J Vet Diagn Invest 4:416-418 (1992)
Salmonella enteritidis in commercial layer farms in New York state; environmental survey results and significance of available monitoring tests A. Mutalib, P. McDonough, S. Shin, V. Patten, D. Lein Abstract. Seven hundred fifty-one environmental samples were collected from 76 chicken layer houses in a voluntary Salmonella enteritidis (SE) survey study carried out in New York state between January 15 and April 8, 1991. SE was recovered from both houses on 1 farm. Sampling of manure pits and mice in hen houses was useful for SE screening. Phage types of SE from the environment, birds, and mice were identical. The rapid whole-blood test was unreliable, and culture of cloaca1 swabs was inadequate for detection of SE carriers. Culture of organs from chickens did not correlate well with results of environmental samples.
isons were also made using chickens from a known SEinfected flock from another state.
Although Salmonella enteritidis (SE) infection is actually not a serious disease of chickens, the negative publicity that has resulted from the incrimination of fresh eggs in recent human SE outbreaks’ has now made SE 1 of the most important problems confronting the egg industry. The detection of SE in flocks of laying hens has thus become a public health priority and a matter of great concern to egg producers. A variety of diagnostic procedures have been developed for detection of salmonella infections in poultry. Serologic tests for paratyphoid salmonellae have low sensitivity and poor reliability.9,11 Bacteriologic culture of environmental samples has become a popular method for SE survey studies in poultry houses. The recovery of SE from internal tissues is an indication of infection with an invasive strain with a potential of transovarian contamination of eggs.2 Cloaca1 swab culture was selected for inclusion in this study to detect SE in live birds that were needed for research purpose. Although cloaca1 culture has been applied widely under field conditions, its reliability for detecting avian salmonellosis seems limited.4,5,9 Rats and mice are frequently intestinal carriers of paratyphoid organisms.5 This paper reports findings of a field surveillance study on SE infection in commercial layers in New York state. The results of salmonella isolation from internal organs, cloaca1 swabs, and fecal samples were compared with serologic results using a rapid wholeblood test with S. pullorum antigen. Similar compar-
Materials and methods Environmental sampling for SE culture. Seven hundred fifty-one environmental samples were collected from 76
From the Diagnostic Laboratory, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. Presented at the 34th AAVLD Annual Meeting, October 27-29, 1991, San Diego, CA. Received for publication January 23, 1992.
houses holding 2,484,000 layers on 28 farms in New York state between January 15 and April 8, 1991. Egg belts, egg elevators, and manure pits were sampled in each house. At least 1 m of each egg belt and half of the total surface area of each egg elevator were wiped with 2 sterile 4 x 4 gauze pads, premoistened with approximately 5 ml of doublestrength skim milk (200 g/liter solution). The manure piles, drop boards, or manure scrapers were sampled by drag swabs premoistened with milk as above. Samples were transferred to sterile plastic cups, diluted with 45 ml of selenite brotha (1:10 dilution), and incubated at 42 C for 24 hr. Broths were then streaked onto brilliant green agara (BG) plates supplemented with 0.02 mg/g novobiocinb and onto XLT-4 agar (XL base,b Tergitolc) plates and incubated at 37 C for 24 hr. Suspicious and typical salmonella colonies were transferred to Kligler’s Iron agar slants,a and final identification was made biochemically and serologically. All serogroup D1 salmonellae were sent to the National Veterinary Services Laboratory, Ames, Iowa, for sero- and phage typing. Serologic testing for SE. Blood from 300 chickens was tested for antibodies to SE in flocks with SE-positive environmental samples. Blood was collected from the brachial vein and was evaluated in a rapid whole-blood test11 using a commercially available S. pullorum antigen.d Reactors were submitted for culture of internal organs. Sampling of organs for SE culture. Samples of the heart, liver, spleen, ovary, and oviduct from each of 60 birds from environmentally SE-positive houses were removed aseptically, transferred to sterile plastic cups, minced, and diluted with selenite brotha to make a 1:10 dilution (w/v). Cecal tonsils were collected separately, and samples from groups of 5 birds were pooled and cultured in broth as above. Broths were then streaked onto BG plates, and suspicious salmonella colonies were screened and identified as above.
