BACKGROUND: Trypanosoma rangeli is a protozoan that infects a variety of mammalian hosts, including humans. Its main insect vector is Rhodnius prolixus and is found in several Latin American ...countries. The R. prolixus vector competence depends on the T. rangeli strain and the molecular interactions, as well as the insect’s immune responses in the gut and haemocoel. This work focuses on the modulation of the humoral immune responses of the midgut of R. prolixus infected with T. rangeli Macias strain, considering the influence of the parasite on the intestinal microbiota. METHODS: The population density of T. rangeli Macias strain was analysed in different R. prolixus midgut compartments in long and short-term experiments. Cultivable and non-cultivable midgut bacteria were investigated by colony forming unit (CFU) assays and by 454 pyrosequencing of the 16S rRNA gene, respectively. The modulation of R. prolixus immune responses was studied by analysis of the antimicrobial activity in vitro against different bacteria using turbidimetric tests, the abundance of mRNAs encoding antimicrobial peptides (AMPs) defensin (DefA, DefB, DefC), prolixicin (Prol) and lysozymes (LysA, LysB) by RT-PCR and analysis of the phenoloxidase (PO) activity. RESULTS: Our results showed that T. rangeli successfully colonized R. prolixus midgut altering the microbiota population and the immune responses as follows: 1 - reduced cultivable midgut bacteria; 2 - decreased the number of sequences of the Enterococcaceae but increased those of the Burkholderiaceae family; the families Nocardiaceae, Enterobacteriaceae and Mycobacteriaceae encountered in control and infected insects remained the same; 3 - enhanced midgut antibacterial activities against Serratia marcescens and Staphylococcus aureus; 4 - down-regulated LysB and Prol mRNA levels; altered DefB, DefC and LysA depending on the infection (short and long-term); 5 - decreased PO activity. CONCLUSION: Our findings suggest that T. rangeli Macias strain modulates R. prolixus immune system and modifies the natural microbiota composition.
Chagas disease is a complex anthropozoonosis with distinct domestic and sylvatic mammal species acting as potential reservoirs. The diversity of vector species and their habitats are among the ...factors that hinder the control of the disease. Control programs periodically monitor the prevalence of T. cruzi infection in insect bugs through microscopical observation of diluted feces. However, microscopy presents limited sensitivity in samples with low parasite numbers, difficulties in examining all evolutionary stages of the insect and may in turn be limited to differentiate T. cruzi from other morphologically similar trypanosomatids. Here, we report two highly sensitive and accurate methodologies to infer T. cruzi infection rates and to quantify parasite load in the gut of field-collected triatomines.
Triatomines were manually collected in the period 2011-2012 and 2014-2015, in domestic, peridomestic or sylvatic habitats in rural areas of 26 municipalities, encompassing three distinct Brazilian biomes: Caatinga, Cerrado and Atlantic Rainforest. Following morphological and taxonomical identification, the search for flagellated protozoa was performed by optical microscopy. A conventional PCR targeting T. cruzi kDNA and a TaqMan qPCR directed to the parasite nuclear satellite DNA (SAT) were developed, both in multiplex, with the triatomine 12S subunit ribosomal RNA gene, used as internal amplification control. Both methods were used for detection (kDNA-PCR) and parasite load quantification (SAT-DNA-qPCR), to investigate T. cruzi infection in captured triatomines.
The combined methods were assayed on a panel of 205 field-collected triatomine samples. Diagnostic analysis revealed 21% positivity for the kDNA-PCR, whereas microscopic examination enabled identification of T. cruzi in only 7.0% of the PCR-positive samples. Negative PCR results were confirmed by the absence of T. cruzi flagellates using microscopy. Caatinga biome yielded the highest T. cruzi infection rate (60%), followed by the Atlantic Rainforest and Cerrado with 7.1 and 6.1%, respectively. In addition, a wide range distribution of parasite load, varying from 8.05 × 10
to 6.31 × 10
was observed with a median of 2.29 × 10
T. cruzi/intestine units. When parasite load was analyzed by triatomine species, a significantly higher median was found for Panstrongylus lutzi in comparison with Triatoma brasiliensis.
Our results demonstrate highly sensitive PCR-based methodologies to monitor T. cruzi infection in triatomines. In addition, the qPCR assay offers the possibility of further evaluation parasite load, as a promising biomarker of the vectorial capacity of triatomines in Chagas disease endemic areas.
•A MDR strain was isolated from a fly collected next to a public hospital.•K. quasipneumoniae subsp. similipneumoniae carries a blaNDM-1 on Tn3000•K. quasipneumoniae subsp. similipneumoniae harboured ...numerous resistance genes•Flies can be involved in the spread of antibiotic resistance.
Flies have been implicated in the dispersal of medically important bacteria including members of the genus Klebsiella between different environmental compartments. The aim of this study was to retrieve and characterize antibiotic-resistant bacteria from flies collected near to hospitals.
