In Guatemala, there is a significant gap in our understanding of the prevalence of antibiotic resistance across different reservoirs likely to affect human exposures. We conducted a One Health study of produce, poultry, water, and humans within peri-urban and urban Guatemalan markets to characterize the prevalence of third-generation cephalosporin-resistant Escherichia coli (3GCR-EC). We screened a total of 132 samples for 3GCR-EC using selective media. Samples were collected across three markets in Guatemala and included produce (n = 32), public tap water (n = 30), commercial and non-commercial poultry (n = 40), and human fecal matter (n = 30). We measured phenotypic and genotypic resistance using culture-based methods and whole-genome sequencing. Among the 132 samples, 87.1% (n = 115) were positive for E. coli, and 67.4% (n = 43) were positive for 3GCR-EC. After removing duplicates, a total of 40 3GCR-EC isolates were sequenced from commercial chicken carcasses (n = 8), non-commercial chicken carcasses (n = 16), water (n = 4), and human feces (n = 12). Out of 11 unique extended-spectrum beta-lactamase genes, the most prevalent gene was blaCTX-M-55. There was high clonal diversity, with 32 distinct sequence types (ST) detected. Clinically important pandemic lineages of E. coli were identified: ST10, ST648, and ST410. This study identified a high prevalence of antibiotic resistance across diverse samples within public Guatemalan markets. The frequent detection of 3GCR-EC, their resistance genes, and epidemiologically important lineages of E. coli identified from humans, produce, water, and poultry samples highlight the importance of implementing more extensive surveillance using a One Health approach to develop coordinated strategies to mitigate the spread of antibiotic resistance.
Vector-borne pathogens, which are transmitted by blood-feeding arthropods to animals and people, are common in tropical regions where, combined with economic factors, can cause significant public health burden. A community-level study was undertaken in southwestern Guatemala to assess the presence of vector-borne pathogens in blood samples from humans (n = 98), their animals (n = 90), and ectoparasites (n = 83) over a period of 2 weeks. Human capillary blood was collected from participant's index finger, and animal venous blood (chickens, pigs, dogs, and cats) was collected from the jugular or cephalic veins at the enrollment period of a concurrent study. Ectoparasites (fleas, ticks, and lice) were collected from dogs at the time of the blood collection. Total DNA was extracted from the human blood, animal blood, and ectoparasites and assayed using published PCR assays for Anaplasma spp., Bartonella spp., and Ehrlichia spp. Ectoparasites were also tested for the presence of Rickettsia spp. DNA by PCR. Anaplasma spp. DNA was amplified from 1 of 39 (2.6 %) chickens and 1 of 6 (16.6 %) turkeys. All human and dog blood samples were negative for Bartonella spp. in the same community. Ehrlichia spp. DNA was amplified from 12 (60 %) of 20 dogs and sequencing documented Ehrlichia spp. in 2 dogs and the ticks and fleas collected from these dogs. All the Ehrlichia spp.-positive sequences showed 100 % homology to E. canis sequences and other uncultured Ehrlichia spp. strains isolated from animals. Rickettsia spp. DNA was not amplified from any of the ectoparasites assessed. Our findings suggest that Ehrlichia spp. are common in dogs and Anaplasma spp. are circulating in poultry in a rural community in southwest Guatemala. We expect these results to be used in awareness campaigns and public health interventions to reduce vector borne pathogens in the region.
In many countries, soiled toilet paper is placed in trash bins rather than flushed down the toilet. We investigated the use of soiled toilet paper in Guatemalan markets to surveil for pathogenic sequence types (STs) of E. coli and third generation cephalosporin-resistant E. coli (3GCR-EC). We collected used toilet paper from trash bins in the restrooms of three Guatemalan public markets. We screened samples for E. coli and 3GCR-EC. Whole genome sequencing was used to characterize the isolates. E. coli was successfully cultured from all 30 toilet paper samples. Soiled toilet paper was an effective matrix for surveilling multidrug-resistant E. coli and could be an efficient method in certain contexts.
