An automated sonic tomography system for the inspection of historical masonry walls.

Background: The conservation of the built masonry heritage requires a comprehensive understanding of its geometrical, structural, and material characteristics. Non-destructive techniques are a preferred approach to survey historical buildings, given the cultural value of their fabric. However, currently available techniques are typically operated manually, consuming much time at operational and processing level and thus hindering their use for the on-site inspection of heritage structures. Methods: A novel automated sonic tomography system was designed and built to inspect and obtain information about the inner structure and damage of historic masonry walls. The system consists of a hitting device mounted on a frame that can be placed adjacent to the wall under analysis. The hitting device can move along the surface within the frame area in X, Y and Z directions, generating the sonic wave. The receiving system is a scanning laser vibrometer, able to measure from the distance the displacement of a focused point over time, recording the wave when it reaches the opposite surface. Results: Six stone masonry walls with different interior geometries were constructed at the laboratory by a professional stonemason. The construction of the walls was carefully documented, including the generation of detailed photogrammetric models of each single stone. The system was applied to survey the six masonry walls. Since the inner morphology of the walls is known, the resulting tomographic images could be compared with the ground truth. Conclusions: Automating the inspection allowed to collect thousands of data in a few hours. New software was also developed to automate the processing of the data. Results are expected to highlight the potential of tomography to obtain quantitative information about the interior of heritage structures, while providing new tools that make the implementation of the technique more practical for professionals. Data, software and models have been made publicly available.

The rediscovery of Heteragrion azulum Dunkle, 1989 with additional notes on the female (Odonata: Heteragrionidae).

Some details of the morphology of the female of Heteragrion azulum Dunkle, 1989 are described for the first time such as the intersternite, and illustrated with high quality photographs, based upon two specimens collected in the tropical rain forest at the region of Los Tuxtlas, in the state of Veracruz, Mexico. A comparison with females of the other three species of Heteragrion Selys, 1862 occurring in Mexico is also provided. Additional data of males of H. azulum collected together with the females are also given, including some illustrations.

Ultrasonic Propagation in Liquid and Ice Water Drops. Effect of Porosity.

This work studies ultrasonic propagation in liquid and ice water drops. The effect of porosity on attenuation of ultrasonic waves in the drops is also explored. The motivation of this research was the possible application of ultrasonic techniques to the study of interstellar and cometary ice analogs. These ice analogs, made by vapor deposition onto a cold substrate at 10 K, can display high porosity values up to 40%. We found that the ultrasonic pulse was fully attenuated in such ice, and decided to grow ice samples by freezing a liquid drop. Several experiments were performed using liquid or frozen water drops with and without pores. An ultrasonic pulse was transmitted through each drop and measured. This method served to estimate the ultrasonic velocity of each drop by measuring drop size and time-of-flight of ultrasonic transmission. Propagation of ultrasonic waves in these drops was also simulated numerically using the SimNDT program developed by the authors. After that, the ultrasonic velocity was related with the porosity using a micromechanical model. It was found that a low value of porosity in the ice is sufficient to attenuate the ultrasonic propagation. This explains the observed lack of transmission in porous astrophysical ice analogs.

A full-scale experimental study of sub-slab pressure fields induced by underground perforated pipes as a soil depressurisation technique in radon mitigation.

Sub-slab depressurisation systems have proven to effectively mitigate radon entry. A poor understanding of the fluid physics underlying the technique has been shown to lower the success rate substantially. This article describes a study of pressure fields in a sub-slab gravel bed induced by a soil depressurisation system consisting of perforated pipes run under the slab at a depth of 75 cm. The advantage of the approach is that pipes can be laid from outside the building to be protected. The study was conducted on a large-scale experimental facility where the variations in morphology and scope of pressure fields with different pipe combinations could be monitored and characterised. The findings showed that pressure was uniform across the entire area in the gravel bed, whereas the sensors buried in natural soil showed pressure to depend on distance from the source. Pressure transfer to the sub-slab plane was also observed to vary depending on the active pipe. Air-flow resistance studies in the layers of soil lying between the pipes and the gravel delivered different results for each pipe. That finding would appear to be related to the presence of preferential pathways in some parts of the soil. Total pressure when several pipes were activated was observed to be practically the same as the sum of the pressures transferred by each when working separately. The correlation between extraction fan power and pressure generated was also analysed. These and other factors are discussed and analysed from a perspective of the understanding of such highly effective techniques.

