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This study longitudinally investigated the association between Triatoma dimidiata infestation, triatomine infection with Trypanosoma cruzi and household/backyard environmental characteristics in 101 homesteads in Molas and Yucatan, Mexico, between November 2009 (rainy season) and May 2010 (dry season). Logistic regression models tested the associations between insect infestation/infection and potential household-level risk factors. A total of 200 T. dimidiata were collected from 35.6% of the homesteads, mostly (73%) from the peridomicile. Of all the insects collected, 48% were infected with T. cruzi. Infected insects were collected in 31.6% of the homesteads (54.1% and 45.9% intra- and peridomiciliary, respectively). Approximately 30% of all triatomines collected were found in chicken coops. The presence of a chicken coop in the backyard of a homestead was significantly associated with both the odds of finding T. dimidiata (OR = 4.10, CI 95% = 1.61-10.43, p = 0.003) and the presence of triatomines infected with T. cruzi (OR = 3.37, CI 95% = 1.36-8.33, p = 0.006). The results of this study emphasize the relevance of chicken coops as a putative source of T. dimidiata populations and a potential risk for T. cruzi transmission.  相似文献   

3.
Phylogenetic approaches based on mitochondrial DNA variation (fragments of Cyt B and 16S ribosomal RNA) have revealed Triatoma sherlocki as the most recent species addition to the Triatoma brasiliensis species complex; a monophyletic group which includes T. brasiliensis, Triatoma melanica, and Triatoma juazeirensis. T. sherlocki is the most differentiated among all species of this complex: it is unable to fly, possesses longer legs than the other members, and has reddish tonality in some parts of its exochorion. We question whether these species are reproductively compatible because of this pronounced morphological differentiation, and therefore, we present a series of cross breeding experiments that test compatibility between T. sherlocki and other members of the T. brasiliensis complex. We extended our analyses to include crosses between T. sherlocki and Triatoma lenti, because the latter has been suggested as a possible member of this complex. T. sherlocki male × T. lenti female pairs failed to produce hybrids. All other crosses of T. sherlocki and members of T. brasiliensis species complex, as well as backcrosses, produced viable offspring through the third generation. This study stresses the importance of searching for the features that may isolate members of the T. brasiliensis species complex.  相似文献   

4.
Snails of the family Lymnaeidae act as intermediate hosts in the biological cycle of Fasciola hepatica, which is a biological agent of fasciolosis, a parasitic disease of medical importance for humans and animals. The present work aimed to update and map the spatial distribution of the intermediate host snails of F. hepatica in Brazil. Data on the distribution of lymnaeids species were compiled from the Collection of Medical Malacology (Fiocruz-CMM, CPqRR), Collection of Malacology (MZUSP), “SpeciesLink” (CRIA) network and through systematic surveys in the literature. Our maps of the distribution of lymnaeids show that Pseudosuccinea columella is the most common species and it is widespread in the South and Southeast with few records in the Midwest, North and Northeast regions. The distribution of the Galba viatrix, G. cubensis and G. truncatula showed a few records in the South and Southeast regions, they were not reported for the Midwest, North and Northeast. In addition, in the South region there are a few records for G. viatrix and one occurrence of Lymnaea rupestris. Our findings resulted in the first map of the spatial distribution of Lymnaeidae species in Brazil which might be useful to better understand the fasciolosis distribution and delineate priority areas for control interventions.  相似文献   

5.
Cytochrome P450s constitute a superfamily of genes encoding mostly microsomal hemoproteins that play a dominant role in the metabolism of a wide variety of both endogenous and foreign compounds. In insects, xenobiotic metabolism (i.e., metabolism of insecticides and toxic natural plant compounds) is known to involve members of the CYP6 family of cytochrome P450s. Use of a 3′ RACE (rapid amplification of cDNA ends) strategy with a degenerate primer based on the conserved cytochrome P450 heme-binding decapeptide loop resulted in the amplification of four cDNA sequences representing another family of cytochrome P450 genes (CYP28) from two species of isoquinoline alkaloid-resistant Drosophila and the cosmopolitan species Drosophila hydei. The CYP28 family forms a monophyletic clade with strong regional homologies to the vertebrate CYP3 family and the insect CYP6 family (both of which are involved in xenobiotic metabolism) and to the insect CYP9 family (of unknown function). Induction of mRNA levels for three of the CYP28 cytochrome P450s by toxic host-plant allelochemicals (up to 11.5-fold) and phenobarbital (up to 49-fold) corroborates previous in vitro metabolism studies and suggests a potentially important role for the CYP28 family in determining patterns of insect–host-plant relationships through xenobiotic detoxification.  相似文献   

