Trypanosoma evansi isolated from capybara (Hidrochaeris hidrochaeris)

A study was conducted to determine the morphological and biometric characteristics of Trypanosoma isolated from 50 capybaras animals, raised in captivity in the Peruvian Amazon. Trypanosoma was found in 14 blood samples using the microhaematocrit, wide drop, and Giemsa-stain methods and T. evansi was identified through morphological details in all 14 positive samples (the subterminal kinetoplast, the developed undulating membrane, and a long free flagellum were used for the identification of the agent).

Genetic epidemiology of fecal egg excretion during Schistosoma mansoni infection in an endemic area in Minas Gerais, Brazil

There is considerable variation in the level of fecal egg excretion during Schistosoma mansoni infections. Within a single endemic area, the distribution of egg counts is typically overdispersed, with the majority of eggs excreted coming from a minority of residents. The purpose of this study was to quantify the influence of genetic factors on patterns of fecal egg excretion in a rural study sample in Brazil. Individual fecal egg excretions, expressed in eggs per gram of feces, were determined by the Kato-Katz method on stool samples collected on three different days. Detailed genealogic information was gathered at the time of sampling, which allowed assignment of 461 individuals to 14 pedigrees containing between 3 and 422 individuals. Using a maximum likelihood variance decomposition approach, we performed quantitative genetic analyses to determine if genetic factors could partially account for the observed pattern of fecal egg excretion. The quantitative genetic analysis indicated that between 21-37% of the variation in S. mansoni egg counts was attributable to additive genetic factors and that shared environment, as assessed by common household, accounted for a further 12-21% of the observed variation. A maximum likelihood heritability (h²) estimate of 0.44 ± 0.14 (mean ± SE) was found for the 9,604 second- and higher-degree pairwise relationships in the study sample, which is consistent with the upper limit (37%) of the genetic factor determined in the variance decomposition analysis. These analyses point to the significant influence of additive host genes on the pattern of S. mansoni fecal egg excretion in this endemic area.

Schistosomiasis mansoni in Bananal (State of São Paulo, Brazil): I. Efficiency of diagnostic and treatment procedures

Bananal is an important focus of Schistosoma mansoni in the State of São Paulo. Accordingly, programmed active search for human cases, annual coproscopic surveys and treatment of infected cases were started in 1998, aiming at producing a sharp prevalence rate drop by the year 2000. S. mansoni eggs were searched for in two Kato-Katz slides per patient. Cases were followed up according to the routine of the local Family Health Program. In 1998, 130 samples out of 3,860 showed S. mansoni eggs; in 1999, 105 out of 3,550, and in 2000, 64 out of 3,528. Prevalence rates were 3.4%, 2.9%, and 1.8%, and average egg-counts 59, 64, and 79 eggs per gram of feces respectively. Prevalence rates decreased steadily after treatment, but persistently positive cases showed no significant decrease in parasite burdens. Egg count variation depended on sex and age bracket. Persistent residual cases admittedly preclude the eradication of this infection by only searching for and treating carriers. In addition, resistance to therapy and low sensitivity of fecal examinations, can not be ignored. Moderate to heavy worm burdens, frequently associated with hepatomegaly elsewhere, produced no serious cases in Bananal.

Use of polymerase chain reaction and enzymatic cleavage in the identification of Helicobacter spp. in gastric mucosa of human beings from North Paraná, Brazil

Helicobacter pylori is the most common gastric bacteria of human beings. Animal-borne helicobacter have been associated with gastritis, ulceration, and gastric mucosa-associated lymphoid-tissue lymphoma in people. We attempted to identify the species of Helicobacter spp. that infect human beings in north Paraná, Brazil. Samples of gastric mucosa from 38 dyspeptic patients were analyzed by optic microscopy on silver stained slides, polimerase chain reaction (PCR), and enzymatic cleavage. Genus and species-specific primers to H. pylori, H. heilmannii, H. felis, and consensual primers to H. bizzozeronii or H. salomonis were used. The PCR products were submitted to enzymatic cleavage by VspI (Helicobacter spp. product) and HinfI (species products) enzymes. Thirty-two out of 38 patients evaluated had 3.2 to 5 µm long bacteria that resembled H. pylori in Warthin-Starry stained slides and were positive to the genus Helicobacter by PCR. In 30 of these patients the bacteria were identified as H. pylori. Two samples positive by silver stain were negative to all species tested by PCR. None of the 38 samples was positive to animal-origin helicobacter species. These results show that PCR and enzymatic restriction are practical methods to identify the species of helicobacters present in gastric mucosa of human beings. People in north Paraná appear to be infected mostly with H. pylori.

