Serotypes and antimicrobial resistance of Streptococcus pneumoniae in children under 5 years of age pre- and post-pneumococcal conjugate vaccine introduction in Paraguay.

Introduction. Streptococcus pneumoniae remains a major cause of mortality and morbidity worldwide in children <5 years of age, even with advances in vaccination programmes.Hypothesis/Gap Statement. Reviewing and reporting trends in the distribution of pneumococcal serotypes and antimicrobial resistance in Paraguay will be useful for decision-making in public health.Aim. This study analysed the serotype distribution and antimicrobial resistance of S. pneumoniae and the characteristics of pneumococcal disease in children <5 years old before and after the introduction of pneumococcal conjugate vaccines (PCVs).Methodology. A total of 885 isolates and 278 S. pneumoniae PCR-positive clinical specimens were referred to the Central Laboratory of Public Health (LCSP) within the meningitis and pneumonia laboratory based-surveillance network in the period 2006-2020. Conventional and molecular microbiological techniques were used for confirmation and characterization.Results. We identified 563 cases of pneumococcal disease in the pre-vaccination period, 325 cases in the post-PCV10 period and 275 cases in the post-PCV13 period. The serotypes covered by PCV10 decreased from 78.6-6.5 %. However, additional serotypes covered by PCV13 increased from 6.6-57.5% and non-PCV13 serotypes increased from 14.8-36.0 % (P<0.001) in the post-PCV13 period. In cases of meningitis, the rate of resistance to penicillin decreased after the introduction of conjugate vaccines. No resistance to ceftriaxone was found in any period. In cases without meningitis, the rate of resistance to penicillin and ceftriaxone decreased slightly. However, the rate of resistance to erythromycin and tetracycline increased and that to trimethoprim-sulfamethoxazole (SXT) decreased in the post-PCV13 period compared to the pre-PCV period. The multidrug resistance rate was 8.5 %.Conclusion. A change in the circulating serotypes and antimicrobial resistance to certain antibiotics was observed. Non-vaccine serotype circulation and multidrug resistance may compromise the success of the conjugate vaccines.

Microorganismos productores de carbapenemasa en muestras clínicas de pacientes internados en el hospital de clínicas durante los años 2020-2021

La Organización Mundial de la Salud ha declarado que la resistencia a los antimicrobianos es una de las 10 principales amenazas de salud pública a las que se enfrenta la humanidad. Actualmente, enzimas de las familias Klebsiella pneumoniae carbapenemase (KPC), Oxacillinase (OXA), New Delhi Metallo-beta-lactamase (NDM), Verona Integron En coded Metallo-beta-lactamase (VIM) e Imipenemase (IMP) son las que se detectan con mayor frecuencia a nivel mundial. El objetivo es describir los hallazgos de los aislamientos de microorganismos productores de carbapenemasas de pacientes internados en el Hospital de Clínicas durante los años 2020 y 2021. Se realizó un estudio descriptivo retrospectivo de corte transversal de datos obtenidos del laboratorio de microbiología del Hospital entre enero 2020 y diciembre 2021. Se estudiaron 216 muestras clínicas de las cuales 196(91%) fueron en pacientes adultos, 172 (80%) fueron positivos para enzimas metalo-ß-lactamasa (MBL), Klebsiella pneumoniae fue la especie más frecuente. En pacientes internados en la Unidad de Cuidados Intensivos predominaron estos aislamientos y en muestras de orina 91 (42%). Según sexo, 108(50%) para ambos sexos y una mediana de edad de 52 años, con un rango de 6 días de vida a 92 años. En cuanto a número de aislamientos hallados, fue mayor en el año 2020 con 121 (56%).La vigilancia activa junto a medidas de control de infecciones son necesarias para limitar la diseminación de microorganismos productores de carbapenemasas, además se hallan datos necesarios para justificar la introducción al país de antibióticos de elección para estos microorganismos.

