Pseudomonas aeruginosa: una bella oportunista

Las bacterias son infinitamente más antiguas que el hombre y se reproducen más rápido, cada quince minutos y en una hora tienen cuatro generaciones, mientras que el hombre necesita un siglo para ello, de modo que en la larga existencia bacteriana somos apenas un minúsculo accidente. Toda la maravillosa maquinaria reunida en una sola bacteria de la especie Pseudomonas aeruginosa no fue planeada contra nosotros, incluyendo señales de quorum, bombas de expulsión, integrones, biofilm y piocinas, ya presentes en su vida natural o planctónica. Su adaptación a la vida nosocomial forzó a estudiarla y la organización de sus múltiples capacidades hace plantear que en su vida hay un propósito, una suerte de "inteligencia bacteriana" en contraposición a la tesis de Jacques Monod que estima la vida en este planeta como fruto del azar y de la necesidad.

Bacteria are infinitely older tan man and reproduce faster, every fifteen minutes and in one hour they have four generations, while man needs a century for have the same, so that in the long bacterial existence we are just a tiny accident. All the wonderful machinery assembled in a single bacterium of the species Pseudomonas aeruginosa it was not planned against us, including quorum sensing, efflux pumps, integrons, biofilm and pyocins, already presents in their natural or planktonic life. Her adaptation to hospital life forced to study this wonderful creature, and the organization of such multiple capacities suggests the existence of a vital purpose, a kind of bacterial intelligence, contrary to Jacques Monod's thesis, which estimate life in this planet as the result of chance and necessity.

Respuesta de procalcitonina ante co-infección e infección secundaria por bacterias multirresistentes en pacientes COVID -19 / Procalcitonin response in co-infection and secondary infection by multidrug resistant bacteria in COVID -19 patients

INTRODUCCIÓN. La procalcitonina, es un biomarcador que puede usarse como apoyo diagnóstico en infecciones bacterianas y la monitorización del tratamiento antibiótico, sobre todo en pacientes con sepsis. De ahí que, fue utilizado durante la pandemia COVID-19 OBJETIVO. Determinar los valores de procalcitonina en pacientes con COVID-19 y definir una p osible correlación entre su incremento y vinculación en coinfección o infección secundaria por Klebsiella pneumoniae y Pseudomonas aeruginosa con multidrogo resistencia y resistencia extendida a los antibióticos. MATERIALES Y MÉTODOS. Estudio retrospectivo observacional, descriptivo transversal, realizado del 1 de mayo al 31 de octubre del 2020 en el Hospital de Especialidades Carlos Andrade Marín sobre 7028 pacientes adultos, hospitalizados, con diagnóstico de COVID-19, y resultados de procalcitonina, cuyas muestras de secreción traqueal y/o hemocultivo presentaron desarrollo de Klebsiella pneumoniae y Pseudomonas aeruginosa. Su análisis estadístico fue desarrollado mediante la prueba Chi Cuadrado de Pearson. RESULTADOS. Se recibieron 861 muestras de hemocultivo y 391 de secreción traqueal, obteniéndose: 32% aislamientos de Klebsiella pneumoniae y Pseudomonas aeruginosa multidrogo y extremadamente resistente. Entre los pacientes COVID-19 que fallecieron, 34,4% mostraron incrementos de procalcitonina. Al contrario, entre los pacientes que sobrevivieron sólo en 8,8% se observó incrementos de procalcitonina evidenciándose un vínculo entre el incremento de procalcitonina y mortalidad. CONCLUSIONES. No existe diferencia en relación al incremento en los valores de procalcitonina en pacientes COVID-19 con co-infección o infección secundaria por Klebsiella pneumoniae y Pseudomonas aeruginosa multidrogo y extremadamente resistente y los valores de procalcitonina en pacientes con coinfección e infección secundaria con otro tipo de aislamientos bacterianos.

INTRODUCTION. Procalcitonin is a biomarker that can be used as a diagnostic support in bacterial infections and the monitoring of antibiotic treatment, especially in patients with sepsis. Hence, it was used during the COVID-19 pandemic OBJECTIVE. To determine the values of procalcitonin in patients with COVID-19 and to define a possible correlation between its increase and linkage in co-infection or secondary infection by Klebsiella pneumoniae and Pseudomonas aeruginosa with multidrug resistance and extended resistance to antibiotics. MATERIALS AND METHODS. Retrospective observational, descriptive cross-sectional study, conducted from May 1 to October 31, 2020 at the Hospital de Especialidades Carlos Andrade Marín on 7028 adult patients, hospitalized, with diagnosis of COVID-19, and procalcitonin results, whose tracheal secretion and/or blood culture samples presented development of Klebsiella pneumoniae and Pseudomonas aeruginosa. Their statistical analysis was developed using Pearson's Chi-squared test. RESULTS. We received 861 blood culture and 391 tracheal secretion samples, obtaining: 32% isolates of Klebsiella pneumoniae and multidrug-resistant and extremely resistant Pseudomonas aeruginosa. Among the COVID-19 patients who died, 34.4% showed increased procalcitonin levels. On the contrary, among patients who survived, only 8.8% showed increased procalcitonin levels, showing a link between increased procalcitonin levels and mortality. CONCLUSIONS. There is no difference in relation to the increase in procalcitonin values in COVID-19 patients with co-infection or secondary infection by Klebsiella pneumoniae and multidrug-resistant and extremely resistant Pseudomonas aeruginosa and procalcitonin values in patients with co-infection and secondary infection with other types of bacterial isolates.

Caracterización de la utilización de colistín en un hospital de alta complejidad

Resumen: El aumento de la resistencia y la escasez de nuevos antibacterianos ha requerido la reintroducción de antiguos antimicrobianos entre ellos colistín. Objetivo: Caracterizar la utilización de colistín durante el año 2017 en un hospital universitario, mediante la descripción de los pacientes, los tratamientos, la microbiología asociada y efectos adversos. Pacientes y Métodos: Trabajo observacional retrospectivo. Se revisaron los datos de todos los pacientes que recibieron colistín intravenoso (IV) por al menos 48 horas, durante el año 2017. Resultados: Se incluyeron 53 pacientes, equivalentes a 91 tratamientos. El foco respiratorio fue el principal (46,2%). El 68,1% de los tratamientos fue iniciado en la UCI. La mayoría de los pacientes tenía una hospitalización reciente (83,5%), y presentaban uso previo de antibacterianos (89%). Los dos patógenos mayoritariamente identificados fueron Pseudomonas aeruginosa y Klebsiella spp. El consumo promedio de colistín fue de 2,4 DDD/100 camas/día. El servicio que más consumió colistín fue la UCI, con 45,5 DDD/100 camas/día, usando generalmente la dosis de 3 MUI cada 8 horas IV y con una baja utilización de dosis de carga. Conclusión: Colistín corresponde a un antimicrobiano de uso restringido a infecciones sospechadas o confirmadas por agentes bacterianos multi resistentes. En esta serie, su uso inicial fue principalmente empírico, en pacientes con factores de riesgo para resistencia antibacteriana; se usó en forma asociada a otros antimicrobianos, siendo el foco principal el respiratorio.