Wild aquatic birds are considered the natural hosts of 16 HA (H1–H16) and 9 NA (N1–N9) subtypes of influenza A viruses (FLUAV) found in different combinations. H14 FLUAVs are rarely detected in nature. Since 2011, H14 FLUAVs have been consistently detected in Guatemala, leading to the largest collection of this subtype from a single country. All H14 FLUAVs in Guatemala were detected from blue-winged teal samples. In this report, 17 new full-length H14 FLUAV genome sequences detected from 2014 until 2019 were analyzed and compared to all published H14 sequences, including Guatemala, North America, and Eurasia. The H14 FLUAVs identified in Guatemala were mostly associated with the N3 subtype (n = 25), whereas the rest were paired with either N4 (n = 7), N5 (n = 4), N6 (n = 1), and two mixed infections (N3/N5 n = 2, and N2/N3 n = 1). H14 FLUAVs in Guatemala belong to a distinct H14 lineage in the Americas that is evolving independently from the Eurasian H14 lineage. Of note, the ORF of the H14 HA segments showed three distinct motifs at the cleavage site, two of these containing arginine instead of lysine in the first and fourth positions, not previously described in other countries. The effects of these mutations on virus replication, virulence, and/or transmission remain unknown and warrant further studies.
Despite increased surveillance efforts, the epidemiology of FLUAVs circulating in swine in Latin America remains understudied. For instance, the 2009 H1N1 influenza pandemic strain (H1N1 pdm09) emerged in Mexico, but its circulation remained undetected in pigs. Commercial swine farms provide unique systems for interspecies transmission of influenza A viruses (FLUAVs) at the animal-human interface. Bidirectional transmission of FLUAVs between pigs and humans plays a significant role in the generation of novel strains that become established in the new host population. Active FLUAV surveillance was conducted for 2 years on a commercial pig farm in Southern Guatemala with no history of FLUAV vaccination. Nasal swabs (n = 2,094) from fattening pigs (6 to 24 weeks old) with respiratory signs were collected weekly from May 2016 to February 2018. Swabs were screened for FLUAV by real-time reverse transcriptase PCR (RRT-PCR), and full virus genomes of FLUAV-positive swabs were sequenced by next-generation sequencing (NGS). FLUAV prevalence was 12.0% (95% confidence interval [CI], 10.6% to 13.4%) with two distinct periods of high infection. All samples were identified as FLUAVs of the H1N1 subtype within the H1 swine clade 1A.3.3.2 and whose ancestors are the human origin 2009 H1N1 influenza pandemic virus (H1N1 pdm09). Compared to the prototypic reference segment sequence, 10 amino acid signatures were observed on relevant antigenic sites on the hemagglutinin. The Guatemalan swine-origin FLUAVs show independent evolution from other H1N1 pdm09 FLUAVs circulating in Central America. The zoonotic risk of these viruses remains unknown but strongly calls for continued FLUAV surveillance in pigs in Guatemala.IMPORTANCE Despite increased surveillance efforts, the epidemiology of FLUAVs circulating in swine in Latin America remains understudied. For instance, the 2009 H1N1 influenza pandemic strain (H1N1 pdm09) emerged in Mexico, but its circulation remained undetected in pigs. In Central America, Guatemala is the country with the largest swine industry. We found a unique group of H1N1 pdm09 sequences that suggests independent evolution from similar viruses circulating in Central America. These viruses may represent the establishment of a novel genetic lineage with the potential to reassort with other cocirculating viruses and whose zoonotic risk remains to be determined.
Free-roaming domestic dogs (FRDD), as vectors of zoonotic diseases, are of high relevance for public health. Understanding roaming patterns of dogs can help to design disease control programs and disease transmission simulation models. Studies on GPS tracking of dogs report stark differences in recording periods. So far, there is no accepted number of days required to capture a representative home range (HR) of FRDD. The objective of this study was to evaluate changes in HR size and shape over time of FRDD living in Chad, Guatemala, Indonesia and Uganda and identify the period required to capture stable HR values. Dogs were collared with GPS units, leading to a total of 46 datasets with, at least, 19 recorded days. For each animal and recorded day, HR sizes were estimated using the Biased Random Bridge method and percentages of daily change in size and shape calculated and taken as metrics. The analysis revealed that the required number of days differed substantially between individuals, isopleths, and countries, with the extended HR (95% isopleth value) requiring a longer recording period. To reach a stable HR size and shape values for 75% of the dogs, 26 and 21 days, respectively, were sufficient. However, certain dogs required more extended observational periods.
