Isolation of a Chromosomal Region ofKlebsiella pneumoniaeAssociated with Allantoin Metabolism and Liver Infection

Abstract

Klebsiella pneumoniae liver abscess with metastatic complications is an emerging infectious disease in Taiwan. To identify genes associated with liver infection, we used a DNA microarray to compare the transcriptional profiles of three strains causing liver abscess and three strains not associated with liver infection. There were 13 clones that showed higher RNA expression levels in the three liver infection strains, and 3 of these 13 clones contained a region that was absent in MGH 78578. Sequencing of the clones revealed the replacement of 149 bp of MGH 78578 with a 21,745-bp fragment in a liver infection strain, NTUH-K2044. This 21,745-bp fragment contained 19 open reading frames, 14 of which were proven to be associated with allantoin metabolism. The K2044 (⌬allS) mutant showed a significant decrease of virulence in intragastric inoculation of BALB/c mice, and the prevalence of this chromosomal region was significantly higher in strains associated with liver abscess than in those that were not (19 or 32 versus 2 of 94; P ‫؍‬ 0.0001 [ 2 test]). Therefore, the 22-kb region may play a role in K. pneumoniae liver infection and serve as a marker for rapid identification.

Genomic analysis of diversity, population structure, virulence, and antimicrobial resistance in Klebsiella pneumoniae , an urgent threat to public health

“…These data build on previous observations made from a restricted number of isolates (47,56,57) by showing that the effect on virulence of acquiring iron-scavenging genes is not dependent on strain background or on specific combinations of siderophores and that the acquisition of iron-scavenging systems is central to the ability of K. pneumoniae to cause invasive disease in nonimmunocompromised patients. Importantly, this finding suggests that the acquisition of any one of the siderophore clusters increases the risk of severe infection in humans.…”

“…Several genetic loci have been identified as virulence factors in K. pneumoniae on the basis of murine models of infection. These include gene clusters associated with the synthesis of siderophore systems yersiniabactin, aerobactin, colibactin, salmochelin (40)(41)(42)(43), or microcin (44); the "regulators of mucoid phenotype" rmpA and rmpA2, which can up-regulate capsule production (45,46); an allantoinase gene cluster (47); the ferric uptake operon kfuABC (48); and the two-component regulator kvgAS (49). Most of these genes were detected only in KpI, except for kfuABC (found in all KpII-B, 75% of KpIII, and 20% of KpI) and allantoinase (found in 50% of KpII-B and 5% of KpI).…”

Strain-resolved community genomic analysis of gut microbial colonization in a premature infant

“…Only UC1SER contains pga operon genes involved in polysaccharide synthesis for biofilm adhesion and a regulon for allantoin utilization, which may be associated with virulence (23). It is also the only genome with yjf-sga operon genes (phosphotransferase system components sgaH, U, E), which enable some strains of gut bacteria to use vitamin C as an energy source (24).…”

TheKlebsiella pneumoniaeYfgL (BamB) lipoprotein contributes to outer membrane protein biogenesis, type-1 fimbriae expression, anti-phagocytosis, andin vivovirulence

“…Total RNA (40 mg) labeling, microarray hybridization, colorimetric detection, and densitometry were performed and analyzed as described previously. 11,46 Expression level of 23S rRNA on each membrane was used as an internal standard for normalization. Processed microarray data files have been deposited in the National Center for Biotechnology Information under GEO accession number GSE69327.…”

“…[4][5][6][7][8][9][10] Mortality rates are 10% for those with K. pneumoniae PLA alone, and 30-40% among those with metastatic meningitis. [5][6][7][8]11 Cases suffering from K. pneumoniae endophthalmitis usually became blind in the affected eyes.…”