Resistance to carbapenems in non-typhoidal Salmonella enterica serovars from humans, animals and food

Non-typhoidal serovars of Salmonella enterica (NTS) are a leading cause of food-borne disease in animals and humans worldwide. Like other zoonotic bacteria, NTS have the potential to act as reservoirs and vehicles for the transmission of antimicrobial drug resistance in different settings. Of particular concern is the resistance to critical “last resort” antimicrobials, such as carbapenems. In contrast to other Enterobacteriaceae (e.g., Klebsiella pneumoniae, Escherichia coli, and Enterobacter, which are major nosocomial pathogens affecting debilitated and immunocompromised patients), carbapenem resistance is still very rare in NTS. Nevertheless, it has already been detected in isolates recovered from humans, companion animals, livestock, wild animals, and food. Five carbapenemases with major clinical importance—namely KPC (Klebsiella pneumoniae carbapenemase) (class A), IMP (imipenemase), NDM (New Delhi metallo-β-lactamase), VIM (Verona integron-encoded metallo-β-lactamase) (class B), and OXA-48 (oxacillinase, class D)—have been reported in NTS. Carbapenem resistance due to the production of extended spectrum- or AmpC β-lactamases combined with porin loss has also been detected in NTS. Horizontal gene transfer of carbapenemase-encoding genes (which are frequently located on self-transferable plasmids), together with co- and cross-selective adaptations, could have been involved in the development of carbapenem resistance by NTS. Once acquired by a zoonotic bacterium, resistance can be transmitted from humans to animals and from animals to humans through the food chain. Continuous surveillance of resistance to these “last resort” antibiotics is required to establish possible links between reservoirs and to limit the bidirectional transfer of the encoding genes between S. enterica and other commensal or pathogenic bacteria

Analysis of the Degradation of Broad-Spectrum Cephalosporins by OXA-48-Producing Enterobacteriaceae Using MALDI-TOF MS

The objective of the study was to evaluate the activity of OXA-48 against different broad-spectrum cephalosporins and to identify the reaction products by MALDI-TOF MS. The action of OXA-48 on cefotaxime, ceftazidime, and ceftriaxone was assessed by this method, using an Escherichia coli J53 transconjugant carrying only the ~62 Kb IncL plasmid containing the blaOXA-48 gene, and the same strain without any plasmid was included as a negative control. In addition, a collection of 17 clinical OXA-48-producing Enterobacteriaceae, which were susceptible to broad-spectrum cephalosporins, was evaluated. MALDI-TOF MS-based analysis of the E. coli transconjugant carrying the blaOXA-48-harboring plasmid, and also the clinical isolates, showed degradation of cefotaxime into two inactive compounds-decarboxylated and deacetylated cefotaxime (~370 Da) and deacetyl cefotaxime (~414 Da), both with the hydrolyzed beta-lactam ring. Reaction products were not obtained when the experiment was performed with ceftriaxone or ceftazidime. From a clinical point of view, our study supports the idea that the efficacy of cefotaxime against OXA-48-producing Enterobacteriaceae is doubtful, in contrast to ceftazidime and ceftriaxone which could be valid choices for treating infections caused by these bacteria. However, further clinical studies confirming this hypothesis are required

Identification of an Emergent and Atypical Pseudomonas viridiflava Lineage Causing Bacteriosis in Plants of Agronomic Importance in a Spanish Region

Pseudomonas strains with an atypical LOPAT profile (where LOPAT is a series of determinative tests: L, levan production; O, oxidase production; P, pectinolitic activity; A, arginine dihydrolase production; and T, tobacco hypersensibility) can be regarded as emergent pathogens in the Principality of Asturias (Spain), where they have been causing, since 1999, severe damage in at least three taxonomically unrelated orchard plants of agronomic importance: common bean (Phaseolus vulgaris), kiwifruit (Actinidia deliciosa), and lettuce (Lactuca sativa). These strains are mainly differentiated by production of yellowish mucoid material in hypersucrose medium, used for the levan test, and by a variable pectinolytic activity on different potato varieties. The atypical organisms were identified as Pseudomonas viridiflava based on their 16S rRNA sequences. Among them a certain intraspecies genetic heterogeneity was detected by randomly amplified polymorphic DNA (RAPD) typing. To differentiate between isolates of P. viridiflava and Pseudomonas syringae pathovars, a 16S ribosomal DNA restriction fragment length polymorphism method employing the restriction endonucleases SacI and HinfI was developed. This could be used as a means of reliable species determination after the usual phenotypical characterization, which includes the LOPAT tests

Las malas hierbas contribuyen a la supervivencia de algunas bacterias fitopatógenas

En Asturias es muy frecuente que las malas hierbas acompañen a nuestros cultivos, por lo que, para controlarlas, es imprescindible realizar labores de escarda. En el Laboratorio de Fitopatología del SERIDA se encontraron bacterias patógenas de la judía en algunas malas hierbas, que constituyen una fuente de inóculo y un reservorio que permite sobrevivir a la bacteria cuando no hay cultivo

A Pseudomonas viridiflava-Related Bacterium Causes a Dark-Reddish Spot Disease in Glycine max

A virulent Pseudomonas viridiflava-related bacterium has been identified as a new pathogen of soybean, one of the most important crops worldwide. The bacterium was recovered from forage soybean leaves with dark-reddish spots, and damage on petioles and pods was also observed. In contrast, common bean was not affected

AppDIXITOU: xogo educativo para móbil co que se conciencia a xente adolescente no bo uso das redes sociais

Hoxe en día, a maioría da xente adolescente posúe un móbil e boa parte dela usa as redes sociais para socializar. Pero, ata que punto saben como usalas correctamente? Este traballo describe a necesidade e o desenvolvemento dunha ferramenta informática educativa para o móbil (AppDIXITOU), na que se aplica a gamificación coa pretensión de concienciar e de educar nun uso máis racional e saudable das redes sociais o estudantado de educación secundaria obrigatoria da provincia de Ourense. Unha das recomendacións que realizan diversos estudos para reducir os perigos, que afrontan os e as menores cando empregan as redes sociais, consiste en realizar campañas formativas destinadas a eles e elas onde, ademais de informalos deses riscos,se intente modificar o seu comportamento ante o uso destas. AppDIXITOU pretende formar parte desa «misión». Este soporte lóxico (software) desenvolveuse para que se use nun móbil, dispositivo tan cotián hoxe en día entre a xente adolescente. Despois dun estudo sobre o sistema operativo para móbil máis empregado entre os móbiles que dispoñen a maioría da mocidade, decidiuse que a aplicación funcione sobre Android. A gamificación é o uso do pensamento e a mecánica de xogabilidade en contextos alleos aos xogos, co fin de que as persoas adopten certo comportamento. Se se aplica ao ámbito educativo, a finalidade desta técnica de aprendizaxe é aumentar a motivación e favorecer o coñecemento. O obxectivo de aplicar esta metodoloxía no software desenvolvido foi dobre: por unha banda, mellorar o coñecemento que ten a poboación adolescente dos riscos que supón un uso incorrecto das redes sociais e, por outra, non menos importante, provocar cambios no comportamento destes ante situacións perigosas orixinadas polo uso das citadas redes