INTRODUCTION Performance variation among PCR systems in detecting Toxoplasma gondii has been extensively reported and associated with target genes, primer composition, amplification parameters, treatment during pregnancy, host genetic susceptibility and genotypes of different parasites according to geographical characteristics. PATIENTS A total of 467 amniotic fluid samples from T. gondii IgM- and IgG-positive Brazilian pregnant women being treated for 1 to 6 weeks at the time of amniocentesis (gestational ages of 14 to 25 weeks). METHODS One nested-B1-PCR and three one-round amplification systems targeted to rDNA, AF146527 and the B1 gene were employed. RESULTS Of the 467 samples, 189 (40.47%) were positive for one-round amplifications: 120 (63.49%) for the B1 gene, 24 (12.69%) for AF146527, 45 (23.80%) for both AF146527 and the B1 gene, and none for rDNA. Fifty previously negative one-round PCR samples were chosen by computer-assisted randomization analysis and re-tested (nested-B1-PCR), during which nine additional cases were detected (9/50 or 18%). DISCUSSION The B1 gene PCR was far more sensitive than the AF146527 PCR, and the rDNA PCR was the least effective even though the rDNA had the most repetitive sequence. Considering that the four amplification systems were equally affected by treatment, that the amplification conditions were optimized for the target genes and that most of the primers have already been reported, it is plausible that the striking differences found among PCR performances could be associated with genetic diversity in patients and/or with different Toxoplasma gondii genotypes occurring in Brazil. CONCLUSION The use of PCR for the diagnosis of fetal Toxoplasma infections in Brazil should be targeted to the B1 gene when only one gene can be amplified, preferably by nested amplification with primers B22/B23.
Clonal outbreaks due to azole-resistant Candida parapsilosis (ARCP) isolates have been reported in numerous studies, but the environmental niche of such isolates has yet to be defined. Herein, we aimed to identify the environmental niche of ARCP isolates causing unremitting clonal outbreaks in an adult ICU from a Brazilian cancer referral center. C. parapsilosis sensu stricto isolates recovered from blood cultures, pericatheter skins, healthcare workers (HCW), and nosocomial surfaces were genotyped by multilocus microsatellite typing (MLMT). Antifungal susceptibility testing was performed by the EUCAST (European Committee for Antimicrobial Susceptibility Testing) broth microdilution reference method and ERG11 was sequenced to determine the azole resistance mechanism. Approximately 68% of isolates were fluconazole-resistant (76/112), including pericatheter skins (3/3, 100%), blood cultures (63/70, 90%), nosocomial surfaces (6/11, 54.5%), and HCW’s hands (4/28, 14.2%). MLMT revealed five clusters: the major cluster contained 88.2% of ARCP isolates (67/76) collected from blood (57/70), bed (2/2), pericatheter skin (2/3), from carts (3/7), and HCW’s hands (3/27). ARCP isolates were associated with a higher 30 day crude mortality rate (63.8%) than non-ARCP ones (20%, p = 0.008), and resisted two environmental decontamination attempts using quaternary ammonium. This study for the first time identified ARCP isolates harboring the Erg11-Y132F mutation from nosocomial surfaces and HCW’s hands, which were genetically identical to ARCP blood isolates. Therefore, it is likely that persisting clonal outbreak due to ARCP isolates was fueled by environmental sources. The resistance of Y132F ARCP isolates to disinfectants, and their potential association with a high mortality rate, warrant vigilant source control using effective environmental decontamination.
The present study has intended to contribute to the elucidation of the pathogenic mechanisms, involved in the thrombocytopenia and in the bleeding diathesis seen in the course of Leptospirosis. The group of cases included in the present prospective study consisted of 30 patients with Leptospirosis, admitted to the Infectious and Parasitic Diseases Ward, Hospital das Clínicas, Faculty of Medicine, University of São Paulo. The following possible mechanisms of thrombocytopenia have been considered and therefore investigated: platelet consumption, due to disseminated intravascular coagulation; immune-mediated platelet destruction, due to platelet-associated antibodies and an inhibited platelet production in the bone marrow. Thrombocytopenia occurred in 86.6% of 30 patients and did not seem to be immune-mediated by platelet-associated antibodies. Furthermore it did not seem to be due to a disseminated intravascular coagulation consumption. Although there was a statistically-significant correlation between bone marrow platelet production and platelet counts we think that the static microscopic examination of a bone marrow aspirate cannot accurately depict the dynamic mechanisms of platelet production when these cells are being consumed in peripheral blood. Vasculitis should be considered as the most important factor for the pathogenesis of the bleeding disturbances in Leptospirosis. However, we believe that thrombocytopenia, uremia and coagulation disorders, individually or as a group, should be included among the contributing factors that lead to and worsen bleeding episodes, which represent the leading cause of death in this disease.
Horizontal transmission of fluconazole-resistant Candida parapsilosis (FRCP) through healthcare workers’ hands has contributed to the occurrence of candidemia outbreaks worldwide. Since the first COVID-19 case in Brazil was detected in early 2020, hospitals have reinforced hand hygiene and disinfection practices to minimize SARS-CoV-2 contamination. However, a Brazilian cardiology center, which shares ICU patients with a cancer center under a FRCP outbreak since 2019, reported an increased FRCP candidemia incidence in May 2020. Therefore, the purpose of this study was to investigate an inter-hospital candidemia outbreak caused by FRCP isolates during the first year of the COVID-19 pandemic in Brazil. C. parapsilosis bloodstream isolates obtained from the cancer (n = 35) and cardiology (n = 30) centers in 2020 were submitted to microsatellite genotyping and fluconazole susceptibility testing. The ERG11 gene of all isolates from the cardiology center was sequenced and compared to the corresponding sequences of the FRCP genotype responsible for the cancer center outbreak in 2019. Unprecedentedly, most of the FRCP isolates from the cardiology center presented the same genetic profile and Erg11-Y132F mutation detected in the strain that has been causing the persistent outbreak in the cancer center, highlighting the uninterrupted horizontal transmission of clonal isolates in our hospitals during the COVID-19 pandemic.
Bartonella spp. constitute emerging pathogens of worldwide distribution. Bacillary angiomatosis is the most frequent skin manifestation of bartonelloses; nevertheless, B. henselae infection should always be considered systemic, especially in immunodeficient individuals. The authors report the case of an AIDS patient with bacillary angiomatosis, who had concurrent severe anemia, hepatitis, peritonitis, pleuritis, and pericarditis. Clinical manifestation, electronic microscopic examination of erythrocytes, and histopathology of a papule biopsy suggested a Bartonella sp. infection. Multiple genes were target by PCR and B. henselae DNA was amplified and sequenced (GenBank accession number EF196804) from the angiomatous papule. Treatment with clarithromycin resulted in resolution of the bacillary angiomatosis, fever, anemia, panserosites, and hepatitis.
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