Prevalencia de Staphylococcus aureusy su sensibilidad antibiótica en aislamientos en infecciones de piel y partes blandas en pacientes ambulatorios / Staphylococcus aureus prevalence and antimicrobial susceptibility in isolates from skin and soft tissue infections in outpatients

ntroducción: Las infecciones de piel y partes blandas (IPPB) constituyen la tercera causa de consulta en nuestro centro. S.aureus es el agente etiológico más frecuente en este tipo de infecciones y la meticilino resistencia es clínicamente el mecanismo de resistencia más importante. El objetivo de este trabajo fue analizar la prevalencia de los distintos agentes etiológicos en IPPB en pacientes ambulatorios, así como también estudiar su sensibilidad a los antibióticos y resistencias acompañantes más frecuentes. Materiales y métodos: Estudio descriptivo y retrospectivo que incluyó todas las muestras provenientes de IPPB de pacientes ambulatorios desde octubre de 2017 a abril de 2022. Resultados: Se obtuvieron 180 cultivos positivos de muestras provenientes de IPPB durante el periodo estudiado, 12 fueron infecciones polimicrobianas. En total se obtuvieron 307 aislamientos: el microorganismo aislado con mayor frecuencia fue S.aureus (111; 36,2%). Se hallaron 71 SAMR (64%) y 40 SAMS (36%). De los SAMR, 67 (95%) fueron comunitarios (SAMRC) por criterios microbiológicos, y 4 SAMR hospitalarios (5%). De las cepas SAMRC, 44 (66%) no presentaron resistencias acompañantes, 15 (22% ) fueron resistentes a eritromicina, 12 (18%) a gentamicina y 7 (10%) a clindamicina. Conclusiones: El microorganismo más frecuentemente aislado en IPPB en pacientes ambulatorios fue el S.aureus y 67 aislamientos fueron categorizados como SAMRC por lo cual es necesario considerar al SAMRC como un patógeno frecuente. Debido a la baja resistencia hallada para CLI y TMS ambos podrían ser de elección en el tratamiento empírico en las IPPB en pacientes ambulatorios

Background:S. aureus is the main cause of skin and soft tissues infections (SSTIs) in immunocompetent patients. This type of infection is the third cause of medical consultation in our center. Our objective was to evaluate the prevalence of S. aureus, as well as its sensitivity to antimicrobials, isolated from skin and soft tissue samples from outpatients at an interzonal general acute care hospital located in Buenos Aires, Argentina.Methods: Descriptive and retrospective study that included all outpatient SSTIs samples from October 2017 to April 2022.Results: We obtained 215 positive cultures of samples from SSTIs during the study period. Of a total of 276 isolates: the most frequently isolated microorganism wasS. aureus (111; 40.22%). The prevalence of S. aureuswas 51.63%. We found 71 MRSA (63.96%). Of the SAMR strains, 60.56% did not present accompanying resistance, and only 8 isolates (11.27%) showed resistance to clindamycin. All SAMRs remained sensitive to minocycline and trimethoprim-sulfamethoxazole.Conclusions: The most frequently isolated microorganism in SSTIs was S. aureus and 71 isolates were categorized as SAMR, therefore it is necessary to consider SAMR as a frequent pathogen. Due to the low resistance found for CLI and TMS, they should be considered for empirical treatment in SSTIs in outpatients

Detección de Staphylococcus aureus en teléfonos móviles de estudiantes de último año de odontología / Detection of Staphylococcus aureus in mobile phones of final year dental students

Objetivo: El propósito de este estudio fue detectar la incidencia de Staphylococcus aureus (S. aureus) en pantallas de teléfonos móviles de estudiantes de último año de odontología mediante técnicas microbiológicas. Métodos: Estudio observacional de tipo transversal descriptivo. Se tomaron 92 muestras de pantallas de teléfonos móviles, se realizó la identificación de S. aureus mediante pruebas microbiológicas: fermentación del manitol, reacciones positivas a las pruebas de desoxirribonucleasa, catalasa y coagulasa. Resultados: Se aisló 16 cepas de S. aureus 16/92 (17,4%) en pantallas de teléfonos móviles. El 100% de las cepas aisladas dieron reacciones positivas a las pruebas de desoxirribonucleasa, catalasa y coagulasa. Conclusiones: Se evidencia la presencia de S. aureus en pantallas de celulares de los teléfonos móviles de los estudiantes de último año lo que representa un riesgo para la diseminación de este patógeno.

Objective: The purpose of this study was to detect the incidence of S. aureus on mobile phone screens of last-year dental students using microbiological techniques. Methodology: Descriptive cross-sectional observational study. 92 samples were taken from mobile phone screens, S. aureus was identified by microbiological tests: mannitol fermentation, positive reactions to deoxyribonuclease, catalase and coagulase tests. Results: 16 strains of S. aureus 16/92 (17.4%) were isolated on mobile phone screens. 100% of the strains emerged positive reactions to deoxyribonuclease, catalase and coagulase tests. Conclusions: The presence of S. aureus is evidenced in cell phone screens of senior students' mobile phones, which represents a risk for the spread of this pathogen.

Celulitis facial por Staphylococcus aureus con metástasis infecciosas y evolución tórpida. Caso pediátrico / Facial cellulitis due to Staphylococcus aureus with metastatic infection and torpid course. A pediatric case report

La bacteriemia por Staphylococcus aureus se define como el aislamiento de dicho germen en al menos un cultivo de sangre. Las metástasis infecciosas se originan por diseminación hematógena y su posterior localización en un sitio distinto al órgano en donde se originó el proceso infeccioso. La prevalencia en la presentación de estos focos infecciosos secundarios es baja en la edad pediátrica, por lo que representa un desafío diagnóstico. Se presenta el caso de un paciente pediátrico con una celulitis facial por Staphylococcus aureus, con metástasis infecciosas y evolución tórpida.

