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The whole carcass rinse (WCR) procedure is routinely used as a sampling method for determining the presence and number of quality-indicator organisms or pathogens associated with broiler chicken carcasses in processing facilities. Collection of a cumulative drip sample by placing collection vessels under the processing line could potentially capture a more representative sample of bacterial populations associated with an entire flock with less labor than individual bird rinses. The purpose of this study was to evaluate a cumulative drip sampling method for recovery of Campylobacter spp. and 3 types of quality indicator organisms from broiler carcasses. Cumulative drip and WCR samples were collected on 14 d from a commercial broiler processing facility over a 3-mo period. No statistically significant difference was demonstrated between the WCR and cumulative drip sampling methods in recovery of Campylobacter spp., total aerobes, Enterobacteriaceae, or Escherichia coli associated with the postevisceration samples (P > 0.01). Analysis of the pyrosequencing census data demonstrated high interbird variability and indicates cumulative sampling may be required to obtain fully representative sampling of a flock. For most bacterial taxa, the relative abundance in individual WCR was correlated with cumulative drip samples, but some taxa were undercounted or missed entirely by individual WCR. Consequently, individual carcass rinses may not be representative of the flock microbial community. The cumulative drip sampling technique may save labor and provide a more representative summary of process control in poultry processing facilities.

The unacceptably high frequency of Campylobacter jejuni transmission from poultry to humans encourages scientists to consider and create alternative intervention strategies to control the pathogen in poultry production. Extremely high numbers of Campylobacter (often >10(8) cfu/g of poultry intestinal material) potentiate high numbers of the organism on the processed broiler carcass with increasing consequent human health risk. Many scientists believe interventions during poultry production portend the greatest opportunity for reducing risk of disease. Over the past 10 yr, we have focused our studies on nonantibiotic bacteriocin application to intervene during animal production and this is the subject of the current review. The application of therapeutic bacteriocin treatments to reduce poultry colonization diminishes Campylobacter from >10(8) cfu/g of cecal materials to nondetectable or very low levels in treated birds. Further, the review provides scientists with a useful starting point for the further development of industry-applicable interventions leading to reduced transmission of this agent in human disease.

The carcass rinse procedure is a method commonly used for the detection of Campylobacter spp. on processed poultry products. Alternatively, carcass exudate (weep or drip), a viscous fluid comprised of blood and water that leaks into packaging, can also be sampled. It is unknown however if direct carcass rinse or exudate/weep can be utilized to preferentially recover different Campylobacter spp. subtypes. If there is a difference in subtypes recovered, the Campylobacter spp. subtypes from carcass rinse analysis may not be indicative of consumer exposure, as the exudate is the fluid to which consumers are potentially exposed to due to kitchen cross-contamination. Experiments were conducted to determine if there are differences in recovery of Campylobacter spp. subtypes between the two methodologies. The experiment was performed in triplicate using three flocks located on different farms. For each flock, 50 fecal samples were obtained on the farm, 25 carcass rinses during pre-chill processing, 25 carcass rinses during post-chill processing, and 50 samples from exudate from carcasses stored at 4 degrees C (25 after 2-day storage and 25 after 6-day storage). Each sample type was cultured for Campylobacter spp. Isolates recovered from positive samples were subtyped using flaA SVR (flagellin A-short variable region) DNA sequence typing and compared for relatedness. The data demonstrated that multiple subtypes of Campylobacter jejuni were present in a flock, and that subtypes present in a flock during production were also present on the final processed product. Subtypes recovered by the two recovery methodologies were similar based on flaA SVR classification. Combining the totals from all 3 flocks a total of 10 flaA SVR subtypes were recovered from post-chill carcass rinses and 9 subtypes recovered from 6-day exudate 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.

