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Horton BC, Gehring KB, Sawyer JE, Arnold AN. Evaluation of Autogenous Vaccine Use in Mitigating Salmonella in Lymph Nodes from Feedlot Cattle in Texas. J Food Prot 2021; 84:80-86. [PMID: 32853371 DOI: 10.4315/jfp-20-171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 08/24/2020] [Indexed: 11/11/2022]
Abstract
ABSTRACT Managing the presence of Salmonella in ground beef has been an ongoing challenge for the beef industry. Salmonella prevalence can vary regionally, seasonally, and within the animal, making the development of interventions difficult. The objective of this study was to assess the efficacy of an autogenous Salmonella vaccine in mitigating Salmonella in lymph nodes (LNs) of feedlot cattle. An autogenous vaccine was developed using the most common Salmonella enterica serovars (Salmonella Kentucky, Salmonella Anatum, Salmonella Muenchen, Salmonella Montevideo, and Salmonella Mbandaka) identified from cattle managed at a South Texas feedlot with historically high Salmonella prevalence. Fifty-five heifers were selected for even distribution across five groups: (i) BASE, which received no autogenous vaccinations and were harvested after the stocker stage, (ii) CNTRL, which received no autogenous vaccinations, (iii) FARM, which received autogenous vaccinations at the ranch only, (iv) SPLIT, which received autogenous vaccinations at both the ranch and feedlot, and (v) YARD, which received vaccinations at the feedlot only. One heifer each from the BASE and CNTRL groups did not complete the study. All treatment groups except BASE were harvested after reaching market weight. Left and right superficial cervical and subiliac LNs from each carcass were collected and analyzed for Salmonella presence, and positive samples were serotyped. No salmonellae were recovered from LNs derived from BASE, FARM, SPLIT, or YARD groups. Cattle in the BASE group were expected to have a low occurrence of Salmonella based on previous research. However, the percentage of Salmonella-positive animals in the CNTRL group was 20.0% (2 of 10), which is lower than expected based on historical data from the same feeding location. There could be several causes of decreased Salmonella presence in the LNs of control cattle, creating an opportunity for future investigation into the development of preharvest interventions to combat Salmonella in feedlots. HIGHLIGHTS
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Affiliation(s)
- Brogan C Horton
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471 (ORCID: https://orcid.org/0000-0001-6346-9437 [A.N.A.]); and
| | - Kerri B Gehring
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471 (ORCID: https://orcid.org/0000-0001-6346-9437 [A.N.A.]); and
| | - Jason E Sawyer
- King Ranch Institute for Ranch Management, Texas A&M University, Kingsville, MSC 137, Kingsville, Texas 78363, USA
| | - Ashley N Arnold
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471 (ORCID: https://orcid.org/0000-0001-6346-9437 [A.N.A.]); and
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2
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Nickelson KJ, Taylor TM, Griffin DB, Savell JW, Gehring KB, Arnold AN. Assessment of Salmonella Prevalence in Lymph Nodes of U.S. and Mexican Cattle Presented for Slaughter in Texas. J Food Prot 2019; 82:310-315. [PMID: 30682264 DOI: 10.4315/0362-028x.jfp-18-288] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Foodborne salmonellosis has been traced to undercooked ground beef and other beef products in the past, and peripheral lymph node (LN) presence in the fatty tissues of beef carcasses is one possible source of Salmonella contamination. Researchers have previously reported higher rates of Salmonella prevalence in LNs from cattle raised and harvested in Mexico compared with rates typically observed from cattle harvested in the United States. With cattle of Mexican origin comprising the majority of U.S. live cattle imports, the objectives of this study were designed to determine whether Salmonella prevalence in LNs differed (i) between cattle of Mexican and U.S. origins when exposed to the same South Texas feeding operation and (ii) between warm and cool seasons. To meet these objectives, paired (left and right sides) subiliac LNs ( n = 800 LNs; n = 400 pooled samples) were collected from 100 carcasses per origin (Mexico and United States) per season (cool, December to January; warm, July to September). Overall, Salmonella prevalence in LN samples was 52.0% (208 of 400). No difference ( P = 0.4836) was seen in Salmonella prevalence as a function of origin, with 54.0% (108 of 200) and 50.0% (100 of 200) of LN samples returning Salmonella-positive results from cattle of Mexican and U.S. origin, respectively. Salmonella prevalence differed ( P = 0.0354) between seasons, with 46.5% (93 of 200) of cool and 57.5% (115 of 200) of warm season samples returning Salmonella-positive results. Serotyping of PCR-confirmed positive samples resulted in 14 different serovars being identified, with Cerro (21.6%), Anatum (19.7%), Muenchen (17.8%), Montevideo (14.4%), and Kentucky (12.0%) comprising the majority of serovars. These results suggest that factors other than cattle origin may be impacting Salmonella prevalence rates in bovine LNs and that additional research is needed to better understand the role of environment and management-related factors on Salmonella prevalence in bovine LNs.
