Lymph Nodes Of Sheep Research Articles

Investigation of Inhibitory Effect of Sheep Lymph Nodes and Antibiotics on Cutibacterium Acnes, Staphylococcus Aureus, and Staphylococcus Epidermidis in the Laboratory Condition: A Short Report

Investigation of Inhibitory Effect of Sheep Lymph Nodes and Antibiotics on Cutibacterium Acnes, Staphylococcus Aureus, and Staphylococcus Epidermidis in the Laboratory Condition: A Short Report

An Experimental Infection Model in Sheep and Goats to Evaluate Salmonella Colonization in Deep Tissue Lymph Nodes and after Carcass Vascular Rinsing with Bacteriophages in Goats

An animal infection model was evaluated on sheep and goats to confirm which species infected with Salmonella enterica serovar Enteritidis C StR (SE13) would provide a consistent and high frequency of Salmonella colonization in lymph nodes (LNs) without causing undue animal morbidity. Sheep and goats (n = 5) were intradermally inoculated with Salmonella, postincubated for 7 days, and euthanized. Superficial cervical, medial iliac, subiliac, mammary, and popliteal LNs were excised from each carcass. Goat LNs had approximately 53% greater Salmonella level compared to sheep. Also, Salmonella was inconsistently recovered from the sheep LNs. Thus, goats were selected to determine the ability of carcass vascular rinsing (with and without bacteriophages) to reduce Salmonella in infected LNs. Goats with similar characteristics were grouped together before being randomly assigned to 3 postharvest treatments; control (CN, not vascularly rinsed; n = 10), vascularly rinsed with a standard Rinse & Chill® solution (RC; 98.5% water and a blend of saccharides and phosphates; n = 10), or vascularly rinsed with a standard Rinse & Chill® solution plus the addition of bacteriophages (BP; n = 10). Rinse & Chill® system was able to successfully deliver a mean 7.0 log PFU/g to the S. Enteritidis-infected LNs (mean 3.5 log CFU/g). However, neither Rinse & Chill® without bacteriophages nor with bacteriophages caused Salmonella reduction (P > 0.05) compared to the nonrinsed goat carcasses.

Effects of caseous lymphadenitis agent (corynebacterium pseudotuberculosis) isolated from superficial abscesses of sheep on oxidative stress factors

In this study, it was aimed to determine the incidence of Corynebacterium pseudotuberculosis (C. pseudotuberculosis) in caseous lymphadenitis cases in superficial lymph nodes of sheep and to evaluate its effect on oxidative stress factors. Thus, it was aimed to determine the early diagnosability of superficial and visceral caseous lymphadenitis cases and to prevent the spread of diseases and related economic losses. A total of 103 sheep, 50 of which were healthy and 53 of which had caseous lymphadenitis, were evaluated in the study. Microbiological examinations were performed by taking 3-5 ml of pyogenic aspirate from the superficial lymph nodes of sheep with caseous lymphadenitis. Blood samples were taken from sheep with C. pseudotuberculosis isolated in microbiological examinations and the levels of oxidative stress factors were determined. C. pseudotuberculosis was isolated in 23 of the pyogenic aspirates of 53 sheep with caseous lymphadenitis. When sheep isolated from C. pseudotuberculosis were compared with healthy sheep, it was determined that there was a statistically significant decrease in the levels of antioxidant molecules such as GSH-pX (14.62%), GSH (23.81%), SOD (4.70%), CAT (22.23%) (p˂0.001). The level of toxic malondialdehyde (MDA) (18.62%), the end product of lipid peroxidation, was found to be statistically significantly increased in sheep isolated from C. pseudotuberculosis (p˂0.001). As a result, it was determined that oxidative stress factors showed statistically significant variability in cases of superficial caseous lymphadenitis (caused by C.pseudotuberculosis). For this reason, by determining the levels of oxidative stress factors in suspected herds, it was possible to make early diagnosis of the superficial and visceral forms of caseous lymphadenitis, and a basis was established for future studies.