Bacteremia due to Staphylococcus aureus is defined as the isolation of this microorganism in at least one blood culture. A metastatic infection is caused by the hematogenous dissemination and subsequent location of the microorganism in a site other than the one where the infection started. The prevalence of these secondary sources of infection is low in the pediatric population, which is a diagnostic challenge. Here we describe the case of a pediatric patient with facial cellulitis due to Staphylococcus aureus, with metastatic infection and torpid course.

Osteomielitis primaria de esternón / Primary sternal osteomyelitis

La osteomielitis primaria de esternón es muy infrecuente en niños, con menos de 100 casos publicados hasta la actualidad. Su presentación clínica es a menudo inespecífica, lo que causa un retraso en el diagnóstico. Se presentan dos nuevos casos de osteomielitis primaria de esternón. Ambos referían un cuadro de fiebre, malestar general, dolor torácico y rechazo del decúbito, con eritema preesternal en uno de los casos. La velocidad de sedimentación globular y la proteína C-reactiva estaban elevadas en ambos casos. El diagnóstico se confirmó mediante estudios de imagen y en un caso se aisló Staphylococcus aureus sensible a meticilina en el hemocultivo. Ambos se recuperaron sin complicaciones con tratamiento antibiótico. Debe tenerse en cuenta la osteomielitis primaria de esternón en el diagnóstico diferencial del dolor torácico, especialmente si se acompaña de fiebre, signos inflamatorios locales, intolerancia al decúbito o elevación de reactantes de fase aguda.

Primary sternal osteomyelitis is very rare in children, with less than 100 cases published to date. Its clinical presentation is often non-specific, which results in a diagnostic delay. Here we describe 2 new cases of primary sternal osteomyelitis. Both referred fever, malaise, chest pain, and refusal to lie down, with pre-sternal erythema in one of the cases. The erythrocyte sedimentation rate and C-reactive protein values were high in both cases. The diagnosis was confirmed by imaging studies; methicillin-sensitive Staphylococcus aureus was isolated in the blood culture of one of them. Both recovered without complications with antibiotic treatment. Primary sternal osteomyelitis should be considered in the differential diagnosis of chest pain, especially if accompanied by fever, local inflammatory signs, intolerance to lying down, or increased acute phase reactants.

Síndrome de compresión medular de etiología infecciosa

El síndrome de compresión medular es una urgencia neuroquirúrgica debido a que un diagnóstico precoz y un tratamiento temprano podría revertir las incapacitantes secuelas ocasionadas por esta enfermedad. Las causas de este síndrome pueden ser traumática, metastásica, infecciosa y vascular (hematomas). La etiología infecciosa no es frecuente y el principal germen involucrado suele ser Staphylococcus aureus. A continuación presentamos el caso de una paciente de 58 años con síndrome de compresión medular de etiología infecciosa quien fue ingresada en el Servicio de Clínica Médica del Centro Médico Nacional.

Spinal cord compression syndrome is a neurosurgical emergency because early diagnosis and early treatment could reverse the disabling consequences caused by this disease. The causes of this syndrome can be traumatic, metastatic, infectious, and vascular (hematomas). Infectious etiology is not frequent and the main germ involved is usually Staphylococcus aureus. Below we present the case of a 58-year-old patient with spinal cord compression syndrome of infectious etiology who was admitted to the Medical Clinic Service of the National Medical Center.

Molecular Detection of Enterotoxigenic Staphylococcus aureus in Ready-to-eat Cowhide (‘Ponmo’) Collected from Lagos Metropolis, Nigeria

Aims: Ready-to-eat [RTE] animal products like ponmo are preferred by consumers due to its palatability and quality. However, foodborne pathogens particularly Staphylococcus aureus are sources of concern due to cross-contamination of raw and cooked cowhide. This study aimed to investigate the incidence of enterotoxigenic S. aureus in ready-to-eat locally processed cowhide. Methodology: Sixty (60) RTE cowhide samples were collected from different locations in Lagos, Nigeria and analyzed using conventional microbiological and molecular techniques for the detection of toxigenic S. aureus contamination. Suspected S. aureus isolates were confirmed by the presence of thermostable endonuclease [nuc] gene in their genome. Results: Result showed that 25 (41.67%) and 20 (33.50%) samples harbored coagulase-positive S. aureus and 20 other bacterial species different from S. aureus, respectively while 15 (24.83%) of the tested ponmo samples yielded no bacterial growth. Thirteen of the 15 randomly selected from the 25 suspected isolates were confirmed as S. aureus by the presence of thermostable endonuclease [nuc] gene in their genome. Enterotoxigenic genes were confirmed in all the 13 PCR detected S. aureus. Enterotoxin B gene is most prevalent in ponmo. Multiplex PCR detection of S. aureus enterotoxins [SE] genes revealed the molecular detection of different isolates carrying staphylococcal enterotoxin types A and B, mixed strain carrying both staphylococcal enterotoxins type A and type D. Antibiotic susceptibility of 20 S. aureus isolates revealed varying degrees of susceptibility patterns against the antimicrobial agents. Generally, gentamicin 70% (14/20), azithromycin 75% (15/20), co-trimoxazole 85% (17/20), levofloxacin 95% (19/20) were the most effective antibiotics to S. aureus. A low, ?50% susceptibility was recorded to chloramphenicol 55% (11/20) and nitrofurantoin 65% (13/20). A higher resistance to streptomycin (90%; 18/20) and ceftazidime (95%; 19/20) was identified, with resistance to ceftazidime being the highest (95%; 19/20). Conclusion: It can be concluded that RTE ponmo vended in the study sites is of low hygienic quality and may be of health risk to consumers. High level hygiene practice and good manufacturing practices are required during the production, distribution and marketing of ponmo to curb the potential health consequences of eating ponmo.

