[Antimicrobial susceptibility in Chile 2012]. / Susceptibilidad antimicrobiana en Chile 2012.

Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

Head-to-head comparison of CAMPYAIR aerobic culture medium versus standard microaerophilic culture for Campylobacter isolation from clinical samples.

Campylobacter spp. are considered the most frequent cause of acute gastroenteritis worldwide. However, outside high-income countries, its burden is poorly understood. Limited published data suggest that Campylobacter prevalence in low- and middle-income countries is high, but their reservoirs and age distribution are different. Culturing Campylobacter is expensive due to laboratory equipment and supplies needed to grow the bacterium (e.g., selective culture media, microaerophilic atmosphere, and a 42°C incubator). These requirements limit the diagnostic capacity of clinical laboratories in many resource-poor regions, leading to significant underdiagnosis and underreporting of isolation of the pathogen. CAMPYAIR, a newly developed selective differential medium, permits Campylobacter isolation without the need for microaerophilic incubation. The medium is supplemented with antibiotics to allow Campylobacter isolation in complex matrices such as human feces. The present study aims to evaluate the ability of the medium to recover Campylobacter from routine clinical samples. A total of 191 human stool samples were used to compare the ability of CAMPYAIR (aerobic incubation) and a commercial Campylobacter medium (CASA, microaerophilic incubation) to recover Campylobacter. All Campylobacter isolates were then identified by MALDI-TOF MS. CAMPYAIR showed sensitivity and specificity values of 87.5% (95% CI 47.4%-99.7%) and 100% (95% CI 98%-100%), respectively. The positive predictive value of CAMPYAIR was 100% and its negative predictive value was 99.5% (95% CI 96.7%-99.9%); Kappa Cohen coefficient was 0.93 (95% CI 0.79-1.0). The high diagnostic performance and low technical requirements of the CAMPYAIR medium could permit Campylobacter culture in countries with limited resources.

Genomic Analysis of Chilean Strains of Campylobacter jejuni from Human Faeces.

Campylobacter spp., especially C. jejuni, are recognized worldwide as the bacterial species that most commonly cause food-related diarrhea. C. jejuni possesses many different virulence factors, has the ability to survive in different reservoirs, and has shown among isolates the emergence of Antimicrobial Resistance (AMR). Genome association analyses of this bacterial pathogen have contributed to a better understanding of its pathogenic and AMR associated determinants. However, the epidemiological information of these bacteria in Latin American countries is scarce and no genomic information is available in public databases from isolates in these countries. Considering this, the present study is aimed to describe the genomic traits from representative Campylobacter spp. strains recovered from faecal samples of patients with acute diarrhoea from Valparaíso, Chile. Campylobacter spp. was detected from the faeces of 28 (8%) out of 350 patients with acute diarrhoea, mainly from young adults and children, and 26 (93%) of the isolates corresponded to C. jejuni. 63% of the isolates were resistant to ciprofloxacin, 25.9% to tetracycline, and 3.5% to erythromycin. Three isolates were selected for WGS on the basis of their flaA-RFLP genotype. They belonged to the multilocus sequence typing (MLST) clonal clomplex (CC) 21(PUCV-1), CC-48 (PUCV-3), and CC-353 (PUCV-2) and presented several putative virulence genes, including the Type IV and Type VI Secretion Systems, as well as AMR-associated genes in agreement with their susceptibility pattern. On the basis of the wgMLST, they were linked to strains from poultry and ruminants. These are the first genomes of Chilean C. jejuni isolates available in public databases and they provide relevant information about the C. jejuni isolates associated with human infection in this country.

[Chilean strains of clinical origin of non-O1, non-O139 Vibrio cholerae carry the genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF from secretion system T3SS2 present in an island of pathogenicity]. / Cepas chilenas de origen clínico de Vibrio cholerae no-O1, no-O139 portan los genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF del sistema de secreción T3SS2 presentes en una isla de patogenicidad.

Backgound: The virulence factors of the Vibrio cholerae non-O1, non-O139 strains are not clearly known. The strain of septicemic origin NN1 Vibrio cholerae non-O1, non-O139 was sequenced previously by the Illumina platform. A fragment of the pathogenicity island VPaI-7 of V. parahaemolyticus was detected in its genome. AIM: To detect the virulence genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF in Chilean strains of V. cholerae non-O1, non-O139. METHODS: A total of 9 Chilean strains of clinical origin of Vibrio cholerae non-O1, non-O139 isolated between 2006-2012 were analyzed by conventional PCR assays for type III secretion genes encoded on that island: vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF. Additionally, the presence of the virulence genes hylA and rtxA was determined. In addition, REP-PCR and ERIC-PCR assays were performed. RESULTS: most (6/9) Chilean V. cholerae non-O1, non-O139 strains contain the type III secretion genes vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF, encoded in an island of pathogenicity. In addition, all (9/9) the strains contain the virulence genes hylA and rtxA. CONCLUSION: These results strongly suggest the possibility that those strains possess an important virulence potential in humans.

