Molecular Epidemiology of Campylobacter Isolates from Poultry Production Units in Southern Ireland

This study aimed to identify the sources and routes of transmission of Campylobacter in intensively reared poultry farms in the Republic of Ireland. Breeder flocks and their corresponding broilers housed in three growing facilities were screened for the presence of Campylobacter species from November 2006 through September 2007. All breeder flocks tested positive for Campylobacter species (with C. jejuni and C. coli being identified). Similarly, all broiler flocks also tested positive for Campylobacter by the end of the rearing period. Faecal and environmental samples were analyzed at regular intervals throughout the rearing period of each broiler flock. Campylobacter was not detected in the disinfected house, or in one-day old broiler chicks. Campylobacter jejuni was isolated from environmental samples including air, water puddles, adjacent broiler flocks and soil. A representative subset of isolates from each farm was selected for further characterization using flaA-SVR sub-typing and multi-locus sequence typing (MLST) to determine if same-species isolates from different sources were indistinguishable or not. Results obtained suggest that no evidence of vertical transmission existed and that adequate cleaning/disinfection of broiler houses contributed to the prevention of carryover and cross-contamination. Nonetheless, the environment appears to be a potential source of Campylobacter. The population structure of Campylobacter isolates from broiler farms in Southern Ireland was diverse and weakly clonal

A farm-level study of risk factors associated with the colonization of broiler flocks with Campylobacter spp. in Iceland, 2001 – 2004

<p>Abstract</p> <p>Background</p> <p>Following increased rates of human campylobacteriosis in the late 1990's, and their apparent association with increased consumption of fresh chicken meat, a longitudinal study was conducted in Iceland to identify the means to decrease the frequency of broiler flock colonization with <it>Campylobacter</it>. Our objective in this study was to identify risk factors for flock colonization acting at the broiler farm level.</p> <p>Methods</p> <p>Between May 2001 and September 2004, pooled caecal samples were obtained from 1,425 flocks at slaughter and cultured for <it>Campylobacter</it>. Due to the strong seasonal variation in flock prevalence, analyses were restricted to a subset of 792 flocks raised during the four summer seasons. Flock results were collapsed to the farm level, such that the number of positive flocks and the total number of flocks raised were summed for each farm. Logistic regression models were fitted to the data using automated and manual selection methods. Variables of interest included manure management, water source and treatment, other poultry/livestock on farm, and farm size and management.</p> <p>Results</p> <p>The 792 flocks raised during the summer seasons originated from 83 houses on 33 farms, and of these, 217 (27.4%) tested positive. The median number of flocks per farm was 14, and the median number of positive flocks per farm was three. Three farms did not have any positive flocks. In general, factors associated with an increased risk of <it>Campylobacter </it>were increasing median flock size on the farm (p ≤ 0.001), spreading manure on the farm (p = 0.004 to 0.035), and increasing the number of broiler houses on the farm (p = 0.008 to 0.038). Protective factors included the use of official (municipal) (p = 0.004 to 0.051) or official treated (p = 0.006 to 0.032) water compared to the use of non-official untreated water, storing manure on the farm (p = 0.025 to 0.029), and the presence of other domestic livestock on the farm (p = 0.004 to 0.028).</p> <p>Conclusion</p> <p>Limiting the average flock size, and limiting the number of houses built on new farms, are interventions that require investigation. Water may play a role in the transmission of <it>Campylobacter</it>, therefore the use of official water, and potentially, treating non-official water may reduce the risk of colonization. Manure management practices deserve further attention.</p

Risk factors for antibiotic resistance in Campylobacter spp. isolated from raw poultry meat in Switzerland

