Biomedical subjects

R J Buhr

Publications and source records attributed to R J Buhr.

At least 19 recordsLinked to original sources

PubMed2007

Comparison of four sampling methods for the detection of Salmonella in broiler litter.

Experiments were conducted to compare litter sampling methods for the detection of Salmonella. In experiment 1, chicks were challenged orally with a suspension of naladixic acid-resistant Salmonella and wing banded, and additional nonchallenged chicks were placed into each of 2 challenge pens. Nonchallenged chicks were placed into each nonchallenge pen located adjacent to the challenge pens. At 7, 8, 10, and 11 wk of age the litter was sampled using 4 methods: fecal droppings, litter grab, drag swab, and sock. For the challenge pens, Salmonella-positive samples were detected in 3 of 16 fecal samples, 6 of 16 litter grab samples, 7 of 16 drag swabs samples, and 7 of 16 sock samples. Samples from the nonchallenge pens were Salmonella positive in 2 of 16 litter grab samples, 9 of 16 drag swab samples, and 9 of 16 sock samples. In experiment 2, chicks were challenged with Salmonella, and the litter in the challenge and adjacent nonchallenge pens were sampled at 4, 6, and 8 wk of age with broilers remaining in all pens. For the challenge pens, Salmonella was detected in 10 of 36 fecal samples, 20 of 36 litter grab samples, 14 of 36 drag swab samples, and 26 of 36 sock samples. Samples from the adjacent nonchallenge pens were positive for Salmonella in 6 of 36 fecal droppings samples, 4 of 36 litter grab samples, 7 of 36 drag swab samples, and 19 of 36 sock samples. Sock samples had the highest rates of Salmonella detection. In experiment 3, the litter from a Salmonella-challenged flock was sampled at 7, 8, and 9 wk by socks and drag swabs. In addition, comparisons with drag swabs that were stepped on during sampling were made. Both socks (24 of 36, 67%) and drag swabs that were stepped on (25 of 36, 69%) showed significantly more Salmonella-positive samples than the traditional drag swab method (16 of 36, 44%). Drag swabs that were stepped on had comparable Salmonella detection level to that for socks. Litter sampling methods that incorporate stepping on the sample material while in contact with the litter appear to detect Salmonella in greater incidence than traditional sampling methods of dragging swabs over the litter surface.

Animals↗

PubMed2006

Evaluation of eggshell quality of hens infected with Salmonella enteritidis by application of compression.

Eggs collected from hens of different ages and that differed in infection status with Salmonella enteritidis were evaluated for the ability to resist cracking following application of maximum compression load from an Instron materials testing machine. Orally infected 24-wk-old hens that were prepeak produced eggs with significantly lower hardness units (HU) of shells compared with a paired control group (P < or = 0.01). However, 1 of 3 additional infection trials in hens at peak (29 wk) and older hens postpeak (58 wk) showed an increase in HU in one trial and no difference in the other 2 trials. Thus, Salmonella enteritidis may be able to alter HU in a manner that is influenced by multiple factors, which include the age of the hen and the strain used for infection. Hardness was overall a sensitive physiological barometer of age, because readings correlated positively (all R > 0.50) with hens entering peak production, regardless of infection status. Detection of a very low HU reading (<1.0) was indicative of a hairline crack in the egg, which increased in incidence from 0.01% preinfection to 0.08% postinfection. Two other clinical signs noted postinfection in hens were that i) daily egg production significantly increased in older hens, and ii) emaciation was evident in a few hens that were infected by contact. These results suggest that there may be supportive approaches to achieve reduction of S. enteritidis in table eggs that do not rely on culturing.

Aging↗

PubMed2006

Broiler carcass bacterial counts after immersion chilling using either a low or high volume of water.

