Campylobacter-positive Flocks Research Articles

The effects of Campylobacter numbers in caeca on the contamination of broiler carcasses with Campylobacter

For the presence and number of Campylobacter, 18 broiler flocks were sampled over a period of 18 months. A total of 70% of the flocks were positive for Campylobacter, with higher prevalence found in summer and autumn, compared to winter and spring. Positive flocks showed contamination rates above 90%, in negative flocks this was lower, mostly below 50%. The enumeration showed a decrease in Campylobacter during processing of positive flocks. The numbers were highest in carcasses after scalding/defeathering (mean 5.9 log 10 cfu/carcass) and dropped by 0.7 log 10 cfu/carcass after chilling. A positive correlation was observed between the number of Campylobacter present in the caeca and the number of bacteria present on carcasses and cut products. When a negative flock was slaughtered after Campylobacter positive flocks, the number of positive samples was higher compared to the case when a negative flock had been slaughtered previously. C. jejuni was isolated from 73.6% of the poultry samples.

Antimicrobial Resistance ofCampylobacterSpp. Isolated from Broiler Flocks in Iceland 2001–2005

Minimum inhibitory concentrations of six antimicrobial agents were determined for one Campylobacter sp. isolate from each of the 362 Campylobacter-positive commercial chicken flocks in Iceland in the years 2001-2005. Of all isolates tested, 6.9% were resistant, although none were multiresistant. Resistance to ampicillin was most commonly observed (3.6%) followed by resistance to enrofloxacin (3%), nalidixic acid (1.9%), and oxytetracyclin (0.3%), with cross-resistance between enrofloxacin and nalidixic acid. All isolates were susceptible to erythromycin and gentamicin. Resistance rates among Campylobacter coli isolates (7/13 or 53.8%) were much higher than among Campylobacter jejuni isolates (18/349 or 5.2%), and resistance patterns differed. Resistant strains were compared using pulsed field gel electrophoresis. Macrorestriction with SmaI and KpnI restriction enzymes yielded 13 different pulsotypes, none of which indicated a predominant genotype. Specific pulsotypes with uniform resistance patterns arising on geographically separated farms indicate clonal dissemination. Although resistance levels were low and similar to that seen in the other Nordic countries, further research on this matter is needed as there is no antimicrobial selective pressure in chicken farming in Iceland.

Evaluation of Logistic Processing To Reduce Cross-Contamination of Commercial Broiler Carcasses with Campylobacter spp.

Cross-contamination of broiler carcasses with Campylobacter is a large problem in food production. Here, we investigated whether the contamination of broilers carcasses from Campylobacter-negative flocks can be avoided by logistic scheduling during processing. For this purpose, fecal samples were collected from several commercial broiler flocks and enumerated for Campylobacter spp. Based on enumeration results, flocks were categorized as Campylobacter negative or Campylobacter positive. The schedule of processing included the testing of Campylobacter-positive flocks before or after the testing of Campylobacter-negative flocks. During processing, flocks were also sampled for Campylobacter spp. before and after chilling. Campylobacter strains were identified with multiplex PCR and analyzed for relatedness with pulsed-field gel electrophoresis. Our results show that Campylobacter-negative flocks were indeed contaminated with Campylobacter strains originating from previously processed Campylobacter-positive flocks. Campylobacter isolates collected from carcasses originating from different farms processed on the same day showed similar pulsed-field gel electrophoresis patterns, confirming cross-contamination. These findings suggest that a simple logistic processing schedule can preserve the Campylobacter-negative status of broiler carcasses and result in products with enhanced food safety.

Prevalence and risk factors for Salmonella spp. and Campylobacter spp. caecal colonization in broiler chicken and turkey flocks slaughtered in Quebec, Canada

We conducted an observational study to estimate prevalence and risk factors for Salmonella spp. and Campylobacter spp. caecal colonization in poultry. Eighty-one broiler chicken and 59 turkey flocks selected among flocks slaughtered in the province of Quebec, Canada, were included in the study. Flock status was evaluated by culturing pooled caecal contents from about 30 birds per flock. Exposure to potential risk factors was evaluated with a questionnaire. Odds ratios were computed using multivariable logistic regression. The prevalence of Salmonella-positive flocks was 50% (95% CI: 37, 64) for chickens and 54% (95% CI: 39, 70) for turkeys, respectively. Odds of Salmonella colonization were 2.6 times greater for chicken flocks which failed to lock the chicken house permanently. In turkeys, odds of Salmonella colonization were 4.8–7.7 times greater for flocks which failed to be raised by ≤2 producers with no other visitors allowed onto the premises, or origin from a hatchery. The prevalence of Campylobacter-positive flocks was 35% (95% CI: 22, 49) for chickens and 46% (95% CI: 30, 62) for turkeys. Odds of colonization were 4.1 times higher for chicken flocks raised on farms with professional rodent control and 5.2 times higher for flocks with manure heap >200 m from the poultry house, and also increased with the number of birds raised per year on the farm and with the age at slaughter. For turkeys, odds of Campylobacter flock colonization were 3.2 times greater in flocks having a manure heap at ≤200 m from poultry house and 4.2 times greater in flocks drinking unchlorinated water.