The World Health Organization has declared antimicrobial resistance one of the top 10 public health threats facing humanity. Currently, enzymes from the families Klebsiella pneumoniae carbapenemase (KPC), Oxacillinase (OXA), New Delhi Metallo-beta-lactamase (NDM), Verona Integron En coded Metallo-beta-lactamase (VIM) and Imipenemase (IMP) are those that are more frequently detected worldwide. The objective is to describe the findings of the isolates of carbapenemase-producing microorganisms from patients hospitalized at the Hospital de Clínicas during the years 2020 and 2021. A retrospective descriptive cross-sectional study of data obtained from the Hospital's microbiology laboratory was carried out between January 2020and December 2021. 216 clinical samples were studied, of which 196 (91%) were in adult patients, 172 (80%) were positive for metallo-ß-lactamase (MBL) enzymes, Klebsiella pneumoniae was the most frequent species. In patients hospitalized in the Intensive Care Unit these isolates predominated and in urine samples 91 (42%). According to sex, 108 (50%) for both sexes and a median age of 52 years, with a range of 6 days to 92 years. Regarding the number of isolates found, it was higher in 2020 with 121 (56%). Active surveillance together with infection control measures are necessary to limit the spread of carbapenemase-producing microorganisms, in addition, there are necessary data to justify the introduction of antibiotics of choice for these microorganisms into the country.

Utilidad del panel FilmArray® BCID en la detección de bacteriemia: estudio multicéntrico latinoamericano / Usefulness of the FilmArray® BCID panel in the detection of bacteremia: Latin American multicenter study

Resumen Los objetivos de este estudio fueron determinar el desempeño del panel BCID de FilmArray® y establecer el impacto de estos resultados en el tratamiento antimicrobiano de pacientes con bacteriemia en 11 hospitales de Latinoamérica. Se incluyeron 397 episodios de bacteriemia y se documentaron 551 microorganismos aislados de hemocultivos. La identificación microbiana fue correcta en el 91,4% (504/551) de los aislados y en el 98,6% (504/511) si se consideran solo los microorganismos incluidos en el panel BCID. La sensibilidad en la detección de los genes mecA, vanA/B y blaKPC fue del 100% y la especificidad fue del 97%, 100% y 99,6% respectivamente. La notificación temprana del resultado permitió cambios terapéuticos en 242 episodios (60,9%). El panel BCID es un método confiable y rápido para la detección de mecanismos críticos de resistencia y de los microorganismos más frecuentemente aislados de bacteriemias y permite la optimización temprana del tratamiento antimicrobiano.

Abstract The objectives of this study were to determine the performance of the BCID panel and to establish the impact of these results on the antimicrobial treatment of patients with bacteremia in 11 hospitals in Latin America. Three hundred and ninety-seven episodes of bacteremia were included and 551 microorganisms isolated from blood cultures were documented. Microbial identification was correct in 91.4% (504/551) of the isolates and in 98.6% (504/511) if only the microorganisms included in the BCID panel are considered. The sensitivity in the detection of the genes mecA, vanA/B and blaKPC was 100% and the specificity was 97%, 100% and 99.6% respectively. Early notification of the outcome allowed therapeutic changes in 242 episodes (60.9%). The BCID panel is a reliable and rapid method for the detection of critical resistance mechanisms and of the microorganisms most frequently isolated from bacteremia and it enables early optimisation of antimicrobial treatment.

Resumo Os objetivos deste estudo foram determinar o desempenho do painel BCID do FilmArray® e estabelecer o impacto desses resultados no tratamento antimicrobiano de pacientes com bacteremia em 11 hospitais da América Latina. Trezentos e noventa e sete episódios de bacteremia foram incluídos e 551 microrganismos isolados de hemoculturas foram documentados. A identificação microbiana foi correta em 91,4% (504/551) dos isolados e em 98,6% (504/511) considerando apenas os microrganismos incluídos no painel BCID. A sensibilidade na detecção dos genes mecA, vanA/B e blaKPC foi de 100% e a especificidade foi de 97%, 100% e 99,6% respectivamente. A notificação precoce do desfecho permitiu mudanças terapêuticas em 242 episódios (60,9%). O painel BCID é um método confiável e rápido para a detecção de mecanismos críticos de resistência e dos microrganismos mais frequentemente isolados da bacteremia e permite a otimização precoce do tratamento antimicrobiano.

