[Meningitis and myelitis by hypervirulent Klebsiella pneumoniae]. / Meningitis y mielitis por Klebsiella pneumoniae hipervirulenta.

Invasive liver abscess syndrome caused by hypervirulent Klebsiella. pneumoniae is a rare disease. This type of K. pneumoniae is aggressive and invasive, despite its sensitivity profile. We report the case of a 62-year-old man with diabetes mellitus, who was admitted to our hospital with meningeal syndrome. Within 24 hours of admission, Gram negative bacilli were isolated blood and cerebrospinal fluid cultures, which were later identified as K. pneumoniae. Liver abscess was detected by computed tomography. Despite early antibiotic treatment, the patient developed back pain that prevented him from moving and right hemiparesis. Increased signal from the central region of the spinal medulla compatible with myelitis was identified by magnetic resonance, for which he received methylprednisolone 1 g/day for 5 days. The patient evolved favorably. Infections caused by hypermucoviscous K. pneumoniae are aggressive and invasive, and more common in men with a history of diabetes mellitus, as in this case. These infections require early antibiotic treatment and the search of metastatic infections.

El síndrome de absceso hepático invasivo causado por cepas hipermucoviscosas de Klebsiella pneumoniae es una enfermedad poco frecuente. Esta serovariedad de Klebsiella se caracteriza por ser agresiva e invasiva pese a su perfil de sensibilidad. Se presenta el caso de un varón de 62 años con antecedentes de diabetes mellitus, que ingresó a nuestro centro con síndrome meníngeo. A las 24 horas del ingreso se aislaron en hemocultivos y en líquido cefalorraquídeo (LCR) bacilos Gram negativos que luego fueron tipificados como Klebsiella pneumoniae. Se identificó la presencia de un absceso hepático mediante tomografía computarizada. Pese al tratamiento antibiótico instaurado de manera temprana, el paciente evolucionó con dolor dorsal que le impedía movilizarse y hemiparesia derecha. En la resonancia magnética nuclear de columna se identificó aumento de la señal de la región central de la médula espinal compatible con mielitis por lo cual recibió tratamiento con metilprednisolona 1g/día por 5 días consecutivos. El paciente evolucionó de manera favorable. Las infecciones por K. pneumoniae hipermucoviscosas son agresivas e invasoras y más frecuentes en varones con antecedentes de diabetes mellitus, como en este caso. Su control requiere de un tratamiento antibiótico temprano y búsqueda de focos a distancia.

Geography and public health: analysis of the epidemiological dynamics of meningitis in Brazil, between 2010 and 2019.

OBJECTIVE: To analyze the spatiotemporal epidemiological dynamics of meningitis in Brazil, between 2010 and 2019. METHODS: Descriptive ecological study with cases and deaths due to meningitis in Brazil (2010-2019) in the National Notifiable Diseases Information System (Sistema de Informações de Agravos de Notificação - SINAN). The following analyses were performed: (I) frequency analyses of cases and deaths, prevalence rates, mortality, lethality, Fisher's exact test, and chi-square test; (II) Prais-Winstein regression; and (III) Global, Local Moran's index, and Kernel density. RESULTS: 182,126 cases of meningitis were reported in Brazil, of which 16,866 (9.26%) resulted in death, with prevalence rates of 9.03/100,000 inhabitants, mortality of 0.84/100,000 inhabitants, and lethality of 9.26%. There was a noted trend of decreasing prevalence rates (-9.5%, 95% confidence interval - 95%CI -13.92; -4.96, p<0.01) and mortality (-11.74%, 95%CI -13.92; -9.48, p<0.01), while lethality remained stable (-2.08%, 95%CI -4.9; 0.8; p<0.1941). The majority of cases were viral meningitis (45.7%), among 1-9 years old (32.2%), while the highest proportion of deaths was due to bacterial meningitis (68%), among 40-59 years old (26.3%). In the Moran and Kernel maps of prevalence and mortality rates, municipalities in the South, Southeast, and the capital of Pernambuco in the Northeast stood out with high rates; as for lethality, the North, Northeast, and Southeast coastal areas were highlighted. CONCLUSION: A decrease in meningitis cases and deaths was found in this study; however, the lethality rate was higher in areas with lower prevalence, emphasizing the need to enhance actions for identifying, monitoring, and providing health care for cases, as well as expanding vaccination coverage.

