Multidrug-resistant Acinetobacter baumannii outbreaks: a global problem in healthcare settings

Abstract INTRODUCTION: The increase in the prevalence of multidrug-resistant Acinetobacter baumannii infections in hospital settings has rapidly emerged worldwide as a serious health problem. METHODS: This review synthetizes the epidemiology of multidrug-resistant A. baumannii, highlighting resistance mechanisms. CONCLUSIONS: Understanding the genetic mechanisms of resistance as well as the associated risk factors is critical to develop and implement adequate measures to control and prevent acquisition of nosocomial infections, especially in an intensive care unit setting.

Prevalence and molecular analysis of multidrug-resistant Acinetobacter baumannii in the extra-hospital environment in Mthatha, South Africa

ABSTRACT Introduction: The presence of Acinetobacter baumannii outside hospitals remains unclear. This study aimed to determine the prevalence of multidrug-resistance (MDR) A. baumannii in the extra-hospital environment in Mthatha, South Africa and to investigate the frequency of carbapenemase-encoding genes. Material and Methods: From August 2016 to July 2017 a total of 598 abattoir samples and 689 aquatic samples were collected and analyzed presumptively by cultural methods for the presence of A. baumannii using CHROMagar™ Acinetobacter medium. Species identification was performed by autoSCAN-4 (Dade Behring Inc., IL) and confirmed by the detection of their intrinsic blaOXA-51 gene. Confirmed MDR A. baumannii isolates were screened for the presence of carbapenemase-encoding genes, ISAba1 insertion sequence and integrase intI1. Results: In total, 248 (19.3%) Acinetobacter species were isolated. Acinetobacter. baumannii was detected in 183 (73.8%) of which 85 (46.4%) and 98 (53.6%) were recovered from abattoir and aquatic respectively. MDR A. baumannii was detected in 56.5% (48/85) abattoir isolates and 53.1% (52/98) aquatic isolates. Isolates showed high resistance to antimicrobials most frequently used to treat Acinetobacter infections such as piperacillin/tazobactam; abattoir (98% of isolates resistant), aquatic (94% of isolates resistant), ceftazidime (84%, 83%), ciprofloxacin (71%, 70%), amikacin (41%, 42%), imipenem (75%, 73%), and meropenem (74%, 71%). All the isolates were susceptible to tigecycline and colistin. All the isolates carried blaOXA-51-like. The blaOXA-23 was detected in 32 (66.7%) abattoir isolates and 11 (21.2%) aquatic isolates. The blaOXA-58-like was positive in 7 (14.6%) and 4 (7.7%) abattoir and aquatic isolates, respectively. Both groups of isolates lacked blaOXA-24-like, blaIMP-type, blaVIM-type, blaNDM-1, blaSIM, blaAmpC, ISAba1 and inI1. Isolates showed high level of Multiple Antibiotic Resistance Index (MARI) ranging from 0.20-0.52. Conclusion: Extra-hospital sources such as abattoir and aquatic environments may be a vehicle of spread of MDR A. baumannii strains in the community and hospital settings.

Aislamientos de Acinetobacter spp. en infecciones asociadas a la asistencia sanitaria / Isolation of Acinetobacter spp. in infections associated with health care

Introducción: El Acinetobacter spp. se ha convertido en un germen de gran relevancia clínica, resulta un verdadero paradigma de las infecciones nosocomiales multirresistentes. Objetivo: Caracterizar los aislamientos microbiológicos de Acinetobacter spp. en infecciones asociadas a la asistencia sanitaria. Métodos: Estudio descriptivo que incluyó 280 aislamientos de Acinetobacter spp. de las muestras provenientes de pacientes hospitalizados, en el periodo de tres años (del 2016 al 2018) en el Hospital Comandante "Manuel Fajardo Rivero". Las variables del estudio fueron: salas de procedencia del aislamiento, tipo de muestra, factor predictivo, diagnóstico infectológico, susceptibilidad antimicrobiana in vitro y multidrogorresistencia, Resultados: El mayor número de aislamientos de Acinetobacter spp. se obtuvo en la unidad de cuidados intensivos (78,9 por ciento), las secreciones respiratorias fueron las muestras con más aislamientos (58,9 por ciento), la ventilación mecánica resultó el factor predictivo más frecuente (67,9 por ciento) y como diagnóstico infectológico, la neumonía asociada al ventilador (66,8 por ciento). Se encontró un porcentaje elevado de cepas con multidrogorresistencia (73,6 por ciento). Conclusiones: El Acinetobacter spp. se encuentra vinculado a las infecciones asociadas a los servicios de salud, fundamentalmente en los cuidados intensivos. Los antimicrobianos probados evidenciaron altos porcentajes de resistencia, con predominio de las cepas multidrogorresistentes(AU)

