Genomic diversity of prevalent Staphylococcus epidermidis multidrug-resistant strains isolated from a Children's Hospital in México City in an eight-years survey.

Staphylococcus epidermidis is a human commensal and pathogen worldwide distributed. In this work, we surveyed for multi-resistant S. epidermidis strains in eight years at a children's health-care unit in México City. Multidrug-resistant S. epidermidis were present in all years of the study, including resistance to methicillin, beta-lactams, fluoroquinolones, and macrolides. To understand the genetic basis of antibiotic resistance and its association with virulence and gene exchange, we sequenced the genomes of 17 S. epidermidis isolates. Whole-genome nucleotide identities between all the pairs of S. epidermidis strains were about 97% to 99%. We inferred a clonal structure and eight Multilocus Sequence Types (MLSTs) in the S. epidermidis sequenced collection. The profile of virulence includes genes involved in biofilm formation and phenol-soluble modulins (PSMs). Half of the S. epidermidis analyzed lacked the ica operon for biofilm formation. Likely, they are commensal S. epidermidis strains but multi-antibiotic resistant. Uneven distribution of insertion sequences, phages, and CRISPR-Cas immunity phage systems suggest frequent horizontal gene transfer. Rates of recombination between S. epidermidis strains were more prevalent than the mutation rate and affected the whole genome. Therefore, the multidrug resistance, independently of the pathogenic traits, might explain the persistence of specific highly adapted S. epidermidis clonal lineages in nosocomial settings.

Response of IFN-gamma and IgG to ESAT-6 and 38 kDa recombinant proteins and their peptides from Mycobacterium tuberculosis in tuberculosis patients and asymptomatic household contacts may indicate possible early-stage infection in the latter.

BACKGROUND: The ESAT-6 antigen from Mycobacterium tuberculosis evokes a protective immune response in murine models and is widely recognized by tuberculosis patients (TB) and healthy household contacts (HHC). However, little is known about human immune response to this antigen in populations from areas of high endemicity. This study aimed to determine the capacity of T-cells from a group of TB patients and HHC for cell proliferation and production of cytokines type Th1 or Th2 (IL-4, IL-10, and IFN-gamma) and to identify total IgG reactivity to the recombinant protein rESAT-6 and five overlapping synthetic peptides as well as to r38 kDa and two peptides. METHODS: T-cells from nine TB patients and nine HHC were stimulated with rESAT-6 and five overlapping synthetic peptides, previously selected from a set of 21 peptides and each of 16 amino acids in length (P1, P4, P6, P8, and P20). Similar experiments were carried out with r38 kDa and two peptides of 20 amino acids in length (38G and 38K). Cytokines in supernatants and total IgG from serum were determined by ELISA. RESULTS: Stimulation index (SI) was highest in HHC to rESAT-6 and peptides P1, P8, and P20. Differences in response to 38 kDa and 38G peptide between TB patients and HHC were not demonstrated. Cytokines from T-cell cultures were tested with a resulting SI=3.0. IFN-gamma was produced predominantly in HHC to rESAT-6, P8, and P20, while in TB patients production of IL-10 was detected in relation to r38 kDa. IL-4 was detected in minimal amounts in both groups. IgG from TB patients was predominantly recognized in connection with rESAT-6 and the P4 peptide, with an important response against r38 kDa detected in HHC. CONCLUSIONS: ESAT-6 recognition by HHC could indicate that these responses represent possible early-stage infections.

Antibiotic Resistance and Biofilm Production in Staphylococcus epidermidis Strains, Isolated from a Tertiary Care Hospital in Mexico City.

Staphylococcus epidermidis strains isolated from nosocomial infections represent a serious problem worldwide. In various Mexican states several reports have shown isolates from hospitals with antibiotic resistance to methicillin. In Mexico City, there is scarce information on staphylococcal infections in hospitals. Here, our research findings are shown in a four-year period study (2006-2010) for Staphylococcus epidermidis strains. Susceptibility and/or resistance to antibiotics in SE strains were assessed by phenotypic and molecular methods as mecA gene by PCR, as well as the correlation with biofilm production for these isolates and the relationship to the infection site. Out of a total of 161 (66%) negative biofilm SE strains, just 103 (64%) SE strains were confirmed as MRSE by PCR to mecA gene. From 84 (34%) positive biofilm SE strains, 76 (91%) were confirmed as MRSE by PCR to mecA gene. Higher percentages of resistance to antibiotics and higher number of resistance markers were found in biofilm-forming clinical strains (9 to 14) than non-biofilm-forming SE strains (3 to 8). These research findings represent a guide to establish infection control programs for this hospital.