416
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
S. enteritidis in layer farms
In 1 SE-positive house, 5 mice were trapped, and pooled samples of internal organs from each mouse were collected and cultured as above. Cloaca1 and fecal sampling for SE culture. Cloaca1 sampling was carried out on 2,500 chickens in 1 of the survey flocks that was found to be naturally infected with SE phage type 2. A sterile cotton swab, premoistened with sterile tetrathionate broth,” was inserted into the cloaca of each bird and rotated gently against the lining of the cloaca to collect a sample. Swabs from groups of 5 birds were pooled and transferred to 10-ml tubes of tetrathionate broth, incubated at 42 C for 24 hr, and streaked onto BG plates. Isolated salmonellae were identified as above. In the above flock, 25 layers that escaped the cages to the manure pit for at least 2 wk were captured and blood tested. Cloaca1 swabs and pools of internal organs were collected and processed as above. Comparative evaluation of monitoring methods. Results from the survey suggested that some monitoring methods were more efficient than others in detection of SE in infected flocks. To test the monitoring methods on a comparative basis, layers were obtained from a known SE-positive flock in another state. Sixty-four chickens, naturally infected with SE phage type 8, were randomly collected and housed in individual cages in the Poultry Virus Isolation Building at Cornell University. Cloaca1 swabs and fecal samples were collected and cultured individually as above. Blood from each bird was evaluated in the rapid whole-blood test utilizing S. pullorum antigen from two commercial sources.d,e
Results Salmonellae other than SE were isolated from all houses on the 28 farms included in the survey. A complete typing of these salmonellae was not done for economic reasons. SE was recovered from both houses on 1 farm. In the first house, which consisted of 4 rows, each housing 3,000 birds, SE was isolated from both the egg belts and elevators in row 2. Blood tests and organ cultures of birds from this row were negative for SE In the second house, where there were 5 rows, each with 3,000 birds, SE was isolated from the manure pile under row 1. Organ cultures were positive in 1 bird from this row; however, the blood test was negative in this bird. Organ cultures of mice in this house were positive for SE. Isolated SE from the chicken, manure pile, and mice were all phage type 2. Cloacal swabs from 2,500 of the 3,000 chickens in this row cultivated negative for SE. Cloacal swabs, organ cultures, and blood tests from the 25 birds that escaped to the manure pit in this house were also negative. SE was isolated from fecal samples of 3 of the 64 chickens that were obtained from a known infected flock and individually housed in an isolation unit at Cornell. Other salmonellae were isolated from 12 of the 64 birds. Cloacal cultures of the same birds were negative. Salisbury S. pullorum antigen was more sensitive than Vineland antigen (Table 1).
417
Table 1. Comparison* between fecal and cloaca1 cultures of commercial chickens and serologic results using Salmonella pullorum antigen from two sources.
Discussion Under most practical circumstances, it is more important to detect infection in a flock than in an individual bird. Culture and serologic methods have been used for detecting paratyphoid infections in chickens; however, both methods have advantages and disadvantages. The culture of environmental samples is an effective method; but success can be influenced by various factors: moisture content ammonia, and pH of litter; antagonisms among organisms; and bird infec3,6,8,9 The use of disinfectants and other baction level. terial growth inhibitors can also affect successful culture. In the present study, SE was recovered from the environment in 2 houses but was isolated from internal organs of birds in only 1 of those houses. Isolation of SE from the environment of a poultry house may not necessarily mean that the flock is infected at that time. Other biological and mechanical means of introducing infection should be considered. Discovery of SE-positive mice is a good example. Also, litter may remain positive well after birds in a flock have turned negative.3 Serologic detection of salmonella infection is less dependable in young birds because of relatively poor antibody production3,10 and can produce confusing results in later stages after salmonella can no longer be isolated from birds or environmental samples.4,12 Although the rapid whole-blood test using S. pullorum antigen is widely applied in the field, it is reported to be the least sensitive and most unreliable of available tests to serologically diagnose paratyphoid infections. 9,11 False-positive and false-negative reactions are commonly encountered with this test. Based on findings in the present study and on past experience, the Salisbury S. pullorum antigen is more sensitive than the Vineland antigen in detecting positive birds with SE infection; however, the Salisbury antigen also gives the most false-positive reactions, as has been found by previous workers. 1 In the present study, culture of cloacal swabs was insensitive in detecting salmonella infection in individual birds. Culture of fecal samples was more useful
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
Mutalib et al.
