A new serotype 14 variant of the pneumococcal Spain9V-3 international clone detected in the central region of Argentina

The penicillin-resistant Spain9V-3 clone of Streptococcus pneumoniae is widespread and presents different serotype variants originating from recombination of the capsular genes. In this work, the genetic relatedness of 29 invasive pneumococci isolated from the central region of Argentina (Cordoba, Buenos Aires, Santa Fe and La Pampa provinces) was assessed by multilocus sequence typing (MLST). All of the penicillin-non-susceptible isolates studied (21/29) belonged to a serotype 14 variant of the Spain 9V-3 clone. This clone was predominant, suggesting that it was responsible for the penicillin resistance spread in this region. Interestingly, this serotype 14 variant (named Cordoba S14V) could be differentiated from the European one by its pbp1a gene, suggesting a different recombinational replacement of the capsular genes. The putative recombination sites were analysed, resulting in the proximal crossover point being clearly localized in the spr0309 gene, with the distal site restricted to the recU gene, confirming a different recombination event. Analysis of the dexB, cpsB, aliA and pbp1a genes from these strains showed a high similarity with the corresponding genes of the Spain14-5 clone, suggesting that the capsular genes were provided by this international clone. Analysis of the genetic polymorphisms of the pbp1a (nt 1473-1922) and spr0309 (nt 1-790) genes is proposed as an epidemiological tool to help recognize the Cordoba S14V of the Spain9V-3 clone. On the other hand, BOX-repeat-based PCR and MLST analyses of serotype 14 strains revealed a divergent epidemiology of the Cordoba S14V, suggesting a non-recent dissemination in the paediatric population. It is suggested that this molecular epidemiology work will be a reference for monitoring the evolution of S14Vs of Spain9V-3, the emergence of new clones and the impact of pneumococcal vaccination programmes in Argentina.Fil: Albarracín Orio, Andrea Georgina. Universidad Católica de Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Recursos Naturales y Sustentabilidad José Sanchez Labrador S. J.; ArgentinaFil: Cortes, Paulo. Hospital Pediátrico del Niño Jesús; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Tregnaghi, Miguel. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Piñas, German Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Echenique, Jose Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Córdoba. Centro de Investigaciones en Bioquímica Clínica e Inmunología; ArgentinaFil: Yudowski, Silvia. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Carvajal, Lydia. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Culasso, Catalina. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Nobile, Carmen Beatriz. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Figueroa, Myriam Haydee. Centro de Desarrollo de Proyectos Avanzados en Pediatria; ArgentinaFil: Lopardo, Horacio. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; ArgentinaFil: Hernández, Claudia. Fundacion Hospital de Pediatria Professor Dr. Juan P. Garrahan; ArgentinaFil: Regueira, Mabel. Instituto Nacional de Enfermedades Infecciosas; Argentin

Spread of Epidemic MRSA-ST5-IV Clone Encoding PVL as a Major Cause of Community Onset Staphylococcal Infections in Argentinean Children

BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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). CONCLUSIONS/SIGNIFICANCE: 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

Resistencia de Shigella spp. a los antimicrobianos en Córdoba, Argentina, durante el período 1990-1997

En este estudio se analiza la evolución de la resistencia a los antimicrobianos en 771 aislados de Shigella spp. obtenidos de un total de 9 195 coprocultivos efectuados entre 1990 y 1997 en un hospital infantil de Córdoba, Argentina. S. flexneri, responsable de 73% de las infecciones por Shigella, fue la especie más resistente. La frecuencia de la multirresistencia de S. flexneri a los tres antibacterianos más utilizados (ampicilina, trimetoprima-sulfametoxazol y cloranfenicol) aumentó de 10% en 1990 a 58% en 1997 (P < 0,001). Cuando se considera separadamente cada uno de ellos, la resistencia a la ampicilina aumentó de 60 a 100% (P < 0,001), la resistencia al cloranfenicol de 13 a 71% (P < 0,001) y la resistencia a la trimetoprima-sulfametoxazol de 79 a 84% (P = 0,22). Para S. sonnei, el aumento de la resistencia a la ampicilina (de 36% en 1990 a 54% en 1997) no fue estadísticamente significativo (P = 0,20), ni tampoco lo fue la disminución de la resistencia a la trimetoprima-sulfametoxazol, que pasó de 82% en 1990 a 55% en 1997 (P = 0,08); solo se detectaron dos aislados resistentes al cloranfenicol, uno en 1995 y otro en 1997, y dos con resistencia múltiple a los tres antibióticos. Consideramos obligatorio realizar pruebas de susceptibilidad en cada aislado clínico de Shigella, ya que permiten detectar cambios en el perfil de la resistencia y, con ello, adecuar el tratamiento empírico

