Synergistic action of synthetic peptides and amphotericin B causes disruption of the plasma membrane and cell wall in Candida albicans.

The objective of this work was to evaluate the combination of synthetic peptides based on the γ-core motif of defensin PvD1 with amphotericin B (AmB) at different concentrations against Candida albicans. We applied the checkerboard assay using different concentrations of the commercial drug AmB and the synthetic peptides γ31-45PvD1++ and γ33-41PvD1++ against C. albicans, aiming to find combinations with synergistic interactions. Between these two interactions involving γ31-45PvD1++ and AmB, an additive effect was observed. One such interaction occurred at concentrations of 0.009 µM of peptide γ31-45PvD1++ and 13.23 µM of AmB and another condition of 0.019 µM of peptide γ31-45PvD1++ and 6.61 µM of AmB. The other two concentrations of the interaction showed a synergistic effect in the combination of synthetic peptide γ31-45PvD1++ and AmB, where the concentrations were 1.40 µM peptide γ31-45PvD1++ and 0.004 µM AmB and 0.70 µM γ31-45PvD1++ peptide and 0.002 µM AmB. We proceeded with analysis of the mechanism of action involving synergistic effects. This examination unveiled a range of impactful outcomes, including the impairment of mitochondrial functionality, compromise of cell wall integrity, DNA degradation, and a consequential decline in cell viability. We also observed that both synergistic combinations were capable of causing damage to the plasma membrane and cell wall, causing leakage of intracellular components. This discovery demonstrates for the first time that the synergistic combinations found between the synthetic peptide γ31-45PvD1++ and AmB have an antifungal effect against C. albicans, acting on the integrity of the plasma membrane and cell wall.

Foveavelia, a new South American genus of Veliinae (Hemiptera: Heteroptera: Veliidae).

Background: Semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha) are distributed worldwide and play fundamental roles in limnic ecosystems. They are the most successful group of organisms to occupy the air-water interface, are important models to study ecology and evolution, and can be relevant tools in biomonitoring. Veliidae is the second most speciose family of semiaquatic bugs, but its internal classification, including subfamilies and genera, is artificial and based on symplesiomorphies. One of these non-monophyletic entities is Paravelia Breddin, 1898, the largest genus in the subfamily Veliinae. Results: In an effort to better classify the Veliinae, we describe Foveavelia to hold five South American species previously placed in Paravelia. The new genus is characterized by the following combination of features: unusual coarse cuticular punctures throughout the thorax and abdomen; a pair of small, frosty, pubescent areas formed by a very dense layer of short setae on the anterior lobe of the pronotum; fore tibial grasping comb present only in males; middle tibia with a row of elongate dark-brown trichobothria-like setae on the distal third, decreasing in size distally; macropterous specimens with the apical macula of the forewings elongate and constricted at mid-length, reaching the wing apex; and the male proctiger with a pair of anterodorsal projections. Besides the description, a key to the species of Foveavelia is provided, accompanied by illustrations and a species distribution map.

A New Species of Spelaeometra Polhemus & Ferreira, 2018 (Hemiptera: Heteroptera: Hydrometridae) from a Hotspot of Troglobites in Brazil, Serra do Ramalho Karst Area.

Spelaeometra Polhemus & Ferreira, 2018 (Hemiptera: Heteroptera: Hydrometridae) is a monotypic and troglobitic genus, recently described based on material collected in the state of Minas Gerais, Brazil. From specimens collected in the Gruna do Enfurnado Cave in the Serra do Ramalho karst area, municipality of Coribe, state of Bahia, Brazil, we describe Spelaeometra hypogea Cordeiro & Moreira, sp. nov. and compare it with Spelaeometra gruta Polhemus & Ferreira, 2018. The new species is diagnosed by the general body color being pale-yellow to light-brown; antennal segments I and II being subequal in length; the reduced gular lobe, not covering any labial segment; the male proctiger without apical projections; and the male paramere with convex dorsal margin after the curvature, with a narrow hook-like apex.

