Graphene-Based Sensor for Detection of Bacterial Pathogens

Microbial colonization to biomedical surfaces and biofilm formation is one of the key challenges in the medical field. Recalcitrant biofilms on such surfaces cause serious infections which are difficult to treat using antimicrobial agents, due to their complex structure. Early detection of microbial colonization and monitoring of biofilm growth could turn the tide by providing timely guidance for treatment or replacement of biomedical devices. Hence, there is a need for sensors, which could generate rapid signals upon bacterial colonization. In this study, we developed a simple prototype sensor based on pristine, non-functionalized graphene. The detection principle is a change in electrical resistance of graphene upon exposure to bacterial cells. Without functionalization with specific receptors, such sensors cannot be expected to be selective to certain bacteria. However, we demonstrated that two different bacterial species can be detected and differentiated by our sensor due to their different growth dynamics, adherence pattern, density of adhered bacteria and microcolonies formation. These distinct behaviors of tested bacteria depicted distinguishable pattern of resistance change, resistance versus gate voltage plot and hysteresis effect. This sensor is simple to fabricate, can easily be miniaturized, and can be effective in cases when precise identification of species is not needed.

Forgiveness of dolutegravir-based triple therapy compared to older antiretroviral regimens: a prospective multicenter cohort of adherence patterns and HIV-RNA replication

Background For many people living with HIV (PLWH), taking antiretroviral therapy (ARV) every day is difficult. Methods Average adherence (Av-Adh) and log-transformed treatment interruption (TI) to ARV were prospectively measured over 6 months using electronic drug monitoring (EDM) in several cohorts of PLWH. Multivariate linear regression models including baseline confounders explored the influence of EDM-defined adherence (R 2) on 6-month Log10 HIV-RNA. Multivariate logistic regression models were used to compare the risk of HIV-RNA detection within subgroups stratified by lower (≤95%) and higher (>95%) Av-Adh. Results Three hundred ninety nine PLWH were analyzed with different ARV: dolutegravir (n=102), raltegravir (n=90), boosted PI (bPI; n=107), and NNRTI (n=100). In the dolutegravir group, the influence of adherence pattern measures on R 2 for HIV-RNA levels was marginal (+2%). Av-Adh, TI and Av-Adh x TI increased the R 2 for HIV-RNA levels by 54% and 40% in the raltegravir and bPI treatment groups, respectively. TI increased the R 2 for HIV-RNA levels by 36% in the NNRTI treatment group. Compared to dolutegravir-based regimen, the risk of VR was significantly increased for: raltegravir (adjusted OR (aOR), 45.6; 95% confidence interval (CI) [4.5 - 462.1], p=0.001); NNRTIs (aOR, 24.8; 95% CI [2.7 - 228.4], p=0.005) and bPIs (aOR, 28.3; 95%CI [3.4 - 239.4], p=0.002) in PLWH with Av-Adh ≤95%. Among PLWH with >95% Av-Adh, there were no significant differences on the risk of VR among the different ARV. Conclusion These findings support the concept that dolutegravir in combination with two other active ARVs achieves a greater virological suppression than older ARV, including raltegravir, NNRTI and bPI among PLWH with lower adherence.

Treatment non-adherence pattern among persons with neuropsychiatric disorders: A study from a rural community mental health centre in India

Background: Treatment gap causes significant loss to individuals, families, societies and the nation. Treatment adherence enhancement is a major challenge in psychiatric disorders. Globally, the community mental health services are obligated to minimize the treatment and adherence gap. In recent years’ retrospective studies are gaining importance to measure the trend of mental health service utilization, cost effectiveness, resources allocation and similar aspects. Aim: To explore the treatment adherence pattern of persons with neuropsychiatric illness from a rural community mental health centre. Method: Five hundred and ninety-six medical records of persons with neuropsychiatric disorders who registered for outpatient treatment between 2015 and 2017 at Sakalawara Rural mental health centre of National Institute of Mental Health and Neuro Sciences, Bangalore, India, were reviewed to understand their adherence pattern Results: Out of 596 patients, 68 (11.4%) were referred to tertiary care mental health and District Mental Health Programme (DMHP) services. Out of the remaining 528 patients, 29.7% were regular to mental health services over a period of 12 months and above; majority of the patients (36.2%) dropped out of their treatment after their first contact and 34.1% discontinued their follow up visits over a period of first week to 12 months. Conclusion: Community based mental health centres too face challenges of and problems related to treatment non-adherence. Persons with neuropsychiatric disorders require continuity of care through regular home visits, out-reach services and innovative methods which will enhance treatment adherence.

Characterization of Potential Virulence Factors of Vibrio mimicus Isolated from Fishery Products and Water

Vibrio mimicus is a Gram-negative bacterium that is closely related to V. cholerae and causes gastroenteritis in humans due to contaminated fish consumption and seafood. This bacterium was isolated and identified from 238 analyzed samples of sea water, oysters, and fish. Twenty strains were identified as V. mimicus according to amplification of the vmhA gene, which is useful as a marker of identification of the species. The production of lipases, proteases, and nucleases was detected; 45% of the strains were able to produce thermonucleases and 40% were capable of producing hydroxamate-type siderophores, and the fragment of the iuT gene was amplified in all of the V. mimicus strains. Seventy-five percent of V. mimicus strains showed cytopathic effect on Chinese hamster ovary (CHO) cells and destruction of the monolayer, and 100% of the strains were adherent on the HEp-2 cell line with an aggregative adherence pattern. The presence of virulence factors in V. mimicus strains obtained from fishery products suggests that another member of the Vibrio genus could represent a risk to the consumer due to production of different metabolites that allows it to subsist in the host.

