Chromoblastomycosis murine model and in vitro test to evaluate the sensitivity of Fonsecaea pedrosoi to ketoconazole, itraconazole and saperconazole

An experimental model of murine chromoblastomycosis and in vitro tests with Fonsecaea pedrosoi were used to test the sensitivity of this fungus to three different antimycotics. The experimental model was standardized in BALB/c mice inoculated intraperitoneally with a 10(6) CFU/ml suspension of a F. pedrosoi isolate. Clinical infection was evident after 5 days of inoculation. Three groups of 27 mice each were used in the experiment. One group was treated with ketoconazole (KTZ), another with itraconazole (ITZ) and the other with saperconazole (SPZ). Antimycotic therapy was continued for 21 days. The control group consisted of 40 mice which were inoculated, but not treated. Infection was documented by macroscopic and microscopic examination of affected tissue in addition to culture of tissue macerates. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) for the F. pedrosoi strain used were done. The in vitro results showed that SPZ was the most active with MIC 0.01 mg/ml and MFC 0.1 mg/ml, followed by ITZ. SPZ was also the most effective in vivo since 63% of the treated animals (p=0.01) showed a curative effect after the observation period. We concluded that SPZ had the best in vitro and in vivo activity against F. pedrosoi.

Attempts to Improve Xenodiagnosis: Comparative Test of Sensibility Using Rhodnius neglectus, Panstrongylus megistus, Triatoma vitticeps and Triatoma infestans in Endemic Areas of Brazil

From June 1984 to July 1992, 392 xenodiagnostic tests were applied on 264 patients with chronic Chagas disease from Brazilian endemic areas of Virgem da Lapa and Coronel Murta, situated in the Jequitinhonha Valley, in the State of Minas Gerais. The susceptibilities of Rhodnius neglectus, Panstrongylus megistus, Triatoma vitticeps and Triatoma infestans were compared. Most of the time 20 nymphs (fourth instar) of each species were applied to 161 women and 103 men aged between 5 and 83 years of age. The tests were prepared to compare the susceptibilities of two species at a time, using the same patients for each test. Results showed a xenopositiveness of 26.28% (103 tests) being 27.98% in women (68 positive in 243 applied tests) and 23.49% in men (35 positive in 149 applied tests). The relative frequency of xenopositiveness displayed a great superiority of P. megistus and T. vitticeps. In tests from type I, for example, P. megistus was the unique responsible for 10.73% of positive xenodiagnosis vs. only 0.98% in T. infestans. Other parameters analized in this work confirm this superiority, and corroborate that T. infestans can be replaced by P. megistus and /or T. vitticeps in order to upgrade the efficacy of xenodiagnosis

Tuberculin Skin Test and CD4+/CD8+ T Cell Counts in Adults Infected with the Human Immunodeficiency Virus in Medellín, Colombia

To evaluate the effect of BCG vaccination and T lymphocyte subpopulations on the reactivity to the tuberculin skin test, 113 asymtomatic HIV+ individuals were tuberculin tested by intradermal injection of 5TU of purified protein derivative and the levels of circulating lymphocyte (CD3, CD4 and CD8) subpopulations determined by indirect immunofluorescence. Ninety-two percent of the subjects included in the study were males. The mean age of the group was 32.1±7.4 years. Sixty-two percent presented a BCG scar. However, only 22% exhibited positive tuberculin reactions (³5mm) irrespective of the presence of the BCG scar. Tuberculin positive individuals exhibited higher CD4+ cell counts (p=0.004) and CD4+/CD8+ ratios (p=0.006) than tuberculin negative (<5mm) HIV+ individuals. The number of individuals with positive tuberculin reactions was significantly higher in subjects with more than 500 CD4+ lymphocytes/ml (p=0.02) or CD4+/CD8+ ratios ³1.12 (p=0.002). These results suggest that a prior BCG vaccination does not influence the reactivity to the tuberculin skin test in HIV+ asymptomatic individuals and that the number of CD4+ lymphocytes and the CD4+/CD8+ ratio positively correlate with the tuberculin reactivity

