Biology subjects

Ferreira, F. C.

Publications and source records attributed to Ferreira, F. C..

6 recordsLinked to original sources

bioRxiv2023

Ticks (Acari: Ixodida) on synanthropic small and medium-sized mammals in areas of the northeastern United States infested with the Asian longhorned tick, Haemaphysalis longicornis

The northeastern United States is a hot spot for tick-borne diseases. Adding to an already complex vector landscape, in 2017 large populations of the invasive Haemaphysalis longicornis, the Asian longhorned tick, were detected in New Jersey (NJ) and later found to be widespread from Connecticut to Georgia. In its native range in northeastern Asia, H. longicornis is considered an important vector of deadly pathogens to humans, companion animals, and livestock. To identify the primary hosts of H. longicornis we surveyed synanthropic small and medium-sized mammals in three different sites in suburban New Brunswick, NJ. Specifically, we collected approximately 9,000 tick specimens belonging to nine species from 11 different species of mammals sampled between May and September 2021. We found that H. longicornis feeds more frequently on rodents than previously thought, and that this invasive tick is likely exposed to important enzootic and zoonotic pathogens. Overall, we obtained detailed information about the seasonal dynamics and feeding patterns of six tick species common in the northeastern US, Haemaphysalis longicornis, Amblyomma americanum, Dermacentor variabilis, Ixodes scapularis, I. texanus and I. cookei. We found that unlike I. scapularis that feeds on mammals of all sizes, H. longicornis feeds on hosts following the general pattern of A. americanum, favoring larger species such as skunks, groundhogs, and raccoons. However, our survey revealed that unlike A. americanum, H. longicornis reaches high densities on Virginia opossum. Overall, the newly invasive H. longicornis was the most abundant tick species both on multiple host species and in the environment, raising significant questions regarding its role in the epidemiology of tick-borne pathogens, especially those affecting livestock, companion animals and wildlife. In conclusion, our findings provide valuable insights into the tick species composition on mammal hosts in New Jersey and the ongoing national expansion of H. longicornis.

ecology↗

bioRxiv2023

Cell-derived ECM loaded electrospun Polycaprolactone/Chitosan nanofibrous scaffolds for periodontal regeneration

Periodontitis is an inflammatory infection caused by bacterial plaque accumulation that affects the periodontium, a complex structure of different tissues (cementum, periodontal ligament and alveolar bone) that surrounds and supports the teeth. Current treatments lack bioactive signals to induce tissue repair and coordinated regeneration of the periodontium, thus alternative strategies are needed to improve clinical outcomes. Cell-derived extracellular matrix (ECM) has been combined with biomaterials to enhance their biofunctionality for various tissue engineering (TE) applications. In this work, bioactive cell-derived ECM loaded electrospun polycaprolactone/chitosan (PCL/CTS) nanofibrous scaffolds were developed combining polymer solutions with lyophilized decellularized ECM (dECM) derived from human Periodontal Ligament Stem/Stromal Cells (PDLSCs). The works aims were to fabricate and characterize cell-derived ECM electrospun PCL/CTS scaffolds in terms of morphology, physico-chemical, thermal and mechanical properties and assess their ability to enhance the osteogenic differentiation of PDLSCs, envisaging periodontal TE applications. PDLSCs were cultured and used for dECM production. PDLSCs-derived dECM was characterized regarding morphology, protein expression, DNA removal efficiency, and glycosaminoglycans and collagen contents. Osteogenic differentiation of PDLSCs was performed on PCL, PCL/CTS and PCL/CTS/ECM electrospun scaffolds for 21 days. The obtained results demonstrate that PCL/CTS/ECM scaffolds promoted cell proliferation compared to PCL and PCL/CTS scaffolds, while maintaining similar physical and mechanical properties of PCL/CTS scaffolds. PCL/CTS/ECM scaffolds enhanced the osteogenic differentiation of PDLSCs, confirmed by increased alkaline phosphatase activity, calcium deposition, and bone-specific marker genes expression. Moreover, PCL/CTS scaffolds showed higher levels of cell mineralization than PCL scaffolds. Overall, this work describes the first use of lyophilized cell-derived ECM loaded electrospun scaffolds for periodontal TE applications and highlights its potential as a promising therapeutic strategy for periodontitis treatment.

bioengineering↗

bioRxiv2022

Great-tailed Grackles (Quiscalus mexicanus) as a tolerant host of avian malaria parasites

Great-tailed Grackles (Quiscalus mexicanus) are a social, polygamous bird species whose populations have rapidly expanded their geographic range across North America over the past century. Before 1865, Great-tailed Grackles were only documented in Central America, Mexico, and southern Texas in the USA. Given the rapid northern expansion of this species, it is relevant to study its role in the dynamics of avian blood parasites. Here, 87 Great-tailed grackles in Arizona (a population in the new center of the range) were screened for haemosporidian parasites using microscopy and PCR targeting the parasite mitochondrial cytochrome b gene. Individuals were caught in the wild from January 2018 until February 2020. Haemosporidian parasite prevalence was 60.9% (53/87). A high Plasmodium prevalence was found (59.8%, 52/87), and one grackle was infected with Haemoproteus (Parahaemoproteus) sp. (lineage SIAMEX01). Twenty-one grackles were infected with P. cathemerium, sixteen with P. homopolare, four with P. relictum (strain GRW04), and eleven with three different genetic lineages of Plasmodium spp. that have not been characterized to species level (MOLATE01, PHPAT01, and ZEMAC01). Gametocytes were observed in birds infected with three different Plasmodium lineages, revealing that grackles are competent hosts for some parasite species. This study also suggests that grackles are highly susceptible and develop chronic infections consistent with parasite tolerance, making them competent to transmit some generalist haemosporidian lineages. It can be hypothesized that, as the Great-tailed Grackle expands its geographic range, it may affect local bird communities by increasing the transmission of local parasites but not introducing new species into the parasite species pool.

