Relation Between Oceanic Plate Structure, Patterns of Interplate Locking and Microseismicity in the 1922 Atacama Seismic Gap

We deployed a dense geodetic and seismological network in the Atacama seismic gap in Chile. We derive a microseismicity catalog of >30,000 events, time series from 70 GNSS stations, and utilize a transdimensional Bayesian inversion to estimate interplate locking. We identify two highly locked regions of different sizes whose geometries appear to control seismicity patterns. Interface seismicity concentrates beneath the coastline, just downdip of the highest locking. A region with lower locking (27.5°S–27.7°S) coincides with higher seismicity levels, a high number of repeating earthquakes and events extending toward the trench. This area is situated where the Copiapó Ridge is subducted and has shown previous indications of both seismic and aseismic slip, including an earthquake sequence in 2020. While these findings suggest that the structure of the downgoing oceanic plate prescribes patterns of interplate locking and seismicity, we note that the Taltal Ridge further north lacks a similar signature

Resistance to non-beta-lactamantibiotics in the clinicalisolates of Streptococcuspneumoniaeof children inLatin America. SIREVA II,2000–2005

Fil: Agudelo, Clara Inés. Instituto Nacional de Salud; Colombia.Fil: Castañeda, Elizabeth. Instituto Nacional de Salud; Colombia.Fil: Corso, Alejandra. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Regueira, Mabel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: de Cunto Brandileone, María Cristina. Instituto Adolfo Lutz; Brasil.Fil: Pires Brandão, Angela. Fundação Oswaldo Cruz; Brasil.Fil: Maldonado, Aurora. Instituto de Salud Pública; Chile.Fil: Hormazabal, Juan Carlos. Instituto de Salud Pública; Chile.Fil: Tamargo, Isis. Instituto de Medicina Tropical Pedro Kourí; Cuba.Fil: Echániz-Avilés, Gabriela. Instituto Nacional de Salud Pública; México.Fil: Soto, Araceli. Instituto Nacional de Salud Pública; México.Fil: Viveros, Mónica Guadalupe. Instituto de Diagnóstico y Referencia Epidemiológicos; México.Fil: Hernández, Irma. Instituto de Diagnóstico y Referencia Epidemiológicos; México.Fil: Chamorro, Gustavo. Laboratorio Central de Salud Pública; Paraguay.Fil: Weiler, Natalie. Laboratorio Central de Salud Pública; Paraguay.Fil: Sánchez, Jacqueline. Hospital Infantil Dr. Robert Reid Cabral; República Dominicana.Fil: Feris, Jesús M. Hospital Infantil Dr. Robert Reid Cabral; República Dominicana.Fil: Camou, Teresa. Servicio Nacional de Laboratorios de Salud Pública; Uruguay.Fil: García, Gabriela. Servicio Nacional de Laboratorios de Salud Pública; Uruguay.Fil: Spadola, Enza. Instituto Nacional de Higiene Rafael Rangel; Venezuela.Fil: Payares, Daisy. Instituto Nacional de Higiene Rafael Rangel; Venezuela.Fil: Gabastou, Jean-Marc. Organización Panamericana de la Salud; Estados Unidos.Fil: di Fabio, José Luis. Organización Panamericana de la Salud; Estados Unidos.Fil: Grupo SIREVA II; Argentina.Objetivo. Determinar la evolución de la resistencia a la eritromicina, el cloranfenicol, el trimetoprim-sulfametozaxol (SXT) y la vancomicina de aislamientos invasores de Streptococcus pneumoniaeobtenidos de niños de 10 países de América Latina y del Caribe en seis años de vigilancia. Métodos. Se analizaron 8 993 aislamientos de S. pneumoniaerecuperados entre 2000 y 2005 de niños menores de 6 años con infecciones invasoras, procedentes de Argentina, Brasil, Chile, Colombia, Cuba, México, Paraguay, República Dominicana, Uruguay y Venezuela. La sensibilidad a los antibióticos se determinó mediante los métodos establecidos y estandarizados en el proyecto SIREVA. La resistencia a múltiples antibióticos se definió como la resistencia a tres o más familias de antibióticos, de los no betalactámicos analizados en este estudio o de los betalactámicos evaluados en un estudio previo en el que 37,8% de estos aislamientos presentaron sensibilidad disminuida a la penicilina. Resultados. Se encontró algún grado de resistencia al SXT y la eritromicina (56,4% y 15,4% de los aislamientos estudiados, respectivamente) y 4,6% presentó alta resistencia al cloranfenicol. Todos los aislamientos fueron sensibles a la vancomicina. Se observó la mayor frecuencia de resistencia al SXT en los aislamientos de neumonía y a la eritromicina en los casos de sepsis (61,6% y 25,5%, respectivamente; P< 0,01). La mayor frecuencia de resistencia al SXT se observó en Brasil (71,9%) y a la eritromicina en México (38,2%) y Venezuela (32,9%). Los serotipos 14, 6B, 19F y 23F fueron los que más frecuentemente se asociaron con la resistencia a los antibióticos estudiados. Conclusiones. Se observó una elevada y creciente frecuencia de aislamientos resistentes al SXT y la eritromicina, y una disminución en la proporción de aislamientos resistentes al cloranfenicol. Estas tendencias mostraron diferencias entre los países estudiado