Clearance of bacteria from lymph nodes in sheep immunized with Brucella suis S2 vaccine is associated with M1 macrophage activation

Ovine brucellosis is a global zoonotic disease of sheep caused by Brucella melitensis, which inflicts a significant burden on human and animal health. Brucella suis strain S2 (B. suis S2) is a smooth live attenuated vaccine for the prevention of ovine brucellosis in China. However, no previous studies have assessed the immunogenicity of B. suis S2 vaccine after oral immunization in sheep. Here, we attempted to evaluate the ovine immune response over the course of B. suis S2 immunization and to identify in vivo predictors for vaccine development. Body temperature, serum Brucella antibodies, serum cytokines (IL-12p70 and interferon [IFN]-γ), and bacterial load in the mandibular lymph nodes (LN), superficial cervical LN, superficial inguinal LN, and spleen were investigated to determine the safety and efficacy of the vaccine. The abnormal body temperature of sheep occurred within 8 days post-infection (dpi). Brucella suis S2 persisted for a short time (< 21 dpi) in the mandibular LN. The highest level of IL-12p70 was observed at 9 dpi, whereas serum IFN-γ levels peaked at 12 dpi. Transcriptome analysis and quantitative reverse transcription PCR were performed to determine gene expression profiles in the mandibular LN of sheep. Antigen processing and presentation pathway was the dominant pathway related to the dataset. Our studies suggest that the immune response in ovine LN resembled type 1 immunity with the secretion of IL-12p70 and IFN-γ after B.suis S2 immunization and the vaccine may eliminate Brucella via stimulation of M1 macrophages through the course of Th cells.

Early pregnancy regulates the expression of prolactin and its receptor in the thymus, the liver, the spleen and lymph nodes in sheep

As a pituitary hormone, prolactin (PRL) is also synthesized by immune system cells, and exerts its effects on the immune system by binding to its receptor (PRLR) via endocrine and paracrine/autocrine pathways. The immune organs adapt to the presence of fetal alloantigens during pregnancy, and the immune system is composed of primary organs and secondary organs. The objective of this study is to analyze the effects of early pregnancy on expression of PRL and PRLR in maternal immune organs in sheep. In this study, the thymus, lymph node, the spleen and the liver were sampled at day 16 of the estrous cycle, and at days 13, 16, and 25 of pregnancy in ewes. Expression of PRL and PRLR was analyzed through quantitative real-time PCR, Western blot and immunohistochemistry. Our data showed that there were an upregulation of PRL and PRLR in the thymus, lymph node and the spleen, and a downregulation in the liver during early pregnancy in ewes. In conclusion, it is reported for the first time that early pregnancy has tissue specific effects on expression of PRL isoform and PRLR isoform in the thymus, lymph node, the spleen and the liver, which may be owing to these organs exerting different functions during early pregnancy, and necessary for the successful pregnancy in sheep.

Downregulation of Three Novel miRNAs in the Lymph Nodes of Sheep Immunized With the Brucella suis Strain 2 Vaccine.

Ovine and caprine brucellosis, both caused by Brucella melitensis, lead to substantial economic losses in the animal industry and health problems in human populations. Brucella suis strain 2 (B.suis S2), as a live attenuated vaccine, is used extensively in China to prevent brucellosis. It has been proven that microRNA (miRNAs) are involved in the immunopathogenesis of brucellosis; however, the miRNA-driven mechanism of immune response to B.suis S2 in vivo remains unknown. To determine which new miRNAs are involved in the host immune response to B.suis S2 and elucidate the function of these miRNAs, we performed a comprehensive analysis of miRNA expression profiles in sheep immunized with B.suis S2 using the high-throughput sequencing approach. The submandibular lymphatic nodes from sheep seropositive for Brucella were collected at 7, 14, 21, 30, 60 and 90 days post-immunization. MiRNA sequencing analysis revealed that 282 differentially expressed miRNAs (|log2 fold-change |>0.5 and p < 0.05) were significantly enriched in the immune pathways, including the NF-kappa B signaling pathway, B cell receptor signaling pathway, p53 signaling pathway and complement and coagulation cascades. Increasing the threshold to |log2 fold change|>1 and p < 0.01 revealed 48 differentially expressed miRNAs, 31 of which were novel miRNAs. Thirteen of these novel miRNAs, which were differentially expressed for at least two time points, were detected via RT-qPCR assays. The novel_229, novel_609, novel_973 and oar-miR-181a assessed by RT-qPCR were detectable and consistent with the expression patterns obtained by miRNA sequencing. Functional analyses of these miRNAs demonstrated that their target genes participated in the immune response pathways, including the innate and adaptive immunity pathways. The immune-related target genes of novel_229 included ENSOARG00000000649 and TMED1, as well as LCN2, PDPK1 and LPO were novel_609 target genes. The immune-related target genes of novel_973 included C6orf58, SPPL3, BPIFB1, ENSOARG00000021083, MPTX1, CCL28, FGB, IDO1, OLR1 and ENSOARG00000020393. The immune-related target genes of oar-miR-181a included ENSOARG00000002722, ARHGEF2, MFAP4 and DOK2. These results will deepen our understanding of the host miRNA-driven defense mechanism in sheep immunized with B.suis S2 vaccine, and provide the valuable information for optimizing vaccines and developing molecular diagnostic targets.