A study was conducted to investigate the bacteriological impact of using different volumes of water during immersion chilling of broiler carcasses. Market-aged broilers were processed, and carcasses were cut into left and right halves along the keel bone immediately after the final bird wash. One half of each carcass pair was individually chilled at 4 degrees C in a separate bag containing either 2.1 L/kg (low) or 16.8 L/kg (high) of distilled water. Carcass halves were submersed in a secondary chill tank containing approximately 150 L of an ice-water mix (0.6 degrees C). After chilling for 45 min, carcass halves were rinsed with 100 mL of sterile water for 1 min. Rinses and chill water were analyzed for total aerobic bacteria (APC), Escherichia coli, Enterobacteriaceae, and Campylobacter. After chilling with a low volume of water, counts were 3.7, 2.5, 2.6, and 2.1 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. When a high volume of chill water was used, counts were 3.2, 1.7, 1.6, and 1.8 log(10) cfu/mL of rinse for APC, E. coli, Enterobacteriaceae, and Campylobacter, respectively. There was no difference in bacterial counts per milliliter of chill water among treatments. These results show that using additional water during immersion chilling of inoculated broilers will remove more bacteria from the carcass surfaces, but numbers of bacteria per milliliter in the chiller water will remain constant. The bacteriological impact of using more water during commercial immersion chilling may not be enough to offset economic costs.

Animals↗

PubMed2006

Release of Escherichia coli from feathered and featherless broiler carcasses in warm water.

Release of bacteria from individual broiler carcasses in warm water was measured as a model of bacterial contamination of scald water. Immediately after shackling and electrocution, feathered and genetically featherless broiler carcasses (n = 24 of each) were immersed individually in 42 degrees C, air-agitated tap water for 150 s. Although any visible fecal material expelled as a result of electrocution was removed before sampling, carcass condition was typical for market-age broilers subjected to 12 h of feed withdrawal. Duplicate water samples were taken at 10, 30, 70, 110, and 150 s, and Escherichia coli counts were determined. Samples of initial tap water and contaminated water approximately 2 min after removal of carcasses indicated that E. coli could not be detected in the original water source and that mortality of E. coli in the warm water was negligible. Mean numbers of E. coli released were 6.2 and 5.5 log(10) (cfu/carcass) at 150 s for feathered and featherless carcasses, respectively. For both feathered and featherless carcasses, the rate of release of E. coli was highest in the first 10 s, and the rate declined steadily during the remaining sampling period. This result is compatible with published reports of sampling of operating multiple-tank scalders, indicating that a high proportion of total bacteria in a multiple-tank scalder are in the first scald tank that carcasses enter. Higher numbers of E. coli released from feathered carcasses are probably due to the much greater surface area of contaminated feathers compared with the skin of featherless carcasses.

Animals↗

PubMed2006

Apparent attachment of Campylobacter and Salmonella to broiler breeder rooster spermatozoa.

It has been demonstrated that horizontal and vertical transmission of Salmonella and Campylobacter can occur in broiler breeder flocks. The mechanism of this transmission is still unclear. Previously negative broiler breeder flocks have been reported to become positive with Salmonella, Campylobacter, or both after the introduction of "spike" roosters at 45 wk of age. To determine whether the rooster semen is a possible source of transmission to hens for colonization, we evaluated the association of both Salmonella and Campylobacter spp. to segments (head, midpiece, and tail) of individual spermatozoa after artificial inoculation. Salmonella typhimurium, Salmonella heidelberg, and Salmonella montevideo, or Campylobacter jejuni (in 0.85% saline) was added to a freshly collected (by abdominal massage) aliquot of pooled semen from roosters housed in individual cages. The semen and bacteria solutions were incubated 1 h at room temperature. Samples were fixed using Karnosvsky and Zamboni fixatives for 24 h prior to centrifuging and rinsing in 0.1 M cacodylate x HCl buffer. Individual aliquot samples were then subjected to both scanning (JSM-5800) and transmission (JEM-1210) electron microscopy. The scanning electron microscopy showed that Salmonella was associated with all 3 segments (head, midpiece, and tail) of the spermatozoa and apparently equally distributed. Campylobacter was mainly associated with the midpiece and tail segments; few isolates were located on the head segment. The transmission electron microscopy showed apparent attachment of Salmonella and Campylobacter to the spermatozoa.