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Affiliation(s)
- Kathryn J Nickelson
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - T Matthew Taylor
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - Davey B Griffin
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - Jeffrey W Savell
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - Kerri B Gehring
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - Ashley N Arnold
- Department of Animal Science, Texas A&M AgriLife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
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Belk AD, Arnold AN, Sawyer JE, Griffin DB, Taylor TM, Savell JW, Gehring KB. Comparison of Salmonella Prevalence Rates in Bovine Lymph Nodes across Feeding Stages. J Food Prot 2018; 81:549-553. [PMID: 29513102 DOI: 10.4315/0362-028x.jfp-17-254] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Peripheral lymph nodes (LNs) located in the fatty tissues of beef carcasses have been shown to harbor Salmonella and, thus, potentially contaminate ground beef. Salmonella prevalence within LNs is known to differ among feedlots. Two South Texas feeding operations (identified as locations A and B) known to harbor salmonellae in the feedlot environment, while historically producing cattle with opposing rates (one "high" and one "low") of Salmonella prevalence in LNs, were used in this study. To determine whether this difference was due to cattle source or factors associated with different stages of feeding, weanling steers of common and known origin were followed through normal feeding stages at both operations. Eighty Angus-sired beef steers were harvested at each of four feeding stages: 1, postweaning; 2, background or stocker; 3, 60 days on feed; and 4, 120 days on feed. Left and right subiliac and superficial cervical LNs ( n = 304) were collected from each carcass, and similar node types were pooled by animal ( n = 152). Results showed a difference ( P < 0.05) in prevalence of Salmonella in bovine lymph nodes between location A and location B and among feeding stages in location B. Salmonella was not isolated from any feeding stage 1 (postweaning) or location A LN samples. Within location B, there was an increase in Salmonella prevalence as cattle moved into later stages of feeding: at 22.2% (4 of 18), 77.8% (14 of 18), and 94.4% (17 of 18) for feeding stages 2, 3, and 4, respectively. Although the reasons for the differences seen between feeding operations and for increased Salmonella prevalence in LNs at later feeding stages remain unexplained, these results indicate that factors other than cattle source are likely influencing Salmonella prevalence in LNs.
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Affiliation(s)
- A D Belk
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - A N Arnold
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - J E Sawyer
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - D B Griffin
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - T M Taylor
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - J W Savell
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
| | - K B Gehring
- Department of Animal Science, Texas A&M Agrilife Research, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
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Quantifying the Survival of Multiple Salmonella enterica Serovars In Vivo via Massively Parallel Whole-Genome Sequencing To Predict Zoonotic Risk. Appl Environ Microbiol 2018; 84:AEM.02262-17. [PMID: 29180370 PMCID: PMC5795071 DOI: 10.1128/aem.02262-17] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/14/2017] [Indexed: 01/24/2023] Open
Abstract
Salmonella enterica is an animal and zoonotic pathogen of worldwide importance. Salmonella serovars that differ in their host and tissue tropisms exist. Cattle are an important reservoir of human nontyphoidal salmonellosis, and contaminated bovine peripheral lymph nodes enter the food chain via ground beef. The relative abilities of different serovars to survive within the bovine lymphatic system are poorly understood and constrain the development of control strategies. This problem was addressed by developing a massively parallel whole-genome sequencing method to study mixed-serovar infections in vivo. Salmonella serovars differ genetically by naturally occurring single nucleotide polymorphisms (SNPs) in certain genes. It was hypothesized that these SNPs could be used as markers to simultaneously identify serovars in mixed populations and quantify the abundance of each member in a population. The performance of the method was validated in vitro using simulated pools containing up to 11 serovars in various proportions. It was then applied to study serovar survival in vivo in cattle challenged orally with the same 11 serovars. All the serovars successfully colonized the bovine lymphatic system, including the peripheral lymph nodes, and thus pose similar risks of zoonosis. This method enables the fates of multiple genetically unmodified strains to be evaluated simultaneously in a single animal. It could be useful in reducing the number of animals required to study mixed-strain infections and in testing the cross-protective efficacy of vaccines and treatments. It also has the potential to be applied to diverse bacterial species which possess shared but polymorphic alleles. IMPORTANCE While some Salmonella serovars are more frequently isolated from lymph nodes rather than the feces and environment of cattle, the relative abilities of serovars to survive within the lymphatic system of cattle remain ill defined. A sequencing-based method which used available information from sequenced Salmonella genomes to study the dynamics of mixed-serovar infections in vivo was developed. The main advantages of the method include the simultaneous identification and quantification of multiple strains without any genetic modification and minimal animal use. This approach could be used in vaccination trials or in epidemiological surveys where an understanding of the dynamics of closely related strains of a pathogen in mixed populations could inform the prediction of zoonotic risk and the development of intervention strategies.
