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1.
Emerg Infect Dis ; 29(12): 2583-2586, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37966098

RESUMEN

We describe substantial variant diversity among 23 detected SARS-CoV-2 Omicron lineage viruses cocirculating among healthcare workers and inpatients (272 sequenced samples) from Porto Alegre, Brazil, during November 2022-January 2023. BQ.1 and related lineages (61.4%) were most common, followed by BE.9 (19.1%), first described in November 2022 in the Amazon region.


Asunto(s)
Personal de Salud , Hospitales , Humanos , Brasil/epidemiología , Pacientes Internos , SARS-CoV-2
2.
Int J Mol Sci ; 24(17)2023 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-37685863

RESUMEN

In 2020, a global pandemic caused by SARS-CoV-2 was declared. Different institutes proposed diagnostic molecular methods to detect the virus in clinical samples. This study aims to validate and standardize the use of a loop-mediated isothermal amplification (LAMP)-based methodology targeting the viral RP gene, as a faster and low-cost diagnostic method for SARS-CoV-2 infections. The results obtained with RT-LAMP (Reverse Transcriptase) were compared to the results of real-time polymerase chain reaction (RT-PCR) to assess its sensitivity and specificity. In total, 115 samples (nasopharyngeal samples) were used for detecting SARS-CoV-2 by RT-LAMP, with 43 positives and 72 negatives. The study showed a positive predictive value (PPV) of 90.7% and a negative predictive value (VPN) of 100%. The LAMP assay also demonstrated a high sensitivity of 90.7% and a specificity of 100% (confidence interval 77.9-97.4%) when using the lower detection limit of 40 copies/µL. The RT-LAMP described here has the potential to detect even the new variants of SARS-CoV-2, suggesting that it may not be significantly affected by gene mutations. The RT-LAMP targeting the RP viral region is faster and less expensive than other molecular approaches, making it an alternative for developing countries.


Asunto(s)
COVID-19 , Transcripción Reversa , Humanos , ARN Viral/genética , COVID-19/diagnóstico , SARS-CoV-2/genética , ARN Polimerasas Dirigidas por ADN
3.
Curr Microbiol ; 74(12): 1461-1468, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28840339

RESUMEN

This study determined the occurrence of potentially pathogenic free-living amoebae (FLA) and bacteria associated with amoebae in air-conditioning cooling towers in southern Brazil. Water samples were collected from 36 cooling systems from air-conditioning in the state of Rio Grande do Sul, Brazil. The organisms were identified using polymerase chain reaction (PCR) and sequencing automated. The results showed that these aquatic environments, with variable temperature, are potential "hot spots" for emerging human pathogens like free-living amoebae and bacteria associated. In total, 92% of the cooling-tower samples analyzed were positive for FLA, and Acanthamoeba was the dominant genus by culture and PCR. Amoebal isolates revealed intracellular bacteria in 39.3% of them and all were confirmed as members of the genus Pseudomonas. The results obtained show the important role of cooling towers as a source of amoebae-associated pathogens.


Asunto(s)
Acanthamoeba/aislamiento & purificación , Acanthamoeba/microbiología , Pseudomonas/aislamiento & purificación , Microbiología del Agua , Aire Acondicionado , Brasil/epidemiología , Humanos , Reacción en Cadena de la Polimerasa , Prevalencia , Análisis de Secuencia de ADN
4.
BMC Microbiol ; 16(1): 134, 2016 06 29.
Artículo en Inglés | MEDLINE | ID: mdl-27357587

