Bacterial and Viral Diversity of Didelphid Opossums from Brazil

Marsupials belonging to the Didelphis genus are widely distributed in the American Continent, and Didelphis albiventris and Didelphis aurita, are common in all of their areas of distribution in Brazil. Here we describe the bacterial and viral diversity of samples from opossums captured in three forest fragments in the State of São Paulo, Brazil. Microbiomes from the same body site were more similar across species and sampling sites while oral swabs presented higher bacterial diversity than rectal swabs. We also identified sequences related to bacterial species involved in zoonotic diseases. The detection of pathogens in such abundant mammal species warns for the possibility of emergence in other species.

Population genetic structure and phenotypic diversity of Aspidodera raillieti (Nematoda: Heterakoidea), a parasite of Didelphini marsupials in Brazil's South and Southeast Atlantic Forest

Background

The population genetics of parasites may be influenced by host specificity, life cycle, host geographical range, evolutionary history, and host population structure. The nematode Aspidodera raillieti infects different marsupial and rodent hosts in the Nearctic and Neotropical regions, implying a gene flow among populations. However, niche diversification of the main hosts of A. raillieti in superimposed areas may provide conditions for population genetic structuring within this parasite species. We examined the genetic structuring of A. raillieti infecting three marsupial species co-occurring along the South and Southeast Brazilian Atlantic Forest, a hotspot of biodiversity.

Methods

We employed morphometric analyses and partial mitochondrial cytochrome c oxidase I gene sequences (MT-CO1) to characterize populations via phylogenetic and phylogeographic analyses.

Results

Among 175 A. raillieti specimens recovered from the marsupial hosts Didelphis aurita, D. albiventris, and Philander quica, we identified 99 MT-CO1 haplotypes forming four haplogroups and four clades in networks and phylogenetic trees, respectively. Clades I and II encompassed parasites of D. albiventris from the South region, clade III comprised parasites of D. aurita from the South and Southeast regions, and clade IV encompassed parasites of D. aurita and D. albiventris from the South and Southeast regions and parasites of P. quica from the South region. High genetic differentiation between clades, with a high fixation index and greater genetic variation in the analysis of molecular variance (AMOVA), indicated low gene flow between clades. Haplotypes shared among host species revealed a lack of host specificity. A significant correlation in the Mantel test suggested parasite isolation by distance, while there was no evidence of geographical structure between populations. Negative neutrality test values for clades III and IV suggested recent population expansion. Morphometric differentiation between A. raillieti specimens recovered from different host species, as well as from different localities, was more evident in males.

Conclusion

The genetic structure of A. raillieti populations in the South and Southeast Atlantic Forest resulted from historical events rather than from current geographical distribution or host specificity. We also demonstrate morphometric variation associated with host species and localities, suggesting phenotypic plasticity to host attributes and to spatial variables.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05288-6.

Bioecological aspects of triatomines and marsupials as wild Trypanosoma cruzi reservoirs in urban, peri-urban and rural areas in the Western Brazilian Amazon

In the Amazon region, Trypanosoma cruzi transmission cycles involve a great diversity of Triatominae vectors and mammal reservoirs. Some Rhodnius spp. mainly inhabit palm trees that act as microhabitats for hosts and vectors. The current study aimed to describe aspects of the bio-ecology of the vectors and reservoirs of T. cruzi in relation to human populations resident near areas with large quantities of palm trees, in rural, peri-urban and urban collection environments, located in the Western Brazilian Amazon. Rhodnius pictipes and Didelphis marsupialis were respectively the most predominant vector and reservoir, with rates of 71% for R. pictipes and 96.5% for D. marsupialis. The vast majority of T. cruzi isolates clustered with TcI. The most prevalent haplotype was TcI COII1 (69.7%). Mauritia flexuosa and Attalea phalerata were the main ecological indicators of infestation by triatomines. Birds were the most common food source (27,71%). T. cruzi isolated from R. robustus has the haplotype HUM-13, previously detected in a chronic Chagas patient living in the same area. Our results demonstrate the relevance of this study, with the occurrence of elevated infection rates in animals, and suggest the importance of the Amazon zones where there is a risk of infection in humans.

Serological investigation of protozoan pathogens (Trypanosoma cruzi, Toxoplasma gondii and Neospora caninum) in opossums from southern Brazil

South American opossums of the order Didelphimorphia are considered sentinels for zoonotic infections and environmental diseases, such as for Chagas disease caused by Trypanosoma cruzi. Nevertheless, there is a paucity of data regarding protozoan diseases such Toxoplasma gondii and Neospora caninum in Neotropical marsupials; despite these pathogens have been considered threats to some marsupial species. The aim of this study was to determine whether Didelphis albiventris and Philander frenatus opossums from southern Brazil had been previously exposed to T. cruzi, T. gondii or N. caninum. Opossum samples were obtained by live-trapping of free-ranging animals and collection at wildlife rehabilitation centers in Rio Grande do Sul (RS) state, Brazil. The detection of anti-T. cruzi and anti-T. gondii antibodies was performed by indirect hemagglutination and anti-N. caninum antibodies by competitive enzyme-linked immunosorbent assay. In total, samples were collected from 76 marsupials from nine municipalities in RS state, including 69 D. albiventris (white-eared opossum), and seven were P. frenatus (southern four-eyed opossum). For T. cruzi, 11% were seropositive, and for T. gondii 26% were seropositive. None of the marsupials sampled here were seropositive for N. caninum. Risk factor analysis showed that free-living animals were about five-fold more likely to be infected by T. gondii than were rescued animals. Our study showed the exposure of Neotropical marsupials (D. albiventris and P. frenatus) to protozoan pathogens T. cruzi and T. gondii, while no evidence of N. caninum exposure was found. The set of results presented here may have an effect on ecology and conservation of the studied species and may also indicate possible sentinels of these pathogen circulation.

