Cysteine proteinases from promastigotes of <Emphasis Type="Italic">Leishmania</Emphasis> (<Emphasis Type="Italic">Viannia</Emphasis>) <Emphasis Type="Italic">braziliensis</Emphasis>

Leishmania (Viannia) braziliensis is the major causative agent of American tegumentary leishmaniasis, a disease that has a wide geographical distribution and is a severe public health problem. The cysteine proteinase B (CPB) from Leishmania spp. represents an important virulence factor. In this study, we characterized and localized cysteine proteinases in L. (V.) braziliensis promastigotes. By a combination of triton X-114 extraction, concanavalin A-affinity, and ion exchange chromatographies, we obtained an enriched fraction of hydrophobic proteins rich in mannose residues. This fraction contained two proteinases of 63 and 43 kDa, which were recognized by a CPB antiserum, and were partially sensitive to E-64 in enzymatic assays with the peptide Glu-Phe-Leu. In confocal microscopy, the CPB homologues localized in the peripheral region of the parasite. This data together with direct agglutination and flow cytometry assays suggest a surface localization of the CPB homologues. The incubation of intact promastigotes with phospholipase C reduced the number of CPB-positive cells, while anti-cross-reacting determinant and anti-CPB antisera recognized two polypeptides (63 and 43 kDa) derived from phospholipase C treatment, suggesting that some CPB isoforms may be glycosylphosphatidylinositol-anchored. Collectively, our results suggest the presence of CPB homologues in L. braziliensis surface and highlight the need for further studies on L. braziliensis cysteine proteinases, which require enrichment methods for enzymatic detection.     

Redescription of <Emphasis Type="Italic">Lemuricola</Emphasis> (<Emphasis Type="Italic">Madoxyuris</Emphasis>) <Emphasis Type="Italic">bauchoti</Emphasis> (Nematoda,Oxyuridae) from <Emphasis Type="Italic">Lemur catta</Emphasis> in Madagascar

Lemuricola (Madoxyuris) bauchoti Chabaud, Brygoo et Petter, 1965 is redescribed from material collected from the ring-tailed lemur, Lemur catta, from the Beza Mahafaly Special Reserve in Madagascar using the scanning electron microscope. This is a new host record and the first oxyurid reported from the ring-tailed lemur. Previously, records of each species of the subgenus Madoxyuris have been restricted to a single host species, but the close relationship between these nematodes and their Strepsirrhini hosts will only be proven when additional records fill in the gaps in their distribution.     

<Emphasis Type="Italic">Trypanosoma</Emphasis> (<Emphasis Type="Italic">Herpetosoma</Emphasis>) <Emphasis Type="Italic">kuseli</Emphasis> sp. n. (Protozoa: Kinetoplastida) in Siberian flying squirrels (<Emphasis Type="Italic">Pteromys volans</Emphasis>)

All trypanosome species classified in the subgenus Herpetosoma in sciurid hosts have been recorded from ground and tree squirrels to date, but not from any flying squirrels. We describe in this paper a novel trypanosome species, Trypanosoma (Herpetosoma) kuseli sp. n., from Siberian flying squirrels (Pteromys volans) imported from China, and compare it with T. (H.) otospermophili in Richardson's ground squirrels (Spermophilus richardsonii) and Columbian ground squirrels (Spermophilus columbianus) from the USA. Due to a short free flagellum, the new species appeared stumpy compared with T. otospermophili (length of free flagellum 7.0 +/- 0.8 microm, total length 32.1 +/- 0.8 microm, n = 13 and length of free flagellum 15.5 +/- 1.6 microm, total length 35.9 +/- 1.0 microm, n = 13, respectively). Another conspicuous morphological feature of the new species was an anteriorly positioned kinetoplast, found approximately at the midpoint between the nucleus and the posterior end. These characters have not been recorded from any squirrel Herpetosoma trypanosome species. Comparison of the nucleotide sequences of the small and large subunit rRNA genes indicated that T. kuseli sp. n. was more homologous to T. otospermophili than murid Herpetosoma species, such as T. grosi, T. lewisi, T. musculi, T. microti and T. evotomys.     

Antiviral biflavonoids from <Emphasis Type="Italic">Radix Wikstroemiae</Emphasis> (<Emphasis Type="Italic">Liaogewanggen</Emphasis>)

Background  

Radix Wikstroemiae is a common Chinese herbal medicine. The ethyl acetate fraction of the ethanolic extract of W. indica possesses potent in vitro antiviral activity against respiratory syncytial virus (RSV). This study aims to identify the antiviral components of the active fraction.     

