In Vitro Investigation of the Antibacterial Activity of Nine Commercial Water Disinfectants, Acidifiers, and Glyceride Blends against the Most Important Poultry Zoonotic Bacteria

Identifying and monitoring the efficiency of alternative biocides that are presently used in livestock is gaining vast attention. The objective of this study was to determine, in vitro, the antibacterial activity of nine commercial water disinfectants, acidifiers, and glyceride blends against clinical isolates or reference strains of zoonotic pathogens belonging to the genera Escherichia spp., Salmonella spp., Campylobacter spp., Listeria spp., and Staphylococcus spp. For each product, the antibacterial activity was tested in concentrations ranging from 0.002 to 1.136% v/v and expressed as the minimum concentration of the product that inhibits bacterial growth (MIC). Water disinfectants Cid 2000™ and Aqua-clean® recorded MICs ranging from 0.002 to 0.142% v/v, while the lowest MICs were recorded at two strains of Campylobacter (0.002–0.004% v/v). Virkon® S displayed various MICs (0.013–0.409% w/v) and was highly effective at suppressing the growth of Gram-positive bacteria such as S. aureus (0.013–0.026% w/v). The MICs of water acidifiers (Agrocid Super™Oligo, Premium acid, and Ultimate acid) and glyceride blends (CFC Floramix, FRA®LAC34, and FRA®Gut Balance) ranged from 0.036 to 1.136% v/v, and for most of these products, MICs were closely correlated by their ability to modify the pH of the culture medium close to 5. In conclusion, most of the tested products showed promising antibacterial activity; as a result, they would be good candidates for pathogen control in poultry farms and for reducing the emergence of antimicrobial resistance. However, further in vivo studies are recommended to provide relevant information for the underlying mechanisms, as well as for the establishment of the optimal dosage scheme for each product and their possible synergies

The use of a blend of acids for the control of campylobacteriosis in broiler chicks

