Colistin against colistin-only-susceptible Acinetobacter baumannii-related infections: Monotherapy or combination therapy.

Purpose: To evaluate the outcomes of the patients who were infected with colistin-only-susceptible (COS) Acinetobacter baumannii and treated with either colistin monotherapy or colistin combined therapy. Materials and Methods: This retrospective case-control study was conducted in the training and research hospital with an 800 beds between August 2008 and December 2011. The patients, who were infected with COS A. baumannii and received either colistin monotherapy or colistin combined therapy, were included into the study. Results: In total, 51 patients fulfilling study criteria were evaluated. Colistin monotherapy was found effective as much as colistin combined therapy in terms of clinical and microbiological responses in patients with ventilator associated pneumonia (VAP) and also in patients with blood stream infections. Conclusion: Although there is no randomised controlled study yet, colistin monotherapy and colistin combined therapy are likely to achieve similar treatment responses rates. Heteroresistant strains can emerge in patients who receive colistin monotherapy.

Acinetobacter baumannii versus Pseudomonas aeruginosa: comportamiento en pacientes críticos con ventilación mecánica / Acinetobacter baumannii versus Pseudomonas aeruginosa. Behavior in mechanically-ventilated patients

Tanto Acinetobacter baumannii como Pseudomonas aeruginosa son considerados agentes causales de severas infecciones respiratorias bajas en pacientes sometidos a ventilación mecánica en las unidades de cuidados intensivos. Se realizó un estudio descriptivo de corte transversal a 36 pacientes con ventilación mecánica en estas unidades con el objetivo de comparar la la repercusión de ambas especies. Los resultados más relevantes indicaron que de 20 pacientes con A. baumannii, 15 (75,00 por ciento) desarrollaron neumonía asociada a la ventilación y 10 (50,00 por ciento) fallecieron sépticos vs. 13 (100 por ciento) pacientes con Ps. aeruginosa de los cuales 12 (92,30 por ciento) desarrollaron neumonía asociada a la ventilación y 4 (30,76 por ciento) fallecieron sépticos. Se concluye que entre ambas especies microbianas Acinetobacter baumannii fue encontrado en la mayoría de los pacientes con neumonía asociada a la ventilación y en aquellos en los que la sepsis desempeñó un papel significativo como causa de muerte

Both Acinetobacter baumannii and Pseudomonas aeruginosa are considered to be causal agents of severe lower respiratory tract infections in patients under mechanical ventilation in intensive care units. A descriptive cross-sectional study was conducted with 36 mechanically ventilated patients from intensive care units to compare the importance of the two species. The most relevant results showed that of 20 patients with A. baumannii, 15 (75.00 percent) developed ventilator-associated pneumonia, and 10 (50.00 percent) died with sepsis vs. 13 (100 percent) patients with Ps. aeruginosa, of whom 12 (92.30 percent) developed ventilator-associated pneumonia and 4 (30.76 percent) died with sepsis. It is concluded that of the two microbial species, Acinetobacter baumannii was found in most patients with ventilator-associated pneumonia and in those for whom sepsis played a significant role as a cause of death

Acinetobacter baumannii: No more a choosy intruder.

Context: Acinetobacter baumannii, a non-fermenter, is fast coming up the list of pathogens causing nosocomial infections. Earlier considered to be a harmless colonizer, or at the most, a pathogen causing mostly respiratory tract infections, it has slowly but successfully emerged as a ubiquitous pathogen causing both community as well as health care associated infections. It has acquired multidrug resistance, and seems to be no more selective in mainly attacking any one or two body systems. According to recent reports, a shy selective bacterium has turned into a dangerous pathogen, capable of causing infections anywhere in the body, thereby adding extra furrows on the forehead of medical community worldwide. AIMS: To determine the range of infections caused by A. baumannii, and the frequencies thereof, in our tertiary care hospital; and to study their resistance patterns. Materials and Methods: A total of 88 isolates of A. baumannii were found from a variety of clinical samples, from hospitalized patients as well as patients attending the outpatient departments. The isolates were subjected to disc-diffusion method for antibiotic sensitivity testing. Results: Acinetobacter was mostly recovered from samples of pus, followed by endotracheal tube, urine, sputum samples, etc., Imipenem showed highest sensitivity, while other drugs with good sensitivity patterns were aminoglycosides and piperacillin-tazobactum. Conclusions: In this tertiary care institution of ours, A. baumannii isolates have shown a high frequency of drug resistance, with imipenem being the best sensitive drug. This non-fermenter is the cause of a variety of infections, irrespective of whether the individuals are hospitalized or are outdoor patients.

The genomic identification of Colombian Acinetobacter baumannii clinical isolates by RFLP-PCR analysis of the 16S-23S rRNA gene spacer region / Identificación genómica de aislamientos colombianos de Acinetobacter baumannii mediante RFLP-PCR de la región intergénica espaciadora de los genes 16S y 23S rRNA

The 16S-23S rRNA gene intergenic spacer (ITS) was analysed by RFLP in this study to identify A. baumannii from 139 isolates from four hospitals (identified as A, B, C and D). One hundred and twenty of these isolates (86.3%) belonged to the A. baumannii species; those identified as being A. baumannii were found to be polyclonal (19 clone groups) when determining the genetic relationships, 16 of them being found in hospital C. Hospitals A, B and D shared two clone groups isolated during different years. This study describes a rapid and easy method for genospecies identification of Acinetobacter baumannii.

