On-farm Campylobacter and Escherichia coli in commercial broiler chickens: Re-used bedding does not influence Campylobacter emergence and levels across sequential farming cycles

Limitations in quality bedding material have resulted in the growing need to re-use litter during broiler farming in some countries, which can be of concern from a food-safety perspective. The aim of this study was to compare the Campylobacter levels in ceca and litter across three litter treatments under commercial farming conditions. The litter treatments were (a) the use of new litter after each farming cycle; (b) an Australian partial litter re-use practice; and (c) a full litter re-use practice. The study was carried out on two farms over two years (Farm 1, from 2009–2010 and Farm 2, from 2010–2011), across three sheds (35,000 to 40,000 chickens/shed) on each farm, adopting three different litter treatments across six commercial cycles. A random sampling design was adopted to test litter and ceca for Campylobacter and Escherichia coli, prior to commercial first thin-out and final pick-up. Campylobacter levels varied little across litter practices and farming cycles on each farm and were in the range of log 8.0–9.0 CFU/g in ceca and log 4.0–6.0 MPN/g for litter. Similarly the E. coli in ceca were ∼log 7.0 CFU/g. At first thin-out and final pick-up, the statistical analysis for both litter and ceca showed that the three-way interaction (treatments by farms by times) was highly significant (P < 0.01), indicating that the patterns of Campylobacter emergence/presence across time vary between the farms, cycles and pickups. The emergence and levels of both organisms were not influenced by litter treatments across the six farming cycles on both farms. Either C. jejuni or C. coli could be the dominant species across litter and ceca, and this phenomenon could not be attributed to specific litter treatments. Irrespective of the litter treatments in place, cycle 2 on Farm 2 remained campylobacter-free. These outcomes suggest that litter treatments did not directly influence the time of emergence and levels of Campylobacter and E. coli during commercial farming

On-farm Campylobacter and Escherichia coli in commercial broiler chickens: Re-used bedding does not influence Campylobacter emergence and levels across sequential farming cycles

Limitations in quality bedding material have resulted in the growing need to re-use litter during broiler farming in some countries, which can be of concern from a food-safety perspective. The aim of this study was to compare the Campylobacter levels in ceca and litter across three litter treatments under commercial farming conditions. The litter treatments were (a) the use of new litter after each farming cycle; (b) an Australian partial litter re-use practice; and (c) a full litter re-use practice. The study was carried out on two farms over two years (Farm 1, from 2009–2010 and Farm 2, from 2010–2011), across three sheds (35,000 to 40,000 chickens/shed) on each farm, adopting three different litter treatments across six commercial cycles. A random sampling design was adopted to test litter and ceca for Campylobacter and Escherichia coli, prior to commercial first thin-out and final pick-up. Campylobacter levels varied little across litter practices and farming cycles on each farm and were in the range of log 8.0–9.0 CFU/g in ceca and log 4.0–6.0 MPN/g for litter. Similarly the E. coli in ceca were ∼log 7.0 CFU/g. At first thin-out and final pick-up, the statistical analysis for both litter and ceca showed that the three-way interaction (treatments by farms by times) was highly significant (P < 0.01), indicating that the patterns of Campylobacter emergence/presence across time vary between the farms, cycles and pickups. The emergence and levels of both organisms were not influenced by litter treatments across the six farming cycles on both farms. Either C. jejuni or C. coli could be the dominant species across litter and ceca, and this phenomenon could not be attributed to specific litter treatments. Irrespective of the litter treatments in place, cycle 2 on Farm 2 remained campylobacter-free. These outcomes suggest that litter treatments did not directly influence the time of emergence and levels of Campylobacter and E. coli during commercial farming

Bacteriophages to Control Campylobacter in Commercially Farmed Broiler Chickens, in Australia

