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.

Acquisition of plasmids from Shiga toxin-producing Escherichia coli strains had low or neutral fitness cost on commensal E. coli.

Although it has been hypothesized that the acquisition of plasmids-especially those bearing virulence factors and antimicrobial resistance genes-increases the energetic burden and reduces the fitness of a bacterium in general, some results have challenged this view, showing little or no effect on fitness after plasmid acquisition, which may lead to change in the view that there are evolutionary barriers for a wide spread of such plasmids among bacteria. Here, to evaluate the fitness impact of plasmid-encoded antibiotic resistance and virulence genes, plasmids from O26:H11, O111:H8, and O118:H16 Shiga toxin-producing Escherichia coli (STEC) human and bovine isolates were transferred to the non-virulent E. coli HS and K-12 MG1655 strains. Sequencing and PCR were used to characterize plasmids, and to identify the presence of antimicrobial resistance and/or virulence genes. The fitness impact of plasmids encoding virulence and antimicrobial resistance upon bacterial hosts was determined by pairwise growth competition. Plasmid profile analysis showed that STEC strains carried one or more high and low molecular weight plasmids belonging to the B/O, F, I, K, P, Q, and/or X incompatibility groups encoding virulence genes (SPATE-encoding genes) and/or antimicrobial resistance genes (aadA1, strAB, tetA, and/or tetB). Competition experiments demonstrated that the biological cost of carriage of these plasmids by the commensal E. coli strain HS or the laboratory strain E. coli K-12 MG1655 was low or non-existent, ranging from - 4.7 to 5.2% per generation. This suggests that there are few biological barriers-or, alternatively, it suggests that there are biological barriers that we were not able to measure in this competition model-against the spread of plasmid encoding virulence and resistance genes from STEC to other, less pathogenic E. coli strains. Thus, our results, in opposition to a common view, suggest that the acquisition of plasmids does not significantly affect the bacteria fitness and, therefore, the theorized plasmid burden would not be a significant barrier for plasmid spread.

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.

Tuberculosis/COVID-19 co-infection detected in a single sputum sample using a rapid molecular test.

Tuberculosis (TB) and COVID-19 affect the lungs and are transmitted mainly by aerosols or particles of saliva from infected persons. Clinical similarities between diseases can affect correct diagnosis. Individuals belonging to the population deprived of liberty (PDL) are at increased risk of contagion due to precarious sanitary conditions and overcrowded environments. A variety of specimens may be suitable for the diagnosis of COVID-19, using molecular diagnostic techniques; however, there is little data on the analysis of sputum samples with the Xpert Xpress SARS-CoV-2® for the diagnosis of COVID-19, especially in this population group. The present study reports a case of TB and COVID-19 co-infection detected in sputum from an individual belonging to the PDL. For the detection, it used the GeneXpert platform (Cepheid, USA). Mycobacterium tuberculosis complex (MTC) was detected using the Xpert MTB/RIF Ultra® cartridge and SARS-CoV-2 was detected using the Xpert Xpress SARS-CoV-2® cartridge. The genes IS6110 and IS1081 were detected within 80 min indicating the presence of MTC, with no mutations related to resistance to rifampicin. The SARS-CoV-2 E and N2 genes were detected within 45 min. The result was confirmed by RT-qPCR with detection of E, N, and RdRP/S genes in the sputum and nasopharyngeal (NP) specimens. Rapid diagnoses that allow the identification and differentiation of such diseases are important for adequate epidemiological surveillance, isolation of infected individuals, and interruption of the transmission chain. Using the GeneXpert platform, specimens can be tested as soon as they are received, without the need for prior preparation. The US Food and Drug Administration has issued emergency authorization for the use of the Cepheid Xpert Xpress SARS-CoV-2 for the rapid detection of SARS-CoV-2 using specimens from a NP or nasal wash/aspirate. The case presented here gains an innovation with the use of the sputum to COVID-19 diagnosis.

SARS-CoV-2 intralineage variation and temporal patterns of COVID-19 risk factors in three cities of southeastern Brazil: Age, sex, and race.

