An investigation and evaluation on species and characteristics of pathogenic microorganisms in Chinese local hospital settings

•We isolated 26 distinct bacterial strains from a Chinese hospital.•There genera were determined, and a MIC evaluation was performed.•Eight strains were resistant to a chlorine-containing disinfectant.•Twelve strains were resistant to Povidone–iodine.•Strain 14 killed all silkworms within 12 h with an LD50 of 4 × 104 CFU/larva.

There are currently great concerns about the level of bacterial contamination in hospitals, as well as resistance to antimicrobial agents. The species and characteristics of microbes in Chinese hospitals are closely related to healthcare safety and the prevention and control of infections. However, data on the exposure of patients to microbes in Chinese hospitals are limited. The present study investigated the genera of microorganisms in Chinese hospitals. We evaluated their characteristics, such as antibiotic susceptibility, tolerance to disinfectants, and toxicity, using silkworms (Bombyx mori) as an animal model. Twenty-six distinct bacterial strains were isolated, and their genera were determined by sequencing their 16S rDNA regions. Twenty-five strains were resistant to one or more antibiotics, and six strains were resistant to multiple antibiotics. The results of minimal inhibitory concentration testing showed that eight strains were resistant to a chlorine-containing disinfectant, and 12 strains were resistant to Povidone–iodine. Following the injection of bacterial cultures into the silkworm hemolymph, 15 strains killed all of the silkworms within 5 d. Additionally, bacterial strain 14 killed all of silkworms within 12 h with a median lethal dose of 4 × 104 colony-forming units/larva. This study provides useful information for healthcare safety in Chinese hospitals.