TABLE 1.
Impact of BKC exposure/treatment on antimicrobial susceptibility in bacteria
| Bacteria | Exposure/treatment | MIC before exposure | MIC post exposure | Reference |
|---|---|---|---|---|
| Stepwise training | ||||
| P. aeruginosa ATCC 9027 | Subculture in increasing concentrations of BKC | ND | MIC: >200 mg l−1 | Adair et al. (1975) |
| E. coli O157; S enterica serovar enteritidis, typhimurium, virchow | Growth in increasing concentration ‐ starting sub‐MIC level | MIC: 400 mg l−1 S. enterica, virchow and enterica, <100 mg l−1 virchow | MIC: >1000 mg l−1 for E. coli | Braoudaki and Hilton (2004) |
| S enterica serovar enteritidis, typhimurium, virchow | Growth in increasing concentration ‐ starting sub‐MIC level | MIC for S. enterica serovar enteritidis 32 mg l−1, virchow 256 mg l−1 and typhimurium 64 mg l−1 | MIC for S. enterica serovar enteritidis 256 mg l−1; virchow 256 mg l−1 and typhimurium from 64 mg l−1 | Braoudaki and Hilton (2005) |
| Cronobacter sakazakii and enterocolitica | Subculture in increasing concentrations of BKC; starting sub‐MIC level |
MIC: 15 mg l−1 for C. sakazakii MIC: 20 mg l−1 for Y. enterocolitica |
MIC: 56.95 mg l−1 for C. sakazakii MIC: 50.63 mg l−1 for Y. enterocolitica |
Capita et al. (2019) |
| S. marcescens (Breed's no. 1377) | Subculture in increasing concentrations of BKC from highest concentration showing growth | MIC: 50–100 mg l−1 | MIC: 100,000 mg l−1 in three passages over a period of 15 days, and 50,000 mg l−1 in eight passages during 45 days | Chaplin (1951) |
| S. enterica isolates from poultry (n = 125) and swine (n = 132) | Exposure to sub‐inhibitory concentrations | MIC: 32–256 mg l−1 ‐ most at 64 mg l−1 | MIC: 128–256 mg l−1 | Chuanchuen et al. (2008) |
| 189 Salmonella strains, including 48 serotypes from various origins (such as clinical sources, food, the environment and water) | Growth in (0.25 or 0.5 MIC). Biocide formulation concentration increased in a stepwise manner until the biocide concentration reached 4X MIC | MIC:15 mg l−1 | MIC: 50 mg l−1 | Condell et al. (2014) |
| E. coli and K. pneumoniae mutants with different TRI susceptibility | Growth in sub‐inhibitory concentrations (0.5 MIC), followed by agar with concentration of 2.5 to 33 × MIC | MIC: 16 mg l−1 | MIC: 32 mg l−1 | Curiao et al. (2015) |
| P. aeruginosa NCIMB 10421 clinical isolates of P. aeruginosa | Subculture in increasing concentrations of BKC (2‐fold steps) | MIC: 50 mg l−1 | MIC: 580 mg l−1 after 25 subcultures | Joynson et al. (2002) |
| P. aeruginosa | Subculture in increasing concentrations of BKC until cessation of growth | MIC: 200 mg l−1 | Growth in BKC up to 1600 mg l−1 | Kim et al. (2018) |
| 16 P. aeruginosa from hospital environment | Subculture in increasing concentrations of BKC | MIC: 15–30 mg l−1 | MIC: >500 mg l−1 for clinical isolate; Reference standard culture strain PAO1: 500 mg l−1 | Loughlin et al. (2002) |
