Table 1 Comparison of the findings of other studies on the survival of bacteria on various inanimate surfaces under different environmental conditions
From: Bacterial survival on inanimate surfaces: a field study
Pathogen | Methods and results | Refs. | ||||
|---|---|---|---|---|---|---|
Surface | Inoculum | Environment | Sampling | Survival | ||
PAE, EFA | Polypropylene, polystyrene, glass and other specific surfaces | n.m | 18–21 °C; 40–70% RH | wet and dry swabs, vortexed in NB or BPS or area was cut out and directly vortexed in BPS | PAE: < 2 days EFA: > 11 weeks | [43] |
SAU, PAE, KPN, SMA, ECO (clinical isolates) | Aluminum foil (dry), aqua dest., tap water | Aluminum: log 6.4–7.3/cm2 Aqua dest.: log 2.8–3.7/mL tap water: log 3.3–3.9/mL | Aluminum: RT; 40–50% RH Aqua dest: RT Tap Water: RT; 30 °C, 40 °C | Aluminum: Foil was put in NB; serial dilution; plateled on agar plates Water samples: directly plated on agar plates | Aluminum: SAU, KPN, SMA, ECO: ≥ 25 days PAE: < 2 days Aqua dest: SAU: < 5 days PAE: < 4 days SMA: ≥ 25 days ECO: < 24 days Tap water: SAU: < 7 days (RT), < 2d (30 °C, 40 °C) PAE: ≥ 12 days ECO: ≥ 12 days (RT), < 5 days (30 °C), < 1d (40 °C) SMA: ≥ 12 days (RT), < 7 days (30 °C), < 2 days (40 °C) | [44] |
SAU, PAE, ECO | Dust | 106 CFU in NB diluted with aqua dest | 0%, 32%, 42%, 58%, 99% | Culture of samples on China blue lactose agar | SAU: 0.6–5.4 m (> 0% RH); > 7.6 m (0% RH) PAE: 5.7–11.9 m (< 99% RH); > 16.9 m (99% RH) ECO: 4.5–11.8 m | [45] |
ABA (clinical isolates and type strains) | Glas coverslips | 2 × 107 CFU in 20 µL of bovine serum albumin or distilled water | 22 °C; 10%, 31%, 93% | Coverslips were vortexted in sterile distilled water | 30 days (clinical strain) 2 days (ATCC strain) 60 days (suspended in bovine serum albumin) 11 days (suspended in distilled water) 11 days (31% RH) 4 days (10% RH) | [46] |
SAU, PAE, ECO (type strains) | Polymer w/o silver-impregnated | ≥ 106–107 CFU dry/liquid inoculum | 37 °C; humid chamber | Neutralizing silver by TSB and horse serum, dilution on agar, filtration on cellulose nitrate membrane | SAU: ≤ 7 days (dry inoculum); > 7 days (liquid inoculum) PAE: ≥ 7 days (better survival in liquid inoculum) ECO: ≤ 7 days (data for dry inoculum only available) | [47] |
PAE, KPN, SMA, ECO (clinical and environmental strains) | Different textiles such as cotton, polyester and polyethylene | 102 CFU 104–105 CFU | 22.5–26.2 °C 20–49% RH | Incubation in thioglycolate bouillon | PAE: < 1 h-–7 h (inoculum 102 CFU) 2 h–7 days (inoculum 104–105 CFU) KPN: 1–3 days (inoculum 102 CFU) 4–32 days (inoculum 104–105 CFU) SMA: < 1–2 h (inoculum 102 CFU) 12 h–10 days (inoculum 104–105 CFU) ECO: < 1–8 h (inoculum 102 CFU) 13 h–36 days (inoculum 104–105 CFU) | [6] |
SAU (MRSA and MSSA), EFA (VRE and VSE) | Different textiles (cotton, polyester, polyethylene, other) | 4.1 × 105 CFU | 22.9–24.5 °C; 30–49% RH | Incubation in thioglycolate bouillon | SAU: 1– > 90 days EFA: 22–> 90 days | [7] |
EFA (VRE; clinical isolates) | Various environmental surfaces | 102 / 104 CFU | n.m | Rodac contact plates | Countertops (104 CFU): 7 days Bedrails (104 CFU): 1 days Telephone (102 CFU): 1 h Stethoscope (102 CFU): 0.5 h | [48] |
PAE (clinical, environmental, mucoid and non-mucoid strains) | Sterile petri dish | 5 × 106 CFU in saline on 6 cm2 | n.m | Sampling with moistened sterile cotton swabs, vortexed in NB, serial dilution, cultured on blood agar | ≥ 2 days (most mucoid and non-mucoid strains) | [49] |
SAU, PAE, KPN, ECO (laboratory strains and wild type) | White laminate surface (soiled, clean) | 3 × 102 CFU in water or broth | 30° C; 40–45% RH | Tryptone soya agar contact plates | Soiled: SAU ≥ 24 h (laboratory strain and wild type) PAE ≥ 24 h (laboratory strain) KPN < 24 h (wild type) ECO ≤ 24 h (laboratory strain and wild type) Clean: SAU ≤ 24 h (laboratory strain and wild type) PAE ≤ 24 h (laboratory strain) KPN ≥ 24 h (wild type) ECO ≤ 24 h (laboratory strain and wild type) | [50] |
SAU (MRSA: clinical, outbreak, sporadic strains) | Bottels w/o dust | 109 CFU in sterile PBS | RT; conventional RH; dust protected | Samples vortexted in PBS before incubation on sheep blood agar | > 6 m (w/o dust); longest survival in outbreak strains | [51] |
SAU (MSSA and MRSA) | Bottels w/o dust | 108 CFU in sterile PBS | 22–27 °C; 27–45% RH; dust protected | Samples vortexted in PBS before incubation on sheep blood agar | MSSA: < 28 days (no dust); shorter with dust MRSA: < 175 days (no dust); < 126 days (with dust) | [52] |
SAU, PAE (type strains) ABA (clinical isolate) | Enamel, formica, stainless steel | 2.5 × 105 on 8 cm2 | 20–22 °C 60–70% RH | CLED agar contact plates Enamel: swab moistened in sterile saline inoculated onto CLED agar | SAU: 3–10 days PAE: 1–5 days ABA: 6–12 days | [53] |
ABA (clinical isolates and type strains) | Ceramic, PVC, rubber, stainless steel | 8 × 106 CFU | 22 °C; 50% RH; darkness; dust protected | Samples shaked in 0.9% NaCl, membrane filtration and serial dilution | ≥ 104 days (isolates from dry sources better than wet sources) | [5] |
EFA (VSE and VRE; clinical and environmental isolates) | PVC | 107 CFU | 22 °C; 50% RH; dust protected | Samples shaked in 0.9% NaCl, membrane filtration and or serial dilution | 7 days—> 4 m | [54] |
ECO | Glas | “one McFarland suspension” 1:1 diluted in water, saline, sheep blood | RT | Samples vortexed in BHI | ≤ 70 days | [55] |
ECO (type strain) | Stainless steel, copper, copper-containing alloys | 107 CFU | 4 °C and 20 °C | Samples vortexed in PBS, serial dilution, pipetted onto nutrient agar | > 28 days (stainless steel; for both temperatures) 1.5 h (copper at 22 °C); 4.5 h (copper at 4 °C) < 2 h (copper nickel alloy at 20 °C); < 6 h (copper nickel alloy at 4 °C) | [56] |