scholarly journals Disentangling Trypanosoma cruzi transmission cycle dynamics through the identification of blood meal sources of natural populations of Triatoma dimidiata in Yucatán, Mexico

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Joel Israel Moo-Millan ◽  
Audrey Arnal ◽  
Silvia Pérez-Carrillo ◽  
Anette Hernandez-Andrade ◽  
María-Jesús Ramírez-Sierra ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Blood Meal ◽  
Control Strategies ◽  
Yucatan Peninsula ◽  
Universal Primers ◽  
Effective Control ◽  
Transmission Cycle ◽  
Yucatán Peninsula ◽  
Transmission Cycles ◽  
Blood Meals

Abstract Background In the Yucatán Peninsula, Mexico, Triatoma dimidiata is the main vector of Trypanosoma cruzi, the causative agent of Chagas disease. Little effort has been made to identify blood meal sources of T. dimidiata in natural conditions in this region, although this provides key information to disentangle T. cruzi transmission cycles and dynamics and guide the development of more effective control strategies. We identified the blood meals of a large sample of T. dimidiata bugs collected in different ecotopes simultaneously with the assessment of bug infection with T. cruzi, to disentangle the dynamics of T. cruzi transmission in the region. Methods A sample of 248 T. dimidiata bugs collected in three rural villages and in the sylvatic habitat surrounding these villages was used. DNA from each bug midgut was extracted and bug infection with T. cruzi was assessed by PCR. For blood meal identification, we used a molecular assay based on cloning and sequencing following PCR amplification with vertebrate universal primers, and allowing the detection of multiple blood meals in a single bug. Results Overall, 28.7% of the bugs were infected with T. cruzi, with no statistical difference between bugs from the villages or from sylvatic ecotopes. Sixteen vertebrate species including domestic, synanthropic and sylvatic animals, were identified as blood meal sources for T. dimidiata. Human, dog and cow were the three main species identified, in bugs collected in the villages as well as in sylvatic ecotopes. Importantly, dog was highlighted as the main blood meal source after human. Dog was also the most frequently identified animal together with human within single bugs, and tended to be associated with the infection of the bugs. Conclusions Dog, human and cow were identified as the main mammals involved in the connection of sylvatic and domestic transmission cycles in the Yucatán Peninsula, Mexico. Dog appeared as the most important animal in the transmission pathway of T. cruzi to humans, but other domestic and synanthropic animals, which most were previously reported as important hosts of T. cruzi in the region, were evidenced and should be taken into account as part of integrated control strategies aimed at disrupting parasite transmission.

scholarly journals Triatomine Feeding Profiles and Trypanosoma cruzi Infection, Implications in Domestic and Sylvatic Transmission Cycles in Ecuador

Pathogens ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 42
Author(s):  
Sofía Ocaña-Mayorga ◽  
Juan José Bustillos ◽  
Anita G. Villacís ◽  
C. Miguel Pinto ◽  
Simone Frédérique Brenière ◽  
...  
Keyword(s):  
Blood Meal ◽  
Mitochondrial Gene ◽  
Intestinal Content ◽  
Human Infection ◽  
Dispersal Capacity ◽  
Transmission Cycle ◽  
Rhodnius Ecuadoriensis ◽  
Transmission Cycles ◽  
Endemic Areas ◽  
Southern Highland

Understanding the blood meal patterns of insects that are vectors of diseases is fundamental in unveiling transmission dynamics and developing strategies to impede or decrease human–vector contact. Chagas disease has a complex transmission cycle that implies interactions between vectors, parasites and vertebrate hosts. In Ecuador, limited data on human infection are available; however, the presence of active transmission in endemic areas has been demonstrated. The aim of this study was to determine the diversity of hosts that serve as sources of blood for triatomines in domestic, peridomestic and sylvatic transmission cycles, in two endemic areas of Ecuador (central coastal and southern highland regions). Using conserved primers and DNA extracted from 507 intestinal content samples from five species of triatomines (60 Panstrongylus chinai, 17 Panstrongylus howardi, 1 Panstrongylus rufotuberculatus, 427 Rhodnius ecuadoriensis and 2 Triatoma carrioni) collected from 2006 to 2013, we amplified fragments of the cytb mitochondrial gene. After sequencing, blood meal sources were identified in 416 individuals (146 from central coastal and 270 from southern highland regions), achieving ≥ 95% identity with GenBank sequences (NCBI-BLAST tool). The results showed that humans are the main source of food for triatomines, indicating that human–vector contact is more frequent than previously thought. Although other groups of mammals, such as rodents, are also an available source of blood, birds (particularly chickens) might have a predominant role in the maintenance of triatomines in these areas. However, the diversity of sources of blood found might indicate a preference driven by triatomine species. Moreover, the presence of more than one source of blood in triatomines collected in the same place indicated that dispersal of vectors occurs regardless the availability of food. Dispersal capacity of triatomines needs to be evaluated to propose an effective strategy that limits human–vector contact and, in consequence, to decrease the risk of T. cruzi transmission.

