There is still limited knowledge about the prevalence and risk factors of nasal carriage for Staphylococcus aureus among healthy carriers in China. We investigated 2448 healthy adults (≥18 years of age) from Beijing (n = 1530) and Harbin (n = 918) by nasal screening. Participants were checked for carriage of S. aureus, and health-related and demographic information between 2009 and 2011 was gathered. A total of 403 S. aureus (403/2448, 16.5%) were recovered, 8 of which were methicillin resistant (8/2448, 0.33%). Three factors were independently associated with S. aureus nasal carriage: Harbin as city of residence (odds ratio (OR) = 2.0, 95% confidence interval (CI) = 1.41 to 2.85), age ≤24 years (OR = 1.77, 95% CI = 1.30-2.44) and non-Han ethnicity (OR = 1.58, 95% CI = 1.05 to 2.38). On the basis of population genetic analysis using multiple locus variable number of tandem repeats analysis (MLVA) and spa typing, MLVA complex (MC) 398 and MC5a were the most prevalent clonal lineages in this collection. In multivariate models, residing in Harbin (OR = 1.77, 95% CI = 1.07-2.92) and having household members in the healthcare profession (OR = 3.69, 95% CI = 1.14-11.92) were factors associated with carriage of clonal lineage MC398. On the other hand, female sex (OR = 3.15, 95% CI = 1.35-7.33) and a history of chronic liver disease (OR = 16.93, 95% CI = 2.91-98.59) were associated with the clonal lineage MC5a. The three most common spa types were t571 (10.9%), t189 (9.9%) and t701 (7.2%). These findings provide insight into the determinants of nasal carriage and ecology for some of the most successful strains of S. aureus among healthy people in Northern China.

No abstract

Whole-genome sequencing (WGS) was used to investigate the genetic features of the recently identified lsa(E) gene in porcine S. aureus ST9 isolates. Three quinupristin/dalfopristin-resistant isolates harboring the lsa(E) gene (two MRSA and one MSSA) were sequenced. Phylogenetic analysis of 184S. aureus genomes showed that ST9 porcine isolates belong to a distinct sequence cluster. Further analysis showed that all isolates were deficient in the recently described type IV restriction-modification system and SCCmec type XII was identified in the two MRSA isolates, which included a rare class C2 mec gene complex. A 24kb ΨSCC fragment was found in the MRSA and MSSA isolates sharing 99% nucleotide sequence homology with the ΨSCCJCSC6690 (O-2) element of a ST9 MRSA isolate from Thailand (accession number AB705453). Comparison of these ST9 isolates with 181 publically available S. aureus genomes identified 24 genes present in all (100%) ST9 isolates, that were absent from the most closely related human isolate. Our analysis suggests that the sequenced quinupristin/dalfopristin-resistant ST9 lineage represent a reservoir of mobile genetic elements associated with resistance and virulence features.

No abstract

No abstract

No abstract

Vibrio parahaemolyticus is a common pathogenic marine bacterium that causes gastrointestinal infections and other health complications, which could be life-threatening to immunocompromised patients. For the past two decades, the pathogenicity of environmental V. parahaemolyticus has increased greatly, and the genomic change behind this phenomenon still needs an in-depth exploration. To investigate the difference in pathogenicity at the genomic level, three strains with different hemolysin expression and biofilm formation capacity were screened out of 69 environmental V. parahaemolyticus strains. Subsequently, 16S rDNA analysis, de novo sequencing, pathogenicity test, and antibiotic resistance assays were performed. Comparative genome-scale interpretation showed that various functional region differences in pathogenicity of the selected V. parahaemolyticus strains were due to dissimilarities in the distribution of key genetic elements and in the secretory system compositions. Furthermore, the genomic analysis-based hypothesis of distinct pathogenic effects was verified by the survival rate of mouse models infected with different V. parahaemolyticus strains. Antibiotic resistance results also presented the multi-directional evolutionary potential in environmental V. parahaemolyticus, in agreement with the phylogenetic analysis results. Our study provides a theoretical basis for better understanding of the increasing pathogenicity of environmental V. parahaemolyticus at the genome level. Further, it has a key referential value for the exploration of pathogenicity and prevention of environmental V. parahaemolyticus in the future.

Background:This study aimed to compare olanzapine and haloperidol efficacies in the treatment of acute psychiatric symptoms due to amphetamine-type stimulants (ATSs).Methods:The Zelen II design method was used; 124 patients with acute mental disorders due to amphetamine were randomly divided into olanzapine group (n = 63) and haloperidol group (n = 61). Then, a 4-week open-label medical therapy was performed. Clinical Global Impression Scale Item 2 was employed to evaluate the onset time; meanwhile, Brief Psychiatric Rating Scale (BPRS) was used at baseline and at posttreatment weeks 1, 2, and 4. Moreover, adverse reactions during the treatment were recorded.Results:Onset time in the olanzapine group was significantly earlier than in the haloperidol group; BPRS scores in the olanzapine group were significantly lower than haloperidol group values at 1 and 2 weeks of treatment. The overall effective rates had no statistically significant difference.Conclusion:Short-term olanzapine and haloperidol treatments had equivalent efficacies in the treatment of acute symptoms of mental disorders due to ATSs; however, olanzapine administration resulted in relatively earlier disease onset, with less adverse reactions.