Absceso en miocardio secundario a neumonía adquirida en la comunidad por Pseudomona aeruginosa en lactante inmunocompetente: reporte de caso / Myocardial abscess secondary to community acquired Pseudomona aeruginosa pneumonia in an immunocompetent infant: case report

La Pseudomona aeruginosa es una causa importante de infecciones asociadas a la atención de la salud y en las neumonías adquiridas en la comunidad, rara vez se identifica como el agente patógeno, siendo estas de progresión rápida y de mal pronóstico. Se trata de un menor de un año de edad inmunocompetente el cual fallece en casa una semana después de una lesión en la planta del pie derecho que según familiares le sacaron "pus", tratado con antinflamatorios y analgésicos. Se le realizó necropsia que evidenció cicatriz en planta de pie derecho sin lesiones traumáticas. Pulmones de consistencia indurada, con adherencias y áreas que impresionan necróticas, asociada a efusión pleural. El estudio histológico reportó un proceso infeccioso pulmonar agudo abscedado que se diseminó por continuidad a tejido cardiaco y en estudios microbiológicos de pulmón y bazo se reportó Pseudomona aeruginosa.

Pseudomona aeruginosa is an important cause of health care-associated infections and in community-acquired pneumonias, it is rarely identified as the pathogenic agent, being of rapid progression and poor prognosis. This is a one-year-old immunocompetent minor who died at home one week after a lesion in the sole of the right foot which, according to family members, caused "pus", treated with anti-inflammatory and analgesic drugs. A necropsy was performed, which showed a scar on the sole of the right foot with no traumatic lesions. Lungs of indurated consistency, with adhesions and areas that appear necrotic, associated with pleural effusion. The histological study reported an abscessed acute pulmonary infectious process that spread by continuity to cardiac tissue and microbiological studies of lung and spleen reported Pseudomona aeruginosa.

Síndrome de la uña verde: revisión actualizada de una patología emergente en la era COVID-19 / 19Green nail syndrome: updated review of an emerging disease in the era of COVID-19

El síndrome de la uña verde o cloroniquia corresponde a la infección por Pseudomonas aeruginosa de una lámina ungueal dañada en pacientes con algún factor de riesgo identificable, siendo los más frecuentes la inmunosupresión, el ambiente húmedo constante y la patología ungueal preexistente. Su diagnóstico es relativamente sencillo si se logra observar la tríada característica de coloración verdosa de la lámina ungueal, paroniquia proximal crónica y onicolisis distal; en casos de duda diagnóstica se puede enviar una muestra de la uña afectada para cultivos o estudio histopatológico. El pilar de su tratamiento corresponde al uso de antibióticos tópicos o sistémicos en conjunto con medidas generales que protejan de la humedad. Es muy importante enfatizar la prevención de esta patología en el personal de salud, especialmente en el contexto del lavado de manos frecuente y riguroso implementado durante la pandemia COVID-19, ya que existen reportes de transmisión nosocomial de P. aeruginosa por profesionales de la salud con infección ungueal.(AU)

Green nail syndrome or chloronychia is the infection of a damaged nail plate by Pseudomonas aeruginosa in a patient with an identifiable risk factor; the most frequently described are immunosuppression, a persistent moist environment and preexisting nail disease. Its diagnosis is relatively simple if the characteristic triad of green discoloration of the nail plate, chronic proximal paronychia and distal onycholysis can be observed, in cases of doubt a sample of the affected nail can be sent for cultures or histopathology. The cornerstone of treatment is the use of topical or systemic antibiotics along with measures to protect the nail from moisture. Prevention of this disease must be emphasized in health care personnel, especially in the context of frequent and rigorous handwashing practices implemented during the COVID-19 pandemic, since there are reports of nosocomial transmission of P. aeruginosaby health care professionals with nail infection.(AU)

Effect of Trigonella foenum Extract and ZiO2 Nanoparticles on Some Pathogenic Fungi and Bacteria