Cercarial shedding from <Emphasis Type="Italic">Galba</Emphasis><Emphasis Type="Italic">truncatula</Emphasis> infected with <Emphasis Type="Italic">Fasciola</Emphasis><Emphasis Type="Italic">gigantica</Emphasis> of distinct geographic origins

Galba truncatula snails were experimentally infected with either of two different isolates of Fasciola gigantica, originating from Egypt or China, to determine the influence of these isolates on the characteristics of snail infections. The survival rates of G. truncatula on day 30 post-exposure were 90.0% and 60.2% in the Egyptian and Chinese groups, respectively. The frequency of cercaria-shedding snails within the Egyptian group was 79.8%, whereas in the Chinese group it was 22.4%. The parasite origin had a significant effect on the durations of the prepatent and patent periods. The mean number of cercariae shed from the Egyptian group was significantly greater than that shed from the Chinese group (a mean of 275.5 per cercaria-shedding snail compared with 29.0). These results could be explained by the fact that G. truncatula might be a natural intermediate host for F. gigantica in Egypt, and the greater adaptability of the Egyptian miracidia of F. gigantica to unusual snail hosts. These results demonstrate the influence of the geographic origin of the parasite on the success of trematodes infecting snails.     

<Emphasis Type="Italic">Leishmania</Emphasis> (<Emphasis Type="Italic">Viannia</Emphasis>) <Emphasis Type="Italic">shawi</Emphasis> purified antigens confer protection against murine cutaneous leishmaniasis

Objective  

Leishmania (Viannia) shawi was characterized only recently, and few studies concerning the immunogenic and protective properties of its antigens have been performed. The present study aimed to evaluate the protective potential of the five antigenic fractions isolated from L. (V.) shawi promastigotes in experimental cutaneous leishmaniasis.     

Subcellular localization of an extracellular serine protease in<Emphasis Type="Italic"> Leishmania</Emphasis> (<Emphasis Type="Italic">Leishmania</Emphasis>)<Emphasis Type="Italic"> amazonensis</Emphasis>

Extracellular proteolytic activity was detected in a Leishmania (L.) amazonensis culture supernatant and a 56-kDa protein was purified using (NH₄)₂SO₄ precipitation followed by affinity chromatography on aprotinin–agarose. A rabbit serum obtained against the 56-kDa extracellular serine protease was used in order to analyze its location in L. (L.) amazonensis parasites. Immunocytochemistry studies revealed that the enzyme is mainly found in the flagellar pocket and cytoplasmic vesicles of promastigote forms, whereas in amastigotes, it is located in electron-dense structures resembling megasomes. These results indicate that the 56-kDa serine protease is released into the extracellular environment through the flagellar pocket; and its intracellular location suggests either a correlated enzymatic activity or intracellular trafficking.     

Occurrence of <Emphasis Type="Italic">Cryptosporidium hominis</Emphasis> in pigeons (<Emphasis Type="Italic">Columba livia</Emphasis>)

This study demonstrated the presence of Cryptosporidium hominis in pigeons for the first time. Previously, C. hominis had been cited only in another bird species, Branta canadiensis. The present findings suggest that pigeons may act as mechanical vectors for this protozoan.     

Epidemiology of invasive neonatal <Emphasis Type="Italic">Cronobacter</Emphasis> (<Emphasis Type="Italic">Enterobacter sakazakii</Emphasis>) infections

About 120–150 neonatal Cronobacter spp. (Enterobacter sakazakii) infections have been described. An analysis of current case numbers, epidemiological measures and risk factors is warranted. Data of microbiologically confirmed cases, published between 2000 and 2008, have been analysed statistically. More than 100 neonatal Cronobacter infections have been reported in this period. The overall lethality of the 67 invasive infections was 26.9%. The lethality of Cronobacter meningitis, bacteraemia and necrotising enterocolitis (NEC) was calculated to be 41.9% (P < 0.0001), <10% and 19.0% (P < 0.05), respectively. Logistic regression models (P < 0.0001) revealed a higher gestational age at birth and parentage not from Europe as significant factors for a higher reporting probability of neonatal Cronobacter meningitis. Neonates with Cronobacter meningitis not originating from North America have a higher risk for lethal outcome than other neonatal Cronobacter infections (P < 0.0001). Continental differences of risk factors for Cronobacter meningitis and for the lethal outcome of neonatal meningitis should be elucidated. Neonatal Cronobacter infections are mainly associated with the contamination of infant formula and of the relevant cleaning and preparation equipment. Eleven neonatal Cronobacter infections, not caused by contaminated infant formula, have been retrieved. Other environmental sources of infection should be considered. Consistent and sufficiently informative data of invasive neonatal Cronobacter infections should be recorded in a centralized reporting system.     