Introduction: Acinetobacter spp. has become a germ of great clinical relevance, it is a true paradigm of multiresistant nosocomial infections. Objective: To characterize the microbiological isolates of Acinetobacter spp. in infections associated with health care. Methods: Descriptive study that included 280 isolates of Acinetobacter spp. from the samples of hospitalized patients, in the period of three years (from 2016 to 2018) in the Hospital Comandante "Manuel Fajardo Rivero". The variables of the study were: wards of origin of the isolation, type of sample, predictive factor, infectious diagnosis, antimicrobial susceptibility in vitro and multidrug resistance. Results: The highest number of isolates of Acinetobacter spp. was obtained in the intensive care unit (78.9 percent), the respiratory secretions were the samples with the most isolations (58.9 percent), mechanical ventilation was the most frequent predictor (67.9 percent) and as an infectious diagnosis, ventilator-associated pneumonia (66.8 percent). A high percentage of strains with multidrug resistance (73.6 percent) was found. Conclusions: Acinetobacter spp. is linked to infections associated with health services, mainly in intensive care. The antimicrobials tested showed high percentages of resistance, with a predominance of multidrug resistant strains(AU)

Earliest identification of New Delhi metallo-ß-lactamase 1 (NDM-1) in Acinetobacter pittii in Brazil

Abstract We report the occurrence in Brazil of the bla NDM-1 gene in Acinetobacter pittii, prior to the previously described first reports regarding the species Providencia rettgeri and Enterobacter hormaechei. Clinical isolates were investigated by polymerase chain reaction followed by bidirectional sequencing, and species was confirmed by 16S rDNA sequencing and matrix-assisted laser desorption-ionization time-of-flight spectrometry. A. pittii carrying bla NDM-1 was confirmed in a patient with no national or international travel history, or transfer from another hospital. The findings warn of the possibility of silent spread of bla NDM-1 to the community.

Characterization of multidrug-resistant Acinetobacter ssp. strains isolated from medical intensive care units in Cali - Colombia / Caracterización de cepas de Acinetobacter spp. resistentes a múltiples fármacos aisladas de unidades de cuidados intensivos en Cali - Colombia

Abstract Introduction: The extensive use of antibiotics has led to the emergence of multi-resistant strains in some species of the genus Acinetobacter. Objective: To investigate the molecular characteristics of multidrug-resistant of Acinetobacter ssp. strains isolated from 52 patients collected between March 2009 and July 2010 in medical intensive care units in Cali - Colombia. Methods: The susceptibility to various classes of antibiotics was determined by disc diffusion method, and the determination of the genomic species was carried out using amplified ribosomal DNA restriction analysis (ARDRA) and by sequencing of the 16s rDNA gene. Also, the genes of beta-lactamases as well as, integrases IntI1 and IntI2 were analyzed by PCR method. Results: The phenotypic identification showed that the isolates belong mainly to A. calcoaceticus- A. baumannii complex. All of them were multi-resistant to almost the whole antibiotics except to tigecycline and sulperazon, and they were grouped into five (I to V) different antibiotypes, being the antibiotype I the most common (50.0%). The percent of beta-lactamases detected was: blaTEM (17.3%), blaCTX-M (9.6%), blaVIM (21.2%), blaIMP (7.7%), blaOXA-58 (21.2%), and blaOXA-51 (21.2%). The phylogenetic tree analysis showed that the isolates were clustering to A. baumannii (74.1%), A. nosocomialis (11.1%) and A. calcoaceticus (7.4 %). Besides, the integron class 1 and class 2 were detected in 23.1% and 17.3% respectively. Conclusion: The isolates were identified to species A. baumanii mainly, and they were multiresistant. The resistance to beta-lactams may be by for presence of beta-lactamases in the majority of the isolates.

