Simulación de la propagación de un brote por Acinetobacter baumannii en entornos hospitalarios / Simulation of an outbreak of Acinetobacter baumannii in hospitals

Introducción. Las infecciones por Acinetobacter baumannii se han convertido en un hecho habitual y preocupante en los ambientes hospitalarios. Consecuentemente son de especial importancia aquellas aplicaciones que permitan no sólo simular la aparición y propagación de un brote, sino también evaluar las posibles medidas de control. El desarrollo de modelos matemáticos juega un papel decisivo en esta tarea. Material y métodos. Se desarrolló un modelo matemático determinista basado en ecuaciones diferenciales ordinarias, cuyas variables y parámetros fueron identificados a partir del conocimiento de la epidemiología y de las características de A. baumannii. Dicho modelo fue analizado cualitativamente e implementado computacionalmente. Resultados. La implementación computacional del modelo teórico posibilitó obtener múltiples simulaciones a partir de diferentes condiciones iniciales. El análisis cualitativo de las mismas permitió definir de manera explícita las medidas de control más efectivas a la hora de controlar esta infección nosocomial. Conclusiones. La herramienta desarrollada es de gran utilidad en la gestión (predicción del comportamiento y evaluación de contramedidas profilácticas) de brotes por A. baumannii. Se demuestra de manera teórica la eficacia de medidas higiénicas y de cribado (AU)

Introduction. Acinetobacter baumannii infections have increased over time becoming a significant issue. Consequently, those applications that allow to predict the evolution of an outbreak and the relevance of the different control methods, are very important. The design of mathematical models plays a central role in this topic. Material and methods. Development of a deterministic mathematical model based on ordinary differential equations whose variables and parameters are defined upon the basis of knowledge of the epidemiology and characteristics of A. baumannii. This model is analyzed from a qualitative point of view and, also, its computational implementation is derived. Results. Several simulations were obtained developed from different initial conditions. The qualitative analysis of these simulations provides formal evidence of most effective control measures. Conclusions. The implementation of the computational model is an extremely useful tool in terms of managing A. baumannii outbreaks. There is mathematical proof of the fact that the observance of efficient hygiene and screening rules reduces the number of infected patients (AU)

La polio, el largo camino hacia el final de la partida / Polio, the long walk to the endgame

A pesar de que para la OMS la polio debería haber sido erradicada en el año 2000 -gracias a la vacunación y a los recursos institucionales, públicos y privados, destinados a tal fin- en 2013 la enfermedad siguió siendo endémica en tres países, Afganistán, Pakistán y Nigeria y se describieron casos en otros cinco. La circulación de poliovirus tipo 1 salvaje en Israel, Gaza y Cisjordania y los casos de Siria fueron una llamada de atención, como en su momento lo fueron los virus derivados de la vacuna oral que siguen siendo un problema. Los viajes «desde» y «a» zonas endémicas son un factor a tener en cuenta en la exportación de los virus y su difusión cuando llegan a zonas con carencias vacunales. Los conflictos bélicos, las persecuciones, la intolerancia, la incultura y la proliferación de grupos y movimientos «antivacunación» son en gran parte la causa de la ausencia y del abandono de la vacunación. En 2014 la situación se ha complicado, tanto que el Comité de Emergencias de la OMS se reunió en mayo para abordar el problema. Es necesario conocer la enfermedad y su agente causal, en el primer caso porque habrá que pensar en ella a la hora de hacer un diagnóstico diferencial de la parálisis flácida y seguir vacunando y en el segundo porque será imprescindible seguir buscando en muestras ambientales el virus de la polio, del que se desconocen muchos aspectos, pues es un modelo para el estudio de otros muchos virus

