Comparing Two Mycobacterium tuberculosis Genomes from Chinese Immigrants with Native Genomes Using Mauve Alignments / 결핵및호흡기질환

BACKGROUND: The number of immigrants with tuberculosis (TB) increases each year in South Korea. Determining the transmission dynamics based on whole genome sequencing (WGS) to cluster the strains has been challenging. METHODS: WGS, annotation refinement, and orthology assignment for the GenBank accession number acquisition were performed on two clinical isolates from Chinese immigrants. In addition, the genomes of the two isolates were compared with the genomes of Mycobacterium tuberculosis isolates, from two native Korean and five native Chinese individuals using a phylogenetic topology tree based on the Multiple Alignment of Conserved Genomic Sequence with Rearrangements (Mauve) package. RESULTS: The newly assigned accession numbers for two clinical isolates were CP020381.2 (a Korean-Chinese from Yanbian Province) and CP022014.1 (a Chinese from Shandong Province), respectively. Mauve alignment classified all nine TB isolates into a discriminative collinear set with matched regions. The phylogenetic analysis revealed a rooted phylogenetic tree grouping the nine strains into two lineages: (1) strains from Chinese individuals and (2) strains from Korean individuals. CONCLUSION: Phylogenetic trees based on the Mauve alignments were supposed to be useful in revealing the dynamics of TB transmission from immigrants in South Korea, which can provide valuable information for scaling up the TB screening policy for immigrants.

Vertebral Osteomyelitis Resulting from Hematogenous Spread of Vibrio Vulnificus Gastroenteritis / 대한내과학회지

Vibrio vulnificus is a halophilic gram-negative bacillus capable of causing severe to life-threatening infections in high-risk populations. Osteomyelitis caused by V. vulnificus is extremely rare, and a previously reported case had been associated with an adjacent soft-tissue infection. Herein we report the first case of vertebral osteomyelitis resulting from hematogenous spread of V. vulnificus gastroenteritis. The patient was successfully treated with a combination of cefotaxime and ciprofloxacin.

Predictors and clinical outcomes of persistent methicillin-resistant Staphylococcus aureus bacteremia: a prospective observational study

BACKGROUND/AIMS: The high mortality attributable to persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia in spite of glycopeptide treatment has heightened the need for early detection and intervention with alternative agents. The purpose of this study was to determine the clinical characteristics of and risk factors for persistent MRSA bacteremia. METHODS: All first episodes of significant MRSA bacteremia at a 710-bed academic medical center from November 2009 through August 2010 were recorded. Blood cultures were conducted at 3 days and every 2 to 3 days thereafter until clearance. Clinical characteristics and outcomes were compared between persistent MRSA bacteremia (> or = 7 days) and nonpersistent MRSA bacteremia (< or = 3 days). RESULTS: Of 79 patients with MRSA bacteremia during the study period, 31 (39.2%) had persistent MRSA bacteremia. The persistent MRSA bacteremia group had significantly higher 30-day mortality than the nonpersistent MRSA bacteremia group (58.1% vs. 16.7%, p < 0.001). Multivariate analysis indicated that metastatic infection at presentation (odds ratio [OR], 14.57; 95% confidence interval [CI], 3.52 to 60.34; p < 0.001) and delayed catheter removal in catheter-related infection (OR, 3.80; 95% CI, 1.04 to 13.88; p = 0.004) were independent predictors of persistent MRSA bacteremia. Patients with a time to blood culture positivity (TTP) of < 11.8 hours were at increased risk of persistent MRSA bacteremia (29.0% vs. 8.3%, p = 0.029). CONCLUSIONS: High mortality in patients with persistent MRSA bacteremia was noted. Early detection of metastatic infection and early removal of infected intravascular catheters should be considered to reduce the risk of persistent MRSA bacteremia. Further studies are needed to evaluate the role of TTP for predicting persistent MRSA bacteremia.