The larva of Phyllogomphoides pugnifer Donnelly, 1979 (Odonata: Gomphidae).

The larva of Phyllogomphoides pugnifer Donnelly, 1979 is described for the first time based on reared specimens to emergence, and several F-0 larvae collected in Chiapas and Veracruz states, Mexico. The larva of P. pugnifer can be separated from other larvae of the genus by the length/width proportion of structures such as prementum, ligula, and abdominal segment 10, as well as length of cercus relative to epiproct.

A Multisensor System for the Characterization of the Field Pressure in Terrain. Accuracy, Response, and Adjustments.

In different disciplines of science, the knowledge of the resulting pressures in the subsoil can help to understand physical phenomena of mass exchange between the atmosphere and the terrain. The measurement of lower differential pressures is complicated given the low range of detected values. In this paper, a multisensor system has been designed and developed to measure differential pressures in radon gas transport studies. The adequacy of this system has been proven using a purpose-built pressure chamber and an automatic motion system developed by the authors. The temporal response frequencies, the pressure values measured by the sensors, and their ability to link in series were analyzed to offer a multisensor spatial and temporal mapping. At the same time, the influence of the components required for a real deployment were studied using different tube lengths and diameters, connectors, and obstructions across the operating range of the pressure sensors. The system has also been tested for measuring differential pressures in a real model with a concrete slab above the soil and a pressure generator system below. It was found that this system is very suitable for outdoor measurements that demand a quick temporal response and accuracy.

The Challenge of Universal Eye Health in Latin America: distributive inequality of ophthalmologists in 14 countries.

BACKGROUND: No comprehensive study currently exists on the supply of ophthalmologists across Latin America. We explored sociogeographic inequalities in the availability and distribution of ophthalmologists across 14 Latin American countries. METHODS: The National Ophthalmologic Societies of Argentina, Bolivia, Brazil, Colombia, Costa Rica, Chile, the Dominican Republic, Ecuador, Guatemala, Mexico, Paraguay, Peru, Uruguay and Venezuela provided data on affiliated ophthalmologists by first-order subnational divisions in 2013. Human Development Index (HDI) estimates at the corresponding subnational division were used as equity stratifiers. Distributional inequality of ophthalmologists within each country was assessed by the health concentration index (HCI) and the index of dissimilarity (ID), along with the mean level of ophthalmologists per population. RESULTS: Across all countries studied, there were 5.2 ophthalmologists per 100 000 population on average (95% CI 5.0 to 5.4) in 2013, with a mean HCI of 0.26 (0.16 to 0.37) and a mean relative ID of 22.7% (20.9% to 24.7%). There was wide inequality in ophthalmologist availability between countries, ranging from 1.2 (1.1 to 1.4) in Ecuador to 8.6 (8.5 to 8.8) in Brazil. All countries had positive (ie, pro-rich) HCI values ranging from 0.68 (0.66 to 0.71) in Guatemala to 0.02 (-0.11 to 0.14) in Venezuela. Correspondingly, redistributive potential to achieve equity was closest in Venezuela (ID: 1.5%) and farthest in Guatemala (ID: 60.3%). Benchmarked against regional averages, most countries had a lower availability of ophthalmologists and higher relative inequality. CONCLUSIONS: There is high inequality in the level and distribution of ophthalmologists between and within countries in Latin America, with a disproportionate number concentrated in more developed, socially advantaged areas. More equitable access to ophthalmologists could be achieved by implementing incentivised human resources redistribution programmes and by improving the social determinants of health in underserved areas.

Intravehicular, Short- and Long-Range Communication Information Fusion for Providing Safe Speed Warnings.