6.
Sandflies transmit pathogens of leishmaniasis. The natural infection of sandflies by Leishmania (Viannia) was assessed in municipalities, in the state of Paraná, in Southern Brazil. Sandflies were collected with Falcão and Shannon traps. After dissection in search of flagellates in digestive tubes and identification of the species, female sandflies were submitted to the Multiplex Polymerase Chain Reaction (multiplex PCR) for detection of the fragment of the kDNA of Leishmania (Viannia) and the fragment from the IVS6 cacophony gene region of the phlebotomine insects. The analysis was performed in pools containing seven to 12 guts from females of the same species. A total of 510 female sandflies were analyzed, including nine Migonemyia migonei, 17 Pintomyia fischeri, 216 Nyssomyia neivai, and 268 Nyssomyia whitmani. Although none of the females was found naturally infected by flagellates through dissection, the fragment of DNA from Leishmania (Viannia) was shown by multiplex PCR in one sample of Ny. neivai (0.46%) and three samples of Ny. whitmani (1.12%). It was concluded that Ny. neivai and Ny. whitmani are susceptible to Leishmania infection, and that multiplex PCR can be used in epidemiological studies to detect the natural infection of the sandfly vector, because of its sensitivity, specificity and feasibility.  相似文献   

7.
Triatoma sordida is a secondary vector of Trypanosoma cruzi in the Gran Chaco and Cerrado eco-regions where it frequently infests peridomestic and domestic habitats. In a well-defined area of the humid Argentine Chaco, very few T. sordida were found infected when examined by optical microscopic examination (OM). In order to further assess the role of T. sordida and the relative magnitude of subpatent bug infections, we examined the insects for T. cruzi infection, parasite Discrete Typing Units (DTUs) and bloodmeal sources using various molecular techniques. Among 205 bugs with a negative or no OM-based diagnosis, the prevalence of infection determined by kDNA-PCR was nearly the same in bugs captured before (6.3%) and 4 months after insecticide spraying (6.4%). On average, these estimates were sixfold higher than the prevalence of infection based on OM (1.1%). Only TcI was identified, a DTU typically associated with opossums and rodents. Chickens and turkeys were the only bloodmeal sources identified in the infected specimens and the main local hosts at the bugs’ capture sites. As birds are refractory to T. cruzi infection, further studies are needed to identify the infectious bloodmeal hosts. The persistent finding of infected T. sordida after community-wide insecticide spraying highlights the need of sustained vector surveillance to effectively prevent T. cruzi transmission in the domestic and peridomestic habitats.  相似文献   

8.
To determine the infestation and trypanosome infection of triatomines captured in Mauritia flexuosa palm trees across its geographic distribution in the Brazilian savanna (Cerrado), we sampled 42 localities in eight states and in the Federal District, Brazil, between July 2005 and January 2010. Overall, 2154 specimens of the species Rhodnius neglectus, Psammolestes tertius, Triatoma sordida, and Microtriatoma borbai, were collected. Among the 341 palms sampled, 182 (53.3%) were infested with R. neglectus, which resulted in the capture of 1639 specimens (9.0 insects per infested palm). P. tertius occurred in 26 palms (8%), which resulted in the capture of 484 specimens (19 insects per infested palm). T. sordida (n = 30) and M. borbai (n = 1) occurred in only one location. From 537 R. neglectus examined, 44 were infected (8%) with Trypanosoma rangeli and/or Trypanosoma cruzi (Tc Id). M. flexuosa was previously recognized as a suitable breeding ecotope for R. neglectus in the Brazilian states of Minas Gerais, Goiás, Tocantins and the Federal District. Our results expand this distribution to other states (São Paulo, Bahia, Mato Grosso, Maranhão and Piauí), and also show that this particular palm tree harbors other triatomine species. Finally, we show that R. neglectus plays an important role in maintaining the enzootic circulation of T. cruzi and T. rangeli in the Brazilian savanna.  相似文献   

