Antimicrobial use in poultry flocks in Austria between 2013 and 2019.

BACKGROUND: The increase in bacteria that are resistant to antimicrobials-often selected for a high level of antimicrobial uses (AMUs) in human beings or food-producing animals-is a global concern. The Austrian Poultry Health Service (QGV) has established a database containing comprehensive information on poultry flocks in Austria. METHODS: AMU in 32,411 broiler flocks and 2946 turkey flocks between 2013 and 2019 is analysed by calculating different metrics, including the treatment incidence TI1000 . Furthermore, the Austrian benchmarking system for poultry is introduced. RESULTS: Annual AMU in broilers decreased from 1030.8 kg of active ingredient to 762.5 kg between 2013 and 2016 but rose again to 1165.0 kg in 2019; while for turkeys annual AMU dropped from 1196.4 kg to 569.0 kg between 2013 and 2019. At the same time, the proportion of treated flocks decreased from 34.2% to 24.8% for broilers and from 54.3% to 44.0% for turkeys. In both broilers and turkeys, the most frequently used antimicrobial class, according to the TI1000 unit, in broilers and turkeys is polymyxins. CONCLUSION: Calculating different metrics enables a deeper insight into AMU. Total AMU reduced without legislation but the increase of AMU in broiler production needs further investigation.

Differences in antimicrobial resistance of commensal Escherichia coli isolated from caecal contents of organically and conventionally raised broilers in Austria, 2010-2014 and 2016.

The prevalence of antimicrobial resistance in commensal Escherichia coli isolated from organically raised broiler flocks was compared to the prevalence in isolates from conventional flocks. From 2010 to 2014, and in 2016, resistance trends and multidrug resistance in isolates from the caecal contents of flocks from both broiler production forms were analyzed. Samples were taken in four abattoirs accounting for at least 90% of the national slaughtered broiler population. In total, 962 commensal E. coli were obtained from organically raised broiler flocks (n = 142) and from conventionally raised broiler flocks (n = 820). The mean prevalence of commensal E. coli isolates, which were fully susceptible to the antimicrobials tested, was 43.3% in organically raised broiler flocks and thus significantly higher (P < 0.001) compared to 16.7% in conventionally operated flocks. During the study period, the proportion of fully susceptible isolates increased significantly in both broiler populations. Antimicrobial resistance rates were significantly lower in commensal E. coli isolated from organic compared to conventional production regarding ciprofloxacin (33.3% versus 69.1%), nalidixic acid (33.7% versus 67.4%), sulfamethoxazole (26.7% versus 39.9%), ampicillin (19.0% versus 33.8%) and trimethoprim (12.8% versus 24.9%). Regarding tetracycline, tigecycline and ceftazidime resistance rates were slightly but not significantly higher in isolates from organic flocks (27.6% versus 25.9%; 4.0% versus 1.4%; 2.0% versus 1.9%). This fact is surprising for tetracycline, as none of the investigated organic flocks had been treated with this antimicrobial during their lifetime. No resistances were found in isolates from both production forms against colistin and meropenem, and from organic flocks against azithromycin. The annual prevalence of resistance against ciprofloxacin and nalidixic acid decreased significantly in isolates from both broiler production forms. In isolates from organic flocks, it also decreased regarding ampicillin and sulfamethoxazole. Significant increasing trends were observed in the resistance prevalence against trimethoprim and borderline significantly for ampicillin in commensal E. coli from conventional flocks. Multidrug resistance was detected at a significantly higher prevalence in isolates from conventionally raised flocks (35.1%) compared to organic flocks (22.7%). Findings from this study clearly indicate the influences of organic compared to conventional broiler production practices on the prevalence of antimicrobial resistance in commensal E. coli from broiler flocks.

[Implementation and results of the EU-wide baseline study on the prevalence of Salmonella spp. in flocks of turkeys in Austria]. / Umsetzung und Ergebnisse der EU-weiten Grundlagenstudie zur Prävalenz von Salmonella spp. in Putenherden in Osterreich.

The member states of the European Union (EU) are following a common strategy on the control of Salmonella and other foodborne zoonotic pathogens (Anonym, 2003). In order to establish the prevalence of Salmonella (S.) spp. in turkeys, a baseline survey was organised in between October 2006 and September 2007. In Austria a total of 202 turkey flocks in 104 holdings was included. By doing so, all holdings with fattening turkeys were covered by the sampling scheme, whereas breeding turkey flocks did not exist in the survey period. A prevalence of Salmonella spp. of 17.3% in flocks or 25% of holdings was obtained. A total of nine different serovars were identified, S. Hadar being the most frequently isolated with eleven flocks infected representing 31.4% of all. S. Montevideo and S. Saintpaul were both found in eight flocks, and S. Senftenberg in six flocks. Two flocks were colonized with S. Newport, while one flock each had S. Typhimurium, S. Derby, S. Blockley and a monophasic strain of Salmonella group B. Of the two serovars of highest relevance for human health, S. Typhimurium was detected in only 0.5% of flocks or 1% of holdings tested and S. Enteritidis was not detected at all. Taking into account the high prevalence of the various Salmonella serovars however control measures to prohibit horizontal transmission and entry of Salmonella spp. from the turkey reservoir into the food chain in Austria seem justified.

Prevalence of Salmonella spp. in Austrian broiler flocks in the context of the EU-wide baseline survey 2005-2006.

In Austria an EU-wide baseline survey on the prevalence of Salmonella spp. in broilers organized by the EU commission was conducted from October 2005 to September 2006. The aim of this study was to produce comparable data on the prevalence of Salmonella in broiler flocks and holdings for all member states and for the EU-Commission to set EU-wide targets for the control of Salmonella in the broiler populations. A randomised sampling plan was designed according to EU-commission parameters (p = 50%; CI = 95%, a = 5%). Sampling was carried out regularly throughout the whole year. On every farm one flock was sampled with five pairs of boot swabs and analysed in the lab according to appendix D of ISO 6579 (2002). In Austria, 363 flocks on farms consisting of at least 5000 broilers each were tested. 28 flocks (7.7%) showed infections with Salmonella spp., eight flocks (2.2%) had either S. Enteritidis (six flocks) or S. Typhimurium (two flocks). In detail, S. Enteritidis (1.7%), S. Typhimurium (0.6%), S. Montevideo (4.1%), S. Infantis 0.6%, S. Senftenberg, S. Tennessee and S. Virchow (0.3% each) have been found. Data indicated that the risk of vertical transmission of Salmonella spp. to broiler flocks has almost been kept at bay; however, the risk of horizontal transmission still needs attention. Contamination of feeding stuff, possible persistence, spreading between barns of a farm as well as introduction of Salmonella spp. through individuals or materials are important factors for future control strategies.