Campylobacter is a leading cause of food-borne illness in the United States. Recent evidence has demonstrated that bacteriocins produced by Bacillus circulans and Paenibacillus polymyxa reduce cecal Campylobacter colonization in broiler chickens infected with Campylobacter jejuni. As Campylobacter coli is the most prevalent Campylobacter isolate recovered in turkeys, the objectives of the present study were to evaluate the efficacy of these bacteriocins against C. coli colonization and their influence on the gastrointestinal architecture of young turkeys. In 3 separate trials, a total of 135 day-of-hatch poults (n = 45/trial) were orally challenged on d 3 with approximately 10(6) cfu of a mixture of 3 C. coli isolates. Immediately before bacteriocin treatment (d 10), cecal Campylobacter concentrations averaged 1.1 x 10(7) cfu/ g of cecal contents (n = 15/trial). On d 10 to 12 posthatch, 2 bacteriocin treatment groups were given free access to feed supplemented with purified, microencapsulated bacteriocins, whereas the positive control treatment group had access to untreated feed (n = 10/treatment group per trial). At the end of the 3-d dosing period, ceca and duodenal loops were collected for analysis. In each of the 3 separate trials, treatment with bacteriocin eliminated detectable ceca Campylobacter concentrations (detection limit, 1 x 10(2) cfu/g of cecal contents) vs. controls (1.0 x 106 cfu of Campylobacter/g of cecal contents). Duodenum crypt depth and goblet cell numbers were also reduced in turkeys treated with either bacteriocin vs. controls (P < 0.05). The dynamic reduction in crypt depth and goblet cell density in turkeys dosed with bacteriocin may provide clues to how bacteriocins inhibit enteric Campylobacter.

Transmission of Campylobacter to humans has been prominently associated with mishandling or improperly preparing contaminated poultry carcasses. The number of organisms per carcass represents an important measure of human exposure to the agent. Therefore, we wished to estimate this public exposure over 1 yr among Italian broiler carcasses. We sampled 213 broiler carcasses from rinse water samples collected from a single slaughterhouse. Groups of carcasses had mean processed weights ranging from 1.2 to 2.7 kg. These were produced from 22 commercial broiler chicken flocks collected from 12 different farms, 3 of which were seasonally tested. Carcasses were rinsed with sterile water, and the rinse suspension was then serially diluted and spread-plated directly onto Campy-Cefex agar plates. One to 5 typical Campylobacter colonies per plate were identified by polymerase chain reaction as Campylobacter thermo-tolerant species. The overall estimated mean count per carcass in our study was 5.16 +/- 0.80 log10 cfu. This value increased in summer and autumn, as well as on carcasses collected from farms located > 100 km far from the slaughterhouse. A total of 678 Campylobacter colonies were identified by polymerase chain reaction. The majority of isolates were classified as Campylobacter jejuni (49.2%) or Campylobacter coli (47.5%). The overall number of C. jejuni was significantly higher on 1) carcasses weighing > 2 kg, 2) carcasses belonging to flocks with > 10,000 birds, and 3) carcasses collected from farms located > 100 km from the slaughterhouse. Moreover, among farms tested seasonally, C. jejuni was significantly greater than C. coli in winter. These data provide the first results of a continuing survey on Campylobacter loads and species identification from Italian broiler carcasses and represents an important baseline to estimate the human exposure to Campylobacter in Italy.

Campylobacter jejuni remains the most frequently reported bacterial cause of human gastroenteritis in Nordic countries. The primary source of transmission to humans is suggested as mishandled raw poultry or consuming improperly prepared chicken. The focus of this report was to characterize the prevalence and cell numbers of the organism within the commercial Icelandic poultry industry. Commercial broiler flocks were sampled from May 2001 through 2003 in a total population study. At the slaughter plant, 40 randomly selected ceca were obtained from each flock, pooled into four samples containing 10 ceca each, and analyzed. Cell numbers and prevalence of Campylobacter spp. were estimated by direct plating of dilutions onto Campy-Cefex agar and incubating the plates at 42 degrees C under microaerobic atmosphere; colonies were confirmed as Campylobacter spp. by microscopy and latex agglutination to provide quantification of cell numbers per gm of cecal material. A total of 15.4% of the flocks carried the organism at at a maximum cell number of 8.1 x 10(7) cfu/g, having a mean raw count of colonized birds at 1.3 x 10(7) cfu/g (geometric mean of 1.5 x 10(6)). During the 3 years of sampling, the prevalence ranged from 17.6% to 17.3% to 12.7% for slaughter years 2001, 2002, and 2003, respectively. Isolation rates varied with numbers of catch lots (groups of birds taken for slaughter)/flock; with one catch lot/flock, the prevalence was 13.7%, with two 17.5%, and with three 33.3%. With increased flock size, isolation rates also increased; flocks of greater than 5,000 birds had a prevalence of 12.0% positive, 14.0% of flocks with 5,000-10,000 birds were positive, and 25.5% of flocks with more than 10,000 birds were positive for Campylobacter spp. Isolation rates varied with the processing lines: M was positive at 17.3%, B was positive at 10.1%, and G at 17.2%. Flocks were more frequently colonized in the warmer months, and younger birds were less frequently colonized than were older slaughtered birds. This study provides descriptive microbiology pertaining to Iceland broilers in a total population study.