418
and correlated better with serologic tests. The lack of isolation of salmonellae from cloacal swabs was perhaps because of a low excretion rate, intermittent shedding, or insensitivity of the cloacal swab method itself 4,5,12 This method is highly dependable if large numbers of salmonella are being excreted, as is characteristic during the first few weeks of infection.9 Because of the low sensitivity and poor reliability of currently available serologic tests, culture of internal organs was used as the ultimate determinant of the SE infection status of a flock. Culture of internal organs from birds that had escaped the cages to the manure pit was not useful for indirect detection of salmonellae in the environment. The isolation of SE from mice is significant because mice can play an important role in transmission of SE. Very importantly, they can act as a biological reservoir of salmonella on a farm from which a multitude of salmonella serotypes can infect chickens and contaminate the eggs and environment. Acknowledgements The tremendous assistance of the New York State Department of Agriculture and Markets, state veterinarians, and technicians is greatly appreciated.
Sources and manufacturers a. b. c. d. e.
Becton Dickinson Microbiology Systems, Cockeysville, MO. Difco Laboratories, Detroit, MI. Sigma Chemical Corp., St. Louis, MO. Salisbury Laboratories, Charles City, IA. Vineland Laboratories, Vineland, NJ.
2. Gast RK, Beard CW: 1990, Isolation of Salmonella enteritidis from internal organs of experimentally infected hens. Avian Dis 34:991-993. 3. Olesiuk OM, Carlson VL, Snoeyenbos GH, et al.: 1969, Experimental Salmonella typhimurium infection in two chicken flocks. Avian Dis 13:500-508. 4. Sadler WW, Brownell JR, Fanelli MJ: 1969, Influences of age and inoculum level on shed pattern of Salmonella typhimurium in chickens. Avian Dis 13:793-803. 5. Sato G, Miyamae T, Miura S: 1970, A long-term epizootiological study of chicken salmonellosis on a farm with reference to elimination of paratyphoid infection by cloacal swab culture. Jpn J Vet Res 18:47-63. 6. Snoeyenbos GH, Carlson VL, Smyser CF, et al.: 1969, Dynamics of salmonella infection in chicks reared on litter. Avian Dis 13:72-83. 7. St. Louis ME, Morse DL, Potter ME, et al.: 1988, The emergence of grade A eggs as a major source of Salmonella enteritidis infections: new implications for the control of salmonellosis. J Am Med Assoc 259:2103-2107. 8. Tumbull PC, Snoeyenbos GH: 1973, The role of ammonia, water activity, and pH in the salmonellacidal effect of long-used poultry litter. Avian Dis 17:72-86. 9. Weinack OM, Smyser CF, Snoeyenbos GH: 1979, Evaluation of several methods of detecting salmonellae in groups of chickens. Avian Dis 23:179-193. 10. Williams JE, Whittemore: 1975, Influence of age on the serological response of chickens to Salmonella typhimurium infection. Avian Dis 19:745-760. 11. Williams JE, Whittemore: 1976, Comparison of six methods of detecting Salmonella typhimurium infection of chickens. Avian Dis 20:728-734. 12. Yamamoto R, Kilian JG, Babcock WE, et al.: 1962, Some observations on serological testing for Salmonella typhimurium in breeder turkeys. Avian Dis 6:444-454.
