Surveillance of Amphotericin B and Azole Resistance in Aspergillus Isolated from Patients in a Tertiary Teaching Hospital

The genus Aspergillus harbors human infection-causing pathogens and is involved in the complex one-health challenge of antifungal resistance. Here, a 6-year retrospective study was conducted with Aspergillus spp. isolated from patients with invasive, chronic, and clinically suspected aspergillosis in a tertiary teaching hospital. A total of 64 Aspergillus spp. clinical isolates were investigated regarding molecular identification, biofilm, virulence in Galleria mellonella, antifungal susceptibility, and resistance to amphotericin B and azoles. Aspergillus section Fumigati (A. fumigatus sensu stricto, 62.5%) and section Flavi (A. flavus, 20.3%; A. parasiticus, 14%; and A. tamarii, 3.1%) have been identified. Aspergillus section Flavi clinical isolates were more virulent than section Fumigati clinical isolates. Furthermore, scant evidence supports a link between biofilm formation and virulence. The susceptibility of the Aspergillus spp. clinical isolates to itraconazole, posaconazole, voriconazole, and amphotericin B was evaluated. Most Aspergillus spp. clinical isolates (67.2%) had an AMB MIC value equal to or above 2 µg/mL, warning of a higher probability of therapeutic failure in the region under study. In general, the triazoles presented MIC values above the epidemiological cutoff value. The high triazole MIC values of A. fumigatus s.s. clinical isolates were investigated by sequencing the promoter region and cyp51A locus. The Cyp51A amino acid substitutions F46Y, M172V, N248T, N248K, D255E, and E427K were globally detected in 47.5% of A. fumigatus s.s. clinical isolates, and most of them are associated with high triazole MICs. Even so, the findings support voriconazole or itraconazole as the first therapeutic choice for treating Aspergillus infections. This study emphasizes the significance of continued surveillance of Aspergillus spp. infections to help overcome the gap in knowledge of the global fungal burden of infections and antifungal resistance, supporting public health initiatives.

Evaluation of bone repair with platelet-rich fibrin following the extraction of impacted third molars - randomized clinical trial

BACKGROUND

The aim of the present study was to evaluate postoperative effects of platelet-rich fibrin (PRF) in wound and bone healing, pain, swelling and periodontal complications outcomes after impacted third molars extraction.

MATERIAL AND METHODS

A prospective, randomized, split-mouth, double-blind clinical trial was conducted. PRF was placed within sockets following tooth removal and before suturing mucoperiosteal flap while no treatment was performed on control group's sockets. Patients were evaluated considering bone volume which was obtained in the 90-day postoperative period. Other variables included trabecular thickness, trabecular distance and grey values, pain, swelling, and wound healing. A Wilcoxon test and a t-Student test were used at a 5% significance level and a Friedman test was used to multiple comparisons.

RESULTS

Forty-four surgeries were performed in the present study. The patients' mean age was 22.41 (± 2.75 years) and 72.73% were women. PRF was associated to increased trabecular thickness and bone volume means (p < 0.001). The experimental group had significantly lower pain scores at 4h, 6h, 8h, 16h, 24h, and 72h (p ˂ 0.05). Mean swelling was lower on the experimental group (p < 0.001). The PRF group showed significant higher wound healing (p ˂ 0.001).

CONCLUSIONS

Alveolar filling with PRF improves wound and bone healing after extractions while also decreasing pain and swelling in the postoperative period.

In vitro and in vivo photodynamic efficacies of novel and conventional phenothiazinium photosensitizers against multidrug-resistant Candida auris

The fast-emerging and multidrug-resistant Candida auris is the first fungal pathogen to be considered a threat to global public health. Thus, there is a high unmet medical need to develop new therapeutic strategies to control this species. Antimicrobial photodynamic therapy (APDT) is a promising alternative that simultaneously targets and damages numerous microbial biomolecules. Here, we investigated the in vitro and in vivo effects of APDT with four phenothiazinium photosensitizers: (i) methylene blue (MB), (ii) toluidine blue (TBO), and two MB derivatives, (iii) new methylene blue (NMBN) and (iv) the pentacyclic derivative S137, against C. auris. To measure the in vitro efficacy of each PS, minimal inhibitory concentrations (MICs) and survival fraction were determined. Also, the efficiency of APDT was evaluated in vivo with the Galleria mellonella insect model for infection and treatment. Although the C. auris strain used in our study was shown to be resistant to the most-commonly used clinical antifungals, it could not withstand the damages imposed by APDT with any of the four photosensitizers. However, for the in vivo model, only APDT performed with S137 allowed survival of infected G. mellonella larvae. Our results show that structural and chemical properties of the photosensitizers play a major role on the outcomes of in vivo APDT and underscore the need to synthesize and develop novel photosensitizing molecules against multidrug-resistant microorganisms.