Inappropriate speed is a relevant concurrent factor in many traffic accidents. Moreover, in recent years, traffic accidents numbers in Spain have fallen sharply, but this reduction has not been so significant on single carriageway roads. These infrastructures have less equipment than high-capacity roads, therefore measures to reduce accidents on them should be implemented in vehicles. This article describes the development and analysis of the impact on the driver of a warning system for the safe speed on each road section in terms of geometry, the presence of traffic jams, weather conditions, type of vehicle and actual driving conditions. This system is based on an application for smartphones and includes knowledge of the vehicle position via Ground Positioning System (GPS), access to intravehicular information from onboard sensors through the Controller Area Network (CAN) bus, vehicle data entry by the driver, access to roadside information (short-range communications) and access to a centralized server with information about the road in the current and following sections of the route (long-range communications). Using this information, the system calculates the safe speed, recommends the appropriate speed in advance in the following sections and provides warnings to the driver. Finally, data are sent from vehicles to a server to generate new information to disseminate to other users or to supervise drivers' behaviour. Tests in a driving simulator have been used to define the system warnings and Human Machine Interface (HMI) and final tests have been performed on real roads in order to analyze the effect of the system on driver behavior.

Evaluation of the impact on non-communicable chronic diseases of a major integrated primary health care program in Mexico.

BACKGROUND: Primary health care is the best framework for implementing actions for the prevention and control of non-communicable diseases at an appropriate scale. In 2002, the Mexican Institute for Social Security (IMSS), which provides health care to half of the Mexican population, implemented a primary care-based integrated program that included the improvement of the family health care practice and a preventive strategy called PREVENIMSS, to reduce the burden of disease. OBJECTIVE: To asess the impact of this program on selected non-communicable chronic diseases. METHODS: Morbidity and mortality were compared before and after implementation of the program and time trends in IMSS affiliates and non-affiliates using the difference-in-differences (DD) method. RESULTS: Incidence rates of diabetes and hypertension increased whereas those of cervical cancer, breast cancer and other cerebrovascular diseases decreased from 2000 to 2013. The DD in mortality rates, expressed per 100000 persons, showed a decrease of 49.4 for diabetes mellitus, 9.1 for hypertensive disease, 42.9 for ischemic heart disease, 17.4 for cerebrovascular disease, 7.5 for cervical cancer and 5.8 for breast cancer. CONCLUSIONS: The reductions in mortality rates could be explained by both changes in incidence rates and changes in case fatality rates associated with early detection and treatment. These initial findings can be interpreted as the potential impact of integrated programs based on primary health care in a developing country.

Description of the larva of Epigomphus crepidus Kennedy, 1936 (Odonata: Gomphidae).

The larva of Epigomphus crepidus Kennedy is described and figured and compared with other described congeners. It is characterized by 3rd antennomere spindle-shaped, flattened dorso-ventrally, twice longer than its widest part; ventral pad of hypopharynx pentagonal; prementum subrectangular, with lateral margins slightly convex on apical 0.60; ligula very poorly developed, with a ventral row of nine short, truncate teeth on middle, and dorsal rows of short, stout piliform setae. Abdomen lacking dorsal protuberances, lateral spines on S7-9 divergent; sternites 3-8 divided into five plates, sternites 2 and 9 divided into three plates; male epiproct with a pair of dorsal tubercles rounded apically and divergent at basal 0.30. It differs from other species mainly in 3rd antennomere, sides of prementum and serrations on lateral margins of S7-9.

A case of successful restoration of a tropical wetland evaluated through its Odonata (Insecta) larval assemblage

etlands are important wildlife habitats that also provide vital services for human societies. Unfortunately, they have been disappearing due to human activities such as conversion to farmland, pollution, habitat fragmentation, invasion of alien species, and inappropriate management, resulting in declines in species diversity, wildlife habitat quality, and ecosystem functions and services. In some countries, many programs and actions have been undertaken to reverse the rate of wetland loss by restoring, creating and constructing new wetlands. We report on the assessment of Odonata larvae from a tropical and putatively restored wetland located in the La Mancha Biological Station, CICOLMA (LM, Ramsar site #1336), Veracruz, Mexico. Larval surveys were performed during the 2010 and 2011 dry and rainy seasons in both LM and a reference site, Cansaburro (CB), located approximately 2 km South of LM. Twelve samples were collected during each survey using a D-frame aquatic net (0.2 mm mesh size), sweeping 1 m2 areas along shorelines using a random design. The effect of site, season and year on Odonata larval abundance was explored and diversity and abundance patterns of the assemblages were compared. A total of 3 718 larvae from 25 species (five Zygoptera and 20 Anisoptera) in 14 genera and three families were collected from both wetlands. Species number was equal in both wetlands although abundance was significantly higher in LM. Renyi´s diversity profiles and species abundance patterns (rank abundance curves) in both sites were similar, suggesting an apparent recovery at LM. Differences in species composition (sites shared 13 species), and species dominance between both assemblages were observed and were related to differences in the aquatic plant structure between both wetlands as a result of extensive plant management in LM and cattle grazing in CB. Most evidence derived from this work shows that the LM wetland may be recovered. Rev. Biol. Trop. 63 (4): 1043-1058. Epub 2015 December 01.