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Hanlon KE, Miller MF, Guillen LM, Brashears MM. Salmonella Presence in Mandibular, Mesenteric, and Subiliac Lymph Nodes Collected from Sheep and Goats in the United States. J Food Prot 2016; 79:1977-1981. [PMID: 28221907 DOI: 10.4315/0362-028x.jfp-16-193] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Even though often underappreciated in the United States, meat derived from goats and lambs is a valuable global commodity. Although extensive studies have been conducted examining pathogen prevalence in beef, pork, and poultry species, less research is available about pathogen presence in small ruminants. Understanding the presence of Salmonella in small ruminants can influence processing method improvements for these species to minimize food safety risks. The objective of this study was to establish the Salmonella presence in lymph nodes from sheep (n = 311) and goats (n =357) in the United States. Mandibular, mesenteric, and subiliac lymph nodes were collected from animals at abattoirs located in California, New Mexico, and Texas over a 14-month period. Lymph nodes were analyzed for Salmonella presence by using standard isolation methods, and presumptive isolates were confirmed with latex agglutination. Salmonella was detected in 3.15% of mandibular lymph nodes (n = 222), 5.83% of mesenteric lymph nodes (n = 223), and 7.62% of subiliac lymph nodes (n = 223). A total of 30 animals (13.39%) were found to have one or more Salmonella -positive lymph nodes. Our data indicate Salmonella is harbored within the lymph nodes of small ruminants. With this knowledge, further work can target strategies and interventions to minimize the risk associated with this pathogen during the processing of small ruminants.
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Affiliation(s)
- Keelyn E Hanlon
- International Center for Food Industry Excellence, Department of Animal and Food Sciences, Texas Tech University, P.O. Box 42141, Lubbock, Texas 79409, USA
| | - Markus F Miller
- International Center for Food Industry Excellence, Department of Animal and Food Sciences, Texas Tech University, P.O. Box 42141, Lubbock, Texas 79409, USA
| | - Lacey M Guillen
- International Center for Food Industry Excellence, Department of Animal and Food Sciences, Texas Tech University, P.O. Box 42141, Lubbock, Texas 79409, USA
| | - Mindy M Brashears
- International Center for Food Industry Excellence, Department of Animal and Food Sciences, Texas Tech University, P.O. Box 42141, Lubbock, Texas 79409, USA
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6
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Yang R, Jacobson C, Gardner G, Carmichael I, Campbell AJ, Ryan U. Longitudinal prevalence, faecal shedding and molecular characterisation of Campylobacter spp. and Salmonella enterica in sheep. Vet J 2014; 202:250-4. [DOI: 10.1016/j.tvjl.2014.08.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 07/31/2014] [Accepted: 08/03/2014] [Indexed: 10/24/2022]
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7
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Olafson PU, Lohmeyer KH, Edrington TS, Loneragan GH. Survival and fate of Salmonella enterica serovar Montevideo in adult horn flies (Diptera: Muscidae). JOURNAL OF MEDICAL ENTOMOLOGY 2014; 51:993-1001. [PMID: 25276929 DOI: 10.1603/me13217] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Contamination of cattle peripheral lymph nodes with Salmonella enterica is proposed to occur via a transdermal route of entry. If so, bacteria may be introduced to cattle by biting arthropods. Biting flies, such as horn flies (Haematobia irritans irritans (L.)) (Diptera: Muscidae), are intriguing candidates for transmitting Salmonella to cattle because they provide a route of entry when they breach the skin barrier during blood feeding. Using a green fluorescent protein-expressing strain of Salmonella Montevideo (S. Montevideo-GFP), the current study demonstrated that horn fly grooming subsequent to tactile exposure to the bacteria resulted in acquisition of the bacteria on mouthparts as well as microbial ingestion. Consumption of a bloodmeal containing approximately 10(2), approximately 10(4), or 10(6) S. Montevideo-GFP resulted in horn fly colonization for up to 72 h postingestion (PI). Epifluorescent microscopy indicated that the bacteria were not localized to the crop but were observed within the endoperitrophic space, suggesting that regurgitation is not a primary route of transmission. S. Montevideo-GFP were cultured from excreta of 100% of flies beginning 6-7 h PI of a medium or high dose meal and > 12 h PI in excreta from 60% of flies fed the low-dose meal. Animal hides and manure pats are sources for horn flies to acquire the Salmonella and mechanically transmit them to an animal while feeding. Mean quantities of 5.65-67.5 x 10(2) CFU per fly were cultured from fly excreta passed within 1 d after feeding, suggesting the excreta can provide an additional microbial source on the animal's hide.
