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1.
Immunobiology ; 228(2): 152346, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36805110

RESUMO

Mycobacterium tuberculosis is one of the most successful pathogens affecting humans, being the main cause of tuberculosis. It accounts for most infectious agent-related deaths worldwide; it has been estimated that a third of the world's population are bacillus carriers. This pathogen's evolutionary adaptation is mainly due to its ability to block a host's immune system by preventing it using an effective immune response in cases of active tuberculosis. Peptide-based synthetic vaccines represent an alternative for counteracting tuberculosis; however, although peptide antigens can be identified, they are not recognised by a host's immune system. An approach using dendritic cells as immunomodulating agents for increasing synthetic peptides' antigenic capacity has thus been advanced. Dendritic cells obtained from IL to 4- and GM-CSF-treated peripheral blood mononuclear cells were pulsed with synthetic Mtb protein peptides which have been reported as participating in mycobacteria-host interactions; their amino acid sequences were modified to improve MHC-II coupling and thus increase their recognition by a host's immune system. pMHC-II/TCR interaction triggered a lymphocyte response which controlled Mtb intracellular growth in infected macrophages. This work has been aimed at contributing to understanding dendritic cells' role in Mycobacterium tuberculosis protein peptide antigen presentation, thereby increasing individuals' immune response as a means of controlling the disease.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Leucócitos Mononucleares , Peptídeos/química , Macrófagos , Células Dendríticas
2.
Curr Microbiol ; 76(4): 485-494, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30783798

RESUMO

Burkholderia contaminans is a member of the Burkholderia cepacia complex (Bcc), a pathogen with increasing prevalence among cystic fibrosis (CF) patients and the cause of numerous outbreaks due to the use of contaminated commercial products. The antibiotic resistance determinants, particularly ß-lactamases, have been poorly studied in this species. In this work, we explored the whole genome sequence (WGS) of a B. contaminans isolate (FFH 2055) and detected four putative ß-lactamase-encoding genes. In general, these genes have more than 93% identity with ß-lactamase genes found in other Bcc species. Two ß-lactamases, a class A (Pen-like, suggested name PenO) and a class D (OXA-like), were further analyzed and characterized. Amino acid sequence comparison showed that Pen-like has 82% and 67% identity with B. multivorans PenA and B. pseudomallei PenI, respectively, while OXA-like displayed strong homology with class D enzymes within the Bcc, but only 22-44% identity with available structures from the OXA family. PCR reactions designed to study the presence of these two genes revealed a heterogeneous distribution among clinical and industrial B. contaminans isolates. Lastly, blaPenO gene was cloned and expressed into E. coli to investigate the antibiotic resistance profile and confers an extended-spectrum ß-lactamase (ESBL) phenotype. These results provide insight into the presence of ß-lactamases in B. contaminans, suggesting they play a role in antibiotic resistance of these bacteria.


Assuntos
Proteínas de Bactérias/genética , Complexo Burkholderia cepacia/enzimologia , Complexo Burkholderia cepacia/genética , Genoma Bacteriano/genética , beta-Lactamases/genética , Sequência de Aminoácidos , Antibacterianos/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Infecções por Burkholderia/microbiologia , Complexo Burkholderia cepacia/efeitos dos fármacos , Fibrose Cística/microbiologia , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Homologia de Sequência de Aminoácidos , beta-Lactamases/química , beta-Lactamases/metabolismo
3.
Toxicol Rep ; 5: 593-597, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29854629

RESUMO

The seeds germination, stem and root elongation of water lettuces (Lactuca sativa L) were used to evaluate the phytotoxicity of water and soil of Champotón River, Campeche, Mexico. water and soil sample were collected from two sampling sites. Lettuce seeds were exposed to three different dilutions of water and aqueous extract of soil. Significant differences on germination, root and stem elongation of lettuce were detected. Water showed more phytotoxic effect than aqueous extract of soil and inhibitory concentration 50 (IC50) for radicle exposed to river water was 52% while stem elongation was 69%. Due to paucity the previously available phytotoxicological studies onto Champotón River, it is now essential to allocate time and resources to consider development of suitable chronic phytotoxicity tests.

4.
Rev. argent. microbiol ; 46(4): 298-301, dic. 2014.
Artigo em Espanhol | LILACS | ID: biblio-1008447

RESUMO

Se presenta el caso de un absceso cerebral causado por Haemophilus infl uenzae tipo e, en un paciente de 12 años con síndrome de Apert. El síndrome de Apert se caracteriza por el cierre prematuro de las suturas craneales. En 2010, el paciente presentó traumatismo craneano en región frontal, fractura y fístula de líquido cefalorraquídeo. En febrero de 2013 consultó por fi ebre, vómitos y convulsión tónica clónica generalizada, con deterioro progresivo del sensorio. La tomografía axial computarizada mostró una lesión frontal derecha, edema perilesional, leve dilatación ventricular y pansinusitis. Se diagnosticó absceso cerebral con pioventriculitis y se realizó drenaje. Se obtuvo desarrollo de un cocobacilo gram negativo, que fue identifi cado como H. infl uenzae serotipo e. Se realizó tratamiento empírico con meropenem (120 mg/kg/día) y vancomicina (60 mg/kg/día). Luego del resultado del cultivo, se rotó a ceftriaxona (100 mg/kg/día) y metronidazol (500 mg/8 h). El paciente cumplió 8 semanas de tratamiento y se observó evolución favorable


