[ impact of fluoroquinolones use on antibiotic resistance in an intensive care burn department]

Fluoroquinolones [FQ] use has been identified as a risk factor for colonization and infection to methicillin resistant Staphylococcus aureus [MRSA], Pseudomonas aeruginosae multiresistant [PMR]. Acinetobacter multiresistant [AMR] and multidrug resistant bacteria [MDRB]. Our study proposes to measure the annual antibiotic use of FQ and antimicrobial resistance in P. aeruginosa, S.aureus, Klebsiella pneumoniae and A. baumannii in an intensive care burn unit. The study was conducted during a 4 year period [1 January 2000 to 31 December 2003]. Antimicrobial susceptibility testing was performed using the disk diffusion method as recommended by the French Society of Microbiology. The consumption of the following antibiotics: ofloxacin, ciprofloxacin was expressed as the antimicrobial use density [AD] taking into account the quantity of antibiotics in Grams converted to defined daily doses [DDD] and the number of day hospitalization. Statistical significance was defined as p value <0.05 for the corresponding correlation coefficient. There were statistically significant relationship between use of ciprofloxacin and resistance in P. aeruginosa to this drug [rs=0.95, p<0.05]. Moreover, the ciprofloxacin consumption was correlated with resistance to imipenem [rs= 0.95, p<0.05] and ceftazidime [rs=0.95, p<0.05] in P. aeruginosa. A restriction use of ciprofloxacin has been taken during 2003, it is followed by a significant decrease of resistance to imipenem, ceftazidime and ciprofloxacin in P. aeruginosa [p< 0,05]. The use of fluoroquinolones was correlated significantly with MRSA [rs= 0.96, p>0.05] in P. aeruginosa. A restriction use of ciprofloxacin has been taken during 2003, it is followed by a significant decrease of resistance to imipenem, ceftazidime and ciprofloxacin in P. aeruginosa [p<0,05]. The use of fluoroquinolones was correlated significantly with MRSA [rs=0.96, P<0.05. The restriction of FQ was significantly associated with a decrease of MRSA. The consumption of ciprofloxacin was also correlated [P<0.05] with resistance of ceftazidime in K. pneumoniae. However, there is not a correlation [P>0.05] between fluoroquinolones use and resistance in A. baumannii as well in ciprofloxacin, imipenem and ceftazidime. Our study illustrates the pressure of selection of fluoroquinolones use in the department of MDRB. The use and or the duration of treatment with these antibiotics should be rationalized as part of efforts to control the emergence of multidrug resistant bacteria

[Bacteriological profile of urinary tract infections in women in Aziz Othmana hospital: a 495 cases study]

Urinary infection is a frequent pathology in the community as well as at the hospital. To analyze the profile of bacteria isolated from urinary tract infectious in women and their antimicrobial resistance. During two year period [1 January 2005 to 31 December 2006], 4536 urinary specimens were analyzed at the Laboratory of Aziza Othmana Hospital. All bacteria isolated from urinary tract infection [UTI] at women were retrospectively reviewed. 495 cases of UTI were collected during this period. They were recovered from out patients [67%] or from hospitalized patients in Gynecology and obstetrics [23%]. Enterobacteriacae were the most frequently identified strains [90.4%] including Escherichia coli [71%]. The identified strains presented natural resistance and a high frequency of acquired resistance to betalactams[60.3% of E.coli, 72% of P.mirabilis were resistant to amoxicillin]and cotrimoxazole[30.4% of E.coli, 19,1 of K.pneumoniae, 21.4% of P.mirabilis]. 5.7% of K.pneumoniae and 1.8% of E.coli were producing extended spectrum betalactamase[ESBL]. Aminoglycosides remained active on enterobacteriacae[resistance to amikacin<14%,gentamicin<5%].Ofloxacin was highly active against enterobacteriacae [resistance <14%]. Enterobacteriacae were the most frequent species in women urinary tract infection. Among these isolates, a high frequency of acquired resistance to betalactams and cotrimoxazole was shown. Aminoglysosides and fluoroquinolones remained the most active drugs. In every case antibiotherapy should have been prescribed after performing an antibiogram for each strain. These data were useful for the first line antibiotherapy, however the antimicrobial susceptibility testing is necessary for the rational use to limit the highly active drugs to multiresistant strains

[Bacteriological profile and antibiotic resistance of bacteria isolates in a burn department]