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8
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Scientific Opinion on the public health risks related to the maintenance of the cold chain during storage and transport of meat. Part 1 (meat of domestic ungulates). EFSA J 2014. [DOI: 10.2903/j.efsa.2014.3601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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9
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Pointon A, Kiermeier A, Fegan N. Review of the impact of pre-slaughter feed curfews of cattle, sheep and goats on food safety and carcase hygiene in Australia. Food Control 2012. [DOI: 10.1016/j.foodcont.2012.01.034] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Haneklaus AN, Harris KB, Griffin DB, Edrington TS, Lucia LM, Savell JW. Salmonella prevalence in bovine lymph nodes differs among feedyards. J Food Prot 2012; 75:1131-3. [PMID: 22691483 DOI: 10.4315/0362-028x.jfp-11-530] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Lymphatic tissue, specifically lymph nodes, is commonly incorporated into ground beef products as a component of lean trimmings. Salmonella and other pathogenic bacteria have been identified in bovine lymph nodes, which may impact compliance with the Salmonella performance standards for ground beef established by the U.S. Department of Agriculture. Although Salmonella prevalence has been examined among lymph nodes between animals, no data are currently available regarding feedyard origin of the cattle and Salmonella prevalence. Bovine lymph nodes (279 superficial cervical plus 28 iliofemoral = 307) were collected from beef carcasses at a commercial beef harvest and processing plant over a 3-month period and examined for the prevalence of Salmonella. Cattle processed were from seven feedyards (A through G). Salmonella prevalence was exceptionally low (0% of samples were positive ) in cattle from feedyard A and high (88.2%) in cattle from feedyard B. Prevalence in the remaining feedyards ranged widely: 40.0% in feedyard C, 4.0% in feedyard D, 24.0% in feedyard E, 42.9% in feedyard F, and 40.0% in feedyard G. These data indicate the range of differences in Salmonella prevalence among feedyards. Such information may be useful for developing interventions to reduce or eliminate Salmonella from bovine lymph nodes, which would assist in the reduction of Salmonella in ground beef.
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Affiliation(s)
- Ashley N Haneklaus
- Department of Animal Science, Texas A&M University, 2471 TAMU, College Station, Texas 77843-2471, USA
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Hoelzer K, Moreno Switt AI, Wiedmann M. Animal contact as a source of human non-typhoidal salmonellosis. Vet Res 2011; 42:34. [PMID: 21324103 PMCID: PMC3052180 DOI: 10.1186/1297-9716-42-34] [Citation(s) in RCA: 280] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2010] [Accepted: 09/07/2010] [Indexed: 12/25/2022] Open
Abstract
Non-typhoidal Salmonella represents an important human and animal pathogen world-wide. Most human salmonellosis cases are foodborne, but each year infections are also acquired through direct or indirect animal contact in homes, veterinary clinics, zoological gardens, farm environments or other public, professional or private settings. Clinically affected animals may exhibit a higher prevalence of shedding than apparently healthy animals, but both can shed Salmonella over long periods of time. In addition, environmental contamination and indirect transmission through contaminated food and water may complicate control efforts. The public health risk varies by animal species, age group, husbandry practice and health status, and certain human subpopulations are at a heightened risk of infection due to biological or behavioral risk factors. Some serotypes such as Salmonella Dublin are adapted to individual host species, while others, for instance Salmonella Typhimurium, readily infect a broad range of host species, but the potential implications for human health are currently unclear. Basic hygiene practices and the implementation of scientifically based management strategies can efficiently mitigate the risks associated with animal contacts. However, the general public is frequently unaware of the specific disease risks involved, and high-risk behaviors are common. Here we describe the epidemiology and serotype distribution of Salmonella in a variety of host species. In addition, we review our current understanding of the public health risks associated with different types of contacts between humans and animals in public, professional or private settings, and, where appropriate, discuss potential risk mitigation strategies.
