Virulence Genotype and Correlation of Clinical Severeness with Presence of the Type VI Secretion System in Klebsiella pneumoniae Isolates Causing Bloodstream Infections

Zhang, Yin; Xu, Yuanhong; Huang, Ying

doi:10.2147/idr.s353858

Cited by 8 publications

(10 citation statements)

References 45 publications

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“…We identified hvKp in 41.42% (70/169) of patients and hypermucoviscosity phenotype in 47.93% (81/169). Moreover, the results indicated that there were more hvKp strains among T6SS-positive strains than among T6SS-negative strains ( p < 0.001), which was similar to the findings of a study by Yin et al ( Zhang et al, 2022 ). The most prevalent hvKp isolates were ST23 (36/70), and ST23 in T6SS-positive isolates was significantly higher than in the T6SS-negative isolates.…”

Section: Discussionsupporting

confidence: 90%

“…Positive results for hcp , icmF , and vgrG genes confirmed T6SS positivity ( Zhou et al, 2020 ; Liao et al, 2022 ; Zhang et al, 2022 ), and 36.1% (61/169) of our strains were T6SS-positive; this was much higher than the rate in blood stream infection (BSI) (20.1%) ( Zhou et al, 2020 ). We identified hvKp in 41.42% (70/169) of patients and hypermucoviscosity phenotype in 47.93% (81/169).…”

Section: Discussionsupporting

confidence: 68%

“…In vitro competition assays were performed as described previously, with slight modification ( Zhang et al, 2022 ). K. pneumoniae isolates and Escherichia coli strain 25,922 were cultured overnight at 37°C in liquid Luria-Bertani (LB) medium.…”

Section: Methodsmentioning

confidence: 99%

“…Genomic analysis identified that several genes coding for iron uptake are encoded around the T6SS gene; thus, T6SS could be involved in iron uptake in hvKp and may be a new virulence factor in hvKp strains ( Barbosa and Lery, 2019 ; Zhu et al, 2021 ; Altayb et al, 2022 ). Two studies reported the frequency of the T6SS gene in K. pneumoniae isolated from bloodstream infections ( Zhou et al, 2020 ; Zhang et al, 2022 ). However, the incidence rate of the T6SS gene in K. pneumoniae causing abscesses and in vivo studies of T6SS virulence has not been reported.…”

Section: Introductionmentioning

confidence: 99%

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Molecular epidemiology and clinical characteristics of the type VI secretion system in Klebsiella pneumoniae causing abscesses

et al. 2023

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PurposeThe type VI system (T6SS) has the potential to be a new virulence factor for hypervirulent Klebsiella pneumoniae (hvKp) strains. This study aimed to characterize the molecular and clinical features of T6SS-positive and T6SS-negative K. pneumoniae isolates that cause abscesses.Patients and methodsA total of 169 non-duplicate K. pneumoniae strains were isolated from patients with abscesses in a tertiary hospital in China from January 2018 to June 2022, and clinical data were collected. For all isolates, capsular serotypes, T6SS genes, virulence, and drug resistance genes, antimicrobial susceptibility testing, and biofilm formation assays were assessed. Multilocus sequence typing was used to analyze the genotypes of hvKp. T6SS-positive hvKp, T6SS-negative hvKp, T6SS-positive cKP, and T6SS-negative cKP (n = 4 strains for each group) were chosen for the in vivo Galleria mellonella infection model and in vitro competition experiments to further explore the microbiological characteristics of T6SS-positive K. pneumoniae isolates.ResultsThe positive detection rate for T6SS was 36.1%. The rates of hvKp, seven virulence genes, K1 capsular serotype, and ST23 in T6SS-positive strains were all higher than those in T6SS-negative strains (p < 0.05). Multivariate logistic regression analysis indicated that the carriage of aerobactin (OR 0.01) and wcaG (OR 33.53) were independent risk factors for T6SS-positive strains (p < 0.05). The T6SS-positive strains had a stronger biofilm-forming ability than T6SS-negative strains (p < 0.05). The T6SS-positive and T6SS-negative strains showed no significant differences in competitive ability (p = 0.06). In the in vivo G. mellonella infection model, the T6SS(+)/hvKP group had the worst prognosis. Except for cefazolin and tegacyclin, T6SS-positive isolates displayed a lower rate of antimicrobial resistance to other drugs (p < 0.05). The T6SS-positive isolates were more likely to be acquired from community infections (p < 0.05).ConclusionKlebsiella pneumoniae isolates causing abscesses have a high prevalence of T6SS genes. T6SS-positive K. pneumoniae isolates are associated with virulence, and the T6SS genes may be involved in the hvKp virulence mechanism.

