Boot Swabs Research Articles

Estimation of the sensitivity of various environmental sampling methods for detection of Salmonella in duck flocks

Reports of Salmonella in ducks in the UK currently rely upon voluntary submissions from the industry, and as there is no harmonized statutory monitoring and control programme, it is difficult to compare data from different years in order to evaluate any trends in Salmonella prevalence in relation to sampling methodology. Therefore, the aim of this project was to assess the sensitivity of a selection of environmental sampling methods, including the sampling of faeces, dust and water troughs or bowls for the detection of Salmonella in duck flocks, and a range of sampling methods were applied to 67 duck flocks. Bayesian methods in the absence of a gold standard were used to provide estimates of the sensitivity of each of the sampling methods relative to the within-flock prevalence. There was a large influence of the within-flock prevalence on the sensitivity of all sample types, with sensitivity reducing as the within-flock prevalence reduced. Boot swabs (individual and pool of four), swabs of faecally contaminated areas and whole house hand-held fabric swabs showed the overall highest sensitivity for low-prevalence flocks and are recommended for use to detect Salmonella in duck flocks. The sample type with the highest proportion positive was a pool of four hair nets used as boot swabs, but this was not the most sensitive sample for low-prevalence flocks. All the environmental sampling types (faeces swabs, litter pinches, drag swabs, water trough samples and dust) had higher sensitivity than individual faeces sampling. None of the methods consistently identified all the positive flocks, and at least 10 samples would be required for even the most sensitive method (pool of four boot swabs) to detect a 5% prevalence. The sampling of dust had a low sensitivity and is not recommended for ducks.

Within-herd prevalence thresholds for the detection of Mycobacterium avium subspecies paratuberculosis-positive dairy herds using boot swabs and liquid manure samples.

The control of Johne's disease requires the identification of Mycobacterium avium ssp. paratuberculosis (MAP)-positive herds. Boot swabs and liquid manure samples have been suggested as an easy-to-use alternative to sampling individual animals in order to diagnose subclinical Johne's disease at the herd level, but there is a need to evaluate performance of this approach in the field. Using a logistic regression model, this study aimed to calculate the threshold level of the apparent within-herd prevalence as determined by individual faecal culture, thus allowing the detection of whether a herd is MAP positive. A total of 77 boot swabs and 75 liquid manure samples were taken from 19 certified negative and 58 positive dairy herds. Faecal culture, three different polymerase chain reaction (PCR) methods and the combination of faecal culture with PCR were applied in order to detect MAP. For 50% probability of detection, a within-herd prevalence threshold of 1·5% was calculated for testing both matrices simultaneously by faecal culture and PCR, with the threshold increased to 4·0% for 90% probability of detection. The results encourage the use of boot swabs or liquid manure samples, or a combination both, for identifying MAP-positive herds and, to a certain extent, for monitoring certified Johne's disease-negative cattle herds.

High levels of contamination and antimicrobial-resistant non-typhoidal Salmonella serovars on pig and poultry farms in the Mekong Delta of Vietnam.

We investigated the prevalence, diversity, and antimicrobial resistance (AMR) profiles of non-typhoidal Salmonella (NTS) and associated risk factors on 341 pig, chicken, and duck farms in Dong Thap province (Mekong Delta, Vietnam). Sampling was stratified by species, district (four categories), and farm size (three categories). Pooled faeces, collected using boot swabs, were tested using ISO 6575: 2002 (Annex D). Isolates were serogrouped; group B isolates were tested by polymerase chain reaction to detect S. Typhimurium and (monophasic) serovar 4,[5],12:i:- variants. The farm-level adjusted NTS prevalence was 64·7%, 94·3% and 91·3% for chicken, duck and pig farms, respectively. Factors independently associated with NTS were duck farms [odds ratio (OR) 21·2], farm with >50 pigs (OR 11·9), pig farm with 5-50 pigs (OR 4·88) (vs. chickens), and frequent rodent sightings (OR 2·3). Both S. Typhimurium and monophasic S. Typhimurium were more common in duck farms. Isolates had a high prevalence of resistance (77·6%) against tetracycline, moderate resistance (20-30%) against chloramphenicol, sulfamethoxazole-trimethoprim, ampicillin and nalidixic acid, and low resistance (<5%) against ciprofloxacin and third-generation cephalosporins. Multidrug resistance (resistance against ⩾3 classes of antimicrobial) was independently associated with monophasic S. Typhimurium and other group B isolates (excluding S. Typhimurium) and pig farms. The unusually high prevalence of NTS on Mekong Delta farms poses formidable challenges for control.

