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Biomedical subjects

G L Cooper

Publications and source records attributed to G L Cooper.

At least 19 recordsLinked to original sources
PubMed2004

Hexamita meleagridis (Spironucleus meleagridis) infection in chukar partridges associated with high mortality and intracellular trophozoites.

An outbreak of infectious catarrhal enteritis, associated with the flagellated protozoan Spironucleus meleagridis (syn. Hexamita meleagridis), is reported from a commercial flock of chukar partridges in California. The disease affected birds between the ages of 4 and 6 wk and resulted in diarrhea, listlessness, depression, and high mortality. Concurrent infection with other intestinal pathogens, including Cryptosporidia, group E Salmonella, long-segmented filamentous microorganisms (LSFMOs), and Rotavirus-like virus particles, was found in some but not all affected birds. Dermatitis of the face, shanks, and feet, suggestive of B-complex vitamin deficiency, was present in most affected birds as well. Flagellated protozoan parasites could be found in the lumen of the duodenum and jejunum and in the intestinal crypts. In some cases the flagellates were wedged between epithelial cells or were located intracellularly within cells of the mucosal epithelium and the intestinal lamina propria.

Animals↗
PubMed2003

Postural and neurological deficits in broiler chicks after cervical vaccination with live vaccine.

A disease characterized by paresis and paralysis was seen in 7-9-day-old broiler chicks after vaccination in the neck area at day-of-age with a live virus vaccine containing viruses of Marek's disease, fowl pox, and infectious bursal disease. Affected birds presented with variable signs of ataxia, lateral recumbency, leg paralysis, and twisting or S-shaped flexure of the neck. Gross lesions noted at necropsy included swelling and edema of the subcutaneous tissues and muscles of the neck at the injection site area. A heavy mononuclear inflammatory cell infiltration was seen in the subcutaneous tissues, connective tissues, and muscles of the neck at the injection site. In some cases, the inflammatory process extended along fascial planes to involve the epidural spaces surrounding the spinal cord. Fatty changes with possible demyelination of nerve fibers were noted in some sections of the spinal cord adjacent to the inflammatory lesions. Clusters of poxviruses were found within some inflammatory lesions on transmission electron photomicrographs.

Animals↗
PubMed1996

Evaluation of SEF14 fimbrial dot blot and flagellar western blot tests as indicators of Salmonella enteritidis infection in chickens.

The serological responses to Salmonella enteritidis flagella (H: g,m) and its fimbrial antigen SEF14 were evaluated as indicators of infection in chickens and to confirm serological results obtained by an ELISA using S enteritidis lipopolysaccharide (LPS) (O: 9,12) as the detecting antigen. The SEF14 antigen and flagella were extracted from S enteritidis and transferred to nitrocellulose paper for use in Western and dot blot tests. Antisera to 19 salmonella serotypes including S enteritidis were raised in rabbits and their cross reactivity to the flagellar and SEF14 antigens was evaluated. Cross reactivity with the SEF14 antigen was found in one antiserum, raised against S blegdam, and to flagella in eight of 19 antisera raised against various salmonella serotypes, most of which shared the flagellar factors g or m with S enteritidis. The intensity of cross reaction to flagella was strongest in S derby and S blegdam antisera. Antisera raised in chickens against S typhimurium and S panama did not cross react in either test, and neither did pooled sera from eight-week-old salmonella-free, broiler breeder parent chickens. Field sera from two commercial flocks with no history of salmonella infection were negative when tested by the LPS ELISA. These sera were also negative when tested by the flagellar and SEF14 blots. S enteritidis infection in a commercial laying flock was detected initially when the sera were tested by the LPS ELISA and confirmed in individual and pooled sera by the SEF14 and flagellar tests. S enteritidis PT4 was isolated from this flock post mortem.

Animals↗
PubMed1994

Invasiveness and persistence of Salmonella enteritidis, Salmonella typhimurium, and a genetically defined S. enteritidis aroA strain in young chickens.