Bacteria of the genus Campylobacter are recognized as the leading causes of human bacterial foodborne gastroenteritis worldwide, and campylobacteriosis ranks first among the zoonoses recorded in the European Union, with over 220,000 cases in 2019. Poultry meat, and especially that of broilers, is considered the most common source of human infection, and Campylobacter jejuni (C. jejuni) is the species involved in the majority of the reported cases. It is estimated that 60-80% of the commercial broiler flocks are positive for Campylobacter spp. at the slaughter age and therefore constitute the most important reservoir of the pathogen in nature. According to recommendations of the international health organizations (WHO, EFSA and CDC), but also from the results of various statistical and epidemiological models, the control of Campylobacter spp. in the production chain of broilers, and in particular during primary production, is expected to reduce significantly the bacterial counts in the carcasses and thus the likelihood of human infection. It is estimated that a 1 log10 reduction of the Campylobacter spp. counts in the ceca of broilers could reduce the risk of human infection up to 48%. Recently, EFSA, based on data from epidemiological studies, concluded that the addition of organic acids or biocidal blends, based on hydrogen peroxide or chlorine, in drinking the water could reduce the prevalence of Campylobacter spp. positive broiler flocks by 55%. Currently, several commercially available products-blends of acids are used in poultry farms to maintain the hygiene of the drinking water or for growth enhancement. However, the anti-Campylobacter activity of these commercial acidic blends remains unknown. In addition, the role of these products in the control of zoonotic pathogens, such as C. jejuni, still needs to be elucidated. Finally, the urgent need for the development of innovative methods to control the prevalence of Campylobacter spp. in broilers, as well as the frequent use of the commercial blends of acids in the drinking water of commercial livestock, were the motivation for the present study and formed its main objectives. The first objective of the doctoral thesis was the in vitro investigation of the anti-Campylobacter activity of nine commercial products, which are approved by the EU for use in the drinking water of birds and consist of specific blends of organic and/or inorganic acids. In this study, a total of two C. jejuni strains and one C. coli strain were used. The evaluation of the antibacterial activity of the tested products was performed with the method of the Minimum Inhibitory Concentration (MIC), according to CLSI standards M07-A10 (CLSI, 2015) and M100-S28 (CLSI, 2018), with some modifications. The MIC is defined as the lowest concentration of a chemical that visually inhibits the growth of a particular microbe. Each product was tested in triplicate against each of the selected Campylobacter spp. strain. According to the results of this study, all the tested commercial products were able to inhibit the growth of the tested Campylobacter spp. strains at the dose proposed by their manufacturer. CID 2000™ and Aqua-clean® products demonstrated the most potent activity in this study against C. jejuni and C. coli (0.002%–0.004% v/v). Based on the results of the in vitro study, the current legislative framework, the frequency of use in poultry farming, and the lack of references in the international literature regarding the product's action on the control of C. jejuni in broilers, the commercial blend of acids selected for the in vivo study was CID 2000™.The second objective of the doctoral thesis was the in vivo investigation of the effect of CID 2000™ on controlling C. jejuni in experimentally challenged broiler chicks. Additionally, through the in vivo study, the impact of CID 2000™ on the health and welfare of broilers was assessed for the first time. The experimental design included the random allocation of one hundred and twenty-eight 1-day old broilers chicks (Ross 308®) in 4 experimental groups of 32 birds. Each group consisted of 4 subgroups-replicates of 8 birds. Specifically, the experimental groups were as follows: Group A: the negative control (chicks were not challenged and received only tap water), Group B: birds were challenged by C. jejuni and received tap water treated by 0.01-0.05 % v/v CID 2000™; Group C: birds were challenged by C. jejuni and received tap water without treatment; Group D: birds were challenged by C. jejuni and received tap water treated by 0.01-0.05 % v/v CID 2000™. The duration of the experiment was 36 days and the birds infected by oral ingestion of 106 CFU C. jejuni on the 18th day of life. During the trial, birds were examined daily for clinical signs. On the 7th, 13th, 18th, 