Prevalence and risk factors for carriage of antimicrobial-resistant Escherichia coli on household and small-scale chicken farms in the Mekong Delta of Vietnam.

To describe the prevalence of antimicrobial resistance among commensal Escherichia coli isolates on household and small-scale chicken farms, common in southern Vietnam, and to investigate the association of antimicrobial resistance with farming practices and antimicrobial usage. We collected data on farming and antimicrobial usage from 208 chicken farms. E. coli was isolated from boot swab samples using MacConkey agar (MA) and MA with ceftazidime, nalidixic acid or gentamicin. Isolates were tested for their susceptibility to 11 antimicrobials and for ESBL production. Risk factor analyses were carried out, using logistic regression, at both the bacterial population and farm levels. E. coli resistant to gentamicin, ciprofloxacin and third-generation cephalosporins was detected on 201 (96.6%), 191 (91.8%) and 77 (37.0%) of the farms, respectively. Of the 895 E. coli isolates, resistance to gentamicin, ciprofloxacin and third-generation cephalosporins was detected in 178 (19.9%), 291 (32.5%) and 29 (3.2%) of the isolates, respectively. Ciprofloxacin resistance was significantly associated with quinolone usage (OR = 2.26) and tetracycline usage (OR = 1.70). ESBL-producing E. coli were associated with farms containing fish ponds (OR = 4.82). Household and small farms showed frequent antimicrobial usage associated with a high prevalence of resistance to the most commonly used antimicrobials. Given the weak biocontainment, the high prevalence of resistant E. coli could represent a risk to the environment and to humans.

Emission of ESBL/AmpC-producing Escherichia coli from pig fattening farms to surrounding areas

The presence of ESBL/AmpC-producing Escherichia coli in livestock such as pigs has been known for some time. However, to date there is little information about the transmission of these resistant bacteria between pig farms and their surroundings. Thus, the aim of this study was to explore this topic by investigating seven German pig fattening farms. Samples from outside (including ground surfaces, ambient air, slurry and digestate from biogas plants) and, in parallel, from inside the pig barns (including pig feces, dust, barn air, flies and mice feces) were examined for ESBL/AmpC-producing E. coli and selected isolates were compared by pulsed-field gel electrophoresis (PFGE) analysis. 14/17 (82.4%) slurry samples and three of four samples of digestate from biogas plants tested positive for ESBL/AmpC-producing E. coli. In the vicinity of the pig barns these resistant bacteria were detected in 14/87 (16.1%) boot swabs taken from various ground surfaces and in 2/36 (6%) ambient air samples. Inside the pig barns, 6/63 (9.5%) barn air samples and a small proportion of flies and mice feces samples were ESBL/AmpC-positive. PFGE analysis proved fecal emission as well as a possible spread via flies, as identical ESBL-E. coli isolates were detected in slurry and on fertilized fields, as well as in flies and pooled feces from inside the barn and slurry. Contaminated slurry presented the major emission source for ESBL/AmpC-producing E. coli in the pig fattening farms, but a spread via the airborne route or via different vectors also seems possible.

A review of the official sampling of flocks of laying hens in the Salmonella National Control Programme in Great Britain

1. In line with European legislation and the UK National Control Programme for Salmonella, poultry farms are sampled to establish their Salmonella status. Regular samples are collected by the farmer (operator), with annual routine (official) samples being collected by the competent authority to verify achievement of the Salmonella programme reduction target.2. To confirm sampling was being carried out effectively, a questionnaire-based survey was conducted. The aim was to identify any complicating factors the samplers encountered and the decisions made in these circumstances.3. There was good compliance with the official sampling visits, with few delays reported. However, farm-specific clothing/separate boots for non-caged houses were rarely provided by the operator, whereas boot dips and hand washing facilities were usually available. The collection of dust was often a problem for official samplers, operator boot swabs were not always moistened before sampling and both sampler groups did not always follow the recommended method for the collection of faeces from belts and scrapers.4. Overall, there was a good application of the sampling protocol, although a few areas for improvement were identified.

