Taxonomy and biology of Culex (Culex) maxi Dyar (Diptera: Culicidae) in South America

Culex (Culex) maxi Dyar is described in the adult, pupal and larval stages, and the male genitalia and parts of the fourth-instar larva are illustrated. The larva is described for the first time. The paper includes a summary of available information on the taxonomy, bionomics and distribution of the species. The taxonomy and identification of the species are reviewed in light of current knowledge of the subgenus Culex in the New World.

On Leishmania enriettii and Other Enigmatic Leishmania Species of the Neotropics

There are 20 named species of the genus Leishmania at present recognized in the New World, of which 14 are known to infect man. The present paper discusses the biological, biochemical and ecological features, where known, of six species which have not till now been found to cause human leishmaniasis; namely, Leishmania (Leishmania) enriettii, L. (L.) hertigi, L. (L.) deanei, L. (L.) aristidesi, L. (L.) forattinii and L. (Viannia) equatorensis. A protocol is suggested for attempts to discover the natural mammalian host(s) and sandfly vector of L. (L.) enriettii. Doubt is cast on the validity of the species L. herreri, described in Costa Rican sloths. Following the concensus of opinion that modern trypanosomatids derive from monogenetic intestinal flagellates of arthropods, phlebotomine sandflies are best regarded as the primary hosts of Leishmania species, with mammals acting as secondary hosts providing a source of parasites for these insects. There are probably natural barriers limiting the life-cycle of most leishmanial parasites to specific sandfly vectors

Evolution and recent developments of Spanish wine sector, 1950-2008

Since the 1980s the traditional European winegrowing regions have been carrying out deep changes in response to the onslaught of winegrowers in the New World. In recent years Spanish regions have been foremost in Europe in terms of change in areas turned over to wine production and distribution. This study analyses the main sequences of changes the Spanish wine industry has undergone: the evolution of consumption through the changes in consumer drinking habits; the leading role of exports in international markets; the spread of different types of marketing and business organization; the distribution in large and small sellers, and the main factors that have been involved in the chain of production and in the modernization of the wineries.

Molecular and Antigenic Characterization of the Leishmania (Viannia) panamensis Kinetoplastid Membrane Protein-11

The kinetoplastid membrane protein 11 (KMP-11) has been recently described in Leishmania (Leishmania) donovani as a major component of the promastigote membrane. Two oligonucleotide primers were synthesized to PCR-amplify the entire coding region of New World Leishmania species. The Leishmania (Viannia) panamensis amplification product was cloned, sequenced and the putative amino acid sequence determined. A remarkably high degree of sequence homology was observed with the corresponding molecule of L. (L) donovani and L. (L) infantum (97% and 96%, respectively). Southern blot analysis showed that the KMP-11 locus is conformed by three copies of the gene. The L. (V) panamensis ORF was subsequently cloned in a high expression vector and the recombinant protein was induced and purified from Escherichia coli cultures. Immunoblot analysis showed that 80%, 77% and 100% sera from cutaneous, mucocutaneous and visceral leishmaniasis patients, respectively, recognized the recombinant KMP-11 protein. In a similar assay, 86% of asymptomatic Leishmania-infected individuals showed IgG antibodies against the rKMP-11. We propose that KMP-11 could be used as a serologic marker for infection and disease caused by Leishmania in America.

Reinfection in American Cutaneous Leishmaniasis: Evaluation of Clinical Outcomes in the Hamster Model

There is no clear understanding of the outcome of reinfection in New World cutaneous leishmaniasis, and its role in the relationship to the development of protection or secondary disease. For this reason, reinfection experiments with homologous (Leishmania panamensis-L. panamensis) and heterologous (L. major-L. panamensis) species of leishmaniae were conducted in the hamster model. The different protocols for primary infections prior to the challenge with L. panamensis were as follows: (a) L. major, single promastigote injection, (b) L. major, three booster infections, (c) L. panamensis, followed by antimonial treatment to achieve subclinical infection, (d) L. panamensis, with active lesions, (e) sham infected, naive controls. Although all reinfected hamsters developed lesions upon challenge, animals with active primary lesions due to L. panamensis, and receiving booster infections of L. major had the most benign secondary lesions (58-91% and 69-76% smaller than controls, respectively, P<0.05). Subclinically infected animals had intermediate lesions (40-64% smaller than controls, P<0.05), while hamsters which received a single dose of L. major had no significant improvement over controls. Our results suggested that L. major could elicit a cross protective response to L. panamensis, and that the presence and number of amastigotes persisting after a primary infection may influence the clinical outcome of reinfections.