RESUMEN

BACKGROUND: S. pneumoniae is the leading cause of acute bacterial meningitis (ABM) in children. Vaccination using the 10-valent conjugate vaccine (PCV-10) was recently introduced into the National Immunization Program in Mozambique, but data on serotype coverage of this vaccine formulation are scarce. In this study, we investigated the serotype distribution and antimicrobial resistance of isolates of S. pneumoniae causing ABM in children < 5 years at the two largest hospitals in Mozambique. METHODS: Between March 2013 and March 2014, a total of 352 cerebrospinal fluid (CSF) samples were collected from eligible children, of which 119 (33.8 %) were positive for S. pneumoniae. Of these, only 50 samples met the criteria for serotyping and were subsequently serotyped using sequential multiplex PCR (SM-PCR), but 15 samples were non-typable. RESULTS: The most common serotypes of S. pneumoniae were 1 (18.2 %), 5 (15.2 %), 14 (12.1 %), 9 V (12.1 %), 23 F (9.1 %), 6A (9.1 %), 4 (9.1 %) and 6B (6.1 %). Serotypes 1, 5, 9 V, 6A and 12 were mostly prevalent in Northern Mozambique, while serotypes 23 F, 4, 6B, 3 and 15B were predominant in Southern. Serotype coverage of PCV-10 and PCV-13 vaccine formulations were 81.8 % and 93.9 %, respectively. Serotypes 1, 3, 4, 6B, 14, 23 F were resistant to penicillin and sensitive to ceftriaxone. CONCLUSIONS: Our findings shows that changing the current in use PCV-10 vaccine formulation to PCV-13 formulation might increase substantially the protection against invasive strains of S. pneumoniae as the PCV-10 vaccine formulation does not cover the serotypes 3 and 6A, which are prevalent in Mozambique.


Asunto(s)
Antibacterianos/farmacología , Farmacorresistencia Bacteriana Múltiple , Meningitis Bacterianas/líquido cefalorraquídeo , Meningitis Bacterianas/microbiología , Streptococcus pneumoniae/clasificación , Ceftriaxona/farmacología , Preescolar , ADN Bacteriano/análisis , Monitoreo Epidemiológico , Femenino , Humanos , Programas de Inmunización , Lactante , Recién Nacido , Masculino , Meningitis Bacterianas/epidemiología , Meningitis Bacterianas/prevención & control , Pruebas de Sensibilidad Microbiana , Mozambique/epidemiología , Penicilinas/farmacología , Infecciones Neumocócicas/inmunología , Infecciones Neumocócicas/microbiología , Vacunas Neumococicas/administración & dosificación , Reacción en Cadena de la Polimerasa , Prevalencia , Serotipificación , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación
5.
J Clin Microbiol ; 52(3): 974-6, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24391203

RESUMEN

Real-time PCR based on the recN and gyrB genes was developed to detect four Streptococcus bovis/Streptococcus equinus complex (SBEC) subspecies from rectal swab specimens. The overall prevalence was 35.2%: Streptococcus gallolyticus subsp. gallolyticus (11.1%), S. gallolyticus subsp. pasteurianus (13%), Streptococcus infantarius subsp. coli (20.4%), and S. infantarius subsp. infantarius (11.1%). To conclude, these real-time PCR assays provide a reliable molecular method to detect SBEC pathogenic subspecies from rectal swab specimens.


Asunto(s)
Técnicas Bacteriológicas/métodos , Portador Sano/diagnóstico , Heces/microbiología , Técnicas de Diagnóstico Molecular/métodos , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Infecciones Estreptocócicas/diagnóstico , Streptococcus/aislamiento & purificación , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Bacterianas/genética , Portador Sano/epidemiología , Portador Sano/microbiología , Girasa de ADN/genética , Enzimas de Restricción del ADN/genética , ADN Bacteriano/genética , Femenino , Humanos , Masculino , Persona de Mediana Edad , Sondas de Oligonucleótidos/genética , Prevalencia , Infecciones Estreptocócicas/epidemiología , Infecciones Estreptocócicas/microbiología , Streptococcus/clasificación , Streptococcus/genética
6.
Bioprocess Biosyst Eng ; 37(3): 469-79, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23872848

