ABSTRACT
Insulin (INS) resistance is often found in cancer-bearing, but its correlation with cachexia development is not completely established. This study investigated the temporal sequence of the development of INS resistance and cachexia to establish the relationship between these factors in Walker-256 tumor-bearing rats (TB rats). INS hepatic sensitivity and INS resistance-inducing factors, such as free fatty acids (FFA) and tumor necrosis factor-α (TNF-α), were also evaluated. Studies were carried out on Days 2, 5, 8, and/or 12 after inoculation of tumor cells in rats. The peripheral INS sensitivity was assessed by the INS tolerance test and the INS hepatic sensitivity in in situ liver perfusion. TB rats with 5, 8, and 12 days of tumor, but not 2 days, showed decreased peripheral INS sensitivity (INS resistance), retroperitoneal fat, and body weight, compared to healthy rats, which were more pronounced on Day 12. Gastrocnemius muscle wasting was observed only on Day 12 of tumor. The peripheral INS resistance was significantly correlated (r = -.81) with weight loss. Liver INS sensitivity of TB rats with 2 and 5 days of tumor was unchanged, compared to healthy rats. TB rats with 12 days of tumor showed increased plasma FFA and increased TNF-α in retroperitoneal fat and liver, but not in the gastrocnemius, compared to healthy rats. In conclusion, peripheral INS resistance is early, starts along with fat and weight loss and before muscle wasting, progressive, and correlated with cachexia, suggesting that it may play an important role in the pathogenesis of the cachectic process in TB rats. Therefore, early correction of INS resistance may be a therapeutic approach to prevent and treat cancer cachexia.
Subject(s)
Insulin Resistance , Neoplasms , Rats , Animals , Cachexia/etiology , Cachexia/pathology , Insulin , Tumor Necrosis Factor-alpha , Rats, Wistar , Weight Loss , Neoplasms/complicationsABSTRACT
This study evaluated the scope and genetic basis of polymyxin-resistant Klebsiella aerogenes in Brazil. Eight polymyxin-resistant and carbapenemase-producing K. aerogenes strains were isolated from patients admitted to the ICU of a tertiary hospital. Bacterial species were identified by automated systems and antimicrobial susceptibility profile was confirmed using broth microdilution. The strains displayed a multidrug resistant profile and were subjected to whole-genome sequencing. Bioinformatic analysis revealed a variety of antimicrobial resistance genes, including the blaKPC-2. No plasmid-mediated colistin resistance gene was identified. Nonetheless, nonsynonymous mutations in mgrB, pmrA, pmrB, and eptA were detected, justifying the colistin resistance phenotype. Virulence genes encoding yersiniabactin, colibactin, and aerobactin were also found, associated with ICEKp4 and ICEKp10, and might be related to the high mortality observed among the patients. In fact, this is the first time ICEKp is identified in K. aerogenes in Brazil. Phylogenetic analysis grouped the strains into two clonal groups, belonging to ST93 and ST16. In summary, the co-existence of antimicrobial resistance and virulence factors is deeply worrying, as it could lead to the emergence of untreatable invasive infections. All these factors reinforce the need for surveillance programs to monitor the evolution and dissemination of multidrug resistant and virulent strains among critically ill patients.
ABSTRACT
INTRODUCTION: Plant products are sources for drug development against multidrug resistant bacteria. METHODS: The antimicrobial activity of Origanum vulgare L. essential oil (OVeo) against carbapenem-resistant strains was assessed by disk-diffusion, microdilution (REMA-Resazurin Microtiter Assay), and time kill assays. RESULTS: Carbapenemase production was confirmed for all strains. OVeo exhibited a minimum inhibitory concentration of 0.059% v/v for Klebsiella pneumoniae and Serratia marcescens, and of 0.015 % v/v for Acinetobacter baumannii. A decrease in cell count was observed after a 4 h treatment. CONCLUSIONS: OVeo antimicrobial effect was rapid and consistent, making it a candidate for developing alternative therapeutic options against carbapenem-resistant strains.
Subject(s)
Acinetobacter baumannii/drug effects , Anti-Bacterial Agents/pharmacology , Gram-Negative Bacteria/drug effects , Klebsiella pneumoniae/drug effects , Oils, Volatile/pharmacology , Origanum/chemistry , Serratia marcescens/drug effects , Acinetobacter baumannii/growth & development , Anti-Bacterial Agents/classification , Bacterial Proteins , Carbapenems/pharmacology , Drug Resistance, Multiple, Bacterial , Gram-Negative Bacteria/growth & development , Humans , Klebsiella pneumoniae/growth & development , Microbial Sensitivity Tests , Serratia marcescens/growth & development , beta-LactamasesABSTRACT
Abstract INTRODUCTION: Plant products are sources for drug development against multidrug resistant bacteria. METHODS The antimicrobial activity of Origanum vulgare L. essential oil (OVeo) against carbapenem-resistant strains was assessed by disk-diffusion, microdilution (REMA-Resazurin Microtiter Assay), and time kill assays. RESULTS Carbapenemase production was confirmed for all strains. OVeo exhibited a minimum inhibitory concentration of 0.059% v/v for Klebsiella pneumoniae and Serratia marcescens, and of 0.015 % v/v for Acinetobacter baumannii. A decrease in cell count was observed after a 4 h treatment. CONCLUSIONS OVeo antimicrobial effect was rapid and consistent, making it a candidate for developing alternative therapeutic options against carbapenem-resistant strains.
