Binary genomotyping using lipooligosaccharide biosynthesis genes distinguishes between Campylobacter jejuni isolates within poultry-associated multilocus sequence types.

Campylobacter jejuni is a leading cause of human bacterial gastroenteritis throughout the industrialized world. We investigated whether or not differences in gene complement at the lipooligosaccharide (LOS) biosynthesis locus can identify epidemiologically useful binary genomotypes in 87 C. jejuni isolates from poultry-associated multilocus sequence types (STs) collected during the course of a sentinel surveillance study. Using a PCR-based approach, we correlated assignment of both isolate LOS locus class and binary genomotype with ST. We found that isolates within STs 45, 190, 354 and 474 displayed mosaicism in gene complement at the intra-ST level. For example, based upon their binary genomotypes, we assigned individual ST-45 isolates from human clinical cases as probably originating from either a poultry or wild-bird source. However, intra-ST mosaicism in gene complement was observed alongside broader patterns of congruence in LOS locus class and gene complement that distinguished between isolates from different STs.

[Microdialysis study of tolcapone effect during blockage of neuronal dopamine reuptake caused by GBR-12909]. / Mikrodializnoe izuchenie éffekta tolkapona na fone blokady obratnogo neironal'nogo zakhvata dofamina, vyzvannoi GBR-12909.

In vivo brain functions analysis was conducted to assess the effect of tolcapone, a novel catechol-O-methyltransferase (COMT) inhibitor on extracellular levels of dopamine (DA) and its metabolites dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the striatum of awake, freely moving eats during GBR 12909-induced blockade of DA uptake. Tolcapone administration (30 mg/kg, i.p.) failed to change the dopamine output but caused a marked and long-lasting decrease in the extracellular level of HVA and increase in that of DOPAC. In contrast, injection of the DA uptake inhibitor GBR 12909 directly into the striatum (5 microM) or i.p. (20 mg/kg) led to increase in the DA level but had no significant effect on the metabolites. Co-administration of tolcapone (30 mg/kg i.p.) and CBR 12909 (20 mg/kg) increased the DA level further, whereas the changes in HVA and DOPAC levels remained approximately the same as after injection of tolcapone alone. Behavioral observation showed GBR 12909-induced hyperactivity and stereotypy to be potentiated by tolcapone. These findings show that in the rat striatum under conditions of normal nerve activity DA uptake completely inhibits the increase in striatal DA neurotransmission induced by tolcapone (30 mg/kg i.p.) through COMT inhibition.