Batflies Parasitic on Some Phyllostomid Bats in Southeastern Brazil: Parasitism Rates and Host-parasite Relationships

Ectoparasitic batflies were studied on 12 species of phyllostomid bats, by making 35 nightly collections of bats using mist nets at the "Panga" Ecological Reservation near Uberlândia, State of Minas Gerais, southeastern Brazil, from August 1989 to July 1990. Eleven species of Streblidae and one of Nycteribiidae were collected on 12 species of bats. Prevalence of ectoparasitic flies was lower than those reported by other authors for the New World and may be the result of the lack of caves in the study area, causing bats to roost in less favorable locations, forming smaller colonies. The fly, Trichobius joblingi Wenzel, was found on Carollia perspicillata (Linnaeus), showing preference for adult male bats. This could be explained by the predominance of males in the bat colonies, and by the fact that females rest in isolation during the reproductive period making them less exposed to the parasites. The streblid flies, Aspidoptera falcata Wenzel and Megistopoda proxima (Séguy), were found on Sturnira lilium (Geoffroy). A. falcata occurred mainly on young and adult females, whereas M. proxima did not show any preferences relative to the reproductive condition of the host. Ecological factors are important in determining differential numbers of parasites occurring on the different sexes, ages and reproductive state of the hosts.

Quantitative phenetics and taxonomy of some phlebotomine taxa

Elucidating the evolution of Phlebotominae is important not only to revise their taxonomy, but also to help understand the origin of the genus Leishmania and its relationship with humans. Our study is a phenetic portrayal of this history based on the genetic relationships among some New Word and Old Word taxa. We used both multilocus enzyme electrophoresis and morphometry on 24 male specimens of the Old Word genus Phlebotomus (with three of its subgenera: Phlebotomus, Spelaeophlebotomus and Australophlebotomus), and on 67 male specimens of the three New World genera, Warileya, Brumptomyia and Lutzomyia, (with three subgenera of Lutzomyia: Lutzomyia, Oligodontomyia and Psychodopygus). Phenetic trees derived from both techniques were similar, but disclosed relationships that disagree with the present classification of sand flies. The need for a true evolutionary approach is stressed.

Quantitative morphological evidence for incipient species within Lutzomyia quinquefer (Diptera: Psychodidae)

Morphological variation among geographic populations of the New World sand fly Lutzomyia quinquefer (Diptera, Phlebotominae) was analyzed and patterns detected that are probably associated with species emergence. This was achieved by examining the relationships of size and shape components of morphological attributes, and their correlation with geographic parameters. Quantitative and qualitative morphological characters are described, showing in both sexes differences among local populations from four Departments of Bolivia. Four arguments are then developed to reject the hypothesis of environment as the unique source of morphological variation: (1) the persistence of differences after removing the allometric consequences of size variation, (2) the association of local metric properties with meristic and qualitative attributes, rather than with altitude, (3) the positive and significant correlation between metric and geographic distances, and (4) the absence of a significant correlation between altitude and general-size of the insects.

A review of the ticks (Acari, Ixodida) of Brazil, their hosts and geographic distribution - 1. The State of Rio Grande do Sul, Southern Brazil

A review of the ticks (Acari, Ixodida) of the State of Rio Grande do Sul, southern Brazil, was completed as a step towards a definitive list (currently indicated as 12) of such species, their hosts and distribution. The ticks: Argas miniatus (poultry), Ixodes loricatus (opossums), Amblyomma aureolatum (dogs), A. calcaratum (anteaters), A. cooperi (capybaras), A. nodosum (anteaters), A. tigrinum (dogs) (Neotropical) and Rhipicephalus sanguineus (dogs) (introduced, cosmopolitan, Afrotropical) were confirmed as present, in addition to the predominant, Boophilus microplus (cattle) (introduced, pan-tropical, Oriental). Of the further 18 species thus far reported in the literature as present in the state, but unavailable for examination: only Ornithodoros brasiliensis (humans and their habitations) (Neotropical), Ixodes affinis (deer) (Nearctic/Neotropical) and I. auritulus (birds) (Nearctic/Neotropical/Afrotropical/ Australasian) are considered likely; 13 species would benefit from corroborative local data but the majority appear unlikely; reports of A. maculatum (Nearctic/Neotropical, but circum-Caribbean) are considered erroneous; the validity of A. fuscum is in doubt. The very recent, first known report of the tropical Anocentor nitens (horses)(Nearctic/Neotropical), but still apparent absence of the tropical A. cajennense (catholic) (Nearctic/Neotropical) and the sub-tropical/temperate Ixodes pararicinus (cattle) (Neotropical) in Rio Grande do Sul are important for considerations on their current biogeographical distribution and its dynamics in South America. The state has relatively long established, introduced ("exotic"), Old World tick species (B. microplus, R. sanguineus) that continue to represent significant pests and disease vectors to their traditional, introduced domestic animal hosts, cattle and urban dogs. There are also indigenous, New World ticks (A. miniatus, O. brasiliensis, A. aureolatum, A. nitens), as both long established and possibly newly locally introduced species in the state, that should be considered as potential and emergent pests and pathogen vectors to humans and their more recently acquired, introduced domestic animal hosts; rural poultry, dogs and horses.