20th, 23rd and 36th day of the experiment, a calibration assessment of the incidence rate and the degree of intensity of diarrheal feces was carried out, through the assessment of plumage besmirchment in the area around the cloaca. Additionally, the birds' BW was measured on the 1st, 7th, 13th, 18th, 23rd and 36th day, while the ADFI, the FCR and the ADWI were calculated for the intervals of the 1st-13th, 14th- 23rd, 24th-36th and 1st- 36th day. Finally, the EPEF was calculated for the total period of experimentation (1st- 36th day). During the experiment 2 samplings were performed, on day 23 (5 days post-infection) and day 36 (18 days post-infection). The tests carried out were: a) enumeration of C. jejuni in the crop and ceca, b) isolation of C. jejuni from the liver, c) histomorphometric and histopathological evaluation of tissue samples from the duodenum, jejunum and ileum, d) histopathological investigation of liver tissue samples, e) macroscopic assessment of lesions in the footpads, in the gizzard, liver and intestines g) measurement of the pH value of the contents in the crop, duodenum, jejunum, ileum and ceca, and h) measuring the viscosity of the contents of the jejunum and the ileum of birds. According to the results of the in vivo study, the infection of broilers with the C. jejuni KC40 strain resulted in significantly high counts of the microorganism in the ceca of birds. The challenge also increased significantly the occurrence and severity of diarrheic feces, induced adverse alterations on intestinal histomorphology, and led to a high isolation rate of the microorganism from the liver of the infected birds. The sanitation of the drinking water, by CID 2000™ significantly reduced the counts of C. jejuni in the ceca of broilers (5 days after infection), reduced the occurrence and severity of diarrheic feces, ameliorated the histomorphometric changes caused by C. jejuni in the intestine, and significantly reduced the isolation rate of the microorganism from the liver of the challenged birds. However, CID 2000™ did not reduce the transmission rate of C. jejuni among broiler chicks, with the protocol applied in this study.Η μόλυνση του ανθρώπου με βακτήρια του γένους Campylobacter αποτελεί την κύρια αιτία βακτηριακής τροφιμογενούς γαστρεντερίτιδας παγκοσμίως, με την καμπυλοβακτηρίωση να είναι η συχνότερη ζωονόσος που καταγράφεται στην Ευρωπαϊκή Ένωση, με πάνω από 220.000 κρούσματα για το 2019. Το κρέας πουλερικών και κυρίως αυτό των κρεοπαραγωγών ορνιθίων, αποτελεί την κύρια πηγή μόλυνσης του ανθρώπου και το Campylobacter jejuni (C. jejuni) είναι το είδος που εμπλέκεται στη πλειονότητα των περιστατικών. Υπολογίζεται ότι το 60-80% των εμπορικών σμηνών κρεοπαραγωγών ορνιθίων, είναι θετικά στο Campylobacter spp. σε ηλικία σφαγής και ως εκ τούτου, αποτελούν την πιο σημαντική δεξαμενή του μικροοργανισμού στη φύση. Σύμφωνα με τις εκτιμήσεις των Διεθνών Οργανισμών Υγείας (ΠΟΥ, EFSA και CDC), αλλά και από τα αποτελέσματα στατιστικών και επιδημιολογικών μοντέλων, ο έλεγχος του Campylobacter spp. στην αλυσίδα παραγωγής κρεοπαραγωγών ορνιθίων και ειδικότερα κατά τη διάρκεια της πρωτογενούς παραγωγής, αναμένεται να μειώσει σημαντικά τους πληθυσμούς Campylobacter spp. στα τελικά σφάγια και κατ’ επέκταση την πιθανότητα μόλυνσης του ανθρώπου. Πρόσφατα, η EFSA βασιζόμενη σε επιδημιολογική ανάλυση για τον πληθυσμό, κατέληξε στο συμπέρασμα ότι η προσθήκη οργανικών οξέων ή βιοκτόνων συνδυασμών οξέων με βάση το χλώριο ή το υπεροξείδιο του υδρογόνου στο πόσιμο νερό των πτηνών, θα μπορούσε να μειώσει τον επιπολασμό του Campylobacter spp. στις εκτροφές κρεοπαραγωγών ορνιθίων κατά 55%. Υπάρχουν αρκετά εμπορικά διαθέσιμα προϊόντα που περιέχουν συγκεκριμένους συνδυασμούς οργανικών ανόργανων οξέων, τα οποία χρησιμοποιούνται στην εξυγίανση του πόσιμου νερού των εκτρεφόμενων πτηνών. Ωστόσο, η δράση αυτών των εμπορικών μιγμάτων οξέων κατά του Campylobacter παραμένει άγνωστη, ενώ ελάχιστα δεδομένα είναι γνωστά σε σχέση με τη δυνατότητα των μικροοργανισμών να αναπτύσσουν ανθεκτικότητα σε αυτά τα προϊόντα. Μέχρι στιγμής, καμία μέθοδος ελέγχου του μικροοργανισμού σε επίπεδο εκτροφής δεν έχει αποδειχθεί πλήρως αποτελεσματική και ταυτόχρονα οικονομικά βιώσιμη για τον έλεγχο του Campylobacter spp. στα κρεοπαραγωγά ορνίθια. Η επιτακτική ανάγκη για την ανάπτυξη καινοτόμων μεθόδων ελέγχου του επιπολασμού του Campylobacter spp. στα εμπορικά σμήνη πτηνών, καθώς και η συχνή χρήση των εμπορικών προϊόντων-μιγμάτων οξέων στο πόσιμο νερό των εκτροφών, αποτέλεσαν το κίνητρο για την παρούσα μελέτη και διαμόρφωσαν τους βασικούς της στόχους. Ο πρώτος στόχος της διδακτορικής διατριβής αφορούσε την in vitro αξιολόγηση της αντί-Campylobacter δράσης εννέα (9) εμπορικών προϊόντων, τα οποία έχουν εγκριθεί από την Ευρωπαϊκή Ένωση για χρήση στο πόσιμο νερό των ορνιθίων, και περιέχουν