Reservoirs of Listeria Species in Three Environmental Ecosystems

Soil and water are suggested to represent pivotal niches for the transmission of Listeria monocytogenes to plant material, animals, and the food chain. In the present study, 467 soil and 68 water samples were collected in 12 distinct geological and ecological sites in Austria from 2007 to 2009. Listeria was present in 30% and 26% of the investigated soil and water samples, respectively. Generally, the most dominant species in soil and water samples were Listeria seeligeri, L. innocua, and L. ivanovii. The human- and animal-pathogenic L. monocytogenes was isolated exclusively from 6% soil samples in regions A (mountainous region) and B (meadow). Distinct ecological preferences were observed for L. seeligeri and L. ivanovii, which were more often isolated from wildlife reserve region C (Lake Neusiedl) and from sites in proximity to wild and domestic ruminants (region A). The higher L. monocytogenes detection and antibiotic resistance rates in regions A and B could be explained by the proximity to agricultural land and urban environment. L. monocytogenes multilocus sequence typing corroborated this evidence since sequence type 37 (ST37), ST91, ST101, and ST517 were repeatedly isolated from regions A and B over several months. A higher L. monocytogenes detection and strain variability was observed during flooding of the river Schwarza (region A) and Danube (region B) in September 2007, indicating dispersion via watercourses.     

Stress survival islet 1 (SSI-1) survey in Listeria monocytogenes reveals an insert common to listeria innocua in sequence type 121 L. monocytogenes strains

Listeria monocytogenes strains (n = 117) were screened for the presence of stress survival islet 1 (SSI-1). SSI-1(+) strains (32.5%) belonged mainly to serotypes 1/2c, 3b, and 3c. All sequence type 121 (ST-121) strains included (n = 7) possessed homologues to Listeria innocua genes lin0464 and lin0465 instead of SSI-1.     

Domestication effects on behavioural synchronization and individual distances in chickens (Gallus gallus)

Behavioural synchrony (allelomimetic behaviour), and inter-individual distances are aspects of social and anti-predator strategies which may have been affected by domestication. Chickens are known to adjust synchronization and inter-individual distances depending on behaviour. We hypothesized that White Leghorn (WL) chickens would show less synchronized behaviour than the ancestor, the red jungle fowl (RJF). Sixty birds, 15 female and 15 male WL and the same number of RJF (28 weeks old) were studied in groups of three in furnished pens (1 m × 2 m) for 24 consecutive hours per group, following 24 h of habituation. Video tapes covering 4 h per group (dawn, 9-10 am, 1-2 pm and dusk) were analysed. Red junglefowl perched significantly more, but there were no breed effects on the frequency or daily rhythm of any other activities, or on average inter-individual distances. Red junglefowl were more synchronized during perching and a tendency for the same was found for social behaviour. After performance of the two most synchronized behaviours, perching and comfort behaviour, individual distance increased more for RJF than WL. According to this study domestication of chickens appears not to have significantly altered the relative frequencies of different activities or average inter-individual distances, but have caused some changes in behavioural synchronization and maintenance of activity-specific inter-individual distances in chickens. The changes may indicate an adaptive response to captivity and domestication.     

mGluR7 Genetics and Alcohol: Intersection Yields Clues for Addiction

Development of addiction to alcohol or other substances can be attributed in part to exposure-dependent modifications at synaptic efficacy leading to an organism which functions at an altered homeostatic setpoint. Genetic factors may also influence setpoints and the stability of the homeostatic system of an organism. Quantitative genetic analysis of voluntary alcohol drinking, and mapping of the involved genes in the quasi-congenic Recombinant QTL Introgression strain system, identified Eac2 as a Quantitative Trait Locus (QTL) on mouse chromosome 6 which explained 18% of the variance with an effect size of 2.09 g/kg/day alcohol consumption, and Grm7 as a quantitative trait gene underlying Eac2 [Vadasz et al. in Neurochem Res 32:1099–1112, 100, Genomics 90:690–702, 102]. In earlier studies, the product of Grm7 mGluR7, a G protein-coupled receptor, has been implicated in stress systems [Mitsukawa et al. in Proc Natl Acad Sci USA 102:18712–18717, 63], anxiety-like behaviors [Cryan et al. in Eur J Neurosci 17:2409–2417, 14], memory [Holscher et al. in Learn Mem 12:450–455, 26], and psychiatric disorders (e.g., [Mick et al. in Am J Med Genet B Neuropsychiatr Genet 147B:1412–1418, 61; Ohtsuki et al. in Schizophr Res 101:9–16, 72; Pergadia et al. in Paper presented at the 38th Annual Meeting of the Behavior Genetics Association, Louisville, Kentucky, USA, 76]. Here, in experiments with mice, we show that (1) Grm7 knockout mice express increased alcohol consumption, (2) sub-congenic, and congenic mice carrying a Grm7 variant characterized by higher Grm7 mRNA drink less alcohol, and show a tendency for higher circadian dark phase motor activity in a wheel running paradigm, respectively, and (3) there are significant genetic differences in Grm7 mRNA abundance in the mouse brain between congenic and background mice identifying brain areas whose function is implicated in addiction related processes. We hypothesize that metabotropic glutamate receptors may function as regulators of homeostasis, and Grm7 (mGluR7) is involved in multiple processes (including stress, circadian activity, reward control, memory, etc.) which interact with substance use and the development of addiction. In conclusion, we suggest that mGluR7 is a significant new therapeutic target in addiction and related neurobehavioral disorders.     