Nosocomial infections remain the main cause of morbidity and mortality in burn patients. Ongoing surveillance of infections in burned patients is essential to detect changes in epidemiology and to guide better empirical antibiotherapy and infection control policies. The aim of this study is to analyze the bacterial flora and the antibiotic resistance of isolates in a burn department during a two year period. From 1 January 2005 to 31 December 2006, 1268 strains were isolated from different specimens. Antimicrobial susceptibility testing has been carried out by disk diffusion method as referred to the French Society of Microbiology. All data were stored in a laboratory data base using whonet 5.3 software. Duplicate isolates defined as the same bacterial species for the same patient with the same antimicrobial susceptibility profile were excluded. The most frequently identified species were Staphylococcus aureus [19,8%], Pseudomonas aeruginosa [15.8%], Acinetobacter baumannii [11.8%],Providencia stuarttii.The rate of meticillin resistant S.aureus was 68,1%, all isolates were fully susceptibles to glycopeptide. P.aeruginosa resistance was 35,6% and 35.4% respectively for ceftazidime and imipeneme. Concerning A.baumannii, 98.7% of strains were resistant to ceftazidime, 59.5% to imipenem and 87. 5% to ciprofloxacin. 77.3% of P.stuarttii isolates were resistant to ceftazidime and were producing extended spectrum, lactamase [ESBL]. The frequencies of resistance to ceftazidime, ofloxacin and amikacin of K.pneumoniae were respectively 60. 9%, 25.4% and 47. 1%. Comparatively to the previous years, S.aureus still be the commonest pathogen in the burn department. The incidence of antimicrobial resistance has decreased during 2006 after a peak of multiresistance during 2005. Our results should be helpful in providing useful information regarding antimicrobial resistance among the burn isolates and this will help in formulation of effective guideline for therapy

[Surveillance of multidrug resistant bacteria in a Tunisian hospital]

Controlling antibiotic resistance of bacteria is a priority for public healthcare. This study concerned the frequency of multidrug resistant bacteria [MDRB] in a Tunisian Hospital with the aim of establishing guidelines for MDRB prevention. The study was conducted during two years [1 January 2005-31 December 2006]. Samples collected for the clinical diagnostic were included. The MDRB concerned were: methicillin resistant Staphylococcus aureus [MRSA], Enterobacteriacae resistant to of third generation cephalosporin [ER3GC]. Acinetobacter baumannii resistant to both imipenem and ceftazidime, Pseudomonas aeruginosa resistant to both imipenem and ceftazidime. During the study period, 2475 bacteria were tested by disk diffusion. 597 MDRB were collected, the rate of MBR was 24.1%. These MDRB were mainly recovered in burn unit [82.6%]. ER3GC [47%] and MRSA [29, 2%] were the most frequent MDRB. A. baumannii and P. aeruginosa multiresistant concerned 4, 8% and 9% of MDRB. MDRB were isolated mainly from blood cultures [45%]. The rate of MRSA was 46.4% among 375 strains of S. aureus. ER3GC represented 25, 6% among 1096 isolates. Concerning A. baumannii and P. aeruginosa, 51.7% and 20.5% were resistant to both imipenem and ceftazidime among 170 and 264 isolates. Antiobiotic resistance evolution showed a decrease of resistance in 2006 versus 2005. This decrease should be explained by the improvement of hygiene measure especially hand washing with the introduction of hydro- alcoholic solutions, a better targeted antibiotherapy promoved by a close cooperation between microbiologists and clinicians. The MDRB were frequent in our hospital. They were mainly isolated from the burn department. The measures of prevention already implemented are effective and must be strengthened with the continuous surveillance of MDRB

Bacterial flora and antibiotic resistance in a clinical haematology unit

Infections are among the most serious complications in neutropenic patients and are associated with an increased morbidity and mortality. Ongoing surveillance of infection in neutropenic patients is essential to detect changes in epidemiology and to guide better empirical antibiotic regimens and infection control policies. The aim of this study is to analyze the bacterial flora and the antibiotic resistance of isolates in a clinical haematology unit during three years period. From 1 January 2003 to 31 December 2005, 437 strains were isolated from different specimens. Antimicrobial susceptibility testing has been carried out by disk diffusion method as referred to the French Society of Microbiology. All susceptibility data were stored in a laboratory data base using Whonet software. Duplicate isolates defined as the same bacterial species for the same patient with the same profile of susceptibility were excluded. Gram negative bacilli [GNB] rate was 47.1% and Gram positive cocci [GPC] rate 52.9%.The most frequently identified species were coagulase negative staphylococci [CNS]: 29.3%, Escherichia coli:14%, Staphylococcus aureus: 10.7%, Klebsiella pneumoniae: 9.1% and Pseudomonas aeruginosa:7.5%. The global rate of methicillin resistant staphylococci was 27.7% for S. aureus and 61.4% for CNS, no GISA [glycopeptide intermediate S.aureus] was detected during the study period. For E. coli, the frequencies of resistance to ceftazidime, ciprofloxacin and amikacin were respectively: 45%, 26. 3% and 21.3%.Concerning K. pneumoniae, 84, 8% of strains were resistant to ceftazidime and were producing extended spectrum,-lactamase [BLSE]. The trends of resistance showed an increasing rate of K. pneumoniae BLSE: 57.1% in 2003 versus 95.5% in 2005. However; all isolates remained susceptibles to imipenem and colistin. Concerning P. aeruginosa, 50% were resistant to ceftazidime, 50% to imipenem, 51.6% to ciprofloxacin and 54.5% to amikacin. An increasing rate of imipenem resistance in P. aeruginosa was observed from 2003 to 2005[28. 6% in 2003 versus 45. 5% in 2005]. Following this study, a restriction use of ceftazidime [substituted by piperacillin-tazobatam] was instaured in the unit. A further study should be conducted to evaluate the impact of piperacillin-tazobactam as a first line treatment in neutropenic patients