Evaluation of the Molluscicidal Properties of Euphorbia splendens var. hislopii (N.E.B.) Latex: Experimental Test in an Endemic Area in the State of Minas Gerais, Brazil

Following the positive results obtained regarding the molluscicidal properties of the latex of Euphorbia splendens that were corroborated in laboratory and field tests under restricted conditions, a field study was conducted in experimental streams located in an endemic area. After recording the average annual fluctuations of vectors in three streams, a solution of E. splendens latex at 12 ppm was applied in stream A, a solution of niclosamide at 3 ppm that was applied in stream B and a third stream (C) remained untreated for negative control. Applications of E. splendens and niclosamide resulted in a mortality of 100% among the snails collected in the streams A and B. No dead snails were found in the negative control stream. A monthly follow-up survey conducted during three consecutive months confirmed the return of vectors to both experimental streams treated with latex and niclosamide. This fact has called for a need to repeat application in order to reach the snails that remained buried in the mud substrate or escaped to the water edge, as well as, newly hatched snails that did not respond to the concentration of these molluscicides. Adults snails collected a month following treatment led us to believe that they had migrate from untreated areas of the streams to those previously treated

Genetic and Antigenic Analysis of Adenovirus Type 3 Strains Showing Intermediate Behavior in Standard Seroneutralization Test

During an epidemiological survey of acute respiratory infection in Rio de Janeiro, among 208 adenovirus isolates, we found two strains that we were not able, by a standard neutralization procedure, to distinguish between type 3 or 7. However, DNA restriction pattern for the two strains with different enzymes were analyzed and showed a typical Ad3h profile. Using a cross-neutralization test in which both Ad3p and Ad7p antisera were used in different concentration against 100 TCID50 of each adenovirus standard and both isolates, we were able to confirm that the two isolates belong to serotype 3. An hemagglutination inhibition test also corroborated the identification of both strains as adenovirus type 3. Comparing Ad3h and Ad3p genome, we observed 16 different restriction enzyme sites, three of which were located in genomic regions encoding polypeptides involved in neutralization sites

In vitro Comparison of Disk Diffusion and Agar Dilution Antibiotic Susceptibility Test Methods for Neisseria gonorrhoeae

At present, most Neisseria gonorrhoeae testing is done with ß-lactamase and agar dilution tests with common therapeutic agents. Generally, in bacteriological diagnosis laboratories in Argentina, study of antibiotic susceptibility of N.gonorrhoeae is based on ß-lactamase determination and agar dilution method with common therapeutic agents. The National Committee for Clinical Laboratory Standards (NCCLS) has recently described a disk diffusion test that produces results comparable to the reference agar dilution method for antibiotic susceptibility of N.gonorrhoeae, using a dispersion diagram for analyzing the correlation between both techniques. We obtained 57 gonococcal isolates from patients attending a clinic for sexually transmitted diseases in Tucumán, Argentina. Antibiotic susceptibility tests using agar dilution and disk diffusion techniques were compared. The established NCCLS interpretive criteria for both susceptibility methods appeared to be applicable to domestic gonococcal strains. The correlation between the MIC's and the zones of inhibition was studied for penicillin, ampicillin, cefoxitin, spectinomycin, cefotaxime, cephaloridine, cephalexin, tetracycline, norfloxacin and kanamycin. Dispersion diagrams showed a high correlation between both methods.

Immunofluorescence test on Schistosoma mansoni worm paraffin sections (IgM-IFT) for the study of schistosomiasis transmission in Campinas, São Paulo, Brazil