Vanilloid Receptor-1 (TRPV1) Expression and Function in the Vasculature of the Rat

Transient receptor potential (TRP) cation channels are emerging in vascular biology. In particular, the expression of the capsaicin receptor (TRPV1) was reported in vascular smooth muscle cells. This study characterized the arteriolar TRPV1 function and expression in the rat. TRPV1 mRNA was expressed in various vascular beds. Six commercially available antibodies were tested for TRPV1 specificity. Two of them were specific (immunostaining was abolished by blocking peptides) for neuronal TRPV1 and one recognized vascular TRPV1. TRPV1 was expressed in blood vessels in the skeletal muscle, mesenteric and skin tissues, as well as in the aorta and carotid arteries. TRPV1 expression was found to be regulated at the level of individual blood vessels, where some vessels expressed, while others did not express TRPV1 in the same tissue sections. Capsaicin (a TRPV1 agonist) evoked constrictions in skeletal muscle arteries and in the carotid artery, but had no effect on the femoral and mesenteric arteries or the aorta. In blood vessels, TRPV1 expression was detected in most of the large arteries, but there were striking differences at level of the small arteries. TRPV1 activity was suppressed in some isolated arteries. This tightly regulated expression and function suggests a physiological role for vascular TRPV1.     

Comparative Histochemical and Biochemical Analysis of Endogenous Receptors for Glycoproteins in Human and Pig Peripheral Nerve

Endogenous sugar-binding proteins were localized in sections of human and pig peripheral nerves by the application of two types of labelled ligands: neoglycoproteins (chemically glycosylated carrier proteins that had proven to be histochemically inert) and desialylated, naturally occurring glycoproteins. These proteins allowed evaluation of the presence and distribution of endogenous receptors for carbohydrates, commonly present in cellular glycoconjugates. (Neo)glycoprotein binding was similar, but not identical, for the two types of mammalian peripheral nerves. The pig nerve differed from the human nerve in more pronounced staining when using different types of beta-galactoside-terminated (neo)glycoproteins and charge-carrying neoglycoproteins, such as bovine serum albumin, bearing galactose-6-phosphate residues, glucuronic acid residues, and sialic acid residues. Comparative biochemical analysis of certain classes of sugar receptors by affinity chromatography and gel electrophoresis revealed the presence of sugar receptors that can contribute to the histochemical staining in a pattern with certain significant differences among rather similar expression for the two species. The assessment of sugar receptor distribution by application of (neo)glycoprotein binding among morphologically defined regions in nerves may hold promise in detecting developmental regulation and changes during nerve degeneration and subsequent regeneration after trauma or pathological states. Correlation of these results to changes in the structure and abundance of glycoconjugates, which are the potential physiological ligands of endogenous sugar receptors commonly detected by plant lectins, may help to infer functional relationships.     

Formation and degradation of gluconate by Zymomonas mobilis

Summary Zymomonas mobilis ATCC 29191 is able to degrade gluconate but cannot use it as a single carbon and energy source. Gluconate is phosphorylated by a gluconate kinase (EC 2.7.1.12) and the resulting 6-phosphogluconate is further catabolized to yield about 0.8 mol ethanol per mol of gluconate, considerable amounts of acetate and acetoin. This product spectrum agrees with the theoretical yield of only one reduction equivalent if gluconate is phosphorylated by a kinase and subsequently metabolized via the Entner-Doudoroff pathway.Furthermore, Z. mobilis contains a membrane-bound enzyme system which is able to oxidize glucose to gluconate. Cell-free extracts were active in an assay system with Wurster's blue as electron acceptor, and various aldoses as well as maltose, mannitol and sorbitol could be oxidized. The affinity for sorbitol was very low (K _m =330 mM) but reasonable for glucose (K _m =2.8 mM). The pH optimum for the glucose-oxidizing reaction was 6.5, while that for sorbitol oxidation was 5.5.Dedicated to Prof. Dr. H. Dörfel on the occasion of his 60th birthday