Con el objeto de identificar la genomoespecie Acinetobacter baumannii, se estudiaron 189 aislamientos pertenecientes al Complejo Acinetobacter baumannii-Acinetobacter calcoaceticus provenientes de cuatro hospitales colombianos (denominados A,B,C,D) mediante el análisis por RFLP-PCR de la región intergénica espaciador (ITS) de los genes 16S y 23S rRNA. Se encontraron 120 aislamientos (86.3%) pertenecientes a la especie A. baumannii. La estructura de la población fue policlonal, con 19 grupos clonales, 16 de los cuales se hallaron en el hospital C. En los hospitales A,B y D se encontraron 2 grupos clonales aislados durante diferentes años. En este estudio se propone un método rápido y fácil para la identificación de Acinetobacter baumannii.

Ambu bag as a source of Acinetobacter baumannii outbreak in an intensive care unit

This case report describes an outbreak of multidrug resistant Acinetobacter baumannii in the intensive care unit of a tertiary care hospital. Three patients were infected on the same day from an Ambu bag which was used on all the patients. The outbreak was immediately identified and the source was traced within one week. Appropriate measures were taken and a continuous surveillance was carried out resulting in reporting of no such case from the intensive care unit in the last 6 months

Semmelweis: de médicos: estetoscopios: corbatas y otros atuendos / Semmelweis: about physicians: athetoscopes: neckties and other garments

Por la heroica historia de Ignaz Semmelweis (1818-1865), los médicos hemos sido aconsejados a lavarnos las manos cada vez que examinamos un paciente. Deberíamos hacerlo antes y después, y estar seguros de que él nos viera… Una manifiesta y justificada cruzada a favor de la limpieza de los estetoscopios y contra del uso de batas blancas. Corbatas y otras prendas de vestir, ha venido expresándose en ambientes médicos, primero en forma tímida y ahora con mayor fuerza, al aportarse pruebas convenientes acerca de la inconveniencia de llevarlas. La consigna es la eliminación de las corbatas durante la visita o revistas médicas al considerárselas como diseminadoras de infecciones adquiridas en el hospital. Las corbatas más que un probable reservorío de gérmenes son prendas innecesarias por lo que el médico debe reconocer su eventual riesgo. Las nuevas guías de la Brithish Medical Association incluyen un mayor énfasis en el lavado de las manos y de acuerdo a ella, “es la intervención más importante en el control de las infecciones”. Igualmente, se aboga por un mejor diseño de las salas de hospitalización, mejor provisión de lavamanos o geles antisépticos, políticas más inteligentes en la prescripción de antibióticos y eliminar el uso de ítems tales como corbatas, a veces usadas continuamente y por semanas y solo por raridad enviadas a la lavandería

Since the heroic history of Ignaz Semmelweis (1818´1865), we doctors have been advised to wash our hands every time we examine a patient. We should have to do it before and sfter, and be sure that the patients is seeing us… An overt and warranted crusade in favor of cleaning stethoscopes and against the use of medical gowns, neckties and other clothing items has begun expressing itselfin medical spheres, first in timed form and now with greater force, thanks to convincing test regarding the inconvenience of their use. The main message is the alimination of neckties during examinations or medical rounds, considering that these are vehicles of infection acquired in the hospital. Neckties, more than probable reservoirs of germs, are unnecessary clothing items, reason why doctors must recognize their possible risk. The new guidelines of the Medical Brithish Association include a greater emphasis on the washing of hands and according to it, “(it) is the most important intervention in the control of infections”. Also, it pleads for a better design of hospital rooms, better provision of sink and/or antiseptic gels, more intelligent policies for antibiotic prescriptions and the elimination of the use of items such as neckties, sometimes used continuously and for weeks and only rarely washed

Mutación en el gen gyrA de aislamientos hospitalarios de Acinetobacter baumannii en Montería, Colombia / Mutation of the gyrA Gen in Acinetobacter baumannii nosocomial isolates in Monteria, Colombia

Objetivo: Determinar las mutaciones delgen gyrA asociadas con la resistencia a fluoroquinolonas en Acinetobacter baumannii. Materiales y métodos: Entre agosto de 2005 y febrero de 2007 se recolectaron 23 aislamientos de A. baumannii de una clínica privada de tercer nivel de Montería. Se investigaron los genes gyrA, parC y adeB; este último codifica para la bomba de salida. Se realizó secuenciación del ADN y, para elanálisis de las secuencias, se usaron la base de datos GenBank y el motor de búsqueda BLASTX. Resultados: La amplificación del gen gyrA en aislamientos de A. baumannii generó unfragmento de 343 pb, el cual presentó pérdida del sitio de restricción con la enzima Hinfl en 12/23 (52,1%) de los aislamientos resistentes a fluoroquinolonas. La secuenciacióndel fragmento mostró mutación puntual con el cambio de Ser-83 a Leu, código de acceso GenBank EU886740. No se encontraron mutaciones en el gen parC, ni la presencia de la bomba de salida Ade. Conclusión: Los aislamientos de A. baumannii resistentes a fluoroquinolonas sugieren que la mutación del gen gyrA que codifica elcambio del aminoácido serina a leucina en el codón 83 de estos aislamientos, es responsable o, al menos, contribuye con la resistencia expresada a las fluoroquinolonas.