Domestic dogs can affect human health through bites and pathogen transmission, particularly in resource-poor countries where dogs, including owned ones, predominantly roam freely. Habitat and resource selection analysis methods are commonplace in wildlife studies but have not been used to investigate the environmental resource use of free-roaming domestic dogs (FRDD). The present study implements GPS devices to investigate habitat selection by FRDD from an urban site and a rural site in Indonesia, and one urban and two rural sites in Guatemala (N = 321 dogs). Spatial mixed effects logistic regression models, accounting for heterogeneous distribution of the resources, showed that patterns of habitat selection by FRDD were similar across study sites. The most preferred resources were anthropogenic, being buildings and roads, which implies selection for human proximity. Vegetation and open fields were less preferred and steep terrain was avoided, indicating that FRDD were synanthropic and that their space patterns likely optimised energy use. Results presented here provide novel data on FRDD habitat selection patterns, while improving our understanding of dog roaming behaviour. These findings provide insights into possible high-risk locations for pathogen transmission for diseases such as rabies, and can assist management authorities in the planning and deployment of efficient disease control campaigns, including oral vaccination.
Commercial swine farms provide unique systems for interspecies transmission of influenza A viruses (FLUAVs) at the animal-human interface. Bidirectional transmission of FLUAVs between pigs and humans plays a significant role in the generation of novel strains that become established in the new host population. Active FLUAV surveillance was conducted for two years on a commercial pig farm in Southern Guatemala with no history of FLUAV vaccination. Nasal swabs (n=2,094) from fattening pigs (6 to 24 weeks old) with respiratory signs were collected from May 2016 to February 2018. Swabs were screened for FLUAV by RRT-PCR and full virus genomes of FLUAV-positive swabs were sequenced by next-generation sequencing (NGS). FLUAV prevalence was 12.0% (95% CI: 10.6% – 13.4%) with two distinct periods of high infection. All samples were identified as FLUAVs of the H1N1 subtype within the H1 swine clade 1A.3.3.2 and whose ancestors are the human origin 2009 H1N1 influenza pandemic virus (H1N1 pdm09). Compared to the prototypic reference segment sequence, 10 amino acid signatures were observed on relevant antigenic sites on the hemagglutinin. We also found that Guatemalan swine-origin FLUAVs show independent evolution from other H1N1 pdm09 FLUAVs circulating in Central America. The zoonotic risk of these viruses remains unknown, but strongly calls for continued FLUAV surveillance in pigs in Guatemala. Importance Despite increased surveillance efforts, the epidemiology of FLUAVs circulating in swine in Latin America remains understudied. For instance, the 2009 H1N1 influenza pandemic strain (H1N1 pdm09) emerged in Mexico, but its circulation remained undetected in pigs. In Central America, Guatemala is the country with the largest swine industry. We found a unique group of H1N1 pdm09 sequences that suggests independent evolution from similar viruses circulating in Central America. These viruses may represent the establishment of a novel genetic lineage with the potential to reassort with other co-circulating viruses, and whose zoonotic risk remains to be determined.
Due to their documented epidemiological relevance as hosts for influenza A viruses (IAV), humans, poultry and pigs in backyard production systems (BPS) within wetlands could be key to the emergence of novel IAV variants able to transmit between humans or animals. To better understand the circulation of IAV at the human–animal interface of BPS within wetlands, we studied IAV in backyard duck flocks and pig herds in the Pacific Coast of Guatemala. From April 2013 to October 2014, we estimated the monthly IAV per cent seropositive and viral positive flocks and herds in two resource‐limited communities. We detected antibodies in sera against the IAV nucleoprotein through ELISA. We also detected IAV viral RNA in respiratory (ducks and pigs) and cloacal (ducks) swabs through rRT‐PCR directed at the matrix gene. We attempted viral isolation in eggs or MDCK cells followed by sequencing from swabs positive for IAV. During our study period, IAV seropositivity in duck flocks was 38%, and viral positivity was 23% (n = 86 BPS sampled). IAV seropositivity in pig herds was 42%, and viral positivity was 20% (n = 90 BPS sampled). Both flocks and herds had detectable antibodies against IAV mostly year‐round, and IAV was detected in several months. We isolated an H3N2 virus from one pig sampled at the end of 2013. Standard nucleotide BLAST searches indicate that the isolated virus was similar to seasonal viruses circulating in humans, suggesting human‐to‐pig transmission. Our data show concurrent circulation of IAV in multiple species of poultry and pigs that were commingled in rudimentary conditions in proximity to humans, but no significant risk factors could be identified.
