Unraveling Antimicrobial Resistance Genes and Phenotype Patterns among Enterococcus faecalis Isolated from Retail Chicken Products in Japan

Multidrug-resistant enterococci are considered crucial drivers for the dissemination of antimicrobial resistance determinants within and beyond a genus. These organisms may pass numerous resistance determinants to other harmful pathogens, whose multiple resistances would cause adverse consequences. Therefore, an understanding of the coexistence epidemiology of resistance genes is critical, but such information remains limited. In this study, our first objective was to determine the prevalence of principal resistance phenotypes and genes among Enterococcus faecalis isolated from retail chicken domestic products collected throughout Japan. Subsequent analysis of these data by using an additive Bayesian network (ABN) model revealed the co-appearance patterns of resistance genes and identified the associations between resistance genes and phenotypes. The common phenotypes observed among E. faecalis isolated from the domestic products were the resistances to oxytetracycline (58.4%), dihydrostreptomycin (50.4%), and erythromycin (37.2%), and the gene tet(L) was detected in 46.0% of the isolates. The ABN model identified statistically significant associations between tet(L) and erm(B), tet(L) and ant(6)-Ia, ant(6)-Ia and aph(3’)-IIIa, and aph(3’)-IIIa and erm(B), which indicated that a multiple-resistance profile of tetracycline, erythromycin, streptomycin, and kanamycin is systematic rather than random. Conversely, the presence of tet(O) was only negatively associated with that of erm(B) and tet(M), which suggested that in the presence of tet(O), the aforementioned multiple resistance is unlikely to be observed. Such heterogeneity in linkages among genes that confer the same phenotypic resistance highlights the importance of incorporating genetic information when investigating the risk factors for the spread of resistance. The epidemiological factors that underlie the persistence of systematic multiple-resistance patterns warrant further investigations with appropriate adjustments for ecological and bacteriological factors.     

Skill-Specific Changes in Somatosensory Nogo Potentials in Baseball Players

Athletic training is known to induce neuroplastic alterations in specific somatosensory circuits, which are reflected by changes in somatosensory evoked potentials and event-related potentials. The aim of this study was to clarify whether specific athletic training also affects somatosensory Nogo potentials related to the inhibition of movements. The Nogo potentials were recorded at nine cortical electrode positions (Fz, Cz, Pz, F3, F4, C3, C4, P3 and P4) in 12 baseball players (baseball group) and in 12 athletes in sports, such as track and field events and swimming, that do not require response inhibition, such as batting for training or performance (sports group). The Nogo potentials and Go/Nogo reaction times (Go/Nogo RTs) were measured under a somatosensory Go/Nogo paradigm in which subjects were instructed to rapidly push a button in response to stimulus presentation. The Nogo potentials were obtained by subtracting the Go trial from the Nogo trial. The peak Nogo-N2 was significantly shorter in the baseball group than that in the sports group. In addition, the amplitude of Nogo-N2 in the frontal area was significantly larger in the baseball group than that in the sports group. There was a significant positive correlation between the latency of Nogo-N2 and Go/Nogo RT. Moreover, there were significant correlations between the Go/Nogo RT and both the amplitude of Nogo-N2 and Nogo-P3 (i.e., amplitude of the Nogo-potentials increases with shorter RT). Specific athletic training regimens may induce neuroplastic alterations in sensorimotor inhibitory processes.     

The transepithelial shunt pathway in the renal proximal tubule of newt kidney

The transepithelial shunt pathway of newt proximal tubule was examined with glass micro-electrode and electron microscopic methods. The input resistance of the peritubular (basal) membrane and tubular wall were found to be $\text{4.2 ± 0.1 · 10}{}^6$ ($\text{mean ± S.E.}\text{, n = 16}$) and $\text{11.4 ± 0.2 · 10}{}^4\text{(n = 11)}$, respectively. The input resistance of the peritubular membrane was approximately 40-times larger than that of the tubular wall. When the kidneys were perfused in a lanthanum solution, the lanthanum ions were then observed in the junctional complexes and in the intercellular spaces on both the basal and apical sides. The results indicate that the electrical shunt pathway corresponds to the apical junctional complexes and the intercellular spaces, and that the tight junctions are not truly ‘tight’ for the transepithelial movement of small ions in the proximal tubule of the newt kidney.     

Photo-movement of coral larvae influences vertical positioning in the ocean

Coral Reefs - Behaviour can have profound consequences for the dispersal potential of an organism. In the marine environment, larvae rely heavily on oceanic currents to migrate from one area to...     