Background: The increase in resistance and the shortage of new antibiotics has led to the reintroduction of old antimicrobials such as colistin. Aim: To evaluate the use of colistin during 2017 in a university hospital, through the characterization of patients and treatment, associated microbiology, response to treatment and adverse effects. Methods: Retrospective observational design. The data of all patients who received colistin for at least 48 hours during the year 2017 were reviewed. Results: 55 patients were included, equivalent to 144 treatments. The respiratory focus was the main one (57.9%). 64% of the treatments began in the ICU, while 7% in the ward. Most of the patients has a recent hospitalization (86.8%) and has previous use of antibiotics (90.4%). The two main pathogens identified were Pseudomonas aeruginosa and Klebsiella spp. In 87.1% of the cases with microbiological justifications for the use of colistin, a favorable response was obtained. The average consumption of colistin was 2.4 DDD/100 beds/day. The department that consumed the most colistin was the ICU, with 45,5 DDD/100 beds/day, generally using a dose of 3 MIU every 8 hours IV and with low use of loading doses. Conclusion: Colistin corresponds to an antibiotic whose use is restricted to infections suspected or confirmed by multi-resistant bacterial agents. Its initial use in this serie was mainly empirical, in patients with risk factors for antibiotics resistance, it was used in association with other antimicrobials, being the respiratory the main infectious focus.

Antibacterial Activity of Lawsonia inermis Leaf Extracts against Multidrug-resistant Pseudomonas aeruginosa from Infected Wounds

Background: Wound infection comprises numerous different organisms that have the ability to surface colonization of wounds. Multidrug-resistant Pseudomonas aeruginosa is one of the pathogenic bacteria associated with wound infections. Aim: This study isolated and identified multidrug-resistant Pseudomonas aeruginosa from infected wounds and determine the antibacterial activity of Lawsonia inermis leaf extracts against it. Design: This is a Clinical and laboratory-based study involving patients with defined cases of wound infections. Place and Duration of Study: This study was conducted in the Microbiology (Bacteriology) laboratory of Specialist Hospital, Bauchi, Nigeria, from February to November 2021. Methods: Twenty-eight (28) Pseudomonas aeruginosa isolates were recovered from 179 wound swabs using standard laboratory procedures and were screened for multidrug-resistant patterns according to the Kirby-Bauer disc diffusion method. Antibacterial efficacy of the aqueous, ethanolic, and methanolic leaf extracts of Lawsonia inermis was tested against the multidrug-resistant isolates using agar well diffusion techniques. The zone of inhibition was measured and the differences between means were statistically analyzed (p<0.05). Results: A total of twenty-eight (28) multidrug-resistant Pseudomonas aeruginosa were confirmed, showing resistance to Amoxicillin (64.3%), Ceftazidime (85.71%), and Cefotaxime (78.57%) but sensitivity to Imipenem (95.5%). The phytochemical screening revealed the presence of flavonoids, glycosides, saponins, steroids, and tannins among others. MDR P. aeruginosa was inhibited at varied concentrations of the extracts with the diameter mean zone of inhibition increasing as the concentration increased. The Methanol extracts showed the highest antibacterial activity against MDR P. aeruginosa with a mean zone of inhibition of 9.500±0.288mm at 400mg/ml. Conclusion: These results indicated that Lawsonia inermis leaf extracts possess antibacterial activities on Multidrug-resistant Pseudomonas aeruginosa which could be a good source for the production of plant-based antibacterial drugs., although somewhat less than the synthetic standard drugs (Imipenem) having a mean of 13.83±0.288mm.

Evaluation of toxin-antitoxin genes, antibiotic resistance, and virulence genes in Pseudomonas aeruginosa isolates

SUMMARY OBJECTIVE: Toxin-antitoxin genes RelBE and HigBA are known to be involved in the formation of biofilm, which is an important virulence factor for Pseudomonas aeruginosa. The purpose of this study was to determine the presence of toxin-antitoxin genes and exoenzyme S and exotoxin A virulence genes in P. aeruginosa isolates and whether there is a relationship between toxin-antitoxin genes and virulence genes as well as antibiotic resistance. METHODS: Identification of the isolates and antibiotic susceptibilities was determined by a VITEK 2 (bioMérieux, France) automated system. The presence of toxin-antitoxin genes, virulence genes, and transcription levels were detected by real-time polymerase chain reaction. RESULTS: RelBE and HigBA genes were detected in 94.3% (82/87) of P. aeruginosa isolates, and exoenzyme S and exotoxin A genes were detected in all of the isolates (n=87). All of the isolates that harbor the toxin-antitoxin and virulence genes were transcribed. There was a significant increase in the RelBE gene transcription level in imipenem- and meropenem-sensitive isolates and in the HigBA gene transcription level in amikacin-sensitive isolates (p<0.05). There was a significant correlation between RelBE and exoenzyme S (p=0.001). CONCLUSION: The findings suggest that antibiotic resistance may be linked to toxin-antitoxin genes. Furthermore, the relationship between RelBE and exoenzyme S indicates that toxin-antitoxin genes in P. aeruginosa isolates are not only related to antibiotic resistance but also play an influential role in bacterial virulence. Larger collections of comprehensive studies on this subject are required. These studies should contribute significantly to the solution of the antibiotic resistance problem.

Ação antimicrobiana de extratos de gengibre (Zingiber officinale) e quilaia (Quillaja saponaria) isolados e associados sobre Pseudomonas aeruginosa resistente a antibióticos / Antimicrobial action of isolated and associated extracts of ginger (Zingiber officinale) and quilaia (Quillaja saponaria) on antibiotic-resistant Pseudomonas aeruginosa