Cepas chilenas de origen clínico de Vibrio cholerae no-O1, no-O139 portan los genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF del sistema de secreción T3SS2 presentes en una isla de patogenicidad / Chilean strains of clinical origin of non-O1, non-O139 Vibrio cholerae carry the genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF from secretion system T3SS2 present in an island of pathogenicity

Resumen Introducción. Los factores de virulencia de las cepas de Vibrio cholerae no-O1, no-O139 no son claramente conocidos. La cepa de origen septicémico NN1 Vibrio cholerae no-O1, no-O139 fue secuenciada previamente mediante la plataforma Illumina, detectándose en su genoma un fragmento de la isla de patogenicidad VPaI-7 de V. parahaemolyticus. Objetivo: detectar los genes de virulencia vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF en cepas chilenas clínicas de V. cholerae no-O1, no-O139. Material y Métodos: Un total de 9 cepas chilenas de origen clínico de Vibrio cholerae no-O1, no-O139 aisladas entre 2006-2012 fueron analizadas mediante ensayos de reacción de polimerasa en cadena (RPC, en inglés PCR) convencional para los genes de secreción tipo III codificados en dicha isla: vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF. Adicionalmente se determinó la presencia de los genes de virulencia hylA y rtxA. Además, se realizaron ensayos de repetitive element palindromic PCR (REP-PCR) y Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR). Resultados: la mayoría (6/9) de las cepas chilenas de V. cholerae no-O1, no-O139 contiene todos los genes de secreción tipo III vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF, codificados en una isla de patogenicidad. Además, el total de las cepas (9/9) contiene los genes de virulencia hylA y rtxA. Conclusión: Estos resultados sugieren fuertemente la posibilidad que dichas cepas posean un potencial de virulencia importante en seres humanos.

Backgound: The virulence factors of the Vibrio cholerae non-O1, non-O139 strains are not clearly known. The strain of septicemic origin NN1 Vibrio cholerae non-O1, non-O139 was sequenced previously by the Illumina platform. A fragment of the pathogenicity island VPaI-7 of V. parahaemolyticus was detected in its genome. Aim: To detect the virulence genes vcsN2, vcsC2, vcsV2, vspD, toxR2 y vopF in Chilean strains of V. cholerae non-O1, non-O139. Methods: A total of 9 Chilean strains of clinical origin of Vibrio cholerae non-O1, non-O139 isolated between 2006-2012 were analyzed by conventional PCR assays for type III secretion genes encoded on that island: vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF. Additionally, the presence of the virulence genes hylA and rtxA was determined. In addition, REP-PCR and ERIC-PCR assays were performed. Results: most (6/9) Chilean V. cholerae non-O1, non-O139 strains contain the type III secretion genes vcsN2, vcsC2, vcsV2, vspD, toxR2 and vopF, encoded in an island of pathogenicity. In addition, all (9/9) the strains contain the virulence genes hylA and rtxA. Conclusion: These results strongly suggest the possibility that those strains possess an important virulence potential in humans.

Susceptibilidad antimicrobiana en Chile 2012 / Antimicrobial susceptibility in Chile 2012

Bacteria antimicrobial resistance is an uncontrolled public health problem that progressively increases its magnitude and complexity. The Grupo Colaborativo de Resistencia, formed by a join of experts that represent 39 Chilean health institutions has been concerned with bacteria antimicrobial susceptibility in our country since 2008. In this document we present in vitro bacterial susceptibility accumulated during year 2012 belonging to 28 national health institutions that represent about 36% of hospital discharges in Chile. We consider of major importance to report periodically bacteria susceptibility so to keep the medical community updated to achieve target the empirical antimicrobial therapies and the control measures and prevention of the dissemination of multiresistant strains.

La resistencia bacteriana es un problema de salud pública que lejos de estar controlado, aumenta en cantidad y complejidad. El Grupo Colaborativo de Resistencia, es un conjunto de profesionales que representan a 39 establecimientos de salud del país y que se ha ocupado desde 2008 de recolectar información sobre la susceptibilidad antimicrobiana de bacterias en Chile. En este documento se presenta la susceptibilidad in vitro acumulada del año 2012, de 28 establecimientos de salud del país que representan, al menos, 36% de los egresos hospitalarios de Chile. Consideramos de la mayor relevancia reportar periódicamente la susceptibilidad bacteriana de modo de mantener a la comunidad médica actualizada para orientar las terapias empíricas y las medidas de control y prevención de la diseminación de cepas multi-resistentes.