The detection of mupirocin resistance and the distribution of methicillin-resistant Staphylococcus aureus at the University Hospital of the West Indies, Jamaica / Detección de la resistencia a la mupirocina y distribución de Staphylococcus aureus resistente a la meticilina en el Hospital Universitario de West Indies, Jamaica

OBJECTIVES: The objectives of this study were to determine the susceptibility of Methicillin Resistant Staphylococcus aureus (MRSA) isolates to Mupirocin and other antimicrobial agents and to record the prevalence and distribution of this organism at the University Hospital of the West Indies (UHWI). METHODS: MRSA isolates collected between January 1, 2008 and December 31, 2008, were tested for low and high level resistance to Mupirocin. Susceptibility testing to other antibiotics including cotrimoxazole, minocycline, tetracycline, clindamycin, erythromycin, gentamicin and vancomycin was also done. Laboratory records for all patients from whom MRSA was recovered were reviewed and data on type and source of isolates, clinical diagnosis, history of previous hospitalization and use of mupirocin were extracted. In addition, the laboratory records for 2004 and 2005 were also reviewed to determine prevalence during these periods. RESULTS: Seven per cent of Staphylococcus aureus isolates were resistant to methicillin (MRSA) and of these, 30% and 24% showed low level and high level resistance to mupirocin, respectively. Ninety-four per cent of MRSA strains were resistant to erythromycin while 52% showed resistance to clindamycin. Resistance to tetracycline, co-trimoxazole and minocycline was 27%, 12% and 6%, respectively, while about one-third ofthe isolates were resistant to gentamicin. There was no resistance to vancomycin. More than half (58%) of the isolates were from skin and soft tissue specimens while isolates from respiratory and urinary tracts and the bloodstream accounted for 19%, 13% and 4%, respectively. There has been a steady increase in prevalence from 4% in 2004 to 5% in 2007 and 7% in 2008. CONCLUSION: Resistance of MRSA to mupirocin appears to be an emerging problem at the UHWI and must be monitored carefully. There is also significant resistance to commonly used antimicrobial agents and strict adherence to antibiotic policy is required to preserve the usefulness of these agents.

OBJETIVOS: Los objetivos de este estudio fueron determinar la susceptibilidad de aislados de Staphylococcus aureus resistentes (MRSA) frente a la mupirocina y otros agentes antimicrobianos, y grabar la prevalencia y distribución de este organismo en el Hospital Universitario de West Indies (UHWI). MÉTODOS: Aislados de MRSA recogidos entre el 1ero. de enero de 2008 y el 31 de diciembre de 2008, fueron sometidos a prueba a fin de determinar sus niveles bajo y alto de resistencia a la mupirocina. También se investigó la susceptibilidad frente a otros antibióticos tales como co-trimoxazol, minociclina, tetraciclina, clindamicina, eritromicina, gentamicina y vancomicina. Se revisaron las historias de laboratorio de todos los pacientes de quienes de recobró MRSA, y se extrajeron datos sobre el tipo y fuente de los aislados, el diagnóstico clínico, la historia de hospitalización previa, y el uso de mupirocina. Además, se revisaron las historias clínicas de laboratorio de 2004 y 2005 a fin de determinar la prevalencia durante estos periodos. RESULTADOS: Setenta por ciento de los ailados de estafilococo dorado era resistente a la meticilina (MRSA) y de éstos, 30% y 24% mostraron un bajo nivel y un alto nivel de resistencia a la mupirocina, respectivamente. Noventa y cuatro por ciento de las cepas de MRSA eran resistentes a la eritromicina, mientras que el 52% mostró resistencia a la clindamicina. La resistencia a la tetraciclina, el cotrimoxazol, y la minociclina fue de 27%, 12% y 6%, respectivamente, mientras que aproximadamente un tercio de los aislados eran resistentes a la gentamicina. No hubo resistencia a la vancomicina. Más de la mitad (58%) de los aislados procedían de especimenes de tejido blando y de la piel, mientras que los aislados de las vías respiratorias y urinarias así como del torrente sanguíneo constituyeron el 19%, 13% y 4%, respectivamente. Ha habido un aumento constante de la prevalencia de 4% en 2004 a 5% en 2007 y 7% en 2008. CONCLUSIÓN: La resistencia de MRSA a la mupirocina parece ser un problema emergente en el HUWI y debe monitorearse cuidadosamente. Hay también una resistencia significativa a los agentes antimicrobianos normalmente usados y se requiere una adhesión estricta a la política antibiótica a fin de preservar la utilidad de estos agentes.