The Santo André Regional Center from Adolfo Lutz Institute evaluated 91 537 samples by reverse transcription-polymerase chain reaction (RT-PCR) to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from March 2020 to April 2021. The age, sex, and race of patients from three cities in southeastern Brazil, namely São Bernardo do Campo (SBC), Diadema, and Mauá were assessed in association to the rate of positive results using generalized linear models. Circulating lineages were obtained from GISAID and intralineage genetic variation was investigated employing Lasergene software. A declining number of reported cases around October to November 2020 separate two epidemic waves in the three cities. Mauá differed by the highest positive RT-PCR scores in January and February. GISAID classification of 38 SARS-CoV-2 complete genomic sequences showed the circulation of lineages P.1, B.1.1.28, P.2, B.1.1.332; P.1, P.2, B.1.1.28, B.1.1.33; and P.1, P.2 in SBC, Diadema and Mauá, respectively. Intralineage variation revealed a significant amino-acid substitution in the ORF3a encoding protein (A33S) present in four out of six (67%) P.1 Mauá isolates. As ORF3a encodes a nonselective Ca2+ permeable cation channel, supposed to interfere in airway homeostasis, specific mutations could increase its pathogenic effect resulting in a higher number of symptomatic individuals explaining why the second wave was more intense in Mauá city.

Viability assessment of Mycobacterium tuberculosis complex in OMNIgene • SPUTUM reagent using the BACTEC MGIT 960 System and Xpert MTB/RIF assay.

The World Health Organization advocates that sputum specimens submitted to tuberculosis (TB) diagnostic should be processed within 48 h after collection and be stored under cooling. We aimed to assess the performance of OMNIgene • SPUTUM reagent in maintaining viable specimens of Mycobacterium tuberculosis complex (MTBC) during transportation of sputum samples without refrigeration, in comparison to the standard protocol of the National TB Control Program. Sputum samples obtained in southeastern Brazil (June 2017 to July 2018) from 100 sequential patients with positive acid-fast bacillus smear microscopy were divided into two portions. Portion 1 continued to be cooled (standard protocol, STA), but portion 2 was added to OMNIgene • SPUTUM reagent (alternative protocol, OMS) until concomitant further processing. Both portions of all samples were cultured using MGIT and tested by Xpert MTB/RIF assay. Growth of MTBC in the first 42 days was detected in 96% of the cultures under the STA and 88% under the OMS. Intervals between processing and detecting MTBC growth in the two portions significantly differed (p = 0.0001). Portions under the two protocols showed similar results in the MTBC detection by Xpert assay and culture contamination by non-MTBC. The OMNIgene reagent liquefies and decontaminates sputum leading to a decrease in processing time. Although there was a small delay in mycobacterial growth, the OMNIgene reagent can be useful in specimens transported from collection sites over a long distance to centralized testing centers, maintaining viable MTBC for at least 8 days at room temperature.

Virulence Profiling and Molecular Typing of Shiga Toxin-Producing E. coli (STEC) from Human Sources in Brazil.

Since no recent data characterizing Shiga toxin-producing E. coli (STEC) from human infections in Brazil are available, the present study aimed to investigate serotypes, stx genotypes, and accessory virulence genes, and also to perform pulsed-field gel electrophoresis (PFGE) and multi-locus sequence typing (MLST) of 43 STEC strains recovered from 2007 to 2017. Twenty-one distinct serotypes were found, with serotype O111:H8 being the most common. However, serotypes less frequently reported in human diseases were also found and included a hybrid STEC/ETEC O100:H25 clone. The majority of the strains carried stx1a as the sole stx genotype and were positive for the eae gene. Regarding the occurrence of 28 additional virulence genes associated with plasmids and pathogenicity islands, a diversity of profiles was found especially among the eae-harboring strains, which had combinations of markers composed of up to 12 distinct genes. Although PFGE analysis demonstrated genetic diversity between serotypes such as O157:H7, O111:H8, O26:H11, O118:H16, and O123:H2, high genetic relatedness was found for strains of serotypes O24:H4 and O145:H34. MLST allowed the identification of 17 distinct sequence types (STs) with ST 16 and 21 being the most common ones. Thirty-five percent of the strains studied were not typeable by the currently used MLST approach, suggesting new STs. Although STEC O111:H8 remains the leading serotype in Brazil, a diversity of other serotypes, some carrying virulence genes and belonging to STs incriminated as causing severe disease, were found in this study. Further studies are needed to determine whether they have any epidemiological relevance.