Aim: The current venture, were made to evaluate the inhibitory effect of Trigonella foenum seed Extract and ZiO2 Nanoparticles on some selected species of Fungi and Bacteria. Materials and Methods: two bacterial species included Pseudomonas aeruginosa and Staphylococcus aureus and three fungal species which is Cryptococcus neoformans, Candidda albicans and Chaetomium were used to evaluate the antibacterial activity of Trigonella foenum Extract and ZiO2 Nanoparticles. Results: This study showed that the Zirconium Oxide (ZiO2) nanoparticles have antifungal and antibacterial activities on the isolates of Cryptococcus neoformans, Candida alicans and Staphylococcus aureus, respectively. While the antimicrobial activity of Zirconium Oxide nanoparticles on the Chaetomium and Pseudomonas aeruginosa was negative. All tested fungi and bacterial isolates were found to be sensitive to Trigonella foenum seed extract, the results of the compination of the ZiO2 Nanoparticle and the Trigonella foenum seed extract were poisitive for all tested fungi isolates and bacterial isolates. The XRD analysis was done for Zirconium Oxide nanoparticles and the result showed that the biocrystallization on the surface of the Zirconium Oxide manoparticles. The average partides size was about (29.8) nm. Conclusions: This investigation conclude that the use of Trigonella foenum seed Extract has the effect of killing all bacteria and fungi under study, result indicate the Trigonella foenun seed Extract best antibacterial efficacy than the ZiO2 together (AU)

Pseudomonas aeruginosa: patogenicidad y resistencia antimicrobiana en la infección urinaria / Pseudomonas aeruginosa: pathogenicity and antimicrobial resistance in urinary tract infection

Resumen Dentro de las infecciones nosocomiales más frecuentes asociadas a bacterias multi-resistentes y de peor pronóstico, se encuentran las producidas por Pseudomonas aeruginosa. Esta bacteria posee una alta capacidad de adaptación a condiciones adversas como por ejemplo el pH y la osmolaridad de la orina. Pseudomonas aeruginosa es uno de los principales patógenos implicados en infecciones nosocomiales y de pacientes inmunosuprimidos. Esta bacteria se considera un agente infeccioso oportunista que posee diversos mecanismos de patogenicidad, así como de resistencia a antimicrobianos, lo que contribuye a la dificultad en el tratamiento de estas infecciones. En la presente revisión bibliográfica se analizan la taxonomía, los mecanismos de patogenicidad y genes de resistencia de P. aeruginosa. Así también, se abordan los factores microambientales de la infección urinaria producida por esta bacteria, haciendo un acercamiento al entendimiento de las bases fisiopatológicas de esta infección.

Among the most frequent nosocomial infections associated with polyresistant bacteria and with a worse prognosis, are those produced by Pseudomonas aeruginosa. This bacterium has a high capacity to adapt to adverse conditions such as pH and osmolarity of urine. Pseudomonas aeruginosa is one of the main pathogens involved in nosocomial infections and immunosuppressed patients. This bacterium is considered an opportunistic infectious agent that has diverse mechanisms of pathogenicity, as well as resistance to antimicrobials, which contributes to the difficulty in the treatment of these infections. In the present bibliographic review, the taxonomy, pathogenicity mechanisms and resistance genes of P. aeruginosa are analyzed. Likewise, the micro-environmental factors of the urinary infection produced by this bacterium are approached, making an approach to the understanding of the pathophysiological bases of this infection.

Principais patógenos envolvidos em casos de sepse em pacientes queimados: uma revisão de literatura / Main pathogens involved in the cases of sepsis in burned patients: a review on the literature / Principales patógenos en los casos de sepsis em pacientes quemados: una revisión de literatura

Objetivo: Buscou-se no presente trabalho identificar os principais patógenos envolvidos em infecções em pacientes queimados, bem como enfatizar a relevância do diagnóstico adequado para o tratamento de sepse. Método: Para a realização do presente trabalho, foi feito levantamento bibliográfico de caráter exploratório e obtidos 33 estudos relevantes. A coleta de informações ocorreu nos meses de março a novembro de 2016. Resultados: Dentre os principais patógenos presentes em queimados, que podem gerar quadro de sepse, estão Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans e Proteus sp. Esses podem, ou não, estar relacionados à própria microbiota do paciente. O processo de infecção, com perda da primeira linha de defesa imunológica, deixa o organismo suscetível à entrada e instalação de microrganismos. O tratamento da sepse depende de fatores relevantes, que incluem a gravidade da lesão e o agente causador da infecção. Conclusão: O risco de ocorrência de sepse, associada às infecções em queimados nas unidades de tratamento intensivo, pode ser reduzido com o diagnóstico adequado e acompanhamento do paciente.