9.
A 56-year-old postmenopausal woman with out-of-hospital cardiac arrest caused by acute myocardial infraction was successfully resuscitated by intensive treatments and recovered without any neurological disability. She was diagnosed as having familial hypercholesterolemia (FH) based on a markedly elevated low-density lipoprotein cholesterol (LDL-C) level and family history of premature coronary artery disease. Genetic testing in her family members showed that a variant of the proprotein convertase subtilisin/kexin type 9 ( PCSK9 ) gene (c.2004C>A, p.S668R), which had been previously reported as having uncertain significance, was associated with FH, indicating that the variant is a potential candidate for the FH phenotype. Next-generation sequencing analysis for the proband also showed that there was a heterozygous mutation of the ATP-binding cassette sub-family G member 5 ( ABCG5 ) gene (c.1166G>A, R389H), which has been reported to increase LDL-C level and the risk of cardiovascular disease. She was also diagnosed as having type 1 CD36 deficiency based on a lack of myocardial uptake of 123 I-labeled 15-(p-iodophenyl)-3-R,S-methyl-pentadecanoic acid in scintigraphy and the absence of CD36 antigen in both monocytes and platelets in flow cytometry. She had a homozygous mutation of the CD36 gene (c.1126-5_1127delTTTAGAT), which occurs in a canonical splice site (acceptor) and is predicted to disrupt or distort the normal gene product. To our knowledge, this is the first report of a heterozygous FH phenotype caused by possibly oligogenic variants of the PCSK9 and ABCG5 genes complicated with type I CD36 deficiency caused by a novel homozygous mutation. Both FH phenotype and CD36 deficiency might have caused extensive atherosclerosis, leading to acute myocardial infarction in the present case.  相似文献   

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Photoinhibition, exacerbated by elevated temperatures, underlies coral bleaching, but sensitivity to photosynthetic loss differs among various phylotypes of Symbiodinium, their dinoflagellate symbionts. Symbiodinium is a common symbiont in many cnidarian species including corals, jellyfish, anemones, and giant clams. Here, we provide evidence that most members of clade A Symbiodinium, but not clades B–D or F, exhibit enhanced capabilities for alternative photosynthetic electron-transport pathways including cyclic electron transport (CET). Unlike other clades, clade A Symbiodinium also undergo pronounced light-induced dissociation of antenna complexes from photosystem II (PSII) reaction centers. We propose these attributes promote survival of most cnidarians with clade A symbionts at high light intensities and confer resistance to bleaching conditions that conspicuously impact deeper dwelling corals that harbor non-clade A Symbiodinium.  相似文献   

12.
Large dsDNA viruses are involved in the population control of many globally distributed species of eukaryotic phytoplankton and have a prominent role in bloom termination. The genus Phaeocystis (Haptophyta, Prymnesiophyceae) includes several high-biomass-forming phytoplankton species, such as Phaeocystis globosa, the blooms of which occur mostly in the coastal zone of the North Atlantic and the North Sea. Here, we report the 459,984-bp-long genome sequence of P. globosa virus strain PgV-16T, encoding 434 proteins and eight tRNAs and, thus, the largest fully sequenced genome to date among viruses infecting algae. Surprisingly, PgV-16T exhibits no phylogenetic affinity with other viruses infecting microalgae (e.g., phycodnaviruses), including those infecting Emiliania huxleyi, another ubiquitous bloom-forming haptophyte. Rather, PgV-16T belongs to an emerging clade (the Megaviridae) clustering the viruses endowed with the largest known genomes, including Megavirus, Mimivirus (both infecting acanthamoeba), and a virus infecting the marine microflagellate grazer Cafeteria roenbergensis. Seventy-five percent of the best matches of PgV-16T–predicted proteins correspond to two viruses [Organic Lake phycodnavirus (OLPV)1 and OLPV2] from a hypersaline lake in Antarctica (Organic Lake), the hosts of which are unknown. As for OLPVs and other Megaviridae, the PgV-16T sequence data revealed the presence of a virophage-like genome. However, no virophage particle was detected in infected P. globosa cultures. The presence of many genes found only in Megaviridae in its genome and the presence of an associated virophage strongly suggest that PgV-16T shares a common ancestry with the largest known dsDNA viruses, the host range of which already encompasses the earliest diverging branches of domain Eukarya.  相似文献   

13.
In September 2018 in Brescia province, northern Italy, an outbreak of Legionnaires'' disease (LD) caused by Legionella pneumophila serogroup 2 (Lp2) occurred. The 33 cases (two fatal) resided in seven municipalities along the Chiese river. All cases were negative by urinary antigen test (UAT) and most were diagnosed by real-time PCR and serology. In only three cases, respiratory sample cultures were positive, and Lp2 was identified and typed as sequence type (ST)1455. In another three cases, nested sequence-based typing was directly applied to respiratory samples, which provided allelic profiles highly similar to ST1455. An environmental investigation was undertaken immediately and water samples were collected from private homes, municipal water systems, cooling towers and the river. Overall, 533 environmental water samples were analysed and 34 were positive for Lp. Of these, only three samples, all collected from the Chiese river, were Lp2 ST1455. If and how the river water could have been aerosolised causing the LD cases remains unexplained. This outbreak, the first to our knowledge caused by Lp2, highlights the limits of UAT for LD diagnosis, underlining the importance of adopting multiple tests to ensure that serogroups other than serogroup 1, as well as other Legionella species, are identified.  相似文献   