Serogrupos y resistencia antimicrobiana de Neisseria meningitidis causantes de enfermedad invasiva en Paraguay

RESUMEN La enfermedad meningocócica representa un problema de salud pública y una de las principales causas de morbilidad y mortalidad en todo el mundo. Los serogrupos que causan la mayor carga de enfermedad a nivel global son A, B, C, W e Y. El objetivo del estudio fue describir los serogrupos y la resistencia antimicrobiana de Neisseria meningitidis aisladas de enfermedad invasiva en Paraguay durante el periodo 2010-2020. Se estudiaron todas las muestras de líquido cefalorraquídeo y sangre con aislamientos o detección de ADN por PCR de N. meningitidis de pacientes de diversas edades, que fueron remitidas al Laboratorio Central de Salud Pública durante el periodo 2010-2020, dentro del marco de la vigilancia epidemiológica de meningitis (n=163) en Paraguay. La mayor frecuencia de hallazgos de N. meningitidis se observó en el grupo de edad de < 1 año. El 25,7% de los casos correspondió al serogrupo B, el 52,1% al serogrupo C, 18,4% al serogrupo W y 3,7% al serogrupo Y. En el 2018, se evidenció la mayor cantidad de casos por serogrupo C (n=27). La menor frecuencia de sensibilidad disminuida a penicilina G fue en el 2010 (12,5%) y la mayor en el 2014 (100,0%). Se registró un aumento de casos por serogrupo C a partir del 2017, posicionándose como serogrupo prevalente hasta el 2020, y además, un aumento de la sensibilidad disminuida a la penicilina. La vigilancia es de importancia en el control de la enfermedad meningocócica para detección de brotes, estimación de la carga de enfermedad, análisis de resistencia antimicrobiana, distribución de serogrupos y evaluaciones de estrategias de control.

ABSTRACT Meningococcal disease represents a public health problem and one of the main causes of morbidity and mortality worldwide. The serogroups that cause the highest burden of disease globally are A, B, C, W, and Y. The aim of the study was to describe serogroups and antimicrobial resistance of Neisseria meningitidis isolated from invasive disease in Paraguay during the 2010-2020 period. Samples of cerebrospinal fluid and blood with isolates or detection of DNA by PCR of N. meningitidis from patients of different ages referred to the Central Public Health Laboratory during the period 2010-2020 within the framework of the epidemiological surveillance of meningitis (n = 163) in Paraguay were studied. The highest frequency of N. meningitidis findings was observed in the <1 year age group, 25.7% of the cases corresponded to serogroup B, 52.1% to serogroup C, 18.4% to serogroup W and 3.7% to serogroup Y. In 2018, the highest number of cases by serogroup C (n = 27) was found. The lowest frequency of decreased sensitivity to penicillin G was in 2010 (12.5%) and the highest in 2014 (100.0%). There was an increase in cases due to serogroup C in 2017, positioning itself as the prevalent serogroup until 2020, in addition, there was an increase in decreased sensitivity to penicillin. Surveillance is important in the control of meningococcal disease for outbreak detection, estimation of the burden of disease, analysis of antimicrobial resistance, serogroup distribution, and evaluations of control strategies.

Epidemiologic study of Haemophilus influenzae causing invasive and non-invasive disease in Paraguay (1999-2017). / Estudio epidemiológico de Haemophilus influenzae causante de enfermedad invasiva y no invasiva en Paraguay (1999-2017).