Extratos de plantas têm demonstrado diversos efeitos positivos para a saúde, incluindo ação antimicrobiana, no entanto, o uso clínico da fitoterapia ainda é discreto, de modo que mais estudos sobre os efeitos benéficos do sinergismo farmacológico de extratos poderiam contribuir para sua aplicação terapêutica. O objetivo deste estudo foi avaliar os efeitos dos extratos glicólicos de gengibre (EG) e quilaia (EQ) isolados e em associação sobre 7 cepas clínicas de Pseudomonas aeruginosa e uma cepa padrão em forma planctônica e biofilmes monotípicos. Para a análise antimicrobiana sobre cultura planctônica foram feitos testes para determinação de Concentração Inibitória Mínima (CIM) e Concentração Microbicida Mínima (CMM) (CLSI, M07-A9) dos extratos isolados, além do Índice de Concentração Inibitória Fracionada (ICIF) e do Índice de Concentração Microbicida Fracionada (ICMF) para os extratos combinados. A análise estatística foi feita com método ANOVA e teste de Tukey para dados com distribuição normal e Kruskall-Wallis com Teste de Comparação Múltipla de Dunn para dados sem distribuição normal (significância de 5%). Para cepa padrão foram determinadas CIM igual a 3,12 mg/mL e CMM igual a 6,25 mg/mL para ambos os extratos. Para cepas clínicas as CIM do EG foram 3,12 ou 6,25 mg/mL e de EQ 1,56 ou 3,12 mg/mL, enquanto os valores de CMM foram de 6,25 mg/mL para EG e de 1,56, 3,12 ou 6,25 mg/mL para EQ. Os resultados de ICIF indicaram 15 associações sinérgicas e 4 associações aditivas dos extratos contra a cepa padrão e, dentre cepas clínicas, foram obtidos 15 resultados aditivos. A partir dos resultados de ICMF foram identificadas 6 associações sinérgicas e 1 associação aditiva contra a cepa padrão, além de 8 associações com efeito aditivo contra cepas clínicas. A partir dos resultados de testes em culturas planctônicas foi avaliada a ação antibiofilme sobre as cepas em que foram observadas reduções de viabilidade de 36,7 e 34% para o EG (50 e 25 mg/mL) e 51,3 e 51,4% para EQ (25 e 12,5 mg/mL) contra cepa padrão. As reduções em cepas clínicas variaram de 43 a 73% com EG e de 36 a 79% para EQ. As associações dos extratos promoveram reduções de viabilidade de 8 a 35% contra 5 das 7 cepas clínicas. Conclui-se que os extratos glicólicos de gengibre e quilaia apresentam ação antimicrobiana de forma isolada e combinados com efeito aditivo sobre a forma planctônica de cepas clínicas resistentes de P. aeruginosa. De forma isolada, os extratos apresentaram importante ação preventiva na formação dos biofilmes dessas cepas, podendo ser considerados potenciais fitoterápicos com aplicações terapêuticas para o combate das infecções por P. aeruginosa. (AU)

Plant extracts have demonstrated several positive health effects, including antimicrobial action, however, the clinical use of phytotherapy is still discreet, so that more studies on the beneficial effects of pharmacological synergism of extracts could contribute to its therapeutic application. The aim of this study was to evaluate the effects of glycolic extracts of ginger (EG) and quilaia (EQ) alone and in combination on 7 clinical strains of Pseudomonas aeruginosa and a standard strain in planktonic form and monotypic biofilms. For the antimicrobial analysis on planktonic culture, tests were performed to determine the Minimum Inhibitory Concentration (MIC) and Minimum Microbicidal Concentration (MMC) (CLSI, M07-A9) of the isolated extracts, in addition to the Fractional Inhibitory Concentration Index (FICI) and the Fractionated Microbicidal Concentration Index (FICM) for the combined extracts. Statistical analysis was performed using the ANOVA method and Tukey's test for data with normal distribution and Kruskall-Wallis with Dunn's Multiple Comparison Test for data without normal distribution (5% significance). For the standard strain, MIC were determined equal to 3.12 mg/mL and MMC equal to 6.25 mg/mL for both extracts. For clinical strains the MIC of EG were 3.12 or 6.25 mg/mL and 1.56 or 3.12 mg/mL of EQ, while the MMC values were 6.25 mg/mL for EG and 1.56, 3.12 or 6.25 mg/ml for EQ. The FICI results indicated 15 synergistic and 4 additive associations of the extracts against the standard strain and, among clinical strains, 15 additive results were obtained. From the FICM results, 6 synergistic and 1 additive association against the standard strain were identified, in addition to 8 associations with additive effect against clinical strains. Based on the results of tests on planktonic cultures, the antibiofilm action were evaluated on the strains in which viability reductions of 36 and 34% were observed for EG (50 and 25 mg/mL) and 51% were observed for EQ (25 and 12, 5 mg/mL) against the standard strain. Reductions in clinical strains ranged from 43 to 73% with EG and from 36 to 79% for EQ. Associations of extracts promoted viability reductions of 8 to 35% against 5 out of 7 clinical strains. It is concluded that the glycolic extracts of ginger and quilaia have antimicrobial action in isolation and combined with additive effect on the planktonic form of resistant clinical strains of P. aeruginosa. Isolated, the extracts showed an important preventive action in the formation of biofilms of these strains and may be considered potential herbal medicines with therapeutic applications to combat P. aeruginosa infections. (AU)

In vitro activity of imipenem/relebactam against non-Morganellaceae Enterobacterales and Pseudomonas aeruginosa in Latin America: SMART 2018‒2020

Abstract Carbapenem-resistant Enterobacterales and Pseudomonas aeruginosa are being isolated from patient specimens with increasing frequency in Latin America and worldwide. The current study provides an initial description of the in vitro activity of imipenem/relebactam (IMR) against non-Morganellaceae Enterobacterales (NME) and P. aeruginosa infecting hospitalized patients in Latin America. From 2018 to 2020, 37 clinical laboratories in nine Latin American countries participated in the SMART global surveillance program and contributed 15,466 NME and 3408 P aeruginosa isolates. MICs for IMR and seven comparators were determined using CLSI broth microdilution and interpreted by CLSI M100 (2022) breakpoints. β-lactamase genes were identified in selected isolate subsets. IMR (96.9% susceptible), amikacin (95.9%), meropenem (90.7%), and imipenem (88.7%) were the most active agents against NME. Among piperacillin/tazobactam-nonsusceptible NME (n= 4124), 90.4% of isolates were IMR-susceptible (range by country, 97.2 [Chile] to 67.0% [Guatemala]) and among meropenem-nonsusceptible NME isolates (n= 1433), 74.0% were IMR-susceptible (94.1% [Puerto Rico] to 5.1% [Guatemala]). Overall, 6.3% of all collected NME isolates carried a KPC (metallo-β-lactamase [MBL]-negative), 1.8% an MBL, 0.4% an OXA-48-like carbapenemase (MBL-negative), and 0.1% a GES carbapenemase (MBL-negative). Amikacin (85.2% susceptible) and IMR (80.1%) were the most active agents against P. aeruginosa; only 56.5% of isolates were imipenem-susceptible. Relebactam increased susceptibility to imipenem by 22.0% (from 23.9% to 45.9%) in piperacillin/tazobactam-nonsusceptible isolates (n= 1031) and by 35.5% (from 5.5% to 41.0%) in meropenem-nonsusceptible isolates (n= 1128). Overall, 7.6% of all collected P. aeruginosa isolates were MBL-positive and 0.7% carried a GES carbapenemase. In conclusion, in 2018‒2020, almost all NME (97%) and most P. aeruginosa(80%) isolates from Latin America were IMR-susceptible. Continued surveillance of the in vitro activities of IMR and comparator agents against Gram-negative pathogens, and monitoring for β-lactamase changes (in particular for increases in MBLs), is warranted.

