sodium-dodecyl-sulfate and Enterobacteriaceae-Infections

The interleukin-17 (IL-17) family of cytokines has emerged as a critical player in inflammatory diseases. Among them, IL-25 has been shown to be important in allergic inflammation and protection against parasitic infection. Here we have demonstrated that IL-17B, a poorly understood cytokine, functions to inhibit IL-25-driven inflammation. IL-17B and IL-25, both binding to the interleukin-17 receptor B (IL-17RB), were upregulated in their expression after acute colonic inflammation. Individual inhibition of these cytokines revealed opposing functions in colon inflammation: IL-25 was pathogenic but IL-17B was protective. Similarly opposing phenotypes were observed in Citrobacter rodentium infection and allergic asthma. Moreover, IL-25 was found to promote IL-6 production from colon epithelial cells, which was inhibited by IL-17B. Therefore, our data demonstrate that IL-17B is an anti-inflammatory cytokine in the IL-17 family.

Topics: Animals; Anti-Bacterial Agents; Asthma; Cell Line; Citrobacter rodentium; Colitis; Dysbiosis; Enterobacteriaceae Infections; Epithelial Cells; Gene Expression Regulation; Interleukin-17; Interleukin-6; Interleukins; Intestinal Mucosa; Mice; Mice, Inbred C57BL; Mice, Knockout; Ovalbumin; Protein Binding; Receptors, Interleukin-17; Signal Transduction; Sodium Dodecyl Sulfate

Enterobacter cloacae is an emerging clinical pathogen that may be responsible for nosocomial infections. Management of these infections is often difficult, owing to the high frequency of strains that are resistant to disinfectants and antimicrobial agents in the clinical setting. Multidrug efflux pumps, especially those belonging to the resistance-nodulation-division family, play a major role as a mechanism of antimicrobial resistance in gram-negative pathogens. In the present study, we cloned and sequenced the genes encoding an AcrAcB-TolC-like efflux pump from an E. cloacae clinical isolate (isolate EcDC64) showing a broad antibiotic resistance profile. Sequence analysis showed that the acrR, acrA, acrB, and tolC genes encode proteins that display 79.8%, 84%, 88%, and 82% amino acid identities with the respective homologues of Enterobacter aerogenes and are arranged in a similar pattern. Deletion of the acrA gene to yield an AcrA-deficient EcDC64 mutant (EcDeltaacrA) showed the involvement of AcrAB-TolC in multidrug resistance in E. cloacae. However, experiments with an efflux pump inhibitor suggested that additional efflux systems also play a role in antibiotic resistance. Investigation of several unrelated isolates of E. cloacae by PCR analysis revealed that the AcrAB system is apparently ubiquitous in this species.

Topics: Bacterial Proteins; Base Sequence; beta-Lactamases; Carrier Proteins; Cloning, Molecular; DNA, Bacterial; Drug Resistance, Bacterial; Enterobacter cloacae; Enterobacteriaceae Infections; Genes, MDR; Genetic Vectors; Humans; Microbial Sensitivity Tests; Molecular Sequence Data; Plasmids; Porins