Abstract Background Rituximab is a monoclonal antibody that increases the disease-free and overall survival of patients with non-Hodgkin lymphoma (NHL) CD20+. The objective of this study is to describe the prevalence and spectrum of infections in patients with NHL receiving rituximab-containing chemotherapy and the impact on survival. Materials and Methods From January 2011 to December 2012, all patients diagnosed with NHL who received at least one dose of rituximab were included. Results During the study period, 265 patients received rituximab; 108 (40.8%) males; the mean age was 60 ± 15 years. There were 177 infections in 85 patients, being the most common febrile neutropenia (n = 38; 21.5%) and mucosal barrier injury-related infections (n = 28; 15.8%). In 88 events (49%), there was a microbiologic diagnosis, being bacterial infection the most frequent (39.6%), but tuberculosis (TB) was developed in 4 cases (1.5%; incidence rate 721/100,000 person-year). During follow-up, 71 patients died (27%); in 35 cases, it was related to infection. There were no differences in follow-up between those who died due to infection versus those who died from another cause (p = 0.188). Multivariate analysis for mortality showed that age >60 years, failure to achieve a complete response, and development of an infectious complication increased the risk of death. Conclusions It is important to perform a screening test for TB in all patients who will receive rituximab and maintain a constant monitoring to detect an infectious process and begin treatment as soon as possible.

ABSTRACT This study assessed the microbiology, clinical syndromes, and outcomes of oncologic patients with viridans group streptococci isolated from blood cultures between January 1st, 2013 and December 31st, 2016 in a referral hospital in Mexico using the Bruker MALDI Biotyper. Antimicrobial sensitivity was determined using BD Phoenix 100 according to CLSI M100 standards. Clinical information was obtained from medical records and descriptive analysis was performed.Forty-three patients were included, 22 females and 21 males, aged 42 ± 17 years. Twenty (46.5%) patients had hematological cancer and 23 (53.5%) a solid malignancy. The viridans group streptococci isolated were Streptococcus mitis, 20 (46.5%); Streptococcus anginosus, 14 (32.6%); Streptococcus sanguinis, 7 (16.3%); and Streptococcus salivarius, 2 (4.7%). The main risk factors were pyrimidine antagonist chemotherapy in 22 (51.2%) and neutropenia in 19 (44.2%) cases, respectively. Central line associated bloodstream infection was diagnosed in 18 (41.9%) cases. Septic shock occurred in 20.9% of patients, with an overall mortality of 18.6%. Only four S. mitis revealed penicillin-resistance.Our results are similar to those of other series, identifying these bacteria as emerging pathogens with significant morbidity and mortality in oncologic patients. The MALDI-TOF system increased the rate of viridans group streptococci isolation in this population.

Abstract: Objective: To describe the trend of multidrug resistant (MDR) strains isolated from blood in patients with cancer from 2005 to 2015. Materials and methods: 33 127 blood cultures were processed by retrospective analysis. Identification and antimicrobial sensitivity were performed through automated methods: WaLK away (Siemens Laboratory Diagnostics) and BD Phoenix (Becton, Dickinson and Company). Resistant strains were determined according to the minimum inhibitory concentration, following the parameters of the Clinical and Laboratory Standards Institute (CLSI). Results: Of 6 397 isolates, 5 604 (16.9%) were positive; 3 732 (58.4%) Gram- bacilli; 2 355 (36.9%) Gram+ cocci; 179 (2.7%) yeasts, and 126 (1.9%) Gram+ bacilli. Escherichia coli (n=1 591, 24.5%) was the most frequent bacteria, with 652 (41%) strains being extended-spectrum beta-lactamases producers (ESBL); of Enterococcus faecium (n=143, 2.1%), 45 (31.5%) were vancomycin resistant; of Staphylococcus aureus (n=571, 8.7%), 121 (21.2%) methicillin resistant (MRSA); of Klebsiella pneumoniae (n=367, 5.6%), 41 (11.2%) ESBL; of Acinetobacter baumanii (n=96, 1.4%), 23 (24%) MDR, and of Pseudomonas aeruginosa (n=384, 5.6%), 43 (11.2%) MDR. MDR strains were significantly more frequent in patients with hematological malignancies, compared to those with solid tumors: MRSA (OR=4.48, 95%CI 2.9-6.8), ESBL E. coli (OR=1.3, 95%CI 1.10-1.65) and MDR Acinetobacter baumanii (OR=3.2, 95%CI 1.2-8.3). Conclusions: We observed significantly higher isolations of E-ESPAKE MDR strains in patients with hematological malignancies.