In vitro anti-Leishmania activity of new isomeric cobalt(II)complexes and in silico insights: Mitochondria impairment and apoptosis-like cell death of the parasite.

The synthesis, physico-chemical characterization and in vitro antiproliferative activity against the promastigote form of Leishmania amazonensis of two new cobalt(II) coordination compounds (i.e. [Co(HL1)Cl2]0.4,2H2O (1) and [Co(HL2)(Cl)(CH3OH)](ClO4).2H2O (2)) are reported, where HL1 = 4-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one and HL2 = 7-{3-[bis(pyridin-2-ylmethyl)amino]-2-hydroxypropoxy}-2H-chromen-2-one. X-ray diffraction studies were performed for complex (2) and the structure of complex (1) was built through Density Functional Theory (DFT) calculations. Complex (1) presented no cytotoxicity to LLC-MK2, but complex (2) was toxic. IC50 against promastigotes of L. amazonensis for complex (1) were 4.90 (24 h), 3.50 (48 h) and 3. 80 µmol L-1 (72 h), and for complex (2) were 2.09, 4.20 and 2.80 µmol L-1, respectively. Due to the high toxicity presented by complex (2) against LLC-MK2 host cells, mechanistic studies, to shed light on the probable mode of leishmanicidal activity, were carried out only for the non-cytotoxic complex. Complex (1) was able to elevate mitochondrial membrane potential of the parasites after treatment. Transmission electron microscopy revealed typical apoptotic condensation of chromatin, altered kinetoplast and mitochondria structures, suggesting that apoptosis-like cell death of the protozoa is probably mediated by an apoptotic mechanism associated with mitochondrial dysfunction (intrinsic pathway). Molecular docking studies with complex (1) upon protein tyrosine phosphatase (LmPRL-1) suggests a plausible positive complex anchoring mainly by hydrophobic and hydrogen bond forces close to the enzyme's catalytic site. These promising results for complex 1 will prompt future investigations against amastigote form of L. amazonensis.

Hexane extracts from fruit of two varieties of Capsicum chinense Jacq.: their volatile constituents and antiacetylcholinesterase, antileishmanial and antiproliferative activities.

This article aims to investigate volatile constituents and antiacetylcholinesterase, antileishmanial and antiproliferative activities of hexane extracts from Capsicum chinense fruit (unripe bode pepper 'HE-UB' and ripe little beak pepper 'HE-RB'). HE-UB and HE-RB were screened by the microplate assay method to determine their antiacetylcholinesterase activity. Both exhibited inhibitory potential, i. e., IC50 = 41.5 and 20.3 µg/mL, respectively. HE-UB (IC50 = 67.19 µg/mL) and HE-RB (IC50 = 38.16 µg/mL) exhibited antileishmanial activity against promastigote forms of Leishmania (Leishmania) amazonensis. In addition, HE-UB and HE-RB demonstrated cytotoxic activity against different human tumor cell lines with IC50 ranging from 325.40 to 425.0 µg/mL. Both GC-FID and GC-MS analyses revealed that the major component in both extracts was E-caryophyllene. In short, HE-RB was more satisfactory than HE-UB in all in vitro activities under evaluation. These findings may be used as initial data for further studies of Capsicum species.

Gerromorpha (Hemiptera: Heteroptera) from the Metropolitan Region of Santarém, Brazil, including three new species of Microvelia Westwood, 1834 (Veliidae: Microveliinae).