INTRODUCTION: Haemophilus influenzae is a cause of mild and severe invasive infections, especially among children under 5 years old. Serotype b (Hib) was very frequent before the introduction of the vaccine, which was introduced in Paraguay in 2004. METHODS: A total of 523 isolates of H. influenzae obtained from 1999 to 2017 and referred to the National Reference Laboratory in Paraguay were studied by conventional microbiological methods and molecular techniques. RESULTS: The most frequent serotype was non-typeable (HiNT) (51.8%; 271/523), followed by Hib (43%; 225/523), Hia and Hif (1.5%; 8/523, respectively), Hic (1%; 5/523), Hie (0.8%; 4/523), and Hid (0.4%; 2/523). A total of 48.4% invasive infections were caused by HiNT, and 46.1% by Hib; 88.6% of isolates corresponded to meningitis, 70.8% to sepsis and 50.9% to pneumonia in children under 5 years. A total of 84% (181/217) of isolates corresponded to invasive infections caused by Hib in children under 5 years, with the highest proportion observed between 2001 and 2003. The most prevalent biotypes were biotype I (29%), biotype II (12%), biotype III (24%), and biotype IV (13%). Among the total of isolates, 13% (68/523) of isolates were resistant to ampicillin. CONCLUSION: After the introduction of the Hib vaccine in Paraguay, the number of invasive Hib cases decreased in children under 5 years old, although we observed an increase of HiNT in children over 5 years. Continuous surveillance is necessary in order to monitor the effectiveness of the vaccine and for the development of preventive interventions.

Genomic diversity of the human pathogen Paracoccidioides across the South American continent.

Paracoccidioidomycosis (PCM) is a life-threatening systemic mycosis widely reported in the Gran Chaco ecosystem. The disease is caused by different species from the genus Paracoccidioides, which are all endemic to South and Central America. Here, we sequenced and analyzed 31 isolates of Paracoccidioides across South America, with particular focus on isolates from Argentina and Paraguay. The de novo sequenced isolates were compared with publicly available genomes. Phylogenetics and population genomics revealed that PCM in Argentina and Paraguay is caused by three distinct Paracoccidioides genotypes, P. brasiliensis (S1a and S1b) and P. restrepiensis (PS3). P. brasiliensis S1a isolates from Argentina are frequently associated with chronic forms of the disease. Our results suggest the existence of extensive molecular polymorphism among Paracoccidioides species, and provide a framework to begin to dissect the connection between genotypic differences in the pathogen and the clinical outcomes of the disease.

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clones from Paraguayan children.

INTRODUCTION: Staphylococcus aureus is considered one of the most important human pathogens, and its levels of resistance to methicillin have increased even in strains isolated from people without nosocomial risk factors. Molecular analysis is essential for understanding the patterns of dissemination. The objective of this study was to identify community-acquired methicillin-resistant S. aureus (CA-MRSA) clones that infected Paraguayan children patients in two periods of time. METHODOLOGY: An observational, descriptive study was designed to determine the genetic variability of 115 isolates of CA-MRSA recovered from children who attended four reference centers in Paraguay between 2009-2010 and 2012-2013. RESULTS: The combined use of Pulsed Field Gel Electrophoresis (PFGE), Multi-Locus Sequencing Typing, Multi-Locus Variable Analysis (MLVA) and Spa typing techniques allowed the identification of two dominant clones: ST30-IV-t019 (77%) and ST5-IV-t311 (10%), and the establishment of the former as the leading cause of CA-MRSA infections in children during the study period. CONCLUSIONS: This is the first study that provides epidemiological information as well as microbiological and molecular characteristics of CA-MRSA isolates recovered from children from Asunción and the Central Department of Paraguay.

Frecuencia de Streptococcus pneumoniae aislados de enfermedad invasiva en Paraguay, serotipos y perfil de sensibilidad (2010-2018) / Frequency of Streptococcus pneumoniae isolated from invasive disease in Paraguay, serotypes and sensitivity profile (2010-2018)

Streptococcus pneumoniae sigue siendo una de las causas más importantes de morbilidad y mortalidad en niños y adultos alrededor del mundo. El objetivo del estudio fue describir la frecuencia de aislamiento de S. pneumoniae en enfermedad invasiva, distribución de serotipos y sensibilidad antimicrobiana en Paraguay (2010-2018). Se estudiaron 793 cepas de S. pneumoniae aisladas de pacientes de todas las edades con enfermedad invasiva en Paraguay, provenientes de los diferentes centros centinelas y colaboradores en el marco de la vigilancia de meningitis y neumonías, durante el periodo 2010-2018. La frecuencia general según diagnóstico resultó 74.9% de neumonías (n=594), 18.4% de meningitis (n=146) y 6.7% de sepsis (n=53). El serotipo 14 fue más frecuente con 174 aislamientos (22.0%), seguido del serotipo 19A con 84 aislamientos (10.6%), el serotipo 3 con 66 aislamientos (8.3%) y el 6A con 37 aislamientos (4.7%). En meningitis se registró una frecuencia general de resistencia a penicilina del 32,2% y de ceftriaxona del 1,4%. En los casos de no meningitis la resistencia a penicilina fue del 0,8% y ceftriaxona del 0,3%. Los resultados de serotipos y sensibilidad antimicrobiana proporcionarán información necesaria para la implementación de estrategias de prevención y tratamiento de la enfermedad neumocócica en nuestro país, por lo que es necesaria una vigilancia continua para evaluar la carga de enfermedad, los serotipos circulantes y el aumento de la resistencia a los antibióticos

