Prevention and treatment of infection in burn patients involve a wide range of issues. This present article is to introduce only briefly clinical experience focusing on this problem. Among them, satisfactory timely prevention and treatment of burn shock is imperative because it exerts tremendous impact on homeostasis, including especially deterioration of immune functions. Early gastro-intestinal feeding is known to help restore gastro-intestinal circulation after shock, and it is an important avenue to give important nutritional elements like glutamine. It is also very important to excise devitalized tissue, followed by total coverage of all open wounds as early as possible, so that nidus of infection is removed. Rational use of antibiotic, immunological modulation and other measured were also important contributory factors in successfully preventing and treating infection in patients with major burns.
Burns ; microbiology ; Humans ; Infection Control

Burns ; microbiology ; Humans ; Wound Infection ; prevention & control

Early in 1962, after an extensive review including 312 cases of bacteremia in burn patients, we were surprised to find that there was about 30% of bacteremia in the patients who had no detectable microorganisms from repeated wound cultures, but blood cultures were usually positive for gut flora. From that time on the idea of gut-origin infection emerged. In following twenty years, a series of experiments were carried on in Wistar rats with 30% TBSA full-thickness burn. The results showed that the fluorescein labeled enteric microbes (Pseudomonas aeruginosa, Bacteroid fragilis and Candida albicans) could translocate through the stress injured intestinal wall and were recovered in visceral organs. The radioisotope 125I labeled endotoxin began to ascend in concentration in portal vein since 15 minutes postburn. Radioautography of liver sections demonstrated the labeled endotoxin granules. With the creation of minute mesenteric lymph fistulas, the clearance of endotoxin and TNFalpha was found to be significantly high in lymph fluid exited from the intestine. All above evidences indicated that the gut is a potential route of endogenous infection, and it also explained how did the patients manifest sepsis early after burn injury without a definite infectious focus. Now the concepts of gut-origin infection are commonly accepted, the measures like early enteral feeding for the protection of intestinal barrier has been established.
Bacteremia ; etiology ; Bacterial Translocation ; Burns ; microbiology ; Gastrointestinal Tract ; microbiology ; Humans

OBJECTIVETo investigate the role of lymphatics in bacterial translocation from intestine of rats with burn.

METHODSEscherichia coli (E. coli) labeled with chloromethylbenzamidodialkylcarbocyanine (CM-DIL) were prepared. Sixty adult male Wistar rats were randomly divided into scald group and sham injury group according to the envelope method, with 30 rats in each group. Rats in both groups were gavaged with 0.5 mL fluid containing CM-DIL-labeled E. coli. Rats in scald group were inflicted with 30% TBSA deep partial-thickness scald (verified by pathological section) and resuscitated with fluid. Rats in sham injury group were sham injured by bathing in 25 degrees C water for 10 s (verified by pathological section) and also received with fluid infusion. Mesenteric lymph node (MLN), liver, mesenteric lymph fluid (MLF), and liver vein blood (LVB) were harvested at post injury hour (PIH) 2, 24, and 72. Bacteria translocation was detected with fluorescent tracing technique and bacteria culture. The endotoxin content in above-mentioned four kinds of specimens was quantitatively determined with chromogenic substrate limulus amebocyte lysate. The carrying capacity of endotoxin in MLF and LVB was calculated. Data were processed with t test or one-way analysis of variance.

RESULTS(1) Living bacteria were in short-stick form, and they were seen moving in single or in doubles or triples in sample fluid. Dead bacteria were in irregular aggregates. Labeled bacteria in small amount were detected in sham injury group, their number peaked at PIH 24. A large amount of labeled bacteria were detected in scald group at PIH 2, which peaked at PIH 24 and decreased at PIH 72. The largest amount of labeled bacteria were found in MLN in scald group as compared to those in the other samples, and the number peaked at PIH 24 [(5872 +/- 1976) x 10(3) CFU/g], which was obviously higher than that [(216 +/- 110) x 10(3) CFU/g, t = 30.129, P = 0.000] in sham injury group. The number of bacteria decreased at PIH 72, but it was still significantly different from that in sham injury group ( t = 4.323, P = 0.000). The number of bacteria in LVB was the smallest. (2) 29 (24.2%) samples out of the 120 samples in sham injury group were positive for bacteria. 72 (60.0%) samples out of the 120 samples in scald group were positive for bacteria. No alive bacterium was detected at any time point in LVB sample in both group; the other three samples were detected with alive bacteria since PIH 2. There were more alive bacteria detected in MLN and liver as compared with the other two kinds of samples in scald group. The amount of bacteria in MLN, liver, and MLF in scald group were higher than those in sham injury group (with t value respectively 4.353, 4.354, 4.965, P values all equal to 0.000). (3) The endotoxin level in each kind of sample at each time point was obviously higher in scald group than that in sham injury group, and it peaked at PIH 2 in liver and MLF. The difference of endotoxin level among 4 kinds of samples in scald group at PIH 2 was statistically significant ( F = 258.47, P = 0.000), and the endotoxin level was higher in liver, MLN, and MLF. They were obviously higher than those in sham injury group (with t value respectively 43.378, 43.123, 22.423, P values all equal to 0.000). The endotoxin level in MLF was 9 times of that in LVB. (4) The carrying capacity of endotoxin in LVB and MLF at each time point in scald group was higher than that in sham injury group.

