Longitudinal Study of the Persistence of Antimicrobial-Resistant Campylobacter Strains in Distinct Swine Production Systems on Farms, at Slaughter, and in the Environment

ABSTRACTThe objectives of this study were to compare and characterize the prevalence of antimicrobial-resistant (AR)Campylobacterin conventional and antimicrobial-free (ABF) production systems on farms, at slaughter, and in the environment. Fecal and environmental samples were collected from ABF farms (pigs, 1,239; environment, 797) and conventional farms (pigs, 1,650; environment, 1,325). At slaughter, we collected samples from carcasses, including postevisceration swabs, postchill swabs, and mesenteric lymph nodes from ABF systems (postevisceration swabs, 182; postchill swabs, 199; mesenteric lymph nodes, 184) and conventional systems (postevisceration swabs, 272; postchill swabs, 271; mesenteric lymph nodes, 255) at separate processing facilities. We also sampled the processing plant environment, including truck and lairage floor swab samples (ABF, 115; conventional, 90). Overall, a total of 2,908Campylobacterisolates, includingCampylobacter coli(farm, 2,557, 99.8%; slaughter, 341, 98.3%) andCampylobacter jejuni(farm, 4, 0.2%; slaughter, 6, 1.7%), were isolated in the study. There was no significant difference in the prevalence ofCampylobacterbetween ABF and conventionally raised pigs (farrowing,P= 0.20; nursery,P= 0.06; finishing,P= 0.24) and the environment (P= 0.37). At slaughter,Campylobacterwas isolated from all of the stages, including postchill. The highest frequencies of resistance were exhibited against tetracycline (ABF, 48.2%; conventional, 88.3%). Ciprofloxacin-resistantC. coliisolates were observed in conventionally raised (17.1%) and ABF (1.2%) pigs (P= 0.11). Antimicrobial use data from conventional farms indicated significant associations between oxytetracycline use and tetracycline resistance in the nursery pigs (P= 0.01), between tiamulin exposure and azithromycin and erythromycin resistance in nursery (P< 0.01) and finishing (P< 0.01) pigs, and between enrofloxacin exposure and ciprofloxacin and nalidixic acid resistance in farrowing (P< 0.01) and nursery (P< 0.01) pigs. Identical antimicrobial resistance profiles were observed in the pigs and their environments on farms and at slaughter. In summary, our results highlight the persistence and dissemination of ARCampylobacterfrom farm to slaughter in ABF and conventionally raised pigs and their environments.

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Expression of Regulatory T Cells in Jejunum, Colon, and Cervical and Mesenteric Lymph Nodes of Dogs Naturally Infected with Leishmania infantum

Infection and Immunity ◽

10.1128/iai.01862-14 ◽

2014 ◽

Vol 82 (9) ◽

pp. 3704-3712 ◽

Cited By ~ 19

Author(s):

Maria M. Figueiredo ◽

Beatriz Deoti ◽

Izabela F. Amorim ◽

Aldair J. W. Pinto ◽

Andrea Moraes ◽

...

Keyword(s):

T Cells ◽

Regulatory T Cells ◽

Lymph Nodes ◽

Leishmania Infantum ◽

Parasite Load ◽

Mesenteric Lymph Nodes ◽

Content Type ◽

Mesenteric Lymph ◽

Tnf Α ◽

Ifn Γ

ABSTRACTUsing flow cytometry, we evaluated the frequencies of CD4+and CD8+T cells and Foxp3+regulatory T cells (Tregs) in mononuclear cells in the jejunum, colon, and cervical and mesenteric lymph nodes of dogs naturally infected withLeishmania infantumand in uninfected controls. All infected dogs showed chronic lymphadenitis and enteritis. Despite persistent parasite loads, no erosion or ulcers were evident in the epithelial mucosa. The colon harbored more parasites than the jejunum. Frequencies of total CD4+, total Foxp3, and CD4+Foxp3+cells were higher in the jejunum than in the colon. Despite negative enzyme-linked immunosorbent assay (ELISA) serum results for cytokines, levels of interleukin-10 (IL-10), gamma interferon (IFN-γ), transforming growth factor beta (TGF-β), and tumor necrosis factor alpha (TNF-α) were higher in the jejunum than in the colon for infected dogs. However, IL-4 levels were higher in the colon than in the jejunum for infected dogs. There was no observed correlation between clinical signs and histopathological changes or immunological and parasitological findings in the gastrointestinal tract (GIT) of canines with visceral leishmaniasis. However, distinct segments of the GIT presented different immunological and parasitological responses. The jejunum showed a lower parasite load, with increased frequencies and expression of CD4, Foxp3, and CD8 receptors and IL-10, TGF-β, IFN-γ, and TNF-α cytokines. The colon showed a higher parasite load, with increasing expression of IL-4.Leishmania infantuminfection increased expression of CD4, Foxp3, IL-10, TGF-β, IFN-γ, and TNF-α and reduced CD8 and IL-4 expression in both the jejunum and the colon.