We report a case of a brain abscess caused by Haemophilus infl uenzae type e in a 12 year-old patient suffering from Apert syndrome. Apert syndrome is characterized by the premature closure of cranial sutures. In 2010 the patient suffered head trauma in the frontal area with cranial fracture and a cerebrospinal fl uid fi stula. In February 2013 he was admitted to hospital with fever, vomiting and generalized tonic-clonic seizure with deteriorating mental status/progressive sensory impairment. The computerized axial tomographic scan showed a right frontal lesion, perilesional edema, mild ventricular dilatation and pansinusitis. A brain abscess was diagnosed and drained. The clinical sample was then cultured. A gram negative coccobacillus was isolated and identifi ed as Haemophilus infl uenzae serotype e. Empirical treatment was started with meropenem (120 mg/kg/day) and vancomycin (60 mg/kg/day), which was later switched to ceftriaxone (100 mg/kg/day) and metronidazole (500 mg/8 h) after culture results arrived. The patient was discharged in good clinical condition


Assuntos
Humanos , Masculino , Criança , Abscesso Encefálico/etiologia , Infecções por Haemophilus/diagnóstico , Infecções por Haemophilus/terapia , Acrocefalossindactilia , Haemophilus influenzae/isolamento & purificação , Haemophilus influenzae/patogenicidade
5.
Rev Argent Microbiol ; 46(4): 298-301, 2014.
Artigo em Espanhol | MEDLINE | ID: mdl-25576411

RESUMO

We report a case of a brain abscess caused by Haemophilus influenzae type e in a 12 year-old patient suffering from Apert syndrome. Apert syndrome is characterized by the premature closure of cranial sutures. In 2010 the patient suffered head trauma in the frontal area with cranial fracture and a cerebrospinal fluid fistula. In February 2013 he was admitted to hospital with fever, vomiting and generalized tonic-clonic seizure with deteriorating mental status/progressive sensory impairment. The computerized axial tomographic scan showed a right frontal lesion, perilesional edema, mild ventricular dilatation and pansinusitis. A brain abscess was diagnosed and drained. The clinical sample was then cultured. A gram negative coccobacillus was isolated and identified as Haemophilus influenzae serotype e. Empirical treatment was started with meropenem (120 mg/kg/day) and vancomycin (60 mg/kg/day), which was later switched to ceftriaxone (100 mg/kg/day) and metronidazole (500 mg/8 h) after culture results arrived. The patient was discharged in good clinical condition.


Assuntos
Abscesso Encefálico/microbiologia , Infecções por Haemophilus/complicações , Haemophilus influenzae , Acrocefalossindactilia , Criança , Humanos , Masculino
6.
Rev. Argent. Microbiol. ; 46(4): 298-301, 2014 Oct-Dec.
Artigo em Espanhol | BINACIS | ID: bin-133265

RESUMO

We report a case of a brain abscess caused by Haemophilus influenzae type e in a 12 year-old patient suffering from Apert syndrome. Apert syndrome is characterized by the premature closure of cranial sutures. In 2010 the patient suffered head trauma in the frontal area with cranial fracture and a cerebrospinal fluid fistula. In February 2013 he was admitted to hospital with fever, vomiting and generalized tonic-clonic seizure with deteriorating mental status/progressive sensory impairment. The computerized axial tomographic scan showed a right frontal lesion, perilesional edema, mild ventricular dilatation and pansinusitis. A brain abscess was diagnosed and drained. The clinical sample was then cultured. A gram negative coccobacillus was isolated and identified as Haemophilus influenzae serotype e. Empirical treatment was started with meropenem (120 mg/kg/day) and vancomycin (60 mg/kg/day), which was later switched to ceftriaxone (100 mg/kg/day) and metronidazole (500 mg/8 h) after culture results arrived. The patient was discharged in good clinical condition.

7.
Acta Otorrinolaringol Esp ; 64(1): 12-6, 2013.
Artigo em Espanhol | MEDLINE | ID: mdl-22858160

RESUMO

BACKGROUND AND OBJECTIVE: Acute otitis media (AOM) is one of the most common diseases in childhood and is the most common cause of antibiotic prescriptions in children. The gold standard for identifying the pathogens causing AOM is tympanocentesis. This is only possible in the stage of AOM when exudate is retained in the middle ear. The aim of this study was to describe the prevalence of organisms causing AOM in eutrophic patients at a public paediatric hospital. MATERIAL AND METHODS: We included all patients with AOM diagnosed by otomicroscopy with purulent exudate retained in middle ear and suppurative AOM with inadequate drainage consulting at the Otorhinolaryngology Department in a paediatric tertiary care centre from 2 May 2009 to 31 August 2010. RESULTS: There were 324 patients included in the study, with 180/324 (55.6%) being male. The median age was 8 months (interquartile range: 4 to 15 months). Bilateral AOM was recorded in 109/324 (33.6%) patients (433 samples for culture were obtained by tympanocentesis in 324 patients). At diagnosis, 37% (120/324) of the children had been receiving antimicrobial treatment. Of the patients who had received antibiotics, 71/120 (59.1%) had bacterial growth in middle ear fluid (MEF) cultures, with 51/71 (71.8%) being susceptible to the antibiotic they received; 20/71 (28.2%) patients were receiving an antibiotic that did not cover the spectrum of organisms isolated. CONCLUSION: The pathogens most frequently isolated are Streptococcus pneumoniae (39.5%), Haemophilus influenzae (37.4%), Moraxella catarrhalis (6.1%) and Streptococcus pyogenes (3.0%).


Assuntos
Orelha Média/microbiologia , Otite Média/microbiologia , Doença Aguda , Estudos Transversais , Feminino , Hospitais Públicos , Humanos , Lactente , Masculino , Estudos Prospectivos
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