Although the WHO original target date for the global eradication of poliomyelitis was the year 2000 –thanks to vaccination and institutional, public and private, resources for that purpose–, in 2013 the disease remained endemic in three countries, Afghanistan, Pakistan and Nigeria, and some cases were described in five others. The circulation of wild type 1 poliovirus in Israel, Gaza and the West Bank and the cases in Syria were a wakeup call, as at that time there were polioviruses derived from the oral vaccine that are still circulating among the human population and can cause the development of the disease. Travelling “from” and “to” endemic areas are factors to consider in poliovirus exportation and in its spread when it reaches areas with poor immunogenicity. Wars, terrorism, intolerance, lack of culture and proliferation of anti-vaccine groups and the rise of the anti-vaccination movement are important factors in the maintenance and expansion of the virus and in the “non-vaccination” against it. Based on the international situation to date, the Emergency Committee of WHO met in May 2014 to address the problem. It is still necessary to enhance the knowledge of the disease and its agent. In the first case to perform a differential diagnosis of flaccid paralysis and to continue vaccination programs, and in the second case to keep studying and looking for the poliovirus in environmental samples, which is a model for the study of many other viruses

[Noma/Cancrum oris: a neglected disease]. / La enfermedad de Noma/cancrum oris: una enfermedad olvidada.

Noma is an aggressive orofacial gangrenous pathology that damages hard and soft tissues of the mouth and the face. Throughout the centuries it has been present around the globe, but nowadays it has practically disappeared from developed countries and mainly affects children from the most disadvantaged places, especially in Africa. Noma disease is a multifactorial process; malnutrition, debilitating diseases (bacterial or viral systemic diseases, HIV-associated immunosuppression, etc.) and intraoral infections are some of the factors implied. The characteristic tissue necrosis is produced by a polymicrobial infection. Fusobacterium necrophorum, Prevotella intermedia, Prevotella melaninogenica, Fusobacterium nucleatum, Bacteroides fragilis, Bacillus cereus, Trueperella pyogenes, spyrochetes, etc, are some of the species that have been isolated from the affected areas. Without treatment, noma is lethal in a short period of time, and the patients that survive show severe sequelae that hinder their life and interpersonal relationships. The aim of this paper is to unify the existing information and to promote wider knowledge and awareness among the population.

La enfermedad de Noma/cancrum oris: una enfermedad olvidada / Noma/Cancrum oris: a neglected disease

La enfermedad de Noma es una patología gangrenosa agresiva orofacial que daña a tejidos duros y blandos de la boca y de la cara. A lo largo de los siglos ha estado presente en todo el planeta, aunque en la actualidad ha desaparecido prácticamente de los países desarrollados, afectando casi siempre a niños de los lugares más desfavorecidos, especialmente en el continente africano. Es un proceso multifactorial en el que intervienen factores como la malnutrición, las enfermedades debilitantes (infecciones sistémicas bacterianas o víricas, inmunodepresión asociada al VIH, etc.) y las infecciones intraorales. La necrosis tisular característica la origina una infección polimicrobiana. Algunas de las especies que se han aislado de las zonas afectadas son: Fusobacterium necrophorum, Prevotella intermedia, Prevotella melaninogenica, Fusobacterium nucleatum, Bacteroides fragilis, Bacillus cereus, Trueperella pyogenes, espiroquetas, etc. Sin tratamiento es letal en poco tiempo, y los pacientes que sobreviven presentan graves secuelas que dificultan su vida y sus relaciones interpersonales. El objetivo de esta revisión es unificar la información existente y promover un mayor conocimiento y concienciación de la población (AU)

Noma is an aggressive orofacial gangrenous pathology that damages hard and soft tissues of the mouth and the face. Throughout the centuries it has been present around the globe, but nowadays it has practically disappeared from developed countries and mainly affects children from the most disadvantaged places, especially in Africa. Noma disease is a multifactorial process; malnutrition, debilitating diseases (bacterial or viral systemic diseases, HIV-associated immunosuppression, etc.) and intraoral infections are some of the factors implied. The characteristic tissue necrosis is produced by a polymicrobial infection. Fusobacterium necrophorum, Prevotella intermedia, Prevotella melaninogenica, Fusobacterium nucleatum, Bacteroides fragilis, Bacillus cereus, Trueperella pyogenes, spyrochetes, etc, are some of the species that have been isolated from the affected areas. Without treatment, noma is lethal in a short period of time, and the patients that survive show severe sequelae that hinder their life and interpersonal relationships. The aim of this paper is to unify the existing information and to promote wider knowledge and awareness among the population (AU)

[Prevention of an outbreak of Acinetobacter baumannii in intensive care units: study of the efficacy of different mathematical methods]. / Prevención de un brote de Acinetobacter baumannii en una unidad de cuidados intensivos: eficacia de diversos métodos matemáticos.