BACKGROUND: Gerromorpha (Hemiptera: Heteroptera) comprises more than 2100 species of semiaquatic bugs, most of which have the ability to walk on the surface of the water. So far, 238 species have been recorded from Brazil, but several portions of the country remain poorly explored. The Metropolitan Region of Santarém (MRS), Pará State, Brazil, lacks faunistic and taxonomic studies concerning this group and the local fauna is under threat due to human actions. NEW INFORMATION: Aiming to fill gaps concerning the diversity and distribution of Gerromorpha in the Amazon, a survey of the semi-aquatic bugs from the MRS is presented. Collections were made in 33 aquatic ecosystems in the different phytophysiognomies within this area from July 2019 to October 2020. As a result, a checklist with 44 species recorded from the three municipalities of the MRS is presented. Furthermore, three new species of the genus Microvelia Westwood, 1834 (M.belterrensis sp. nov., M.hamadae sp. nov. and M.sousorum sp. nov.) are described, two species are recorded for the first time from Brazil (Microveliaaschnakiranae Makhan, 2014 and Rhagoveliagraziae Galindo-Malagón, Morales & Moreira, 2021), two from Pará State (Microvelialongipes Uhler, 1894 and Paraveliadilatata Polhemus & Polhemus, 1984) and 15 from the MRS (Brachymetralata Shaw, 1933, B.shawi Hungerford & Matsuda, 1957, Tachygerrisadamsoni (Drake, 1942), Microveliapulchella Westwood, 1834, Rhagoveliabrunae Magalhães & Moreira, 2016, R.evidis Bacon, 1948, R.jubata Bacon, 1948, Calliveliaconata (Hungerford, 1929), Oioveliacunucunumana Drake & Maldonado-Capriles, 1952, Paraveliabullialata Polhemus & Polhemus, 1984, Striduliveliaalia (Drake, 1957), S.stridulata (Hungerford, 1929), S.strigosa (Hungerford, 1929), S.tersa (Drake & Harris, 1941) and S.transversa (Hungerford, 1929)).

Telmatometropsis fredyi gen. nov., sp. nov.: a new water strider from the Colombian Pacific region (Insecta, Hemiptera, Gerridae).

A new genus of Gerridae (Insecta, Hemiptera, Heteroptera) in the subfamily Trepobatinae, Telmatometropsis gen. nov., with a single included species, T. fredyi sp. nov., is described from the Colombian Pacific region. Representatives of the new genus were collected in mangrove lagoons of Buenaventura Bay, Valle del Cauca Department. The new genus can be diagnosed by the relative proportions of the antennomeres, the shape of the male fore tarsus, and by the black markings on the head, thorax and abdomen.

Rediscovery of the holotype of Horvathinia lenti De Carlo, 1958, new junior synonym of H. pelocoroides Montadon, 1911 (Insecta: Hemiptera: Belostomatidae).

Horvathinia pelocoroides Montandon, 1911 was described as a new genus and species based on two specimens collected in Brazil, one from Minas Gerais deposited in the Naturhistoriska Riksmuseet (Stockholm) and the other from Rio Grande do Sul deposited in the Magyar Természettudományi Múzeum (Budapest) (Montandon 1911). Subsequently, nine additional species were described based on a single specimen each, collected at different localities in southern South America: H. doellojuradoi De Carlo, 1930; H. pelleranoi De Carlo, 1930; H. castilloi De Carlo, 1938; H. meyeri De Carlo, 1938; H. bollei De Carlo, 1958; H. lenti De Carlo, 1958; H. schubarti De Carlo, 1958; H. forsteri Lauck, 1958; and H. argemii Schnack, 1972 (Schnack Estévez 2005).

Diversity in Morphology and Locomotory Behavior Is Associated with Niche Expansion in the Semi-aquatic Bugs.

Acquisition of new ecological opportunities is a major driver of adaptation and species diversification [1-4]. However, how groups of organisms expand their habitat range is often unclear [3]. We study the Gerromorpha, a monophyletic group of heteropteran insects that occupy a large variety of water surface-associated niches, from small puddles to open oceans [5, 6]. Due to constraints related to fluid dynamics [7-9] and exposure to predation [5, 10], we hypothesize that selection will favor high speed of locomotion in the Gerromorpha that occupy water-air interface niches relative to the ancestral terrestrial life style. Through biomechanical assays and phylogenetic reconstruction, we show that only species that occupy water surface niches can generate high maximum speeds. Basally branching lineages with ancestral mode of locomotion, consisting of tripod gait, achieved increased speed on the water through increasing midleg length, stroke amplitude, and stroke frequency. Derived lineages evolved rowing as a novel mode of locomotion through simultaneous sculling motion almost exclusively of the midlegs. We demonstrate that this change in locomotory behavior significantly reduced the requirement for high stroke frequency and energy expenditure. Furthermore, we show how the evolution of rowing, by reducing stroke frequency, may have eliminated the constraint on body size, which may explain the evolution of larger Gerromorpha. This correlation between the diversity in locomotion behaviors and niche specialization suggests that changes in morphology and behavior may facilitate the invasion and diversification in novel environments.

