Σημασία του βακτηρίου Salmonella enterica subsp. diarizonae στο διαρροϊκό σύνδρομο των αρνιών

Περίληψη

Η παρούσα διατριβή εστιάζεται στην αξιολόγηση του ρόλου του βακτηρίου Salmonella enterica subsp. diarizonae στην αιτιολογία του διαρροϊκού συνδρόμου των αρνιών και αποσκοπεί ειδικότερα: (α) στη μελέτη της έκτασης της μόλυνσης από S. enterica subsp. diarizonae σε εκτροφές προβάτων με κλινικά περιστατικά διαρροϊκού συνδρόμου των αρνιών και (β) στη μελέτη της παθογένειας της μόλυνσης από S. enterica subsp. diarizonae για τα αρνιά. Η διατριβή χωρίζεται σε τρία κεφάλαια και ακολουθεί η Γενική Συζήτηση. Στο Κεφάλαιο Ι, ανασκοπείται η σχετική βιβλιογραφία. Το Κεφάλαιο υποδιαιρείται σε τρία τμήματα. Στο τμήμα Α, ανασκοπείται συνοπτικά η βιβλιογραφία σχετικά με την ταξινόμηση και της ονοματολογία του γένους Salmonella. Στο τμήμα Β, ανασκοπείται η βιβλιογραφία η σχετική με τις λοιμώξεις από Salmonella στα πρόβατα. Στο τμήμα Γ, ανασκοπείται η βιβλιογραφία η σχετική με τις λοιμώξεις από Salmonella enterica subsp. diarizonae σε ζώα. Στο Κεφάλαιο II, μετά από σύντομη παρουσίαση του βακτηρίου S. ente ...
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Περίληψη σε άλλη γλώσσα