Extended-spectrum beta-lactamases (ESBL)/AmpC beta-lactamases-producing Escherichia coli in German fattening pig farms: a longitudinal study.

The presence of ESBL/AmpC-producing Enterobacteriaceae in healthy livestock, such as pigs, was frequently reported worldwide in the last years. The development and potential spread of these resistant microorganisms in farm animals is discussed critically. Therefore, the main objectives of this longitudinal study were to determine potential sources and prevalence dynamics of ESBL/AmpC-producing Escherichia coli in seven German ESBL/AmpC-positive conventional fattening pig farms in the course of the fattening period. Samples tested were taken at three different times within one finishing fattening period and included 20 individual faeces samples as well as various samples of the animals' housing environment such as pooled faeces, boot swabs, dust and environmental swabs. In individual faeces average carriage levels of 45%, 29% and 36% at the three sampling times were accompanied by decreasing faecal counts from 2.97 x 10(4) cfu/g at the first to 2.17 x 10(3) cfu/g at the third visit. In the animals' housing environment 47.6% of pooled faeces and boot swab samples respectively and 5.9% of environmental swabs but none of the dust samples were tested positive. Altogether 228 E. coli isolates were analysed by combination disc tests, PCR and partly via sequencing.Thereby, a novel gene bla(TEM-206) was detected. This study shows different detection levels of ESBL/AmpC-producing E. coli amongst the different farms and in the course of the fattening period. Pooled faeces and boot swab samples but not dust samples seem to be appropriate to assess the herd status of pigs with respect to ESBL/AmpC-producing Escherichia coli.

Prevalence and potential risk factors for the occurrence of cefotaxime resistant Escherichia coli in German fattening pig farms—A cross-sectional study

A cross-sectional study concerning farm prevalence and risk factors for the count of cefotaxime resistant Escherichia coli (E. coli) (CREC) positive samples per sampling group on German fattening pig farms was performed in 2011 and 2012. Altogether 48 farms in four agricultural regions in the whole of Germany were investigated. Faecal samples, boot swabs and dust samples from two sampling groups per farm were taken and supplemental data were collected using a questionnaire. On 85% of the farms, at least one sample contained cefotaxime resistant E. coli colonies. Positive samples were more frequent in faeces (61%) and boot swabs (54%) than in dust samples (11%). Relevant variables from the questionnaire were analysed in a univariable mixed effect Poisson regression model. Variables that were related to the number (risk) of positive samples per sampling group with a p-value <0.2 were entered in a multivariable model. This model was reduced to statistically significant variables via backward selection. Factors that increased the risk for positive samples involved farm management and hygienic aspects. Farms that had a separate pen for diseased pigs had a 2.8 higher mean count of positive samples (95%-CI [1.71; 4.58], p=0.001) than farms without an extra pen. The mean count was increased on farms with under-floor exhaust ventilation compared to farms with over floor ventilation (2.22 [1.43; 3.46], p=0.001) and more positive samples were observed on farms that controlled flies with toxin compared to farms that did not (1.86 [1.24; 2.78], p=0.003). It can be concluded, that CREC are wide spread on German fattening pig farms. In addition the explorative approach of the present study suggests an influence of management strategies on the occurrence of cefotaxime resistant E. coli.

Transmission of ESBL/AmpC-producing Escherichia coli from broiler chicken farms to surrounding areas

Although previous studies have demonstrated high carriage of ESBL/AmpC-producing Escherichia coli in livestock, especially in broiler chickens, data on emission sources of these bacteria into the environment are still rare. Therefore, this study was designed to systematically investigate the occurrence of ESBL/AmpC-producing E. coli in slurry, air (inside animal houses), ambient air (outside animal houses) and on soil surfaces in the areas surrounding of seven ESBL/AmpC-positive broiler chicken fattening farms, including investigation of the possible spread of these bacteria via the faecal route and/or exhaust air into the environment. Seven German broiler fattening farms were each investigated at three points in time (3–36h after restocking, 14–18 and 26–35 days after housing) during one fattening period. The occurrence of ESBL/AmpC genes in the investigated samples was confirmed by PCR, detecting blaCTX-M, blaSHV, blaTEM and blaCMY-genes, and, if necessary, by sequencing and/or the disc diffusion method. The results showed a wide spread of ESBL/AmpC-producing E. coli in broiler farms, as well as emissions into the surroundings. 12 out of 14 (86%) slurry samples were positive for ESBL/AmpC-producing E. coli. Additionally, 28.8% (n=23/80) of boot swabs taken from various surfaces in the areas surrounding of the farms as well as 7.5% (n=3/40) of the exhaust air samples turned out to be positive for these microorganisms. Moreover, a small proportion of air samples from inside the barns were ESBL/AmpC-positive. By comparing selected isolates using pulsed field gel electrophoresis, we proved that faecal and airborne transfer of ESBL/AmpC-producing microorganisms from broiler fattening farms to the surrounding areas is possible. Two isolates from farm G2 (slurry and boot swab 50m downwind), two isolates from farm G3 (slurry and individual animal swab) as well as two isolates from farm G6 (air sample in the barn and air sample 50m downwind) showed 100% similarity in PFGE analysis.