[Streptococcus suis meningitis]. / Meningitis por Streptococcus suis.

Streptococcus suis (S. suis) is a globally prevalent swine pathogen, capable of generating infections in humans who were in contact with the animal or its raw meat. Clinical manifestations range from asymptomatic cases to systemic involvement, with low mortality, but with the possibility of leaving definitive sequelae such as ataxia and hearing loss. There are few case reports, due to lack of knowledge of the disease and its atypical presentation. The objective of this article is to report the case of a man with an occupational history of contact with pigs, who was admitted for meningitis and in whom the isolation of S. suis was obtained in cerebrospinal fluid and paired blood cultures; He completed antibiotic treatment adjusted to bacterial sensitivity, and was left with mild hearing loss as a consequence.

Streptococcus suis (S. suis) es un patógeno porcino prevalente a nivel mundial, capaz de generar infecciones en humanos que estuvieron en contacto con el animal o la carne cruda del mismo. Las manifestaciones clínicas comprenden desde casos asintomáticos hasta compromiso sistémico, con una baja mortalidad, pero con la posibilidad de dejar secuelas definitivas como la ataxia e hipoacusia. Son pocos los reportes de casos, debido al desconocimiento de la enfermedad y a su forma atípica de presentación. El objetivo de este artículo es relatar el caso de un varón con antecedentes ocupacionales de contacto con porcinos, que ingresó por meningitis y en el cual se obtuvo el aislamiento de S. suis en líquido cefalorraquídeo y hemocultivos pareados; completó tratamiento antibiótico ajustado a la sensibilidad bacteriana, quedó con hipoacusia leve como secuela.

Streptococcus suis meningitis: An emerging zoonotic disease in Brazil.

Streptococcus suis has been widely reported as a pathogen in animals, especially pigs. In terms of human health implications, it has been characterized as a zoonosis associated with the consumption of pork products and occupational exposure, particularly in Southeast Asian countries. Here, we present a rare case of human S. suis infection in Brazil, diagnosed in an older adult swine farmer, a small rural producer residing in the semi-arid region of Bahia, Brazil.

Listeria monocytogenesy mecanismo de caballo de Troya a través de la barrera hematoencefálica / isteria monocytogenesand Trojan horse mechanism across the blood-brain barrier

Las infecciones del sistema nervioso central son potencialmente mortales, causadas por patógenos, como bacterias, virus y hongos. Para llegar hasta el cerebro, los microorganismos utilizan diversas vías y formas. Este patogeno es una bacteria grampositiva corta, flagelar e intracelular, con la capacidad de inducir su internalización en células fagocíticas (monocitos/macrófagos) y no fagocíticas (células endoteliales). Al infectar los macrófagos, estos microorganismos se valen de su capacidad de fijación, adhesión y migración transendotelial, para cruzar la barrera hematoencefálica, finalmente, generando meningitis bacteriana. En esta revisión describimos el mecanismo de caballo de Troya usado por Listeria monocytogenespara invadir el cerebro en el desarrollo de enfermedades infecciosas e incorporamos nuevos conocimientos sobre moléculas que intervienen en dicho mecanismo(AU)

Central nervous system infections are life-threatening, caused by pathogens such as bacteria, viruses and fungi. To access the brain, microorganisms use various mechanisms. Listeria monocytogenes is a short, flagellar and intracellular gram-positive bacterium, with the ability to induce its internalization in phagocytic (monocytes/macrophages) and non-phagocytic (endothelial cells) cells. By infecting macrophages, these microorganisms take advantage of their binding, adhesion, and transendothelial migrationcapacity to cross the blood-brain barrier, finally generating bacterial meningitis. In this review we describe the Trojan horse mechanism used by Listeria monocytogenesto invade the brain in the development of infectious diseases and we incorporate new knowledge about molecules that intervene in this mechanism(AU)

Predictors of Invasive Bacterial Infection in Febrile Infants Aged 2 to 6 Months in the Emergency Department.

