Quinolone resistance and ornithine decarboxylation activity in lactose-negative Escherichia coli

Quinolones and fluoroquinolones are widely used to treat uropathogenic Escherichia coli infections. Bacterial resistance to these antimicrobials primarily involves mutations in gyrA and parC genes. To date, no studies have examined the potential relationship between biochemical characteristics and quinolone resistance in uropathogenic E. coli strains. The present work analyzed the quinolone sensitivity and biochemical activities of fifty-eight lactose-negative uropathogenic E. coli strains. A high percentage of the isolates (48.3%) was found to be resistant to at least one of the tested quinolones, and DNA sequencing revealed quinolone resistant determining region gyrA and parC mutations in the multi-resistant isolates. Statistical analyses suggested that the lack of ornithine decarboxylase (ODC) activity is correlated with quinolone resistance. Despite the low number of isolates examined, this is the first study correlating these characteristics in lactose-negative E. coli isolates.

Topical antiinflammatory activity and chemical composition of the epicuticular wax from the leaves of eugenia beaurepaireana (Myrtaceae) / Atividade antiinflamatória tópica e composição química da cera epicuticular das folhas de Eugenia beaurepaireana (Myrtaceae)

In order to verify the topical antiinflammatory effect of epicuticular wax from leaves of Eugenia beaurepaireana, it was tested in mice croton oil-induced inflammation. Our findings show that topical application of Eugenia beaurepaireana epicuticular wax was significantly active in inhibiting both oedema (Inhibitory dose 50 percent (ID50) = 0.31 (0.26 - 0.39) mg.ear -1, inhibition = 79 ± 6 percent) and tissue myeloperoxidase activity (indicative of polymorphonuclear leukocytes influx) (ID50 =0.34 (0.20 - 0.41) mg.ear -1, inhibition = 77 ± 4 percent) in mice ear treated with croton oil. Two main compounds were detected on epicuticular wax of E. beaurepaireana. These compounds were identified as α- and β-amyrin by flame ionization detection (GC-FID) and spectroscopic methods (IR, NMR ÕH and 13C). In conclusion, the results indicate a topical antiinflammatory activity for the Eugenia specie studied and, that, at least in part, α- and β-amyrin are responsible for this activity.

A atividade antiinflamatória tópica da cera epicuticular das folhas de Eugenia beaurepaireana foi avaliada pelo modelo do edema de orelha induzido pelo óleo de cróton em camundongos. Os resultados do estudo mostram que a aplicação tópica da cera epicuticular de Eugenia beaurepaireana inibiu significativamente a formação do edema (Dose inibitória 50 por cento (DI50) = 0,31 (0,26 - 0,39) mg.orelha-1, inibição = 79 ± 6 por cento) e a atividade da mieloperoxidase tissular (indicativo do influxo de leucócitos polimorfonucleares) (DI50 =0,34 (0,20 - 0,41) mg.orelha-1, inibição = 77 ± 4 por cento) em camundongos tratados com o óleo de cróton. Dois compostos majoritários foram detectados e isolados da cera epicuticular de E. beaurepaireana. Estes compostos foram identificados como os triterpenos α-amirina e β-amirina, através de técnicas cromatográficas (CG-FID) e espectroscópicas (IV, RMN ÕH e 13C). Em conclusão, os resultados indicam que a espécie E. beaurepaireana apresenta um efeito antiinflamatório tópico relevante, sendo os compostos α-amirina e β-amirina responsáveis, pelo menos em parte, por esta atividade.