Vertical transmission of Escherichia coli carrying plasmid-mediated AmpC (pAmpC) through the broiler production pyramid

In Sweden the prevalence of Enterobacteriaceae with transferable resistance to extended-spectrum cephalosporins (ESCs) is low. However, in broilers ESC-resistant Escherichia coli is common, with a clear dominance of blaCMY-2. Antimicrobials are rarely used in broiler production in Sweden and cephalosporins are never used. Introduction through imported breeding stock and subsequent vertical transmission of the bacteria through the production pyramid could be one explanation for this high prevalence. To test this hypothesis, paper linings from imported flocks of grandparent animals were screened for the presence of ESC-resistant E. coli and a positive flock, together with its progeny, was followed longitudinally through the production pyramid using boot swabs. The relationship of isolated ESC-resistant E. coli was investigated using multiple-locus variable number tandem repeat analysis (MLVA). ESC-resistant E. coli carrying blaCMY-2 was isolated from six out of eight imported flocks of grandparent animals. One clone of E. coli carrying blaCMY-2 occurred in all levels of the production pyramid and in flocks of imported grandparent animals. E. coli carrying blaCMY-2 is frequently present among grandparent animals imported to Sweden for breeding purposes. The occurrence of one clone in all levels of the production pyramid indicates that its introduction through imported breeding stock and vertical transmission through the production pyramid could be one explanation for the high proportion of Swedish broilers colonized with ESC-resistant E. coli.

Low-Cost Monitoring of Campylobacter in Poultry Houses by Air Sampling and Quantitative PCR

The present study describes the evaluation of a method for the quantification of Campylobacter by air sampling in poultry houses. Sampling was carried out in conventional chicken houses in Poland, in addition to a preliminary sampling in Denmark. Each measurement consisted of three air samples, two standard boot swab fecal samples, and one airborne particle count. Sampling was conducted over an 8-week period in three flocks, assessing the presence and levels of Campylobacter in boot swabs and air samples using quantitative real-time PCR. The detection limit for air sampling was approximately 100 Campylobacter cell equivalents (CCE)/m3. Airborne particle counts were used to analyze the size distribution of airborne particles (0.3 to 10 μm) in the chicken houses in relation to the level of airborne Campylobacter. No correlation was found. Using air sampling, Campylobacter was detected in the flocks right away, while boot swab samples were positive after 2 weeks. All samples collected were positive for Campylobacter from week 2 through the rest of the rearing period for both sampling techniques, although levels 1- to 2-log CCE higher were found with air sampling. At week 8, the levels were approximately 10(4) and 10(5) CCE per sample for boot swabs and air, respectively. In conclusion, using air samples combined with quantitative real-time PCR, Campylobacter contamination could be detected earlier than by boot swabs and was found to be a more convenient technique for monitoring and/or to obtain enumeration data useful for quantitative risk assessment of Campylobacter.