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Affiliation(s)
- Karin Hoelzer
- Department of Food Science, 410 Stocking Hall, Cornell University, Ithaca, NY 14853, USA.
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Duffy LL, Small A, Fegan N. Concentration and prevalence ofEscherichia coliO157 andSalmonellaserotypes in sheep during slaughter at two Australian abattoirs. Aust Vet J 2010; 88:399-404. [DOI: 10.1111/j.1751-0813.2010.00623.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- LL Duffy
- CSIRO Food & Nutritional Sciences, Cnr Creek and Wynnum Roads, Cannon Hill, Queensland 4170, Australia
| | - A Small
- CSIRO Food & Nutritional Sciences, Cnr Creek and Wynnum Roads, Cannon Hill, Queensland 4170, Australia
| | - N Fegan
- CSIRO Food & Nutritional Sciences, Cnr Creek and Wynnum Roads, Cannon Hill, Queensland 4170, Australia
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Molla W, Molla B, Alemayehu D, Muckle A, Cole L, Wilkie E. Occurrence and antimicrobial resistance of Salmonella serovars in apparently healthy slaughtered sheep and goats of central Ethiopia. Trop Anim Health Prod 2007; 38:455-62. [PMID: 17243472 DOI: 10.1007/s11250-006-4325-4] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The present study was undertaken to determine the occurrence, distribution and antimicrobial resistance pattern of Salmonella serovars in apparently healthy slaughtered sheep and goats in central Ethiopia. A total 1224 samples consisting of faeces, mesenteric lymph nodes, liver, spleen, and abdominal and diaphragmatic muscle samples were collected from 104 sheep and 100 goats. Salmonella was isolated from 12 of 104 (11.5%) sheep and 3 of 100 (3%) goats. Of the total 624 and 600 samples examined from sheep and goats, 18 (2.9%) and 4 (0.7%), respectively, were Salmonella positive. The 22 Salmonella isolates belonged to 9 different serovars. The common serovars isolated were S. typhimurium, followed by S. heidelberg, S. reading, S. give, and S. poona. Seven of the 22 isolates (31.8%) were multidrug-resistant to various antimicrobials.
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Affiliation(s)
- W Molla
- Faculty of Veterinary Medicine, Gondar University, Gondar, Ethiopia
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Fegan N, Vanderlinde P, Higgs G, Desmarchelier P. A study of the prevalence and enumeration of Salmonella enterica in cattle and on carcasses during processing. J Food Prot 2005; 68:1147-53. [PMID: 15954700 DOI: 10.4315/0362-028x-68.6.1147] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Salmonella prevalence and counts were estimated for samples from the oral cavity, hide, rumen, and feces of 100 cattle at slaughter and from the pre- and postchill carcasses of these cattle. Samples were collected from 25 consecutively slaughtered cattle from each of four unrelated groups slaughtered at a single abattoir on different days. Ten additional fecal samples from each group were collected from their respective abattoir holding pens prior to slaughter. The prevalence of Salmonella was estimated using automated immunomagnetic separation, and the counts were estimated using a combination of most probable number (MPN) and automated immunomagnetic separation. A total of 606 samples were collected with Salmonella isolated from 157 (26%), including 29% of oral cavities, 68% of hides, 16% of feces collected after evisceration, 25% of rumen samples, 2% of prechill carcasses, 3% of postchill carcasses, and 48% of feces collected from holding pens. The prevalence and count of Salmonella varied between the different groups of animals tested. The highest count obtained was from a rumen sample (1.1 x 10(4) MPN/g). Other counts were generally low, with a maximum count in feces collected after evisceration and in the abattoir holding pens of 93 and 23 MPN/g, respectively. The highest count on hides, in oral cavities, and on carcasses was 4.8 MPN/cm2, 23 MPN/g, and 0.31 MPN/cm2, respectively. Even though Salmonella was present on the hides and in the rumen and feces of at least one animal from each group of cattle, the processing of animals at this abattoir resulted in few contaminated carcasses, and when contamination occurred, Salmonella was detected at low numbers.