SUMMARY. Discriminating viable from dead cells is of importance in the development of bacterial detection methods. A positive reverse transcriptase-polymerase chain reaction (RT-PCR) amplification signal was tested as a potential predictor of chick colonization. Some researchers have suggested that the presence of messenger RNA (mRNA) may not correlate with cell viability. Chicken colonization by cells that have positive mRNA signal but that are noncultivable would provide a correlation in cell viability and persistence of mRNA. The role of a viable but noncultivable (VBNC) form of Campylobacter spp. for colonization of poultry could be verified by such an mRNA signal. The levels of four strains of Campylobacter spp., previously isolated from poultry feces, declined progressively over time, and loss of cultivability occurred after 6 to 7 wk incubation in phosphate-buffered saline (PBS) at 4 C. Cold-stored, noncultivable and heat-inactivated (60 C for 10 min) Campylobacter spp. produced inconsistent amplified products from RT-PCR assay, depending on the target transcripts and strains used, although all fresh cultures showed mRNA signals. For the most part, signals of mRNA species from VBNC and heat-killed Campylobacter spp. AH-1, AH-2, and CH-3 persisted. RT-PCR amplification of transcripts originating from the tkt and cmp genes and a 256-base pair amplicon (from a previously described putative haem-copper oxidase) provided consistent signals, whereas transcripts from the flaA gene did not. Presumed VBNC and heat-inactivated Campylobacter spp., which produced positive mRNA signal but was not cultivable by conventional culture-based methods, did not establish colonization in the intestine of chicks 7 days after challenge. These results lead us to question the correlation between mRNA durability with cell viability as well as the significance of the VBNC cells in environmental transmission of Campylobacter spp.

The distribution of Campylobacter spp. on 13 poultry farms (broiler chicken, quail, pheasant, peacock, and turkey) from eight regions (Vladimir, Vologda, Voronezh, Kaluga, Liptsk, Moscow, Orenburg, and Orel) in Russia was surveyed. Intestinal materials were plated onto Campylobacter-selective medium and plates were incubated microaerobically at 42 degrees C for 24 or 48 h. Identification was based on colonial morphology, microscopic examination, and biochemical tests; latex agglutination assays were used for confirmation. In total, 116 isolates were derived from 370 samples. Isolation rates were similar, regardless of whether the birds were from small or large broiler production farms. Susceptibility of 48 representative (from these production sources) strains of Campylobacter spp. to 38 antimicrobial compounds was determined by disk diffusion assays. All strains tested were sensitive to amikacin, gentamycin, sisomycin, chloramphenicol, imipenem, oleandomycin, erythromycin, azitromycin, and ampicillin. The strains were also sensitive to 100 microg/disk of carbenicillin, fluoroquinolones, and to nitrofurans. Fluoroquinolone sensitivity was most notable and may be related to its limited application in poultry production within Russia. Hippurate and ribosomal RNA gene primers were developed and used to distinguish Campylobacter jejuni and Campylobacter coli and to provide a measure of strain discrimination. The combination of PCR analysis and randomly amplified polymorphic DNA (RAPD) typing were conducted for selected isolates. The various poultry species and the different locations yielded Campylobacter isolates with discrete randomly amplified polymorphic DNA patterns. The distribution and substantial diversity of Campylobacter spp. isolates appears similar to that previously reported in other countries.

Campylobacter, a foodborne pathogen closely associated with poultry, is considered to be an important agent of human gastroenteritis in New Zealand. The pathways involved in the contamination of poultry flocks remain unclear; however, many vectors, such as insects, rodents, and wild birds, have been implicated. Infestation of poultry houses by insects, particularly darkling beetles (Alphitobius diaperinus), is difficult to control. Furthermore, darkling beetles are known vectors for a variety of pathogens that include Salmonella, infectious bursal disease virus, Aspergillus, Escherichia coli, and Marek's disease virus. In this investigation, the relationship between darkling beetles and Campylobacter contamination of poultry flocks was investigated. A New Zealand breeder flock and four of its progeny broiler flocks were included in the study. Samples of beetles and of intestinal excreta of the birds were cultured for the presence of Campylobacter spp. A subset of the recovered isolates was subsequently genotyped using flaA short variable region (SVR) DNA sequence analysis. A large number of Campylobacter subtypes were isolated, indicating that Campylobacter colonization of poultry is likely to arise from a number of different reservoirs. However, a set of genetically distinct isolates were found to be common to the broiler flocks and to the beetles. This research provides data that indicates that Alphitobius diaperinus may serve as a source of Campylobacter contamination of poultry. A more thorough understanding of the relationship between beetle infestation and the Campylobacter status of poultry flocks should enable progress in further development of biosecurity control measures.