Frequency and Enumeration of Campylobacter Species from Processed Broiler Carcasses by Weep and Rinse Samples

Frequency and numbers of Campylobacter spp. were assessed per freshly processed, contaminated broiler carcass. Campylobacter-positive flocks were identified by cecal sample analysis at slaughter. These flocks had been tested as Campylobacter negative at 4.1 +/- 0.9 d prior to slaughter. Levels of contamination were estimated using 2 sampling approaches per carcass: (1) free weep fluids and (2) whole-carcass, 100 mL of distilled water rinses. Estimations of counts were determined by directly plating dilutions of weeps and rinses onto Campy-Cefex agar and incubating the plates at 41.5 degrees C under microaerobic atmosphere. Confirmation was provided by latex agglutination to quantify levels per milliliter of weep and per 100 mL of rinse. Thirty-two slaughter groups ( approximately 20 carcasses per group) were compared from 2003 to 2004. The Campylobacter-positive weep frequency was 84.8%, whereas the frequency for rinse samples was 74.4% (P < 0.001). Enumeration of Campylobacter spp. on positive samples ranged from 0.70 to 6.13 log(10) cfu/mL of weep (geometric mean of 2.84) and from 2.30 to 7.72 log(10) cfu/100 mL of rinse (geometric mean of 4.38). The correlations between weep and rinse were 0.814 with 0.5 mL of rinse and 0.6294 when applying 0.1 mL of rinse The quantitative regression analyses for these 2 corresponding tests were log(10) rinse (for 0.5 mL of inoculum) = 1.1965 log(10) weep + 0.4979, and log(10) rinse (for 0.1 mL of inoculum) = 1.322 log(10) weep - 0.1521. FlaA SVR sequencing of isolates indicated that the same genotypes were found in weep and rinse samples. Weep and rinse sampling led to different proportions of Campylobacter-positive carcasses detection, but we demonstrated that this difference was reduced by increasing the amount of rinse fluid used for plating.

Genotyping of Campylobacter jejuni from Broiler Carcasses and Slaughterhouse Environment by Amplified Fragment Length Polymorphism

We examined the occurrence and diversity of Campylobacter jejuni on broiler carcasses during slaughter of an infected flock and in the slaughterhouse environment during slaughter and postdisinfection before a new production run. During the slaughter of a known C. jejuni infected broiler flock, samples were taken from broiler carcasses at 7 different stages during the process. Thirty-seven sites in the slaughterhouse environment were sampled both during process and postdisinfection. The samples were analyzed for C. jejuni, and genetic fingerprinting was performed using amplified fragment length polymorphism. All carcass samples were positive. Of the environmental samples collected during slaughter, 89% were positive; 100% of those from the arrival, stunning, scalding, defeathering, and evisceration facilities and 67% of those from the cooling and sorting facilities. Postdisinfection, 41% of the samples were positive; 71% of those from the arrival and stunning area, 60% of those from the scalding and defeathering area, and 20% of those from the evisceration, cooling, and sorting area. The C. jejuni isolates (n = 60) recovered were grouped into 4 different amplified fragment length polymorphism clones with a similarity index of 95% or greater. All isolates obtained from the flock and 94% of the isolates obtained from the environment during slaughtering belonged to clone A, whereas 1 environmental isolate belonged to each of the clones B and C. Isolates from clones A, B, and D were present postdisinfection. Only clone B was detected on flocks slaughtered during the previous week. The high level and continuous presence of Campylobacter in the environment constitutes a risk for transmission to negative carcasses. In Norway, where above 96% of the broiler flocks are Campylobacter-negative, this aspect is of special importance. The ability of Campylobacter to remain in the slaughterhouse environment through washing and disinfection is associated with constructional conditions of equipment and buildings, complicating cleaning and providing sufficient moisture. To reduce the probability of the workers acquiring campylobacteriosis, precautions should be taken when slaughtering Campylobacter-positive flocks.