Cryptococcosis by Cryptococcus neoformans/Cryptococcus gattii Species Complexes in non-HIV-Infected Patients in Southeastern Brazil

INTRODUCTION:

The clinical manifestations of cryptococcosis are usually associated with the infecting agents Cryptococcus neoformans (CN) and C. gattii (CG) species complexes and the host. In this study, non-HIV-infected patients, at a university hospital in southeastern Brazil, had epidemiological and clinical data associated with cryptococcal disease and isolated Cryptococcus species: CN - 24 patients and CG - 12 patients.

METHODS:

The comparison was comprised of demographic data, predisposing factors, clinical and laboratory manifestations, and outcomes of cryptococcosis patients treated between 2000 and 2016. Immunocompetent and immunosuppressed patients were also compared, irrespective of the infecting species. Cryptococcus spp. were genotyped by PCR-RFLP analysis of the URA5 gene.

RESULTS:

Infections by the CN species complex (100% VNI genotype) were associated with drug immunosuppression and fungemia, and patients infected with the CG species complex (83% VG II and 17% VGI genotypes) had more evident environmental exposure and higher humoral response. CN and CG affected patients with or without comorbidities.

CONCLUSIONS:

Diabetes mellitus, other chronic non-infectious diseases, and alcoholism were likely predisposing factors for infection by both CN and CG species. Immunocompetent patients, independent of the infecting Cryptococcus species complexes, showed a higher occurrence of meningitis and a trend toward less fungal dissemination and longer survival than immunosuppressed hosts.

Clinical Outcome of Kidney Transplant Patients on the Allograft Function, Loss, Effects of HLA-DQB1-DSA+, and Graft Survival

INTRODUCTION

Matching for HLA-DQB1 molecules and anti-DQ donor-specific antibodies (DSAs) has been less studied to allocate transplants from deceased donors in developed countries. The aim of this study was to evaluate the clinical outcome of 519 kidney transplant recipients on the allograft function, loss, and survival and with emphasis on effects of HLA-DQB1-DSA⁺ at minimum of 10 years' follow-up.

METHODS

Five hundred nineteen kidney transplant patients were allocated into 3 groups (G) by immunologic profiles, namely, G1 (SPI-SAB HLA-DQ negative [DQ^-]), G2 (SPI-SAB HLA-DQ positive DSA negative [DQ⁺/DSA^-]), and G3 (SPI-SAB HLA-DQ DSA positive [DQ⁺ DSA⁺]), and the outcomes were reported until 10 years after transplantation.

RESULTS

The proportion of rejection episodes was higher in G3 (25.0% and 26.32%, respectively) than in G1 (8.63% and 6.82%, respectively) and G2 (10.0% and 0%, respectively; P = .047 and P = .014, respectively). In G3, 3 patients lost their grafts by antibody-mediated rejection. Patients who received kidneys from deceased donors (G3) showed worse graft survival rates than those from G1 donors (P = .001). Patients from G3 had a 2.18-fold higher risk of graft loss than patients from G1 (P = .028).

CONCLUSION

Allograft function was worse in G3 than in G2 or G1, and graft losses were more frequent by T-cell-mediated rejection in G1, and graft losses by antibody-mediated rejection were similar in G1 and G3 due to HLA class I (A1, 11 and B 8, 52) and HLA class II by DR7 and DQ 2, 5, 9 DSA, respectively. Allograft survival decreased in patients with HLA-DQB1 DSA. The risk of graft loss was 1.75-fold that in patients who received transplants from living donors.

An open-label randomized clinical trial to evaluate the efficacy of everolimus versus tacrolimus in triple maintenance immunosuppressive therapy for kidney transplant patients

Tacrolimus (TAC), a calcineurin inhibitor, and everolimus (EVL), an mTOR inhibitor, have been used as immunosuppressive (ISS) drugs in post-kidney transplantation therapy. The objective of this study was to compare the efficacy of EVL vs TAC in the ISS maintenance triple therapy. Ninety-seven kidney transplant patients, who received triple maintenance therapy with TAC, mycophenolate mofetil (MMF), and methyl prednisone (PRED), were evaluated. After four months of post-kidney transplant therapy, 30 patients enrolled in a randomized controlled clinical trial, in which 16 patients received TAC+MMF+PRED (cohort 1), and 14 patients switched to EVL+MMF+PRED (cohort 2). The patients were followed-up for 36 months. Two patients from cohort 1 lost their grafts after one year due to non-adherence. Two patients from cohort 2 had intolerance to mTOR inhibitors and were switched back to TAC from EVL. One case (6.25%) in cohort 1 and three cases (21.43%) in cohort 2 of acute T-cell-mediated rejection was observed. Antibody-mediated acute rejection (ABMAR) was observed in four patients (25.0%) in cohort 1, and antibody-mediated chronic rejection (ABMCR) was observed in two patients (12.50%). One patient from cohort 2 lost the graft after 15 months due to polyomavirus infection. The graft survival rate was 87.50% in cohort 1 and 92.86% in cohort 2. This clinical trial showed that the EVL+MMF+PRED triple maintenance therapy was efficacious compared with TAC during 32 months of follow-up. However, further studies are needed to confirm the efficacy of this regimen for long-term graft survival.

