Un caso inusual de quiste sebáceo infectado por Dermabacter hominis

ResumenLa especie Dermabacter hominis está constituida por bacilos gram positivos corineformes, anaerobios facultativos, que forman parte de la microbiota residente de la piel. Excepcionalmente se ha asociado a estos microorganismos con infecciones en pacientes inmunocomprometidos o muy debilitados. Se describe el caso de una mujer adulta joven, inmunocompetente, con un quiste sebáceo en el cuello, infectado por D. hominis como único agente etiológico. Se logró la identificación fenotípica del agente causal mediante pruebas simples basadas en el esquema originalmente propuesto por Funke y Bernard, factibles de ser realizadas en un laboratorio hospitalario de microbiología. Características fenotípicas como la morfología cocoide, el olor acre/espermático, la hidrólisis de la esculina, la producción de pirrolidonil arilamidasa y de lisina y ornitina descarboxilasas son pruebas claves en la identificación de D. hominis. La espectrometría de masas (MALDI-TOF MS) confirmó la identificación fenotípica.AbstractDermabacter hominis species is constituted by Gram positive facultative anaerobic coryneform rods being part of the resident microbiota human skin, and exceptionally associated to infections in immunocompromised or severely debilitated patients. An immunocompetent young adult woman with a neck sebaceous cyst infected by D. hominis as unique etiologic agent is presented. Phenotypic identification of the causative agent was achieved through simple tests, based on the originally scheme proposed by Funke and Bernard, and feasible to be performed in a hospital Microbiology Laboratory. Phenotypic characteristics as coccoid morphology, the acrid/spermatic odor, esculin hydrolysis, the production of pyrrolidonyl-arylamidase, lysine and ornithine decarboxylase, are key tests to identify D. hominis. The matrix-asisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) confirmed the phenotypic identification

First national survey of antibiotic susceptibility of the Bacteroides fragilis group: emerging resistance to carbapenems in Argentina

The antibiotic susceptibility rates of 363 clinical Bacteroides fragilis group isolates collected from 17 centers in Argentina during the period from 2006 to 2009 were as follows: piperacillin-tazobactam, 99%; ampicillin-sulbactam, 92%; cefoxitin, 72%; tigecycline, 100%; moxifloxacin, 91%; and clindamycin, 52%. No metronidazole resistance was detected in these isolates during this time period. Resistance to imipenem, doripenem, and ertapenem was observed in 1.1%, 1.6%, and 2.3% of B. fragilis group strains, respectively. B. fragilis species showed a resistance profile of 1.5% to imipenem, 1.9% to doripenem, and 2.4% to ertapenem. This is the first report of carbapenem resistance in Argentina. The cfiA gene was present in 8 out of 23 isolates, all of them belonging to the B. fragilis species and displaying reduced susceptibility or resistance to carbapenems (MICs ≥ 4 μg/ml). Three out of eight cfiA-positive isolates were fully resistant to carbapenems, while 5 out of 8 isolates showed low-level resistance (MICs, 4 to 8 μg/ml). The inhibition by EDTA was a good predictor of the presence of metallo-β-lactamases in the fully resistant B. fragilis strains, but discrepant results were observed for low-level resistant isolates. B. fragilis was more susceptible to antimicrobial agents than other Bacteroides species. Bacteroides vulgatus species was the most resistant to ampicillin-sulbactam and piperacillin-tazobactam, and B. thetaiotaomicron/ovatus strains showed the highest level of resistance to carbapenems, with an unknown resistance mechanism. B. vulgatus and the uncommon non-Bacteroides fragilis species were the most resistant to moxifloxacin, showing an overall resistance rate of 15.1%.Fil: Fernández Canigia, Liliana. Asociación Argentina de Microbiología; ArgentinaFil: Litterio, Mirta. Asociación Argentina de Microbiología; ArgentinaFil: Legaria, María C.. Asociación Argentina de Microbiología; ArgentinaFil: Castello, Liliana. Asociación Argentina de Microbiología; ArgentinaFil: Predari, Silvia C.. Asociación Argentina de Microbiología; ArgentinaFil: Di Martino, Ana. Asociación Argentina de Microbiología; ArgentinaFil: Rossetti, Adelaida. Asociación Argentina de Microbiología; ArgentinaFil: Rollet, Raquel. Asociación Argentina de Microbiología; ArgentinaFil: Carloni, Graciela. Asociación Argentina de Microbiología; ArgentinaFil: Bianchini, Hebe. Asociación Argentina de Microbiología; ArgentinaFil: Cejas, Daniela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Radice, Marcela Alejandra. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gutkind, Gabriel Osvaldo. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Anaerobe Surveillance Team