RESUMEN

The aims of this research were to screen and characterize a new microbial source of γ-PGA, to optimize aspects of culture conditions and medium composition using central composite design and response surface methodologies. The influence of bioreactor stirring rates on the production of γ-PGA was also investigated and the oxygen volumetric mass transfer coefficients (k La) were established. The most productive strain was identified by 16S rDNA analysis as Bacillus subtilis, and its γ-PGA production in rotatory shaker was threefold increased under optimized conditions (37 °C, pH 6.9, and 1.22 mM Zn(2+)), compared to conventional medium. In bioreactor, the γ-PGA production was further increased, reaching 17 g l(-1), 70 % higher than shaker cultures. γ-PGA production showed high dependency on oxygen transfer. At k La of 210 h(-1), the cultivation time could be reduced to 48 h, about 50 % of the time required for operations at k La 55 h(-1).


Asunto(s)
Bacillus subtilis/metabolismo , Ácido Poliglutámico/biosíntesis , Bacillus subtilis/genética , Bacillus subtilis/aislamiento & purificación , Reactores Biológicos , Brasil , Medios de Cultivo , ADN Ribosómico/genética , Cinética , ARN Ribosómico 16S/genética
7.
IJID Reg ; 11: 100363, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38634071

RESUMEN

Objectives: This study aimed to determine the SARS-CoV-2 variants in the first four COVID-19 waves using polymerase chain reaction (PCR)-based variant detection in Addis Ababa, Ethiopia. Methods: A cross-sectional study was conducted using repository nasopharyngeal samples stored at the Ethiopian Public Health Institute COVID-19 testing laboratory. Stored positive samples were randomly selected from the first four waves based on their sample collection date. A total of 641 nasopharyngeal samples were selected and re-tested for SARS-CoV-2. RNA was extracted using nucleic acid purification instrument. Then, SARS-CoV-2 detection was carried out using 10 µl RNA and 20 µl reverse transcription-PCR fluorescent mix. Cycle threshold values <38 were considered positive. Results: A total of 374 samples qualified for B.1.617 Lineage and six spike gene mutation variant typing kits. The variant typing kits identified 267 (71.4%) from the total qualifying samples. Alpha, Beta, Delta, and Omicron were dominantly identified variants from waves I, II, III, and IV, respectively. From the total identified positive study samples, 243 of 267 (91%) of variants identified from samples had cycle threshold values <30. Conclusions: The study data demonstrated that reverse transcription-PCR-based variant typing can provide additional screening opportunities where sequencing opportunity is inaccessible. The assays could be implemented in laboratories performing SARS-CoV-2 molecular testing.

