Recurrent community-acquired pneumococcal meningitis in adults with and without identified predisposing factors.

Bacterial meningitis is still a significant public health concern, with high morbidity and mortality rates. Despite this, it is still a rare event that requires the bacterial invasion of the meninges. However, some predisposing factors can trigger recurrent episodes of meningitis. This study is aimed at determining the clinical characteristics and the molecular epidemiology of episodes of recurrent community-acquired meningitis with and without predisposing factors. For this purpose, we performed a retrospective study of our laboratory database during the period of 2010 to 2020. Additionally, using molecular tools developed in our previous works, the epidemiology of the pathogens causing these episodes was analyzed using cerebrospinal fluid samples, especially in the absence of isolated strains. We observed a total of 1,779 meningitis cases and 230 were caused by Streptococcus pneumoniae. Of those, 16 were recurrent meningitis episodes (16/1,779; 0.9%) from seven patients. Pneumococcus was the main agent responsible in these recurrent episodes and only two episodes were caused by Haemophilus influenzae. The mean age of these patients was 20 years old and three had predisposing factors which could have led to contracting meningitis. The samples presented different pneumococcal serotypes. Most of them were non-vaccine-covered serotypes and antibiotic susceptible strains. Therefore, it was demonstrated how the practical employment of molecular tools, developed for research, when applied in the routine of diagnosis, can provide important information for epidemiological surveillance. Furthermore, it was shown how pneumococcus was the leading cause of recurrent community-acquired meningitis without predisposing factors, suggesting that pneumococcal vaccination may be necessary, even in those groups of individuals considered to be less susceptible.

Multiplex PCR to Streptococcus pneumoniae serotype identification directly in cerebrospinal fluid samples.

Streptococcus pneumoniae causes invasive diseases of significant public health concern, such as meningitis. The culture of cerebrospinal fluid (CSF) samples, the standard technique for meningitis diagnoses, is not always positive. Consequently, meaningful information about the etiological agent is lost, which can compromise effective epidemiological surveillance and the improvement of immunization policies. This study aims to standardize a method to genotype pneumococcus in the CSF samples which could mitigate the absence of isolated strains, and also evaluate the prediction of this assay. We applied eight multiplex PCR (mPCR) assays to CSF samples paired with the Quellung reaction applied to the isolated strains. We also compared different master mix kits in the mPCR. Moreover, a retrospective study was conducted with CSF samples considered pneumococcus positive due to the presence of the lytA gene. Results showed that genotyping by the mPCR correlated 100% with the Quellung reaction, and genotyping was dependent on the master mix applied. In the retrospective study (2014-2020), 73.4% were successfully genotyped. The analyses of the receiver operating characteristic curve showed that the cycle threshold (Ct value) around 30 for the lytA gene had a 75% positive chance of successful genotyping, whereas with a Ct value > 35, the chance was 12.5%. Finally, we observed that genotype 19A was prevalent in the period (12%), information unknown until now due to the lack of isolated strains. Therefore, the mPCR of CSF samples can efficiently predict S. pneumoniae serotypes, especially in the absence of isolated strains, which can be a great tool for pneumococcal serotype surveillance.

Multiplex PCR to Streptococcus pneumoniae serotype identification directly in cerebrospinal fluid samples

Streptococcus pneumoniae causes invasive diseases of significant public health concern, such as meningitis. The culture of cerebrospinal fluid (CSF) samples, the standard technique for meningitis diagnoses, is not always positive. Consequently, meaningful information about the etiological agent is lost, which can compromise effective epidemiological surveillance and the improvement of immunization policies. This study aims to standardize a method to genotype pneumococcus in the CSF samples which could mitigate the absence of isolated strains, and also evaluate the prediction of this assay. We applied eight multiplex PCR (mPCR) assays to CSF samples paired with the Quellung reaction applied to the isolated strains. We also compared different master mix kits in the mPCR. Moreover, a retrospective study was conducted with CSF samples considered pneumococcus positive due to the presence of the lytA gene. Results showed that genotyping by the mPCR correlated 100% with the Quellung reaction, and genotyping was dependent on the master mix applied. In the retrospective study (2014–2020), 73.4% were successfully genotyped. The analyses of the receiver operating characteristic curve showed that the cycle threshold (Ct value) around 30 for the lytA gene had a 75% positive chance of successful genotyping, whereas with a Ct value > 35, the chance was 12.5%. Finally, we observed that genotype 19A was prevalent in the period (12%), information unknown until now due to the lack of isolated strains. Therefore, the mPCR of CSF samples can efficiently predict S. pneumoniae serotypes, especially in the absence of isolated strains, which can be a great tool for pneumococcal serotype surveillance.

Multiplex real-time PCR using SYBR Green: Unspecific intercalating dye to detect antimicrobial resistance genes of Streptococcus pneumoniae in cerebrospinal fluid.