Neumonía por Pasteurella multocida y Staphylococcus aureus en una paciente sin patología subyacente / Pneumonia by Pasteurella multocida and Staphylococcus aureus in a patient whithout underlying conditions / Pneumonia por Pasteurella multocida e Staphylococcus aureus em uma paciente sem patologia subjacente

Resumen Muchos microorganismos capaces de producir infecciones en el ser humano son de origen zoonótico. Entre éstos está Pasteurella multocida, la cual se encuentra como comensal y/o patógeno oportunista, colonizando el tracto gastrointestinal y respiratorio de gran cantidad de mamíferos y aves. Por otro lado, Staphylococcus aureus es un colonizante de piel y nasofaringe y un patógeno oportunista para seres humanos y animales y su transmisión podría ser bidireccional. Se presenta un caso de neumonía por P. multocida y S. aureus en una mujer sin enfermedad subyacente, que acogía perros y gatos abandonados e ingresó con politraumatismo por caída desde un quinto piso. Ambos microorganismos fueron recuperados en una muestra de aspirado traqueal e identificados por Vitek®2 Compact. La identificación de P. multocida fue confirmada por espectrometría de masas (MALDI-TOF-MS) y presentó sensibilidad a penicilina, cefotaxima, amoxicilina-ácido clavulánico, ciprofloxacina, tetraciclina y trimetoprima-sulfametoxazol. S. aureus era sensible a meticilina sin resistencia acompañante.

Abstract Many microorganisms capable of producing infections in humans are of zoonotic origin. Among them, Pasteurella multocida, is a commensal and/or opportunistic pathogen that colonises the gastrointestinal and the respiratory tract of a great number of mammals and birds. On the other hand, Staphylococcus aureus is a coloniser of skin and nasopharynx and an opportunistic pathogen in humans and animals, whose transmission might be bidirectional. A case of pneumonia by P. multocida and S. aureus was presented in a woman without an underlying condition, who sheltered stray dogs and cats and was admitted with multiple trauma due to a fall from a fifth floor. Both microorganisms were recovered from a tracheal aspirate sample and identified by Vitek®2 Compact. Identification of P. multocida was confirmed by mass spectrometry (MALDI-TOF MS) and was susceptible to penicillin, cefotaxime, amoxicillin-clavulanic acid, ciprofloxacin, tetracycline and trimethoprim-sulfamethoxazole. S. aureus was methicillin-susceptible without accompanying resistance.

Resumo Muitos dos microrganismos capazes de produzir infecções no ser humano têm origem zoonótico. Entre eles está a Pasteurella multocida, que se encontra como comensal e/ou patógeno oportunista, colonizando o trato gastrintestinal e respiratório de grande quantidade de mamíferos e aves. Por outro lado, Staphylococcus aureus é um colonizador de pele e nasofaringe e um patógeno oportunista para seres humanos e animais e sua transmissão poderia ser bidirecional. Apresenta-se um caso de pneumonia por P. multocida e S. aureus em uma mulher, sem doença subjacente, que abrigava cães e gatos abandonados e entrou com múltiplos traumatismos devido à queda desde o quinto andar. Ambos os microrganismos foram obtidos da amostra de aspiração traqueal e identificados por Vitek®2 Compact. A identificação de P. multocida foi validada por espectrometria de massas (MALDI-TOF MS) e apresentou sensibilidade à penicilina, cefotaxima, amoxicilina-ácido clavulânico, ciprofloxacina, tetraciclina e trimetoprim-sulfometoxazol. S. aureus era meticilino sensível sem resistência acompanhante.

Shock séptico en niños con bacteriemia por Staphylococcus aureus de la comunidad en un hospital pediátrico de alta complejidad

Introducción: La información disponible sobre los factores de riesgo para el desarrollo de shock séptico es escasa, especialmente en población pediátrica. Objetivo: Describir las características epidemiológicas y clínicas de los niños con bacteriemia adquirida en la comunidad por Staphylococcus aureus y comparar las características de los pacientes con y sin shock séptico. Pacientes y Métodos: Estudio de cohorte retrospectivo. Criterios de inclusión: niños entre 30 días y 16 años de edad, internados en el Hospital de Pediatría Juan P. Garrahan entre enero de 2017 y diciembre de 2019 por infecciones adquiridas en la comunidad con desarrollo de S. aureus en hemocultivos. Criterios de exclusión: antecedente de internación dentro de los 3 meses previos al ingreso, vivir en una comunidad cerrada, presencia de catéter de larga permanencia, dispositivos intraventriculares o intraperitoneales. Análisis estadístico: STATA 16. Resultados: Se incluyeron 142 niños. 21 niños (15%) presentaron shock séptico. En el análisis multivariado, se asociaron con shock séptico, la bacteriemia persistente (OR 7,15; IC95% 4,39-23,81; p: 0,001) y el foco secundario de infección (OR 6,72; IC 95% 2,02-22,2; p 0,002). La mortalidad relacionada con la infección fue 3,5% (5 pacientes). Conclusiones: El shock séptico se asoció con la bacteriemia persistente y la presencia de focos secundarios de infección.