Objective: Determine mutations in thegyrA gene associated to resistance tofluoroquinolones in A. baumannii. Materials and methods: From August,2005 to February, 2007, 23 A. baumanniiisolates were collected in a third level private clinic in Monteria. Research on gyrA, parC and AdeB genes was carried out, and the latter encodes for the efflux pump. DNA sequencing was performed, and the GenBank database and BLASTX search engine were used for sequence analysis. Results: Amplification of the gyrA gene in A. baumannii isolates generated a 343pb fragment which presented loss of restriction site with the enzyme HinfI in 12/23 (52.1%) of the isolates resistant to fluoroquinolones. The fragment sequencing showed mutationcharacterized by the change of Ser-83 to Leu GenBank acces code EU886740. None of the isolates showed mutations in the parC gene or presence of the AdeB efflux pump. Conclusion: The A. baumannii isolates resistant to fluoroquinolones suggest thatmutation of the gyrA gene encoding the serine amino acid change to leucine at codon 83 of these isolates is responsible or at least contributes to the mentioned resistance to fluoroquinolones.

Pseudo-outbreak of stenotrophomonas maltophilia and acinetobacter baumannii by a contaminated bronchoscope in an intensive care unit

Stenotrophomonas maltophilia and Acinetobacter baumannii are serious offending agents of nosocomial pneumonia and of serious morbidity and mortality in intensive care units [ICU]. We report an unexpected sudden surge in cases of pneumonias caused by the above organisms in an intensive care unit of a community hospital in a span of two months. The source was traced back to a contaminated bronchoscope. The records from the patients with diagnosis of pneumonia with the above organisms were retrospectively reviewed. Specimens from the ports and channels of the bronchoscope that was suspected to be the cause were taken and microbiologically analyzed. Two patients with Acinetobacter and four patients with Stenotrophomonas positive bronchoalveolar lavage [BAL] fluid cultures were identified within a 2-month period in one of our two intensive care units. All of the patients were mechanically ventilated, and had clinical features of pneumonia. Their bronchoscopies were performed and their BALs were obtained by a scope with an identical serial number. The microbiologic evaluation of samples taken from the suspected scope revealed that it was improperly decontaminated between procedures. After implementation of strict and revised decontamination protocol, there were no further cases of pneumonia caused by the above organisms in a span of several months in mechanically ventilated patients. Inadequate disinfection of bronchoscopes and cross contamination between patients could be a potential cause of ventilator-associated pneumonia. Strict implementation of infection prevention guidelines in bronchoscopies of mechanically ventilated patients could prevent cases of ventilator-associated pneumonias by nosocomial agents including S. maltophilia and A. baumannii

Infecciones por Acinetobacter baumannii pan-resistente: consideraciones epidemiológicas y de manejo antimicrobiano actualizado / Acinetobacter baumannii pandrug-resistant: update in epidemiological and antimicrobial managing issues

En las últimas dos décadas Acinetobacter baumannii ha emergido como un patógeno nosocomial de la mayor relevancia mundial. A baumannii puede ser agente causal de infecciones como neumonía, bacteriemia, meningitis, infecciones del tracto urinario y de partes blandas, asociándose a alta mortalidad. Diversas comunicaciones nacionales y extranjeras revelan el aislamiento de cepas resistentes a casi todos los agentes antimicrobianos comercialmente disponibles, por lo que las opciones terapéuticas se han limitado drásticamente. Esto plantea la necesidad de desarrollar nuevos agentes antibacterianos y resucitar ciertos compuestos abandonados, como las polimixinas, para optimizar la terapéutica de este microorganismo con múltiple resistencia. Con el objeto de revisar y evaluar los datos sobre el manejo de infecciones multirresistentes por A baumannii, se realizó una revisión sistemática de la literatura médica que incluyó Medline y Lilacs, identificando y categorizando la relevancia clínica de las fuentes recolectadas a la fecha de esta investigación. Se repasan aspectos epidemiológicos clínicamente relevantes, datos microbiológicos y estudios clínicos realizados con infecciones por A baumannii pan resistente (AB-PDR) o multirresistente (AB-MDR). La respuesta apropiada al manejo de infecciones por AB-PDR es compleja, su erradicación requiere de adherencia a prácticas adecuadas de control de infecciones y del uso prudente de antimicrobianos, además del empleo de antibioterapia eficaz. Potenciales opciones de terapia serían la colistina, asociaciones de betalactámicos con sulbactam y tetraciclinas pero no existen estudios controlados y aleatorios al respecto.