Browsing by Author "Castillo, Claudia"
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- ItemA multispecies outbreak of carbapenem-resistant bacteria harboring the blaKPC gene in a non-classical transposon element(2021) Wozniak Banchero, Aniela; Figueroa, Cristian; Moya-Flores, Francisco; Guggiana, Piero; Castillo, Claudia; Rivas Jiménez, Lina María; Munita, José M.; García Cañete, PatriciaAbstract Background Klebsiella pneumoniae is the most frequent KPC-producing bacteria. The blaKPC gene is frequently embedded in Tn4401 transposon, and less frequently in non-Tn4401 elements (NTEKPC) variants I-III. The first case of KPC in the UC-CHRISTUS Clinical Hospital was detected in Pseudomonas aeruginosa. Soon after this event, KPC was detected in 2 additional Pseudomonas aeruginosa, 3 Escherichia coli, 3 Enterobacter cloacae, 3 Klebsiella pneumoniae, and 1 Citrobacter freundii, isolated from 6 different patients. We aimed to elucidate the possible mechanisms of genetic transfer and dissemination of the blaKPC gene among isolates of this multispecies outbreak. A molecular epidemiology analysis of the above mentioned clinical isolates (n = 13) through Multi-Locus Sequence Typing, plasmid analysis, Pulsed-Field Gel-Electrophoresis, and Whole-genome sequencing (WGS) was performed. Results High-risk sequence types were found: K. pneumoniae ST11, P. aeruginosa ST654, and E. cloacae ST114. All enterobacterial isolates were not clonal except for 3 E. coli isolated from the same patient. WGS analysis in 6 enterobacterial isolates showed that 4 of them had blaKPC embedded in a novel variant of NTEKPC designated NTEKPC-IIe. Upstream of blaKPC gene there was a 570 pb truncated blaTEM-1 gene followed by an insertion sequence that was 84% similar to ISEc63, a 4473 bp element of the Tn3 family. Downstream the blaKPC gene there was a truncated ISKpn6 gene, and the inverted repeat right sequence of Tn4401. The ISec63-like element together with the blaKPC gene plus Tn4401 remnants were inserted in the Tra operon involved in conjugative transfer of the plasmid. This NTE was carried in a broad host-range IncN plasmid. P. aeruginosa isolates carried blaKPC gene embedded in a typical Tn4401b transposon in a different plasmid, suggesting that there was no plasmid transfer between Enterobacteriaceae and P. aeruginosa as initially hypothesized. Conclusions Most enterobacterial isolates had blaKPC embedded in the same NTEKPC-IIe element, suggesting that this multispecies KPC outbreak was due to horizontal gene transfer rather than clonal spread. This poses a greater challenge to infection control measures often directed against containment of clonal spread.
- ItemComparison of manual and automated nucleic acid extraction methods from clinical specimens for microbial diagnosis purposes(2016) Wozniak Banchero, Aniela; Geoffroy, Enrique; Miranda, Carolina; Castillo, Claudia; Sanhueza, Francia
- ItemEvaluación de test rápidos y diseño de una estrategia para la detección y caracterización de carbapenemasas en cepas de bacilos gramnegativos(2017) Muñoz, Constanza; Zumarán, Cecilia; González, Tamara; Wozniak Banchero, Aniela; Castillo, Claudia; García Cañete, Patricia
- ItemPresence of Bordetella holmesii in an outbreak of pertussis in Chile(SOC CHILENA INFECTOLOGIA, 2013) Miranda, Carolina; Wozniak, Aniela; Castillo, Claudia; Geoffroy, Enrique; Zumaran, Cecilia; Porte, Lorena; Roman, Juan C.; Potin, Marcela; Garcia, PatriciaThe incidence of whooping cough in Chile ranges from 4.1 and 7.5 per hundred thousand inhabitants. B. pertussis detection is performed by Real Time PCR (Q-PCR) directed to the insertion sequence IS481. However, this sequence is also found in the genome of B. bronchiseptica and B. holmesii. The latter is also a respiratory pathogen whose clinical features are similar to B. pertussis. However, it is important to differentiate between these species because in immunosuppressed patients B. holmesii is more likely to cause bacteremia and is less susceptible to erythromycin. The goal of this work is to measure prospectively and retrospectively the presence of B. holmesii in samples reported positive for B. pertussis in the period 2010-2011. During this period, 1994 nasopharyngeal specimens entered the laboratory for Bordetella sp. PCR, of which 224 were positive. The analysis by Q-PCR directed to the recA gene of B. holmesii of all 224 positive samples determined a prevalence of B. holmesii of 0.6% (12/1994). Because of its more aggressive behavior in immunosupressed patients and its different resistance pattern, routine screening of B. pertussis and B. holmesii is currently performed for all samples in which Bordetella sp PCR is initially detected.
