scholarly journals 657. Genomic Insights into Virulence Factors Affecting a Tissue-invasive Klebsiella pneumoniae Infection

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S430-S431
Author(s):  
Takashi Matono ◽  
Masatomo Morita ◽  
Nodoka Nakao ◽  
Yuji Teshima ◽  
Ryosuke Yamate ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Klebsiella Pneumoniae ◽  
Virulence Factors ◽  
Population Genomics ◽  
Positive Likelihood Ratio ◽  
Virulence Gene ◽  
Invasive Infection ◽  
Factors Affecting ◽  
Non Invasive ◽  
Metastatic Infection

Abstract Background Japan is one of the hypervirulent Klebsiella pneumoniae (hvKp) endemic areas, resulting in an alarming issue in actual clinical settings. However, little is known regarding key virulence factors responsible for hvKp infection. Methods We analyzed K. pneumoniae isolates collected between 2017 and 2019, and defined hvKp as a pyogenic infection. Classical K. pneumoniae (cKp) involved a non-invasive infection or uncomplicated bacteremia. Isolates belonging to the K. pneumoniae species complex were excluded. Results We analyzed 112 isolates, including 19 hvKp, 67 cKp, and 26 colonizers, by whole-genome sequencing. Population genomics revealed that the K1-sequence type (ST) 82 clade was distinct from that of K1-ST23 clone (Figure 1). The virulence-gene profiles also differed between K1-ST82 (aerobactin and rmpA) and K1-ST23 (aerobactin, yersiniabactin, salmochelin, colibactin, and rmpA/rmpA2). The K2 genotype was more diverse than that of K1. A neighboring subclade of K1-ST23 (comprising ST29, ST412, ST36, and ST268) showed multidrug-resistance and hypervirulence potentials. Logistic-regression analysis revealed that diabetes mellitus was associated with K. pneumoniae infection (odds ratio [OR]: 4.11; 95% confidence interval [CI]: 1.14–14.8). No significant association was found between hvKp diagnosis and clinical characteristics, such as diabetes mellitus or community acquisition (Table 1). The K1 genotype (OR: 9.02; 95% CI: 2.49–32.7; positive-likelihood ratio [LR]: 4.08), rmpA (OR: 8.26; 95% CI: 1.77–38.5; positive LR: 5.83), and aerobactin (OR: 4.59; 95% CI: 1.22–17.2; positive LR: 3.49) were substantial diagnostic predictors of hvKp (Table 2). Figure 1. Phylogenetic distribution of genetic virulence factors in 112 K. pneumoniae isolates The highlighted strains are clinically pathogenic (orange, hypervirulent K. pneumoniae; yellow, classical K. pneumoniae; sky blue, colonization). The non-highlighted strain (NTUH-K2044) is a reference K. pneumoniae strain. Conclusion In hvKp-rich settings, diabetes mellitus, community-acquisition, and siderophores other than aerobactin were not remarkable predictors of hvKp infection. However, the K1 genotype, rmpA, and aerobactin were found to be substantial predictors, warranting clinical assessment of any possible/further pyogenic (metastatic) infection. We believe that these findings shed light on key hvKp virulence factors. Disclosures All Authors: No reported disclosures

Clinical and molecular epidemiology of community-onset invasive Staphylococcus aureus infection in New Zealand children

2014 ◽  
Vol 142 (8) ◽  
pp. 1713-1721 ◽  
Author(s):  
D. A. WILLIAMSON ◽  
S. R. RITCHIE ◽  
S. A. ROBERTS ◽  
G. W. COOMBS ◽  
M. G. THOMAS ◽  
...  
Keyword(s):  
New Zealand ◽  
Virulence Factors ◽  
Virulence Gene ◽  
Invasive Disease ◽  
Future Research ◽  
Gene Repertoire ◽  
Non Invasive ◽  
Strong Focus ◽  
Genes Encoding ◽  
Community Onset

SUMMARYOur aim was to describe the epidemiology and incidence of community-onset invasive S. aureus disease in children presenting to our hospital, and to compare the clonal complexes and virulence genes of S. aureus strains causing invasive and non-invasive disease. The virulence gene repertoire of invasive disease isolates was characterized using DNA microarray and compared with the virulence gene repertoire of non-invasive S. aureus isolates. Over the study period, 163 children had an invasive S. aureus infection. There was no difference in the distribution of clonal complexes or in the prevalence of genes encoding virulence factors between invasive and non-invasive isolates. Future research should include a strong focus on identifying the host and environmental factors that, along with organism virulence factors, are contributing to the patterns of invasive S. aureus disease observed in New Zealand.

