Siderophore Production of Klebsiella Species Isolated from Different Sources

Podschun, Rainer; Fischer, Arno; Ullmann, U.

doi:10.1016/s0934-8840(11)80673-0

Cited by 54 publications

(64 citation statements)

References 18 publications

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“…Serum bactericidal activity was measured using the method of Podschun et al, 15 with a slight modification. Isolation of neutrophils and serum from healthy volunteers was ethically approved by a human IRB committee (IRB-1-103-05-155).…”

Section: Detection Of Virulence Determinants For Hypervirulent Strainmentioning

confidence: 99%

Effect in virulence of switching conserved homologous capsular polysaccharide genes fromKlebsiella pneumoniaeserotype K1 into K20

et al. 2016

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The capsular polysaccharides in different serotypes of Klebsiella pneumoniae (KP) coded by the (CPS) gene cluster are characterized by a conserved and a hyper-variable region. We performed a virulence study by switching genes in the highly conserved region of the CPS cluster between strains. Six genes in the CPS conserved region in serotype K20, including galF, acidPPc, wzi, wza, wzb and wzc, were knocked out and replaced by the homologous genes from serotype K1. Compared to the parental K20 strain, the mutants showed a decline in lethality (LD 50 ) in mice from 10-fold to > 10 5 -fold and were categorized in terms of the effect on virulence as low (L) for galF and acidPPC, moderate (M) for wzi, and high (H) for wza, wzb and wzc. Although substituting the acidPPC gene from K1 for acidPPC in the K20 strain fully restored virulence, substitution with the wzi, wza, wzb or wzc homologs from K1 did not. The restoration with wzi from K1 led to a partial restoration of virulence, with the LD 50 in mice changing from 10 4 to 10 3 CFU . For the wza, wzb and wzc genes, Complementation of K20 wza, wzb and wzc from K1 resulted in varied degrees of lethality in mice. Variable improvement in serum killing and phagocytosis was observed when the knockout mutants were compared with the geneswitched strains. In conclusion, homologous genes for capsule synthesis failed to exhibit the same functionality when switched between serotypes and virulence was decreased in different degree in according to the genes' homology.

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Section: Detection Of Virulence Determinants For Hypervirulent Strainmentioning

confidence: 99%

Effect in virulence of switching conserved homologous capsular polysaccharide genes fromKlebsiella pneumoniaeserotype K1 into K20

et al. 2016

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“…The expression of MSHA indicating type 1 fimbriae and MR/K-HA indicating type 3 fimbriae was examined as described previously [18]. MSHA was assessed on guinea-pig erythrocytes and MR=K-HA was determined on tanned ox erythrocytes.…”

Section: Haemagglutination Assaymentioning

confidence: 99%

“…Enterobactin and aerobactin production was detected by the cross-feeding bioassay of Hantke [19] as described elsewhere [20]. Nutrient agar supplemented with 2,29-dipyridyl (final concentration 200 ìM) served as iron-restricted agar medium.…”

Section: Determination Of Siderophore Productionmentioning

confidence: 99%

“…The susceptibility of bacteria to human serum was determined by the method of Hughes et al [22] with slight modifications [13]. Bacteria were diluted to 2 3 10 6 cells=ml in physiological saline.…”

Section: Serum Bactericidal Assaymentioning

confidence: 99%

“…Another characteristic regarded as a klebsiella virulence factor is the ability to resist the bactericidal effect of human serum. In K. pneumoniae, serum resistance properties are more common among isolates from clinical specimens than in faecal or environmental isolates [13]. Furthermore, Klebsiella isolates have been shown to produce highaffinity iron-chelating siderophores [11,14,15].…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Expression of putative virulence factors by clinical isolates of Klebsiella planticola

Podschun

Fischer

Ullman

2000

Journal of Medical Microbiology

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A total of 92 clinical isolates of Klebsiella planticola from man was examined with respect to the production of haemagglutinins and siderophores, serum resistance and distribution of capsular types. For comparison, a group of 207 clinical isolates of K. pneumoniae was also studied. The percentages of K. planticola strains able to express mannose-sensitive haemagglutination, indicating type 1 fimbriae (83%) and mannose-resistant and Klebsiella-like agglutination, indicating type 3 fimbriae (69%), as well as to produce the siderophores enterobactin (100%) and aerobactin (2.2%) were almost identical to those of the K. pneumoniae strains. Similarly, the proportion of serum-resistant strains (30%) was comparable to that of K. pneumoniae (25%). The capsule types most often detected in K. planticola were K14 (13%), K2 (9%) and K70 (9%). The incidence of K2, which is the predominant capsular type in K. pneumoniae, was similar in both species. These findings show that K. planticola, which is being detected with increasing frequency in clinical specimens from man, has the ability to express similar putative virulence factors to K. pneumoniae, suggesting that they may have similar pathogenicity.

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Relatedness of Strains Isolated from Clinical Specimens and Such from Food-stuffs, Humans and Technology

Baumgärtner

Kueffer

Simmen

et al. 1998

LWT - Food Science and Technology

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Siderophore Production of Klebsiella Species Isolated from Different Sources

Cited by 54 publications

References 18 publications

Effect in virulence of switching conserved homologous capsular polysaccharide genes fromKlebsiella pneumoniaeserotype K1 into K20

Effect in virulence of switching conserved homologous capsular polysaccharide genes fromKlebsiella pneumoniaeserotype K1 into K20

Expression of putative virulence factors by clinical isolates of Klebsiella planticola

Relatedness of Strains Isolated from Clinical Specimens and Such from Food-stuffs, Humans and Technology

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