Methicillin-resistant Staphylococcus aureus (MRSA) burden is increasing worldwide in hospitals [healthcare-associated (HA)-MRSA] and in communities [community-associated (CA)-MRSA]. However, the impact of CA-MRSA within hospitals remains limited, particularly in Latin America. A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross-sectional, multicenter study (Nov-2009). This work involved healthcare-onset infections-(HAHO, >48 hospitalization hours) and community-onset (CO) infections [including both, infections (HACO) in patients with healthcare-associated risk-factors (HRFs) and infections (CACO) in those without HRFs]. MRSA strains were genetically typed as CA-MRSA and HA-MRSA genotypes (CA-MRSAG and HA-MRSAG) by SCCmec- and spa-typing, PFGE, MLST and virulence genes profile by PCR. Considering all isolates, 63% were from CO-infections and 55% were MRSA [39% CA-MRSAG and 16% HA-MRSAG]. A significantly higher MRSA proportion among CO- than HAHO-S. aureus infections was detected (58% vs 49%); mainly in children (62% vs 43%). The CA-MRSAG/HA-MRSAG have accounted for 16%/33% of HAHO-, 39%/13% of HACO- and 60.5%/0% of CACO-infections. Regarding the epidemiological associations identified in multivariate models for patients with healthcare-onset CA-MRSAG infections, CA-MRSAG behave like HA-MRSAG within hospitals but children were the highest risk group for healthcare-onset CA-MRSAG infections. Most CA-MRSAG belonged to two major clones: PFGE-type N-ST30-SCCmecIVc-t019-PVL(+) and PFGE-type I-ST5-IV-SCCmecIVa-t311-PVL(+) (45% each). The ST5-IV-PVL(+)/ST30-IV-PVL(+) clones have caused 31%/33% of all infections, 20%/4% of HAHO-, 43%/23% of HACO- and 35%/60% of CACO- infections, with significant differences by age groups (children/adults) and geographical regions. Importantly, an isolate belonging to USA300-0114-(ST8-SCCmecIVa-spat008-PVL(+)-ACME(+)) was detected for the first time in Argentina. Most of HA-MRSAG (66%) were related to the Cordobes/Chilean clone-(PFGE-type A-ST5-SCCmecI-t149) causing 18% of all infections (47% of HAHO- and 13% of HACO-infections). Results strongly suggest that the CA-MRSA clone ST5-IV-PVL(+) has begun to spread within hospitals, replacing the traditional Cordobes/Chilean-HA-MRSA clone ST5-I-PVL(-), mainly in children. Importantly, a growing MRSA reservoir in the community was associated with spreading of two CA-MRSA clones: ST5-IV-PVL(+), mainly in children with HRFs, and ST30-IV-PVL(+) in adults without HRFs. This is the first nationwide study in Argentina providing information about the molecular and clinical epidemiology of CA-MRSA, particularly within hospitals, which is essential for designing effective control measures in this country and worldwide.
Methicillin - resistant Staphylococcus aureus ( MRSA ) burden is increasing worldwide in hospitals [ healthcare - associated ( HA)-MRSA ] and in communities [ community - associated ( CA)-MRSA]. However , the impact of CA - MRSA within hospitals remains limited , particularly in Latin America . A countrywide representative survey of S. aureus infections was performed in Argentina by analyzing 591 clinical isolates from 66 hospitals in a prospective cross - sectional , multicenter study ( Nov-2009 ) . This work involved healthcare - onset infections-(HAHO , > 48 hospitalization hours ) and community - onset ( CO ) infections [ including both , infections ( HACO ) in patients with healthcare - associated risk - factors ( HRFs ) and infections ( CACO ) in those without HRFs]. MRSA strains were genetically typed as CA - MRSA and HA - MRSA genotypes ( CA - MRSAG and HA - MRSAG ) by SCCmec- and spa - typing , PFGE , MLST and virulence genes profile by PCR . Considering all isolates , 63 % were from CO - infections and 55 % were MRSA [ 39 % CA - MRSAG and 16 % HA - MRSAG]. A significantly higher MRSA proportion among CO- than HAHO - S. aureus infections was detected ( 58 % vs 49 % ) ; mainly in children ( 62 % vs 43 % ) . The CA - MRSAG / HA - MRSAG have accounted for 16%/33 % of HAHO- , 39%/13 % of HACO- and 60.5%/0 % of CACO - infections . Regarding the epidemiological associations identified in multivariate models for patients with healthcare - onset CA - MRSAG infections , CA - MRSAG behave like HA - MRSAG within hospitals but children were the highest risk group for healthcare - onset CA - MRSAG infections . Most CA - MRSAG belonged to two major clones : PFGE - type N - ST30-SCCmecIVc - t019-PVL(+ ) and PFGE - type I - ST5-IV - SCCmecIVa - t311-PVL(+ ) ( 45 % each ) . The ST5-IV - PVL(+)/ST30-IV - PVL(+ ) clones have caused 31%/33 % of all infections , 20%/4 % of HAHO- , 43%/23 % of HACO- and 35%/60 % of CACO- infections , with significant differences by age groups ( children / adults ) and geographical regions . Importantly , an isolate belonging to USA300 - 0114-(ST8-SCCmecIVa - spat008-PVL(+)-ACME(+ ) ) was detected for the first time in Argentina . Most of HA - MRSAG ( 66 % ) were related to the Cordobes / Chilean clone-(PFGE - type A - ST5-SCCmecI - t149 ) causing 18 % of all infections ( 47 % of HAHO- and 13 % of HACO - infections ) . Results strongly suggest that the CA - MRSA clone ST5-IV - PVL(+ ) has begun to spread within hospitals , replacing the traditional Cordobes / Chilean - HA - MRSA clone ST5-I - PVL(- ) , mainly in children . Importantly , a growing MRSA reservoir in the community was associated with spreading of two CA - MRSA clones : ST5-IV - PVL(+ ) , mainly in children with HRFs , and ST30-IV - PVL(+ ) in adults without HRFs . This is the first nationwide study in Argentina providing information about the molecular and clinical epidemiology of CA - MRSA , particularly within hospitals , which is essential for designing effective control measures in this country and worldwide .
What is MRSA?
What is MRSA ?
MRSA
methicillin-resistant S. aureus MRSA