Resumen: Objetivo: Describir la tendencia de cepas multidrogorresistentes (MDR) aisladas en hemocultivos de pacientes con cáncer durante el periodo de 2005 a 2015. Material y métodos: Análisis retrospectivo en el que se procesaron 33 127 hemocultivos. La identificación y la sensibilidad antimicrobianas se realizaron a través de métodos automatizados WaLK away (Siemens Laboratory Diagnostics) y BD Phoenix (Becton, Dickinson and Company). Se determinaron cepas resistentes de acuerdo con la concentración mínima inhibitoria, según los parámetros del Clinical and Laboratory Standards Institute (CLSI). Resultados: 5604 (16.9%) aislamientos fueron positivos, con 6397 aislamientos, 3732 (58.4%) bacilos gramnegativos, 2355 (36.9%) cocos grampositivos, 179 (2.7%) levaduras y 126 (1.9%) bacilos grampositivos. Escherichia coli (n=1 591, 24.5%) fue la bacteria más frecuente, 652 (41%) productoras de beta-lactamasas de espectro-extendido (BLEE); Enterococcus faecium 143 (2.1%), 45 (31.5%) resistente a vancomicina; Staphylococcus aureus 571 (8.7%), 121 (21.2%) resistentes a meticilina (SARM); Klebsiella pneumoniae 367 (5.6%), 41 (11.2%) BLEE, Acinetobacter baumannii 96 (1.4%), 23 (24%) MDR; Pseudomonas aeruginosa 384 (5.6%), 43 (11.2%) MDR. Las cepas MDR se aislaron más frecuentemente en pacientes con neoplasias hematológicas en comparación con tumores sólidos; SARM (RM=4.48, IC95% 2.9-6.8); E. coli BLEE (RM=1.3, IC95% 1.10-1.65) y A. baumannii-MDR (RM=3.2, IC95% 1.2-8.3). Conclusiones. Se observó un aislamiento significativamente mayor de cepas E-ESKAPE MDR en pacientes con neoplasias hematológicas.

Abstract: Objective: To describe the trend of multidrug resistant (MDR) strains isolated from blood in patients with cancer from 2005 to 2015. Materials and methods: 33 127 blood cultures were processed by retrospective analysis. Identification and antimicrobial sensitivity were performed through automated methods: WaLK away (Siemens Laboratory Diagnostics) and BD Phoenix (Becton, Dickinson and Company). Resistant strains were determined according to the minimum inhibitory concentration, following the parameters of the Clinical and Laboratory Standards Institute (CLSI). Results: Of 6 397 isolates, 5 604 (16.9%) were positive; 3 732 (58.4%) Gram- bacilli; 2 355 (36.9%) Gram+ cocci; 179 (2.7%) yeasts, and 126 (1.9%) Gram+ bacilli. Escherichia coli (n=1 591, 24.5%) was the most frequent bacteria, with 652 (41%) strains being extended-spectrum beta-lactamases producers (ESBL); of Enterococcus faecium (n=143, 2.1%), 45 (31.5%) were vancomycin resistant; of Staphylococcus aureus (n=571, 8.7%), 121 (21.2%) methicillin resistant (MRSA); of Klebsiella pneumoniae (n=367, 5.6%), 41 (11.2%) ESBL; of Acinetobacter baumanii (n=96, 1.4%), 23 (24%) MDR, and of Pseudomonas aeruginosa (n=384, 5.6%), 43 (11.2%) MDR. MDR strains were significantly more frequent in patients with hematological malignancies, compared to those with solid tumors: MRSA (OR=4.48, 95%CI 2.9-6.8), ESBL E. coli (OR=1.3, 95%CI 1.10-1.65) and MDR Acinetobacter baumanii (OR=3.2, 95%CI 1.2-8.3). Conclusions: We observed significantly higher isolations of E-ESPAKE MDR strains in patients with hematological malignancies.