References 1. Gast RK, Beard CW: 1990, Serologic detection of experimental Salmonella enteritidis infections in laying hens. Avian Dis 34: 721-728.
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
450578
JVDXXX10.1177/1040638712450578
Erratum Journal of Veterinary Diagnostic Investigation 24(4) 813 © 2012 The Author(s) Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1040638712450578 http://jvdi.sagepub.com
Corrigendum
Stegelmeier, BL, et al.: 2010, Experimental rayless goldenrod (Isocoma pluriflora) toxicosis in goats. J Vet Diagn Invest. 22: 570–577
In the article “Experimental rayless goldenrod (Isocoma pluriflora) toxicosis in goats” by Bryan L. Stegelmeier et al., the published mean body weight and the means and statistics of serum biochemistries were carried out on groups of 4 animals, not 3, as described in the Material and Methods section. The additional animal in each group was part of an auxiliary physiologic study and though the animals were dosed and treated the same, they were not necropsied and were not included in the histologic study. To correct this oversight, the corrected weight and chemistry table (shaded cells indicate corrected numbers) are listed below. The differences are minimal and do not alter the conclusions. In addition, reference 7 has been deleted. Material and Methods: “Fifteen, yearling, female Spanish goats weighing 29.4 ± 3.4 kg (mean ± standard deviation) were randomly divided into 5 groups with 3 animals per group.”
References: Reference 7 should be deleted Corrected Table 1. Selected mean serum biochemical data from groups of 3 goats dosed with rayless goldenrod (Isocoma pluriflora) to obtain benzofuran ketone doses of 0, 10, 20, 40, and 60 mg/kg body weight for 7 days.* Serum result (mean ± standard deviation) Serum test (reference range†) Creatinine kinase (< 350 U/l) Cardiac troponin-I (
Salmonella enteritidis in commercial layer farms in New York state; environmental survey results and significance of available monitoring tests A. Mutalib, P. McDonough, S. Shin, V. Patten, D. Lein Abstract. Seven hundred fifty-one environmental samples were collected from 76 chicken layer houses in a voluntary Salmonella enteritidis (SE) survey study carried out in New York state between January 15 and April 8, 1991. SE was recovered from both houses on 1 farm. Sampling of manure pits and mice in hen houses was useful for SE screening. Phage types of SE from the environment, birds, and mice were identical. The rapid whole-blood test was unreliable, and culture of cloaca1 swabs was inadequate for detection of SE carriers. Culture of organs from chickens did not correlate well with results of environmental samples.
isons were also made using chickens from a known SEinfected flock from another state.
Although Salmonella enteritidis (SE) infection is actually not a serious disease of chickens, the negative publicity that has resulted from the incrimination of fresh eggs in recent human SE outbreaks’ has now made SE 1 of the most important problems confronting the egg industry. The detection of SE in flocks of laying hens has thus become a public health priority and a matter of great concern to egg producers. A variety of diagnostic procedures have been developed for detection of salmonella infections in poultry. Serologic tests for paratyphoid salmonellae have low sensitivity and poor reliability.9,11 Bacteriologic culture of environmental samples has become a popular method for SE survey studies in poultry houses. The recovery of SE from internal tissues is an indication of infection with an invasive strain with a potential of transovarian contamination of eggs.2 Cloaca1 swab culture was selected for inclusion in this study to detect SE in live birds that were needed for research purpose. Although cloaca1 culture has been applied widely under field conditions, its reliability for detecting avian salmonellosis seems limited.4,5,9 Rats and mice are frequently intestinal carriers of paratyphoid organisms.5 This paper reports findings of a field surveillance study on SE infection in commercial layers in New York state. The results of salmonella isolation from internal organs, cloaca1 swabs, and fecal samples were compared with serologic results using a rapid wholeblood test with S. pullorum antigen. Similar compar-
Materials and methods Environmental sampling for SE culture. Seven hundred fifty-one environmental samples were collected from 76
From the Diagnostic Laboratory, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853. Presented at the 34th AAVLD Annual Meeting, October 27-29, 1991, San Diego, CA. Received for publication January 23, 1992.