Animals↗

PubMed2006

Incidence of unabsorbed yolk sacs in broilers, broiler breeder roosters, white Leghorn hens, and Athens-Canadian randombred control broilers.

Unabsorbed yolk sacs are being investigated as a possible reservoir for internal Campylobacter and salmonellae contamination of processed poultry carcasses. However, it is unknown at what frequency that unabsorbed yolk sacs persist at the time of processing of broilers and spent breeders. Seven sets of 100 broiler carcasses (at 6 or 8 wk of age) were obtained from commercial processing plants. In addition, 100 52-wk-old broiler breeder males, 100 102-wk-old Leghorn hens, and 300 8-wk-old Athens-Canadian randombred control (ACRBC) broilers were euthanized, and their abdominal cavities were opened for determination of the presence of unabsorbed yolk sacs. Carcasses with obliterated yolk stalks or stalks with no detectable yolk material were categorized as normal. Those with unabsorbed yolk sacs were further separated into 2 groups: 1) attached by the yolk stalk to the small intestine or 2) unattached within the abdominal cavity. Yolk sacs were further classified by size: 1) small was <2 mm in diameter, 2) medium was 2 to 10 mm, and 3) large was >10 mm. From the 300 commercial broiler carcasses that were 6 wk old, 54% were categorized as normal with no detectable yolk sac, 35% had an unabsorbed yolk sac attached to the yolk stalk, and 12% had unattached yolk sacs. From the 400 commercial broiler carcasses that were 8 wk old, 49% of the carcasses were normal, 31% had attached unabsorbed yolk sacs, and 20% had unattached yolk sacs. From the 100 rooster carcasses sampled, 73% were normal, 8% had attached unabsorbed yolk sacs, and 19% had unattached yolk sacs. From the 100 White Leghorn hen carcasses sampled, 88% were normal, 8% had attached unabsorbed yolk sacs, and 4% were unattached yolk sacs. From the 300 ACRBC carcasses sampled, 76% were normal, 4% had attached unabsorbed yolk sacs, and 20% were unattached yolk sacs. The incidence of unabsorbed yolk sacs in present day commercial broilers appears twice as high as for mature roosters, hens, or ACRBC broilers.

Animals↗

PubMed2006

Detection of Campylobacter jejuni in various lymphoid organs of broiler breeder hens after oral or intravaginal inoculation.

Two studies were conducted to determine whether Campylobacter jejuni could rapidly spread and reside in the internal organs of adult broiler breeder hens. In Study 1, university-housed broiler breeders at 22 wk of age were obtained and placed in individual cages. Each hen was intravaginally inoculated weekly from 23 to 32 wk of age with a characterized strain of C. jejuni. At wk 23, 27, and 32, 4 d postinoculation, the hens were euthanized, defeathered, and aseptically opened. In Study 2, university-housed broiler breeder hens were obtained at 42, 53, and 56 wk of age, placed in individual cages, and inoculated either orally or intravaginally with a characterized strain of C. jejuni. To reduce the possibility of cross-contamination among samples, the thymus, spleen, liver, and gallbladder were aseptically removed, prior to the ceca. In both studies, all samples were individually analyzed. In Study 1, at 23 wk of age, C. jejuni was recovered from 4/7 thymii, 2/7 spleens, 5/7 livers and gallbladders, and 6/7 ceca. At 27 wk of age, C. jejuni was recovered from 1/7 thymii and 1/7 ceca. At 32 wk of age, C. jejuni was recovered from 4/11 thymii, 1/11 livers and gallbladders, and 2/11 ceca. In Study 2, C. jejuni was recovered from 2/6 thymii and 5/6 ceca after oral inoculation and 1/6 spleens, 1/6 livers and gallbladders, and 4/6 ceca after vaginal inoculation of 43-wk-old hens. Campylobacter jejuni was recovered from 2/5 thymii, 3/5 spleens, 3/5 livers and gallbladders, and 2/5 ceca after oral inoculation of 53-wk-old hens and 1/5 thymii and 1/5 livers and gallbladders after vaginal inoculation. Campylobacter jejuni was recovered from 1/4 thymii, 2/4 livers and gallbladders, and 1/4 ceca and was not detected in any vaginally inoculated birds of 57-wk-old hens. This study provides evidence that C. jejuni can reside in the internal organs of broiler breeder hens following oral or intravaginal inoculation.

