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<b>Objective</b> To evaluate the effectiveness of multi-disciplinary team (MDT) mode in the prevention and control of multidrug resistant organism (MDRO) infection in lung transplant recipients. <b>Methods</b> Lung transplant recipients admitted to the hospital from 2019 to 2022 were enrolled. MDT expert group was established in January, 2020. A series of prevention and control measures were conducted. The implementation rate of MDRO prevention and control measures and the detection rate of MDRO on the environmental surface from 2020 to 2022, and the detection rate of MDRO in lung transplant recipients from 2019 to 2022 were analyzed. <b>Results</b> The overall implementation rate of MDRO prevention and control measures for medical staff was increased from 64.9% in 2020 to 91.6% in 2022, showing an increasing trend year by year (<i>P</i><0.05). The detection rate of MDRO on the environmental surface was decreased from 28% in 2020 to 9% in 2022, showing a downward trend year by year (<i>P</i><0.05). The detection rate of MDRO in lung transplant recipients was decreased from 66.7% in 2019 to 44.3% in 2022, showing a decreasing trend year by year (<i>P</i><0.001). <b>Conclusions</b> MDT mode management may enhance the implementation of MDRO prevention and control measures for medical staff, effectively reduce the infection rate of MDRO in lung transplant recipients and the detection rate of MDRO on the environmental surface, which is worthy of widespread application.
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Objective To establish an inhalation infection pneumonia model of C57BL/6J mice with highly virulent and multi-drug resistant Pseudomonas aeruginosa(PA)strain F291007,and to study the microbiological,pathological and immunological characteristics of this model.Methods The strain F291007 was isolated and identified before the bacterial suspension was administered to the mice via aerosolized intratracheal inoculation to establish the pneumonia infection model.In the course of infection,the conditions and survival of the mice were observed,and the bacterial loads,the histopathological states and the cytokine expression levels in the major organs were detected.Finally,three key cytokines were blocked to observe the survival of mice.Results The strain F291007 was isolated and identified.After lethal dose infection,all the mice died within 24 h.After sub-lethal dose infection,a large number of immune cells in the body were capable of phagocytosis and killing of invading pathogens,which was manifested as rapid clearance of bacteria in lungs and the exponential decrease of bacterial load with the passage of time.The pathological changes in lungs were most severe at 1 to 3 days but gradually recovered.After infection,interleukin-6(IL-6),IL-17A and tumor necrosis factor-α(TNF-α)in alveolar lavage fluid and serum were significantly increased at 1 to 3 days.After blocking of these three cytokines with specific antibodies,the survival rates of infected mice decreased significantly.Conclusion A mouse model of gradually-recovered pneumonia infection caused by PA inhalation has been established,suggesting that the first one to three days are critical to immune response after infection through multiple indicators.This mouse model can be used for research on the pathogenesis,immunoregulation and treatment evaluation of highly virulent and multi-drug resistant PA inhalation pneumonia infection.
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Objective To construct a non-trace deletion mutant of exlA in Pseudomonas aeruginosa strain NY8755(NY8755ΔexlA)and investigate the basic characteristics of pore-forming toxin ExlA.Methods The NY8755ΔexlA was constructed using the secondary homologous recombination method.C57BL/6J female mice ages 6 to 8 weeks were infected with NY8755 and NY8755 ΔexlA via aerosolized intratraheal inoculation respectively.Within 7 days of infection,the survival and weight changes of the mice were observed and recorded before the proinflammatory cytokines in the bronchoal-veolar lavage fluid(BALF)of the infected mice in the two groups were detected.Results The sequencing results showed that NY8755 ΔexlA was constructed.After 1×107 CFU NY8755 and NY8755 ΔexlA were infected,all the mice in the wild-type strain group died within 48 hours,while those in the mutant strain group began to die after 48 hours,and 40%of them remained alive 7 days later.The weight of surviving mice in the mutant strain group decreased but recovered gradually.After 12 hours of infection,there were more bloody exudates(redder in color)in the BALF of the wild-type strain group than in the mutant strain group,and the contents of proinflammatory cytokines interleukin-1β(IL-1β)and interleukin-17A (IL-17A)were significantly different. Conclusion Pseudomonas aeruginosa pore-forming toxin ExlA is the key pathogenic virulence factor of the exlA-positive Pseudomonas aeruginosa,which can significantly affect the survival status of mice and cause obvious inflammation in mice. Very little information is available on the action mechanisms of ExlA. In this study, The NY8755ΔexlA and the C57BL/6J mouse models infected with NY8755 and NY8755ΔexlA have been constructed that may be used for the investigation of pathogenesis of exlA-positive Pseudomonas aeruginosa.
