Effects of treadmill running in a rat model of chronic kidney disease.

Chronic kidney disease (CKD) progression results in musculoskeletal dysfunction that is associated with a higher likelihood of hospitalization and is predictive of hospitalizations and mortality. Despite this, there is a lack of effective interventions to treat the musculoskeletal dysfunction. We studied treadmill running as an intervention to improve musculoskeletal health in a translational rat model that has slowly progressive CKD. CKD rats were subjected to treadmill exercise or no treadmill exercise for 10 weeks (n = 8 each group). Animals ran for 60 min, 5 times per week starting at a speed of 8 m/min and ending at 18 m/min (1 m/min increase/week). Treadmill training had no effect on muscle strength (assessed as maximally stimulated torque), half-relaxation time (time from peak torque to 50%) or muscle cross-sectional area. Overall, there were no biochemical improvements related to CKD progression. Skeletal muscle catabolism was higher than non-exercised animals without a concomitant change in muscle synthesis markers or regeneration transcription factors. These results suggest that aerobic exercise, achieved via treadmill running was not protective in CKD animals and actually produced potentially harmful effects (increased catabolism). Given the high prevalence and dramatic musculoskeletal mobility impairment in patients with CKD, there is a clear need to understand how to effectively prescribe exercise in order to benefit the musculoskeletal system.

Multilocus genotypic characterization of Escherichia coli O157:H7 recovered from food sources.

Escherichia coli O157:H7 strains (n = 33) recovered from different food sources in Egypt were characterized using molecular assays to identify strain genotypes associated with various levels of pathogenic potential. Genotypic characterization included: lineage-specific polymorphism assay (LSPA-6), Shiga-toxin-encoding bacteriophage insertion site assay (SBI), clade 8 typing, Tir (A255 T) polymorphism, and variant analysis of Shiga toxin 2 gene (Stx 2a and Stx 2c), and anti-terminator Q genes (Q 933 and Q 21). Genotypes LI/II (76%), SBI 1 (60·6%), clade 8 (69·7%), Tir (255 T) (72·7%) and Stx 2c (45·5%) were found to be significantly more frequent compared to other genetic markers in the strains analysed. Multivariable analysis revealed a significant association between LPSA-6 and clade types as well as Tir (A255 T). To the best of our knowledge, this is the first study to report the characterization of these genetic markers in E. coli O157:H7 strains in the Middle East and Africa.

Pharmacodynamics of moxifloxacin versus vancomycin against biofilms of methicillin-resistant Staphylococcus aureus and epidermidis in an in vitro model.

The aim of this study was to compare the activities of moxifloxacin and vancomycin against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) biofilms. The study was conducted using a novel in vitro pharmacodynamic model where the biofilms were treated with a simulated clinical dosing of vancomycin 1 g every 12 h or moxifloxacin 400 mg every 24 h. Vancomycin failed to produce a 2 log reduction in the biofilm embedded bacterial count against either of the tested organisms at any time. Moxifloxacin treatment, on the other hand, exhibited a superior anti-biofilm activity and resulted in a 2.5- and 3.7-log reduction in the MRSA and MRSE bacterial bioburdens, respectively, after 24 h of exposure. the results support the implementation of further in vivo and clinical studies aimed at demonstrating the efficacy of moxifloxacin in the treatment of MRSA and MRSE biofilm-associated infections.

Microbiological appraisal of levofloxacin activity against Pseudomonas aeruginosa biofilm in combination with different calcium chanel blockers in vitro.

Chronic multi-drug resistant Pseudomonas aeruginosa infections among hospitalized elderly patients are nearly epidemic in some institutions and biofilms are now recognized as the root cause of such chronic infections such as with cystic fibrosis patients. We address the potential risks and advantages of combining commonly prescribed calcium channel blockers (CCBs) with the fluoroquinolone levofloxacin in the treatment of P. aeruginosa biofilms by using in vitro real-time monitoring of biofilm growth/inhibition over time. while mibefradil and diltiazem appear to be strongly antagonistic toward antimicrobial activity of levofloxacin, amlodipine and bepridil appear to have significant synergistic effects.