Objective: This article aimed to identify the main pathogens involved in infections in burned patients, as well as to emphasize the relevance of the appropriate diagnosis for the treatment of sepsis. Methods: For the accomplishment of the present work, it was carried out a bibliographic survey of exploratory character and 33 relevant studies were obtained. Data collection was carried out from March to November 2016. Results: Among the main pathogens present in burnt patient related with sepsis are Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans and Proteus sp. These pathogens may or may not be related to the patients microbiota. The infection process, with loss of the first line of immune defense, leaves the organism susceptible to the entry and installation of microorganisms. Treatment of sepsis depends on relevant factors including the severity of the lesion and the agent of the infection. Conclusion: The risk associated with sepsis in burned patients may be reduced with appropriate diagnosis and monitoring.

Objetivo: El objetivo de este artículo fue identificar los principales patógenos asociados en infecciones en pacientes com quemaduras, así como enfatizar la relevancia del diagnóstico adecuado para el tratamiento de la sepsis. Métodos: Para el desarrollo del presente trabajo, se realizó una búsqueda bibliográfica de caracter exploratório, siendo considerados relevantes 33 estudios. La búsqueda de datos se realizó de marzo a noviembre de 2016. Resultados: Entre los principales patógenos presentes en pacientes quemados relacionados con la sepsis se destacaron Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter sp, Candida albicans y Proteus sp. Estos patógenos pueden o no estar relacionados con la microbiota del paciente. El proceso de infección, con la pérdida de la primera línea de defensa inmunológica, deja el organismo susceptible a la entrada e instalación de microorganismos. El tratamiento de la sepsis depende de factores relevantes, incluyendo la gravedad de la lesión y el agente de la infección. Conclusión: El riesgo asociado con la sepsis en pacientes quemados puede reducirse con un diagnóstico y seguimiento adecuados.

Balneotherapy is a potential risk factor for Pseudomonas aeruginosa colonization

ABSTRACT The practice of immersion in burn patient has been abandoned in many parts of the world but in Brazil it is still common. The aim of this study was to ascertain if balneotherapy is a risk factor for Pseudomonas aeruginosa colonization in thermally injured patients. Eighteen patients from a Burn Center were studied for 14 weeks for Pseudomonas aeruginosa. Samples were collected by swabbing the exudate of wounds, before and after giving bath to the patients and from balneotherapy table. Pulsed-field gel electrophoresis was used to determine bacterial genetic relatedness. Thirty-seven P. aeruginosa isolates were detected from 292 swabs collected from patients' burn surface area and from the balneotherapy table. Profile analysis of P. aeruginosa DNA fragmentation showed 10 clones among the 37 strains analyzed. Type A is the most prevalent clone, with 23 strains distributed into eight subtypes. These were present in the swabs collected, before and after the patients' bath, from the surface of the bath table, suggesting that there was cross-contamination between the patients in different ways. This work demonstrates that balneotherapy is a risk factor in the Burn Center studied, because the same clone was found among P. aeruginosa isolates collected at various points and times.

RESUMO A prática de balneotarapia em paciente queimado foi abandonada em muitas partes do mundo, mas no Brasil ainda é comum. O objetivo deste estudo foi verificar se a balneoterapia é um fator de risco para a colonização por Pseudomonas aeruginosa em pacientes queimados. Dezoito pacientes internados em um Centro de Queimadura (CQ) foram acompanhados por 14 semanas. Amostras foram coletadas do exsudato de feridas, antes e depois do banho dos pacientes e também da mesa onde a balneoterapia foi realizada. A relação genética entre as cepas de P. aeruginosa foi determinada pela electroforese em gel de campo pulsado. Trinta e sete cepas foram detectadas a partir de 292 swabs coletados de área de superfície das feridas dos pacientes e da mesa de balneoterapia. Análise de fragmentação do DNA das 37 P. aeruginosa mostrou a existência de 10 clones. O tipo A foi o clone mais prevalente, com 23 cepas distribuídas em oito subtipos. Estas estavam presentes nas lesões dos pacientes antes e após o banho e na mesa onde o banho foi realizado, sugerindo contaminação cruzada inter e intra-pacientes e pacientes e mesa de banho. Este trabalho mostra que a balneoterapia é um fator de risco para colonização por P. aeruginosa, no CQ estudado, pois um mesmo clone da bactéria foi encontrado nos isolados coletados em vários pontos e épocas diferentes.

