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Biomedical subjects

R K Hoop

Publications and source records attributed to R K Hoop.

At least 19 recordsLinked to original sources
PubMed2001

[Avian leukosis subgroup J in broiler breeders in Switzerland].

Since a new envelope subgroup (J) of the avian leukosis-sarcomatosis-complex was isolated for the first time from broiler breeders in the United Kingdom in 1989 and was characterized and associated with myeloid leukosis (syn. myelocytomatosis) the emergence of this subgroup was reported from all over the world. Thus the first known case of subgroup J avian leukosis in Switzerland in four imported broiler breeder flocks will be described. A total of 53 broiler breeder birds from four flocks showing reduced performance and increased mortality were submitted for postmortem examination. Approximately 20 blood samples from each flock were monitored serologically for antibodies against avian leukosis virus subgroup J (ALV-J). On necropsy myeloid leukosis (ML) was diagnosed in all four flocks. Furthermore the blood samples of three flocks showed significant ELISA-titres for ALV-J.

Animals↗
PubMed1998

[Reasons for condemnation of slaughtered broilers from two large Swiss producers].

30 broiler flocks from two majors Swiss broiler producing companies were examined for lesions relevant to meat inspection between November 1995 and April 1996. 71.8% of condemned carcasses and viscera were assigned to ascites syndrome, bacterial infections and runting. Other diseases and lesions due to injury or processing were rare. Escherichia coli was responsible for the majority of infections. The average condemnation rate (1.0%) corresponded to findings in literature.

Abattoirs↗
PubMed1998

[Detection of Salmonella enteritidis in suspected flocks of laying hens].

60 birds and environmental samples from 41 suspect flocks (S. enteritidis in faeces or litter, positive serology, close connection with human cases) were investigated to define material and minimal number of birds for detection of infection. S. enteritidis was found in 26/41 (63%) flocks with marked differences in prevalence. S. enteritidis was isolated from ovary (96% of positive flocks), oviduct and liver (87%), spleen (83%), caecal contents (50%) and faeces from the litter floor (57%), but never from egg shells and membranes. As a consequence of this study the bacteriological examination of birds is highly recommended.

Animals↗
PubMed1997

The Swiss control programme for Salmonella enteritidis in laying hens: experiences and problems.

The Swiss control programme for Salmonella Enteritidis began at the end of 1993. All efforts are focused on the elimination of infected parent and layer flocks and on the production of S. Enteritidis-free eggs. The new Zoonosis Order and more stringent import regulations help to identify S. Enteritidis-positive parent layer and layer flocks. Other measures, such as additional voluntary monitoring of parent layer flocks, hatcheries and layer flocks, increased hygiene on poultry farms and the use of heat-treated feed, serve to prevent the spread of S. Enteritidis. An important point of concern is the elimination of S. Enteritidis from contaminated poultry farms, particularly from free-range farms. In the last two years, the number of reported infections of S. Enteritidis in humans has almost fallen to the level of 1988 (the year before the onset of S. Enteritidis infection in laying hens in Switzerland).

Animals↗
PubMed1997

[Salmonella gallinarum-pullorum infection of poultry: experiences in Switzerland].

37 Salmonella gallinarum-pullorum-strains were isolated from dead poultry between 1986 and 1996. All strains except one belonged to the biovar pullorum. 33 isolates were from fancy poultry flocks, four from backyard flocks. 10 of 12 chicks and 10 of 25 adult birds showed clinical signs of disease. The growing significance of fancy and backyard flocks as a reservoir for S. gallinarum-pullorum is emphasized in view of the increase in free range management of commercial layer and broiler flocks.

Animals↗
PubMed1996

Etiological agents of mycobacterioses in pet birds between 1986 and 1995.