Streptococcus pneumoniae remains one of the most important causes of morbidity and mortality in children and adults worldwide. The objective of the study was to describe the frequency of isolation of S. pneumoniae in invasive disease, serotype distribution and antimicrobial susceptibility in Paraguay (2010-2018). We studied 793 strains of S. pneumoniae isolated from patients of all ages with invasive disease in Paraguay, from different sentinel centers and collaborators in the framework of meningitis and pneumonia surveillance during the period 2010-2018. The general frequency according to diagnosis was 74.9% of pneumonia (n = 594), 18.4% of meningitis (n = 146) and 6.7% of sepsis (n = 53). Serotype 14 was more frequent with 174 isolates (22.0%), followed by serotype 19A with 84 isolates (10.6%), serotype 3 with 66 isolates (8.3%) and 6A with 37 isolates (4.70%). In meningitis, there was a general frequency of penicillin resistance of 32.2% and ceftriaxone of 1.4%. In cases of non-meningitis, penicillin resistance was 0.8% and ceftriaxone 0.3%. The results of serotypes and antimicrobial sensitivity will provide necessary information for the implementation of prevention strategies and treatment of pneumococcal disease in our country, therefore it is necessary to continue monitoring in order to assess the burden of the disease, circulating serotypes and increased antibiotic resistance

Resistencia plasmídica a colistin por el gen mcr-1 en Enterobacteriaceae en Paraguay / Plasmid-Mediated Colistin Resistance Gene mcr-1 in Enterobacteriaceae in Paraguay

La resistencia a las polimixinas mediada por plásmidos (gen mcr-1) representa una amenaza para la salud pública, puesto que colistina es utilizada en la práctica médica como una de las últimas alternativas para el tratamiento de gérmenes multiresistentes. Este estudio describe la circulaciónde cepas de Enterobacterias que portan este gen de resistencia, aisladas de pacientes hospitalizados, así como también de la comunidad. Los hallazgos de la Red de Vigilancia de la Resistencia a los Antimicrobianos-Paraguay fueron de casi el 5 % (4,7) en cepas remitidas con criterio de sospecha, siendo las especies involucradas Escherichiacoli, Klebsiella pneumoniae y Salmonella Schwarzengrund. Además, por métodos moleculares se confirmaron en todas ellas la portación de otros genes de resistencia (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) asociados al mcr-1. Palabras claves: Enterobacterias, resistencia, colistina, mcr-1.

Resistance to polymyxins mediated by plasmids (mcr-1 gene) represents a threat to public health, since colistin is used in medical practice, as one of the last alternatives, for the treatment of multi-resistant germs. This study describes the circulation of strains of Enterobacteria that carry this resistance gene, isolated from hospitalized patients, as well as from the community. The findings of the Red de Vigilancia de la Resistencia a los Antimicrobianos­Paraguay were almost 5% (4.7) in strains submitted with suspicion criteria; the species involved being Escherichia coli, Klebsiella pneumoniae and Salmonella Schwarzengrund. In addition, molecular methods confirmed in all of them the carrying of other resistance genes (KPC, CTX-M, Qnr B, Qnr S, aac (6`)-Ib-cr) associated with mcr-1. Key words: Enterobacteria, resistance, colistin, mcr-1.