Multiple antibiotic susceptibility of polyphosphate kinase mutants (ppk1 and ppk2) from Pseudomonas aeruginosa PAO1 as revealed by global phenotypic analysis

BACKGROUND: Pseudomonas aeruginosa is known to be a multidrug resistant opportunistic pathogen. Particularly, P. aeruginosa PAO1 polyphosphate kinase mutant (ppk1) is deficient in motility, quorum sensing, biofilm formation and virulence. FINDINGS: By using Phenotypic Microarrays (PM) we analyzed near 2000 phenotypes of P. aeruginosa PAO1 polyP kinase mutants (ppk1 and ppk2). We found that both ppk mutants shared most of the phenotypic changes and interestingly many of them related to susceptibility toward numerous and different type of antibiotics such as Ciprofloxacin, Chloramphenicol and Rifampicin. CONCLUSIONS: Combining the fact that ppk1 mutants have reduced virulence and are more susceptible to antibiotics, polyP synthesis and particularly PPK1, is a good target for the design of molecules with anti-virulence and anti-persistence properties.

Ativação do estresse oxidativo e da resposta antioxidante por ExoU de Pseudomonas aeruginosa / Activation of oxidative stress and antioxidant response by ExoU of Pseudomonas aeruginosa

ExoU, uma citotoxina produzida pelo patógeno oportunista Pseudomonas aeruginosa e translocada para o citosol de células hospedeiras via sistema de secreção do tipo III, é associada à gravidade de infecções agudas. No presente trabalho, o efeito de ExoU na ativação do estresse oxidativo e da resposta antioxidante foi avaliado em culturas de células epiteliais respiratórias humanas infectadas com a cepa PA103 de P. aeruginosa (produtora de ExoU), com a mutante deletada no gene exoU, PA103∆exoU, ou com a mutante complementada com exoU sem atividade tipo fosfolipase A2, PA103∆UT/S142A. Análises das dosagens de hidroperóxidos lipídicos e isoprostanos, considerados marcadores de estresse oxidativo, revelaram que ExoU promoveu um aumento em suas concentrações. Foi observado, também, que ExoU estimulou a produção de espécies reativas de oxigênio, óxido nítrico e peroxinitrito nas células infectadas, assim como a expressão de iNOS e eNOS, mas não de nNOS. Além disso, ExoU foi responsável pelo aumento da atividade de SOD1 e pela redução dos níveis de GSH, mas não afetou a atividade da catalase ou de NQO1. No modelo in vivo, a dosagem de malondialdeído, um subproduto da lipoperoxidação de membranas, evidenciou uma maior produção deste composto no pulmão de camundongos infectados pela cepa produtora de ExoU, em comparação ao pulmão de camundongos infectados pela cepa mutante. Em conjunto, estes resultados mostram que ExoU ativa a produção de espécies reativas de oxigênio e nitrogênio, levando à peroxidação lipídica e modulando o sistema de defesa antioxidante...

ExoU, a cytotoxin produced by the opportunistic pathogen Pseudomonas aeruginosa and translocated into the cytosol of host cells via a type III secretion system, is associated with severity of acute infections. In the present work, the effect of ExoU in the activation of oxidative stress and antioxidant response was evaluated in cultures of human respiratory epithelial cells infected with P. aeruginosa PA103 strain (producer of ExoU), or with its isogenic mutants, the ExoU-deficient PA103∆exoU or the exoU-depleted mutant complemented with an exoU gene with a site-specific mutation in the PLA2 catalytic site, PA103∆UT/S142A. Analysis of dosages of lipid hydroperoxides and isoprostanes, considered markers of oxidative stress, revealed that ExoU promoted an increase in their concentrations. It was also observed that ExoU stimulated the production of reactive oxygen species, nitric oxide and peroxynitrite in infected cells, as well as the expression of iNOS and eNOS, but not nNOS. Furthermore, ExoU was responsible for the increased activity of SOD1 and the reduced levels of GSH, but did not affect the activity of catalase or NQO1. In the in vivo model, the analysis of malondialdehyde, a byproduct of lipid peroxidation of membranes, showed increased production of this compound in the lungs of mice infected with the ExoU-producing strain compared to the lungs of mice infected with the mutant strain. Together, these results show that ExoU activates the production of reactive oxygen and nitrogen species, leading to lipid peroxidation and modulating the antioxidant defense system...