συγκεκριμένους συνδυασμούς οργανικών ή/και ανόργανων οξέων. Στη μελέτη αυτή χρησιμοποιήθηκαν συνολικά δύο στελέχη C. jejuni και ένα στέλεχος C. coli. H εκτίμηση της δράσης των εμπορικών μιγμάτων οξέων έναντι των στελεχών έγινε με τη μέθοδο της ελάχιστης ανασταλτικής συγκέντρωσης (Minimum Inhibitory Concentration – MIC) σύμφωνα με τα CLSI standards M07-A10 και M100-S28. Η MIC ορίζεται ως η μικρότερη συγκέντρωση μιας χημικής ουσίας η οποία αναστέλλει οπτικά την ανάπτυξη ενός συγκεκριμένου μικροβίου. Η εξέταση για κάθε σκεύασμα έγινε εις τριπλούν έναντι κάθε στελέχους Campylobacter. Σύμφωνα με τα αποτελέσματα της in vitro μελέτης, όλα τα εμπορικά προϊόντα που επιλέχθηκαν ήταν ικανά να αναστείλουν την ανάπτυξη των εξεταζόμενων στελεχών Campylobacter spp. Στη δόση που προτείνεται από τον παρασκευαστή. Δυο προϊόντα, το CID 2000™ και το Aqua-clean® κατέγραψαν την πιο ισχυρή δράση σε αυτή τη μελέτη, έναντι του C. jejuni και του C. coli (0,002%– 0.004%v/v). Με βάση τα αποτελέσματα της in vitro μελέτης, το ισχύον νομοθετικό πλαίσιο, τη συχνότητα χρήσης στη πτηνοτροφία και την απουσία αναφορών από τη διεθνή βιβλιογραφία σχετικά με τη δράση του προϊόντος στον επιπολασμό του C. jejuni στα κρεοπαραγωγά ορνίθια, το εμπορικό μίγμα οξέων που επιλέχθηκε για την in vivo μελέτη ήταν το CID 2000™. Ο δεύτερος στόχος της διδακτορικής διατριβής ήταν η in vivo αξιολόγηση της επίδρασης του CID 2000™ στον έλεγχο του επιπολασμού του C. Jejuni στα κρεοπαραγωγά ορνίθια. Επιπλέον, εκτιμήθηκε για πρώτη φορά η επίδραση της χορήγησης του CID 2000™ στην υγεία και την ευζωία των κρεοπαραγωγών ορνιθίων. Ο πειραματικός σχεδιασμός περιλάμβανε την τυχαία κατανομή 128 νεοσσών (Ross 308®), ηλικίας μιας ημέρας, σε τέσσερις (4) πειραματικές ομάδες των 32 ορνιθίων. Κάθε ομάδα, αποτελούνταν από τέσσερις (4) επιμέρους υποομάδες-επαναλήψεις των οκτώ (8) ορνιθίων. Η συνολική διάρκεια του πειραματισμού ήταν 36 ημέρες. Οι πειραματικοί χειρισμοί που διενεργήθηκαν ήταν η χορήγηση του μίγματος οξέων με το πόσιμο νερό και η μόλυνση των πτηνών με C. jejuni. Συγκεκριμένα, οι πειραματικές ομάδες ήταν οι εξής τέσσερις: 1) Ομάδα Α: τα ορνίθια της ομάδας χρησιμοποιήθηκαν ως αρνητικοί μάρτυρες, 2) Ομάδα Β: στα ορνίθια της ομάδας χορηγήθηκε το εμπορικό μίγμα οξέων, 3) Ομάδα Γ: στα ορνίθια της ομάδας διενεργήθηκε μόλυνση με C. jejuni, 4) Ομάδα Δ: στα ορνίθια της ομάδας χορηγήθηκε το εμπορικό μίγμα οξέων και μολύνθηκαν με C. jejuni. Τα ορνίθια μολυνθήκαν τη 18η ημέρα της ζωής τους με 106 CFU C. jejuni. Η κλινική εικόνα των ορνιθίων ελεγχόταν καθημερινά. Την 7η, 13η, 18η, 20η, 23η και 36η ημέρα του πειραματισμού, διενεργήθηκε βαθμονομική εκτίμηση του ποσοστού εμφάνισης και του βαθμού έντασης διαρροϊκών κοπράνων, μέσω της εκτίμησης της παρουσίας ρυπαρού υλικού στο πτέρωμα της περιοχής της αμάρας. Κατά τη διάρκεια του πειραματισμού το ΣΒ των ορνιθίων εκτιμήθηκε την 1η, 7η, 13η, 18η, 23η και 36η ημέρα, ενώ η ΜΗΚΤ, ο ΔΜΤ και η ΜΗΚΝ υπολογίστηκαν για τα χρονικά διαστήματα από την 1η-13η, την 14η-23η, την 24η-36η και την 1η-36η ημέρα πειραματισμού. Τέλος, ο ΕΔΠ υπολογίστηκε για τη συνολική περίοδο του πειραματισμού (1η-36η ημέρα). Συνολικά, στον in vivo πειραματισμό πραγματοποιήθηκαν δύο (2) δειγματοληψίες, την 23η ημέρα (5 ημέρες μετά τη μόλυνση) και την 36η ημέρα (18 ημέρες μετά τη μόλυνση). Οι εξετάσεις που διενεργήθηκαν ήταν: α) η καταμέτρηση των C. jejuni στον πρόλοβο και τα τυφλά, β) η απομόνωση του C. jejuni από το ήπαρ, γ) η ιστομορφομετρική και ιστοπαθολογική εκτίμηση δειγμάτων από το δωδεκαδάκτυλο, τη νήστιδα και τον ειλεό, δ) η ιστοπαθολογική διερεύνηση δειγμάτων ήπατος, ε) η μακροσκοπική εκτίμηση των αλλοιώσεων στα πέλματα, στους ταρσούς, στον μυώδη στόμαχο, στο ήπαρ και το έντερο των ορνιθίων, ζ) η μέτρηση του pH του περιεχομένου στον πρόλοβο, στο δωδεκαδάκτυλο, στη νήστιδα, στον ειλεό και τα τυφλά, και η) η μέτρηση του ιξώδους του περιεχομένου στη νήστιδας και τον ειλεό των ορνιθίων. Σύμφωνα με τα αποτελέσματα της in vivo μελέτης, η μόλυνση των κρεοπαραγωγών ορνιθίων με το στέλεχος C. jejuni KC40 οδήγησε στην επιτυχή εγκατάσταση του μικροοργανισμού στο έντερο, σχηματίζοντας μεγάλο πληθυσμό στη περιοχή των τυφλών. Επιπλέον, η μόλυνση αύξησε σημαντικά τη συχνότητα εμφάνισης και τον βαθμό έντασης διαρροϊκών κοπράνων, επηρέασε αρνητικά την ιστομορφολογία του εντέρου και οδήγησε σε υψηλό ποσοστό απομόνωσης του μικροοργανισμού από το ήπαρ των ορνιθίων. Η χορήγηση του CID 2000™ μείωσε σημαντικά τον πληθυσμό του C. jejuni στα τυφλά των ορνιθίων (5 ημέρες μετά τη μόλυνση), περιόρισε τη συχνότητα εμφάνισης και το βαθμό έντασης διαρροϊκών κοπράνων, βελτίωσε τις ιστομορφομετρικές μεταβολές που προκάλεσε το C. jejuni στο έντερο και περιόρισε σε σημαντικό βαθμό το ποσοστό απομόνωσης του μικροοργανισμού από το ήπαρ των μολυσμένων ορνιθίων, χωρίς ωστόσο να περιορίσει τη μετάδοση του C. jejuni μεταξύ των ορνιθίων