Los escenarios de riesgo biológico y la protección del personal médico participante en el brote por el virus del Ébola 2014 / Biological risk and protection of the medical staff participant in the outbreak of the Ebola virus 2014

Resumen: El virus del Ébola es el agente causal de una de las enfermedades infecciosas más temidas por el humano: la fiebre hemorrágica del Ébola o enfermedad por el virus del Ébola (EVE). Este filovirus puede llegar a causar hasta un 90% de mortalidad. Tiene su origen en África con brotes epidémicos registrados desde 1976. El más reciente se presentó durante el primer trimestre de 2014 en 3 países de África Occidental, Liberia, Sierra Leona y Nigeria. Es considerado el brote más grave y el que se ha mantenido por más tiempo. En 2014, la Organización Mundial de la Salud consideró el brote como una emergencia de salud pública de importancia internacional. Un aspecto preocupante ha sido la mortalidad generada en el personal médico de los países afectados y personal infectado de las brigadas internacionales que participaron en esta contención. Una de las causas que originaron esta mortalidad fue probablemente el uso inadecuado del Equipo de Protección Personal (EPP). En este artículo se muestran al lector los componentes del EPP con algunos detalles técnicos para su uso como fue requerido al personal médico calificado participante en la contención de la EVE en África. En México es muy baja la probabilidad de la aparición del virus del Ébola. Actualmente se presenta mayor riesgo en el país ante brotes como el virus de chikungunya. El objetivo de esta publicación es presentar el uso apropiado del EPP para el personal médico en alto riesgo de contagio al participar en la contención de brotes causados por agentes infecciosos.

Abstract: The Ebola virus is the causative agent of the most feared human infectious disease, the Ebola virus disease (EVD) or Ebola hemorrhagic fever. This filovirus may reach up to 90% in mortality. The virus was originated in Africa and the outbreaks have been recorded since 1976. The most recent occurred in 2014 in three countries of Western Africa, Liberia, Sierra Leone and Nigeria. Was the outbreak with a highest mortality and long time. The World Health Organization in 2014 mentioned this outbreak as public health emergency of international concern. One point of interest was mortality in medical staff of African countries and the infection in members of international brigades who participated in this containment. The reason that caused this mortality was probably the inappropriate use of Personal Protective Equipment (PPE). In Mexico the risk of an EVD outbreak is very low however a high risk exists in the spread of virus chikungunya. The purpose of this article is showing the components of this equipment with some technical details to the reader. This is an example of the use of personal protective equipment by qualified personnel in outbreaks and necessary in the containment of other outbreaks due to infectious agents.

El trabajador de la salud y el riesgo de enfermedades infecciosas adquiridas. Las precauciones estándar y de bioseguridad / Healthcare providers and the risk of acquired infectious diseases. Standard and biosafety precautions

Resumen El trabajador de la salud (médicos, enfermeras, paramédicos, laboratoristas clínicos, etc.), por su actividad diaria está en riesgo de adquirir accidentalmente una enfermedad infecciosa. El contacto con pacientes, fluidos biológicos y el cultivo o aislamiento de microorganismos infecciosos durante el trabajo de laboratorio son factores que aumentan ese riesgo, y para disminuirlo se requiere de la aplicación de medidas preventivas o precauciones estándar de bioseguridad para cada una de sus actividades, por lo tanto, debe contar con el entrenamiento necesario. El uso de guantes, cubrebocas, mascarillas, bata, así como la disposición adecuada de los residuos peligrosos biológico-infecciosos (RPBI) resultan primordiales en el trabajo diario. Aunado esto, el lavado de manos, el cambio frecuente de la bata u otra vestimenta hospitalaria son de gran importancia para evitar las infecciones nosocomiales. Es importante considerar, que la carga de trabajo y el estrés ocupacional son factores adicionales que aumentan las probabilidades de incurrir en errores o accidentes laborales que provoquen infecciones en el personal de salud. Nuestro objetivo es presentar los factores de riesgo a los que se expone el trabajador de la salud durante sus actividades diarias y contribuir a la difusión y divulgación de la correcta aplicación de las precauciones universales de bioseguridad para disminuir el riesgo de adquirir una enfermedad infecciosa.

Abstract Healthcare providers (doctors, nurses, paramedics, laboratory technicians, surgeons, etc.) are at risk of accidentally acquiring an infectious disease as a consequence of their everyday activities. Preventive measures or standard biosafety precautions for each one of the activities to perform are required; therefore, health providers must know and have the appropriate training to prevent these infections. For instance, the use of gloves, surgical masks, masks, laboratory coat, as well as the correct disposal of trained to Contact with patients, biological fluids and the culture or isolation of infectious microorganisms during laboratory work are factors increasing that risk. To reduce the risk of acquiring an infectious disease, it requires the application of preventive measures or appropriate biosecurity standard precautions for each of the activities to be performed, so the health worker must know and have the necessary training to prevent these infections in this sense the use of gloves, masks, gown, and the correct management of the Biological-infectious Hazardous Waste (BIHW) are of primary importance in daily work. In addition, hand-washing, frequent change of the coat or any other hospital clothes is very important to prevent hospital-acquired infections. Finally, it is important to consider that the workload and occupational stress are additional factors that increase the chances of work mistakes or accidents causing healthcare personnel acquire infections. The aim of this paper is to present a profile of risk factors to which the health worker is exposed during his/her daily activities and contribute to the dissemination and disclosure of the correct application of the universal biosafety precautions in order to decrease the risk of acquiring an infectious disease.