Ectima gangrenoso y osteoartritis por pseudomonas aeruginosa en un paciente previamente sano / Ecthyma gangrenosum and osteoarthritis by pseudomonas aeruginosa in a previously healthy patient

Las infecciones por pseudomonas aeruginosa se presentan habitualmente en individuos con factores predisponentes, siendo excepcional su ocurrencia en los previamente sanos. Se describe el caso de un lactante de 2 meses sin antecedentes patológicos a destacar que presentó una infección grave por pseudomonas aeruginosa, presentando al momentode la consulta en emergencia lesiones en piel características de ectima gangrenoso. El reconocimiento de estas lesiones permite adecuar el tratamiento antibiótico empírico a la susceptibilidad antimicrobiana de este germen. La presencia de una infección por esta bacteria obliga al clínico a la búsqueda de inmunodeficiencias no diagnosticadas previamente...

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

Antimicrobianos antipseudomónicos antiguos, actuales y futuros / Old, present and future anti-Pseudonomas antimicrobials

Hace más de 30 años la Pseudomonas aeruginosa comenzó a ser uno de los principales patógenos de las bacteriemias por gramnegativos, asociada a una mortalidad del 90 por ciento, hoy las tasas de mortalidad oscilan entre 18-61 por ciento

Infective endocarditis of the aortic valve caused by Pseudomonas aeruginosa and treated medically in a patient on haemodialysis

Infective endocarditis [IE] in patients on dialysis is a serious infection with a high mortality rate. It is usually caused by Gram positive bacteria with Gram negative organisms being relatively rare as a cause. Recommended treatment usually involves surgical valve replacement and the extended use of antibiotics. Successful treatment with antibiotics alone is rare. We report a case of IE caused by Pseudomonas aeruginosa in a patient on dialysis treated solely with antibiotics

Non invasive real-time monitoring of bacterial infection & therapeutic effect of anti-microbials in five mouse models.

Background & objectives: In vivo imaging system has contributed significantly to the understanding of bacterial infection and efficacy of drugs in animal model. We report five rapid, reproducible, and non invasive murine pulmonary infection, skin and soft tissue infection, sepsis, and meningitis models using Xenogen bioluminescent strains and specialized in vivo imaging system (IVIS). Methods: The progression of bacterial infection in different target organs was evaluated by the photon intensity and target organ bacterial counts. Genetically engineered bioluminescent bacterial strains viz. Staphylococcus aureus Xen 8.1, 29 and 31; Streptococcus pneumoniae Xen 9 and 10 and Pseudomonas aeruginosa Xen-5 were used to induce different target organs infection and were validated with commercially available antibiotics. Results: The lower limit of detection of colony forming unit (cfu) was 1.7-log10 whereas the lower limit of detection of relative light unit (RLU) was 4.2-log10. Recovery of live bacteria from different target organs showed that the bioluminescent signal correlated to the live bacterial count. Interpretation & conclusions: This study demonstrated the real time monitoring and non-invasive analysis of progression of infection and pharmacological efficacy of drugs. These models may be useful for pre-clinical discovery of new antibiotics.

Screening & profiling of quorum sensing signal molecules in Pseudomonas aeruginosa isolates from catheterized urinary tract infection patients.

Background & objectives: Catheter associated urinary tract infections are the second most common nosocomial infections and Pseudomonas aeruginosa is the third most common organism responsible for these infections. In this study P. aeruginosa isolates from catheterized urinary tract infection patients were screened and profiled for the presence of different type of quorum sensing (QS) signal molecules. Methods: Screening and quantitation of AHLs was done by using cross feeding assay and by determining β-galactosidase activity respectively using Escherichia coli MG4 as reporter strain. Further, AHL profiles were determined by separating AHLs on TLC coupled with their detection using Chromobacterium violaceum CV026 and Agrobacterium tumifaciens A136 biosensor strains. Results: All uroisolates from catheterized patients having urinary tract infections were found to be producers of QS signal molecules. There were differences in amounts and type of AHL produced amongst uroisolates of P. aeruginosa. Several AHLs belonging to C4-HSL, C6-HSL, oxo-C6-HSL, C8-HSL, C10-HSL and C12-HSL were determined in these strains. Interpretation & conclusions: Simultaneous use of more than one reporter strain and assay method proved useful in determining the AHLs profile in uroisolates of P. aeruginosa. Observed differences in the amounts and types of AHLs may reflect differences in virulence potential of P. aeruginosa to cause UTIs which can be further confirmed by employing animal model system. The present study speculates that production of QS signal molecules may act as a new virulence marker of P. aeruginosa responsible for causing catheter associated UTIs and can be considered as futuristic potential drug targets towards treatment of UTIs.

