Massive invasion on a Triatominae insectarium (Hemiptera: Heteroptera: Reduviidae) by Attagenus fasciatus (Thunberg, 1795) (Coleoptera: Dermestidae: Attageninae)

ABSTRACT Background: Triatominae are vectors of the protozoan Trypanosoma cruzi, the causative agent of Chagas disease. This study aims to report an infestation on Triatominae colonies by a beetle, previously identified as a pest. Methods: The management of these colonies should be improved to maximize their usefulness, and factors that may cause harm to them should be avoided as much as possible. Results: This is the first report on a coleopteran infestation on living Triatominae colonies worldwide. Conclusions: The present record provides an important warning to researchers who maintain insectaries in general, especially those who rear triatomines, to carry protective measures against such invasions.

Occurrence of triatomines in public spaces: An atypical case in the Southwestern Brazilian Amazon

ABSTRACT Background: Triatomines infest atypical public spaces in the Western Amazon. Methods: Frequent visitors to these spaces captured the insects in the state of Acre, Brazil (Rio Branco and Cruzeiro do Sul). Results: Six insects were found in a penitentiary, a church, a school, a university, a hospital, and a health center. Five of the insects were adults (three positive for Trypanosoma cruzi) and one was a nymph. Conclusions: This is the first report of triatomine occurrence in schools or churches. These data are important for implementing surveillance strategies and alerting individuals about possible changes in Chagas disease transmission dynamics.

Hydroxymethylnitrofurazone (NFOH) decreases parasitaemia, parasitism and tissue lesion caused by infection with the Bolivia Trypanosoma cruzi type I strain in Swiss and C57BL/6 mice

Abstract The chemical hydroxymethylation of the antimicrobial nitrofurazone leads to the prodrug NFOH, also increases the anti-T. cruzi activities (in vitro and in vivo), as well as showed non-genotoxic (Ames and micronucleus assays). In the present study, we assessed the anti-T. cruzi effect of the NFOH In vivo - in acute Swiss and C57Bl/6 experimental Chagas models. The treatment started at 5 days post-infection during 20 consecutive days (orally, once day, 150mg/kg), and the parasitaemia as well as histopathology analysis were performed. In both experimental murine models, NFOH was able to reduce parasitemia blood avoiding parasitic reactivation, during immunosuppression period (dexamethasone 5mg/kg, 14 days), in 100% of the mice, and decrease tissue parasite nests, demonstrating absence of amastigote forms in all organs (100%) analyzed, data similar to benznidazole (BZN). Therefore, the results shown here pointing to the NFOH as promising compound for further preclinical studies, being a high potential drug to effective and safe chemotherapy to Chagas disease.

First report of Rhodnius montenegrensis (Hemiptera: Reduviidae: Triatominae) in Bolivia

ABSTRACT Background: The subfamily Triatominae, which comprises 157 species, carries the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. This short communication reports for the first time the occurrence of Rhodnius montenegrensis in Bolivia. Methods: Active searches were carried out on palm trees of the genus Oenocarpus in Beni district, Bolivia. Results: Fifteen R. montenegrensis specimens were collected from a rural area of the Beni district, Bolivia, and tested positive for T. cruzi. Conclusions: This new report expands the geographic distribution of the species in Latin America. Due to their ability to transmit trypanosomatids, the species deserves the attention of vector control programs.

Triatominae (Hemiptera, Reduviidae) in homes: Report of their occurrence in the municipality of Cruzeiro do Sul, Acre, South Western Amazon

Abstract INTRODUCTION: Triatomines are hematophagous insects that are important to public health since they are the vectors of American Trypanosomiasis. The objective of this study was to describe the occurrence of triatomines in homes in Cruzeiro do Sul, Acre, Brazil. METHODS The specimens were collected by an active search inside homes and also by a passive search by the residents. RESULTS: A total of 55 triatomines were captured comprising of 5 species each of the genera Rhodnius, Eratyrus, and Panstrongylus. No colonies were detected, ruling out the possibility of domiciliation. CONCLUSIONS: Information on regional epidemiological dynamics contributes to the prevention and control of disease.