Resumen: Objetivo: Describir la tendencia de cepas multidrogorresistentes (MDR) aisladas en hemocultivos de pacientes con cáncer durante el periodo de 2005 a 2015. Material y métodos: Análisis retrospectivo en el que se procesaron 33 127 hemocultivos. La identificación y la sensibilidad antimicrobianas se realizaron a través de métodos automatizados WaLK away (Siemens Laboratory Diagnostics) y BD Phoenix (Becton, Dickinson and Company). Se determinaron cepas resistentes de acuerdo con la concentración mínima inhibitoria, según los parámetros del Clinical and Laboratory Standards Institute (CLSI). Resultados: 5604 (16.9%) aislamientos fueron positivos, con 6397 aislamientos, 3732 (58.4%) bacilos gramnegativos, 2355 (36.9%) cocos grampositivos, 179 (2.7%) levaduras y 126 (1.9%) bacilos grampositivos. Escherichia coli (n=1 591, 24.5%) fue la bacteria más frecuente, 652 (41%) productoras de beta-lactamasas de espectro-extendido (BLEE); Enterococcus faecium 143 (2.1%), 45 (31.5%) resistente a vancomicina; Staphylococcus aureus 571 (8.7%), 121 (21.2%) resistentes a meticilina (SARM); Klebsiella pneumoniae 367 (5.6%), 41 (11.2%) BLEE, Acinetobacter baumannii 96 (1.4%), 23 (24%) MDR; Pseudomonas aeruginosa 384 (5.6%), 43 (11.2%) MDR. Las cepas MDR se aislaron más frecuentemente en pacientes con neoplasias hematológicas en comparación con tumores sólidos; SARM (RM=4.48, IC95% 2.9-6.8); E. coli BLEE (RM=1.3, IC95% 1.10-1.65) y A. baumannii-MDR (RM=3.2, IC95% 1.2-8.3). Conclusiones. Se observó un aislamiento significativamente mayor de cepas E-ESKAPE MDR en pacientes con neoplasias hematológicas.

Abstract: Objective: To describe the distribution of pneumococcal serotypes causing infectious diseases in patients with hematological malignancies and solid tumors and their antimicrobial susceptibility before and after introduction of pneumococcal conjugate vaccine (PCV7) in Mexico. Materials and methods: Consecutive pneumococcal isolates from hospitalized patients from the SIREVA-network were serotyped using the Quellung reaction and antimicrobial susceptibility was performed using the broth microdilution method. Results: A total of 175 pneumococcal isolates were recovered, 105 from patients with hematological malignancies and 70 with solid tumors. Serotypes 19A (22.7%), 19F (20.4%), and 35B (17.7%) were the most frequent isolates in the first group and serotypes 3 (27.2%) and 19A (28.6%) in the second group. No decreased susceptibility to beta-lactams or TMP/SMX was observed after introduction of PCV7. Conclusions: An increase in non-vaccine types is observed without significate changes in antimicrobial susceptibility after introduction of PCV7.

