Acinetobacter pittii: the emergence of a hospital-acquired pathogen analyzed from the genomic perspective.

Acinetobacter pittii has increasingly been associated with several types of hospital-acquired severe infections. Genes implicated in carbapenem resistance, tigecycline resistance, or genes encoding extended spectrum cephalosporinases, such as blaADC, are commonly found in isolates implicated in these infections. A. pittii strains that are pandrug resistant have occasionally been identified. Food for human consumption, animals and plants are environmental sources of this pathogen. An alarming situation is that A. pitti has been identified as responsible for outbreaks in different regions worldwide. In this study, 384 genomes of A. pittii were analyzed, comprising sequences from clinical and non-clinical origins from 32 countries. The objective was to investigate if clinical strains possess genetic traits facilitating hospital adaptation. Results indicate significant genomic variability in terms of size and gene content among A. pittii isolates. The core genome represents a small portion (25-36%) of each isolate's genome, while genes associated with antibiotic resistance and virulence predominantly belong to the accessory genome. Notably, antibiotic resistance genes are encoded by a diverse array of plasmids. As the core genome between environmental and hospital isolates is the same, we can assume that hospital isolates acquired ARGs due to a high selective pressure in these settings. The strain's phylogeographic distribution indicates that there is no geographical bias in the isolate distribution; isolates from different geographic regions are dispersed throughout a core genome phylogenetic tree. A single clade may include isolates from extremely distant geographical areas. Furthermore, strains isolated from the environment or animal, or plant sources frequently share the same clade as hospital isolates. Our analysis showed that the clinical isolates do not already possess specific genes, other than antibiotic-resistant genes, to thrive in the hospital setting.

Bacteria from the skin of amphibians promote growth of Arabidopsis thaliana and Solanum lycopersicum by modifying hormone-related transcriptome response.

Plants and microorganisms establish beneficial associations that can improve their development and growth. Recently, it has been demonstrated that bacteria isolated from the skin of amphibians can contribute to plant growth and defense. However, the molecular mechanisms involved in the beneficial effect for the host are still unclear. In this work, we explored whether bacteria isolated from three tropical frogs species can contribute to plant growth. After a wide screening, we identified three bacterial strains with high biostimulant potential, capable of modifying the root structure of Arabidopsis thaliana plants. In addition, applying individual bacterial cultures to Solanum lycopersicum plants induced an increase in their growth. To understand the effect that these microorganisms have over the host plant, we analysed the transcriptomic profile of A. thaliana during the interaction with the C32I bacterium, demonstrating that the presence of the bacteria elicits a transcriptional response associated to plant hormone biosynthesis. Our results show that amphibian skin bacteria can function as biostimulants to improve agricultural crops growth and development by modifying the plant transcriptomic responses.

Behind closed doors: Exploring the impact of COVID-19 related lockdown on domestic violence in Peru.

Objectives: The COVID-19 pandemic and the lockdown measures implemented have generated an environment conducive to an increase in domestic violence. This study aimed to evaluate changes in calls reporting domestic violence to Línea 100 in Peru before, during and after strict lockdown, using a controlled interrupted time series analysis. Methods: Data from January 2018 to March 2022 from Línea 100, a national toll-free hotline service for survivors of domestic violence, were used. A quasi-experimental research design with controlled interrupted time series analysis was applied. The number of monthly calls reporting domestic violence was the outcome variable, while the sex of the callers was the treatment variable. Results: A significant increase in the number of calls was found during strict lockdown compared to the previous period. In addition, a decrease in the number of calls after confinement was observed. In all analyses, women were the most affected by domestic violence before, during and after lockdown. Conclusions: This study provides evidence on the impact of the COVID-19 pandemic on domestic violence in Peru. The findings highlight the need to strengthen domestic violence prevention and care services, especially during crisis situations such as the pandemic. Also, better targeted intervention strategies aimed at protecting women and promoting safe environments within the home are needed.

Comparative Genomics of Pseudomonas aeruginosa Strains Isolated from Different Ecological Niches.