Epidemiology and genetic screening of diarrheagenic Escherichia coli among symptomatic and asymptomatic children.

PURPOSE: Enteropathogens are frequently associated with diarrheal disease. Knowledge of their etiology and epidemiology is essential for the prevention and control of the sickness. This study describes the microbiological and epidemiological features of diarrheal disease in 197 symptomatic and 223 asymptomatic under-five-year-old children from southeastern Brazil, between January 2015 and September 2016. METHODS: Isolation of Escherichia coli, Salmonella, Shigella and Campylobacter was realized by culture. E. coli strains were screened by multiplex PCR, PFGE and O:H serotyping. Antimicrobial susceptibility testing was also performed. RESULTS: Most of the 127 enteropathogens isolated were diarrheagenic E. coli (96.1 %), with predominance of several serotypes of enteropathogenic E. coli (EPEC) and enteroaggregative E. coli (EAEC). Age, sex, rotavirus vaccination, recent use of antibiotics and previous contact with pets, were factors that revealed no significant effects on the probability of infection by the predominant pathogens. Even so, higher incomes could be related to a lesser chance of testing positive for EPEC. Evidence of possible EAEC clonal spread was detected, as well as genetic similarity among strains from both symptomatic and asymptomatic children. Resistance to antimicrobial agents was more pronounced among EAEC than EPEC. CONCLUSION: The occurrence of genetically similar diarrheagenic E. coli in both groups of children, likewise resistant to these agents, underscores the importance of establishing strategies for the prevention of outbreaks, especially among low-income households.

Surto de doença trasmitida por alimentos nos municipios de Mauá e Ribeirão Pires - SP / Outbreak of foodborne diseases in the municipalities of Maua and Ribeirao Pires - SP

Doenças de transmissão hídrica e alimentar (DTHA) acarretam importantes problemas econômicos e de saúde pública no mundo atual. Este estudo relata um surto de Doença Transmitida por Alimento - DTA que envolveu 12 pessoas de duas residências localizadas na Região do ABC paulista em dezembro de 2012. Quatro pessoas de uma residência tiveram sintomas de diarreia, cólica abdominal, náusea, vômito, febre e prostração, sendo que apenas duas consumiram o bolo preparado em Ribeirão Pires, SP - Brasil. Outras oito pessoas consumiram o mesmo alimento no município de Mauá e, além dos sintomas citados, houve também registro de insuficiência renal e parada cardiorrespiratória. Dentre os envolvidos, uma menina de oito anos veio a óbito após convulsão e bronco-aspiração. O período variou entre 2 e 22 horas após o consumo do alimento. A amostra de bolo foi analisada segundo a metodologia preconizada pelo BAM-FDA e teve como resultados: Coliformes termotolerantes (NMP = 4,6x104/g); Bacillus cereus (1,5x105 U.F.C./g) e presença de Salmonella Enteritidis em 25 gramas. Clostridium perfringens, Staphylococcus aureus e Listeria monocytogenes não foram isolados. Foram realizadas duas coproculturas que apresentaram resultados positivos para Salmonella Enteritidis. As cepas de Salmonella spp isoladas, tanto no alimento como nas fezes dos pacientes, apresentaram similaridade genética e mesmo perfil de suscetibilidade aos antimicrobianos. Assim, foi constatado o envolvimento do bolo como veiculador de patógenos e ressaltada a importância do trabalho em conjunto das vigilâncias sanitárias e epidemiológicas de ambos os municípios e o laboratório de referência em saúde pública, fundamental na elucidação deste surto.

Surto de doença transmitida por alimentos nos municípios de Mauá e Ribeirão Pires - SP / Outbreak of food-borne disease in the municipalities of Maua´and Ribeirão Pires - SP