Our goal was to identify predictors of invasive bacterial infection (ie, bacteremia and bacterial meningitis) in febrile infants aged 2-6 months. In our multicenter retrospective cohort, older age and lower temperature identified infants at low risk for invasive bacterial infection who could safely avoid routine testing.

Shorter versus longer duration of antibiotic treatment in children with bacterial meningitis: a systematic review and meta-analysis.

The optimal duration of antibiotic treatment for the most common bacterial meningitis etiologies in the pediatric population, namely Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis, is not well-established in the literature. Therefore, we aimed to perform an updated meta-analysis comparing shorter versus longer antibiotic treatment in children with meningitis. PubMed, EMBASE, and Cochrane databases were searched for randomized controlled trials (RCTs) that compared shorter (up to 7 days) versus longer (10 days or double the days of the equivalent short course) duration of antibiotic treatment in children with meningitis and reported the outcomes of treatment failure, death, neurologic sequelae, non-neurologic complications, hearing impairment, nosocomial infection, and relapse. Heterogeneity was examined with I2 statistics. RevMan 5.4.1 was used for statistical analysis and RoB-2 (Cochrane) for risk of bias assessment. Of 684 search results, 6 RCTs were included, with a cohort of 1333 children ages 3 weeks to 15.5 years, of whom 49.51% underwent a short antibiotic course. All RCTs included monotherapy with ceftriaxone, except one, which added vancomycin as well. No differences were found comparing the short and long duration of therapy concerning treatment failure, relapse, mortality, and neurologic complications at discharge and at follow-up.  Conclusion: Because no statistically significant differences were found between groups for the analyzed outcomes, the results of this meta-analysis support shorter therapy. However, generalizing these results to complicated meningitis and infections caused by other pathogens should be made with caution. (PROSPERO identifier: CRD42022369843). What is Known: • Current recommendations on the duration of antibiotic therapy for bacterial meningitis are mostly based on clinical practice. • Defining an optimal duration of antibiotic therapy is essential for antimicrobial stewardship achievement, improving patient outcomes, and minimizing adverse effects. What is New: • There are no differences between shorter versus longer antibiotic treatment duration in regard to treatment failure, relapse, mortality, neurologic complications, and hearing impairment at discharge and at follow-up.

The neurotoxic branch of the kynurenine pathway is highly activated in the central nervous system of patients with pneumococcal meningitis.

BACKGROUND: Acute bacterial meningitis (ABM) causes excessive activation of N-methyl-D-aspartate receptors (NMDAr), leading to cortical and hippocampal neuron death. As opposite, enteroviral meningitis is more frequently benign. The kynurenine (KYN) pathway is the major catabolic route of tryptophan (TRP) and some of its metabolites are agonists or antagonists of NMDAr. METHODS: In order to investigate the pathogen-specific patterns of KYN pathway modulation in the central nervous system of children with acute meningococcal (MM), pneumococcal (PM) or enteroviral (VM) meningitis, the cerebrospinal fluid (CSF) concentrations of TRP, KYN, kynurenic acid (KYNA) and quinolinic acid (QUINA) were evaluated by ultra-high performance liquid chromatography (uHPLC) coupled to mass spectrometry. In addition, CSF levels of IL-6, IL-10 and TNF-α were quantified by multi-analyte flow assay. The data was mined and integrated using statistical and machine learning methods. RESULTS: The three forms of meningitis investigated herein up-regulated the neurotoxic branch of the KYN pathway within the intrathecal space. However, this response, represented by the concentration of QUINA, was six and nine times higher in PM patients compared to MM or VM, respectively. CSF levels of IL-6, TNF-α, and IL-10 were increased in MM and PM patients when compared to controls. In VM, CSF IL-6 and IL-10, but not TNF-α were increased compared to controls, although not reaching the high levels found in bacterial meningitis. No correlation was found between the concentrations or the ratios of any pair of KYN metabolites and any cytokine or standard cytochemical parameter tested. CONCLUSIONS: CNS infection with meningococci, pneumococci, and enteroviruses intrathecally activate the KYN pathway, favoring its neurotoxic branch. However, in PM, higher CSF levels of QUINA, compared to MM and VM, may contribute to its poorer neurologic outcome.

