Mortalidad en niños con bacteriemia por Stenotrophomonas maltophilia: revisión sistemática / Mortality in children with Stenotrophomonas maltophilia-related bacteremia: A systematic review

Introducción: En los niños, la bacteriemia por Stenotrophomonas maltophilia es considerada una complicación severa y asociada a una elevada mortalidad. Con el objetivo de conocer la mortalidad asociada a esa condición, se realizó una revisión sistemática de la literatura. Material y métodos: Se aplicó una estrategia de búsqueda bibliográfica con las palabras clave: bacteriemia por Stenotrophomonas maltophilia, niños y adolescentes como únicos filtros. Se informan la mediana y los valores intercuartílicos de la frecuencia de la mortalidad reportada por los estudios incluidos. Resultados: Se identificaron 165 estudios potencialmente útiles. De ellos, se seleccionaron finalmente, 9 estudios para ser incluidos. La incidencia de mortalidad a consecuencia de una bacteriemia por S.maltophilia fue del 25%; Q25: 11­Q75: 36; rango: 6,06 a 40,6. Consideraciones finales: La bacteriemia por Sm tuvo un alto porcentaje de mortalidad en especial en pacientes con patología subyacente y uso de procedimientos invasivos y el uso inadecuado de antibióticos empíricos (AU)

Introduction: In children, Stenotrophomonas maltophilia-related bacteremia is considered a severe complication associated with high mortality. With the aim to determine the mortality associated with this condition, a systematic review of the literature was conducted. Material and methods: A literature search strategy was applied using the keywords: bacteremia due to Stenotrophomonas maltophilia, children, and adolescents as the only filters. The median and interquartile ranges of the mortality rates described in the studies included are reported. Results: A total of 165 potentially useful studies were identified, of which nine were finally selected to be included in the analysis. The incidence of S.maltophilia bacteremia-related mortality was 25%; Q25: 11­Q75: 36; range: 6.06 to 40.6. Final considerations: S.maltophilia-related bacteremia was associated with a high mortality rate especially in patients with an underlying disease, when invasive procedures were performed, and when emperical antibiotics were inadequately used (AU)

Detection of blaNDM-1 in Stenotrophomonas maltophilia isolated from Brazilian soil

This study reports the presence of the blaNDM-1 gene in an isolate of Stenotrophomonas maltophilia obtained from a Brazilian soil, inside an IncA/C plasmid with ~ 45 Kb. To the best of our knowledge, this is the second report in the world and the first in Brazil of NDM-producing bacterium isolated from soil.

Stenotrophomonas maltophilia isolated from gasoline-contaminated soil is capable of degrading methyl tert-butyl ether

Background: Methyl tert-butyl ether (MTBE) is a pollutant that causes deleterious effects on human and environmental health. Certain microbial cultures have shown the ability to degrade MTBE, suggesting that a novel bacterial species capable of degrading MTBE could be recovered. The goal of this study was to isolate, identify and characterize the members of a bacterial consortium capable of degrading MTBE. Results: The IPN-120526 bacterial consortium was obtained through batch enrichment using MTBE as the sole carbon and energy source. The cultivable fraction of the consortium was identified; of the isolates, only Stenotrophomonas maltophilia IPN-TD and Sphingopyxis sp. IPN-TE were capable of degrading MTBE. To the best of our knowledge, this report is the first demonstrating that S. maltophilia and Sphingopyxis sp. are capable of degrading MTBE. The degradation kinetics of MTBE demonstrated that S. maltophilia IPN-TD had a significantly higher overall MTBE degradation efficiency and rate (48.39 ± 3.18% and 1.56 ± 0.12 mg L-1 h-1, respectively) than the IPN-120526 consortium (38.59 ± 2.17% and 1.25 ± 0.087 mg L-1 respectively). The kinetics of MTBE removal by both cultures fit first-order and pseudo-first-order reaction models. Conclusions: These findings suggest that S. maltophilia IPN-TD in axenic culture has considerable potential for the detoxification of MTBE-contaminated water.