Doenças de transmissão hídrica e alimentar (DTHA) acarretam importantes problemas econômicos e de saúde pública no mundo atual. Este estudo relata um surto de Doença Transmitida por Alimento - DTA que envolveu 12 pessoas de duas residências localizadas na Região do ABC paulista em dezembro de 2012. Quatro pessoas de uma residência tiveram sintomas de diarreia, cólica abdominal, náusea, vômito, febre e prostração, sendo que apenas duas consumiram o bolo preparado em Ribeirão Pires, SP - Brasil. Outras oito pessoas consumiram o mesmo alimento no município de Mauá e, além dos sintomas citados, houve também registro de insuficiência renal e parada cardiorrespiratória. Dentre os envolvidos, uma menina de oito anos veio a óbito após convulsão e bronco-aspiração. O período variou entre 2 e 22 horas após o consumo do alimento. A amostra de bolo foi analisada segundo a metodologia preconizada pelo BAM-FDA e teve como resultados: Coliformes termotolerantes (NMP = 4,6x104 /g); Bacillus cereus (1,5x105 U.F.C./g) e presença de Salmonella Enteritidis em 25 gramas. Clostridium perfringens, Staphylococcus aureus e Listeria monocytogenes não foram isolados. Foram realizadas duas coproculturas que apresentaram resultados positivos para Salmonella Enteritidis. As cepas de Salmonella spp isoladas, tanto no alimento como nas fezes dos pacientes, apresentaram similaridade genética e mesmo perfil de suscetibilidade aos antimicrobianos. Assim, foi constatado o envolvimento do bolo como veiculador de patógenos e ressaltada a importância do trabalho em conjunto das vigilâncias sanitárias e epidemiológicas de ambos os municípios e o laboratório de referência em saúde pública, fundamental na elucidação deste surto. (AU)

Foodborne illness are still important public health problems in the world today. This paper reports an outbreak of food poisoning involving 12 people from two residences located in the ABC Region, São Paulo, Brazil in December 2012. Four people of one residence had symptoms of diarrhea, abdominal cramps, nausea, vomiting, fever and prostration, and only two people had eaten the cake. Eight others had consumed the same food in the Mauá city and beyond the symptoms mentioned above, there was kidney failure and cardiac arrest. Among those involved, an eight-year-old girl has died after seizure and bronchial aspiration. The incubation period ranged from 2 to 22 hours. The cake sample was analyzed according to the methods recommended by the FDA-BAM and had the following results:thermotolerant coliforms (NMP = 4.6 X 104 / g); Bacillus cereus (1.5 X 105 CFU / g) and presence of Salmonella Enteritidis in 25 g. Clostridium perfringens, Staphylococcus aureus and Listeria monocytogenes were not isolated. Two stools samples were tested for Salmonella Enteritidis had been positive for both. Salmonella strains isolated in both food and stools of patients has showed genetic similarity and the same profile of antimicrobial susceptibility. Thus, it was found the involvement of the cake as disseminator of pathogens and emphasized the importance of working together of sanitary and epidemiological surveillance of both cities and public health laboratory, fundamental to elucidation of this outbreak. (AU)

Tuberculose pulmonar paucibacilar em Centros de Detenção Provisória / Paucibacillary pulmonary tuberculosis in ProvisionalDetention Centers

Cultura de micobactérias proporciona o crescimento de bacilos viáveis, mesmo presentes emescassa quantidade e não detectados pela baciloscopia. Neste estudo foram analisadas as amostrasde escarro que apresentaram baciloscopia negativa e cultura positiva. As amostras foram coletadasde 2008 a 2013, de indivíduos detidos em Centros de Detenção Provisória de Santo André,Mauá e Diadema, Estado de São Paulo. As metodologias utilizadas foram baciloscopia porcoloração Ziehl-Neelsen e cultura pelo Sistema BACTEC MGIT 960 e Ogawa-Kudoh. Dos11.529 exames realizados, 221 (1,9 %) apresentaram baciloscopias negativas e culturas positivas.Dos 221 isolados, 166 (75,1 %) pertenciam ao Complexo Mycobacterium tuberculosis, 21 (9,5 %)micobactérias não membros do Complexo Mycobacterium tuberculosis (MNT), 33 (14,9 %)Mycobaterium sp e uma cultura mista do Complexo M. tuberculosis e M. avium. MNT maisfrequentes foram M. avium (23,8 %) e M. fortuitum (19,0 %). A maioria dos isolados do ComplexoM. tuberculosis (155/166 - 93,4 %) foi sensível aos antimicrobianos. Sete amostras apresentaramresistência à isoniazida e uma apresentou multirresistência à isoniazida e rifampicina. Este estudomostra a importância da realização da cultura em escarros que apresentam baciloscopia negativano diagnóstico da TB e micobacteriose. O tratamento tardio causa a continuidade da transmissãoda doença e agravamento do quadro clínico.