Guatemala has held dog rabies mass vaccination campaigns countrywide since 1984, yet the virus remains endemic. To eliminate dog-mediated human rabies, dog vaccination coverage must reach at least 70%. The Guatemala rabies program uses a 5:1 human:dog ratio (HDR) to estimate the vaccination coverage; however, this method may not accurately reflect the heterogeneity of dog ownership practices in Guatemalan communities. We conducted 16 field-based dog population estimates in urban, semi-urban and rural areas of Guatemala to determine HDR and evaluate the standard 5:1. Our study-derived HDR estimates varied from 1.7–11.4:1 (average 4.0:1), being higher in densely populated sites and lowest in rural communities. The community-to-community heterogeneity observed in dog populations could explain the persistence of rabies in certain communities. To date, this is the most extensive dog-population evaluation conducted in Guatemala, and can be used to inform future rabies vaccination campaigns needed to meet the global 2030 rabies elimination targets.
Free roaming domestic dogs (FRDD) are the main vectors for rabies transmission to humans worldwide. To eradicate rabies from a dog population, current recommendations focus on random vaccination with at least 70% coverage. Studies suggest that targeting high-risk subpopulations could reduce the required vaccination coverage, and increase the likelihood of success of elimination campaigns. The centrality of a dog in a contact network can be used as a measure of its potential contribution to disease transmission. Our objectives were to investigate social networks of FRDD in eleven study sites in Chad, Guatemala, Indonesia and Uganda, and to identify characteristics of dogs, and their owners, associated with their centrality in the networks. In all study sites, networks had small-world properties and right-skewed degree distributions, suggesting that vaccinating highly connected dogs would be more effective than random vaccination. Dogs were more connected in rural than urban settings, and the likelihood of contacts was negatively correlated with the distance between dogs' households. While heterogeneity in dog's connectedness was observed in all networks, factors predicting centrality and likelihood of contacts varied across networks and countries. We therefore hypothesize that the investigated dog and owner characteristics resulted in different contact patterns depending on the social, cultural and economic context. We suggest to invest into understanding of the sociocultural structures impacting dog ownership and thus driving dog ecology, a requirement to assess the potential of targeted vaccination in dog populations.
Dogs play a major role in public health because of potential transmission of zoonotic diseases, such as rabies. Dog roaming behavior has been studied worldwide, including countries in Asia, Latin America, and Oceania, while studies on dog roaming behavior are lacking in Africa. Many of those studies investigated potential drivers for roaming, which could be used to refine disease control measures. However, it appears that results are often contradictory between countries, which could be caused by differences in study design or the influence of context-specific factors. Comparative studies on dog roaming behavior are needed to better understand domestic dog roaming behavior and address these discrepancies. The aim of this study was to investigate dog demography, management, and roaming behavior across four countries: Chad, Guatemala, Indonesia, and Uganda. We equipped 773 dogs with georeferenced contact sensors (106 in Chad, 303 in Guatemala, 217 in Indonesia, and 149 in Uganda) and interviewed the owners to collect information about the dog [e.g., sex, age, body condition score (BCS)] and its management (e.g., role of the dog, origin of the dog, owner-mediated transportation, confinement, vaccination, and feeding practices). Dog home range was computed using the biased random bridge method, and the core and extended home range sizes were considered. Using an AIC-based approach to select variables, country-specific linear models were developed to identify potential predictors for roaming. We highlighted similarities and differences in term of demography, dog management, and roaming behavior between countries. The median of the core home range size was 0.30 ha (95% range: 0.17–0.92 ha) in Chad, 0.33 ha (0.17–1.1 ha) in Guatemala, 0.30 ha (0.20–0.61 ha) in Indonesia, and 0.25 ha (0.15–0.72 ha) in Uganda. The median of the extended home range size was 7.7 ha (95% range: 1.1–103 ha) in Chad, 5.7 ha (1.5–27.5 ha) in Guatemala, 5.6 ha (1.6–26.5 ha) in Indonesia, and 5.7 ha (1.3–19.1 ha) in Uganda. Factors having a significant impact on the home range size in some of the countries included being male dog (positively), being younger than one year (negatively), being older than 6 years (negatively), having a low or a high BCS (negatively), being a hunting dog (positively), being a shepherd dog (positively), and time when the dog was not supervised or restricted (positively). However, the same outcome could have an impact in a country and no impact in another. We suggest that dog roaming behavior is complex and is closely related to the owner's socioeconomic context and transportation habits and the local environment. Free-roaming domestic dogs are not completely under human control but, contrary to wildlife, they strongly depend upon humans. This particular dog–human bound has to be better understood to explain their behavior and deal with free-roaming domestic dogs related issues.