The Pseudomonas aeruginosa genome can change to adapt to different ecological niches. We compared four genomes from a Mexican hospital and 59 genomes from GenBank from different niches, such as urine, sputum, and environmental. The ST analysis showed that high-risk STs (ST235, ST773, and ST27) were present in the genomes of the three niches from GenBank, and the STs of Mexican genomes (ST167, ST2731, and ST549) differed from the GenBank genomes. Phylogenetic analysis showed that the genomes were clustering according to their ST and not their niche. When analyzing the genomic content, we observed that environmental genomes had genes involved in adapting to the environment not found in the clinics and that their mechanisms of resistance were mutations in antibiotic resistance-related genes. In contrast, clinical genomes from GenBank had resistance genes, in mobile/mobilizable genetic elements in the chromosome, except for the Mexican genomes that carried them mostly in plasmids. This was related to the presence of CRISPR-Cas and anti-CRISPR; however, Mexican strains only had plasmids and CRISPR-Cas. blaOXA-488 (a variant of blaOXA50) with higher activity against carbapenems was more prevalent in sputum genomes. The virulome analysis showed that exoS was most prevalent in the genomes of urinary samples and exoU and pldA in sputum samples. This study provides evidence regarding the genetic variability among P. aeruginosa isolated from different niches.

Conventional and PEGylated Liposomes as Vehicles of Copaifera sabulicola.

Traditional medicine uses resin oils extracted from plants of the genus Copaifera for several purposes. Resin oils are being studied to understand and profile their pharmacological properties. The aim of this work was to prepare and to characterize conventional and pegylated liposomes incorporating resin oils or the hexanic extract obtained from Copaifera sabulicola (copaiba) leaves. The cytotoxic effect of these products was also investigated. Conventional and stealth liposomes with copaiba extract showed similar average diameters (around 126 nm), encapsulation efficiencies greater than 75% and were stable for 90 days. A cytotoxicity test was performed on murine glioma cells and the developed liposomes presented antiproliferative action against these cancer cells at the average concentration of 30 µg/mL. Phytochemicals encapsulated in PEGylated liposomes induced greater reduction in the viability of tumor cells. In addition, bioassay-s measured the cytotoxicity of copaiba resin oil (Copaifera sabulicola) in liposomes (conventional and PEGylated), which was also checked against pheochromocytoma PC12 cells. Its safety was verified in normal rat astrocytes. The results indicate that liposomes encapsulating copaiba oil showed cytotoxic activity against the studied tumor strains in a dose-dependent fashion, demonstrating their potential applications as a chemotherapeutic bioactive formulation.

Correction: Diniz et al. Silver Nanoparticles-Composing Alginate/Gelatine Hydrogel Improves Wound Healing In Vivo. Nanomaterials 2020, 10, 390.

In the original publication, there was a mistake in Figure 6 as published [...].

Entomopathogenic Fungi-Mediated AgNPs: Synthesis and Insecticidal Effect against Plutella xylostella (Lepidoptera: Plutellidae).

The insect Plutella xylostella is known worldwide to cause severe damage to brassica plantations because of its resistance against several groups of chemicals and pesticides. Efforts have been conducted to overcome the barrier of P. xylostella genetic resistance. Because of their easy production and effective insecticidal activity against different insect orders, silver nanoparticles are proposed as an alternative for agricultural pest control. The use of entomopathogenic fungi for nanoparticle production may offer additional advantages since fungal biomolecules may synergistically improve the nanoparticle's effectiveness. The present study aimed to synthesize silver nanoparticles using aqueous extracts of Beauveria bassiana, Metarhizium anisopliae, and Isaria fumosorosea isolates and to evaluate their insecticidal activity against P. xylostella, as innovative nano-ecofriendly pest control. The produced silver nanoparticles were evaluated by measuring the UV-vis spectrum and the mean particle size by dynamic light scattering (DLS). I. fumosorosea aqueous extract with 3-mM silver nitrate solution showed the most promising results (86-nm mean diameter and 0.37 of polydispersity). Scanning electron microscopy showed spherical nanoparticles and Fourier-Transform Infrared Spectroscopy revealed the presence of amine and amide groups, possibly responsible for nanoparticles' reduction and stabilization. The CL50 value of 0.691 mg mL-1 was determined at 72-h for the second-instar larvae of the P. xylostella, promoting a 78% of cumulative mortality rate after the entire larval stage. From our results, the synthesis of silver nanoparticles mediated by entomopathogenic fungi was successful in obtaining an efficient product for insect pest control. The I. fumosorosea was the most suitable isolate for the synthesis of silver nanoparticles contributing to the development of a green nanoproduct and the potential control of P. xylostella.