Antimicrobial susceptibility of hospital acquired Stenotrophomonas maltophilia isolate biofilms

Abstract Aims We sought to characterize the antibiotic susceptibility of strains of Stenotrophomonas maltophilia isolated from clinical samples, and the role of Stenotrophomonas maltophilia biofilm in antibiotic resistance. Methods Fifty-one clinical Stenotrophomonas maltophilia isolates were obtained from patients with nosocomial infection in the surgical wards and ICUs of six general hospitals in Tianjin, China. In vitro models of Stenotrophomonas maltophilia biofilms were established and confirmed by scanning electron microscopy and fluorescence microscopy with silver staining. The minimal inhibitory concentrations and biofilm inhibitory concentrations of commonly used antibiotics were determined. Results 47 of 51 strains were resistant to three or more antibiotics. 42 of 51 strains formed Stenotrophomonas maltophilia biofilms in vitro. Stenotrophomonas maltophilia biofilm formation greatly reduced sensitivity to most tested antibiotics, but not to levofloxacin. However, in the presence of erythromycin scanning electron microscopy revealed that levofloxacin inhibited Stenotrophomonas maltophilia biofilm formation. Factorial ANOVA revealed that erythromycin enhanced susceptibility to levofloxacin, cefoperazone/sulbactam, and piperacillin (p < 0.05), and an ΔE model revealed that levofloxacin and erythromycin acted synergistically in biofilms, suggesting specific use of combined macrolide therapy may represent an effective treatment for Stenotrophomonas maltophilia infection. Conclusions Antibiotics could act synergistically to combat the protection conferred to clinical isolates of Stenotrophomonas maltophilia by biofilms. Macrolide antibiotics may be effective where used in combination.

Stenotrophomonas maltophilia pseudo-outbreak at a University Hospital Bronchoscopy unit in Turkey / Pseudo-brote de Stenotrophomonas maltophilia en una unidad de Broncoscopia del Hospital Universitario en Turquía

OBJECTIVE: Stenotrophomonas maltophilia is an opportunistic pathogen found predominantly in the enviroment and hospital setting. Invasive procedures and treatment methods, instruments used for diagnosis and irrational antibiotic use play major roles in the spread of this pathogen. The study aimed to evaluate consecutive S maltophilia isolation from bronchoalveolar lavage samples during bronchoscopy procedure during a week. METHODS: Four patients consecutively had S maltophilia isolated during bronchoscopy between September 8 and 15, 2012. The identification of the isolates and their antibiotic susceptibility were studied by automated Vitek version 2.0 (Biomerieux, France) system. The clonal relationship between the isolates was studied by enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR). RESULTS: Four consecutive S maltophilia isolates had identical band patterns and showed clonal relatedness. CONCLUSION: Bronchoscopy is a common invasive procedure that is utilized in chest diseases departments and intensive care units (ICUs). Contamination may take place due to inappropiate use and cause spread of infectious pathogens. In the current study, we detected consecutive S maltophilia strains with identical band patterns isolated within a week. After appropiate disinfection and cleaning procedures, no further isolation was detected.

OBJETIVO: Stenotrophomonas maltophilia es un patógeno oportunista que se encuentra predominantemente en el medio ambiente y entorno de los hospitales. Los procedimientos invasivos y los métodos de tratamiento, los instrumentos utilizados para el diagnóstico y tratamiento, así como el uso irracional de antibióticos, desempeñan un importante papel en la propagación de este patógeno. Este estudio persigue evaluar el aislamiento consecutivo de S maltophilia de las muestras de lavado broncoalveolar durante el procedimiento broncoscópico en el período de una semana. MÉTODOS: A cuatro pacientes se les aisló S maltophilia consecutivamente en broncoscopias realizadas entre el 8 y el 15 de septiembre de 2012. La identificación de los aislamientos y su sensibilidad a los antibióticos fueron estudiados por el sistema automatizado Vitek 2 (Biomerieux, Francia). La relación clonal entre los aislamientos fue estudiada mediante consenso intergénico repetitivo enterobacteriano (ERIC) en conjunción con la reacción en cadena de la polimerasa (PCR). RESULTADOS: Cuatro aislados consecutivos de S maltophilia tenían patrones de banda idénticos y exhibían conexidad clonal. CONCLUSIÓN: La broncoscopia es un procedimiento invasivo común que se aplica en los departamentos de enfermedades torácicas, y las unidades de cuidados intensivos (UCI). La contaminación puede ocurrir debido a usos inapropiados y a la propagación de agentes patógenos infecciosos. En el presente estudio, hemos detectado cepas de S maltophilia consecutivas con idénticos patrones de banda aislados en una semana. Después de los procedimientos de limpieza y desinfección adecuada, no se detectó ningún otro aislamiento.