8.
Int J Pediatr Otorhinolaryngol ; 169: 111552, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37120991

RESUMEN

OBJECTIVE: This study aimed to describe the microbiology of the middle ear and nasopharynx, determining the prevalence of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in a group of children vaccinated with pneumococcal conjugate vaccine (PCV) who underwent ventilation tube insertion for recurrent acute otitis media. METHODS: We analyzed 278 middle ear effusion and 139 nasopharyngeal samples obtained from 139 children who underwent myringotomy and ventilation tube insertion for recurrent acute otitis media between June 2017 and June 2021. The children's ages ranged from 9 months to 9 years, 10 months, with a median of 21 months. The patients had no signs of acute otitis media or respiratory tract infection and were not on antibiotic therapy at the time of the procedure. The middle ear effusion and nasopharyngeal samples were collected with an Alden-Senturia aspirator and a swab, respectively. Bacteriological studies and multiplex PCR were performed for the detection of the three pathogens. Direct molecular determination of pneumococcal serotypes was performed by real-time PCR. The chi-square test was used to verify associations between categorical variables and measures of strength of association based on prevalence ratios, considering a 95% confidence interval a 5% significance level. RESULTS: Vaccination coverage was 77.7% with the basic regimen plus booster dose and 22.3% with the basic regimen alone. Middle ear effusion culture identified H. influenzae in 27 children (19.4%), S. pneumoniae in 7 (5.0%), and M. catarrhalis in 7 (5.0%). PCR detected H. influenzae in 95 children (68.3%), S. pneumoniae in 52 (37.4%), and M. catarrhalis in 23 (16.5%), a three-to seven-fold increase compared to culture. In the nasopharynx, culture isolated H. influenzae in 28 children (20.1%), S. pneumoniae in 29 (20.9%), and M. catarrhalis in 12 (8.6%). PCR identified H. influenzae in 84 children (60.4%), S. pneumoniae in 58 (41.7%), and M. catarrhalis in 30 (21.5%), a two-to three-fold increase in detection. The most common pneumococcal serotype was 19A, both in the ears and the nasopharynx. In the ears, of the 52 children who had pneumococcus, 24 (46.2%) had serotype 19A. In the nasopharynx, of the 58 patients who had pneumococcus, 37 (63.8%) had serotype 19A. Of all 139 children, 53 (38.1%) had polymicrobial samples (more than 1 of the 3 otopathogens) in the nasopharynx. Of the 53 children who had polymicrobial samples in the nasopharynx, 47 (88.7%) also had 1 of the 3 otopathogens in the middle ear, mainly H. influenzae (40%-75.5%), especially when it was found in the nasopharynx in conjunction with S. pneumoniae. CONCLUSION: The prevalence of bacteria in a group of Brazilian children immunized with the PCV who required ventilation tube insertion for recurrent acute otitis media was similar to that reported in other parts of the world after the advent of PCV. H. influenzae was the most frequent bacteria, both in the nasopharynx and the middle ear, while S. pneumoniae serotype 19A was the most common pneumococcus in the nasopharynx and middle ear. Polymicrobial colonization of the nasopharynx was strongly associated with detection of H. influenzae in the middle ear.


Asunto(s)
Otitis Media con Derrame , Otitis Media , Humanos , Niño , Lactante , Otitis Media con Derrame/cirugía , Otitis Media con Derrame/microbiología , Vacunas Neumococicas/uso terapéutico , Otitis Media/epidemiología , Oído Medio/microbiología , Streptococcus pneumoniae , Moraxella catarrhalis , Nasofaringe/microbiología , Haemophilus influenzae , Reacción en Cadena de la Polimerasa Multiplex
9.
Diagnostics (Basel) ; 13(8)2023 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-37189571

RESUMEN

We developed a MALDI-TOF mass spectrometry method for the detection of the SARS-CoV-2 virus in saliva-gargle samples using Shimadzu MALDI-TOF mass spectrometers in the UK. This was validated in the USA to CLIA-LDT standards for asymptomatic infection detection remotely via sharing protocols, shipping key reagents, video conferencing, and data exchange. In Brazil, more so than in the UK and USA, there is a need to develop non-PCR-dependent, rapid, and affordable SARS-CoV-2 infection screening tests that also identify variant SARS-CoV-2 and other virus infections. In addition, travel restrictions necessitated remote collaboration with validation on the available clinical MALDI-TOF-the Bruker Biotyper (microflex® LT/SH)-and on nasopharyngeal swab samples, as salivary gargle samples were not available. The Bruker Biotyper was shown to be almost log103 more sensitive at the detection of high molecular weight spike proteins. A protocol for saline swab soaks out was developed, and duplicate swab samples collected in Brazil were analyzed by MALDI-TOF MS. The swab collected sample spectra that varied from that of saliva-gargle in three additional mass peaks in the mass region expected for IgG heavy chains and human serum albumin. A subset of clinical samples with additional high mass, probably spike-related proteins, were also found. Further, spectral data comparisons and analysis, subjected to machine learning algorithms in order to resolve RT-qPCR positive from RT-qPCR negative swab samples, showed 56-62% sensitivity, 87-91% specificity, and a 78% agreement with RT-qPCR scoring for SARS-CoV-2 infection.

10.
Microbiol Spectr ; 11(1): e0117922, 2023 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-36688721

RESUMEN

In 2015, two new species related to the Staphylococcus aureus were proposed. We describe five isolates of the new species Staphylococcus argenteus cultured from human cases of bacteremia and skin and soft tissue infections. This is the first report of S. argenteus, from South America, causing community-acquired and nosocomial infections.