Factors related to adherence to drug treatment in public university workers

Objective: to analyze factors associated with medication adherence among public university workers who reported use of continuous medication. Methods: cross-sectional study carried out with 629 workers from a public university. Data were collected through interviews using forms adapted from the Brazilian Ministry of Health and analyzed using the chi-square test. Results: three hundred thirty-one (52.6%) participants were users of continuous medication, of these, 175 (52.9%) had a partially satisfactory adherence pattern and 156 (47.1%) a totally satisfactory pattern. Workers with chronic back problems, depression, weakness/tiredness, dyspnea, and chest pain had significantly less adherence to drug treatment (p≤0.050). Sociodemographic and labor characteristics, polypharmacy, and type of medication were not associated with medication adherence (p>0.050). Conclusion: satisfactory drug adherence was observed among the participants in relation to drug treatment, and the presence of some symptoms and specific chronic diseases was associated with partially satisfactory drug adherence.

Comparative Genomics of Atypical Enteropathogenic Escherichia coli from Kittens and Children Identifies Bacterial Factors Associated with Virulence in Kittens

Typical enteropathogenic E. coli (tEPEC) is a leading cause of diarrhea and associated death in children worldwide. Atypical EPEC (aEPEC) lacks the plasmid encoding bundle-forming pili and is considered less virulent, but the molecular mechanisms of virulence is poorly understood. We recently identified kittens as a host for aEPEC where intestinal epithelial colonization was associated with diarrheal disease and death. The purpose of this study was to (1) determine the genomic similarity between kitten aEPEC and human aEPEC isolates and (2) to identify genotypic or phenotypic traits associated with virulence in kitten aEPEC. We observed no differences between kitten and human aEPEC in core genome content or gene cluster sequence identities and no distinguishing genomic content was observed between aEPEC isolates from kittens with nonclinical colonization (NC) versus lethal infection (LI). Variation in adherence pattern and ability to aggregate actin in cultured cells mirrored descriptions of human aEPEC. The aEPEC isolated from kittens with LI were significantly more motile than isolates from kittens with NC. Kittens may serve as a reservoir for aEPEC that are indistinguishable from human aEPEC isolates and may provide a needed comparative animal model for the study of aEPEC pathogenesis. Motility seems to be an important factor in pathogenesis of LI associated with aEPEC in kittens.

Chemical, Antimicrobial, Antioxidant and Anti-proliferative Features of the Essential Oil Extracted from the Invasive Plant Solidago canadensis L.

The essential oil from inflorescences of S. canadensis L. (Goldenrod) obtained by hidrodistillation was analysed by gas chromatography-mass spectrometry and it was qualitatively and quantitatively tested against Gram-positive and Gram-negative bacteria and fungi. The samples were also subjected to screening for their possible antioxidant activity by using DPPH assay and the influence on intracellular ROS (reactive oxygen species). The main components identified were a-pinene, germacrene D, and limonene. The tested microbial strains proved to be susceptible to S. canadensis essential oil which exhibited good anti-biofilm activity, inhibiting the adhesion to the inert and cellular substrate, decreasing the Acinetobacter baumannii adhesion index to 17.52% and changing the adherence pattern. Goldenrod essential oil showed good free-radical scavenging activity, but it increased the production of free radicals in Hep-2 tumor cells.

The Effect of Medication Adherence on the Disease Course in Pregnant Women with Inflammatory Bowel Disease

IntroductionMedical therapy to maintain disease remission is important in pregnant women with inflammatory bowel disease (IBD), as disease flares can predispose adverse materno-fetal outcomes. However, women with IBD are more concerned about medication exposure on their newborn during pregnancy, and often discontinue their medications. Objectives and ApproachWe assessed the rate of disease flare on medication adherence pattern during pregnancy for women with IBD. Validated case definition was used to identify women with IBD from the Albertan’s hospitalization, emergency room, and physician claims databases (2010-2016). Pharmaceutical Information Network provided the dispensed medications. Adherence to medication was defined by medical possession ratio (MPR)≥0.8. Women with two consecutive prescriptions and MPR≥0.8 during pre-conception were included. Disease flare was defined by ≥1 hospitalization or emergency visit for IBD, or ≥1 prescription for steroids/rectal therapy. Chi-square tests and log binomial regression were used; covariates included age, drug class, and IBD subtypes. ResultsOf the 370 women identified with IBD, 170 (45.9%) women were adherent to maintenance IBD medications in the one year prior to pregnancy. During pregnancy, 47 (27.6%; 95% CI: 21.4% to 34.9%) women, who demonstrated adherence in the pre-conception period, discontinued or were not adherent to their IBD medications, and 67 (39.4%; 95% CI: 32.3% to 47.0%) women had a disease flare during pregnancy. There was no significant difference between adherence to medication during pregnancy and a disease flare during pregnancy (p=0.38). In comparing women who were not adherent or discontinued their medication to those that were adherent, the adjusted relative risk ratio for a disease flare during pregnancy was 1.22 (95% CI: 0.81 to 2.04). Conclusion/ImplicationsThe rate of disease flare during pregnancy was not significantly different for women with IBD that were adherent or not-adherent to their IBD medications during pregnancy. Future analysis will assess the rate of disease flare on medication adherence pattern prior to pregnancy.