The presence of intestinal pathogenic Escherichia coli in drinking water is well recognized as a risk for diarrhea. The role of drinking water in extraintestinal infections caused by E. coli-such as urinary tract infections (UTIs)-remains poorly understood. Urinary tract infections are a leading cause of outpatient infections globally, with a lifetime incidence of 50-60% in adult women. We reviewed the scientific literature on the occurrence of uropathogenic E. coli (UPEC) in water supplies to determine whether the waterborne route may be an important, overlooked, source of UPEC. A limited number of studies have assessed whether UPEC isolates are present in drinking water supplies, but no studies have measured whether their presence in water may increase UPEC colonization or the risk of UTIs in humans. Given the prevalence of drinking water supplies contaminated with E. coli across the globe, efforts should be made to characterize UTI-related risks associated with drinking water, as well as other pathways of exposure.
Although free-roaming domestic dogs (FRDD) constitute the majority of the dog population worldwide, many aspects of their ecology across habitats are little known. Activity budgets by these dogs may also inform management decisions for domestic dogs in human hands. Here we collected data on the activity patterns of owned FRDD from Guatemala (n = 58) and Indonesia (n = 37), and of farm dogs (n = 11) and family dogs (n = 20) in Switzerland. The FRDD from the two countries and the Swiss farm dogs shared the similarity that although they had owners, they spent most or all of the day outside without confinement. Conversely, activity in family dogs is largely controlled by their owners. This cross-continental study thus allowed us to tease apart environmental effects on dogs' activity from effects due to different levels of control by humans. Dogs were collared with FitBark activity trackers, which measure 3D acceleration, for 2.4-7 days. Activity for each dog was defined as the sum of BarkPoints (a continuous activity metric recorded by the FitBark tracker), calculated for each hour in the 24-hour cycle. The proportion of time resting, in 'moderate' and 'high' activity (defined by fixed thresholds of BarkPoints) over 24 h was calculated for each dog. The activity patterns of all dogs that (partly) roam freely, i.e. owned FRDD in Guatemala and Indonesia and Swiss farm dogs, showed two peaks over 24 h during 5:00-7:00 h and, less pronounced, 16:00-19:00 h. Such a bimodal activity pattern, which is also observed in other canine species, could only be detected in 45% of the family dogs. Their activity is more dependent on the owners' daily routines and predominantly showed one high mid-day peak that often changes from day to day. Swiss dogs spent significantly more time resting and less time with 'moderate' activity than the owned FRDD. However, family dogs were significantly more often highly active than all other dog groups and compensated with longer resting periods. Activity decreased significantly with age, neutering and increased body condition score, whereas sex did not have any significant influence on activity. Within this study, similarities, but also differences of the activity pattern between owned FRDD and pet dogs could be revealed. Although overall activity levels of the pet dog sample fall in the range of those observed in the less controlled FRDD, it would be of interest to investigate the potential benefit of a more structured daily schedule on pet dogs in future studies.