Epidemiology and in vitro activity of ceftazidime-avibactam and comparator agents against multidrug-resistant isolates of Enterobacterales and Pseudomonas aeruginosa collected in Latin America as part of the ATLAS surveillance program in 2015‒2020

Abstract Introduction The incidence of antimicrobial resistance is increasing in many parts of the world. The focus of this report is to examine changes in antimicrobial resistance epidemiology among clinical isolates of Enterobacterales and Pseudomonas aeruginosa collected in six Latin American countries as part of the Antimicrobial Testing Leadership and Surveillance (ATLAS) program from 2015 to 2020, with a focus on the in vitro activity of ceftazidime-avibactam against Multidrug-Resistant (MDR) isolates. Methods Non-duplicate, clinical isolates of Enterobacterales (n= 15,215) and P. aeruginosa (n= 4,614) collected by 40 laboratories in Argentina, Brazil, Chile, Colombia, Mexico, and Venezuela, from 2015 to 2020, underwent centralized Clinical Lab Standards Institute (CLSI) broth microdilution susceptibility testing. Minimum Inhibitory Concentration (MIC) values were interpreted using 2022 CLSI breakpoints. An MDR phenotype was defined by resistance to ≥ 3 of seven sentinel agents. Results In total, 23.3% of Enterobacterales and 25.1% of P. aeruginosa isolates were MDR. Annual percent MDR values for Enterobacterales were stable from 2015 to 2018 (21.3% to 23.7% year) but markedly increased in 2019 (31.5%) and 2020 (32.4%). Annual percent MDR values for P. aeruginosa were stable from 2015 to 2020 (23.0% to 27.6% year). Isolates were divided into two 3-year time-periods, 2015‒2017 and 2018‒2020, for additional analyses. For Enterobacterales, 99.3% of all isolates and 97.1% of MDR isolates from 2015‒2017 were ceftazidime-avibactam-susceptible compared to 97.2% and 89.3% of isolates, respectively, from 2018‒2020. For P. aeruginosa, 86.6% of all isolates and 53.9% of MDR isolates from 2015‒2017 were ceftazidime-avibactam-susceptible compared to 85.3% and 45.3% of isolates, respectively, from 2018‒2020. Among individual countries, Enterobacterales and P. aeruginosa collected in Venezuela showed the greatest reductions in ceftazidime-avibactam susceptibility over time. Conclusion MDR Enterobacterales increased in Latin America from 22% in 2015 to 32% in 2020 while MDR P. aeruginosa remained constant at 25%. Ceftazidime-avibactam remains highly active against all clinical isolates of both Enterobacterales (97.2% susceptible, 2018‒2020) and P. aeruginosa (85.3%), and inhibited more MDR isolates (Enterobacterales, 89.3% susceptible, 2018‒2020; P. aeruginosa, 45.3%) than carbapenems, fluoroquinolones, and aminoglycosides.

Antimicrobial resistance of Pseudomonas aeruginosa isolated from patients with pneumonia during the COVID-19 pandemic and pre-pandemic periods in Northeast Brazil

Healthcare-related infections caused by resistant microorganisms are a severe public health problem and are becoming increasingly prevalent in the hospital environment, especially Pseudomonas aeruginosa. This work aimed to evaluate the resistance profile of Pseudomonas aeruginosa to antimicrobials before the COVID-19 pandemic and during the pandemic period. Bacteria strains were obtained from tracheal aspiration, sputum, and bronchoalveolar lavage for diagnosis and phenotypic characterization. Matrix assisted laser-desorption ionization-time of flight mass spectrometry (MALD-TOF MS) was used to identify strains. Automated Phoenix and VITEK® 2 Compact system and the disc diffusion method were performed to determine the antimicrobial susceptibility profile. A total of 41,000 medical reports from adult patients with pneumonia were analyzed. Of these, 951 patients were positive for P. aeruginosa, of which 373 were related to the pre-pandemic period and 578 to the pandemic period. Older men (≥60 years) were more prevalent in both periods. P. aeruginosa strains were resistant to imipenem in both periods: 38.8 and 42.5%, respectively, followed by meropenem (34.2 and 39.2%), ciprofloxacin (33.6 and 36.7%), and levofloxacin (34.9 and 43.5%). Intensive care units had the highest percentage of affected patients (62 and 65%) compared with other sectors, with a prevalence of 71% in the public network before COVID-19 and 59% during the pandemic. Our data showed a prevalence of P. aeruginosa in elderly patients in both the pre-pandemic and pandemic periods. In addition, an increase in P. aeruginosa resistance to beta-lactams, quinolones, carbapenems, and cephalosporins was observed during the COVID-19 pandemic compared with the period before the pandemic, especially in ICUs.

Calidad microbiológica del agua procedente de tanques y pozos artesianos de establecimientos sanitarios

Introducción: Las aguas procedentes de establecimientos de salud, son comúnmente utilizadas por funcionarios y pacientes. Para que sean aceptables para uso humano, las aguas de los establecimientos deben cumplir con criterios microbiológicos establecidos en normas nacionales. Objetivo: Determinar la calidad microbiológica de muestras de agua de establecimientos sanitarios del departamento de Caaguazú. Métodos: Estudio descriptivo observacional, de corte transversal. Se analizaron 104 muestras de agua potable y tratada de hospitales, unidades de salud familiar y puestos de salud, de los 22 distritos de Caaguazú. Para evaluar la calidad microbiológica del agua se analizaron heterotróficos totales, coliformes totales, coliformes termotolerantes, Escherichia coli y Pseudomonas aeruginosa. Las muestras se procesaron mediante filtración de membrana, placas rehidratables, medios convencionales y sistemas miniaturizados consistentes en una interfaz de programación de aplicaciones. Las muestras se catalogaron como aceptables o inaceptables acorde la norma NP Nº 24-001-80. Resultados: De las 104 muestras, 58 (56 %) fueron aceptables y 46 (44 %) fueron inaceptables. Las causas de esta última condición fueron presencia de coliformes totales (42 %), alto recuento de heterótrofas (13 %), presencia de coliformes termotolerantes (11,5 %), presencia de Escherichia coli (9,6 %) y presencia de Pseudomonas aeruginosa (2 %). Conclusiones: La mayoría de las muestras de agua fueron de calidad microbiológica aceptable; pero como se detectó un porcentaje considerable de muestras inaceptables y la presencia de especies como Escherichia coli y Pseudomonas aeruginosa, es recomendable corregir las técnicas de tratamiento de agua y enfatizar en los controles de calidad microbiológica, en los centros sanitarios estudiados.