Background: Available information about risk factors for the development of septic shock is scarce, especially in the pediatric population. Aim: To describe the epidemiological and clinical characteristics of children with community-acquired Staphylococcus aureus bacteremia and to compare the characteristics of children with and without septic shock. Methods: Retrospective cohort study. Inclusion criteria: Children between 30 days and 16 years old, hospitalized in the Juan P. Garrahan Pediatric Hospital between January 2017 and December 2019 for community-acquired infections with S. aureus isolation in blood cultures. Exclusion criteria: History of hospitalization within 3 months prior to admission, living in a closed community, presence of long-term catheter, intraventricular or intraperitoneal devices. Statistical analysis: STATA 16. Results: 142 children were included. 21 children (15%) experienced septic shock. On multivariate analysis, persistent bacteremia (OR 7.15, 95% CI 4.39-23.81, p: 0.001) and secondary focus of infection (OR 6.72, 95% CI 2.02-22.2, p 0.002) were associated with septic shock. The infection-related mortality rate was 3.5% (5 patients). Conclusions: Septic shock was associated with persistent bacteremia and the presence of secondary foci of infection.

Detection and expression of SapS, a class C nonspecific acid phosphatase with O-phospho-L- tyrosine-phosphatase activity, in Staphylococcus aureus isolates from patients with chronic osteomyelitis / Detección y expresión de SapS, una fosfatasa ácida no específica de clase C con actividad de fosfatasa O-fosfotirosina, en aislamientos de Staphylococcus aureus de pacientes con osteomielitis crónica

Introduction. The identity of Staphylococcus aureus virulence factors involved in chronic osteomyelitis remains unresolved. SapS is a class C non-specific acid phosphatase and a well-known virulence factor that has been identified in S. aureus strain 154 but in protein extracts from rotting vegetables. Objective. To identify the SapS gene and characterize the activity of SapS from S. aureus strains: 12 isolates from bone infected samples of patients treated for chronic osteomyelitis and 49 from a database with in silico analysis of complete bacterial genomes. Materials and methods. The SapS gene was isolated and sequenced from 12 S. aureus clinical isolates and two reference strains; 49 S. aureus strains and 11 coagulase-negative staphylococci were tested using in silico PCR. Culture media semi-purified protein extracts from the clinical strains were assayed for phosphatase activity with p-nitro-phenyl- phosphate, O-phospho-L-tyrosine, O-phospho-L-serine, and OphosphoL-threonine in conjunction with various phosphatase inhibitors. Results. SapS was detected in the clinical and in-silico S. aureus strains, but not in the in silico coagulase-negative staphylococci strains. Sec-type I lipoprotein-type N-terminal signal peptide sequences; secreted proteins, and aspartate bipartite catalytic domains coding sequences were found in the SapS nucleotide and amino acid sequence analysis. SapS dephosphorylated with p-nitro-phenyl-phosphate and ophosphoLtyrosine were selectively resistant to tartrate and fluoride, but sensitive to vanadate and molybdate. Conclusion. SapS gene was found in the genome of the clinical isolates and the in silico S. aureus strains. SapS shares biochemical similarities with known virulent bacterial, such as protein tyrosine phosphatases, suggesting it may be a virulence factor in chronic osteomyelitis.

Introducción. Se desconoce la identidad de los factores de virulencia de Staphylococcus aureus implicados en la osteomielitis crónica. Sin embargo, SapS, una fosfatasa ácida no específica de clase C, es un factor de virulencia reconocido y ya fue identificada en la cepa 154 de S. aureus, pero en extractos proteicos de vegetales podridos. Objetivo. Detectar el gen SapS y caracterizar la actividad de la fosfatasa SapS en cepas de S. aureus aisladas de pacientes con osteomielitis crónica y en las reportadas en una base de datos de análisis in silico de genomas bacterianos completos. Materiales y métodos. Se aisló y secuenció el gen SapS en los 12 aislamientos clínicos de S. aureus y en dos cepas de referencia; estas secuencias se analizaron junto con las secuencias de las cepas reportadas en la base de datos de genomas bacterianos: 49 cepas de S. aureus y 11 cepas de estafilococos negativos para coagulasa. Se evalúo la actividad de la fosfatasa SapS, presente en los extractos de los sobrenadantes de los cultivos de las cepas clínicas, mediante la hidrólisis de fosfato p-nitrofenil, O-fosfo-L- tirosina, O-fosfo-L serina y O-fosfo-L treonina junto con varios inhibidores de fosfatasas. Resultados. Se detectó el gen SapS en el genoma de las cepas clínicas y en las 49 cepas de S. aureus analizadas in silico, pero no en las 11 cepas de estafilococos negativos para coagulasa. La secuenciación de SapS reveló un péptido señal presente en el extremo N-terminal de proteínas extracelulares y los dominios bipartitos de aspartato (DDDD) en su sitio catalítico. SapS hidroliza selectivamente el fosfato p-nitrofenil y la O-fosfo-L-tirosina, pero es sensible a vanadato y molibdato. Conclusión. Se encontró SapS en el genoma de S. aureus de las cepas clínicas y de las cepas de simulación computacional. La SapS con actividad específica para la hidrólisis de la O-fosfo-L-tirosina comparte similitudes bioquímicas con las fosfatasas-tirosina bacterianas, por lo que puede formar parte de la red de factores de virulencia de la osteomielitis crónica.

