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.

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.

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.

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.

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.

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.

Functional synergism of pyoverdine and the S-type pyocins of Pseudomonas aeruginosa / 生物工程学报

Pyocin S2 and S4 in Pseudomonas aeruginosa use the same uptake channels as the pyoverdine does in bacteria, indicating a possible connection between them. In this study, we characterized the single bacterial gene expression distribution of three S-type pyocins (Pys2, PA3866, and PyoS5) and examined the impact of pyocin S2 on bacterial uptake of pyoverdine. The findings demonstrated that the expression of the S-type pyocin genes was highly differentiated in bacterial population under DNAdamage stress. Moreover, exogenous addition of pyocin S2 reduces the bacterial uptake of pyoverdine so that the presence of pyocin S2 prevents the uptake of environmental pyoverdine by non-pyoverdine synthesizing 'cheaters', thereby reducing their resistance to oxidative stress. Furthermore, we discovered that overexpression of the SOS response regulator PrtN in bacteria significantly decreased the expression of genes involved in the synthesis of pyoverdine, significantly decreasing the overall synthesis and exocytosis of pyoverdine. These findings imply a connection between the function of the iron absorption system and the SOS stress response mechanism in bacteria.

Analysis of risk factors of multidrug-resistant organism infection in lung transplant recipients based on restricted cubic spline model / 器官移植

Objective To summarize current status of multidrug-resistant organism (MDRO) infection in lung transplant recipients and analyze the risk factors of MDRO infection. Methods Clinical data of 321 lung transplant recipients were retrospectively analyzed. According to the incidence of postoperative MDRO infection, they were divided into the MDRO group (n=122) and non-MDRO infection group (n=199). The incidence of MDRO infection in lung transplant recipients was summarized. The risk factors of MDRO infection in lung transplant recipients were analyzed by logistic regression model. The dose-response relationship between MDRO infection and time of ventilator use was determined by restricted cubic spline model. Results Among 321 lung transplant recipients, 122 cases developed MDRO infection, with an infection rate of 38.0%. Two hundred and twenty-nine strains of pathogenic bacteria were detected in the MDRO infection group, mainly Gram-negative bacteria (92.6%), and the top three strains were carbapenem-resistant acinetobacter baumannii (46.3%), carbapenem-resistant pseudomonas aeruginosa (22.3%) and carbapenem-resistant klebsiella pneumoniae (14.8%), respectively. MDRO infection mainly consisted of lower respiratory tract infection (61.5%), followed by ventilator-associated pneumonia (26.2%). Univariate analysis showed that the risk factors of MDRO infection in lung transplant recipients were single-lung transplantation, long-time postoperative use of extracorporeal membrane oxygenation (ECMO), long operation time, long-time urinary catheterization, long-time central venous catheterization and long-time ventilator use (all P < 0.05). Multivariate logistic regression analysis indicated that single-lung transplantation and long-time ventilator use were the independent risk factors for MDRO infection in lung transplant recipients (both P < 0.05). Results of restricted cubic spline model analysis showed that the risk of infection continued to increase with the prolongation of ventilator use time within 20 d. After 20 d, prolonging the time of ventilator use failed to increase the risk of infection, showing a plateau effect. Conclusions The MDRO infection rate tends to decline in lung transplant recipients year by year. Single-lung transplantation and long-time ventilator use are the independent risk factors for MDRO infection in lung transplant recipients.

Preparation of colloidal gold immunochromatographic test strip for rapid detection of Pseudomonas aeruginosa / 中国生物制品学杂志

@#Objective To develop a colloidal gold immunochromatographic test strip for rapid and accurate detection of Pseudomonas aeruginosa(P.aeruginosa,Pa).Methods After bioinformatics analysis of Pa outer membrane protein OprF,the gene sequence with abundant antigenic determinants and high intraspecific homology was chemically synthesized,and then connected to pET-28a(+)vector to construct the expression vector pET-28a-OprF,which was transformed into E.coli BL21(DE3)and induced by IPTG. The recombinant OprF protein was purified by Ni Sepharose~(TM)6 Fast Flow and used to immunize two female BALB/c mice for 3～4 times by multi-point subcutaneous injection in the back at the first immunization and intraperitoneal injection at subsequent immunizations. The monoclonal antibodies were screened by animal cell fusion technique,and the colloidal gold immunochromatographic test strip for rapid detection of Pa was prepared by using monoclonal antibody and double antibody sandwich immunochromatography technique. The specificity,sensitivity and stability of the test strip were evaluated.Results Two monoclonal antibodies,Pa-1# and Pa-2#,were obtained with the titer of 1∶409 600,and both of them recognized OprF specifically. The prepared colloidal gold immunochromatographic test strip showed a sensitivity of 1. 0×10~6CFU/mL and had no cross reaction with 9 common respiratory pathogens with a good stability.Conclusion The prepared colloidal gold immunochromatographic test strip can detect Pa rapidly within 15 min,with high specificity and good stability.

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

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

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.

Evaluation of antibacterial activity of vitamin C against human bacterial pathogens / Avaliação da atividade antibacteriana da vitamina C contra patógenos bacterianos humanos

Now a day’s multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.