A Plasmid Carrying blaIMP-56 in Pseudomonas aeruginosa Belonging to a Novel Resistance Plasmid Family.

blaIMP and blaVIM are the most detected plasmid-encoded carbapenemase genes in Pseudomonas aeruginosa. Previous studies have reported plasmid sequences carrying blaIMP variants, except blaIMP-56. In this study, we aimed to characterize a plasmid carrying blaIMP-56 in a P. aeruginosa strain isolated from a Mexican hospital. The whole genome of P. aeruginosa strain PE52 was sequenced using Illumina Miseq 2 × 150 bp, with 5 million paired-end reads. We characterized a 27 kb plasmid (pPE52IMP) that carried blaIMP-56. The phylogenetic analysis of RepA in pPE52IMP and 33 P. aeruginosa plasmids carrying resistance genes reported in the GenBank revealed that pPE52IMP and four plasmids (pMATVIM-7, unnamed (FDAARGOS_570), pD5170990, and pMRVIM0713) were in the same clade. These closely related plasmids belonged to the MOBP11 subfamily and had similar backbones. Another plasmid (p4130-KPC) had a similar backbone to pPE52IMP; however, its RepA was truncated. In these plasmids, the resistance genes blaKPC-2, blaVIM variants, aac(6')-Ib4, blaOXA variants, and blaIMP-56 were inserted between phd and resolvase genes. This study describes a new family of plasmids carrying resistance genes, with a similar backbone, the same RepA, and belonging to the MOBP11 subfamily in P. aeruginosa. In addition, our characterized plasmid harboring blaIMP-56 (pPE52IMP) belongs to this family.

Protein tyrosine phosphatase 1B (PTP1B) as a potential therapeutic target for neurological disorders.

Protein tyrosine phosphatase 1B (PTP1B) is a typical member of the PTP family, considered a direct negative regulator of several receptor and receptor-associated tyrosine kinases. This widely localized enzyme has been involved in the pathophysiology of several diseases. More recently, PTP1B has attracted attention in the field of neuroscience, since its activation in brain cells can lead to schizophrenia-like behaviour deficits, anxiety-like effects, neurodegeneration, neuroinflammation and depression. Conversely, PTP1B inhibition has been shown to prevent microglial activation, thus exerting a potent anti-inflammatory effect and has also shown potential to increase the cognitive process through the stimulation of hippocampal insulin, leptin and BDNF/TrkB receptors. Notwithstanding, most research on the clinical efficacy of targeting PTP1B has been developed in the field of obesity and type 2 diabetes mellitus (TD2M). However, despite the link existing between these metabolic alterations and neurodegeneration, no clinical trials assessing the neurological advantages of PTP1B inhibition have been performed yet. Preclinical studies, though, have provided strong evidence that targeting PTP1B could allow to reach different pathophysiological mechanisms at once. herefore, specific interventions or trials should be designed to modulate PTP1B activity in brain, since it is a promising strategy to decelerate or prevent neurodegeneration in aged individuals, among other neurological diseases. The present paper fails to include all neurological conditions in which PTP1B could have a role; instead, it focuses on those which have been related to metabolic alterations and neurodegenerative processes. Moreover, only preclinical data is discussed, since clinical studies on the potential of PTP1B inhibition for treating neurological diseases are still required.

Infección por VIH y COVID 19 en un paciente pediátrico: reporte de un caso / HIV and COVID-19 infection in a pediatric patient: case report

El Virus de la Inmunodeficiencia Humana (V.I.H.) en etapas avanzadas confiere al portador la susceptibilidad para desarrollar infecciones oportunistas. Se sabe poco sobre el COVID-19 en pacientes con infección por el VIH, y a pesar de que la mayoría estos pacientes coinciden con los factores de riesgo de mal pronóstico cuando hay una coinfección con el COVID-19, se han informado muy pocos casos referentes al tema. En este artículo se presentamos un caso clínico de una paciente pediátrica, sin antecedentes patológicos de importancia, con diagnósticos iniciales de pénfigo y neumonía que, después de posteriores estudios pasó a diagnóstico de VIH-SIDA/ COVID 19.

The Human Immunodeficiency Virus (H.I.V.) in advanced stages confers the carrier susceptibility to develop opportunistic infections. Little is known about COVID 19 in patients with HIV infection, and although the majority of patients in this group coincide with risk factors for poor prognosis when coinfected with COVID 19, very few cases have been reported referring to the subject. In this article we present a clinical case of a pediatric patient, with no significant pathological history, which after further studies went on to a diagnosis of HIV-AIDS/COVID 19.

[Recurrent Cupriavidus Pauculus catheter-related bacteremia]. / Bacteriemia recurrente relacionada con catéter por Cupriavidus pauculus.