Resumen: Objetivo: Describir la distribución de serotipos neumocócicos en pacientes con neoplasias hematológicas y tumores sólidos, así como la susceptibilidad antimicrobiana antes y después de la introducción de la vacuna conjugada contra neumococo (PCV7) en México. Material y métodos: Se tipificaron, mediante la reacción de Quellung, los aislamientos consecutivos en hospitales de la Red SIREVA-México. Se determinó la susceptibilidad antimicrobiana mediante microdilución en placa. Resultados: Se recuperaron 175 aislamientos, de los cuales 105 provenían de pacientes con neoplasias hematológicas y 70 con tumores sólidos. Los serotipos 19A (22.7%), 19F (20.4%) y 35B (17.7%) fueron los más frecuentes en el primer grupo y los serotipos 3 (27.2%) y 19A (28.6%) en el segundo. No se observó disminución de la resistencia a betalactámicos o TMP/SMX después de la introducción de PCV7. Conclusiones: Se observa un incremento de serotipos no vacunales, sin cambios significativos en la susceptibilidad antimicrobiana antes y después de la introducción de PCV7.

Abstract: Objective: To describe the distribution of pneumococcal serotypes causing infectious diseases in patients with hematological malignancies and solid tumors and their antimicrobial susceptibility before and after introduction of pneumococcal conjugate vaccine (PCV7) in Mexico. Materials and methods: Consecutive pneumococcal isolates from hospitalized patients from the SIREVA-network were serotyped using the Quellung reaction and antimicrobial susceptibility was performed using the broth microdilution method. Results: A total of 175 pneumococcal isolates were recovered, 105 from patients with hematological malignancies and 70 with solid tumors. Serotypes 19A (22.7%), 19F (20.4%), and 35B (17.7%) were the most frequent isolates in the first group and serotypes 3 (27.2%) and 19A (28.6%) in the second group. No decreased susceptibility to beta-lactams or TMP/SMX was observed after introduction of PCV7. Conclusions: An increase in non-vaccine types is observed without significate changes in antimicrobial susceptibility after introduction of PCV7.

Resumen: Objetivo: Describir la distribución de serotipos neumocócicos en pacientes con neoplasias hematológicas y tumores sólidos, así como la susceptibilidad antimicrobiana antes y después de la introducción de la vacuna conjugada contra neumococo (PCV7) en México. Material y métodos: Se tipificaron, mediante la reacción de Quellung, los aislamientos consecutivos en hospitales de la Red SIREVA-México. Se determinó la susceptibilidad antimicrobiana mediante microdilución en placa. Resultados: Se recuperaron 175 aislamientos, de los cuales 105 provenían de pacientes con neoplasias hematológicas y 70 con tumores sólidos. Los serotipos 19A (22.7%), 19F (20.4%) y 35B (17.7%) fueron los más frecuentes en el primer grupo y los serotipos 3 (27.2%) y 19A (28.6%) en el segundo. No se observó disminución de la resistencia a betalactámicos o TMP/SMX después de la introducción de PCV7. Conclusiones: Se observa un incremento de serotipos no vacunales, sin cambios significativos en la susceptibilidad antimicrobiana antes y después de la introducción de PCV7.

Abstract: Objective: To describe the incidence and patterns of bacterial resistance in urine samples from a tertiary care oncology hospital in Mexico, from 2004 to 2013. Materials and methods: We included the strains obtained from urine cultures, describing separately multidrug-resistant (MDR) bacteria. We analyzed the susceptibility to different antibiotics. Results: 51 202 urine cultures were processed during the study; 14 480 (28.3%) cultures were positive. In 11 427 samples Gram negative (79%) were isolated, 2 080 Gram positive (14.4%), and 973 yeasts (6.6%). Escherichia coli was the most frequent bacteria identified (56.1%); 24% of the community strains and 65.7% of the nosocomial were extended-spectrum beta-lactamase producers (ESBL). Klebsiella pneumoniae was isolated in 705 samples (4.8%); 115 were ESBL (16%), 13.1% from community and 29.8% from nosocomial source. Pseudomonas aeruginosa was identified in 593 cultures (4.1%): 9% from community and 51% nosocomial. Conclusions: MDR bacteria were more frequent in nosocomial isolates. It should be a priority to intensify the rational use of antimicrobials in the community and antibiotic stewardship in the hospital.