INTRODUCTION: Although in past decades, Acinetobacter baumanni infections have been sporadically identified in hospitals, nowadays the nosocomial infections due to this pathogen have notably increased. Its importance is due to its multidrug- resistance, morbidity and mortatility in healthcare settings. Consequently, it is important to predict the evolution of these outbreaks in order to stablish the most efficient control measures. There are several experimental studies shown that the compliance with hand and environmental hygiene and the efficient management of the healthcare work help to control the evolution of these outbreaks. The goal of this work is to formally proof these experimental results by means of the analysis of the results provided by the model. METHODS: A stochastic mathematical model based on cellular automata was developed. The variables and parameters involved in it have been identified from the knowledge of the epidemiology and main characteristics of Acinetobacter infections. RESULTS: The model provides several simulations from different initial conditions. The analysis of these results proofs in a formal way that the compliance with hand and environmental hygiene and an efficient plannification of the work of healtcare workers yield a decrease in the colonized patients. Moreover, this is the unique model proposed studying the dynamics of an outbreak of A. baumanni. CONCLUSIONS: The computational implementation of the model provides us an efficient tool in the management of outbreaks due to A. baumanni. The analysis of the simulations obtained allows us to obtain a formal proof of the behaviour of the measures for control and prevention.

Las bacterias anaerobias 150 años después de su descubrimiento por Pasteur / Anaerobic bacteria 150 years after their discovery by Pasteur

El año 2011 marcó el 150 aniversario del descubrimiento de las bacterias anaerobias por Louis Pasteur. Tras este tiempo el interés biomédico por ellas se mantiene, y Clostridium difficile es probablemente la que más interés despierta en la actualidad. En estos últimos años se han producido importantes avances en taxonomía gracias al desarrollo tecnológico e informático, particularmente en el campo de la genética; así, se han caracterizado un número importante de nuevas especies implicadas en infecciones humanas y se han reclasificado algunas ya conocidas. A nivel patogénico, algunos anaerobios de la microflora que no se habían aislado de infecciones humanas se han aislado en algún cuadro clínico, ha habido emergencia o reemergencia de algunas especies y cuadros, ciertos anaerobios se han relacionado con síndromes infecciosos establecidos, ha aumentado la virulencia de algunas cepas y se han formulado hipótesis sobre su participación en ciertas enfermedades. En cuanto al diagnóstico, la generalización del MALDI-TOF ha supuesto una reducción de tiempo y un abaratamiento en la identificación que mejora día a día según se optimizan las bases de datos. La aplicación de la PCR en tiempo real ha sido otro gran avance, y la secuenciación del ARNr 16S y otros genes es ya una realidad para muchos laboratorios. Los anaerobios han ido aumentando su resistencia a los antimicrobianos, y la aparición de la resistencia a carbapenem y metronidazol y la mutirresistencia son ya una realidad. En esta última situación linezolid puede ser una buena alternativa en Bacteroides. Fidaxomicina es el único antianaerobio introducido en los últimos años, en concreto para la diarrea por C. difficile. Por último, se han desarrollado modelos matemáticos para el estudio de esta especie

In 2011 we celebrated the 150 th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16s rRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C. difficile. Moreover, some mathematical models have also been proposed in relation with this species

Prevención de un brote de Acinetobacter baumannii en una unidad de cuidados intensivos: eficacia de diversos métodos matemáticos / Prevention of an outbreak of Acinetobacter baumannii in intensive care units: study of the efficacy of different mathematical methods