Prevalence of nosocomial stenotrophomonas maltophilia infections in Assiut University Hospitals

Stenotrophomonas maltophilia is an emerging multidrug-resistant global opportunistic pathogen and is acquiring increasing importance as a nosocomial pathogen. This study aimed to determine the prevalence of nosocomial S. maltophilia infections and the important risk factors associated with such infections in Assiut University Hospitals. This study included 362 patients with nosocomial infections admitted to different wards and intensive care units [ICU] from March 2011 to March 2012. A total of 690 different clinical samples according to the site of infection were collected from them. The samples were processed and diagnosed by conventional bacteriological methods. A total of 35 strains of S. maltophilia were isolated from 362 patients [9.6%]. The commonest clinical manifestations were lower respiratory tract infections [71.43%], wound infections [17.14%], bacteraemia [8.57%] and urinary tract infections [2.86%]. The chest ICU showed the highest percentage of isolation [14.75%]. Previous antibiotic intake was found to be a significant risk factor for nosocomial Stenotrophomonas maltophilia infections. We conclude that nosocomial Stenotrophomonas maltophilia infections are significant in Assiut University Hospitals with lower respiratory tract infections being the commonest and previous antibiotic intake an important risk factor

Smqnr VARIANTS IN CLINICAL ISOLATES OF Stenotrophomonas maltophilia IN BRAZIL / Variantes de Smqnr de isolados clínicos de Stenotrophomonas maltophilia no Brasil

SUMMARY Stenotrophomonas maltophilia contains a novel chromosomally-encoded qnr gene named Smqnr that contributes to low intrinsic resistance to quinolone. We described Smqnr in 13 clinical isolates of S. maltophilia from two Brazilian hospitals, over a 2-year period. The strains were identified by API 20 NE (bioMérieux, France). Susceptibility by microdilution method to trimetroprim/sulfamethoxazole, ciprofloxacin, levofloxacin, minocycline, ceftazidime, chloramphenicol and ticarcillin/clavulanate was performed according to CLSI. PCR detection of Smqnr gene was carried out. The sequence of Smqnr was compared with those deposited in GenBank. Pulsed-field gel electrophoresis (PFGE) of all strains was performed. Thirteen Smqnr positives isolates were sequenced and three novel variants of Smqnr were identified. All 13 Smqnr isolates had distinguishable patterns by PFGE. This is the first report of Smqnr in S. maltophilia isolated in Brazil. .

RESUMO S. maltophilia contem um novo gene qnr cromossômico denominado Smqnr que contribui para baixa resistência intrínseca a quinolonas. Descrevemos Smqnr em 13 isolados clínicos de S. maltophilia de dois hospitais brasileiros, ao longo do período de dois anos. Os isolados foram identificados pela API 20 NE (bioMérieux, França). Susceptibilidade pelo método de microdiluição dos seguintes antibióticos trimetroprim/sulfametoxazol, ciprofloxacina, levofloxacina, minociclina, ceftazidima, cloranfenicol e ticarcilina/clavulanato foi realizada segundo o CLSI. Detecção do gene de Smqnr foi realizada por PCR. A sequência de Smqnr foi comparada com aquelas depositadas no GenBank. Foi realizada eletroforese em gel de campo pulsado (PFGE) de todos os isolados. Treze isolados contendo Smqnr foram sequenciados e identificados três variantes do gene Smqnr. Todos os 13 isolados de Smqnr apresentaram diferentes padrões por PFGE. Este é o primeiro relato de Smqnr em isolados de S. maltophilia no Brasil. .