© Copyright © 2020 The State of Queensland (through the Department Agriculture and Fisheries). This study describes the development and use of bacteriophage cocktails to control Campylobacter in broiler chickens, in a commercial setting, in Queensland Australia, following the birds from farm to the processing plant. The components of the bacteriophage cocktails were selected to be effective against the maximum number of Campylobacter jejuni and Campylobacter coli isolates encountered on SE Queensland farms. Farms were identified that had suitable Campylobacter target populations and phage were undetectable 1 week prior to the intended treatment. Cocktails of phages were administered at 47 days of age. Groups of study birds were slaughtered the following day, on-farm, at the end of flock transport to the plant, and at processing (approximately 28 h post-treatment). On Farm A, the phage treatment significantly reduced Campylobacter levels in the ceca at the farm in the range of 1–3 log10 CFU/g (p = 0.007), compared to mock treated controls. However, individual birds sampled on farm (1/10) or following transport (2/10) exhibited high cecal Campylobacter counts with low phage titers, suggesting that treatment periods > 24 h may be required to ensure phage replication for effective biocontrol in vivo. At the time of the trial the control birds in Farm B were phage positive despite having been negative one week earlier. There was no significant difference in the cecal Campylobacter counts between the treatment and control groups following treatment but a fall of 1.7 log10 CFU/g was observed from that determined from birds collected the previous week (p = 0.0004). Campylobacter isolates from both farms retained sensitivity to the treatment phages. These trials demonstrated bacteriophages sourced from Queensland farms have the potential to reduce intestinal Campylobacter levels in market ready broiler chickens

A lytic bacteriophage isolate reduced Clostridium perfringens induced lesions in necrotic enteritis challenged broilers

Background Bacteriophages are viral predators of bacteria and are common in nature. Their host-specific infections against specific bacteria make them an attractive natural agent to control bacterial pathogens. Interest in the potential of bacteriophages as antibacterial agents in the production animal industries has increased. Methods A total of 18 bacteriophages were isolated from Australian commercial poultry environments, from which three highly active phages were chosen for enrichment. Sequencing libraries were prepared using a Nextera XT kit (Illumina) and sequenced on an Illumina MiSeq instrument using 2 × 300 bp paired-end chemistry. The sequence data were then assembled and aligned with a2 bacteriophage as the reference. An animal trial was performed by oral gavaging Clostridium perfringens netB containing strain EHE-NE18 to the Ross 308 broiler chickens prior inoculation with Eimeria species. The chickens were raised following the management guide for Ross 308 from d 0 to d 21 and fed with starter and grower diets met the specific breed nutrient requirements. Body weight gain and feed intake were measured on d 9 and d 21 and FCR adjusted with mortality was calculated. Results The isolated bacteriophages only had only 96.7% similarity to the most closely related, previously characterized, Clostridium bacteriophage indicated that they might represent a novel strain of bacteriophage. A “cocktail” containing the three bacteriophages was capable of lysing four known disease-inducing C. perfringens strains in vitro. Oral administration of the bacteriophages cocktail to broilers challenged with necrotic enteritis markedly alleviated intestinal necrotic lesions in the duodenum and jejunum on day 16 post-hatch. The phage treatment significantly reduced the lesion scores of birds challenged with NE (P 0.05). However, no effect on the growth performance was observed during the recorded period of days 9-21. Conclusion These findings suggest that bacteriophage treatment is a promising approach to protect intestinal health from C. perfringens induced necrotic enteritis. Further research will be required on the dosing, route of administration, and large scale validation studies to further advance this approach to pathogen control

Load estimation and state estimation in distribution networks using data from smart meters