Resumen: Objetivo: Describir los patrones de resistencia bacteriana en cultivos de orina de pacientes de un hospital oncológico en la Ciudad de México, de 2004 a 2013. Material y métodos: Se obtuvo el porcentaje de susceptibilidad para diferentes antibióticos, describiendo por separado las bacterias multidrogorresistentes (MDR). Se analizaron por separado las cepas obtenidas de pacientes hospitalizados de las de la comunidad. Resultados: Se realizaron 51 202 cultivos, de los cuales se identificaron 14 480 bacterias (28.3%). De éstas, se reportaron 11 427 Gram negativos (78.9%); 2 080 Gram positivos (14.4%); y 973 (6.6%) levaduras. Escherichia coli fue el principal microorganismo aislado (56.1%); 24% de las cepas de la comunidad y 66% de las nosocomiales fueron productoras de beta-lactamasas de espectro extendido (BLEE). Klebsiella pneumoniae se identificó en 705 cultivos (4.8%), 115 de los cuales fueron BLEE (16%): 13.1% de la comunidad y 29.8% nosocomiales. Pseudomonas aeruginosa se identificó en 593 cultivos (4.1%): 9% de la comunidad y 51% nosocomiales. Conclusiones: Las cepas MDR son mucho más frecuentes en muestras de origen nosocomial. Es prioritario intensificar el uso racional de antibióticos en la comunidad y el programa de desescalamiento de antimicrobianos en el hospital.

Abstract: Objective: To describe the incidence and patterns of bacterial resistance in urine samples from a tertiary care oncology hospital in Mexico, from 2004 to 2013. Materials and methods: We included the strains obtained from urine cultures, describing separately multidrug-resistant (MDR) bacteria. We analyzed the susceptibility to different antibiotics. Results: 51 202 urine cultures were processed during the study; 14 480 (28.3%) cultures were positive. In 11 427 samples Gram negative (79%) were isolated, 2 080 Gram positive (14.4%), and 973 yeasts (6.6%). Escherichia coli was the most frequent bacteria identified (56.1%); 24% of the community strains and 65.7% of the nosocomial were extended-spectrum beta-lactamase producers (ESBL). Klebsiella pneumoniae was isolated in 705 samples (4.8%); 115 were ESBL (16%), 13.1% from community and 29.8% from nosocomial source. Pseudomonas aeruginosa was identified in 593 cultures (4.1%): 9% from community and 51% nosocomial. Conclusions: MDR bacteria were more frequent in nosocomial isolates. It should be a priority to intensify the rational use of antimicrobials in the community and antibiotic stewardship in the hospital.

Resumen: Objetivo: Describir los patrones de resistencia bacteriana en cultivos de orina de pacientes de un hospital oncológico en la Ciudad de México, de 2004 a 2013. Material y métodos: Se obtuvo el porcentaje de susceptibilidad para diferentes antibióticos, describiendo por separado las bacterias multidrogorresistentes (MDR). Se analizaron por separado las cepas obtenidas de pacientes hospitalizados de las de la comunidad. Resultados: Se realizaron 51 202 cultivos, de los cuales se identificaron 14 480 bacterias (28.3%). De éstas, se reportaron 11 427 Gram negativos (78.9%); 2 080 Gram positivos (14.4%); y 973 (6.6%) levaduras. Escherichia coli fue el principal microorganismo aislado (56.1%); 24% de las cepas de la comunidad y 66% de las nosocomiales fueron productoras de beta-lactamasas de espectro extendido (BLEE). Klebsiella pneumoniae se identificó en 705 cultivos (4.8%), 115 de los cuales fueron BLEE (16%): 13.1% de la comunidad y 29.8% nosocomiales. Pseudomonas aeruginosa se identificó en 593 cultivos (4.1%): 9% de la comunidad y 51% nosocomiales. Conclusiones: Las cepas MDR son mucho más frecuentes en muestras de origen nosocomial. Es prioritario intensificar el uso racional de antibióticos en la comunidad y el programa de desescalamiento de antimicrobianos en el hospital.