scholarly journals Comparison of small mammal prevalence of Leishmania (Leishmania) mexicana in five foci of cutaneous leishmaniasis in the State of Campeche, Mexico

2009 ◽  
Vol 51 (2) ◽  
pp. 87-94 ◽  
Author(s):  
N.R. Van Wynsberghe ◽  
S.B. Canto-Lara ◽  
E.I. Sosa-Bibiano ◽  
N.A. Rivero-Cárdenas ◽  
F.J. Andrade-Narváez
Keyword(s):  
Cutaneous Leishmaniasis ◽  
Yucatan Peninsula ◽  
The State ◽  
Control Measures ◽  
Effective Control ◽  
Leishmania Mexicana ◽  
Wild Rodents ◽  
Terrestrial Mammals ◽  
Yucatán Peninsula ◽  
Reservoir Species

In the Yucatan Peninsula of Mexico, 95% of the human cases of Cutaneous Leishmaniasis are caused by Leishmania (Leishmania) mexicana with an incidence rate of 5.08 per 100,000 inhabitants. Transmission is limited to the winter months (November to March). One study on wild rodents has incriminated Ototylomys phyllotis and Peromyscus yucatanicus as primary reservoirs of L. (L.) mexicana in the focus of La Libertad, Campeche. In the present study, the prevalence of both infection and disease caused by L. (L.) mexicana in small terrestrial mammals were documented during five transmission seasons (1994-2004) in five foci of Leishmaniasis in the state of Campeche. Foci separated by only 100 km, with similar relative abundances of small mammals, were found to differ significantly in their prevalence of both symptoms and infection. Transmission rates and reservoir species seemed to change in space as well as in time which limited the implementation of effective control measures of the disease even in a small endemic area such as the south of the Yucatan Peninsula.

scholarly journals Genetic diversity of Trypanosoma cruzi parasites infecting dogs in southern Louisiana sheds light on parasite transmission cycles and serological diagnostic performance

2020 ◽  
Vol 14 (12) ◽  
pp. e0008932
Author(s):  
Eric Dumonteil ◽  
Ardem Elmayan ◽  
Alicia Majeau ◽  
Weihong Tu ◽  
Brandy Duhon ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Trypanosoma Cruzi ◽  
Test Performance ◽  
Serological Test ◽  
Parasite Transmission ◽  
Parasite Diversity ◽  
Serological Tests ◽  
Transmission Cycle ◽  
Southern Us ◽  
Transmission Cycles

Background Chagas disease is a neglected zoonosis of growing concern in the southern US, caused by the parasite Trypanosoma cruzi. We genotyped parasites in a large cohort of PCR positive dogs to shed light on parasite transmission cycles and assess potential relationships between parasite diversity and serological test performance. Methodology/principal findings We used a metabarcoding approach based on deep sequencing of T. cruzi mini-exon marker to assess parasite diversity. Phylogenetic analysis of 178 sequences from 40 dogs confirmed the presence of T. cruzi discrete typing unit (DTU) TcI and TcIV, as well as TcII, TcV and TcVI for the first time in US dogs. Infections with multiple DTUs occurred in 38% of the dogs. These data indicate a greater genetic diversity of T. cruzi than previously detected in the US. Comparison of T. cruzi sequence diversity indicated that highly similar T. cruzi strains from these DTUs circulate in hosts and vectors in Louisiana, indicating that they are involved in a shared T. cruzi parasite transmission cycle. However, TcIV and TcV were sampled more frequently in vectors, while TcII and TcVI were sampled more frequently in dogs. Conclusions/significance These observations point to ecological host-fitting being a dominant mechanism involved in the diversification of T. cruzi-host associations. Dogs with negative, discordant or confirmed positive T. cruzi serology harbored TcI parasites with different mini-exon sequences, which strongly supports the hypothesis that parasite genetic diversity is a key factor affecting serological test performance. Thus, the identification of conserved parasite antigens should be a high priority for the improvement of current serological tests.