Asunto(s)
Infecciones Comunitarias Adquiridas , Infecciones Estafilocócicas , Humanos , Brasil/epidemiología , Staphylococcus , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus , Infecciones Comunitarias Adquiridas/epidemiología
11.
PLoS One ; 17(5): e0267949, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35544535

RESUMEN

BACKGROUND: Meningitis remains an important cause of morbi-mortality in adults in sub-Saharan Africa. Data on the etiological investigation of meningitis in adults in Mozambique is limited and most studies were conducted in southern Mozambique. Identification of the etiology of meningitis in adults are crucial to guide prevention and treatments strategies. In this study, we determine the burden of fungal and bacterial meningitis among adults at the three largest hospitals in Mozambique. METHOD: We performed analysis of data from the routine sentinel surveillance system for meningitis in Mozambique from January 2016 to December 2017. Cerebrospinal fluid (CSF) samples were collected from eligible adults (≥18 years old) who met World Health Organization (WHO) case definition criteria for Meningitis. All samples were tested by cryptococcal antigen (CrAg) lateral flow assay (LFA), culture and triplex real-time polymerase chain reaction (qPCR) assay and all patients were tested for human immunodeficiency virus (HIV) using the national algorithm for HIV testing. RESULTS: Retrospective analysis of 1501 CSF samples from adults clinically suspected of meningitis revealed that 10.5% (158/1501) were positive for bacterial and fungal meningitis. Of these 158 confirmed cases, the proportion of Cryptococcal meningitis and pneumococcal meningitis was38.6% (95% CI: 31.0% to 46.7%) and 36.7% (95% CI: 29.2% to 44.7%), respectively. The other bacterial agents of meningitis identified include Neisseria meningitidis (8.9%; 14/158), Escherichia coli (6.3%; 10/158), Haemophilus influenzae (5.1%; 8/158) and S. aureus (4.4%; 7/158), which represent (24.7%; 39/158) of the total confirmed cases. CONCLUSION: Altogether, our findings show a high burden of Cryptococcal meningitis among adults in Mozambique, especially in people living with HIV, followed by pneumococcal meningitis. Our findings suggest that rollout of CrAg Lateral Flow Assay in the health system in Mozambique for early detection of cryptococcus neoformans is necessary to improve overall patient care.


Asunto(s)
Cryptococcus neoformans , Cryptococcus , Infecciones por VIH , Meningitis Criptocócica , Meningitis Neumocócica , Adolescente , Adulto , Antígenos Fúngicos/análisis , Infecciones por VIH/complicaciones , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Hospitales , Humanos , Meningitis Criptocócica/diagnóstico , Meningitis Criptocócica/epidemiología , Mozambique/epidemiología , Estudios Retrospectivos , Staphylococcus aureus
12.
Nat Microbiol ; 7(9): 1490-1500, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35982313

RESUMEN

The high numbers of COVID-19 cases and deaths in Brazil have made Latin America an epicentre of the pandemic. SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, but important gaps remain in our understanding of virus transmission dynamics at a national scale. We use 17,135 near-complete genomes sampled from 27 Brazilian states and bordering country Paraguay. From March to November 2020, we detected co-circulation of multiple viral lineages that were linked to multiple importations (predominantly from Europe). After November 2020, we detected large, local transmission clusters within the country. In the absence of effective restriction measures, the epidemic progressed, and in January 2021 there was emergence and onward spread, both within and abroad, of variants of concern and variants under monitoring, including Gamma (P.1) and Zeta (P.2). We also characterized a genomic overview of the epidemic in Paraguay and detected evidence of importation of SARS-CoV-2 ancestor lineages and variants of concern from Brazil. Our findings show that genomic surveillance in Brazil enabled assessment of the real-time spread of emerging SARS-CoV-2 variants.