BACKGROUND: The world-wide increase of foodborne infections with antibiotic resistant pathogens is of growing concern and is designated by the World Health Organization as an emerging public health problem. Thermophilic Campylobacter have been recognised as a major cause of foodborne bacterial gastrointestinal human infections in Switzerland and in many other countries throughout the world. Poultry meat is the most common source for foodborne cases caused by Campylobacter. Because all classes of antibiotics recommended for treatment of human campylobacteriosis are also used in veterinary medicine, in view of food safety, the resistance status of Campylobacter isolated from poultry meat is of special interest. METHODS: Raw poultry meat samples were collected throughout Switzerland and Liechtenstein at retail level and examined for Campylobacter spp. One strain from each Campylobacter-positive sample was selected for susceptibility testing with the disc diffusion and the E-test method. Risk factors associated with resistance to the tested antibiotics were analysed by multiple logistic regression. RESULTS: In total, 91 Campylobacter spp. strains were isolated from 415 raw poultry meat samples. Fifty-one strains (59%) were sensitive to all tested antibiotics. Nineteen strains (22%) were resistant to a single, nine strains to two antibiotics, and eight strains showed at least three antibiotic resistances. Resistance was observed most frequently to ciprofloxacin (28.7%), tetracycline (12.6%), sulphonamide (11.8%), and ampicillin (10.3%). One multiple resistant strain exhibited resistance to five antibiotics including ciprofloxacin, tetracycline, and erythromycin. These are the most important antibiotics for treatment of human campylobacteriosis. A significant risk factor associated with multiple resistance in Campylobacter was foreign meat production compared to Swiss meat production (odds ratio = 5.7). CONCLUSION: Compared to the situation in other countries, the data of this study show a favourable resistance situation for Campylobacter strains isolated from raw poultry meat produced in Switzerland. Nevertheless, the prevalence of 19% ciprofloxacin resistant strains is of concern and has to be monitored. "Foreign production vs. Swiss production" was a significant risk factor for multiple resistance in the logistic regression model. Therefore, an adequate resistance-monitoring programme should include meat produced in Switzerland as well as imported meat samples

Salmonella in Broiler Litter and Properties of Soil at Farm Location

Contamination of litter in a broiler grow-out house with Salmonella prior to placement of a new flock has been shown to be a precursor of the flock's Salmonella contamination further down the production continuum. In the southern USA, broiler grow-out houses are primarily built on dirt pad foundations that are placed directly on top of the native soil surface. Broiler litter is placed directly on the dirt pad. Multiple grow-out flocks are reared on a single litter batch, and the litter is kept in the houses during downtime between flocks. The effects of environmental determinants on conditions in broiler litter, hence Salmonella ecology within it, has received limited attention. In a field study that included broiler farms in the states of Alabama, Mississippi and Texas we assessed Salmonella in broiler litter at the end of downtime between flocks, i.e. at the time of placement of a new flock for rearing. Here we utilized these results and the U.S. General Soil Map (STATSGO) data to test if properties of soil at farm location impacted the probability of Salmonella detection in the litter. The significance of soil properties as risk factors was tested in multilevel regression models after accounting for possible confounding differences among the farms, the participating broiler complexes and companies, and the farms' geographical positioning. Significant associations were observed between infiltration and drainage capabilities of soil at farm location and probability of Salmonella detection in the litter

Validatie van de TBX gietplaat-methode (ISO 16649-2) voor het tellen van Escherichia coli in levende tweekleppige weekdieren: hernieuwde studie om in lijn te brengen met EN ISO 16140- 2:2016

