RESUMO
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.
Assuntos
COVID-19 , Transcrição Reversa , Humanos , RNA Viral/genética , COVID-19/diagnóstico , SARS-CoV-2/genética , RNA Polimerases Dirigidas por DNARESUMO
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.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Meningites Bacterianas/líquido cefalorraquidiano , Meningites Bacterianas/microbiologia , Streptococcus pneumoniae/classificação , Ceftriaxona/farmacologia , Pré-Escolar , DNA Bacteriano/análise , Monitoramento Epidemiológico , Feminino , Humanos , Programas de Imunização , Lactente , Recém-Nascido , Masculino , Meningites Bacterianas/epidemiologia , Meningites Bacterianas/prevenção & controle , Testes de Sensibilidade Microbiana , Moçambique/epidemiologia , Penicilinas/farmacologia , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/microbiologia , Vacinas Pneumocócicas/administração & dosagem , Reação em Cadeia da Polimerase , Prevalência , Sorotipagem , Streptococcus pneumoniae/efeitos dos fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificaçãoRESUMO
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.
Assuntos
Técnicas Bacteriológicas/métodos , Portador Sadio/diagnóstico , Fezes/microbiologia , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções Estreptocócicas/diagnóstico , Streptococcus/isolamento & purificação , Adulto , Idoso , Idoso de 80 Anos ou mais , Proteínas de Bactérias/genética , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , DNA Girase/genética , Enzimas de Restrição do DNA/genética , DNA Bacteriano/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sondas de Oligonucleotídeos/genética , Prevalência , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus/classificação , Streptococcus/genéticaRESUMO
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).
Assuntos
Bacillus subtilis/metabolismo , Ácido Poliglutâmico/biossíntese , Bacillus subtilis/genética , Bacillus subtilis/isolamento & purificação , Reatores Biológicos , Brasil , Meios de Cultura , DNA Ribossômico/genética , Cinética , RNA Ribossômico 16S/genéticaRESUMO
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.
Assuntos
Infecções Comunitárias Adquiridas , Infecções Estafilocócicas , Humanos , Brasil/epidemiologia , Staphylococcus , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus , Infecções Comunitárias Adquiridas/epidemiologiaRESUMO
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.
Assuntos
Cryptococcus neoformans , Cryptococcus , Infecções por HIV , Meningite Criptocócica , Meningite Pneumocócica , Adolescente , Adulto , Antígenos de Fungos/análise , Infecções por HIV/complicações , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Hospitais , Humanos , Meningite Criptocócica/diagnóstico , Meningite Criptocócica/epidemiologia , Moçambique/epidemiologia , Estudos Retrospectivos , Staphylococcus aureusRESUMO
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.
Assuntos
COVID-19 , SARS-CoV-2 , Brasil , Genômica , HumanosRESUMO
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.
RESUMO
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.
Assuntos
Bocavirus Humano/isolamento & purificação , Metapneumovirus/isolamento & purificação , Nasofaringe/virologia , Infecções Respiratórias/virologia , Doença Aguda , Feminino , Bocavirus Humano/genética , Humanos , Lactente , Masculino , Metapneumovirus/genética , Reação em Cadeia da Polimerase , Infecções Respiratórias/diagnóstico , Estações do Ano , População UrbanaRESUMO
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.
RESUMO
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.
Assuntos
Infecções por Bartonella/veterinária , Bartonella/genética , Doenças do Gato/microbiologia , Animais , Bartonella/classificação , Bartonella/isolamento & purificação , Infecções por Bartonella/epidemiologia , Infecções por Bartonella/microbiologia , Bartonella henselae/genética , Bartonella henselae/isolamento & purificação , Brasil/epidemiologia , Doenças do Gato/epidemiologia , Gatos , DNA Bacteriano/sangue , DNA Bacteriano/genética , Filogenia , Reação em Cadeia da Polimerase , PrevalênciaRESUMO
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.
Assuntos
Dermatomicoses/diagnóstico , Histoplasmose/diagnóstico , Dermatomicoses/microbiologia , Infecções por HIV , Histoplasmose/microbiologia , Humanos , Masculino , Pessoa de Meia-Idade , VietnãRESUMO
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.
