Virulence determinants associated with biofilm formation by Klebsiella pneumoniae causing hospital-acquired bloodstream infection

Background: Klebsiella pneumoniae is a major cause of hospital-acquired infections in Jamaica. Objective: We aimed to determine their antimicrobial resistance profiles and to assess biofilm formation in the presence of antibiotic, nicotine and amino acid starvation stresses. Methodology: Antimicrobial susceptibility and multiple antimicrobial resistance (MAR) index were determined for 23 K. pneumoniae strains. Biofilm production was evaluated in the presence of 50 μg/ml ceftazidime or gentamicin, 0–4 mg/ml nicotine, or 0.5 mg/ml serine hydroxamate (to induce amino acid starvation). Genetic relatedness, and the presence of type 3 fimbriae (mrkA) and determinants for extended spectrum β-lactamase and carbapenamases (bla-IMP, bla-VIM, bla-GIM and bla-SIM) were assessed by PCR-based amplification. Results: All strains were susceptible to imipenem (p<0.05); frequencies of resistance varied from 4% (for amikacin) and 8.7% (for meropenem) to over 30% for the other antimicrobials. About half of strains were resistant to ceftazidime, gentamicin and piperacillin. Mean MAR index was 0.31. The presence of antibiotics and nicotine at 2 and 4 mg/ml negatively affected biofilm formation for most strains. However, with amino acid starvation, almost 60% of strains retained medium or high biofilm production. Most strains harboured determinants for carbapenemase or metallo--lactamase, and one-third were PCRpositive for the OXA-1 gene. Strains were clustered into three groups based on ERICPCR analysis. Conclusion: These data suggest that certain antibiotics could inhibit biofilm production in K. pneumoniae even as multidrug resistance in this organism is evident. Further, this species has the propensity to harbour several genetic determinants for antimicrobial resistance.

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Comparison of biofilm formation and efflux pumps in ESBL and carbapenemase producing Klebsiella pneumoniae

The Journal of Infection in Developing Countries ◽

10.3855/jidc.9677 ◽

2018 ◽

Vol 12 (03) ◽

pp. 156-163 ◽

Cited By ~ 1

Author(s):

Burak Yazgan ◽

Ibrahim Türkel ◽

Rıdvan Güçkan ◽

Kılınç Kılınç ◽

Tuba Yıldırım

Keyword(s):

Klebsiella Pneumoniae ◽

Biofilm Formation ◽

Cell Communication ◽

Opportunistic Pathogen ◽

Efflux Pumps ◽

Microtiter Plate ◽

Virulence Determinants ◽

Clinical Environment ◽

Microtiter Plate Assay ◽

Significant Difference

Introduction: Klebsiella pneumoniae is an opportunistic pathogen that causes a range of diseases. The appearance of extended-spectrum β-lactamase -and carbapenemase-producing strains, in addition to the biofilm-forming phenotype, is a major problem in the clinical environment. Methodology: A total of 33 clinical K. pneumoniae isolates were used in this study. Antimicrobial susceptibilities were assessed by a disc diffusion assay. Biofilm formation was determined by a microtiter plate assay, staining with 1% crystal violet and measuring absorbance after destaining. Moreover, expression of acrA, kdeA, ketM, kpnEF, and kexD efflux associated genes was measured by qRT-PCR. Results: Isolates displayed high resistance to β-lactams such as cefazolin, cefuroxime, ceftriaxone, cefepime, piperacillin-tazobactam, imipenem, and meropenem and decreased resistance to gentamicin, amikacin, ciprofloxacin, and levofloxacin. ESBL-producing isolates formed more biofilm than carbapenemase-producing isolates. The mRNA expression levels in KPC isolates for acrA (2-fold), kdeA (2.7-fold), ketM (2.2-fold), and kpnEF (3.4-fold) were significantly increased compared to ESBL-producing isolates. There was no significant difference in kexD expression level. Conclusions: Under the conditions used here ESBL-producing isolates formed more biofilm than KPC postive isolates; this was associated with virulence determinants which were also transferred by plasmids together with ESBLs enzymes. Moreover, the upregulation of acrA, kdeA, ketM, and kpnEF efflux pumps was seen in carbapenemase-producing isolates demonstrating that high expression of efflux pumps alone could not confer resistance but may act as a physiological determinant such as bacterial pathogenicity and virulence, and cell-to-cell communication for bacteria.

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Klebsiella pneumoniae yfiRNB operon affects biofilm formation, polysaccharide production and drug susceptibility

Microbiology ◽

10.1099/mic.0.081992-0 ◽

2014 ◽

Vol 160 (12) ◽

pp. 2595-2606 ◽

Cited By ~ 11

Author(s):

Mónica G. Huertas ◽

Lina Zárate ◽

Iván C. Acosta ◽

Leonardo Posada ◽

Diana P. Cruz ◽

...

