Faecal shedding of antimicrobial-resistant Clostridium difficile strains by dogs.

OBJECTIVES: To longitudinally assess the shedding of antimicrobial resistant Clostridium difficile strains by clinically healthy dogs raised at breeding facilities. METHODS: 18 puppies from three different litters (#1, 2 and 3) were sampled weekly from parturition to day 20-55 postpartum. Faecal samples from the mothers of litters #2 and 3 were also available for analysis. Bacterial isolates were ribotyped, tested for in vitro antimicrobial susceptibility and further characterised. RESULTS: C. difficile was recovered from all sampled animals of litters #1 and 2, and a third of puppies from litter #3, but marked differences in C. difficile recovery were detected in different age groups (0-100%). Recovered PCR ribotypes included 056 (22 isolates), 010 (6 isolates), 078 and 213 (2 isolates each), and 009 and 020 (1 isolate each). Different ribotypes were shed by four individual animals. Regardless of their origin and ribotype, all isolates demonstrated full resistance to levofloxacin. Additionally, all but one isolate (belonging to ribotype 078) were resistant to ertapenem, and all ribotype 010 isolates displayed high-level resistance to clindamycin, clarithromycin and erythromycin. A single ribotype 078 isolate showed metronidazole heteroresistance. CLINICAL SIGNIFICANCE: Healthy dogs can shed antimicrobial-resistant C. difficile strains.

Supercritical fluid extraction of polycyclic aromatic hydrocarbons from seaweed samples before and after the prestige oil spill.

Samples of seaweed which are used for human consumption were collected along the Galician coast (NW Spain), in order to determine the level of contamination from polycyclic aromatic hydrocarbons, by supercritical fluid extraction and liquid chromatographic analysis. No detection was made of benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, benzo[ghi]perylene and dibenzo[ah]anthracene. PAHs were found and quantified in only two samples. The PAHs found were the following: anthracene, chrysene, fluoranthene, fluorene and pyrene. The levels found were below maximum limits established by the Spanish Food Safety authority (<200 mg/kg dry weight). Here we show that no relevant effects were detected in terms of PAHs contamination in seaweed.

Participation of epidermal langerhans cells in human pathology and their potential as targets for drug development: a review of literature.

Langerhans cells (LC) are antigen presenting cells of the epidermis originated from bone marrow progenitors that arrive into the epidermis through the blood vessels LC are also referred to as dendritic cells. In the presence of antigens LC become activated and migrate from the skin to the lymph nodes where they induce T cells responses, therefore, LC function as sentinels of the epidermis and constitute, in part the Skin Immune System (SIS). LC have been implicated in the pathogenesis and pathophysiology of diverse diseases such as atopic dermatitis, alopecia areata, human immunodeficiency virus infection (HIV) and melanoma, among others. The aim of this review is to draw the attention of pharmacologists towards LC as targets for drug action and drug development due to their immunesurveillance function. LC modulate the SIS as an endogenous mechanism of defense against many infectious agents, xenobiotics, and for the treatment of cancer, infections, and autoimmune diseases. A review of the literature on LC is presented here giving emphasis to LC cell cycle and cellular and molecular characteristics, LC possible role in human pathologies, and LC therapeutic potential.

Effects of single administration of diethylstilbestrol on murine langerhans cells.

Diethylstilbestrol (DES) is a synthetic compound with potent estrogenic actions useful in the treatment of prostate carcinoma despite the fact that it can also induce some forms of neoplasia. Both effects are thought to be related to its estrogenic actions and very little attention has been focused on the possible effect of DES on the immune response. Skin is the largest organ of the body and constitutes the first line of defense against xenobiotics. The Skin Immune System (SIS) has become the center of attention of research for the development of new therapeutic approaches for neoplasic diseases. Langerhans cells (LC), as an element of SIS, are "professional" antigen presenting cells resident in the skin that participate in the immune response associated with tolerance and acquired immunity to antigens. Hence in this work we studied the effect of DES on LC of murine skin as a model to analyze the possible effect of DES on the immune response. Male CD-1 mice (20 to 35 g body weight) were treated topically (TO) or subcutaneously (SC) with DES (10 and 100 mg/kg, dissolved in ethanol) and sacrificed at 12, 84 and 228 hr. LC were quantified in the ear skin of mice using both an enzymatic histochemical technique to demonstrate ATP-ase activity; and an indirect immunohistochemical assay for detecting class II molecules of the major histocompatibility complex (MHC-II). DES induced a significant time- and dose- dependent reduction in the number of LC (P < 0.05). Data presented here suggest that estrogens may exert a modulatory action on LC.

ATPase and MHC class II molecules co-expression in Rana pipiens dendritic cells.

Mammalian Langerhans cells are antigen-presenting cells located in different epithelia. These cells have a characteristic ultrastructural pattern, present a plasmatic membrane ATPase activity and constitutively express class II molecules of the major histocompatibility complex. ATPase-positive dendritic cells that are morphologically similar to Langerhans cells have also been found in amphibian epidermis. In order to demonstrate that ATPase-positive dendritic cells of amphibian epidermis express class II molecules and are present in other stratified epithelia, histochemical and immunohistochemical as well as ultrastructural analysis were performed. ATPase-positive dendritic cells and class II-positive dendritic cells were observed in epidermis, nictitant membrane and cornea. In epidermis the number of ATPase-positive dendritic cells was 656+/-186/mm2 while class II-positive dendritic cells was 119+/-45/mm2. Some ATPase-positive dendritic cells showed co-expression of class II molecules. These results suggest the existence of dendritic cell subsets in amphibians as is clearly demonstrated in mammals.