zoology↗

bioRxiv2022

Transcriptional response of individual Hawaiian Culex quinquefasciatus mosquitoes to the avian malaria parasite Plasmodium relictum

Culex quinquefasciatus, the mosquito vector of avian malaria in Hawai{square}i, became established in the islands in the 1820s and the deadly effects of malaria on endemic bird species have been documented for many decades. To evaluate the gene expression response of the mosquito to the parasite, we let the offspring of wild-collected Hawaiian Cx. quinquefasciatus feed on a domestic canary infected with Plasmodium relictum GRW4 freshly isolated from a wild-caught Hawaiian honeycreeper. Control mosquitoes were fed on an uninfected canary. We sequenced the individual transcriptomes of five infected and three uninfected individual mosquitoes at three different stages of the parasite life cycle: 24 h post feeding (hpf) during ookinete invasion; 5 days post feeding (dpf) when oocysts are developing; 10 dpf when sporozoites are released and invade the salivary glands. Differential gene expression analyses showed that during ookinete invasion (24 hpf), genes related to oxidoreductase activity and galactose catabolism had lower expression levels in infected mosquitoes compared to controls. Oocyst development (5 dpf) was associated with reduced expression of a gene with a predicted innate immune function. At 10 dpf, infected mosquitoes had reduced expression levels of a serine protease inhibitor. Overall, the gene expression response of Hawaiian Culex exposed to a Plasmodium infection intensity that occur naturally in Hawaii was low, but more pronounced during ookinete invasion. The low fitness costs often documented in Culex infected with avian Plasmodium likely reflect the relatively small transcriptional changes observed in mosquito genes related to immune response and nutrient metabolism.

microbiology↗

bioRxiv2022

Bio-inspired artificial printed bioelectronic cardio-3D-cellular constructs

Bioelectronics is a growing field where novel smart materials are required to interface biology with electronic components. Conductive hydrogels have recently emerged as a promising material for biosensing/actuating applications as they can provide a wet, nanostructured and electrically conductive environment, minimising the mismatch between biological and electronic systems. In this work, we propose a strategy to develop conductive bioinks compatible with the freeform reversible embedding of suspended hydrogels (FRESH) extrusion bioprinting method. These bioinks are based on decellularized extracellular matrix (dECM), extracted from three different tissues (small intestine submucosa, liver and bone) and were characterised. 3D structures were manufactured containing human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs), exhibiting cell viabilities >80%. Multi-walled carbon nanotubes (MWCNTs) were selected as an additional component of the bioinks. The addition of the MWCNTs enhanced the conductive features of the hydrogels and the morphology of the dECM fibres. Electrical stimulation (ES) through alternating currents was applied to hPSC-CMs encapsulated in 3D structures manufactured with the previous material and our results indicated two main findings: (1) in the absence of external ES, the conductive properties of the materials can improve the contractile behaviour of the hPSC-CMs and (2) this effect is significantly enhanced under the application of external ES. Genetic markers analysed showed a trend towards a more mature state of the cells evaluated by the TNNI3/TNNI1 ratio, with upregulated SERCA2 and RYR2 calcium handling proteins when compared to controls and downregulation of calcium channels involved in the generation of pacemaking currents (CACNA1H). These results demonstrate the potential of our strategy to manufacture conductive hydrogels in complex geometries for bioactuating purposes. However, further development of the 3D bioprinting techniques is required to achieve higher control over the nano- and microarchitectures of the structures to improve their biomimicry.

bioengineering↗

bioRxiv2021

A gene-based capture assay for surveying patterns of genetic diversity and insecticide resistance in a worldwide group of invasive mosquitoes

Understanding patterns of diversification, genetic exchange, and pesticide resistance in insect species of human health concern is necessary for effective population reduction and management. With the broad availability of next-generation sequencing technologies, one of the best approaches for surveying such patterns involves the simultaneous genotyping of many samples for large numbers of genetic markers from across the known genome. To this end, the targeting of gene sequences of known function or inheritance can be a cost-effective strategy. One insect group of substantial health concern are the mosquito taxa that make up the Culex pipiens complex. Members of this complex transmit damaging arboviruses and filariae worms to humans, as well as other pathogens that are detrimental to endangered vertebrate species such as bird malaria. Here we describe our development of a targeted gene-based assay for surveying genetic diversity and population structure in this mosquito complex. To test the utility of this assay, we examined taxonomic divergence among samples from several members of the complex, as well as distinct populations of the relatively under-studied Culex quinquefasciatus, an urban pantropical species. We also examined the presence of known insecticide-resistance conferring alleles. Broadly, our developed gene-based assay proved effective for examining patterns of taxonomic and geographic clustering within the species complex, as well as for surveying genetic variants that have been associated with insecticide resistance. This assay will be useful for future studies that aim to understand the genetic mechanisms underlying the evolution of ubiquitous and increasingly damaging disease vectors.

genomics↗