<Emphasis Type="Italic">P</Emphasis>. <Emphasis Type="Italic">aeruginosa</Emphasis> Biofilms in CF Infection

Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. In cystic fibrosis (CF), P. aeruginosa causes acute and chronic lung infections that result in significant morbidity and mortality. P. aeruginosa possesses several traits that contribute to its ability to colonize and persist in acute and chronic infections. These include high resistance to antimicrobials, ability to form biofilms, plethora of virulence products, and metabolic versatility. In P. aeruginosa, a cell-to-cell communication process termed quorum sensing (QS) regulates many of these factors that contribute to its pathogenesis. Recent evidence suggests that the CF lung environment presents a specialized niche for P. aeruginosa. The relationship of P. aeruginosa QS, biofilm formation, and the CF lung environment is discussed.     

Functional polymorphisms in <Emphasis Type="Italic">XRCC</Emphasis>-<Emphasis Type="Italic">1</Emphasis> and <Emphasis Type="Italic">APE</Emphasis>-<Emphasis Type="Italic">1</Emphasis> contribute to increased apoptosis and risk of ulcerative colitis

Objective  

The present study was designed to investigate the role of X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1 (APE1) polymorphisms in apoptosis and the risk of ulcerative colitis (UC).     

<Emphasis Type="Italic">Trichinella</Emphasis> T6 and <Emphasis Type="Italic">Trichinella nativa</Emphasis> in Wolverines (<Emphasis Type="Italic">Gulo gulo</Emphasis>) from Nunavut,Canada

Infection of Trichinella spp. is common among animals in the Canadian Arctic. We determined the prevalence of Trichinella spp. infection in wolverines (Gulo gulo) from Nunavut, Canada. Diaphragms from 41 wolverines were examined by artificial digestion. Trichinella spp. larvae were detected in 36 (87.8%) examined animals. Trichinella T6 was detected in 33 (91.7%), Trichinella nativa in only one (2.8%), and a mixed Trichinella T6 and T. nativa infections were detected in two (5.6%) wolverines. This is the first report of Trichinella spp. infection in wolverines from Nunavut and the first report of sympatric Trichinella T6 and T. nativa in any host. The high prevalence of Trichinella spp. infection in combination with the natural history of wolverines suggests that the mustelid may be a key species in the natural cycle of these parasites in Arctic and Subarctic areas.     

Infections by the Yeast<Emphasis Type="Italic"> Kodomaea</Emphasis> (<Emphasis Type="Italic">Pichia</Emphasis>)<Emphasis Type="Italic"> ohmeri</Emphasis>: Two Cases and Literature Review

A 14-year-old boy who was neutropenic following chemotherapy for leukemia developed fungemia caused by the yeast Kodomaea ohmeri (Pichia ohmeri). The infection was cured by catheter removal and the use of fluconazole. A 74-year-old man who had undergone surgeries for a subcutaneous tumor developed polymicrobic cellulitis involving Kodomaea ohmeri. Despite surgical debridement and antibiotic therapy, the patient died of complications. Including these 2 cases, there have been 10 Kodomaea ohmeri infections reported thus far, all occurring in patients with pre-existing conditions. There have been seven cases of fungemia and one case each of peritonitis, funguria, and cellulitis. The treatment employed varied depending on the site/source of infection. Seven patients recovered and three died. The microbiological data available suggest that Kodomaea ohmeri can be identified definitively by biochemical tests and is susceptible to amphotericin B and either susceptible to or dose dependently susceptible to itraconazole and fluconazole.     

