Identification of intestinal and fecal microbial biomarkers using a porcine social stress model.

Understanding the relationships between social stress and the gastrointestinal microbiota, and how they influence host health and performance is expected to have many scientific and commercial implementations in different species, including identification and improvement of challenges to animal welfare and health. In particular, the study of the stress impact on the gastrointestinal microbiota of pigs may be of interest as a model for human health. A porcine stress model based on repeated regrouping and reduced space allowance during the last 4 weeks of the finishing period was developed to identify stress-induced changes in the gut microbiome composition. The application of the porcine stress model resulted in a significant increase in salivary cortisol concentration over the course of the trial and decreased growth performance and appetite. The applied social stress resulted in 32 bacteria being either enriched (13) or depleted (19) in the intestine and feces. Fecal samples showed a greater number of microbial genera influenced by stress than caecum or colon samples. Our trial revealed that the opportunistic pathogens Treponema and Clostridium were enriched in colonic and fecal samples from stressed pigs. Additionally, genera such as Streptococcus, Parabacteroides, Desulfovibrio, Terrisporobacter, Marvinbryantia, and Romboutsia were found to be enriched in response to social stress. In contrast, the genera Prevotella, Faecalibacterium, Butyricicoccus, Dialister, Alloprevotella, Megasphaera, and Mitsuokella were depleted. These depleted bacteria are of great interest because they synthesize metabolites [e.g., short-chain fatty acids (SCFA), in particular, butyrate] showing beneficial health benefits due to inhibitory effects on pathogenic bacteria in different animal species. Of particular interest are Dialister and Faecalibacterium, as their depletion was identified in a human study to be associated with inferior quality of life and depression. We also revealed that some pigs were more susceptible to pathogens as indicated by large enrichments of opportunistic pathogens of Clostridium, Treponema, Streptococcus and Campylobacter. Generally, our results provide further evidence for the microbiota-gut-brain axis as indicated by an increase in cortisol concentration due to social stress regulated by the hypothalamic-pituitary-adrenal axis, and a change in microbiota composition, particularly of bacteria known to be associated with pathogenicity and mental health diseases.

Evaluation of direct and maternal responses in reproduction traits based on different selection strategies for postnatal piglet survival in a selection experiment.

BACKGROUND: Postnatal piglet survival is important both in economic and animal welfare terms. It is influenced by the piglet's own direct genetic effects and by maternal genetic effects of the dam, associated with milk production and mothering abilities. These genetic effects might be correlated, affected by other non-genetic factors and unfavourably associated with other reproduction traits such as litter size, which makes the development of optimal breeding strategies a challenge. To identify the optimum selection strategy for piglet survival, a selection experiment was carried out to compare responses in survival and reproduction traits to selection on only direct, only maternal, or both genetic effects of postnatal survival. The data of the experiment were recorded from outdoor reared pigs, with first- and second-generation sires selected based on their estimated breeding values for maternal and direct effects of postnatal survival of indoor reared offspring, respectively, with the opportunity to identify potential genotype-by-environment interaction. RESULTS: A Bayesian multivariate threshold-linear model that was fitted to data on 22,483 piglets resulted in significant (Pr(h2 > 0) = 1.00) estimates of maternal and direct heritabilities between 0.12 and 0.18 for survival traits and between 0.29 and 0.36 for birth weight, respectively. Selection for direct genetic effects resulted in direct and maternal responses in postnatal survival of 1.11% ± 0.17 and - 0.49% ± 0.10, respectively, while selection for maternal genetic effects led to greater direct and maternal responses, of 5.20% ± 0.34 and 1.29% ± 0.20, respectively, in part due to unintentional within-litter selection. Selection for both direct and maternal effects revealed a significant lower direct response (- 1.04% ± 0.12) in comparison to its expected response from single-effect selection, caused by interactions between direct and maternal effects. CONCLUSIONS: Selection successfully improved post- and perinatal survival and birth weight, which indicates that they are genetically determined and that genotype-by-environment interactions between outdoor (experimental data) and indoor (selection data) housed pigs were not important for these traits. A substantially increased overall (direct plus maternal) response was obtained using selection for maternal versus direct or both direct and maternal effects, suggesting that the maternal genetic effects are the main limiting factor for improving piglet survival on which selection pressure should be emphasized.

Right anterolateral mini-thoracotomy without inferior vena cava cannulation for atrial septal defect repair in small children: A feasible technique.