os humedales son hábitats importantes para la vida silvestre y también proporcionan servicios vitales para la sociedad que, por desgracia, han ido desapareciendo debido al uso del suelo que produce una disminución en la diversidad de especies, la calidad del hábitat de vida silvestre, y de la función de los ecosistemas. En algunos países se han llevado a cabo programas y acciones para revertir la tasa de pérdida de los humedales mediante la restauración, la creación y la construcción de nuevos humedales. En este trabajo se reporta un estudio numérico de las larvas de odonatos de un humedal tropical asumido como restaurado, localizado en la Estación de Biología La Mancha, CICOLMA (LM, sitio Ramsar # 1336), Veracruz, México. Los muestreos de las larvas se realizaron durante las estaciones de secas y lluvias de 2010 y 2011 tanto en LM como en el sitio de referencia Cansaburro (CB) situado a unos 2 km al sur de LM. Se tomaron doce muestras al azar en las orillas durante cada recolecta en cada sitio utilizando una red acuática D-net (abertura de malla de 0.2 mm) barriendo una área aproximada de 1 m2. El efecto del sitio, la temporada y el año sobre la abundancia de larvas fue explorado y los patrones de diversidad y abundancia de ambas comunidades fueron comparadas. Un total de 3 718 larvas de 25 especies (cinco Zygoptera y 20 Anisoptera) de 14 géneros y tres familias se obtuvieron de ambos humedales. El número de especies fue igual en ambos humedales aunque la abundancia fue significativamente mayor en LM. Los perfiles de diversidad de Renyi y los patrones de abundancia de especies (curvas de rango abundancia) en ambos sitios fueron similares sugiriendo una evidente recuperación de LM. Las diferencias observadas en la composición de especies (los sitios compartieron 13 especies) y la dominancia de las especies entre ambas comunidades se explica con base en las diferencias en la estructura vegetal acuática entre los dos humedales que es principalmente el resultado de una amplio manejo en LM y del pastoreo de ganado en CB. La mayoría de las pruebas derivadas de este trabajo muestran que el humedal de LM puede estar recuperado.

The Transformation of the Mexican Social Security Institute (IMSS): Progress and Challenges.

Abstract-In 2013, the Mexican Social Security Institute (IMSS), the largest social security institution in Latin America, began a major transformation with two clear objectives: first, to improve the quality of its services in order to achieve better health outcomes and increase satisfaction among its 70 million beneficiaries and, second, to stabilize the Institute's finances. As in many other emerging economies, Mexico's demographic and epidemiological transitions, in conjunction with bureaucratic inefficiencies, left the Institute in a precarious financial situation. In 2012, the previous administration reported to the Mexican Congress that the Institute could remain financially self-sufficient until 2014. In the first year of this administration (2013), the deficit was reduced by half. By the second year (2014), the deficit was stabilized at the same level and the trend in the use of reserves consolidated. These results consolidated financial stability of the IMSS and, even better, were carried out while maintaining service quality and improving productivity. This article discusses how the IMSS transformation prioritized micro reforms over a macro approach to solve short-term problems by administering IMSS's limited resources in a more efficient and productive manner. The article also discusses the deep transformation that IMSS health care and resource management models will need to undergo in order to face pending medium and long-term challenges to ensure that IMSS can be sustainable in the long-term.

Vehicle tracking for an evasive manoeuvres assistant using low-cost ultrasonic sensors.