Identification of Regulatory Functions of LncRNAs Associated With T. circumcincta Infection in Adult Sheep

Several recent studies have demonstrated the role of long non-coding RNAs (lncRNAs) in regulating the defense mechanism against parasite infections, but no studies are available that investigated their relevance for immune response to nematode infection in sheep. Thus, the aim of the current study was to (i) detect putative lncRNAs that are expressed in the abomasal lymph node of adult sheep after an experimental infection with the gastrointestinal nematode (GIN) Teladorsagia circumcincta and (ii) to elucidate their potential functional role associated with the differential host immune response. We hypothesized that putative lncRNAs differentially expressed (DE) between samples from animals that differ in resistance to infection may play a significant regulatory role in response to nematode infection in adult sheep. To obtain further support for our hypothesis, we performed co-expression and functional gene enrichment analyses with the differentially expressed lncRNAs (DE lncRNAs). In a conservative approach, we included for this predictive analysis only those lncRNAs that are confirmed and supported by documentation of expression in gastrointestinal tissues in the current sheep gene atlas. We identified 9,105 putative lncRNA transcripts corresponding to 7,124 gene loci. Of these, 457 were differentially expressed lncRNA loci (DELs) with 683 lncRNA transcripts. Based on a gene co-expression analysis via weighted gene co-expression network analysis, 12 gene network modules (GNMs) were found significantly correlated with at least one of 10 selected target DE lncRNAs. Based on the principle of “guilt-by-association,” the DE genes from each of the three most significantly correlated GNMs were subjected to a gene enrichment analysis. The significant pathways associated with DE lncRNAs included ERK5 Signaling, SAPK/JNK Signaling, RhoGDI Signaling, EIF2 Signaling, Regulation of eIF4 and p70S6K Signaling and Oxidative Phosphorylation pathways. They belong to signaling pathway categories like Cellular Growth, Proliferation and Development, Cellular Stress and Injury, Intracellular and Second Messenger Signaling and Apoptosis. Overall, this lncRNA study conducted in adult sheep after GIN infection provided first insights into the potential functional role of lncRNAs in the differential host response to nematode infection.

Scrapie infection and endogenous retroviral expression in sheep lymphoid tissues

Transmissible spongiform encephalopathies, or prion diseases, are fatal neurodegenerative diseases affecting humans and animals. Although many host tissues express PrPC (essential for prion replication), relatively few cell types accumulate significant levels of infectivity, including neurons and other cell types in the nervous system, and follicular dendritic cells in secondary lymphoid organs. This suggests that tissue or cell-specific receptors or cofactors could play a role in controlling differential susceptibility to infection. Endogenous retroviruses (ERV), the remnants of ancient retroviral integration into the host germline, may represent one such cofactor. We examined the effect of scrapie infection on expression of three ovine ERV families (enJSRV/β1-OERV, γ1-OERV, γ2-OERV) in secondary lymphoid tissues of sheep at different time points following subcutaneous inoculation, using RT-qPCR. These OERVs were constitutively expressed in the prescapular lymph node and spleen of uninfected sheep. However, we were unable to find convincing evidence of specific differential expression of OERV in the same tissues following scrapie infection, in contrast to previous studies of ERV expression in brains of prion-infected mice and macaques. This study is the first to quantify the expression of potentially functional OERV transcripts in sheep lymphoid tissues, opening up interesting questions about the consequences for host immune function.