Catheter-related bacteriemia by Cupriavidus spp. is a rare condition with very few cases reported in the literature. Most of them occurred in immunocompromised patients. OBJECTIVE: To report a case of recurrent catheter-related bacteriemia by Cupriavidus pauculus in an immunocompromised infant in order to analyze possible therapeutic options, especially in relation to the need or not for central venous catheter (CVC) removal. CLINICAL CASE: 22-month-old infant with B-cell acute lymphoblas tic leukemia (ALL) in reinduction phase, CVC carrier. He presented to the Emergency Room with fever without focus on examination. Blood tests were performed (without increase of acute phase reactants) and differential blood cultures (peripheral and CVC). He was hospitalized and empirical antibiotic therapy was started with intravenous fourth-generation cephalosporin (cefepime). After 24 hours, blood cultures were positive for Cupriavidus pauculus, growing first in the CVC culture. We maintained cefepime, adding catheter lock therapy with ciprofloxacin. Afterward, the infection was resolved, allowing us to keep the CVC. Seven months later, in the context of fever, Cupriavidus pauculus was again identified in CVC blood culture. We decided this time to remove the catheter, in addition to the administration of intravenous cefepime. The patient has not presented new episodes nine months after de removal of the CVC. CONCLUSION: Catheter-related bacteremia by Cupriavidus is a rare condition in children that usually occurs in immunocompromised patients. Catheter lock therapy associated with systemic antibiotics could be a safe option in patients with difficult CVC re moval. However, if persistent colonization of the CVC is suspected, it may be necessary to remove it.

Replication initiator proteins of Acinetobacter baumannii plasmids: An update note.

The bioinformatic analysis that we made of 492 Acinetobacter baumannii plasmid sequences identified 418 genes encoding Replication Initiator (Rep) proteins that fell into at least fourteen groups according to the protein domains that they contained. The most abundant group of Rep proteins contained a Rep_3 superfamily domain, followed by Rep proteins containing Replicase/PriCT_1 superfamily domains, and then by Reps possessing only an HTH_MerR-SF superfamily domain. The remaining eleven groups contain only a few members. To evaluate the diversity of these Rep proteins, we classify them using the current scheme of GR homology groups, which contains 34 groups. However, we needed to create 22 additional GR homology groups to capture all the Rep protein diversity of the plasmid collection. Finally, our bioinformatic analysis suggests that a large fraction of the plasmids seem to have a restricted host range limited to Acinetobacter species, except for those belonging to GR38 that have a very wide host range. To facilitate the future analysis of the Rep proteins, we included a list of the DNA and protein sequences, in fasta format, of the representatives of each one of the GR homology groups.

Silver nanoparticles obtained from Brazilian pepper extracts with synergistic anti-microbial effect: production, characterization, hydrogel formulation, cell viability, and in vitro efficacy.

The synthesis of silver nanoparticles using plant extracts is known as a green approach, as it does not require the use of high pressure, energy, high temperature, or toxic chemicals. The approach makes use of plant extracts in a process called bioreduction, which is mediated by enzymes, proteins, amino acids, and metabolites found in bark, seed, and leaf extracts, transforming silver ions into metallic silver. This work aimed at developing silver nanoparticles (AgNPs) from Brazilian pepper, applying this green methodology. Hydroalcoholic extract of leaves of Schinus terebinthifolius Raddi was prepared and its concentration of polyphenols, tannins, and saponins quantified. The produced nanoparticles were characterized by UV-Vis spectroscopy, thermogravimetric analysis (TG), dynamic light scattering (DLS), and zeta potential (ZP). AgNPs were formulated in sodium alginate hydrogels to obtain a nano-based semi-solid formulation for skin application. The obtained silver nanoparticles of mean size between 350 and 450 nm showed no cytotoxicity against L929 mouse fibroblasts within the concentration range of 0.025 mg/mL and 10 mg/mL. Schinus terebinthifolius Raddi was found to enhance microbial inhibition against the tested strains, especially against gram-negative bacteria. Its potential use as an alternative to overcome bacterial resistance can be expected.

Music Therapy in Pain and Anxiety Management during Labor: A Systematic Review and Meta-Analysis.