Asunto(s)
COVID-19 , SARS-CoV-2 , Brasil , Genómica , Humanos
13.
medRxiv ; 2022 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-35378755

RESUMEN

Brazil has experienced some of the highest numbers of COVID-19 cases and deaths globally and from May 2021 made Latin America a pandemic epicenter. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of virus transmission dynamics at the national scale. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and a bordering country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed under an absence of effective restriction measures, there was a local emergence and onward international spread of Variants of Concern (VOC) and Variants Under Monitoring (VUM), including Gamma (P.1) and Zeta (P.2). In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the usefulness and need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring that provides a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies.

14.
Microb Pathog ; 51(6): 454-65, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21963679

RESUMEN

AexU is a type three secretion system (TTSS) effector of Aeromonas hydrophila which has an in vitro ADP-ribosyltransferase (ART) and GTPase-activating protein (GAP) activities on Rac1, RhoA and Cdc42. Here we show that, AexU of Aeromonas veronii bv. sobria AeG1 strain disrupts actin cytoskeleton of HeLa cells during AeG1 infection, aexU transfection or direct application of AexU protein. Such cellular disruption was rescued by either inactivation of AexU-GAP activity by substitution of arginine residue 143 to alanine or expression of a constitutively active (CA) Rac1 but not CA RhoA or CA Cdc42. On the other hand, AexU was found co-localized with ß4-integrin probably through its Arg-Gly-Asp (RGD) integrin binding motif (319-321) residues. Interestingly, direct application of GST-AexU-HA fusion protein caused significant cytotoxic effect on ß4-integrin expressing HT-29 cells. In contrast, ß4-integrin blockade with a specific antibody reduced such cytotoxicity. Consequently, AexU cytotoxic effect was exaggerated with a greater expression of ß4-integrin in Caco-2 and HeLa cells, while it was incompetent on ß4-integrin non-expressing CHO cells. As far as we know, this is a novel TTSS effector which specifically inactivates Rac1 to disrupt actin cytoskeleton and has an alternative cytotoxic pathway through ß4-integrin mediation.


Asunto(s)
Citoesqueleto de Actina/metabolismo , Aeromonas/patogenicidad , Interacciones Huésped-Patógeno , Integrina beta4/metabolismo , Factores de Virulencia/metabolismo , Proteína de Unión al GTP rac1/antagonistas & inhibidores , Aeromonas/metabolismo , Sustitución de Aminoácidos , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Línea Celular , Supervivencia Celular/efectos de los fármacos , Humanos , Mutagénesis Sitio-Dirigida , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Unión Proteica , Mapeo de Interacción de Proteínas , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Factores de Virulencia/genética
15.
Mem Inst Oswaldo Cruz ; 106(1): 56-60, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21340356

RESUMEN

The introduction of newer molecular methods has led to the discovery of new respiratory viruses, such as human metapneumovirus (hMPV) and human bocavirus (hBoV), in respiratory tract specimens. We have studied the occurrence of hMPV and hBoV in the Porto Alegre (PA) metropolitan area, one of the southernmost cities of Brazil, evaluating children with suspected lower respiratory tract infection from May 2007-June 2008. A real-time polymerase chain reaction method was used for amplification and detection of hMPV and hBoV and to evaluate coinfections with respiratory syncytial virus (RSV), influenza A and B, parainfluenza 1, 2 and 3, human rhinovirus and human adenovirus. Of the 455 nasopharyngeal aspirates tested, hMPV was detected in 14.5% of samples and hBoV in 13.2%. A unique causative viral agent was identified in 46.2% samples and the coinfection rate was 43.7%. For hBoV, 98.3% of all positive samples were from patients with mixed infections. Similarly, 84.8% of all hMPV-positive results were also observed in mixed infections. Both hBoV and hMPV usually appeared with RSV. In summary, this is the first confirmation that hMPV and hBoV circulate in PA; this provides evidence of frequent involvement of both viruses in children with clinical signs of acute viral respiratory tract infection, although they mainly appeared as coinfection agents.