Administration, Intravaginal↗

PubMed2006

Natural presence of Campylobacter spp. in various internal organs of commercial broiler breeder hens.

Campylobacter are known to cause acute bacterial gastroenteritis in humans. Poultry products have been implicated as a significant source of these infections. Six experiments were performed to determine whether Campylobacter could be isolated naturally from the primary and secondary lymphoid organs, liver/gallbladder, and ceca of commercial broiler breeder hens. Broiler breeder hens were acquired from different commercial sources during the early, middle, and late lay cycles. The birds were euthanatized, defeathered, and aseptically opened. To reduce the possibility of cross-contamination between samples, the thymus, spleen, and liver/gallbladder were aseptically removed prior to removal of the ceca. Individual samples were placed in sterile bags, packed on ice, and transported to the laboratory for evaluation. In this study Campylobacter were found in 11 of 43 thymii, eight of 43 spleens, four of 43 liver/gallbladders, and 30 of 43 ceca. Overall, 28 of 53 isolates from the above samples were Campylobacter coli and 25 of 53 isolates were found to be Campylobacter jejuni.

Animals↗

PubMed2006

Presence of inoculated Campylobacter and Salmonella in unabsorbed yolks of male breeders raised as broilers.

Day-old male broiler breeder chicks were obtained from a commercial hatchery and raised as broilers. For Experiment 1, at 5 wk of age, the broilers were orally inoculated with a 10(6) cfu/ml of a characterized strain of Campylobacter jejuni and a cocktail (three naladixic acid-resistant strains) of Salmonella serovars. One week after inoculation, the birds were euthanatized and defeathered. The abdominal cavity was examined and any unabsorbed yolk material (and remaining yolk stalk) and ceca were aseptically removed for microbiological analyses. For each pooled sample (two birds per pool), an aerobic plate count (APC), an Enterobacteriaceae (ENT) count, and a test for the presence of Campylobacter and Salmonella was performed. For Experiment 2, at 5 wk of age, the broilers were orally inoculated with 10(5) cfu/ml of a characterized strain of Campylobacter jejuni. One week after inoculation, the birds (n = 20) were killed, defeathered, and the yolk stalk, attached yolk, or free-floating yolk and ceca were individually analyzed for presence of Campylobacter. For Experiment 1, the Salmonella-inoculated birds had 2/12 ceca and 0/12 unabsorbed yolk samples positive for Salmonella. The average yolk APC was log10 3.4 cfu/g and the average ENT was log10 1.9 cfu/g. For the Campylobacter-inoculated birds, 12/12 ceca and 9/12 unabsorbed yolk samples were positive for Campylobacter. The average yolk APC was log10 3.5 cfu/g and the average ENT was log10 3.1 cfu/g. For Experiment 2, the inoculated Campylobacter birds had 19/20 ceca, 5/20 free floating yolks, and 19/20 yolk stalks positive. In Experiment 1, the inoculated Campylobacter colonized the ceca in every instance and were present in 75% of the unabsorbed yolks. Alternatively, the inoculated Salmonella were not found in any of the unabsorbed yolks and only rarely in the ceca. In Experiment 2, the inoculated Campylobacter was found in very high numbers in the yolk and internal body samples. Determining to what extent these internal bodies and unabsorbed yolks play in bacterial colonization and contamination of the birds at processing has not been determined. The next step will be to determine the incidence of unabsorbed yolks and presence of Campylobacter and Salmonella in these bodies of commercial broilers at processing.

Animal Husbandry↗

PubMed2005

Recovery of bacteria from broiler carcass respiratory tracts before and after immersion scalding.

