Neodymium (Nd) and strontium (Sr) isotopic signatures in marine sediments reflect the geology of the associated drainage basin from which those sediments are supplied. These signatures are ...significantly affected by relief, weathering, transport, and deposition of sedimentary contributions from the respective sources. This work makes available new data of SrNd isotope ratios and Rare Earth Element (REE) concentrations, which provides a record of the sedimentary provenance of marine sediment supplied to the continental slope off the coast of northeastern Brazil since the last 130 thousand years. Our results indicate the main source of sediments to this site was the Parnaíba sedimentary basin. Furthermore, the fluctuations in Fe/K, Al/Si ratios, and Sr values are explained by geochemical processes operating within the region, which likely reflects changes in the hydrological regime and relative sea-level, and intensity of weathering in continental rocks in glacial-interglacial timescales. We suggest that low values of 87Sr/86Sr ratios during glacial are a result of dry conditions. Also, minor fluctuations within the last glacial period may be a consequence of displacements of the Intertropical Convergence Zone (ITCZ). Such displacements cause changes in rainfall and consequently variations in chemical weathering which affect Sr isotopic fractionation. During past humid intervals, the low Nd (non-radiogenic) signal observed could be explained as a process of penetration of rainwater into the deepest non-radiogenic sediment and subsequent replacement of the isotopic signal in the environment in glacial-interglacial timescales.
•The low 87Sr/86Sr ratios during the glacial period in northeastern Brazil.•Changes in rainfall and chemical weathering causing Sr isotopic fractionation.•The low Nd values agree with the increase in wet conditions.•The Parnaiba river is the main source of sediments to off northeastern Brazil.
Coccidioides is a primary pathogenic fungus, which infects humans through highly infectious arthroconidia, causing substantial morbidity including life-threatening disseminated infections. Due to the ...low infectious dose, laboratory personnel might become infected during diagnostic procedures. Accordingly, coccidioidomycosis is reported as the most frequent laboratory-acquired systemic mycosis worldwide. This risk is aggravated in non-endemic countries, where the diagnosis may not be suspected. We report on an inadvertent exposure of 44 persons to Coccidioides posadasii in a clinical microbiology laboratory in Chile, the measures of containment after rapid diagnosis with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and the lessons learnt in a non-endemic setting.
Between May and September 2016, mosquitoes were collected on a biweekly basis at 55 locations with CO
2
-baited encephalitis vector surveillance traps along the Upper Rhine, Germany, to evaluate the ...species composition, geographical distribution and abundance of the
Anopheles maculipennis
complex, some members of this complex being considered vectors of historical malaria in Germany. A total of 2115
Anopheles maculipennis
complex specimens were collected during the season, of which a sample of 1252 individuals was determined to species level by amplification of species-specific internal transcribed spacer 2 (ITS2) sequences. A total of 856 individuals of
Anopheles daciae
(68.37%), 394
Anopheles messeae
(31.47%) and 2
Anopheles maculipennis
s.s. (0.16%) were recorded. The number and proportion of
A. daciae
was remarkably higher in the northern meandering zone of the Upper Rhine (843 specimens, 79.90%), than in the more canalised southern furcation zone where
A. messeae
with 183 collected specimens represented 92.89% of 197 classified individuals. The average number of collected
A. maculipennis
s.l. individuals per trapping site was 38.45, equalling 0.64% of the total mosquito collection. Despite an increase in imported malaria cases, this comparatively low abundance of
A. maculipennis
s.l. may indicate a low risk of endemic malaria transmission by members of the
A. maculipennis
complex today. The proportionally dominance of
A. daciae
suggests that this species could be suspected the main historical vector of malaria in the Upper Rhine region. Sequence analyses of the ITS2 fragment revealed intraindividual polymorphisms within 3 of 5 diagnostic nucleotides in all specimens of
A. daciae
, raising the question if additional loci should be considered, to gain further insight into the taxonomical relation to
A. messeae
.
Stool samples from patients with abdominal symptoms were used to evaluate different copro-diagnostic assays for the detection of Giardia and Cryptosporidium. Results from microscopical examination ...following conventional stool concentration and direct fluorescent-antibody methods were compared with various commercially available immunochromatographic and enzyme immunoassays. Of 220 samples, 45 were positive for Giardia and 17 for Cryptosporidium. For Giardia, the sensitivities obtained by Ridascreen Giardia, Rida Quick Giardia, Rida Quick Combi and Giardia-Strip were 82%, 80%, 80% and 44%, respectively. For Cryptosporidium, the sensitivities obtained by Rida Quick Cryptosporidium, Ridascreen Cryptosporidium, Rida Quick Combi and Cryptosporidium-Strip were 88%, 82%, 82% and 75%, respectively. The specificity of all tests was ≥ 98%. Other intestinal parasites were present in 68 samples, but cross-reactions with other protozoan or helminthic parasites were not observed. Overall, the copro-antigen assays were less time-consuming and easier to perform, but were less sensitive than conventional microscopical methods. Thus, these tests might be a useful addition to, but not a substitute for microscopical methods in the diagnosis of travel-associated giardiasis and cryptosporidiosis.