houses holding 2,484,000 layers on 28 farms in New York state between January 15 and April 8, 1991. Egg belts, egg elevators, and manure pits were sampled in each house. At least 1 m of each egg belt and half of the total surface area of each egg elevator were wiped with 2 sterile 4 x 4 gauze pads, premoistened with approximately 5 ml of doublestrength skim milk (200 g/liter solution). The manure piles, drop boards, or manure scrapers were sampled by drag swabs premoistened with milk as above. Samples were transferred to sterile plastic cups, diluted with 45 ml of selenite brotha (1:10 dilution), and incubated at 42 C for 24 hr. Broths were then streaked onto brilliant green agara (BG) plates supplemented with 0.02 mg/g novobiocinb and onto XLT-4 agar (XL base,b Tergitolc) plates and incubated at 37 C for 24 hr. Suspicious and typical salmonella colonies were transferred to Kligler’s Iron agar slants,a and final identification was made biochemically and serologically. All serogroup D1 salmonellae were sent to the National Veterinary Services Laboratory, Ames, Iowa, for sero- and phage typing. Serologic testing for SE. Blood from 300 chickens was tested for antibodies to SE in flocks with SE-positive environmental samples. Blood was collected from the brachial vein and was evaluated in a rapid whole-blood test11 using a commercially available S. pullorum antigen.d Reactors were submitted for culture of internal organs. Sampling of organs for SE culture. Samples of the heart, liver, spleen, ovary, and oviduct from each of 60 birds from environmentally SE-positive houses were removed aseptically, transferred to sterile plastic cups, minced, and diluted with selenite brotha to make a 1:10 dilution (w/v). Cecal tonsils were collected separately, and samples from groups of 5 birds were pooled and cultured in broth as above. Broths were then streaked onto BG plates, and suspicious salmonella colonies were screened and identified as above.
416
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
S. enteritidis in layer farms
In 1 SE-positive house, 5 mice were trapped, and pooled samples of internal organs from each mouse were collected and cultured as above. Cloaca1 and fecal sampling for SE culture. Cloaca1 sampling was carried out on 2,500 chickens in 1 of the survey flocks that was found to be naturally infected with SE phage type 2. A sterile cotton swab, premoistened with sterile tetrathionate broth,” was inserted into the cloaca of each bird and rotated gently against the lining of the cloaca to collect a sample. Swabs from groups of 5 birds were pooled and transferred to 10-ml tubes of tetrathionate broth, incubated at 42 C for 24 hr, and streaked onto BG plates. Isolated salmonellae were identified as above. In the above flock, 25 layers that escaped the cages to the manure pit for at least 2 wk were captured and blood tested. Cloaca1 swabs and pools of internal organs were collected and processed as above. Comparative evaluation of monitoring methods. Results from the survey suggested that some monitoring methods were more efficient than others in detection of SE in infected flocks. To test the monitoring methods on a comparative basis, layers were obtained from a known SE-positive flock in another state. Sixty-four chickens, naturally infected with SE phage type 8, were randomly collected and housed in individual cages in the Poultry Virus Isolation Building at Cornell University. Cloaca1 swabs and fecal samples were collected and cultured individually as above. Blood from each bird was evaluated in the rapid whole-blood test utilizing S. pullorum antigen from two commercial sources.d,e
Results Salmonellae other than SE were isolated from all houses on the 28 farms included in the survey. A complete typing of these salmonellae was not done for economic reasons. SE was recovered from both houses on 1 farm. In the first house, which consisted of 4 rows, each housing 3,000 birds, SE was isolated from both the egg belts and elevators in row 2. Blood tests and organ cultures of birds from this row were negative for SE In the second house, where there were 5 rows, each with 3,000 birds, SE was isolated from the manure pile under row 1. Organ cultures were positive in 1 bird from this row; however, the blood test was negative in this bird. Organ cultures of mice in this house were positive for SE. Isolated SE from the chicken, manure pile, and mice were all phage type 2. Cloacal swabs from 2,500 of the 3,000 chickens in this row cultivated negative for SE. Cloacal swabs, organ cultures, and blood tests from the 25 birds that escaped to the manure pit in this house were also negative. SE was isolated from fecal samples of 3 of the 64 chickens that were obtained from a known infected flock and individually housed in an isolation unit at Cornell. Other salmonellae were isolated from 12 of the 64 birds. Cloacal cultures of the same birds were negative. Salisbury S. pullorum antigen was more sensitive than Vineland antigen (Table 1).