Assuntos
Infecções por Corynebacterium/microbiologia , Corynebacterium/isolamento & purificação , Dermatopatias Bacterianas/microbiologia , Úlcera Cutânea/microbiologia , Anti-Infecciosos/uso terapêutico , Ciprofloxacina/uso terapêutico , Corynebacterium/classificação , Humanos , Hospedeiro Imunocomprometido , Masculino , Dermatopatias Bacterianas/diagnóstico , Dermatopatias Bacterianas/tratamento farmacológico , Úlcera Cutânea/diagnóstico , Úlcera Cutânea/tratamento farmacológicoRESUMO
Detection of AmpC beta-lactamase production by enterobacteria has been problematic. Contrary to ESBLs, no specific guidelines are available for detection and confirmation of AmpC production by clinical relevant microorganisms. Moreover, some bacterial species may produce inducible AmpC beta-lactamases that can be easily overlooked by routine susceptibility tests. We reported here a new test based on the strong inducible effect of imipenem on AmpC genes and the consequent antagonism with ceftazidime. This test is very simple and proved to be helpful in detecting AmpC-inducible enzymes among several species of clinical isolates.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/efeitos dos fármacos , Ceftazidima/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Imipenem/farmacologia , beta-Lactamases/efeitos dos fármacos , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Enterobacteriaceae/enzimologia , Humanos , Fenótipo , beta-Lactamases/biossíntese , beta-Lactamases/genéticaRESUMO
BACKGROUND: Vaccination using the 10-valent conjugate vaccine (PCV-10) was introduced into the Extended Program on Immunization in Mozambique in March 2013, however its impact on pediatric pneumococcal meningitis is unknown. In this study, we assessed for the first time the impact of PCV10 on the burden of pneumococcal meningitis in children less than 5 years of age at the three largest hospitals in Mozambique. METHOD: Between March 2013 and December 2015, a total of 744 cerebrospinal fluid (CSF) samples were collected from eligible children, of which 160 (21.5%) were positive for S. pneumoniae. Of these, only 86 samples met the criteria for serotyping and were subsequently serotyped using sequential multiplex PCR (SM-PCR), but 17 samples were non-typable. RESULTS: The proportion of cases of pneumococcal meningitis decreased from 33.6% (124 of 369) in 2013 to 1.9% (3 of 160) in 2015 (p < 0.001). The relative frequency of PCV10 serotype cases also decreased from 84.2% (48 of 57) in 2013 to 0% (0 of 3) in 2015 (p = 0.006). Between 2013 and 2015, serotype coverage of PCV-10 and PCV13 vaccine formulations was 66.7% and 81.2%, respectively. CONCLUSION: Altogether, our findings shows that introduction of PCV-10 immunization resulted in rapid decline of pneumococcal meningitis children less than 5 years old in Mozambique. This decline was accompanied by substantial changes in the pattern of circulating pneumococcal serotypes.
Assuntos
Meningite Pneumocócica/epidemiologia , Meningite Pneumocócica/prevenção & controle , Vacinas Pneumocócicas/imunologia , Vigilância em Saúde Pública , Pré-Escolar , Estudos Transversais , Feminino , História do Século XXI , Humanos , Lactente , Recém-Nascido , Masculino , Moçambique/epidemiologia , Vacinas Pneumocócicas/administração & dosagem , Sorogrupo , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/imunologia , VacinaçãoRESUMO
We report the 1st case of sinusitis and human infection by Xylaria enteroleuca (anamorph Nodulisporium sp.), a rare fungal endophyte of rain forest trees. The patient was a Brazilian woman who had her lung transplanted. Diagnosis was established by direct microscopic examination, computed tomographic scan, cultures, and sequencing of a ribosomal RNA gene. The in vitro antifungal susceptibility of the isolate is provided.
Assuntos
Ascomicetos/isolamento & purificação , Transplante de Pulmão/efeitos adversos , Micoses/microbiologia , Sinusite/microbiologia , Evolução Fatal , Feminino , Humanos , Itraconazol/uso terapêutico , Pessoa de Meia-Idade , Micoses/diagnóstico , Sinusite/diagnósticoRESUMO
Corynebacterium species have often been considered normal skin flora or contaminants; however, in recent years they have been increasingly implicated in serious infections. Moreover, many new species have been discovered and old species renamed, especially after molecular biology techniques were introduced. Corynebacterium mucifaciens is mainly isolated from blood and from other normally-sterile body fluids; it forms slightly yellow, mucoid colonies on blood agar. We report a fatal case of bacteremia due to an atypical strain of C. mucifaciens. This strain had atypical colony morphology; analysis of the 16S rRNA gene was used to define the species.