Further support for a palaearctic origin of Leishmania

The fossil record and systematics of murid rodents, reservoirs of zoonotic cutaneous leishmaniasis in the Palaearctic, Oriental, African, Nearctic and Neotropical, strongly support a Palaearctic origin of Leishmania. The fossil record and systematics of phlebotomine sand flies reinforce this idea. Interpretations of molecular data that place the origin of Leishmania in the Neotropical are inconsistent with the natural histories of reservoirs and vectors. The evolutionary pattern of New World rats (Sigmodontinae) indicates that they may be the most important reservoirs of zoonotic cutaneous leishmaniasis throughout their range.

Speculations on the origin and evolution of the genus Leishmania

Recently two hypotheses have been proposed for the evolution of Leishmania involving respectively a Neotropical or Paleartic origin for the species. Here an alternative proposal on the phylogeny of Leishmania based on the major divisions within the genus is presented. In this hypothesis a Neotropic origin is retained for L. (Viannia) and Paraleishmania, a recently desribed section within the genus Leishmania, while an African origin is proposed for L. (Leishmania) and possibly Sauroleishmania. The current distribution of Leishmania in the Neotropics is explained as the product of multiple introductions of Leishmania parasites into the New World. Problems with organismal identity in Sauroleishmania and the use of molecular sequence data in inferring phylogenies are also discussed.

Brain cell karyotype of the phlebotomine sand fly Lutzomyia shannoni (Dyar) (Diptera: Psychodidae)

The brain cell karyotype of New World sand fly Lutzomyia shannoni was described. This species has four pairs of chromosomes, 2N=8, with one pair of heteromorphic chromosomes.

Evaluation of the anti-arenaviral activity of the subtilisin kexin isozyme-1/site-1 protease inhibitor PF-429242.

The cellular protease subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P) is implicated in the proteolytic processing of the viral envelope glycoprotein precursor (GPC) of arenaviruses, a step strictly required for production of infectious progeny. The small molecule SKI-1/S1P inhibitor PF-429242 was shown to have anti-viral activity against Old World arenaviruses. Here we extended these studies and show that PF-429242 also inhibits GPC processing and productive infection of New World arenaviruses, making PF-429242 a broadly active anti-arenaviral drug. In combination therapy, PF-429242 potentiated the anti-viral activity of ribavirin, indicating a synergism between the two drugs. A hallmark of arenaviruses is their ability to establish persistent infection in vitro and in vivo. Notably, PF-429242 was able to efficiently and rapidly clear persistent infection by arenaviruses. Interruption of drug treatment did not result in re-emergence of infection, indicating that PF-429242 treatment leads to virus extinction.

Redescription of the Male of Lutzomyia lutziana (Costa Lima) and Description of the Female (Diptera: Psychodidae)

During the course of taxonomic studies of New World phlebotomine sand flies, it was discovered that the female specimen considered to be the female of Lutzomyia lutziana does not belong to this species. A new description of the female of L. lutziana is presented, based on specimens captured in Lassance, State of Minas Gerais, the type locality of the species. The male of L. lutziana is also redescribed, based on an exemplar caught in Curvelo, State of Minas Gerais.

Combinatorial Anti-arenaviral Therapy with the Small Molecule SKI-1/S1P Inhibitor PF-429242 and Ribavirin

Arenaviruses are enveloped negative strand viruses that cause acute and chronic infections. Several Arenaviruses can cause severe hemorrhagic fever in humans. In West Africa Lassa virus causes several hundred thousand infections per year, while Junin, Machupo, Guanarito, and Sabia virus have emerged in South America. So far, only one drug is licensed against arenaviruses, the nucleoside analogue Ribavirin (Rib), which is effective when given early in disease, but shows only minor therapeutic effects in late stages of the infection. Previous works demonstrated that processing of the arenavirus glycoprotein precursor (GPC) by the cellular proprotein convertase site 1 protease (S1P), also known as subtilisin-kexinisozyme 1 (SKI-1), is crucial for cell-to-cell propagation of infectionand production of infectious virus. Recently, the SKI-1/S1P inhibitor PF-429242wasshownto inhibit Old World arenavirusGPCprocessing, cell-to-cell propagation, and infectious virus production. In the present study, we assessed the activity of PF-429242 against processing of the GPCs of the genetically and structurally more distant New World arenaviruses and found potent inhibition of processing of the GPCs of Junin, Machupo, and Guanarito virus. Using the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV), we studied the potency of PF-429242 in the context of acute and chronic infection. In line with published data, PF-429242 potently inhibited acute LCMV infection. PF-429242 was also highly active against chronic infection and drug treatment resulted in rapid extinction of the virus without emergence of drug-resistant variants. In a combinatorial drug approach, we found that PF-429242 potentiated the anti-viral effect of Rib in treatment of acute andchronic infection. Taken together, we showed that the SKI-1/S1P inhibitor PF-429242 is broadly active against GPC processing of all major human pathogenic arenaviruses. Apart from being potent in acute infection, the drug is remarkably active in clearing chronic infection and potentiated the anti-arenaviral activity of Rib.