Prevalence of Invasive Bacterial Infection in Hypothermic Young Infants: A Multisite Study.

OBJECTIVE: To determine the prevalence of bacteremia and meningitis (invasive bacterial infection [IBI]) in hypothermic young infants, and also to determine the prevalence of serious bacterial infections (SBI) and neonatal herpes simplex virus and to identify characteristics associated with IBI. STUDY DESIGN: We conducted a retrospective cohort study of infants ≤90 days of age who presented to 1 of 9 hospitals with historical or documented hypothermia (temperature ≤36.0°C) from September 1, 2017, to May 5, 2021. Infants were identified by billing codes or electronic medical record search of hypothermic temperatures. All charts were manually reviewed. Infants with hypothermia during birth hospitalization, and febrile infants were excluded. IBI was defined as positive blood culture and/or cerebrospinal fluid culture treated as a pathogenic organism, whereas SBI also included urinary tract infection. We used multivariable mixed-effects logistic regression to identify associations between exposure variables and IBI. RESULTS: Overall, 1098 young infants met the inclusion criteria. IBI prevalence was 2.1% (95% CI, 1.3-2.9) (bacteremia 1.8%; bacterial meningitis 0.5%). SBI prevalence was 4.4% (95% CI, 3.2-5.6), and neonatal herpes simplex virus prevalence was 1.3% (95% CI, 0.6-1.9). Significant associations were found between IBI and repeated temperature instability (OR, 4.9; 95% CI, 1.3-18.1), white blood cell count abnormalities (OR, 4.8; 95% CI, 1.8-13.1), and thrombocytopenia (OR, 5.0; 95% CI, 1.4-17.0). CONCLUSIONS: IBI prevalence in hypothermic young infants is 2.1%. Further understanding of characteristics associated with IBI can guide the development decision tools for management of hypothermic young infants.

Accurate, fast and cost-effective simultaneous detection of bacterial meningitis by qualitative PCR with high-resolution melting.

Neisseria meningitidis, Haemophilus influenzae and Streptococcus pneumoniae are leading causes of meningitis and acute invasive infections. PCR-based methods are widely used for the diagnosis and surveillance of bacterial pathogens because of their high sensitivity, specificity and high-throughput capabilities compared with conventional laboratory methods. This study evaluated a high-resolution melting qualitative PCR analysis method for the simultaneous detection of these three pathogens. The assay has been optimized to detect three species-specific genes of each organism isolated from clinical samples, enabling accurate identification of the etiological agent. The method proved to be highly sensitive and cheaper than the real-time PCR TaqMan® system because it is probe-free; it could be used for the diagnosis of invasive diseases in public health laboratories of developing countries.

Perfil etiológico de las meningitis adquiridas en la comunidad en pacientes adultos en el Complejo Asistencial Sótero del Río, Santiago 2011-2017 / Community acquired meningitis in Santiago, Chile, 2011-2017