Asunto(s)
Bocavirus Humano/aislamiento & purificación , Metapneumovirus/aislamiento & purificación , Nasofaringe/virología , Infecciones del Sistema Respiratorio/virología , Enfermedad Aguda , Femenino , Bocavirus Humano/genética , Humanos , Lactante , Masculino , Metapneumovirus/genética , Reacción en Cadena de la Polimerasa , Infecciones del Sistema Respiratorio/diagnóstico , Estaciones del Año , Población Urbana
16.
J Clin Virol Plus ; 1(3): 100032, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35262017

RESUMEN

Background: The efficiency of isolation and purification of the viral genome is a critical step to the accuracy and reliability of RT-qPCR to detect SARS-CoV-2. However, COVID-19 testing laboratories were overwhelmed by a surge in diagnostic demand that affected supply chains especially in low and middle-income facilities. Objectives: Thus, this study compares the performance of alternative methods to extraction and purification of viral RNA in samples of patients diagnosed with COVID-19. Study design: Nasopharyngeal swabs were submitted to three in-house protocols and three commercial methods; viral genome was detected using the primer-probe (N1 and N2) described by CDC and viral load of samples were determined. Results: The in-house protocols resulted in detection of virus in 82.4 to 86.3% of samples and commercial methods in 94.1 to 98%. The disagreement results were observed in samples with low viral load or below the estimated limit of detection of RT-qPCR. Conclusion: The simplified methods proposed might be less reliable for patients with low viral load and alternative commercial methods showed comparable performance.

17.
Mem Inst Oswaldo Cruz ; 105(7): 873-8, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21120356

RESUMEN

Bartonella spp are the causative agent of cat scratch disease in humans. Cats are the natural reservoir of these bacteria and may infect humans through scratches, bites or fleas. Blood samples from 47 cats aged up to 12 months were collected for this study. All animals were lodged in municipal animal shelters in the Vale do Sinos region, Rio Grande do Sul, Brazil. Bartonella spp were detected by genus-specific polymerase chain reaction (PCR) and when the PCR was positive, the species were determined by DNA sequencing. A Giemsa-stained blood smear was also examined for the presence of intraerythrocytic elements suggestive of Bartonella spp infection. Phylogenetic analysis was also performed for all positive samples. Using molecular detection methods, Bartonella spp were detected in 17.02% (8/47) of the samples. In seven out of eight samples confirmed to be positive for Bartonella spp, blood smear examination revealed the presence of intraerythrocytic elements suggestive of Bartonella spp. Phylogenetic analysis characterized positive samples as Bartonella henselae (5) or Bartonella clarridgeiae (3). To the best of our knowledge, this is the first molecular study demonstrating the presence of Bartonella spp in cats from the Southern Region of Brazil.


Asunto(s)
Infecciones por Bartonella/veterinaria , Bartonella/genética , Enfermedades de los Gatos/microbiología , Animales , Bartonella/clasificación , Bartonella/aislamiento & purificación , Infecciones por Bartonella/epidemiología , Infecciones por Bartonella/microbiología , Bartonella henselae/genética , Bartonella henselae/aislamiento & purificación , Brasil/epidemiología , Enfermedades de los Gatos/epidemiología , Gatos , ADN Bacteriano/sangre , ADN Bacteriano/genética , Filogenia , Reacción en Cadena de la Polimerasa , Prevalencia
18.
Rev Iberoam Micol ; 36(3): 147-150, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31383539

RESUMEN

BACKGROUND: Histoplasmosis is a systemic infection caused by the dimorphic fungus Histoplasma capsulatum, naturally found in nitrogen-rich soil, whose main transmission route is the inhalation of conidia. Up to 95% of histoplasmosis cases are asymptomatic or transient, and the remaining 5% of cases have pathological manifestations in the lungs, bone marrow, liver, spleen, intestine, mucous membranes, and rarely on the skin. This mycosis has been reported from many endemic areas, mainly in immunosuppressed patients, such as HIV-positive patients, and its disseminated form is rarely reported. CASE REPORT: Histoplama capsulatum was isolated and identified by means of microscopy, culture characteristics and nested PCR from the cutaneous lesions of a non-HIV patient from Vietnam. The patient improved significantly with systemic itraconazole treatment. CONCLUSIONS: Disseminated histoplasmosis with cutaneous involvement in non-HIV patients is an extremely unusual presentation.