Comparison of antibiotic resistance and virulence factors in pigmented and Non-pigmented Pseudomonas aeruginosa / Comparación de la resistencia antibiótica y los factores de virulencia en las Pseudomonas aeruginosa pigmentadas y no pigmentadas

OBJECTIVES: Pseudomonas aeruginosa produces multiple virulence factors that have been implicated in pathogenesis and quorum sensing. The aim of this study was to determine differences in the virulence factors of pigmented and non-pigmented P aeruginosa isolates. METHODS: Associations were assessed between pigment production (pyocyanin and pyoverdin) and production of DNase, elastase, lipase, protease, siderophore, twitching motility, antibiotic resistance patterns and virulence-associated genes in 57 non-duplicate P aeruginosa isolates from wounds, sputum, urine, high vaginal swab (HVS), ear, eye and respiratory tract swabs and aspirates of peritoneum and ulcers. RESULTS: Most (82.5%) of the isolates produced either pigment. Pigmented isolates produced more frequently and significant more (p < 0.05) DNase, elastase, lipase protease, and siderophore. Imipenem was the only antibiotic to which all isolates were susceptible (p < 0.05), while 93% and 32% were resistant to tetracycline and norfloxacin, respectively. There was however no significant difference between pigmented and non-pigmented isolates when antibiotic resistance was compared. While isolates had multiple virulence-associated genes, exoS (51%), rhlA (37%) and rhlB (46%) were the predominant genes detected. Except for exoY, genes were present in pigmented isolates more frequently than in non-pigmented isolates. CONCLUSION: The results of this study suggest that antibiotic resistance per se might not be associated with the pigment production in P aeruginosa. However, pigment production appeared to be more significantly associated with multi-drug resistance, presence ofvirulence-associated genes, and expression ofcertain virulence factors, most notably elastase, protease, siderophore and DNase activity. Since pigment production is easy to determine, this might to be a good starting point to identify the virulence status ofan isolate.

OBJETIVO: Pseudomonas aeruginosa produce múltiples factores de virulencia que han estado implicados en patogénesis y detección de quórum (quorum sensing). El objetivo de este estudio fue determinar las diferencias en los factores de virulencia de aislados de P aeruginosa pigmentada y no pigmentada. MÉTODO: Se evaluaron las asociaciones entre la producción de pigmentos (piocianina y pioverdina) y la producción de Dnasa, elastasa, lipasa, proteasa, sideróforos, motilidad asociada a superficies (twitching), patrones de resistencia antibiótica, y genes asociados con virulencia en 57 aislados de P aeruginosa no duplicados, de heridas, esputo, orina, exudado vaginal, exudados de oídos, ojos, y vías respiratorias, y aspirados de peritoneo y úlceras. RESULTADOS: La mayor parte (82.5%) de los aislados produjeron uno de los pigmentos. Los aislados pigmentados produjeron con mayor frecuencia y más significativamente (p < 0.05). Dnasa, elastasa, lipasa, proteasa, y siderósforos. Imipenem fue el único antibiótico al que todos los aislados eran susceptibles (p < 0.05), mientras que el 93% y el 32% fueron resistentes a la tetraciclina y a la norfloxacina, respectivamente. Sin embargo, no hubo diferencia significativa entre los aislados pigmentados y los no pigmentados cuando se comparaba la resistencia antibiótica. Si bien los aislados tenían múltiples genes asociados con la virulencia, exoS (51%), rhlA (37%) y rhlB (46%) fueron los genes predominantes detectados. Con excepción de exoY, los genes estuvieron presentes en aislados pigmentados con mayor frecuencia que en los aislados no pigmentados. CONCLUSIÓN: Los resultados de este estudio sugieren que la resistencia antibiótica per se podría no estar asociada con la producción de pigmentos en P aeruginosa. Sin embargo, la producción de pigmentos parecía estar asociada más significativamente con la resistencia a las multidrogas, la presencia de genes asociados con la virulencia, y la expresión de ciertos factores de virulencia, en particular la actividad de la elastasa, la proteasa, los sideróforos, y la Dnasa. Puesto que la producción de pigmentos es fácil de determinar, esto podría ser un buen punto de partida para identificar el estado de virulencia de un aislado.