| Three C. jejuni (NCTC11168, ATCC33560 and the K49/4 poultry isolate) and two C. coli (ATCC33559, and the 137 poultry isolate) | Subculture in increasing concentrations of BKC | MIC: 0.5–2 mg l−1 | 1–4‐fold increase in MIC; ATCC33559 strain: 4‐fold MIC increase after 15 days of exposure | Mavri and Smole Možina (2000) |
| 6 antimicrobial‐susceptible E. coli and 6 antimicrobial‐susceptible non‐typhoidal Salmonella (NTS) isolates | Subculture in increasing concentrations of BKC: 0.5 MIC exposure over 12 days | MIC: 21–30 mg l−1 for Salmonella and 12–27 mg l−1 for E. coli | Post exposure MIC increase: <2‐fold to 2‐fold in one Salmonella and one E. coli | Nhung et al. (2015) |
| L. monocytogenes SLCC2540 | Subculture in increasing concentrations of BKC; starting concentration of 0.002 mg l−1; growth in increasing concentration of 0.001 mg l−1 every 48 h |
MICL: 0.004 mg l−1 MBC: 0.011 mg l−1 |
MIC: 0.008 mg l−1 MBC: unchanged |
Noll et al. (2020) |
| 81 E. coli from biofilm collected from raw milk line, pasteurizer inlet, outlet and, milk tank of a small scale and commercial scale dairy | Subculture in increasing concentrations of BKC; starting with sub‐MIC (well immediately below MIC step of 10 mg l−1) | MIC: 50–250 mg l−1 | MIC: 70–350 mg l−1; largest increased from 50 to 130 mg l−1 | Pagedar et al. (2012) |
| E. coli veterinary isolates | Subculture in increasing concentrations of BKC starting 1/4 MIC for 24 h | MIC range from 4 to 64 mg l−1 | Only 2/24 isolates showed increased MIC >4‐fold (6‐ and 9‐folds increased). All the others <2‐fold | Puangseree et al. (2021) |
| 9 avian and porcine E. coli strains and E. coli ATCC25922 | Subculture in increasing concentrations of BKC daily for 7 days | MIC: 16–32 mg l−1 | 2‐fold increase in MIC | Soumet et al. (2012) |
| P. aeruginosa ATCC 10145 and deletion mutants | Subculture in increasing concentrations of BKC | MIC: 18.2 mg l−1 | MIC: 51.2 mg l−1 | Tabata et al. (2003) |
| Two resistant (4 mg l−1) and four sensitive (1 mg l−1) L. monocytogenes strain | Subculture in increasing concentrations of BKC (1–10 mg l−1) | MIC: 1–4 mg l−1 | MIC increased to 5–6 mg l−1 for sensitive strains and to 8 mg l−1 for resistant ones | To et al. (2002) |
| GROWTH IN BKC (sub‐MIC level) | ||||
| E. faecium Aus0004 and S. aureus HG003 | Growth in sub‐inhibitory concentration; 1/2 MIC | E. faecium Aus0004 MIC: 4 mg l−1; S. aureus HG003 MIC: 2 mg l−1 | ND | Dejoies et al. (2021) |
| 49 clonally unrelated isolates of A. baumannii | Growth in BKC 0.25 × MIC (10 mg l−1) for 30 days ‐ one clinical isolate only | MIC: 1–15.6 mg l−1 ‐ majority at 3.9 and 7.8 mg l−1 | 2–16‐fold increase | Fernández‐Cuenca et al. (2015) |
| 205 L. monocytogenes food isolates | Exposure to 0.6 mg l−1 BKC in broth for 24 h at 37°C. | MIC range from 0.63 to 5 mg l−1 | MIC increased to 4 mg l−1 | Guérin et al. (2021) |
| 283 Acinetobacter spp. strains from 97 hospitals | Repeated exposure to 1/2 MIC for 72 h | MIC: mostly 5–10 mg l−1 | MIC: 10–50 mg l−1 | Kawamura‐Sato et al. (2018) |
