The occurrence of Salmonella enterica in the environment of tropical and desert regions has remained largely uninvestigated in many areas of the world, including Africa. In the present study, we investigated the presence of Salmonella spp. along 122 km of the coastline of Agadir (southern Morocco) in relation to environmental parameters. A total of 801 samples of seawater (243), marine sediment (279), and mussels (279) were collected from six sites between July 2004 and May 2008. The overall prevalence of Salmonella spp. was 7.1%, with the highest occurrence in mussels (10%), followed by sediment (6.8%) and seawater (4.1%). Only three serotypes were identified among the 57 Salmonella sp. strains isolated. S. enterica serotype Blockley represented 43.8% of all Salmonella strains and was identified in mussel and sediment samples. S. enterica serotype Kentucky (29.8%) was found almost exclusively in mussels, whereas S. enterica serotype Senftenberg (26.3%) was detected in sediment and seawater. Statistical analysis using generalized additive models identified seawater temperature, environmental temperature, rainfall, and solar radiation as significant factors associated with the presence of Salmonella. Rainfall was the only variable showing a linear positive effect on the presence of Salmonella in the sea, whereas the remaining variables showed more complex nonlinear effects. Twenty-eight (49.1%) Salmonella isolates displayed resistance to ampicillin (22 isolates), nalidixic acid (9 isolates), sulfonamide compounds (2 isolates), and tetracycline (1 isolate), with six of these isolates displaying multiple resistance to two of these antimicrobial agents. Pulsed-field gel electrophoresis analysis revealed homogenous restriction patterns within each serotype that were uncorrelated with the resistance pattern profiles.
We performed a systematic review and meta-analysis to determine whether the use of local antibiotics is a beneficial prophylactic treatment for endophthalmitis in patients treated with anti-VEGF agents. We searched the MEDLINE and EMBASE databases, and the Cochrane Library over the period January 2007 to December 2016. The search terms used included “Endophthalmitis”, “Antibiotic” and “Intravitreal injection”. Studies in which the patients were treated exclusively with intravitreal injections of anti-VEGF were selected. Eight studies fit the inclusion criteria, which included a total of 276,774 injections; 109,178 (39.45%) were associated with the use of antibiotics and 114,821 (60.55%) were not associated with the use of antibiotics. Our meta-analysis indicated a significant risk for endophthalmitis that was 1.70 times greater with the use of antibiotics than that without antibiotics, with a confidence interval of 1.08 to 2.66 (p = 0.02). A meta-regression indicated that the location (operating rooms versus outpatient clinics) of injection did not have a significant effect on the incidence of endophthalmitis. The prophylactic use of antibiotics when administering anti-VEGF intravitreal injections may contribute to a greater incidence of endophthalmitis. This finding, in addition to reducing costs, would eliminate a treatment that has been shown to be unnecessary and even harmful to patients.
Biolog EcoPlates™ can be used to measure the carbon substrate utilisation patterns of microbial communities. This method results in a community-level physiological profile (CLPP), which yields a very large amount of data that may be difficult to interpret. In this work, we explore a combination of statistical techniques (particularly the use of generalised additive models [GAMs]) to improve the exploitation of CLPP data. The strength of GAMs lies in their ability to address highly non-linear relationships between the response and the set of explanatory variables. We studied the impact of earthworms (Aporrectodea caliginosa Savigny 1826) and cadmium (Cd) on the CLPP of soil bacteria. The results indicated that both Cd and earthworms modified the CLPP. GAMs were used to assess time-course changes in the diversity of substrate utilisation (DSU) using the Shannon-Wiener index. GAMs revealed significant differences for all treatments (compared to control -S-). The Cd exposed microbial community presented very high metabolic capacities on a few substrata, resulting in an initial acute decrease of DSU (i.e. intense utilization of a few carbon substrata). After 54 h, and over the next 43 h the increase of the DSU suggest that other taxa, less dominant, reached high numbers in the wells containing sources that are less suitable for the Cd-tolerant taxa. Earthworms were a much more determining factor in explaining time course changes in DSU than Cd. Accordingly, Ew and EwCd soils presented similar trends, regardless the presence of Cd. Moreover, both treatments presented similar number of bacteria and higher than Cd-treated soils. This experimental approach, based on the use of DSU and GAMs allowed for a global and statistically relevant interpretation of the changes in carbon source utilisation, highlighting the key role of earthworms on the protection of microbial communities against the Cd.
The classical dogma states that brown adipose tissue (BAT) plays a major role in the regulation of temperature in neonates. However, although BAT has been studied in infants for more than a century, the knowledge about its physiological features at this stage of life is rather limited. This has been mainly due to the lack of appropriate investigation methods, ethically suitable for neonates. Here, we have applied non-invasive infrared thermography (IRT) to investigate neonatal BAT activity. Our data show that BAT temperature correlates with body temperature and that mild cold stimulus promotes BAT activation in newborns. Notably, a single short-term cold stimulus during the first day of life improves the body temperature adaption to a subsequent cold event. Finally, we identify that bone morphogenic protein 8B (BMP8B) is associated with the BAT thermogenic response in neonates. Overall, our data uncover key features of the setup of BAT thermogenesis in newborns.
How reliable are results on spatial distribution of biodiversity based on databases? Many studies have evidenced the uncertainty related to this kind of analysis due to sampling effort bias and the need for its quantification. Despite that a number of methods are available for that, little is known about their statistical limitations and discrimination capability, which could seriously constrain their use. We assess for the first time the discrimination capacity of two widely used methods and a proposed new one (FIDEGAM), all based on species accumulation curves, under different scenarios of sampling exhaustiveness using Receiver Operating Characteristic (ROC) analyses. Additionally, we examine to what extent the output of each method represents the sampling completeness in a simulated scenario where the true species richness is known. Finally, we apply FIDEGAM to a real situation and explore the spatial patterns of plant diversity in a National Park. FIDEGAM showed an excellent discrimination capability to distinguish between well and poorly sampled areas regardless of sampling exhaustiveness, whereas the other methods failed. Accordingly, FIDEGAM values were strongly correlated with the true percentage of species detected in a simulated scenario, whereas sampling completeness estimated with other methods showed no relationship due to null discrimination capability. Quantifying sampling effort is necessary to account for the uncertainty in biodiversity analyses, however, not all proposed methods are equally reliable. Our comparative analysis demonstrated that FIDEGAM was the most accurate discriminator method in all scenarios of sampling exhaustiveness, and therefore, it can be efficiently applied to most databases in order to enhance the reliability of biodiversity analyses.
Philasterides dicentrarchi is a histophagous scuticociliate that causes important losses in aquaculture. Several strains that differ in morphological, genetic and serological characteristics and virulence have been isolated from outbreaks of turbot scuticociliatosis. In the present study, seven isolates of the ciliate were exposed in vitro to formalin, hydrogen peroxide and resveratrol (a phytoalexin produced by plants) in order to evaluate the susceptibility of the isolates to the different compounds. The LD50 values for the three compounds tested varied widely among the isolates. The LD100 values were similar among isolates for formalin (25-30 ppm) and resveratrol (60-70 ppm) but were very different for hydrogen peroxide (25->80 ppm). The results indicate that there are many physiological differences among isolates and even among specimens of the same isolates, which must be taken into account in designing control programmes. The naturally occurring resveratrol may be a good alternative to other compounds for reducing the amounts of viable ciliates in water.
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