Newly hatched chicks were dosed orally with a Salmonella typhimurium wild-type strain, an S. enteritidis wild-type strain, and a genetically defined S. enteritidis aroA vaccine candidate, strain CVL30. The S. typhimurium strain, 2391 Nalr, was virulent in newly hatched chicks and caused deaths in 7 of 20 chicks after an oral dose of 10(5) organisms. The S. enteritidis wild-type strain, LA5, caused death in 1 of 25 chicks and gross pathology including pericarditis and perihepatitis in 6 of the 24 survivors after an oral dose of 10(9) organisms. S. enteritidis aroA CVL30, attenuated by ca. 6.5 log10 in BALB/c mice, was nonvirulent when administered orally to chicks and did not cause morbidity. When newly hatched chicks were dosed, the pattern of invasion and colonization of the reticuloendothelial system by strain CVL30 was similar to that of its parent strain, LA5, irrespective of the dose. Oral inoculation of newly hatched chicks with < 10 organisms of S. enteritidis LA5 or CVL30 was followed by multiplication in the cecal contents. Within 3 days of hatching, the pH of the cecal contents was reduced from ca. 7 to 5. Samples of gut contents were inoculated in vitro. The S. enteritidis strains multiplied in samples taken from the ileum and duodenum irrespective of age but multiplied in the cecal samples from newly hatched chicks only. Invasion from the gut by S. enteritidis LA5 and CVL30 was both age and dose dependent.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1994

Vaccination of chickens with strain CVL30, a genetically defined Salmonella enteritidis aroA live oral vaccine candidate.

Newly hatched chicks were vaccinated orally with a genetically defined Salmonella enteritidis aroA candidate, strain CVL30. In chickens immunized with 10(5) or 10(9) CFU and challenged by the intravenous route with 10(8) CFU of S. enteritidis 109 Nalr at 8 weeks old, there were similar reductions in colonization of the spleens, livers, and ceca of vaccinees compared with unvaccinated controls. Two groups of newly hatched female chicks were vaccinated orally with 10(9) CFU of strain CVL30, and one group was revaccinated intramuscularly with 10(9) CFU at 16 weeks old. When challenged intravenously with S. enteritidis 109 Nalr at 23 weeks old, there was a reduction in the colonization of spleens, livers, ovaries, and ceca compared with unvaccinated controls. Inclusion of the intramuscular booster gave increased protection to the ovary, although the vaccine strain was isolated on one occasion from a batch of eggs laid at 20 weeks old. In chickens immunized with 10(9) CFU of strain CVL30 and challenged orally with 10(9) CFU of S. enteritidis 109 Nalr, there was a reduction in intestinal shedding of the challenge strain from vaccines compared with unvaccinated controls. Circulating immunoglobulin G antibodies to lipopolysaccharide (LPS) were detected in unvaccinated controls within 7 to 10 days of oral challenge. In contrast, circulating immunoglobulin G antibodies to LPS in vaccinees were not altered by the oral challenge, which suggested that vaccination reduced or prevented invasion by the challenge strain from the gut or multiplication of the challenge strain in the tissues. Newly hatched chicks were vaccinated orally with ca. 10(9) CFU of strain CVL30, and 1 day later, the vaccines and unvaccinated controls were challenged orally with 10(5) or 10(9) CFU of S. enteritidis 109 Nalr. Colonization of the ceca and invasion from the gut by the S. enteritidis challenge strain was reduced in the vaccines up to 5 days postchallenge compared with controls. In a second trial, vaccinees and controls were challenged orally with 10(7) or 10(9) CFU of S. typhimurium 2391 Nalr. In contrast to the challenge with S. enteritidis, colonization of the ceca and invasion by the S. typhimurium strain were not greatly reduced.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗
PubMed1993

Further studies of the application of live Salmonella enteritidis aroA vaccines in chickens.

A model was developed to simulate the lateral spread of Salmonella enteritidis infection among chickens. One group of newly hatched chicks was vaccinated orally with S enteritidis aroA. At three weeks old naive chickens were infected with a wild-type strain of S enteritidis and brought into contact with separate groups of aroA vaccinated chickens and unvaccinated control chickens. The vaccinated chickens were well protected against colonisation of the gut by the wild-type strain whereas the control group became heavily colonised. The IgG responses to a lipopolysaccharide extract of S enteritidis in the vaccinated chickens indicated a limitation of invasion from the gut. Chickens vaccinated orally at one day old with S enteritidis aroA were not protected against oral or intravenous challenge at eight weeks old with a wild-type strain of S typhimurium. A group of newly hatched female chicks was vaccinated orally with S enteritidis aroA and again at two weeks old. A second group also received oral booster doses at 16 and 18 weeks. When challenged intravenously with a wild-type strain of S enteritidis at 23 weeks old there was a significant reduction in the numbers of this strain in the spleens, livers, ovaries and caeca of both vaccinated groups. Booster vaccination at 16 and 18 weeks of age induced the greatest protection of the caeca.

