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.

The detection of mupirocin resistance and the distribution of methicillin-resistant Staphylococcus aureus at the University Hospital of the 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 of the 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.