Potential of Tamarix africana and other halophyte species for phytostabilisation of contaminated salt marsh soils

Purpose

Salt marsh plants are colonising wastes from a steel plant deposited on the Coina River Banks posing a potential contamination risk to the Tagus estuary ecosystem. The objectives of this study were to assess the uptake, accumulation and translocation of hazardous elements/nutrients in three spontaneous halophytic species, to evaluate the capacity of Tamarix africana to stabilise a contaminated salt marsh soil, and to evaluate the ecotoxicity of the pore water and elutriates from phytostabilised soils.

Materials and methods

The work comprises the following: fieldwork collection of soil samples from Coina River (an affluent of Tagus River) bank landfill, estuarine water and spontaneous plants (Aster tripolium, Halimione portulacoides and Sarcocornia sp.), and greenhouse studies (microcosm assay) with T. africana growing in one landfill salt marsh soil, for 97 days, and watered with estuarine water. Soils were analysed for pH, EC, C_organic, NPK, iron and manganese oxides. Soils total (acid digestion) elemental concentrations were determined by ICP/INAA. Estuarine waters, plants roots and shoots (acid digestion), soils available fraction (diluted organic acids extraction-RHIZO or pore water), and salts collected from the T. africana leaves surface were analysed for metals/metalloids (ICP-MS). Ecotoxicity assays were performed in T. africana soil elutriates and pore waters using Artemia franciscana and Brachionus plicatillis.

Results and discussion

Soils were contaminated, containing high total concentrations of arsenic, cadmium, chromium, copper, lead and zinc. However, their concentrations in the available fraction were <4 % of the total. The estuarine waters were contaminated with cadmium, but negligible ecotoxicological effect was observed. The spontaneous plants had significant uptake of the above elements, being mostly stored in the roots. Elemental concentrations in the shoots were within the normal range for plants. These species are not hazardous elements accumulators. Tamarix africana was well adapted to the contaminated saline soils, stored the contaminants in the roots, and had small concentrations of hazardous elements in the shoots. Excretion of hazardous elements by the salt glands was also observed. Elutriates from soils with and without plant did not show ecotoxicity.

Conclusions

The salt marsh species play an important role in the stabilisation of the soils in natural conditions. Tamarix africana showed potential for phytostabilisation of saline-contaminated soils. The low translocation of the elements from roots to shoots and/or active excretion of the elements by the salt glands was a tolerance mechanism in T. africana.

     

Pulmonary vasculature in dogs assessed by three‐dimensional fractal analysis and chemometrics

Fractal analysis of canine pulmonary vessels could allow quantification of their space‐filling properties. Aims of this prospective, analytical, cross‐sectional study were to describe methods for reconstructing three dimensional pulmonary arterial vascular trees from computed tomographic pulmonary angiogram, applying fractal analyses of these vascular trees in dogs with and without diseases that are known to predispose to thromboembolism, and testing the hypothesis that diseased dogs would have a different fractal dimension than healthy dogs. A total of 34 dogs were sampled. Based on computed tomographic pulmonary angiograms findings, dogs were divided in three groups: diseased with pulmonary thromboembolism (n = 7), diseased but without pulmonary thromboembolism (n = 21), and healthy (n = 6). An observer who was aware of group status created three‐dimensional pulmonary artery vascular trees for each dog using a semiautomated segmentation technique. Vascular three‐dimensional reconstructions were then evaluated using fractal analysis. Fractal dimensions were analyzed, by group, using analysis of variance and principal component analysis. Fractal dimensions were significantly different among the three groups taken together (P = 0.001), but not between the diseased dogs alone (P = 0.203). The principal component analysis showed a tendency of separation between healthy control and diseased groups, but not between groups of dogs with and without pulmonary thromboembolism. Findings indicated that computed tomographic pulmonary angiogram images can be used to reconstruct three‐dimensional pulmonary arterial vascular trees in dogs and that fractal analysis of these three‐dimensional vascular trees is a feasible method for quantifying the spatial relationships of pulmonary arteries. These methods could be applied in further research studies on pulmonary and vascular diseases in dogs.     

Antimicrobial resistance and virulence profile of enterococci isolated from poultry and cattle sources in Nigeria

This study investigated the occurrence, antimicrobial resistance and virulence of Enterococcus from poultry and cattle farms. Three hundred and ninety samples: cloacal/rectal swabs (n?=?260) and manure (n?=?130] were processed for recovery of Enterococcus species. Standard bacteriological methods were used to isolate, identify and characterize Enterococcus species for antimicrobial susceptibility and expression of virulence traits. Detection of antibiotic resistance and virulence genes was carried out by polymerase chain reaction. Enterococcus was recovered from 167 (42.8%) of the 390 samples tested with a predominance of Enterococcus faecium (27.7%). Other species detected were Enterococcus gallinarum, Enterococcus faecalis, Enterococcus hirae, Enterococcus raffinosus, Enterococcus avium, Enterococcus casseliflavus, Enterococcus mundtii and Enterococcus durans. All the isolates tested were susceptible to vancomycin, but resistance to tetracycline, erythromycin, ampicillin and gentamicin was also observed among 61.0, 61.0, 45.1 and 32.7% of the isolates, respectively. Sixty (53.1%) of the isolates were multidrug resistant presenting as 24 different resistance patterns with resistance to gentamicin-erythromycin-streptomycin-tetracycline (CN-ERY-STR-TET) being the most common (n?=?11) pattern. In addition to expression of virulence traits (haemolysin, gelatinase, biofilm production), antibiotic resistance (tetK, tetL, tetM, tetO and ermB) and virulence (asa1, gelE, cylA) genes were detected among the isolates. Also, in vitro transfer of resistance determinants was observed among 75% of the isolates tested. Our data revealed poultry, cattle and manure in this area are hosts to varying Enterococcus species harbouring virulence and resistance determinants that can be transferred to other organisms and also are important for causing nosocomial infection.     