133 σ.Η παρούσα εργασία παρουσιάζει την συνδυασμένη λειτουργία ενός κλασικού εκτιμητή κατάστασης και μιας μεθόδου εκτίμησης φορτίου, αξιοποιώντας τις δυνατότητες προηγμένων συστημάτων αυτοματισμού AMR- AMI. Το έργο της εκτίμησης κατάστασης δυσχεραίνεται στα δίκτυα διανομής εξ αιτίας της έλλειψης πραγματικών μετρήσεων. Γι΄αυτό το λόγο, επισημαίνεται ως καθοριστικός ο ρόλος των έξυπνων μετρητών σε καταναλωτές χαμηλής τάσης για την αποτελεσματική εκτίμηση φορτίου ζυγών δικτύου διανομής με απουσία πραγματικών δεδομένων. Μετά από μελέτη της υπάρχουσας βιβλιογραφίας πάνω στο θέμα, αναπτύχθηκε πρόγραμμα σε περιβάλλον Matlab που αφορά την εκτίμηση φορτίου και πραγματοποιήθηκαν προσομοιώσεις σε δίκτυο διανομής 55 ζυγών. Τα δεδομένα που προέκυψαν εισήχθησαν στον εκτιμητή κατάστασης μαζί με δεδομένα μετρήσεων πραγματικού χρόνου. Στόχος είναι η εκτίμηση κατάστασης του δικτύου διανομής, ώστε να επιτευχθεί η βέλτιστη, οικονομικά αποδοτική και ασφαλής λειτουργία του. Συνολικά από τη μελέτη, συμπεραίνεται ότι προκύπτει ακριβέστερη εκτίμηση κατάστασης με την αποστολή δεδομένων από τους μετρητές προς τα κέντρα ελέγχου ενέργειας ανά μικρότερα χρονικά διαστήματα.This paper presents the combined operation of a classical state estimator and a load estimation method, through the potential of advanced automation systems AMR-AMI. State estimation becomes complicated in distribution networks due to the lack of actual measurements. The key role of smart meters at low voltage consumers is noted for effective load estimation at distribution network buses where absence of real data is marked. After studying the existing literature on the subject, a program was developed in Matlab environment on load estimation and simulations were performed in distribution network of 55 buses. The data acquired were introduced into the state estimator along with data of real-time measurements. The aim of the study is to obtain an accurate state estimation algorithm for distribution networks in order to achieve optimal, cost-efficient and safe operation. Overall the study, it is concluded that more precise state estimation is resulted as data transmission from smart meters towards management centers get more frequent.Γεώργιος Δ. Καρλή

Volatile components associated with bacterial spoilage of tropical prawns

Analysis of headspace volatiles by gas chromatography/mass spectrometry from king (Penaeus plebejus), banana (P. merguiensis), tiger (P. esculentus/semisulcatus) and greasy (Metapenaeus bennettae) prawns stored in ice or ice slurry, which is effectively an environment of low oxygen tension, indicated the presence of amines at the early stages of storage (less than 8 days) irrespective of the nature of the storage media. Esters were more prevalent in prawns stored on ice (normal oxygen conditions) at the latter stages of storage (more than 8 days) and were only produced by Pseudomonas fragi, whereas sulphides and amines occurred whether the predominant spoilage organism was Ps.fragi or Shewanella putrefaciens. The free amino acid profiles of banana and king prawns were high in arginine (12–14%) and low in cysteine (0.1–0.17%) and methionine (0.1–0.2%). Filter sterilised raw banana prawn broth inoculated with a total of 15 cultures of Ps. fragi and S. putrefaciens and incubated for two weeks at 5°C, showed the presence of 17 major compounds in the headspace volatiles analysed using gas chromatography/mass spectrometry (GC/MS). These were mainly amines, sulphides, ketones and esters. Principal Component Analysis of the results for the comparative levels of the volatiles produced by pure cultures, inoculated into sterile prawn broth, indicated three subgroupings of the organisms; I, Ps. fragi from a particular geographic location; II, S. putrefaciens from another geographic location; and III, a mixture of Ps. fragi and S. putrefaciens from different geographic locations. The sensory impression created by the cultures was strongly related to the chemical profile as determined by GC/MS. Organisms, even within the same subgrouping classified as identical by the usual tests, produced a different range of volatiles in the same uniform substrate