Resumen Introducción: El uso extensivo de antibióticos ha llevado a la emergencia de cepas multirresistentes en algunas especies del género Acinetobacter. Objetivo: Investigar las características moleculares de resistencia a múltiples fármacos de cepas aisladas de Acinetobacter spp. colectadas entre marzo de 2009 y julio de 2010 en 52 pacientes de unidades de cuidados intensivos en Cali - Colombia. Métodos: La susceptibilidad a diversas clases de antibióticos se determinó mediante el método de difusión de disco, y la determinación de la especie genómica se llevó a cabo usando un análisis de restricción de ADN ribosómico amplificado (ARDRA) y mediante la secuenciación del gen 16s de ADNr. Además, se analizaron por el método de PCR los genes de las beta-lactamasas, como también, las integrasas IntI1 e IntI2. Resultados: La identificación fenotípica mostró que los aislamientos pertenecen principalmente al complejo A. calcoaceticus - A. baumannii. Todos ellos eran multirresistentes a casi todos los antibióticos excepto tigeciclina y sulperazón, y se agruparon en cinco (I a V) antibitipos diferentes, siendo el antibiotipo I el más común (50%). El porcentaje de betalactamasas detectadas fue: blaTEM (17,3%), blaCTX-M (9,6%), blaVIM (21,2%), blaIMP (7,7%), blaOXA-58 (21,2%), blaOXA- 51 (21.2%). El análisis del árbol filogenético mostró que los aislados se agrupaban en A. baumannii (74.1%), A. nosocomialis (11.1%) y A. calcoaceticus (7.4%). Además, el integrón clase 1 y clase 2 se detectaron en 23.1% y 17.3% respectivamente. Conclusión: los aislamientos se identificaron principalmente como la especie A. baumanii, y fueron multirresistentes. La resistencia a los betalactámicos puede deberse a la presencia de betalactamasas en la mayoría de los aislamientos.

Carbapenem resistant Acinetobacter spp restricted the Therapeutic alternatives

Carbapenem resistant Acinetobacter has appeared an organism of uncertain resistivity towards antimicrobial agents. Among non-fermenting bacterium Acinetobacter is the second-most-commonly-isolated organisms in human. The fast intensify of their resistance to antibiotics, especially global emergence and extend of Acinetobacter strains resistant to carbapenem more restricted the therapeutic alternatives. The importation of A. baumannii and subsequent presence in hospitals has been well documented. In this study we evaluate the resistivity of Acinetobacter against carbapenem antibiotics at Jinnah University for Women, Karachi. Total 439 isolates of Acinetobacter were collected from different clinical samples of hospitalized patients, identified by standard microbiological methods. Antibiograms were done on Mueller-Hinton agar plates with disk diffusion method [Kirby Bauer method]. Disc tested: Meropenem [10 micro g/disk]. Among 439 samples, 300 [68.3%] samples were resistant to Meropenem and the remaining that is 139 [31.7%] showed sensitivity to the drugs. In developing countries including Pakistan the contentment of multi drug resistance and their dissemination in Acinetobacter species is not a simple task. While multiple drug resistance is increasing in this pathogen and Carbapenem conflict is quickly spreading which may become a major threat in future

New Delhi metallo-beta-lactamase-1-producing Acinetobacter spp. infection: report of a survivor

Abstract: New Delhi metallo-beta-lactamase-1 (NDM-1) is a bacterial enzyme that renders the bacteria resistant to a variety of beta-lactam antibiotics. A 20-year-old man was hospitalized several times for surgical treatment and complications caused by a right-sided vestibular schwannoma. Although the patient acquired several multidrug-resistant infections, this study focuses on the NDM-1-producing Acinetobacter spp. infection. As it was resistant to all antimicrobials tested, the medical team developed a 20-day regimen of 750mg/day metronidazole, 2,000,000IU/day polymyxin B, and 100mg/day tigecycline. The treatment was effective, and the patient recovered and was discharged from the hospital.