Characterization of Extended Spectrum Cephalosporin-Resistant <i>Escherichia coli</i> Strains Isolated from Raw Poultry Carcasses in Catering Services in Northern Greece

Antimicrobial resistance is considered a topic of utmost interest under the concept of “One Health”, having severe implications in both human and veterinary medicine. Among the antibiotic-resistant bacteria, gram-negative bacteria, especially those belonging to the order of Enterobacterales (such as Escherichia coli), hold a prominent position in terms of both virulence and possessing/disseminating antimicrobial resistance (AMR) traits. The aim of this study was to examine the presence of extended-spectrum β-lactamase producing E. coli isolates in raw poultry carcasses collected from a university club. Five hundred raw poultry skin samples were collected from the Aristotle University of Thessaloniki (AUTh) club in Thessaloniki, Greece. A total of 64% of the samples were positive for the presence of extended-spectrum β-lactamase (ESBL)-producing E. coli. The isolates were further examined for their susceptibility to selected antibiotics by the disc diffusion method and were characterized as true ESBL, as producing class C cephalosporinases (AmpC) or “of unknown etiology” by the combination disc test. The 86 of the 120 isolates (71.67%) were classified as true ESBL, 24 (20.00%) as AmpC, and 10 (8.33%) as “of unknown etiology”. The isolates were screened for the occurrence of β-lactamase genes (blaTEM, blaCTX-M, blaSHV, and blaOXA). Thirty-six isolates (32 ESBL- and 4 AmpC-phenotype) harbored both blaTEM and blaCTX-M genes, twenty-two isolates (among which 19 ESBL-phenotype and 2 AmpC-phenotype) harbored blaCTX-M only, whereas twenty-six (14 ESBL- and 12 AmpC-phenotype) isolates harbored blaTEM alone. No isolate harboring blaSHV or blaOXA was detected. The results demonstrate the existence of E. coli isolates producing extended-spectrum β-lactamases in poultry carcasses from Greece, pausing a risk for antibiotic resistance transfer to humans