Bloodstream infections in late-stage acquired immunodeficiency syndrome patients evaluated by a lysis centrifugation system

Opportunistic infections, which affect acquired immunodeficiency syndrome (Aids) patients, are frequently disseminated and may cause bloodstream infections (BSI). The aim of this study was to evaluate the main causes of BSI in Aids patients with advanced stage of the disease, with special emphasis on the identification of fungemia. During a 21 months period, all patients with Aids (CD4 < 200) and febrile syndrome admitted to 3 university hospitals were systematically evaluated. For each patient presenting fever, a pair of blood cultures was collected and processed by using a commercial lysis-centrifugation system. One hundred and eleven patients (75 males) with a mean age of 36 years (median 33 years) and mean CD4 count of 64 cells/ml were included. Among the 111 patients evaluated we documented 54 episodes of BSI, including 46 patients with truly systemic infections and 8 episodes considered as contaminants. BSI were caused by gram-positive bacteria (43%), fungi (20%), gram-negative bacteria (15%), mycobacteria (15%), and mixed flora (7%). The crude mortality rate of our patients was 39%, being 50% for patients with BSI and 31% for the others. In conclusion, BSI are a common related to systemic infections on Aids patients with advanced stage of disease and is associated with a high rate of mortality.

Schistosomiasis mansoni: follow-up of control program based on parasitologic and serologic methods in a Brazilian community of low endemicity

A field survey on schistosomiais was carried out in 1998, in the municipality of Pedro de Toledo, a low endemic area in the state of São Paulo, Brazil. According to the parasitologic Kato-Katz method, the prevalence rate was 1.6%, with an infection intensity of 40.9 eggs per gram of stool. By the immunofluorescence test (IFT) for detection of IgG and IgM antibodies in the serum, IgG-IFT and IgM-IFT, respectively, prevalence indices of 33.2% and 33.5% were observed. To assess the impact of the schistosomiasis control program in the area, parasitologic and serologic data obtained in 1998, analyzed according to the age, sex, and residence zone, were compared to previous data obtained in a epidemiologic study carried out in 1980, when prevalence indices were of 22.8% and 55.5%, respectively by Kato-Katz and IgG-IFT. A significant fall of the prevalence was observed, indicating that the control measures were effective. Nonetheless, residual transmission was observed, demonstrating the need for a joint effort to include new approaches for better understanding the real situation and improving the control of the disease in low endemic areas.

Haematozoan parasites of the lizard Ameiva ameiva (Teiidae) from Amazonian Brazil: a preliminary note

Three different haematozoan parasites are described in the blood of the teiid lizard Ameiva ameiva Linn. from North Brazil: one in the monocytes and the other two in erythrocytes. The leucocytic parasite is probably a species of Lainsonia Landau, 1973 (Lankesterellidae) as suggested by the presence of sporogonic stages in the internal organs, morphology of the blood forms (sporozoites), and their survival and accumulation in macrophages of the liver. One of the erythrocytic parasites produces encapsulated, stain-resistant forms in the peripheral blood, very similar to gametocytes of Hemolivia Petit et al., 1990. The other is morphologically very different and characteristically adheres to the host-cell nucleus. None of the parasites underwent development in the mosquitoes Culex quinquefasciatus and Aedes aegypti and their behaviour in other haematophagous hosts is under investigation. Mixed infections of the parasites commonly occur and this often creates difficulties in relating the tissue stages in the internal organs to the forms seen in the blood. Concomitant infections with a Plasmodium tropiduri-like malaria parasite were seen and were sometimes extremely heavy.

Antibacterial activity of extracts and neolignans from Piper regnellii (Miq.) C. DC. var. pallescens (C. DC.) Yunck

The evaluation of the activity of the aqueous and ethyl acetate extracts of the leaves of Piper regnellii was tested against gram-positive and gram-negative bacteria. The aqueous extractdisplayed a weak activity against Staphylococcus aureus and Bacillus subtilis with minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of 1000 µg/ml. The ethyl acetate extract presented a good activity against S. aureus and B. subtilis with MIC and MBC at 15.62 µg/ml. In contrast to the relative low MICs for gram-positive bacteria, gram-negative bacteria were not inhibited by the extracts at concentrations < 1000 mg/ml. The ethyl acetate extract was fractionated on silica gel into nine fractions. The hexane and chloroform fractions were active against S. aureus (MIC at 3.9 µg/ml) and B. subtilis (MIC at 3.9 and 7.8 µg/ml, respectively). Using bioactivity-directed fractionation, the hexane fraction was rechromatographed to yield the antimicrobial compounds 1, 2, 5, and 6identified as eupomatenoid-6, eupomatenoid-5, eupomatenoid-3, and conocarpan, respectively. The pure compounds 1 and 2 showed a good activity against S. aureus with MIC of 1.56 µg/ml and 3.12 µg/ml, respectively. Both compounds presented MIC of 3.12 µg/ml against B. subtilis. The pure compound 6 named as conocarpan was quite active against S. aureus and B. subtilis with MIC of 6.25 µg/ml. The antibacterial properties of P. regnellii justify its use in traditional medicine for the treatment of wounds, contaminated through bacteria infections.