Exogenous Small Ruminant Betaretrovirus Envelope Protein Is Detected in Draining Lymph Nodes in Contagious Respiratory Tumors of Sheep and Goats.

Contagious respiratory tumors of sheep and goats are epithelial neoplasms of the lung and nasal cavities. They are associated with oncogenic betaretroviruses known as jaagsiekte sheep retrovirus and enzootic nasal tumor retrovirus of sheep and goats. We investigated the presence of the envelope protein (ENV) of these retroviruses in retropharyngeal and mediastinal lymph nodes using a specific monoclonal antibody by immunohistochemistry methods, single-labeled or combined with ovine B or T lymphocytes or macrophage cell markers. Samples of lymph nodes, fixed in formalin and zinc fixative, were obtained from paraffin-embedded material. Four groups of samples were used: 24 natural cases of ovine pulmonary adenocarcinoma (OPA), 13 of enzootic nasal adenocarcinoma of sheep (ENAS), 19 of enzootic nasal adenocarcinoma of goats (ENAG), and 14 control samples. ENV was detected by single labeling in cortical lymphoid follicles. Six of 24 OPA samples were positive and only in those from sheep with extensive neoplasia. Immunolabeling was detected in 5/13 ENAS and 10/19 ENAG samples. Positive labeling was found either in the intercellular spaces, membranes, or cytoplasm of cells in follicles. Control samples were not correspondingly labeled. Double immunohistochemistry demonstrated co-labeling of ENV and CD21 (B cells and follicular dendritic cells) in all samples, CD14 (macrophage) in OPA samples, and Pax-5 (B cells) in ENAG samples, but not with CD8 or CD4 (T lymphocytes). These results demonstrate the presence of betaretrovirus ENV proteins in nontumor cells in regional lymph nodes in sheep and goats with contagious respiratory tumors.

Bacteriological, cytological, and molecular investigation of Corynebacterium pseudotuberculosis, mycobacteria, and other bacteria in caseous lymphadenitis and healthy lymph nodes of slaughtered sheep.

Caseous lymphadenitis (CL) in sheep is a chronic contagious disease caused by Corynebacterium pseudotuberculosis, commonly characterized by abscess formation in peripheral lymph nodes and disseminated infections. Nonetheless, other microorganisms, including with zoonotic relevance, can be isolated from CL-resembling lymph nodes. Currently, mycobacteria have been reported in visceral granulomatous lesions in small ruminants, a fact that poses a public health issue, particularly in slaughtered sheep intended for human consumption. Cytology using fine needle aspiration and microbiological culturing are suitable tests for routine diagnostic, whereas present drawbacks and molecular methods have been confirmatory. Data about the occurrence of mycobacteria in both lymph nodes with aspect of CL and apparently healthy visceral nodes of sheep slaughtered for human consumption are scarce. In this study, 197 visceral lymph nodes of sheep showed lymphadenitis and 202 healthy visceral lymph nodes of slaughtered sheep intended for human consumption were submitted to conventional bacteriological diagnosis, mycobacteria culturing, and cytological evaluation. Compatible Corynebacterium isolates were subjected to multiplex PCR targeting 16S rRNA, rpoB, and pld genes to detect C. pseudotuberculosis. Based on microbiological identification, C. pseudotuberculosis (86/197; 43.7%), streptococci γ-hemolytic (17/197; 8.6%), and Trueperella pyogenes (12/197; 6.1%) were prevalent in lymph nodes with abscesses, as opposed to staphylococci (53/202; 26.2%) in apparently healthy lymph nodes. No mycobacteria were isolated. Cytology identified 49.2% (97/197) Gram-positive pleomorphic organisms (coryneform aspect). Multiplex PCR confirmed genetic material of C. pseudotuberculosis in 74.4% (64/86) of the samples with C. pseudotuberculosis isolation and 66% (64/97) samples with cytological coryneform aspect (κ= 86.78%; 95% CI = 79.87-93.68%). These findings emphasize the prevalence of C. pseudotuberculosis in abscess formation among peripheral lymph nodes of sheep. Other bacteria were also identified in lymph nodes sampled that resembling C. pseudotuberculosis-induced infections that may difficult the diagnosis. Multiplex PCR revealed a valuable assay to detect C. pseudotuberculosis, in addition to routine methods applied to CL-diagnosis. No mycobacteria were identified in lymph nodes sampled, with and without apparent lesions. Nonetheless, due to public health impacts, this pathogen should be considered as a differential diagnosis of C. pseudotuberculosis-induced infections during inspection procedures of slaughtered sheep intended for human consumption.

