Molecular diversity of <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> isolates from patients with tuberculosis in Honduras

Background  

Tuberculosis persists as a public health problem in Honduras. A better knowledge of the molecular characteristics of Mycobacterium tuberculosis strains will contribute to understand the transmission dynamics of the disease within the country. The aim of this study was to provide an insight of the genetic biodiversity of M. tuberculosis clinical isolates collected in Honduras between 1994 and 2002. Genotyping was performed using spoligotyping and RFLP. The spoligotypes obtained were compared with the SITVIT2 proprietary database of the Pasteur Institute of Guadeloupe.     

Selective cytotoxicity evaluation in anticancer drug screening of fractionated plant extracts

Chosen to reflect biodiversity in a phylogenetic sense, 100 fractionated plant extracts were screened in vitro for cytotoxicity following extraction and fractionation (polypeptide isolation). Of these 100 extracts, 30 were selected and then characterized preliminarily for antitumor potency and mode of action by testing them on two cell lines and primary cultures of human tumor cells. On the basis of cytotoxicity potency, 10 of the extracts were further characterized for anticancer activity in 10 human tumor cell lines. This final testing resulted in seven potential lead plants with superior evidence of antitumor potential: Colchicum autumnale L. (Colchicaceae), Digitalis lanata Ehrh. and Digitalis purpurea L. (Plantaginaceae), Helleborus cyclophyllus Boiss. (Ranunculaceae), Menyanthes trifoliata L. (Menyanthaceae), and Viola arvensis Murr. and Viola patrinii Ging. (Violaceae). Within a database of antitumor compounds, the activity profiles of the extracts from these seven plants were compared, by correlation analysis, with those of more than 100 other compounds, including 39 standard drugs from different classes of cytotoxic mechanisms. The activity profiles of six of these candidates were uncorrelated with those of the standard drugs, possibly indicating new pathways of drug-mediated cell death.     

Loss of STK11 expression is an early event in prostate carcinogenesis and predicts therapeutic response to targeted therapy against MAPK/p38

Prostate cancer (PCa) is the second leading cause of cancer-related death in men; however, the molecular mechanisms leading to its development and progression are not yet fully elucidated. Of note, it has been recently shown that conditional stk11 knockout mice develop atypical hyperplasia and prostate intraepithelial neoplasia (PIN). We recently reported an inverse correlation between the activity of the STK11/AMPK pathway and the MAPK/p38 cascade in HIF1A-dependent malignancies. Furthermore, MAPK/p38 overactivation was detected in benign prostate hyperplasia, PIN and PCa in mice and humans. Here we report that STK11 expression is significantly decreased in PCa compared to normal tissues. Moreover, STK11 protein levels decreased throughout prostate carcinogenesis. To gain insight into the role of STK11-MAPK/p38 activity balance in PCa, we treated PCa cell lines and primary biopsies with a well-established MAPK14-MAPK11 inhibitor (SB202190), which has been extensively used in vitro and in vivo. Our results indicate that inhibition of MAPK/p38 significantly affects PCa cell survival in an STK11-dependent manner. Indeed, we found that pharmacologic inactivation of MAPK/p38 does not affect viability of STK11-proficient PCa cells due to the triggering of the AMPK-dependent autophagic pathway, while it induces apoptosis in STK11-deficient cells irrespective of androgen receptor (AR) status. Of note, AMPK inactivation or autophagy inhibition in STK11-proficient cells sensitize SB202190-treated PCa cells to apoptosis. On the other end, reconstitution of functional STK11 in STK11-deficient PCa cells abrogates apoptosis. Collectively, our data show that STK11 is a key factor involved in the early phases of prostate carcinogenesis, and suggest that it might be used as a predictive marker of therapeutic response to MAPK/p38 inhibitors in PCa patients.     

Knowledge and Attitudes towards Antibiotic Use and Resistance - A Latent Class Analysis of a Swedish Population-Based Sample

BackgroundIn 2006, a study investigating knowledge and attitudes regarding antibiotic use and resistance in Sweden, indicated high level of knowledge but also areas in need of improvement.Objective(i) To provide an update on the knowledge and attitudes to antibiotic use and resistance of the Swedish population, and (ii) to identify which groups within the population are in particular need of improved knowledge or attitudes.MethodsA questionnaire was sent by post in 2013 to 2,500 randomly-selected individuals aged 18–74, living in Sweden. Latent class analyses were conducted to group respondents based on their responses. The association between socio-demographic characteristics and the probability of belonging to each latent class was assessed.ResultsThe response rate was 57%. Ninety-four per cent of the responders knew that bacteria could become resistant to antibiotics and the majority answered correctly to the questions regarding antibiotic resistance development. The respondents expressed confidence in doctors who decided not to prescribe antibiotics. Three latent classes related to ‘knowledge regarding antibiotic use and resistance’, two regarding ‘attitudes towards antibiotic accessibility and infection prevention’ and three regarding ‘attitudes towards antibiotic use and effects’ were revealed. Men, younger and more educated people were more knowledgeable but males had a less restrictive attitude. Respondents with high levels of knowledge on antibiotics were more likely to have appropriate restrictive attitudes to antibiotics.ConclusionKnowledge on antibiotic use and resistance is maintained high and has improved in Sweden compared to 2006. People with lower education and elderly are especially in need of improved knowledge about antibiotic use and resistance.     

Procalcitonin Predicts Real-Time PCR Results in Blood Samples from Patients with Suspected Sepsis

Background

Early diagnosis and rapid bacterial identification are of primary importance for outcome of septic patients. SeptiFast® (SF) real-time PCR assay is of potential utility in the etiological diagnosis of sepsis, but it cannot replace blood culture (BC) for routine use in clinical laboratory. Procalcitonin (PCT) is a marker of sepsis and can predict bacteremia in septic patients. The aim of the present study was to investigate whether PCT serum levels could predict SF results, and could help screening febrile patients in which a SF assay can improve the etiological diagnosis of sepsis.

Methods

From 1009 febrile patients with suspected sepsis, 1009 samples for BC, SF real-time PCR, and PCT determination were obtained simultaneously, and results were compared and statistically analysed. Receiver operating characteristic (ROC) curves were generated to determine the area under the curve and to identify which cut-off of PCT value produced the best sensitivity to detect SF results.

Results

Mean PCT values of sera drawn simultaneously with samples SF positive (35.42±61.03 ng/ml) or BC positive (23.14±51.56 ng/ml) for a pathogen were statistically higher than those drawn simultaneously with SF negative (0.84±1.67 ng/ml) or BC negative (2.79±16.64 ng/ml) samples (p<0.0001). For SF, ROC analysis showed an area under the curve of 0.927 (95% confidence interval: 0.899–0.955, p<0.0001). The PCT cut-off value of 0.37 ng/ml showed a negative predictive value of 99%, reducing the number of SF assays of 53.9%, still identifying the 96.4% of the pathogens.

Conclusion

PCT can be used in febrile patients with suspected sepsis to predict SF positive or negative results. A cut-off value of 0.37 ng/ml can be considered for optimal sensitivity, so that, in the routine laboratory activity, SF assay should not be used for diagnosis of sepsis in an unselected patient population with a PCT value <0.37 ng/ml.