Critical role of multidrug efflux pump CmeABC in bile resistance and in vivo colonization of Campylobacter jejuni

CmeABC functions as a multidrug efflux pump contributing to the resistance of Campylobacter to a broad range of antimicrobials. In this study, we examined the role of CmeABC in bile resistance and its contribution to the adaptation of Campylobacter jejuni in the intestinal tract of the chicken, a natural host and a major reservoir for Campylobacter. Inactivation of cmeABC drastically decreased the resistance of Campylobacter to various bile salts. Addition of choleate (2 mM) in culture medium impaired the in vitro growth of the cmeABC mutants but had no effect on the growth of the wild-type strain. Bile concentration varied in the duodenum, jejunum, and cecum of chicken intestine, and the inhibitory effect of the intestinal extracts on the in vitro growth of Campylobacter was well correlated with the total bile concentration in the individual sections of chicken intestine. When inoculated into chickens, the wild-type strain colonized the birds as early as day 2 postinoculation with a density as high as 10(7) CFU/g of feces. In contrast, the cmeABC mutants failed to colonize any of the inoculated chickens throughout the study. The minimum infective dose for the cmeABC mutant was at least 2.6 x 10(4)-fold higher than that of the wild-type strain. Complementation of the cmeABC mutants with a wild-type cmeABC allele in trans fully restored the in vitro growth in bile-containing media and the in vivo colonization to the levels of the wild-type strain. Immunoblotting analysis indicated that CmeABC is expressed and immunogenic in chickens experimentally infected with C. jejuni. Together, these findings provide compelling evidence that CmeABC, by mediating resistance to bile salts in the intestinal tract, is required for successful colonization of C. jejuni in chickens. Inhibition of CmeABC function may not only control antibiotic resistance but also prevent the in vivo colonization of pathogenic Campylobacter.     

Acute type A aortic dissection in a patient with ventricular septal defect

We report the case of a 38-year-old man with a long-standing history of a small ventricular septal defect presented with chest pain. Electrocardiography revealed sinus rhythm, ST-segment elevation in leads V1–6. The chest X-ray showed mild cardiomegaly. He underwent cardiac catheterisation laboratory to primary coronary angioplasty. Coronary angiography showed normal coronary arteries. Aortic root angiography revealed type A aortic dissection. Transthoracic and transesophageal echocardiography showed aortic dissection in ascending aorta and a perimembranous ventricular septal defect. Thoracoabdominal CT angiography confirmed the aortic dissection before the surgery.The patient underwent cardiac surgery immediately. The ventricular septal defect and aortic dissection were repaired successfully. The postoperative recovery was uneventful and he has thus far remained asymptomatic at 6 months' follow-up.     

Leukocyte lipid peroxidation, superoxide dismutase and catalase activities of type 2 diabetic patients with retinopathy

Increased oxidative stress might play an important role in the initiation and progression of diabetic complications. The present study has been undertaken to investigate whether there is any relationship between retinopathy degree and leukocyte superoxide dismutase (SOD) and catalase (CAT) activities and lipid peroxidation (LPO) in diabetic individuals with type 2 diabetic retinopathy. Patients were groupped with respect to the degree of retinopathy. Leukocyte malondialdehyde (MDA) levels, and SOD and CAT activities were measured in patients with type 2 diabetes mellitus (n=41) and nondiabetic healthy controls (n=23). Leukocyte LPO of the type 2 diabetic patients with retinopathy was significantly increased (p < 0.001), whereas SOD and CAT activities were decreased (p<0.001 and p<0.001, respectively) compared to those of controls. MDA concentrations rose while SOD and CAT activities fell with increasing severity of diabetic retinopathy, altough there was no significant difference in comprasion of the parameters mentioned above between the diabetic patients with and without retinopathy. Our results show that leukocytes in patients with type 2 diabetic retinopathy are affected by oxidative stress which might be contribute to pathogenesis of diabetic retinopathy. Prospective studies are needed to evaulate the relationship between the leukocyte antioxidants status and DR.     

