138 research outputs found

    Thermoregulatory strategy may shape immune investment in Drosophila melanogaster

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    As temperatures change, insects alter the amount of melanin in their cuticle to improve thermoregulation. However, melanin is also central to insect immunity, suggesting that thermoregulatory strategy may indirectly impact immune defense by altering the abundance of melanin pathway components (a hypothesis we refer to as thermoregulatory-dependent immune investment). This may be the case in the cricket Allonemobius socius, where warm environments (both seasonal and geographical) produced crickets with lighter cuticles and increased pathogen susceptibility. Unfortunately, the potential for thermoregulatory strategy to influence insect immunity has not been widely explored. Here we address the relationships between temperature, thermoregulatory strategy and immunity in the fruit fly Drosophila melanogaster. To this end, flies from two separate Canadian populations were reared in either a summer-or autumn-like environment. Shortly after adult eclosion, flies were moved to a common environment where their cuticle color and susceptibility to a bacterial pathogen (Pseudomonas aeruginosa) were measured. As with A. socius, individuals from summer-like environments exhibited lighter cuticles and increased pathogen susceptibility, suggesting that the thermoregulatory-immunity relationship is evolutionarily conserved across the hemimetabolous and holometabolous clades. If global temperatures continue to rise as expected, then thermoregulation might play an important role in host infection and mortality rates in systems that provide critical ecosystem services (e.g. pollination), or influence the prevalence of insect-vectored disease (e.g. malaria)

    Methicillin Resistant Staphylococcus aureus (MRSA) in market age pigs on-farm, at slaughter and retail pork

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    This study was conducted to determine the occurrence and prevalence of methicillin resistant Staphylococcus aureus (MRSA) in finishing pigs on-farm, at lairage and assess the likelihood of carriage at slaughter and retail levels. A cross-sectional study targeting ten cohorts of commercial swine farms was conducted for carriage of MRSA

    Effect of competitive exclusion on salmonella shedding in swine

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    Despite the efforts of researchers and public health agencies, the incidence of human salmonellosis has continued to increase over the past 20 years. Salmonellosis is now the most common cause of food-borne gastroenteritis. The number of reported cases of human Salmonella infection exceeds 40,000 per year. The Communicable Disease Center estimates that the true annual incidence of human salmonellosis in the United States may be as high as 4 million cases

    Transcriptomic Analysis of Equine Chorioallantois Reveals Immune Networks and Molecular Mechanisms Involved in Nocardioform Placentitis

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    Nocardioform placentitis (NP) continues to result in episodic outbreaks of abortion and preterm birth in mares and remains a poorly understood disease. The objective of this study was to characterize the transcriptome of the chorioallantois (CA) of mares with NP. The CA were collected from mares with confirmed NP based upon histopathology, microbiological culture and PCR for Amycolatopsis spp. Samples were collected from the margin of the NP lesion (NPL, n = 4) and grossly normal region (NPN, n = 4). Additionally, CA samples were collected from normal postpartum mares (Control; CRL, n = 4). Transcriptome analysis identified 2892 differentially expressed genes (DEGs) in NPL vs. CRL and 2450 DEGs in NPL vs. NPN. Functional genomics analysis elucidated that inflammatory signaling, toll-like receptor signaling, inflammasome activation, chemotaxis, and apoptosis pathways are involved in NP. The increased leukocytic infiltration in NPL was associated with the upregulation of matrix metalloproteinase (MMP1, MMP3, and MMP8) and apoptosis-related genes, such as caspases (CASP3 and CASP7), which could explain placental separation associated with NP. Also, NP was associated with downregulation of several placenta-regulatory genes (ABCG2, GCM1, EPAS1, and NR3C1), angiogenesis-related genes (VEGFA, FLT1, KDR, and ANGPT2), and glucose transporter coding genes (GLUT1, GLUT10, and GLUT12), as well as upregulation of hypoxia-related genes (HIF1A and EGLN3), which could elucidate placental insufficiency accompanying NP. In conclusion, our findings revealed for the first time, the key regulators and mechanisms underlying placental inflammation, separation, and insufficiency during NP, which might lead to the development of efficacious therapies or diagnostic aids by targeting the key molecular pathways

    Remission and Relapse of Dyslipidemia After Vertical Sleeve Gastrectomy vs Roux-en-Y Gastric Bypass in a Racially and Ethnically Diverse Population.

