Nosocomial infections caused by antibiotic-resistant Klebsiella pneumoniae are emerging as a major health problem worldwide, while community-acquired K. pneumoniae infections present with a range of diverse clinical pictures in different geographic areas. In particular, an invasive form of K. pneumoniae that causes liver abscesses was first observed in Asia and then was found worldwide. We are interested in how differences in gene content of the same species result in different diseases. Thus, we sequenced the whole genome of K. pneumoniae NTUH-K2044, which was isolated from a patient with liver abscess and meningitis, and analyzed differences compared to strain MGH 78578, which was isolated from a patient with pneumonia. Six major types of differences were found in gene clusters that included an integrative and conjugative element, clusters involved in citrate fermentation, lipopolysaccharide synthesis, and capsular polysaccharide synthesis, phage-related insertions, and a cluster containing fimbria-related genes. We also conducted comparative genomic hybridization with 15 K. pneumoniae isolates obtained from community-acquired or nosocomial infections using tiling probes for the NTUH-K2044 genome. Hierarchical clustering revealed three major groups of genomic insertion-deletion patterns that correlate with the strains' clinical features, antimicrobial susceptibilities, and virulence phenotypes with mice. Here we report the whole-genome sequence of K. pneumoniae NTUH-K2044 and describe evidence showing significant genomic diversity and sequence acquisition among K. pneumoniae pathogenic strains. Our findings support the hypothesis that these factors are responsible for the changes that have occurred in the disease profile over time.
Mosquito-borne diseases, including dengue, malaria, and lymphatic filariasis, exact a devastating toll on global health and economics, killing or debilitating millions every year (54). Mosquito innate immune responses are at the forefront of concerted research efforts aimed at defining potential target genes that could be manipulated to engineer pathogen resistance in vector populations. We aimed to describe the pivotal role that circulating blood cells (
In Taiwan, during the period March 2000 to June 2009, 1,495,132 neonates were screened for phenylketonuria (PKU) and homocystinuria (HCU), and 1,321,123 neonates were screened for maple syrup urine disease (MSUD), methylmalonic academia (MMA), medium-chain acyl-coenzyme A (CoA) dehydrogenase (MCAD) deficiency, isovaleric academia (IVA), and glutaric aciduria type 1 (GA-1) using tandem mass spectrometry (MS/MS). In a pilot study, 592,717 neonates were screened for citrullinemia, 3-methylcrotonyl-CoA carboxylase deficiency (3-MCC) and other fatty acid oxidation defects in the MS/MS newborn screening. A total of 170 newborns and four mothers were confirmed to have inborn errors of metabolism. The overall incidence was approximately 1/5,882 (1/6,219 without mothers). The most common inborn errors were defects of phenylalanine metabolism [five classic PKU, 20 mild PKU, 40 mild hyperphenylalaninemia (HPA), and 13 6-pyruvoyl-tetrahydropterin synthase (PTPS) deficiency]. MSUD was the second most common amino acidopathy and, significantly, most MSUD patients (10/13) belonged to the Austronesian aboriginal tribes of southern Taiwan. The most frequently detected among organic acid disorders was 3-MCC deficiency (14 newborns and four mothers). GA-1 and MMA were the second most common organic acid disorders (13 and 13 newborns, respectively). In fatty acid disorders, five carnitine transport defect (CTD), five short-chain acyl-CoA dehydrogenase deficiency (SCAD), and two medium-chain acyl-CoA dehydrogenase (MCAD) deficiency were confirmed. This is the largest case of MS/MS newborn screening in an East-Asian population to date. We hereby report the incidences and outcomes of metabolic inborn error diseases found in our nationwide MS/MS newborn screening program.
We report the genome organization and analysis of the first completely sequenced T4-like phage, AR1, of Escherichia coli O157:H7. Unlike most of the other sequenced phages of O157:H7, which belong to the temperate Podoviridae and Siphoviridae families, AR1 is a T4-like phage known to efficiently infect this pathogenic bacterial strain. The 167,435-bp AR1 genome is currently the largest among all the sequenced E. coli O157:H7 phages. It carries a total of 281 potential open reading frames (ORFs) and 10 putative tRNA genes. Of these, 126 predicted proteins could be classified into six viral orthologous group categories, with at least 18 proteins of the structural protein category having been detected by tandem mass spectrometry. Comparative genomic analysis of AR1 and four other completely sequenced T4-like genomes (RB32, RB69, T4, and JS98) indicated that they share a well-organized and highly conserved core genome, particularly in the regions encoding DNA replication and virion structural proteins. The major diverse features between these phages include the modules of distal tail fibers and the types and numbers of internal proteins, tRNA genes, and mobile elements. Codon usage analysis suggested that the presence of AR1-encoded tRNAs may be relevant to the codon usage of structural proteins. Furthermore, protein sequence analysis of AR1 gp37, a potential receptor binding protein, indicated that eight residues in the C terminus are unique to O157:H7 T4-like phages AR1 and PP01. These residues are known to be located in the T4 receptor recognition domain, and they may contribute to specificity for adsorption to the O157:H7 strain.
Streptococcus gallolyticus infections in humans are often associated with bacteremia, infective endocarditis and colon cancers. The disease manifestations are different depending on the subspecies of S. gallolyticus causing the infection. Here, we present the complete genomes of S. gallolyticus ATCC 43143 (biotype I) and S. pasteurianus ATCC 43144 (biotype II.2). The genomic differences between the two biotypes were characterized with comparative genomic analyses. The chromosome of ATCC 43143 and ATCC 43144 are 2,36 and 2,10 Mb in length and encode 2246 and 1869 CDS respectively. The organization and genomic contents of both genomes were most similar to the recently published S. gallolyticus UCN34, where 2073 (92%) and 1607 (86%) of the ATCC 43143 and ATCC 43144 CDS were conserved in UCN34 respectively. There are around 600 CDS conserved in all Streptococcus genomes, indicating the Streptococcus genus has a small core-genome (constitute around 30% of total CDS) and substantial evolutionary plasticity. We identified eight and five regions of genome plasticity in ATCC 43143 and ATCC 43144 respectively. Within these regions, several proteins were recognized to contribute to the fitness and virulence of each of the two subspecies. We have also predicted putative cell-surface associated proteins that could play a role in adherence to host tissues, leading to persistent infections causing sub-acute and chronic diseases in humans. This study showed evidence that the S. gallolyticus still possesses genes making it suitable in a rumen environment, whereas the ability for S. pasteurianus to live in rumen is reduced. The genome heterogeneity and genetic diversity among the two biotypes, especially membrane and lipoproteins, most likely contribute to the differences in the pathogenesis of the two S. gallolyticus biotypes and the type of disease an infected patient eventually develops.
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