scholarly journals Ventriculitis Associated with Liver Abscess Caused by Klebsiella Pneumoniae

2020 ◽  
Vol 38 (3) ◽  
pp. 210-213
Author(s):  
Yongwoo Lee ◽  
Young-Mok Song
Keyword(s):  
Diabetes Mellitus ◽  
Central Nervous System ◽  
Nervous System ◽  
Klebsiella Pneumoniae ◽  
Antibiotic Treatment ◽  
Liver Abscess ◽  
Metastatic Infection ◽  
Appropriate Treatment ◽  
The Central Nervous System ◽  
Prompt Diagnosis

<i>Klebsiella pneumoniae</i> has been recognized to cause an invasive syndrome characterized by liver abscess and its metastatic infection. The characteristics of metastatic infection involving the central nervous system in this invasive syndrome are poorly understood. The authors report an 84-year-old woman with diabetes mellitus who developed liver abscess caused by <i>K. pneumoniae</i>, complicated with ventriculitis. The patient died despite the antibiotic treatment. Ventriculitis is a rare CNS complication of <i>K. pneumoniae</i> invasive syndrome and requires prompt diagnosis for the appropriate treatment.

Glucose Calibration Modeling in Blood with Spline Regression Approaching to Non-Invasive Tools

2018 ◽  
pp. 144-149
Author(s):  
Ria Hayatun Nur ◽  
Indahwati A ◽  
Erfiani A
Keyword(s):  
Diabetes Mellitus ◽  
Linear Regression ◽  
Good Health ◽  
Cubic Spline ◽  
The Body ◽  
Spline Regression ◽  
Linear Quadratic ◽  
Important Thing ◽  
Non Invasive

In this globalization era, health is the most important thing to be able to run various activities. Without good health, this will hinder many activities. Diabetes mellitus is one of the diseases caused by unhealty lifestyle.There are many treatments that can be done to prevent the occurrence of diabetes. The treatments are giving the insulin and also checking the glucose rate to the patients.Checking the glucose rate needs the tools which is safety to the body. This research want to develop non invasive tool which is safety and do not injure the patient. The purpose of this research is also finding the best model which derived from Linear, Quadratic, and Cubic Spline Regression. Some respondents were taking to get the glucose measuring by invasive and non invasive tools. It could be seen clearly that Spline Linear Regression was the best model than Quadratic and Cubic Spline Regression. It had 70% and 33.939 for R2 and RMSEP respectively.

scholarly journals Nutritional Regulation of the Sae Two-Component System by CodY inStaphylococcus aureus

2018 ◽  
Vol 200 (8) ◽  
Author(s):  
Kevin D. Mlynek ◽  
William E. Sause ◽  
Derek E. Moormeier ◽  
Marat R. Sadykov ◽  
Kurt R. Hill ◽  
...  
Keyword(s):  
Gene Expression ◽  
Virulence Factors ◽  
Virulence Gene ◽  
Nutrient Depletion ◽  
Global Regulator ◽  
Two Component System ◽  
Component System ◽  
Content Type ◽  
Virulence Gene Expression ◽  
Two Component

