comparison of guinea pig and protozoan models for determining virulence of Legionella species.

Legionella pneumophila organisms are able to infect and multiply within the ciliated protozoan Tetrahymena pyriformis. This ability may be associated with virulence, because an attenuated strain of L. pneumophila fails to multiply within this protozoan, whereas a virulent strain increases 10,000-fold in number when coincubated with T. pyriformis. Seventeen strains (11 species) of legionellae were evaluated for virulence by intraperitoneal injection of guinea pigs and inoculation of protozoan cultures. Analysis of the data indicates that there are four categories of legionellae with respect to virulence as follows: organisms that infect and kill guinea pigs and multiply in T. pyriformis; organisms that infect but do not kill guinea pigs and multiply in T. pyriformis; organisms that do not infect guinea pigs but are lethal at high concentrations and multiply in T. pyriformis; and organisms that neither infect nor kill guinea pigs and fail to multiply in T. pyriformis. Evidence suggests that these distinctions are based on two virulence factors: intracellular multiplication in a host and toxic activity.

Animals↗
PubMed1986

Antimicrobial susceptibility of Edwardsiella ictaluri.

Edwardsiella ictaluri isolates collected over the past 7 yr from outbreaks of disease in fish occurring in different geographic areas were screened against 37 antimicrobial agents. Edwardsiella ictaluri were found to be susceptible to most agents active against gram negative bacteria such as aminoglycosides, cephalosporins, the "newer" penicillins, quinolones, tetracyclines, chloramphenicol, nitrofurantoin, and potentiated sulfonamides. Resistance was observed against colistin, sulfonamides, and several agents regarded as effective for gram positive bacteria. There was no evidence of unusual antimicrobial resistance associated with E. ictaluri or of developing resistance.

Alabama↗
PubMed1986

Effect of induced prostatic infection on semen quality in the dog.

Chronic Escherichia coli prostatitis was induced in 6 dogs, with 5 sham-operated dogs serving as controls. Semen volume and sperm motility, concentration, and appearance were measured 3 times (every other day) before surgery and 3 times during the 3rd and 5th week after surgery. When values for these collections were compared, using a 2-factor analysis of variance, no significant differences (P greater than 0.05) were found. However, the percentage of normal sperm decreased markedly (from 92% to 61% to 64%) in 2 infected dogs because of an increase in primary (from 6% to 32%) or secondary (from 2% to 28%) sperm abnormalities. Testes from both of these dogs were histologically normal.

Analysis of Variance↗
PubMed1985

Postspawning mortality of rainbow trout (Salmo gairdneri) associated with Lactobacillus.

A Lactobacillus sp. was consistently isolated from dead and moribund postspawning brood stock rainbow trout. Pathology was characterized by massive chronic inflammation throughout the abdominal cavity and formation of pseudomembranes. The bacteria were most abundant in spent testes. Repeated handling was considered to be the major stressor leading to this infection and subsequent high mortality.

Animals↗
PubMed1985

Bluetongue and epizootic hemorrhagic disease in ruminants in Georgia: survey by serotest and virologic isolation.

The frequencies of precipitating antibodies to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV) in domestic ruminants and white-tailed deer (WTD) in Georgia were 36% and 32%, respectively (n = 2,200). The frequencies of seropositivity to BTV and EHDV were high among cattle (47% and 42%, respectively [n = 1,068]) and less so in WTD (36% and 34% [n = 414]). The frequencies among sheep were 34% for BTV and 29% for EHDV (n = 286), whereas among goats, seropositivity was 8% for BTV and 7% for EHDV (n = 433). Serum samples from northeastern Georgia (1 of the 4 regions in the survey) had the highest frequency of precipitating antibodies for BTV (45%) and EHDV (38%). The lowest frequency was in southeastern Georgia, with 29% seropositivity for BTV and 24% seropositivity for EHDV. Of the 175 farms or herds in the serosurvey, 70% included animals that had BTV-precipitating antibodies, and 67% included animals which had EHDV-precipitating antibodies. Seventeen viral isolates were obtained from individual animals on 9 different farms. Fifteen of the isolates were BTV--8 from cattle, 4 from sheep, and 3 from WTD; 8 of them were serotype 11, and 7 were serotype 17. Viral isolates from each of 2 WTD were identified as EHDV serotype 1 and serotype 2. Of the total 17 isolates, 11 were from clinically healthy ruminants, and 6 were from animals with clinical signs of BT or EHD. Five of the viral isolates originated from northeastern Georgia, 7 from the northwestern region, and 5 from the southwestern region; none was obtained from specimens from the southeastern region.