Pasteurella multocida y otras especies de Pasteurella

La familia Pasteurellaceae es el único miembro del orden Pasteurellales incluido en la clase Gammaproteobacteria del phylum Proteobacteria; ésta clasificación se basa en la secuenciación y comparación de genes de las subunidades 16S ADNr y 16S ARNr [1]. Actualmente (noviembre 2009), la familia Pasteurellaceae está constituida por 14 géneros (Pasteurella, Actinobacillus, Aggregatibacter, Avibacterium, Bibersteinia, Chelonobacter, Gallibacterium, Haemophilus, Histophilus, Lonepinella, Mannheimia, Nicoletella, Phocoenobacter y Volucribacter) y más de 60 especies [2, 3]. El género Pasteurella incluye un grupo monofilogenético y fenotípicamente homogéneo denominado Pasteurella sensu stricto (cluster 12, 16S ARNr) constituido por 5 especies: P. multocida, P. canis, P. dagmatis, P. stomatis y Pasteurella sp. B. Aún y hasta tanto se les pueda asignar una ubicación taxonómica más adecuada, la especie P. multocida incluye 3 subespecies: P. multocida subesp. multocida, P. multocida subesp. gallicida y P. multocida subesp. septica. A su vez, existen otras 8 especies ubicadas de modo provisorio en el género Pasteurella, pero genéticamente no relacionadas con éste. Debido a su ubicación taxonómica incierta y provisoria en el género Pasteurella se las indica entre corchetes: [Pasteurella] aerogenes, [Pasteurella] bettyae, [Pasteurella] caballi, [Pasteurella] langaaensis, [Pasteurella] mairii, [Pasteurella] pneumotropica, [Pasteurella] skyensis y [Pasteurella] testudinis [4, 5].Fil: Leotta, Gerardo Anibal. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico CONICET- La Plata. Instituto de Genética Veterinaria "Ing. Fernando Noel Dulout". Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias. Instituto de Genética Veterinaria; ArgentinaFil: Predari, Silvia C.. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentin

Five-Test Simple Scheme for Species-Level Identification of Clinically Significant Coagulase-Negative Staphylococci

A working scheme developed in our laboratory for identification (by species group and species) of coagulase-negative staphylococci (CNS) was evaluated with 201 consecutive isolates and then validated by using the reference method of Kloos and Schleifer (W. E. Kloos and K. H. Schleifer, J. Clin. Microbiol. 1:82-88, 1975). This five-test simple scheme (referred to here as the simple scheme) combines the novobiocin susceptibility test with tests for urease, pyrrolidonyl arylamidase, ornithine decarboxylase, and aerobic acid from mannose. The addition of one or two tests within a particular species group could then positively identify the isolate. Two commercial systems, Staph-Zym (Rosco) and API-Staph (bioMérieux), along with results obtained by using Rosco diagnostic tablets (nongrowth tests), were also compared with the reference method. One isolate could not be identified even by the reference method. Of the remaining 200 strains, 191 (95.5%) strains were correctly identified with Staph-Zym and 171 strains (85.5%) were correctly identified with API-Staph. The most frequent clinical CNS species isolated were Staphylococcus epidermidis (50.5%), S. haemolyticus (18.5%), S. saprophyticus subsp. saprophyticus (16.0%), S. lugdunensis (6.0%), and S. warneri (2.5%). The simple scheme validated with the reference method has demonstrated an excellent correlation in the identification of the three most frequent species isolated: S. epidermidis, S. haemolyticus, and S. saprophyticus subsp. saprophyticus. With the simple scheme, identification of CNS was possible within 24 h after the enzymatic tests were used, whereas up to 72 h is necessary for the growth tests. This methodology would be very useful in any clinical microbiology laboratory for the presumptive identification of CNS species groups and species

Detección de Clostridioides [Clostridium] difficile toxigénico: utilidad de dos métodos de enzimoinmunoensayo comerciales y una PCR en las muestras de materia fecal y en los respectivos aislamientos