Flies were collected in the vicinity of medical facilities and examined for bacteria demonstrating phenotypic resistance to ceftriaxone, followed by determination of phenotypic and genotypic resistance profiles. In addition, whole genome sequencing followed by phylogenetic analysis and resistance genotyping were performed with the multidrug-resistant (MDR) strain Lemef23, identified as Klebsiella quasipneumoniae subsp. similipneumoniae.
The strain Lemef23, classified by multiple locus sequence typing as novel ST 3397, harboured numerous resistance genes. The blaNDM was located on a Tn3000 element, a common genetic platform for the carriage of this gene in Brazil. Inference of phylogenetic orthology of strain Lemef23 and other clinical isolates suggested an anthropogenic origin.
The findings of this study support the role of flies as vectors of MDR bacteria of clinical importance and provide the first record of blaNDM-1 and blaCTXM-15 in a Brazilian isolate of K. quasipneumoniae subsp. similipneumoniae, demonstrating the value of surveying insects as reservoirs of antibiotic resistance.
Since 1991 several outbreaks of acute coccidioidomycosis (CM) were diagnosed in the semi-arid Northeast of Brazil, mainly related to disturbance of armadillo burrows caused by hunters while digging ...them for the capture of these animals. This activity causes dust contaminated with arthroconidia of Coccidioides posadasii, which, once inhaled, cause the mycosis. We report on the identification of C. posadasii in soil samples related to outbreaks of CM.
Twenty four soil samples had their DNA extracted and subsequently submitted to a semi-nested PCR technique using specific primers. While only 6 (25%) soil samples were positive for C. posadasii by mice inoculation, all (100%) were positive by the molecular tool.
This methodology represents a simple, sensitive and specific molecular technique to determine the environmental distribution of Coccidioides spp. in endemic areas, but cannot distinguish the species. Moreover, it may be useful to identify culture isolates. Key-words: 1. Coccidioidomycosis. 2. Coccidioides spp. 3. C. posadasii. 4. Semi-arid. 5. Semi-nested PCR.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
β-lactam is the most used antibiotic class in the clinical area and it acts on blocking the bacteria cell wall synthesis, causing cell death. However, some bacteria have evolved resistance to these ...antibiotics mainly due the production of enzymes known as β-lactamases. Hospital sewage is an important source of dispersion of multidrug-resistant bacteria in rivers and oceans. In this work, we used next-generation DNA sequencing to explore the diversity and dissemination of serine β-lactamases in two hospital sewage from Rio de Janeiro, Brazil (South Zone, SZ and North Zone, NZ), presenting different profiles, and to compare them with public environmental data available. Also, we propose a Hidden-Markov-Model approach to screen potential serine β-lactamases genes (in public environments samples and generated hospital sewage data), exploring its evolutionary relationships. Due to the high variability in β-lactamases, we used a position-specific scoring matrix search method (RPS-BLAST) against conserved domain database profiles (CDD, Pfam, and COG) followed by visual inspection to detect conserved motifs, to increase the reliability of the results and remove possible false positives. We were able to identify novel β-lactamases from Brazilian hospital sewage and to estimate relative abundance of its types. The highest relative abundance found in SZ was the Class A (50%), while Class D is predominant in NZ (55%). CfxA (65%) and ACC (47%) types were the most abundant genes detected in SZ, while in NZ the most frequent were OXA-10 (32%), CfxA (28%), ACC (21%), CEPA (20%), and FOX (19%). Phylogenetic analysis revealed β-lactamases from Brazilian hospital sewage grouped in the same clade and close to sequences belonging to Firmicutes and Bacteroidetes groups, but distant from potential β-lactamases screened from public environmental data, that grouped closer to β-lactamases of Proteobacteria. Our results demonstrated that HMM-based approach identified homologs of serine β-lactamases, indicating the specificity and high sensitivity of this approach in large datasets, contributing for the identification and classification of a large number of homologous genes, comprising possible new ones. Phylogenetic analysis revealed the potential reservoir of β-lactam resistance genes in the environment, contributing to understanding the evolution and dissemination of these genes.
Introdução: Bactérias do gênero Acinetobacter são uma das principais causas de Infecções Relacionadas à Assistência à Saúde (IRAS) em todo o mundo, causando principalmente severas bacteremias e ...pneumonias, além de infecções urinárias, dentre outras. A maioria desses isolados é multirresistente a antibióticos ou biocidas, o que aumenta tanto a sua persistência quanto a disseminação no ambiente hospitalar, tornando-os grandes desafios na prática clínica. Indivíduos portadores de doenças crônicas, como a fibrose cística, são mais suscetíveis a infecções respiratórias e necessitam de internações frequentes, sendo um grupo de risco para IRAS por bactérias multirresistentes. A multirresistência está entre as três principais ameaças à saúde pública global e A. baumannii é prioridade crítica da OMS dentre os 12 patógenos bacterianos de maior ameaça mundial; desta forma, compreender os mecanismos de virulência dessas bactérias é crucial para o desenvolvimento de novos agentes antimicrobianos ou novas alternativas para combater esses patógenos. Métodos: A partir da utilização de bases de dados públicas de dados ômicos, como Refseq e Biosample do NCBI, algumas centenas de isolados de Acinetobacter spp. (53% de origem clínica e 47% de origem não-clínica) foram comparadas com bioinformática e scripts desenvolvidos em linguagem Python, que auxiliaram na identificação dos mecanismos de virulência através da ciência de dados ômicos. Resultados: Mecanismos de captura, transporte e utilização de ferro, histidina, taurina e ureia em tecidos do hospedeiro, se mostraram evolutivamente importantes em infecções por Acinetobacter spp. patogênicos. Assim como alguns mecanismos de evasão do sistema imune ‒ vias de síntese de polissacarídeos capsulares a partir da trealose e a via de indução de morte celular no hospedeiro através do sistema de secreção do tipo II, um complexo proteico que transporta proteínas efetoras diretamente para dentro de células de defesa do hospedeiro. Conclusão: Este estudo revelou importantes mecanismos de virulência de Acinetobacter spp. envolvidos na colonização de tecidos do hospedeiro e evasão do sistema imune, os quais são mantidos evolutivamente nas linhagens patogênicas e podem auxiliar na identificação de novos alvos terapêuticos para o combate de cepas multirresistentes destes patógenos emergentes.