A specific polymerase chain reaction method to identify Stenotrophomonas maltophilia

Stenotrophomonas maltophilia is a multidrug-resistant nosocomial pathogen that is difficult to identify unequivocally using current methods. Accordingly, because the presence of this microorganism in a patient may directly determine the antimicrobial treatment, conventional polymerase chain reaction (PCR) and real-time PCR assays targeting 23S rRNA were developed for the specific identification of S. maltophilia. The PCR protocol showed high specificity when tested against other species of Stenotrophomonas, non-fermentative Gram-negative bacilli and 100 clinical isolates of S. maltophilia previously identified using the Vitek system.

Unilateral conjunctival ulcer due to Stenotrophomonas maltophilia infection.

We report a case of unilateral conjunctival ulcer due to Stenotrophomonas maltophilia infection in an immunocompetent individual. A 44-year-old male presented with complaints of pain and yellowish discharge in the right eye for one week. Patient underwent complete ophthalmic evaluation and relevant laboratory investigations. Anterior segment examination revealed localized conjunctival and episcleral congestion with conjunctival ulceration on the bulbar conjunctiva in the right eye. Gram's stain revealed gram-negative bacilli. Culture and sensitivity revealed S. maltophilia and responded well to topical moxifloxacin with systemic co-trimoxazole therapy.

Stenotrophomonas maltophilia: resistência emergente ao SMX-TMP em isolados brasileiros: uma realidade / Stenotrophomonas maltophilia: emerging resistance to TMP-SMX in Brazilian isolate: a reality

INTRODUÇÃO: Stenotrophomonas maltophilia é um importante patógeno hospitalar emergente, naturalmente resistente aos carbapenêmicos, que possui sulfametoxazol/trimetoprima (SMX-TMP) como opção terapêutica. Porém, relatos de resistência a essa droga começaram a aparecer. OBJETIVO: Avaliar o perfil de sensibilidade das cepas de S. maltophilia e comparar os resultados obtidos por diferentes metodologias. MÉTODOS: As cepas isoladas na rotina microbiológica do Hospital das Clínicas de São Paulo em 2007 foram avaliadas quanto ao perfil de suscetibilidade por disco-difusão e microdiluição. Respeitando a padronização do Clinical and Laboratory Standard Institute (CLSI), SMX-TMP e levofloxacino foram testados pelas duas técnicas, bem como a tigeciclina, interpretada segundo a agência norte-americana Food and Drug Administration (FDA). Ticarcilina/clavulanato, ceftazidima, imipenem, meropenem e moxifloxacino foram avaliados apenas por microdiluição. O percentual de correlação entre as metodologias foi analisado pelo programa WHONET®. RESULTADOS: Das 126 cepas, 1,6 por cento apresentaram resistência a SMX-TMP; 2,4 por cento, a levofloxacino; 23 por cento, a ticarcilina/clavulanato; 54 por cento, a ceftazidima. Todas apresentaram concentração inibitória mínima (CIM) < 2 µg/mL para tigeciclina e 96,8 por cento, CIM < 2 µg/mL para moxifloxacino. O índice de concordância categórica entre as metodologias foi de 100 por cento para SMX-TMP e de 89,6 por cento para levofloxacino. DISCUSSÃO E CONCLUSÃO: Embora SMX-TMP seja a droga de escolha para o tratamento de infecções por S. maltophilia, há possibilidade de resistência a esse antibiótico, dificultando a decisão terapêutica empírica, sendo fundamental a realização do teste de sensibilidade. A técnica de disco-difusão demonstrou boa correlação com a microdiluição. Entre as novas opções terapêuticas, tigeciclina e moxifloxacino apresentaram boa atividade in vitro.