The best laboratory diagnostic approach to detect Clostridioides [Clostridium] difficile infection (CDI) is a subject of ongoing debate. With the aim of evaluating four laboratory diagnostic methods, 250 unformed stools from patients with suspected CDI submitted to nine medical center laboratories from November 2010 to December 2011, were studied using: (1) an immunochromatographic rapid assay test that combines the qualitative determination of glutamate dehydrogenase (GDH) plus toxins A and B (QAB), the CDIFF QUIK CHEK COMPLETE assay; (2) an enzyme immunoassay for qualitative determination of toxins A and B, the RIDASCREEN™ C. difficile Toxin A/B assay (RAB); (3) a PCR for the toxin B gene assay (PCR); and (4) the toxigenic culture (TC). C. difficile isolates from direct toxin negative stools by QAB, RAB and PCR were evaluated for toxigenicity by the same direct tests, in order to assess the contribution of the TC (QAB-TC, RAB-TC, PCR-TC). A combination of the cell culture cytotoxicity neutralization assay (CCCNA) in stools, and the same assay on isolates from direct negative samples (CCCNA-TC) was considered the reference method (CCCNA/CCCNA-TC). Of the 250 stools tested, 107 (42.8%) were positive by CCCNA/CCCNA-TC. The GDH and PCR/PCR-TC assays were the most sensitive, 91.59% and 87.62%, respectively. The QAB, RAB, QAB/QAB-TC and RAB/RAB-TC had the highest specificities, ca. 95%. A negative GDH result would rule out CDI, however, its low positive likelihood ratio (PLR) of 3.97 indicates that a positive result should always be complemented with the detection of toxins. If the RAB, QAB, and PCR assays do not detect toxins from direct feces, the toxigenic culture should be performed. In view of our results, the most accurate and reliable methods to be applied in a clinical microbiology laboratory were the QAB/QAB-TC, and RAB/RAB-TC, with PLRs >10 and negative likelihood ratios 10 y una razón de verosimilitud negativa < 0,30.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Detección de Clostridioides [Clostridium] difficile toxigénico: utilidad de dos métodos de enzimoinmunoensayo comerciales y una PCR en las muestras de materia fecal y en los respectivos aislamientos

The best laboratory diagnostic approach to detect Clostridioides [Clostridium] difficile infection (CDI) is a subject of ongoing debate. With the aim of evaluating four laboratory diagnostic methods, 250 unformed stools from patients with suspected CDI submitted to nine medical center laboratories from November 2010 to December 2011, were studied using: (1) an immunochromatographic rapid assay test that combines the qualitative determination of glutamate dehydrogenase (GDH) plus toxins A and B (QAB), the CDIFF QUIK CHEK COMPLETE assay; (2) an enzyme immunoassay for qualitative determination of toxins A and B, the RIDASCREEN™ C. difficile Toxin A/B assay (RAB); (3) a PCR for the toxin B gene assay (PCR); and (4) the toxigenic culture (TC). C. difficile isolates from direct toxin negative stools by QAB, RAB and PCR were evaluated for toxigenicity by the same direct tests, in order to assess the contribution of the TC (QAB-TC, RAB-TC, PCR-TC). A combination of the cell culture cytotoxicity neutralization assay (CCCNA) in stools, and the same assay on isolates from direct negative samples (CCCNA-TC) was considered the reference method (CCCNA/CCCNA-TC). Of the 250 stools tested, 107 (42.8%) were positive by CCCNA/CCCNA-TC. The GDH and PCR/PCR-TC assays were the most sensitive, 91.59% and 87.62%, respectively. The QAB, RAB, QAB/QAB-TC and RAB/RAB-TC had the highest specificities, ca. 95%. A negative GDH result would rule out CDI, however, its low positive likelihood ratio (PLR) of 3.97 indicates that a positive result should always be complemented with the detection of toxins. If the RAB, QAB, and PCR assays do not detect toxins from direct feces, the toxigenic culture should be performed. In view of our results, the most accurate and reliable methods to be applied in a clinical microbiology laboratory were the QAB/QAB-TC, and RAB/RAB-TC, with PLRs >10 and negative likelihood ratios 10 y una razón de verosimilitud negativa < 0,30.Fil: Legaria, María C.. Asociación Argentina de Microbiología; Argentina. Hospital General de Agudos Dr. Enrique Tornú; ArgentinaFil: Rollet, Raquel. Asociación Argentina de Microbiología; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Infecciosas "Dr. Francisco Javier Muñiz"; ArgentinaFil: Di Martino, Ana. Sanatorio de la Trinidad; Argentina. Asociación Argentina de Microbiología; ArgentinaFil: Castello, Liliana. Asociación Argentina de Microbiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; ArgentinaFil: Barberis, Claudia. Universidad de Buenos Aires. Facultad de Medicina. Hospital de Clínicas General San Martín; Argentina. Asociación Argentina de Microbiología; ArgentinaFil: Rossetti, María A.. Asociación Argentina de Microbiología; Argentina. Hospital Interzonal General de Agudos Presidente Perón; ArgentinaFil: Guardati, María C.. Hospital de Emergencias Dr. Clemente Alvarez; Argentina. Asociación Argentina de Microbiología; ArgentinaFil: Fernández Canigia, Liliana. Hospital Alemán; Argentina. Asociación Argentina de Microbiología; ArgentinaFil: Carloni, Graciela Herminia. Asociación Argentina de Microbiología; Argentina. Universidad de Buenos Aires; ArgentinaFil: Litterio, Mirta. Asociación Argentina de Microbiología; Argentina. Gobierno de la Ciudad de Buenos Aires. Hospital de Pediatría "Juan P. Garrahan"; ArgentinaFil: Rocchi, Marta. Hospital de Urgencias de Cordoba; ArgentinaFil: Anchart, Eduardo G.. Secretaría de Salud Pública de Rosario; ArgentinaFil: Trejo, Fernando Miguel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Minnaard, Jessica. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Klajn, Diana. Hospital General de Agudos Dr. Enrique Tornú; ArgentinaFil: Predari, Silvia C.. Asociación Argentina de Microbiología; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Médicas; Argentin