Giardia duodenalis isolates from German travellers returning from tropical areas were characterised by PCR amplification and sequencing of fragments of the beta-giardin (bg), glutamate dehydrogenase ...(gdh) and triose phosphate isomerase (tpi) genes. Assignment of isolates to specific G. duodenalis assemblages was found to differ according to the marker used. Indeed, at the bg locus, assemblages A and B were identified, with a higher prevalence of the former over the latter, whereas at the tpi and gdh loci, most samples were classified as assemblage B. In agreement with previous studies, sequence analysis showed that assemblage B isolates have a higher genetic polymorphism than assemblage A isolates, and novel variants were described. The degree of polymorphism was shown in a graphical representation of the polymorphic sites generating a novel sequence, the heterogeneous positions common to assemblages A and B (double peaks), that may represent mixed assemblage infection and the heterogeneous positions detected at random sites. Notably, assemblage D, which is considered to be adapted to dogs, was found at the gdh locus in two samples originating from southern Asia, as novel genotypes. By comparing the geographical origin of the infected cases and the number of German travellers visiting the areas considered, India and west Africa appeared to be the areas associated to the highest risk of acquiring Giardia infection. The analysis of the geographical distribution of the genotypes did not suggest any particular geographical clustering pattern, but it may be useful to evaluate these results with a higher number of isolates. Most of the samples typed at the three markers could not be assigned unequivocally to either assemblage A or B, and this was confirmed also by a real-time PCR assay, using a set of assemblage-specific primers. The results of this study reinforce the notion that genetic exchanges and allelic sequence heterogeneity represent major obstacles towards understanding the epidemiology of giardiasis and that exposure to Giardia parasites in endemic areas often results in mixed infections in returning travellers.
Experimental tissue fusion benefits from the selective heating of superparamagnetic iron oxide nanoparticles (SPIONs) under high frequency irradiation. However, the metabolic pathways of SPIONs for ...tissue fusion remain unknown. Hence, the goal of this in vivo study was to analyze the distribution of SPIONs in different organs by means of magnetic resonance imaging (MRI) and histological analysis after a SPION-containing patch implantation.
SPION-containing patches were implanted in rats. Three animal groups were studied histologically over six months. Degradation assessment of the SPION-albumin patch was performed in vivo using MRI for iron content localization and biodistribution.
No SPION degradation or accumulation into the reticuloendothelial system was detected by MRI, MRI relaxometry, or histology, outside the area of the implantation patch. Concentrations from 0.01 μg/mL to 25 μg/mL were found to be hyperintense in T1-like gradient echo sequences. The best differentiation of concentrations was found in T2 relaxometry, susceptibility-sensitive gradient echo sequences, and in high repetition time T2 images. Qualitative and semiquantitative visualization of small concentrations and accumulation of SPIONs by MRI are feasible. In histological liver samples, Kupffer cells were significantly correlated with postimplantation time, but no differences were observed between sham-treated and induction/no induction groups. Transmission electron microscopy showed local uptake of SPIONs in macrophages and cells of the reticuloendothelial system. Apoptosis staining using caspase showed no increased toxicity compared with sham-treated tissue. Implanted SPION patches were relatively inert with slow, progressive local degradation over the six-month period. No distant structural alterations in the studied tissue could be observed.
Systemic bioavailability may play a role in specific SPION implant toxicity and therefore the local degradation process is a further aspect to be assessed in future studies.
Because of its infrequent and protean presentation and the lack of clinical data, the management of acute infections with the foodborne trematode Fasciola hepatica is challenging. We report four ...serologically confirmed cases that illustrate our experience with this parasitic infection in Chile. All patients were adults presenting with upper abdominal pain. Other symptoms included fever, nausea/vomiting, and cutaneous manifestations. In all cases, marked eosinophilia was present. All patients lived in an urban environment, and three reported the consumption of raw watercress. Computed tomography (CT) scans showed hypodense hepatic lesions, whereas ultrasonography findings were unremarkable. One patient suffered portal vein thrombosis, which might be a rare complication of acute fascioliasis. All patients were successfully treated with triclabendazole. Our case series demonstrates that patients with acute fascioliasis typically present with a combination of upper abdominal pain, marked eosinophilia, and hypodense hepatic lesions on CT imaging. Diagnosis should be confirmed by serological investigation. A history of recent consumption of raw watercress is an important finding, but in some patients the source of infection remains obscure.
Summary
Although pets provide physiological and psychological benefits to their owners, they are a potential source of zoonotic infections, especially for vulnerable individuals such as ...immunocompromised patients. During 1 year, we therefore performed a pilot project, which included 32 immunocompromised Chilean children and their family pets (35 dogs and 9 cats) with the aim of detecting, treating and preventing zoonotic infections. Children were examined by Infectious Diseases paediatricians and demographical and clinical information related to zoonotic infections were recorded. Pets were examined and sampled by veterinarians, who also administered missing routine vaccines and anti‐parasitics. During family visits, all members were informed and educated about zoonoses and a satisfaction survey was performed. Visits also included vector control and indoor residual spraying with pyrethroids. Children were re‐examined and re‐tested according to the findings of their pets, and all detected zoonotic infections were treated both in children and pets. Physical examination revealed abnormalities in 18 dogs (51.4%) and three cats (33.3%). Twenty‐eight (63.6%) of the pets were diagnosed with a zoonotic pathogen, and seven (15.9%) with a facultative pathogen. Most zoonotic agents were isolated from the pet's external ear and intestine. Bacteria with the highest pathogenic potential were Campylobacter jejuni and Brucella canis. In two children and their respective pets, the same zoonotic diseases were diagnosed (toxocariasis and giardiasis). Arthropods serving as potential vectors of zoonotic infections were found in 49% of dogs and 44% of cats. The pilot project was positively evaluated by the participating families. Our pilot project confirmed that pets are reservoir for various zoonotic agents in Chile and that the implementation of an integrated multidisciplinary programme was a valuable tool to prevent, diagnose and treat such zoonotic infections in vulnerable patients such as immunocompromised children.
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