Distribution of nosocomial organisms and their resistance patterns in the Intensive Care Unit of the University Hospital of the West Indies, Kingston, Jamaica / Distribución de los organismos nosocomiales y sus patrones de resistencia en la Unidad de Cuidados Intensivos del Hospital Universitario de West Indies, Kingston, Jamaica

OBJETIVES: To determine the distribution and antibiotic susceptibility patterns of nosocomial pathogens in the Intensive Care Unit (ICU) at the University Hospital of the West Indies (UHWI). METHODS: A retrospective review of the laboratory records of all ICU patients from 2002-2004 was done. All organisms isolated from blood, urine, sputum, wound swabs and CVP tips were recorded. Sensitivity reports for organisms isolated in 2004 were also obtained. Results were analysed according to source of isolates and type of infection. RESULTS: Gram-negative organisms account for the majority of ICU isolates and show resistance to multiple antibiotics. The common Gram negative pathogens in the ICU are Pseudomonas aeruginosa, Acinetobacter spp and Stenotrophomonas maltophilia while the common Gram positive nosocomial organisms are Group D Streptococcus and coagulase negative Staphylococcus. CONCLUSION: The organisms isolated in the ICU at the UHWI are similar to those isolated in many ICUs all over the world. Surveillance data are necessary to monitor nosocomial pathogens and their resistance patterns to guide empirical antibiotic therapy.

OBJETIVOS: Determinar la distribución y los patrones de susceptibilidad antibiótica de los patógenos nosocomiales en la Unidad de Cuidados Intensivos (UCI) del Hospital Universitario de West Indies (HUWI). MÉTODOS: Se realizó una revisión retrospectiva de las historias clínicas de laboratorio de todos los pacientes de la UCI de 2002-2004. Se registraron todos los organismos aislados a partir de sangre, orina, esputo, hisopos de heridas, y las puntas de catéteres de PVC. Los resultados fueron analizados de acuerdo con las fuentes de los aislados y el tipo de infección. RESULTADOS: Los organismos gramnegativos representan la mayor parte de aislados de la UCI y muestran resistencia a múltiples antibióticos. Los patógenos gramnegativos comunes en la UCI son Pseudomonas aeruginosa, Acinetobacter spp y Stenotrophomonas maltophilia mientras que los organismos nosocomiales grampositivos comunes son Group D Streptococcus y coagulase negative Staphylococcus. CONCLUSIÓN: Los organismos aislados en la UCI en el HUWI son similares a los aislados en muchas UCIs en todo el mundo. La información sobre la vigilancia es necesaria a fin de monitorear los patógenos nosocomiales y sus patrones de resistencia para guiar la terapia antibiótica empírica.

The emergence of Stenotrophomonas maltophilia as a significant nosocomial pathogen at the University Hospital of the West Indies

Stenotrophomonas maltophilia is emerging worldwide as a nosocomial pathogen. It is associated with certain risk factors and a wide range of infections. This study was done to document its emergence at the University Hospital of the West Indies and to determine the incidence, distribution and risk factors associated with it. A retrospective study was conducted over the period April 1997 to December 2000. Clinical records were available for 46 of the 66 patients identified over the study period. Fifty-five per cent of the cases came from the Intensive Care Unit (ICU) and the rest from other wards. There was a slight increase in the prevalence of infection with increasing age. The surgical service accounted for the largest number of isolates. Of the cases presented, 95.7 were exposed to a wide range of antibiotics and had some form of instrumentation. Underlying disease was found in 71.7 of the patients. S maltophilia was found most often in the sputum of ICU patients whereas it was most often isolated from wound swabs in the ward patients. The organism was isolated from blood more often in ICU patients (23.3) than in ward patients (9.5) and there was a 44 mortality rate among the cases in ICU compared with those on the wards (4.8). Stenotrophomonas maltophilia is an important nosocomial pathogen and occurs in a wide cross-section of patients. The risk factors must be addressed and infection control measures implemented to restrict the spread of this organism