The initial epidemiological studies in the low endemicity schistosomiasis area in esteio, Rio Grande do Sul, the southernmost Brazilian State, 1997 to 2000

Nor Biomphalaria glabrata neither Schistosoma mansoni were reported from Rio Grande do Sul, the southernmost Brazilian state before 1997. Their detection next to the Sinos River, Esteio, confirmed predictions of schistosomiasis expansion to the south. Parasitological examinations both in snails and fecal samples from the human population were performed from 1997 to 2000. The last 3 out of 5 surveys were performed after a preliminar serological screening procedure in a risk group identified at a population census. A total of 11 infected individuals were found infected and snails from 2 different sites were positive for S. mansoni. Samples from these 2 and other sites were identified as B. glabrata. Egg counts in feces were below 1 per gram in 6 out of 11 patients. Some socio-cultural perceptions of water contact activities next to the Sinos River may cause difficulties to control efforts, but they also may be partially acting against a very rapid increase in transmission intensity. The southernmost schistomiasis mansoni foci in Americas rise the alert for its ongoing expansion.

Bacterial and fungal colonization of burn wounds

A prospective study of fungal and bacterial flora of burn wounds was carried out from February 2004 to February 2005 at the Burns Unit of Hospital Regional da Asa Norte, Brasília, Brazil. During the period of the study, 203 patients were treated at the Burns Unit. Wound swab cultures were assessed at weekly intervals for four weeks. Three hundred and fifty four sampling procedures (surface swabs) were performed from the burn wounds. The study revealed that bacterial colonization reached 86.6% within the first week. Although the gram-negative organisms, as a group, were more predominant, Staphylococcus aureus (28.4%) was the most prevalent organism in the first week. It was however surpassed by Pseudomonas aeruginosa form third week onwards. For S. aureus and P. aeruginosa vancomycin and polymyxin were found to be the most effective drugs. Most of the isolates showed high level resistance to antimicrobial agents. Fungi were found to colonize the burn wound late during the second week postburn, with a peak incidence during the third and fourth weeks. Species identification of fungi revealed that Candida tropicalis was the most predominant, followed by Candida parapsilosis. It is crucial for every burn institution to determine the specific pattern of burn wound microbial colonization, the time-related changes in the dominant flora, and the antimicrobial sensitivity profiles. This would enable early treatment of imminent septic episodes with proper empirical systemic antibiotics, without waiting for culture results, thus improving the overall infection-related morbidity and mortality.

Antibacterial and cytotoxic activity of Brazilian plant extracts - Clusiaceae

Twelve extracts obtained from nine plants belonging to six different genera of Clusiaceae were analyzed against Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus and Enterococcus faecalis) bacteria using the microdilution broth assay. Tovomita aff. longifolia, T. brasiliensis, Clusia columnaris, Garcinia madruno, Haploclathra paniculata, and Caraipa grandifolia extracts showed significant results against the bacteria. The organic extract obtained from the leaves of T. aff. longifolia showed minimal inhibitory concentration (MIC) = 70 µg/ml and minimal bactericidal concentration (MBC) = 90 µg/ml against E. faecalis and the organic extract made with the stem of C. columnaris showed MIC = 180 µg/ml and MBC = 270 µg/ml against P. aeruginosa. None of the antibacterial extracts showed lethal activity against brine shrimp nauplii. On the other hand, both aqueous and organic extracts obtained from the aerial organs of Vismia guianensis that were cytotoxic to brine shrimp nauplii did not show a significant antibacterial activity in the assay.

Clinical outcome and risk factors related to extended-spectrum beta-lactamase-producing Klebsiella spp. infection among hospitalized patients

Over the past two decades, nosocomial infections caused by extended-spectrum beta-lactamase (ESBL)-producing Klebsiella spp. have become a major problem all around the world. This situation is of concern because there are limited antimicrobial options to treat patients infected with these pathogens, and also because this kind of resistance can spread to a wide variety of Gram-negative bacilli. Our objectives wereto evaluate among in-patients at a publicuniversity tertiary-care hospital with documented infection due to Klebsiella spp., which were the risk factors (cross-sectional analysis) and the clinical impact (prospective cohort) associated with an ESBL-producing strain. Study subjects were all patients admitted at the study hospital between April 2002 and October 2003, with a clinically and microbiologically confirmed infection caused by Klebsiella spp. at any body site, except infections restricted to the urinary tract. Of the 104 patients studied, 47 were infected with an ESBL-producing strain and 57 with a non-ESBL-producing strain. Independent risk factors associated with infection with an ESBL-producing strain were young age, exposure to mechanical ventilation, central venous catheter, use of any antimicrobial agent, and particularly use of a 4th generation cephalosporin or a quinolone. Length of stay was significant longer for patients infected with ESBL-producing strains than for those infected with non-ESBL-producing strains, although fatality rate was not significantly affected by ESBL-production in this cohort. In fact, mechanical ventilation and bacteremia were the only variables withindependent association withdeath detected in this investigation.