Plasmablastic lymphoma (PL) is an uncommon B-cell lymphoma that is strongly associated with human immunodeficiency virus (HIV) infection, and displays distinctive affinity for extranodal presentation in the oral cavity. We report the case of a PL involving the stomach in a 36 year-old man HIV+ patient, associated with Kaposi sarcoma (KS) in sections adjacent to lymphoma. He had a positive history of Castleman disease and KS in a lymphoid node biopsy.

El linfoma plasmablástico (LP) es un linfoma de células B poco común que está fuertemente asociado con la infección por el virus de inmunodeficiencia humana (VIH), y muestra una afinidad característica de presentación extra-ganglionar en la cavidad oral. Informamos el caso de un LP afectando el estómago en un paciente masculino de 36 años de edad con infección por VIH, asociado con sarcoma de Kaposi (SK) en áreas adyacentes al linfoma. Tenía el antecedente de enfermedad de Castleman y SK en una biopsia de ganglio linfático.

OBJECTIVE: To describe the patterns of antimicrobial resistance of organisms isolated from urine cultures at a teaching oncological hospital for adult patients. MATERIAL AND METHODS: All strains obtained from urine cultures from 1998 to 2005 were included. Mean susceptibilities were obtained for each antimicrobial tested; nosocomial and community-acquired isolates were analyzed separately. RESULTS: A total of 9 232 positive urine cultures were obtained (20.7%) from 44 447 samples taken. Gram negative bacteria were reported in 78.8%, Gram-positive in 13.8% and yeasts in 7.4%. Escherichia coli was the most frequently isolated bacterium (41.3%); antimicrobial resistance was higher in nosocomial isolates than in community strains (amikacin 92.4 vs. 97%, ceftazidime 83.1 vs. 95.1% and ciprofloxacin 46.2 vs. 58.6%). Pseudomonas aeruginosa showed a greater resistance to amikacin and ceftazidime in nosocomial cultures compared to community-acquired bacterial cultures (55.7 vs. 66.6% and 65.5 vs. 84.8% respectively). Vancomycin-resistant enterococci were found in only 2.5% (3 of 119 E. faecium isolates). CONCLUSIONS: Higher bacterial resistance was observed in nosocomial cultures than in community ones. Antimicrobial resistance was found to be progressively increasing for E. coli, the most frequent pathogen isolated both in nosocomial and community infections. We consider imperative the establishment of an intense educational campaign for the use and control of antibiotics.

OBJETIVOS: Describir los patrones de resistencia bacteriana en cultivos de orina en un hospital oncológico. MATERIAL Y MÉTODOS: Se incluyeron las cepas obtenidas de cultivos de orina de 1998 a 2005. Se obtuvo el porcentaje de sensibilidad para diferentes antibióticos, tras analizar por separado cepas nosocomiales y compararlas con las de la comunidad. RESULTADOS: Se detectaron 9 232 cultivos positivos (20.7%) de 44 447 muestras: gramnegativos, 78.8%; grampositivos, 13.8%; y levaduras, 7.4 por ciento. Escherichia coli fue el principal microorganismo identificado (41.3%); la resistencia en aislados nosocomiales fue mayor que en la comunidad para amikacina (92.4 y 97%), ceftazidima (83.1 y 95.1%) y ciprofloxacina (46.2 y 58.6%). De igual manera, Pseudomonas aeruginosa presentó mayor resistencia para amikacina y ceftazidima en las cepas nosocomiales (55.7 y 66.6%; y 65.5 y 84.8%, respectivamente). Enterococcus resistente a vancomicina se encontró sólo en 2.5% (3/119 aislados de E. faecium). CONCLUSIONES: Existe una mayor resistencia bacteriana en las cepas de origen nosocomial en comparación con las cepas comunitarias. Se encontró un incremento progresivo de la resistencia para E. coli, el patógeno aislado con más frecuencia de infecciones nosocomiales y comunitarias. Es prioritario intensificar una campaña educativa para el control y uso racional de los antibióticos.