Surveillance of phlebotomine fauna and Didelphis marsupialis (Didelphimorphia: Didelphidae) infection in an area highly endemic for visceral leishmaniasis in Colombia

INTRODUCTION

The study of the interaction between the parasite, the vector and the mammalian hosts, including man, allows to understand the behavior of the leishmaniases.

OBJECTIVE

To determine the presence of Lutzomyia species and to detect the Leishmania infection in Didelphis marsupialis in an endemic area for visceral leishmaniasis.

MATERIALS AND METHODS

Phlebotomine fauna and individuals of D. marsupialis were collected with CDC and Tomahawk™ traps, respectively. The species of Lutzomyia were identified using the Young and Duncan key (1994). Ear and tail biopsies and blood samples from D. marsupialis were taken to identify the Leishmania species by amplifying a fragment of the gene associated with the 70 kD heat shock protein.

RESULTS

Seven Lutzomyia species were identified: Lu. evansi, Lu. gomezi, Lu. panamensis, Lu. dubitans, Lu. cayennensis cayennensis, Lu. rangeliana and Lu. trinidadensis. The first three species have epidemiological importance in Colombia because of their implications in the transmission of the Leishmania parasite. Sixty-five tissue samples from 19 D. marsupialis individuals were negative for Leishmania spp.

CONCLUSIONS

The presence of the Lutzomyia species that have been identified as vectors for Leishmania inside and around houses in the village of El Bledo, in El Carmen de Bolívar represents a risk of infection. Furthermore, the presence of Lu. panamensis is reported for first time in El Carmen de Bolívar in Colombia. Although the lack of detection of Leishmania spp. in D. marsupialis samples may suggest that D. marsupialis does not play an important role in the transmission cycle of Leishmania in this region, it is necessary to carry out further longitudinal studies to confirm this hypothesis.

COMPOSITION AND CHARACTERISTICS OF A DIVERSE DIDELPHID COMMUNITY (MAMMALIA: DIDELPHIMORPHIA) IN SUB-TROPICAL SOUTH AMERICA

Few studies have reported didelphid communities of ≥10 species, and all of these have been from within the tropics sensu stricto of South America. Herein a community of 12 species of didelphids is described from a sub-tropical site in south-central South America. The Reserva Natural del Bosque Mbaracayú, in northeastern Paraguay, lies at the western margin of the Interior Atlantic Forest and the southwestern limit of the Cerrado, two important South American ecoregions. The rich didelphid community in this area likely results from the mosaic of habitats encountered at the distributional limits of these two ecoregions. Within the context of this mosaic, the species' habitat associations and vertical occupancy are discussed, as well as the reproductive patterns and population abundance variation of the more commonly encountered species. Three Monodelphis species were found in sympatry, all strictly terrestrial, along with Cryptonanus chacoensis. Marmosa paraguayana shared all habitats with Gracilinanus agilis, and both of these species primarily were arboreal. Although this natural reserve has been more extensively sampled than any other area in Paraguay, numerous questions remain unanswered regarding this rich didelphid community.

Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial

Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann's, Allen's and Gloger's rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity size and pigmentation are related to the resource seasonality, heat conservation, and pathogen-resistance hypotheses, respectively. Our findings suggest that marsupials may be highly susceptible to environmental changes, and in the case of the Virginia opossum, the drastic phenotypic evolution in northern populations may have arisen rapidly, facilitating the colonization of seasonal and colder habitats of temperate North America.

Prevalence of Trypanosoma cruzi and organ alterations in Virginia opossums (Didelphis virginiana) from western Mexico - short communication

Small populations of Virginia opossum (Didelphis virginiana) in western Mexico are endangered by hunting and natural predators as well as by different kinds of diseases. After two serological analyses using Serodia® latex particle agglutination and indirect haemagglutination (IHA) tests, 35 (53.03%) of 66 collected opossums in two small towns in western Mexico were positive for the presence of Trypanosoma cruzi. Twenty-eight of the 35 seropositive opossums had pathological lesions: 11 had changes in only one organ, 13 in two organs, and four had pathological changes in three organs. Splenomegaly was the most common finding in the examined opossums, followed by hepatomegaly. These potentially fatal pathological changes could contribute to the scarcity of the opossum population, even leading to the extinction of this species in western Mexico.

