- Microbial biomass recovered from single-surface infection models by various methods
In the SA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 611 ± 101 CFU/ml (95% CI: 538-683), 999 ± 141 CFU/ml (95% CI: 898- 1100), 609 ± 96 CFU/ml (95% CI: 540-679), 938 ± 136 CFU/ml (95% CI: 840-1035), and 533 ± 108 CFU/ml (95% CI: 455-611), respectively. The amount of microorganisms obtained in MH group was significantly higher than that in the MM (P <0.01), SC (P <0.01), and UL groups (P <0.01), but there was no difference with that of the DTT group (P = 0.26). (Fig 2A).
In the EC infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 451 ± 192 CFU/ml (95% CI: 313-588), 1373 ± 132 CFU/ml (95% CI: 1278-1468), 480 ± 135 CFU/ml (95% CI: 383-576), 1347 ± 162 CFU/ml (95% CI: 1231-1463), and 393 ± 178 CFU/ml (95% CI: 265-520), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), UL (P <0.01), and DC groups (P <0.01), but there was no difference from that of the DTT group (P = 0.71). (Fig 2A).
In the CA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 440 ± 70 CFU/ml (95% CI: 391-488), 818 ± 122 CFU/ml (95% CI: 730-905), 435 ± 68 CFU/ml (95% CI: 386-484), 771 ± 108 CFU/ml (95% CI: 694-849), and 360 ± 85 CFU/ml (95% CI: 298-421), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), UL (P <0.01) and DC groups (P <0.01), but there was no difference with that of the DTT group (P = 0.945). (Fig 2A).
- Microbial biomass recovered from full-surface infection models by various methods
In the SA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 4014 ± 888 CFU/ml (95% CI: 3378-4650), 6268 ± 1019 CFU/ml (95% CI: 5539-6997), 3960 ± 875 (95% CI: 3334-4568) CFU/ml, 6227 ± 1000 CFU/ml (95% CI: 5512-6942), and 3255 ± 1048 CFU/ml (95% CI: 2505-4005), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), UL (P <0.01) and DC groups (P <0.01), but there was no difference compared with that of the DTT group (P = 0.924). (Fig 2B).
In the EC infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 3079 ± 934 CFU/ml (95% CI: 2410-3747), 7058 ± 920 CFU/ml (95% CI: 6400-7717), 3060 ± 902 CFU/ml (95% CI: 2415-3706), 6853 ± 858 CFU/ml (95% CI: 6239-7466), and 2533 ± 637 CFU/ml (95% CI: 2077-2989), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), the UL (P <0.01), and DC groups (P <0.01), but there was no difference compared with that of the DTT group (P = 0.964). (Fig 2B).
In the CA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 3080 ± 842 CFU/ml (95% CI: 2477-3682), 5274 ± 966 CFU/ml (95% CI: 4583-5966), 2971 ± 890 CFU/ml (95% CI: 2334-3608), 5269 ± 853 CFU/ml (95% CI: 4658-5879), and 2287 ± 851 CFU/ml (95% CI: 1678-2896), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), UL (P <0.01), and DC groups (P <0.01), but there was no difference compared with that of the DTT group (P = 0.989). (Fig 2B).
- Microbial biomass recovered from internal infection models by various methods
In the SA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 267 ± 68 CFU/ml (95% CI: 218-316), 636 ± 90 CFU/ml (95% CI: 571-701), 300 ± 73 CFU/ml (95% CI: 247-353), 270 ± 63 CFU/ml (95% CI: 224-315), and 208 ± 95 CFU/ml (95% CI: 140-277), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM (P <0.01), SC (P <0.01), DTT (P <0.01), and UL groups (P <0.01). (Fig 2C).
In the EC infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 313 ± 78 CFU/ml (95% CI: 257-369), 698 ± 134 CFU/ml (95% CI: 601-794), 298 ± 72 CFU/ml (95% CI: 246-351), 306 ± 93 CFU/ml (95% CI: 239-373), and 234 ± 82 CFU/ml (95% CI: 175-293), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM group (P <0.01), UL group (P <0.01), DTT group (P <0.01), and DC group (P <0.01). (Fig 2C).
In the CA infection groups, the average CFU of the MM, MH, UL, DTT, and DC groups were 169 ± 60 CFU/ml (95% CI: 125-212), 359 ± 55 CFU/ml (95% CI: 319-399), 164 ± 58 CFU/ml (95% CI: 122-206), 172 ± 58 CFU/ml (95% CI: 130-213), and 119 ± 47 CFU/ml (95% CI: 85-154), respectively. The amount of microorganisms obtained in the MH group was significantly higher than that in the MM group (P <0.01), UL group (P <0.01), DTT group (P <0.01), and DC group (P <0.01). (Fig 2C).
- Culture results incontrol samples
Negative (sterile) control samples consisted of 30 cubes of pork tissue (10 for each single-surface/full-surface/internal model). In the MM group, growth of Streptococcus viridans and Staphylococcus epidermidis was found in the negative control of the single-surface and full-surface models, respectively. In the negative control of the UL group, a pork cube was found to have growth of the bacterial contaminant Corynebacterium (Table 1).
- Tissue culture results of periprosthetic joint infection specimens
The numbers of colonies obtained from PJI patient specimens subjected to various pretreatment methods are listed in Table 2. Out of a total of 30 original samples from 8 patients, 10 original samples received at least one positive result, distributed in 7 cases. Only one patient's 4 original specimens were negative with the various pretreatment methods. The total number of pathogenic bacterial colonies obtained by MH was significantly higher than that obtained by the other pretreatment methods (Fig 2D, P = 0.004).