Agora, a resistência antimicrobiana de um dia em patógenos aos antibióticos tornou-se a principal causa de preocupação e houve uma realização inadequada no desenvolvimento de novos antibióticos para tratar infecções bacterianas. Portanto, há uma necessidade de pesquisar um novo adjuvante, e a vitamina C é um desses adjuvantes promissores. O objetivo do presente estudo foi elucidar o efeito antibacteriano da vitamina C em diferentes temperaturas (4 °C, 37 °C e 50 °C) e pH (3, 8 e 11), contra Gram-positivos e Gram-cepas bacterianas negativas em várias concentrações (5-20 mg / ml) através do método de difusão em ágar bem. A inibição do crescimento de todas as cepas bacterianas pela vitamina C era dependente da concentração. A vitamina C inibiu significativamente o crescimento de bactérias Gram-positivas: Bacillus licheniformis (25,3 ± 0,9 mm), Staphylococcus aureus (22,0 ± 0,6 mm), Bacillus subtilis (19,3 ± 0,3 mm) e bactérias Gram- negativas: Proteus mirabilis (27,7 ± 0,9 mm), Klebsiella pneumoniae (21,3 ± 0,9 mm), Pseudomonas aeruginosa (18,0 ± 1,5 mm) e Escherichia coli (18,3 ± 0,3 mm). A estabilidade da vitamina C foi observada em vários valores de pH e várias temperaturas. A vitamina C mostrou atividade antibacteriana significativa em pH ácido contra todas as cepas bacterianas. A estabilidade da vitamina C permaneceu nas mesmas diferentes temperaturas (4 °C, 37 °C e 50 °C). Concluímos que a vitamina C é um agente antibacteriano eficaz e seguro que pode ser usado no futuro como uma opção de tratamento auxiliar para combater infecções em humanos, pois pode apoiar o sistema imunológico diretamente.

Evaluation of antibacterial activity of vitamin C against human bacterial pathogens

Abstract Now a days multidrug resistance phenomenon has become the main cause for concern and there has been an inadequate achievement in the development of novel antibiotics to treat the bacterial infections. Therefore, there is an unmet need to search for novel adjuvant. Vitamin C is one such promising adjuvant. The present study was aimed to elucidate the antibacterial effect of vitamin C at various temperatures (4°C, 37°C and 50°C) and pH (3, 8, and 11), against Gram-positive and Gram-negative bacteria at various concentrations (5-20 mg/ml) through agar well diffusion method. Growth inhibition of all bacterial strains by vitamin C was concentration-dependent. Vitamin C significantly inhibited the growth of Gram-positive bacteria: Bacillus licheniformis (25.3 ± 0.9 mm), Staphylococcus aureus (22.0 ± 0.6 mm), Bacillus subtilis (19.3 ± 0.3 mm) and Gram-negative bacteria: Proteus mirabilis (27.67 ± 0.882 mm), Klebsiella pneumoniae (21.33±0.9 mm), Pseudomonas aeruginosa (18.0 ± 1.5 mm) and Escherichia coli (18.3 ± 0.3 mm). The stability of vitamin C was observed at various pH values and various temperatures. Vitamin C showed significant antibacterial activity at acidic pH against all bacterial strains. Vitamin C remained the stable at different temperatures. It was concluded that vitamin C is an effective and safe antibacterial agent that can be used in the future as an adjunct treatment option to combat infections in humans.

Resumo Agora, a resistência antimicrobiana de um dia em patógenos aos antibióticos tornou-se a principal causa de preocupação e houve uma realização inadequada no desenvolvimento de novos antibióticos para tratar infecções bacterianas. Portanto, há uma necessidade de pesquisar um novo adjuvante, e a vitamina C é um desses adjuvantes promissores. O objetivo do presente estudo foi elucidar o efeito antibacteriano da vitamina C em diferentes temperaturas (4 °C, 37 °C e 50 °C) e pH (3, 8 e 11), contra Gram-positivos e Gram-cepas bacterianas negativas em várias concentrações (5-20 mg / ml) através do método de difusão em ágar bem. A inibição do crescimento de todas as cepas bacterianas pela vitamina C era dependente da concentração. A vitamina C inibiu significativamente o crescimento de bactérias Gram-positivas: Bacillus licheniformis (25,3 ± 0,9 mm), Staphylococcus aureus (22,0 ± 0,6 mm), Bacillus subtilis (19,3 ± 0,3 mm) e bactérias Gram- negativas: Proteus mirabilis (27,7 ± 0,9 mm), Klebsiella pneumoniae (21,3 ± 0,9 mm), Pseudomonas aeruginosa (18,0 ± 1,5 mm) e Escherichia coli (18,3 ± 0,3 mm). A estabilidade da vitamina C foi observada em vários valores de pH e várias temperaturas. A vitamina C mostrou atividade antibacteriana significativa em pH ácido contra todas as cepas bacterianas. A estabilidade da vitamina C permaneceu nas mesmas diferentes temperaturas (4 °C, 37 °C e 50 °C). Concluímos que a vitamina C é um agente antibacteriano eficaz e seguro que pode ser usado no futuro como uma opção de tratamento auxiliar para combater infecções em humanos, pois pode apoiar o sistema imunológico diretamente.