Sarcocystis neurona and Neospora caninum in Brazilian opossums (Didelphis spp.): Molecular investigation and in vitro isolation of Sarcocystis spp

Sarcocystis neurona and Neospora spp. are protozoan parasites that induce neurological diseases in horses and other animal species. Opossums (Didelphis albiventris and Didelphis virginiana) are definitive hosts of S. neurona, which is the major cause of equine protozoal myeloencephalitis (EPM). Neospora caninum causes abortion in cattle and infects a wide range of animal species, while N. hughesi is known to induce neurologic disease in equids. The aims of this study were to investigate S. neurona and N. caninum in tissues from opossums in the northeastern Brazil, and to isolate Brazilian strains of Sarcocystis spp. from wild opossums for comparison with previously isolated strains. Carcasses of 39 opossums from Bahia state were available for molecular identification of Sarcocystis spp. and N. caninum in their tissues, and for sporocyst detection by intestinal scraping. In addition, Sarcocystis-like sporocysts from nine additional opossums, obtained in São Paulo state, were tested. Sarcocystis DNA was found in 16 (41%) of the 39 opossums' carcasses; N. caninum DNA was detected in tissues from three opossums. The sporocysts from the nine additional opossums from São Paulo state were tested by bioassay and induced infection in nine budgerigars, but in none of the gamma-interferon knockout mice. In vitro isolation was successful using tissues from all nine budgerigars. The isolated strains were maintained in CV-1 and Vero cells. Three of nine isolates presented contamination in cell culture and were discarded. Analysis of six isolates based on five loci showed that these parasites were genetically different from each other and also distinct from S. neurona, S. falcatula, S. lindsayi, and S. speeri. In conclusion, opossums in the studied regions were infected with N. caninum and Sarcocystis spp. and represent a potential source of infection to other animals. This is the first report of N. caninum infection in tissues from black-eared opossum (D. aurita or D. marsupialis) and white-eared opossum (D. albiventris). Brazilian opossums are probably infected by different Sarcocystis spp. distinct from S. neurona and S. falcatula, or present a high level of genetic recombination.

[Risk of transmission of Chagas disease by intrusion of triatomines and wild mammals in Bucaramanga, Santander, Colombia]

INTRODUCTION

Notice of triatomines in dwellings of some neighborhoods in Bucaramanga motivated the realization of this study.Objetive: To evaluate the intrusion of triatomines and mammals, as well as some risk factors in urban dwellings.

MATERIALS AND METHODS

Triatomines were collected in a neighborhood in Bucaramanga, Santander, on a monthly basis during one year with participation of the community. Collection included manual search in lamp posts, use of light traps, animal bait, and chemical attractants in nearby forests. Reservoirs were collected with bait traps. Insects and mammals were identified and examined in order to determine their natural infection. Risk factors in homes were assessed by means of a social-environmental survey.

RESULTS

Eleven adult specimens of Pastrongylus geniculatus, as well as 63 of Rhodnius pallescens were collected in the forest, recreational peridomiciliary areas, and houses. Even two females and 21 nymphs of R. pallescens were found in bedrooms. Two specimens of Didelphis marsupialis were captured in neighboring forests. Out of the eleven P. geniculatus captured, nine were examined. Of these, five were positive for Trypanosoma cruzi. It was not possible to establish a significant risk factor;however, the dwellings with report of triatomines were located nearer to the adjacent forest.

CONCLUSIONS

The finding of intrusive triatominae species and mammals with T. cruzi in intradomiciliary and peridomiciliary areas and periurban forests prove the potential risk to acquire infection from these populations that dwell in urban housing adjacent to these ecotopes where the sylvan cycle is kept.

The Herlyn-Werner-Wunderlich Syndrome - A Case Report with Radiological Review

Background

HWW syndrome is a very rare congenital anomaly of urogenital tract involving Mullerian ducts and mesonephric ducts. It is characterised by a triad of symptoms - uterus didelphys, obstructed hemivagina and ipsilateral renal agenesis. It can be classified based on a completely or incompletely obstructed hemivagina. It presents soon after menarche or shows delayed presentation depending on the type. It can exhibit acute pelvic pain shortly after menarche and may show non-specific and variable symptoms with resultant delay in diagnosis. The most common presentation is pain and dysmenorrhea, and pain and abdominal mass in the lower abdomen secondary to haematocolpos and/or haematometra.

Case Report

Presentation of a clinical case of a 13-year-old patient with HWW syndrome presenting with regular menses, dysmenorrhea and painful lump in hypogastric region on the left side of midline. We described the role of imaging modalities in diagnosis of the Herlyn-Werner-Wunderlich syndrome with a review of literature. USG and MRI showed left renal agenesis with compensatory hypertrophy of the right kidney, uterus didelphys with haematometra and haematocervix in the left uterus with evidence of blood in a dilated retort-shaped left fallopian tube and a normal right uterus. The unique feature of our case is haematometra and haematocervix with cervical and vaginal atresia found on the left side (classification 1.2) with associated left renal agenesis.

Conclusions

HWW syndrome can present early or late, depending on the type. In patients with uterine and vaginal abnormalities, a work-up for associated renal anomalies should be performed. Early intervention is needed to reduce the risk of endometriosis and infertility.