Introduction: The waters from health establishments are commonly used by officials and patients. To be acceptable for human use, water from establishments must meet microbiological criteria established in national standards. Objective: To determine the microbiological quality of water samples from sanitary establishments in the department of Caaguazú. Methods: A descriptive, observational, cross-sectional study was conducted in 104 samples of drinking and treated water from hospitals, family health units and health posts from the 22 districts of Caaguazú. These samples were studied to evaluate the microbiological quality of the water, total heterotrophs, total coliforms, thermotolerant coliforms, Escherichia coli and Pseudomonas aeruginosa were analyzed. Samples were processed by membrane filtration, rehydratable plates, conventional media, and miniaturized systems consisting of an application programming interface. They were classified as acceptable or unacceptable according to standard NP Nº 24-001-80. Results: Fifty eight (56%) samples, out of the 104, were acceptable and 46 (44%) were unacceptable. The causes of this last condition were the presence of total coliforms (42%), high count of heterotrophs (13%), presence of thermotolerant coliforms (11.5%), presence of Escherichia coli (9.6%) and presence of Pseudomonas aeruginosa (2%). Conclusions: Most of the water samples were assessed to be acceptable in microbiological quality; however, since a considerable percentage of unacceptable samples and the presence of species such as Escherichia coli and Pseudomonas aeruginosa were detected, it is recommended to correct the water treatment techniques emphasizing microbiological quality controls in the health centers studied.

Extratos hidroetanólicos de canela (Cinnamomum verum) e romã (Punica granatum L) promovem ação antibacteriana frente cepas resistentes a antibióticos de Acinetobacter baumannii e Pseudomonas aeruginosa / Cinnamon (Cinnamomum verum) and pomegranate (Punica granatum L) hydroethanolic extracts promote antibacterial action against antibiotic-resistant strains of Acinetobacter baumannii and Pseudomonas aeruginosa

A resistência bacteriana tem aumentado progressivamente no mundo, assim, há necessidade de novas opções de tratamentos. A fitoterapia tem ganhado notoriedade para combater infecções, principalmente as causadas por bactérias resistentes aos antibacterianos disponíveis. Diante do exposto, o presente estudo teve como objetivo preparar e analisar a composição fitoquímica e a ação antibacteriana dos extratos hidroetanólicos de canela (EHC) e romã (EHR) isolados e associados frente culturas planctônicas e biofilmes de cepas padrão e clínicas de Acinetobacter baumannii e Pseudomonas aeruginosa, além disso, analisar a ação citotóxica dos extratos em queratinócitos humanos (HaCat). Para isso, os EHC e EHR foram preparados e quantificado o teor de sólidos solúveis. Posteriormente, foi quantificado o teor de flavonoides e fenóis totais, análise antioxidante por meio da redução do radical 2,2'-difenil-1-picrilhidrazila (DPPH), e a fitoquímica por cromatografia líquida (HPLC). Em relação a ação antibacteriana dos extratos, foi aplicado o teste de microdiluição em caldo (CLSI ­ M7-A9) e a ação sinérgica realizada por meio do ensaio de checkerboard. As concentrações mais efetivas foram analisadas sobre biofilmes em formação (prevenção) e biofilmes formados (tratamento de 24 h), e quantificada a viabilidade por meio do teste colorimétrico MTT. Para avaliar a citotoxidade, os tratamentos foram aplicados sobre cultura celular de HaCat por 24 h e analisados por meio do teste colorimétrico MTT. A análise estatística foi realizada com 5% de significância (p<0.05), analisados pelo método ANOVA complementado pelo Teste de Tukey. Os resultados demonstraram que os EHC e EHR possuem ação antioxidante e presença de fitocompostos. Os extratos apresentaram ação antibacteriana para todas as cepas avaliadas, quando os mesmos foram associados, obteve-se concentrações sinérgicas para as cepas clínicas de A. baumannii. Em relação a ação antibiofilme, o EHC inibiu a formação em 95% e EHR em 96% do biofilme de #Ab 1, enquanto a cepa #Pa 2 teve 92% e 93% de inibição quando em contato com EHC e EHR, respectivamente. Após tratamento de 24 h em biofilmes formados, as reduções da viabilidade foram de 72% para as cepas #Ab 2 e #Ab 3 quando em contato com o EHC, já EHR inibiu em 83% a viabilidade da cepa #Ab ATCC. Para P. aeruginosa (#Pa 2), as reduções da viabilidade foram de 84% e 88,5% quando tratados com EHC e EHR, respectivamente. A avaliação da citotoxicidade em HaCat demonstrou que após tratamentos com diferentes concentrações dos extratos a viabilidade celular se manteve acima de 70% em todos os grupos. Diante disso, conclui-se que os EHC e EHR apresentam importante ação antioxidante e antibacteriana, tanto em culturas planctônicas quanto em biofilmes, e não apresentaram efeitos citotóxicos na faixa de concentração testada. (AU)

Bacterial resistance has progressively increased in the world, thus, there is a need for new treatment options. Phytotherapy has gained notoriety for fighting infections, mainly those caused by bacteria resistant to available antibacterials. In view of the above, the present study aimed to prepare and analyze the phytochemical composition and antimicrobial action of hydroethanolic extracts of cinnamon (EHC) and pomegranate (EHR) isolated and associated against planktonic cultures and biofilms of standard and clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa, in addition, analyze the cytotoxic action of the extracts on human keratinocytes (HaCat). For this, the EHC and EHR were prepared and the soluble solids content was quantified. Subsequently, the content of flavonoids and total phenols, antioxidant analysis through the reduction of the radical 2,2'-diphenyl1-picrylhydrazyl (DPPH), and phytochemistry by liquid chromatography (HPLC) were quantified. Regarding the antimicrobial action of the extracts, the broth microdilution test (CLSI ­ M7-A9) was applied and the synergistic action was performed through the checkerboard test. The most effective concentrations were analyzed on forming biofilms (prevention) and formed biofilms (24 h treatment), and viability was quantified using the MTT colorimetric test. To evaluate the cytotoxicity, the treatments were applied on HaCat cell culture for 24 h and analyzed using the MTT colorimetric test. Statistical analysis was performed with 5% significance (p<0.05), analyzed by the ANOVA method complemented by the Tukey test. The results showed that the EHC and EHR have antioxidant action and presence of phytocompounds. The extracts showed antibacterial action for all evaluated strains, when they were associated, synergistic concentrations were obtained for the clinical strains of A. baumannii. Regarding the antibiofilm action, EHC inhibited formation by 95% and EHR by 96% of the #Ab 1 biofilm, while the #Pa 2 strain had 92% and 93% inhibition when in contact with EHC and EHR, respectively. After 24 h treatment in formed biofilms, viability reductions were 72% for strains #Ab 2 and #Ab 3 when in contact with EHC, whereas EHR inhibited the viability of strain #Ab ATCC by 83%. For P. aeruginosa (#Pa 2), viability reductions were 84% and 88.5% when treated with EHC and EHR, respectively. The evaluation of cytotoxicity in HaCat showed that after treatments with different concentrations of extracts, cell viability remained above 70% in all groups. Therefore, it is concluded that EHC and EHR have important antioxidant and antibacterial action, both in planktonic cultures and in biofilms, and did not show cytotoxic effects in the tested concentration range. (AU)