Infecciones causadas por Staphylococcus aureus de la Comunidad. Estudio de sensibilidad y tendencias en población pediátrica. Años 2015 a 2020

Introducción: Staphylococcus aureus (SA) puede ocasionar cuadros infecciosos severos y muerte. La emergencia de cepas resistentes a meticilina constituye un desafío terapéutico. Objetivos: determinar el perfil de resistencia antimicrobiana de: Staphylococcus aureus adquirido en la comunidad (SA-CA), obtenidos de muestras biológicas de niños, entre 2015 a 2020. Material y Método: estudio descriptivo, observacional y retrospectivo. Las muestras para cultivos se extrajeron al ingreso hospitalario del paciente. Para determinación de resistencia y sensibilidad se utilizó normas de CSLI. Resultados: 244 aislamientos de SA-CA. Masculinos 99 (59%), menores de un año: 42 (25%), de 2 a 5 años: 34 (20%), de 6 a 11 años: 50 (30%) y entre 12 a 15 años: 42 (25%). De los aislados, 72% fueron SAMR (121/168) y 28% SAMS (47/168). Se observó un incremento de tasas anuales de aislamientos SAMR en infecciones de la comunidad desde el 2015 al 2020. Los aislamientos se originaron en piel y partes blandas 53,2 %; sangre 37,4%, orina 3,5%, LCR 2,4%, liquido articular 1,7%, abscesos profundos 1,2% y liquido pleural 0,6%. La prevalencia de SAMR-CA fue de 60,5 en el 2015, 59,6 %, 61,5%, 72,2 %, 67,3% y 75,5 % en los años sucesivos. No se aisló ninguna cepa resistente a la vancomicina. El 10,1% de las cepas estudiadas presentó resistencia inducida a la clindamicina. Conclusión: El SAMR se ha establecido como patógeno de la comunidad. La resistencia inducida por clindamicina fue del 10,1%. Un tercio de las infecciones fueron causadas por SAMS. Las prevalencias de SAMS muestran tendencia a la disminución.

Introduction: Staphylococcus aureus (SA) can cause severe infectious conditions and death. The emergence of methicillin-resistant strains constitutes a therapeutic challenge. Objectives: to determine the antimicrobial resistance profile of: Staphylococcus aureus acquired in the community (SA-CA), obtained from biological samples of children, between 2015 and 2020. Material and Method: descriptive, observational and retrospective study. The samples for cultures were extracted upon hospital admission of the patient. To determine resistance and sensitivity, CSLI standards were used. Results: 244 isolates of SA-CA. Males 99 (59%), under one-year-old: 42 (25%), from 2 to 5 years old: 34 (20%), from 6 to 11 years old: 50 (30%) and between 12 and 15 years old: 42 (25%). Of the isolates, 72% were SAMR (121/168) and 28% SAMS (47/168). An increase in annual rates of MRSA isolates in community infections was observed from 2015 to 2020. The isolates originated in skin and soft parts 53.2 %; blood 37.4%, urine 3.5%, CSF 2.4%, joint fluid 1.7%, deep abscesses 1.2% and pleural fluid 0.6%. The prevalence of MRSA-CA was 60.5 in 2015, 59.6%, 61.5%, 72.2%, 67.3%, and 75.5% in subsequent years. No vancomycin resistant strain was isolated. 10.1% of the strains studied presented induced resistance to clindamycin. Conclusion: MRSA has been established as a community pathogen. The resistance induced by clindamycin was 10.1%. One third of the infections was caused by SAMS. The prevalence of SAMS shows a downward trend.

Clinical Profile, Intensive Care Needs, and Short-Term Outcome of Toxic Shock Syndrome Among Children: A 10-Year Single-Centre Experience from North India

Objective To describe the clinical and laboratory profle, management, intensive care needs, and outcome of children with toxic shock syndrome (TSS) admitted to the pediatric intensive care unit (PICU) of a tertiary care center in North India. Methods This retrospective study was conducted in the PICU of a tertiary care hospital in North India over a period of 10 y (January 2011–December 2020) including children<12 y with TSS (n=63). Results The median (interquartile range, IQR) age was 5 (2–9) y, 58.7% were boys, and Pediatric Risk of Mortality III (PRISM-III) score was 15 (12–17). The primary focus of infection was identifed in 60.3% children, 44.5% had skin and soft tissue infections, and 17.5% (n=11) had growth of Staphylococcus aureus. Common manifestations were shock (100%), rash (95.2%), thrombocytopenia (79.4%), transaminitis (66.7%), coagulopathy (58.7%), and acute kidney injury (AKI) (52.4%); and involvement of gastrointestinal (61.9%), mucus membrane (55.5%), respiratory (47.6%), musculoskeletal (41.3%), and central nervous system (CNS) (31.7%). The treatment included fuid resuscitation (100%), vasoactive drugs (92.1%), clindamycin (96.8%), intravenous immunoglobulin (IVIG) (92.1%), blood products (74.6%), mechanical ventilation (58.7%), and renal replacement therapy (31.7%). The mortality was 27% (n=17). The duration of PICU and hopsital stay was 5 (4–10) and 7 (4–11) d, respectively. Higher proportion of nonsurvivors had CNS involvement, transaminitis, thrombocytopenia, coagulopathy, and AKI; required mechanical ventilation and blood products; and had higher vasoactive–inotropic score. Conclusion TSS is not uncommon in children in Indian setup. The management includes early recognition, intensive care, antibiotics, source control, and adjunctive therapy (IVIG and clindamycin). Multiorgan dysfunction and need for organ supportive therapies predicted mortality.

