- Email: [email protected]
Effect of delayed placement on the incidence of Campylobacter jejuni in broiler chickens1
Effect of Delayed Placement on the Incidence of Campylobacter jejuni in Broiler Chickens1 W. L. Willis,2 C. Murray, and C. Talbott Department of Animal Science, North Carolina Agricultural and Technical State University, Greensboro, North Carolina 27411 respectively. At 28 d of age, 100% of all chicks sampled tested positive. In Trial 2, 60 market age broilers were evaluated for the presence of C. jejuni in the crop by subjecting them to 0-, 4-, 8-, 12-, and 16-h feed withdrawal times on litter or in wire cages. Crops were collected aseptically from the broilers, stomached, enriched in Bolton broth, and then plated on BBL agar. There were no significant (P < 0.05) differences between cage and floor withdrawal times for the presence of C. jejuni in the crop samples of broilers; however, there were significant differences in the length of withdrawal on the presence of C. jejuni. Collectively, these results suggested that the isolation of C. jejuni occurred earlier in broilers that were subjected to delayed placement on reused litter and that extended feed withdrawal times in cages or on litter may increase the possibility that the crop of broilers may contain a higher isolation rate of C. jejuni.
(Key words: Campylobacter jejuni, delayed placement, broilers, crop feed withdrawal) 2000 Poultry Science 79:1392–1395
INTRODUCTION Campylobacter is the most frequent cause of food-borne illness in the United States, according to many sets of survey results (Altekruse et al., 1997). Poultry have been cited as a major source of Campylobacter jejuni in human infections (Blaser et al., 1983; Franco, 1988; Tauxe, 1992). The high occurrence of C. jejuni is problematic for both broilers and turkeys in growout and processing. There is a lack of knowledge and understanding concerning the epidemiology and behavior of this pathogen in poultry. Infection rates have exceeded 60% in breeder flocks and 80% in broiler flocks (Shane, 1998). The presence of C. jejuni in processed broiler carcasses offered for retail sale was reported to range from 7 to 32% during the winter months and from 87 to 97% during the summer
Received for publication November 9, 1999. Accepted for publication June 19, 2000. 1 Research was supported by Evans-Allen funding through the United States Department of Agriculture/Cooperative State Research Service (USDA/Cooperative State Research, Education, and Extension Service, Washington, DC 20250). 2 To whom correspondence should be addressed: [email protected].
months (Willis and Murray, 1997). Seasonal variations in C. jejuni colonization have been reported for broiler flocks (Jacobs-Reitsma et al., 1994; Willis et al., 1991). Campylobacter jejuni infections in humans have shown peak isolation rates during the summer (Tauxe, 1992). Carcass contamination in a poultry processing plant generally results when intestinal contents are released from the birds. Recently, Byrd et al. (1998) reported that the incidence of Campylobacter contamination of crop contents exceeded that of the cecal contents. Those researchers further observed an association between extended withdrawal time and higher incidence of Campylobacter in the crop. Kotula and Pandya (1995) reported higher C. jejuni contamination on the breast tissue of broiler carcasses than on other areas. They further reported that the feathers over the breast were more heavily contaminated with Campylobacter than were feathers over the thigh and drum. Specific studies on husbandry at broiler farms and marketing practices with regard to Campylobacter infection are lacking. For that reason, this study was conducted to assess the effect of delayed placement on C. jejuni isolation rates and to determine whether removing market broilers
1392
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
ABSTRACT An experiment was conducted with broiler chickens to evaluate the effect of delayed placement on reused litter and the isolation of Campylobacter jejuni. The experiment also assessed the presence of C. jejuni in the crop following feed withdrawal periods in cages vs floor environments. Trial 1 utilized 320 female broiler chicks obtained from a commercial hatchery. The chicks were randomly placed into the following experimental groups that were replicated four times with 20 chicks per pen: 1) 0-h, 2) 24-h, 3) 48-h, and 4) 72-h delayed placement. Fecal samples were collected via the cloaca at 7, 14, 21, and 28 d of age; enriched in Bolton broth; and plated onto BBL agar. Campylobacter jejuni was isolated at 1 wk of age in the 48- and 72-h experimental groups but did not differ significantly from the others. Sampling results at 14 d of age showed that 63, 68, 73, and 80% of chicks were positive for the 0-, 24-, 48-, and 72-h treatments,
1393
CAMPYLOBACTER JEJUNI AND DELAYED BROILER PLACEMENT
from litter during withdrawal would lead to a reduction in the presence of Campylobacter in the crop as the withdrawal period increased.