Ação antimicrobiana e antibiofilme dos extratos combinados de canela e própolis sobre cepas clínicas de Acinetobacter baumannii e Pseudomonas aeruginosa multirresistentes / Antimicrobial and antibiofilm action of combined extracts of cinnamon and propolis on multiresistant clinical strains of Acinetobacter baumannii and Pseudomonas aeruginosa

Os microrganismos resistentes a diferentes classes de agentes antimicrobianos têm se tornado cada vez mais comuns e atualmente são denominados como multirresistentes. Nos hospitais, tais microrganismos apresentam maior perigo, pois são causadores de infecções nosocomiais e a higienização bucal deficiente dos pacientes internados pode tornar a cavidade bucal um sítio para proliferação desses microrganismos multirresistentes. Diante do exposto, novos compostos com ação antimicrobiana precisam ser estudados. O objetivo deste estudo foi avaliar quimicamente o extrato hidroalcóolico de própolis verde de Baccharis dracunculifolia e de Cinnamomum verum (canela) que foram obtidos a partir da extração da matériaprima, analisar a atividade antimicrobiana e antibiofilme dos extratos isolados e combinados contra quatro cepas clínicas multirresistentes de Pseudomonas aeruginosa e Acinetobacter baumannii e verificar a citotoxicidade dos produtos vegetais in vitro em linhagem celular de queratinócitos humanos (HaCat). Para tanto, os extratos vegetais foram preparados a partir da matéria-prima da canela em casca e da própolis bruta. Em seguida, foram caracterizados quimicamente por cromatografia líquida de alta eficiência (HPLC-DAD) para identificação dos principais compostos e a análise do teor de sólidos solúveis dos extratos vegetais também foi realizada. Para avaliação antimicrobiana, foram performados o teste de microdiluição em caldo de acordo com a Clinical and Laboratory Standards Institute (CLSI) e a análise de Checkerboard, para avaliar o efeito combinado dos extratos. A atividade antibiofilme dos extratos combinados foi realizada por meio do teste de MTT, no qual diferentes tempos de contato (5 e 30 min) e diferentes modalidades (inibição na formação do biofilme bacteriano e erradicação do biofilme bacteriano já formado) foram testadas. Para ação citotóxica, as células foram cultivadas em meio DMEM e semeadas na placa de 96 poços. Após aderência inicial, aplicou-se os extratos em diferentes concentrações baseadas nas análises microbiológicas para avaliação da viabilidade celular por meio do teste de MTT. Os dados foram analisados por ANOVA e teste de Tukey, ou Kruskal-Wallis e Dunn, considerando um nível de significância de 5%. Os compostos identificados no extrato de própolis verde de B. dracunculifolia foram ácido clorogênico, derivado do ácido cinâmico e apigenina. O aldeído cinâmico foi o principal composto identificado no extrato de C. verum. Os extratos vegetais apresentaram ação bactericida sobre todas as cepas analisadas e, quando combinados, os extratos atuaram de modo aditivo e algumas combinações sinérgicas foram encontradas. O protocolo de inibição da formação do biofilme promoveu percentuais de redução superiores quando comparado ao protocolo de erradicação. Valores expressivos de 83,86% (p < 0,05) de inibição da formação de biofilme de uma cepa clínica de A. baumannii e 89,31% (p < 0,05) de inibição em uma cepa clínica de P. aeruginosa foram encontrados com a aplicação dos extratos combinados. A atuação dos produtos vegetais foi estatisticamente semelhante a atuação da clorexidina 0,12%. Em conclusão, os extratos de própolis verde e canela na forma isolada ou combinada apresentaram ação antimicrobiana e antibiofilme sobre cepas clínicas de A. baumannii e P. aeruginosa multirresistentes. Dessa forma, os produtos vegetais são promissores agentes antissépticos para futuras formulações odontológicas. (AU)

Microorganisms resistant to different classes of antimicrobial agents have become increasingly common and are currently called multidrug resistant. In hospitals, such microorganisms are more dangerous, as they cause nosocomial infections and poor oral hygiene in hospitalized patients can make the oral cavity a site for the proliferation of these multiresistant microorganisms. Given the above, new compounds with antimicrobial action need to be studied. The objective of this study was to chemically evaluate the hydroalcoholic extract of green propolis from Baccharis dracunculifolia and Cinnamomum verum (cinnamon) that were obtained from the extraction of the raw material, to analyze the antimicrobial and antibiofilm activity of the isolated and combined extracts against four clinical strains multiresistant strains of Pseudomonas aeruginosa and Acinetobacter baumannii and verify the cytotoxicity of plant products in vitro in human keratinocyte cell lineage (HaCat). For this purpose, plant extracts were prepared from raw cinnamon bark and raw propolis. Then, they were chemically characterized by high performance liquid chromatography (HPLC-DAD) to identify the main compounds and the analysis of the soluble solids content of the plant extracts was also performed. For antimicrobial evaluation, the broth microdilution test according to the Clinical and Laboratory Standards Institute (CLSI) and the Checkerboard analysis were performed to evaluate the combined effect of the extracts. The antibiofilm activity of the combined extracts was performed using the MTT test, in which different contact times (5 and 30 min) and different modalities (inhibition of bacterial biofilm formation and eradication of already formed bacterial biofilms) were tested. For cytotoxic action, cells were cultured in DMEM medium and seeded in the 96-well plate. After initial adhesion, the extracts were applied at different concentrations based on microbiological analyzes to assess cell viability through the MTT test. Data were analyzed by ANOVA and Tukey's test, or Kruskal-Wallis and Dunn, considering a significance level of 5%. The compounds identified in the green propolis extract of B. dracunculifolia were chlorogenic acid, cinnamic acid derivative and apigenin. Cinnamic aldehyde was the main compound identified in the C. verum extract. The plant extracts showed bactericidal action on all strains analyzed and, when combined, the extracts acted additively and some synergistic combinations were found. The biofilm formation inhibition protocol promoted higher reduction percentages when compared to the eradication protocol. Significant values of 83.86% (p < 0.05) inhibition of biofilm formation in a clinical strain of A. baumannii and 89.31% (p < 0.05) inhibition in a clinical strain of P. aeruginosa were found with the application of the combined extracts. The performance of plant products was statistically similar to the performance of 0.12% chlorhexidine. In conclusion, extracts of green propolis and cinnamon, in isolated or combined form, showed antimicrobial and antibiofilm action on multiresistant clinical strains of A. baumannii and P. aeruginosa. Thus, plant products are promising antiseptic agents for future dental formulations. (AU)