Culture of mycobacteria induces the growth of viable bacillus occurring in small quantity,which are no detectable by bacilloscopy. This study aimed at identifying the mycobacteria isolatesfrom sputum presenting negative bacilloscopy and positive culture. The samples were collectedfrom 2008 to 2013 from criminals of Provisional Detention Centers in Santo André, Mauáand Diadema/SP. Smears were stained by Ziehl-Neelsen staining and the cultures were performedby the BACTEC MGIT 960 system and Ogawa-Kudoh culture medium. Of 11,529 isolates, 221(1.9 %) showed negative bacilloscopy and positive cultures. Of 221 isolates, 166 (75.1 %) belongedto Mycobacterium tuberculosis complex, 21 (9.5 %) were nontuberculous mycobacteria (NTM),33 (14.9 %) Mycobacterium sp, and one identified as a mixed culture of M. tuberculosis andM. avium complex. The most common NTM species were M. avium (23.8 %) and M. fortuitum(19.0 %). Most of the isolates (155/166-93.4 %) were susceptible to antimicrobial agents.Seven samples were resistant to isoniazid, and one presented multiresistance to isoniazid andrifampicin. This study shows the importance in performing sputum culture, when these samplesare negative on bacilloscopy in diagnosing TB and mycobacteriosis. The treatment delay resultsin the maintenance of disease transmission and worsening of clinical symptoms.

Tuberculose pulmonar paucibacilar em Centros de Detenção Provisória / Paucibacillary pulmonary tuberculosis in Provisional Detention Centers

Cultura de micobactérias proporciona o crescimento de bacilos viáveis, mesmo presentes em escassa quantidade e não detectados pela baciloscopia. Neste estudo foram analisadas as amostras de escarro que apresentaram baciloscopia negativa e cultura positiva. As amostras foram coletadas de 2008 a 2013, de indivíduos detidos em Centros de Detenção Provisória de Santo André, Mauá e Diadema, Estado de São Paulo. As metodologias utilizadas foram baciloscopia por coloração Ziehl-Neelsen e cultura pelo Sistema BACTEC MGIT 960 e Ogawa-Kudoh. Dos 11.529 exames realizados, 221 (1,9 %) apresentaram baciloscopias negativas e culturas positivas. Dos 221 isolados, 166 (75,1 %) pertenciam ao Complexo Mycobacterium tuberculosis, 21 (9,5 %) micobactérias não membros do Complexo Mycobacterium tuberculosis (MNT), 33 (14,9 %) Mycobaterium sp e uma cultura mista do Complexo M. tuberculosis e M. avium. MNT mais frequentes foram M. avium (23,8 %) e M. fortuitum (19,0 %). A maioria dos isolados do Complexo M. tuberculosis (155/166 - 93,4 %) foi sensível aos antimicrobianos. Sete amostras apresentaram resistência à isoniazida e uma apresentou multirresistência à isoniazida e rifampicina. Este estudo mostra a importância da realização da cultura em escarros que apresentam baciloscopia negativa no diagnóstico da TB e micobacteriose. O tratamento tardio causa a continuidade da transmissão da doença e agravamento do quadro clínico.

Culture of mycobacteria induces the growth of viable bacillus occurring in small quantity, which are no detectable by bacilloscopy. This study aimed at identifying the mycobacteria isolates from sputum presenting negative bacilloscopy and positive culture. The samples were collected from 2008 to 2013 from criminals of Provisional Detention Centers in Santo André, Mauá and Diadema/SP. Smears were stained by Ziehl-Neelsen staining and the cultures were performed by the BACTEC MGIT 960 system and Ogawa-Kudoh culture medium. Of 11,529 isolates, 221 (1.9 %) showed negative bacilloscopy and positive cultures. Of 221 isolates, 166 (75.1 %) belonged to Mycobacterium tuberculosis complex, 21 (9.5 %) were nontuberculous mycobacteria (NTM), 33 (14.9 %) Mycobacterium sp, and one identified as a mixed culture of M. tuberculosis and M. avium complex. The most common NTM species were M. avium (23.8 %) and M. fortuitum (19.0 %). Most of the isolates (155/166-93.4 %) were susceptible to antimicrobial agents. Seven samples were resistant to isoniazid, and one presented multiresistance to isoniazid and rifampicin. This study shows the importance in performing sputum culture, when these samples are negative on bacilloscopy in diagnosing TB and mycobacteriosis. The treatment delay results in the maintenance of disease transmission and worsening of clinical symptoms.