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Objective:To investigate the safety and efficacy of pseudomonas aeruginosa Injection (PAI) in the treatment of coeliac leakage after cervical lymph node dissection for robotic thyroid cancer.Methods:Retrospective analysis of 1262 patients who underwent robotic thyroid surgery at the 960th Hospital of the People’s Liberation Army from Jan. 2021 to Aug. 2023 was made. Postoperative celiac leakage happened in 28 patients. The control and injection groups were divided according to whether pseudomonas aeruginosa injection was used or not. In the control group, there were 4 males and 11 females out of 15 patients, with an average age of (46.20±9.02) years old, and the treatment methods of low-fat diet, negative pressure suction, and pressure bandage were used. In the injection group, there were 7 males and 6 females among 13 patients, with an average age of (41.00±8.87) years. They were treated with low-fat diet, negative pressure suction, pressure bandage, and PAI .The number of lymph node dissection, total drainage volume, peak drainage volume, days of hospitalization and the rate of decline in drainage volume within 24 h after the use of PAI in the injection group, post-injection temperature, number of injections, and post-injection extubation time were statistically analyzed in both groups. Independent samples t test, Mann-Whitney U test, χ2 test or Fisher’s exact test were used for comparison between groups. Results:There was no statistically significant difference in age, gender, extent of thyroidectomy, highest daily drainage volume, and total drainage volume between the two groups ( P>0.05). The difference in the number of lymph node dissection (49.15±23.05 vs. 30.80±11.76, P=0.012) and hospitalization time (11.77±4.64 vs. 16.40±6.42, P=0.041) between the injection group and the control group was statistically significant. After the use of pseudomonas aeruginosa injection, the draining fluid decreased from the previous day (69.56± 20.82) % in the injection group; Twelve patients were successfully extubated after one injection of pseudomonas aeruginosa injection, and one patient was successfully extubated after two injections; the mean time to extubation after injection was (3.85±1.28) days; 76.9% patients (10/13) had fever symptoms within 48 h with body temperature (38.05±0.89) ℃ after injection, body temperature returned to normal after symptomatic treatment,and no other adverse reactions occurred except fever. Conclusion:Pseudomonas aeruginosa injection is safe and effective in the treatment of celiac leakage after cervical lymph node dissection for robotic thyroid cancer, effectively reducing cervical drainage and shortening hospitalization days.
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Objective To explore the drug resistance mechanism and characteristics of carbopenem-resistant pseudo-monas aeruginosa(CRPA)in our hospital.Methods BD phoenix 100 automatic bacterial identification and drug sensitivity an-alyzer was used to identify and detect the drug sensitivity of the strains.The minimum inhibitory concentration(MIC)of ceftazi-dime/acibactam was detected by micro broth dilution method.The modified carbapenem inactivation method(mCIM)and colloi-dal gold immunochromatography were used to detect the carbapenemase phenotype of the strains.The whole genome sequencing was used to detect the carbapenemase resistance gene and ST typing of the screened positive strains.Results A total of 22 strains of clinically isolated CRPA were collected,of which the antibacterial drugs with the lowest resistance rate were ceftidine/avibatan(22.7% ),followed by gentamicin and amikacin(27.3% ),pyracillin/tazobactam(59.09% ),cefuroxime(63.6% ).Ceftazide and aminotransferrane(77.27% ),ciprofloxacin(86.36% ),levofloxacin(95.45% ).There are a total of 5 strains(22.7% )of carbapenems in 22 CRPA by phenotypic detection.The whole genome sequencing results show that 4 strains of ST549 CRPA carry metal β-lactamase IMP-45 and serine β-lactamase OXA-1,OXA-50,one strain is ST245 CRPA carries metal β-lactamase NDM-1,that is,all five CRPA strains produce metal β-lactamase.Conclusion The resistance rate of CRPA to ceftazidime/avibactam is low in our hospital.Carbapenemase-producing is not the main mechanism of CRPA resistance to car-bapenems,while metal β-Lactamase-producing is the main mechanism of CRPA resistance to ceftazidime avibactam.
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The application of Pseudomonas aeruginosa-mannose-sensitive hemagglutinin(PA-MSHA)in the field of an-titumors has been increasing.PA-MSHA has been found to promote tumor cell apoptosis,inhibit tumor cell invasion and migration,differentiation,and change drug resistance and epithelial-mesenchymal transformation(EMT)by inhibiting the EGFR pathway.Meanwhile,PA-MSHA also enhances the immune killing and inhibition of macrophages and T cells to tumor cells through toll-like receptors(TLRs).In this paper,we reviewed the reported anti-tumor mechanism and clinical application of PA-MSHA,suggesting that PA-MSHA may alter the glycosylation of EGFR and TLR proteins by acting on the regulatory process of the cellular mannosy-lation process.PA-MSHA can act on cell membrane proteins,including more receptors with high-mannosylation of signaling path-ways.Elucidating the deep relationship between PA-MSHA and mannosylation is of great significance for the mechanism research and clinical application of PA-MSHA.