Presence of Presumptive Shiga Toxin–Producing Escherichia coli and Salmonella on Sheep during Harvest in Honduras

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) and Salmonella are foodborne pathogens commonly harbored in the gastrointestinal tract of sheep. These pathogens can be on the hide of sheep and transferred to the carcass, causing a foodborne hazard. Salmonella can also be found in the lymph nodes of sheep, creating a biological hazard during harvest and processing. Developing countries lack baseline data on the presence of these foodborne pathogens on meat products, specifically sheep meat. Therefore, the objective of this study was to evaluate the presence of STEC and Salmonella on sheep hides, preevisceration carcasses, and final carcasses and Salmonella in subiliac lymph nodes from two small Honduran harvest facilities, plants A and B. Sponge swabs from the foreshank region of hides and carcasses and subiliac lymph node samples were collected from 96 sheep (86 at plant A; 10 at plant B). Microbial detection of STEC and Salmonella was performed by using the BAX System to screen for prevalence, and suspect samples were subjected to conventional culture isolation for confirmation. Overall baseline contamination on hides were 34.4 and 10.4% present for STEC and Salmonella; however, through implementation of sanitary procedures, preevisceration and final carcass samples were significantly decreased from the hide for both pathogens (P = 0.05). Moreover, overall plant A had significantly higher rates (P = 0.05) of STEC and Salmonella at each carcass sampling site compared with plant B. After each sampling was performed, recommendations were provided to each facility on the basis of pathogen presence, performance techniques, and contamination risks. Through recommendations and implementation of hazard analysis and critical control points, good manufacturing practices, and sanitation standard operating procedures in each facility, the meat supply in Honduras will become safer and more wholesome. Therefore, the development of a baseline with continued sampling is crucial to understand the risk of foodborne pathogens to consumers in the Honduran sheep meat supply. HIGHLIGHTS

Microbiological assessment of sheep lymph nodes with lymphadenitis found during post-mortem examination of slaughtered sheep: implications for veterinary-sanitary meat control

BackgroundMicrobiological examination of lesions found in slaughtered animals during meat inspection is an important part of public health protection as such lesions may be due to zoonotic agents that can be transmitted by meat. Examination of inflamed lymph nodes also plays a particular important role, as lymphadenitis may reflect a more widespread infection. Such lesions in sheep are mainly caused by pyogenic bacteria but also mycobacteria are occasionally found. Meat inspection data from 2017 to 2018 from southern Poland, especially from the Małopolska region, indicate that purulent or caseous lymphadenitis involving the mediastinal and tracheobronchial lymph nodes (MTLNs) is a common finding. The primary aim of the current study was to determine the aetiology of these lesions. Furthermore, it was investigated how presence of lesions was correlated with age and grazing strategy of affected sheep.ResultsPost-mortem examination revealed purulent or caseous lymphadenitis in the MTLNs of 49 out of 284 animals (17.3%). Subsequent microbiological examination revealed the presence of Corynebacterium pseudotuberculosis (34.7%), Streptococcus dysgalactiae subsp. equisimilis (34.7%), Staphylococcus aureus (8.2%), Enterococcus spp. (2.0%), Trueperella pyogenes (2.0%), and β-haemolytic strains of Escherichia coli (2.0%). Mycobacterium spp. and Rhodococcus equi were not detected. In older sheep, the probability of the presence of purulent or caseous lymphadenitis was higher than in younger, and the risk was increasing by 1.5% with each month of life. Sheep grazing locally had 4.5-times greater risk of having purulent or caseous lymphadenitis than individuals summer grazing in the mountains.ConclusionThe most common aetiological agents of purulent or caseous lymphadenitis in the MTLNs of sheep in the Małopolska region were C. pseudotuberculosis and S. dysgalactiae subsp. equisimilis. Particular attention during post-mortem examination should be paid to the carcasses of older sheep and sheep grazing on permanent pastures, as they seem more prone to develop purulent or caseous lymphadenitis.

