Disinfection Strategies for Carbapenem-Resistant Klebsiella pneumoniae in a Healthcare Facility

Abstract

Disinfectant resistance is evolving into a serious problem due to the long-term and extensive use of disinfectants, which brings great challenges to hospital infection control. As a notorious multidrug-resistant bacterium, carbapenem-resistant Klebsiella pneumoniae (CRKP) is one of the most common and difficult pathogens of nosocomial infection. 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, 2000 mg/L chlorine-containing disinfectants, and 3% hydrogen peroxide) were detected by the broth dilution method. Three efflux pump genes (oqxA, oqxB, and qacE∆1-sul1) were detected by PCR. The mean MIC value of aqueous chlorhexidine from the intensive care unit (ICU) (0.0034%) was significantly higher than that from non-ICUs (0.0019%) (p < 0.05). The positive rates of three efflux pump genes oqxA, oqxB and qacE∆1-sul1 were 60.9% (39/64), 17.2% (11/64) and 71.9% (46/64) in the detected CRKP isolates, respectively. This study discovered that CRKP strains demonstrated extensive resistance to clinical disinfectants and suggest that it is necessary to perform corresponding increases in the concentration of aqueous chlorhexidine and chlorine-containing disinfectants on the basis of current standards in the healthcare industry.

Resveratrol Reverts Tolerance and Restores Susceptibility to Chlorhexidine and Benzalkonium in Gram-Negative Bacteria, Gram-Positive Bacteria and Yeasts

“…In accordance with the previous data [ 19 ], the reduction in MIC and MBC of CHX and BZK due to CCCP was only four- and two-fold, respectively, in A. baumannii ATCC 19606 carrying the deletion of the adeB EP gene, consistent with the role of AdeB in CHX and BZK extrusion ( Table 1 ). The data shown herein indicate that tolerance to CHX and BZK is mediated by activation of the EPs and are in agreement with previous publications showing that CHX and BZK tolerance in K. pneumoniae and A. baumannii clinical isolates is mediated by RND superfamily EP activation [ 13 , 16 ], and that CHX tolerance in P. aeruginosa clinical isolates is mediated by an increased expression of the mexA, mexC, mexE and mexX EP genes, and a decreased expression of the oprD gene [ 15 ].…”

“…The median MIC and MBC values of BZK were significantly higher in the P. aeruginosa strains compared with those of susceptible strains ( p < 0.05 and p < 0.001, respectively). The above overall data are in agreement with previous studies showing that microbial pathogens responsible for health care-associated infection, in particular Gram-negative bacteria such as K. pneumoniae and P. aeruginosa , are highly tolerant to CHX and BZK biocides [ 11 , 12 , 13 , 14 , 15 ].…”

“…To evaluate whether the tolerance to CHX and BZK was mediated by the activation of EP, as demonstrated in the Gram-negative and Gram-positive bacteria [ 13 , 14 , 15 , 16 , 17 , 18 , 19 ], we analyzed the effect of the EP inhibitor CCCP on CHX and BZK susceptibility. As shown in Table 1 , CCCP reduced dose-dependently the CHX MIC and MBC or MFC in A. baumannii , Burkholderia spp., K. pneumoniae , K. aerogenes , Enterobacter spp., Enterococcus spp., S. maltophilia , S. enterica and C. parapsilosis with a decrease between 4- and 64-fold.…”

“…BZK has been widely used as a disinfectant in hospitals, or as an antiseptic in antimicrobial soaps [ 10 ]. Tolerance to CHX and BZK is emerging in major nosocomial pathogens [ 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ].…”

“…A reduced susceptibility to biocides in A. baumannii , K. pneumoniae and other pathogens has been correlated with the activation of different efflux pump (EP) systems [ 13 , 16 , 17 , 18 , 19 , 20 ]. In particular, the inhibition of the AdeB RND superfamily and AceI PACE superfamily EP systems has been demonstrated to restore susceptibility to CHX and BZK in A. baumannii [ 19 , 20 ].…”