INTRODUCCIÓN: En Chile existe poca información sobre los microorganismos causantes de meningitis adquirida en la comunidad (MAC), la que es relevante a la hora de escoger el esquema antimicrobiano empírico. OBJETIVO: Describir la microbiología de MAC en pacientes mayores de 15 años atendidos en un hospital público de Santiago (Chile). METODOLOGÍA: Revisión de cultivos de líquido cefalorraquídeo positivos durante 2011-2017. Se recolectó la información clínica de los pacientes incluidos. Se excluyeron cultivos considerados como contaminación y las meningitis post-quirúrgicas. RESULTADOS: Se identificaron 20 episodios de meningitis bacteriana aguda (MBA) y seis episodios de meningitis criptocócica (MC) entre 2.720 cultivos. Los microorganismos causantes de MBA fueron: Streptococcus pneumoniae (50%), Listeria monocytogenes (25%) y otros cinco agentes (25%). Todos los pacientes con infección por L. monocytogenes presentaban alguna comorbilidad significativa. Cuatro de cinco casos de MC presentaban infección por VIH. CONCLUSIÓN: Streptococcus pneumoniae fue el microorganismo más frecuente de las MAC en esta serie, seguido por L. monocytogenes. Las recomendaciones actuales de esquemas empíricos de MAC consideran adecuadamente la cobertura de S. pneumoniae en todos los pacientes y de L. monocytogenes solo ante factores de riesgo. Además, es relevante considerar MC en casos en pacientes inmunocomprometidos.

BACKGROUND: In Chile, there is scarce information on the frequency of the causative microorganisms of community-acquired meningitis (CAM), which is relevant for the choice of empiric treatment. AIM: To describe the microbiology of CAM in patients over 15 years treated at a public hospital in Santiago (Chile). METHODS: Retrospective review of positive cerebrospinal fluid cultures during 2011-2017. Clinical information of the included patients was collected. Cultures considered as contamination and cases of post-surgical meningitis were excluded. RESULTS: We identified 20 episodes of bacterial meningitis (BM) and six episodes of cryptococcal meningitis (CM) in 2720 cultures. The microorganisms identified in BM cases were Streptococcus pneumoniae (50%), Listeria monocytogenes (25%) and five other agents (25%). All patients with L. monocytogenes infection had at least one well-known risk factor for this infection. Four of the five cases of CM had HIV infection. CONCLUSION: Streptococcus pneumoniae was the most frequent causative microorganism of CAM in this series, followed by L. monocytogenes. Current recommendations for empiric CAM regimens adequately consider coverage for S. pneumoniae in all patients and for L. monocytogenes only in those with risk factors. Furthermore, it is relevant to consider CM in cases involving immunocompromised patients.

The value of next-generation sequencing for the diagnosis of Streptococcus suis meningitis.

OBJECTIVE: The aim of this study was to investigate the value of next-generation sequencing for the diagnosis of Streptococcus suis meningitis. METHODS: Patients with meningitis in the Department of Neurology of the Hainan General Hospital were recruited and divided into a next-generation sequencing group and a control group. In the next-generation sequencing group, we used the next-generation sequencing method to detect the specific pathogenic bacteria in the patients. In the control group, we used the cerebrospinal fluid bacterial culture method to detect the specific pathogenic bacteria in the patients. RESULTS: A total of 28 participants were recruited for this study, with 14 participants in each group. The results showed similarities in both the average age and average course of the disease between the two groups (p>0.05). The white blood cell count, percentage of neutrophils, and level of C-reactive protein in the next-generation sequencing group were significantly higher than those in the control group (p<0.05). There were similarities in both the temperature and intracranial pressure between the two groups (p>0.05). In the next-generation sequencing group, all patients (100%) were detected as having had the S. suis meningitis infection by next-generation sequencing, while only 6 (43%) patients in the control group had been detected as having the S. suis meningitis infection by cerebrospinal fluid bacterial culture. CONCLUSIONS: The positive detection rate of S. suis by the next-generation sequencing method was significantly higher compared with using a cerebrospinal fluid bacterial culture. Therefore, the next-generation sequencing method is valuable for the diagnosis of S. suis meningitis and is worthy of clinical application.

Risk Factors for Death and Severe Neurological Sequelae in Childhood Bacterial Meningitis.