MATERIALS AND METHODS Trial 1
Trial 2 To determine the presence of C. jejuni in the crops of broilers subjected to extended feed withdrawal on floor litter and wire cages, 60 broilers from the previous trial were utilized. These 7-wk-old broilers tested positive for the C. jejuni organism prior to the withdrawal regimens. Broilers (n = 30) were randomly selected from the floorreared broilers, and 6 each were placed in wire cage pens for 0-, 4-, 8-, 12-, and 16-h feed withdrawal periods before
3
Becton Dickinson Microbiology Systems, Cockeysville, MD 21030. Tekmar Stomacher 400, Laboratory Blender, Cincinnati, OH 45242-9576. 4
Campylobacter [positive/total (%)]
Placement times (h)
1
7d
0 24 48 72 Pooled SEM
0/40 0/40 1/40 3/40 4.08
14 d a
(0) (0)a (2.5)a (7.5)a
25/40 27/40 29/40 32/40 8.91
21 d a
(62.5) (67.5)a (72.5)a (80)a
37/40 38/40 39/40 40/40 3.81
28 d a
(92.5) (95)a (97.5)a (100)a
40/40 40/40 40/40 40/40 0.0
(100)a (100)a (100)a (100)a
a Means within columns with unlike superscripts are different (P < 0.05). 1 Number of days sampled.
their crops were aseptically collected. Six broilers were randomly selected from the floor pens in which they were reared and subjected to 0-, 4-, 8-, 12-, and 16-h withdrawal periods on the same litter. Each crop was removed, placed into sterile plastic bags, and transported in an ice cooler to the laboratory for analysis. The presence of Campylobacter in the crop was determined by adding 10 mL of 0.85% saline to each bag containing the crop of each bird and stomached4 for 120 s. Two mL of the stomached material was placed into 5 mL of a Bolton broth and incubated for 4 h at 32 C and then placed for 20 h at 42 C in a micro-aerobic environment (5% 02, 10% C02, 85% N2). After enrichment, the samples were streaked onto BBL media, placed in air-locked baggies with the gas mixture, and incubated for 24 to 48 h at 42 C. Confirmation of C. jejuni was achieved in the same way as in Trial 1.
Statistical Analysis Data in Trial 1 were subjected to analysis of variance using the General Linear Models procedure of SAS威 (SAS Institute, 1991). Treatment means were separated by the test of least significance. The main effects in Trial 2 were analyzed using Duncan’s multiple range test to assess significant (P ≤ 0.05) differences among means (Duncan, 1955).