Occurrence of triatomines (Hemiptera, Reduviidae) and their natural infection by Trypanosoma cruzi (Chagas, 1909) in Boca do Moa community, Cruzeiro do Sul, Acre, Brazil

Abstract INTRODUCTION: Triatomines are insect vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. METHODS: Triatomines were collected from households and by dissecting palm trees in the peri-urban areas of Cruzeiro do Sul (Acre); they were identified using a specific key and via genital analyses. Trypanosomatid infection was determined through microscopy and polymerase chain reaction. RESULTS: In total, 116 triatomines of the species Eratyrus mucronatus, Rhodnius pictipes, R. stali, and R. montenegrensis were collected, of which 13.8% were positive for T. cruzi. CONCLUSIONS: Four species of triatomines presented an infection rate above 13% in the Boca do Moa community.

Confirmation of the first report of Psammolestes tertius Lent and Jurberg, 1965 (Hemiptera, Reduviidae, Triatominae) in Paraná State, Brazil

Abstract INTRODUCTION This study confirms the occurrence of Psammolestes tertius Lent & Jurberg, 1965 (Hemiptera, Reduviidae, Triatominae) in the state of Paraná, Brazil. METHODS: In 2002, a male specimen of P. tertius was collected in the municipality of Porto Rico, Paraná, Brazil. RESULTS: This finding adds to the data on the geographical distribution of P. tertius from 14 to 15 known occurrences in Brazilian states and, therefore, reports the increase in the diversity of triatomines in Paraná. CONCLUSIONS: The presence of P. tertius in the state of Paraná demonstrates that the biodiversity of these insects may have been underestimated.

Psammolestes tertius Lent & Jurberg, 1965 (Hemiptera, Reduviidae, Triatominae): first report in Sergipe State, Brazil

Abstract INTRODUCTION: This study reports the first occurrence of Psammolestes tertius (Hemiptera, Reduviidae, Triatominae) in the state of Sergipe, Brazil. METHODS: In 2020, 95 specimens were collected from the municipality of Porto da Folha, Sergipe, Brazil. RESULTS: This finding expands the geographical distribution of the species from 15 states in Brazil to 16 and increases the biodiversity of triatomines in the state of Sergipe. CONCLUSIONS: The presence of P. tertius in the state of Sergipe demonstrated a wider distribution of this species in northeastern Brazil.

Differentiation of Rhodnius neglectus and Rhodnius prolixus (Hemiptera: Reduviidae: Triatominae) by multiple parameters

Abstract Introduction: The genus Rhodnius in the subfamily Triatominae comprises 20 species, which can transmit Trypanosoma cruzi and Trypanosoma rangeli. Due to the development of molecular techniques, Triatominae species can now be characterized by mitochondrial and nuclear markers, making it possible to verify and/or correct the existing data on these species. The results achieved in this study provide a more detailed and accurate differentiation of the Rhodnius species, helping the establishment of a more appropriate classification. Methods: Data collection was performed by DNA analysis, morphological and morphometric studies to distinguish four populations of R. neglectus and four of R. prolixus. Phylogenetic data were compared to morphological and morphometric data. Results: The analysis of Cytb fragments suggests that the four colonies designated to Rhodnius neglectus as well as those of R. prolixus were correctly identified. Conclusions: The morphological characters observed in the specimens of the colonies originally identified as R. prolixus and R. neglectus, such as the presence or absence of collar in the eggs, the patterns of the median process of the pygophore, and anterolateral angle, are consistent with the species. Geometric morphometrics also show an intraspecific variability in R. prolixus.

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in Amazonas, Brazil

Abstract INTRODUCTION: Triatomines are hematophagous insects of epidemiological importance because they are vectors of Chagas disease. We present here the first report of Rhodnius montenegrensis in Amazonas, Brazil. METHODS: Triatomines were collected from Attalea butyracea palm trees in the municipality of Guajará. RESULTS: Two adult female R. montenegrensis specimens were identified. CONCLUSIONS: The present study confirms that the number of triatomine species within the Amazon has increased from 10 to 11, and the number of Brazilian states with R. montenegrensis has increased from two to three.