Boot swabs to collect environmental samples from common locations in dairy herds for Mycobacterium avium ssp. paratuberculosis (MAP) detection

The aim of the present study was the examination of the boot swab sampling technique for the collection of environmental material in order to identify Mycobacterium avium ssp. paratuberculosis (MAP)-infected herds. Eight dairy herds were included into the study. Four of them had a well-known history of MAP-infection from a herd surveillance programme conducted since 2006. Cows in these herds were repeatedly tested positive in Pourquier® MAP-ELISA (Pourquier, Montepellier, France); in some MAP could be isolated in individual faecal culture despite that symptoms of paratuberculosis were never reported. In four presumably negative herds nearly all cows were repeatedly tested serologically negative for MAP. The pathogen was never isolated from faecal samples of cows by culture. The study was initiated with the aim of standardising environmental samples as a herd diagnostics, in which overall 130 pairs of boot swab samples from the cows' surroundings were taken In 58 of 64 swab samples (90·6%) from confirmed MAP-infected herds the organism could be isolated by mycobacterial culture of the boot swab. Contrarily, in 66 samples from presumably MAP-negative herds only one swab was positive (1·5%). The utilisation of boot swabs as a standardised technique for environmental sampling offers an effective and inexpensive tool for identifying herds infected with MAP. This is the first report of using boot swabs for the collection of environmental samples for MAP- detection in cattle herds. This easy to perform technique enables the economical detection of MAP herd status.

Estimation of the sensitivity of environmental sampling for detection ofSalmonellain commercial layer flocks post-introduction of national control programmes

A key element of national control programmes (NCPs) for Salmonella in commercial laying flocks, introduced across the European Union, is the identification of infected flocks and holdings through statutory sampling. It is therefore important to know the sensitivity of the sampling methods, in order to design effective and efficient surveillance for Salmonella. However, improved Salmonella control in response to the NCP may have influenced key factors that determine the sensitivity of the sampling methods used to detect Salmonella in NCPs. Therefore the aim of this study was to compare estimates of the sensitivity of the sampling methods using data collected before and after the introduction of the NCP, using Bayesian methods. There was a large reduction in the sensitivity of dust in non-cage flocks between the pre-NCP studies (81% of samples positive in positive flocks) and post-NCP studies (10% of samples positive in positive flocks), leading to the conclusion that sampling dust is not recommended for detection of Salmonella in non-cage flocks. However, cage dust (43% of samples positive in positive flocks) was found to be more sensitive than cage faeces (29% of samples positive in positive flocks). To have a high probability of detection, several NCP-style samples need to be used. For confirmation of Salmonella, five NCP faecal samples for cage flocks, and three NCP faecal boot swab samples for non-cage flocks would be required to have the equivalent sensitivity of the EU baseline survey method, which was estimated to have an 87% and 75% sensitivity to detect Salmonella at a 5% within-flock prevalence in cage and non-cage flocks, respectively.

Estimation of the Prevalence of Salmonella Species on the Slatted Area Compared to the Scratch Area of Broiler Breeder Chicken Houses

With the objective of detecting Salmonella species in the poultry house environment, sampling broiler breeder houses in the two-thirds slatted area and the one-third scratch area with pine shavings bedding can be difficult. The slatted area is where the females, consisting of approximately 90% of the population, eat, drink, and spend the majority of their time. The scratch area is where the males eat and drink, as well as where mating and mortality occur. Besides the nest boxes, the female feeders and water lines make the slatted areas more difficult to sample. However, it is important to take samples from the area with the greatest likelihood of isolating Salmonella. Therefore, boot swab samples were collected from 21 commercial broiler breeder chicken houses representing three different companies in north Georgia to estimate the prevalence of Salmonella on the slat vs. the scratch area in each chicken house. Every house sampled had a central scratch area covered with litter and two elevated slat areas constructed of wood. Four boot swab samples were collected on each side slat area by walking the entire length of the house for each swab. Eight samples were collected in the same manner from the scratch area. Results of 335 total samples were acquired, 167 of which were obtained from the slat area and 168 of which came from the scratch area, yielding 242 total Salmonella isolations. Salmonella was found in 117 of the slat samples, representing 70.1%, compared to 125 of the scratch area samples, representing 74.4%. Both the univariate (P = 0.311) and the multivariable (P = 0.303) analysis showed that sampling location was not associated with Salmonella prevalence.