Resistance to non-beta-lactamantibiotics in the clinicalisolates of Streptococcuspneumoniaeof children inLatin America. SIREVA II,2000–2005

Fil: Agudelo, Clara Inés. Instituto Nacional de Salud; Colombia.Fil: Castañeda, Elizabeth. Instituto Nacional de Salud; Colombia.Fil: Corso, Alejandra. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: Regueira, Mabel. ANLIS Dr.C.G.Malbrán. Instituto Nacional de Enfermedades Infecciosas; Argentina.Fil: de Cunto Brandileone, María Cristina. Instituto Adolfo Lutz; Brasil.Fil: Pires Brandão, Angela. Fundação Oswaldo Cruz; Brasil.Fil: Maldonado, Aurora. Instituto de Salud Pública; Chile.Fil: Hormazabal, Juan Carlos. Instituto de Salud Pública; Chile.Fil: Tamargo, Isis. Instituto de Medicina Tropical Pedro Kourí; Cuba.Fil: Echániz-Avilés, Gabriela. Instituto Nacional de Salud Pública; México.Fil: Soto, Araceli. Instituto Nacional de Salud Pública; México.Fil: Viveros, Mónica Guadalupe. Instituto de Diagnóstico y Referencia Epidemiológicos; México.Fil: Hernández, Irma. Instituto de Diagnóstico y Referencia Epidemiológicos; México.Fil: Chamorro, Gustavo. Laboratorio Central de Salud Pública; Paraguay.Fil: Weiler, Natalie. Laboratorio Central de Salud Pública; Paraguay.Fil: Sánchez, Jacqueline. Hospital Infantil Dr. Robert Reid Cabral; República Dominicana.Fil: Feris, Jesús M. Hospital Infantil Dr. Robert Reid Cabral; República Dominicana.Fil: Camou, Teresa. Servicio Nacional de Laboratorios de Salud Pública; Uruguay.Fil: García, Gabriela. Servicio Nacional de Laboratorios de Salud Pública; Uruguay.Fil: Spadola, Enza. Instituto Nacional de Higiene Rafael Rangel; Venezuela.Fil: Payares, Daisy. Instituto Nacional de Higiene Rafael Rangel; Venezuela.Fil: Gabastou, Jean-Marc. Organización Panamericana de la Salud; Estados Unidos.Fil: di Fabio, José Luis. Organización Panamericana de la Salud; Estados Unidos.Fil: Grupo SIREVA II; Argentina.Objetivo. Determinar la evolución de la resistencia a la eritromicina, el cloranfenicol, el trimetoprim-sulfametozaxol (SXT) y la vancomicina de aislamientos invasores de Streptococcus pneumoniaeobtenidos de niños de 10 países de América Latina y del Caribe en seis años de vigilancia. Métodos. Se analizaron 8 993 aislamientos de S. pneumoniaerecuperados entre 2000 y 2005 de niños menores de 6 años con infecciones invasoras, procedentes de Argentina, Brasil, Chile, Colombia, Cuba, México, Paraguay, República Dominicana, Uruguay y Venezuela. La sensibilidad a los antibióticos se determinó mediante los métodos establecidos y estandarizados en el proyecto SIREVA. La resistencia a múltiples antibióticos se definió como la resistencia a tres o más familias de antibióticos, de los no betalactámicos analizados en este estudio o de los betalactámicos evaluados en un estudio previo en el que 37,8% de estos aislamientos presentaron sensibilidad disminuida a la penicilina. Resultados. Se encontró algún grado de resistencia al SXT y la eritromicina (56,4% y 15,4% de los aislamientos estudiados, respectivamente) y 4,6% presentó alta resistencia al cloranfenicol. Todos los aislamientos fueron sensibles a la vancomicina. Se observó la mayor frecuencia de resistencia al SXT en los aislamientos de neumonía y a la eritromicina en los casos de sepsis (61,6% y 25,5%, respectivamente; P< 0,01). La mayor frecuencia de resistencia al SXT se observó en Brasil (71,9%) y a la eritromicina en México (38,2%) y Venezuela (32,9%). Los serotipos 14, 6B, 19F y 23F fueron los que más frecuentemente se asociaron con la resistencia a los antibióticos estudiados. Conclusiones. Se observó una elevada y creciente frecuencia de aislamientos resistentes al SXT y la eritromicina, y una disminución en la proporción de aislamientos resistentes al cloranfenicol. Estas tendencias mostraron diferencias entre los países estudiado

The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

Multiple Introductions of Salmonella enterica Serovar Typhi H58 with Reduced Fluoroquinolone Susceptibility into Chile.