Keyword(s):

Klebsiella Pneumoniae ◽

Biofilm Formation ◽

Surface Characteristics ◽

Opportunistic Pathogen ◽

Drug Susceptibility ◽

Cellulose Production ◽

Resistant Strains ◽

Drug Resistant Strains ◽

Type 3 ◽

Hospital Acquired

Klebsiella pneumoniae is an opportunistic pathogen important in hospital-acquired infections, which are complicated by the rise of drug-resistant strains and the capacity of cells to adhere to surfaces and form biofilms. In this work, we carried out an analysis of the genes in the K. pneumoniae yfiRNB operon, previously implicated in biofilm formation. The results indicated that in addition to the previously reported effect on type 3 fimbriae expression, this operon also affected biofilm formation due to changes in cellulose as part of the extracellular matrix. Deletion of yfiR resulted in enhanced biofilm formation and an altered colony phenotype indicative of cellulose overproduction when grown on solid indicator media. Extraction of polysaccharides and treatment with cellulase were consistent with the presence of cellulose in biofilms. The enhanced cellulose production did not, however, correlate with virulence as assessed using a Caenorhabditis elegans assay. In addition, cells bearing mutations in genes of the yfiRNB operon varied with respect to the WT control in terms of susceptibility to the antibiotics amikacin, ciprofloxacin, imipenem and meropenem. These results indicated that the yfiRNB operon is implicated in the production of exopolysaccharides that alter cell surface characteristics and the capacity to form biofilms – a phenotype that does not necessarily correlate with properties related with survival, such as resistance to antibiotics.

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CRISPR-cas system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of Enterococcus faecalis

10.21203/rs.2.13402/v3 ◽

2019 ◽

Author(s):

Pourya Gholizadeh ◽

Mohammad Aghazadeh ◽

Reza Ghotaslou ◽

Mohammad Ahangarzadeh Rezaee ◽

Tahereh Pirzadeh ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Root Canal ◽

Biofilm Formation ◽

Virulence Genes ◽

Virulence Determinants ◽

Root Canals ◽

Causative Agents ◽

Life Threatening ◽

Selective Forces ◽

Hospital Acquired

Abstract Introduction Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- cas is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of E. faecalis .Methods and materials Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as efaA , esp , cylA , hyl , gelE , ace , ebpR , and asa1 .Results Biofilm formation, and gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was ace , which was followed by efaA , whereas cylA was the least identified. The presence of CRISPR1- cas , orphan CRISPR2 and CRISPR3- cas was determined in 13%, 55.3% and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canals isolates. An inverse significant correlation was found between CRISPR- cas loci, esp and gelE , while direct correlations were observed in the case of cylA , hyl , gelE (among CRISPR-loci 1 and 3), asa1 , ace , biofilm formation, and hemolysis activity.Conclusion Findings, therefore, indicate that CRISPR- cas might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits.

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The Inhibitory Effects of Lactobacillus Supernatants and Their Metabolites on the Growth and Biofilm Formation of Klebsiella pneumoniae

Infectious Disorders - Drug Targets ◽

10.2174/1871526520666200106122632 ◽

2020 ◽

Vol 20 ◽

Author(s):

Fatemeh Kheiri ◽

Rouha Kasra Kermanshahi ◽

Mohammad Mehdi Feizabadi

Keyword(s):

Klebsiella Pneumoniae ◽

Biofilm Formation ◽

In Vitro Study ◽

Bacterial Cells ◽

Inhibitory Effects ◽

Beta Lactamases ◽

Extended Spectrum Beta Lactamases ◽

Effective Product ◽

Hospital Acquired

Background: Klebsiella pneumoniae is a common cause of hospital acquired infections including urinary tract infection (UTI). Biofilm formation makes the K. pneumoniae infection more complicated and carrying extended spectrum beta-lactamases (ESBLs) genes limits antibiotic choices for treatment. Lactobacillus strains are known as natural protective barriers against UTIs. Objectives: This is a small in-vitro study aimed to determine the effect of probiotic Lactobacillus strains and some types of their metabolites on the growth and biofilm of UTI isolated and reference strain of Klebsiella pneumoniae. Methods: The efficacy of Lactobacillus supernatants and antibiotics in prevention and elimination of K. pneumoniae biofilms was determined using a quantitative adherence assay. A rapid colorimetric microplate bioassay was applied for detection of survived bacterial cells after treatment with antibacterial agents. Biofilm phenotypes were studied by scanning electron microscopy (SEM). Results: The results showed that seven out of eight ESBL producing uropathogenic K. pneumoniae isolates in this study were able to produce biofilm. Lactobacillus supernatants at 1:1 to 1:16 dilutions, had more than 95% biofilm-inhibitory and biofilm-killing properties on strong biofilm producer isolate. Supra-MIC levels of antibiotics had much lower anti-biofilm effect than Lactobacillus supernatant and left considerable alive biofilm cells. Conclusions: Although antibiotic resistance increases in biofilm forms of Klebsiella pneumoniae, Lactobacillus supernatants have strong antibiofilm efficacy even in concentrations lower than MIC. Biofilm formation decreases considerably in the presence of Lactobacillus supernatants. Hydrogen peroxide is an effective product against growth and biofilm formation of Klebsiella pneumoniae.