Background and Objective: The study of music therapy in labor is unknown. The main objective of this research was to evaluate the effectiveness of music therapy to manage pain and anxiety during labor. Materials and Methods: A search strategy was used with PubMed/MEDLINE, LILACS, Cochrane, TRIPDATABASE, and Google Scholar. The selection criteria were based on randomized clinical trials; quasi-experimental research on pain intensity and anxiety during labor was evaluated. The primary outcomes were measured by the Visual Analogue Scale (VAS). A meta-analysis of the fixed effects was performed using mean differences (MD). Twelve studies were included for the final analysis, six (778 women) of which were meta-analyzed. Results: Decreased VAS scores for pain intensity associated with music therapy were found in the latent (MD: -0.73; 95% CI -0.99; -0.48) and active (MD: -0.68; 95% CI -0.92; -0.44) phases of labor. VAS scores for anxiety decreased both in the latent (MD: -0.74; 95% CI -1.00; -0.48) and active (MD: -0.76; 95% CI -0.88; -0.64) phases. Conclusion: Music therapy seems to have beneficial effects on pain intensity and anxiety during labor, especially for women giving birth for the first time. However, the evidence is qualified as low.

Antibiotic resistance mechanisms in Acinetobacter spp. strains isolated from patients in a paediatric hospital in Mexico.

OBJECTIVES: The aim of this study was to identify Acinetobacter spp. strains from paediatric patients, to determine their genetic relationship, to detect antibiotic resistance genes and to evaluate the role of efflux pumps in antibiotic resistance. METHODS: A total of 54 non-duplicate, non-consecutive Acinetobacter spp. isolates were collected from paediatric patients. Their genetic relationship, antibiotic resistance profile, efflux pump activity, antibiotic resistance genes and plasmid profile were determined. RESULTS: The isolates were identified as 24 Acinetobacter haemolyticus, 24 Acinetobacter calcoaceticus-baumannii (Acb) complex and 1 strain each of Acinetobacter junii, Acinetobacter radioresistens, Acinetobacter indicus, Acinetobacter lwoffii, Acinetobacter ursingii and Acinetobacter venetianus. The 24 A. haemolyticus were considered genetically unrelated. One strain was resistant to carbapenems, two to cephalosporins, two to ciprofloxacin and sixteen to aminoglycosides. The antibiotic resistance genes blaOXA-214 (29%), blaOXA-215 (4%), blaOXA-264 (8%), blaOXA-265 (29%), blaNDM-1 (4%), aac(6')-Ig (38%) and the novel variants blaOXA-575 (13%), blaTEM-229 (75%), aac(6')-Iga (4%), aac(6')-Igb (13%) and aac(6')-Igc (42%) were detected. Among 24 Acb complex, 5 were multidrug-resistant, carbapenem-resistant strains carrying blaOXA-51 and blaOXA-23; they were genetically related and had the same plasmid profile. Other species were susceptible. In some strains of A. haemolyticus and Acb complex, the role of RND efflux pumps was evidenced by a decrease in the MICs for cefotaxime, amikacin and ciprofloxacin in the presence of an efflux pump inhibitor. CONCLUSIONS: This study identified isolates of A. haemolyticus carrying new ß-lactamase variants and shows for the first time the contribution of efflux pumps to antibiotic resistance in this species.

Learning musculoskeletal anatomy through new technologies: a randomized clinical trial.

OBJECTIVE: to investigate the influence of the application of new methodologies on learning and the motivation of students of the Anatomy discipline. METHOD: randomized, longitudinal, prospective, intervention study. Sixty-two students were recruited to assess the impact of different methodologies. The sample was randomized to compare the results of teaching with a 3D atlas, ultrasound and the traditional method. The parameters were assessed through a satisfaction evaluation questionnaire and anatomical charts. Repeated measures ANOVA was used to determine statistical significance. RESULTS: in terms of the usefulness of the seminars, 98.1% of the students considered them to be very positive or positive, stating that they had stimulated their interest in anatomy. The students who learned with the 3D atlas improved their understanding of anatomy (p=0.040). In general, the students improved their grades by around 20%. CONCLUSION: the traditional method combined with new technologies increases the interest of students in human anatomy and enables them to acquire skills and competencies during the learning process.