Phylogenetic Species of Paracoccidioides spp. Isolated from Clinical and Environmental Samples in a Hyperendemic Area of Paracoccidioidomycosis in Southeastern Brazil

Paracoccidioides brasiliensis complex and P. lutzii are the etiological agents of paracoccidioidomycosis. The geographic distribution of these species in South America is still poorly comprehended. Fifty samples of Paracoccidioides spp. were genotyped, with 46 clinical isolates predominantly isolated in the geographic area of Ribeirão Preto, SP, and four environmental isolates collected in Ibiá, MG, southeastern Brazil. These isolates were evaluated by PCR-RFLP (Restriction Fragment Length Polymorphism) of the tub1 gene and the sequencing of the gp43 exon 2 loci. The species P. lutzii was confirmed by sequencing the internal transcribed spacer (ITS) region of the ribosomal DNA. P. brasiliensis sensu stricto S1b (n = 42) and S1a (n = 5), P. americana (n = 1), P. restrepiensis (n = 1), and P. lutzii (n = 1) were identified among the clinical isolates. All the environmental isolates were characterized as P. brasiliensis sensu stricto S1b. The patient infection by P. lutzii, P. americana (PS2), and one isolate of P. brasiliensis sensu stricto S1b most likely occurred in a geographic area far from the fungal isolation site. No association was found between the infecting genotype and the disease form. These results expand the knowledge of the Paracoccidioides species distribution and emphasize that human migration must also be considered to pinpoint the genotypes in the endemic area.

Trauma and work factors as predictors of firefighters' psychiatric distress

BACKGROUND

Studies into the mental health of firefighters have primarily focussed on individual factors (e.g. biological and psychological factors). Little is known about how exposure to traumatic events and psychosocial and organizational work factors influence firefighters' mental health despite the evidence that these are important for employee health.

AIMS

To study job demands, job control, social support and operational trauma as predictors of firefighters' psychiatric morbidity, and whether job control and social support moderate these relationships.

METHODS

Participants were drawn from a longitudinal cohort study of firefighters in Brazil. Portuguese-language variants of the Self-Report Questionnaire (SRQ-20) and Traumatic Events List for Emergency Professionals measured psychiatric morbidity and exposure to traumatic events. Job demands, job control and social support were measured by the Job Stress Scale. Hierarchical regressions were run controlling for socio-demographics and previous psychiatric morbidity. Subsequent regression steps first included the proposed predictors followed by their interactions.

RESULTS

Thirteen per cent of the sample (n = 40/312) met the caseness criteria indicating psychiatric morbidity. Operational trauma, job demands, job control and social support predicted psychiatric morbidity. Both job control and social support functioned as moderators and where these moderators were high, the job demands and psychiatric morbidity relationships were weaker.

CONCLUSIONS

These findings show that psychosocial factors and operational trauma predict firefighters' psychiatric morbidity. Crucially, the results that improving social support and job control could mitigate the detrimental influence of job demands highlight the need for more research and practice towards organizational-level interventions.

Characterization of a Paracoccidioides spp. strain from southeastern Brazil genotyped as Paracoccidioides restrepiensis (PS3) and review of this phylogenetic species

Phylogenetic species of Paracoccidioides brasiliensis complex (S1a and S1b, PS2, PS3, and PS4) and Paracoccidioides lutzii are agents of paracoccidioidomycosis, an endemic fungal disease in Latin America. P. restrepiensis (PS3 genotype) was classified as monophyletic and geographically restricted to Colombia and neighboring territories. BAT (or Pb-327B) was isolated from a patient living in the southeast region of Brazil but with genotype similar to Colombian Paracoccidioides spp. strains. This study aimed to define the phylogenetic species of BAT isolate by using additional genotyping methods, as well as reviewing the epidemiological and clinical studies related to P. restrepiensis isolates. Genomic DNA of BAT isolate and reference strains of P. brasiliensis sensu stricto (S1b), P. americana (PS2), P. restrepiensis (PS3), and P. lutzii were analyzed by conventional polymerase chain reaction (PCR) of partial gp43 exon 2 loci, by PCR-RFLP technique of tub1 gene, and by sequencing of the whole gp43 exon 2 loci. Here, we show that BAT isolate belongs to P. restrepiensis species, which is an unusual identification in southeastern Brazil, where P. brasiliensis sensu stricto is the prevalent genotype. This identification has relevance for geographical distribution and propagation of the genus Paracoccidioides in South America.

