ABSTRACT
Objective To study the mechanisms on drug susceptibility and resistance of clinically multidrug-resistant Escherichia coli isolates,to provide information on related treatment.Methods The susceptibility of E.coli strains that isolated from different kinds of samples in the last 3 years on drugs was analyzed by agar dilution test,with strains that exhibiting resistances to cefotuxime,ciprofloxacin and amikacin simultaneously collected for further analysis.Resistant genes which mediate resistance to β-lactamases,fluoroquinolone and aminoglycoside as well as phylogenic type were detected by PCR amplification while genetic relation was analyzed by PFGE.Transferability of resistant plasmids was identified by conjugation test.Results In total,137 multidrug-resistant E.coli isolates were collected.Only 1％ of the isolates exhibited resistance to both imipenem and meropenem while 4％ of the strains were resistant to piperacillin/tazobactam.Most (85％) of the isolates were positive to ESBL and majority of them produced CTX-M.Target substitution and production of methylases were the main mechanisms causing resistance to fluoroquinolones and aminoglycosides respectively.Conclusion The main source of clinical multidrug-resistance was collected from urine samples.Carbapenem and enzyme inhibitor-containing antibiotics seemed to be the available antibiotics that were sentitive to the clinically multidrug-resistant E.coli isolates.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the role of adiponectin in regulating tumor necrosis factor alpha (TNF alpha) production and preventing fulminant autoimmunological damage of hepatocytes following concanavalin A (Con A) injection into mice.</p><p><b>METHODS</b>Three days after recombinant plasmids pAA-neo-mAd were injected into the mice via the tail veins, Con A was injected into the mice. Mice transfected with empty pAA-neo vector served as controls. The serum levels of alanine aminotransferase (ALT), TNF alpha and adiponectin were detected, and histological examination of livers was carried out at different time points after the Con A injection. All results were subjected to statistical analyses.</p><p><b>RESULTS</b>Histological examinations showed that the damage in livers of mice with high serum adiponectin levels was milder than that of the controls. The serum levels of ALT and TNF alpha were both lower than those of the controls (P less than 0.01, respectively). Statistical analyses showed the serum levels of ALT was negatively related to the levels of adiponectin in the sera (r=-0.5034).</p><p><b>CONCLUSION</b>Adiponectin is effective in protecting hepatocytes from Con A-induced immunological injury. The mechanism of this protective effect may be caused by inhibiting the synthesis and/or release of TNF alpha.</p>