INTRODUCTION: Stenotrophomonas maltophilia is an important emerging nosocomial pathogen naturally resistant to carbapenems. Although trimethoprim/sulfamethoxazole (TMP-SMX) is commonly used as a treatment option, resistance to this drug has been recently reported. OBJECTIVE: To evaluate the susceptibility profile of S. maltophilia strains and compare the results obtained by different methods. METHODS: As to susceptibility profile, all strains, which had been routinely isolated at Hospital das Clínicas, São Paulo, in 2007, were evaluated through disk diffusion and microdilution. In accordance with the Clinical and Laboratory Standard Institute (CLSI), TMP-SMX and levofloxacin were tested through both techniques, as well as tigecycline, which was interpreted in conformity with Food and Drug Administration (FDA) regulations. Ticarcillin/clavulanate, ceftazidime, imipenem, meropenem and moxifloxacin were evaluated only through microdilution. The correlation between these methods was assessed by WHONET®. RESULTS: 1.6 percent of 126 strains were resistant to TMP-SMX, 2.4 percent to levofloxacin, 23 percent to ticarcillin/clavulanate, and 54 percent to ceftazidime. All strains showed minimum inhibitory concentration (MIC) < 2 µg/mL for tigecycline and 96.8 percent MIC < 2 µg/mL for moxifloxacin. The correlation index between both methods was 100 percent for TMP-SMX and 89.6 percent for levofloxacin, respectively. DISCUSSION AND CONCLUSION: Although TMP-SMX is the standard treatment for S. maltophilia infections, there may be resistance to this antibiotic, which hinders the therapeutic approach, hence the significance of susceptibility tests. The disk diffusion technique showed a good correlation with microdilution. Among the new therapeutic options, both tigecycline and moxifloxacin presented significant activity in vitro.

A Case of Stenotrophomonas maltophilia Keratitis Effectively Treated with Moxifloxacin

A 70-year-old man with a long history of diabetes mellitus presented to our hospital (Department of Ophthalmology, Sahm Yook Medical Center, Seoul, Korea) complaining of severe ocular pain and visual disturbance in his left eye that had started three days prior to admission. A round 3.7 x 5.0 mm dense central stromal infiltrate with an overlying epithelial defect was noted on slit-lamp examination. Following corneal scrapings and culture, topical 0.5% moxifloxacin and 0.5% tobramycin were administered hourly. A few days later, Stenotrophomonas maltophilia was isolated in a bacterial culture from a corneal specimen. According to the results of susceptibility tests, topical 0.5% moxifloxacin was given every hour and 0.5% tobramycin was stopped. The patient's clinical features improved steadily with treatment. The corneal epithelium healed rapidly, and the infiltrate resolved within four weeks of the initiation of treatment. The patient's best corrected visual acuity improved from hand motion to 20 / 25.

A Case of Stenotrophomonas maltophilia Keratitis Effectively Treated with Moxifloxacin

A 70-year-old man with a long history of diabetes mellitus presented to our hospital (Department of Ophthalmology, Sahm Yook Medical Center, Seoul, Korea) complaining of severe ocular pain and visual disturbance in his left eye that had started three days prior to admission. A round 3.7 x 5.0 mm dense central stromal infiltrate with an overlying epithelial defect was noted on slit-lamp examination. Following corneal scrapings and culture, topical 0.5% moxifloxacin and 0.5% tobramycin were administered hourly. A few days later, Stenotrophomonas maltophilia was isolated in a bacterial culture from a corneal specimen. According to the results of susceptibility tests, topical 0.5% moxifloxacin was given every hour and 0.5% tobramycin was stopped. The patient's clinical features improved steadily with treatment. The corneal epithelium healed rapidly, and the infiltrate resolved within four weeks of the initiation of treatment. The patient's best corrected visual acuity improved from hand motion to 20 / 25.

Isolation and characterization of a novel strain of Stenotrophomonas maltophilia possessing various dioxygenases for monocyclic hydrocarbon degradation / Isolamento e caracterização de uma nova cepa de Stenotrophomonas maltophilia com várias dioxigenases para degradação de hidrocarbonetos monocíclicos

A Gram-negative bacterium, designated as strain KB2, was isolated from activated sludge and was found to utilize different aromatic substrates as sole carbon and energy source. On the basis of morphological and physiochemical characteristics and 16S rRNA gene sequence analysis, the isolated strain KB2 was identified as Stenotrophomonas maltophilia. Strain KB2 is from among different Stenotrophomonas maltophilia strains the first one described as exhibiting the activities of three types of dioxygenases depending on the structure of the inducer. The cells grown on benzoate and catechol showed mainly catechol 1,2- dioxygenase activity. The activity of 2,3-dioxygenase was detected after phenol induction. Protocatechuate 3,4-dioxygenase was found in crude cell extracts of this strain after incubation with 4-hydroxybenzoic acid, protocatechuic acid and vanillic acid. Because of broad spectrum of dioxygenases' types that Stenotrophomonas maltophilia KB2 can exhibit, this strain appears to be very powerful and useful tool in the biotreatment of wastewaters and in soil decontamination.