Comparison of the expression of cell surface poly-N-acetyllactosamine-type oligosaccharides in PC12 cells with those in its variant PC12D.

To explore the biological role of carbohydrate chains in the process of nerve cell differentiation, we carried out a characterization of the carbohydrate structure of glycoproteins by comparing conventional PC12 cells with variant cells (PC12D). In vitro metabolic labeling of cells with either [(3)H] glucosamine or [(3)H] threonine, together with tomato lectin staining, revealed that nerve growth factor (NGF) stimulation caused a decrease in the poly-N-acetyllactosamine synthesis of high-molecular-weight glycopeptides from PC12 cells. By comparison, the amount of glycopeptides with poly-N-acetyllactosamine from PC12D cells was already significantly low and it was not changed by NGF stimulation. By assaying the glycosyltransferases that participate in poly-N-acetyllactosamine synthesis, the decrease in the amount of the poly-N-acetyllactosamine in PC12D cells as well as NGF-stimulated PC12 cells could be accounted for by a reduction in the activity of poly-N-acetyllactosamine extension enzyme (GnT-i), because the amount of poly-N-acetyllactosamine in both cells precisely correlated with changes in GnT-i activity, whereas the activities of N-acetylglucosaminyltransferase V (GnT-V) and beta 1-4 galactosyltransferase remained unchanged. These results demonstrate that the decrease in poly-N-acetyllactosamine synthesis in PC12 cells occurred prior to neurite formation, whereas PC12D cells were insensitive to this effect. Next, we showed that GnT-i but not GnT-V catalyzed a rate-limiting reaction in the expression of poly-N-acetyllactosamine chains, especially in pheochromocytoma.     

Phylogenetic relationships and convergent evolution of ocean‐shore ground beetles (Coleoptera: Carabidae: Trechinae: Bembidion and relatives)

Through phylogenetic analysis of seven genes, we show that there have been at least six independent entries into intertidal habitats in the history of bembidiine carabids, in the ancestors of: (i) Orzolina Machado, (ii) Bembidion (Desarmatocillenus Netolitzky), (iii) Bembidion laticeps (LeConte) + palosverdes Kavanaugh & Erwin, (iv) Bembidion laterale (Samouelle), (v) Bembidion umi Sasakawa and Bembidion quadriimpressum (Motschulsky) (which may represent two separate entries), and (vi) B. nigropiceum (Marsham). The following lineages are widely separated within the subtribe Bembidiina: Orzolina is sister to the genus Ocys Stephens; subgenus Desarmatocillenus appears to be sister to all Bembidion Latreille excluding subgenus Phyla Motschulsky; B. laticeps + B. palosverdes is a clade in the Bembidion series; B. laterale is a member of the Princidium Motschulsky complex; B. umi and B. quadriimpressum are related to the Nearctic Clade of the Ocydromus Clairville complex; B. nigropiceum is sister to B. praeustum Dejean among sampled species. There are three separate lineages of ocean‐shore bembidiines that are known to prey on amphipods, and adults of these lineages [Bembidion (Desarmatocillenus), B. laterale, and B. mandibulare Solier] have unusually wide heads with long mandibles. Also common among independent lineages restricted to ocean shores are prominent front angles of the prothorax, larger numbers of setae on the elytral disc, a notable sinuation in the margin of each elytron near its apex, and short, wide mesotarsi. The reasons for the repeated evolution of these features are not evident. Our results also suggest that inland species of the Nearctic Clade may have arisen from an ocean‐shore ancestor. The close genetic similarities between the gravel river shore dwelling B. praeustum and the intertidal specialist B. nigropiceum suggest that the striking morphological adaptations of B. nigropiceum to the intertidal zone arose rapidly. We make one nomenclatural change: we resurrect the subgenus Lymneops Casey to accommodate B. palosverdes and B. laticeps.     

Stabilization of ribose-5-phosphate isomerase from tobacco

The highly purified ribose phosphate isomerase from tobaccoleaves is heat labile. 0.2% of various kinds of proteins stabilizedisomerase activity when Mg⁺⁺ was present. 1x10^–3% polyethyleneglycol2,000 showed the same effect as the proteins did. Smaller polyediyleneglycolswere less effective. Polyhydroxyl compounds showed litde effect.Mn⁺⁺ or Sr⁺⁺ was also effective as a stabilizer instead of Mg⁺⁺. (Received March 8, 1976; )