Transmission of Campylobacter spp. in a poultry slaughterhouse and genetic characterisation of the isolates by pulsed-field gel electrophoresis

1. Contamination of retail products with Campylobacter spp. during the slaughter of poultry is a well-known problem of product hygiene. Mechanical evisceration often leads to intestinal rupture and discharge of gut contents, which can contain zoonotic and human pathogens. Processes along the slaughter line cause aerosols and airborne droplets, containing bacterial loads. 2. To estimate the possible transmission routes of intestinal Campylobacter, 36 measurements of the bioaerosol (Andersen sampler and SKC BioSampler), 30 cloacal (of three flocks), 10 equipment and 4 sedimentation samples were tested for the presence of Campylobacter species. 3. The results imply that, in addition to contaminated equipment, which was Campylobacter-positive in 80% of cases, aerosols with peak values of 4·0 × 104 (test series 1) and 1·4 × 104 (test series 2) CFU/m3 also provide a potential vector for horizontal transmission. 4. To explore the genetic similarities of isolates from different origins, 18 isolates recovered from air, 26 cloacal, 8 equipment and 4 sedimentation isolates were analysed by pulsed-field gel electrophoresis (PFGE), using the restriction enzymes Sma I and Sal I. The similarity of cloacal isolates with isolates from equipment, air and sediment, suggest that the contamination is of intestinal origin. 5. There were direct links between Campylobacter-positive flocks and the presence of the same strains in the aerosol of the slaughter hall. Air as a potential source for microbial transmission must be taken into account.

Pulsed-field gel electrophoresis types of Campylobacter spp. in Danish turkeys before and after slaughter

In this study, seven Danish turkey flocks were investigated at the farm, on arrival to the slaughterhouse, and during and after slaughter. Flocks were selected based on their Campylobacter spp. status at the farm and three Campylobacter negative and four Campylobacter positive flocks were included in the study. At the slaughterhouse, 70–75 samples were collected at different points from the shackling station to packaging of the final meat cuttings. Samples included cloacal swabs, neckskin, liver, heart, meat and environmental samples. Detection of Campylobacter . was carried out by conventional culture and by the EiaFoss system (Foss Electric, Hilleroed, Denmark) for detecting Campylobacter spp. in food, using Preston Broth as enrichment medium. The two methods were compared and sensitivities and specificities were calculated using the conventional culture as gold standard. The three negative flocks were consistently negative from the farm and all through processing. Among the samples from the positive flocks, the frequency of positive samples obtained at the slaughterhouse varied. The frequency of positive samples obtained from the four positive flocks varied and was found to be 4%, 49%, 87% and 96%, respectively. In 31 out of 424 samples, discrepancies were observed between results obtained by the EiaFoss system and the conventional culture technique. The sensitivity for the EiaFoss system was calculated to be 0.94 for meat and neckskin samples. A total of 161 strains were genotyped by pulsed-field gel electrophoresis (PFGE) in order to investigate possible changes in carriage of Campylobacter spp. strains during processing. In three flocks, only one PFGE type was encountered in samples collected at the farm level and, in one flock, two different types were observed. In two flocks, the strain from the farm was also isolated in samples collected at the slaughterhouse. Changes in carriage were observed in two flocks during processing, in particular post chilling.

Distribution of Campylobacter jejuni Penner serotypes in broiler flocks 1998-2000 in a small Danish community with special reference to serotype 4-complex.

During the period January 1998-December 2001, all Danish broiler flocks were monitored bacteriologically for thermophilic campylobacters and isolates were stored at -80 degrees C. Six neighbouring broiler farms in a small community were selected for detailed examination of all Campylobacter jejuni isolated (n = 180) from these farms during 1998-2000 using Penner serotyping and pulsed-field gel electrophoresis (PFGE). The area and the farms were selected according to their prevalence of campylobacter so that both farms with low and high frequencies of campylobacter positive flocks were included in the study. The frequency of campylobacter positive flocks on the six farms ranged from 24.5 to 72.7%. One hundred and eighty of the isolates were C. jejuni (included in this study), 14 isolates were C. coli whereas 7 isolates belonged to other species but were not further identified. By serotyping of all C. jejuni 56 isolates (31.5%) were assigned to the 4-complex, 32 isolates (18.0%) to serotype 2, 12 isolates (6.7%) to serotype 11, and 11 isolates (6.2%) were assigned to serotype 12. In three farms, 4-complex was the most prevalent serotype, in one farm it was the second most frequently isolated serotype, while serotypes 2 and 1,44, respectively, were the most frequently isolated from the two remaining farms. This serotype distribution differed from the overall country-wide distribution where serotypes 2 and 1,44 are the most prevalent. All serotype 4-complex isolates from the six selected farms were compared by PFGE to serotype 4-complex isolates from the rest of the country. The results showed that there was a high level of diversity among isolates from the whole country, whereas isolates from the six farms were very homogeneous and only displayed one or a few different PFGE patterns on each farm. It is suggested that certain campylobacter clones persist in a confined geographical area, probably at the farm, and that the broiler houses may be repeatedly infected with a few C. jejuni clones during succeeding broiler flocks. New clones may be introduced, however, the sources and vehicles are yet unknown.