417
Table 1. Comparison* between fecal and cloaca1 cultures of commercial chickens and serologic results using Salmonella pullorum antigen from two sources.
Discussion Under most practical circumstances, it is more important to detect infection in a flock than in an individual bird. Culture and serologic methods have been used for detecting paratyphoid infections in chickens; however, both methods have advantages and disadvantages. The culture of environmental samples is an effective method; but success can be influenced by various factors: moisture content ammonia, and pH of litter; antagonisms among organisms; and bird infec3,6,8,9 The use of disinfectants and other baction level. terial growth inhibitors can also affect successful culture. In the present study, SE was recovered from the environment in 2 houses but was isolated from internal organs of birds in only 1 of those houses. Isolation of SE from the environment of a poultry house may not necessarily mean that the flock is infected at that time. Other biological and mechanical means of introducing infection should be considered. Discovery of SE-positive mice is a good example. Also, litter may remain positive well after birds in a flock have turned negative.3 Serologic detection of salmonella infection is less dependable in young birds because of relatively poor antibody production3,10 and can produce confusing results in later stages after salmonella can no longer be isolated from birds or environmental samples.4,12 Although the rapid whole-blood test using S. pullorum antigen is widely applied in the field, it is reported to be the least sensitive and most unreliable of available tests to serologically diagnose paratyphoid infections. 9,11 False-positive and false-negative reactions are commonly encountered with this test. Based on findings in the present study and on past experience, the Salisbury S. pullorum antigen is more sensitive than the Vineland antigen in detecting positive birds with SE infection; however, the Salisbury antigen also gives the most false-positive reactions, as has been found by previous workers. 1 In the present study, culture of cloacal swabs was insensitive in detecting salmonella infection in individual birds. Culture of fecal samples was more useful
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
Mutalib et al.
418
and correlated better with serologic tests. The lack of isolation of salmonellae from cloacal swabs was perhaps because of a low excretion rate, intermittent shedding, or insensitivity of the cloacal swab method itself 4,5,12 This method is highly dependable if large numbers of salmonella are being excreted, as is characteristic during the first few weeks of infection.9 Because of the low sensitivity and poor reliability of currently available serologic tests, culture of internal organs was used as the ultimate determinant of the SE infection status of a flock. Culture of internal organs from birds that had escaped the cages to the manure pit was not useful for indirect detection of salmonellae in the environment. The isolation of SE from mice is significant because mice can play an important role in transmission of SE. Very importantly, they can act as a biological reservoir of salmonella on a farm from which a multitude of salmonella serotypes can infect chickens and contaminate the eggs and environment. Acknowledgements The tremendous assistance of the New York State Department of Agriculture and Markets, state veterinarians, and technicians is greatly appreciated.
Sources and manufacturers a. b. c. d. e.
Becton Dickinson Microbiology Systems, Cockeysville, MO. Difco Laboratories, Detroit, MI. Sigma Chemical Corp., St. Louis, MO. Salisbury Laboratories, Charles City, IA. Vineland Laboratories, Vineland, NJ.