Occurrence of triatomines in an urban residential complex in the municipality of Rio Branco, Acre, South-Western Amazon

Abstract INTRODUCTION: This study describes the occurrence of triatomines, and their positivity for trypanosomatids, in a residential complex in Rio Branco, Acre, Brazil. METHODS: Triatomines were collected through direct capture in a home environment. Positivity analysis for trypanosomatids was performed by PCR assays. RESULTS Collected insects consisted of 31 Rhodnius robustus, 4 Rhodnius montenegrensis, and 1 Panstrongylus geniculatus specimens. All were adults, with no presence of domiciliation, and with an infection rate of 30.6%. CONCLUSIONS Future studies are recommended in other locations of Rio Branco in order to develop a georeference database of the occurrence of triatomines in urban areas.

First report of Rhodnius neglectus (Hemiptera, Reduviidae, Triatominae) from the State of Acre, Brazil, and the Brazilian Western Amazon Region

Abstract INTRODUCTION This communication reports the occurrence of Rhodnius neglectus in the State of Acre, Brazil. METHODS An adult male R. neglectus specimen was collected from the Catuaba Experimental Reserve, which is located in the municipality of Senador Guiomard. RESULTS This increases the number of triatomine species reported from the State of Acre to eight and is also the first report of R. neglectus from the Brazilian Western Amazon Region. CONCLUSIONS The occurrence of R. neglectus is alarming because even though the species is wild, it can invade and colonize human dwellings and peridomiciles, thereby increasing Chagas disease transmission.

Response to different benznidazole doses in animal models of chronic phase Chagas disease: a critical review

Abstract Chagas disease is a protozoan infection that was identified over a century ago. No drugs are available to treat the indeterminate and determinate chronic phases of the disease. Success of a drug design is dependent on correct biological evaluation. Concerning new drug designs for Chagas disease, it is essential to first identify the most effective, existing, experimental chronic protocols that can be used for comparison purposes. Here, we present a literature review regarding experimental models with chronic Chagas disease to evaluate the efficacy of benznidazole (BZN). We searched literature published in PubMed and Web of Science databases, using these keywords: animal model, BZN, Chagas disease, T. cruzi, and chronic phase, with no timeframe limitations. We excluded articles involving acute phase animal models and/or those without BZN treatment. The selected studies were conducted using different BZN concentrations (10mg-100mg) involving several different periods (5-70 days). Concentrations and durations of use are directly related to side effects, but do not prevent chronic tissue lesions. BZN use during the late/chronic phases of Chagas disease is unable to eliminate amastigote forms present in infected tissues. This study suggests the administration of a lower BZN concentration (<100mg/kg/day) during the chronic phase of the animal model, as this had been reported to result in fewer side effects.

First report of Triatoma sordida Stål, 1859 (Hemiptera, Reduviidae, Triatominae) in the State of Acre and Brazilian Western Amazon

Abstract INTRODUCTION The occurrence of Triatoma sordida in the Brazilian Western Amazon is reported for the first time. METHODS Triatoma sordida specimens were collected from a Gallus gallus nest in a peridomiciliary area of Senador Guiomard municipality in the state of Acre. RESULTS The number of triatomine species in Acre increased from six to seven with this first report of T. sordida in the Brazilian Western Amazon. CONCLUSIONS The occurrence of T. sordida in Acre is of concern since it is among the most captured triatomines in peridomiciliary environments in Brazil, and carries a high potential for vector transmission.