Twenty north Georgia commercial flocks of broiler chickens sampled in 1995 and 11 flocks sampled in 2001 were tested for Campylobacter spp. Direct plating on Campy-Cefex agar was carried out to determine levels of Campylobacter colonization within each flock through the enumeration of the organism in 50 fresh fecal samples 1 day prior to slaughter. The next morning, these flocks were the first to be processed, and levels of the organism per carcass before the chilling operation (50 carcasses per flock) in 2001 and after the chilling operation (50 carcasses per flock) in both 1995 and 2001 were estimated. Levels of the organism on freshly processed broiler carcasses were estimated by the same methods in 1995 and 2001, and a significant reduction from an average of 10(4.11) CFU per carcass in 1995 to an average of 10(3.05) CFU per carcass in 2001 was observed. Levels of Campylobacter spp. found in production and in processing were not strongly correlative, indicating the existence of complex parameters involving production factors and variables associated with flock transport and the processing of the broilers. The reduction in Campylobacter levels on processed carcasses may have contributed to the reduction in the frequency of human disease observed by the Centers for Disease Control during the same period. These data characterize the distribution of Campylobacter in north Georgia poultry operations and should assist in the development of risk assessment models for Campylobacter spp. The results obtained in this study suggest that the implementation of antimicrobial interventions by the poultry industry has already reduced consumer exposure to the organism.

Campylobacter isolates from diverse samples within broiler production and processing environments were typed by using flaA short variable region DNA sequence analysis. Sixteen flocks from four different farms representing two broiler producers in Arkansas and California were analyzed. Fourteen of the flocks (87.5%) were Campylobacter-positive; two remained negative throughout the 6-week rearing period. In general, multiple clones were present within a flock. Additionally, clones found within a flock were also present on the final product, although the diversity of Campylobacter spp. on the final product appeared to be reduced relative to that observed within the flock. Comparison of clones between flocks on the same farm revealed that some clones of Campylobacter persisted in multiple flocks. Furthermore, some clones were identified across the two farms that were under the same management. In two sampling periods, environmental isolates were positive for Campylobacter prior to flock shedding. Environmental samples associated with five additional flocks were positive for Campylobacter concomitantly with recovery of Campylobacter from the birds. Analysis of the environmental isolates that were positive prior to flock shedding demonstrated that in some instances the environmental isolates possessed genotypes identical to those of isolates originating from the flock, while in other cases the environmental isolates possessed genotypes that were distantly related to isolates obtained from the flock. Analyses of environmental isolates that tested positive concurrently with the positive isolates from the flocks demonstrated varied results; in some instances the environmental isolates possessed genotypes identical to those of isolates originating from the flock, while in other cases the environmental isolates possessed genotypes that were distantly related to isolates obtained from the flock. These data suggest that the external environment may contribute to Campylobacter contamination during poultry production and processing. However, environmental contamination with Campylobacter does not appear to be the sole contributing factor.

Three groups of >60-wk-old broiler breeder hens were assessed for the presence of Campylobacter within segments of the reproductive tract. In the first group, after stunned, the hens were bled, scalded, and defeathered, the reproductive tracts were aseptically excised from 18 hens, six from each of three adjacent floor pens that were feces positivefor Campylobacter. The reproductive tract segments (infundibulum, magnum-isthmus, shell gland, vagina, and cloaca) were pooled by pen. In the second group, 10 individual hens were sampled from the pens; the reproductive tract was divided into the following segments: magnum, isthmus, shell gland, vagina, and cloaca. For the third group, hens were obtained from two commercial farms that had been determined to be feces positive for Campylobacter, and the reproductive tract was divided into five segments, as described for the second group. Segments of the reproductive tract were placed into sterile plastic bags and suspended 1:3 (w/v) in Bolton enrichment broth, and serial dilutions were plated (0.1 ml) onto Campy-Cefex agar. The agar places were incubated at 42 C for 24 hr in a microaerobic atmosphere. In group 1, the pooled reproductive tract segments for hens from pen A were Campylobacter positive for the shell gland, vagina, and cloaca; hens from pen B were positive for the cloaca only; and hens from pen C were positive for the magnum-isthmus and doaca. In the second group, 9 of 10 cloaca samples were Campylobacter positive. Commercial hens in group 3 had campylobacter-positive cloaca samples (12/12), vagina (10/12), shell gland (7/12), isthmus (2/12), and magnum (4/12). Campylobacter colonization of the reproductive tract of the hen could enable vertical transmission of Campylobacter from the hen to the chick.