Volgens Europese wetgeving moet worden aangetoond of consumenten veilig schelpdieren kunnen eten. Hiervoor wordt geteld hoeveel Escherichia coli bacteriën er in het schelpdiervlees zitten. Om ze rauw of gekookt te mogen eten is een maximum aantal bacteriën toegestaan. Om bijvoorbeeld oesters rauw te kunnen eten mogen er niet meer dan 230 E. coli bacteriën in zitten. Wanneer er meer bacteriën in de schelpdieren zitten, dan moeten ze bijvoorbeeld gekookt worden om de bacteriën te doden voordat je ze veilig kunt eten. De Europese regelgeving verplicht de Europese lidstaten de MPN-methode te gebruiken om de aantallen te tellen. Om een andere methode te kunnen gebruiken, moet worden aangetoond dat deze methode dezelfde resultaten geef t als de MPN. Dit gebeurt met een validatiestudie. Het RIVM heeft dat eerder gedaan voor de TBX-methode (MicroVal-certificaat met certificaatnummer: 2007-LR07). De regels om dat aan te tonen staan beschreven in een ISO-norm (EN ISO 16140:2003). Maar deze eerdere studie is in 2017 verlopen en de ISO is veranderd. Daarom heef t het RIVM een nieuwe validatiestudie gedaan volgens de nieuwe regels (EN ISO 16140-2:2016). Ook nu blijkt dat de TBXmethode dezelfde resultaten geef t als de MPN-methode. De TBXmethode mag daarom nu ook worden gebruikt om de Escherichia coli bacterie in schelpdieren te tellen. Voor deze studie moesten enkele nieuwe experimenten worden gedaan. Hiervoor zijn de volgende schelpdiersoorten gebruikt: oesters, mosselen, kokkels en ensis. Alle proeven gaven dezelfde conclusies.EU regulations need to be in place to determine the safety of shellfish consumption. To achieve this, it is necessary to count the number of Escherichia coli bacteria present in shellfish flesh. In order to be able to eat raw shellfish, a maximum number of bacteria is permitted. For instance, to safely consume raw oysters, they cannot contain more than 230 E. coli bacteria per 100 gram. If more bacteria are present, additional treatment like cooking is necessary to inactivate all bacteria present for the shellfish to be consumed safely. The European legislation prescribes Member States to use the MPN method to count E. coli in shellfish. To be able to use an alternative method, a validation study needs to be performed to prove that the alternative method gives equivalent results to the MPN method. RIVM has conducted similar studies for the TBX method (MicroVal, Certificate: 2007-LR07). EN ISO 16140:2003 sets out the rules on how to perform such a validation study. The previous validation study expired in 2017 and since then, the ISO rules have changed. Therefore it was necessary for RIVM to perform a new validation study based on the new rules (EN ISO 16140-2:2016). This new study shows that the alternative TBX method gives equivalent results to the MPN method. Therefore, the TBX method is now an approved alternative for counting E. coli bacteria in shellfish. New experiments were carried out for this study. A range of shellfish species were used: oysters, mussels, cockles and ensis; all experiments gave the same results.NVW

Twintigste EURL-Salmonella ringonderzoek (2015) voor de typering van Salmonella spp

The National Reference Laboratories (NRLs) of all 28 European Union (EU) Member States performed well in the 2015 quality control test on Salmonella typing. One laboratory was found to require a follow-up study after the initial test. Overall, the EU-NRLs were able to assign the correct name to 97% of the strains tested. In addition to the standard method for typing Salmonella (serotyping), sixteen laboratories performed typing at DNA level, using Pulsed Field Gel Electrophoresis (PFGE). This more detailed typing method is sometimes needed to trace the source of a contamination. For quality control, the participants received another ten strains of Salmonella to be tested by this method. Fourteen of the sixteen participating laboratories were suitably equipped to use the PFGE method. Since 1992, the NRLs of the EU Member States are obliged to participate in annual quality control tests which consist of interlaboratory comparison studies on Salmonella. Each Member State designates a specific laboratory within their national boundaries to be responsible for the detection and identification of Salmonella strains in animals and/or food products. These laboratories are referred to as the National Reference Laboratories (NRLs). The performance of these NRLs in Salmonella typing is assessed annually by testing their ability to identify twenty Salmonella strains. NRLs from countries outside the European Union occasionally participate in these tests on a voluntary basis. The EU-candidate-countries Former Yugoslav Republic of Macedonia and Turkey, and EFTA countries Iceland, Norway and Switzerland took part in the 2015 assessment. The annual interlaboratory comparison study on Salmonella typing is organised by the European Union Reference Laboratory for Salmonella (EURL-Salmonella). The EURL-Salmonella is located at the National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.European Commission, Directorate-General for Health and Consumer Protection (DG-Sanco

Eenentwintigste EURL-Salmonella ringonderzoek (2016) voor de typering van Salmonella spp

The National Reference Laboratories (NRLs) of all 28 European Union (EU) Member States performed well in the 2016 quality control test on Salmonella typing. Overall, the EU-NRLs were able to assign the correct name to 99% of the strains tested. In addition to the standard method for typing Salmonella (serotyping), fifteen laboratories performed typing at DNA level using Pulsed Field Gel Electrophoresis (PFGE). This more detailed typing method is sometimes needed to trace the source of a contamination. For quality control, participants received another ten strains of Salmonella to be tested by this method. Thirteen of the fifteen participating laboratories were suitably equipped to use the PFGE method. Since 1992, the NRLs of the EU Member States are obliged to participate in annual quality control tests which consist of interlaboratory comparison studies on Salmonella. Each Member State designates a specific laboratory within their national boundaries to be responsible for the detection and identification of Salmonella strains in animals and/or food products. These laboratories are referred to as the National Reference Laboratories (NRLs). The performance of these NRLs in Salmonella typing is assessed annually by testing their ability to identify 20 Salmonella strains. NRLs from countries outside the European Union occasionally participate in these tests on a voluntary basis. The EU-candidate-countries Former Yugoslav Republic of Macedonia and Serbia, and EFTA countries Iceland, Norway and Switzerland took part in the 2016 assessment. The annual interlaboratory comparison study on Salmonella typing is organised by the European Union Reference Laboratory for Salmonella (EURL-Salmonella). The EURL-Salmonella is located at the National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.European Commission, Directorate-General for Health and Food Safety (DG-Sante

