Community-associated methicillin-resistant Staphylococcus aureus-(CA-MRSA) strains have emerged in Argentina. We investigated the clinical and molecular evolution of community-onset MRSA infections (CO-MRSA) in children of Córdoba, Argentina, 2005-2008. Additionally, data from 2007 were compared with the epidemiology of these infections in other regions of the country. Two datasets were used: i) lab-based prospective surveillance of CA-MRSA isolates from 3 Córdoba pediatric hospitals-(CBAH1-H3) in 2007-2008 (compared to previously published data of 2005) and ii) a sampling of CO-MRSA from a study involving both, healthcare-associated community-onset-(HACO) infections in children with risk-factors for healthcare-associated infections-(HRFs), and CA-MRSA infections in patients without HRFs detected in multiple centers of Argentina in 2007. Molecular typing was performed on the CA-MRSA-(n: 99) isolates from the CBAH1-H3-dataset and on the HACO-MRSA-(n: 51) and CA-MRSA-(n: 213) isolates from other regions. Between 2005-2008, the annual proportion of CA-MRSA/CA-S. aureus in Córdoba hospitals increased from 25% to 49%, P<0.01. Total CA-MRSA infections increased 3.6 fold-(5.1 to 18.6 cases/100,000 annual-visits, P<0.0001), associated with an important increase of invasive CA-MRSA infections-(8.5 fold). In all regions analyzed, a single genotype prevailed in both CA-MRSA (82%) and HACO-MRSA(57%), which showed pulsed-field-gel electrophoresis-(PFGE)-type-"I", sequence-type-5-(ST5), SCCmec-type-IVa, spa-t311, and was positive for PVL. The second clone, pulsotype-N/ST30/CC30/SCCmecIVc/t019/PVL(+), accounted for 11.5% of total CA-MRSA infections. Importantly, the first 4 isolates of Argentina belonging to South American-USA300 clone-(USA300/ST8/CC8/SCCmecIVc/t008/PVL(+)/ACME(-)) were detected. We also demonstrated that a HA-MRSA clone-(pulsotype-C/ST100/CC5) caused 2% and 10% of CA-MRSA and HACO-MRSA infections respectively and was associated with a SCCmec type closely related to SCCmecIV(2B&5). The dissemination of epidemic MRSA clone, ST5-IV-PVL(+) was the main cause of increasing staphylococcal community-onset infections in Argentinean children (2003-2008), conversely to other countries. The predominance of this clone, which has capacity to express the h-VISA phenotype, in healthcare-associated community-onset cases suggests that it has infiltrated into hospital-settings.
Community - associated methicillin - resistant Staphylococcus aureus-(CA - MRSA ) strains have emerged in Argentina . We investigated the clinical and molecular evolution of community - onset MRSA infections ( CO - MRSA ) in children of Córdoba , Argentina , 2005 - 2008 . Additionally , data from 2007 were compared with the epidemiology of these infections in other regions of the country . Two datasets were used : i ) lab - based prospective surveillance of CA - MRSA isolates from 3 Córdoba pediatric hospitals-(CBAH1-H3 ) in 2007 - 2008 ( compared to previously published data of 2005 ) and ii ) a sampling of CO - MRSA from a study involving both , healthcare - associated community - onset-(HACO ) infections in children with risk - factors for healthcare - associated infections-(HRFs ) , and CA - MRSA infections in patients without HRFs detected in multiple centers of Argentina in 2007 . Molecular typing was performed on the CA - MRSA-(n : 99 ) isolates from the CBAH1-H3-dataset and on the HACO - MRSA-(n : 51 ) and CA - MRSA-(n : 213 ) isolates from other regions . Between 2005 - 2008 , the annual proportion of CA - MRSA / CA - S. aureus in Córdoba hospitals increased from 25 % to 49 % , P<0.01 . Total CA - MRSA infections increased 3.6 fold-(5.1 to 18.6 cases/100,000 annual - visits , P<0.0001 ) , associated with an important increase of invasive CA - MRSA infections-(8.5 fold ) . In all regions analyzed , a single genotype prevailed in both CA - MRSA ( 82 % ) and HACO - MRSA(57 % ) , which showed pulsed - field - gel electrophoresis-(PFGE)-type-"I " , sequence - type-5-(ST5 ) , SCCmec - type - IVa , spa - t311 , and was positive for PVL . The second clone , pulsotype - N / ST30/CC30/SCCmecIVc / t019/PVL(+ ) , accounted for 11.5 % of total CA - MRSA infections . Importantly , the first 4 isolates of Argentina belonging to South American - USA300 clone-(USA300/ST8/CC8/SCCmecIVc / t008/PVL(+)/ACME(- ) ) were detected . We also demonstrated that a HA - MRSA clone-(pulsotype - C / ST100/CC5 ) caused 2 % and 10 % of CA - MRSA and HACO - MRSA infections respectively and was associated with a SCCmec type closely related to SCCmecIV(2B&5 ) . The dissemination of epidemic MRSA clone , ST5-IV - PVL(+ ) was the main cause of increasing staphylococcal community - onset infections in Argentinean children ( 2003 - 2008 ) , conversely to other countries . The predominance of this clone , which has capacity to express the h - VISA phenotype , in healthcare - associated community - onset cases suggests that it has infiltrated into hospital - settings .
What is MRSA?
What is MRSA ?
MRSA
methicillin-resistant S. aureus MRSA