We investigated the relationship between the resistance rate of erythromycin-resistant Streptococcus pneumoniae (SP) in 31 provinces of China from 2014 to 2021, along with the isolate rate and geographical distribution across the country. A map was utilized to visually depict the distribution of both the drug resistance rate and the isolate rate of erythromycin-resistant SP in each province, where darker colors indicate higher values (Fig. 1). Supplementary Table A provides statistical descriptions of meteorological data, economic indicators, medical facilities, dietary structures, and population changes for each province and city.
Differences in the drug resistance rate and isolate rate of erythromycin-resistant SP under different Hu Huanyong line distributions
We observed significant differences in the drug resistance rate of Streptococcus pneumoniae (SP) across different distributions relative to the Hu Huanyong line (P < 0.001). Here were the specific findings:Northwest side of the Hu Huanyong line: Sample size = 36, Median (Quartile) = 89.50 [86.72, 91.80]; On the Hu Huanyong line: Sample size = 24, Median (Quartile) = 96.15 [94.30, 96.80]; Southeast side of the Hu Huanyong line: Sample size = 184, Median (Quartile) = 95.65 [93.50, 96.70].These results indicated a statistically significant variation in the drug resistance rate of SP across different regions relative to the Hu Huanyong line, with the lowest median resistance rate observed on the northwest side and the highest on the southeast side. (Table 1)
Table 1
Table of isolate rate of drug resistance under different Hu line distribution
Level | N | resi | N | dete |
Hu Line | | | | |
Northwest | 36 | 89.50[86.72,91.80] | 15 | 3.65[3.00,5.03] |
On | 24 | 96.15[94.30,96.80] | 6 | 4.25[3.95,4.89] |
Southeast | 184 | 95.65[93.50,96.70] | 45 | 2.90[2.25,3.52] |
P | | <0.001** | | 0.008** |
* p < 0.05 ** p < 0.01 Resi (N = 244) Dete (N = 66); Resi: Resistance rate of erythromycin-resistant SP Dete: Isolate rate of erythromycin-resistant SP |
Isolate rate: On the northwest side of the Hu Huanyong line, the sample size was N = 15, with a median (quartile) of 3.65 [3.00, 5.03]. On the Hu Huanyong line, the sample size was N = 6, with a median (quartile) of 4.25 [3.95, 4.89]. On the southeast side of the Hu Huanyong line, the sample size was N = 45, with a median (quartile) of 2.90 [2.25, 3.52]. The isolate rate of SP showed significant differences under different distributions of the Hu Huanyong line distributions. (P = 0.008) (Table 2) There are significant differences in the rates of drug resistance and detection (Fig. 2).
Differences in drug resistance and isolate rates of erythromycin-resistant SP in different climate types.
The drug resistance rate exhibited significant differences among different climate types (P < 0.001).
The isolate rate exhibited a significant difference between plateau mountain climates and non-plateau mountain climates (P = 0.003). Additionally, there was a significant difference in the isolate rate between monsoon climates and non-monsoon climates (P = 0.002). (Table 2)
Table 2
Table of the isolate rate of drug resistance under different climate types
Level | N | Resi | N | Dete |
Tropical | | | | |
No | 232 | 95.25[92.50,96.70] | 60 | 3.15[2.48,4.22] |
Yes | 16 | 92.30[90.23,94.70] | 6 | 4.47[2.61,7.47] |
P | | 0.010* | | 0.255 |
Temperate | | | | |
No | 132 | 94.70[92.22,96.20] | 42 | 3.08[2.31,4.41] |
Yes | 112 | 95.85[91.50,97.00] | 24 | 3.21[2.82,3.69] |
P | | 0.038* | | 0.889 |
Subtropic | | | | |
No | 116 | 94.00[90.10,96.50] | 27 | 3.28[2.70,3.92] |
Yes | 128 | 95.70[93.80,96.70] | 39 | 3.06[2.25,4.30] |
P | | 0.002** | | 0.648 |
Plateau | | | | |
No | 208 | 95.65[93.22,96.70] | 51 | 2.91[2.26,3.72] |
Yes | 36 | 90.60[87.87,92.95] | 15 | 4.13[3.43,5.03] |
P | | <0.001** | | 0.003** |
Monsoon | | | | |
No | 20 | 89.20[84.82,91.05] | 9 | 4.35[3.79,5.61] |
Yes | 224 | 95.50[92.93,96.70] | 57 | 3.00[2.30,3.96] |
P | | <0.001** | | 0.002** |
Mainland | | | | |
No | 196 | 95.10[92.12,96.70] | 54 | 3.26[2.55,4.35] |
Yes | 48 | 95.35[92.65,96.67] | 12 | 2.96[2.35,3.45] |
P | | 0.836 | | 0.178 |
* p < 0.05 ** p < 0.01 Resi (N = 244); Dete (N = 66) |
There are significant differences in the rates of drug resistance and detection among different climates (Fig. 3).
