摘要:

Abstract.Stages of development of chlamydial organisms were found in intracellular ‘cysts’ in the epithelium of the gill lamellae of brown bullheads. Early, irregularly shaped stages with granular cytoplasm occurred in membrane‐bound vacuotes in host cells of undetermined origin. The organisms enlarged and divided within the grossly hypertrophied host cell. Dense nucleoids were first seen in single, closely packed organisms, which became enlarged and irregular in shape. Small, spherical organisms were formed from larger ones by fission and budding. Mature cysts contained many small, dense, spherical forms, each of which contained a dense central nucleoid. Fine filaments arranged perpendicular to the plasma membrane traversed the space between the inner and outer membranes of the dense spherical forms, which appeared to be the terminal stage of development. The ultrastructural features of the chlamydial agent of epitheliocystis are compared with those in other fish and with chlamydiae in higher verteb

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00744.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.An enzootic, Australian, atypical strain ofAeromonas salmonicidaisolated from diseased goldfish,Carassius auratus(L.), was inoculated into Atlantic salmon,Salmo salarL., brown trout,S. truttaL., rainbow trout,S. gairdneriRichardson, and brook trout,Salvelinus fontinalis(Mitchill), fingerlings by intraperitoneal injection (i.p.) and by bath challenge, the latter with and without prior abrasion of skin. The 10‐day LD50(i.p.) was estimated to be 7·4 × 10‐3colony forming units (cfu) for Atlantic salmon, 3·0 × 10‐2cfu for brown trout, 3·7 × 102cfu for brook trout and 6·4 × 103cfu for rainbow trout. Brown, rainbow and brook trout succumbed to bath challenges with between 105–106cfu/ml, developing ulcers of the skin and septicaemia. The organism was trasmitted from inoculated fish to five of 195 within‐tank control fish via water and established a carrier state in one of 14 Atlantic salmon. It was concluded that the organism poses a significant threat to the salmonid farming industry and wild salmonid fishe

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00745.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.An atypical strain ofAeromonas salmonicidawas isolated from goldfish.Carassitis auraiusL., with cutaneous ulcerativc lesions. Atlantic salmon,Salmo salarL., weighing 30–40 g were challenged parentcrally and by hath immersion with this strain. It was found to be highly virulent in both forms of challenge and was capable of achieving an LD50of three colony‐forming units in parenterally challenged fish. The gross lesions and histopathology of infected fish bore a close resemblance to classical furunculosis in salmonids. Goldfish ulcer disease is endemic to some regions of Australia and represents a potential threat to the emerging salmonid farming indus

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00746.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Two outbreaks of viral haemorrhagic septicaemia (VHS) have been detected in grayling,Thymallus thymallusL., in Switzerland, The affected fry showed a septicaemic haemorrhage. Due to their similar biotopes, the susceptibility of grayling and rainbow trout to the VHS virus has been compared. The mortality rates varied between 56 and 100% depending on the age of the fish and the infection dose, but no distinct loss‐associated difference occurred between grayling and rainbow trout when comparing the same age group and infection dose. Anaemia, scattered subcutaneous and intermuscular haemorrhages and enteritis were frequent macroscopic findings. The major histopathological changes included necrotic foci in the liver, spleen, intestinal mucosa and haematopoietic part of the kidney, whereas a severe tubulonephrosis was detectable in the urinary part of the kidne

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00747.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.The prcsporogonic developmental stages ofSphaerospora renicola, the causative agent of swimbladder inflammation (SBI), develop in the swimbladder of common carp by multiple internal cleavage. The earliest development stage is the secondary cell enclosed by the primary cell. The secondary cells undergo multiple amitotic division within the mother cell and the dividing forms are connected by narrow cytoplasmic bridges. As a result of further internal cleavage, two tertiary cells appear in each secondary cell. The triple formation enclosing a secondary and two tertiary cells is identical with the pansporoblast containing two sporoblasts which occurs in the renal tubules.

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00748.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Monoclonal antibodies were made against the reference strain ofEdwardsiella ictaluri(ATCC 3320). Antibody produced by one of seven anti‐E. ictalurihybridomas reacted positively by the immunofluorescent antibody technique against 17 otherE. ictaluriisolates. All hybridoma antibodies failed to react with six other bacterial species pathogenic to fish includingE. tarda. Ouchterlony tests indicated that four anti‐E. ictaluriclones produced only one kind of immunoglobulin. Electrophoresis of 14 differentE. ictaluriisolates indicated identical protein bands at 36 and 60 kilodaltons (KD) in all isolates except an isolate from Thailand. Using the immunoblot method, channel catfish anti‐E. ictaluriserum reacted with protein bands at 34 and 60 KD, which indicates that this molecular weight protein in the bacterium may be the dominant immunopr

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00749.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

摘要:

Abstract.Changes induced in intestinal and rectal structure of the stone loach,Noemacheilus barbatulus(L.) byPomphorhynchus laevisMüller infection are described. Within the gut, the main effect of the infection is the abrasion and flattening of the mucosa by the parasite. Where the praesoma penetrates the gut wall, there is a marked inflammatory response. This inflammatory response tissue is well vascularized and displays esterase activity. Granulocytes and phagocytic cells, which are found both within the inflammation tissue and within capillaries, are probably host leucocytes. The integument ofP. laevisappears undamaged by granulocytes in its proximity and it is unlikely that the host's inflammatory response is capable of rejecting the parasite

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00750.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00751.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY

ISSN:0140-7775    

DOI:10.1111/j.1365-2761.1988.tb00752.x

出版商:Blackwell Publishing Ltd    

年代:1988

数据来源: WILEY