Pooled semen samples from 12 groups of mature commercial broiler breeder roosters were analyzed for the presence of Campylobacter. Each of the 12 groups was comprised of eight individuals and was sampled weekly for five consecutive weeks. Once a day, roosters were allowed to have a restricted amount of feed after the semen samples were collected by abdominal massage. This feeding schedule reduced the amount of fecal contamination in and around the vent as well as in the semen sample. For replications 1, 2, and 3, the numbers of Campylobacter-positive groups were 8, 5, and 5, respectively, out of 12. For replications 4 and 5, 6 of 8 and 6 of 11 groups were positive, respectively. Only two groups were positive for Campylobacter at all sampling times, two groups were negative each time, and eight groups produced variable results. Also, fecal droppings, external swabs of the genitalia, and semen samples were taken from individual roosters between 49 to 65 wk of age. Of the total 275 semen samples collected, 9.47% contained naturally occurring Campylobacter, whereas 9.6% of 114 fecal droppings and 7.9% of the 114 genital swabs were positive. Levels of the organism present in the fecal samples ranged from 1.0 to 4.2 log colony-forming units (CFU)/g with an average of 2.9 log CFU/g feces. For semen, the levels ranged from as low as enrichment recovery only to as high as 3.1 log CFU/ml of semen with an average of 1.2 log CFU/ml. For swabs of genitalia, the levels of Campylobacter were so low that recovery was achieved only through enrichment. These data suggest that rooster semen may serve as a vehicle for transmission of Campylobacter to the reproductive tract of the hen and subsequently to the fertile egg.

The main source for Campylobacter spp. transmission from the environment to broiler chickens is still unclear. One implicated reservoir for the organism has been untreated broiler drinking water. This study was conducted with broilers first using experimental conditions (isolation units) and second under commercial conditions. We compared the rate of intestinal colonization in chickens provided 2 to 5 parts per million (ppm) chlorinated drinking water in relation to the frequency of colonization in chickens given unsupplemented drinking water. No significant difference (P > 0.05) was detected in isolation frequency or level of Campylobacter spp. colonization in birds provided chlorinated drinking water and control birds provided water without supplemental chlorine. In the isolation unit experiments, 86.3% (69/80) of the control and 85.0% (68/80) of the treated birds were colonized at levels corresponding to an average of 10(5.2) and 10(5.1) log colony-forming units (cfu) Campylobacter spp./g of cecal contents, respectively. Additionally, two sets of paired 20,000 bird broiler houses, with and without chlorination (2-5 ppm chlorine), were monitored in a commercial field trial. Effectiveness of chlorination was judged by prevalence of Campylobacter spp. in fecal droppings (960 samples) taken from the flocks in treated and control houses. Birds from the control houses were 35.5% (175/493) Campylobacter spp. positive, while 45.8% (214/467) of the samples from the houses having chlorinated drinking water yielded the organism. Chlorination of flock drinking water at the levels tested in this study was not effective in decreasing colonization by Campylobacter spp. under commercial production practices presently used in the United States.

A study was conducted of 32 broiler flocks on eight different farms, belonging to four major U.S. producers. The farms were studied over I complete calendar year. Overall, 28 (87.5%) of the flocks became Campylobacter positive, and only four (12.5%) remained negative throughout the 6- to 8-week rearing period. In the majority of flocks, sampled every 2 weeks throughout production, Campylobacter-positive fecal and cecal samples were not detected until 4 to 8 weeks of age. In only six of the flocks were environmental samples found to be positive before shedding of Campylobacter was detected in the birds. Even in some of the Campylobacter-negative flocks, contamination of the rearing environment was positive for Campylobacter but did not result in the birds subsequently excreting the organism. These findings are discussed in relation to U.S. husbandry practices and present uncertainty about sources of Campylobacter infection for poultry flocks. Birds were often transported to the processing plant in coops that were already contaminated with Campylobacter, and the organisms were sometimes found in samples of scald water and chill water. After chilling, the proportions of Campylobacter-positive carcasses from different producers ranged from 21.0 to 40.9%, which is lower than in other studies, and possible reasons are considered.

