Optimized methods for detecting Salmonella Typhi in the environment using validated field sampling, culture and confirmatory molecular approaches.

AIMS: This study evaluated detection methods for Salmonella Typhi (S. Typhi) in the environment, to establish a novel pathway from field sampling to isolation of viable organisms and molecular confirmation from complex environmental samples, thus enabling environmental surveillance of typhoid. METHODS AND RESULTS: Multiple media were assessed using clinical isolates from the Public Health England's (PHE) Culture collection. The culture pathway selected consisted of a primary 2% bile broth and secondary Selenite F broth, followed by modified Chromogenic Agar for Salmonella Esterase (mCASE). A qPCR assay was adapted from a validated S. Typhi PCR panel for confirmation of isolates, with comparison to biochemical and serological tests showing good specificity. Sampling locations in Blantyre, Malawi were used to compare sampling methods. Viable S. Typhi were isolated from a mixture of trap and grab river water samples on six occasions. CONCLUSIONS: Culture of viable S. Typhi from environmental samples was possible using effective capture and culture techniques. SIGNIFICANCE AND IMPACT OF STUDY: Whilst several studies have attempted to detect S. Typhi from the environment, this is the first successful attempt to isolate the organism from river water since the 1980s. Supplementing clinical data with environmental screening offers the potential for enhanced surveillance, which might inform interventions and assess vaccination programmes.

Incidence of invasive non-typhoidal Salmonella in Blantyre, Malawi between January 2011-December 2019.

Background: The Malawi-Liverpool Wellcome Trust Clinical Research Programme (MLW) has undertaken sentinel surveillance of bloodstream infection and meningitis at Queen Elizabeth Central Hospital (QECH), Blantyre, Malawi for 20 years. Previously, three epidemics of Salmonella bloodstream infection have been identified. Here we provide updated surveillance data on invasive non-typhoidal Salmonella disease from 2011 - 2019. Methods: Surveillance data describing trends in invasive non-typhoidal Salmonella disease and associated antimicrobial susceptibility profiles are presented for the period January 2011 - December 2019. Results: Between January 2011-December 2019, 128,588 blood cultures and 40,769 cerebrospinal fluid cultures were processed at MLW. Overall, 1.00% of these were positive for S. Typhimurium, 0.10% for S. Enteritidis, and 0.05% positive for other Salmonella species. Estimated minimum incidence of invasive non-typhoidal Salmonella (iNTS) disease decreased from 21/100,000 per year in 2011 to 7/100,000 per year in 2019. Over this period, 26 confirmed cases of Salmonella meningitis were recorded (88.5% S. Typhimurium). Between 2011-2019 there was a substantial decrease in proportion of S. Typhimurium (78.5% to 27.7%) and S. Enteritidis (31.8% in 2011 to 0%) that were multidrug-resistant. Resistance to fluoroquinolones and third-generation generation cephalosporins (3GC) remained uncommon, however 3GC increased amongst Salmonella spp. and S. Typhimurium in the latter part of the period. Conclusions: The total number of iNTS bloodstream infections decreased between 2011-2019. Although the number multidrug resistance (MDR) S. Typhimurium and S. Enteritidis isolates has fallen, the number of MDR isolates of other Salmonella spp. has increased, including 3GC isolates.

Packing Defects in Fatty Amine Self-Assembled Monolayers on Mica as Revealed from AFM Techniques.

Self-assembled monolayers of n-octadecylamine (ODA-SAMs) on mica have been prepared and studied by contact and jumping mode atomic force microscopy (AFM). Adhesion and friction data show that the compactness of the monolayers spontaneously increases as they are allowed to ripen. Molecular packing can also be induced by the controlled mechanical perturbation exerted by the probe when getting into and out of contact intermittently. Under these conditions, defects and vacancies aggregate giving rise to detectable pinholes uniformly distributed in AFM images. Created pinhole density was found to decrease with ripening time, thus confirming the proposed spontaneous self-healing mechanism. Pinhole density is also suggested as a parameter characterizing the packing degree of ODA-SAMs, and it has been related to their tribological properties. Additionally, molecular dynamics simulations were used to corroborate the compatibility between the packing degree and the observed topography of ODA-SAMs on mica.

Detection of Erysiphe necator in Air Samples Using the Polymerase Chain Reaction and Species-Specific Primers.

ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi, primer pairs Uncin144 and Uncin511 were developed to select unique sequences of the internal transcribed spacer regions of E. necator. Using these primers in PCR amplifications, a 367-bp amplicon specific to E. necator was generated, but no amplicons were generated from other erysiphaceous species collected from 48 disparate hosts representing 26 vascular plant families. The PCR limit of detection was one to five conidia of E. necator placed directly into reaction mixtures or 100 to 250 conidia placed on glass rods coated with silicon grease. During field studies, this PCR assay facilitated the detection of E. necator inoculum in air samples within hours of sample rod collection and prior to disease onset. Amplification of E. necator DNA did not occur when the PCR assay was conducted on vineyard air samples collected while grapes were dormant or during periods when vine growth occurred but E. necator remained dormant. The initial PCR detection of E. necator of the season occurred during seasonal ascospore releases caused by precipitation events between bud burst and the prebloom period during the 3 years of the study. Detection ceased for 7 to 11 days following ascospore release and then resumed several days prior to the observance of microscopic symptoms and signs of powdery mildew in the field. Results of this study represent the initial step toward the goal of incorporating an inoculum availability component into current and future grapevine powdery mildew risk assessment models.

Reliability, Concurrent Validity, and Minimal Detectable Change for iPhone Goniometer App in Assessing Knee Range of Motion.

Much of the published works assessing the reliability of smartphone goniometer apps (SG) have poor generalizability since the reliability was assessed in healthy subjects. No research has established the values for standard error of measurement (SEM) or minimal detectable change (MDC) which have greater clinical utility to contextualize the range of motion (ROM) assessed using the SG. This research examined the test-retest reproducibility, concurrent validity, SEM, and MDC values for the iPhone goniometer app (i-Goni; June Software Inc., v.1.1, San Francisco, CA) in assessing knee ROM in patients with knee osteoarthritis or those after total knee replacement. A total of 60 participants underwent data collection which included the assessment of active knee ROM using the i-Goni and the universal goniometer (UG; EZ Read Jamar Goniometer, Patterson Medical, Warrenville, IL), knee muscle strength, and assessment of pain and lower extremity disability using quadruple numeric pain rating scale (Q-NPRS) and lower extremity functional scale (LEFS), respectively. Intraclass correlation coefficients (ICCs) were calculated to assess the reproducibility of the knee ROM assessed using the i-Goni and UG. Bland and Altman technique examined the agreement between these knee ROM. The SEM and MDC values were calculated for i-Goni assessed knee ROM to characterize the error in a single score and the index of true change, respectively. Pearson correlation coefficient examined concurrent relationships between the i-Goni and other measures. The ICC values for the knee flexion/extension ROM were superior for i-Goni (0.97/0.94) compared with the UG (0.95/0.87). The SEM values were smaller for i-Goni assessed knee flexion/extension (2.72/1.18 degrees) compared with UG assessed knee flexion/extension (3.41/1.62 degrees). Similarly, the MDC values were smaller for both these ROM for the i-Goni (6.3 and 2.72 degrees) suggesting smaller change required to infer true change in knee ROM. The i-Goni assessed knee ROM showed expected concurrent relationships with UG, knee muscle strength, Q-NPRS, and the LEFS. In conclusion, the i-Goni demonstrated superior reproducibility with smaller measurement error compared with UG in assessing knee ROM in the recruited cohort. Future research can expand the inquiry for assessing the reliability of the i-Goni to other joints.

Evaluating two health care facilities' ability to meet health literacy needs: a role for occupational therapy.

ABSTRACT Many clients have difficulty understanding health information, which may lead to less use of preventive services, greater use of hospital emergency services, poor physical and mental health, and an increased risk of death. Therefore, the objective of this article is to present a review of the accessibility of a rehabilitation center and an independent living facility with regard to navigation of the facility, understandability of written and oral communication, use of technology, and implementation of policies and procedures within these facilities. Findings from the reviews identified areas for improvement for both facilities in navigation as well as written and oral communication. Recommendations to the facilities are discussed for revision of signage and written and oral communication. Implications for occupational therapy practitioners, including establishment of best practices for health literacy and providing consultation for other health care professions, are highlighted. Possible future research is explored regarding evaluation of the effectiveness of the intervention.