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Objective:To evaluate the impact of three small compounds, namely sodium diethyldithiocarbamate (DTC), levamisole (LMS) and imiquimod (Imi), on the immunogenicity and protective efficacy of the candidate antigen PA0833 from Pseudomonas aeruginosa ( Pa) and analyze the underlying mechanisms. Methods:PA0833 was formulated with aluminum adjuvant and the above small compounds, respectively. BALB/c mice were immunized with these vaccines intramuscularly on days 0, 14 and 21. Serum samples were collected and the levels of PA0833-specific IgG were measured by ELISA. The protective efficacy of these vaccines was evaluated by assessment of survival rates, body weights, clinical scores, inflammatory factors, and histopathological changes after infecting the immunized mice with Pa PAO1 strains. Besides, the mice were injected with DTC intramuscularly for seven consecutive days to analyze the mechanism of DTC in enhancing immune response using transcriptome sequencing and flow cytometry. Results:All these small compounds were capable of effectively enhancing the immunogenicity of PA0833 formulated with aluminum adjuvant, reducing bacterial loads in lung tissues, inhibiting the secretion of TNF-α, IL-6 and IL-1β, and improving mouse survival rates upon Pa infection. DTC was more effective than the other two compounds. Transcriptome sequencing identified 121 up-regulated genes and 18 down-regulated genes in DTC-treated group as compared with PBS control group. These differentially expressed genes were significantly enriched in immune pathways, with a strong activation of the IL-17 pathway. Flow cytometry analysis demonstrated significant activation of dendritic cells and proliferation of Th17 cells in splenocytes in DTC-treated group as compared with PBS control group. Conclusions:All three small compounds are able of effectively enhance antigen immunogenicity with DTC being the most effective, indicating that DTC can be used as a novel adjuvant in vaccine development.
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Aims@#The aim of this study was to investigate plasmid profiles and antibiotic resistance patterns of multidrug resistant Pseudomonas aeruginosa strains isolated from different clinical specimens in Jordan.@*Methodology and results@#Pseudomonas aeruginosa strains were isolated from different clinical specimens from different hospitals and primary health care centers. The antimicrobial susceptibility of P. aeruginosa isolates was determined using the disc diffusion method against 16 commonly used antimicrobial drugs. Plasmid DNAs were extracted from lysed P. aeruginosa cells using the plasmid alkaline lysis method and visualized using agarose gel electrophoresis followed by ethidium bromide staining. The isolated strains of P. aeruginosa were resistant to cefepime (90%), meropenem (70%), ceftazidime (60%), piperacillin (55%), aztreonam (50%), ciprofloxacin and tobramycin (35%), gentamicin (29%), imipenem and amikacin (20%). All the isolates were sensitive to colistin. Plasmid analysis of the clinical isolates showed the presence of 0 to 3 plasmids with a size range of 1 to 25 kb compared to the standard strain of Escherichia coli (ATCC 25922).@*Conclusion, significance and impact of study: @#The results obtained in this study showed some correlation between the patterns of antibiotic resistance and plasmid profiles.
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Aims@#Mycobacterium tuberculosis and Pseudomonas aeruginosa are still a problem in the world. This study was aimed to develop the self-nano emulsifying drug delivery system (SNEDDS) formulation of red betel vine leaf ethanol extract, which has the potential as an antibacterial agent against M. tuberculosis and P. aeruginosa. @*Methodology and results@#Red betel vines were extracted using the maceration method with 70% ethanol. SNEDDS ethanol extract was prepared using high-energy and low-energy methods, while the formulation was evaluated in the form of % transmittance, particle size, polydispersion index and zeta potential to accelerated stability tests. The SNEDDS formula of the extract, passing the stability test, was further tested for accelerated antibacterial activity. The presence of M. tuberculosis was tested using the resazurin microtiter assay (REMA) method, while P. aeruginosa was tested using the dilution method by determining the minimum bactericidal concentration (MBC) value. In this study, the SNEDDS formula of the extract, which included nanoemulsion, had a particle size of 16-17 nm (<200 nm), PI 0.52-0.55 D (<0.7 D), zeta potential -18.03-24.96 mV (<30 mV) and % transmittance of 94-96% (>90%). MBC of SNEDDS formula against M. tuberculosis becomes apparent at concentrations <1%, whereas in the case of P. aeruginosa, this phenomenon is observed at a concentration as low as 0.0312%. @*Conclusion, significance and impact of study: @#Research findings suggest that the SNEDDS formula of red betel vine leaf ethanol extract was stable and has the potential as an antibacterial agent against M. tuberculosis and P. aeruginosa.