RESULTS AND DISCUSSION Campylobacter jejuni was isolated at 7 d of age in the 48- and 72-h delayed placement experimental groups (Table 1). There are few reports citing isolation of C. jejuni at 7 d of age in broiler flocks. The isolation of C. jejuni this early in the production period is probably due to a very strong colonizing C. jejuni organism that was already established in the broiler house or was carried in the chicks from the hatchery and became detectable earlier because of the stress of feed withdrawal. The previous flock was positive, and placing the new chicks 1 d post removal enhanced colonization. Broiler chicks may experience considerable delay between hatching from the egg and gaining access to feed and water at the growout farm. There were no reports cited in the literature on the effect of delayed placement of chicks on used litter and the isolation of C. jejuni colonization in broiler chickens. It is an
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
To compare the incidence of C. jejuni in broilers subjected to delayed placement, 320 female broiler chicks were obtained from a commercial hatchery. The chicks were vaccinated at the hatchery for Marek’s disease virus, infectious bronchitis virus, and Newcastle disease virus. The chicks were randomly assigned to experimental pens with 20 chicks per pen. Treatment groups (in replicates of 4) were assigned randomly for placement times of 0, 24, 48, and 72 h after removal from the hatchery. Treatment groups of 24, 48, and 72 h were held in transportation boxes in their assigned pens until given access to feed and water. At the designated times, chicks were placed in floor pens (1.2 m2) on reused woodshavings. The woodshavings had been previously used by one flock that had tested positive in all pens for the C. jejuni organism. The average load for C. jejuni in the woodshavings was not tested. The litter pens were unoccupied for 1 d prior to the first placement of chicks. Prior to placement, the feeders and waterers were cleaned and sanitized. The litter was top-dressed with a layer of new woodshavings. The chicks were sampled weekly via the cloaca for C. jejuni using the Mini-Tip Culturette Collection and Transport System威3 starting at 7 d of age with 10 birds per replicate and ending at 28 d of age. Samples were transported to the laboratory in an ice cooler and cultured within 2 h after collection. Bolton broth (Musgrove et al., 1997) was used to enrich samples at 37 C for 4 h and at 42 C for the remaining 20 h prior to being cultured on BBL agar plates. The plates were placed in a micro-aerobic environment (5% 02, 10% C02, 85% N2) utilizing air-locked baggies and then incubated for 24 to 48 h at 42 C. Campylobacter jejuni colonies were confirmed using a latex-agglutination kit, microscopic observations, and other biochemical tests (Gram-stain, catalase, oxidase, and hydrolyzed hippurate).
TABLE 1. Isolation of Campylobacter jejuni in broilers subjected to delayed placement
1394
WILLIS ET AL.
TABLE 2. Percent isolation of Campylobacter jejuni in crops of broilers placed in cages or on floors Housing type
Percent isolation (n = 30)
Floor Cage MSE1
83.3a 76.7a 8.20
Means with unlike superscripts are different (P < 0.05). Mean square error.
a 1
TABLE 3. Percent isolation of Campylobacter jejuni in crops of broilers subjected to various withdrawal times Length of feed withdrawal (h)
Percent isolation (n = 12)
0 4 8 12 16 MSE1
25.0b 75.0a 100.0a 100.0a 100.0a 8.20
Means with unlike superscripts are different (P < 0.05). Mean square error.
a,b 1
creases after the crop is emptied of feed. It was also cited that, during feed withdrawal, a reduction in the lactic acid population decreases the ability of the crop to inhibit the growth of organisms. Although small, the present study clearly suggests that the consumption of Campylobacter-contaminated litter does not necessarily result in increased crop contamination, but rather increased crop presence and detection of C. jejuni. From this study, it may be concluded that delayed placement (by 48 and 72 h) when birds are placed on feed and water does affect the isolation rate. Further, longer withdrawal periods show a higher incidence of Campylobacter detection in the crop, but it is not necessarily caused by the consumption of contaminated litter.
ACKNOWLEDGMENTS The authors thank Linda Guy and Anthony Hooks for their clerical and technical assistance during this study. We acknowledge with appreciation the critical review of this manuscript by Patricia Beetham and Mitch Arnold (School of Agriculture, Greensboro, North Carolina 27411).
