Determining the susceptibility of carbapenem resistant Klebsiella pneumoniae and Escherichia coli strains against common disinfectants at a tertiary hospital in China

Abstract

Background: Carbapenem-resistant Enterobacteriaceae (CRE) infections have become a global health threat. Controlling CRE transmission in hospitals is increasingly dependent on the use of disinfectants to restrict the risk of infection. Here, the susceptibility of patient-derived carbapenem resistant Klebsiella pneumoniae (CRKP) and Escherichia coli (CREC) strains against three common disinfectants and the determinants of resistance to disinfectants were investigated. Methods: The minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) of three common chemical disinfectants: chlorhexidine, trichloroisocyanuric (TCCA) acid and Povidone iodine (PVP-I) against 50 CRE strains were measured. The drug-resistance genes-qacEΔ1, qacA/B and cepA-were determined using polymerase chain reaction. Results: A total of 36 CRKP and 14 CREC strains were collected in our hospital from 2016 to 2018. The MIC ranges of 36 CRKP strains against chlorhexidine, TCCA and PVP-I were 8~512 mg/L, 64~128 mg/L and 8~128 mg/L, respectively. For 14 CREC strains, the MIC ranges against chlorhexidine, TCCA and PVP-I were 4~128 mg/L, 64~128 mg/L and 4~128 mg/L, respectively. Moreover, against chlorhexidine and PVP-I, the MIC 90 of 36 CRKP strains was higher than that of 50 CSKP strains. The qacE△1 gene was detected in 15 isolates among 36 CRKP strains (41.7%), and 8 isolates among 14 CREC strains (57.1%); while the qacA/B gene was not detected. Specifically, the cepA gene was much more prevalent than the qacEΔ1; it reached over 80% among CRKP strains. Compared to the CSKP strains, the presence of the qacEΔ1 and cepA genes was significantly higher among the CRKP strains (p < 0.05). Conclusion: CRE strains collected from patients in our hospital exhibit various degree of resistance to the commonly used chemical disinfectants. It is of great help to keep monitoring the tendency of the reduced susceptibility of the pan-resistant strains against disinfectants, in order to effectively control and prevent the spread of the super resistant bacteria.

Tolerance to disinfectants (chlorhexidine and isopropanol) and its association with antibiotic resistance in clinically-relatedKlebsiella pneumoniaeisolates

“…Moreover, it has been described that the qacEΔ1 gene is located in an integron class 1 structure upstream of the sul1 gene that confers sulfonamide resistance and is often flanked by the dihydrofolate reductase gene dfrA1 related to trimethoprim resistance [18]. These gene cassette structures are related to the CHG tolerance, and TMP/SMX resistance found in our study (p < 0.05), with both genes likely being disseminated together in the same mobile structure within the same plasmid.…”

“…Our results correlate with a previous study performed in China that suggested decreased sensitivity against commonly used disinfectants, including CHG, in carbapenem-resistant strains. Furthermore, Chen et al [18] reported the presence of carbapenem-resistant K. pneumoniae with decreased susceptibility to CHG (MIC 32 µg/ml, which is the limit of the ecological cutoff of 64 µg/ml). It is important to mention that only six phylogenetically related strains were included in the study and all carbapenemases that were found were bla NDM [19].…”

“…These qac genes encode for Qac efflux proteins belonging to the MFS and SMR efflux pump families. While the role of these proteins is well known in Gram-positive strains, previous findings have led to controversy about the role and frequency of the cepA, qacA, and qacE genes in Gram-negative strains, with more or less importance being given depending on the study [18,21,24,25].…”

Has resistance to chlorhexidine increased among clinically-relevant bacteria? A systematic review of time course and subpopulation data

“…Analyzing the log 2 (MIC) values reported for 45 antibiotic resistant strains, including carbapenem-resistant [ 18 ], extended spectrum beta-lactamase expressing cells [ 8 ], or strains expressing the New Delhi metallo-beta-lactamase [ 10 ], showed a mean (± Std Dev) of 4.14 (± 1.54) log 2 (MIC) units for the pooled antibiotic-resistant strains. This is different than the mean of all other strains (n = 2134) with mean = 1.81 (± 1.69) log 2 (MIC) units.…”

Bacterial Sensitivity to Chlorhexidine and Povidone-Iodine Antiseptics Over Time: A Systematic Review and Meta-Analysis of Human-Derived Data

“…Articles were published between 1976 and 2021, although the majority (95%) were published this century. The antiseptics used included five different CHX salts (digluconate (33,35,37,40,47,50,(55)(56)(57)(58)61,63,67,69,74,75,81,83,88,90,94,97,99,101,106,107,111,113), gluconate (34,36,42,42,53,91,102,103,108,108,109,112), dichlorohydrate (85)(86)(87), diacetate (71,99) and dihydrochloride( 96)) and povidone-iodine (37,46,49,…”