[Molecular detection and identification of virulence factors of Pseudomonas aeruginosa isolated from wound and burn infections]

In recent decades, Pseudomonas aeruginosa has emerged as one of the most important nosocomial pathogens. Due to the clinical importance this bacterium, various methods have been developed to rapidly and accurately identify it. The aim of this research was to detect P. aeruginosa isolated from wound and burn infections on the basis of the amplification of the oprl, oprL and toxA genes, and to determine the prevalence of nanl and exoS genes among them. A total of 150 P. aeruginosa isolates was collected from patients with burn and wound infections of Imam-Khomaini, Tohid and Motahari hospitals in Tehran. The isolates were identified as P. aeruginosa using specific biochemical tests. Chromosomal DNA of the isolates was extracted with phenol chloroform method and used for PCR of oprl, oprL, toxA, exoS and nanl genes by specific primers. Among 150 P. aeruginosa isolates all carried the oprl and oprL genes; 98 [65.3%] 142 [94.7%] and 19 [12.66%] of the isolates were positive for exoS, toxA and nanl genes respectively. The presence of nanl gene in wound isolates [30%] was significantly higher [p<0.05] than in burn isolates [4%].Our results indicated that simultaneous use of oprl, oprL and toxA genes provide sufficient sensitivity to detect P. aeruginosa in clinical samples. The high prevalence of exoS in isolates suggests invasive phenotype of wound and burn isolates. The high prevalence of nanl in wound isolates suggests a possible role of this gene in those infections

Pseudomonas aeruginosa isolated from otitis externa associated with recreational waters in some public swimming pools in Tehran

Pseudomonas aeruginosa is the most significant bacteria capable of multiplying in water especially in recreational waters. This bacterium is also the most commonly bacterial pathogen in ear infections. Although the bacterium is infrequently found in the normal ear, but the users of swimming pools may be at risk of acquiring disease. The bacteriological quality and health risk of the water of eleven public outdoor and indoor swimming pools in East and North-East of Tehran was assayed. Useful information was recorded at the time of sampling. Samples tested for aerobic colony count, coliforms, Escherichia coli and P. aeruginosa according to the standard method. Ear swabs were collected from 179 users with a history of ear problems during the previous two weeks. An adequate control group was chosen randomly from those who never used the investigated pools. P. aeruginosa was isolated from 9 [81.8%] of the pools. P. aeruginosa was the only bacterium grew in 7 [63.6%] swimming pools, while in the other 2 [18.2%] swimming pools high rates of total bacterial count, total coliforms and fecal coliform counts were also found besides P. aeruginosa. Meanwhile, P. aeruginosa was isolated from the ear swabs of 142 [79.3%] swimming pool users, as compared to 4% of the controls. Results revealed that otitis externa was strongly associated with swimming in pools, due to P. aeruginosa. Furthermore, contamination of the swimming pools with P. aeruginosa and often the chlorination process could not remove the pollution, especially when high numbers of people led to overuse of the pools, hence, more strict bathing water standards should be met in the public swimming pools in the city

Hematological and immunological responses of Nile tilapia after polyvalent vaccine administration by different routes / Resposta hematológica e imunológica de tilápia do Nilo após administração de vacina polivalente por diferentes vias

The efficacy of a polyvalent bacterin vaccine against Aeromonas hydrophila, Pseudomonas aeroginosa and Enterococcus durans administered by different routes in Nile tilapia was assessed by analyzing hematological and immunological parameters 7 and 21 days after vaccination. Treatments consisted of: non-vaccinated tilapia; tilapia vaccinated by intraperitoneal injection with 2x10(8) formalin-inactivated bacteriaÀmL-1; tilapia vaccinated orally with 2x10(7) formalin-inactivated bacteriaÀg-1, feed for 5 days; tilapia vaccinated by immersion bath in 2x10(7) formalin-inactivated bacteriaÀmL-1, for 20 minutes. Vaccinated fish groups presented higher hematocrit, number of erythrocytes and leukocytes than the non-vaccinated group. Serum agglutination titer of intraperitoneally vaccinated fish was higher on both evaluation periods for the three bacteria strains. Only on day 21 post-vaccination fish from the oral and immersion vaccination groups presented higher serum agglutination titer than the non-vaccinated fish for A. hidrophyla and E. durans. Serum antimicrobial activity in vaccinated fish was higher for P. aeroginosa and E. coli than in non-vaccinated fish on both evaluation periods. The different vaccine administration routes stimulated hematological and immunological responses in Nile tilapia 21 days post-vaccination, but intraperitoneal vaccination presented higher total number of leukocytes, lymphocytes and serum agglutination titer.