The detection of IgM antibodies for Schistosoma mansoni using gut-associated antigens (IgM-IFT) was compared to the parasitological Kato-Katz method for study of the transmission of schistosomiasis in an urban area in Campinas. About 400 schoolchildren whose ages ranged from 6 to 18 years, were observed for a period of two years. Blood samples on filter paper and fecal samples were collected, at intervals of six months. Serological (IgM-IFT) prevalence rates of 1.2%, 4.3%, 3.6%, 2.9% and 3.4% were obtained in five surveys carried out. S. mansoni eggs were detected in only one child out of the 225 children (0.4%) who were submitted to the Kato-Katz method (three slides for each fecal sample) in the 1st survey. Sixty eight children who submitted five blood samples, one for each survey, were found IFT negative throughout the study. No child was found to be IFT positive in all five surveys, and only four children showed IFT positive results in at least four surveys. Seroconversion from IFT negative to positive was observed from the 1st to the 2nd survey in six chidren, from the 2nd to the 3rd survey in three children, from the 3rd to the 4th survey in four children, and from the 4th to the 5th survey in two cases. However, confirmation of S. mansoni infection using the fecal examination was not possible in any of the cases. Also, in most of them the IFT result oscillated from negative to positive and vice versa. Our data implied that recent transmission of schistosomiasis in the study area was not possible.

Immunotherapy for Visceral Leishmaniasis: Ability of Factors Produced during Anti-leishmania Responses of Skin Test Positive Adults to Inhibit Peripheral Blood Mononuclear Cell Activities Associated with Visceral Leishmaniasis

The course of human Leishmania chagasi infections appears to be determined by the balance between type 1 (T1) CD4+ and CD8+ T suppressor (Ts) cell activities. Skin test positive adults living in hyperendemic areas who have no history of visceral leishmaniasis (VL) have T1 CD4+ T cell immunodominant responses against L. chagasi. The cytokines they secrete during anti-leishmania responses are a probable source of cytokines which inhibit the CD8+ Ts cells associated with VL. The ability of supernatants generated from peripheral blood mononuclear cells derived from skin test positive adults to reverse immune responses which appear to be mediated by CD8+ Ts cells was assessed in three sets of screening assays. The supernatants displayed three candidate factors. One, which could be explained by Leishmania antigens in the supernatant, decreased high endogenous IL-10 secretion characteristic of one class of VL patients. A second activity decreased high endogenous proliferation characteristic of the same class of patients without decreasing antigen specific proliferation. The third activity inhibited or killed CD8+ T cells but not CD4+ T cells. These activities might be useful in treating VL.

Humoral Immune Response Kinetics in Philander opossum and Didelphis marsupialis Infected and Immunized by Trypanosoma cruzi Employing an Immunofluorescence Antibody Test

Philander opossum and Didelphis marsupialis considered the most ancient mammals and an evolutionary success, maintain parasitism by Trypanosoma cruzi without developing any apparent disease or important tissue lesion. In order to elucidate this well-balanced interaction, we decided to compare the humoral immune response kinetics of the two didelphids naturally and experimentally infected with T. cruzi and immunized by different schedules of parasite antigens, employing an indirect fluorescence antibody test (IFAT). Both didelphids responded with high serological titers to different immunization routes, while the earliest response occurred with the intradermic route. Serological titers of naturally infected P. opossum showed a significant individual variation, while those of D. marsupialis remained stable during the entire follow-up period. The serological titers of the experimentally infected animals varied according to the inoculated strain. Our data suggest that (1) IFAT was sensitive for follow-up of P. opossum in natural and experimental T. cruzi infections; (2) both P. opossum and D. marsupialis are able to mount an efficient humoral immune response as compared to placental mammals; (3) experimentally infected P. opossum and D. marsupialis present distinct patterns of infection, depending on the subpopulation of T. cruzi, (4) the differences observed in the humoral immune responses between P. opossum and D. marsupialis, probably, reflect distinct strategies selected by these animals during their coevolution with T. cruzi.

Human Immunodeficiency Virus Seroprevalence among Inmates of the Penitentiary Complex of the Region of Campinas, State of São Paulo, Brazil

Six hundred and ninety three male inmates from three penitentiaries, two (A and B) maximum-security systems and one (C) minimum-security facility, located in Campinas, State of São Paulo, Brazil were studied for the presence of human immunodeficiency virus (HIV) antibodies, using a cross-sectional design. The search for anti-HIV antibodies in 693 samples of sera collected was carried out by two serological tests: (a) the Microparticle enzyme immunoassay-HIV-1 and HIV-2 (MEIA) (Abbott Laboratories) and (b) the Western Blot-HIV-1 (WB) (Cambridge Biotech Corporation) to confirm positive results with MEIA. Sera reactivity for HIV antibodies was 14.4%. The highest frequency of anti-HIV antibodies was found in the A and B maximum-security prisons: 17% and 21.5%, respectively. In prison C, the frequency of reagents was 10.9%. Seventy three inmates, initially negative in the MEIA test, were checked again five and seven months later. Three of them, all from the maximum-security facilities, became reactive in the MEIA test, with confirmation in the WB, suggesting that serological conversion had occurred after imprisonment.