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Affiliation(s)
- Narelle Fegan
- Food Science Australia, Brisbane Laboratory, Cnr Wynnum and Creek Roads, Cannon Hill, Queensland 4170, Australia.
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15
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Fegan N, Vanderlinde P, Higgs G, Desmarchelier P. Quantification and prevalence of Salmonella in beef cattle presenting at slaughter. J Appl Microbiol 2004; 97:892-8. [PMID: 15479403 DOI: 10.1111/j.1365-2672.2004.02380.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS A survey to determine the prevalence and numbers of Salmonella in beef cattle presented for slaughter at abattoirs across Australia was conducted between September 2002 and January 2003. METHODS AND RESULTS Automated immunomagnetic separation (AIMS) was used for detection and isolation of Salmonella enriched from cattle faeces. Salmonella were enumerated from positive samples using a combination of the Most Probable Number (MPN) technique and AIMS. A total of 310 faecal samples were tested, 155 were from lot-fed cattle and 155 from grass-fed cattle. Salmonella spp. were isolated from 21 (6.8%) of the cattle and the prevalence amongst grass-fed cattle (4.5%) was not significantly different to that found in lot-fed cattle (9%). Counts of Salmonella in positive faeces varied from <3 MPN g(-1) of faeces to 2.8 x 10(3) MPN g(-1) and 71% of positive samples had counts <10 MPN g(-1) faeces. There was no significant difference in the mean log10 number of Salmonella in faeces of cattle from each production system. CONCLUSION Low numbers of beef cattle were found to shed Salmonella at the time of slaughter and the prevalence and the associated faecal concentrations did not vary significantly with the pre-slaughter production system (grass or lot feeding). The faecal concentration of Salmonella in the majority of faeces was low (<10 MPN g(-1)) with few high concentrations up to 3 x 10(3) MPN g(-1), suggesting there may be a low risk of carcase contamination. SIGNIFICANCE AND IMPACT OF THE STUDY Beef cattle do not appear to be a major source of entry of Salmonella into the human food chain and the quantitative information contained in this study can be used in quantitative assessments of the associated risk of human salmonellosis.
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Affiliation(s)
- N Fegan
- Microbiology Section, Food Science Australia, Cannon Hill, Queensland.
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16
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Kingsley RA, Abi Ghanem D, Puebla-Osorio N, Keestra AM, Berghman L, Bäumler AJ. Fibronectin binding to the Salmonella enterica serotype Typhimurium ShdA autotransporter protein is inhibited by a monoclonal antibody recognizing the A3 repeat. J Bacteriol 2004; 186:4931-9. [PMID: 15262930 PMCID: PMC451617 DOI: 10.1128/jb.186.15.4931-4939.2004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2004] [Accepted: 04/26/2004] [Indexed: 11/20/2022] Open
Abstract
ShdA is a large outer membrane protein of the autotransporter family whose passenger domain binds the extracellular matrix proteins fibronectin and collagen I, possibly by mimicking the host ligand heparin. The ShdA passenger domain consists of approximately 1,500 amino acid residues that can be divided into two regions based on features of the primary amino acid sequence: an N-terminal nonrepeat region followed by a repeat region composed of two types of imperfect direct amino acid repeats, called type A and type B. The repeat region bound bovine fibronectin with an affinity similar to that for the complete ShdA passenger domain, while the nonrepeat region exhibited comparatively low fibronectin-binding activity. A number of fusion proteins containing truncated fragments of the repeat region did not bind bovine fibronectin. However, binding of the passenger domain to fibronectin was inhibited in the presence of immune serum raised to one truncated fragment of the repeat region that contained repeats A2, B8, A3, and B9. Furthermore, a monoclonal antibody that specifically recognized an epitope in a recombinant protein containing the A3 repeat inhibited binding of ShdA to fibronectin.
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Affiliation(s)
- Robert A Kingsley
- Department of Medical Microbiology and Immunology, College of Medicine, College Station, TX 77843, USA.