CONCLUSIONSCM-DIL marked bacteria can reflect the microbial translocation condition. The lymphatic route is an important pathway for bacteria translocation.

Animals ; Bacterial Translocation ; Burns ; microbiology ; Intestinal Mucosa ; microbiology ; Lymph Nodes ; microbiology ; Lymphatic System ; microbiology ; Lymphatic Vessels ; Male ; Rats ; Rats, Wistar

OBJECTIVETo observe the biofilm (BF) formation of Staphylococcus aureus (SA), Acinetobacter baumannii (AB) and Pseudomonas aeruginosa (PA) on the surface of deep vein catheters in burn patients after infection.

METHODSThe bacteria from deep vein catheters in 20 patients hospitalized from November 2008 to August 2009 were isolated, and were compared with their respective standard stains. Catheters tips were examined with scanning electron microscope (SEM). The semi-quantitative adhesion assay of bacterial BF was performed with modified microtiter-plate test, and the thickness of BF was scanned and measured by confocal laser scanning microscopy (CLSM) after double fluorescence staining, after being cultured in vitro for 12, 24, 48, 72 hours and 5 days, respectively. Data were processed with grouped t test.

RESULTSSix strains of SA, 8 strains of AB, and 6 strains of PA, all drug resistant, were isolated from the deep vein catheters. SEM showed that the BF structures on the inner surfaces of catheters were in diverse in their shape and degree, characterized by adherence and flake formation, and embedded in polysaccharide matrix. BF gathered in clusters, forming three-dimensional structure, in which small amount of red blood cells were found. A small number of bacteria were incompletely embedded, with some bacteria adhered to them. The absorbance values for SA after 24, 48 and 72 hours of culture (PCH) were above the cut-off value, the same for AB at PCH 12, 24, 48 and 72, and PA after PCH 48. Except for PA standard strain, CLSM showed scattered green fluorescence, mainly close to the bottom of plate, while the red fluorescence was observed in full scope at PCH 24 for each strain. At PCH 48 green fluorescence increased obviously and extended upward from the bottom, overlapping partly with red fluorescence, forming yellow fluorescence, and among the bacteria it was most obvious in AB culture, with SA the next. Compared with those of the standard stains, the intensity and quantity of fluorescence from the clinical strains were stronger; at PCH 72 the green fluorescence increased obviously especially for PA and its standard strain, while the yellow fluorescence was full of the scope for other strains. On in vitro culture day 5, the green fluorescence was dispersed and was obvious on the bottom of the plate. BF mature time for AB and SA was PCH 48, and for PA was PCH 72. The BF thickness of AB was (18.2 +/- 3.6) microm at PCH 72, which was thicker than that [(9.4 +/- 2.6) microm] of its standard strain (t = 5.42, P < 0.05), and was also the thickest among the three clinically found strains.

CONCLUSIONSSA, AB and PA, which are commonly found bacteria in burn patients, can form BF in deep vein catheters. Their ability to form BF seems to be stronger than other usually pathogenic strains, especially AB, which is the important pathogen leading to catheter related infection.

Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; growth & development ; Bacterial Adhesion ; Biofilms ; Burns ; microbiology ; Catheters ; microbiology ; Humans ; Pseudomonas Infections ; microbiology ; Pseudomonas aeruginosa ; growth & development ; Staphylococcal Infections ; microbiology ; Veins ; microbiology

Infection is still the major cause of death in severe burn patients, thus the optimization of antibiotic therapy is an important approach to the annihilation of pathogenic bacteria and the decrease of drug-resistance bacteria. It is urgent for burn surgeons to face the selection pressure of antibiotics and the fungous infections following the incorrect use of antibiotics. Regardless of its complexity, the treatment of sepsis associated with post-burn bacterial infections should be systematical. Besides the effective anti-shock therapy, early enteral feeding, excision of necrotic tissues, and effective anti-infection treatment, the immunological regulation and the prevention and cure of coagulation disorders are necessary in the treatment of severely burned patients.
Burns ; microbiology ; Cross Infection ; Humans ; Infection Control ; Mycoses ; prevention & control

OBJECTIVETo reproduce a reliable rat model of burn with infection for the study of prevention and treatment of infected wound.