Prediction of Putative Resistance Islands in a Carbapenem-Resistant Acinetobacter baumannii Global Clone 2 Clinical Isolate

BACKGROUND: We investigated the whole genome sequence (WGS) of a carbapenem-resistant Acinetobacter baumannii isolate belonging to the global clone 2 (GC2) and predicted resistance islands using a software tool. METHODS: A. baumannii strain YU-R612 was isolated from the sputum of a 61-yr-old man with sepsis. The WGS of the YU-R612 strain was obtained by using the PacBio RS II Sequencing System (Pacific Biosciences Inc., USA). Antimicrobial resistance genes and resistance islands were analyzed by using ResFinder and Genomic Island Prediction software (GIPSy), respectively. RESULTS: The YU-R612 genome consisted of a circular chromosome (ca. 4,075 kb) and two plasmids (ca. 74 kb and 5 kb). Its sequence type (ST) under the Oxford scheme was ST191, consistent with assignment to GC2. ResFinder analysis showed that YU-R612 possessed the following resistance genes: four β-lactamase genes bla(ADC-30), bla(OXA-66), bla(OXA-23), and bla(TEM-1); armA, aadA1, and aacA4 as aminoglycoside resistance-encoding genes; aac(6')Ib-cr for fluoroquinolone resistance; msr(E) for macrolide, lincosamide, and streptogramin B resistance; catB8 for phenicol resistance; and sul1 for sulfonamide resistance. By GIPSy analysis, six putative resistant islands (PRIs) were determined on the YU-R612 chromosome. Among them, PRI1 possessed two copies of Tn2009 carrying bla(OXA-23), and PRI5 carried two copies of a class I integron carrying sul1 and armA genes. CONCLUSIONS: By prediction of resistance islands in the carbapenem-resistant A. baumannii YU-R612 GC2 strain isolated in Korea, PRIs were detected on the chromosome that possessed Tn2009 and class I integrons. The prediction of resistance islands using software tools was useful for analysis of the WGS.

In Vitro Interactions of Antibiotic Combinations of Colistin, Tigecycline, and Doripenem Against Extensively Drug-Resistant and Multidrug-Resistant Acinetobacter baumannii

BACKGROUND: Acinetobacter baumannii infections are difficult to treat owing to the emergence of various antibiotic resistant isolates. Because treatment options are limited for multidrug-resistant (MDR) A. baumannii infection, the discovery of new therapies, including combination therapy, is required. We evaluated the synergistic activity of colistin, doripenem, and tigecycline combinations against extensively drug-resistant (XDR) A. baumannii and MDR A. baumannii. METHODS: Time-kill assays were performed for 41 XDR and 28 MDR clinical isolates of A. baumannii by using colistin, doripenem, and tigecycline combinations. Concentrations representative of clinically achievable levels (colistin 2 microg/mL, doripenem 8 microg/mL) and achievable tissue levels (tigecycline 2 microg/mL) for each antibiotic were used in this study. RESULTS: The colistin-doripenem combination displayed the highest rate of synergy (53.6%) and bactericidal activity (75.4%) in 69 clinical isolates of A. baumannii. Among them, thedoripenem-tigecycline combination showed the lowest rate of synergy (14.5%) and bacteri-cidal activity (24.6%). The doripenem-tigecycline combination showed a higher antagonistic interaction (5.8%) compared with the colistin-tigecycline (1.4%) combination. No antagonism was observed for the colistin-doripenem combination. CONCLUSIONS: The colistin-doripenem combination is supported in vitro by the high rate of synergy and bactericidal activity and lack of antagonistic reaction in XDR and MDR A. baumannii. It seems to be necessary to perform synergy tests to determine the appropri-ate combination therapy considering the antagonistic reaction found in several isolates against the doripenem-tigecycline and colistin-tigecycline combinations. These findings should be further examined in clinical studies.

