Study of antiretroviral mutants in HIV patients with treatment failures and the effect of risk factors in the virological failures

INTRODUCTION: Information about HIV phenotypes of resistant to available ART and the influence of different risk factors on virological failures (VF) in Costa Rican HIV positive patients prior or during HAART is unknown. MATERIALS AND METHODS: Eighty nine samples, 72 VF and 17 basal (before treatment) were analyzed by examining resistant mutants in reverse transcriptase (RT) and protease (PT) regions using Trugene or LIPA genotyping kits. Sixty eight control patients were selected and relevant information was collected in a questionnaire. RESULTS: Poor adherence, presence of resistant mutations and number of treatment's changes were the only significant factors found (p = 0.006, 0.04 and 0.01 respectively). From 66 sequenced samples, 78%, 50% and 50% showed resistance to NRTI (nucleoside reverse transcriptase inhibitors), NNRT (non-nucleoside reverse transcriptase inhibitors) and PI (protease inhibitors), respectively. The most frequent mutations were M41L, M184V, and T215FY in RT and L62PI, L10FIRV and M36I in PT. DISCUSSION: The most important factor related to treatment response in this study was adherence to treatment. Mutations in RT were related to the treatment failure while the ones found in PT were secondary mutations which have been previously described to influence the selection of primary resistance mutations in these regions. The study reveals the urgency to detect resistant mutations in VF to be considered by physicians for selection of treatment schedule, to analyze basal HIV patients for monitoring of the spread of resistant mutations and the importance to reinforce the adherence in the patients for overall treatment outcome.

Morphometric changes of Triatoma flavida Neiva, 1911 (Hemiptera:Triatominae) in the transition from sylvatic to laboratory conditions

The one-generational metric changes occurring in Triatoma flavida (Hemiptera: Triatominae) when carried from its wild habitat (caves) to laboratory, were examined using traditional morphometric techniques. As for other species of Triatoma, Rhodnius or Panstrongylus studied in similar conditions, a significant reduction of head, thorax and wing size was observed. Sexual dimorphism of the wings, while present in the wild sample, was not detected anymore in the laboratory individuals. Biological significance and epidemiological importance are discussed.

Seroprevalence of selected viral, bacterial and parasitic infections among inpatients of a public psychiatric hospital of Mexico

We sought to determine the frequency of serological markers of selected infections in a population of psychiatric patients in Durango City, Mexico, and to determine whether there are any epidemiological characteristics of the subjects associated with the infections. One hundred and five inpatients of a public psychiatric hospital of Durango were examined for HBsAg, anti-HCV antibodies, anti-HIV antibodies, anti-Brucella antibodies, rapid plasma reagin and anti-Cysticercus antibodies by commercially available assays. Anti-Cysticercus antibodies were confirmed by Western blot and HBsAg by neutralization assay. Epidemiological data from each participant were also obtained. Seroprevalences of HBsAg, anti-HCV, anti-HIV, anti-Brucella, rapid plasma reagin and anti-Cysticercus antibodies found were 0.0%, 4.8%, 0.9%, 0.0%, 1.9%, and 0.9%, respectively. Overall, 9 (8.6%) inpatients showed seropositivity to any infection marker. We concluded that our psychiatric inpatients have serological evidence of a number of infections. HCV is an important pathogen among our psychiatric inpatients. Health care strategies for prevention and control of infections in Mexican psychiatric patients should be considered.

Neurotoxic activity and ultrastructural changes in muscles caused by the brown widow spider Latrodectus geometricus venom

Brown widow spider (Latrodectus geometricus) venom (BrWSV) produces few local lesions and intense systemic reactions such as cramps, harsh muscle pains, nausea, vomiting and hypertension. Approximately 16 protein bands under reducing conditions and ~ 14 bands under non-reducing conditions on a 12.5% sodium dodecyl sulfate-polyacrylamide gel electrophoresis were observed. Neurotoxic clinical manifestations were confirmed in vivo, while proteolytic activity was demonstrated on gelatine film. Severe ultrastructural damages in mice skeletal muscles were observed at 3, 6, 12 and 24 h postinjection with at total of 45 µg of venom protein. Infiltration of eosinophils and ruptures of the cellular membranes were observed in the muscles along with swelling of the nuclear cover and interruption of the collagen periodicity. Altered mitochondrias and autophage vacuoles, nuclear indentation and mitochondria without cristae, slight increment of intermyofibrillar and subsarcolemic spaces and myelinic figures formation were also observed. In the capillary, endothelial membrane unfolding into the lumen was noticed; along with myelinic figures compatible with a toxic myopathy. Swollen sarcotubular systems with lysis of membrane, intense mitochondria autophagia and areas without pinocytic vesicles were observed. Swollen mitochondria surrounded by necrotic areas, myofibrillar disorganization and big vacuolas of the sarcotubular system, degenerated mitochondrium with formation of myelinic figure was seen. Glycogenosomes with small particulate, muscle type glycogen was noticed. Autophagic vacuole (autophagolysosomes) and necrotic areas were also noticed. These damages may be due to interactive effects of the multifactorial action of venom components. However, Latrodectus geometricus venom molecules may also be utilized as neuro therapeutic tools, as they affect neuronal activities with high affinity and selectivity. To our knowledge, the present study is the first ultrastructural report in the literature of muscle injuries and neurological and proteolytic activities caused by BrWSV.