Between May 1986 and June 1995, mycobacteriosis was diagnosed by histology and microscopy in 204 (3.8%) of 5,345 necropsied pet birds. The predominant macroscopic changes were enlargement of the liver and spleen and thickening of intestinal walls. Attempts to cultivate mycobacteria were made in 110 cases. Acid-fact bacilli grew in 66 specimens (60%) only. In 18 cases we failed to obtain subcultures. Therefore, species identification could be performed for only 48 isolates. Identification was carried out by conventional biochemical tests as well as by PCR-mediated sequencing of the 16S rRNA gene. The majority of the isolates were Mycobacterium genavense (34 isolates), followed by M. avium complex (8), M. fortuitum (2), M. tuberculosis (2), M. gordonae (1), and M. nonchromogenicum (1). The significance of M. genavense as a zoonotic agent remains to be determined.

Animals↗
PubMed1994

Molecular epidemiology of Salmonella enteritidis.

Sixteen strains of Salmonella enteritidis isolated in 1991 from 13 unrelated poultry-associated sources, 7 strains from 2 community outbreaks, and 18 human sporadic isolates were investigated by phage typing, analysis of rRNA gene restriction patterns (ribotyping) and plasmid profiles. Four different phage types and 10 SphI patterns were found, whereas plasmids were identical in all but 4 isolates. Only one ribotype (RT A) occurred among both human and avian strains. This particular ribotype was also responsible for the two outbreaks investigated, suggesting that such strains may be of special significance for the increase of S. enteritidis infections.

Animals↗
PubMed1994

[Diarrheal diseases in 1 to 4 week old suckling piglets from problem herds: microbial spectrum, histology, enzyme histochemistry].

Postmortem investigation was performed on 54 scouring (soon after onset of diarrhea) and 23 healthy suckling piglets. The animals were 1 to 4 weeks of age and were collected from 27 herds. In 21 herds diarrhea had been observed for a long time in piglets in this age group. Coccidia were found in 34 piglets, rotavirus in 2, cryptosporidia in 2, enterotoxigenic E. coli in 6, attaching and effacing E. coli in 1, Cl. perfringens type C in 1, Campylobacter coli in 53 and C. hyointestinalis in 8 piglets. Some of these microorganisms were isolated from healthy piglets as well. TGE- and PED-Virus antigen, as well as Salmonella were not recovered from any of the pigs. Results of the histopathological and enzyme histochemical investigations were in agreement with data from the literature. They confirmed and emphasized the role of coccidia as enteropathogenic agents in the animals examined. On the other hand evidence was shown, that C. coli is non-pathogenic. The role of C. hyointestinalis could not be fully elucidated. At least one sort of enteropathogenic agent was detected in about 68% (n = 37) of the scouring pigs or was present in 81% (n = 17) of the herds, respectively.

Animals↗
PubMed1994

[Mycobacteriosis of ornamental birds--frequency, pathologo-anatomic, histologic and microbiologic data].

Mycobacteriosis was diagnosed in 146 (3.8%) of 3801 necropsied pet birds between 1986 und 1991. Gross changes in 62 pet birds with histologically and culturally confirmed mycobacteriosis were predominantly enlargement of liver and spleen and thickening of intestinal walls. Three histological patterns could be observed: granulomas, sheet-like proliferations of mycobacteria-laden epithelioid cells and single scattered macrophages filled with acid-fast bacteria. Mycobacteria grew in 27 (43.6%) of 62 cultures, but the species could only be identified in 13 (21.0%) cases (5 x M. avium-Complex, 3 x M. genavense, 2 x M. fortuitum, 1 x M. gordonae, 1 x M. nonchromogenicum and 1 x M. tuberculosis). The significance of mycobacteriosis in pet birds as a zoonosis remains to be determined.

Animals↗
PubMed1993

Bacteriological, serological, histological and immunohistochemical findings in laying hens with naturally acquired Salmonella enteritidis phage type 4 infection.

Salmonella enteritidis phage type 4 was isolated from the reproductive tract of 10 (27 per cent) of 37 laying hens from three small flocks with a naturally acquired infection. The rapid slide agglutination test with Salmonella pullorum-antigen was positive in 24 (64.9 per cent) of the 37 hens including the six hens in which the ovary was colonised and the 10 in which the oviduct was colonised. By immunohistochemical labelling S enteritidis was demonstrated in seven of eight culture-positive hens on the surface of and within the epithelial cells in the lumen and in the tuberine glands of the oviduct.

Agglutination Tests↗