Assuntos
Bacteriemia/microbiologia , Infecções por Corynebacterium/microbiologia , Corynebacterium/isolamento & purificação , Idoso de 80 Anos ou mais , Bacteriemia/diagnóstico , Corynebacterium/classificação , Corynebacterium/genética , Infecções por Corynebacterium/diagnóstico , DNA Bacteriano/análise , Evolução Fatal , Feminino , Humanos , RNA Ribossômico 16S/análiseRESUMO
Diphyllobothriasis is caused in humans by infection with adult tapeworms of the genus Diphyllobothrium acquired by consuming raw or undercooked freshwater fish. Diphyllobothrium latum was confirmed by examination of the gravid proglottids and typical operculated eggs in the stool. The patient had a history of eating crustaceans and fish. This is the case report of the first Brazilian infected.
Assuntos
Difilobotríase/diagnóstico , Diphyllobothrium/isolamento & purificação , Fezes/parasitologia , Idoso , Animais , Anti-Helmínticos/uso terapêutico , Brasil , Humanos , Praziquantel/uso terapêuticoRESUMO
Anaerobiospirillum succiniciproducens is an anaerobic, Gram-negative, spiral shaped bacteria, which is motile by means of bipolar tuffs of flagella. This organism appears to be a rare cause of bacteremia in humans, and it usually affects patients submitted to immunosuppressive therapy. Anaerobiospirillum succiniciproducens resembles Campylobacter spp. in Gram-stained preparations, however, it is considered resistant to most antimicrobial drugs that are used to treat Campylobacter infections. We observed Gram-negative, spiral shaped bacteria in Gram-stained preparations from blood culture flasks. Growth occurred only under anaerobic incubation, and identification to the species level was achieved by PCR amplification of the 16S rRNA gene, followed by direct sequencing and a GenBank homology search. To the best of our knowledge, this is the first reported Brazilian case of Anaerobiospirillum succiniciproducens bacteremia.
Assuntos
Anaerobiospirillum/isolamento & purificação , Bacteriemia/microbiologia , Infecções por Bactérias Gram-Negativas/microbiologia , Idoso , Anaerobiospirillum/genética , Brasil , DNA Bacteriano/análise , Evolução Fatal , Feminino , Humanos , Reação em Cadeia da Polimerase , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genéticaRESUMO
BACKGROUND: In Sub-Saharan Africa, including Mozambique, acute bacterial meningitis (ABM) represents a main cause of childhood mortality. The burden of ABM is seriously underestimated because of the poor performance of culture sampling, the primary method of ABM surveillance in the region. Low quality cerebrospinal fluid (CSF) samples and frequent consumption of antibiotics prior to sample collection lead to a high rate of false-negative results. To our knowledge, this study is the first to determine the frequency of ABM in Mozambique using real-time polymerase chain reaction (qPCR) and to compare results to those of culture sampling. METHOD: Between March 2013 and March 2014, CSF samples were collected at 3 regional hospitals from patients under 5 years of age, who met World Health Organization case definition criteria for ABM. Macroscopic examination, cytochemical study, culture, and qPCR were performed on all samples. RESULTS: A total of 369 CSF samples were collected from children clinically suspected of ABM. qPCR showed a significantly higher detection rate of ABM-causing pathogens when compared to culture (52.3% [193/369] versus 7.3% [27/369], p = 0.000). The frequency of Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococci, and Neisseria meningitidis were 32.8% (121/369), 12.2%, (45/369), 3.0% (16/369) and 4.3% (11/369), respectively, significantly higher compared to that obtained on culture (p < 0.001 for each). CONCLUSION: Our findings demonstrate that culture is less effective for the diagnosis of ABM than qPCR. The common use of culture rather than qPCR to identify ABM results in serious underestimation of the burden of the disease, and our findings strongly suggest that qPCR should be incorporated into surveillance activities for ABM. In addition, our data showed that S. pneumoniae represents the most common cause of ABM in children under 5 years of age.