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Longitudinal Study of Salmonella Dispersion and the Role of Environmental Contamination in Commercial Swine Production Systems

Applied and Environmental Microbiology ◽

10.1128/aem.01632-08 ◽

2009 ◽

Vol 75 (6) ◽

pp. 1478-1486 ◽

Cited By ~ 35

Author(s):

Paul M. Dorr ◽

Daniel A. Tadesse ◽

Bayleyegn Molla Zewde ◽

Pamela Fry ◽

Siddhartha Thakur ◽

...

Keyword(s):

Lymph Nodes ◽

Susceptibility Testing ◽

Fragment Length Polymorphism ◽

Production Systems ◽

Swine Production ◽

Mesenteric Lymph Nodes ◽

Cross Sectional ◽

Mesenteric Lymph ◽

Swine Herds

ABSTRACT This study investigated the roles of various environmental sources, such as truck-washing systems, waste-processing lagoons, and other sources, as potential contributors to the exposure and dissemination of Salmonella in commercial swine production systems. Four cohorts of nursery age swine herds which originated from distinct farm flows were selected. In addition, cross-sectional sampling of four truck wash stations selected based on the types of disinfectants and sources of water used for sanitizing trucks were tested. Salmonella isolates were recovered from pigs (feces, cecal contents, and mesenteric lymph nodes) and environmental sources (barn floor, lagoon, barn flush, trucks, and holding pens). Antimicrobial susceptibility testing and genotyping were conducted using Kirby-Bauer disk diffusion and amplified fragment length polymorphism, respectively. Salmonella prevalence significantly increased with age from late nursery to slaughter for all of the cohorts (P = 0.007). In two of three instances, all three pig holding pens (lairage) sampled at processing were Salmonella positive. The predominant antibiotypes for all sources included ACSSuT (51.8%), SSuT (16.8%), T (6%), and pansusceptible (7.4%). For the isolates obtained at the farms, the ACSSuT phenotype was 5.6 times more likely to be found in the animals than in the environment (95% confidence interval, 4.4 to 7.2 times). Serogroup B was the most common serogroup (79%), followed by serogroup E (10.4%). Despite the fact that the four production flows were independent, 1 of the 11 genotypic clusters (cluster A1) was commonly detected in any type of sample regardless of its origin. Five of the genotypic clusters (clusters A3, A4, A5, A6, and A7) contained isolates that originated from trucks and lairage swabs and also from cecal contents and/or mesenteric lymph nodes. More interestingly, genotypic clusters A3, A4, and A6 (but not clusters A5 and A7) were not detected on the farms. They originated from the trucks and lairage swabs and then were identified from the cecal contents and/or mesenteric lymph nodes. These findings underscore the significance of various environmental factors, including inadequate truck-washing systems, and emphasize the role of lairage contamination by Salmonella that has food safety significance.

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Oral Infection with Signature-Tagged Listeria monocytogenes Reveals Organ-Specific Growth and Dissemination Routes in Guinea Pigs

Infection and Immunity ◽

10.1128/iai.05958-11 ◽

2011 ◽

Vol 80 (2) ◽

pp. 720-732 ◽

Cited By ~ 50

Author(s):

Jody A. Melton-Witt ◽

Susanne M. Rafelski ◽

Daniel A. Portnoy ◽

Anna I. Bakardjiev

Keyword(s):

Listeria Monocytogenes ◽

Lymph Nodes ◽

Guinea Pigs ◽

Mesenteric Lymph Nodes ◽

Intestinal Villi ◽

Content Type ◽

Direct Pathway ◽

Mesenteric Lymph ◽

Organ Specific ◽

Small Intestinal

ABSTRACTListeria monocytogenescauses a serious food-borne disease due to its ability to spread from the intestine to other organs, a process that is poorly understood. In this study we used 20 signature-tagged wild-type clones ofL. monocytogenesin guinea pigs in combination with extensive quantitative data analysis to gain insight into extraintestinal dissemination. We show thatL. monocytogenescolonized the liver in all asymptomatic animals. Spread to the liver occurred as early as 4 h after ingestion via a direct pathway from the intestine to the liver. This direct pathway contributed significantly to the bacterial load in the liver and was followed by a second wave of dissemination via the mesenteric lymph nodes (indirect pathway). Furthermore, bacteria were eliminated in the liver, whereas small intestinal villi provided a niche for bacterial replication, indicating organ-specific differences in net bacterial growth. Bacteria were shed back from intestinal villi into the small intestinal lumen and reinfected the Peyer's patches. Together, these results support a novel dissemination model whereL. monocytogenesreplicates in intestinal villi, is shed into the lumen, and reinfects intestinal immune cells that traffic to liver and mesenteric lymph nodes, a process that occurs even during asymptomatic colonization.