Factores de riesgo para la adquisición y características microbiológicas de las bacteriemias por Acinetobacter baumannii multi-resistente en pediatría: Estudio de casos y controles / Microbiological features and risk factors for acquiring multidrug-resistant Acinetobacter baumannii bacteremia in pediatric patients: Case-control study

Background: Multidrug-resistant Acinetobacter baumannii (MAB) is an important nosocomial pathogen. Objectives: To analyze the risk factors for acquiring MAB, and the clinical and microbiological characteristics of MAB bacteremia (MABB) in children. Materials and Methods: Control-case study 2005-2008. Demographic and clinical data from all MABB and from non-multiresistant gram-negative bacteremias were recorded. Identification at species level, antimicrobial susceptibility tests, time-kill studies and clonally relationships were performed. Stata 8.0 was used for data analysis. Results: A total of 50 MABB and 100 controls were included. Ninety four percent of patients acquired MAB in ICU and the 88% had underlying diseases. All patients had invasive procedures previous to MABB. The median of hospitalization stay previous to MABB was different in cases than in controls (16 vs 7 days, p < 0.001). Five clones were detected among the MABB. Time-killing curves showed bactericidal activity of ampicillin/sulbactam plus gentamicin and polymixin B. Three patients with MAB died. In a multivariate analysis final predictors of MABB were: previous use of broad-spectrum antibiotics [OR: 7,0; IC 95% 1,93-25,0; p: 0,003] and mechanical ventilation [OR: 4,19; IC 95% 1,66-10,0; p: 0,002]. Conclusions: MABB were detected in patients with underlying conditions, invasive procedures and prolonged hospitalization. Predictors of MABB were mechanical previous use of broad-spectrum antibiotics and mechanical ventilation.

Introducción: Acinetobacter baumannii multi-resistente (ABM) es un patógeno intrahospitalario de importancia. Objetivos: Analizar factores de riesgo de adquisición y características clínicas y microbiológicas de las bacteriemias por ABM (BABM) en pediatría. Métodos: Estudio de casos y controles período 2005-2008. Se incluyeron variables demográficas y clínicas de pacientes con BABM y por otros bacilos gramnegativos no ABM. Se realizaron pruebas para identificación de especie, susceptibilidad antimicrobiana y detección feno-genotípica de mecanismos de resistencia, sinergia y clonalidad. Análisis estadístico: Stata 8.0. Resultados: Se incluyeron 50 BABM y 100 controles. El 94% de los pacientes adquirieron la BABM en UCI y 88% tenía patologías subyacentes. La mediana de días de internación previa a la bacteriemia fue mayor en los casos (16 vs 7 días, p < 0,001). Se detectaron cinco clones de ABM. Se encontró efecto bactericida in vitro con polimixina B y con ampicilina/sulbactam+gentamicina. Tres casos fallecieron. Análisis multivariado: predictores finales de BABM fueron: antimicrobiano previo de amplio espectro [OR: 7,0; IC 95% 1,93-25,0; p: 0,003] y asistencia respiratoria mecánica (ARM) [OR: 4,19; IC 95% 1,66-10,0; p: 0,002]. Conclusiones: Las BABM fueron detectadas en pacientes con enfermedad subyacente, con procedimientos invasores previos e internación prolongada. Fueron predictores de BABM el tratamiento antimicrobiano de amplio espectro y ARM previa.

Increasing Carbapenem-Resistant Gram-Negative Bacilli and Decreasing Metallo-beta-Lactamase Producers over Eight Years from Korea

The trends and types of carbapenemase-producing Gram-negative bacilli were analyzed from clinical specimens collected between 2005 and 2012 at a Korean teaching hospital. The proportions of carbapenem-resistant Acinetobacter spp. increased markedly to 66%. Metallo-beta-lactamase producers significantly decreased and the majority shifted from the bla(VIM-2) type to the bla(IMP-1) type.

