Distribution and drug resistance of wound pathogenic microorganisms in outpatients of wound healing center / 中华创伤杂志

Objective:To analyze the distribution and drug resistance of wound pathogenic microorganisms in outpatients of wound healing center so as to provide a basis for the standardized construction of wound healing centers.Methods:A retrospective case series study was used to analyzed the data of 365 outpatients treated at Ruijin Hospital, Shanghai Jiaotong University School of Medicine from December 2017 to October 2019. There were 220 males and 145 females, aged (58.8±18.9)years (range, 18-98 years). The patients included 92 first-visit patients and 273 re-visit patients. The culture results (positive rate of pathogenic microorganisms, bacterial species, bacterial distribution) and drug sensitivity results of the wound secretions were compared and analyzed.Results:(1) Among 365 samples of wound secretions, 198 patients were positive for pathogenic microorganisms with a positive rate of 54.3%. A total of 107 strains (51.0%) of Gram-positive bacteria were detected, mainly Staphylococcus aureus (70 strains, 33.3%); 95 strains (45.2%) of Gram-negative bacteria were detected, mainly Escherichia coli (20 strains, 9.5%), followed by Pseudomonas aeruginosa (17 strains, 8.1%); 8 strains (3.8%) of fungi were detected. (2) A total of 26 (28.3%) first-visit patients were positive for pathogenic microorganisms, and 172 (63.0%) re-visit patients were positive for pathogenic microorganisms. The rate of positive microorganism detection had significant differences between first-visit and re-visit patients ( P<0.05). (3) A total of 29 strains were detected in first-visit patients, including 16 strains (55.2%) of Gram-positive bacteria, 11 strains (37.9%) of Gram-negative bacteria and 2 strains (6.9%) of fungi. A total of 181 strains were detected in re-visit patients, including 91 strains (50.3%) of Gram-positive bacteria, 84 strains (46.4%) of Gram-negative bacteria and 6 strains (3.3%) of fungi. The microbial distribution was significantly different between first-visit and re-visit patients ( P<0.05). (4) Compared with first-visit patients, the resistance of Staphylococcus aureus isolated from the re-visit patients to spenicillin, oxacillin, ciprofloxacin, tetracycline, clindamycin, moxifloxacin, erythromycin, and levofloxacin were increased variably. No vancomycin-resistant Staphylococcus aureus was detected, indicating that the staphylococcus aureus presented in the wound was highly sensitive to vancomycin. Conclusions:Staphylococcus aureus is the most common microorganism in wound secretions in outpatients of wound healing center. The rate of positive pathogenic microorganisms in wound secretions of re-visit patients is significantly higher than that of first-visit patients, and the distribution of pathogenic microorganisms of first-visited and revisited patients differs significantly. The Staphylococcus aureus detected in re-visit patients has a higher resistance to common antibiotics compared with first-visit patients. It is suggested that timely detection of pathogenic microorganisms in outpatients and effective control and supervision of outpatient infections are important contents that cannot be ignored in the construction of wound healing center.

Hydrogen peroxide: a potential wound therapeutic target?

Hydrogen peroxide [H[2]O[2]] is a topical antiseptic used in wound cleaning which kills pathogens through oxidation burst and local oxygen production. [H[2]O[2]] has been reported to be a reactive biochemical molecule synthesized by various cells that influences biological behavior through multiple mechanisms: alterations of membrane potential, generation of new molecules, and changing intracellular redox balance, which results in activation or inactivation of different signaling transduction pathways. Contrary to the traditional viewpoint that [H[2]O[2]] probably impairs tissue through its high oxidative property, a proper level of [H[2]O[2]] is considered an important requirement for normal wound healing. Although the present clinical use of [H[2]O[2]] is still limited to the elimination of microbial contamination and sometimes hemostasis, better understanding towards the sterilization ability and cell behavior regulatory function of [H[2]O[2]] within wounds will enhance the potential to exogenously augment and manipulate healing