REFERENCES Altekruse, S. F., M. L. Cohen, and D. L. Swerdlow, 1997. Emerging foodborne diseases. Emerg. Infect. Dis. 3(3):285−293. Blaser, M. J., D. N. Taylor, and R. A. Feldman, 1983. Edipemiology of Campylobacter jejuni. Infect Epidemiol. Rev. 5:157−176. Byrd, J. A., D. E. Corrier, M. E. Hume, R. H. Bailey, L. H. Stanker, and B. M. Hargis, 1998. Incidence of Campylobacter in crops of preharvest market-age broiler chickens. Poultry Sci. 77:1303−1305. Dibner, J. J., C. D. Knight, and F. J. Ivey, 1998. The feeding of neonatal poultry. World’s Poult. Sci. J. 14(5):36−41. Duncan, D. B., 1955. Multiple range and multiple F test. Biometrics 11:1−42. Franco, D. A., 1988. Campylobacter species: Considerations for controlling a foodborne pathogen. J. Food Prot. 51:145−153. Hinton, A., R. J. Buhr, and K. D. Ingram, 2000. Physical, chemical, and microbiological changes in the crop of broiler chickens subjected to incremental feed withdrawal. Poultry Sci. 79:212−218. Jacobs-Reitsma, W. F., N. M. Bolder, and R.W.A.W. Mulder, 1994. Cecal carriage of Campylobacter and Salmonella in Dutch broiler flocks at slaughter: A one-year study. Poultry Sci. 73:1260−1266. Kelley, T. R., O. C. Pancorbo, W. C. Merka, S. A. Thompson, M. L. Cabrera, and H. M. Cabrera, and J. M. Barhart, 1995. Bacterial pathogens and indicators in poultry litter during re-utilization. J. Appl. Poult. Sci. 4:366−373.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
established practice to reuse litter in broiler production. However, microorganisms accumulate with used litter and pose a continual threat when chicks are stressed after an extended posthatch holding time (Kelley et al., 1995). Withholding feed and water from the chicks appeared to enhance the colonization and shedding of C. jejuni, but it is not clear whether the stress associated with lack of feed induced early colonization. There are reports indicating that delaying balanced nutrition for even 24 h can impact the immune system. Dibner et al. (1998) indicated that in gnotobiotic birds, in the absence of oral intake, lymphocytes fail to colonize mucosal sites such as the cecal tonsils, thus increasing opportunities for infections. The absorption of the yolk contents did not help to reduce colonization of C. jejuni. At this time, it remains unknown whether the stresses from placement on used litter increased the chick s vulnerability to C. jejuni infection. There appears to be little effect among experimental groups based upon current management practices. The early increased isolation rate would have little effect at slaughter based on the fact that all birds were (100%) positive at 28 d of age. The results in Trial 2 indicated that the incidence of Campylobacter crop contamination did not differ significantly (P < 0.05) between floor and cage feed withdrawal (Table 2). A study conducted by Byrd et al. (1998) observed that prolonged feed withdrawal is associated with an increase in Campylobacter crop contamination. Our findings also demonstrated that broiler crops full of feed (no withdrawal time) have a lower incidence of positive C. jejuni cultures. Our findings with the cage data suggest that C. jejuni is present in the crop regardless of feed withdrawal time, although better detection occurs when the crop is voided of feed than when it is full. Microbiological changes with Salmonella typhimurium in the crop of broiler chickens subjected to incremental feed withdrawal were recently studied by Hinton et al. (2000). They found that conducting feed withdrawal in crates or on litter produced no significant differences in the changes in crop microflora caused by feed withdrawal. Ramirez et al. (1997) observed that the isolation of Salmonella from the crops of broilers at a commercial rearing house was greater after 8 h of feed withdrawal than before feed withdrawal. Our findings show similar trends, as a higher number of crops tested positive as the withdrawal period lengthened (Table 3). However, we do not attribute this increase to the consumption of contaminated litter, as they suggested. Instead, we agree with the findings of Hinton et al. (2000) with Salmonella. Those researchers indicated that the antibacterial activity of the crop de-
CAMPYLOBACTER JEJUNI AND DELAYED BROILER PLACEMENT Kotula, K. L., and Y. Pandya, 1995. Bacterial contamination of broiler chickens before scalding. J. Food Prot. 58:1326−1329. Musgrove, M. T., N. J. Stern, and J. S. Bailey, 1997. A comparison of enrichment methods for the recovery of Campylobacter spp. in broiler litter samples. Poultry Sci. 76(Suppl. 1):117. Raminez, G. A., L. L. Sarlin, D. J. Caldwell, C. R. Yezak, M. E. Hume, D. E. Carrier, J. R. DeLoach, and B. M. Hargis, 1997. Effect of feed withdrawal on the incidence of Salmonella in the crops and ceca of market age broiler chickens. Poultry Sci. 76:654−656. SAS Institute, 1991. SAS威 User’s Guide: Statistics Versions Edition. SAS Institute, Inc., Cary, NC. Shane, S. M., 1998. Is Campylobacter coming round the corner? Poultry (Oct/Nov):16−18.