Rapid detection of Mycobacterium tuberculosis complex by real-time PCR in sputum samples and its use in the routine diagnosis in a reference laboratory.

Tuberculosis (TB) is an infectious disease of global distribution, constituting a serious public health problem in Brazil. São Paulo State, located in the south-east of Brazil, notified 16,580 new TB cases in 2013. The Instituto Adolfo Lutz is a public health reference laboratory for TB diagnosis for all the State. Considering that rapid and accurate diagnosis is essential for TB control, the aim of this study was to evaluate the use of an in-house real-time (RT)-PCR assay targeting the mpt64 gene in the routine diagnosis of TB, and to compare this technique with smear microscopy and culture. From August 2012 to October 2013, 715 sputum samples from 657 patients were included in the study. Smear microscopy, culture, phenotypic and PRA-hsp65 identification of mycobacteria, and mpt64 RT-PCR were performed. With respect to confirmed TB cases (n = 62/657; 9.4%), smear microscopy had a sensitivity of 82.3%. Culture and RT-PCR showed the same sensitivity, i.e. 90.3%. Specificity was 99.7, 99.4 and 98.6% for smear microscopy, culture and RT-PCR, respectively. mpt64 RT-PCR showed high sensitivity and specificity for the detection of Mycobacterium tuberculosis complex in sputum samples. This technique can be deployed in laboratories that do not have a rapid test for TB available, enabling the performance of TB diagnosis in up to 5 h.

Molecular typing of antimicrobial-resistant Shiga-toxin-producing Escherichia coli strains (STEC) in Brazil.

Antimicrobial resistance patterns and molecular characteristics were determined in thirty-two Shiga-toxin-producing Escherichia coli (STEC) strains previously identified in São Paulo State associated with human infections (n = 21) and in cattle feces (n = 11). The highest resistance rates were identified for tetracycline (100%), streptomycin (78%) and trimethoprim-sulfamethoxazole (56%). Eleven STEC strains showed resistance to ampicillin and carried bla(TEM) that was confirmed as bla(TEM-1) in one representative isolate. The class 1 integrase gene (intI1) was detected in seven (22%) strains, and most of them belonged to the O111:H8 serotype. The class 1 integron was located on plasmids in five of the seven STEC strains, and conjugation assays confirmed the plasmid support of those resistant determinants. STEC strains were genetically classified into the B1 group, and PFGE analysis showed that most of the strains in each serogroup were grouped into the same cluster (80-97% similarity). The presence of a class 1 integron and bla(TEM-1) genes is described for the first time among STEC isolates in Brazil and clearly represents a public health concern.

First description of bla(CTX-M-14)- and bla(CTX-M-15)-producing Escherichia coli isolates in Brazil.

We evaluated the antimicrobial resistance patterns and molecular characteristics of 11 extraintestinal Escherichia coli strains and 1 intestinal E. coli from human infections collected in Brazil. Two E. coli strains were nonsusceptible to extended spectrum cephalosporins (cefotaxime, ceftazidime, and cefepime); one isolated from diarrhea carried bla(CTX-M-14) and bla(TEM-1), whereas the other, isolated from tracheal secretion, carried bla(CTX-M-15) and bla(OXA-1). Five E. coli strains showed resistance to quinolones. Integrase associated with class 1 integron (intl1) was detected in 8 of the 12 E. coli strains belonging to various serotypes and this gene was carried by plasmids showing similar size. Pulsed-field gel electrophoresis showed that E. coli strains were genetically diverse, and phylogenetic grouping showed that the E. coli strains belonged to groups A, B2, and D (33.3%), respectively. This is the first report of E. coli isolates carrying bla(CTX-M-14) and bla(CTX-M-15) in Brazil. The presence of mobile elements containing antimicrobial resistance genes is worrisome since it could promote the dissemination of resistance and lead to the acquisition of resistance to other antimicrobials agents such as the carbapenems.

Distribution of virulence profiles related to new toxins and putative adhesins in Shiga toxin-producing Escherichia coli isolated from diverse sources in Brazil.