METHODS(1) Electrical burn producing apparatus equipped with constant temperature (80°C) and pressure (0.5 kg) was used to reproduce burn injury (with area of 4.5 cm(2)) on both sides of the back in 50 SD rats for different duration (4, 6, 8, 10, 12 s), with 10 rats for each burn duration. On post burn day (PBD) 1, gross condition of wounds was observed with naked eyes. Wounds on the left side were used to observe healing time. The wounds on the right side were used for histological observation to determine the depth of injury, and they were classified into superficial and deep partial-thickness injury. (2) Another 36 SD rats were divided into A (inflicted with superficial partial-thickness burn, n = 18) and B (inflicted with deep partial-thickness burn, n = 18) groups according to the random number table. Rats in both groups were treated in accordance with method of preliminary experiment. Immediately after burn, 0.1 mL of liquid containing 1 × 10(9), 1 × 10(7), 1 × 10(5) CFU Pseudomonas aeruginosa (PA) ATCC 27853 was respectively inoculated to the wounds on one side (with 6 rats for each amount), while the wounds on the other side were treated with the same volume of normal saline as control. Inflammatory reaction of wounds was examined with HE staining on post inoculation day (PID) 1. On PID 1, 2, 3, 5, 7, and 14, the number of subeschar bacteria was respectively counted and the bacteria were identified with Gram stain and biochemical reaction. Wound healing time was recorded. Data were processed with t test.

RESULTS(1) Burn for 6, 8 s was respectively identified as injury time resulting in superficial or deep partial-thickness injury according to histological observation and wound healing time. (2) Obvious inflammatory cell infiltration was observed in the wounds in B group which were inoculated with 1 × 10(7), 1 × 10(9) CFU PA, and the infiltration was less marked in A group with inoculation of 1 × 10(9) CFU PA. (3) The bacteria isolated from wounds of A and B groups was identified as PA. The subeschar bacteria count within PID 14 in A group, in which different amount of PA was inoculated, was mostly less than 1 × 10(5) CFU/g of tissue, while that in B group in which 1 × 10(9) CFU PA was inoculated was more than 1 × 10(5) CFU/g of tissue. (4) There was no obvious difference in wound healing time between wounds inoculated with different amount of PA and wounds treated with normal saline in A group (with t value respectively 1.26, 0.29, 1.07, P values all above 0.05). Wound healing time of wounds in B group, in which 1 × 10(9) CFU PA was inoculated, was longer as compared with that treated with normal saline [(22.5 ± 1.0) d vs. (19.4 ± 1.6) d, t = 2.73, P < 0.05].

CONCLUSIONSIn rat, deep partial-thickness burn wound inoculated with 1 × 10(9) CFU PA ATCC 27853 is a reliable model with high reproducibility for the study of infection of burn wound.

Animals ; Burns ; microbiology ; Disease Models, Animal ; Male ; Rats ; Rats, Sprague-Dawley ; Wound Infection ; microbiology

OBJECTIVETo observe expressions of pgaABC gene clusters and changes in biofilm (BF) phenotype in Acinetobacter baumannii (AB) isolated from burn patients.

METHODSFrom January 2009 to October 2010, 24 strains of AB isolated from burn patients hospitalized in our burn wards were collected for the study, while the standard strain ATCC 19606 was used as control. Expressions of pgaABC gene clusters were detected by real time fluorescence quantitative RT-PCR. All strains were cultured for 16 hours in vitro, BF with semi-quantitative detection was respectively evaluated by modified microtiter-plate test under stable condition and tube test under shaking condition for expression of absorbance value. All strains were cultured for 48 hours in vitro, then stained with fluorescent agent and collected for measurement of BF thickness with confocal laser scanning microscopy (CLSM). Data were processed with t test.