Staphylococcus aureus adquiridos en la comunidad: caracterización clínica, fenotípica y genotípica de aislados en niños paraguayos / Community-acquired Staphylococcus aureus isolated from Paraguayan children: clinical, phenotypic and genotypic characterization

Introduction: The prevalence of Staphylococcus aureus in the community has increased, being the pediatric population the most affected. This fact highlights the need for epidemiological surveillance. Aim: To characterize clinical, phenotypic and genotypic isolates of S. aureus children’s samples with community-acquired infections, collected in hospitals of Asuncion and the Central Department, between November 2009 and December 2010. Materials and Methods: Descriptive and transverse analysis with analytical component. Clinical data collected by medical records, antibiotic susceptibility according to CLSI criteria and detection of mecA (encoding methicillin resistance) and luk-PV genes (encoding Panton Valentine leucocidin) by PCR using specific oligonucleotides. Results: 123 isolates of S. aureus, 76% came from skin and soft tissue infections and 20% from sepsis. 18.7% (n = 23) were resistant to methicillin (MRSA). The presence of the mecA gene, a variant there and the PVL was detected in 12.2 and 48 isolates respectively. 43% of MRSA (n = 10) was carrying luk-PV. The clinical and demographic differences between patients infected with MRSA or MSSA were not statistically significant. Discussion: This study constitutes the first phenotypic and genotypic characterization of S. aureus associated with pediatric patients in Paraguay.

Introducción: La prevalencia de infecciones por Staphylococcus aureus en la comunidad ha aumentado, siendo la población pediátrica la más afectada; poniendo de relieve la necesidad de una vigilancia epidemiológica. Objetivo: Caracterizar clínica, fenotípica y genotípicamente aislados de S. aureus de muestras de niños con infecciones adquiridas en la comunidad, recolectadas en hospitales de Asunción y el Departamento Central, entre noviembre de 2009 y diciembre de 2010. Materiales y Métodos: Estudio descriptivo de corte trasverso. Datos clínicos fueron recabados de fichas, la susceptibilidad a antimicrobianos se hizo según criterio del CLSI y la detección de genes mecA y luk-PV se realizó por RPC empleando oligonucleótidos específicos. Resultados: De 123 aislados de S. aureus, 76% provenían de infecciones de piel y tejidos blandos y 20% de pacientes con bacteriemias. 18,7% (n: 23) fueron resistentes a meticilina (SARM). Se detectó la presencia de genes mecA, una variante del mismo y luk-PV en 9,8%, 1,6 y 39% de los aislados, respectivamente. El 43% de los SARM (n: 10) fue portador de luk-PV. Las diferencias clínicas y demográficas entre pacientes infectados por SARM o SASM no fueron estadísticamente significativas. Discusión: Este estudio constituye la primera caracterización clínica, fenotípica y genotípica de S. aureus asociados a la comunidad en población pediátrica realizada en Paraguay.

Detección molecular de belactamasas de espectro extendido (BLEE) en enterobacterias aisladas en Asunción / Molecular detection of extended spectrum beta-lactamase (esbl) in enterobacteria isolated in Asunción

Las betalactamasas de espectro extendido (BLEE), son enzimas responsables de la hidrólisis del anillo betalactámico de penicilinas y cefalosporinas, excepto carbapemenes, inhibiendo así su actividad terapéutica. Si bien es posible la detección fenotípica de este mecanismo de resistencia por métodos convencionales, sólo los métodos moleculares permiten la identificación del gen responsable de dicha resistencia. El objetivo de este estudio descriptivo retrospectivo fue identificar los genes blaCTX-M2, blaPER-2, blaSHV y blaTEM, en aislamientos de enterobacterias productoras de BLEE,; de muestras clínicas colectadas entre julio 2007 y abril 2008, provenientes de dos hospitales de referencia de Asunción, Paraguay. La detección molecular de los genes se realizó por reacción en cadena de la polimerasa empleando oligonucleótidos específicos. De los 232 aislados BLEE analizados, el 83% (n=192) portó al menos un gen bla, en el 17% (n=40) restante no fue detectado ninguno de los genes incluido en el estudio. Se observaron las siguientes frecuencias: 49% (94/192) blaCTX-M2, 45% (86/192) blaSHV, 40% (77/192) blaTEM y 7% (13/192) blaPER-2. En el 47% (90/192) se detectó más de un gen, siendo la combinación blaCTX-M2+blaTEM+blaSHV, la más frecuente observada en 32 aislados. El blaCTX-M2 como el gen más frecuente en este estudio; concuerda con lo reportado en nuestro país y en Argentina. Este es el primer reporte de la presencia de blaTEM y blaSHV en Paraguay. Es de gran importancia el estudio de otros genes codificantes de resistencia, considerando la emergencia de otras BLEE en la región como blaCTX-M15 con actividad predominantemente ceftazidimasa.