Many driver assistance systems require knowledge of the vehicle environment. As these systems are increasing in complexity and performance, this knowledge of the environment needs to be more complete and reliable, so sensor fusion combining long, medium and short range sensors is now being used. This paper analyzes the feasibility of using ultrasonic sensors for low cost vehicle-positioning and tracking in the lane adjacent to the host vehicle in order to identify free areas around the vehicle and provide information to an automatic avoidance collision system that can perform autonomous braking and lane change manoeuvres. A laser scanner is used for the early detection of obstacles in the direction of travel while two ultrasonic sensors monitor the blind spot of the host vehicle. The results of tests on a test track demonstrate the ability of these sensors to accurately determine the kinematic variables of the obstacles encountered, despite a clear limitation in range.

An embedded stress sensor for concrete SHM based on amorphous ferromagnetic microwires.

A new smart concrete aggregate design as a candidate for applications in structural health monitoring (SHM) of critical elements in civil infrastructure is proposed. The cement-based stress/strain sensor was developed by utilizing the stress/strain sensing properties of a magnetic microwire embedded in cement-based composite (MMCC). This is a contact-less type sensor that measures variations of magnetic properties resulting from stress variations. Sensors made of these materials can be designed to satisfy the specific demand for an economic way to monitor concrete infrastructure health. For this purpose, we embedded a thin magnetic microwire in the core of a cement-based cylinder, which was inserted into the concrete specimen under study as an extra aggregate. The experimental results show that the embedded MMCC sensor is capable of measuring internal compressive stress around the range of 1-30 MPa. Two stress sensing properties of the embedded sensor under uniaxial compression were studied: the peak amplitude and peak position of magnetic switching field. The sensitivity values for the amplitude and position within the measured range were 5 mV/MPa and 2.5 µs/MPa, respectively.

Distributed pedestrian detection alerts based on data fusion with accurate localization.

Among Advanced Driver Assistance Systems (ADAS) pedestrian detection is a common issue due to the vulnerability of pedestrians in the event of accidents. In the present work, a novel approach for pedestrian detection based on data fusion is presented. Data fusion helps to overcome the limitations inherent to each detection system (computer vision and laser scanner) and provides accurate and trustable tracking of any pedestrian movement. The application is complemented by an efficient communication protocol, able to alert vehicles in the surroundings by a fast and reliable communication. The combination of a powerful location, based on a GPS with inertial measurement, and accurate obstacle localization based on data fusion has allowed locating the detected pedestrians with high accuracy. Tests proved the viability of the detection system and the efficiency of the communication, even at long distances. By the use of the alert communication, dangerous situations such as occlusions or misdetections can be avoided.

El dibujo: un facilitador del tratamiento psicoterapéutico de niños con autismo / Drawing as a facilitator of the psychotherapeutic treatment of children with autism

El artículo muestra el proceso terapéutico de un niño con autismo. Dicho proceso pone énfasis en el análisis y manejo de la contratransferencia del terapeuta como herramienta de cura al servicio del tratamiento psicoterapéutico. En este caso se hace uso de mediadores como el agua y la pintura para la disolución de la barrera autista formada por los temores primitivos y finalmente, se utiliza el dibujo como facilitador del proceso terapéutico encaminando al paciente hacia el logro de la simbolización (AU)

This paper shows the therapeutic process of a child with autism. The analysis and management of the therapist's countertransference as a tool at the service of psychotherapy is emphasized. Mediators such as water and paint were used in this occasion for the dissolution of the autistic barrier formed by primitive fears. Finally, the use of drawing as a facilitator of the therapeutic process was used in order to address the patient towards symbolization (AU)

Diversity and distribution of Odonata (Insecta) larvae along an altitudinal gradient in Coalcomán mountains, Michoacán, Mexico

