ABSTRACT
We investigated the infection situation,serotype distribution,sources of etiological food and drug resistance of Salmonella in foodborne disease patients in Henan Province in 2015 and 2016.We evenly arranged 15 sentinel hospitals in Henan Province in 2015 and 2016,and a total of 5 720 patient defined cases were monitored,whose information was collected.A total of 221 Salmonella strains were isolated from the fecal of diarrhea patients,who were studied on serotyping,drug resistance and traceability of related etiological food,and the results were analyzed statistically.Results showed that the S.enteritidis,S.typhimurium and S.thompson were dominant types for serotyping in the 221 Salmonella strains,and 221 strains were widely distributed in 46 serotypes,the serotype distribution was more extensive;dairy and dairy products and meat and meat products were main suspicious etiological foods types caused by Salmonella.For drug susceptibility test of 11 kinds of antibiotics,the susceptibility of Salmonella to Cefoxitin,Cefotaxime,Chloramphenicol and Trimethoprim/Sulfamethoxazole significantly decreased (P＜0.05),and that to Ciprofloxacin,Ampicillin,Tetracycline and Ampicillin/Sulbactam decreased significantly (P＜0.01);only that to Ciprofloxacin,Nalidixic acid and Gentamicin decreased insignificantly (P＜0.05).Relevant departments should strengthen the meat and meat products market supervision,to make great efforts for control the use of antibiotics,strengthen the active surveillance of Salmonella disease and drug resistance,and to reduce the incidence of foodborne diseases.
ABSTRACT
It has been shown that oxidative stress correlates with atrial fibrillation (AF). The purpose of the present study was to investigate the effects of reactive oxygen species (ROS) on the electrophysiological activity of human atrial myocytes. Right atrial appendages were obtained from patients with AF (AF group, n=12) and without AF (non-AF group, n=12). Single human atrial myocytes were isolated through enzymatic dissociation with type XXIV protease and type V collagenase, then divided into three subgroups: control group (n=12), H2O2 group (0.1, 0.2, 0.5, 0.75, 1, 2, 5, 10 mumol/L, n=7 at each concentration) and vitamin C (antioxidant) group (1 mumol/L, n=7). Ultrarapid delayed rectifier K(+) current (I(Kur)), L-type calcium current (I(Ca,L)) and action potential duration (APD) were recorded by whole-cell patch clamp. In AF control group, the maximum current densities of I(Kur) and I(Ca,L) were significantly lower than that in non-AF control group (both P<0.05) and APD(90) was significantly shorter as well (P<0.05). In both non-AF and AF groups, H2O2 showed two-way concentration-dependent effect on I(Kur) and I(Ca,L). The maximum current densities of I(Kur) and I(Ca,L) was significantly increased at lower H2O2 concentration, but was decreased at higher H2O2 concentration. In non-AF group, 0.2 mumol/L H2O2 caused a peak increase in the maximum current identities of I(Kur) [(8.92+/-0.51) pA/pF, P<0.05] and I(Ca,L) [(9.32+/-0.67) pA/pF, P<0.05]. H2O2 at a concentration higher than 0.75 mumol/L decreased I(Kur) and I(Ca,L). When the H2O2 concentrations were 0.2, 1, 2, 5 and 10 mumol/L, APD(90) was significantly shorter compared with that in non-AF control group (P<0.05), meanwhile it had no significant difference from that in AF control group. In AF group, the peak effective concentration of H2O2 was 0.5 mumol/L, and the turning concentration was 1 mumol/L. The H2O2 concentration-current density curve in AF group was similar to that in non-AF group, but the turning point shifted to the right, indicating that the way that H2O2 acted on ion channels in AF was the same as that in non-AF, however, the sensitivity of ion channels to H2O2 was decreased in AF. Vitamin C reversed these changes induced by H2O2, and did not affect the characteristics of ion channels. H2O2-induced electrophysiological changes in human atrial myocytes were similar to atrial electrical remodeling (AER) in AF, suggesting that ROS might induce AF. Meanwhile, H2O2 also could aggravate AER in AF, contributing to the maintenance of AF. The results suggest that antioxidants might play a significant role in the prevention and treatment of AF.