Would Nesotriatoma bruneri Usinger, 1944 be a valid species?

Variation in the size and morphological differences intraspecific of Nesotriatoma flavida led to the description of N. bruneri. However, two years later the same author proposed the synonymization N. bruneri with N. flavida. N. bruneri was revalidated through morphological analysis after 35 years. Thus, given the existing taxonomic questioning between these Cuban triatomines, we analyzed new parameters such as genetic distance from the mitochondrial 16S rDNA deposited in Genbank and cytogenetic characterization, through the constitutive heterochromatin pattern, in order to reassess the specific status of N. bruneri. The analysis of the disposition of constitutive heterochromatin in the genome of these triatomines allowed observing that only the sex chromosome Y is heterochromatic, and the autosomes and the sex chromosomes X are euchromatic. These characteristics are identical to those described for N. flavida. By means of analysis of genetic distance matrix, we found that the genetic distance between N. bruneri and N. flavida was only 0.04%. Thus, by means of extremely low genetic distance and identical cytogenetic characteristics, we suggest that N. bruneri should be back again synonymized with N. flavida. However, we recommend that experimental hybrid crosses and new molecular analysis should be conducted, focusing mainly in the genetic distance based on other genes, on the rate of fertility of eggs and viability of hybrids to confirm the proposed of synonymization.

New distributional data on aquatic and semiaquatic bugs (Hemiptera: Heteroptera: Gerromorpha & Nepomorpha) from South America.

BACKGROUND: Water bugs in general play an important role in freshwater ecosystems, and knowledge about them is essential for the study of water biology and the proper management of aquatic habitats. The Neotropical fauna is relatively well known, but the existence of large under-collected areas makes taxonomic and faunistic studies concerning the aquatic and semiaquatic bugs from tropical America urgent. NEW INFORMATION: Distributional information is presented for thirty-eight species of Gerromorpha and five Nepomorpha, including first records from the Brazilian states of Bahia (Mesoveliaamoena), Ceará (Limnogonusprofugus and Rhagoveliawhitei), Espírito Santo (R.lucida), Goiás (Halobatopsisplatensis and R.zela), Mato Grosso (Rheumatobatesbonariensis), Pará (Nerthraterrestris), Paraná (H.spiniventris, Hydrometrafruhstorferi and R.janeira), Piauí (Microveliaayacuchana, M.pulchella, Neogerrislubricus and Platyveliabrachialis), Rio de Janeiro (Martaregabentoi) and São Paulo (Rheumatobatesminutusflavidus); and the Peruvian region of Madre de Dios (Rhagoveliafontanalis).

The genus Paravelia Breddin, 1898 (Hemiptera: Heteroptera: Veliidae) in Brazil, with descriptions of eight new species.

Eight new species of Paravelia Breddin, 1898 from Brazil are described and illustrated: P. amapaensis sp. nov. from Amapá State, P. bipunctata sp. nov. from Minas Gerais, Mato Grosso and Mato Grosso do Sul States, P. bilobata sp. nov. and P. polhemusi sp. nov. from Mato Grosso State, P. bahiana sp. nov. from Bahia State, P. lacrymosa sp. nov. from Minas Gerais State, P. micromaculata sp. nov. from Maranhão State, and P. ornata sp. nov. from Amazonas State. The genus is redescribed, with photos of the dorsal view for nineteen species: P. basalis (Spinola), P. biae Spangler, P. boliviana Breddin, P. bullialata Polhemus & Polhemus, P. capillata (Drake& Harris), P. capixaba Moreira, Nessimian & Rúdio, P. conata (Hungerford), P. dilatata Polhemus & Polhemus, P. foveata Polhemus & Polhemus, P. itatiayana (Drake), P. lanemeloi Moreira & Barbosa, P. manausana Polhemus & Polhemus, P. nieseri Moreira & Barbosa, P. platensis (Berg), P. recens (Drake & Harris), P. rotundanotata (Hungerford), P. spinifera Polhemus & Polhemus, P. splendoris (Drake & Harris) and P. williamsi (Hungerford). Three of these species are recorded for the first time from Brazil: P. platensis, P. spinifera and P. williamsi. Also, the macropterous forms of P. capixaba and P. dilatata are described. Lastly, an identification key to the 36 species of Paravelia recorded from Brazil and a checklist of described species are presented.

