<em>Staphylococcus aureus</em> in the Meat Supply Chain: Detection Methods, Antimicrobial Resistance, and Virulence Factors

Staphylococcus aureus (S. aureus) can cause a wide variety of infections in humans, such as skin and soft tissue infections, bacteremia, pneumonia, and food poisoning. This pathogen could be carried on the nares, skin, and hair of animals and humans, representing a serious problem at the hospital and the community level as well as in the food industry. The pathogenicity of S. aureus is given by bacterial structures and extracellular products, among which are toxins, which could cause staphylococcal diseases transmitted by food (SFD). S. aureus has the ability to develop resistance to antimicrobials (AMR), highlighting methicillin-resistant strains (MRSA), which have resistance to all beta-lactam antibiotics, except to the fifth-generation cephalosporins. Methicillin resistance is primarily mediated by three mechanisms: production of an altered penicillin-binding protein PBP2’ (or PBP2a), encoded by the mecA gene; high production of β-lactamase in borderline oxacillin-resistant Staphylococcus aureus (BORSA); and mutations in the native PBPs, called modified S. aureus (MODSA). Emerging strains have been isolated from meat-producing animals and retail meat, such as MRSA, MRSA ST398 (associated with livestock), multidrug-resistant (MDR) S. aureus, and enterotoxin-producing S. aureus. Therefore, there is a risk of contamination of meat and meat products during the different processing stages of the meat supply chain

Antibacterial activity of the Antarctic bacterium Janthinobacterium sp. SMN 33.6 against multi-resistant Gram-negative bacteria

Background: The increment of resistant strains to commonly used antibiotics in clinical practices places in evidence the urgent need to search for new compounds with antibacterial activity. The adaptations that Antarctic microorganisms have developed, due to the extreme environment that they inhabit, promote them as a potential new source of active compounds for the control of microorganisms causing infections associated with health care. The aim of this study was to evaluate the antibacterial activity of an ethanol extract of the Antarctic bacterium Janthinobacterium sp., strain SMN 33.6, against nosocomial multi-resistant Gram-negative bacteria. Results: Inhibitory activity against human Gram-negative bacterial pathogens, with concentrations that varied between 0.5 and 16 \u3bcg ml-1, was demonstrated. Conclusions: The ethanolic extract of Janthinobacterium sp. SMN 33.6 possesses antibacterial activity against a chromosomal AmpC beta-lactamase-producing strain of Serratia marcescens , an extended-spectrum beta-lactamase-producing Escherichia coli and also against carbapenemase-producing strains of Acinetobacter baumannii and Pseudomonas aeruginosa . This becomes a potential and interesting biotechnological tool for the control of bacteria with multi-resistance to commonly used antibiotics

Draft Genome Sequence of a Multidrug-Resistant Acinetobacter baumannii Strain from Chile

Date of Acceptance: 20/05/2015 Copyright © 2015 Opazo et al. This is an open-access article distributed under the terms of the Creative Commons Attribution 3.0 Unported license. ACKNOWLEDGMENTS This work was supported through funds granted by the Chilean National Commission for Scientific and Technological Research (CONICYT) and by the National Fund for Scientific and Technological Development (FONDECYT) of Chile (project 3150286).Peer reviewedPublisher PD

El periurbano en México: identificación y caracterización sociodemográfica y territorial

Scientific production and territorial politics in Mexico have been built basically from the country-city dichotomy. Consequently, peri-urban phenomena have not been clearly explained and the policies addressed at these spaces are not explicit or differentiated. This article aims to provide panoramic information on the peri-urban in Mexico. First, a method is proposed for the identification of the peri-urban based on the Shannon entropy index that measures the heterogeneity of land use. Second, we characterize the peri-urban space by demographic, social and territorial attributes. Finally, the study identifies four sociodemographic and territorial dimensions of the peri-urban space: 1) socio-occupational polarization, 2) the opposition between natural land and cultivated land, 3) urbanization as a built environment, and demographic dynamics, and 4) social marginalization and informal dwelling. These dimensions suggest differentiated simultaneous processes in the peri-urban space.La producción científica y la política territorial en México se ha construido básicamente a partir de la dicotomía campo-ciudad. En consecuencia, los fenómenos periurbanos no han sido claramente explicados y, las políticas dirigidas a estos espacios no son explícitas o diferenciadas. En ese sentido, este artículo busca aportar información panorámica del periurbano en México. Primeramente, se propone un método para la identificación del periurbano basado en el índice de entropía de Shannon que mide la heterogeneidad del uso del suelo. En un segundo tiempo, el estudio caracteriza el espacio periurbano a través de atributos demográficos, sociales y territoriales. Finalmente, el estudio identifica cuatro dimensiones sociodemográficas y territoriales del espacio periurbano: 1) polarización socio-ocupacional, 2) la oposición entre suelo natural y suelo para el cultivo, 3) urbanización como entorno construido y dinámica demográfica, y 4) marginación social e informalidad residencial. Estas dimensiones sugieren procesos simultáneos diferenciados en el espacio periurbano

Enterococcus spp. isolated from root canals with persistent chronic apical periodontitis in a Chilean population

isolate and identify in a Chilean population, Enterococcus spp. from root canals with persistent chronic apical periodontitis (CAP) and to investigate the potential correlation between the bacteria and the observed clinical features. Methods: Twenty patients with indication for endodontic retreatment due to persistent CAP were selected. Data from patient general health and dental clinical history were recorded. During retreatment, a microbial sample was obtained from the root canal and inoculated in a selective Enterococcus medium. Using bacterial cultivation methods, bacterial isolates belonging to the genus Enterococcus were identified. The relationship between the number of colony-forming units of Enterococcus spp. and patient clinical data was assessed statistically by the Pearson Chi square and Fisher exact tests. Finally, a Polymerase Chain Reaction (PCR) assay to determine the most prevalent species of Enterococcus spp. Was conducted in the clinical samples, and the results were analyzed by a proportion comparison test. Results: Enterococcus spp. strains were isolated in 70% of the patients. Most of them (98.8%) accounted for Enterococcus faecalis and only 1.2% for Enterococcus faecium. A high frequency of E. faecalis was found in teeth with inadequate endodontic treatment or dental crown restorations. Conclusions: This study concluded that E. faecalis is prevalent in root canals with persistent CAP in a Chilean population. E. faecium as found in a single case with the poorest root canal filling. Further studies are still required to investigate the presence of other species, which may be linked to persistent chronic apical periodontitis