In vitro antimalarial activity and cytotoxicity of some selected cuban medicinal plants

Terrestrial plants have been demonstrated to be sources of antimalarial compounds. In Cuba, little is known about antimalarial potentials of plant species used as medicinals. For that reason, we evaluated the antimalarial activity of 14 plant species used in Cuba as antimalarial, antipyretic and/or antiparasitic. Hydroalcoholic extracts were prepared and tested in vitro for the antimalarial activity against Plasmodium falciparum Ghana strain and over human cell line MRC-5 to determine cytotoxicity. Parasite multiplication was determined microscopically by the direct count of Giemsa stained parasites. A colorimetric assay was used to quantify cytotoxicity. Nine extracts showed IC50 values lower than 100 µg/mL against P. falciparum, four extracts were classified as marginally active (SI < 4), one as partially active (Parthenium hysterophorus) exhibiting SI equal to 6.2 and two extracts as active (Bambusa vulgaris and Punica granatum), showing SI > 10. B. vulgaris showed the most potent and specific antiplasmodial action (IC50 = 4.7 µg/mL, SI = 28.9). Phytochemical characterization of active extracts confirmed the presence of triterpenoids in B. vulgaris and polar compounds with phenol free groups and fluorescent metabolites in both extracts as major phytocompounds, by thin layer chromatography. In conclusion, antimalarial use of B. vulgaris and P. hysterophorus was validated. B. vulgaris and P. granatum extracts were selected for follow-up because of their strong antimalarial activity.

Neutralization of bitis parviocula (Ethiopian mountain adder) venom by the south african institute of medical research (SAIMR) antivenom

BACKGROUND: The Ethiopian mountain adder (Bitis parviocula) is a viperid known only from a few locations in southwestern Ethiopia. METHODS: a total of 30 µg of B. arietans and B. parviocula venoms were run on a 10-20% Tricine gel. To assay lethality dose fifty (LD50), five groups of eight mice for each venom were used. Hemorrhagic activity for crude venom was tested. Fibrinogenolytic activity of crude venom was measured using (2.5 mg/mL) of fibrinogen solution and (0.03 mg/mL) of crude venom. Gelatinase activity of the venom was tested on a Kodak X-OMAT TM film. Crude venoms of B. parviocula and B. arietans were tested for their abilities to affect clotting time, clotting rate and platelet function on whole human blood. RESULTS: The (SAIMR) antivenom was confirmed in this study to neutralize the lethal activity of venom from Bitis parviocula. The ED50s of SAIMR antivenom on B. parviocula and B. arietans neutralized half of 18.2 and 66.7 mg of venom, respectively. The hemorrhagic activities (MHDs) of B. parviocula and B. arietans were 0.88 and 1.7 µg, respectively. Bitis arietans and B. parviocula venoms degradated α and β chains at different times. The γ chains remained unaffected. Bitis parviocula venom did not exhibit gelatinase activity, while B. arietans had a MGD of 6.9 µg. At 3 mg/mL, the crude venoms of B. parviocula and B. arietans did not significantly affect clotting time or clotting rate. CONCLUSIONS: The SAIMR antivenom is very effective in neutralizing the venom of B. parviocula and should be considered in treating envenomations by these snakes.

Prevalence of pediculosis capitis in children from a rural school in Yucatan, Mexico

We conducted an analytical cross-sectional survey to estimate the prevalence of and factors associated with active head lice infestation. In total 140 children, aged 6 to 16-years, from a public school in rural Yucatan, Mexico, were examined by wet-combing. A structured questionnaire was used to collect information on individuals and the conditions in the surrounding environment. Head lice infestation was found in 19 out of the 140 children tested (13.6%) and this was associated with both lower income (OR 9.9, 95% CI 2.15-45.79, p = 0.003) and a higher frequency of hair washing (OR 8, 95% CI 1.58-50, p = 0.012). Intersectoral control programs that take into account the socioeconomic differences of children should be implemented.

Antiretroviral activity of protease inhibitors against Toxoplasma gondii

The introduction of highly active antiretroviral therapy (HAART) has caused a marked reduction in the occurrence and severity of parasitic infections, including the toxoplasmic encephalitis (TE). These changes have been attributed to the restoration of cell-mediated immunity. This study was developed to examine the activity of six antiretroviral protease inhibitors (API) on Toxoplasma gondii tachyzoites. The six API showed anti-Toxoplasma activity, with IC50 value between 1.4 and 6.6 µg/mL. Further studies at the molecular level should be performed to clarify if the use of API could be beneficial or not for AIDS patients with TE.