Coccidioidomycosis is a deep mycotic infection endemic in the Southwestern part of the United States and Mexico and certain areas of Central and South America. The causative agents are fungi of the genus Coccidioides. Primary infection usually involves the lungs, and dissemination occurs in less than 1% of cases. While the extrapulmonary disease usually involves the skin, central nervous system, bones or joints, it can involve any tissue or organ. We present a case of extrapulmonary coccidioidomycosis in a 20-year-old male, in whom the diagnosis was made by a lymph node biopsy. His past history was not significant and the biopsy was performed because the physical findings were suggestive of lymphoma

La coccidioidomicosis es una micosis endémica en el sudoeste de los Estados Unidos, México y ciertas áreas de centro y Sudamérica. Los agentes causales son hongos del género Coccidioides. La infección primaria, habitualmente, involucra los pulmones, ocurriendo su diseminación en menos de 1% de los casos. Si bien la enfermedad extrapulmonar, usualmente, involucra la piel, el sistema nervioso central, los huesos y las articulaciones, tiene la capacidad de infectar cualquier órgano o tejido. Presentamos un caso de coccidioidomicosis extrapulmonar en un paciente masculino, con 20 años de edad, cuyo diagnóstico se estableció en una biopsia de ganglio linfático. La historia clínica no fue relevante y la biopsia se realizó debido a los hallazgos físicos sugerentes de linfoma

OBJECTIVE: To describe the patterns of antimicrobial resistance of organisms isolated from urine cultures at a teaching oncological hospital for adult patients. MATERIAL AND METHODS: All strains obtained from urine cultures from 1998 to 2005 were included. Mean susceptibilities were obtained for each antimicrobial tested; nosocomial and community-acquired isolates were analyzed separately. RESULTS: A total of 9 232 positive urine cultures were obtained (20.7%) from 44 447 samples taken. Gram negative bacteria were reported in 78.8%, Gram-positive in 13.8% and yeasts in 7.4%. Escherichia coli was the most frequently isolated bacterium (41.3%); antimicrobial resistance was higher in nosocomial isolates than in community strains (amikacin 92.4 vs. 97%, ceftazidime 83.1 vs. 95.1% and ciprofloxacin 46.2 vs. 58.6%). Pseudomonas aeruginosa showed a greater resistance to amikacin and ceftazidime in nosocomial cultures compared to community-acquired bacterial cultures (55.7 vs. 66.6% and 65.5 vs. 84.8% respectively). Vancomycin-resistant enterococci were found in only 2.5% (3 of 119 E. faecium isolates). CONCLUSIONS: Higher bacterial resistance was observed in nosocomial cultures than in community ones. Antimicrobial resistance was found to be progressively increasing for E. coli, the most frequent pathogen isolated both in nosocomial and community infections. We consider imperative the establishment of an intense educational campaign for the use and control of antibiotics.

OBJETIVOS: Describir los patrones de resistencia bacteriana en cultivos de orina en un hospital oncológico. MATERIAL Y MÉTODOS: Se incluyeron las cepas obtenidas de cultivos de orina de 1998 a 2005. Se obtuvo el porcentaje de sensibilidad para diferentes antibióticos, tras analizar por separado cepas nosocomiales y compararlas con las de la comunidad. RESULTADOS: Se detectaron 9 232 cultivos positivos (20.7%) de 44 447 muestras: gramnegativos, 78.8%; grampositivos, 13.8%; y levaduras, 7.4 por ciento. Escherichia coli fue el principal microorganismo identificado (41.3%); la resistencia en aislados nosocomiales fue mayor que en la comunidad para amikacina (92.4 y 97%), ceftazidima (83.1 y 95.1%) y ciprofloxacina (46.2 y 58.6%). De igual manera, Pseudomonas aeruginosa presentó mayor resistencia para amikacina y ceftazidima en las cepas nosocomiales (55.7 y 66.6%; y 65.5 y 84.8%, respectivamente). Enterococcus resistente a vancomicina se encontró sólo en 2.5% (3/119 aislados de E. faecium). CONCLUSIONES: Existe una mayor resistencia bacteriana en las cepas de origen nosocomial en comparación con las cepas comunitarias. Se encontró un incremento progresivo de la resistencia para E. coli, el patógeno aislado con más frecuencia de infecciones nosocomiales y comunitarias. Es prioritario intensificar una campaña educativa para el control y uso racional de los antibióticos.

