ABSTRACT
Objective@#To analyses the antimicrobial resistance and molecular characterization of 21 MRSA isolates cultured from retail foods from different provinces in China, and evaluate the molecular typing methods.@*Methods@#Twenty-one MRSA isolates were obtained from national foodborne pathogen surveillance network in 2012 (Chinese salad, n=3; milk, n=1; cake, n=2; rice, n=1; cold noodle, n=1; spiced beef, n=1; dumpling, n=1; packed meal, n=1; salad, n=1; raw pork, n=9). The antimicrobial resistance of 21 strains to 12 antimicrobial agents was tested by broth dilution method. Polymerase chain reaction (PCR) and DNA sequencing were performed to obtain the genetic types of MLST (ST) and spa typing. The clonal complex (CC) was assigned by eBURST soft and the MLVA type (MT) and MLVA complex (MC) were identified via the database of the MLVA website (http://www.mlva.net). SmaI pulsed-field gel electrophoresis (SmaⅠ-PFGE) was also carried out to obtain the PFGE patterns of 21 strains. The genetic diversity and discriminatory power of typing were calculated by the Simpson's index of diversity (diversity index, DI) to find out the best genotyping method for MRSA.@*Results@#All MRSA isolates showed multi-drug resistance(MDR), and were resistant to oxacillin, benzylpenicillin, clindamycin and erythromycin, and 71.4% (15/21), 47.6% (10/21), 42.9% (9/21) and 28.6% (6/21) of the MRSA isolates were resistant to tetracycline, ciprofloxacin, trimethoprim/sulfamethoxazole and gentamicin, respectively. Moreover, one strain was found to be resistant to all three antimicrobials of levofloxacin, moxifloxacin and rifampicin. Great diversity was found in these food-associated MRSA (6 STs, 7 spa types, and 9 MTs). PFGE patterns were more diverse than those of other three molecular typing methods (19 pulse types). The index of diversity (DI) of PFGE, MLVA, spa typing and MLST was 0.99, 0.80, 0.73, and 0.61, respectively. Among the MRSA isolates, CC9-ST9-t899-MT929-MC2236 (PFGE Cluster Ⅴ) was the most prevalent clone, which were all cultured from raw pork (9 isolates). Besides, two MRSA were identified as CC59-ST338-t437-MT621-MC621 (PFGE Cluster Ⅳ). Different clone had their own resistance spectrum profiles.@*Conclusion@#The food-borne MRSA isolates were all MDR in this study. Different clones had their own resistance spectrum profiles. MLVA represented a promising tool for molecular epidemiology tracing of MRSA in foodborne disease events.
ABSTRACT
Objective To explore the big five personality characteristics of the first-episode, treatment-naive major depressive disorder. Method Neuroticism Extraversion Openness Five-Factor Inventory (NEO-FFI) was used to assess the personality. A comparison was conducted between 112 first-episode, treatment-naive major depressive disorder (MDD) patients and 99 sex-, age- and education level-matched healthy controls (HC). The Hamilton depression scale (HAMD) was used to evaluate patients’symptom. Result Compared with HC, the neuroticism score in MDD group was significantly higher, while the extraversion, openness, agreeableness and conscientiousness were significantly lower. Lo?gistic regression analysis showed that MDD was significantly associated with higher neuroticism (OR=1.106, 95%CI:1.029~1.189, P=0.006) and lower extraversion (OR=0.809, 95%CI: 0.733~0.893, P<0.001) and agreeableness (OR=0.870, 95%CI:0.794~0.953, P=0.003). Linear regression showed that the HAMD score was significantly associated with higher neuroticism (B=0.121, P=0.003). The onset age of MDD was significantly associated with conscientiousness (B=0.015, P=0.001). Conclusion This study confirms that the personality of MDD is different from HC. Higher neuroticism is an important personality facets in treatment-naive patients with first-episode MDD. The low conscientiousness might associate with early age of depression onset.