Infiltration of macrophages and their phenotype in the healing process of full-thickness wound in rat / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the infiltration of macrophages and their phenotype in the healing process of full-thickness wound in rat.</p><p><b>METHODS</b>Thirty healthy SD rats were divided into control group (n = 6) and injury group (n = 24) according to the random number table. Two round full-thickness skin defects (11 mm diameter) were created on both sides of dorsal spine of rats in injury group with surgical scissors and homemade trephine. After injury, wound area was measured immediately. The wounds were disinfected with iodophor every day. Rats in control group received anesthesia and hair removal only. On post injury day (PID) 1, 3, 7, and 13, respectively, 6 rats of injury group were sacrificed after the measurement of wound area (wound healing rate was calculated). Wound samples were obtained by excision down to healthy fascia along wound edge. Histological study was done with HE staining. The expression of CD68 (the surface marker of macrophage) in the wound tissue was observed with immunohistochemical staining. The double positive expressions of induced nitric oxide synthase (iNOS) plus CD68 (type I macrophage) and arginase 1 (Arg-1) plus CD68 (type II macrophage) were observed with immunofluorescence staining. The levels of interferon-γ (IFN-γ), TNF-α, IL-4, IL-13, IL-10, and IL-12 in wound tissue were assayed by double-antibody sandwich ELISA, and the ratio of IL-10/IL-12 was calculated. Full-thickness skin tissues (11 mm diameter) in rats of control group were excised at the same site as rats in injury group, and the histological observation and cytokines assay were performed as well. Data were processed with one-way analysis of variance or LSD- t test.</p><p><b>RESULTS</b>Wound area of rats in injury group was gradually reduced after injury, and the overall difference of the wound healing rate on each PID was statistically significant (F = 358.55, P < 0.01). No abnormal appearance of skin tissue was observed in rats of control group. In injury group, inflammatory cell infiltration was obvious in wound tissue on PID 1 and 3; vascular structure and fresh collagen were observed in wound tissue on PID 7 and 13. Numbers of CD68 positive cells in skin tissue of rats in control group and wound tissue of rats in injury group on PID 1, 3, 7, and 13 were respectively (2.7 ± 1.5), (31.8 ± 3.5), (40.8 ± 4.7), (20.8 ± 2.8), (3.2 ± 2.4) per 200 times visual field (F = 180.55, P < 0.01). Compared with that in control group, the number of CD68 positive cells of rats in injury group was increased on PID 1, 3, and 7 (with t values respectively 18.81, 18.79, 14.05, P values below 0.01). No double positive expression of iNOS plus CD68 or Arg-1 plus CD68 was observed in normal tissue of rats in control group. In injury group, proportions of iNOS plus CD68 double positive cells on PID 1, 3, 7, and 13 were respectively (12.2 ± 2.8)%, (16.5 ± 2.9)%, (4.2 ± 2.3)%, (0.7 ± 0.8)% (F = 72.50, P < 0.01); proportions of Arg-1 plus CD68 double positive cells on PID 1, 3, 7, and 13 were respectively 0, (8.2 ± 1.9)%, (21.5 ± 3.4)%, (4.7 ± 2.0)% (F = 120.93, P < 0.01). In injury group, proportion of iNOS plus CD68 double positive cells on PID 3 was significantly higher than that on other PID (with t values respectively 2.65, 8.17, 12.95, P values below 0.05); proportion of Arg-1 plus CD68 double positive cells on PID 7 was higher than that on other PID (with t values respectively 15.27, 8.25, 10.38, P values below 0.01). Compared with that of Arg-1 plus CD68 double positive cells, proportion of iNOS plus CD68 double positive cells was higher on PID 1 and 3 (with t values respectively 10.71 and 5.88, P values below 0.01) and lower on PID 7 and 13 (with t values respectively 10.24 and 4.60, P values below 0.01). The overall differences of IFN-γ, TNF-α, IL-4, IL-13, and IL-10/IL-12 ratio in skin tissue of rats in control group and wound tissue of rats in injury group on every PID were statistically significant (with F values from 14.08 to 631.03, P values below 0.01). Compared with those in control group, levels of IFN-γ, TNF-α, IL-4, and IL-13 in wound tissue of rats in injury group were significantly higher on every PID (with t values from 4.58 to 9.17, P values below 0.05), while IL-10/IL-12 ratio was significantly higher on PID 1, 3, and 7 (with t values respectively 27.70, 30.51, 9.49, P values below 0.05) . In injury group, IFN-γ level on PID 1 [(61 ± 5) pg/mL] and IL-10/IL-12 ratio on PID 3 (1.647 ± 0.098) were significantly higher than those of control group and those on other PID in injury group [with IFN-γ level respectively (32 ± 4), (54 ± 6), (46 ± 7), (47 ± 4) pg/mL and IL-10/IL-12 ratio respectively 0.328 ± 0.045, 0.960 ± 0.034, 0.530 ± 0.028, 0.289 ± 0.040, with t values respectively from 3.19 to 8.20 and from 16.59 to 31.84, P values below 0.05].</p><p><b>CONCLUSIONS</b>Macrophage infiltration increases in the healing process of full-thickness wound in rat with different phenotypes, among which type I macrophage appears in the inflammatory stage, and type II macrophage predominates in the proliferative stage.</p>

Significance of Arterial Base Deficit in Patients with Severe Burn Injuries / 上海第二医科大学学报

ObjectiveTo investigate the changes of arterial base deficits (BD) in the early stageof extensive burned patients. MethodsWe perform a retrospective review of 126 patients with a totalbody surface area (TBSA) over 30% whose resuscitations were initiated with the Ruijin formula to ob-serve the BD changes and analyze the relationship of BD and TBSA at different postburn time intervals insurvivors and deaths. ResultsWithin 48h after burn injury, the BD value improved gradually. Thedifference between survivors and nonsurvivors was significant at 4 to 8h interval after burn injury ( P <0.05). BD was correlated with TBSA strongly during 4 to 16h after burn injury ( P ≤0.05)in nonsur-vivors, but not in survivors. The incidence of the shock－ related complications in survivors was higherthan in nonsurvivors. ConclusionBD could be one of monitor index in the shock stage after severeburM injury.