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    IMPORTANCE: The comparative effectiveness of the most common operations in the long-term management of dyslipidemia is not clear. OBJECTIVE: To compare 4-year outcomes associated with vertical sleeve gastrectomy (VSG) vs Roux-en-Y gastric bypass (RYGB) for remission and relapse of dyslipidemia. DESIGN, SETTING, AND PARTICIPANTS: This retrospective comparative effectiveness study was conducted from January 1, 2009, to December 31, 2016, with follow-up until December 31, 2018. Participants included patients with dyslipidemia at the time of surgery who underwent VSG (4142 patients) or RYGB (2853 patients). Patients were part of a large integrated health care system in Southern California. Analysis was conducted from January 1, 2018, to December 31, 2021. EXPOSURES: RYGB and VSG. MAIN OUTCOMES AND MEASURES: Dyslipidemia remission and relapse were assessed in each year of follow-up for as long as 4 years after surgery. RESULTS: A total of 8265 patients were included, with a mean (SD) age of 46 (11) years; 6591 (79.8%) were women, 3545 (42.9%) were Hispanic, 1468 (17.8%) were non-Hispanic Black, 2985 (36.1%) were non-Hispanic White, 267 (3.2%) were of other non-Hispanic race, and the mean (SD) body mass index (calculated as weight in kilograms divided by height in meters squared) was 44 (7) at the time of surgery. Dyslipidemia outcomes at 4 years were ascertained for 2168 patients (75.9%) undergoing RYGB and 3999 (73.9%) undergoing VSG. Remission was significantly higher for those who underwent RYGB (824 [38.0%]) compared with VSG (1120 [28.0%]) (difference in the probability of remission, 0.10; 95% CI, 0.01-0.19), with no differences in relapse (455 [21.0%] vs 960 [24.0%]). Without accounting for relapse, remission of dyslipidemia after 4 years was 58.9% (1279) for those who underwent RYGB and 51.9% (2079) for those who underwent VSG. Four-year differences between operations were most pronounced for patients 65 years or older (0.39; 95% CI, 0.27-0.51), those with cardiovascular disease (0.43; 95% CI, 0.24-0.62), or non-Hispanic Black patients (0.13; 95% CI, 0.01-0.25) and White patients (0.13; 95% CI, 0.03-0.22). CONCLUSIONS AND RELEVANCE: In this large, racially and ethnically diverse cohort of patients who underwent bariatric and metabolic surgery in clinical practices, RYGB was associated with higher rates of dyslipidemia remission after 4 years compared with VSG. However, almost one-quarter of all patients experienced relapse, suggesting that patients should be monitored closely throughout their postoperative course to maximize the benefits of these operations for treatment of dyslipidemia

    The Impact of the COVID-19 Pandemic on Racial Disparities in Patients Undergoing Total Shoulder Arthroplasty in the United States

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    INTRODUCTION: The purpose of this study was to assess racial disparities in total shoulder arthroplasty (TSA) in the US and to determine whether these disparities were affected by the COVID-19 pandemic. METHODS: Centers for Medicare and Medicaid Services (CMS) 100% sample was used to examine primary TSA volume from April-December from 2019-2020. Utilization was assessed for White/Black/Hispanic/Asian populations to determine if COVID-19 affected these groups differently. A regression model adjusted for age/sex/CMS-Hierarchical Condition Categories (HCC) score, dual enrollment (proxy for socioeconomic status), time fixed effects, and Core-based Statistical Area (CBSA) fixed effects was used to study difference across groups. RESULTS: In 2019, TSA volume/1000 beneficiaries was 1.51 for White and 0.57 for non-White, a 2.6-fold difference. In 2020, the rate of TSA in White patients (1.30/1000) was 2.9 times higher than non-White (0.45/1000) during the COVID-19 pandemic (P\u3c0.01). There was an overall 14% decrease in TSA volume/1000 Medicare beneficiaries in 2020; non-White patients had a larger percentage decrease in TSA volume than White (21% vs. 14%, estimated difference;8.7%,p = 0.02). Black patients experienced the most pronounced disparity with estimated difference of 10.1%,p = 0.05, compared with White patients. Similar disparities were observed when categorizing procedures into anatomic and reverse TSA, but not proximal humerus fracture. CONCLUSIONS: During the COVID-19 pandemic, overall TSA utilization decreased by 14% with White patients experiencing a decrease of 14%, and non-White patients experiencing a decrease of 21%. This trend was observed for elective TSA while disparities were less apparent for proximal humerus fracture