Occlusion of the trachea and decapitation were compared with a conventional unilateral neck cut for effects on bacteria entering into the respiratory tract of broiler carcasses during scalding. In experiment 1, the trachea was occluded prior to the carcass entering the scalder to determine if bacterial recovery from the respiratory tract could be diminished. The first carcass was removed at the end of bleeding, and a plastic cable tie was placed around the neck of a second carcass and tightened to occlude the trachea. After proceeding through the triple-tank immersion scalder, the second carcass (trachea occluded) was removed, and a third carcass (without the trachea occluded during scalding) was removed. In experiment 2, after being stunned, carcasses were unilaterally bled or decapitated. Unilaterally bled and decapitated carcasses were removed at the end of bleeding and after scalding. In both experiments, trachea were cannulated, and respiratory tract rinses were collected. For experiment 1, the numbers of bacteria recovered (log10 cfu/mL of rinse) from prescald nonoccluded carcass respiratory tract rinses were 2.5 Escherichia coli, 2.6 coliforms, and 3.2 total aerobes. Respiratory tract rinses from carcasses sampled postscald (without occluding the trachea) had higher bacteria numbers at 4.6 E. coli, 5.0 coliforms, and 5.4 total aerobes. Respiratory tract rinses from carcasses with the trachea occluded prior to scalding had the lowest number of bacteria at 1.9 E. coli, 2.3 coliforms, and 2.7 total aerobes. In experiment 2, the numbers of bacteria recovered from respiratory tract rinses of unilaterally bled or decapitated carcasses did not differ prescald or postscald, although all postscald values were higher (P < 0.05). Results confirmed that bacteria numbers increased within the respiratory tract during immersion scalding, the increase could have been prevented by occluding the trachea prior to scalding, and decapitation did not alter the number of bacteria recovered from respiratory tract rinses prior to or following immersion scalding.

Animals↗

PubMed2005

Recovery of salmonellae following pH adjusted pre-enrichment of broiler carcasses treated with trisodium phosphate.

Trisodium phosphate (TSP) has been reported to decrease the recovery of salmonellae from processed poultry carcasses. It has been suggested that the high pH and detergent-like properties of TSP solutions are responsible for the reduction in salmonellae recovery. This project was conducted to determine if controlling pH during salmonellae pre-enrichment alters the effect of TSP on salmonellae recovery. Carcasses were obtained from a commercial processing plant immediately after the final inside-outside carcass washer, prior to any other antimicrobial treatments, and before chilling. Carcasses were assigned to 1 of 4 treatment groups: (1) TSP and alkaline pre-enrichment, (2) TSP and neutral pre-enrichment, (3) non-TSP and alkaline pre-enrichment, 4) non-TSP and neutral pre-enrichment. Carcasses were placed into plastic bags with 500 mL of buffered peptone water (with or without pH adjustment) and shaken for 1 min. Preincubation pH of the rinsate was measured. Carcasses were incubated in the rinse at 37 degrees C for 24 h, and incidence of salmonellae was determined. The pH of the preincubation rinsate was 8.4 for the TSP alkaline pre-enrichment, 7.2 for the TSP neutral pre-enrichment, 8.6 for the non-TSP alkaline pre-enrichment, and 7.1 for the non-TSP neutral pre-enrichment. Salmonellae were detected from 40% of the TSP alkaline pre-enrichment carcasses, 44% of the TSP neutral pre-enrichment carcasses, 54% of the non-TSP alkaline pre-enrichment carcasses, and 38% of the non-TSP neutral pre-enrichment carcasses. Neither TSP treatment nor pre-enrichment pH adjustment significantly influenced carcass salmonellae detection.

Animals↗

PubMed2005

Bacteria recovery from genetically feathered and featherless broiler carcasses after immersion chilling.