Rhodnius stali: new vector infected by Trypanosoma rangeli (Kinetoplastida, Trypanosomatidae)

Abstract INTRODUCTION Rhodnius stali infection by Trypanosoma rangeli is reported in this study for the first time. METHODS The triatomines were collected from the campus of the Federal University of Acre in Rio Branco, Acre, Brazil. The identification of T. rangeli was confirmed by multiplex polymerase chain reaction. RESULTS The examinations of two specimens revealed R. stali infection by the epimastigote forms of T. rangeli. CONCLUSIONS The encounter of R. stali infected by T. rangeli generates an alert for the state of Acre, since the simultaneous presence with Trypanosoma cruzi can make the differential diagnosis of Chagas disease difficult.

Trypanosoma cruzi isolated from a triatomine found in one of the biggest metropolitan areas of Latin America

Abstract: INTRODUCTION: To characterize Trypanosoma cruzi (TcI) isolated from a Panstrongylus megistus specimen found in one of the biggest metropolitan areas of Latin America, the relationship between the TcI group of T. cruzi and the transmission cycle in the urban environment was studied. METHODS: The T. cruzi strain, Pm, was isolated in a culture medium from the evolutionary forms present in the hindgut of a live male specimen of P. megistus found in the Jabaquara subway in São Paulo City. The sample from the triatomine showed trypomastigote forms of Trypanosomatidae, which were inoculated in the peritoneum of Balb/c mice. The sample was then inoculated in Liver Infusion Tryptose medium and J774 cells for the molecular identification and characterization of the parasite. The Pm strain of T. cruzi was identified by isolation in axenic culture medium, and based on the morphology, cell infection, growth kinetics, and molecular characterization. RESULTS: After isolation, the protozoan was identified as T. cruzi. No parasites were detected in the peripheral blood of the animal, which can be a characteristic inherent to the strain of T. cruzi that was isolated. Cell invasion assays were performed in triplicate in the J774 cell line to confirm the invasive ability of the Pm strain and revealed amastigote forms of the parasite within macrophages. CONCLUSIONS: Our biological and molecular characterizations helped understand parasite-host interactions and their evolutionary history in context of the associations between vectors, ecotopes, hosts, and groups of the parasite.

First report of Rhodnius montenegrensis (Hemiptera, Reduviidae, Triatominae) in the State of Acre, Brazil

This paper reports, for the first time, the presence of Rhodnius montenegrensis in the State of Acre, Brazil.

Coloration of the testicular peritoneal sheath as a synapomorphy of triatomines (Hemiptera, Reduviidae) / Coloração da bainha peritoneal testicular como uma sinapomorfia dos triatomíneos (Hemiptera, Reduviidae)

Recently, were described some morphological characteristics of 18 species of terrestrial hemipteran grouped in the Alydidae, Coreidae, Corimelaenidae, Lygaeidae, Rhopalidae, Scutelleridae, Tingidae and Reduviidae family that presented found variation in coloration of testicular peritoneal sheath (Reddish, Orange, Yellowish or Transparent). Thus, this study aims to analyzed the coloration of the peritoneal sheath in 44 species of triatomines grouped in nine different genera, with the aim of analyze whether the insects of the Triatominae subfamily also show variations in coloration. By means of analysis of the sheath was possible to observe that members of this subfamily have no interspecific differences, because all species have a transparent sheath. Thus, this paper describes the coloring of the peritoneal sheath in 44 species of the subfamily Triatominae and mainly suggests that the transparent color is one synapomorphy of this important group of insect vectors.

Recentemente, foram descritas algumas características morfológicas de 18 espécies de hemípteros terrestres agrupados nas famílias Alydidae, Coreidae, Corimelaenidae, Lygaeidae, Rhopalidae, Scutelleridae, Tingidae e Reduviidae que apresentaram grandes variações na coloração da bainha peritonial testicular (avermelhada, alaranjada, amarelada ou transparente). Assim, este estudo teve como objetivo analisar a coloração da bainha peritoneal em 44 espécies de triatomíneos agrupadas em nove gêneros diferentes, com o intuito de analisar se os insetos da subfamília Triatominae também apresentam variações na coloração da bainha. Por meio da análise da bainha, foi possível observar que os membros desta subfamília não apresentaram diferenças interespecíficas, pois todas as espécies analisadas possuem bainha transparente. Assim, o presente trabalho descreve a coloração da bainha peritoneal em 44 espécies da subfamília Triatominae e, principalmente, sugere que a cor transparente é uma sinapomorfia deste importante grupo de insetos vetores.