Salmonella enterica serovar Typhi H58, an antimicrobial-resistant lineage, is globally disseminated but has not been reported in Latin America. Genomic analysis revealed 3 independent introductions of Salmonella Typhi H58 with reduced fluoroquinolone susceptibility into Chile. Our findings highlight the utility of enhanced genomic surveillance for typhoid fever in this region

National Seroprevalence of Coxiella burnetii in Chile, 2016–2017

Coxiella burnetii is an intracellular bacterium and the cause of the zoonotic infection, Q fever. National surveillance data on C. burnetii seroprevalence is currently not available for any South American country, making efforts of public health to implement strategies to mitigate infections in different at-risk groups within the population extremely challenging. In the current study, we used two commercial anti-C. burnetii immunoassays to screen sera collected from a sample of the Chilean population as part of a 2016–2017 national health survey (n = 5166), nationwide and age-standardized. The seroprevalence for C. burnetii for persons ≥ 15 years was estimated to be 3.0% (95% CI 2.2–4.0), a level similar to national surveys from The Netherlands (2.4%) and USA (3.1%), but lower than Australia (5.6%). A linear increase of C. burnetii seropositivity was associated with an individual’s age, with the peak seroprevalence 5.6% (95% CI 3.6–8.6) observed in the ≥65 years’ group. C. burnetii seropositivity was significantly higher in the southern macro-zone 6.0% (95% CI 3.3–10.6) compared to metropolitan region 1.8% (95% CI 0.9–3.3), the former region being home to significant livestock industries, particularly dairy farming. These data will be useful to inform targeted strategies for the prevention of Q fever in at-risk populations in Chile

Analysis of <i>Mycobacterium tuberculosis</i> Genotypic Lineage Distribution in Chile and Neighboring Countries

<div><p>Tuberculosis (TB), caused by the pathogen <i>Mycobacterium tuberculosis</i> (MTB), remains a disease of high importance to global public health. Studies into the population structure of MTB have become vital to monitoring possible outbreaks and also to develop strategies regarding disease control. Although Chile has a low incidence of MTB, the current rates of migration have the potential to change this scenario. We collected and analyzed a total of 458 <i>M</i>. <i>tuberculosis</i> isolates (1 isolate per patient) originating from all 15 regions of Chile. The isolates were genotyped using the spoligotyping method and the data obtained were analyzed and compared with the SITVIT2 database. A total of 169 different patterns were identified, of which, 119 patterns (408 strains) corresponded to Spoligotype International Types (SITs) and 50 patterns corresponded to orphan strains. The most abundantly represented SITs/lineages were: SIT53/T1 (11.57%), SIT33/LAM3 (9.6%), SIT42/LAM9 (9.39%), SIT50/H3 (5.9%), SIT37/T3 (5%); analysis of the spoligotyping minimum spanning tree as well as spoligoforest were suggestive of a recent expansion of SIT42, SIT50 and SIT37; all of which potentially evolved from SIT53. The most abundantly represented lineages were LAM (40.6%), T (34.1%) and Haarlem (13.5%). LAM was more prevalent in the Santiago (43.6%) and Concepción (44.1%) isolates, rather than the Iquique (29.4%) strains. The proportion of X lineage was appreciably higher in Iquique and Concepción (11.7% in both) as compared to Santiago (1.6%). Global analysis of MTB lineage distribution in Chile versus neighboring countries showed that evolutionary recent lineages (LAM, T and Haarlem) accounted together for 88.2% of isolates in Chile, a pattern which mirrored MTB lineage distribution in neighboring countries (n = 7378 isolates recorded in SITVIT2 database for Peru, Brazil, Paraguay, and Argentina; and published studies), highlighting epidemiological advantage of Euro-American lineages in this region. Finally, we also observed exclusive emergence of patterns SIT4014/X1 and SIT4015 (unknown lineage signature) that have hitherto been found exclusively in Chile, indicating that conditions specific to Chile, along with the unique genetic makeup of the Chilean population, might have allowed for a possible co-evolution leading to the success of these emerging genotypes.</p></div

Description of clusters containing >1% (n = 5 or more isolates) in this study, and their worldwide distribution in the SITVIT2 database.

<p>Description of clusters containing >1% (n = 5 or more isolates) in this study, and their worldwide distribution in the SITVIT2 database.</p

Spoligoforest tree based on all spoligotypes (n = 458 isolates).

<p>Spoligoforest was drawn using the Fruchterman-Reingold algorithm from the SpolTools software (<a href="http://www.emi.unsw.edu.au/spolTools" target="_blank">http://www.emi.unsw.edu.au/spolTools</a>)[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160434#pone.0160434.ref029" target="_blank">29</a>], and reshaped and colored using the GraphViz software (<a href="http://www.graphviz.org/" target="_blank">http://www.graphviz.org</a>)[<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0160434#pone.0160434.ref030" target="_blank">30</a>]. Each spoligotype pattern from the study is represented by a node with area size being proportional to the total number of isolates with that specific pattern. Changes (loss of spacers) are represented by directed edges between nodes, with the arrowheads pointing to descendant spoligotypes. The heuristic used selects a single inbound edge with a maximum weight using a Zipf model. Solid black lines link patterns that are very similar, i.e., loss of one spacer only (maximum weigh being 1.0), while dashed lines represent links of weight comprised between 0.5 and 1, and dotted lines a weight less than 0.5.</p