Feathered and featherless (scaleless) sibling broilers were reared and processed together to evaluate the influence of feathers and feather follicles on carcass bacteria recovery after chilling. In each experiment, broilers were inoculated 1 wk prior to processing by oral gavage with a suspension of salmonellae or Campylobacter at 106 cells/mL. Broilers were stunned and bled, and carcasses were single-tank or triple-tank scalded, defeathered, eviscerated, and washed. Carcasses were chilled for 45 min in ice and water immersion chillers with or without 20 mg of chlorine/L added. Postchill carcass rinsates were evaluated for Escherichia coli, coliforms, total aerobes, and salmonellae or Campylobacter. Following processing and immersion chilling, genetically featherless carcasses had slightly higher counts (by log10 0.35 cfu/100 mL of carcass rinsate) for E. coli, coliforms, and total aerobes than feathered carcasses. However, there were no significant differences in the prevalence of salmonellae (25%) or Campylobacter (93%) between feathered and featherless carcasses. Recovery of E. coli, coliforms, and total aerobic bacteria were lower for carcasses that were single-tank scalded, and following enrichment, salmonellae were recovered from fewer carcasses subjected to the single-tank (71%) than triple-tank (86%) scalding. Addition of chlorine to chiller water significantly decreased carcass bacteria recovery (by log10 0.43 cfu/100 mL of carcass rinsate) for E. coli, coliforms, total aerobes, and Campylobacter but did not affect salmonellae recovery. The presence of feathers and feather follicles during processing and immersion chilling appears to have minimal influence on the recovery of salmonellae or Campylobacter from carcasses sampled after immersion chilling.

Animals↗

PubMed2005

Presence of Campylobacter jejuni in various organs one hour, one day, and one week following oral or intracloacal inoculations of broiler chicks.

Day-old broiler chicks (n=30) were obtained from a commercial hatchery and inoculated, either orally or intracloacally, with a characterized strain of Campylobacter jejuni. At 1 hr, 1 day, and 1 wk after inoculation, broilers (n = 5) from the orally and intracloacally inoculated groups along with control birds (n=4) were humanely killed by cervical dislocation. The broilers from the control and treatment groups were aseptically opened, and the thymus, spleen, liver/gallbladder, bursa of Fabricius, and ceca were aseptically removed and individually analyzed for C. jejuni. Overall, C. jejuni was isolated after oral inoculation from 13% (10/ 75), 17% (13/75), and 28% (14/50) of the 1-hr, 1-day, and 1-wk samples, respectively. Campylobacter jejuni was isolated from 10% (4/ 40), 8% (3/40), 10% (4/40), 25% (10/40), and 40% (16/40) of the thymus, spleen, liver/gallbladder, bursa of Fabricius, and ceca samples, respectively. Following the intracloacal route of inoculation, C. jejuni was recovered from 32% (24/75), 8% (6/75), and 16% (8/50) of the 1-hr, 1-day, and 1-wk samples, respectively. Campylobacter jejuni was isolated from 5% (2/40), 5% (2/40), 5% (2/40), 45% (18/40), and 40% (16/40) of the thymus, spleen, liver/gallbladder, bursa of Fabricius, and ceca samples, respectively, for all sampling periods. Campylobacter spp. were not recovered from sample sites examined from the control broilers from trial one, trial two, or trial three samples examined after 1 hr and 1 day. However, one control sample was positive from the 1-wk sampling from repetition three; therefore, those data were omitted. The rapid movement of Campylobacter to internal organs following both oral and intracloacal inoculation may be significant, particularly if it persists in these organs as reservoirs throughout the 65-wk life cycle of breeding birds.

Animals↗

PubMed2005

Presence of naturally occurring Campylobacter and Salmonella in the mature and immature ovarian follicles of late-life broiler breeder hens.