Uma bactéria Gram-negativa, denominada KB2, foi isolada de lodo ativado, verificando-se ser capaz de utilizar substratos aromáticos com única fonte de carbono e energia. Com base nas características morfológicas e físico-químicas, e na análise da sequencia do gene 16SrRNA, esta bactéria foi identificada como Stenotrophomonas maltophilia. Entre as diversas cepas de S. maltophilia já descritas, essa cepa é a primeira com atividade de três tipos de dioxigenases, dependendo da estrutura do indutor. As células cultivadas em benzoato e catecol apresentaram atividade de catecol 1,2-dioxigenase principalmente. A atividade de 2,3-dioxigenase foi detectada após indução com fenol. Após incubação com ácidos 4-hidrobenzoico, ácido protocatecuico evanílico, encontrou-se protocatecuato 3,4-dioxigenase no extrato celular. Devido ao amplo espectro de atividade das diferentes dioxigenases de S. maltophilia KB2, esta cepa parece ser uma ferramenta poderosa e útil para o biotratamento de efluentes e descontaminação do solo.

Distribution of nosocomial organisms and their resistance patterns in the Intensive Care Unit of the University Hospital of the West Indies, Kingston, Jamaica / Distribución de los organismos nosocomiales y sus patrones de resistencia en la Unidad de Cuidados Intensivos del Hospital Universitario de West Indies, Kingston, Jamaica

OBJETIVES: To determine the distribution and antibiotic susceptibility patterns of nosocomial pathogens in the Intensive Care Unit (ICU) at the University Hospital of the West Indies (UHWI). METHODS: A retrospective review of the laboratory records of all ICU patients from 2002-2004 was done. All organisms isolated from blood, urine, sputum, wound swabs and CVP tips were recorded. Sensitivity reports for organisms isolated in 2004 were also obtained. Results were analysed according to source of isolates and type of infection. RESULTS: Gram-negative organisms account for the majority of ICU isolates and show resistance to multiple antibiotics. The common Gram negative pathogens in the ICU are Pseudomonas aeruginosa, Acinetobacter spp and Stenotrophomonas maltophilia while the common Gram positive nosocomial organisms are Group D Streptococcus and coagulase negative Staphylococcus. CONCLUSION: The organisms isolated in the ICU at the UHWI are similar to those isolated in many ICUs all over the world. Surveillance data are necessary to monitor nosocomial pathogens and their resistance patterns to guide empirical antibiotic therapy.

OBJETIVOS: Determinar la distribución y los patrones de susceptibilidad antibiótica de los patógenos nosocomiales en la Unidad de Cuidados Intensivos (UCI) del Hospital Universitario de West Indies (HUWI). MÉTODOS: Se realizó una revisión retrospectiva de las historias clínicas de laboratorio de todos los pacientes de la UCI de 2002-2004. Se registraron todos los organismos aislados a partir de sangre, orina, esputo, hisopos de heridas, y las puntas de catéteres de PVC. Los resultados fueron analizados de acuerdo con las fuentes de los aislados y el tipo de infección. RESULTADOS: Los organismos gramnegativos representan la mayor parte de aislados de la UCI y muestran resistencia a múltiples antibióticos. Los patógenos gramnegativos comunes en la UCI son Pseudomonas aeruginosa, Acinetobacter spp y Stenotrophomonas maltophilia mientras que los organismos nosocomiales grampositivos comunes son Group D Streptococcus y coagulase negative Staphylococcus. CONCLUSIÓN: Los organismos aislados en la UCI en el HUWI son similares a los aislados en muchas UCIs en todo el mundo. La información sobre la vigilancia es necesaria a fin de monitorear los patógenos nosocomiales y sus patrones de resistencia para guiar la terapia antibiótica empírica.