Este estudo avaliou a eficácia da administração de vacina polivalente (bacterina), contra Aeromonas hydrophila, Pseudomonas aeroginosa e Enterococcus durans, por diferentes vias de aplicação em tilápia do Nilo, analisando parâmetros hematológicos e imunológicos no 7º e 21º dia após vacinação. Os tratamentos consistiram de: tilápias não vacinadas; tilápias vacinadas via injeção intraperitoneal (i.p.) contendo 2x10(8) bactérias inativadasÀmL-1; tilápias alimentadas com ração contendo vacina na proporção de 2x10(7) bactérias inativadasÀg-1, durante 5 dias; tilápias vacinadas por banho de imersão em 2x10(7) bactérias inativadasÀmL-1, durante 20 minutos. Os peixes vacinados apresentaram maior porcentagem de hematócrito, número de eritrócitos e leucócitos durante o período do experimento, em relação aos não vacinados. O título de aglutinação do soro dos peixes vacinados intraperitonealmente foi superior nos dois períodos de avaliação para todas as bactérias. Apenas no 21º dia os peixes vacinados oralmente e por imersão apresentaram título de aglutinação superior aos peixes não vacinados para A. hidrophyla e E. durans. O soro dos peixes vacinados apresentou maior atividade antimicrobiana para P. aeroginosa e E. coli, do que os peixes não vacinados, nos dois períodos. As diferentes vias de administração da vacina estimularam a resposta hematológica e imunológica da tilápia do Nilo após 21 dias de vacinadas, sendo que o número total de leucócitos, linfócitos, título aglutinante do soro dos vacinados i.p. foi maior do que os demais.

Urinary tract infections caused by Pseudomonas aeruginosa: a minireview

Urinary tract infections [UTIs] are a serious health problem affecting millions of people each year. Infections of the urinary tract are the second most common type of infection in the body. Catheterization of the urinary tract is the most common factor, which predisposes the host to these infections. Catheter-associated UTI [CAUTI] is responsible for 40% of nosocomial infections, making it the most common cause of nosocomial infection. CAUTI accounts for more than 1 million cases in hospitals and nursing homes annually and often involve uropathogens other than Escherichia coli. While the epidemiology and pathogenic mechanisms of uropathogenic Escherichia coli have been extensively studied, little is known about the pathogenesis of UTIs caused by other organisms like Pseudomonas aeruginosa. Scanty available information regarding pathogenesis of UTIs caused by P. aeruginosa is an important bottleneck in developing effective preventive approaches. The aim of this review is to summarize some of the advances made in the field of P. aeruginosa induced UTIs and draws attention of the workers that more basic research at the level of pathogenesis is needed so that novel strategies can be designed

Evaluation of interleukin-10 production in pseudomonas aeruginosa induced acute pyelonephritis

Pseudomonas aeruginosa is an opportunistic pathogen of immunocompromised hosts. This pathogen has a tendency to form biofilms on the surface of indwelling catheters leading to acute and chronic urinary tract infections that result in significant morbidity and mortality. In the present study, kinetics of interleukin-10 [IL-10] production in mouse renal tissue was studied employing experimental mouse model of acute pyelonephritis induced with planktonic and biofilm cells of P. aeruginosa. IL-10 production was found to be significantly lower in biofilm cell instilled mice compared to planktonic cell infected animals, which corroborated with higher bacterial load and tissue damage. The data suggests that downregulation of IL-10 production may be novel strategy employed by biofilm cells to cause tissue damage and hence bacterial persistence. The results of the present study may open up avenues of research that will ultimately provide the foundation for the development of preventative measures and therapeutic strategies to successfully treat P. aeruginosa biofilm infections based on the administration of anti-inflammatory agents