In Vivo Selection of Pan-Drug Resistant Acinetobacter baumannii during Antibiotic Treatment

PURPOSE: Colistin resistance in Acinetobacter baumannii (A. baumannii) is mediated by a complete loss of lipopolysaccharide production via mutations in lpxA, lpxC, and lpxD gene or lipid A modifications via mutations in the pmrA and pmrB genes. However, the exact mechanism of therapy-induced colistin resistance in A. baumannii is not well understood. MATERIALS AND METHODS: We investigated the genotypic and phenotypic changes that underlie pan-drug resistance mechanisms by determining differences between the alterations in extensively drug-resistant (XDR) A. baumannii (AB001 and AB002) isolates and a pan-drug resistant (PDR) counterpart (AB003) recovered from one patient before and after antibiotic treatment, respectively. RESULTS: All three clinical isolates shared an identical sequence type (ST138), belonging to the global epidemic clone, clonal complex 92, and all produced OXA-23 carbapenemase. The PDR AB003 showed two genetic differences, acquisition of armA gene and an amino acid substitution (Glu229Asp) in pmrB gene, relative to XDR isolates. No mutations were detected in the pmrA, pmrC, lpxA, lpxC, or lpxD genes in all three isolates. In matrix-assisted laser desorption ionization-time of flight analysis, the three isolates commonly showed two major peaks at 1728 m/z and 1912 m/z, but peaks at 2034 m/z, 2157 m/z, 2261 m/z, and 2384 m/z were detected only in the PDR A. baumannii AB003 isolate. CONCLUSION: Our results show that changes in lipid A structure via a mutation in the pmrB gene and acquisition of armA gene might confer resistance to colistin and aminoglycosides to XDR A. baumannii strains, resulting in appearance of a PDR A. baumannii strain of ST138.

Infección por Acinetobacter spp. en Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández de Matanzas: 2011-2012 / Infection by Acinetobacter spp. in the University Hospital Comandante Faustino Pérez Hernández of Matanzas: 2011-2012

Las infecciones asociadas a la asistencia sanitaria constituyen un grave problema de la salud pública a nivel mundial por su frecuencia y elevada mortalidad. El Acinetobacter spp. en la última década ha emergido como importante patógeno oportunista nosocomial. Dentro de estas especies, A. baumanii es la principal especie que se aisla hasta en 92 por ciento de las bacteriemias nosocomiales. La mayoría de los reportes de bacteriemia nosocomial por A. baumanii (B Ab) son de brotes en unidades de cuidados intensivos de pacientes adultos. Se ha reportado el incremento de la resistencia a antimicrobianos de este germen. Se realizó un estudio observacional descriptivo transversal acerca de la infección por Acinetobacter spp. en el Hospital Universitario Clínico Quirúrgico Comandante Faustino Pérez Hernández, del municipio de Matanzas, entre los meses de octubre de 2011 a julio de 2012. Teniendo en cuenta la ausencia de un estudio anterior en Matanzas sobre infección por este microorganismo, se decidió identificar la incidencia de Acinetobacter spp. según muestra biológica y servicio de procedencia e identificar la sensibilidad/resistencia del mismo, lo cual permitirá instaurar un tratamiento eficaz a los pacientes portadores de esta bacteria atendiendo al patrón de susceptibilidad encontrado en el estudio. La especie más frecuente fue A. baumanii, fundamentalmente en secreción endotraqueal y hemocultivo, procedentes en su mayoría de UTI, siendo este servicio el que aportó más cantidad de cepas MDR. Se encontró una mayor sensibilidad a antimicrobianos no considerados de primera línea como doxiciclina, tetraciclina y trimetropim-sulfametoxazol.