    Direct and indirect transmission of four Salmonella enterica serotypes in pigs

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    <p>Abstract</p> <p>Background</p> <p>Feed-borne spread of <it>Salmonella </it>spp. to pigs has been documented several times in recent years in Sweden. Experiences from the field suggest that feed-associated serotypes might be less transmittable and subsequently easier to eradicate from pig herds than other serotypes more commonly associated to pigs. Four <it>Salmonella </it>serotypes were selected for experimental studies in pigs in order to study transmissibility and compare possible differences between feed-assoociated (<it>S </it>Cubana and <it>S </it>Yoruba) and pig-associated serotypes (<it>S </it>Derby and <it>S </it>Typhimurium).</p> <p>Methods</p> <p>Direct contact transmission was studied in four groups of pigs formed by six 10-week-old salmonella negative pigs commingled with two fatteners excreting one of the four salmonella serotypes. Indirect transmission was studied by putting six 10-week-old salmonella negative pigs in each of four salmonella contaminated rooms. Each room had previously housed a group of pigs, excreting one of the four selected serotypes.</p> <p>All pigs were monitored for two weeks with respect to the faecal excretion of salmonella and the presence of serum antibodies. At the end of the trial, eight samples from inner tissues and organs were collected from each pig at necropsy.</p> <p>Results</p> <p>In the four direct transmission groups, one pig shed <it>Salmonella </it>(Cubana) at one occasion. At necropsy, <it>S </it>Typhimurium was isolated from one pig.</p> <p>In the indirect transmission groups, two pigs in the Yoruba room and one pig in each of the other rooms were excreting detectable levels of <it>Salmonella </it>once during the study period of two weeks. At necropsy, <it>S </it>Derby was isolated from one of six pigs in the Derby room and <it>S </it>Typhimurium was isolated from four of the six pigs in the Typhimurium room.</p> <p>No significant serological response could be detected in any of the 48 pigs.</p> <p>Conclusions</p> <p>These results show that all four selected serotypes were able to be transmitted in at least one of these field-like trials, but the transmission rate was low in all groups and no obvious differences between feed-associated and pig-associated serotypes in the transmission to naïve pigs and their subsequent faecal shedding were revealed. However, the post mortem results indicated a higher detection of <it>S </it>Typhimurium in the ileocecal lymph nodes of pigs introduced into a contaminated environment in comparison with the other three serotypes.</p

    C. elegans Germline-Deficient Mutants Respond to Pathogen Infection Using Shared and Distinct Mechanisms

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    Reproduction extracts a cost in resources that organisms are then unable to utilize to deal with a multitude of environmental stressors. In the nematode C. elegans, development of the germline shortens the lifespan of the animal and increases its susceptibility to microbial pathogens. Prior studies have demonstrated germline-deficient nematodes to have increased resistance to Gram negative bacteria. We show that germline-deficient strains display increased resistance across a broad range of pathogens including Gram positive and Gram negative bacteria, and the fungal pathogen Cryptococcus neoformans. Furthermore, we show that the FOXO transcription factor DAF-16, which regulates longevity and immunity in C. elegans, appears to be crucial for maintaining longevity in both wild-type and germline-deficient backgrounds. Our studies indicate that germline-deficient mutants glp-1 and glp-4 respond to pathogen infection using common and different mechanisms that involve the activation of DAF-16

    Prebiotic and probiotic agents enhance antibody-based immune responses to Salmonella Typhimurium infection in pigs

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    Salmonellosis causes significant economic losses to the pig industry and contaminated pork products are an important source of Salmonella for humans. The EU ban on the use of antibiotic growth promoters in pig production, and the emergence of antibiotic resistance has meant there is a pressing need for alternative control strategies for pathogenic bacteria such as S. Typhimurium in pigs. Here, we determined the effects of prebiotic, probiotic and synbiotic diet regimes on antibody responses to oral Salmonella challenge of pigs. The data demonstrate that the inclusion of the probiotic Lactobacillus plantarum B2984 in the diet of piglets (∼1 × 1010 cfu/animal/day) enhanced serum IgM (P<0.001), IgG (P=0.001) and IgA (P=0.039) responses to S. Typhimurium infection including cross-reacting antibodies to S. Enteritidis. Similarly, inclusion of the prebiotic lactulose at 1% (w/w) of the feed on a daily basis in the diet enhanced serum IgM (P=0.010), IgG (P=0.004) and IgA (P=0.046) responses to S. Typhimurium infection and also cross-reacting antibodies to S. Enteritidis. Inclusion of both additives in the synbiotic diet also elicited an enhanced immune response with IgM (P=0.009) and IgG (P=0.046) levels being increased, however a significant interaction of the pre and probiotics was observed when considering the immune responses to S. Typhimurium (IgM P=0.004; IgG and IgA, P<0.001 for interaction). With respect to immune responses, the effects of pre or probiotic administration were the same or reduced in the synbiotic diet compared to when used in isolation. The data support the use of Lactobacillus plantarum B2984 or lactulose as strategies to contribute to the protection of weaned piglets from zoonotic bacterial pathogens, but caution must be taken when combining dietary supplements as combinations can interact
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