Extended spectrum beta-lactamases (ESBLs), are enzymes responsible for thehydrolysis of the beta-lactam ring and resistance to both cephalosporins and penicillins,except carbapenems, therefore inhibiting its therapeutics activity. Even though, detectionof the phenotypic resistance mechanism by conventional methods is possible, onlymolecular methods allow identification of the gene responsible for the resistance. Theobjective of this retrospective study was to identify the blaCTX-M2, blaPER-2, blaSHV, blaTEMgenes in ESBL-producing enterobacteriaceae isolates, recovered from clinical samples collected between July 2007 and April 2008, from two reference hospitals in Asunción,Paraguay. Molecular gene detection was performed by polymerase chain reaction usingspecifics oligonucleotides. Out of the tested 232 ESBL-producing isolates, 83% (n=192)carried at least one of the bla genes as follows; 49% (94/192) blaCTX-M2, 45% (86/192)blaSHV, 40% (77/192) blaTEM and 7% (13/192) blaPER-2. In the rest 17% (n=40) none of thegenes included in this study was detected; in 47% (90/192) more than one gene wasdetected, resulting blaCTX-M2 + blaTEM + blaSHV as the most frequent combination in 32isolates. The presence of blaCTX-M2, as the most frequent codifying genes of BLEE is inagreement with previous reports in Paraguay and Argentina. This is the first report of thepresence of blaTEM and blaSHV circulating in Paraguay. It is of much importance the study ofothers codifying resistance genes, taking into account the emergence of other BLEE in theregion, such as blaCTX-M15, predominantly with ceftazidimase activity.

[Community-acquired Staphylococcus aureus isolated from Paraguayan children: clinical, phenotypic and genotypic characterization]. / Staphylococcus aureus adquiridos en la comunidad: caracterización clínica, fenotípica y genotípica de aislados en niños paraguayos.

INTRODUCTION: The prevalence of Staphylococcus aureus in the community has increased, being the pediatric population the most affected. This fact highlights the need for epidemiological surveillance. AIM: To characterize clinical, phenotypic and genotypic isolates of S. aureus children's samples with community-acquired infections, collected in hospitals of Asuncion and the Central Department, between November 2009 and December 2010. MATERIALS AND METHODS: Descriptive and transverse analysis with analytical component. Clinical data collected by medical records, antibiotic susceptibility according to CLSI criteria and detection of mecA (encoding methicillin resistance) and luk-PV genes (encoding Panton Valentine leucocidin) by PCR using specific oligonucleotides. RESULTS: 123 isolates of S. aureus, 76% came from skin and soft tissue infections and 20% from sepsis. 18.7% (n = 23) were resistant to methicillin (MRSA). The presence of the mecA gene, a variant there and the PVL was detected in 12.2 and 48 isolates respectively. 43% of MRSA (n = 10) was carrying luk-PV. The clinical and demographic differences between patients infected with MRSA or MSSA were not statistically significant. DISCUSSION: This study constitutes the first phenotypic and genotypic characterization of S. aureus associated with pediatric patients in Paraguay.

Molecular characterization of methicillin-resistant Staphylococcus aureus isolates collected in Asunción, Paraguay.

We characterized 34 methicillin-resistant Staphylococcus aureus strains isolated in Paraguay in 2005. The strains belonged to two clones. The major clone (sequence type 5 [ST5] or ST221, spa type t149, staphylococcal cassette chromosome mec [SCCmec] type I) was similar to the Cordobes/Chilean clone spreading through South America, and the minor clone (ST239 or ST889, spa type t037, SCCmec type IIIA) was related to the Brazilian clone.