Disinfection Strategies of Carbapenem-resistant Klebsiella Pneumoniae in a Healthcare Facility

Abstract

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infections have become a major global public health challenge. Disinfectants play an important role in controlling horizontal transmission in healthcare facilities. However, the long and extensive routine use of disinfectants, and far less regulated, leading to concern about the development of disinfectant resistance. We detected the susceptibility of CRKP strains against seven kinds of disinfectants commonly used in clinic to guide and assist the infection control work in hospital. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests of seven kinds of disinfectants (0.1% benzalkonium bromide, 4% aqueous chlorhexidine, 75% alcohol, entoiodine II, 2% glutaraldehyde, 2000mg/L chlorine-containing disinfectants and 3% hydrogen peroxide) were detected by broth dilution method. Three efflux pump genes (oqxA、oqxB、and qacE△1-sul1) were detected by PCR. Results: A total of 162 strains of non-repetitive CRKP strains were isolated in SYS Memorial Hospital from 2015 to 2019. The MBCs expressed by diluted multiples of 64 CRKP strains against the seven kinds of disinfectants were 1-128, 16-32768, 2-64, 16-4096, 4-64, 2-8 and 64-2048, respectively. Aqueous chlorhexidine should be ≥ 2.5 g/L when rinsing or gargling mucous membrane and wound, 0.1% benzalkonium bromide should avoided be diluted, and chlorine-containing disinfectants should be ≥ 1000 mg/L. The mean MIC value of aqueous chlorhexidine from intensive care unit (ICU) (0.0034%) was significantly higher than that from non-ICU (0.0019%) (p < 0.05). The positive rates of three efflux pump genes oqxA, oqxB and qacE△1-sul1 were 68.8% (44/64), 15.6% (10/64) and 89.1% (57/64), respectively.Conclusion: The CRKP strains isolated showed extensive resistance to clinically used disinfectants, and the concentration of aqueous chlorhexidine and chlorine-containing disinfectants needs to be increased compared with the current standards of the healthcare industry. It reminds us to strengthen the monitoring of disinfectant resistance to super drug-resistant bacteria.