Infections associated to the sanitary care are serious public health problems at the international level because of their frequency and high mortality. In the last ten years, Acinetobacter spp. has emerged as an important nosocomial opportunistic pathogen. Among these species, A. baumanii (B Ab) is the main isolated species covering as many as 92 per cent of the nosocomial bacteremias. Most of the reports of nosocomial bacteremias by A. baumanii (B Ab) are outbreaks in adult patient intensive care units. It has been reported a boost of this germ antimicrobial resistance. We carried out a cross sectional, descriptive, observational study on Acinetobacter spp. infection, in the University Hospital Comandante Faustino Pérez Hernández of Matanzas municipality, from October 2011 to July 2012. Taking into account the absence of a previous study in Matanzas on infections caused by this microorganism, we decided identifying the Acinetobacter spp. incidence according to biological samples and coming-from service and identifying its sensibility/resistance, allowing the instauration of the efficacious treatment of the patients who carry this bacterium, considering the susceptibility pattern found in the study. The most frequently found species was A. baumanii, mainly in endotracheal secretions and hemo-cultures, most of them coming from Intensive Therapy Units, being this service the one contributing with more quantity of multidrug resistant stocks. We found a bigger sensibility to antimicrobials that are not considered first line ones like doxycycline, tetracycline and trimetoprim-sulfametoxazole.

Clinical characteristics of 1,260 patients during an outbreak of carbapenem-resistant Acinetobacter spp. in Porto Alegre, Brazil

Background: Over the last decade, Acinetobacter baumannii has been an important cause of nosocomial infections worldwide.Aim: To assess clinical and epidemiological characteristics of patients during a large citywide outbreak of carbapenem-resistant A. baumannii (CRAB). Methods: Retrospective cross-sectional study that evaluated the information obtained from the official notification system for CRAB within the Municipal Health Department, Porto Alegre, Brazil, in the period of July 1st, 2007 to December 31st,2008.Results: A total of 1,260 CRAB from infection (608 [48.3%]) or colonization (652[51.7%]) were reported in 18 hospitals. Most patients (53.5%) were hospitalized at intensive care units and have been exposed to invasive procedures, but 757 (60.7%)patients had no underlying comorbidity reported. A total of 1,143 (90.7%) patients received some antimicrobial 90 days before CRAB detection and 36.4% received a carbapenem. Data on the outcome were available for 618 (49.0%) patients and 54.3% of them died. Infection was significantly more common in patients admitted to public hospitals; with trauma, with exposure to antibiotics in the previous 90 days, and in patients submitted to invasive procedures. Conclusion: This study suggests that in the context of an outbreak, baseline comorbidities and previous carbapenem exposure may be less important risk factors for CRAB infection/colonization.

Sulbactam-based therapy for Acinetobacter baumannii infection: a systematic review and meta-analysis

BACKGROUND: A number of studies have reported on the effectiveness of sulbactam-based therapies for Acinetobacter baumannii infection; however, there is little evidence that sulbactam-based therapies are more or less effective than alternative therapies. Unfortunately, there is a distinct lack of high quality data (i.e., from randomized controlled trials) available on this issue. Therefore, we conducted a systematic review and meta-analysis comparing the efficacy of sulbactam-based and non-sulbactam-based regimens in the treatment of A. baumannii infection. METHODS: We searched PubMed, MEDLINE, Biomedical Central, Google Scholar, the China National Knowledge Infrastructure, the Cochrane library, and the Directory of Open Access using the terms "sulbactam and baumannii" or "maxtam and baumannii". Randomized controlled trials, controlled clinical studies, and cohort studies were considered for inclusion. The primary outcome was the clinical response rate for sulbactam-based therapy vs comparator therapies. RESULTS: Four studies (1 prospective, 3 retrospective) were included in the metaanalysis. Sulbactam was given in combination with ampicillin, carbapenem, or cefoperazone (n = 112 participants). Comparator drugs included colistin, cephalosporins, anti-pseudomonas penicillins, fluoroquinolones, minocycline/doxycycline, aminoglycosides, tigecycline, polymyxin, imipenem/cilastatin, and combination therapy (n = 107 participants). The combined clinical response rate odds ratio did not significantly favor sulbactam-based therapy over comparator therapy (odds ratio = 1.054, 95% confidence interval = 0.550-2.019, p = 0.874), nor did any of the individual study odds ratios. CONCLUSIONS: The available evidence suggests that sulbactam-based therapy may be similarly efficacious to alternative antimicrobial therapies for the treatment of A. baumannii infection. Further research on this issue is warranted given the limited availability of data from high quality/randomized controlled trials.