Minimum concentration of Amphotericin B in serum according to the formulation, dose, and daily or prolonged intermittent therapeutic regimen

INTRODUCTION:

The therapeutic efficacy of daily amphotericin B infusion is related to its maximum concentration in blood; however, trough levels may be useful in intermittent regimens of this antifungal drug.

METHODS:

High performance liquid chromatography (HPLC) was used to determine the minimum concentration (Cmin) of amphotericin B in the serum of patients receiving deoxycholate (D-Amph) or liposomal amphotericin B (L-AmB) for the treatment of cryptococcal meningitis (n=28), histoplasmosis (n=8), paracoccidioidomycosis (n=1), and leishmaniasis (n=1).

RESULTS:

Daily use of D-Amph 30 to 50 mg or L-AmB 50 mg resulted in a similar Cmin, but a significant increase ocurred with L-AmB 100 mg/day. The geometric mean Cmin tended to decrease with a reduction in the dose and frequency of intermittent L-AmB infusions: 357 ng/mL (100 mg 4 to 5 times/week) > 263 ng/mL (50 mg 4 to 5 times/week) > 227 ng/mL (50 mg 1 to 3 times/week). The impact on Cmin was variable in patients whose dose or therapeutic scheme was changed, especially when administered the intermittent infusion of amphotericin B. The mean Cmin for each L-AmB schedule of intermittent therapy was equal or higher than the minimum inhibitory concentration of amphotericin B against Cryptococcus isolates from 10/12 patients. The Cmin of amphotericin B in patients with cryptococcal meningitis was comparable between those that survived or died.

CONCLUSIONS:

By evaluating the Cmin of amphotericin B, we demonstrated the therapeutic potential of its intermittent use including in the consolidation phase of neurocryptococcosis treatment, despite the great variability in serum levels among patients.

Delayed Graft Function, Predictive Factors, and 7-Year Outcome of Deceased Donor Kidney Transplant Recipients With Different Immunologic Profiles

BACKGROUND

Delayed graft function (DGF) is the major post-transplant cause of deleterious effects to the allograft and is associated with poor allograft survival. The aim of this study was to report the outcomes of 236 kidney transplant recipients with different immunologic profiles.

METHODS

All patients underwent transplantation (2008-2016) with a deceased donor at the University Hospital of the Faculty of Medical Science, Belo Horizonte, Minas Gerais, Brazil. Patients were classified into 3 groups according to immunologic profiles: nonsensitized (NS), sensitized without donor-specific antibody (SDSA-), or sensitized with donor-specific antibody (SDSA+).

RESULTS

DGF was observed in 128 (54.24%), including 63 (49.22%) NS, 51 (39.84%) SDSA-, and 14 (10.94%) SDSA+ patients. The development of DGF was associated with dialysis for ≥49.25 months (odds ratio [OR] 2.30), donor age ≥42.25 years (OR 1.77), donor end creatinine level >1.22 mg/dL (OR 1.94), and cold ischemia time >12 hours (OR 2.45). Of the 55 patients with rejections, 37 (15.68%) had T-cell-mediated rejection (TCMR) and 18 (7.63%) had antibody-mediated rejection (AMR). Nine patients (16.36%) exhibited graft loss, 2 (0.85%) via TCMR in the SDSA- DGF+ group and 7 (2.97%) via AMR, including 2 NS DGF-, 2 SDSA- DGF-, 1 SDSA- DGF+, and 2 SDSA+ DGF+ patients. Graft survival significantly differed between the NSDGF- and SDSA- DGF+ groups (P = .014) and between the NS DGF- and SDSA+ DGF- groups (P = .036).

CONCLUSION

In the 7-year period following transplantation, TCMR was more prevalent than AMR among patients with DGF. Graft loss was less prevalent among patients with TCMR than among those with AMR.

Identification of the novel allele, HLA-B*14:56, in a Brazilian individual

Novel allele, HLA-B*14:56, generated by a gene conversion event was identified in a Brazilian individual.