RAPD PCR Type of Campylobacter Isolates from Cecum Contents of Broiles Chickens

In this investigation we typed Campylobacter isolates by RAPD PCR from the cecum contents of broiler chickens obtained at a slaughterhouse in Shizuoka prefecture. Campylobacter was isolated from 91 (56.9%) out of 160 birds from five out of eight flocks . Of the five Campylobacter positive flocks, three flocks possessed multiple RAPD types of Campylobacter, and two flocks possessed a single type. In the flocks where multiple types of Campylobacter were obtained, all the birds were positive and multiple RAPD types of Campylobacter were isolated from individual broiler samples. In these flocks, multiple episodes of Campylobacter contamination may have occurred . On the other hand, the three Campylobacter negative flocks were considered to have had no Campylobacter contaminations . The differences in Campylobacter colonization of the flocks in this study may, at least in part, reflect the differences in the hygiene measures of the broiler houses in which these birds are raised.

Prevalence and antimicrobial susceptibility of thermophilic Campylobacter in organic and conventional broiler flocks.

To determine the flock prevalence and to estimate the within flock prevalence of Campylobacter in broiler flocks from different rearing systems, and to determine the antimicrobial susceptibility of Campylobacter isolates to selected antimicrobial substances. One hundred and sixty broiler flocks originating from organic, conventional and extensive indoor production farms were investigated for the presence of Campylobacter at the time of slaughter. Campylobacter isolates from a subsample of positive flocks were subjected to susceptibility testing. Campylobacter spp. were isolated from 100% of organic broiler flocks, from 36.7% of conventional broiler flocks and from 49.2% of extensive indoor broiler flocks. Six of 62 Campylobacter isolates were resistant to one or more of the antimicrobials tested. These results indicate that the special characteristics of organic broiler production provide a high prevalence of Campylobacter-positive flocks. Antimicrobial resistance was scarce among Campylobacter isolates from all rearing systems. Organic broiler flocks constitute a strong potential for introduction of Campylobacter to the processing line upon arrival at slaughter.

Campylobacter incidence on a chicken farm and the spread of Campylobacter during the slaughter process

To get a better understanding of the epidemiology of Campylobacter, a chicken farm was studied for 16 weeks with samplings in each flock weekly from input until the flock became colonized with Campylobacter or slaughtered. Samples were taken from fresh droppings and from drinkers during the rearing period, as well as from the environment in empty houses. The spread of Campylobacter during the slaughter process was also surveyed. No Campylobacter was found in samples from newly-hatched or one-week-old chickens or their drinkers. All flocks but one were colonized at two to five weeks of age. All Campylobacter isolates belonged to the same sero- and biotype; C. jejuni Penner 2. The spread of Campylobacter in the flock was rapid and usually all samples were positive once colonization had been proven. C. jejuni was isolated from flies in ante-rooms as well as from air in chicken units in houses with positive chicken flocks. Samples were taken at slaughter when some of the Campylobacter positive flocks from the farm were slaughtered. Campylobacter were isolated from all sampled equipment along the processing line, from the chicken transport crates to the chillers, as well as from the air.

Distribution and numbers of Campylobacter in newly slaughtered broiler chickens and hens

If Campylobacter is present in the intestinal tract, broiler carcasses become extensively contaminated during the slaughter process. To determine the distribution and numbers of Campylobacter jejuni/coli in newly slaughtered broiler chickens and hens, a total of 100 birds from six Campylobacter-positive flocks were sampled at three Swedish processing plants. Campylobacters were isolated in 89% of neck skins. 93% of peritoneal cavity swab samples and in 75% of subcutaneous samples. Muscle samples were only very sparsely contaminated. It is likely that the feather follicles are the orifices where C. jejuni/coli is introduced into the subcutis layer.