Avian Mycobacteriosis and Molecular Identification of <em>Mycobacterium avium</em> Subsp. <em>avium</em> in Racing Pigeons (<em>Columba livia domestica</em>) in Greece

In this report, cases of avian mycobacteriosis in two lofts of racing pigeons are described. Three racing pigeons of 2-year old from the first loft (A) and four racing pigeons of 4–5 years old from the second loft (B) were submitted to the Unit of Avian Medicine for clinical examination and necropsy. In the case history chronic and debilitating disease was reported. The clinical signs included emaciation, depression, lameness, periorbital swelling and diarrhea, although the appetite was normal. Post mortem lesions involved an enlarged spleen with multiple different sized yellow nodules. Similar lesions were also observed in the liver, conjunctiva of the inferior eyelids and in the femoral bone marrow. The suspicion of avian mycobacteriosis was based on history, clinical signs and typical lesions. In order to confirm the diagnosis, histopathology was performed on tissue sections and revealed the presence of multiple granulomas with central necrosis. In addition, Ziehl-Neelsen positive bacilli were observed in histological sections and smears from the granulomas of the affected tissues. Molecular analysis identified the causative agent as Mycobacterium avium subsp. avium. This is the first case report of avian mycobacteriosis in Greece, which describes the presence of granulomatous conjunctivitis and the molecular identification of M. avium subsp. avium as the causative agent in racing pigeons

A Case of Infectious Laryngotracheitis in an Organic Broiler Chicken Farm in Greece

Infectious laryngotracheitis is an economically significant viral disease of chickens, that mainly affects the upper respiratory tract, and is present worldwide. This case reports the first outbreak of infectious laryngotracheitis in a four-week-old organic broiler farm and surrounding flocks in Greece, with typical clinical symptoms and lesions, allegedly provoked by a wild strain of infectious laryngotracheitis virus. Our findings contradict the general perception indicating that the disease appears mainly in older birds and that vaccine strains are the primary cause of infectious laryngotracheitis outbreaks in most continents. A recombinant vectored vaccine was administered, supplementary to biosecurity measures, containing the viral spread. The responsible strain was potentially circulating in the area; therefore, an industry-wide holistic approach was applied, including the vaccination of neighboring broilers and breeders with the same vaccine, the rapid molecular diagnosis of the disease, and strict biosecurity protocols. The results of this holistic effort were effective because, following the application of vaccine and management protocols, manifestations of the disease in regional flocks dropped significantly, and there was no recurrence to date. These findings suggest that vaccination protocols should be modified, especially for organic broilers, to include vaccination against infectious laryngotracheitis

First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece

Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A–C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH

First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece

Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A&ndash;C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH

Investigation of the Effect of Three Commercial Water Acidifiers on the Performance, Gut Health, and <i>Campylobacter jejuni</i> Colonization in Experimentally Challenged Broiler Chicks