Prevalence of multi-drug resistant Pseudomonas aeruginosa isolated from selected residential sewages in Dutsin-Ma, Katsina State, Nigeria

The global surge in Multidrug resistant (MDR) bacteria is an issue of great concern. Pseudomonas aeruginosa has been implicated in several nosocomial infections, where it has caused grave complications in immunocompromised patients. This is the first study to report the prevalence of MDR P. aeruginosa isolated from residential sewage in Dutsin-Ma, Katsina State, Nigeria. Pseudomonads count, isolation, biochemical characterization and antibiogram were carried out using standard microbiological procedures. This study examined sixty (60) samples from selected residential sewage in the study site collected at different intervals between July and September 2021. A total of 40 (66.7%) P. aeruginosa were isolated from the analyzed sewage samples. The highest (2.84x104) pseudomonad count was recorded from sewage samples collected from Kadangaru. Pseudomonas aeruginosa isolates from this sample site showed the highest (100%) resistance to cephalosporins (cefuroxime) and nitrofurantoin. Similarly, isolates from Miami area also demonstrated the highest (95%) resistance to a cephalosporin (ceftazidime). All (100%) isolates used in this study showed MDR resistance to tested antibiotics. The occurrence of MDR P. aeruginosa from a residential sewage site that may contaminate drinking water sources in the study area is of public health threat to the inhabitants. Surveillance and molecular epidemiology of antibiotics resistant bacteria are urgently needed in the study area.

Clinical Characteristics and Survival Analysis of Carbapenem-Resistant Pseudomonas Aeruginosa Colonized or Infected Patients with Hematological Disorders / 中国实验血液学杂志

OBJECTIVE@#To observe the clinical characteristics and impact on mortality of carbapenem-resistant Pseudomonas aeruginosa (CRPA) colonized or infected patients with hematological disorders in order to provide evidence for the prevention and treatment of CRPA.@*METHODS@#The patients who were colonized or infected with CRPA in the Department of Hematology of The First Affiliated Hospital of Zhejiang Chinese Medical University from January 2020 to March 2021 were selected as the research subjects, the clinical data such as hospitalization time, primary disease treatment regimen, granulocyte count, previous infection and antibiotic regimen of these patients were analyzed, meanwhile, antibiotic regimen and efficacy during CRPA infection, 30-day and long-term survival were also analyzed.@*RESULTS@#A total of 59 patients were included in this study, and divided into CRPA infection group (43 cases) and CRPA colonization group (16 cases). Univariate logistic regression analysis showed that ECOG score (P =0.003), agranulocytosis (P <0.001), and exposure to upper than 3rd generations of cephalosporins and tigecycline within 30 days (P =0.035, P =0.017) were the high-risk factors for CRPA infection. Multivariate logistic regression analysis showed that ECOG score of 3/4 ( OR=10.815, 95%CI: 1.260-92.820, P =0.030) and agranulocytosis ( OR=13.82, 95%CI: 2.243-85.176, P =0.005) were independent risk factors for CRPA infection. There was a statistically significant difference in cumulative survival rate between CRPA colonization group and CRPA infection group ( χ2=14.134, P < 0.001). Kaplan-Meier survival analysis showed that the influencing factors of 30-day survival in patients with CRPA infection were agranulocytosis (P =0.022), soft tissue infection (P =0.03), and time of hospitalization before CRPA infection (P =0.041). Cox regression analysis showed that agranulocytosis was an independent risk factor affecting 30-day survival of patients with CRPA infection (HR=3.229, 95%CI :1.093-3.548, P =0.034).@*CONCLUSIONS@#Patients with hematological disorders have high mortality and poor prognosis after CRPA infection. Bloodstream infection and soft tissue infection are the main causes of death. Patients with high suspicion of CRPA infection and high-risk should be treated as soon as possible.

Clinical analysis of 71 patients with Pseudomonas aeruginosa bloodstream infection / 中国基层医药

Objective:To investigate the clinical manifestations and related risk factors of patients with Pseudomonas aeruginosa (PAE) bloodstream infection, and to provide references for clinical diagnosis and treatment of PAE bloodstream infection after combining with bacterial resistance condition. Methods:The clinical data and biological data of all patients with PAE bloodstream infection who received treatment in the Third Affiliated Hospital of Wenzhou Medical University from January 2019 to December 2020 were analyzed retrospectively. The independent influential factors of PAE bloodstream infection were analyzed using binary logistic regression. Results:Eighty-three patients had PAE bloodstream infection. Among them, 71 patients were included in the final analysis. Among the 71 patients, 36 patients (50.70%) had carbapenem-resistant Pseudomonas aeruginosa ( CRPA). Univariate analysis showed that the history of hospitalization within 90 days ( χ2 = 3.90, P = 0.048), indwelling catheterization ( χ2 = 5.08, P = 0.024), septic shock ( χ2 = 4.00, P = 0.046), mechanical ventilation ( χ2= 12.35, P < 0.001), deep venous catheter ( χ2 = 4.08, P = 0.043), acute physiology and chronic health evaluation score II ≥ 10 points ( χ2 = 4.06, P = 0.044), and multi-drug resistance ( χ2 = 11.75, P = 0.001) were the suspicious influential factors of CRPA bloodstream infection. Multivariate logistic regression analysis showed that mechanical ventilation was an independent risk factor for CRPA bloodstream infection ( OR = 7.43, 95% CI 1.182-46.674, P = 0.032). Multi-drug resistance was an independent risk factor for CRPA bloodstream infection ( OR = 5.842, 95% CI 1.520-22.450, P = 0.010). Conclusion:Mechanical ventilation and multi-drug resistance are the independent influential factors of CRPA bloodstream infection. Invasive operations such as mechanical ventilation should be avoided in the clinic.