Landscape ecology of Trypanosoma cruzi in the southern Yucatan Peninsula

Acta Tropica ◽  
2015 ◽  
Vol 151 ◽  
pp. 58-72 ◽  
Author(s):  
Sury Antonio López-Cancino ◽  
Ezequiel Tun-Ku ◽  
Himmler Keynes De la Cruz-Felix ◽  
Carlos Napoleón Ibarra-Cerdeña ◽  
Amaia Izeta-Alberdi ◽  
...  
Keyword(s):  
Landscape Ecology ◽  
Trypanosoma Cruzi ◽  
Yucatan Peninsula ◽  
Yucatán Peninsula

scholarly journals Diversity and interactions among triatomine bugs, their blood feeding sources, gut microbiota and Trypanosoma cruzi in the Sierra Nevada de Santa Marta in Colombia

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Claribel Murillo-Solano ◽  
Jaime López-Domínguez ◽  
Rafael Gongora ◽  
Andres Rojas-Gulloso ◽  
Jose Usme-Ciro ◽  
...  
Keyword(s):  
Rural Communities ◽  
Gut Microbiota ◽  
Trypanosoma Cruzi ◽  
Sierra Nevada ◽  
Disease Ecology ◽  
Control Strategies ◽  
Blood Feeding ◽  
Vector Species ◽  
Transmission Cycle ◽  
Feeding Sources

AbstractChagas disease remains a major neglected disease in Colombia. We aimed to characterize Trypanosoma cruzi transmission networks in the Sierra Nevada de Santa Marta (SNSM) region, to shed light on disease ecology and help optimize control strategies. Triatomines were collected in rural communities and analyzed for blood feeding sources, parasite diversity and gut microbiota composition through a metagenomic and deep sequencing approach. Triatoma dimidiata predominated, followed by Rhodnius prolixus, Triatoma maculata, Rhodnius pallescens, Panstrongylus geniculatus and Eratyrus cuspidatus. Twenty-two species were identified as blood sources, resulting in an integrated transmission network with extensive connectivity among sylvatic and domestic host species. Only TcI parasites were detected, predominantly from TcIb but TcIa was also reported. The close relatedness of T. cruzi strains further supported the lack of separate transmission cycles according to habitats or triatomine species. Triatomine microbiota varied according to species, developmental stage and T. cruzi infection. Bacterial families correlated with the presence/absence of T. cruzi were identified. In conclusion, we identified a domestic transmission cycle encompassing multiple vector species and tightly connected with sylvatic hosts in the SNSM region, rather than an isolated domestic transmission cycle. Therefore, integrated interventions targeting all vector species and their contact with humans should be considered.

scholarly journals Hosts and vectors of Trypanosoma cruzi discrete typing units in the Chagas disease endemic region of the Paraguayan Chaco

Parasitology ◽  
2017 ◽  
Vol 144 (7) ◽  
pp. 884-898 ◽  
Author(s):  
NIDIA ACOSTA ◽  
ELSA LÓPEZ ◽  
MICHAEL D. LEWIS ◽  
MARTIN S. LLEWELLYN ◽  
ANA GÓMEZ ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Chagas Disease ◽  
Control Strategies ◽  
Triatoma Infestans ◽  
Effective Control ◽  
Primary Role ◽  
Endemic Region ◽  
Triatomine Bugs ◽  
Chaco Region ◽  
Euphractus Sexcinctus