INTRODUCTION: Acute bacterial meningitis (ABM) continues to be a challenge from a diagnostic and therapeutic point of view. Identifying severity risk factors and predictive scores may guide interventions to reduce poor outcome. METHODS: Data from a retrospective study for ABM in children admitted to the Institute of Tropical Medicine in Paraguay was analyzed. ABM was defined as positive cerebrospinal fluid culture, positive latex agglutination, or identification of microorganism by real time-polymerase chain reaction. Univariate and multivariate analyses of risk factors at hospital admission that predicted major morbidity or death during hospitalization were performed. A point-based scoring system that included variables, which were clearly different among those who passed away, was constructed. RESULTS: One hundred fourteen children hospitalized with ABM were eligible for the study. The mean age was 46 ± 57 months (range, 1-192 months). The observed mortality was 33% (38/114 patients). When a point-based scoring system was used, for score of 0 (n = 29) and 1 (n = 12), no death was observed. Among patients with a score of 2 (n = 14), 3 (n = 10 patients), 4 (n = 12 patients), and 5 (n = 13 patients), the mortality rate was 14.3%, 40%, 50%, and 53.8%, respectively. When the score was 6 or higher, the mortality rate was at least 63.6%. CONCLUSIONS: The present score accurately discriminated the probability of death in children hospitalized with ABM, and it could be a useful tool to select candidates for admission to the intensive care unit and for adjunctive therapy in clinical trials.

Diagnosis of bacterial meningitis caused by Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae using a multiplex real-time PCR technique.

Bacterial meningitis is one of the diseases that, despite the introduction of several vaccines, remains a serious public health concern. Streptococcus pneumoniae (Spn), Neisseria meningitidis (Nm), and Haemophilus influenzae (Hi) are responsible for most cases diagnosed in children, adolescents, and adult population. Rapid, sensitive, and specific laboratory assays are critical for effective diagnosis and treatment, particularly in countries like Mexico in which culture positivity rates are very low due to the use of antibiotics prior to sample collection and to delay in transporting samples to the laboratory. The aim of this study was to evaluate the use of real-time polymerase chain reaction (RT-PCR) of cerebrospinal fluid (CSF) as a rapid diagnostic test for bacterial meningitis and compare these results with bacterial culture in three general hospitals in Mexico. During a 5-year period (2014-2018), a total of 512 CSF samples obtained from patients in whom infectious meningitis was suspected as initial clinical diagnosis were tested with RT-PCR with species-specific targets for the three pathogens. For Spn, 5.07% samples were RT-PCR positive; 0.39% for Nm and none for Hi. Only five RT-PCR Spn positive samples had a positive culture. Sensitivity and specificity estimates for RT-PCR are 100% and 95.46%, respectively. DNA amplification methods can provide better sensitive diagnostic tests than the reference standard, which is culture, particularly when antimicrobial treatment is initiated before clinical samples can be obtained.

Importance of underweight in childhood bacterial meningitis in Finland, Latin America and Angola.

Our objective was to explore the importance of underweight on the course of childhood bacterial meningitis (BM) at different study sites, because prior studies showed discrepant results. Using directly comparable, prospective data from three continents, weight-for-age z-scores (WAZ) were determined by WHO Anthro programs in children with BM in Finland (N = 318), LatAm (N = 580), and Angola (N = 780) and compared with data describing the admission, course, and outcome of BM. WAZ < -1 indicates underweight; either mild (< -1 to -2), moderate (< -2 to -3), or severe (< -3). The mean WAZ (SD) was 0.17 (1.17), -0.42 (1.53), and -1.36 (1.44), and the prevalence of moderate-severe underweight 2.8%, 12.6%, and 31.3%, in Finland, LatAm, and Angola, respectively. In univariate analysis, LatAm and Angola showed an association between lower WAZ and poorer condition on admission, slower recovery, and more deaths. In Finland, infrequent underweight limited meaningful analysis. In multivariate analysis of different variables for increasing the odds of death, severe underweight had lower odds compared to disease severity in Angola, but highest in LatAm. Thus, the apparent discrepancy in underweights´ importance for increasing deaths varied from primary to more secondary according to locally more prominent risks.