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Objective To investigate if the 23 strains of highly-resistant P.aeruginosa isolated from different patients in the in- tensive care unit (ICU) have the same origin;and explore the related mechanisms of carbapenem resistance in these multidrug- resistant P.aeruginosa.MethOds Antimicrobial susceptibility testing was performed using disk-diffusion technique.The strains were genotyped by rep-PCR with the primer ERIC2 followed by electrophoresis in agarose gel.We used a previously described imipenem-EDTA double-disk test for screening MBL-producing P.aeruginosa.Polymerase chain reaction for amplification of blaOprD, blaIMP, and bla VIM were performed to detect corresponding mutants.Results The result of antimicrobial suscepti- bility testing showed that 20 of the 23 P.aeruginosa isolates were muhidrug-resistant and highly resistant to imipenem and meropenem, and at least 5 antimicrobial agents tested in this study.The analysis of the rep-PCR products indicated that all the 19 carbapenem-resistant strains had an identical band pattern, which was different from that seen in the sensitive strains.Al- though imipenem-EDTA double-disk test identified 5 MBL-producing strains, PCR found that all the 23 strains were negative for bla VIM and blaIMP.Only one OprD-deficient mutant was identified.Conclusions The 19 highly-resistant strains of P. aeruginosa derive from a common origin.More researches are needed to clarify their mechanism of carbapenem resistance.
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Objective To investigate the effect of probiotic supplement on the microbiology,bacterial translocation,and gut barrier function of the rats with abdominal infection. Methods After making the models of cecal ligation and perforation,the SD rats were divided into two groups.The rats in the control group were administrated with parenteral nutrition.The rats in the experimental group were administrated with parenteral nutrition and probiotics via the needle jejunostomy and neck vein for 5 d.The feces in the cecum were cultured by anaerobic bacterial growth.The vena cava blood and the homogenated tissues of the lives,hungs and mesenteric lymph nodes were cultured to determine bacterial translocation. Results The quantity of normal intestinal bacteria in the experimental group and the control group had significant difference except Enterobacteriaceae.The quantity of L.acidophilus and Bifidobacteria in the experimental group were higher than those in the control group.The quantity of C.perfrigens,the potential pathogenic germ in the experimental group were lower than those in the control group(P
ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influences of enteral nutrition (EN), parenteral nutrition (PN) and probiotics supplement on the intestinal microecology, and barrier function of the rats with abdominal infection.</p><p><b>METHODS</b>Twenty-one Sprague-Dawley (SD) rats with abdominal infection were randomly divided into three groups, and received PN (PN group, n=7), PN+ EN (PN+ EN group, n=7) or PN+ EN+ probiotics (probiotics group, n=7) respectively with isonitrogen and isocaloric nutrition. The rats were sacrificed after six days. The feces in cecum were cultured for anaerobic bacterial growth and DNA fingerprint spectrum was analyzed by randomly amplified polymorphic DNA technique. The transmembrane binding protein (occludin) and IgA levels in colon and terminal ileum were detected by immunohistochemistry method. The bacterial translocation rate and endotoxin level were also measured.</p><p><b>RESULTS</b>The germ numbers of different species were both higher in PN+ EN and probiotic group than those in PN group. The bands of DNA fingerprint spectrum were significantly decreased in PN group, but the bands in both PN+ EN group and probiotic group were similar to that in the normal rats. The expression levels of occludin and IgA in the intestine and colorectum were higher in both PN+ EN group and probiotic group compared with those of PN group (P< 0.05, P< 0.01, respectively), the expression level of occludin was higher in probiotic group than that in PN+ EN group (P< 0.05). The overall bacterial translocation rates and endotoxin levels were significantly reduced in both probiotic and PN+ EN group (P< 0.05), but there was no difference between probiotic group and EN group.</p><p><b>CONCLUSION</b>EN combined with probiotics can increase occluding and IgA expressions, improve the intestinal microecology,maintain the gut barrier function, and decrease the incidence of gut bacterial translocation.</p>