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Section: Discussionsupporting

confidence: 90%

Section: Discussionsupporting

confidence: 68%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Molecular epidemiology and clinical characteristics of the type VI secretion system in Klebsiella pneumoniae causing abscesses

et al. 2023

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“…Escherichia coli ATCC25922 and K. pneumoniae ATCC700603 were used as quality controls as previously described. 26 …”

Section: Methodsmentioning

confidence: 99%

Epidemiological and Antimicrobial Resistant Patterns, and Molecular Mechanisms of Carbapenem-Resistant Klebsiella pneumoniae Infections in ICU Patients

Lu,

Zhang,

et al. 2023

IDR

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Objective To study the epidemiological and antimicrobial resistant patterns, clinical characteristics and risk factors of critically ill patients infected with carbapenem-resistant Klebsiella pneumoniae (CRKP) from intensive care units (ICUs). The potential molecular mechanisms of antimicrobial resistance and virulence of CRKP were investigated through evaluation of associated genes. Methods Totally, 201 ICU patients infected with K. pneumoniae were recruited from January 2020 through January 2021. K. pneumoniae strains were collected from diverse clinical specimens and identified by microbial cultures and matrix-assisted laser desorption ionization–time-of-flight mass spectrometry. Antimicrobial resistance was measured through broth micro-dilution or Kirby–Bauer assays. The carbapenemase-, virulence-, and capsular serotype-associated genes of CRKP were individually detected by PCR and sequencing. Demographic and clinical profiles were acquired from hospital databases to evaluate the correlation of CRKP infection incidence with clinical risk factors. Results Of the 201 K. pneumoniae strains, CRKP accounted for 41.29%. Seasonal bias existed in local prevalence of CRKP infections. CRKP strains mounted significantly strong resistance against major antimicrobial agents except ceftazidime–avibactam, tigecycline and minocycline. Recent exposure to certain antibiotics and prior treatment with invasive interventions were prone to increase CRKP infection risks with worsened infectious outcomes. The local top carbapenemase-encoding and virulence-associated genes of CRKP were bla KPC and irp 2, respectively. Nearly half of CRKP isolates harbored a capsular polysaccharide serotype of K14.K64 ( wzi -64) which preferentially emerged in the cohort with worse outcomes of infection. Conclusion Featured epidemiology and typical clinical characteristics existed extensively in K. pneumoniae infections among ICU patients. The CRKP cohort exhibited substantially high antimicrobial resistance. Distinctive carbapenemase-, virulence-, and serotype-associated genes were intensively involved in the spread and pathogenesis of CRKP. These findings supported careful management of critically ill patients potentially infected with virulent CRKP in the ICUs.

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Comprehensive Genomic Analysis Reveals Extensive Diversity of Type I and Type IV Secretion Systems in Klebsiella pneumoniae

et al. 2023

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Virulence Genotype and Correlation of Clinical Severeness with Presence of the Type VI Secretion System in Klebsiella pneumoniae Isolates Causing Bloodstream Infections

Cited by 8 publications

References 45 publications

Molecular epidemiology and clinical characteristics of the type VI secretion system in Klebsiella pneumoniae causing abscesses

Molecular epidemiology and clinical characteristics of the type VI secretion system in Klebsiella pneumoniae causing abscesses

Epidemiological and Antimicrobial Resistant Patterns, and Molecular Mechanisms of Carbapenem-Resistant Klebsiella pneumoniae Infections in ICU Patients

Comprehensive Genomic Analysis Reveals Extensive Diversity of Type I and Type IV Secretion Systems in Klebsiella pneumoniae

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