SUMMARYActive Trypanosoma cruzi transmission persists in the Gran Chaco region, which is considered hyperendemic for Chagas disease. Understanding domestic and sylvatic transmission cycles and therefore the relationship between vectors and mammalian hosts is crucial to designing and implementing improved effective control strategies. Here we describe the species of triatomine vectors and the sylvatic mammal reservoirs of T. cruzi, in different localities of the Paraguayan and Bolivian Chaco. We identify the T. cruzi genotypes discrete typing units (DTUs) and provide a map of their geographical distribution. A total of 1044 triatomines and 138 sylvatic mammals were captured. Five per cent of the triatomines were microscopically positive for T. cruzi (55 Triatoma infestans from Paraguay and one sylvatic Triatoma guasayana from Bolivia) and 17 animals (12·3%) comprising eight of 28 (28·5%) Dasypus novemcinctus, four of 27 (14·8%) Euphractus sexcinctus, three of 64 (4·7%) Chaetophractus spp. and two of 14 (14·3%) Didelphis albiventris. The most common DTU infecting domestic triatomine bugs was TcV (64%), followed by TcVI (28%), TcII (6·5%) and TcIII (1·5%). TcIII was overwhelmingly associated with armadillo species. We confirm the primary role of T. infestans in domestic transmission, armadillo species as the principal sylvatic hosts of TcIII, and consider the potential risk of TcIII as an agent of Chagas disease in the Chaco.

scholarly journals First Report of Twig Canker on Peach Caused by Phomopsis amygdali in China

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 288-288 ◽  
Author(s):  
F. M. Dai ◽  
R. Zeng ◽  
J. P. Lu
Keyword(s):  
Control Strategies ◽  
Morphological Characteristics ◽  
Universal Primers ◽  
Effective Control ◽  
Fluorescent Light ◽  
First Report ◽  
Ctab Method ◽  
Pcr Products ◽  
Dna Fragment ◽  
Potato Sucrose Agar

During May and June of 2009, canker and twig dieback were observed with 30 to 40% incidence in trees in one peach orchard in Nanhui of Shanghai (cv. YuLu juicy peach) and one orchard (cv. JingXiu yellow peach) in Jiaxin of Zhejiang Province, China. Cankers were generally centrally positioned on the nodes at the base of shoots with sunken, reddish brown/tan-to-silver symptoms. Blight was also observed on a few shoots (1). Five samples were collected from each orchard and isolations were conducted on potato sucrose agar (PSA). Ten isolates were obtained and all had white mycelia on PSA. Black pycnidia, formed in culture, produced two types of conidia: hyaline, fusiform alpha conidia and hyaline, string-like beta conidia. Alpha conidia varied from 5.0 to 6.3 × 1.5 to 2.5 μm and beta conidia ranged from 20 to 25 × 1.2 to 1.5 μm. Morphological characteristics suggested the identity of the fungal isolates to be Phomopsis amygdali. To confirm pathogenicity, an inoculum suspension was made from one isolate (106 conidia/ml) and was sprayed until runoff onto five twigs with buds. Inoculated twigs were maintained at 26°C and 100% relative humidity in a growth chamber with a 12-h period of fluorescent light daily. Twigs inoculated with sterilized water were included as noninoculated controls. After 4 days, dark brown lesions appeared around buds on inoculated twigs. No symptoms were observed on the control twigs. Constriction cankers were reproduced and P. amygdali was reisolated from the lesions. To confirm the identity of the pathogen, total genomic DNA was extracted with the cetyltrimethylammoniumbromide (CTAB) method from the mycelia of two isolates from YuLu juicy peach and Jinxiu yellow peach (2). PCR was performed with universal primers ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) to amplify a DNA fragment of approximately 550 bp. The PCR products were purified and sequenced in both directions (Sangon Biotech (Shanghai) Co., Ltd., China). The sequences (GenBank Accession Nos. HQ632013 and HQ632014) shared 98.9% identity with each other (MegAlign software; DNASTAR, Madison, WI). A comparison of these two sequences with those in GenBank showed that the sequences had the highest nucleotide similarity (99%) with P. amygdali isolate FAU1052 from peach in the southeastern United States (Accession No. AF102998). To our knowledge, this is the first report of P. amygdali causing twig canker on peach in China and will provide useful information for developing effective control strategies. References: (1) D. F. Farr et al. Mycologia 91:1008, 1999. (2) M. A. Saghai-Maroof et al. Proc. Natl. Acad. Sci. USA. 81:8014, 1984.

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