Distribution of virulence-associated genes and antimicrobial susceptibility in clinical isolates.

is undoubtedly one of the most clinically significant pathogens. The multidrug resistance and virulence potential of are responsible for hospital-acquired nosocomial infections. Unlike numerous investigations on the drug-resistant epidemiology of , virulence molecular epidemiology is less studied. Here, we collected 88 clinical isolates, tested their antimicrobial susceptibility to 10 commonly used antibiotics and analyzed the distribution of 9 selected virulence-associated genes, aims to investigate the primary characteristics of the virulence-associated genes that exist in clinically multidrug resistant (MDR) and non-MDR isolates of . The MIC results showed the resistance rates of ciprofloxacin (68.2%, 60/88), gentamicin (67.0%, 59/88), amikacin (58.0%, 51/88), tobramycin (58.0%, 51/88), doxycycline (67.0%, 59/88), meropenem (54.5%, 48/88) and imipenem (65.9%, 58/88) were all above 50%, except for levofloxacin (34.1%, 30/88), minocycline (1.1%, 1/88) and polymyxin B (0%, 0/88). The Pulsed field gel electrophoresis (PFGE) analysis revealed that the resistance rate of MDR isolates in the Epidemic group was predominant (79.5%, 44/58), but in the Sporadic group was only 6.7% (2/30). Further investigation on the distribution of virulence genes showed the virulence genes (95.5%), (92.0%), (92.0%), (88.6%), (87.5%), (62.5%) (59.1%) and (53.4%) were accounted for high proportion, except for (0%). Overall, our results revealed that MDR isolates predominated in the Epidemic isolates, and contained a very high proportion of virulence genes, which may lead to high risk, high pathogenicity and high treatment challenge.