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Community- and Hospital-Acquired Klebsiella pneumoniae Urinary Tract Infections in Portugal: Virulence and Antibiotic Resistance

Microorganisms ◽

10.3390/microorganisms7050138 ◽

2019 ◽

Vol 7 (5) ◽

pp. 138 ◽

Cited By ~ 17

Author(s):

Cátia Caneiras ◽

Luis Lito ◽

José Melo-Cristino ◽

Aida Duarte

Keyword(s):

Antibiotic Resistance ◽

Urinary Tract ◽

Klebsiella Pneumoniae ◽

Urinary Tract Infections ◽

Multidrug Resistant ◽

Hospital Environment ◽

Virulence Determinants ◽

Antibiotic Resistance Profile ◽

Tract Infections ◽

Hospital Acquired

Klebsiella pneumoniae is a clinically relevant pathogen and a frequent cause of hospital-acquired (HA) and community-acquired (CA) urinary tract infections (UTI). The increased resistance of this pathogen is leading to limited therapeutic options. To investigate the epidemiology, virulence, and antibiotic resistance profile of K. pneumoniae in urinary tract infections, we conducted a multicenter retrospective study for a total of 81 isolates (50 CA-UTI and 31 HA-UTI) in Portugal. The detection and characterization of resistance and virulence determinants were performed by molecular methods (PCR, PCR-based replicon typing, and multilocus sequence typing (MLST)). Out of 50 CA-UTI isolates, six (12.0%) carried β-lactamase enzymes, namely blaTEM-156 (n = 2), blaTEM-24 (n = 1), blaSHV-11 (n = 1), blaSHV-33 (n = 1), and blaCTX-M-15 (n = 1). All HA-UTI were extended-spectrum β-lactamase (ESBL) producers and had a multidrug resistant profile as compared to the CA-UTI isolates, which were mainly resistant to ciprofloxacin, levofloxacin, tigecycline, and fosfomycin. In conclusion, in contrast to community-acquired isolates, there is an overlap between virulence and multidrug resistance for hospital-acquired UTI K. pneumoniae pathogens. The study is the first to report different virulence characteristics for hospital and community K. pneumoniae pathogens, despite the production of β-lactamase and even with the presence of CTX-M-15 ESBL, a successful international ST15 clone, which were identified in both settings. This highlights that a focus on genomic surveillance should remain a priority in the hospital environment.

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CRISPR-cas system in the acquisition of virulence genes in dental-root canal and hospital-acquired isolates of Enterococcus faecalis

10.21203/rs.2.13402/v2 ◽

2019 ◽

Author(s):

Pourya Gholizadeh ◽

Mohammad Aghazadeh ◽

Reza Ghotaslou ◽

Mohammad Ahangarzadeh Rezaee ◽

Tahereh Pirzadeh ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Root Canal ◽

Biofilm Formation ◽

Virulence Genes ◽

Virulence Determinants ◽

Root Canals ◽

Causative Agents ◽

Life Threatening ◽

Selective Forces ◽

Hospital Acquired

Abstract Introduction Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies have demonstrated that the presence of CRISPR- cas is associated with antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the phenotypic and genotypic virulence determinants in relation to CRISPR elements from the dental-root canals and hospital-acquired isolates of E. faecalis .Methods and materials Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were assessed in this study. Phenotypic screening of the isolates included biofilm formation, and gelatinase and hemolysis activities. Genotypical screening using PCR was further used to evaluate the presence of CRISPR elements and different virulence-associated genes such as efaA , esp , cylA , hyl , gelE , ace , ebpR , and asa1 .Results Biofilm formation, and gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most prevalent virulence-associated gene was ace , which was followed by efaA , whereas cylA was the least identified. The presence of CRISPR1- cas , orphan CRISPR2 and CRISPR3- cas was determined in 13%, 55.3% and 17.4% of the isolates, respectively. CRISPR elements were significantly more prevalent in the dental-root canals isolates. An inverse significant correlation was found between CRISPR- cas loci, esp and gelE , while direct correlations were observed in the case of cylA , hyl , gelE (among CRISPR-loci 1 and 3), asa1 , ace , biofilm formation, and hemolysis activity.Conclusion Findings, therefore, indicate that CRISPR- cas might prevent the acquisition of some respective pathogenicity factors in some isolates, though not all; so selective forces could not influence pathogenic traits.