The present thesis focuses in the study of infection of lambs by Salmonella enterica subsp. diarizonae, by performing work in the field and in an experimental setting. The general objective of the thesis is to increase available knowledge regarding gastrointestinal infections of lambs, particularly caused by S. enterica subsp. diarizonae. Specific objectives of the thesis are as follows: (i) the investigation of the extent of infection of lambs by S. enterica subsp. diarizonae in sheep farms with the clinically evident diarrhoeic syndrome in lambs and (ii) the evaluation of the potential pathogenicity of S. enterica subsp. diarizonae for lambs. The thesis is divided into three chapters followed by the General Discussion. In Chapter I, the relevant literature is reviewed. The Chapter is subdivided into three Parts. In Part A, the literature about the taxonomy and nomenclature of Salmonella is briefly reviewed. In Part B, the literature about Salmonella infections of sheep is presented. ...
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The present thesis focuses in the study of infection of lambs by Salmonella enterica subsp. diarizonae, by performing work in the field and in an experimental setting. The general objective of the thesis is to increase available knowledge regarding gastrointestinal infections of lambs, particularly caused by S. enterica subsp. diarizonae. Specific objectives of the thesis are as follows: (i) the investigation of the extent of infection of lambs by S. enterica subsp. diarizonae in sheep farms with the clinically evident diarrhoeic syndrome in lambs and (ii) the evaluation of the potential pathogenicity of S. enterica subsp. diarizonae for lambs. The thesis is divided into three chapters followed by the General Discussion. In Chapter I, the relevant literature is reviewed. The Chapter is subdivided into three Parts. In Part A, the literature about the taxonomy and nomenclature of Salmonella is briefly reviewed. In Part B, the literature about Salmonella infections of sheep is presented. In Part C, the literature about the clinical conditions caused by S. enterica subsp. diarizonae in animals is appraised. In Chapter II, after a brief note regarding S. enterica subsp. diarizonae in field studies in sheep farms (Part A), an outbreak of diarrhoeic syndrome in lambs caused by the organism (Part B) and a field investigation of its occurrence in sheep farms in Central Greece (Part C) are presented. An outbreak of diarrhoeic syndrome in lambs was investigated in a sheep farm. Specifically, frequent cases of diarrhoea in 5 to 15-day old lambs were reported by the farmer within a period of 7 days. In total, 25 lambs had been ill with diarrhoea (incidence rate: 0.156). Among these, 10 had already died when the investigation started (case fatality: 0.400). Clinical examination revealed severe diarrhoea in lambs. A detailed post-mortem examination was performed in two lambs, with salient findings being: evidence of inflammation in jejunum and ileum in the small intestine and presence of petechiae in the intestinal wall, which was thinner than normal. From live animals, faecal samples were collected for laboratory investigations by bacteriological, virological and parasitic techniques. The tests revealed only abundant growth of S. enterica in pure culture from small intestine and liver tissue samples. Complete identification of the isolates indicated these as Salmonella enterica subsp. diarizonae 61:k:1,5,(7) isolates. Enrofloxacin was prescribed for administration to lambs. Further faecal samples were collected for up to 42 days post-treatment. The organism was reisolated 22 days after the end of the treatment course. An investigation was performed in 21 sheep farms in central Greece through faecal sample collection from diarrhoeic lambs (n = 119). Samples were processed for potential recovery of Salmonella, using also enrichment techniques. In no case, any Salmonella spp. organism was isolated. In Chapter III, an experimental study regarding the potential role of S. enterica subsp. diarizonae for the diarrhoeic syndrome of lambs is presented (Parts B and C). In total, 12 lambs were challenged with the S. enterica subsp. diarizonae isolate recovered during the field study (Chapter II). The lambs were challenged orally on the first day after birth, with a dose ranging from 0.75 × 109 to 1.80 × 109 c.f.u. Sequential blood samples, faecal samples and buccal swabs were collected at regular intervals after challenge from lambs. Sequential faecal and milk samples were collected from the dams of the lambs. Lambs were sequentially euthanised 1, 2, 4, 7, 10, 14 and 21 days after challenge. Samples were processed by bacteriological techniques for isolation of the challenge organism; they were also subjected to examination by molecular techniques (PCR) for detection of the invA gene. Tissue samples (small intestine, abomasum, liver, gallbladder) harvested from all euthanised lambs were also subjected to bacteriological and molecular examinations and were processed for histopathological examination. Salmonella was isolated from faecal samples of all lambs (1.000) at least once and in total from 45/77 (0.584) postinoculation samples; median duration of bacterial isolation was 2.4 days post-inoculation. Salmonella was isolated from buccal samples from 7 lambs (0.583) at least once and in total from 10/77 (0.130) post-inoculation samples; median duration of bacterial isolation was 0.8 day post-inoculation. Salmonella was not isolated from any faecal sample from any dam of inoculated lambs; it was isolated from two milk samples, collected from the same ewe, dam of an inoculated lamb, on two consecutive sampling occasions. Finally, Salmonella was isolated from tissue samples of 9 lambs: small intestine of 6 (0.500), abomasum of 4 (0.333), liver of 3 (0.250) and gallbladder of 2 (0.167) lambs. The invA gene was detected in samples from all inoculated lambs and from 3 of their dams. In all samples, of all tissues, that had yielded Salmonella at the microbiological examination, the invA gene was also detected (1.000). Median duration of post-challenge detection of the gene was 5.5 days in faecal samples and 1.3 days in buccal samples. Histopathological examination rev
DOI
10.12681/eadd/46017
Διεύθυνση Handle
http://hdl.handle.net/10442/hedi/46017
ND
46017
Εναλλακτικός τίτλος
Significance of Salmonella enterica subsp. diarizonae in the diarrhoeic syndrome of lambs
Συγγραφέας
Χατζόπουλος, Δημήτριος (Πατρώνυμο: Χρήστος)
Ημερομηνία
2019
Ίδρυμα
Πανεπιστήμιο Θεσσαλίας. Σχολή Επιστημών Υγείας. Τμήμα Κτηνιατρικής. Κλινική Μαιευτικής και Αναπαραγωγής
Εξεταστική επιτροπή
Φθενάκης Γεώργιος
Μπιλλίνης Χαράλαμπος
Αθανασίου Λαμπρινή
Αμοιρίδης Γεώργιος
Γκουλέτσου Παγώνα
Μαυρογιάννη Βασιλική
Lacasta Delia
Επιστημονικό πεδίο
Γεωπονικές Επιστήμες και ΚτηνιατρικήΚτηνιατρική
Λέξεις-κλειδιά
Σαλμονέλλα; Διαρροϊκό σύνδρομο; Αρνιά
Χώρα
Ελλάδα
Γλώσσα
Αγγλικά
Άλλα στοιχεία
95 σ., εικ., πιν., γραφ.
Στατιστικά χρήσης
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Αφορά στις μοναδικές επισκέψεις της διδακτορικής διατριβής για την χρονική περίοδο 07/2018 - 07/2023.
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Αφορά στο άνοιγμα του online αναγνώστη για την χρονική περίοδο 07/2018 - 07/2023.
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Αφορά στο σύνολο των μεταφορτώσων του αρχείου της διδακτορικής διατριβής.
Πηγή: Εθνικό Αρχείο Διδακτορικών Διατριβών.
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Αφορά στους συνδεδεμένους στο σύστημα χρήστες οι οποίοι έχουν αλληλεπιδράσει με τη διδακτορική διατριβή. Ως επί το πλείστον, αφορά τις μεταφορτώσεις.
Πηγή: Εθνικό Αρχείο Διδακτορικών Διατριβών.
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