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Morrow WEM, See MT, Eisemann JH, Davies PR, Zering K. Effect of withdrawing feed from swine on meat quality and prevalence of Salmonella colonization at slaughter. J Am Vet Med Assoc 2002; 220:497-502. [PMID: 11862982 DOI: 10.2460/javma.2002.220.497] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine whether withholding feed from pigs prior to slaughter had any effects on meat quality, percentage of pigs with Salmonella spp in cecal contents during slaughter, or percentage of pigs with lacerations of the gastrointestinal tract during slaughter. DESIGN Split-plot design. ANIMALS 873 pigs. PROCEDURES At the finishing barn, pigs were assigned to 30 pens. Feed withdrawal times were assigned to pens at random, and pigs in each pen were marketed in 3 groups. The first marketing group consisted of the 10 heaviest pigs in each pen, the second consisted of the next 10 heaviest pigs, and the third consisted of all remaining pigs. RESULTS Withdrawing feed improved the redness score assigned to the meat but did not have any other significant effects on carcass composition or meat quality. The percentage of pigs with Salmonella spp in the cecal contents decreased from the first (73%) to the second (64%) to the third (52%) marketing group. However, isolation of Salmonella spp from cecal contents was not associated with feed withdrawal time or with pen prevalence of Salmonella shedding during the 2 months prior to slaughter. Feed withdrawal time and marketing group did not have any significant effects on overall prevalence of gastrointestinal tract lacerations. CONCLUSIONS AND CLINICAL RELEVANCE Results suggest that withdrawal of feed from pigs prior to slaughter does not increase the prevalence of Salmonella colonization or the risk of carcass contamination associated with gastrointestinal tract lacerations during slaughter but only slightly enhances meat quality.
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Affiliation(s)
- W E Morgan Morrow
- Department of Animal Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh 27695-7621, USA
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Kingsley RA, van Amsterdam K, Kramer N, Bäumler AJ. The shdA gene is restricted to serotypes of Salmonella enterica subspecies I and contributes to efficient and prolonged fecal shedding. Infect Immun 2000; 68:2720-7. [PMID: 10768965 PMCID: PMC97480 DOI: 10.1128/iai.68.5.2720-2727.2000] [Citation(s) in RCA: 97] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/1999] [Accepted: 02/10/2000] [Indexed: 01/28/2023] Open
Abstract
Little is known about factors which enable Salmonella serotypes to circulate within populations of livestock and domestic fowl. We have identified a DNA region which is present in Salmonella serotypes commonly isolated from livestock and domestic fowl (S. enterica subspecies I) but absent from reptile-associated Salmonella serotypes (S. bongori and S. enterica subspecies II to VII). This DNA region was cloned from Salmonella serotype Typhimurium and sequence analysis revealed the presence of a 6,105-bp open reading frame, designated shdA, whose product's deduced amino acid sequence displayed homology to that of AIDA-I from diarrheagenic Escherichia coli, MisL of serotype Typhimurium, and IcsA of Shigella flexneri. The shdA gene was located adjacent to xseA at 52 min, in a 30-kb DNA region which is not present in Escherichia coli K-12. A serotype Typhimurium shdA mutant was shed with the feces in reduced numbers and for a shorter period of time compared to its isogenic parent. A possible role for the shdA gene during the expansion in host range of S. enterica subspecies I to include warm-blooded vertebrates is discussed.
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Affiliation(s)
- R A Kingsley
- Department of Medical Microbiology and Immunology, College of Medicine, Texas A&M University Health Science Center, College Station, Texas 77843-1114, USA
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Abstract
Despite the efforts of both physicians and veterinarians, the number of cases of salmonellosis per year has held steady or risen. The ability of the organism to live in many different animal species and under inhospitable environmental conditions is likely responsible for Salmonella's prevalence today. Diverse clinical signs occur in salmonellosis; they range from unthriftiness to explosive, necrotizing diarrheas with high mortality. Secondary complications of pneumonia, bone and joint infections, and meningoencephalitis can result from calfhood infections. Treatment of enteric salmonellosis is chiefly aimed at maintaining fluid, acid-base, and electrolyte balance. Bacteremic or septicemic calves also require systemic antibiotics. The control measures for salmonellosis are based on sanitation and management. Individual calf hutches or pens provide adequate isolation if sufficient spacing and good sanitation are maintained. The Salmonella vaccines presently available provide limited protection; however, live vaccines made from auxotrophic strains of Salmonella appear to be more efficacious.
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