Asunto(s)
Dermatomicosis/diagnóstico , Histoplasmosis/diagnóstico , Dermatomicosis/microbiología , Infecciones por VIH , Histoplasmosis/microbiología , Humanos , Masculino , Persona de Mediana Edad , Vietnam
19.
Infect Immun ; 76(9): 4282-9, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18541652

RESUMEN

The type III secretion system (T3SS) translocon complex is composed of several associated proteins, which form a translocation channel through the host cell plasma membrane. These proteins are key molecules that are involved in the pathogenicity of many T3SS-positive bacteria, because they are necessary to deliver effector proteins into host cells. A T3SS designated T3SS2 of Vibrio parahaemolyticus is thought to be related to the enterotoxicity of this bacterium in humans, but the effector translocation mechanism of T3SS2 is unclear because there is only one gene (the VPA1362 gene) in the T3SS2 region that is homologous to other translocon protein genes. It is also not known whether the VPA1362 protein is functional in the translocon of T3SS2 or whether it is sufficient to form the translocation channel of T3SS2. In this study, we identified both VPA1362 (designated VopB2) and VPA1361 (designated VopD2) as T3SS2-dependent secretion proteins. Functional analysis of these proteins showed that they are essential for T3SS2-dependent cytotoxicity, for the translocation of one of the T3SS2 effector proteins (VopT), and for the contact-dependent activity of pore formation in infected cells in vitro. Their targeting to the host cell membrane depends on T3SS2, and furthermore, they are necessary for T3SS2-dependent enterotoxicity in vivo. These results indicate that VopB2 and VopD2 act as translocon proteins of V. parahaemolyticus T3SS2 and hence have a critical role in the T3SS2-dependent enterotoxicity of this bacterium.


Asunto(s)
Proteínas de Transporte de Membrana/genética , Proteínas de Transporte de Membrana/metabolismo , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/metabolismo , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Línea Celular , Técnicas de Cocultivo , Eliminación de Gen , Humanos , Íleon/microbiología , Íleon/patología , Transporte de Proteínas , Conejos , Vibriosis
20.
Rev Inst Med Trop Sao Paulo ; 50(1): 51-2, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18327488

RESUMEN

We report here a rare case of cutaneous infection due to Corynebacterium pseudodiphtheriticum. The patient presented to the clinical laboratory with a skin ulcer on his left leg. Gram-stained preparation of the purulent secretion revealed the presence of numerous rod-shaped Gram-positive organisms in the absence of any other species. The organism was grown in pure culture on sheep blood agar and was further identified as C. pseudodiphtheriticum using a commercial identification system (API-Coryne, BioMérieux, France). The infection was successfully treated with ciprofloxacin. This case emphasizes the importance of the clinical microbiology laboratory in correctly identifying Gram-positive organisms obtained in pure culture from skin ulcers.


Asunto(s)
Infecciones por Corynebacterium/microbiología , Corynebacterium/aislamiento & purificación , Enfermedades Cutáneas Bacterianas/microbiología , Úlcera Cutánea/microbiología , Antiinfecciosos/uso terapéutico , Ciprofloxacina/uso terapéutico , Corynebacterium/clasificación , Humanos , Huésped Inmunocomprometido , Masculino , Enfermedades Cutáneas Bacterianas/diagnóstico , Enfermedades Cutáneas Bacterianas/tratamiento farmacológico , Úlcera Cutánea/diagnóstico , Úlcera Cutánea/tratamiento farmacológico
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