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Presence of IgA-producing cells in rats and mice in relation to microbial status

Laboratory Animals ◽

10.1258/002367784780958196 ◽

1984 ◽

Vol 18 (3) ◽

pp. 252-257 ◽

Cited By ~ 1

Author(s):

J. W. M. A. Mullink ◽

F. H. M. Morsink

Keyword(s):

Lymph Nodes ◽

Intestinal Mucosa ◽

Mesenteric Lymph Nodes ◽

Germ Free ◽

Mesenteric Lymph ◽

Significant Difference ◽

Rats And Mice ◽

Microbial Status

The numbers of IgA-producing cells in intestinal mucosa, mesenteric lymph nodes, lungs and bronchial lymph nodes were scored in rats and mice. A statistically significant difference in the scores existed between germ-free and SPF mice and between gnotobiotic and SPF rats. In a group of SPF rats a statistically significant difference in the scores was demonstrated in relation to several bacterial and viral agents.

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Head-down tilt posture elicits transient lymphocyte mobilization from the iliac, but not mesenteric, lymph nodes of rats

Journal of Applied Physiology ◽

10.1152/japplphysiol.90415.2008 ◽

2008 ◽

Vol 105 (5) ◽

pp. 1595-1601 ◽

Cited By ~ 1

Author(s):

Shigeru Suzuki ◽

Risuke Mizuno ◽

Fumitaka Ikomi ◽

Toshio Ohhashi

Keyword(s):

Lymph Nodes ◽

Flow Rate ◽

Simulated Microgravity ◽

Lymphocyte Subsets ◽

Lymph Flow ◽

Mesenteric Lymph Nodes ◽

Short Term ◽

Mesenteric Lymph ◽

Significant Difference

The effects of short-term simulated microgravity on the lymph dynamics of rat lymph nodes were investigated using a combination of Bollman's cage and head-down tilt (HDT). Efferent lymphatics of the iliac and mesenteric lymph nodes were cannulated for the collection of lymph. There was no significant difference in lymph flow rate from the iliac lymph nodes between non-HDT (control) and HDT rats. Lymph flow rate from the mesenteric lymph nodes in HDT rats was slightly higher than that obtained with the control. The cell count obtained from the iliac lymph nodes in HDT rats was significantly larger than those of the controls, while no significant difference in the number of cells from the mesenteric lymph nodes was observed between the control and HDT groups. The cells from the iliac lymph nodes in the control and HDT rats were mostly lymphocytes. The distribution of subsets of lymphocytes (CD3+, CD4+, CD8a+, and CD45R+) from the iliac lymph nodes in HDT rats was not significantly different from the subsets of lymphocytes in the control. Immunization did not affect the distribution of lymphocyte subsets from the iliac lymph nodes in the control and HDT groups. There was no significant difference in the concentrations of lymph albumin in iliac afferent or efferent lymphatics between the control and HDT groups. These findings suggest that HDT posture in Bollman's cage induces transient output of lymphocytes from the iliac lymph nodes of rats in vivo without changing the flow rate, lymphocyte subsets, or concentration of albumin.

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Role of the Yersinia pseudotuberculosis Virulence Plasmid in Pathogen-Phagocyte Interactions in Mesenteric Lymph Nodes

EcoSal Plus ◽

10.1128/ecosalplus.esp-0014-2021 ◽

2021 ◽

Author(s):

James B. Bliska ◽

Igor E. Brodsky ◽

Joan Mecsas

Keyword(s):

Small Intestine ◽

Lymph Nodes ◽

Family Member ◽

Yersinia Pseudotuberculosis ◽

Oral Route ◽

Virulence Plasmid ◽

Mesenteric Lymph Nodes ◽

Content Type ◽

Mesenteric Lymph

Yersinia pseudotuberculosis is an Enterobacteriaceae family member that is commonly transmitted by the fecal-oral route to cause infections. From the small intestine, Y. pseudotuberculosis can invade through Peyer’s patches and lymph vessels to infect the mesenteric lymph nodes (MLNs).

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