In-feed antibiotic effects on the swine intestinal microbiome

Antibiotics have been administered to agricultural animals for disease treatment, disease prevention, and growth promotion for over 50 y. The impact of such antibiotic use on the treatment of human diseases is hotly debated. We raised pigs in a highly controlled environment, with one portion of the littermates receiving a diet containing performance-enhancing antibiotics [chlortetracycline, sulfamethazine, and penicillin (known as ASP250)] and the other portion receiving the same diet but without the antibiotics. We used phylogenetic, metagenomic, and quantitative PCR-based approaches to address the impact of antibiotics on the swine gut microbiota. Bacterial phylotypes shifted after 14 d of antibiotic treatment, with the medicated pigs showing an increase in Proteobacteria (1-11%) compared with nonmedicated pigs at the same time point. This shift was driven by an increase in Escherichia coli populations. Analysis of the metagenomes showed that microbial functional genes relating to energy production and conversion were increased in the antibiotic-fed pigs. The results also indicate that antibiotic resistance genes increased in abundance and diversity in the medicated swine microbiome despite a high background of resistance genes in nonmedicated swine. Some enriched genes, such as aminoglycoside O-phosphotransferases, confer resistance to antibiotics that were not administered in this study, demonstrating the potential for indirect selection of resistance to classes of antibiotics not fed. The collateral effects of feeding subtherapeutic doses of antibiotics to agricultural animals are apparent and must be considered in cost-benefit analyses.     

Collateral effects of antibiotics on mammalian gut microbiomes

Antibiotics are an essential component of the modern lifestyle. They improve our lives by treating disease, preventing disease, and in the case of agricultural animals by improving feed efficiency. However, antibiotic usage is not without collateral effects. The development and spread of antibiotic resistance is the most notorious concern associated with antibiotic use. New technologies have enabled the study of how the microbiota responds to the antibiotic disturbance, including how the community recovers after the antibiotic is removed. One common theme in studies of antibiotic effects is a rapid increase in Escherichia coli followed by a gradual decline. Increases in E. coli are also associated with systemic host stresses, and may be an indicator of ecosystem disturbances of the intestinal microbiota. Moreover, recent studies have shown additional effects mediated by antibiotics on the gut microbiota, such as the stimulation of gene transfer among gut bacteria and the reduction of immune responses in peripheral organs. Querying the microbiota after antibiotic treatment has led to intriguing hypotheses regarding predicting or mitigating unfavorable treatment outcomes. Here we explore the varied effects of antibiotics on human and animal microbiotas.     

Mapping quantitative trait loci for innate immune response in the pig

The aim of the present study was to detect quantitative trait loci (QTL) for the serum levels of cytokines and Toll‐like receptors as traits related to innate immunity in pig. For this purpose, serum concentration of interleukin 2 (IL2), interleukin 10 (IL10), interferon‐gamma (IFNG), Toll‐like receptor 2 (TLR2) and Toll‐like receptor 9 (TLR9) were measured in blood samples obtained from F₂ piglets (n = 334) of a Duroc × Piétrain resource population (DUPI) after Mycoplasma hypopneumoniae (Mh), tetanus toxoid (TT) and Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) vaccination at 6, 9 and 15 weeks of age. Animals were genotyped at 82 genetic markers covering all autosomes. QTL analysis was performed under the line cross F₂ model using QTL Express and 33 single QTL were detected on almost all porcine autosomes. Among the single QTL, eight, twelve and thirteen QTL were identified for innate immune traits in response to Mh, TT and PRRSV vaccine, respectively. Besides single QTL, six QTL were identified by a two‐QTL model, of which two for TLR9_TT were in coupling phase and one for IL10_PRRSV was in repulsion phase. All QTL were significant at 5% chromosome‐wide level including one and seven at 5% genome‐ and 1% chromosome‐wide level significance. All innate immune traits are influenced by multiple chromosomal regions implying multiple gene action. Some of the identified QTL coincided with previously reported QTL for immune response and disease resistance, and the newly identified QTL are potentially involved in the immune function. The immune traits were also influenced by environmental factors like year of birth, age, parity and litter size. The results of this work shed new light on the genetic background of innate immune response and these findings will be helpful to identify candidate genes in these QTL regions related to immune competence and disease resistance in pigs.     

Platinum disposition after intraarterial and intravenous infusion of cisplatin for osteosarcoma

Summary Preoperative chemotherapy according to the COSS 86 protocol, including two courses of cisplatin, was used for high-risk osteosarcoma. Patients were randomised to receive either intraarterial (i.a.) or intravenous (i.v.) cisplatin infusions. As measured by flameless atomic absorption spectroscopy (FAAS), platinum (Pt) levels in serum, ultrafiltrate, and urine did not show a decrease in systemic drug availability with i.a. administration. Turmors were surgically removed 3 weeks after the last cisplatin dose and analysed for Pt content and response to chemotherapy. A correlation could not be demonstrated between Pt levels in tumor tissue samples and the mode of CDDP application or extent of tumor cell destruction.This work was supported by the Hamburger Krebsgesellschaft and the Bundesministerium für Forschung und Technologie     

Swept period grating stimuli applied to cutaneous receptors

Grating stimuli with successively larger integrate periods (also known as "swept period") are described and characterized. Since the swept period gratings are used to study the temporal frequency response functions of cutaneous receptors, a stimulator that can be used to draw these stimuli over the surface of the skin with precisely controlled motion is also described. The use of a swept period grating stimulus is illustrated for the specific case of stimulating a cat, hairy skin, slowly adapting Type I mechanoreceptor.     

Anthracycline transport in sensitive and resistant leukemia cells

The in-vitro uptake of four anthracyclines into leukemic cells was investigated. The accumulation was found to be dependent on the extracellular anthracycline concentration in a linear fashion. The steady state intracellular drug level was reached very quickly and was found to be correlated to the extracellular pH-value in the range between 6.4 and 7.4. Intracellular anthracycline accumulation was restricted in a leukemic subline (F 4-6 R), which was found to be 86 times more resistant to doxorubicin compared with its wild tpye (F 4-6). The importance of the initial uptake phase of anthracyclines into leukemic cells raises the question whether long-term "cardioprotective" anthracycline application schedules will retain the same antileukemic effect as conventional bolus injection.