Aislamientos de Stenotrophomonas maltophilia en el Hospital Clinicoquirúrgico Hermanos Ameijeiras: año 2006 / Isolates of Stenotrophomonas maltophilia in Hermanos Ameijeiras Clinical and Surgical Hospital: in 2006

Se estudiaron las cepas de Stenotrophomonas maltophilia aisladas en el Laboratorio de Microbiología del Hospital Hermanos Ameijeiras, con la finalidad de conocer el lugar que ocupa por su frecuencia de aislamiento, sus patrones de resistencia, y se comparó con otros bacilos no fermentadores. Se realizó la identificación hasta especie y se determinó la sensibilidad por el sistema diagnóstico API ID 32. Se halló que Stenotrophomonas maltophilia se ubicó en el lugar número 12 de los microorganismos más frecuentemente aislados, durante el año 2006. Se aislaron 28 cepas en su mayoría de hemocultivos. Se reportó resistencia muy alta para meropenem y ceftriaxone, mayor inclusive que la de otros bacilos no fermentadores como Acinetobacter sp. y Pseudomonas sp., pero con mayor sensibilidad al cotrimoxazol y la ticarcilina + ácido clavulßnico, que constituyen las principales alternativas terapéuticas.

The strains of Stenotrophomonas maltophilia isolated in our laboratory were studied aimed at knowing the place it ocuppies according to its isolation frequency, its resistance patterns and the comparison with other non-fermentating bacilli. The identification up to species was carried out and the sensitivity was determined by the API ID 32 diagnostic system. Stenotrophomonas maltophilia occupied the 12th place among the most frequently isolated microorganisms in "Hermanos Ameijeiras" Hospital during 2006. 28 strains were isolated mostly from hemocultures. A very high resistance to meropenem and ceftriaxone was reported, even higher than in other non-fermentating bacilli as Acinetobacter sp and Pseudomonas, but with greater sensitivity to cotrimoxazole and ticarciline + clavulanic acid that are the main therapeutic alternatives.

The immunomodulatory effect of antibiotics on the secretion of tumour necrosis factor alpha by peripheral blood mononuclear cells in response to Stenotrophomonas maltophilia stimulation / Efecto inmunomodulatorio de los antibióticos sobre la secreción del factor de necrosis tumoral alfa por células sanguíneas mononucleares periféricas en respuesta a la estimulación de stenotrophomonas maltophilia

Some antibiotics have been shown to modify the host immune response. Infection with Stenotrophomonas maltophilia, is often difficult to treat due to multiresistance to antibiotics. The authors examined the effect of four commonly used antimicrobial agents (ciprofloxacin, ceftazidime, cotrimoxazole and piperacillin-tazobactam) on tumour necrosis factor alpha (TNF alpha) production by human peripheral blood mononuclear cells (PBMC) stimulated with heat-killed S maltophilia. Cotrimoxazole was the only antibiotic that suppressed TNFa secretion at clinically achievable concentrations. This may explain its use with good effect in the treatment of S maltophilia infections. However at supratherapeutic concentrations, ceftazidime and ciprofloxacin, but not piperacillin-tazobactam, also inhibited significantly the production of TNF alpha. Cotrimoxazole, in addition to its antimicrobial effect against S maltophilia, has an immunomodulatory effect on peripheral blood mononuclear cells stimulated by S maltophilia.