Animals↗
PubMed1993

Fine-needle aspiration biopsy of multiple myeloma in a patient with renal-cell carcinoma: a case report.

A case of multiple myeloma diagnosed by fine-needle aspiration (FNA) biopsy and confirmed by laboratory studies in a patient with a history of renal-cell carcinoma is presented. The patient was diagnosed with renal-cell carcinoma of the right kidney and a radical nephrectomy was performed. Eighteen months after this diagnosis was made, the patient developed chest wall pain and was found to have osteolytic bone lesions of the ribs and vertebral bodies. FNA of an osteolytic rib lesion disclosed multiple myeloma. Additional laboratory studies confirmed the diagnosis of multiple myeloma. This case report demonstrates the value of FNA as a diagnostic tool for the follow-up of cancer patients, the subsequent discrimination between metastatic lesions and a second primary malignancy, and the cytology of multiple myeloma.

Aged↗
PubMed1993

Influence of zinc on Pseudomonas aeruginosa susceptibilities to imipenem.

Serial dilution susceptibility testing of imipenem against 59 clinical isolates of Pseudomonas aeruginosa, conducted simultaneously on single lots of Difco and BBL Mueller-Hinton agar (MHA), resulted in MICs for 90% of strains tested of 8 and 16 micrograms/ml, respectively. MICs for Escherichia coli, Klebsiella pneumoniae, and Pseudomonas spp. were also higher on BBL MHA. Quantification of the cation content of the two MHAs by atomic absorption spectroscopy demonstrated that the zinc concentration in BBL MHA was 15 times greater than that measured in Difco MHA (2.61 and 0.17 micrograms/ml, respectively). Concentrations of calcium, magnesium, iron, manganese, and copper in the two agars were similar. Addition of zinc to Difco MHA resulted in increases in MICs of imipenem for P. aeruginosa but not in the MICs of ceftazidime or cefpirome for P. aeruginosa (P < 0.01). A lesser zinc effect was seen on the activity of imipenem against E. coli, K. pneumoniae, and Pseudomonas spp. The activities of ceftazidime and cefpirome were similar on both MHAs when tested against all gram-negative organisms in this study. Thus, the effect of zinc in MHA was clearly demonstrated by a significant increase in the MICs of imipenem for P. aeruginosa, and, to a lesser extent, for other gram-negative bacilli.

Agar↗
PubMed1993

Preliminary characterization of a pleomorphic gram-negative rod associated with avian respiratory disease.

An unidentified, pleomorphic, gram-negative rod (PGNR) bacterium has been isolated from domestic fowl with respiratory disease. The PGNR was isolated in 5% of turkey accessions and 3% of chicken accessions, primarily from the respiratory tract. Preliminary characterization of this organism included reviewing accession records, conducting cultural and biochemical tests, and analyzing cellular fatty acids. The PGNR was also compared with other bacteria capable of inhabiting the avian respiratory system. Biochemical and cellular fatty acid analysis failed to identify the organism, however all 14 isolates were similar.

Animals↗
PubMed1992

Vaccination of chickens with chicken-derived Salmonella enteritidis phage type 4 aroA live oral Salmonella vaccines.

Two strains of Salmonella enteritidis phage type 4 isolated from chickens, SeLA5 and Se267, were virulent in Balb/c mice by intraperitoneal (i.p.) infection. In 18-20-day-old chickens given 10(7) c.f.u. intravenously (i.v.), both strains caused some deaths. One-day-old chicks infected orally with 10(9) c.f.u. of either strain also suffered limited mortality. Strain SeLA5 was the more virulent by the oral route. AroA mutants SeLA5 aroA and Se267 aroA were reduced in i.p. virulence by up to six logs in the Balb/c mouse model, did not kill 18-20-day-old chickens when injected i.v. and did not multiply in the tissues. Oral vaccination of chicks with either 10(9) c.f.u. at one-day-old or 10(5) c.f.u. at seven-day intervals until day 21 with vaccine strains SeLA5 aroA or Se267 aroA conferred significant protection against intravenous challenge with virulent strain Se109 NalR and reduced intestinal shedding following oral challenge. Seroconversion following oral vaccination was not seen with the lower dose regimen and was low with the higher dose. Seroconversion following oral challenge was marked in unvaccinated birds but much lower in vaccinated birds, suggesting that oral vaccination had prevented invasion by the challenge strain.