Most traditional Campylobacter detection and enumeration procedures are difficult and time consuming. Estimations of Campylobacter populations by the most probable number (MPN) method are especially laborious. The objective of this collaborative study, performed in duplicate in Agricultural Research Service and Food Safety Inspection Service laboratories, was to compare two MPN procedures (utilizing different selective enrichment broths and plating media) to the direct plating technique for enumeration of Campylobacter from freshly processed (postchill, postdrip) broiler chicken carcasses. Results obtained from the direct plating of carcass rinse samples on Campy-cefex agar were not significantly different (P > 0.05) from an MPN procedure employing Hunt's Campylobacter selective enrichment broth followed by recovery on modified Campylobacter charcoal differential agar. However, both of these procedures provided significantly (P < 0.05) better recovery than a second MPN procedure using Rosef's selective enrichment broth followed by plating on Mueller-Hinton blood agar with antibiotics. The direct plating method offers a more simple, less expensive, more rapid alternative to traditional MPN procedures for estimating Campylobacter populations associated with freshly processed broiler carcasses.

The purpose of this experiment was to determine how sampling method (direct plating or enrichment) affected the rate of Campylobacter spp. isolation from crop and cecal samples. In four separate trials, 32 New York-dressed broiler carcasses were obtained from commercial plants (n = 128). Crops and ceca were removed aseptically, direct plated, and enriched. Samples were direct-plated on Campy-Cefex plates that were incubated at 42 C for 36 to 48 h under a microaerobic atmosphere (5% O2, 10% CO2, 85% N2). After direct plating, samples were enriched in Bolton broth at 37 C for 4 h and 42 C for 20 h under a microaerobic atmosphere before plating onto Campy-Cefex plates. Campylobacter spp. was detected in 95.3% of direct-plated crop samples and 99.2% of enriched crop samples. Campylobacter spp. was detected in 100% of direct-plated cecal samples and 63.3% of enriched cecal samples. All 128 crop and cecal samples were positive for the organism by one or both methods. Mean counts of Campylobacter spp. were 3.6 log10 cfu/g of crop sample and 6.8 log10 cfu/g of cecal sample. For these two sample types, both of which tend to be contaminated with many viable cells, direct plating is sufficient for isolation of Campylobacter. Direct plating also provides an estimate of contamination level. Enrichment of cecal samples resulted in a decreased rate of detection and did not allow estimation of numbers of Campylobacter. The large numbers of non-Campylobacter species that inhabit the intestinal tract may out-compete Campylobacter during enrichment, confounding detection.

The purpose of this study was to determine the potential reservoirs for Campylobacter spp. that provide the initial sources involved with broiler chicken colonization during poultry production. We characterized the flagellin A gene (flaA) of the organism by restriction fragment length polymorphism (RFLP) for 59 isolates of the bacterium provided during an epidemiological study. Isolates were obtained from three broiler production houses existing at separate locations. They were cultured and isolated from other (nonbroiler) domestic farm animals, wild birds, rodents, feed, farmers' boots, chicken feathers, and chicken intestinal materials. Eight distinctive flaA types were found in two of the houses. In one house, at least five flaA types (4, 6, 8, 15, and 21) were characterized from the poultry production environment, with three types isolated and identified from the chicken intestinal tract. flaA type 15 was found in flies, on boots, and in chicken intestinal samples. In another house, a distinctive diversity of flaA types existed (4, 7, 43, and 53). At least three flaA types found in samples from chicken intestinal tracts were also found in warm-blooded animals outside of the poultry house (domesticated animals, wild birds, and vermin).

Broiler carcasses were removed from commercial processing lines immediately after defeathering, before chilling, and after chilling to determine whether any relationship exists between aerobic bacteria and the human enteropathogens salmonellae and Campylobacter. In two experiments, a whole carcass rinse procedure was used to sample 30 carcasses after defeathering, 90 carcasses before chilling, and 90 carcasses after chilling, for a total of 210 different carcasses. Aerobic bacteria and Campylobacter spp. were enumerated and the incidence of salmonellae was determined. Salmonellae and Campylobacter incidences were 20 and 94%, respectively, for all carcasses sampled. After picking, neither salmonellae-positive nor Campylobacter-positive carcasses had mean aerobic most probable number (MPN) values that were different from carcasses negative for those organisms. Immediately before chilling, aerobic and Campylobacter counts were 7.12 and 5.33 log10 cfu per carcass, respectively. Immersion chilling reduced aerobic counts by approximately 1.8 log and Campylobacter by 1.5 log, with no change in salmonellae-positive carcasses. There was no difference in aerobic or Campylobacter counts between carcasses that were positive or negative for salmonellae at any of the sampling locations, nor was any correlation found between levels of aerobic organisms and Campylobacter. Carcasses with aerobic counts above the mean or more than one standard deviation above the mean also failed to show any correlation. Discriminant analysis indicated error rates as high as 50% when numbers of aerobic bacteria were used to predict incidence of salmonellae or Campylobacter on individual carcasses. Aerobic bacteria are not suitable as index organisms for salmonellae or Campylobacter on broiler carcasses.