Campylobacter and Salmonella are known to cause acute bacterial gastroenteritis in humans. Raw poultry products have been implicated as a significant source of these infections. Five trials were conducted to determine whether Campylobacter and Salmonella spp. exist naturally in the mature and immature ovarian follicles of late-life broiler breeder hens. Broiler breeder hens ranging from 60 to 66 wk of age were obtained from four different commercial breeder operations. For each trial, the hens were removed from the commercial operation and held overnight at the University of Georgia processing facility. The hens were euthanized, defeathered, and aseptically opened. To reduce the possibility of cross-contamination between samples, first the mature and immature ovarian follicles, then the ceca, were aseptically removed. Individual samples were placed in sterile bags, packed on ice, and transported to the laboratory for evaluation. Overall, Campylobacter was found in 7 of 55 immature follicles, 12 of 47 mature follicles, and 41 of 55 ceca. Campylobacter was found in at least one of each sample of mature follicles and in ceca in each of the five trials. Salmonella was found in 0 of 55 immature follicles, 1 of 47 mature follicles, and 8 of 55 ceca. In this study, the recovery rate of Salmonella from late-life broiler breeder hen ovarian follicles was relatively low. However, the recovery rate of Campylobacter from the hen ovarian follicles was reasonably high, suggesting that these breeder hens could be infecting fertile hatching eggs. Determining how Campylobacter contaminated these ovarian follicles and how many chicks could be colonized from this source are the next steps in helping to elucidate a better understanding of this ecology and the control of Campylobacter in poultry production.

Animals↗

PubMed2005

Recovery of Campylobacter jejuni in feces and semen of caged broiler breeder roosters following three routes of inoculation.

We previously reported the recovery of Campylobacter (naturally colonized) from the ductus deferens of 5 of 101 broiler breeder roosters, and four of those five positive roosters had previously produced Campylobacter-positive semen samples. Those results prompted further evaluation to determine if inoculation route influenced the prevalence or level of Campylobacter contamination of semen, the digestive tract, or reproductive organs. Individually caged roosters, confirmed to be feces and semen negative for Campylobacter, were challenged with a marker strain of Campylobacter jejuni either orally using 1.0 ml of a diluted cell suspension (log(10)4.3 to 6.0 cells), by dropping 0.1 ml of suspension (log(10)5.3 to 7.0 cells) on the everted phallus immediately after semen collection or by dip coating an ultrasound probe in the diluted cell suspension (log(10)4.3 to 6.0 cells) and then inserting the probe through the vent into the colon. Six days postinoculation, individual feces and semen samples were again collected and cultured for Campylobacter. Seven days postinoculation, roosters were killed, the abdomen aseptically opened to expose the viscera, and one cecum, one testis, and both ductus deferens were collected. The samples were then suspended 1:3 (weight/volume) in Bolton enrichment broth for the culture of Campylobacter. Samples were also directly plated onto Cefex agar to enumerate Campylobacter. Campylobacter was recovered 6 days after challenge from feces in 82% of samples (log(10)4.1 colony-forming units [CFU]/g sample), 85% of semen samples (log(10)2.9 CFU/ml), and on the seventh day postchallenge from 88% of cecal samples (log(10)5.8 CFU/g sample). Campylobacter was not directly isolated from any testis sample but was detected following enrichment from 9% (3/33) of ductus deferens samples. Roosters challenged with Campylobacter orally, on the phallus, or by insertion of a Campylobacter dip-coated ultrasound probe were all readily colonized in the ceca and produced Campylobacter-positive semen and feces on day 6 after challenge. The low prevalence of recovery of Campylobacter from the ductus deferens samples and failure to recover from any testis sample suggests that semen may become Campylobacter positive while traversing the cloaca upon the everted phallus. The production of Campylobacter-positive semen could provide a route in addition to fecal-oral for the horizontal transmission of Campylobacter from the rooster to the reproductive tract of the hen.

Administration, Oral↗

PubMed2004

Recovery of Salmonellae from trisodium phosphate-treated commercially processed broiler carcasses after chilling and after seven-day storage.