Inhibitory Effect of Gallium Nitrate against Staphylococcus aureus and Its Action on the Formation of Biofilms on Titanium Surfaces

Aims: This study aimed to investigate the effect of gallium nitrate [Ga(NO3)3], an inorganic antimicrobial agent, against the growth and biofilm formation of Staphylococcus aureus on the titanium surface. Study Design: This study is a laboratory investigation involving the determination of the inhibitory concentration (IC) of Ga(NO3) 3 against the planktonic strain of S. aureus and biofilm formation on titanium coupons. Place and Duration of Study: Sample: Center of Science and Technology for Sustainability (CCTS), Federal University of São Carlos, SP, Brazil, between March 2020 and March 2022. Methodology: The inhibitory concentration of gallium nitrate was determined in a 96-well microtiter plate in Muller Hinton broth. The potential of the antimicrobial agent to inhibit biofilm formation by S. aureus on titanium surfaces was evaluated by Scanning Electron Microscopy (SEM). The cytotoxicity potential of Ga(NO3)3 was determined on V79 cells. Results: The results showed that the susceptibility of gallium nitrate against S. aureus was 1.40 µM, while SEM images revealed that concentrations of 90 µM inhibited biofilm formation by S. aureus. Conclusion: This research has shown promising results regarding gallium nitrate's potential of inhibiting the growth of both planktonic and sessile S. aureus cells. In addition, coating titanium surfaces with Ga(NO3)3 would be an extra alternative to prevent implant-associated infections due to its non-toxicity to cells.

Repositioning of FDA-approved drugs for the treatment of methicillin-resistant Staphylococcus aureus infection: Structure-based virtual screening and in vitro assay

Background: Computer-aided repositioning of approved drugs is an increasingly popular strategy for the discovery of effective therapies. The potency of the newly repositioned drugs can be optimized using them as a component of an effective drug combination, thereby achieving the desired therapeutic effect at a lower and more tolerable drug concentration. Aim and Objectives: The aim of the study was to perform structure-based virtual screening and repurposing of FDA-approved drugs for the treatment of methicillin resistance by Staphylococcus aureus (SA) and perform an in vitro validation of the prediction. Materials and Methods: Following ethical clearance at the Department of Pharmacology and Therapeutics, College of Health Sciences, Usmanu Danfodiyo University Sokoto, molecular docking was performed against 5 validated protein targets involved in the development of methicillin resistance by SA and an in vitro validation of the prediction was done using 3 of the top-ranking drug candidates against methicillin-resistant vancomycin-susceptible strain of the pathogen (ATCC 43300). Results: Desmopressin and docetaxel, two of the 20 top-ranking repurposed drugs discovered through virtual screening, enhanced the inhibitory effect of oxacillin against the ATCC 43300 SA strain in a ratio-dependent manner, although each of the two drugs singly was only weakly effective against the bacterial strain. The standard drug, vancomycin (also among the top-scoring candidates), alone, was effective against ATCC 43300 strain and in combination with oxacillin, the two drugs produced a ratio-dependent synergistic effect against the bacterial strain. Conclusion: These findings suggest that oxacillin-based combinations with desmopressin, docetaxel, and the standard drug vancomycin, three of the 20 top-ranking drugs, at optimum ratios, may be beneficial in reversing the resistance of the ATCC 43300 SA strain to oxacillin, thus supporting the prediction of the molecular docking results.

Diagnosis, evolution, and treatment of a patient with pyomyositis / Diagnóstico, evolução e tratamento de paciente com piomiosite

Pyomyositis is a deep muscle infection of bacterial origin and subacute, which can evolve with multiple intramuscular abscesses. Despite being characterized as an affection of tropical zones, its incidence in temperate zones has been increasing due to immunosuppression factors, such as infection by the human immunodeficiency virus (HIV) and some types of immunosuppressive treatments. Even though it has been known for over a century, it is a rare and potentially serious condition that can lead to septic shock and death. This is a case report of a descriptive nature, which found the relevance of knowledge about this condition for an early diagnosis, enabling positive prognostic repercussions.

A piomiosite é uma infecção muscular profunda, de origem bacteriana e caráter subagudo, que pode evoluir com abcessos intramusculares múltiplos. Apesar de ser caracterizada como uma afecção de zonas tropicais, sua incidência em zonas temperadas vem aumentando por fatores de imunossupressão, como a infecção pelo vírus da imunodeficiência humana (HIV) e alguns tipos de tratamentos imunossupressivos. Mesmo sendo conhecida há mais de um século, é uma condição rara e potencialmente grave, podendo levar ao choque séptico e óbito. Trata-se de um relato de caso de caráter descritivo, que constatou a relevância do conhecimento desta afecção para um diagnóstico precoce, possibilitando repercussões prognósticas positivas.

Phenotypic and molecular characterization of Staphylococcus aureus isolates conducted in nares of psoriatic patients attending a public hospital in Argentina / Caracterización fenotípica y molecular de aislamientos de Staphylococcus aureus portados en narinas de pacientes con psoriasis que concurren a un hospital público en Argentina

Abstract Although Staphylococcus aureus increases its relative abundance in psoriasis when compared with the microbiome of healthy subjects, it is not the most important microorganism underlying this disease. However, there is scant data on the role and molecular features of S. aureus strains in psoriasis; therefore, the aim of this study was to evaluate nasal carriage of this microorganism, its phenotypic and molecular characteristics as well as the impact of host factors on its carriage in psoriatic patients. The presence of S. aureus was analyzed in nasal swabs from 46 healthy volunteers and 50 psoriatic patients by conventional microbiology techniques. Nasal carriage of S. aureus was higher in psoriatic patients than in the control group (37.24% vs 22.98%, respectively), being associated to sex (male), age (adults) and severity of the disease (more frequent in moderate and severe cases). Determination of antibiotic resistance detected 12% of (-lactam resistant isolates, with variable accompanying resistance to macrolides, aminoglycosides and fluoroquinolones. No resistance to rifampicin, vancomycin, mupirocin or trimethoprim/sulfamethoxazole was found. A preliminary molecular characterization of the isolates was performed by PCR amplification of virulence genes. Molecular characterization of the strains did not reveal a predominant strain in psoriatic patients. Although we established host factors related to increased carriage of S. aureus in psoriatic patients, we could not establish the predominance of one type of strain. Genomic and transcriptomic analysis of the isolated strains would be necessary to address this point.