Introducción. Las infecciones nosocomiales por Acinetobacter baumannii han pasado de ser un hecho poco representativo a habitual en muchos servicios de Medicina Intensiva por su frecuencia, mortalidad asociada y resistencia a los antimicrobianos. Cuando se produce un brote es importante poder predecir su evolución y el impacto global e individualizado de los diferentes métodos de control. Se ha demostrado experimentalmente que tomar determinadas medidas (lavado de manos, planificación del trabajo del personal sanitario, etc.) ayuda a controlar y prevenir tanto la aparición como la extensión de dichos brotes. El objetivo es demostrar de manera formal los resultados empíricos comentados anteriormente valiéndonos de un novedoso modelo matemático. Material y Métodos. Se desarrolló un modelo matemático estocástico basado en autómatas celulares. A partir del conocimiento de la epidemiología y de las características de A. baumanii se identificaron las variables y los parámetros del modelo. Resultados. El modelo proporciona múltiples simulaciones usando diferentes condiciones iniciales. Su análisis demuestra formalmente que el cumplimiento con las normas de higiene así como una correcta planificación del trabajo del personal sanitario reduce el número de pacientes colonizados. Asimismo, no existe en la literatura especializada otro modelo matemático que estudie la dinámica de un brote por A. baumannii. Conclusiones. La implementación computacional del modelo proporciona una herramienta de gran utilidad para la comunidad sanitaria en la gestión de brotes por A. baumanii en ambientes hospitalarios. Se prueba matemáticamente como unas eficientes medidas higiénicas y de planificación del trabajo del personal sanitario reducen el número de pacientes colonizados (AU)

Introduction. Although in past decades, Acinetobacter baumanni infections have been sporadically identified in hospitals, nowadays the nosocomial infections due to this pathogen have notably increased. Its importance is due to its multidrug-resistance, morbidity and mortatility in healthcare settings. Consequently, it is important to predict the evolution of these outbreaks in order to stablish the most efficient control measures. There are several experimental studies shown that the compliance with hand and environmental hygiene and the efficient management of the healthcare work help to control the evolution of these outbreaks. The goal of this work is to formally proof these experimental results by means of the analysis of the results provided by the model. Methods. A stochastic mathematical model based on cellular automata was developed. The variables and parameters involved in it have been identified from the knowledge of the epidemiology and main characteristics of Acinetobacter infections. Results. The model provides several simulations from different initial conditions. The analysis of these results proofs in a formal way that the compliance with hand and environmental hygiene and an efficient plannification of the work of healtcare workers yield a decrease in the colonized patients. Moreover, this is the unique model proposed studying the dynamics of an outbreak of A. baumanni. Conclusions. The computational implementation of the model provides us an efficient tool in the management of outbreaks due to A. baumanni. The analysis of the simulations obtained allows us to obtain a formal proof of the behaviour of the measures for control and prevention (AU)

[Polio, the long walk to the endgame]. / La polio, el largo camino hacia el final de la partida.

Although the WHO original target date for the global eradication of poliomyelitis was the year 2000 -thanks to vaccination and institutional, public and private, resources for that purpose-, in 2013 the disease remained endemic in three countries, Afghanistan, Pakistan and Nigeria, and some cases were described in five others. The circulation of wild type 1 poliovirus in Israel, Gaza and the West Bank and the cases in Syria were a wakeup call, as at that time there were polioviruses derived from the oral vaccine that are still circulating among the human population and can cause the development of the disease. Travelling "from" and "to" endemic areas are factors to consider in poliovirus exportation and in its spread when it reaches areas with poor immunogenicity. Wars, terrorism, intolerance, lack of culture and proliferation of anti-vaccine groups and the rise of the anti-vaccination movement are important factors in the maintenance and expansion of the virus and in the "non-vaccination" against it. Based on the international situation to date, the Emergency Committee of WHO met in May 2014 to address the problem. It is still necessary to enhance the knowledge of the disease and its agent. In the first case to perform a differential diagnosis of flaccid paralysis and to continue vaccination programs, and in the second case to keep studying and looking for the poliovirus in environmental samples, which is a model for the study of many other viruses.

[Anaerobic bacteria 150 years after their discovery by Pasteur]. / Las bacterias anaerobias 150años después de su descubrimiento por Pasteur.