Trypanosoma cruzi strains from triatomine collected in Bahia and Rio Grande do Sul, Brazil / Trypanosoma cruzi isolado de triatomíneos coletados na Bahia e Rio Grande do Sul

OBJECTIVE Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship. .

OBJETIVO Isolar cepas de Trypanosoma cruzi em triatomíneos capturados nos ambientes domiciliar, peridomiciliar e silvestre da Bahia e do Rio Grande do Sul. MÉTODOS Os triatomíneos capturados nos estados da Bahia e Rio Grande do Sul foram identificados por meio de chaves entomológicas. O conteúdo intestinal foi examinado por compressão abdominal e as amostras que continham formas de Trypanosomatidae foram inoculadas em meio de cultura Liver Infusion Tryptose e em camundongos Swiss. RESULTADOS Foram identificadas seis espécies de triatomíneos nas coletas realizadas em municípios do Estado da Bahia: Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) e T. sordida (460), e duas no Estado do Rio Grande do Sul: T. circummaculata (11) e T. rubrovaria (115). Dos exemplares examinados, T. cruzi foi isolado de 28 triatomíneos pertencentes a quatro espécies: T. melanocephala (uma), T. lenti (uma), T. rubrovaria (16) e T. sordida (10). O índice de infecção natural de triatomíneos por T. cruzi foi de 6,4%. CONCLUSÕES O isolamento de cepas de T. cruzi em triatomíneos encontrados no intra e peridomicílio reflete o potencial risco de transmissão da doença de Chagas nos municípios estudados. .

Análise das possíveis regiões organizadoras nucleolares e da atividade nucleolar em Triatoma melanocephala e T. lenti, importantes vetores da doença de Chagas / Analysis of nucleolus organizer regions and nucleolar activity in important vectors of Chagas disease (Triatoma melanocephala and T. lenti)

Triatoma melanocephalae T. lentisão espécies crípticas de triatomíneos pertencentes ao subcomplexo Brasiliensis. Esses organismos foram agrupados no subcomplexo apenas por caracteres morfológicos e pela disposição geográfica. Sendo assim, estudos citogenéticos são considerados como importantes ferramentas na classificação dos triatomíneos e, com isso, podem auxiliar na criação de um plano de profilaxia da doença. Por meio da técnica citogenética de impregnação por íons prata, foi possível visualizar a atividade nucleolar e as Regiões Organizadoras Nucleolares (RONs) desses insetos. T. melanocephala apresentou três RONs ativas nos autossomos durante a prófase I. T. lenti apresentou duas RONs ativas nos autossomos durante a prófase I e a metáfase I. Ambas as espécies apresentaram o fenômeno de persistência do material nucleolar encontrado em triatomíneos. Sendo assim, por meio da análise das RONs, foi possível observar que T. lenti, quando comparado com os outros organismos do subcomplexo, apresentou marcações semelhantes à T. tibiamaculata e que T. melanocephala não apresenta nenhuma relação direta com o subcomplexo.

Triatoma melanocephala and T. lenti are important vectors of Chagas disease. These cryptic species of triatomines are grouped in the subcomplex brasiliensis due only to morphological characters and geographical distribution. Cytogenetic studies are important to the classification of insects and can assist in creating a disease prevention plan. The aim of the present study was to determine nucleolar activity and nucleolus organizer regions (NORs) in these insects using the cytogenetic method of silver ion impregnation. T. melanocephala exhibited three active NORs in autosomes during prophase I. T. lentiexhibited two active NORs in autosomes during prophase I and metaphase I. Both species exhibit the persistent nucleolar material found in triatomines. The analysis of NORs in the present study revealed that T. lentiexhibited labeling similar to that found in T. tibiamaculata, which belongs to the subcomplex, whereas T. melanocephala shows no direct relationship with the subcomplex.