Resumen A pesar de que Staphylococcus aureus incrementa su abundancia relativa en la psoriasis cuando se compara con el microbioma de personas sanas, no es el microorganismo más importante subyacente a la enfermedad. Sin embargo, existen pocos datos sobre el papel y las características moleculares de las cepas de S. aureus en pacientes con psoriasis. Nuestro objetivo fue evaluar la portación nasal de este microorganismo, sus características fenotípicas y moleculares, y el impacto de factores del hospedador sobre dicha portación en estos pacientes. Se analizó la presencia de S. aureus en hisopados nasales de 46 voluntarios sanos y 50 pacientes con psoriasis mediante técnicas microbiológicas convencionales. Se encontró mayor portación en pacientes con psoriasis que en el grupo control (37,24% vs. 22,98%, respectivamente) y esta estuvo asociada al sexo (masculino), la edad (adultos) y la gravedad de la enfermedad (más frecuente en casos moderados a graves). El 12% de los aislamientos de S. aureus mostraron resistencia a betalactámicos, con resistencia acompañante a macrólidos, aminoglucósidos y fluoroquinolonas en grado variable. No se encontró resistencia a rifampicina, vancomicina, mupirocina o trimetroprima/sulfametoxazol. Se realizó una caracterización molecular preliminar de los aislamientos por amplificación de genes de virulencia mediante PCR. Si bien se identificaron factores relacionados con el hospedador que incrementan la portación nasal de S. aureus en pacientes con psoriasis, la caracterización molecular de las cepas no reveló ninguna característica genotípica predominante asociada a esta afección. Se necesitan más estudios genómicos y transcriptómicos para profundizar en esta caracterización.

Identification and antibiotic susceptibility pattern of Staphylococcus aureus with special reference to methicillin resistant Staphylococcus aureus in tertiary care hospital

Background: The emergence of Methicillin-resistant Staphylococcus aureus (MRSA) has posed a serious therapeutic challenge. It is responsible for a wide range of infections including superficial skin infections, food poisoning, osteomyelitis and septicemia. Aim of this study was to identify and to determine antibiotic susceptibility pattern of Staphylococcus aureus from various clinical samples. Materials and methods: Different clinical specimens were collected and processed for routine culture and antibiotic sensitivity test by standard microbiology techniques. Results: A total of 129 S. aureus strains were isolated from various clinical specimens out of which 84 (65.12%) were Methicillin Resistance Staphylococcus aureus (MRSA). 66(51.16%) S. aureus were obtained from indoor (IPD) patients. S. aureus was found higher in male than female. S. aureus was found highly resistant to Benzylpenicillin (94.57%) followed by ciprofloxacin (77.51%), Erythromycin (61.24%), and Cotrimoxazole (51.94%), Clindamycin (44.19%), and Gentamicin (17.05%). 1 (0.78%) of the isolates were resistance to Vancomycin and Linezolid. For urine isolates Nitrofurantoin was drug of choice. Conclusion: Methicillin resistant Staphylococcus aureus was found 65.12% of Staphylococcus aureus isolates. It was most common in males and hospitalized patients. Teicoplanin or Tigecyline seems to be drug of choice followed by Vancomycin, Linezolid, Tetracycline and Gentamicin. It would be helpful to formulating and monitoring the antibiotic policy and ensure proper empiric treatment.

Piomiositis en pediatría: experiencia de 10 años en un hospital pediátrico de alta complejidad en Argentina

Introducción: La piomiositis es una infección bacteriana agudasubaguda del músculo esquelético. Objetivo: Estimar la incidencia de piomiositis en pacientes internados, describir e identificar factores de riesgo para bacteriemia y hospitalización, y evaluar diferencias entre Staphylococccus aureus sensible y resistente a meticilina (SASM y SARM). Pacientes y Métodos: Estudio descriptivo, retrospectivo, observacional, con pacientes de 1 mes a 18 años de edad, internados entre el 1 de enero de 2008 y 31 de diciembre de 2018. Variables: sexo, edad, hacinamiento en el hogar, existencia de lesión previa, estacionalidad, localización anatómica e imágenes, antibioterapia previa, estadio clínico, parámetros de laboratorio, cultivos y antibiograma, días de tratamiento intravenoso (IV), de internación, de fiebre y bacteriemia. Resultados: Se incluyeron 188 pacientes. Incidencia: 38,9 casos / 10.000 admisiones (IC95 % 33,7 - 44,9). Días de internación y tratamiento IV: 11 (RQ 8-15 y RQ 8-14, respectivamente). El desarrollo de bacteriemia se asoció a PCR elevada (p = 0,03) y fiebre prolongada (p < 0,001). No hubo diferencias en la evolución y parámetros de laboratorio entre SASM y SARM. La leucocitosis (p = 0,004), neutrofilia (p = 0,005) y bacteriemia (p = 0,001) se asociaron a mayor estadía hospitalaria. Conclusiones: Este estudio recaba la experiencia de más de 10 años de niños internados con diagnóstico de piomiositis y proporciona información sobre sus características. Se describen parámetros asociados a bacteriemia y estadía hospitalaria.