Evaluating components of landscape diversity is essential for the implementation of efficient conservation strategies. We evaluated the diversity of Odonata larval assemblages from the Coalcomán mountains (CM), Michoacán, Mexico, and related it to local (site-level) habitat variables. Larvae were collected from shores, riffles and pools in five streams, counted and identified to species, twice per season during 2005. The Shannon Diversity Index (H’), Margalef’s Richness Index (R), Simpson’s Index as a dominance measure (D) and Pielou’s Equitability (J) were used to describe the assemblages, and Renyi’s Diversity Profiles were used to order diversity. A Bray-Curtis Similarity Index (BC) was used to evaluate beta diversity. Theoretical richness was estimated using non-parametric and parametric methods. A Canonical Correspondence Analysis (CCA) was applied to explore the relationships of species with site-level environmental variables. A total of 12 245 larvae from 75 species, 28 genera and 8 families were recorded. Over all sites, the dominant species were Erpetogomphus elaps, Macrothemis pseudimitans and Argia pulla. The number of species per locality ranged from 18 to 36, and a high number of species (76%) occurred with relative abundances lower than 1%. A differential distribution of species and abundance in streams, time and strata was observed. Renyi’s diversity profiles showed diversity was higher in spring and on shores. Most BC similarity values were smaller than 25%, indicating a high turnover rate in the CM. The high turnover rate reflects a differential distribution of the species along the altitudinal gradient, supporting the hypothesis of Mexico as a betadiverse country. According to the slope of Clench’s curve, a reliable list of species was gathered. The CM larval assemblage is currently the largest reported for Mexico, and our results support previous proposals of the CM as a species-rich area for conservation. Rev. Biol. Trop. 59 (4): 1559-1577. Epub 2011 December 01.

Evaluar los componentes de la diversidad de paisaje es una tarea esencial para implementar estrategias eficientes de conservación. En este estudio se describe la variación geográfica, temporal y por hábitats de la diversidad de larvas de odonatos en un gradiente altitudinal en la sierra de Coalcomán, Michoacán, México, y se explora su relación con variables fisicoquímicas locales. Presentamos diferentes índices de diversidad y gráficos de perfiles de diversidad de Renyi, así como la riqueza teórica por métodos paramétricos y no paramétricos, el recambio de especies en la sierra y, mediante análisis canónico de correspondencias (ACC) la relación de las especies con las variables fisicoquímicas. Recolectamos un total 12 245 larvas de 75 especies, 28 géneros y 8 familias. En todos los hábitats un alto número de especies presentó una abundancia inferior al 1%. El número de especies en los arroyos varió entre 18 y 36, existe además un alto recambio en la sierra. La diversidad beta es un componente importante de la diversidad del paisaje; se apreció una alternancia en la dominancia estacional entre anisópteros y zygópteros y nuestros datos concuerdan con la hipótesis del Mexico betadiverso y también apoya propuestas previas de conservación de la sierra.

Diversity and distribution of Odonata (Insecta) larvae along an altitudinal gradient in Coalcomán mountains, Michoacán, Mexico.

Evaluating components of landscape diversity is essential for the implementation of efficient conservation strategies. We evaluated the diversity of Odonata larval assemblages from the Coalcomán mountains (CM), Michoacán, Mexico, and related it to local (site-level) habitat variables. Larvae were collected from shores, riffles and pools in five streams, counted and identified to species, twice per season during 2005. The Shannon Diversity Index (H'), Margalef's Richness Index (R), Simpson's Index as a dominance measure (D) and Pielou's Equitability (J) were used to describe the assemblages, and Renyi's Diversity Profiles were used to order diversity. A Bray-Curtis Similarity Index (BC) was used to evaluate beta diversity. Theoretical richness was estimated using non-parametric and parametric methods. A Canonical Correspondence Analysis (CCA) was applied to explore the relationships of species with site-level environmental variables. A total of 12 245 larvae from 75 species, 28 genera and 8 families were recorded. Over all sites, the dominant species were Erpetogomphus elaps, Macrothemis pseudimitans and Argia pulla. The number of species per locality ranged from 18 to 36, and a high number of species (76%) occurred with relative abundances lower than 1%. A differential distribution of species and abundance in streams, time and strata was observed. Renyi's diversity profiles showed diversity was higher in spring and on shores. Most BC similarity values were smaller than 25%, indicating a high turnover rate in the CM. The high turnover rate reflects a differential distribution of the species along the altitudinal gradient, supporting the hypothesis of Mexico as a betadiverse country. According to the slope of Clench's curve, a reliable list of species was gathered. The CM larval assemblage is currently the largest reported for Mexico, and our results support previous proposals of the CM as a species-rich area for conservation.