FIRST REPORT OF METALLO-β-LACTAMASES PRODUCING Enterobacter spp. STRAINS FROM VENEZUELA

Clinical strains of Enterobacter were isolated from Cumana's Central Hospital in Venezuela, and classified as E. cloacae (21), E. aerogenes(7), E. intermedium (1), E. sakazakii (1) and three unclassified. The strains showed high levels of resistance, especially to SXT (58.1%), CRO (48.8%), CAZ (46.6%), PIP (46.4%), CIP (45.2%) and ATM (43.3%). This is the first report for South America of blaVIM-2 in two E. cloacae and one Enterobacter sp., which also showed multiple mechanisms of resistance. Both E. cloacaeshowed blaTEM-1, but only one showed blaCTX-M-15 gene, while no blaSHV was detected.

HIGH SENSITIVE PCR METHOD FOR DETECTION OF PATHOGENIC Leptospira spp. IN PARAFFIN-EMBEDDED TISSUES

This study describes the development and application of a new PCR assay for the specific detection of pathogenic leptospires and its comparison with a previously reported PCR protocol. New primers were designed for PCR optimization and evaluation in artificially-infected paraffin-embedded tissues. PCR was then applied to post-mortem, paraffin-embedded samples, followed by amplicon sequencing. The PCR was more efficient than the reported protocol, allowing the amplification of expected DNA fragment from the artificially infected samples and from 44% of the post-mortem samples. The sequences of PCR amplicons from different patients showed >99% homology with pathogenic leptospires DNA sequences. The applicability of a highly sensitive and specific tool to screen histological specimens for the detection of pathogenic Leptospira spp. would facilitate a better assessment of the prevalence and epidemiology of leptospirosis, which constitutes a health problem in many countries.

CHICKEN COOPS, Triatoma dimidiata INFESTATION AND ITS INFECTION WITH Trypanosoma cruzi IN A RURAL VILLAGE OF YUCATAN, MEXICO

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.

Analysis of Toxoplasma gondii antigens with sera from toxoplasmosis patients

Some proteins of the Toxoplasma gondii are recognized by IgG, IgM and IgA antibodies in patients with acute and chronic toxoplasmosis, depending on the strain and stage of the Toxoplasma. Sixty-nine sera from immunocompetent individuals were studied through the Western-Blot Test: 20 has an acute infection, 29 has a chronic toxoplasmosis infection and 20 were healthy (seronegatives). The protein analysis revealed by IgG and IgM antibodies were performed through the Immunoplot method in order to know their recognition frequency (f) and be valued as infection markers. In the acute phase, the IgM antibodies showed a recognition frequency (f = 0.60) for the 60kDa protein, and in the chronic phase the IgG antibodies showed a recognition frequency (f = 0.68) for the 12kDa protein. Seronegatives revealed no type of band. The protein of 12kDa can be a diagnostic marker of the chronic phase while protein 60kDa of the acute phase of toxoplasmosis.

Conservação de oocistos de Cryptosporidium em fezes para exame parasitológico

Por meio de dispositivo facilmente acessível que contém formol a 10% tamponado, dispensa refrigeração, permite execução de maneira higiênica, evita o mau odor e garante biossegurança é possível evidenciar satisfatoriamente oocistos de Cryptosporidium em fezes, sendo utilizado o método de Kinyoun. O sistema possibilita conservação adequada até durante período prolongado, facilitando a execução de tarefas assistências e epidemiológicas.

Blastocistose: controvérsias e indefinições

Blastocistose é a infecção causada pelo Blastocystis hominis. Está relacionada com várias controvérsias e indefinições, sem dúvida muito importantes sobretudo pelas implicações médico-assistenciais que suscitam. A propósito, pendência expressiva diz respeito à patogenicidade do referido protozoário, que precisa ser categoricamente definida. Ao lado dessa particularidade outros assuntos exigem elucidações através de pesquisas bem conduzidas, para que a blastocistose fique devidamente situada no contexto da saúde pública. Aspecto também digno de atenção é o diagnóstico pelo exame parasitológico de fezes, necessariamente executável por meio de métodos adequados, como o direto e os permanentes, exemplificados pelos que usam a a hematoxilina férrica ou a tionina. O emprego de técnicas impróprias propicia resultados falsos-negativos, conturbando o aconselhável bom conhecimento da real participação do microrganismo em questão.

Preliminary assessment of medicinal plants used as antimalarials in the southeastern Venezuelan Amazon

Eighteen species of medicinal plants used in the treatment of malaria in Bolívar State, Venezuela were recorded and they belonged to Compositae, Meliaceae, Anacardiaceae, Bixaceae, Boraginaceae, Caricaceae, Cucurbitaceae, Euphorbiaceae, Leguminosae, Myrtaceae, Phytolaccaceae, Plantaginaceae, Scrophulariaceae, Solanaceae and Verbenaceae families. Antimalarial plant activities have been linked to a range of compounds including anthroquinones, berberine, flavonoids, limonoids, naphthquinones, sesquiterpenes, quassinoids, indol and quinoline alkaloids.