2. Gast RK, Beard CW: 1990, Isolation of Salmonella enteritidis from internal organs of experimentally infected hens. Avian Dis 34:991-993. 3. Olesiuk OM, Carlson VL, Snoeyenbos GH, et al.: 1969, Experimental Salmonella typhimurium infection in two chicken flocks. Avian Dis 13:500-508. 4. Sadler WW, Brownell JR, Fanelli MJ: 1969, Influences of age and inoculum level on shed pattern of Salmonella typhimurium in chickens. Avian Dis 13:793-803. 5. Sato G, Miyamae T, Miura S: 1970, A long-term epizootiological study of chicken salmonellosis on a farm with reference to elimination of paratyphoid infection by cloacal swab culture. Jpn J Vet Res 18:47-63. 6. Snoeyenbos GH, Carlson VL, Smyser CF, et al.: 1969, Dynamics of salmonella infection in chicks reared on litter. Avian Dis 13:72-83. 7. St. Louis ME, Morse DL, Potter ME, et al.: 1988, The emergence of grade A eggs as a major source of Salmonella enteritidis infections: new implications for the control of salmonellosis. J Am Med Assoc 259:2103-2107. 8. Tumbull PC, Snoeyenbos GH: 1973, The role of ammonia, water activity, and pH in the salmonellacidal effect of long-used poultry litter. Avian Dis 17:72-86. 9. Weinack OM, Smyser CF, Snoeyenbos GH: 1979, Evaluation of several methods of detecting salmonellae in groups of chickens. Avian Dis 23:179-193. 10. Williams JE, Whittemore: 1975, Influence of age on the serological response of chickens to Salmonella typhimurium infection. Avian Dis 19:745-760. 11. Williams JE, Whittemore: 1976, Comparison of six methods of detecting Salmonella typhimurium infection of chickens. Avian Dis 20:728-734. 12. Yamamoto R, Kilian JG, Babcock WE, et al.: 1962, Some observations on serological testing for Salmonella typhimurium in breeder turkeys. Avian Dis 6:444-454.
References 1. Gast RK, Beard CW: 1990, Serologic detection of experimental Salmonella enteritidis infections in laying hens. Avian Dis 34: 721-728.
Downloaded from vdi.sagepub.com at UNIV OF BIRMINGHAM on June 4, 2015
450578
JVDXXX10.1177/1040638712450578
Erratum Journal of Veterinary Diagnostic Investigation 24(4) 813 © 2012 The Author(s) Reprints and permission: sagepub.com/journalsPermissions.nav DOI: 10.1177/1040638712450578 http://jvdi.sagepub.com
Corrigendum
Stegelmeier, BL, et al.: 2010, Experimental rayless goldenrod (Isocoma pluriflora) toxicosis in goats. J Vet Diagn Invest. 22: 570–577
In the article “Experimental rayless goldenrod (Isocoma pluriflora) toxicosis in goats” by Bryan L. Stegelmeier et al., the published mean body weight and the means and statistics of serum biochemistries were carried out on groups of 4 animals, not 3, as described in the Material and Methods section. The additional animal in each group was part of an auxiliary physiologic study and though the animals were dosed and treated the same, they were not necropsied and were not included in the histologic study. To correct this oversight, the corrected weight and chemistry table (shaded cells indicate corrected numbers) are listed below. The differences are minimal and do not alter the conclusions. In addition, reference 7 has been deleted. Material and Methods: “Fifteen, yearling, female Spanish goats weighing 29.4 ± 3.4 kg (mean ± standard deviation) were randomly divided into 5 groups with 3 animals per group.”
References: Reference 7 should be deleted Corrected Table 1. Selected mean serum biochemical data from groups of 3 goats dosed with rayless goldenrod (Isocoma pluriflora) to obtain benzofuran ketone doses of 0, 10, 20, 40, and 60 mg/kg body weight for 7 days.* Serum result (mean ± standard deviation) Serum test (reference range†) Creatinine kinase (< 350 U/l) Cardiac troponin-I (