In 2011 we celebrated the 150th anniversary of the discovery of anaerobic bacteria by Louis Pasteur. The interest of the biomedical community on such bacteria is still maintained, and is particularly focused on Clostridium difficile. In the past few years important advances in taxonomy have been made due to the genetic, technological and computing developments. Thus, a significant number of new species related to human infections have been characterised, and some already known have been reclassified. At pathogenic level some specimens of anaerobic microflora, that had not been isolated from human infections, have been now isolated in some clinical conditions. There was emergence (or re-emergence) of some species and clinical conditions. Certain anaerobic bacteria have been associated with established infectious syndromes. The virulence of certain strains has increased, and some hypotheses on their participation in certain diseases have been given. In terms of diagnosis, the routine use of MALDI-TOF has led to a shortening of time and a cost reduction in the identification, with an improvement directly related to the improvement of data bases. The application of real-time PCR has been another major progress, and the sequencing of 16srRNA gene and others is currently a reality for several laboratories. Anaerobes have increased their resistance to antimicrobial agents, and the emergence of resistance to carbapenems and metronidazole, and multi-resistance is a current reality. In this situation, linezolid could be an effective alternative for Bacteroides. Fidaxomicin is the only anti-anaerobic agent introduced in the recent years, specifically for the diarrhoea caused by C.difficile. Moreover, some mathematical models have also been proposed in relation with this species.

[Mathematical modelling of the propagation of infectious diseases: where we came from, and where we are going]. / Modelización matemática de la propagación de enfermedades infecciosas: de dónde venimos y hacia dónde vamos.

This work deals with the study of the use of mathematical models to simulate the spreading of infectious diseases. There is no doubt about the importance of the use of computational tools that allow the health staff to model and predict the spreading of an infectious disease. Using such tools one can establish and simulate disease control strategies. The development of such technologies is a multidisciplinary issue; in this sense, the mathematical algorithms -that must be computationally implemented- play a central role. The main goal of this work is to highlight among health community the increasing importance of the use of mathematical models for epidemic disease spreading. Consequently, the main features of such models are introduced and their classification is stated taking into account the behavior, the basic population unit or the mathematical objects used. An exhaustive search of related papers through the most important databases (Medline and Web of Science) are performed. The main conclusion obtained from this work is the central role that mathematical models can play in the simulation of epidemic spreading; moreover,some ideas about the future research are stated.

Modelización matemática de la propagación de enfermedades infecciosas: de dónde venimos y hacia dónde vamos / Mathematical modelling of the propagation of infectious diseases: where we came from, and where we are going

Es de indudable importancia dotar al gestor sanitario de herramientas que permitan predecir el comportamiento de la propagación de una enfermedad infecciosa, de manera que a partir de las mismas se pueden establecer y simular estrategias de control. El desarrollo de tales herramientas es de carácter pluridisciplinar siendo la base de las mismas, algoritmos o modelos matemáticos que son implementados computacionalmente. En este trabajo se muestra el funcionamiento de estos modelos matemáticos y se detalla su clasificación atendiendo a diferentes factores. Además se lleva a cabo un estudio cuantitativo de los mismos haciendo uso de las principales bases de datos relacionadas con el tema de estudio (Medline y Web of Science). De este trabajo se concluye el importante papel que pueden jugar los modelos matemáticos a la hora de simular los procesos infecciosos y, asimismo, se proponen futuras y eficaces vías de investigación en la modelización matemática de enfermedades infecciosas(AU)

This work deals with the study of the use of mathematical models to simulate the spreading of infectious diseases. There is no doubt about the importance of the use of computational tools that allow the health staff to model and predict the spreading of an infectious disease. Using such tools one can establish and simulate disease control strategies. The development of such technologies is a multidisciplinary issue; in this sense, the mathematical algorithms –that must be computationally implemented- play a central role. The main goal of this work is to highlight among health community the increasing importance of the use of mathematical models for epidemic disease spreading. Consequently, the main features of such models are introduced and their classification is stated taking into account the behavior, the basic population unit or the mathematical objects used. An exhaustive search of related papers through the most important databases (Medline and Web of Science) are performed. The main conclusion obtained from this work is the central role that mathematical models can play in the simulation of epidemic spreading; moreover, some ideas about the future research are stated(AU)

Modelos matemáticos en el estudio de la resistencia a los antimicrobianos. Perspectivas a partir de un metaanálisis / Matematical modeling of antibiotic resistance. Perspectives from a meta-analysys