ABSTRACTStaphylococcus aureussubverts innate defenses during infection in part by killing host immune cells to exacerbate disease. This human pathogen intercepts host cues and activates a transcriptional response via theS. aureusexoprotein expression (SaeR/SaeS [SaeR/S]) two-component system to secrete virulence factors critical for pathogenesis. We recently showed that the transcriptional repressor CodY adjusts nuclease (nuc) gene expression via SaeR/S, but the mechanism remained unknown. Here, we identified two CodY binding motifs upstream of thesaeP1 promoter, which suggested direct regulation by this global regulator. We show that CodY shares a binding site with the positive activator SaeR and that alleviating direct CodY repression at this site is sufficient to abrogate stochastic expression, suggesting that CodY repressessaeexpression by blocking SaeR binding. Epistasis experiments support a model that CodY also controlssaeindirectly through Agr and Rot-mediated repression of thesaeP1 promoter. We also demonstrate that CodY repression ofsaerestrains production of secreted cytotoxins that kill human neutrophils. We conclude that CodY plays a previously unrecognized role in controlling virulence gene expression via SaeR/S and suggest a mechanism by which CodY acts as a master regulator of pathogenesis by tying nutrient availability to virulence gene expression.IMPORTANCEBacterial mechanisms that mediate the switch from a commensal to pathogenic lifestyle are among the biggest unanswered questions in infectious disease research. Since the expression of most virulence genes is often correlated with nutrient depletion, this implies that virulence is a response to the lack of nourishment in host tissues and that pathogens likeS. aureusproduce virulence factors in order to gain access to nutrients in the host. Here, we show that specific nutrient depletion signals appear to be funneled to the SaeR/S system through the global regulator CodY. Our findings reveal a strategy by whichS. aureusdelays the production of immune evasion and immune-cell-killing proteins until key nutrients are depleted.

Phenotypic and Molecular Characteristics of Pseudomonas Aeruginosa Isolated from Burn Unit

2021 ◽  
Vol 30 (1) ◽  
pp. 19-28
Author(s):  
Yasser M. Ismail ◽  
Sahar M. Fayed ◽  
Fatma M. Elesawy ◽  
Nora Z Abd El-Halim ◽  
Ola S. El-Shimi
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Virulence Factors ◽  
Antimicrobial Susceptibility ◽  
Virulence Gene ◽  
Molecular Characteristics ◽  
Drug Resistant ◽  
Burn Wound ◽  
Burn Wounds ◽  
Related Data ◽  
Genes Encoding

Background: The biggest concern for a burn team is a nosocomial infection in burn patients, which is a significant health issue. Pseudomonas aeruginosa is an extremely troublesome drug-resistant bacterium in the world today. We are now faced with rising P. aeruginosa pan-drug-resistant clones in hospital settings. Objectives: To evaluate the distribution of different virulence factors generated by P. aeruginosa isolated from burn wound infections, together with its antimicrobial susceptibility. Methodology: The isolates reported as P. aeruginosa were further tested for the presence of various phenotypic and genotypic virulence factors including (Biofilm formation, lipase, protease, gelatinase, DNase, bile esculin hydrolysis & hemolysin). Also, genes encoding (nan 1 and Exo A) were investigated by PCR using specific primers. All the isolates were tested for their antimicrobial susceptibility patterns. Results: The study reported that toxins and enzymes were expressed by the tested strains in varying proportions; (92.0%) were producing β-hemolysin, lipase (86%), and protease (86%). The formation of biofilm was observed in 84%. Exo A (70%) was the main virulence gene found in the tested strains. Nan 1 gene was identified in 30% of the samples. 82% of MDRPA isolates were found. There is indeed a relationship between biofilm production and drug resistance, as well as the presence of virulence genes (nan 1 and Exo A) were associated with certain patients and burn wounds characteristics as burn size, burn wound depth, length of hospital stays, and socioeconomic status. Conclusions: Correlation of Pseudomonas aeruginosa virulence profiles with burn wounds and patient-related data can be useful in establishing of an appropriate preventive protocol for hospitalized patients with P. aeruginosa burn serious infections. The targeting of these bacterial virulence arsenals is also a promising approach to developing alternative drugs, which act by attenuating the aggressiveness of the pathogen and reducing its potential to cause vigorous infection.

Factores relacionados con infecciones: pacientes quirúrgicos en ventilación mecánica con neumonía nosocomial

2021 ◽  
Vol 5 (2) ◽  
pp. 1-12
Author(s):  
Wilfredo Medina Peña ◽  
Douglas Ernesto Sánchez
Keyword(s):  
Diabetes Mellitus ◽  
Klebsiella Pneumoniae