Relative abundance of interferon-stimulated genes STAT1, OAS1, CXCL10 and MX1 in ovine lymph nodes during early pregnancy

Lymph nodes have functions in the adaptive immune response, and interferon-tau (IFNT), a primary pregnancy recognition signal in domestic ruminants has effects on immune regulation. It, however, is unclear whether early pregnancy induces an increase in the abundance of interferon-stimulated gene (ISG) mRNA transcripts and proteins in lymph nodes of sheep. In this study, lymph nodes were obtained on day 16 of the estrous cycle from non-pregnant ewes and days 13, 16 and 25 of gestation from pregnant ewes, and the abundance of ISG mRNA transcripts, including signal transducer and activator of transcription 1 (STAT1), phosphorylated STAT1 (p-STAT1), 2′,5′-oligoadenylate synthetase (OAS1), myxovirus resistance protein 1 (MX1) and C-X-C motif chemokine 10 (CXCL10), was analyzed using real-time quantitative PCR. Furthermore, Western blot and immunohistochemistry analysis was conducted to assess relative abundance of proteins encoded by these genes. The results indicated that there was a larger abundance of STAT1 mRNA transcript and protein, and p-STAT1 protein in the maternal lymph node at days 16 and 25 of gestation, and that abundances of OAS1, MX1 and CXCL10 mRNA transcripts and protein were greatest on day 16 of gestations. In addition, STAT1 protein was located in the subcapsular sinus, lymph sinuses, B cells and T cells. The larger relative abundances of STAT1, p-STAT1, OAS1, MX1 and CXCL10 mRNA transcripts and/or protein in the lymph nodes of ewes may be associated with maternal immunoregulation through blood circulation and lymph circulation during early pregnancy.

Immunophenotyping of Sheep Paraffin-Embedded Peripheral Lymph Nodes.

Sheep are not only a major livestock species globally, they are also an important large animal model for biomedical research and have contributed to our understanding of the ontogeny and architecture of the mammalian immune system. In this study, we applied immunohistochemistry and multicolor immunofluorescence in fixed and paraffin-embedded lymph nodes to phenotype the key populations of antigen presenting cells, lymphocytes, and stromal cells that orchestrate the host adaptive immune response. We used an extensive panel of antibodies directed against markers associated with dendritic cells (MHC class II, CD83, and CD208), macrophages (CD11b, CD163, and CD169), stromal cells (CNA.42, S100, and CD83), and lymphocytes (CD3, Pax5, CD4, CD8). Using different methods of tissue fixation and antigen retrieval, we provide a detailed immunophenotyping of sheep lymph nodes including the identification of potential subpopulations of antigen presenting cells and stromal cells. By characterizing cells expressing combinations of these markers in the context of their morphology and location within the lymph node architecture, we provide valuable new tools to investigate the structure, activation, and regulation of the sheep immune system in health and disease.

Morphometric development of sheep (Ovis aries) lymph nodes in fetal period.

Immune system plays crucial role in body and lymph nodes are essential parts of this system for combating pathogens. However, no study has ever been conducted on morphometric development of sheep lymph nodes in fetal period. Thus, this study attempted to examine the morphometric characteristics of a number of important lymph nodes of some lymphocenters of sheep during fetal period. To this end, 60 pieces of sheep fetuses collected from Ahvaz slaughterhouse were fixated in 10% formalin and then divided into four categories based on crown-rump length (CRL) following gender and weight determinations. Mandibular, caudal superficial cervical (prescapular), caudal mediastinum, jejunal mesenteric and popliteal lymph nodes were evaluated in five lymphocenters of head, neck, thoracic cavity, abdominal viscera and pelvic limbs, respectively. In each sample, nodes formation was visually checked and in cases of nodes formation, they were measured in terms of weight, length, width and thickness and collected data were statistically analyzed. The longest and shortest fetal CRLs were found to be 48.50 cm and 3.50 cm, respectively. Gender had no effect on study parameters in 32 male and 28 female fetuses. Study of sheep fetuses’ lymph nodes revealed no macroscopic lymph node development by day 45, while all nodes were observable after the day 59. The shortest lymph node was mandibular node and the longest one was caudal mediastinum. Based on the results, it seemed that although the size of lymph nodes grows by age, this increase is not the same for all nodes and groups.