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Comparison of the Value of SOFA and Pitt Bacteremia Scores in the Prognostic Evaluation of Patients With Hospital-acquired Klebsiella Pneumoniae Bloodstream Infection

10.21203/rs.3.rs-954898/v1 ◽

2021 ◽

Author(s):

Jun Guo ◽

Shuaihua Fan ◽

Jinlan Lin ◽

Sheng Wu

Keyword(s):

Klebsiella Pneumoniae ◽

Bloodstream Infection ◽

Sofa Score ◽

Tertiary Hospital ◽

Klebsiella Pneumonia ◽

Survival Group ◽

Hospital Acquired Infection ◽

Prognostic Evaluation ◽

The Difference ◽

Hospital Acquired

Abstract This clinical research studied the value of SOFA score and Pitt bacteremia score in the prognosis assessment of patients with hospital-acquired Klebsiella pneumonia bloodstream infection. We conducted a retrospective analysis of 40 patients with hospital-acquired Klebsiella pneumoniae bloodstream infection in a tertiary hospital from January 2016 to December 2020. For these patients, the SOFA score and Pitt bacteremia score were used to evaluate the prognosis. Logistic regression was performed with the known prognosis results to obtain the best cut-off value, sensitivity, and specificity. Pitt bacteremia score [3 (3-4) points to 6 (5.5-7) points] and SOFA score [7 (6-10) points to 17 (13-17.5) points] in the survival group were lower than those in the death group (P<0.05). The SOFA score predicts the death of hospital-acquired Klebsiella pneumoniae bloodstream infection patients with a sensitivity of 80%, a specificity of 84%, and the area under curve(AUC) of SOFA score is 0.8960 (95% CI 0.7951-0.9969); Pitt bacteremia score predicts the hospital-acquired Klebsiella pneumoniae blood infection with a sensitivity of 86.67%, a specificity of 80%, and AUC of Pitt bacteremia score is 0.9413 (95% CI 0.8700- 1.000). Both the SOFA score and the Pitt bacteremia score have predictive value for the prognosis of patients with HAI (hospital acquired infection) Klebsiella pneumonia blood infection. However, the difference shows that the SOFA score has obvious accuracy and specificity in the prognosis of patients with HAI Klebsiella pneumoniae bloodstream infection, it is better than the Pitt bacteremia score and has greater application prospects in prognostic evaluation.

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CRISPR-cas system in the acquisition of virulence genes in the dental-root canal and hospital-acquired isolates of Enterococcus faecalis

10.21203/rs.2.13402/v1 ◽

2019 ◽

Author(s):

Pourya Gholizadeh ◽

Mohammad Aghazadeh ◽

Reza Ghotaslou ◽

Mohammad Ahangarzadeh Rezaee ◽

Tahereh Pirzadeh ◽

...

Keyword(s):

Enterococcus Faecalis ◽

Root Canal ◽

Biofilm Formation ◽

Inverse Correlation ◽

Virulence Determinants ◽

Gene Encoding ◽

Virulence Traits ◽

Causative Agents ◽

Life Threatening ◽

Hospital Acquired

Abstract Introduction: Enterococcus faecalis is one of the important causative agents of nosocomial and life-threatening infections in human. Several studies demonstrated that the presence of CRISPR-cas is associated with the antibiotic susceptibility and lack of virulence traits. In this study, we aimed to assess the relation between the phenotypic and genotypic virulence determinants of E. faecalis with the CRISPR elements in the dental-root canal and hospital-acquired isolates.Methods and materials: Eighty-eight hospital-acquired and 73 dental-root canal isolates of E. faecalis were subjected for study. The phenotype tests including biofilm formation, gelatinase and hemolysis activity were performed and the genotype characteristics including efaA, esp, cylA, hyl, gelE, ace, ebpR, and asa1 were performed by PCR methods. Presences of different types of CRISPR-cas system were determined by PCR.Results: Biofilm formation, gelatinase and hemolysis activity were detected in 93.8%, 29.2% and 19.2% of the isolates, respectively. The most gene encoding virulence traits were ace, followed by efaA and the lowest was cylA. The presence of CRISPR1-cas, orphan CRISPR2 and CRISPR3-cas were determined in 13%, 55.3%, and 17.4% of isolates, respectively, which were present in proportionally more in the dental-root canal. Inverse correlation were found significantly between CRISPR-cas loci, esp and gelE, and direct correlations were found in cylA, hyl, gelE (between some CRISPR-loci), asa1, ace, biofilm formation, gelatinase and hemolysis activitiesConclusion: Findings indicates that CRISPR-cas might prevent the acquisition of some respective pathogenicity factors in some isolates not all, and could not be selective forces to influence pathogenic traits.

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