Detección de Clostridioides [Clostridium] difficile toxigénico: utilidad de dos métodos de enzimoinmunoensayo comerciales y una PCR en las muestras de materia fecal y en los respectivos aislamientos

The best laboratory diagnostic approach to detect Clostridioides [Clostridium] difficile infection (CDI) is a subject of ongoing debate. With the aim of evaluating four laboratory diagnostic methods, 250 unformed stools from patients with suspected CDI submitted to nine medical center laboratories from November 2010 to December 2011, were studied using: (1) an immunochromatographic rapid assay test that combines the qualitative determination of glutamate dehydrogenase (GDH) plus toxins A and B (QAB), the CDIFF QUIK CHEK COMPLETE assay; (2) an enzyme immunoassay for qualitative determination of toxins A and B, the RIDASCREEN™ C. difficile Toxin A/B assay (RAB); (3) a PCR for the toxin B gene assay (PCR); and (4) the toxigenic culture (TC). C. difficile isolates from direct toxin negative stools by QAB, RAB and PCR were evaluated for toxigenicity by the same direct tests, in order to assess the contribution of the TC (QAB-TC, RAB-TC, PCR-TC). A combination of the cell culture cytotoxicity neutralization assay (CCCNA) in stools, and the same assay on isolates from direct negative samples (CCCNA-TC) was considered the reference method (CCCNA/CCCNA-TC). Of the 250 stools tested, 107 (42.8%) were positive by CCCNA/CCCNA-TC. The GDH and PCR/PCR-TC assays were the most sensitive, 91.59% and 87.62%, respectively. The QAB, RAB, QAB/QAB-TC and RAB/RAB-TC had the highest specificities, ca. 95%. A negative GDH result would rule out CDI, however, its low positive likelihood ratio (PLR) of 3.97 indicates that a positive result should always be complemented with the detection of toxins. If the RAB, QAB, and PCR assays do not detect toxins from direct feces, the toxigenic culture should be performed. In view of our results, the most accurate and reliable methods to be applied in a clinical microbiology laboratory were the QAB/QAB-TC, and RAB/RAB-TC, with PLRs >10 and negative likelihood ratios 10 y una razón de verosimilitud negativa < 0,30.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Digital Modernism Heritage Lexicon

The book investigates the theme of Modernism (1920-1960 and its epigones) as an integral part of tangible and intangible cultural heritage which contains the result of a whole range of disciplines whose aim is to identify, document and preserve the memory of the past and the value of the future. Including several chapters, it contains research results relating to cultural heritage, more specifically Modernism, and current digital technologies. This makes it possible to record and evaluate the changes that both undergo: the first one, from a material point of view, the second one from the research point of view, which integrates the traditional approach with an innovative one. The purpose of the publication is to show the most recent studies on the modernist lexicon 100 years after its birth, moving through different fields of cultural heritage: from different forms of art to architecture, from design to engineering, from literature to history, representation and restoration. The book appeals to scholars and professionals who are involved in the process of understanding, reading and comprehension the transformation that the places have undergone within the period under examination. It will certainly foster the international exchange of knowledge that characterized Modernism