Fig. 1.
Trends in detection rate of Streptococcus mitis from 2020 to 2024_
| Year | Annual patients volume | Cases | Rate (‱) |
|---|---|---|---|
| 2020 | 65,378 | 16 | 2.45 |
| 2021 | 67,020 | 17 | 2.54 |
| 2022 | 70,952 | 36 | 5.10 |
| 2023 | 78,830 | 66 | 8.37 |
| 2024 | 82,557 | 114 | 13.81 |
| Total | 364,737 | 249 | 6.83 |
Specimen sources of Streptococcus mitis isolates during 2020–2024_
| Specimen source | Isolates (n = 249) | Rate (%) |
|---|---|---|
| Skin and soft tissue secretion | 58 | 23.30 |
| bronchoalveolar lavage fluid | 58 | 23.30 |
| Urine | 51 | 20.48 |
| Blood | 44 | 17.67 |
| Punctate fluid | 14 | 5.62 |
| Pus | 8 | 3.21 |
| Bile | 6 | 2.41 |
| Pleural effusion | 5 | 2.01 |
| Ascites | 5 | 2.01 |
Resistance rates of Streptococcus mitis to antimicrobial agents during 2020–2024_
| Antimicrobial agents | 2020 (n = 16) | 2021 (n = 17) | 2022 (n = 36) | 2023 (n = 66) | 2024 (n = 114) | χ2 | p |
|---|---|---|---|---|---|---|---|
| R (%) | R (%) | R (%) | R (%) | R (%) | |||
| Cefepime | 43.75 | 17.65 | 11.11 | 12.12 | 6.14 | 10.644 | 0.001 |
| Ceftriaxone | 25.00 | 29.41 | 22.22 | 22.72 | 6.14 | 7.399 | 0.007 |
| Erythromycin | 68.75 | 88.23 | 83.33 | 71.21 | 37.72 | 6.586 | 0.010 |
| Clindamycin | 50.00 | 100.00 | 63.88 | 48.48 | 28.95 | 8.514 | 0.004 |
| Levofloxacin | 50.00 | 52.94 | 30.55 | 42.42 | 19.30 | 5.564 | 0.018 |
| Linezolid | 0 | 0 | 0 | 0 | 0 | – | – |
| Vancomycin | 0 | 0 | 0 | 0 | 0 | – | – |
| Penicillin G | 55.55 | 41.17 | 72.22 | 46.96 | 24.56 | 6.608 | 0.010 |
Resistance rates of Streptococcus mitis to antimicrobial agents in different age groups_
| Antimicrobial agents Age | ≤ 20 | 21~40 | 41~60 | 61~80 | ≥ 81 |
|---|---|---|---|---|---|
| Cefepime | 0 | 1 | 8 | 16 | 4 |
| Ceftriaxone | 4 | 5 | 10 | 15 | 5 |
| Erythromycin | 13 | 20 | 48 | 73 | 5 |
| Clindamycin | 9 | 18 | 39 | 44 | 3 |
| Levofloxacin | 2 | 11 | 26 | 36 | 3 |
| Linezolid | 0 | 0 | 0 | 0 | 0 |
| Vancomycin | 0 | 0 | 0 | 0 | 0 |
| Penicillin G | 10 | 16 | 31 | 39 | 5 |
Specimen sources of Streptococcus mitis isolates in different ages groups_
| Specimen source | ≤ 20 | 21~40 | 41~60 | 61~80 | ≥ 81 |
|---|---|---|---|---|---|
| Skin and soft tissue secretion | 14 | 10 | 10 | 23 | 1 |
| bronchoalveolar lavage fluid | 24 | 3 | 13 | 17 | 1 |
| Urine | 10 | 4 | 16 | 19 | 2 |
| Blood | 9 | 3 | 16 | 16 | 0 |
| Punctate fluid | 5 | 1 | 2 | 5 | 1 |
| Pus | 1 | 2 | 3 | 2 | 0 |
| Bile | 1 | 3 | 2 | 0 | 0 |
| Pleural effusion | 1 | 0 | 3 | 1 | 0 |
| Ascites | 0 | 1 | 3 | 1 | 0 |
Clinical characteristics of patients with Streptococcus mitis infection from 2020 to 2024_
| Clinical characteristics | Parameters | Cases | Rate (%) |
|---|---|---|---|
| Sex | Male | 147 | 59.04 |
| Female | 102 | 40.96 | |
| Age in years | ≤ 20 | 65 | 26.10 |
| 21~40 | 27 | 10.84 | |
| 41~60 | 68 | 27.31 | |
| 61~80 | 84 | 33.74 | |
| ≥ 81 | 5 | 2.01 | |
| Type of infection | HAI | 21 | 8.43 |
| CAI | 112 | 44.98 | |
| Colonization | 116 | 46.59 | |
| Department | Pediatrics | 55 | 22.09 |
| Urinary | 49 | 19.68 | |
| Stomatology | 29 | 11.65 | |
| ICU | 18 | 7.23 | |
| Radiation | 15 | 6.02 | |
| Respiratory medicine | 10 | 4.02 | |
| Orthopedics | 10 | 4.02 | |
| General surgery | 9 | 3.61 | |
| Endocrine | 8 | 3.21 | |
| Cardiothoracic surgery | 8 | 3.21 | |
| Gastroenterology | 9 | 3.61 | |
| Neonatology | 5 | 2.01 | |
| Hematology | 5 | 2.01 | |
| Others | 18 | 7.23 |
Analysis of different infection types and patient age, specimen source, and antimicrobial resistance_
| Characteristics | Infection type | HAI (21) | CAI (112) | Colonization (116) |
|---|---|---|---|---|
| Parameters | Cases/% | Cases/% | Cases/% | |
| Ages | ≤ 20 | 2/9.52 | 30/26.79 | 33/28.44 |
| 21~40 | 2/9.52 | 10/8.93 | 15/12.93 | |
| 41~60 | 6/28.58 | 35/31.25 | 27/23.28 | |
| 61~80 | 9/42.86 | 36/32.14 | 39/33.62 | |
| ≥ 81 | 2/9.52 | 1/0.89 | 2/1.72 | |
| Source | Skin and soft tissue | 4/19.05 | 18/16.70 | 36/31.03 |
| Secretion bronchoalveolar lavage fluid | 1/4.76 | 25/22.3 | 32/27.59 | |
| Urine | 4/19.05 | 14/12.5 | 33/28.44 | |
| Blood | 10/47.62 | 34/30.35 | 0 | |
| Punctate fluid | 0 | 6/5.36 | 8/6.90 | |
| Pus | 1/4.76 | 4/3.57 | 3/2.59 | |
| Bile | 0 | 2/1.79 | 4/3.45 | |
| Pleural effusion | 0 | 5/4.46 | 0 | |
| Ascites | 1/4.76 | 4/3.57 | 0 | |
| Resistance | Cefepime | 5/23.81 | 11/9.82 | 13/11.21 |
| Ceftriaxone | 11/52.38 | 13/11.61 | 15/12.93 | |
| Erythromycin | 18/85.71 | 48/42.86 | 93/80.17 | |
| Clindamycin | 15/71.43 | 43/38.40 | 55/47.41 | |
| Levofloxacin | 10/47.62 | 30/26.79 | 38/32.76 | |
| Linezolid | 0 | 0 | 0 | |
| Vancomycin | 0 | 0 | 0 | |
| Penicillin G | 19/90.48 | 40/35.71 | 42/36.21 |