A novel allele, HLA-B*51:220, identified in an individual from south of Brazil

Novel allele, HLA-B*51:220 generated by a gene conversion event was identified in a Brazilian individual.

Fluconazole levels in serum and cerebrospinal fluid according to daily dosage in patients with cryptococcosis and other fungal infections

Fluconazole is extensively used for the treatment of candidiasis and cryptococcosis. Among other factors, successful treatment is related to appropriate fluconazole levels in blood and cerebrospinal fluid. In the present study, fluconazole levels were determined in 15 patients, 14 of whom had AIDS and 13 had neurocryptococcosis. The only selection criterion was treatment with fluconazole, which was performed with a generic or similar form of the drug. Fluconazole level was determined by high performance liquid chromatography and the susceptibility profile of Cryptococcus spp. isolated from the patients was assessed by broth microdilution. Blood and cerebrospinal fluid fluconazole levels were found to be related to the fluconazole daily dose, and exceeded the minimum inhibitory concentration of this antifungal for the Cryptococcus spp. isolates. A good correlation was observed between serum and cerebrospinal fluid drug concentration. In conclusion, treatment with non-original fluconazole under usual medical practice conditions results in appropriate blood and cerebrospinal fluid levels of the drug for inhibiting Cryptococcus spp. susceptible to this antifungal drug. The relatively common failures of neurocryptococcosis treatment appear not to be due to insufficient fluconazole levels in the cerebrospinal fluid, especially with the use of daily doses of 400–800 mg.

Two novel alleles, HLA-A*02:643N and HLA-B*53:44, identified in Brazilian individuals

Two novel alleles, HLA-A*02:643N and HLA-B*53:44, generated by different mechanisms, were identified in Brazilian individuals.

Cryptococcus neoformans and C. gattii isolates from both HIV-infected and uninfected patients: antifungal susceptibility and outcome of cryptococcal disease

One of the factors causing treatment failure in cryptococcosis is the resistance of Cryptococcus spp. to antifungal drugs, which has motivated the susceptibility assessment of isolates from patients with cryptococcosis, different clinical conditions and infections outcomes. Clinical isolates of Cryptococcus spp. from three different groups of patients were studied in the present investigation: 19 HIV-positive patients with relapsing and/or refractory meningitis (Group 1), 30 HIV-positive patients who experienced a single and limited episode of cryptococcosis (Group 2), and 19 HIV-negative patients with cryptococcosis (Group 3). Eighty C. neoformans var. grubii isolates and 7 C. gattii isolates were studied. The minimum inhibitory concentration (MIC) of amphotericin B, azole drugs and flucytosine was determined for Cryptococcus spp. by broth microdilution test and E-test. The MIC50 and MIC90 were 0.25 and 0.50 µg/mL for amphotericin B, 4.0 and 8.0 µg /mL for fluconazole, 0.06 and 0.25 µg/mL for itraconazole, 0.25 and 0.50 µg/mL for voriconazole, and 8.0 and 16.0 µg/mL for flucytosine, respectively. Amphotericin B and itraconazole showed higher MICs for C. neoformans var. grubii and C. gattii, respectively. The MICs of fluconazole and itraconazole obtained with the E-test were higher than those obtained with broth microdilution. Isolates from non-HIV coinfected were less sensitive to the azoles. There was no difference in the susceptibility of C. neoformans var. grubii isolates from patients with a favorable or unfavorable outcome or along the episodes of relapsing and/or refractory meningitis.

Kidney Transplantation With Ultralong-Term (42 Years) Survival of a 100-Year-Old Graft

BACKGROUND

In kidney transplantation, long-term graft survival has improved over the last few decades. Study to understand ultralong-term graft survival with graft functioning is rare, but a few researchers have tried to explain the factors involved in long-term graft survival. In this report, we explore the predictive factors that can be involved in ultralong-term graft survival.

MATERIAL AND METHODS

Immunologic evaluations of the patients were performed using crossmatch (XM), serological, and high-resolution HLA typing for 8 loci. A transplant recipient was treated with azathioprine as immunosuppressive monotherapy for 42 years. Donor-specific antibodies (DSAs) were identified using panel reactive antibody single antigen beads (PRA-SAB) followed by EpVix and Matchmaker epitope analysis to define the immunogenic mismatch eplets.

RESULTS

The patient and donor were haploidentical for 7 loci and identical at the HLA-DPA1* locus. Among 61 identified eplet mismatches, DSAs were not detected against 59 eplets after 42 years of exposure to the patient's immune system with the exceptions of antibodies against the public eplets 9Y and 9YL from allele HLA-DPB1*03:01, and the transplanted kidney exhibited preserved structures.