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Tauxe, R. V., 1992. Epidemiology of Campylobacter jejuni infection in the United States and other industrialized nations. Pages 9−19 in: Current Status and Future Trends. I. Nachamkin, M. J. Blaser, and L. S. Tompkins, eds. American Association of Microbiologists, Washington, DC. Willis, W. L., and C. Murray, 1997. Campylobacter jejuni seasonal recovery observations of retail market broilers. Poultry Sci. 76:314−317. Willis, W. L., C. Murray, and T. Hanner, 1991. Evaluation of natural Campylobacter jejuni colonization in broiler environments. Pages 309−313 in: Colonization Control of Human Bacterial Enteropathogens in Poultry. L. C. Blankenship, ed. Academic Press Inc., San Diego, CA.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
(Key words: Campylobacter jejuni, delayed placement, broilers, crop feed withdrawal) 2000 Poultry Science 79:1392–1395
INTRODUCTION Campylobacter is the most frequent cause of food-borne illness in the United States, according to many sets of survey results (Altekruse et al., 1997). Poultry have been cited as a major source of Campylobacter jejuni in human infections (Blaser et al., 1983; Franco, 1988; Tauxe, 1992). The high occurrence of C. jejuni is problematic for both broilers and turkeys in growout and processing. There is a lack of knowledge and understanding concerning the epidemiology and behavior of this pathogen in poultry. Infection rates have exceeded 60% in breeder flocks and 80% in broiler flocks (Shane, 1998). The presence of C. jejuni in processed broiler carcasses offered for retail sale was reported to range from 7 to 32% during the winter months and from 87 to 97% during the summer
Received for publication November 9, 1999. Accepted for publication June 19, 2000. 1 Research was supported by Evans-Allen funding through the United States Department of Agriculture/Cooperative State Research Service (USDA/Cooperative State Research, Education, and Extension Service, Washington, DC 20250). 2 To whom correspondence should be addressed: [email protected].
months (Willis and Murray, 1997). Seasonal variations in C. jejuni colonization have been reported for broiler flocks (Jacobs-Reitsma et al., 1994; Willis et al., 1991). Campylobacter jejuni infections in humans have shown peak isolation rates during the summer (Tauxe, 1992). Carcass contamination in a poultry processing plant generally results when intestinal contents are released from the birds. Recently, Byrd et al. (1998) reported that the incidence of Campylobacter contamination of crop contents exceeded that of the cecal contents. Those researchers further observed an association between extended withdrawal time and higher incidence of Campylobacter in the crop. Kotula and Pandya (1995) reported higher C. jejuni contamination on the breast tissue of broiler carcasses than on other areas. They further reported that the feathers over the breast were more heavily contaminated with Campylobacter than were feathers over the thigh and drum. Specific studies on husbandry at broiler farms and marketing practices with regard to Campylobacter infection are lacking. For that reason, this study was conducted to assess the effect of delayed placement on C. jejuni isolation rates and to determine whether removing market broilers
1392
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
ABSTRACT An experiment was conducted with broiler chickens to evaluate the effect of delayed placement on reused litter and the isolation of Campylobacter jejuni. The experiment also assessed the presence of C. jejuni in the crop following feed withdrawal periods in cages vs floor environments. Trial 1 utilized 320 female broiler chicks obtained from a commercial hatchery. The chicks were randomly placed into the following experimental groups that were replicated four times with 20 chicks per pen: 1) 0-h, 2) 24-h, 3) 48-h, and 4) 72-h delayed placement. Fecal samples were collected via the cloaca at 7, 14, 21, and 28 d of age; enriched in Bolton broth; and plated onto BBL agar. Campylobacter jejuni was isolated at 1 wk of age in the 48- and 72-h experimental groups but did not differ significantly from the others. Sampling results at 14 d of age showed that 63, 68, 73, and 80% of chicks were positive for the 0-, 24-, 48-, and 72-h treatments,
1393
CAMPYLOBACTER JEJUNI AND DELAYED BROILER PLACEMENT
from litter during withdrawal would lead to a reduction in the presence of Campylobacter in the crop as the withdrawal period increased.
