Browsing by Author "Porte, Lorena"

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    A Multicenter Study To Evaluate Ceftaroline Breakpoints : Performance in an Area with High Prevalence of Methicillin-Resistant Staphylococcus aureus Sequence Type 5 Lineage
    (2019) Khan, Ayesha; Rivas, Lina M.; Spencer, María; Martínez, Rodrigo; Lam, Marusella; Rojas, Pamela; Porte, Lorena; Silva, Francisco; Braun, Stephanie; García Cañete, Patricia; Valdivieso, Francisca; Mvlhauser, Margareta; Lafourcade, Mónica; Miller, William R.; Arias, César A.; Munita, José M.
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    Catheter-associated bloodstream infection caused by Leifsonia aquatica in a haemodialysis patient: a case report
    (SOC GENERAL MICROBIOLOGY, 2012) Porte, Lorena; Soto, Andres; Andrighetti, Daniela; Dabanch, Jeannette; Braun, Stephanie; Saldivia, Alejandra; Carlos Flores, Juan; Wozniak, Aniela; Garcia, Patricia; Weitzel, Thomas
    Leifsonia aquatica is an aquatic coryneform rod that is capable of forming biofilms in environmental water sources. It has rarely been associated with human infections and its pathogenicity and clinical significance are uncertain. We describe a case of catheter-related bloodstream infection in a haemodialysis patient. The isolate grew on conventional media as a yellow-pigmented colony, but identification required molecular methods. Although the strain displayed reduced sensitivity to vancomycin, the clinical outcome was favourable after catheter removal and intravenous treatment with this antibiotic. Our report gives further evidence of the capability of this aquatic bacterium to cause human infection.
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    Longitudinal study of wound healing status and bacterial colonisation of Staphylococcus aureus and Corynebacterium diphtheriae in epidermolysis bullosa patients
    (2022) Fuentes, Ignacia; Yubero, María Joao; Morandé, Pilar; Varela, Carmen; Oróstica, Karen; Acevedo, Francisco; Rebolledo‐Jaramillo, Boris; Arancibia, Esteban; Porte, Lorena; Palisson, Francis
    Epidermolysis bullosa (EB) is an inherited disorder characterised by skin fragility and the appearance of blisters and wounds. Patient wounds are often colonised or infected with bacteria, leading to impaired healing, pain and high risk of death by sepsis. Little is known about the impact of bacterial composition and susceptibility in wound resolution, and there is a need for longitudinal studies to understand healing outcomes with different types of bacterial colonisation. A prospective longitudinal study of 70 wounds from 15 severe EB patients (Junctional and Recessive Dystrophic EB) from Chile. Wounds were selected independently of their infected status. Wound cultures, including bacterial species identification, composition and Staphylococcus aureus (SA) antibiotic susceptibility were registered. Wounds were separated into categories according to their healing capacity, recognising chronic, and healing wounds. Hundred-one of the 102 wound cultures were positive for bacterial growth. From these, 100 were SA-positive; 31 were resistant to Ciprofloxacin (31%) and only seven were methicillin-resistant SA (7%). Ciprofloxacin-resistant SA was found significantly predominant in chronic wounds (**P < .01). Interestingly, atoxigenic Corynebacterium diphtheriae (CD) was identified and found to be the second most abundant recovered bacteria (31/101), present almost always in combination with SA (30/31). CD was only found in Recessive Dystrophic EB patients and not related to wound chronicity. Other less frequent bacterial species found included Pseudomonas aeruginosa, Streptococus spp. and Proteus spp. Infection was negatively associated with the healing status of wounds.
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    Micobacterias atípicas en cinco pacientes adultos sin evidencias de inmunosupresión. Construyendo una experiencia
    (2015) Fica, Alberto; Soto, Andrés; Dabanch, Jeannette; Dabanch, Jeannette; Porte, Lorena; Thompson, Luis; Balcells Marty, María Elvira
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    Performance of the VITEK MS System for the Identification of Filamentous Fungi in a Routine Microbiological Laboratory in Chile
    (2024) Porte, Lorena; Cruz, Rodrigo; Pérez, Inia; Varela, Carmen; Díaz, Cristina; García Cañete, Patricia; Legarraga, Paulette; Valdivieso, Francisca; Weitzel, Thomas
    Background: Filamentous fungi are an emergent cause of severe infections in immunocompromised patients. Timely and accurate identification is crucial to initiate appropriate therapy. Traditional identification methods are time-consuming, labor-intensive, and operator-dependent. Ma-trix-assisted laser desorption/ionization-time-of-flight (MALDI-TOF) mass spectrometry is a rapid and easy-to-perform identification method. This study evaluates the effectiveness of a commercial MALDI-TOF MS platform to identify filamentous fungi in a routine laboratory. Material and Methods: We included 67 fungal isolates from 35 species/species complexes within 15 genera, confirmed in mycology reference laboratories. 33 were from clinical samples and 34 from strain collections. The study used the VITEK MS system (v3.2.0 database), after sample extraction by VITEK MS Mould Kit. Results were classified into categories: ‘correct species’, ‘correct species complex’, ‘correct genus’, ‘incorrect identification’, and ‘no identification’. We also evaluated the practicality of the kit. Results: VITEK MS correctly identified 91.0% of isolates (58.2% to species, 29.9% to species complex, and 1.5% to genus level). In 82%, the result matched the species/species complex identified by reference methods. No misidentifications were observed. The kit was rapid and easy to use. Conclusion: The VITEK MS system showed a high capability to accurately identify filamentous fungi in a routine laboratory.
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    Presence 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, Patricia
    The 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.
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    Susceptibility to azoles and amphotericin B of isolates of Candida spp. Experience of a university health network, between 2004 and 2010
    (SOC CHILENA INFECTOLOGIA, 2012) Porte, Lorena; Leon, Pilar; Garate, Cynthia; Maria Guzman, Ana; Labarca, Jaime; Garcia, Patricia
    Objective: To describe antifungal susceptibility testing surveillance (December 2004-September 2010) in Candida spp., for amphotericin B, fluconazole and voriconazole, at the Laboratorio de Microbiologia, Pontificia Universidad Catolica de Chile. Method: The study was performed utilizing E test and included yeasts from invasive origin and isolates in which antifimgal susceptibility testing was asked for by the patient's physician. Results: The yeasts were mainly recovered from urine samples (n: 64), blood cultures (n: 51) and secretions (n: 24). Two hundred ninety three isolates were studied: C. albicans (38%), C. glabrata (30%), C. tropicalis (11%), C. parapsilosis (10%), C. krusei (4%) and others (7%). All Candida species were 100% susceptible to amphotericin B, except C. krusei (1/12). Fluconazole's global susceptibility in C. albicans was 91.8%, but 100% in isolates from blood cultures versus 76% in isolates from urine. C. tropicalis was 93.9% susceptible to fluconazole, C. parapsilosis, 90% and C. glabrata 30.3%. C. krusei had no susceptible isolates to fluconazole. Voriconazole resistance was mainly present in C. glabrata (11.5%). Conclusions: We recommend the study of antifungal susceptibility in isolates from invasive origin, selected urine strains and C. glabrata. Fluconazole remains effective in C. albicans from blood.