Algunos antibióticos han mostrado ser capaces de modificar la respuesta inmune del huésped. Las infecciones con Stenotrophomonas maltophilia – un patógeno emergente – son difíciles de tratar debido a su multiresistencia a los antibióticos. Examinamos el efecto de cuatro agentes antimicrobianos comúnmente usados (ciprofloxacina, ceftazidima, cotrimoxazol, y piperacilina-tazobactam) sobre la producción del factor de necrosis tumoral alfa (FNTa) por las células sanguíneas mononucleares periféricas humanas (PBMC) estimuladas con S maltophilia inactivadas mediante calor. El cotrimoxazol – en concentraciones clínicamente posibles – fue el único antibiótico que eliminó la secreción FNTa. Esto puede explicar su uso efectivo en el tratamiento de las infecciones por S maltophilia. Sin embargo, en concentraciones supraterapéuticas, la ceftazidima y la cipro-floxacina – pero no la piperacilina-tazobactam – también inhibieron significativamente la producción de FNTa. El cotrimoxazol, además de su efecto antimicrobiano contra S maltophilia, tiene un efecto inmuno-modulatorio sobre las células sanguíneas mononucleares periféricas estimuladas por S maltophilia.

Co-infection between influenza virus and flagellated bacteria

Tripsina é necessária na ativação da clivagem do vírus influenza A in vitro. Esta clivagem é importante para entrada do vírus na célula por endocitose mediada pelo receptor celular. Bactérias presentes no trato respiratório são fontes de proteases que podem contribuir na replicação do vírus influenza in vivo. Entre 47 amostras coletadas de cavalos, suínos e humanos, a influenza foi isolada e confirmada em 13 que estavam co-infectadas com bactéria flagelada: Stenotrophomonas maltophilia desde o início destes experimentos. Apesar do tratamento das amostras com antibióticos, as bactérias resistiram em diversas delas (48.39%). A protease (elastase), secretada pela Stenotrophomonas maltophilia, desenvolveu papel decisivo na potencialização da infecção pelo vírus influenza. Essa atividade proteolítica foi detectada pelo teste de ágar-caseína. Amostras positivas para o vírus influenza isolado em animais, bem como em humanos tiveram potencialização da infectividade (ECP) em células MDCK e NCI-H292, sempre que a Stenotrophomonas maltophilia esteve presente. Os referidos microorganismos, bactéria e vírus foram observados ultra-estruturalmente. Esses achados in vitro demonstram como complicações respiratórias podem ocorrer in vivo, através da contribuição de protease microbiana, provocando aumento da inflamação ou destruição dos inibidores celulares de proteases endógenas, nos hospedeiros susceptíveis à influenza.

The emergence of Stenotrophomonas maltophilia as a significant nosocomial pathogen at the University Hospital of the West Indies

Stenotrophomonas maltophilia is emerging worldwide as a nosocomial pathogen. It is associated with certain risk factors and a wide range of infections. This study was done to document its emergence at the University Hospital of the West Indies and to determine the incidence, distribution and risk factors associated with it. A retrospective study was conducted over the period April 1997 to December 2000. Clinical records were available for 46 of the 66 patients identified over the study period. Fifty-five per cent of the cases came from the Intensive Care Unit (ICU) and the rest from other wards. There was a slight increase in the prevalence of infection with increasing age. The surgical service accounted for the largest number of isolates. Of the cases presented, 95.7 were exposed to a wide range of antibiotics and had some form of instrumentation. Underlying disease was found in 71.7 of the patients. S maltophilia was found most often in the sputum of ICU patients whereas it was most often isolated from wound swabs in the ward patients. The organism was isolated from blood more often in ICU patients (23.3) than in ward patients (9.5) and there was a 44 mortality rate among the cases in ICU compared with those on the wards (4.8). Stenotrophomonas maltophilia is an important nosocomial pathogen and occurs in a wide cross-section of patients. The risk factors must be addressed and infection control measures implemented to restrict the spread of this organism

Prevalence of nonfermenters in clinical specimens.

One hundred and thirty three non fermenting gram negative bacilli isolated out of 625 different clinical specimens were identified and characterised. Samples were exudate from chronic suppractive otits media (341), diabetic foot (117) wound (116) and blood (51). Of these isolates Pseudomonas aeruginosa 105(78.94%) predominated followed by Acinetobacter sp 8 [6.1%], Pseudomonas putrifaciens 6(4.5%), Flavobacterium sp 6(4.5%), Xanthomonas maltophilia 5(3.75%), Alkaligenes sp 3 (2.25). 31 (23.30%) were resistant to commonly used antibiotics. Amikacin 85 (63.90%) was found to be more effective than fluoroquinolones (27.8-48.12%).