MATERIALS AND METHODS Trial 1
Trial 2 To determine the presence of C. jejuni in the crops of broilers subjected to extended feed withdrawal on floor litter and wire cages, 60 broilers from the previous trial were utilized. These 7-wk-old broilers tested positive for the C. jejuni organism prior to the withdrawal regimens. Broilers (n = 30) were randomly selected from the floorreared broilers, and 6 each were placed in wire cage pens for 0-, 4-, 8-, 12-, and 16-h feed withdrawal periods before
3
Becton Dickinson Microbiology Systems, Cockeysville, MD 21030. Tekmar Stomacher 400, Laboratory Blender, Cincinnati, OH 45242-9576. 4
Campylobacter [positive/total (%)]
Placement times (h)
1
7d
0 24 48 72 Pooled SEM
0/40 0/40 1/40 3/40 4.08
14 d a
(0) (0)a (2.5)a (7.5)a
25/40 27/40 29/40 32/40 8.91
21 d a
(62.5) (67.5)a (72.5)a (80)a
37/40 38/40 39/40 40/40 3.81
28 d a
(92.5) (95)a (97.5)a (100)a
40/40 40/40 40/40 40/40 0.0
(100)a (100)a (100)a (100)a
a Means within columns with unlike superscripts are different (P < 0.05). 1 Number of days sampled.
their crops were aseptically collected. Six broilers were randomly selected from the floor pens in which they were reared and subjected to 0-, 4-, 8-, 12-, and 16-h withdrawal periods on the same litter. Each crop was removed, placed into sterile plastic bags, and transported in an ice cooler to the laboratory for analysis. The presence of Campylobacter in the crop was determined by adding 10 mL of 0.85% saline to each bag containing the crop of each bird and stomached4 for 120 s. Two mL of the stomached material was placed into 5 mL of a Bolton broth and incubated for 4 h at 32 C and then placed for 20 h at 42 C in a micro-aerobic environment (5% 02, 10% C02, 85% N2). After enrichment, the samples were streaked onto BBL media, placed in air-locked baggies with the gas mixture, and incubated for 24 to 48 h at 42 C. Confirmation of C. jejuni was achieved in the same way as in Trial 1.
Statistical Analysis Data in Trial 1 were subjected to analysis of variance using the General Linear Models procedure of SAS威 (SAS Institute, 1991). Treatment means were separated by the test of least significance. The main effects in Trial 2 were analyzed using Duncan’s multiple range test to assess significant (P ≤ 0.05) differences among means (Duncan, 1955).
RESULTS AND DISCUSSION Campylobacter jejuni was isolated at 7 d of age in the 48- and 72-h delayed placement experimental groups (Table 1). There are few reports citing isolation of C. jejuni at 7 d of age in broiler flocks. The isolation of C. jejuni this early in the production period is probably due to a very strong colonizing C. jejuni organism that was already established in the broiler house or was carried in the chicks from the hatchery and became detectable earlier because of the stress of feed withdrawal. The previous flock was positive, and placing the new chicks 1 d post removal enhanced colonization. Broiler chicks may experience considerable delay between hatching from the egg and gaining access to feed and water at the growout farm. There were no reports cited in the literature on the effect of delayed placement of chicks on used litter and the isolation of C. jejuni colonization in broiler chickens. It is an
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
To compare the incidence of C. jejuni in broilers subjected to delayed placement, 320 female broiler chicks were obtained from a commercial hatchery. The chicks were vaccinated at the hatchery for Marek’s disease virus, infectious bronchitis virus, and Newcastle disease virus. The chicks were randomly assigned to experimental pens with 20 chicks per pen. Treatment groups (in replicates of 4) were assigned randomly for placement times of 0, 24, 48, and 72 h after removal from the hatchery. Treatment groups of 24, 48, and 72 h were held in transportation boxes in their assigned pens until given access to feed and water. At the designated times, chicks were placed in floor pens (1.2 m2) on reused woodshavings. The woodshavings had been previously used by one flock that had tested positive in all pens for the C. jejuni organism. The average load for C. jejuni in the woodshavings was not tested. The litter pens were unoccupied for 1 d prior to the first placement of chicks. Prior to placement, the feeders and waterers were cleaned and sanitized. The litter was top-dressed with a layer of new woodshavings. The chicks were sampled weekly via the cloaca for C. jejuni using the Mini-Tip Culturette Collection and Transport System威3 starting at 7 d of age with 10 birds per replicate and ending at 28 d of age. Samples were transported to the laboratory in an ice cooler and cultured within 2 h after collection. Bolton broth (Musgrove et al., 1997) was used to enrich samples at 37 C for 4 h and at 42 C for the remaining 20 h prior to being cultured on BBL agar plates. The plates were placed in a micro-aerobic environment (5% 02, 10% C02, 85% N2) utilizing air-locked baggies and then incubated for 24 to 48 h at 42 C. Campylobacter jejuni colonies were confirmed using a latex-agglutination kit, microscopic observations, and other biochemical tests (Gram-stain, catalase, oxidase, and hydrolyzed hippurate).
