[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

[ 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

[Evolution of antibiotic consumption in an intensive care burn department]

Background: The increasing consumption of antibiotics in hospitals and the economic implications of this increase lead to survey this consumption in the various hospital units

Aim: Our study proposes to measure the annual antibiotic use and antimicrobial resistance in an intensive care Burn department in order to manage the control measure

Methods: The study was conducted during a 5 year period [1 January 2000 to 31 December 2004]. The average number of admissions was 204/ year and the mean number of hospitalization was 4036/year. Antimicrobial susceptibility testing was performed by disk diffusion method. Susceptibility testing data were stored in a laboratory data base using whonet 5.3 software. The consumption of following antibiotics: imipenem, ceftazidime, ofloxacin, ciprofloxacin, piperacillin-tazobactam was measured by antimicrobial density [AD] which takes into account the quantity of antibiotics in Grams converted to daily defined dose [DDD] and number of hospitalization days. The daily defined dose [DDD] was proposed by WHO. The calculation of the AD for each molecule was carried out according to the following formula: AD=Quantity consumed in grams for the particular antimicrobial X 1000/ DDD for that antimicrobial X number of days hospitalizations

Results: There was statistically significant relationship between increasing use of ceftazidime and ceftazidime resistant Klebsiella pneumoniae [rs = 0.93; p=0.02] The use of ceftazidime was not significantly associated with resistance to this molecule in P.aeruginosa [rs=0.76; p=0.13]. Concerning the fluoroquinolones, there was statistically significant relation ship between increasing use of ciprofloxacin and rate ciprofloxacin resistant P.aeruginosa [rs = =0.89, P=0.043]. Furthermore, the consumption of ciprofloxacin was significantly correlated to imipenem resistance in P.aeruginosa [rs = 0.87, p=0.05]. However, the consumption of imipenem was not significantly correlated to resistance of this drug in P.aeruginosa [rs==0.54; P=0.4]

Conclusion: The monitoring of both antibiotic consumption andantibiotic resistance is necessary to set up targeted policies and to control their effectiveness. Nevertheless this monitoring must be integrated into global policy of good use and control of antibiotics

Study of sensistivity to antibotics for Staphyloccous aureus strains isolation in a department of resuscitation of badly burned patients

Methicillin resistant Staphylococcus aureus [MRSA] constitutes one of the main causes of nosocomial infections in badly burnt patients The purpose of our study was to determine the frequency and evolution of Methicillin resistant Staphylococcus strains in the department of resuscitation of badly burnt patients of Hospital AZIZA OTHMANA From January 1,2000 to December 31, 2003, tests for Staphylococcus aureus proved positive in 139 patients on at least, one occasion. Mean age of patients was 34 years and their sex ratio 1,7. 59,7% of the accidents were house hold accidents, and 70% of them were of thermal native. The average burnt cutaneous surface area was 44%. Sepsis occurred 7 days on average after admission to hospital. Hospital stay for this group varied between 3 and 140 days, outcome was fatal in 13 cases. MRSA occurred in 69% of cases. As for the other families of antibiotics, the frequencies of resistance remained elevated for tetracyclines, Cotrimoxazole, gentamicine, erythromycine

[Bacteriological profile of bacteremias in badly burnt patients]

The purpose of this work is to study the bacteriological profiles of germ responsible for bacteremias/septicemias in badly burnt patients hospitalized in burns units, in order to guide better the antibiotherapy of first intention. During the period of survey going from January 1st, 2001 to December 31 st,2002 71 patients had one or several episodes of bateremia. The average burnt cutaneous surface was 48.7%. All collected bacteremias were contacted in hospital. Empirical antibiotherapy was effective in 30 patients. The hospital stay for this group was long: 45 to 86 days. Acinetobacter baumannii was the most incriminated germ[20.3%], followed Klebsiella pneumoniea [12.7%]. The frequency of resistance was variable according to the considered species

Pseudomonas aeruginosa: etude multicentrique de la resistance aux antibiotiques [1999-2000]

A retrospective multicentric study was carried out over a period of 2 years [1999-2000]. 2659 strains of pseudomonas aeruginosa were collected from 4 university hospitals [charles Nicolle Hospital, pediatric Hospital and national center of Bone Marrow Transplantation in Tunis, Habib Bourguiba Hospital in Sfax]. Epidemiological profile and antibiotic susceptibility were analyesd. All bacteria were identified by conventional methods and antibiotic susceptibility tests were performed according to CA-SFM guidelines. The strains were recovered essrntially from surgical wards [33%] and intensive care units [22%]. Pseudomonas aeruginosa was isolated mainly from pus [36%] urine [32%]and respiratory samples [18%]. 25% of strains were resistant to ticarcilline, 18% to cefsulodine, 9% to ceftazidime, 14% to imipenem and amikacin and 25% to ciprofloxacin. Moreover, the resistance rates varied from hospital to hospital and from unit to another. The resistant strains were isolated particularly from urology and intensive care units: respectively 62% and 39% for ticarcilline; 26% and 13% for ceftazidime. The acquired resistance to b-lactams seems largely due to penicillinase production. The frequency of resistance to ceftazidime was the lowest and seem associated to chromosomal cephalosporinase over production

Interet des bandelettes reactives dans le depistage de l'infection urinaire chez l'enfant

The aim of this study is to specify the role of rapid tests in the screening of chilhood urinary tract infection. During the period between july to December 1998, 572 urinary samples were collected from pediatric outpatient in Hospital d'Enfants de Tunis and aged from 1 month to 15 years. Only 75 amples [12.5%] were culture positive. The predictive value of leucocytes or nitrites test was 97.2%. these results allowed the use of rapid test in the screening of urinary tract infection in children. However, if clinical symptoms are present, the culture of urine must be associated to the rapid test

Profil epidemiologique des infections a H. influenzae en Tunisie

Haemophilus inluenzae, a commensal bacteria, is frequently incriminated in broncho pulmonary surinfections and severe diseases as meningitis, pneumonia and septic arthritis,particularly in young children. A multicenter study was conducted to establish the epidemiological profile of haemophilus influenzae, to determine the rate of antibiotics resistance for guide therapeutic and preventive strategies. The identification was based on the requirements for x and v factors, and the serotype b determined by agglutination. The betalactamase production was done by nitrocefin test. Antimicrobial susceptibility testing was determined on Muller Hinton chocolate agar with isovitalex. During the two year period, [January 1998 December 1999], 192 isolates of H. influenzae were collected, 61% were recovered from invasive infections [44 meninggitis, 8 bacteremia, 2 arthritis]. The serotype b was identified in 55.7% of cases, 67.3% were invasive strains. 24.5% of isolates were producing betalactamase particularly invasive serotype b strains. All isolates of H. influenzae were susceptible to cefotaxim and to ofloxacin. Resistance rates to other antibiotics were: erythromycin 56.2%, tetracycline 10.3%, rifampin 12%, chloramphenicol 1%, cotrimoxazole 16.5%, 11.5% amikacin and 20% gentamicin. The incidence of meningitis remained frequent in our country, involving the introducyion of the vaccination in offical calencedar. Nevertheless, the surveillance of H. influenzae invasives infections and the serotyping of isolates were necessary to evaluate the impact of the immunization