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Objective To investigate the risk factors of infection of Pseudomonas aeruginosa combined with Elizabethkingia anophelis in patients with cerebral hemorrhage and the antimicrobial treatment plan. Methods Clinical pharmacists participated in the treatment of pulmonary infection caused by Pseudomonas aeruginosa combined with Elizabethkingia anophelis in a patient with cerebral hemorrhage. The risk factors of Elizabethkingia anophelis infection and antimicrobial treatment plan were analyzed by referring to literature and combining the patient’s condition, medical history, drug use history and related examination results. Results Based on the infection site, the characteristics of mixed bacterial infection, and the metabolic/pharmacodynamic characteristics of antimicrobial agents, clinical pharmacists made drug recommendations for clinicians in the adjustment of anti-infection protocols, and patients’ systemic infections were effectively controlled. Conclusion Elizabethkingia anophelis is a conditional pathogen with low virulence and is not easy to infect healthy people. When the patient's immunity is low, it is easy to transform into pathogenic bacteria, which should be paid attention to.
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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.
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Humans , Male , Female , Adult , Middle Aged , Pseudomonas aeruginosa , Drug Resistance, Multiple , Coinfection , Procalcitonin , COVID-19 , Klebsiella pneumoniae , Trachea , Biomarkers , Sepsis , Ecuador , Anti-Bacterial AgentsABSTRACT
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.
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Pseudomonas aeruginosaABSTRACT
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.
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Humans , Male , Female , Adult , Middle Aged , Aged , Aged, 80 and over , Young Adult , Colistin/administration & dosage , Drug Resistance, Multiple, Bacterial , Anti-Bacterial Agents/administration & dosage , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/drug effects , Bacterial Infections/drug therapy , Microbial Sensitivity Tests , Retrospective Studies , Risk Factors , Colistin/adverse effects , Administration, Intravenous , Klebsiella/isolation & purification , Klebsiella/drug effects , Anti-Bacterial Agents/adverse effectsABSTRACT
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.
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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.
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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.
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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.
Subject(s)
Pyocins/metabolism , Pseudomonas aeruginosa/metabolismABSTRACT
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.
Subject(s)
Genetic Vectors/genetics , Pseudomonas aeruginosa/genetics , Plasmids/genetics , Promoter Regions, Genetic , GenomeABSTRACT
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.
ABSTRACT
Aims@#A suitable medium and cultivation parameters have an important role in the improvement of the production of pyocyanin pigment by Pseudomonas aeruginosa microorganism. The study aimed to optimize culture conditions and medium components for maximal pyocyanin production in a recombinant strain P. aeruginosa PS39-phzMS created in previous research. In addition, the process of extraction of pyocyanin was also investigated to select a proper applied solvent for recovering a high amount of pyocyanin as well as its quality. @*Methodology and results@#The pyocyanin purification has based on solvent. Among six tested solvents for extracting pyocyanin out of bacterial broth, two out of six recovered a significant amount of pyocyanin, namely dichloromethane and chloroform, in which chloroform showed a higher pyocyanin yield (25.27 ± 1.02 µg/mL) than dichloromethane (20.26 ± 0.88 µg/mL). The thin-layer chromatography (TLC) of the extracted pyocyanin illustrated a similar to pure pyocyanin with Rf of 0.72 and no mark of other impurity metabolites. The UV-Vis spectra showed a similar peak at 520 nm with pure pyocyanin and the highest peak at 274 nm. Each single culture parameter was studied for the maximal production of pyocyanin. Next, a pyocyanin-producing GM medium was modified on the base of the KingA to find the relative capacity to biosynthesize high pyocyanin yield in P. aeruginosa PS39-phzMS. The results showed that pyocyanin production was the highest in optimal culture conditions, at 30 °C, pH 8, 120 h and agitation of 200 rpm. In the combination of culture condition with the GM, pyocyanin was created at the highest amount of 49.57 µg/mL.@*Conclusion, significance and impact of study@#Based on the obtained results of the study, a pyocyanin-producing procedure was optimized, which suggests a promising application to scale-up pyocyanin production by the P. aeruginosa PS39-phzMS.