Rodents are reservoirs and hosts of several pathogens around the world, including zoonotic parasite species. This study aimed to determine the occurrence of zoonotic gastrointestinal helminths in rodents captured inside households in a rural community from southern Guatemala. Sixty-nine rodents were captured in 33% (49/148) of the surveyed households, including Rattus rattus, Rattus norvegicus, Mus musculus, and Sigmodon hispidus. Thirty-six percent (25/69) of these rodents (3 Rattus and 22 Mus musculus), from 45% (22/49) of the households, were parasitized with at least 1 gastrointestinal helminth species. Helminths from 6 species were identified: Hymenolepis diminuta, Moniliformis moniliformis, Heterakis spumosa, Nippostrongylus sp., Strongyloides sp., and Syphacia sp. Two zoonotic species were found in Rattus, H. diminuta in R. rattus (1/6), and M. moniliformis in R. norvegicus (1/1). Coinfection with other non-zoonotic helminth parasites, such as He. spumosa and Strongyloides sp., also was observed in the Rattus genus. Mus musculus had only non-zoonotic helminths: He. spumosa, Nippostrongylus sp., and Syphacia sp. being the most common, and He. spumosa (96%) followed by Nippostrongylus sp. (48%), with a higher presence in males than females, with a similar proportion in adult and young individuals. This is the first report of zoonotic and non-zoonotic helminths parasites in rodents from Guatemala.
Community-acquired antimicrobial resistant Enterobacteriaceae (CA-ARE) are an increasingly important issue around the world. Characterizing the distribution of regionally specific patterns of resistance is important to contextualize and develop locally relevant interventions. This systematic review adopts a One Health framework considering the health of humans, animals, and the environment to describe CA-ARE in Central America. Twenty studies were identified that focused on antimicrobial resistance (AMR) in Enterobacteriaceae. Studies on CA-ARE in Central America characterized resistance from diverse sources, including humans (n = 12), animals (n = 4), the environment (n = 2), and combinations of these categories (n = 2). A limited number of studies assessed prevalence of clinically important AMR, including carbapenem resistance (n = 3), third generation cephalosporin resistance (n = 7), colistin resistance (n = 2), extended spectrum beta-lactamase (ESBL) production (n = 4), or multidrug resistance (n = 4). This review highlights significant gaps in our current understanding of CA-ARE in Central America, most notably a general dearth of research, which requires increased investment and research on CA-ARE as well as AMR more broadly.
Caligus rogercresseyi is the dominant sea louse parasite affecting the salmon and trout industry in southern Chile. This parasite has a wide range of native and endemic fish hosts. The Patagonian blenny Eleginops maclovinus, which is parasitized mostly by the caligid species Lepeophtheirus spp. and C. rogercresseyi, is presumably responsible for the transmission of C. rogercresseyi to salmonids. The aim of this study was to characterize the transmission of parasites between different fish species and parasite cohort development under laboratory conditions. Parasite abundances and intensities were quantified. Transmission of parasites from Patagonian blenny to Atlantic salmon Salmo salar was lower (~9%, mainly corresponding to C. rogercresseyi) than from salmon to Patagonian blenny (14.7-26.9%, where only C. rogercresseyi were observed). This suggests that the transmission of C. rogercresseyi from salmon individuals is higher than the transmission from a native fish. Parasite cohorts developed successfully on both fish species, but apparently under different developmental rates. Water temperature, oxygen, and juvenile abundances were the variables that better explained cohort development success and variation in C. rogercresseyi adult abundances over time.