La resistencia a los antimicrobianos es uno de los principales problemas a los que se enfrenta la comunidad sanitaria internacional. El estudio de la resistencia se debe realizar desde un enfoque pluridisciplinar y en este sentido se analiza el papel que puede jugar la Modelización Matemática en este escenario. Así se realiza un análisis tanto cuantitativo como cualitativo de los trabajos que han aparecido en la literatura científica mediante una búsqueda en las principales bases de datos: MEDLINE, SCOPUS e ISI Web of Science. Tras el análisis realizado en este estudio se observa que son pocos los trabajos relacionados con la temática objeto de estudio pero han sido publicados en revistas de un alto impacto; asimismo podemos afirmar que el desarrollo de modelos matemáticos puede jugar un papel muy importante a la hora de analizar y estudiar tanto los tratamientos para prevenir la aparición de las resistencias como el establecimiento y evaluación de estrategias de control en ambientes hospitalarios y la predicción del comportamiento de las infecciones por cepas resistentes(AU)

The antibiotic resistance is one of the greatest challenges of the international health community. The study of antibiotic resistance must be a multidisciplinary task and, in this sense, the main goal of this work is to analyze the role that Mathematical Modeling can play in this scenario. A qualitative and cuantitative analysis of the works published in the scientific literature is done by means of a search in the most important databases: MEDLINE, SCOPUS and ISI Web of Science. Consequently, there are few papers related to our topic but the existing works have been published in high-quality and impact international journals. Moreover, we can state that mathematical models are a very important and useful tool to analyze and study both the treatments protocols for resistance prevention and the assesment of control strategies in hospital environtment, or the prediction of the evolution of diseases due to resistant strains(AU)

[Antibiotheraphy in the 21st century, antibacterials for the second decade. Posibilities or realities in the future?]. / Antibioterapia para el siglo XXI, antibacterianos para la segunda década. ¿Posibilidades o realidades en un futuro?

A review of some antibacterial products is done motivated by the serious situation arisen by the antimicrobial resistance in bacteria. The attention is focus on those drugs with suitable antimicrobial properties that have prospects to be commercialized in the next years because of they are undergoing a clinical development phase (I, II, III). The search for these antibacterial products has been done by an exhaustive study of conference proceedings and web pages of international congresses on chemotherapy, infectious diseases and new antimicrobial drugs. Some of the new antibacterial products acts on known targets, and they belong to already used families. Furthermore, the great majority acts against the gram-positive bacterium. There is also some limited-spectrum antimicrobial drug whose use would minimize the adverse biological effects.

Antibioterapia para el siglo XXI, antibacterianos para la segunda década. ¿Posibilidades o realidades en un futuro? / Antibiotheraphy in the 21st century, antibacterials for the second decade. Posibilities or realities in the future?

Ante la grave situación planteada por la resistencia de las bacterias a los antibióticos se revisan antibacterianos que por sus propiedades antimicrobianas y por encontrarse en registro o en fase de desarrollo clínico (I, II, III) tienen posibilidades de ser comercializados en años venideros. Su búsqueda se ha realizado investigando en los resúmenes de los libros de actas y páginas web de congresos internacionales de quimioterapia, enfermedades infecciosas y nuevos fármacos. Muchos de los nuevos antibacterianos actúan sobre dianas conocidas y pertenecen a familias ya utilizadas en clínica. La mayor parte actúa sobre grampositivos. Hay alguna sustancia con espectro muy reducido cuya posible utilización minimizaría los efectos biológicos adversos(AU)

A review of some antibacterial products is done motivated by the serious situation arisen by the antimicrobial resistance in bacteria. The attention is focus on those drugs with suitable antimicrobial properties that have prospects to be commercialized in the next years because of they are undergoing a clinical development phase (I, II, III). The search for these antibacterial products has been done by an exhaustive study of conference proceedings and web pages of international congresses on chemotherapy, infectious diseases and new antimicrobial drugs. Some of the new antibacterial products acts on known targets, and they belong to already used families. Furthermore, the great majority acts against the gram-positive bacterium. There is also some limited-spectrum antimicrobial drug whose use would minimize the adverse biological effects(AU)