Nasal carriage of Staphylococcus aureus, including community-associated methicillin-resistant strains, in Queensland adults

Abstract

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) infections are emerging in southeast Queensland, Australia, but the incidence of carriage of CA-MRSA strains is unknown. The aim of this study was to assess the nasal carriage rate of S. aureus, including CA-MRSA strains, in the general adult population of southeast Queensland. 396 patients presenting to general practices in two Brisbane suburbs and 303 volunteers randomly selected from the electoral rolls in the same suburbs completed a medical questionnaire and had nasal swabs performed for S. aureus. All isolates of S. aureus underwent antibiotic susceptibility testing and single-nucleotide polymorphism (SNP) and binary typing, including determination of Panton-Valentine leukocidin (PVL). The nasal carriage rate of methicillin-susceptible S. aureus (MSSA) was 202/699 (28%), a rate similar to that found in other community-based nasal carriage studies. According to multivariate analysis, nasal carriage of S. aureus was associated with male sex, young adult age group and Caucasian ethnicity. Only two study isolates (one MSSA and one CA-MRSA) carried PVL. The nasal carriage rate of MRSA was low, at 5/699 (0.7%), and only two study participants (0.3%) had CA-MRSA strains. CA-MRSA is an emerging cause of infection in southeast Queensland, but as yet the incidence of carriage of CA-MRSA in the general community is low.

Community-onsetStaphylococcus aureusinfections presenting to general practices in South-eastern Australia

“…The association between PVL and young age has also been noted by other investigators [29,31,37]. Possible explanations include age-related acquisition of PVL-specific immunity.…”

Nasal Carriage and Resistance Pattern of Staphylococcus aureus Among Healthy Medical Students

“…In previous studies from the central regions of Iran, which showed the closest findings to ours, Erami et al from Kashan city and Khorvash et al from Isfahan city reported a prevalence of S. aureus healthy carriage at 26.3% and 26.6%, respectively (1,12). In some studies conducted among healthcare workers and healthy people from other parts of the world, the nasal carriage rates of S. aureus were reported to be in the range of 18% to 29% (2,5,6).…”

Frecuencia y susceptibilidad antibiótica del Staphylococcus aureus proveniente de hisopados nasales en una población urbano marginal de Lima, Perú

“…En el presente estudio se halló una frecuencia de 24,6% de portadores nasales de S. aureus; similar a los resultados obtenidos por diversos autores (23,24) . Luego del análisis estadístico, se encontró que el factor asociado a la colonización por S. aureus fue la edad, específicamente en el rango de 1 a 11 años.…”

“…En cuanto a la edad y el estado portador, se halló una relación inversamente proporcional, la cual es congruente con lo descrito en la literatura (24,25) . Sin embargo, existe una serie de estudios en población adulta mayor, residentes de casas de reposo, en las que la prevalencia de portadores varía entre 20 a 30% (26,27) , por lo que la distribución de portadores en comunidad se comportaría como una distribución bimodal, no observada en el estudio.…”