Multivariate regression analysis
Temperature, maxTemp12h, Rainfall, Pressure, H, nHI, GDP, iGDP, rGDP, Distributions by Hu Line, Temperature, Subtropical, and Monsoon were significantly positively correlated with the resistance rate of erythromycin-resistant SP. The Spearman correlation coefficients were as follows: 0.178 (P = 0.005), 0.379 (P < 0.001), 0.175 (P = 0.006), 0.337 (P < 0.001), 0.478 (P < 0.001), 0.376 (P < 0.001), 0.585 (P < 0.001), 0.448 (P < 0.001), 0.172 (P = 0.007), 0.356 (P < 0.001), 0.133 (P = 0.038), 0.195 (P = 0.002), and 0.366 (P < 0.001) (Supplementary Table B, Fig. 4).
There was a significant negative correlation between the Tropical and Plateau and the resistance rate of erythromycin-resistant SP. The Spearman correlation coefficients were − 0.164 (P = 0.010) and − 0.378 (P < 0.001).
There was a significant positive correlation between rGDP, Plateau, and the isolate rate of erythromycin-resistant SP. The Spearman correlation coefficients were 0.311 (P = 0.011) and 0.365 (P = 0.003). Temperature, Rainfall, Pressure, by Hu Huanyong Line, and Monsoon showed a significant negative correlation with the isolate rate of erythromycin-resistant SP. The Spearman correlation coefficients were − 0.262 (P = 0.034), -0.406 (P = 0.001), -0.284 (P = 0.021), -0.341 (P = 0.005), and − 0.386 (P = 0.001) (Supplementary Table B, Fig. 4).
The corresponding stepwise linear regression model was constructed by incorporating the influencing factors of the correlation rate of erythromycin-resistant SP drug resistance (Table 3). The final model of drug resistance rates revealed that Temperate, Subtropical Hu Huanyong line, GDP, and maxTemp12h were the factors influencing the drug resistance rate of SP.
The formula for the drug resistance rate model is as follows:
$$=0.272Temperate\times A+0.183Subtropical \times B+0.297Hu Line+0.250GDP+0.128 maxTemp12h +26.018$$
Table 3
Drug resistance rate stepwise linear regression analysis table
Variable | Unstandardized Coefficients | Standardized Coefficients | t | P value | VIF |
Β | Std. Error |
Temperate | 2.514 | 0.724 | 0.272 | 3.474 | 0.001 | 2.239 |
Subtropical | 1.685 | 0.785 | 0.183 | 2.147 | 0.033 | 2.645 |
Hu Line | 1.870 | 0.386 | 0.297 | 4.845 | <0.001 | 1.369 |
GDP | \(4.915\times\)10− 5 | <0.001 | 0.250 | 4.041 | <0.001 | 1.394 |
maxTemp12h | 0.209 | 0.101 | 0.128 | 2.083 | 0.038 | 1.367 |
Constant | | | | | | |
| F | 25.276 | | | | |
| R2 | 0.347 | | Adjusted R2 | 0.333 | |
p < 0.05 ** p < 0.01 |
The final isolate rate model showed that Monsoon and rGDP were the determinants of the S. pneumoniae isolate rate (Supplementary Table C).
The formula for the drug isolate rate model was as follows:
$$=-0.349Monsoon\times C+0.339rGDP+4.101$$