14.
Enterococci are Gram-positive cocci saprophyte of the human gastrointestinal tract, diners who act as opportunistic pathogens. They can cause infections in patients hospitalized for a long time or who have received multiple antibiotic therapy. Enterococcus faecalis and Enterococcus faecium are the most common species in human infections. To evaluate the possibility of rapid detection of these species and their occurrence in the blood of newborns with suspected nosocomial infection, blood samples were collected from 50 newborns with late infections, admitted to the Neonatal Care Unit of the University Hospital Federal de Mato Grosso do Sul (UFMS-HU), from September 2010 to January 2011. The samples were subjected to conventional PCR and real time PCR (qPCR) to search for Enterococcus faecium and Enterococcus faecalis, respectively. The PCR results were compared with respective blood cultures from 40 patients. No blood cultures were positive for Enterococci, however, eight blood samples were identified as genomic DNA of Enterococcus faecium by qPCR and 22 blood samples were detected as genomic DNA of Enterococcus faecalis by conventional PCR. These findings are important because of the clinical severity of the evaluated patients who were found positive by conventional PCR and not through routine microbiological methods.  相似文献   

15.

OBJECTIVE:

To determine the drug resistance profile of Mycobacterium tuberculosis in Mozambique.

METHODS:

We analyzed secondary data from the National Tuberculosis Referral Laboratory, in the city of Maputo, Mozambique, and from the Beira Regional Tuberculosis Referral Laboratory, in the city of Beira, Mozambique. The data were based on culture-positive samples submitted to first-line drug susceptibility testing (DST) between January and December of 2011. We attempted to determine whether the frequency of DST positivity was associated with patient type or provenance.

RESULTS:

During the study period, 641 strains were isolated in culture and submitted to DST. We found that 374 (58.3%) were resistant to at least one antituberculosis drug and 280 (43.7%) were resistant to multiple antituberculosis drugs. Of the 280 multidrug-resistant tuberculosis cases, 184 (65.7%) were in previously treated patients, most of whom were from southern Mozambique. Two (0.71%) of the cases of multidrug-resistant tuberculosis were confirmed to be cases of extensively drug-resistant tuberculosis. Multidrug-resistant tuberculosis was most common in males, particularly those in the 21-40 year age bracket.

CONCLUSIONS:

M. tuberculosis resistance to antituberculosis drugs is high in Mozambique, especially in previously treated patients. The frequency of M. tuberculosis strains that were resistant to isoniazid, rifampin, and streptomycin in combination was found to be high, particularly in samples from previously treated patients.  相似文献   

16.
Herein, we report the results of study of Anopheles species in Primorsk and Khabarovsk regions of Russia. Three species of the Anopheles hyrcanus group: An. kleini, An. pullus, and An. lesteri were identified by molecular taxonomic diagnostics for the first time in Russia. Surprisingly, An. sinensis, which earlier was considered the only species of Anopheles in Russian Far East, was not observed. We analyzed nucleotide variation in the 610-bp fragment of the 5′ end of the cytochrome c oxidase subunit I (COI) region. All species possessed a distinctive set of COI sequences. A maximum likelihood phylogenetic tree was constructed for members of the hyrcanus group. The examined Anopheles hyrcanus group members could be divided into two major subgroups: subgroup 1 (An. hyrcanus and An. pullus) and subgroup 2 (An. sinensis, An. kleini, and An. lesteri), which were found to be monophyletic.  相似文献   