This study investigated the effect of three commercial water acidifiers on the performance, gut health, and C. jejuni colonization in experimentally challenged broiler chicks. A total of 192 one-day-old broiler chicks (Ross 308®) were randomly allocated into 6 treatment groups with 4 replicates according to the following experimental design: group A, birds were not challenged and received tap water; group B, birds were challenged and received tap water; groups C, D, E, and F, birds were challenged and received tap water treated with 0.1% v/v SPECTRON®, with 0.1–0.2% v/v ProPhorce™ SA Exclusive, with 0.1–0.2% v/v Premium acid, and with 0.1–0.2% v/v Salgard® Liquid, respectively. The continuous water acidification evoked undesirable effects on broilers’ performance and to an increased number of birds with ulcers and erosions in the oral cavity and the upper esophageal area. ProPhorce™ SA Exclusive and Premium acid significantly reduced the C. jejuni counts in the crop, whereas Salgard® Liquid significantly reduced the C. jejuni counts in the ceca of birds. At slaughter age, only Premium acid significantly reduced C. jejuni counts in the ceca of birds. All the tested products ameliorated the changes induced by C. jejuni infection in the pH in the ceca of birds. It can be concluded that besides the effectiveness of the tested products in controlling C. jejuni in broilers, their continuous application evoked undesirable effects on broilers’ performance, leading to the need to modify the dosage scheme in future investigations

Investigation of a Novel Multicomponent Mycotoxin Detoxifying Agent in Amelioration of Mycotoxicosis Induced by Aflatoxin-B1 and Ochratoxin A in Broiler Chicks

The present study was designed to determine the efficacy of a novel multicomponent mycotoxin detoxifying agent (MMDA) containing modified zeolite (Clinoptilolite), Bacillus subtilis, B. licheniformis, Saccharomyces cerevisiae cell walls and silymarin against the deleterious effects of Aflatoxin B1 (AFB1) and Ochratoxin A (OTA) in broiler chicks. A total of 160 one-day-old Ross 308® broiler chicks were randomly allocated in four treatment groups, with four replicates, according to the following experimental design for 42 days. Group A received a basal diet; Group B received a basal diet contaminated with AFB1 and OTA at 0.1 mg/kg and 1 mg/kg, respectively; Group C received a basal diet contaminated with AFB1 and OTA and MMDA at 1 g/kg feed, and Group D received a basal diet contaminated with AFB1 and OTA and MMDA at 3 g/kg feed. Results showed that ingested mycotoxins led to significant (p ≤ 0.05) reduction in body weight and feed conversion from 25 days of age, induced histopathological changes, increased the pH of the intestinal content, and altered the biochemical profile of birds with significantly (p ≤ 0.05) increased aspartate aminotransferase (AST) values (p ≤ 0.05). On the other hand, the supplementation of MMDA significantly (p ≤ 0.05) improved the feed conversion ratio (FCR) during the second part of the study, diminished biochemical alterations, reduced pH in jejunal and ileal content, and E. coli counts in the caeca of birds (p ≤ 0.05). It may be concluded that the dietary supplementation of the MMDA partially ameliorated the adverse effects of AFB1 and OTA in broilers and could be an efficient tool in a mycotoxin control program

New Intrinsically Thermostable Xylanase Improves Broilers&rsquo; Growth Performance, Organ Weights, and Affects Intestinal Viscosity and pH

Exogenous carbohydrases are commonly added to monogastric animal feed to degrade non-starch polysaccharides (NSP) to improve zootechnical performance and nutrient digestion. In the current study, the effects of dietary supplementation of a new, intrinsically thermostable, monocomponent xylanase on intestinal parameters, zootechnical performance and carcass traits of broilers were evaluated. A total of 720 1-day-old broilers were randomly allotted to four wheat-based diets with different levels of xylanase (T1: control; T2: 30,000 U/g; T3: 45,000 U/g; T4: 90,000 U/g) and fed from 1 to 35 days of age. The data showed that xylanase supplementation reduced the intestinal viscosity significantly, especially in the ileum. Duodenum and cecum pH was not influenced by xylanase supplementation, while T3 treatment showed the lowest pH value in jejunum and ileum. Xylanase supplementation reduced significantly feed conversion ratio (FCR) without affecting feed intake (FI). T2 treatment exhibited a higher body weight gain (BWG) compared the other treatments. Live weight, carcass weight, legs, and liver weight were significantly higher in T3 and T4 treatments compared to T1. No significant differences on foot pad lesions were observed among the four treatments. In conclusion, dietary supplementation of this new xylanase significantly improves intestinal tract viscosity and affects beneficially broilers&rsquo; performance and carcass traits