Conservation of a microRNA cluster in parasitic nematodes and profiling of miRNAs in excretory-secretory products and microvesicles of Haemonchus contortus.

microRNAs are small non-coding RNAs that are important regulators of gene expression in a range of animals, including nematodes. We have analysed a cluster of four miRNAs from the pathogenic nematode species Haemonchus contortus that are closely linked in the genome. We find that the cluster is conserved only in clade V parasitic nematodes and in some ascarids, but not in other clade III species nor in clade V free-living nematodes. Members of the cluster are present in parasite excretory-secretory products and can be detected in the abomasum and draining lymph nodes of infected sheep, indicating their release in vitro and in vivo. As observed for other parasitic nematodes, H. contortus adult worms release extracellular vesicles (EV). Small RNA libraries were prepared from vesicle-enriched and vesicle-depleted supernatants from both adult worms and L4 stage larvae. Comparison of the miRNA species in the different fractions indicated that specific miRNAs are packaged within vesicles, while others are more abundant in vesicle-depleted supernatant. Hierarchical clustering analysis indicated that the gut is the likely source of vesicle-associated miRNAs in the L4 stage, but not in the adult worm. These findings add to the growing body of work demonstrating that miRNAs released from parasitic helminths may play an important role in host-parasite interactions.

Isolation and molecular diagnosis of Peste des petits ruminants (PPR) virus from contaminated areas in Iran

Due to the numerous reports concerning the Peste des petits ruminants (PPR) in different regions of Iran, the isolation and genetic characterization of native isolates is very important. During 20132014, 168 samples were collected from whole blood, eye, nasal and oral swabs, and lymph nodes of sheep and goats with clinical signs in nine provinces with infected focal zones in Iran. Vero cell line and primary Lamb Kidney cells were inoculated with isolates and observed at least in 5 consecutive passages for cytopathic effects (CPE). The sheep samples from two provinces, created CPE in both kinds of cell cultures. Observation by electron microscopy and confirmation by RT-PCR was used to confirm PPR.

Prevalence and histopathological characteristics of Linguatula serrata infection among slaughtered ruminants in Mazandaran Province, northern Iran

There is no data concerning the status of Linguatula serrata (L. serrata) infection in ruminants in Mazandaran Province, northern Iran. Therefore, the present study was aimed to investigate the prevalence and pathologic features of linguatulosis, among slaughtered ruminants in several abattoirs in Mazandaran Province. The infection rate of L. serrata in mesenteric lymph nodes of sheep, goats, and cattle were grossly and microscopically examined. Overall, of 6249 goats, sheep, and cattle examined, 16.8% of goats, 6.8% of sheep, and 6.9% of cattle were found to be infected with L. serrata nymphs. In general, the prevalence rate of L. serrata infection was 9.1% in these animals. The prevalence of L.serrata infection in goats was significantly (p < 0.05) higher than the other animals. Locality survey illustrated the majority (86.7%) of sheep and goats infected with L.serrata were non-indigenous and belonged to Eastern parts of Iran; but this proportion in regards to cattle was reverse. Granulomatous reaction was formed with giant cells, lymphocytes, eosinophils, and macrophages around the degenerated parasite were mainly observed. In addition, typical acidophilic glands in the anterior region of the parasite are pathognomonic characteristic for diagnosing nymphs in the tissue sections. The high prevalence of L. serrata infection in the ruminants verified the hyperendemic situation of linguatulosis in the Eastern part of Iran and will represent a risk for inhabitants in Mazandaran Province, northern Iran.