Prevalence of Extended-Spectrum β-Lactamase-Producing Escherichia coli on Bavarian Dairy and Beef Cattle Farms

Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli strains are believed to be widely distributed among humans and animals; however, to date, there are only few studies that support this assumption on a regional or countrywide scale. Therefore, a study was designed to assess the prevalence of ESBL-producing E. coli in dairy cows and beef cattle in the southern part of Bavaria, Germany. The study population included 30 mixed dairy and beef cattle farms and 15 beef cattle farms. Fecal samples, boot swabs, and dust samples were analyzed for ESBL-producing E. coli using selective media. PCR was performed to screen for CTX-M and ampC resistance genes. A total of 598 samples yielded 196 (32.8%) that contained ESBL-producing E. coli, originating from 39 (86.7%) of 45 farms. Samples obtained from mixed farms were significantly more likely to be ESBL-producing E. coli positive than samples from beef cattle farms (fecal samples, P < 0.001; boot swabs, P = 0.014; and dust samples, P = 0.041). A total of 183 isolates (93.4%) of 196 ESBL-producing E. coli-positive strains harbored CTX-M genes, CTX-M group 1 being the most frequently found group. Forty-six additional isolates contained ampC genes, and 5 of the 46 isolates expressed a blaCMY-2 gene. The study shows that ESBL-producing E. coli strains are commonly found on Bavarian dairy and beef cattle farms. Moreover, to our knowledge, this is the first report of the occurrence of blaCMY-2 in cattle in Germany.

Occurrence of Livestock-Associated Methicillin-Resistant Staphylococcus aureus in Turkey and Broiler Barns and Contamination of Air and Soil Surfaces in Their Vicinity

The emission of microorganisms, especially resistant bacteria such as methicillin-resistant Staphylococcus aureus (MRSA), from poultry farms is of public interest, and its occurrence and relevance are controversially discussed. So far, there are limited data on this issue. In this study, we investigated the occurrence of livestock-associated (LA)-MRSA inside and outside previously tested MRSA-positive poultry barns in Germany. In total, five turkey and two broiler fattening farms were investigated four and three times, respectively. In a longitudinal study during one fattening period, samples were collected from animals, the animals' environment inside the barn, including the air, and the barns' surroundings, such as ambient air and boot swabs of ground surfaces at different distances from the barn. Moreover, a cross-sectional study was carried out once inside the barns on five turkey and four broiler farms during the last third of the fatting period. In the cross-sectional study, LA-MRSA was detected in the air of most barns (7 of 9, 77.8%), as well as in many samples originating from animals, with detections levels of 50 to 54% in broiler and 62 to 77% in turkey farms. In the longitudinal study, LA-MRSA was found in the ambient air outside two turkey barns and on the ground surface on the downwind side of many (44.4%) turkey and broiler farms. The same spa types of isolates were observed inside and outside the barns. Transmission of MRSA within poultry farms, as well as emission via the airborne route, seems to be possible.

Characteristics of ciprofloxacin and cephalosporin resistant Escherichia coli isolated from turkeys in Great Britain

1. A field study was performed to investigate the presence and characteristics of ciprofloxacin-resistant, extended spectrum β-lactamase (ESBL) and AmpC Escherichia coli from turkeys in Great Britain. E. coli were isolated from ∼9000 boot swab samples from 27 different farms owned by four different companies. Between 1 and 14 visits were made to each farm (mean 3) at between 0 and 15 m intervals (mean ∼ 5 m). 2. CHROMagar ECC with and without ciprofloxacin or cephalosporin antibiotics was used as selective isolation media. Representative isolates with different phenotypes were tested for mutations in gyrA and for: qnrA, B, S, qepA and aac(6′)-Ib genes, for ESBL phenotype, the presence of bla CTX-M genes and plasmid type, and for ampC genes. Representative ciprofloxacin-resistant and CTX-M isolates were further tested for serotype and PFGE type. On ciprofloxacin selective media 55% of samples yielded ciprofloxacin resistant E. coli and of those further analysed, most had ciprofloxacin MICs >4 mg/l and mutations in gyrA. 3. For the different companies, the mean number of samples per farm with cefoxitin- or cefotaxime-resistant isolates ranged from 1·0% to 61·9% and 4·7% to 31·7% respectively. Cefotaxime-resistance was most commonly associated with an ESBL phenotype, a CTX-M-1 or CTX-M-14 sequence type and an I1-γ or K plasmid inc type. The mechanism of cefoxitin resistance was not determined for most isolates, but where determined it was bla CMY-2. 4. PFGE and serotyping showed clonally-related isolates persisting over multiple visits suggesting both more prudent use of antibiotics and improved farm hygiene are needed to address the issue of antimicrobial resistance in isolates from turkeys.