RESULTS(1) The expression of pgaB gene (27.91 ± 7.93) in clinical AB strains was much higher than that of standard strain ATCC 19606 (1.00, t = 5.77, P < 0.05). There was no statistical difference in expression of pgaA and pagC genes between standard strain ATCC 19606 (1.00) and clinical AB strains (1.01 ± 0.28, 1.15 ± 0.38, with t value respectively 0.04, 0.64, P values all above 0.05). (2) After being cultured for 16 hours, BF of clinical AB strains cultured under shaking condition formed distinct "purple circle", and its absorbance value (1.25 ± 0.31) was higher than that in standard strain ATCC 19606 (0.76 ± 0.03, t = 2.67, P < 0.05). There was no obvious difference in absorbance value between clinical AB strains and standard strain ATCC19606 cultured under stable condition. (3) After being culture for 48 hours, green fluorescence intensity and distribution in extracellular matrix of clinical AB strains were stronger as compared with those of standard strain ATCC 19606, and BF thickness in clinical AB strains [(27.3 ± 9.4)µm] was thicker than that in standard strain ATCC 19606 [(15.6 ± 1.7) µm, t = 2.09, P < 0.05].

CONCLUSIONSThe high expression of pgaB gene in AB strains isolated from burn patients can induce production of extracellular matrix, which may be related to increase in the ability and thickness of BF formation.

Acinetobacter Infections ; microbiology ; Acinetobacter baumannii ; genetics ; isolation & purification ; Biofilms ; Burns ; microbiology ; Genes, Bacterial ; Humans ; Multigene Family

This article reports the treatment of a patient suffering from full-thickness electric burn of skull combined with cerebral contusion and intracranial infection to provide experience in treating such patients. Based on detailed analysis on patient's condition and CT results, several operations of surgery and anti-infection treatment were performed on the patient. The wounds healed 6 weeks after injury. The skull defect was repaired with three-dimensionally reconstructed titanium mesh of computer-aided design two years after wound healing. The treatment of full-thickness electric burn of skull combined with cerebral contusion was quite difficult. The timing and mode of operation were very important. Perioperative prevention and treatment of intracranial infection were essential to save the life of the patient. In the event of intracranial infection, effective systemic use of antibiotics, cerebrospinal fluid drainage, intrathecal injection of drugs, and the application of other comprehensive measures could ensure the success of treatment.
Adult ; Brain Abscess ; microbiology ; therapy ; Brain Injuries ; microbiology ; therapy ; Burns, Electric ; microbiology ; therapy ; Humans ; Infection ; therapy ; Male ; Skull ; injuries

OBJECTIVETo explore the preventive and treatment effects of smectite powder on enteral bacterial translocation in scalded rats.

METHODSFifty-four Sprague-Dawley (SD) rats were randomly divided into three groups, i.e. normal control (A, n = 6), burn control (B, n = 24), and burn treatment (T, n = 24) groups. The rats in B and T groups were fed with tracing bacteria JM109, which was transfected with PUC19 plasmid in advance. The rats were subjected to 30% TBSA scald injury after the plasmid was shown to have colonized in the intestine. Smectite powder (0.6 g/day/kg) was fed to rats of T group immediately after the scalding, while those in B group received no smectite powder. Bacterial translocation in blood and mesenteric lymph nodes in all groups was observed and identified by enzyme digestion at 12 post scald hour (PSH) and on 1, 3 and 5 post-scald days (PSD). The contents of malondialdehyde (MDA) and superoxide dismutase (SOD) were determined in rat intestinal tissue. And the degree of injury to the entire small intestine was observed pathologically. The villus height of intestinal mucosa was measured, and the rate of epithelial nuclear splitting of mucosal crypts was calculated.

RESULTSThe number of rats with positive blood bacterial culture in B group was obviously higher than that in A and T groups (P < 0.05) on 1 and 5 PSD. The bacterial quantity in mesenteric lymph nodes (MLN) in T group on 1 PSD (38 +/- 16 CFU/g) and 5 PSD (68 +/- 20 CFU/g) were obviously lower than those in B group (228 +/- 67 vs 183 +/- 29 CFU/g, P < 0.05). There was significant difference in the intestinal contents of MDA and SOD between B and T groups at each time point (P < 0.05). The rat jejunum villus height and the epithelial nuclear splitting in the small intestine mucosa in T group were evidently higher than those in B group (P < 0.05 or 0.01).

CONCLUSIONSmectite powder is beneficial to the protection of the intestinal mucosa in scalded rats, and can effectively prevent postburn intestinal bacterial translocation in rats.

Animals ; Bacterial Translocation ; Burns ; drug therapy ; microbiology ; Intestinal Mucosa ; microbiology ; pathology ; Rats ; Rats, Sprague-Dawley ; Silicates ; therapeutic use