Antibacterial potentiality of Argemone mexicana solvent extracts against some pathogenic bacteria

The sensitivity of two Gram positive (Staphylococcus aureus and Bacillus subtilis) and two Gram negative (Escherichia coli and Pseudomonas aeruginosa) pathogenic multi-drug resistant bacteria was tested against the crude extracts (cold aqueous, hot aqueous, and methanol extracts) of leaves and seeds of Argemone mexicana L. (Papaveraceae) by agar well diffusion method. Though all the extracts were found effective, yet the methanol extract showed maximum inhibition against the test microorganisms followed by hot aqueous extract and cold aqueous extract.

Assessment of schistosomiasis, through school surveys, in the Forest Zone of Pernambuco, Brazil

This work had the objective of assessing the present epidemiological situation regarding schistosomiasis through performing Kato-Katz coproscopic tests on representative samples of schoolchildren from each of the 43 municipality of endemic area of the state of Pernambuco, Brazil. The methodology is recommended by the World Health Organization to conduct sampled surveys among children at elementary school levels, ideal target group for baseline surveys: (i) schools are accessible; (ii) the greatest prevalence of schistosomiasis is found within this group; (iii) the data gathered from this age group can be used for intervention within the community as a whole. The following infection indicators were utilized: positivity (percentage of individuals examined with eggs of Schistosoma mansoni in the feces) and severity (geometric mean number of eggs per gram of feces, epg). These indicators allowed the area in general and the municipalities in particular to be categorized into prevalence and severity classes for S. mansoni. The prevalence classes were: low (<10%), medium (> 10 and < 50%), and high (> 50%); the severity classes were: low (1-99 epg), moderate (100-399 epg), and severe (> 400 epg). For the geohelminthic diseases, the following indicators were used: positivity for each geohelminth (percentage of individuals examined with eggs of geohelminths), and cumulative positivity (percentage of individuals examined with eggs of at least one geohelminth). The municipalities were categorized by means of their cumulative positivity into the following geohelminth prevalence classes (WHO 2002): low (< 50%), medium (> 50 and < 70%), and high (> 70%). The study covered 271 schools in 179 different localities, thus giving a total of 11,234 examinations performed. The overall positivity for S. mansoni was 14.4% and the egg count for this parasite in the feces gave a geometric mean of 67.9 epg which suggests a low general state of infection. These results allow this mesoregion to be categorized as presenting medium prevalence and low severity of schistosomiasis. The overall positivity rates for the geohelminths, Ascaris lumbricoides, Ancylostomidae, and Trichuris trichiura were, respectively, 30.4, 10.1, and 27.8%; the cumulative positivity was 45.4%. These results allow this mesoregion to be categorized as presenting low prevalence of geohelminthic diseases. The data show some municipalities in Pernambuco with prevalence greater than 20%, while others presented parasite loads greater than 100 epg. These indicators attest to the significant morbidity due to schistosomiasis regarding to the severity of infections established in young populations.

Comparison between morphological and staining characteristics of live and dead eggs of Schistosoma mansoni

Schistosoma mansoni eggs are classified, according to morphological characteristics, as follows: viable mature and immature eggs; dead mature and immature eggs, shells and granulomas. The scope of this study was to compare the staining characteristics of different morphological types of eggs in the presence of fluorescent labels and vital dyes, aiming at differentiating live and dead eggs. The eggs were obtained from the intestines of infected mice, and put into saline 0.85%. The fluorescent labels were Hoechst 33258 and Acridine Orange + Ethidium Bromide and vital dyes (Trypan Blue 0.4% and Neutral Red 1%). When labelled with the probe Hoechst 33258, some immature eggs, morphologically considered viable, presented fluorescence (a staining characteristic detected only in dead eggs); mature eggs did not present fluorescence, and the other types of dead eggs, morphologically defined, showed fluorescence. As far as Acridine Orange + Ethidium Bromide are concerned, either the eggs considered to be live, or the dead ones, presented staining with green color, and only the hatched and motionless miracidium was stained with an orange color. Trypan Blue was not able to stain the eggs, considered to be dead but only dead miracidia which had emerged out of the shell. Neutral Red stained both live and dead eggs. Only the fluorescent Hoechst 33258 can be considered a useful tool for differentiation between dead and live eggs.