TABLE 1. Isolation of Campylobacter jejuni in broilers subjected to delayed placement
1394
WILLIS ET AL.
TABLE 2. Percent isolation of Campylobacter jejuni in crops of broilers placed in cages or on floors Housing type
Percent isolation (n = 30)
Floor Cage MSE1
83.3a 76.7a 8.20
Means with unlike superscripts are different (P < 0.05). Mean square error.
a 1
TABLE 3. Percent isolation of Campylobacter jejuni in crops of broilers subjected to various withdrawal times Length of feed withdrawal (h)
Percent isolation (n = 12)
0 4 8 12 16 MSE1
25.0b 75.0a 100.0a 100.0a 100.0a 8.20
Means with unlike superscripts are different (P < 0.05). Mean square error.
a,b 1
creases after the crop is emptied of feed. It was also cited that, during feed withdrawal, a reduction in the lactic acid population decreases the ability of the crop to inhibit the growth of organisms. Although small, the present study clearly suggests that the consumption of Campylobacter-contaminated litter does not necessarily result in increased crop contamination, but rather increased crop presence and detection of C. jejuni. From this study, it may be concluded that delayed placement (by 48 and 72 h) when birds are placed on feed and water does affect the isolation rate. Further, longer withdrawal periods show a higher incidence of Campylobacter detection in the crop, but it is not necessarily caused by the consumption of contaminated litter.
ACKNOWLEDGMENTS The authors thank Linda Guy and Anthony Hooks for their clerical and technical assistance during this study. We acknowledge with appreciation the critical review of this manuscript by Patricia Beetham and Mitch Arnold (School of Agriculture, Greensboro, North Carolina 27411).
REFERENCES Altekruse, S. F., M. L. Cohen, and D. L. Swerdlow, 1997. Emerging foodborne diseases. Emerg. Infect. Dis. 3(3):285−293. Blaser, M. J., D. N. Taylor, and R. A. Feldman, 1983. Edipemiology of Campylobacter jejuni. Infect Epidemiol. Rev. 5:157−176. Byrd, J. A., D. E. Corrier, M. E. Hume, R. H. Bailey, L. H. Stanker, and B. M. Hargis, 1998. Incidence of Campylobacter in crops of preharvest market-age broiler chickens. Poultry Sci. 77:1303−1305. Dibner, J. J., C. D. Knight, and F. J. Ivey, 1998. The feeding of neonatal poultry. World’s Poult. Sci. J. 14(5):36−41. Duncan, D. B., 1955. Multiple range and multiple F test. Biometrics 11:1−42. Franco, D. A., 1988. Campylobacter species: Considerations for controlling a foodborne pathogen. J. Food Prot. 51:145−153. Hinton, A., R. J. Buhr, and K. D. Ingram, 2000. Physical, chemical, and microbiological changes in the crop of broiler chickens subjected to incremental feed withdrawal. Poultry Sci. 79:212−218. Jacobs-Reitsma, W. F., N. M. Bolder, and R.W.A.W. Mulder, 1994. Cecal carriage of Campylobacter and Salmonella in Dutch broiler flocks at slaughter: A one-year study. Poultry Sci. 73:1260−1266. Kelley, T. R., O. C. Pancorbo, W. C. Merka, S. A. Thompson, M. L. Cabrera, and H. M. Cabrera, and J. M. Barhart, 1995. Bacterial pathogens and indicators in poultry litter during re-utilization. J. Appl. Poult. Sci. 4:366−373.