- ItemSalmonella enterica serovar Typhi and gallbladder cancer : a case control study and meta-analysis(2016) Koshiol, Jill; Wozniak Banchero, Aniela; Cook, María Paz; Adaniel, Christina; Acevedo, Johanna; Azócar, Lorena; Roa Strauch, Juan Carlos Enrique; Miquel P., Juan Francisco; Ferreccio Readi, Catterina; Díaz, Alfonso; Molina, Héctor; Miranda, Carolina; Castillo, Claudia
- ItemTest evaluation and strategy proposal to detect and to characterize carbapenemase-producing gram negative bacilli(SOC CHILENA INFECTOLOGIA, 2017) Munoz, Constanza; Zumaran, Cecilia; Gonzalez, Tamara; Wozniak, Aniela; Castillo, Claudia; Garcia, PatriciaIntroduction: The detection of carbapenemase-producing gram negative bacilli is complicated, because there are available multiple options of test. The confirmation of the enzyme by molecular characterization is not available in all laboratories in our country. Objective: To propose a fast, efficient and simple strategy to detect and confirm CPB. Materials and Methods: 39 CPB isolates and 8 non-producing were used to evaluate the phenotypic test Carba NP, CarbAcineto NP and Blue-Carba, validating the test Xpert (R) Carba-R, to be used directly with bacterial colonies with conventional PCR. Results: The sensitivity of Carba NP, CarbAcineto NP and Blue-Carba was 79,5; 87,2 y 84,6%, respectively; and specificity was 79.5; 87.2 and 84.6%, respectively. The limit of detection of Xpert (R) Carba-R was different for each carbapenemasa: 40.8 ufc/reaction to KPC and NDM and 30.6 ufc/reaction to VIM. Discussion: On isolates with decreased susceptibility to carbapenems we propose to use as screening the test CarbAcineto NP, follow by Xpert (R) Carba-R to characterize the carbapenemase and adopt specific infection control measures.
- ItemThe ways of fish beyond the sea: fish circulation and consumption in the Atacama desert, northern Chile, during the Formative period (500 cal BC-700 cal AD.)(2019) Ballester, Benjamin; Calas, Elisa; Labarca, Rafael; Pestle, William; Gallardo, Francisco; Castillo, Claudia; Pimentel, Gonzalo; Oyarzo, CristobalAlong the Atacama Desert coast, fish has always been a staple food and by the Formative period (500 cal B.C.-700 cal A.D.) it had become a product in high demand by the inhabitants of the inland valleys, oases and ravines of the desert. In this paper we explore the technologies used in coastal fishing activities, the diverse species caught, and fish processing and preserving techniques. We further examine the circulation routes of the product through the desert and associated strategies, the agents involved in transporting it and consumption levels in inland villages. Our study employs a multivariate analysis that includes evidence from zooarchaeology, stable isotope analysis of deceased individuals, and the composition of human coprolites, all of which were recovered from domestic waste, funerary contexts, and rest stops associated with the circulation routes running between the coast and the inland desert regions. Our results suggest that in this ancient social context, food was not only used to quell hunger, but through its associated economic cycles of production, circulation and consumption, was part of a complex and extended web of social relations. Within that network, food functioned as material culture, and as such enabled social distinctions to emerge within local groups and cultural negotiations to be conducted among different localities. Fish circulation and consumption played an active role in the reproduction of a social structure characterized by dose and firm ties between marine hunter-fisher-gatherers and agropastoral communities, despite their long distance from each other.
- ItemVulnerabilidad educativa ante incendios forestales en el Área Metropolitana de Concepción. Caso de estudio: Penco, Chile(2019) Ojeda Leal, Carolina Grace; Jacque Castillo, Edilia; Castillo, Claudia; Díaz Arellano, Patricio