Antimicrobial Resistance and Molecular Characteristics of Nasal Staphylococcus aureus Isolates From Newly Admitted Inpatients

Staphylococcus aureus, or methicillin-resistant S. aureus (MRSA), is a significant pathogen in both nosocomial and community infections. Community-associated MRSA (CA-MRSA) strains tend to be multi-drug resistant and to invade hospital settings. This study aimed to assess the antimicrobial resistance and molecular characteristicsof nasal S. aureus among newlyadmitted inpatients.In the present study, 66 S. aureus isolates, including 10 healthcare-associated MRSA (HA-MRSA), 8 CA-MRSA, and 48 methicillin-sensitive S. aureus (MSSA) strains, were found in the nasal cavities of 62 patients by screening 292 newlyadmitted patients. Antimicrobial resistance and molecular characteristics of these isolates, including spa-type, sequence type (ST) and SCCmec type, were investigated. All isolates were sensitive to linezolid, teicoplanin, and quinupristin/dalfopristin, but high levels of resistance to penicillin and erythromycin were detected. According to D-test and erm gene detection results, the cMLSB and iMLSB phenotypes were detected in 24 and 16 isolates, respectively. All 10 HA-MRSA strains displayed the cMLSB phenotypemediated by ermA or ermA/ermC, while the cMLSB CA-MRSA and MSSA strains carried the ermB gene. Molecular characterization revealedall 10 HA-MRSA strains were derived from the ST239-SCCmec III clone, and four out of eight CA-MRSA strains were t437-ST59-SCCmec V. The results suggest that patients play an indispensable role in transmitting epidemic CA-MRSA and HA-MRSA strains.

Antibacterial Activity of Pazufloxacin in vitro Against Bacteria Isolated from Patients with Respiratory and Urinary Tract Infection / 中华医院感染学杂志

OBJECTIVE To study the antibacterial activity of pazufloxacin in vitro against bacteria isolated from(patients) with respiratory and urinary tract infection,compared with levofloxacin,ciprofloxacin,cefuroxime and(cefotaxime) to provide guideline for clinical application.METHODS The infected bacteria were identified by the(fully) automatic VITEK system.The susceptibility test was determined by MIC method and K-B disk diffusion method respectively.RESULTS The sensitivity of most Gram-negative bacteria to pazufloxacin was basically the same to levofloxacin,cefotaxime, etc.However,the sensitivity of Pseudomonas and Acinetobacter to(pazufloxacin) was higher than to other four antibiotics;the sensitivity of Gram-positive cocci,particularly(Streptococcus) to(pazufloxacin) was obviously lower than cephalosporins and no better than other quinolones.(CONCLUSIONS) The antibacterial activity of pazufloxacin in vitro against the bacteria isolated from patients with(respiratory) and urinary tract infection is comparatively strong,especially in the urinary system.Pazufloxacin has an excellent broad-(spectrum) and strong antibacterial activity.However,the antibacterial activity against Gram-positive cocci is(expected) to promote.