EURL-Salmonella ringonderzoek typering 2018

De Nationale Referentie Laboratoria (NRL's) van de 28 Europese lidstaten scoorden in 2018 goed bij de kwaliteitscontrole op Salmonellatypering. Uit de analyse van alle NRL's als groep bleek dat de laboratoria aan 97 procent van de geteste stammen de juiste naam konden geven. Twaalf laboratoria hebben, behalve de standaardtoets (serotypering) op Salmonella, extra typeringen op DNA-niveau uitgevoerd met behulp van de zogeheten PFGE-typering (Pulsed Field Gel Electroforese). Deze preciezere typering kan soms nodig zijn om de bron van een besmetting op te sporen. Om de kwaliteit ervan te toetsen moeten de laboratoria elf extra stammen met deze methode typeren. Tien van de twaalf deelnemende laboratoria waren daartoe in staat. Sinds 1992 zijn de NRL's van de Europese lidstaten verplicht om deel te nemen aan jaarlijkse kwaliteitstoetsen, die bestaan uit zogeheten ringonderzoeken voor Salmonella. Elke lidstaat wijst een laboratorium aan, het Nationale Referentie Laboratorium (NRL). Deze NRL is namens dat land verantwoordelijk om Salmonella in monsters van levensmiddelen of dieren aan te tonen en te typeren. Om te controleren of de laboratoria hun werk goed uitvoeren moeten zij onder andere twintig Salmonella-stammen op juiste wijze identificeren. Soms doen ook landen van buiten de Europese Unie vrijwillig mee. In 2018 waren dat de EU-kandidaat-lidstaten Albanië, Republiek NoordMacedonië en Servië, de European Free Trade Association (EFTA)-landen IJsland, Noorwegen en Zwitserland, en Israël. De organisatie van het jaarlijkse ringonderzoek Salmonella-typering is in handen van het Europese Unie Referentie Laboratorium voor Salmonella (EURL-Salmonella). Dit laboratorium is ondergebracht bij het RIVM in Nederland.The National Reference Laboratories (NRLs) of all 28 European Union (EU) Member States performed well in the 2018 quality control test on Salmonella typing. Overall, the EU-NRLs were able to assign the correct name to 97% of the strains tested. In addition to the standard method for typing Salmonella (serotyping), twelve laboratories performed typing at DNA level using Pulsed Field Gel Electrophoresis (PFGE). This more detailed typing method is sometimes needed to trace the source of a contamination. For quality control, participants received another eleven strains of Salmonella to be tested by this method. Ten of the twelve participating laboratories were suitably equipped to use the PFGE method. Since 1992, the NRLs of the EU Member States are obliged to participate in annual quality control tests which consist of Proficiency Tests (PTs) on Salmonella. Each Member State designates a specific laboratory within their national boundaries to be responsible for the detection and identification of Salmonella strains in animals and/or food products. These laboratories are referred to as the National Reference Laboratories (NRLs). The performance of these NRLs in Salmonella typing is assessed annually by testing their ability to identify 20 Salmonella strains. NRLs from countries outside the European Union occasionally participate in these tests on a voluntary basis. The EU-candidate-countries Albania, Republic of North Macedonia and Serbia, EFTA countries Iceland, Norway and Switzerland, and Israel took part in the 2018 assessment. The annual Proficiency Test on Salmonella typing is organised by the European Union Reference Laboratory for Salmonella (EURLSalmonella). The EURL-Salmonella is located at the National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands.European Commission, Directorate-General for Health and Food Safety (DG-SANTE