Comparison of Different Sampling Strategies and Laboratory Methods for the Detection of C. jejuni and C. coli from Broiler Flocks at Primary Production

The objective of the study was to evaluate the performance of different combinations of sample type, transport medium and culture methods for the recovery of Campylobacter jejuni and C. coli from broiler flocks at primary production. Boot swabs moistened with one of four different transport media [maximum recovery diluent (n=120), Exeter broth (EX) (n=120), buffered peptone water (n=120) and modified semi-solid Cary-Blair (n=120)], caecal samples (n=40) and faecal samples (n=120) from 40 broiler flocks were compared and sensitivity estimates obtained using a Bayesian model. Samples were cultured onto mCCDA before and after enrichment in EX and incubated microaerobically at 41.5°C. Campylobacter suspect colonies were identified to the species level by multiplex PCR. Results from the Bayesian model indicated that boot swabs after enrichment had higher sensitivity (90-94%) than caecal contents before or after enrichment (84% and 89%, respectively) and faecal samples after enrichment (82%) for the detection of Campylobacter spp., although these differences were not statistically significant. Enrichment significantly increased the sensitivity of boot swab and caecal samples for detection of Campylobacter spp. and C. jejuni, respectively. However, the enrichment of caecal samples resulted in a significant decrease in the sensitivity of these samples for detection of C. coli. There was much greater variation in the sensitivity estimates of the methods for detecting C. coli than for C. jejuni, and the ranking of methods was different between the two species. Boot swabs gave the best sensitivity values for detection of C. jejuni, and enrichment culture of faecal samples was the most sensitive method for detection of C. coli.

Ciprofloxacin resistance in E. coli isolated from turkeys in Great Britain

Fluoroquinolones are a widely used group of antimicrobials in both human and animal medicine, with ciprofloxacin being a critically important fluoroquinolone for serious human infections. The present study reports on a 1-year survey for the presence of ciprofloxacin-resistant Escherichia coli in turkeys from Great Britain. Boot swabs were taken from 442 turkey flocks comprised of 125 breeding flocks and 317 meat flocks from 337 different farms over a 1-year period (2006 to 2007). CHROMagar ECC containing 1 mg/l ciprofloxacin was used to obtain ciprofloxacin-resistant isolates. Isolates were tested for sensitivity to 16 different antimicrobials. Isolates with ciprofloxacin minimum inhibitory concentrations ≥8 mg/l were tested for mutations in gyrA by polymerase chain reaction and DNA sequencing. Selected isolates were tested by multiplex polymerase chain reaction for qnrA, qnrB and qnrS, qepA and aac(6′)-Ib-cr genes. Conjugations were performed to assess the transferability of resistance to quinolones. Ciprofloxacin-resistant E. coli was found in 22.4% of turkey breeding flocks and 60.9% of meat flocks. Two main mutations in gyrA, as well as a range of silent mutations, were identified in resistant isolates. Flocks with transferable resistance genes qnrB, qnrS, and aac(6′)-Ib-cr were found at a low flock prevalence of 4.2%, 1.6% and 1.0%, respectively; however, under laboratory conditions only transfer of qnrS genes could be demonstrated. This work has confirmed the occurrence of ciprofloxacin-resistant E. coli strains throughout turkey breeding and meat flocks, with almost one-third of E. coli isolates being resistant to ciprofloxacin. Of those, more than 87% were also resistant to three or more antimicrobial classes.

Occurrence of MRSA in air and housing environment of pig barns

A high prevalence of MRSA among farm animals, especially pigs, has been observed for some time. However, knowledge on transmission routes of MRSA in livestock production is still scarce. Therefore, the aim of this study was to determine the occurrence of MRSA in pig house air as well as in samples from pigs and their housing environment in 27 MRSA positive pig barns of different sizes and production types.In 85.2% of all barns MRSA was detected in the animal house air. Impingement turned out to be a more sensitive sampling technique than filtration. Other environmental samples such as boot swabs or faeces showed prevalences of MRSA from 55.6% to 85.2% at sample level. The level of MRSA was 88.3% for pooled and 82.1% for single nasal swabs, in skin swabs the one was 87.7%, the others was 78.7%. Spa typing of isolates from air and nasal swabs showed predominantly spa types t011 and t034. MRSA prevalences in pigs as well as in various environmental samples were significantly higher in fattening farms than in breeding farms. This study provides good reference that there could be an airborne transmission of MRSA within pig herds indicating a potential contamination of the environment of barns.