The swabs were cultured on blood and Muller-Hinton agar plates and incubated at 37°C under ambient conditions for 24 h.P. aeruginosa was diagnosed by colony morphology, a zone of hemolysis and oxidase, methyl red, Voges Proskauer, citrate and TSI tests [15]. Results and discussion Mice this website immunized with a semi-purified exotoxin A fromP. aeruginosa (n = 48) and non-immunized mice (n = 25) received full-thickness burns to the skin of the thigh and were then challenged with 108 CFU ofP. aeruginosa (a lethal dose). They were followed for 70 days. Antitoxin

and exotoxin A were detected in the sera of the experimental group by CIEP. The antibody titer ranged from 1:16 to 1:512 in the immunized mice using ELISA (Table1). Table 1 Antitoxin titer of immunized mice using ELISA Antitoxin titer No. (%) 1:16 2 (4.5) 1:32 8 (17.8) 1:64 10 (22.2) 1:128 15 (33.3) selleck 1:256 5 (11.1) 1:512 5 (11.1) During the follow-up period, 3 mice (6.3%) in the experimental group https://www.selleckchem.com/products/c188-9.html died. All non-immunized mice developed septicemia and died within 3 weeks

of inoculation withP. aeruginosa. In serial wound swabs (diluted in 1 ml of distilled water) from the immunized mice, 1.5 × 108 CFU/mL ofP. aeruginosa were detected 1 day after wound inoculation and levels decreased to 0 over 2 weeks. In the non-immunized mice, the colony count increased for 6 days post-inoculation withP. aeruginosa and the majority of the mice (80%) died within this period. Table2 shows the colony count, survival rate and results of cultures of the blood, spleen and liver of the non-immunized mice. The blood cultures of 8%, 32%, 32% and 12% of the non-immunized mice were positive after 2, 3, 4 and 6 days post-inoculation, respectively. The spleen and

liver cultures were positive in 76% of the mice who died within 6 days of inoculation. Exotoxin A was detected in their sera 2 days post-infection and remained detectable for 6 days. Table 2 Survival rates, presence of exotoxin A, culture results and colony counts in the control group (non-immunized mice) inoculated withP. aeruginosa Post-inoculation Adenosine time (day) Number of animals alive (survival rate, %) CFU/mL from inoculated burns Exotoxin A in sera (%)* Positive culture (%)         Liver Spleen Blood 1 25 (100) 1 × 108 – - – - 2 25 (100) 1.14 × 108 2 (8) – - 2 (8) 3 12 (48) 1.25 × 108 8 (32) 2 (8) 2 (8) 8 (32) 4 8 (32) 1.6 × 108 8 (32) 8 (32) 8 (32) 8 (32) 6 5 (20) 1.7 × 108 3 (12) 5 (20) 5 (20) 3 (12) * detected with CIEP Table3 shows the colony count, survival rate, quantity of exotoxin and anti-exotoxin A and the result of cultures of the blood, spleen and liver of the mice in the experimental group. As expected, no exotoxin A was detected in the sera by CIEP, which may be due to neutralization of the toxin by previously antitoxins formed following immunization. Bacterial infection is a major complication after thermal injury, especially in developing countries [16–18]. 75% of deaths following burns are related to microbial infections [19].