Administration, Oral↗
PubMed1990

Vaccination of chickens with a Salmonella enteritidis aroA live oral Salmonella vaccine.

A mouse-virulent strain of Salmonella enteritidis, Se795 (LD50 less than 10 organisms for mice), was non-virulent for 12-day-old chickens given 10(6) cfu intravenously; the organisms were cleared from liver and spleen by day 14 as measured by direct plating and by day 21 by enrichment. An Se795aroA mutant, CU58, was also cleared from liver and spleen by day 14 after intravenous inoculation of 10(7) cfu. Day-old chicks vaccinated orally with either one dose of 10(9) CU58 at 1 day of age, 10(7) at 1 and 14 days, or 10(5) at 1 and 7 days followed by 10(9) at 14 and 21 days of age, were challenged orally with a nalidixic acid resistant variant of the virulent phage type 4 S. enteritidis strain 109. All vaccinated groups showed a reduction in faecal shedding of the challenge. Chickens given four doses of CU58 showed a significant reduction of cfu in liver, spleen and faeces following intravenous challenge with virulent strain 109. Intramuscular vaccination with 10(9) cfu of Aro strain CU58 at 1 day of age gave no protection against oral challenge with virulent strain 109. Serum antibody production to LPS (ELISA) was minimal in all vaccinated birds. The results indicate that oral vaccination with Aro- S. enteritidis can confer protection to day old chicks against virulent S. enteritidis.

Animals↗
PubMed1989

Serological and bacteriological investigations of chickens from flocks naturally infected with Salmonella enteritidis.

Groups of 10 birds were obtained from four flocks which had shown evidence of natural salmonella infection. S enteritidis had been isolated from three flocks and S typhimurium from the fourth. Each bird was housed in a separate cage and blood samples and cloacal swabs were taken weekly to follow the course of natural infection. After four weeks the birds were killed and examined post mortem. The isolation of Salmonella species could not be related to the serological results. In individual birds the rapid slide test and tube agglutination test could not be relied upon to detect infection; the microantiglobulin test and the enzyme-linked immunosorbent assay (ELISA) were more sensitive than the other tests and detected some infected birds that were negative by the rapid slide and tube agglutination tests, and also showed high titres in some birds from which Salmonella species could not be isolated post mortem. Sera obtained from two flocks which had a history of natural S enteritidis infection were evaluated by all the tests; evidence of infection was found with the microantiglobulin and ELISA tests but not with the other tests.

Agglutination Tests↗
PubMed1988

Diffuse neonatal gastric infarction.

Diffuse neonatal gastric infarction can be a devastating complication of invasion of the gastric wall and vessels by fungi colonizing the gastric mucosa. Even in the presence of extensive transmural necrosis, however, the radiographs do not necessarily show evidence of gastric mucosal abnormality. Instead, plain films and positive contrast studies may erroneously suggest a mechanical gastric outlet obstruction. Ancillary evidence of a devitalized viscus in a baby who appears to have complete gastric outlet obstruction should suggest the diagnosis of gastric infarction.

Candidiasis↗
PubMed1988

Possible role of capillary action in pathogenesis of experimental catheter-associated dermal tunnel infections.

An animal model of vascular-catheter-associated dermal tunnel infections was developed to study the pathogenesis of such infections. Bacteria inoculated onto entry sites of catheters into skin could be identified by culture and Gram stain on the tips of plastic catheters (4 cm from the entry site) within 1 h of inoculation, whether the animal was inoculated at the time of insertion of the catheter or 1 week afterwards. Histological examination of dermal tunnels revealed that the introduction of bacteria preceded the development of tissue inflammation. Bacteria on entry sites of percutaneous catheters moved rapidly from the entry site into the dermal tunnel along the external catheter surface, perhaps suspended in a fluid phase and propelled by capillary action.

Animals↗