The minimal inhibitory concentration for sulbactam was not associated with the outcome of infections caused by carbapenem-resistant Acinetobacter sp. treated with ampicillin/sulbactam

OBJECTIVE: The objective of this study was to evaluate whether the outcomes of carbapenem-resistant Acinetobacter infections treated with ampicillin/sulbactam were associated with the in vitro susceptibility profiles. METHODS: Twenty-two infections were treated with ampicillin/sulbactam. The median treatment duration was 14 days (range: 3-19 days), and the median daily dose was 9 g (range: 1.5-12 g). The median time between Acinetobacter isolation and treatment was 4 days (range: 0-11 days). RESULTS: The sulbactam minimal inhibitory concentration (MIC) ranged from 2.0 to 32.0 mg/L, and the MIC was not associated with patient outcome, as 4 of 5 (80%) patients with a resistant infection (MIC≥16), 5 of 10 (50%) patients with intermediate isolates (MIC of 8) and only 1 of 7 (14%) patients with susceptible isolates (MIC ≤4) survived hospitalization. CONCLUSION: These findings highlight the need to improve the correlation between in vitro susceptibility tests and clinical outcome. .

Doripenem vs meropenem against Pseudomonas and Acinetobacter.

Recently, doripenem has been approved for the treatment of nosocomial pneumonia (NP), including ventilator-associated pneumonia (VAP). The E-test was performed to determine the MICs of doripenem and meropenem in 203 endotracheal aspirate isolates that consisted of 140 Acinetobacter calcoaceticus-Acinetobacter baumannii complexes and 63 Pseudomonas aeruginosa. Doripenem showed minimum concentration necessary for inhibition of 50% (MIC 50 ) of P. aeruginosa isolates at 0.38 mg/L which is several times (84.2 times) lower than the corresponding MIC 50 value of >32 mg/L for meropenem. The MIC 50 and MIC 90 were similar for both the drugs against A. baumannii. Thus, P. aeruginosa was consistently more susceptible than the A. baumannii.

A case of community-acquired Acinetobacter junii-johnsonii cellulitis / Celulitis por Acinetobacter junii-johnsonii adquirida en la comunidad: una presentación de caso

Acinetobacter skin and soft tissue infection outside of the traumatic wound setting are rare occurrences. The majority of cases occur in the presence of significant comorbilities and by Acinetobacter baumanii. Herein a case is reported of community-onset, health-care-associated, non-traumatic cellulitis caused by Acinetobacter, species junii-johnsonii with bacteremia. This is the first reported case of Acinetobacter junii-johnsonii skin and soft tissue infection. Hemorrhagic bullae might be one of the clinical features of Acinetobacter cellulitis.

La infección de piel y tejidos blandos por Acinetobacter no relacionada con trauma es una presentación inusual. La mayoría de los casos descritos presentan enfermedades concomitantes y son causados por Acinetobacter baumanii. Se describe un caso de celulitis no traumática por A. junii-johnsonii con bacteriemia, de inicio en la comunidad y asociado con el tratamiento médico. De acuerdo con nuestro conocimiento, éste sería el primer caso reportado de infección de tejidos blandos y piel por A. junii-johnsonii. La vesícula hemorrágica podría ser una característica clínica de celulitis por Acinetobacter.

Leuconostoc garlicum: An unusual pathogen in the era of vancomycin therapy.

Leuconostoc garlicum, belonging to the family of Leuconostocaceae, is a catalase-negative, Gram-positive ovoid cocci, intrinsically resistant to vancomycin. Clinical infection by Leuconostoc garlicum is rare. We report a case of respiratory tract infection subsequent to vancomycin therapy.