Population size estimation is performed for several reasons including disease surveillance and control, for example to design adequate control strategies such as vaccination programs or to estimate a vaccination campaign coverage. In this study, we aimed at investigating the possibility of using Unmanned Aerial Vehicles (UAV) to estimate the size of free-roaming domestic dog (FRDD) populations and compare the results with two regularly used methods for population estimations: foot-patrol transect survey and the human: dog ratio estimation. Three studies sites of one square kilometer were selected in Petén department, Guatemala. A door-to-door survey was conducted in which all available dogs were marked with a collar and owner were interviewed. The day after, UAV flight were performed twice during two consecutive days per study site. The UAV’s camera was set to regularly take pictures and cover the entire surface of the selected areas. Simultaneously to the UAV’s flight, a foot-patrol transect survey was performed and the number of collared and non-collared dogs were recorded. Data collected during the interviews and the number of dogs counted during the foot-patrol transects informed a capture-recapture (CR) model fit into a Bayesian inferential framework to estimate the dog population size, which was found to be 78, 259, and 413 in the three study sites. The difference of the CR model estimates compared to previously available dog census count (110 and 289) can be explained by the fact that the study population addressed by the different methods differs. The human: dog ratio covered the same study population as the dog census and tended to underestimate the FRDD population size (97 and 161). Under the conditions within this study, the total number of dogs identified on the UAV pictures was 11, 96, and 71 for the three regions (compared to the total number of dogs counted during the foot-patrol transects of 112, 354 and 211). In addition, the quality of the UAV pictures was not sufficient to assess the presence of a mark on the spotted dogs. Therefore, no CR model could be implemented to estimate the size of the FRDD using UAV. We discussed ways for improving the use of UAV for this purpose, such as flying at a lower altitude in study area wisely chosen. We also suggest to investigate the possibility of using infrared camera and automatic detection of the dogs to increase visibility of the dogs in the pictures and limit workload of finding them. Finally, we discuss the need of using models, such as spatial capture-recapture models to obtain reliable estimates of the FRDD population. This publication may provide helpful directions to design dog population size estimation methods using UAV.
High-fat diet (HFD)-fed mice show obesity with development of liver steatosis and a proinflammatory state without establishing an inflammatory reaction. The aim of this work was to assess the hypothesis that eicosapentaenoic acid (EPA) plus hydroxytyrosol (HT) supplementation prevents the inflammatory reaction through enhancement in the hepatic resolvin content in HFD-fed mice. Male C57BL/6J mice were fed an HFD or a control diet and supplemented with EPA (50 mg/kg/day) and HT (5 mg/kg/day) or their respective vehicles for 12 weeks. Measurements include liver levels of EPA, DHA and palmitate (gas chromatography), liver resolvins and triglyceride (TG) and serum aspartate transaminase (AST) (specific kits) and hepatic and serum inflammatory markers (quantitative polymerase chain reaction and enzyme-linked immunosorbent assay). Compared to CD, HFD induced body weight gain, liver steatosis and TG accumulation, with up-regulation of proinflammatory markers in the absence of histological inflammation or serum AST changes; these results were accompanied by higher hepatic levels of resolvins RvE1, RvE2, RvD1 and RvD2, with decreases in EPA and DHA contents. EPA+HT supplementation in HFD feeding synergistically reduced the steatosis score over individual treatments and increased the hepatic levels of EPA, DHA and resolvins, with attenuation of proinflammatory markers. Lack of progression of HFD-induced proinflammatory state into overt inflammation is associated with resolvin up-regulation, which is further increased by EPA+HT supplementation eliciting steatosis attenuation. These findings point to the importance of combined protocols in hepatoprotection due to the involvement of cross-talk mechanisms, which increase effectiveness and diminish dosages, avoiding undesirable effects.
Thiamethoxam (TMX) and clothianidin (CLO) are neonicotinoids insecticides. The main characteristic of these pesticides is their agonist action on nicotinic acetylcholine receptors (nAChRs). In the present work it was studied and characterized the effects of TMX and CLO, in different concentrations, on dopaminergic system of rat striatum using in vivo brain microdialysis coupled to HPLC-EC. Intrastriatal administration of 1 mM or 5 mM TMX has not produced significant increases on dopamine (DA) levels, nonetheless the infusion of 10 mM TMX increases the DA output to 841 ± 132%, when compared to basal levels. Infusion of 1 mM CLO has not induced a significant increase in DA levels, even so 2, 3.5 and 5 mM CLO have produced an increase of 438 ± 8%, 2778 ± 598% and 4604 ± 516%, respectively, every compared to basal levels. Mecamylamine (MEC), a non-competitive nAChRs antagonist, was used to investigate the role of nAChRs on DA release induced by TMX and CLO. The increases in extracellular DA levels induced by TMX and CLO when associated to MEC are 80% and 68% lower than the effect produced by CLO and TMX isolated. These results confirm that TMX and CLO appear to induce in vivo DA increased release in striatum of rats and it seems to be concentration dependent. Moreover, these results indicate that this effect might be related to nAChRs.