OBJETIVO: presentar los factores más comunes relacionados con infecciones nosocomiales en pacientes ventilados y quirúrgicos. MÉTODO: Estudio descriptivo transversal. Se tomaron un total de 75 pacientes quirúrgicos sometidos a ventilación mecánica en unidad de cuidados intensivos de Hospital Roosevelt de marzo 2017 a abril 2018. RESULTADOS: El único factor que se asoció significativamente a la incidencia de infecciones nosocomiales en pacientes quirúrgicos con ventilación mecánica fue el tiempo prolongado de intubación (> 8 días, p = 0.002); sin embargo, la incidencia de infecciones nosocomiales fue mayor en pacientes con enfermedad respiratoria de base (100%) e insuficiencia renal (83.3%). Las características sobresalientes fueron sexo masculino (62.7%), y edad promedio de 43 años. Las patologías o condiciones clínicas observadas con mayor frecuencia fueron trauma craneoencefálico (58.7%), patología abdominal (41.3%), diabetes mellitus (32.0%) e hipertensión arterial (29.3%), obesidad (22.5%) y un promedio de 13 días de intubación. La frecuencia acumulada de infecciones nosocomiales asociadas a ventilación mecánica correspondió al 68.0% (neumonía nosocomial), y el microorganismo aislado con mayor frecuencia fue Klebsiella pneumoniae (66.2%). Se observó una importante tasa de mortalidad asociada a ventilación mecánica en pacientes quirúrgicos correspondiente al 42.7%. CONCLUSIÓN: Se concluye que la neumonía nosocomial y la muerte son eventos frecuentes en pacientes quirúrgicos con ventilación mecánica y a la vez no se identificaron predictores individuales de infección nosocomial.

Photo-enhanced Acetone Adsorption on δ-MnO2 Nanoparticles: A Step towards Non-invasive Detection of Diabetes Mellitus

2021 ◽  
pp. 130944
Author(s):  
Vigneshwaran Mohan ◽  
Gobinath Marappan ◽  
David Chidambaram ◽  
Kumaresan Rajendran ◽  
Velappa Jayaraman Surya ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Non Invasive ◽  
Acetone Adsorption ◽  
Mno2 Nanoparticles

scholarly journals An In-Vitro Study of Molecular Effects of a Combination Treat-ment with Antibiotics and Nanofluid Containing Carbon Nano-tubes on Klebsiella pneumoniae

2021 ◽  
Author(s):  
Maryam Mehdizadeh ◽  
Mojgan Sheikhpour ◽  
Iman Salahshourifar ◽  
Seyed Davar Siadat ◽  
Parvaneh Saffarian
Keyword(s):  
Klebsiella Pneumoniae ◽  
Virulence Genes ◽  
Ultrasonic Method ◽  
Virulence Gene ◽  
In Vitro Study ◽  
Negative Control ◽  
Resistant Isolate ◽  
Simultaneous Treatment ◽  
Virulence Gene Expression

Background: We aimed to prepare a nanofluid, containing f-MWCNTs, and investigate the antibacterial efficacy of f-MWCNTs+ ciprofloxacin (cip) on Klebsiella pneumoniae by evaluating the virulence gene expression. Methods: This study was carried out from 2019 to 2020, in the Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran. The nanofluid containing antibiotic and f-MWCNTs were prepared by the ultrasonic method. The minimum inhibitory concentrations (MICs) of ciprofloxacin and f-MWCNTs were determined using the broth micro dilution MIC tests. For examining the antibacterial effects, the expression level of virulence genes, under the influence of f-MWCNTs, was evaluated by a real-time PCR. Results: The effect of 8 µg/ml ciprofloxacin + 400 µg/ml f-MWCNTs, completely inhibited the growth of the resistant isolate of K. pneumoniae, while, in the ATCC 700,603 isolate, 2 µg/ml ciprofloxacin with 100 µg/ml f-MWCNT could inhibit a bacterial growth. In the resistant K. pneumoniae clinical isolate, after f-MWCNT+cip treatment, the expression of fimA, fimD, wza, and wzi genes was significantly downregulated, compared to the ciprofloxacin treatment, and upregulated, compared to the negative control. For the ATCC 700,603 isolate treated with f-MWCNT+cip, the expression of fimA, fimD and wza virulence genes showed upregulation, compared to the negative control and downregulated in comparison with the ciprofloxacin treatment. Conclusion: Simultaneous treatment of resistant isolate of K. pneumoniae with f-MWCNTs +antibiotic could improve the effectiveness of antibiotic at lower doses, due to the reduced expression of virulence genes in comparison with antibiotic treatment, besides the increased cell wall permeability to antibiotics.

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