Ambiente genético del gen blaCTX-M-12 en aislamientos hospitalarios de klebsiella pneumoniae / The blaCTX-M-12 gene's genetic environmnt in klebsiella pneumoniae hospital isolates

En Colombia se han detectado genes del grupo CTX-M-1 con alta frecuencia en aislamientos de Klebsiella pneumoniae causantes de infección intrahospitalaria. El conocimiento de los factores genéticos que pueden favorecer la diseminación de estos genes entre especies bacterianas es un aspecto importante para el control de la resistencia. En este estudio se identificaron los plásmidos portadores del gen blaCTX-M-12 en 21 aislamientos clínicos de K. pneumoniae. Se evaluó por conjugación la transferencia de resistencia a antibióticos. Integrones, secuencias de inserción y otros elementos genéticos fueron detectados por amplificación del ADN plasmídico con la reacción en cadena de la polimerasa (PCR). Mediante análisis por PCR se determinó la relación entre el gen blaCTX-M-12 y los elementos genéticos detectados. En todos los aislamientos, el gen blaCTX-M-12 se encontró en plásmidos conjugativos de tamaños entre 65 y 106 kpb. La transferencia por conjugación de estos elementos móviles puede explicar la amplia diseminación de este gen entre enterobacterias causantes de infección nosocomial en hospitales de Bogotá, Colombia. El gen blaCTX-M-12 se encontró corriente abajo de ISEcp1, secuencia de inserción que se ha asociado con la movilización de determinantes genéticos de resistencia. Los promotores de ISEcp1, detectados por análisis de secuencia, pueden facilitar la expresión de la cefotaximasa codificada por este gen.

Genes from CTX-M-1 group have been detected with great frequency in Colombia in intrahospital infection-causing Klebsiella pneumoniae isolates. Knowledge regarding the genetic factors favouring such genes’ dissemination amongst bacterial species is an important issue for resistance control blaCTX-M-12 gene-carrying plasmids were identified in this study in 21 clinical K. pneumoniae isolates. Antibiotic resistance transfer was evaluated by mating. Integrons, insertion sequences and other genetic elements were detected by plasmid DNA amplification using polymerase chain reaction (PCR). The relationship between the blaCTX-M-12 gene and other genetic elements was determined by PCR analysis. The blaCTX-M-12 gene was disemifound on 52 to 106 Kpb conjugative plasmids in all isolates. These mobile elements’ transfer by mating may explain their wide dissemination amongst nosocomial infection-causing enterobacteria in hospitals in Bogota, Colombia. The blaCTX-M-12 gene was found downstream from ISEcp1, this being an insertion sequence which has been associated with resistance genetic determinants’ mobilisation. ISEcp1 promoters (detected by sequence analysis) may increase the expression of cefotaximase encoded by this gene.

[Resistance to cefepime in Enterobacter cloacae isolates from hospitals in Bogotá, Colombia]. / Resistencia a cefepime en aislamientos de Enterobacter cloacae provenientes de hospitales de Bogotá, Colombia.

OBJECTIVE: The aim of this research was to detect the presence of genes encoding beta-lactamases which can confer cefepime resistance on Enterobacter cloacae isolates, meaning that this antibiotic may be considered an important therapeutic alternative. MATERIALS AND METHODS: 28 E. cloacae isolates collected from 4 hospitals in Bogotá during 2003 were analysed. Extended spectrum beta-lactamases and cephalosporinase production were phenotypically determined. The presence of extended spectrum beta-lactamase genes was determined by PCR amplification. Mating assays were done to determine the possible transfer of bla-genes encoding cefotaximases. RESULTS: Microbiological tests detected 57% of extended-spectrum beta-lactamase-producing isolates. blaTEM, blasHv and blacTX-M genes were detected by PCR in 82% of the isolates. 7 out of 9 isolates carrying group 1 blacTX-M genes were in the resistant or intermediate range for cefepime. These isolates produced cefotaxime-resistant transconjugants. CONCLUSION: A relationship was found between resistance to cefepime and the presence of cefotaximases in E. cloacae. blacTx-M genes were present in 32% of the isolates, indicating an significant spread in the hospitals being studied. The facility of these genes' transfer between other species and Enterobacteria genera becomes an important reason for detecting them and controlling their spread in hospital settings. These results suggest a cautious use of cefepime for treating infection caused by E. cloacae strains which might produce CTX-M enzymes.