Extended-spectrum beta-lactamases in Shigella flexneri from Argentina: first report of TOHO-1 outside Japan

Fil: Andres, Patricia. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Petroni, Alejandro. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Faccone, Diego. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Pasterán, Fernando. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Melano, Roberto. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Rapoport, Melina. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.Fil: Martínez, Mariela. Hospital de Pediatría Juan P. Garraham; Argentina.Fil: Culasso, Catalina. Hospital de Niños de la Santísima Trinidad de Córdoba; Argentina.Fil: Di Bella, Adriana. Hospital Nacional Prof. Dr. Alejandro Posadas; Argentina.Fil: Irigoyen, Bettina. Hospital General de Agudos Dr. Julio C. Perrando; Argentina.Fil: Mulki, Jorgelina. Hospital Materno Infantil de Salta; Argentina.Fil: Procopio, Adriana. Hospital de Niños Dr. Ricardo Gutiérrez; Argentina.Fil: von Specht, Martha. Hospital Público Provincial de Pediatría; Argentina.Fil: Galas, Marcelo. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas. Departamento de Bacteriología. Servicio Antimicrobianos; Argentina.A 9-year nation-wide survey of the presence of extended-spectrum beta-lactamases (ESBLs) in Shigella flexneri is described. Ten of 9033 (0.1%) isolates produced ESBLs, which were characterized by isoelectric focusing, PCR and DNA sequencing. These were CTX-M-2 (five isolates), TOHO-1 (one isolate), SHV-2 (two isolates) and PER-2 (two isolates, the first report in S. flexneri world wide). The emergence of each ESBL type in S. flexneri was not restricted to a particular region of Argentina. TOHO-1 showed a more basic isoelectric point (8.4) than that previously found (7.8) and its encoding gene (bla(TOHO-1a)) harboured a silent change, G825A, relative to the reported bla(TOHO-1). All the ESBL-encoding genes were transferred to Escherichia coli by conjugation. PFGE analysis indicated that the 10 ESBL-producing S. flexneri isolates were subtypes of a unique clone

Genotypes of methicillin resistant <i>S. aureus</i> (MRSA) isolates recovered from children with Community-onset infections (invasive and non-invasive) in central, northen and eastern regions of Argentina, by epidemiologic case classification.

<p><b>INVI</b>: Invasive infections.</p>a<p>CBAH1-H3: Prospective surveillance of CO-<i>S. aureus</i> infections in children from three children's hospitals of Córdoba (CBAH1, CBAH2 and CBAH3) 2007 and 2008.</p>b<p>CSACHARG and: Prospective surveillance of CO-<i>S. aureus</i> infections in children from Argentina, 2007 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030487#pone.0030487-Paganini1" target="_blank">[16]</a>.</p>c<p>Genotypes are denoted as: type (by PFGE)-Sequence Type (ST by MLST)-SCC<i>mec</i> type.</p

Characteristics, incidence of CA-MRSA infections and location of children's hospitals of northern, eastern and central of Argentina, 2007.

a<p>Number of all CA-MRSA isolates detected in the three Cordoba children's hospitals during 2007 and those recovered in each hospital from the surveillance study for community onset <i>S. aureus</i> infections in children from Argentina-(CSACHARG) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0030487#pone.0030487-Paganini1" target="_blank">[16]</a>.</p>b<p>annual visits: include outpatient facility and emergency service.</p>c<p>Incidence: Number of cases/100,000 annual visits.</p

Evolution of community-associated <i>Staphylococcus aureus</i> infections from children in Cordoba-Argentina, 2003–2008.