Downloaded from http://ps.oxfordjournals.org/ at East Carolina University on April 27, 2015
established practice to reuse litter in broiler production. However, microorganisms accumulate with used litter and pose a continual threat when chicks are stressed after an extended posthatch holding time (Kelley et al., 1995). Withholding feed and water from the chicks appeared to enhance the colonization and shedding of C. jejuni, but it is not clear whether the stress associated with lack of feed induced early colonization. There are reports indicating that delaying balanced nutrition for even 24 h can impact the immune system. Dibner et al. (1998) indicated that in gnotobiotic birds, in the absence of oral intake, lymphocytes fail to colonize mucosal sites such as the cecal tonsils, thus increasing opportunities for infections. The absorption of the yolk contents did not help to reduce colonization of C. jejuni. At this time, it remains unknown whether the stresses from placement on used litter increased the chick s vulnerability to C. jejuni infection. There appears to be little effect among experimental groups based upon current management practices. The early increased isolation rate would have little effect at slaughter based on the fact that all birds were (100%) positive at 28 d of age. The results in Trial 2 indicated that the incidence of Campylobacter crop contamination did not differ significantly (P < 0.05) between floor and cage feed withdrawal (Table 2). A study conducted by Byrd et al. (1998) observed that prolonged feed withdrawal is associated with an increase in Campylobacter crop contamination. Our findings also demonstrated that broiler crops full of feed (no withdrawal time) have a lower incidence of positive C. jejuni cultures. Our findings with the cage data suggest that C. jejuni is present in the crop regardless of feed withdrawal time, although better detection occurs when the crop is voided of feed than when it is full. Microbiological changes with Salmonella typhimurium in the crop of broiler chickens subjected to incremental feed withdrawal were recently studied by Hinton et al. (2000). They found that conducting feed withdrawal in crates or on litter produced no significant differences in the changes in crop microflora caused by feed withdrawal. Ramirez et al. (1997) observed that the isolation of Salmonella from the crops of broilers at a commercial rearing house was greater after 8 h of feed withdrawal than before feed withdrawal. Our findings show similar trends, as a higher number of crops tested positive as the withdrawal period lengthened (Table 3). However, we do not attribute this increase to the consumption of contaminated litter, as they suggested. Instead, we agree with the findings of Hinton et al. (2000) with Salmonella. Those researchers indicated that the antibacterial activity of the crop de-
CAMPYLOBACTER JEJUNI AND DELAYED BROILER PLACEMENT Kotula, K. L., and Y. Pandya, 1995. Bacterial contamination of broiler chickens before scalding. J. Food Prot. 58:1326−1329. Musgrove, M. T., N. J. Stern, and J. S. Bailey, 1997. A comparison of enrichment methods for the recovery of Campylobacter spp. in broiler litter samples. Poultry Sci. 76(Suppl. 1):117. Raminez, G. A., L. L. Sarlin, D. J. Caldwell, C. R. Yezak, M. E. Hume, D. E. Carrier, J. R. DeLoach, and B. M. Hargis, 1997. Effect of feed withdrawal on the incidence of Salmonella in the crops and ceca of market age broiler chickens. Poultry Sci. 76:654−656. SAS Institute, 1991. SAS威 User’s Guide: Statistics Versions Edition. SAS Institute, Inc., Cary, NC. Shane, S. M., 1998. Is Campylobacter coming round the corner? Poultry (Oct/Nov):16−18.
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Tauxe, R. V., 1992. Epidemiology of Campylobacter jejuni infection in the United States and other industrialized nations. Pages 9−19 in: Current Status and Future Trends. I. Nachamkin, M. J. Blaser, and L. S. Tompkins, eds. American Association of Microbiologists, Washington, DC. Willis, W. L., and C. Murray, 1997. Campylobacter jejuni seasonal recovery observations of retail market broilers. Poultry Sci. 76:314−317. Willis, W. L., C. Murray, and T. Hanner, 1991. Evaluation of natural Campylobacter jejuni colonization in broiler environments. Pages 309−313 in: Colonization Control of Human Bacterial Enteropathogens in Poultry. L. C. Blankenship, ed. Academic Press Inc., San Diego, CA.
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