Animals↗
PubMed1984

Uptake of antibodies in gram-negative bacteria exposed to EDTA-Tris.

Ethylene diamine tetra-acetic acid disodium salt (3.22 mM) and Tris (hydroxymethyl aminomethane) (50 mM) was found to cause potentiation of antibiotic actions and/or increased uptake of antibiotics when assessed by bacterial inhibition kinetic studies and uptake of radiolabeled antibiotics. Solutions of EDTA-Tris potentiate the effect of tetracycline, dihydrostreptomycin and penicillin when reacted with Escherichia coli. A similar effect was observed for tetracycline when incubated with Proteus vulgaris and penicillin, chloramphenicol, dihydrostreptomycin and tetracycline when incubated with Pseudomonas aeruginosa. These effects were noted by decreasing bacterial counts in the bacterial inhibition kinetic studies and increased uptake of radiolabeled antibiotics.

Animals↗
PubMed1984

Proliferation of Legionella pneumophila as an intracellular parasite of the ciliated protozoan Tetrahymena pyriformis.

In a series of experiments, we have determined that Legionella pneumophila will proliferate as an intracellular parasite of the ciliated holotrich Tetrahymena pyriformis in sterile tap water at 35 degrees C. After 7 days of incubation, serpentine chains of approximately 10(3) L. pneumophila cells were observed throughout the cytoplasm of the protozoan infected initially with 1 to 30 L. pneumophila cells. The overall L. pneumophila population increased from ca. 1.0 X 10(2) to ca. 5.0 X 10(4) cells per ml in the coculture within this time frame. The interactions between the protozoan and the bacterium appear to depend upon their concentrations as well as temperature of incubation. L. pneumophila did not multiply in sterile tap water alone, in suspensions of lysed T. pyriformis, or in cell-free filtrates of a T. pyriformis culture. In addition to establishing an ecological model, we found that addition of T. pyriformis to environmental specimens served as an enrichment method that improved isolation of legionella from the specimens.

Culture Media↗
PubMed1984

Antimicrobic effects of Lactobacillus fermentation on edible waste material contaminated with infected carcasses.

Survival of Newcastle disease virus (NDV) and Salmonella enteritidis serovar typhimurium (introduced as infected carcasses) in Lactobacillus-fermented edible waste material was studied to determine the ability of the fermentation to activate disease agents in carcasses. Two trials were conducted. In the 1st trial, the fermented wastes contained 20% infected carcasses (protein) consisting of equal numbers of chicken (NDV) and rat (Salmonella) carcasses, and the 2nd trial contained 40% carcasses (protein). Mixtures were incubated at 20 C, 30 C, and 40 C for 216 hours. Samples were obtained daily for quantitative virus and bacterial isolation. Temperature, pH, and redox potential were monitored. In both trials, pH and redox potential changes occurred between 24 and 48 hours depending on the incubation temperature. In both trials, NDV survived 4 days at 20 C, 2 days at 30 C, and 1 day at 40 C. Salmonella enteritidis serovar typhimurium survived 5 days at 20 C, 1 day at 30 C, and was not isolated from the 40 C samples after 24 hours in both trials.

Animal Feed↗