Persistent Colonization of Nine Cystic Fibrosis Patients with an<Emphasis Type="Italic"> Achromobacter</Emphasis> (<Emphasis Type="Italic">Alcaligenes</Emphasis>)<Emphasis Type="Italic"> xylosoxidans</Emphasis> Clone

The present study was conducted to investigate the increasing incidence of Achromobacter (previously Alcaligenes) xylosoxidans isolates being recovered from sputum samples of cystic fibrosis patients at a cystic fibrosis department for adults in Athens, Greece. During the 1-year study period, a total of 34 isolates were detected persistently in 9 of 71 cystic fibrosis patients. The isolates exhibited resistance to multiple antimicrobial agents. Isolates that were recovered repeatedly from each patient exhibited identical macrorestriction profiles with pulsed-field gel electrophoresis, indicating that the same strain persisted in the lungs of these patients. Isolates from five of the patients were genetically related, suggesting a common-source outbreak of Achromobacter xylosoxidans colonization or infection.     

Selective activity of extracts of <Emphasis Type="Italic">Margaritaria discoidea</Emphasis> and <Emphasis Type="Italic">Homalium africanum</Emphasis> on <Emphasis Type="Italic">Onchocerca ochengi</Emphasis>

Background  

The current treatment of onchocerciasis relies on the use of ivermectin which is only microfilaricidal and for which resistant parasite strains of veterinary importance are increasingly being detected. In the search for novel filaricides and alternative medicines, we investigated the selective activity of crude extracts of Margaritaria discoidea and Homalium africanum on Onchocerca ochengi, a model parasite for O. volvulus. These plants are used to treat the disease in North West Cameroon.     

Insecticidal properties of essential oils from <Emphasis Type="Italic">Lippia turbinata</Emphasis> and <Emphasis Type="Italic">Lippia polystachya</Emphasis> (Verbenaceae) against <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis> (Diptera: Culicidae)

Mosquitoes are important vectors of diseases to humans and domestic animals. Chemical control of vectors remains a main resource for the prevention and control of vector-borne diseases. Due to the development of insecticide resistance and risks to human health and the environment of synthetic compounds, the search for alternative pesticides is encouraged. This work assessed the insecticidal activity of essential oils (EOs) from Lippia turbinata and L. polystachya from Argentina on Culex quinquefasciatus mosquitoes. EOs were extracted by hydro-distillation and analyzed with gas–liquid chromatography and mass spectrometry. The insecticidal activity against mosquito larvae, pupae, and adults were evaluated according to World Health Organization protocols. Concentrations ranking from 10 to 160 ppm were assessed at 1, 2, 3, and 24 h posttreatment. The composition of the EO of L. polystachya and L. turbinata were qualitatively similar, with α-thujone and carvone as main constituent; differences were mostly due to the proportion of each component. β-caryophyllene was also an important constituent of the EO of L. turbinata. Both EO were larvicidal at concentrations of 80 ppm or higher, but only L. turbinata was adulticidal. No pupal mortality was detected. The potential of these EOs for vector control is discussed.     

In vitro efficacy of plant extracts and synthesized substances on <Emphasis Type="Italic">Rhipicephalus</Emphasis> (<Emphasis Type="Italic">Boophilus</Emphasis>) <Emphasis Type="Italic">Microplus</Emphasis> (Acari: Ixodidae)

Herbal drugs have been widely evaluated as an alternative method of parasite control, aiming to slow development of resistance and obtain low-cost biodegradable parasiticides. This study evaluated the in vitro efficacy on Rhipicephalus (Boophilus) microplus of extracts from Carapa guianensis seed oil, Cymbopogon martinii and Cymbopogon schoenanthus leaf essential oil, and Piper tuberculatum leaf crude extract and similar synthesized substances. In the immersion test, engorged females were evaluated in five dilutions ranging from 10% to 0.030625% concentration. In the larval test on impregnated filter paper, the concentration ranged from 10% to 0.02%. The treatments and controls were done in three replicates. Chemical analysis of the oils was performed by gas chromatography. The main compounds were oleic acid (46.8%) for C. guianensis and geraniol for C. martinii (81.4%), and C. schoenanthus (62.5%). The isolated and synthesized substances showed no significant effect on larvae and adult. C. martinii and P. tuberculatum showed the best efficacy on the engorged females. The LC₅₀ and LC₉₀ were 2.93% and 6.66% and 3.76% and 25.03%, respectively. In the larval test, the LC₅₀ and LC₉₀ obtained for C. martinii, P. tuberculatum, and C. schoenanthus were 0.47% and 0.63%, 0.41% and 0.79%, 0.57% and 0.96%, respectively. The fact that geraniol is present in greater quantities in C. martinii explains its higher activity in relation to C. shoenanthus. It is necessary to validate the in vivo use of safe and effective phytoparasiticidal substances. Efforts should be focused on developing formulations that enhance the efficacy in vivo and lengthen the residual period.