Meningitis caused by Streptococcus pneumoniae is still a disease of great impact on Public health, which requires immediate diagnosis and treatment. However, the culture of clinical specimens is often negative and antibiotic susceptibility testing (AST) must be performed with isolated strains. Multiplex real-time polymerase chain reaction (qPCR) has high sensitivity and specificity, produces faster results to identify the pathogen, and it can also be an important tool to identify resistance antibiotic genes earlier than AST, especially in the absence of an isolated strain. This study developed a multiplex qPCR assay, using SYBR Green as a nonspecific dye, to detect antibiotic resistance genes to predict pneumococcal susceptibility/resistance in cerebrospinal fluid (CSF) samples from meningitis patients. From 2017 to 2020, CSF samples were cultured and analyzed by qPCR to detect the main three bacteria causing meningitis. Isolated and reference strains were applied in SYBR Green qPCR multiplex to detect pbp2b, ermB, and mef genes, and the results were compared with the AST. Pneumococcal-positive CSF samples (lytA-positive gene) without isolated strains were also tested to evaluate the antimicrobial susceptibility profile in the region from 2014 to 2020. From the received 873 CSF samples; 263 were cultivated, 149 were lytA-positive in the qPCR, and 25 produced viable isolated pneumococci strains, which were evaluated by AST. Melting temperature for each gene and the acceptance criteria were determined (pbp2b: 78.24-79.86; ermB: 80.88-82.56; mef: 74.85-76.34 ºC). A total of 48/51 strains presented a genetic profile in agreement with the AST results. Resistant strains to erythromycin and clindamycin were ermB-positive, and two were also mef-positive, indicating both resistance mechanisms were present. In the retrospective study of the genetic profile of resistance, 82 lytA-positive CSF samples plus 4 strains were applied in the SYBR Green qPCR multiplex: 51% of samples presented the wild genotype (pbp2b positive and ermB/mef negative); 15% were negative for all the three evaluated, indicating pneumococci resistant to penicillin; and 17% represented the multidrug-resistant pneumococci (pbp2b negative and ermB positive or pbp2b negative and ermB and mef positive). Therefore, SYBR Green qPCR multiplex proved to be a reliable tool to identify resistance genes in S. pneumoniae and would be less expensive than multiplex qPCR using specific probes. This could be easily introduced into the routine of diagnostic laboratories and provide a strong presumption of pneumococcal resistance, especially in the absence of isolated strains.

Multiplex real-time PCR using SYBR Green: unspecific intercalating dye to detect antimicrobial resistance genes of Streptococcus pneumoniae in cerebrospinal fluid

Meningitis caused by Streptococcus pneumoniae is still a disease of great impact on Public health, which requires immediate diagnosis and treatment. However, the culture of clinical specimens is often negative and antibiotic susceptibility testing (AST) must be performed with isolated strains. Multiplex real-time polymerase chain reaction (qPCR) has high sensitivity and specificity, produces faster results to identify the pathogen, and it can also be an important tool to identify resistance antibiotic genes earlier than AST, especially in the absence of an isolated strain. This study developed a multiplex qPCR assay, using SYBR Green as a nonspecific dye, to detect antibiotic resistance genes to predict pneumococcal susceptibility/resistance in cerebrospinal fluid (CSF) samples from meningitis patients. From 2017 to 2020, CSF samples were cultured and analyzed by qPCR to detect the main three bacteria causing meningitis. Isolated and reference strains were applied in SYBR Green qPCR multiplex to detect pbp2b, ermB, and mef genes, and the results were compared with the AST. Pneumococcal-positive CSF samples (lytA-positive gene) without isolated strains were also tested to evaluate the antimicrobial susceptibility profile in the region from 2014 to 2020. From the received 873 CSF samples; 263 were cultivated, 149 were lytA-positive in the qPCR, and 25 produced viable isolated pneumococci strains, which were evaluated by AST. Melting temperature for each gene and the acceptance criteria were determined (pbp2b: 78.24­79.86; ermB: 80.88­82.56; mef: 74.85­76.34 ºC). A total of 48/51 strains presented a genetic profile in agreement with the AST results. Resistant strains to erythromycin and clindamycin were ermB-positive, and two were also mef-positive, indicating both resistance mechanisms were present. In the retrospective study of the genetic profile of resistance, 82 lytA-positive CSF samples plus 4 strains were applied in the SYBR Green qPCR multiplex: 51% of samples presented the wild genotype (pbp2b positive and ermB/mef negative); 15% were negative for all the three evaluated, indicating pneumococci resistant to penicillin; and 17% represented the multidrug-resistant pneumococci (pbp2b negative and ermB positive or pbp2b negative and ermB and mef positive). Therefore, SYBR Green qPCR multiplex proved to be a reliable tool to identify resistance genes in S.pneumoniae and would be less expensive than multiplex qPCR using specific probes. This could be easily introduced into the routine of diagnostic laboratories and provide a strong presumption of pneumococcal resistance, especially in the absence of isolated strains. (AU)