OBJECTIVE: To describe the patterns of antimicrobial resistance organisms isolated in blood cultures from patients detected in a tertiary level of care, teaching oncological hospital. MATERIAL AND METHODS: All strains obtained from blood cultures from 1998 to 2003 were included and processed using the Bactec and Microscan system to determinate isolates and susceptibility to antimicrobials. The percent difference (increase or decrease) was obtained by comparing the frequency of resistance at baseline and at the end of the study. RESULTS: A total of 2 071 positive blood cultures were obtained; 59.7% of isolates were Gram negative bacteria, 35.7% Gram-positive bacteria and 4.6% were yeasts. E.coli was the most frequent isolated (18.6%), followed by Staphylococcus. epidermidis (12.7%) and Klebsiella spp (9%). Throughout the study the susceptibility of Gram negative bacteria was stable and over 88% for most of the antimicrobials tested (except for Pseudomonas aeruginosa). Ciprofloxacin susceptibility for Escherichia coli stayed around 50%. Susceptibility to amikacin was higher than that to gentamicin. Staphylococcus aureus susceptibility for oxacillin was 96% and that for vancomycin 100%. S. epidermidis susceptibility for oxacillin was 14% and for vancomycin was 98.6%. No strains of vancomycin-resistant enterococci were found. All Streptococcus pneumoniae strains were penicillin susceptible. CONCLUSIONS: The drug-resistance found in this hospital is the result of the control in the use of antimicrobials, the hospital nosocomial infection program and the use of drug combination in all patients with bacteremia.

OBJETIVO: Describir la frecuencia de la resistencia en microrganismos aislados en cultivos de sangre en pacientes de un hospital oncológico de tercer nivel. MATERIAL Y MÉTODOS: De enero de 1998 a diciembre de 2003, en el Instituto Nacional de Cancerología se desarrolló un estudio retrospectivo en el cual se obtuvieron cepas de cultivos de sangre que fueron incluidas y procesadas por sistema Bactec y Microscan, para determinar identificación y sensibilidad antimicrobiana. Se determinó la tendencia anual de la resistencia de cada organismo especificado a los diferentes antibióticos. Se obtuvo la diferencia porcentual (incremento o decremento) comparando la frecuencia de resistencia al inicio y al final del estudio. RESULTADOS: Se detectaron 2 071 cultivos positivos. Se recuperaron Gram negativos en 59.7% de las muestras, Gram positivos en 35.7% y levaduras en 4.6%. Escherichia coli fue el principal germen identificado (18.6%), seguido de S. epidermidis (12.7%) y Klebsiella spp (9%). Durante el periodo de estudio la sensibilidad se mantuvo estable y por arriba de 88% (excepto para Pseudomonas aeruginosa). La sensibilidad de ciprofloxacina para E. coli se encontró alrededor de 50%. Amikacina presentó mayor sensibilidad que gentamicina. Staphylococcus aureus presentó una sensibilidad a oxacilina de 96% y a vancomicina de 100%. S.epidermidis de 14% a oxacilina y de 98.6% a vancomicina. No se encontraron cepas de enterococo resistente a vancomicina. Todas las cepas de S. pneumoniae fueron sensibles a penicilina. CONCLUSIONES: Se considera que los patrones de resistencia encontrados en este hospital son el resultado del control en el uso de antimicrobianos, del programa de vigilancia de infecciones nosocomiales y de la utilización de terapia combinada en todos los pacientes con bacteremia.