<p>Evolution of the rates of all community-associated <i>Staphylococcus aureus</i> infections: <i>i)</i> methicillin-resistant <i>S. aureus</i> (CA-MRSA) infections [total (squares) and invasive-INVI (circles)], and <i>ii)</i> total methicillin-susceptible <i>S. aureus</i> (CA-MSSA) infections (triangles) in Córdoba children's hospitals, [H1 (CBAH1): 2003–2008: filled figures, and in H1, H2 and H3 (CBAH1-3): 2005 vs 2007–2008: empty figures] <i>iii)</i> methicillin-resistant community-associated <i>Staphylococcus aureus</i> infections caused by the ST5-IV-PVL⁺clone [total (gray squares) and invasive (INVI) (gray circles)] in H1 (CBAH1): 2003–2008.</p

Characteristics of MRSA clones isolated from children with community onset MRSA infections (CO-MRSA), Argentina.

<p><i>agr</i> type, type of accessory gene regulator, ST: Sequence Type, SCC<i>mec</i>: Staphylococcal Cassette Chromosome <i>mec</i>, PFGE, Pulsed Field Gel Electrophoresis; RIDOM <i>spa</i> type: staphylococcal protein A (<i>spa</i>) type assigned through the RIDOM databases (<a href="http://spaserver.ridom.de" target="_blank">http://spaserver.ridom.de</a>).</p>a<p>n (%), total number and % of strains with this molecular characteristic [PFGE subtype (only those more frequent are indicated) or ST or <i>spa</i> type or <i>SCCmec</i> type]. % is not expressed when only one isolate with this characteristic was detected.</p>b<p><i>pvl</i>, Panton-Valentine leukocidin genes (<i>lukS</i>-PV-<i>lukF</i>-PV); indicated as number and % of isolates harboring (PVl⁺) or not (PVL⁻) <i>pvl</i> genes.</p>c<p>virulence genes profile: From all virulence genes analyzed, only those detected are indicated (number and % of positive isolates is expressed when not all isolates harbor this virulence factor).</p>d<p>Drug resistance to non-β-Lactams (%), is indicated as follows: Gentamicin (GEN), Ciprofloxacin (CIP), Erythromycin (ERY), Clindamycin (CLIc and CLIi: constitutive and inducible resistance to macrolides, lincosamide and streptogramine B, respectively), rifampin (RIF), chloramphenicol (CHL), trimethoprim/sulfamethoxazole (SXT) and minocycline (MIN) (%) of strains resistant to these antibiotics within each pulsotype is indicated when more than one isolate was detected. h-VISA (1): means one isolate belonging to this clone with phenotype h-VISA.</p>e<p>IV NT: SCC<i>mec</i> type IV non typable.</p>f<p>Vr: SCC<i>mec</i> related to V.</p

Molecular characteristics and proportion from different regions of Argentina of dominant community methicillin-resistant-<i>Staphylococcus aureus</i> clones.

<p><b>A</b>. PFGE pattern analysis for representative isolates belonging to the most prevalent subtypes of community-onset-MRSA clones (CA-MRSA and HA-MRSA) detected in central, eastern and northern regions of Argentina during 2007–2008. The schematic presentation of <i>SmaI</i> restriction patterns (middle) and dendrogram (left) by the unweighted-pair group method using average linkage clusterings are shown. Genotypes are denoted as subtype (by PFGE)-ST (by MLST)-SCC<i>mec</i> type-<i>spa</i> type (right). CA-MRSA clones appear in gray. The presence (+) or absence (−) of <i>pvl</i> genes (by PCR) is also indicated for each subtype; strains with and other without <i>pvl</i> genes belonging to the same PFGE subtype (I9) are indicated as +/−. The PFGE pattern of USA300-0114 (ST8-IVa-<i>t008</i>-ACME+) is shown for comparison purposes. The first (A1-ST5-I-t149-Cordobes/Chilean), second (B1-ST239-IIIA-t037-Brazilian) and third (C1-ST100-IVNv-t002-Pediatric) more frequent HA-MRSA clones in our country, detected among community-onset MRSA infections, are also shown (dotted gray). <b>B</b>: Proportion of CA-MRSA clones among representative isolates from different regions of Argentina in 2007.</p