| S. enterica serovar Typhimurium strains (SL1344 and 14028S) | Exposure to during use concentration ‐ 0.015 mg l−1 or 0.004 mg l−1 | Salmonella SL1344 MIC: 0.03 mg l−1 14028S MIC: 0.004 mg l−1; MBC 0.003 and 0.008 mg l−1 | Salmonella SL1344 MIC: 3 mg l−1 14028S MIC: 0.2 mg l−1; MBC 8 and 20 mg l−1 | Knapp et al. (2015) |
| Burkholderia lata strain 283 | Exposure to 50 mg l−1 BKC; 5 min or to mid‐log phase at 20°C | MIC: 0.5 mg l−1 | No change in MIC | Knapp et al. (2013) |
| A. baumannii standard culture collection strain and mutants | Exposure to 32 mg l−1 in agar for 24 h then growth in 16 mg l−1 | MIC: 16 mg l−1 | MIC: 32 mg l−1 | Knauf et al. (2017) |
| S. aureus laboratory constructs | Pre‐exposure test in 5 mg l−1 BKC for 60 min | MIC: 4 mg l−1 in parent strain; 1 mg l−1 in ΔnorA; 8 mg l−1 in norA construct; 16 mg l−1 in pCN38‐qacA qacR construct | ND (increased expression of norA and qacA) | LaBreck et al. (2020) |
| E. coli ATCC 11775 and E. coli DSM 682 | Sub‐MIC growth 5 mg l−1 overnight or 20 mg l−1 during exponential phase | MIC: 25 mg l−1 for 1175 and DSM682 | Exposure to 5 mg l−1: 1175; MIC 25 mg l−1; DSM682: MIC: 35 mg l−1; exposure to 20 mg l−1 1175; MIC 35 mg l−1; DSM682 MIC: 45 mg l−1 | Langsrud et al. (2004) |
| E. coli CFT073 | Exposure to 2 mg l−1 until sufficient increase in OD | MIC: 8 mg l−1 | ND | Ligowska‐Marzeta et al. (2019) |
| 24 coagulase‐negative Staphylococci isolates (12 isolates with decreased susceptibility to CHX and 12 isolates with decreased susceptibility to BKC) | Repeated exposures (3 passages) to 1/2 MIC (range 1–4 mg l‐1) BKC for 24 h at 37C | MIC range from 2 to 8 mg l−1 and MBC from 2 to 16 mg l−1 | 2‐fold increase in BKC MIC in 58% of CHX isolates and 83% of BKC isolates |
Marzoli et al. (2021) |
| L monocytogenes; food and veterinary isolates | Repeated exposure to 10 mg l−1 BKC | MIC: 10 mg l−1 | MIC: 30 mg l−1 | Rakic‐Martinez et al. (2011) |
| Salmonella Enteritidis NCTC13349 and one food isolate | Exposure to 1/2 MBEC (400 mg l−1 BKC) for 6 days every other day | MBEC: NCTC13349 800 mg l−1 MBEC isolate: 1600 mg l−1 | ND | Romeu et al. (2020) |
| S. maltophilia D457, and isogenic mutant D457R, overexpressing SmeDEF | Growth on agar containing 128 mg l−1 BKC | MIC: 128 mg l−1 | MIC: 256 mg l−1 | Sánchez et al. (2015) |
| Three aerobic communities from water effluent. BKCs unexposed (DP, fed a mixture of dextrin/peptone), BKCs exposed (DPB, fed a mixture of dextrin/peptone and BKCs) and BKCs enriched (B, fed only BKCs). BKC concentration 50 mg l−1 | Exposure of community to 50 mg l−1 for 4 years | ND | DPB MIC: 250 mg l−1, B MIC: 460 mg l−1 | Tandukar et al. (2013) |
| P. aeruginosa ATCC27853 | Repeated (10 cycles) exposure to BKC | MIC: 80 mg l−1 | MIC: Max 150 mg l−1 | Voumard et al. (2020) |
Note: term resistant/resistance as reported in the paper but does not correspond to the definition of resistance used in the main document.
Abbreviations: BKC, Benzalkonium chloride, ND, not determined; TRI, triclosan.