Streptococcus agalactiae: causa de artritis séptica inusual a partir de los 3 meses de edad. Caso clínico / Streptococcus agalactiae: an unusual cause of septic arthritis beyond 3 months of age. Case report

La artritis séptica es una patología poco frecuente, pero con una alta morbilidad, debido a las importantes secuelas que puede originar. La etiología varía según la edad, y Staphylococcus aureus es el microorganismo más frecuente en todas ellas. Streptococcus agalactiae odel grupo B es una causa infrecuente de infección fuera del período neonatal; se asocia, a partir de los 3 meses de edad, con infecciones graves en pacientes inmunocomprometidos. El tratamiento de elección es penicilina G o ampicilina.Aquí se describe el caso de un niño de cuatro meses y medio de edad que desarrolló una artritis séptica por Streptococcus agalactiae odel grupo B, con inicio insidioso de la clínica. El diagnóstico etiológico obligó a descartar meningitis y una inmunodeficiencia asociada. La frecuencia extremadamente baja de dicha artritis a esta edad y la importancia de descartar una enfermedad diseminada son importantes puntos de aprendizaje en este caso.

Septic arthritis is not a very frequent disease, but with a high morbidity due to the important sequelae that it can cause. The etiology is age-specific, with Staphylococcus aureus being the most frequent microorganism in all ages. Streptococcus agalactiae or group B Streptococcus is an uncommon cause of infection outside the neonatal period. Beyond 3 months of age, infections by this pathogen are associated with serious infections in immunocompromised patients. The treatment of choice is penicillin G or ampicillin. A 4.5-month-old child who developed a group B Streptococcus septic arthritis is reported. The onset was insidious, and the etiological diagnosis prompted us to rule out meningitis and associated immunodeficiency. The extremely low frequency of group B Streptococcus septic arthritis at this age and the importance of ruling out a disseminated disease are crucial learning points in this case

Chromosome Architecture and Gene Content of the Emergent Pathogen Acinetobacter haemolyticus.

Acinetobacter haemolyticus is a Gammaproteobacterium that has been involved in serious diseases frequently linked to the nosocomial environment. Most of the strains causing such infections are sensitive to a wide variety of antibiotics, but recent reports indicate that this pathogen is acquiring very efficiently carbapenem-resistance determinants like the blaNDM-1 gene, all over the world. With this work we contribute with a collection set of 31 newly sequenced nosocomial A. haemolyticus isolates. Genome analysis of these sequences and others collected from RefSeq indicates that their chromosomes are organized in 12 syntenic blocks that contain most of the core genome genes. These blocks are separated by hypervariable regions that are rich in unique gene families, but also have signals of horizontal gene transfer. Genes involved in virulence or encoding different secretion systems are located inside syntenic regions and have recombination signals. The relative order of the synthetic blocks along the A. haemolyticus chromosome can change, indicating that they have been subject to several kinds of inversions. Genomes of this microorganism show large differences in gene content even if they are in the same clade. Here we also show that A. haemolyticus has an open pan-genome.

[Streptococcus agalactiae: an unusual cause of septic arthritis beyond 3 months of age. Case report]. / Streptococcus agalactiae: causa de artritis séptica inusual a partir de los 3 meses de edad. Caso clínico.

Septic arthritis is not a very frequent disease, but with a high morbidity due to the important sequelae that it can cause. The etiology is age-specific, with Staphylococcus aureus being the most frequent microorganism in all ages. Streptococcus agalactiae or group B Streptococcus is an uncommon cause of infection outside the neonatal period. Beyond 3 months of age, infections by this pathogen are associated with serious infections in immunocompromised patients. The treatment of choice is penicillin G or ampicillin. A 4.5-month-old child who developed a group B Streptococcus septic arthritis is reported. The onset was insidious, and the etiological diagnosis prompted us to rule out meningitis and associated immunodeficiency. The extremely low frequency of group B Streptococcus septic arthritis at this age and the importance of ruling out a disseminated disease are crucial learning points in this case.

La artritis séptica es una patología poco frecuente, pero con una alta morbilidad, debido a las importantes secuelas que puede originar. La etiología varía según la edad, y Staphylococcus aureus es el microorganismo más frecuente en todas ellas. Streptococcus agalactiae o del grupo B es una causa infrecuente de infección fuera del período neonatal; se asocia, a partir de los 3 meses de edad, con infecciones graves en pacientes inmunocomprometidos. El tratamiento de elección es penicilina G o ampicilina. Aquí se describe el caso de un niño de cuatro meses y medio de edad que desarrolló una artritis séptica por Streptococcus agalactiae o del grupo B, con inicio insidioso de la clínica. El diagnóstico etiológico obligó a descartar meningitis y una inmunodeficiencia asociada. La frecuencia extremadamente baja de dicha artritis a esta edad y la importancia de descartar una enfermedad diseminada son importantes puntos de aprendizaje en este caso.