Traumatic bilateral stylohyoid bone fracture in an Appaloosa

An Appaloosa gelding presented for a traumatic puncture wound of the head ventral to the base of his left ear, bilateral epistaxis and upper respiratory compromise. The horse did not exhibit dysphagia or cranial nerve deficits. The horse suffered bilateral oblique fractures of both stylohyoid bones due to the traumatic incident, diagnosed upon endoscopy of the guttural pouches. Treatment consisted of anti‐inflammatory medication, broad‐spectrum antibiotics, guttural pouch lavage and dietary management with soft feeds. At a one‐month follow‐up examination, endoscopic evaluation revealed a union at both stylohyoid bone fracture sites. Guttural pouch mycosis was diagnosed in the left guttural pouch on the lateral wall at the entrance of the lateral compartment. The guttural pouch mycosis was treated with a nystatin and gentamicin flush, followed by a course of oral fluconazole. At the 3‐month re‐evaluation, the guttural pouch mycosis had completely responded to treatment.     

Label-Free Darkfield-Based Technique to Assist in the Detection of <Emphasis Type="Italic">Giardia</Emphasis> Cysts

Giardia is a pathogenic protozoan that has caused giardiasis outbreaks worldwide, and this water-borne disease may occur due to faults in water supply and treatment systems. To support surveillance and control programs, the monitoring of this parasite is essential in water samples. Although Giardia cyst detection is usually based on standard light microscopy, the resulting low contrasted cysts together with a wide array of particles of comparable size to the target protozoan demands a high level of observer skill and experience, as well as a long time to process the individual samples. The visualization of this protozoan can be significantly improved by using staining procedures, e.g., Lugol’s iodine in brightfield or fluorescence-based methods such as fluorescence-isothiocyanate (FITC) and 4′,6-diamidino-2-phenylindole (DAPI). However, the significant costs make fluorescence microscopy difficult to be performed in less-developed countries. Accordingly, the present study evaluated the effectiveness of inexpensive darkfield (DF) setups to acquire higher contrasted images of unstained cyst samples as a direct and rapid method for monitoring protozoa. Two low-cost custom-made DF illumination modes, transmitted and reflected, were evaluated on a standard light microscope. Examination of purified Giardia cyst suspensions with both DF setups revealed a direct correlation between morphological appearance and uptake of DAPI. Images captured under transmitted illumination showed higher contrast and sharpness when compared to the reflected images. DF microscopy might provide a simple, direct, and inexpensive method for observing Giardia cysts, which shows basic aspects of their intracellular structure, although the applicability of the method to raw water concentrates remains to be demonstrated.     

Toxicity of soybean-registered agrochemicals to <Emphasis Type="Italic">Telenomus podisi</Emphasis> and <Emphasis Type="Italic">Trissolcus basalis</Emphasis> immature stages

Biological control of phytophagous bugs in soybean crops is efficiently performed by egg parasitoids, such as Telenomus podisi and Trissolcus basalis. Based on this, the use of agrochemicals in these crops must be managed consciously, making use of pesticides that are selective to the egg of these parasitoids, in order to ensure a balanced ecosystem. The aim of this study was to assess the selectivity of 15 registered pesticides to the immature stages (pre and post-parasitism) of T. podisi and T. basalis, following the method proposed by the “International Organization for Biological and Integrated Control” (IOBC). Pesticides were classified as class 1 – harmless (RP?<?30%); class 2 – slightly harmful (30%?≤?RP?≤?79%); class 3 – moderately harmful (80%?≤?RP?≤?99%); and class 4 – harmful (RP?>?99%). During pre-parasitism, the insecticides imidacloprid+beta-cyfluthrin, deltamethrin, lambda-cyhalothrin+thiamethoxam, acephate, and fenitrothion reduced parasitism of both parasitoids. The others: flubendiamide, diflubenzuron, Bacillus thuringiensis, lufenuron, and the herbicide isopropylamine were selective, i.e. harmless (class 1), to both parasitoids, except for pyraclostrobin+metconazole, which significantly reduced T. basalis parasitism, being considered slightly harmful (class 2). In post parasitism, all the aforementioned pesticides were harmless to T. podisi and T. basalis. Moreover, in pre-parasitism, T. basalis was found to be more sensitive to the tested pesticides when compared to T. podisi. Still, more studies must be conducted to provide a better understanding of the impact of agrochemicals on these parasitoid species in semi-field conditions.     

Cross-protection interactions in insect pests: Implications for pest management in a changing climate

Agricultural insect pests display an exceptional ability to adapt quickly to natural and anthropogenic stressors. Emerging evidence suggests that frequent and varied sources of stress play an important role in driving protective physiological responses; therefore, intensively managed agroecosystems combined with climatic shifts might be an ideal crucible for stress adaptation. Cross-protection, where responses to one stressor offers protection against another type of stressor, has been well documented in many insect species, yet the molecular and epigenetic underpinnings that drive overlapping protective responses in insect pests remain unclear. In this perspective, we discuss cross-protection mechanisms and provide an argument for its potential role in increasing tolerance to a wide range of natural and anthropogenic stressors in agricultural insect pests. By drawing from existing literature on single and multiple stressor studies, we outline the processes that facilitate cross-protective interactions, including epigenetic modifications, which are understudied in insect stress responses. Finally, we discuss the implications of cross-protection for insect pest management, focusing on the consequences of cross-protection between insecticides and elevated temperatures associated with climate change. Given the multiple ways that insect pests are intensively managed in agroecosystems, we suggest that examining the role of multiple stressors can be important in understanding the wide adaptability of agricultural insect pests. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.