Background: Pyomyositis is an acute-subacute bacterial infection of skeletal muscle. Aim: To estimate the incidence of pyomyositis in hospitalized patients, describe and identify risk factors for bacteremia and hospitalization, and evaluate differences between MSSA and MRSA. Methods: Descriptive, retrospective, observational study with patients aged 1 month to 18 years hospitalized between January, 1, 2008 and December 1, 2018. Variables: sex, age, home overcrowding, previous injury, seasonality, anatomical location and images, previous antibiotherapy, clinical stage, laboratory, cultures and antibiogram, days of intravenous (IV) treatment, hospitalization, fever and bacteremia. Results: 188 patients were included. Incidence: 38.9 cases/10,000 admissions (95% CI 33.7 - 44.9). Days of hospitalization and IV treatment: 11 (RQ 8-15 and RQ 8-14, respectively). The development of bacteremia was associated with elevated CRP (p = 0.03) and prolonged fever (p < 0.001). There were no differences in the evolution and laboratory parameters between MSSA and MRSA. Leukocytosis (p = 0.004), neutrophilia (p = 0.005), and bacteremia (p = 0.001) were associated with a longer hospital stay. Conclusions: This study collects the experience of more than 10 years of hospitalized children diagnosed with pyomyositis and provides information on its characteristics. Parameters associated with bacteremia and hospital stay are described.

Factores asociados a la contaminación microbiológica de la carne de pollo comercializada en El Salvador / Factors associated with microbiological contamination of chicken meat marketed in El Salvador

Objetivo. Determinar los factores higiénico-sanitarios asociados a la contaminación microbiológica de la carne de pollo comercializada en los mercados municipales de El Salvador. Materiales y métodos. Se realizó un estudio transversal analítico en los 33 mercados municipales de las cabeceras departamentales de El Salvador. La muestra se calculó a partir de 456 puestos de venta, obteniendo un total de 256 puestos. Por cada puesto se obtuvo una muestra de carne de pollo. El análisis microbiológico se realizó en el Laboratorio Nacional de Salud Pública. Se calcularon frecuencias, porcentajes, medidas de tendencia central y de asociación utilizando SPSS versión 21. Resultados. En el 74% de las muestras se encontró Escherichia coli, en el 24%, Staphylococcus aureus y en el 16%, Salmonela spp. La presencia de Salmonella spp, estuvo asociada con el no uso de desinfectante para las manos y no utilizar toalla para secarse las manos. La presencia de E. coli estuvo asociada al uso de accesorios personales y la inadecuada temperatura de almacenamiento. Mientras que la presencia de S. aureus, estuvo asociada a la falta de lavado de manos, no utilizar toalla para secarse las manos y no utilizar delantal. Conclusión. Las condiciones higiénico-sanitarias de los manipuladores y de los puestos de venta están asociadas a la contaminación microbiológica en la carne de pollo comercializada en El Salvador.

Objective. To determine the hygienic-sanitary factors associated with the microbiological contamination of chicken meat sold at the municipal markets of El Salvador. Materials and methods. An analytical cross-sectional study was conducted in 33 municipal markets of the 14 departmental capitals of El Salvador. The sample consisted of 256 out of 456 possible market stalls. A sample of chicken meat was obtained from each market stall. The microbiological analysis was conducted at the National Public Health Laboratory. Frequencies, percentages, measures of central tendency and association were calculated with SPSS version 21. Results. Escherichia coli was found in 74% of the samples, Staphylococcus aureus in 24% and Salmonella spp. in 1%. The presence of Salmonella spp. was associated with not using hand sanitizer and not using towels for drying the hands. S. aureus was associated with the use of personal accessories and improper storage. The presence of S. aureus was associated with the lack of hand washing, not using a towel to dry the hands and not wearing an apron. Conclusion. The hygienic-sanitary conditions of the handlers and the market stalls were associated with microbiological contamination of chicken meat marketed in El Salvador.

Molecular epidemiology progress of community-associated Methicillin-resistant Staphylococcus aureus infection in children / 中华实用儿科临床杂志

Antimicrobial resistance of Staphylococcus aureus is a main factor for the poor prognosis.In China, the detection rate of Methicillin-resistant Staphylococcus aureus (MRSA) in children is annually increasing, especially the community-acquired MRSA (CA-MRSA). This review discussed molecular characteristics, antimicrobial resistance mechanism and antimicrobial resistance progress of CA-MRSA, and analyzed recent molecular epidemiology and changes of drug resistance to CA-MRSA in children from China, thus providing theoretical basis for the prevention and control of CA-MRSA in children.

Prevalence and Susceptibility of Staphylococcus aureus Nasal Carriage Strains Isolated from Haemodialysis Patients

@#Introduction: Staphylococcus aureus is part of the normal human flora that can commonly be found on the skin and mucous membranes of the nasal area. However, in immunosuppressed patients such as those with kidney failures, colonization can potentially lead to infection. There is a concern of increasing antibiotic resistance in S. aureus. This study aimed to determine the prevalence of S. aureus nasal colonization and its antimicrobial susceptibility among haemodialysis-dependent populations. Methods: A cross-sectional study at the Nephrology Unit, Hospital Canselori Tuanku Mukhriz (HCTM) was conducted among haemodialysis-dependent patients between February 2017 to February 2018. Nasal swabs were obtained and cultured on mannitol salt agar. S. aureus isolates were identified by gram staining, tube coagulase and Deoxyribonuclease (DNase). Cefoxitin disc (30 µg) were used to identified the presence of MRSA (methicillin-resistance S. aureus). The S. aureus colonies were further tested against six antibiotics using Kirby Bauer disc diffusion. Result: A total of 134 patients were recruited. S. aureus isolates were detected from 27 patients (20.1%). All S. aureus were phenotypically identified as methicillin-sensitive S. aureus (MSSA) based on the cefoxitin disc. Teicoplanin and linezolid were the most effective with 100% susceptibility. S. aureus exhibited a high resistance rate towards erythromycin (29.6%). No MRSA was isolated in this study. Conclusion: This study highlighted the high prevalence of S. aureus nasal colonization in haemodialysis patients. Teicoplanin and linezolid were found to be the most effective antibiotics against isolated S. aureus.