Impacto do uso da reação em cadeia da polimerase para o diagnóstico de meningite bacteriana em substituição a contraimunoeletroforese / Impact of using polymerase chain reaction for the diagnosis of bacterial meningitis in substitution for counterimmunoelectrophoresis

Introdução: a meningite bacteriana é um grave problema de Saúde Pública mundial, tendo como principais agentes: Neisseria meningitidis, Streptococcus pneumoniae e Haemophilus influenzae. A metodologia de diagnóstico empregada no Instituto Adolfo Lutz ­ Centro de Laboratório Regional Santo André até o ano de 2011 era a contraimunoeletroforese (CIE), depois foi substituída pela reação em cadeia da polimerase em tempo real (qPCR), que apresenta maior sensibilidade. Objetivo: este trabalho objetivou comparar ambas as metodologias no período de 2009 a 2018, para avaliação do impacto da introdução da qPCR no diagnóstico das meningites bacterianas nos 7 municípios da região do ABC do Estado de São Paulo. Metodologia: foram avaliadas a quantidade total de exames realizados, a média mensal, a positividade no período, os municípios requisitantes e a prevalência das bactérias causadoras de meningite, no período de abril/2009 até dezembro/2018. Resultados: Foram 377 exames de CIE e 1305 de qPCR, com média anual de 230 exames em 2010-2013 e 130 exames em 2014-2018. Observou-se aumento da positividade entre as técnicas, 17,8% para CIE e 33,8% para qPCR. N. meningitidis foi responsável pela maioria dos casos entre 2011 e 2013, cerca de 61% dos casos positivos, enquanto que entre 2014 e 2018 foi S. pneumoniae, cerca de 53%. Conclusão: os resultados indicaram que a qPCR foi mais eficiente em detectar os agentes causadores de meningite bacteriana na região do que a técnica de CIE. Por fim, este trabalho suporta a implantação da metodologia de qPCR para diagnóstico de meningite em substituição de técnicas menos sensíveis.

Introduction: bacterial meningitis is still a serious worldwide public health problem, and the main etiological agents are: Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae. The diagnostic methodology employed at the Adolfo Lutz Institute ­ Santo André Regional Laboratory Center until 2011 was the ounterimmunoelectrophoresis (CIE), then it was replaced by the real-time polymerase chain reaction (qPCR), which is more sensitivity. Objective: this study aimed to compare both methodologies from 2009 to 2018 to evaluate the impact of the introduction of qPCR in the diagnosis of bacterial meningitis in the 7 cities of the ABC region of São Paulo State. Methodology: the total number of tests performed, the month average, the positivity in the period, the requesting cities and the prevalence of bacteria causing meningitis were evaluated from April/2009 to December/2018. Results: there were 377 CIE exams and 1305 qPCR exams, with an annual average of 230 exams in 2010-2013 and 130 exams in 2014-2018. There was an increase in positivity between the performed techniques, 17.8% for CIE and 33.8% for qPCR. N. meningitidis accounted for most cases of bacterial meningitis between 2011 and 2013, about 61% of positive cases, whereas between 2014 and 2018 it was S. pneumoniae, with about 53%. Conclusion: the results indicated that qPCR was more efficient in detecting the agents that cause bacterial meningitis in the region than the CIE technique. Finally, this work supports the implementation of qPCR methodology for diagnosis of meningitis in replacement of less sensitive techniques.

Identificação dos principais agentes bacterianos causadores de meningites na região do ABC paulista, 2018

A meningite bacteriana é uma doença de importância em saúde pública, causada principalmente por três agentes etiológicos, Neisseria meningitidis, Streptococcus pneumoniae e Haemophilus influenzae. Tendo em vista a inexistência de dados sobre esses agentes bacterianos na região do ABC paulista, o objetivo deste trabalho foi avaliar amostras de líquido cefalorraquidiano (LCR) e secreções da nasofaringe e lavados bronco alveolares (LBA) durante o período de abril a dezembro de 2018. Foram analisadas um total de 287 amostras clínicas, encaminhadas pelas Vigilâncias Epidemiológicas Municipais ao Centro de Laboratório Regional do Instituto Adolfo Lutz de Santo André VIII (IAL Santo André) - 87 LCRs e 200 secreções - através do método da cultura bacteriana e identificações microbiológica e bioquímica. A idade dos 87 pacientes que colheram LCR variou de 15 dias a 85 anos e 60% deles pertenciam ao sexo masculino. As culturas dos LCRs identificaram 12 amostras positivas para S. pneumoniae e 2 amostras de N. meningitdis. Haemophilus influenzae não foi identificado por essa técnica. Os resultados obtidos das culturas foram comparados...(AU)