CONCLUSION

The transplanted kidney has the preserved structure based on magnetic resonance imaging, the 2 DSAs were not deleterious to the graft until now, and the eplet mismatches were considered acceptable. The patient is in good clinical condition living with a 100-year-old graft, a serum creatinine level of 1.5 mg/dL, and an estimated glomerular filtration rate of 50 mL/1.72 m².

Refractory and/or Relapsing Cryptococcosis Associated with Acquired Immune Deficiency Syndrome: Clinical Features, Genotype, and Virulence Factors of Cryptococcus spp. Isolates

Refractory and relapsing crytocococcosis in acquired immune deficiency syndrome (AIDS) patients have a poor prognosis. The risk factors for this complicated infection course were evaluated by comparing refractory and/or relapsing cryptococcosis in human immunodeficiency virus-coinfected patients (cohort 1) with another group of AIDS patients who adequately responded to antifungals (cohort 2). Except for one isolate of Cryptococcus gattii from a cohort 2 case, all other isolates were identified as Cryptococcus neoformans var. grubii, sex type α, genotype VNI, including Cryptococcus reisolated from the relapse or in the refractory state. No differences were observed with respect to Cryptococcus capsule size and in the melanin and phospholipase production. The cohort 1 patients presented higher prevalence of cryptococcemia, cerebral dissemination, chronic liver disease, and leucopenia, and have increased death rate. Apparently, the refractory and/or relapsing cryptococcosis in the AIDS patients were more related to the host and the extent of the infection than to the fungal characteristics.

A novel HLA allele, HLA-DRB1*13:204, detected in a Brazilian unrelated hematopoietic stem cell donor

The HLA-DRB1*13:204 allele differs from HLA*13:64 by two nucleotide substitutions at positions 181 and 189 in the exon 2.

Primary cutaneous cryptococcosis in an immunocompetent patient due to Cryptococcus gattii molecular type VGI in Brazil: a case report and review of literature

Primary Cutaneous Cryptococcosis is an uncommon infection caused by the yeast Cryptococcus neoformans and C. gattii. Few case reports are available in the literature describing in detail primary cutaneous cryptococcosis due to C. gattii in immunocompetent patients. Herein, we present a case of a 68-year-old immunocompetent male patient with erythematous nodular lesions on the right forearm due to C. gattii mating-type α and molecular type VGI. The virulence factors test was performed for capsule diameter, melanin production and phospholipase activity. In vitro fluconazole testing showed the sensitivity profile of this clinical isolate. In addition, a review of the literature on this subject was carried out and verified that this is the first reported case of VGI in the south-east region of Brazil.

Immunodiagnosis of human neurocysticercosis using a synthetic peptide selected by phage-display

The usefulness of a synthetic peptide in the serodiagnosis of Taenia solium human neurocysticercosis (NC) has been evaluated. Phage-displayed peptides were screened with human antibodies to scolex protein antigen from cysticercus cellulosae (SPACc). One clone was found to interact specifically with anti-SPACc IgGs. The corresponding synthetic peptide was found to be recognized in ELISA by NC patient's sera. The study was carried out with sera from 28 confirmed NC patients, 13 control sera and 73 sera from patients suffering from other infectious diseases. A 93% sensibility and a 94.3% specificity was achieved. Figures of 89% and 31.4% of sensibility and specificity were obtained in a SPACc-based ELISA. Immunoblotting of SPACc with anti-peptide antibodies revealed a single band of approximately 45 kDa in 1D and four 45 kDa isoforms in 2D-gel electrophoresis. A strong and specific immunostaining in the fibers beneath the suckers, at the base of the rostellum, and in the tissue surrounding the scolex of cysticerci was observed by immunomicroscopy. Our results show that a peptide-based immunodiagnostic of neurocisticercosis can be envisioned.

Identification of highly specific and cross-reactive antigens of Leishmania species by antibodies from Leishmania (Leishmania) chagasi naturally infected dogs

The Leishmania species present a genetic homology that ranges from 69 to 90%. Because of this homology, heterologous antigens have been used in the immunodiagnosis and vaccine development against Leishmania infections. In the current work, we describe the identification of species-specific and cross-reactive antigens among several New World Leishmania species, using symptomatic and asymptomatic naturally Leishmania chagasi-infected dog sera. Soluble antigens from five strains of New World Leishmania were separated by electrophoresis in SDS-PAGE and immunoblotted. Different proteins were uniquely recognized in the L. chagasi panel by either symptomatic or asymptomatic dog sera suggesting their use as markers for the progression of disease and diagnosis of the initial (sub-clinical) phase of the infection. Cross-reactive antigens were identified using heterologous antigenic panels (L. amazonensis strains PH8 and BH6, L. guyanensis and L. braziliensis). L. guyanensis panel showed the highest cross-reactivity against L. chagasi specific antibodies, suggesting that proteins from this extract might be suitable for the diagnosis of visceral canine leishmaniasis. Interestingly, the 51 and 97 kDa proteins of Leishmania were widely recognized (77.8% to 100%) among all antigenic panels tested, supporting their potential use for immunodiagnosis. Finally, we identified several leishmanial antigens that might be useful for routine diagnosis and seroepidemiological studies of the visceral canine leishmaniasis.