Flies have been implicated in the dispersal of medically important bacteria including members of the genus Klebsiella between different environmental compartments. The aim of this study was to ...retrieve and characterize antibiotic-resistant bacteria from flies collected near to hospitals.
Flies were collected in the vicinity of medical facilities and examined for bacteria demonstrating phenotypic resistance to ceftriaxone, followed by determination of phenotypic and genotypic resistance profiles. In addition, whole genome sequencing followed by phylogenetic analysis and resistance genotyping were performed with the multidrug-resistant (MDR) strain Lemef23, identified as Klebsiella quasipneumoniae subsp. similipneumoniae.
The strain Lemef23, classified by multiple locus sequence typing as novel ST 3397, harboured numerous resistance genes. The bla
was located on a Tn3000 element, a common genetic platform for the carriage of this gene in Brazil. Inference of phylogenetic orthology of strain Lemef23 and other clinical isolates suggested an anthropogenic origin.
The findings of this study support the role of flies as vectors of MDR bacteria of clinical importance and provide the first record of bla
and bla
in a Brazilian isolate of K. quasipneumoniae subsp. similipneumoniae, demonstrating the value of surveying insects as reservoirs of antibiotic resistance.
Iron depletion was suggested to be protective against the development of ischemic heart disease. Population studies have led to conflicting results, and such an association has not been addressed in ...patients with heart failure due to cardiomyopathy. We studied the distribution of hemochromatosis-related mutations in 319 patients with heart failure due to cardiomyopathy of different etiologies. The genotypic distribution showed a significantly higher prevalence of heterozygotes for the C282Y mutation in patients with ischemic cardiomyopathy than in patients with cardiomyopathy of nonischemic etiologies (p = 0.0036). The frequency of the D63 mutation was not significantly different between ischemic versus nonischemic groups. In multiple logistic regression models adjusted for age, sex, ethnicity, and different degrees of disease progression, there was a strong and significant association of the C282Y mutation with ischemic cardiomyopathy compared with the nonischemic group (odds ratio 6.64, 95% confidence interval 1.71 to 25.73, after adjustment). In our sample, genetic variation in the HFE gene was associated with ischemic cardiomyopathy. Such association merits further study regarding its value as a prognostic marker in patients with ischemic heart disease.
ABSTRACTMontrezol, FT, Marinho, R, Mota, GdFAd, Dʼalmeida, V, de Oliveira, EM, Gomes, RJ, and Medeiros, A. ACE gene plays a key role in reducing blood pressure in the hyperintensive elderly after ...resistance training. J Strength Cond Res 33(4)1119–1129, 2019—Hypertension is a difficult disease to control and exercise training plays a key role in hypertension control. Some individuals are not responsive to exercise training; so, we highlight the polymorphism of I allele of angiotensin-converting enzyme (ACE) as a factor responsible for this lack of responsiveness. The aim of this study was to evaluate the influence of ACE insertion/deletion genotypes on effects of resistance training on blood pressure (BP) and chronic inflammation. Eighty-six hypertensive volunteers, aged between 60 and 80, were evaluated. They performed 16 weeks of resistance training at 50% of 1 maximal repetition. The greatest benefits were seen on homozygous of the Insertion allele, whom presented reduction of systolic blood pressure (SBP129.31 ± 13.34 vs. 122.56 ± 9.68 mm Hg, p < 0.001) and diastolic blood pressure (DBP79.18 ± 8.05 vs. 70.12 ± 7.71 mm Hg, p < 0.01) during daytime period, and in 24-hour period (SBP127.12 ± 13.65 vs. 121.06± 9.68 mm Hg, p < 0.001 and DBP71.87 ± 8.39 vs. 68.75 ± 8.72 mm Hg, p < 0.05) and also increased circulating adiponectin levels (4.04 ± 1.79 vs. 6.00 ± 2.81 ng·ml, p < 0.01). Other genotypes showed no changes in BP and biochemical parameters. Our results suggest a cardio protective factor of I allele because only those homozygous showed reductions in BP and increases in adiponectin.
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