Epidemiological characteristics and antiseptic resistance gene detection of Pseudomonas aeruginosa in children in Suzhou, Jiangsu Province / 中国热带医学

@#Abstract: Objective To investigate the clinical distribution characteristics, drug resistance trends and the carrying of antiseptic resistance gene of Pseudomonas aeruginosa infection in children in Suzhou, in order to provide theoretical basis for the prevention and treatment of Pseudomonas aeruginosa infection in children. Methods The clinical distribution characteristics and drug resistance trends of Pseudomonas aeruginosa isolated from Children's Hospital of Soochow University from 2016 to 2021 were retrospectively analyzed. Forthermore, 101 strains of Pseudomonas aeruginosa were randomly selected to detect the expression of 9 antiseptic resistance genes (qacEΔ1-sul1, qacE, qacEΔ1, qacG, sugE(p), sugE©, emrE, ydgE, ydgF) by polymerase chain reaction. Results Pseudomonas aeruginosa in Soochow University Children's Hospital was mainly isolated from respiratory specimen (47.83%), pus (28.60%) and urine (11.72%); the main departments were intensive care unit(21.45%), general surgery department (15.71%) and respiratory department (12.31%). Patients were mainly aged from 1 month to 1 year old and older than 6 years old (34.31% and 25.38%). The top three drug resistance rates of Pseudomonas aeruginosa were imipenem (11.25%), aztreonam (9.26%) and meropenem (8.02%). Among the 853 strains of Pseudomonas aeruginosa, the drug-resistant strains were mainly from the intensive care unit (58/183), hematology department (33/91), neonatology department (31/96), and there were 57 strains of multi-drug-resistant strains with the detection rate of 6.68%. There were 98 strains (11.49%) of Carbapenem resistant Pseudomonas aeruginosa, and the annual detection rates were 22.06%, 8.40%, 3.60%, 5.67%, 9.85% and 17.20%, respectively. Among the 9 antiseptic resistance genes, the carrying rate of ydgF, sugE© and qacE was 98.02%, 94.06% and 0 respectively. Conclusion Pseudomonas aeruginosa has high resistance to some drugs, so attention should be paid to rational drug use. The carriage rates of of two antiseptic resistance genes exceeded 90%, indicating the need to strengthen research on the mechanism of antiseptic resistance research and rational use of disinfectants

Pseudomonas aeruginosa infection and drug resistance in the elderly with respiratory tract infection / 公共卫生与预防医学

Objective To analyze Pseudomonas aeruginosa (PA) infection and drug resistance in the elderly with respiratory tract infection, so as to provide a basis for the control of nosocomial infection and rational use of antibiotics. Methods The samples from elderly inpatients with respiratory tract infection were collected between March 2020 and March 2022. PA infection/colonization were investigated, and the drug resistance of pathogens was determined according to CLSI criteria (2019 version). Results There were 123 strains of PA isolated from the sputum and bronchoscopy lavage fluid of elderly patients with respiratory tract infection. The main departments with positive PA detection were respiratory department, ICU ward and neurology department. The difference of PA detection in different years was not statistically significant (P>0.05). The proportion of nosocomial infection in 2021 was lower than that in 2020 (44.44% vs 63.33%, c2=4.410, P=0.036). The resistance rate of 123 isolated PA strains to piperacillin was >90.00%, and they were resistant to ceftazidime, cefotaxime, cefepime, aztreonam and gentamicin to varying degrees. There was no significant difference in resistance rate of PA to antibiotics in different years (P>0.05). In the 123 strains of pathogens, there were 17 strains (13.82%) of carbapenem-resistant PA, and their resistance to common antibiotics was significantly higher than that of carbapenem-sensitive PA (P<0.05). Conclusion The main pathogen of nosocomial infection is PA, and the proportion of nosocomial infection shows a downward trend. The detection rate of carbapenem-resistant PA is high. In clinical treatment, targeted antibiotics can be applied.

Aryl hydrocarbon receptors regulate pyocyanin-induced inflammatory factor expression in macrophages via p38MAPK/p65NF-κB signaling pathway / 中国药理学通报

Aim To investigate the effect of the aryl hydrocarbon receptor (AhR) on the expression of inflammatory factors in macrophages RAW264. 7 induced by pyocyanin (PCN) and the regulatory mechanism of its signaling pathway. Methods RAW264. 7 cells were treated with different concentrations of PCN for 24 h, respectively, and the effect of PCN on cell activity was detected by CCK8 assay to determine the optimal PCN concentration for manufacturing infection models. The cells were divided into the control group (given 0. 1% dimethyl sulfoxide DMSO), PCN group, PCN + AhR inhibitor (CH223191) group, and PCN + AhR agonist (FICZ) group, and the expression of AhR was detected by immunofluorescence. The expression levels of inflammatory factors (IL-6, IL-1β, and TNF-α) were detected by ELISA. The protein expression of AhR, pp38 MAPK and p-p65NF-κB, was detected by Western blotting. Results PCN induced a significant quantitative effect on AhR expression in RAW264. 7 cells. CH223191 increased PCN-induced inflammatory factor secretion and enhanced the phosphorylation of p38MAPK and p65NF-κB compared with the control group. FICZ decreased PCN-induced inflammatory factor production and reduced the phosphorylation of p38MAPK and p65NF-κB phosphorylation capacity. Conclusions AhR can regulate PCN-induced inflammatory factor expression in RAW264. 7 cells, and the p38MAPK/p65NF-κB signaling pathway may be an essential pathway for the involvement of AhR in immune regulation.

In vitro bacteriostatic and serum pharmacological tests of Qiguiyin decoction combined with levofloxacin against pseudomonas aeruginosa / 中国药理学通报

Aim To investigate the antibacterial activity and anti-resistant mutation ability of Qiguiyin decoction (a traditional Chinese herbal formula) combined with levofloxacin against pseudomonas aeruginosa byantibacterial experiment in vitro and serum pharmacology. Methods The minimal inhibitory concentrations (MICs) of levofloxacin and Qiguiyin decoction were detected respectively by the broth dilution technique.The MIC of the combination of two drugs was determined by the micro chessboard dilution method. The effects of combined drugs on enhancing the antibacterial activity of different strains were evaluated respectively by calculating the fractional inhibitory concentration index (FICI). The drug-containing serum of levofloxa-cin group, Qiguiyin decoction group, Qiguiyin decoction combined with levofloxacin group and control group was prepared. The antibacterial rate, MIC and MBC of 10% ~ 90% serum against the two strains were determined. Results Combined with Qiguiyin decoction, MIC of levofloxacin against pseudomonas aeruginosa (standard/resistant) decreased significantly, 0. 5 < FICI

Development and application of a rapid gene manipulating toolbox for Pseudomonas aeruginosa / 生物工程学报

Manipulation of genes, including knock-out or knock-in, replacement of gene elements (such as promoters), fusion with a fluorescent protein gene, and construction of in situ gene reporter, is required in most of the biotechnological laboratories. The widely used gene manipulating methods based on two-step allelic exchange are cumbersome in terms of constructing plasmids, transforming and screening. In addition, the efficiency of using this method for long fragment knockout is low. To simplify the process of gene manipulation, we constructed a minimized integrative vector pln2. When a gene needs to be inactivated, an internal fragment of the target gene (non-frameshift) is cloned into the pln2 plasmid. Once the single-crossover recombination between genome and the constructed plasmid occurs, the endogenous gene is segmented by the plasmid backbone and thus inactivated. We developed a toolbox based on pln2 that can be used for different genomic operation mentioned above. With the help of this toolbox, we successfully knocked out large fragments of 20-270 kb.