Colonization of the ceca and contamination on carcasses of chickens by Campylobacter spp. was investigated. Samples were taken on the farm and after transport and holding. In the first set of experiments, 20 chickens, obtained from each of 10 broiler farms, were collected from houses containing 6- to 7-wk-old birds. Half of the birds were slaughtered at the farm; the other half were transported (10 birds per chicken coop) to a holding facility and killed within 16 to 18 h. The levels of Campylobacter spp. on the carcass and in the ceca were assessed. Ceca from birds in 9 of the 10 farms sampled were positive for Campylobacter spp. Colonization levels ranged from 10(4.11) to 10(7.28) cfu Campylobacter spp./g cecal matter, except on one farm, where the organism was not isolated. The mean count on the farm was 10(5.44) cfu Campylobacter spp./g cecal material, and after transport the mean was 10(6.15) cfu/g. Significant increases (P = .0085) in levels of Campylobacter spp. on the chicken carcasses occurred after transport. Levels of Campylobacter spp. enumerated from unprocessed chicken carcasses after transport averaged 10(7.11) per carcass, up from an average of 10(3.66) cfu per carcass of the farm. To further verify this observation, field trials were conducted to assess levels on carcasses before and after commercial transport. Employing five farms and 200 6-wk-old chickens, the above observations were confirmed: prior to transport 12.1% of the chickens harbored an average of 10(2.71) cfu per carcass, but after transport 56.0% of the chicken exteriors harbored an average of 10(5.15) cfu per carcass. The results of this study indicate that transport and holding prior to processing contributes to the Campylobacter spp. of > 10(4) cfu normally found on processed poultry carcasses.

Ground beef was inoculated with mixed cultures of Campylobacter jejuni, and the samples were subjected to various cooking and cold-storage temperatures. When samples were heated in an oven at either 190 or 218 degrees C, approximately 10(7) cells of C. jejuni per g were inactivated (less than 30 cells per g) in less than 10 min after the ground beef reached an internal temperature of 70 degrees C. When the samples were held at -15 degrees C over 14 days of storage, the numbers of C. jejuni declined by 3 log10. When inoculated samples were stored with an equal amount of Cary-Blair diluent at 4 degrees C, no changes in viability were observed over 14 days of storage. Twenty-five times as much C. jejuni was recovered from inoculated ground beef when either 10% glycerol or 10% dimethyl sulfoxide was added to an equal amount of ground beef before freezing as was recovered from peptone-diluted ground beef. Twice as much inoculated C. jejuni was recovered from ground beef plus Cary-Blair diluent as was recovered from ground beef plus peptone diluent.

We report a simple diagnostic characteristic useful in the presumptive identification of Campylobacter jejuni and Campylobacter coli. Filter paper disks impregnated with cadmium chloride were placed on streaked agar medium. Zones of growth inhibition for Campylobacter spp. occurred at 1.25 micrograms per disk. Other enteropathogens (Salmonella spp., Shigella spp., Vibrio cholerae, Vibrio parahaemolyticus, Escherichia coli, and Yersinia enterocolitica) were resistant to at least 40 micrograms per disk, with the exception of a strain of Shigella flexneri, which showed first susceptibility at 10 micrograms per disk. Most of the 52 Campylobacter strains, which were isolated from human clinical and animal sources, showed zones of inhibition greater than 10 mm with 2.5 micrograms of cadmium chloride per disk. At 20 micrograms per disk, Campylobacter isolates from clinical sources were significantly (P less than 0.01) more susceptible to cadmium chloride inhibition than were those from meat samples.