Atlas iconográfico dos triatomíneos do Brasil (vetores da doença de Chagas) / Iconographic atlas of triatomine Brazil (vectors of Chagas' disease)

O material conta com ilustrações e informações sobre a morfologia dos insetos, tamanho, habitat, ciclo de vida, além de mapas sobre a diversidade e distribuição geográfica das 66 espécies de barbeiros registradas até o momento...

Taxonomy and distribution of aquatic and semiaquatic Heteroptera (Insecta) from Cuba

Heteroptera is a worldwide distributed group of insects inhabiting both terrestrial and aquatic habitats and has an important ecological role. A survey of aquatic and semiaquatic Heteroptera from Cuba is provided based on literature reports and field collections. General data on species geographical distribution are given, along with altitude and collection season. Representatives of 86 species and morphospecies of the infraorders Dipsocoromorpha, Leptopodomorpha, Gerromorpha and Nepomorpha are listed, distributed in 35 genera and 16 families were found. Based on distributional data, a preference for habitats of stagnant water or slow current and lower altitudes is inferred. Fifteen species are distributed throughout the entire island. A higher species diversity was found in the Eastern sector, with 53 species (61.63%), 16 of which (18.60%) are confined to this area. The strongest biological similarity was found between Eastern and Western sectors (25%), and the weakest between Western and Central sectors (14%). Rev. Biol. Trop. 58 (3): 897-907. Epub 2010 September 01.

Heteroptera es un grupo de insectos que se distribuyen en todo el mundo, viven en ambientes terrestres y acuáticos, en los que tienen un papel ecológico muy importante. Mediante la literatura y colecciones en el campo se estudiaron los Heterópteros acuáticos y semiacuáticos de Cuba, junto con datos sobre la distribución geográfica de las especies, altitud y estaciones de colecta. Se enumeran representantes de 86 especies y morfospecies de los infraórdenes Dipsocoromorpha, Leptopodomorpha, Gerromorpha y Nepomorpha, con un total de 35 géneros y 16 familias. Los datos de distribución muestran una preferencia por los ambientes de aguas lentas o estancadas y áreas de baja altitud. Quince especies se distribuyen en toda la isla; el sector Oriental es el mejor representado, con 53 especies (61.63%), 16 de ellas (18.60%) confinadas a este sector. La similitud biológica más fuerte se encontró entre los sectores oriental y occidental (25%) y la más débil entre los sectores occidental y central (14%).

Taxonomy and distribution of aquatic and semiaquatic Heteroptera (Insecta) from Cuba.

Heteroptera is a worldwide distributed group of insects inhabiting both terrestrial and aquatic habitats and has an important ecological role. A survey of aquatic and semiaquatic Heteroptera from Cuba is provided based on literature reports and field collections. General data on species geographical distribution are given, along with altitude and collection season. Representatives of 86 species and morphospecies of the infraorders Dipsocoromorpha, Leptopodomorpha, Gerromorpha and Nepomorpha are listed, distributed in 35 genera and 16 families were found. Based on distributional data, a preference for habitats of stagnant water or slow current and lower altitudes is inferred. Fifteen species are distributed throughout the entire island. A higher species diversity was found in the Eastern sector, with 53 species (61.63%), 16 of which (18.60%) are confined to this area. The strongest biological similarity was found between Eastern and Western sectors (25%), and the weakest between Western and Central sectors (14%).