17.
Aim: Originally developed for predicting the risk of stroke in patients with atrial fibrillation (AF), the CHA 2 DS 2 -VASc score also has the potential to predict the risk of other cardiovascular disease. This study aimed to investigate the prognostic value of the CHA 2 DS 2 -VASc score in patients with peripheral artery disease (PAD) requiring Femoral popliteal (FP) endovascular therapy (EVT). Methods: This multicenter, retrospective study analyzed the clinical database of 2190 patients who underwent FP EVT for symptomatic PAD (Rutherford categories 2–4) between January 2010 and December 2018. We calculated the CHA 2 DS 2 -VASc score and then investigated the association between the score, as well as AF, and their prognosis. Outcome measures were major adverse cardiovascular events (MACEs) and major adverse limb events (MALEs). Results: During a median follow-up of 3.0 years (interquartile range, 1.5–5.0 years), 532 MACEs and 562 MALEs occurred. The CHA 2 DS 2 -VASc score and AF were independently associated with an increased risk of MACEs; their adjusted hazard ratios [95% confidence intervals] were 1.28 [1.20–1.36] ( P <0.001) per 1-point increase and 1.49 [1.06–2.09] ( P =0.022), respectively. The CHA 2 DS 2 -VASc score was almost linearly associated with MACEs, without any clear threshold point. On the other hand, these variables were not associated with MALEs risk ( P =0.32 and 0.48). Conclusion: The CHA 2 DS 2 -VASc score and AF were independently associated with the increased risk of MACEs but not of MALEs in patients with symptomatic PAD who underwent FP EVT. The score might be useful in stratifying the MACEs risk in this type of patients.  相似文献   

18.
Infections by Candida species are a high-impact problem in public health due to their wide incidence in hospitalized patients. The goal of this study was to evaluate frequency, susceptibility to antifungals, and genetic polymorphism of Candida species isolated from clinical specimens of hospitalized patients. The Candida isolates included in this study were obtained from blood cultures, abdominal fluids, and central venous catheters (CVC) of hospitalized patients at the Clinical Hospital of the Federal University of Uberlândia during the period of July 2010 - June 2011. Susceptibility tests were conducted by the broth microdilution method. The RAPD-PCR tests used employed initiator oligonucleotides OPA09, OPB11, and OPE06. Of the 63 Candida isolates, 18 (28.5%) were C. albicans, 20 (31.7%) were C. parapsilosis complex species, 14 (22.2%) C. tropicalis, four (6.4%) C. glabrata, four (6.4%) C. krusei, two (3.3%) C. kefyr, and one (1.6%) C. lusitaniae. In vitro resistance to amphotericin B was observed in 12.7% of isolates. In vitroresistance to azoles was not detected, except for C. krusei. The two primers, OPA09 and OPB11, were able to distinguish different species. Isolates of C. albicans and C. parapsilosis complex species presented six and five clusters, respectively, with the OPA09 marker by RAPD-PCR, showing the genetic variability of the isolates of those species. It was concluded that members of the C. parapsilosis complex were the most frequent species found, and most isolates were susceptible to the antifungals amphotericin B, flucozanole, and itraconazole. High genetic polymorphisms were observed for isolates of C. albicans and C. parapsilosis complex species, mainly with the OPA09 marker.  相似文献   

19.
The genus Androctonus, commonly known as fat-tailed scorpions, contains 22 species distributed from Togo and Mauritania in the west, North Africa, through the Middle East and to as far east as India. With 13 species, a substantial amount of this genus’ diversity occurs in North Africa, which is a major hotspot of scorpion sting incidents. Androctonus are among the most medically relevant animals in North Africa. Since venom composition within species is known to vary regionally, the improvement of therapeutic management depends on a correct assessment of the existing regional specific and sub-specific variation. In this study, we assessed the phylogeographical patterns in six species of Androctonus scorpions from North Africa using mitochondrial DNA markers. We sequenced COX1, 12S, 16S and ND1 genes from 110 individuals. Despite lacking basal resolution in the tree, we found taxonomical and geographically coherent clades. We discovered deep intraspecific variation in the widespread Androctonus amoreuxi and Androctonus australis, which consisted of several well-supported clades. Genetic distances between some of these clades are as high as those found between species. North African A. australis have a deep split in Tunisia around the Chott el-Djerid salt-lake. A novel split between A. amoreuxi scorpions was found in Morocco. We also found deep divergences in Androctonus mauritanicus, corresponding to areas attributed to invalidated subspecies. In addition we uncovered a clade of specimens from coastal south Morocco, which could not be ascribed to any know species using morphological characters. Based on these findings we recommend a reassessment of venom potency and anti-venom efficacy between these deep intraspecific divergent clades.  相似文献   

20.
During the annual fly survey at Doi Nang Kaew in Doi Saket District, Chiang Mai Province of Thailand in 2011, Isomyia paurogonita Fang & Fan, 1986 (Diptera: Calliphoridae) and Sumatria latifrons Malloch, 1926 (Diptera: Calliphoridae) were collected for the first time in Thailand. They are the rare species of the subfamily Rhiniinae (tribe Cosminini). Prior to this finding, fifteen species of Isomyia and two species of Sumatria were recorded from Thailand. Therefore, 96 blow fly species have been found in this country. These new locality records of both flies are very important for further research on their biology and ecology in Thailand.  相似文献   

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