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Automated urine culture system with reduced turnaround time: A prospective real-world evaluation
(Elsevier BV, 2025-07)
PORTE TORRE, LORENA ISABEL
;
María Jesús Alfaro
;
Carmen Varela
;
Jorge Reyes
;
WEITZEL, THOMAS
6Scopus© Citations 2
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Microbial Community and Enzyme Activity of Forest Plantation, Natural Forests, and Agricultural Land in Chilean Coastal Cordillera Soils
(2023)
Yessica Rivas
;
Humberto Aponte
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RIVERA SALAZAR, DIEGO ANDRÉS
;
Francisco Matus
;
Oscar Martínez
<jats:p>Despite the global expansion of forest plantations in Chile, their effect on biology properties of soil has still been only scarcely studied. Land use change in the Chilean Coastal Cordillera (36° to 40° S) is mainly attributed to the conversion of native forest to agriculture and forest plantations (Eucalyptus globulus and Pinus radiata de Don). The aim of this paper was to evaluate the changes in microbial composition (PCR-DGGE) and enzyme activity after the substitution of a native forest (e.g., Nothofagus spp.) by fast-growing exotic species and cropping. The most important factors that influence the abundance and diversity of bacteria and the fungi community were the soil organic matter (SOM) content, phosphorous (P-Olsen), calcium (Ca), boron (B), and water-holding capacity. These variables can better predict the microbial community composition and its enzymatic activity in the surface Ah horizon. Land use change also affected chemical soil properties of biogeochemical cycles. However, to deeply understand the connection between chemical and physical soil factors and microbial community composition, more research is needed. On the other hand, the expansion of forest plantations in Chile should be subject to legislation aimed to protect the biological legacy as a strategy for forest productivity as well as the soil microbial biodiversity.</jats:p>
2Scopus© Citations 5
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High Burden of Intestinal Colonization With Antimicrobial-Resistant Bacteria in Chile: An Antibiotic Resistance in Communities and Hospitals (ARCH) Study
(2023)
ARAOS BRALIC, RAFAEL IGNACIO
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Rachel M Smith
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Ashley Styczynski
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Felipe Sánchez
;
Lea Maureira
<jats:title>Abstract</jats:title> <jats:sec> <jats:title>Background</jats:title> <jats:p>Antimicrobial resistance is a global threat, heavily impacting low- and middle-income countries. This study estimated antimicrobial-resistant gram-negative bacteria (GNB) fecal colonization prevalence in hospitalized and community-dwelling adults in Chile before the coronavirus disease 2019 pandemic.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>From December 2018 to May 2019, we enrolled hospitalized adults in 4 public hospitals and community dwellers from central Chile, who provided fecal specimens and epidemiological information. Samples were plated onto MacConkey agar with ciprofloxacin or ceftazidime added. All recovered morphotypes were identified and characterized according to the following phenotypes: fluoroquinolone-resistant (FQR), extended-spectrum cephalosporin-resistant (ESCR), carbapenem-resistant (CR), or multidrug-resistant (MDR; as per Centers for Disease Control and Prevention criteria) GNB. Categories were not mutually exclusive.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>A total of 775 hospitalized adults and 357 community dwellers were enrolled. Among hospitalized subjects, the prevalence of colonization with FQR, ESCR, CR, or MDR-GNB was 46.4% (95% confidence interval [CI], 42.9–50.0), 41.2% (95% CI, 37.7–44.6), 14.5% (95% CI, 12.0–16.9), and 26.3% (95% CI, 23.2–29.4). In the community, the prevalence of FQR, ESCR, CR, and MDR-GNB colonization was 39.5% (95% CI, 34.4–44.6), 28.9% (95% CI, 24.2–33.6), 5.6% (95% CI, 3.2–8.0), and 4.8% (95% CI, 2.6–7.0), respectively.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>A high burden of antimicrobial-resistant GNB colonization was observed in this sample of hospitalized and community-dwelling adults, suggesting that the community is a relevant source of antibiotic resistance. Efforts are needed to understand the relatedness between resistant strains circulating in the community and hospitals.</jats:p> </jats:sec>
Scopus© Citations 10 2
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A multispecies outbreak of carbapenem-resistant bacteria harboring the blaKPC gene in a non-classical transposon element
(2021)
Aniela Wozniak
;
Cristian Figueroa
;
Francisco Moya-Flores
;
Piero Guggiana
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Claudia Castillo
<jats:title>Abstract</jats:title><jats:sec> <jats:title>Background</jats:title> <jats:p><jats:italic>Klebsiella pneumoniae</jats:italic> is the most frequent KPC-producing bacteria. The <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> gene is frequently embedded in Tn4401 transposon, and less frequently in non-Tn4401 elements (NTE<jats:sub>KPC</jats:sub>) variants I-III. The first case of KPC in the UC-CHRISTUS Clinical Hospital was detected in <jats:italic>Pseudomonas aeruginosa</jats:italic>. Soon after this event, KPC was detected in 2 additional <jats:italic>Pseudomonas aeruginosa</jats:italic>, 3 <jats:italic>Escherichia coli</jats:italic>, 3 <jats:italic>Enterobacter cloacae</jats:italic>, 3 <jats:italic>Klebsiella pneumoniae,</jats:italic> and 1 <jats:italic>Citrobacter freundii</jats:italic>, isolated from 6 different patients. We aimed to elucidate the possible mechanisms of genetic transfer and dissemination of the <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> gene among isolates of this multispecies outbreak. A molecular epidemiology analysis of the above mentioned clinical isolates (<jats:italic>n</jats:italic> = 13) through Multi-Locus Sequence Typing, plasmid analysis, Pulsed-Field Gel-Electrophoresis, and Whole-genome sequencing (WGS) was performed.</jats:p> </jats:sec><jats:sec> <jats:title>Results</jats:title> <jats:p>High-risk sequence types were found: <jats:italic>K. pneumoniae</jats:italic> ST11, <jats:italic>P. aeruginosa</jats:italic> ST654, and <jats:italic>E. cloacae</jats:italic> ST114. All enterobacterial isolates were not clonal except for 3 <jats:italic>E. coli</jats:italic> isolated from the same patient. WGS analysis in 6 enterobacterial isolates showed that 4 of them had <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> embedded in a novel variant of NTE<jats:sub>KPC</jats:sub> designated NTE<jats:sub>KPC</jats:sub>-IIe. Upstream of <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> gene there was a 570 pb truncated <jats:italic>bla</jats:italic><jats:sub>TEM-1</jats:sub> gene followed by an insertion sequence that was 84% similar to ISEc63, a 4473 bp element of the Tn3 family. Downstream the <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> gene there was a truncated ISKpn6 gene, and the inverted repeat right sequence of Tn4401. The ISec63-like element together with the <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> 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. <jats:italic>P. aeruginosa</jats:italic> isolates carried <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> gene embedded in a typical Tn4401b transposon in a different plasmid, suggesting that there was no plasmid transfer between <jats:italic>Enterobacteriaceae</jats:italic> and <jats:italic>P. aeruginosa</jats:italic> as initially hypothesized.</jats:p> </jats:sec><jats:sec> <jats:title>Conclusions</jats:title> <jats:p>Most enterobacterial isolates had <jats:italic>bla</jats:italic><jats:sub>KPC</jats:sub> embedded in the same NTE<jats:sub>KPC</jats:sub>-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.</jats:p> </jats:sec>
Scopus© Citations 21 3

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