Identification, characterization and manipulation of Babesia-bovis-infected red blood cells using microfluidics technology

Nowadays numerous microfluidic systems are being developed to address a variety of clinical problems. Latest advances in microfluidic technology are promising to revolutionize the detection of pathogens in vivo through the development of integrated lab-on-chip devices. Such microfabricated systems will undertake all steps in sample analysis from collection and preparation to molecular detection. Micro total analysis systems are suitable candidates for point of care diagnostics due to small size, low cost production and enabled portability. The work here presented aimed the use of microfluidic platforms to identify and manipulate bovine red blood cells infected by the protozoan parasite Babesia bovis. A microfabricated device based on impedance spectroscopy was used for single cell discrimination and its sensitivity and applicability as a diagnostic method for bovine babesiosis was studied. Furthermore, manipulation and sorting of normal and infected red blood cells was performed on a dielectrophoresis based microfabricated cell cytometer. Single cell analysis of normal and B. bovis infected red blood cells was performed by electrorotation and dielectric parameters such as permittivities and conductivities of the cellular membrane and cytoplasm were determined.

Detection and selection of microsatellites in the genome of Paracoccidioides brasiliensis as molecular markers for clinical and epidemiological studies

Paracoccidioides brasiliensis, a thermodimorphic fungus, is the causative agent of the prevalent systemic mycosis in Latin America, paracoccidioidomycosis (PCM). Here, we describe the microsatellite patterns observed in a collection of P. brasiliensis random sequence tags. We identified 1,117 microsatellite patterns in about 3.8 Mb of unique sequences (0.47% of the total DNA used in the analysis). The majority of these microsatellites (87.5%) are found in noncoding sequences. We used two polymorphic microsatellites located on noncoding and coding sequences, as well as two microsatellites located on introns, as molecular markers to discriminate P. brasiliensis isolates, to look for relationships between the genetic background of the strains and the types of human disease they cause. We did not observe any correlation between the clinical form of human PCM and four simple sequence repeat patterns analyzed.

Flow cytometric assay in peripheral blood of dogs--reference values for leukocytes from Brazilian beagles

Use of domestic reference values in the flow cytometry analysis is known to improve its accuracy by integrating local variations as gender, race and age. Up to date application of flow cytometry in veterinary medicine has been limited to describe the percentual values just for peripheral lymphocytes subsets of blood. We now report establishment of reference values for a wide range of proportional and absolute numbers of peripheral blood leukocytes, including T cells subsets, B cells, monocytes and eosinophils, applicable to the healthy population of Beagles in Brazil and other regions with similar demographic characteristics. Normal reference values were also established to estimate the gender-related differences. This information will provide clinical aid in the evaluation of immunologic status as well as standard values for experimental animals of dogs from Brazil and other similar regions.

Protective immunity of single and multi-antigen DNA vaccines against schistosomiasis

We evaluated the usefulness of the combination of three plasmids encoding tegumental (pECL and pSM14) and muscular (pIRV5) antigens of the Schistosoma mansoni on improving the protective immunity over the use of a single antigen as DNA vaccines. Female BALB/c mice were inoculated twice with 25 micro g DNA plasmid within two weeks interval. The challenge was performed with 80 cercarias of a regional isolate of S. mansoni (SLM) one week after the last immunization. Six weeks after challenge, all mice were perfused for worm load determination. The following groups were analyzed: saline; empty vector; monovalent formulations of pECL; pSM14 and pIRV5 and also double combinations of pECL/pIRV5 and pIRV5/pSM14 and a triple combination of pECL/pIRV5/pSM14. The protection was expressed as a percentage of worm loads in each group compared with the saline group. The results obtained were 41% (p < 0.05); 52% (p < 0.05); 51% (p < 0.05); 48% (p < 0.05); 55% (p < 0.05); 45% (p < 0.05); 65% (p < 0.05) for each group respectively.

Analysis of the distribution of HLA-B alleles in populations from five continents

A two stage PCR-SSOP typing procedure, that permitted HLA-B allele assignment, was applied to DNA samples obtained from six diverse populations -Brazilian, Mexican (Series and Mestizos), Cuban (Caucasoid and Mulatto), South African Zulu, Omani, and Singapore Chinese. HLA-B allele frequencies and HLA-A/B two locus haplotype frequencies were compiled for each population.