Th1/Th2 balance in the liver and hepatic lymph nodes of vaccinated and unvaccinated sheep during acute stages of infection with Fasciola hepatica

The expression of IFNγ and IL4 was quantified using q-PCR in the liver and hepatic lymph nodes (HLN) of sheep during early stages of infection with Fasciola hepatica (1, 3, 9 and 18days post-infection, dpi). A group of animals (Group 1) were vaccinated with Fasciola hepatica recombinant cathepsin L1 (FhCL1) in montanide 70 VG prior to infection, a second group (group 2) was used as infected control and a third (group 3) was used as uninfected control. To study vaccine efficacy three additional groups were sacrificed 19 weeks post-infection (group 4 immunized with CL1, group 5 with the adjuvant and group 6 was used as infected control). The vaccinated group did not show significant fluke reduction compared to the adjuvant group and infected control group. IL4 expression was observed to increase at 9 dpi and was further elevated at 18 dpi in the liver and HLN of vaccinated and infected control groups compared to the uninfected group. IFNγ expression exhibited different dynamics in the liver and HLN compared to IL4; thus, in the liver this cytokine increased at 9 dpi in the vaccinated and at 18 dpi in vaccinated and infected control groups, while in the HLN it decreased gradually and significantly from 1 dpi onwards. These results suggest that a marked Th2 polarization is present from 9 dpi in HLN and from 18 dpi in the liver. The increase of IFNγ in the liver may correspond with tissue damage response with granuloma formation. The FhCL1 vaccine did not alter the Th1/Th2 balance when compared to unvaccinated and infected sheep. The study of IFNγ and IL4 in the various tissue compartments in sheep could facilitate selection of new adjuvants inducing a strong Th1 response for a more rationale vaccine formulation.

Salmonella Presence in Mandibular, Mesenteric, and Subiliac Lymph Nodes Collected from Sheep and Goats in the U.S.

ObjectivesTo survey the presence of Salmonella harbored within lymph nodes of sheep and goats in the United States.Materials and MethodsMandibular, mesenteric and subiliac lymph nodes were collected from 125 sheep and 130 goat carcasses at harvest. Samples were collected at small abattoirs (n = 578; 1 to 30 animals/d) and large (n = 183; 800 to 1,000 animals/d) facilities in California, New Mexico and Texas over a 2-yr period.Lymph nodes were trimmed from fat and fascia, boiled, pulverized and enriched in Tryptone Soy Broth (TSB). Enrichments were subjected to standard immunomagnetic separation (IMS) procedures for Salmonella, selective enrichment in Rappaport-Vassiliadis (RV) broth, and plating onto Xylose Lysine Desoxycholate (XLD) and Brilliant Green Sulfa (BGS) agars. Typical colonies from either medium were latex-agglutinated. A Chi-square test was performed via PROC FREQ on SAS (version 9.4; SAS Inst. Inc., Cary, NC) to compare the frequency of Salmonella by species and lymph node type. Significance was detected at P ≤ 0.05.ResultsIn sheep, Salmonella was detected in 4.0% (5/125) of mandibular, 7.2% (9/125) of mesenteric, and 1.9% (7/125) of subiliac lymph nodes, with no significant difference among lymph node types. In goats, significant differences among lymph node types were detected with Salmonella present in 1.6% (2/128) of mandibular, 3.1% (4/129) of mesenteric and 7.8% (10/129) of subiliac lymph nodes (P = 0.035). Overall Salmonella detection in the combined species was 2.8% in mandibular lymph nodes (n = 253), 5.1% in mesenteric lymph nodes (n = 254) and 6.7% in subiliac lymph nodes (n = 254). Salmonella presence differed significantly by month of collection, with the highest frequency of detection in March (12.36%), and no Salmonella detected in April or November (P < 0.0001). Thirty animals (11 goats, 19 sheep) were found to have 1 or more Salmonella-positive lymph nodes.ConclusionOur data indicate that Salmonella is harbored within the lymph nodes of small ruminants. Further studies are needed to further assess seasonal and geographical effects on the prevalence of this pathogen in sheep and goats, and the potential influence of production practices on Salmonella contamination in ovine and caprine food products.