Salmonella and Campylobacter are of concern to the poultry industry because of the continuing association of poultry-borne transmission of these diseases to humans. Live, mature bird interventions can be demonstrated only by comparing colonization in nontreated groups of control birds with treated bird groups. This study attempted to create a reproducible broiler chicken colonization model. When chicks were challenged 2 d posthatch with both Salmonella and Campylobacter, cecal colonization was achieved. By 4 wk posthatch, Salmonella counts per gram of cecal content diminished to very low or nondetectable levels. Campylobacter counts remained high throughout the test period. To achieve the goal of creating a mature bird Salmonella intestinal colonization model, oral treatment of 10 to 25 mg of vancomycin was given to 4-wk-old broilers, and 3 h later a composite of 3 Salmonella isolates were gavaged into the chickens. Birds were sampled 1 and 2 wk later. The data indicated that colonization was achieved at levels of 10[sup6-7] cfu g[sup-1] of cecal materials (at wk 5) and >10[sup2] to 10[sup4] cfu g[sup-1] of cecal materials (at wk 6). [ABSTRACT FROM AUTHOR]

Background: There has been a recent resurgent interest in bacteriophage biology. Research was initiated to examine Campylobacter jejuni-specific bacteriophage in the Russian Federation to develop alternative control measures for this pathogen. Results: A C. jejuni flagellum-specific phage PV22 from Proteus vulgaris was identified in sewage drainage. This phage interacted with C. jejuni by attachment to flagella followed by translocation of the phage to the polar region of the bacterium up to the point of DNA injection. Electron microscopic examination revealed adsorption of PV22 on C. jejuni flagella after a five minute incubation of the phage and bacteria. A different phenomenon was observed after incubating the mix under the same conditions, but for twenty minutes or longer. Phage accumulated primarily on the surface of cells at sites where flagella originated. Interestingly, PV22 did not inject DNA into C. jejuni and PV22 did not produce lytic plaques on medium containing C. jejuni cells. The constant of velocity for PV22 adsorption on cells was 7 × 10-9 ml/min. Conclusion: It was demonstrated that a bacteriophage that productively infects P. vulgaris was able to bind C. jejuni and by a spot test that the growth of C. jejuni was reduced relative to control bacteria in the region of phage application. There may be two interesting applications of this effect. First, it may be possible to test phage PV22 as an antimicrobial agent to decrease C. jejuni colonization of the chicken intestine. Second, the phage could potentially be utilized for investigating biogenesis of C. jejuni flagella. [ABSTRACT FROM AUTHOR]

Isolates of Cam pylobacter jejuni shipped internationally often arrive in a noncultivable state. We describe a PCR-based methodology whereby phylogenetic information can be recovered from noncultivable C. jejuni stored in Wang's transport medium. The robustness of this methodology was initially tested using 5 previously characterized strains of C. jejuni isolated from various sources associated with poultry production. These isolates were stored in Wang's transport medium before being subjected to 1 of 5 treatments designed to render the stored cells noncultivable: prolonged storage at room temperature, prolonged incubation at 42°C, multiple rounds of freezing and thawing, boiling, or contamination with Pseudomonas aeruginosa (ATCC 27853). This method resulted in DNA appropriate for PCR. An approximately 400-nucleotide amplicon from the flaA gene and an approximately 800-nucleotide amplicon from 16S rDNA were readily obtained, and a 1.5-kb section of the flaA locus was amplified from about half of the samples. These results indicate that this method may be useful for isolate typing schemes based on PCR amplification of Cam pylobacter DNA, including flaA short variable region (flaA SVR) sequencing, multilocus sequence typing (MLST), and flaA PCR-RFLP. By using this method, isolates unrecoverable from transport medium can still be used to provide phylogenetic information for epidemiological studies. [ABSTRACT FROM AUTHOR]

The prevention and control of Campylobacter colonization of poultry flocks are important public health strategies for the control of human campylobacteriosis. A critical review of the literature on interventions to control Campylobacter in poultry on farms was undertaken using a systematic approach. Although the focus of the review was on aspects appropriate to the United Kingdom poultry industry, the research reviewed was gathered from worldwide literature. Multiple electronic databases were employed to search the literature, in any language, from 1980 to September 2008. A primary set of 4,316 references was identified and scanned, using specific agreed-upon criteria, to select relevant references related to biosecurity-based interventions. The final library comprised 173 references. Identification of the sources of Campylobacter in poultry flocks was required to inform the development of targeted interventions to disrupt transmission routes. The approach used generally involved risk factor-based surveys related to culture-positive or -negative flocks, usually combined with a structured questionnaire. In addition, some studies, either in combination or independently, undertook intervention trials. Many of these studies were compromised by poor design, sampling, and statistical analysis. The evidence for each potential source and route of transmission on the poultry farm was reviewed critically, and the options for intervention were considered. The review concluded that, in most instances, biosecurity on conventional broiler farms can be enhanced and this should contribute to the reduction of flock colonization. However, complementary, non-biosecurity-based approaches will also be required in the future to maximize the reduction of Campylobacter-positive flocks at the farm level. [ABSTRACT FROM AUTHOR]