Early Rhegmatogenous Retinal Detachment Following Laser in situ Keratomileusis for High Myopia

PURPOSE

Four eyes had early rhegmatogenous retinal detachment within 3 months of laser in situ keratomileusis (LASIK) for correction of high myopia using the microkeratome, Clear Corneal Molder.

METHODS

In two eyes, retinal detachment resulted from horseshoe tears, one occurring in an otherwise normal region of the retina and the other at the margin of an area of lattice degeneration detected during preoperative examination. The first eye was treated with retinopexy using a 287 encircling scleral exoplant, drainage of subretinal fluid, and laser photocoagulation by indirect ophthalmoscopy. The other eye was treated with pneumatic retinopexy and cryotherapy. In the other eyes, retinal detachment was the result of giant tears with no evidence of prior retinal degeneration. These eyes were treated with pars plana vitrectomy, fluid-gas exchange with 15% perfluoropropane (C3F8), endolaser photocoagulation, and a 42 encircling scleral exoplant.

RESULTS

After treatment, the first two eyes achieved spectacle-corrected visual acuity of 20/40. In the last two eyes, final spectacle-corrected visual acuity was 20/400 in one eye and light perception in the other.

CONCLUSIONS

Although no cause-effect relationship between LASIK and retinal detachment can be stated, these cases suggest that LASIK may be associated with retinal detachment, particularly in highly myopic eyes. Further studies are necessary to determine high-risk patient characteristics.

Analysis of the distribution of HLA-A alleles in populations from five continents

The variation and frequency of HLA-A genotypes were established by PCR-SSOP typing in diverse geographically distributed populations: Brazilian, Colombian Kogui, Cuban, Mexican, Omani, Singapore Chinese, and South African Zulu. HLA-A allelic families with only one allele were identified for HLA-A*01, -A*23, -A*25, -A*31, -A*32, -A*36, -A*43, -A*69, -A*80; and with two alleles for HLA-A*03, -A*11, -A*26, -A*29, -A*33, -A*34, and -A*66. Greater variation was detected for HLA-A*02, -A*24, and -A*68 allele families. Colombian Kogui and Mexican Seris showed the least diversity with respect to HLA-A alleles, albeit with small numbers tested, with only four and five HLA-A alleles identified, respectively. It would appear by their presence in all populations studied, either rural or indigenous, that certain alleles are very important in pathogen peptide presentation.

Protection of C57BL/10 mice by vaccination with association of purified proteins from Leishmania (Leishmania) amazonensis

In the past few years, induction of protective immunity to cutaneous leishmaniasis has been attempted by many researchers using a variety of antigenic preparations, such as living promastigotes or promastigote extracts, partially purified, or defined proteins. In this study, eleven proteins from Leishmania (Leishmania) amazonensis (LLa) with estimated molecular mass ranging from 97 to 13.5kDa were isolated by polyacrylamide gel electrophoresis and electro-elution. The proteins were associated as vaccine in different preparations with gp63 and BCG (Bacilli Calmette-Guérin). The antigenicity of these vaccines was measured by their ability to induce the production of IFN-gamma by lymphocyte from subjects vaccinated with Leishvacinregister mark or target. The immunogenicity was evaluated in vaccinated mice. C57BL/10 mice were vaccinated with three doses of each vaccine consisting of 30 microg of each protein at 15 days interval. One hundred microg of live BCG was only used in the first dose. Seven days after the last dose, they received a first challenge infection with 10(5) infective promastigotes and four months later, a second challenge was done. Two months after the second challenge, 42.86% of protection was obtained in the group of mice vaccinated with association of proteins of gp63+46+22kDa, gp63+13.5+25+42kDa, gp63+46+42kDa, gp63+66kDa, and gp63+97kDa; 57. 14% of protection was demonstrated with gp63+46+97+13.5kDa, gp63+46+97kDa, gp63+46+33kDa, and 71.43% protection for gp63 plus all proteins. The vaccine of gp63+46+40kDa that did not protect the mice, despite the good specific stimulation of lymphocytes (LSI = 7. 60) and 10.77UI/ml of IFN-gamma production. When crude extract of L. (L.) amazonensis was used with BCG a 57.14% of protection was found after the first challenge and 28.57% after the second, the same result was observed for gp63. The data obtained with the vaccines can suggest that the future vaccine probably have to contain, except the 40kDa, a cocktail of proteins that would protect mice against cutaneous leishmaniasis.