[Comparative study of antibiotic resistance in bacteria isolated from the burned patients during two periods [2005-2008, 2008-2011] and in two hospitals [hospital Aziza Othmana, trauma and burn center]]

Continuous monitoring of the bacterial flora and antibiotic resistance of the main bacteria involved in nosocomial infections helps improve treatment and prevention strategies. To compare the bacteriological profile and antibiotic susceptibility of the main bacterial isolates within the burned patients over two periods of 3 years and in two hospitals. During two three-year periods: period 1 [P1]: 1/7/2005-30/6/2008 and period 2 [P2]: 1/7/2008-30/6/2011] and in two hospitals: Hospital Aziza Othmana [HAO] and the traumatology and burn center [CTGB], 2153 and 3719 non-repetitive strains were isolated from burn patients from different samples. The transfer of the intensive care unit was made on 01/07/2008 from the Hospital Aziza Othmana to CTGB. The study of antibiotic sensitivity was performed according to CA-SFM. During the period P1, Pseudomonas aeruginosa was the main bacteria isolated [18%] followed by Staphylococcus aureus [14%] and Acinetobacter baumannii [12%]. After the transfer of intensive care burn unit to the traumatology center, ecology bacterial varied with S. aureus [20%] in the first place followed by P. aeruginosa [15%] and Proteus mirabilis [11%]. The study of the evolution of antibiotic susceptibility showed an overall downward trend of resistance in the second half of 2008, immediately after the transfer of service in the new hospital structure. The rate of ceftazidim resistant Klebsilella pneumoniae decreased from 80.4% to 50%, Similary the resistance of P. aeruginosa to ceftazidime and imipenem decreased respectively from 61% to 39.4% and from 63.3% to 37.1%. Nevertheless, the reduction of resistance was followed by a rapid increasing during the year 2009 to reach overall rates of resistance previously observed in the hospital Aziza Othmana. Concerning S. aureus, the rate of MRSA [methicillin-resistant S. aureus] showed no significant variation throughout the study period: 60% versus 56.3% at HAO and CTGB. A. baumannii brings up the problem of mutir‚sistance: 92.7% of strains were resistant to ceftazidime and 63.9% to imipenem during P1 with an emphasis on resistance to imipenem during P2 increased to 89.3%.Resistance is a problem in the intensive care burn unit. Preventive measures have to be taken

[Epidemiological profile and antibiotic resistance of pseudomonas aeruginosa isolates in burn and traumatology center in Tunisia over a three-year period]

Pseudomonas aeruginosa is a known opportunistic pathogen frequently causing serious infections in burned patients. To analyze the epidemiological profile of Pseudomonas aeruginosa isolated in a Tunisian burn unit. During a 3-year period [from 01 July 2008 to 30 June 2011], 544 non repetitive strains of P. aeruginosa were isolated from burn patients. Susceptibility to antibiotics was assessed according to CA-SFM guidelines. Serotypes were identified by slide agglutination test using P.aeruginosa O antisera [Biorad]. Producing carbapenemase was analyzed for 202 imipenem resistant isolates by EDTA test. Susceptibility testing data were stored in a laboratory data base using whonet 5.3 software. The most frequent sites of isolation were cutaneous infections and blood cultures [83.4%]. The percentages of resistant isolates were as follows: ceftazidime: 34%; imipenem: 37.1%, ciprofloxacin: 27.1% and amikacin: 29.6%. The most prevalent serotypes were: 011[51%], 06[17%], 03 [8%], 04[12%], 012[5%]. Among the 202 imipenem resistant strains, 58% expressed a metallocarbapenemase. All theses strains were resistant to all tested antibiotics except colistin and belonged to the serotype O11. The dissemination of carbapenemases strains must be contained by implementation of timely identification, strict isolation methods and better hygienic procedures