OBJECTIVE: To evaluate the effectiveness and safety of right anterolateral mini-thoracotomy without inferior vena cava (IVC) cannulation for closing atrial septal defect (ASD) in small children. METHODS: From February 2016 to August 2017, 10 patients (the mean age was 18.5 ±â€¯10.1 months and the mean weight was 8.3 ±â€¯2.1 kg) underwent ASD closure via right anterolateral mini-thoracotomy. The superior vena cava cannula was placed through the right internal jugular vein. A 3-4 cm incision was made on the right chest. The pleural and pericardial cavities were filled with CO2 and the heart was beating during the surgery. Blood returned from IVC was drained by a right heart sucker. All ASDs were closed using artificial patch, continuous suture. Mean follow-up was 18 months (range, 15-22 months). RESULTS: No post-operative complications or deaths occurred. Mean operation time and mean cardiopulmonary bypass time were 140.5 ±â€¯27.8 min and 50.3 ±â€¯16.5 min, respectively. These patients were extubated within the first 6 h. The intensive care unit stay time and the post-operative hospital stay time were 19.6 ±â€¯2.6 h and 7.1 ±â€¯1.2 days, respectively. Follow-up transthoracic echocardiography showed no residual shunts or lung atelectasis. CONCLUSIONS: The right anterolateral mini-thoracotomy without IVC cannulation is feasible for repairing ASD in small children. This technique is effective and safe and can be used as a therapeutic option for ASD.

Bacterial brothers in arms: cooperation of Staphylococcus aureus and Pseudomonas aeruginosa during antimicrobial exposure.

OBJECTIVES: The optimal selection of antibacterials during polymicrobial infections is poorly defined. The objective of the current investigation was to quantify the pharmacodynamics of relevant antimicrobials during co-culture of Pseudomonas aeruginosa with two separate Staphylococcus aureus phenotypes. METHODS: Time-kill experiments were conducted against co-cultures of the P. aeruginosa strain PA01 paired with either the normal phenotype (NP) MRSA isolate COL or the small colony variant phenotype (SCVP) MRSA isolate Ia48. The killing by levofloxacin, gentamicin, clindamycin, vancomycin and polymyxin B was evaluated to investigate drugs with activity against one or both pathogens. A Hill-type function and a mechanism-based model were used to describe bacterial killing. RESULTS: P. aeruginosa attenuated the activity of clindamycin against NP MRSA, with a reduction in the Emax (maximal killing) from 3.67 (95% CI 2.79-4.56) in monoculture to 1.86 (95% CI 1.35-2.37) during co-culture, whereas a significant protective effect was not observed for other antibacterials. The reduction in NP MRSA killing by clindamycin was described well by a mechanism-based model that generated a maximal killing rate constant of clindamycin against the susceptible NP MRSA subpopulation of 0.267 h-1 in monoculture and 0.0395 h-1 in the presence of P. aeruginosa. During exposure to gentamicin, P. aeruginosa was the dominant organism in co-culture experiments regardless of the drug concentration or S. aureus phenotype; however, the SCVP MRSA was able to dominate the joint population beginning at a levofloxacin concentration of 1.5 mg/L. CONCLUSIONS: The anti-staphylococcal activity of clindamycin was attenuated by the presence of P. aeruginosa.

Current dietary zinc intake has a greater effect on fractional zinc absorption than does longer term zinc consumption in healthy adult men.

BACKGROUND: No studies have examined the independent effects of current and longer-term dietary zinc intakes on zinc absorption. OBJECTIVE: We determined the effects of current compared with longer-term zinc intake on fractional zinc absorption (FZA). DESIGN: We studied 9 men whose usual zinc intakes were >11 mg/d. FZA was measured at baseline, depletion (0.6 mg Zn/d for 1 wk and 4 mg Zn/d for 5 wk), and repletion (11 mg Zn/d for 4 wk with 20 mg supplemental Zn/d for first 7 d). During 2 successive days after each dietary period, subjects consumed either adequate-zinc meals (11 mg Zn/d) with a zinc stable isotope tracer for 1 d, followed by low-zinc meals (4 mg Zn/d) with zinc tracer, or vice versa. Five days after oral dosing, a zinc tracer was infused intravenously. FZA was measured with the use of a modified double isotope tracer ratio method with urine samples collected on days 5-7 and 10-12 of absorption studies. RESULTS: Plasma and urinary zinc did not vary by dietary period. Mean FZA was greater from low-zinc meals than from adequate-zinc meals (60.9% +/- 13.8% compared with 36.1% +/- 8.9%; P < 0.0001), whereas mean total absorbed zinc was greater from adequate-zinc meals than from low-zinc meals (3.60 +/- 0.91 compared with 2.48 +/- 0.56; P < 0.0001), regardless of the longer-term dietary period. CONCLUSIONS: FZA was inversely related to current zinc intake, but there was no detectable effect of longer-term dietary zinc. If longer- term zinc intake does modify FZA, such changes are smaller than those caused by current zinc intake, or they occur only after more severe zinc depletion.