Antimicrobial susceptibility of Campylobacter jejuni subsp. jejuni assessed by E-test and double dilution agar method in Southern Chile

The susceptibility patterns of 108 Campylobacter jejuni subsp. jejuni clinical strains, to six antimicrobial agents was determined by using the E-test and the double dilution agar methods. Using both metods, no strain was found to be resistant to ciprofloxacin, erythromycin and gentamicin, but two (1.8%) were resistant to tetracycline and all to aztreonam. Seven (6.5%) strains were resistant to ampicillin by the E-test and five (4.6%) by the double dilution agar method and by both meyhods. No great discrepancies were observed between both methods.

Age structure and abundance in populations of muscoid flies from a poultry facility in Southeast Brazil

Muscina stabulans, M. domestica, Chrysomya putoria, C. megacephala and Stomoxys calcitrans were the most abundant muscoid flies captured in a poultry facility in southeastern Brazil. We examined the gonadotrophic profiles of the females caught at different sites and different times and found that Mu. stabulans and M. domestica, the predominant species, presented similar gonadotrophic profiles only when captured on the manure under the cages, but very different and sometimes opposite gonadotrophic profiles when sampled from wooden posts, vegetation or electric cords. We also determined sex ratios and relative abundance for these two species and found significant differences between them. More than 50% of the females of both species of Chrysomya captured on manure carried eggs or exhibited signs of recent oviposition. The vast majority of S. calcitrans presented ovaries with eggs or signs of recent oviposition. A small proportion of them had ovaries in the recent emerged condition. Our data on ovarian stages, sex ratio and relative abundance allowed us to associate different gonadotrophic profiles with each site and characterize each site as a resting, ovipositing or mating site.

Diagnostic performance characteristics of rapid dipstick test for Plasmodium vivax malaria

We compared the diagnostic performance characteristics of newly developed method, the rapid dipstick test, which provides colorimetric determination by developing antibody to the lactate dehydrogenase enzyme of parasites, with conventional standard thick-blood film examination. For the rapid test, OptiMAL commercial kits were used. The results were also evaluated with clinical findings from patients. The parasites were determined by microscopic examination of thick-blood films from 81 patients with vivax malaria from southeastern Anatolia, Turkey. The OptiMAL test results were found to be negative in five patients who were diagnosed clinically and through thick-film testing as having vivax malaria. There was no false positivity observed with the OptiMAL test. We concluded that this rapid malaria test has a lower level of sensitivity than the classical thick-blood-film test for malaria, but that these methods have equal specificity.

Comparison between the Counter Immunoelectrophoresis Test and Mouse Neutralization Test for the Detection of Antibodies against Rabies Virus in Dog Sera

The detection of rabies antibodies is extremely valuable for epidemiological studies, determination of immune status in man, animals, and for the diagnosis of the disease. Several serological procedures have been described for this purpose. The present study reports a comparison between counterimmunoelectrophoresis test (CIET) and mouse neutralization test (MNT) in the detection of antibodies against rabies virus from 212 serum samples of vaccinated dogs. The agreement between both techniques was 79.7% and a significative association was demonstrated. The correlation coefficients between MNT and the CIET titers was determined considering 88 samples showing positive results in both techniques [CIET = 2 and MNT = 5 (0.13 IU/ml)] and resulted r² = 0.7926 (p < 0.001). The performance of CIET system was technically simple, cheap and rapid, and thereby it could be useful for serological monitoring of dog vaccination campaigns as well as for individual analysis.