ABSTRACT
The use of intensive chemotherapy has improved survival of children with cancer. However, this is associated to severe and maintained neutropenia, increasing risks of severe infections like bacteremia. Aim: To update information on microorganisms involved in bloodstream infections in cancer patients and their antimicrobial resistance patterns during the last 3 years in our hospital, comparing it with our previous experience and with other Chilean centres. Material and Methods: Analysis of positive blood cultures belonging to cancer patients during 2006-2008 registered in the Microbiology Lab at the Roberto Del Rio Children's Hospital. Results: In 52 patients, 96 blood cultures yielded bacteria: 59.4% gram positive cocci and 34.4%, gram negative rods. Coagulase negative Staphylococci (CNS) were the most frequent bacteria isolated and enterobacteria were in the second place. Susceptibility to cloxacillin was 11% in CNS and 70 % in Staphylococcus aureus isolates. Enterobacteria maintained susceptibility to third generation cephalosporins and aminoglycosides. Conclusion: Despite the low sensitivity of CNS to cloxacillin, the empirical antibiotic treatment in our unit must include cloxacillin because of the high susceptibility of S. aureus. Switching to vancomycin should be considered only if SCN is isolated or there is an unfavorable evolution.
El uso de quimioterapia más intensiva ha mejorado la sobrevida de los niños con cáncer. Sin embargo, esto se asocia a neutropenia intensa y mantenida, aumentando el riesgo de infecciones graves como bacteriemias. Objetivo: Actualizar la información sobre los microorganismos implicados en las infecciones del torrente circulatorio en pacientes oncológicos atendidos en nuestro hospital, comparar con la literatura médica y describir el patrón de resistencia antimicrobiana. Material y Métodos: Se revisaron los registros de hemocultivos del Laboratorio de Microbiología del Hospital de Niños Roberto Del Río entre los años 2006 y 2008, seleccionando aquellos con resultado positivo y que pertenecieran a pacientes con cáncer. Resultados: En 52 pacientes, 96 hemocultivos resultaron positivos: cocáceas grampositivas 59,4% (Staphylococcus coagulasa negativa-SCN fue el más frecuente); bacilos gramnegativos 34,4%, predominando las enterobacterias, en segundo lugar. Se observó en SCN una susceptibilidad a cloxacilina de 11% y en Staphylo-coccus aureus de 70%. Las enterobacterias mantuvieron una susceptibilidad estable para cefalosporinas de tercera generación y aminoglucósidos. Conclusión: A pesar de la baja susceptibilidad de SCN a cloxacilina, el tratamiento antimicrobiano empírico de primera línea en nuestra unidad debe incluir cloxacilina dada la alta susceptibilidad de S. aureus, y el cambio a vancomicina debería plantearse frente al aislamiento de SCN o evolución desfavorable.
Subject(s)
Adolescent , Child , Child, Preschool , Female , Humans , Infant , Male , Bacteremia/microbiology , Fever/microbiology , Gram-Negative Bacteria/classification , Gram-Positive Bacteria/classification , Neoplasms/microbiology , Neutropenia/microbiology , Anti-Bacterial Agents/pharmacology , Chile , Gram-Negative Bacteria/drug effects , Gram-Negative Bacteria/isolation & purification , Gram-Positive Bacteria/drug effects , Gram-Positive Bacteria/isolation & purification , Microbial Sensitivity TestsABSTRACT
We analyzed the in vitro effects of the anti-tumoral drugs doxorubicin, cytosine arabinoside and hydroxyurea on the G2-prophase checkpoint in lymphocytes from healthy individuals. At biologically equivalent concentrations, the induced DNA damage activated the corresponding checkpoint. Thus: i) there was a concentration-dependent delay of G2 time and an increase of both the total DNA lesions produced and repaired before metaphase and; ii) G2-checkpoint adaptation took place as chromosome aberrations (CAs) started to appear in the metaphase, indicating the presence of unrepaired double-strand breaks (DSBs) in the previous G2. The checkpoint ATM/ATR kinases are involved in DSB repair, since the recorded frequency of CAs increased when both kinases were caffeine-abrogated. In genotoxic-treated cells about three-fold higher repair activity was observed in relation to the endogenous background level of DNA lesions. The maximum rate of DNA repaired was 3.4 CAs/100 metaphases/hour, this rise being accompanied by a modest 1.3 fold lengthening of late G2 prophase timing. Because of mitotic chromosome condensation, no DSBs repair can take place until the G1 phase of the next cell cycle, when it occurs by DNA non-homologous end joining (NHEJ). Chromosomal rearrangements formed as a consequence of these error-prone DSB repairs ensure the development of genome instability through the DNA-fusion-bridge cycle. Hence, adaptation of the G2 checkpoint supports the appearance of secondary neoplasia in patients pretreated with genotoxic drugs.
Subject(s)
Adult , Female , Humans , Male , Young Adult , Antibiotics, Antineoplastic/toxicity , Chromosome Aberrations/chemically induced , /drug effects , Lymphocytes/drug effects , Prophase/drug effects , Cytarabine/toxicity , DNA Damage/drug effects , Doxorubicin/toxicity , /genetics , Hydroxyurea/toxicity , Lymphocytes/cytologyABSTRACT
A pesar del desarrollo alcanzado por la pediatría, hay un grupo de pacientes, con diferentes patologías, que van a fallecer durante la evolución de su enfermedad. La implementación de unidades de cuidado paliativo en pediatría, es una necesidad, sobre todo en hospitales de gran complejidad como el nuestro, para ofrecer una atención de calidad a los niños y sus familias cuando no hay posibilidad de mejoría.