Experiments were conducted to determine the effect of prechill trisodium phosphate (TSP) treatment on reducing salmonellae recovery from broiler carcasses immediately after chilling or following 7 d of storage. Carcasses were sampled for salmonellae using whole carcass enrichment for 24 h at 37 degrees C. In each of 7 trials, 40 carcasses were obtained from a commercial processing plant. Batches of 4 carcasses were subjected to a 5-s dip in 10% TSP (treatment) or not dipped (control). Two carcasses from each batch were sampled immediately after chilling (d 0) and 2 carcasses were sampled after 7 d of storage. For trials 1 and 2, TSP treatment and control groups were chilled in separate chill tanks for 45 min. For trials 3 through 7, carcasses were rinsed with water and individually bagged with ice and water before chilling. For trials 1 and 2, 85% (17/20) of control carcasses were salmonellae-positive on d 0 compared with 45% (9/ 20) of the TSP-treated carcasses; after 7 d, 75% (15/20) of control carcasses were positive compared with 35% (7/ 20) for the TSP-treated carcasses. For trials 3 through 7, 46% (23/50) of control carcasses were salmonellae-positive on d 0 compared with 26% (13/50) of the TSP-treated carcasses; after 7 d, 20% (10/50) of control carcasses were positive compared with 4% (2/50) of the TSP-treated carcasses. TSP treatment resulted in significantly higher pH values for rinses. Salmonella recovery was decreased by refrigerated storage and treatment with TSP before immersion chilling.

Animals↗

PubMed2004

Impact of feathers and feather follicles on broiler carcass bacteria.

Genetically featherless and feathered broiler siblings were used to test the contribution of feathers and feather follicles to the numbers of aerobic bacteria, Escherichia coli, and Campylobacter in whole-carcass rinse samples taken immediately after carcasses were defeathered for 30 or 60 s. Numbers of spoilage bacteria were counted after the same fully processed carcasses were stored for 1 wk at 2 degrees C. In each of 3 replications, twenty-eight 11-wk-old, mixed-sex, genetically featherless or feathered broilers were processed in a laboratory processing facility. Immediately after individual defeathering in a mechanical picker, carcasses were sampled using a carcass rinse technique. Carcasses were eviscerated, immersion chilled at 2 degrees C for 30 min, individually bagged, and stored for 1 wk at 2 degrees C, after which all carcasses were rinsed again, and spoilage bacteria in the rinsate were enumerated. There were no significant differences (P < or = 0.05) between the featherless and feathered broilers in numbers of aerobic bacteria, E. coli, and Campylobacter in rinse samples taken immediately after defeathering and no differences between carcasses picked for 30 or 60 s. There were no differences in numbers of spoilage bacteria after 1 wk of refrigeration for any of the feather presence-picking length combinations. Although the defeathering step in poultry processing has been identified as an opportunity for bacterial contamination from the intestinal tract and cross-contamination between carcasses, the presence of feathers and feather follicles does not make a significant difference in carcass bacterial contamination immediately after defeathering or in spoilage bacteria after 1 wk of refrigeration.

Animals↗

PubMed2004

Effect of prechill fecal contamination on numbers of bacteria recovered from broiler chicken carcasses before and after immersion chilling.

Paired carcass halves were used to test whether fecal contamination of skin during processing of broiler chickens can be detected by increased bacterial counts in samples taken before and after immersion chilling. In each of three trials, six freshly defeathered and eviscerated carcasses were cut in half, and a rectangle (3 by 5 cm) was marked with dots of ink on the breast skin of each half. One half of each pair was chosen randomly, and 0.1 g of freshly collected feces was spread over the rectangle with a spatula. After 10 min, both halves were sprayed with tap water for 10 to 15 s until feces could no longer be seen in the marked area. Both halves were sampled with a 1-min carcass rinse and were then put in a paddle chiller with other eviscerated carcasses for 45 min to simulate industrial immersion chilling. Immediately after chilling, each carcass half was subjected to another 1-min rinse, after which the skin within the rectangle was aseptically removed from the carcass halves and stomached. Rinses of fecally contaminated halves had significantly higher Enterobacteriaceae immediately before chilling, but there were no differences in coliform and Escherichia coli counts. After chilling, there were no differences in Enterobacteriaceae, coliform, and E. coli counts in rinse or skin samples from the paired carcass halves. Correlations were generally poor between counts in rinse and skin samples but were significant between prechill and postchill rinses for both control and fecally contaminated halves. Correlations were also significant between counts in rinses of control and contaminated halves of the same carcass after chilling. Bacterial counts in postchill carcass rinses did not indicate that fecal contamination occurred before chilling.

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