Maastricht Ⅱ treatment scheme and efficacy of different proton pump inhibitors in eradicating Helicobacter pylori

AIM: The Maastricht Ⅱ criteria suggest the use of amoxicillin and clarithromycin in addition to a proton pump inhibitor over 7-10 d as a first line therapy in the eradication of Helicobacter pylori(H pylori). For each proton pump inhibitor, various rates of eradication have been reported. The present study was to compare the efficacy of different proton pump inhibitors like omeprazole, lansoprazole and pantoprazole in combination with amoxicillin and clarithromycin in the first line eradication of H pylori and to investigate the success of H pylori eradication in our district.METHODS: A total of 139 patients were included having a Helicobacter pylori(+) gastroduodenal disorders diagnosed by means of histology and urease test. Besides amoxicillin (1 000 mg twice a day) and clarithromycin (500 mg twice a day), they were randomized to take omeprazole (20 mg twice a day), or lansoprazole (30 mg twice a day), or pantoprozole (40 mg twice a day) for 14 d. Four weeks after the therapy, the eradication was assessed by means of histology and urease test. It was evaluated as eradicated if the H pylori was found negative in both. The complaints (pain in epigastrium, nocturnal pain, pyrosis and bloating)were graded in accordance with the Licert scale. The compliance of the patients was recorded.RESULTS: The eradication was found to be 40.8% in the omeprazole group, 43.5% in the lansoprazole group and 47.4% in the pantoprazole group. Sixty-three out of 139patients (45%) had eradication. No statistically significant difference was observed between the groups. Significant improvements were seen in terms of the impact on the symptom scores in each group.CONCLUSION: There was no difference between omeprazole, lansoprazole and pantoprazole in H pylori eradication, and the rate of eradication was as low as 45%.Symptoms were improved independent of the eradication in each treatment group. The iow eradication rates suggest that the antibiotic resistance or the genetic differences of the microorganism might be in effect. Further studies are required to verify these suggestions.     

Removal of hydrosalpinges increases endometrial leukaemia inhibitory factor (LIF) expression at the time of the implantation window

BACKGROUND: The presence of hydrosalpinges is associated with lower implantation and pregnancy rates in women undergoing IVF-embryo transfer, while salpingectomy improves these parameters. Although the mechanism by which hydrosalpinges affects fertility is not entirely understood, an adverse effect on endometrial receptivity has been postulated. In this study, we hypothesized that the adverse effects of hydrosalpinges on fertility may be in part mediated by inappropriate endometrial expression of leukaemia inhibitory factor (LIF), a cytokine implicated in implantation. METHODS: In order to test our hypothesis, we prospectively examined the expression of LIF during the window of implantation in the endometrium of infertile women (n = 10) with hydrosalpinges prior to and following salpingectomy and of fertile controls (n = 10) by Western blotting and immunohistochemistry. RESULTS: LIF expression was significantly lower in infertile women with hydrosalpinges compared with fertile controls (P < 0.05). Salpingectomy resulted in an increase in LIF expression in eight out of 10 women with hydrosalpinges. LIF levels were increased by 231 +/-49% (mean +/- SEM) following salpingectomy. Immunohistochemical analysis confirmed the Western blot findings. The increased LIF immunoreactivity was predominantly localized to luminal and glandular epithelial cells. CONCLUSIONS: Our findings suggest that observed benefit from salpingectomy in infertile women with hydrosalpinges may be in part mediated by the up-regulation of endometrial LIF expression.     

An unusual primary left ventricular hydatid cyst complicated by cardiac tamponade and mitral regurgitation--a case report

Cardiac involvement in hydatidosis is rare but because of potentially lethal complications, its recognition is of great importance. The authors present a 55-year-old woman admitted to the clinic with cardiac tamponade and moderate mitral regurgitation caused by a hydatid cyst located at the inferoposterior wall of the left ventricle.