The distribution of virulence markers related to cytolethal distending toxin-V (CDT-V), subtilase cytotoxin (SubAB), the enterohemorrhagic Escherichia coli factor for adherence (Efa1), the adhesin similar to IrgA (Iha), the long polar fimbriae (LpfO113), the autoagglutinating adhesin (Saa), and the protein required for full expression of adherence of O157:H7 Sakai strain (ToxB) was investigated in 121 Shiga toxin-producing E. coli (STEC) strains isolated in Brazil. STEC strains were isolated from human infections (n=49), cattle (n=68) and ground meat samples (n=4). Overall, the lpfA(O113), iha, efa1, saa, and toxB sequences were observed in 89.2%, 87.6%, 47.1%, 43%, and 13.2% of the strains, respectively. The genes efa1 (96.6%) and toxB (27%) were only identified among eae-positive strains, while saa (83.8%), cdt-V (12.9%), and subAB (48.4%) just occurred in eae-negative STEC strains. STEC strains harboring cdt-V and subAB were for the first time described in the South American subcontinent. In addition, the simultaneous presence of cdt-V and subAB has not been previously reported, nor the presence of subAB in STEC O77, O79, O105, O174, and O178 serogroups. A diversity of virulence profiles was observed among the STEC strains studied. The most prevalent profile observed among eae-positive STEC strains mainly isolated from humans was eae efa1 iha lpfA(O113), whereas iha lpfA(O113) saa ehxA subAB prevailed among eae-negative STEC strains, mostly isolated from cattle and foods.

Stx genotypes and antimicrobial resistance profiles of Shiga toxin-producing Escherichia coli strains isolated from human infections, cattle and foods in Brazil.

A total of 107 Shiga toxin-producing Escherichia coli strains (STEC) isolated from different origins in São Paulo, Brazil, and belonging to different serotypes were characterized regarding stx subtypes and susceptibility to antimicrobial agents. Most of the human STEC strains harbored stx1 (85.7%), while stx2, associated or not to stx1, was identified preferentially in the animal and food strains. None of the STEC strains carried stx1c. Some genotypes occurred exclusively among strains of bovine origin as stx2c, stx1+2+2c (16.5% each), and stx2d (0.9%), whereas stx2+2c2vha) was only identified among the O157:H7 human strains. Moreover, the stx(2c2vhb) subtype was found more frequently among bovine than human strains (39% vs. 4.8%). The highest frequencies of susceptibility to antimicrobial agents were observed among bovine (87%) and food (100%) STEC strains, while 47.6% of the human isolates were resistant to at least one drug. Multiresistance occurred among O111 STEC strains from human and bovine origin. The antimicrobials to which resistance was most frequently observed were tetracycline (90%) and streptomycin (75%) among human strains, and also sulphazotrin (88%) in animal strains. A few serotypes were commonly identified among STEC strains isolated from diverse sources in Brazil, but in general the strains presented distinct stx subtypes and/or antimicrobial resistance profiles.

Genetic heterogeneity of Shiga toxin-producing Escherichia coli strains isolated in Sao Paulo, Brazil, from 1976 through 2003, as revealed by pulsed-field gel electrophoresis.

The pulsed-field gel electrophoresis (PFGE) patterns of 46 Shiga toxin-producing Escherichia coli (STEC) strains isolated in São Paulo, Brazil, during the period from 1976 to 2003 were compared with those found among 30 non-STEC strains that carried eae and that belonged to the same serogroups as the STEC strains. All except two of the STEC and non-STEC strains of human origin were from sporadic and unrelated cases of infection; two O111 strains originated from the same patient. Multiple PFGE patterns were found among STEC strains of distinct serotypes. Moreover, the PFGE restriction patterns of STEC strains differed substantially from those observed among non-STEC strains of the same serogroup except serotype O26 strains. Based on the indistinguishable PFGE pattern for two O157:H7 STEC strains isolated in the same geographic area at an interval of approximately 15 days and toxin profile data, the first occurrence of an O157:H7 outbreak in Brazil during that period can be suggested. In general, a close relationship between types of intimin, serotypes, and diarrheagenic groups of E. coli was observed. This is the first time that a large collection of STEC strains from Brazil has been analyzed, and a great genetic diversity was shown among O157:H7 and non-O157:H7 STEC strains isolated in São Paulo, Brazil.