Carbapenem-resistant Acinetobacter baumannii producing the carbapenemase OXA-23 in Tunisia

To analyze the mechanisms of resistance to carbapenems among imipenem resistant A. baumannii recovered from different wards at Charles Nicolle Hospital. From January to December 2007, 50 carbapenem-resistant A. baumannii isolates were recovered from hospitalized patients. MICs were performed by agar dilution method and interpreted according to CLSI guidelines. Metallo-beta-lactamase production was evaluated using imipenem-EDTA disk synergy test. PCR and DNA sequencing targeting blaOXA genes were performed and pulsed field gel electrophoresis was used for epidemiologic study. Most of the isolates were obtained from patients hospitalized in surgery [62%] and Intensive Care Units [22%]. All strains showed high level of resistance to ticarcillin [MIC50 > 2048micro g/ml], ticarcillin-clavulanic acid [MIC50 >1024micro g/ml], aztreonam [MIC50 = 512micro g/ml], ceftazidim [MIC50 = 512micro g/ml], imipenem [MIC50 = 512micro g/ml], meropenem [MIC50 =128micro g/ml] and cefepime [MIC50 = 256micro g/ml]. Metallo-beta-lactamase production was negative for all isolates. The co-existence of blaOXA-51-like/ blaOXA-23-like was detected in 82% [n= 41]. The genes blaOXA- 24-like and blaOXA-58-like were not found in any isolate. All isolates harboured a blaOXA-51-like gene. Sequencing confirmed the presence of blaOXA-23 and blaOXA-69 genes. Eight distinct patterns were observed [A: 41 isolates, B: 1 isolate, C: 1 isolate, D: 1 isolate, E: 1 isolate, F: 2 isolates, G: 1 isolate, H: 2 isolates]. Production of OXA-23 was the important mechanism of resistance to carbapenem among A. baumannii. Strengthening of prevention measures are required to control further spread of carbapenemases in Tunisia

Corynebacterium propinquum isolated from a pus collection in a patient with an osteosynthesis of the elbow

Although non- diphtherial corynebacteria are ubiquitous in nature and commonly colonize the skin and mucous membranes of humans, they rarely account for clinical infections. Aim: we report a case of infection due to non- diphtherial corynebacteria, Corynebacterium propinquum. A Tunisian male patient of 67 years old was admitted to orthopedic surgery and traumatology ward of Charles Nicolle university hospital of Tunis [Tunisia] for a left elbow trauma. He was treated by osteosynthesis and received an antibioprophylactic therapy with amoxicilline-clavulanate and gentamicin association. No postoperative incident was noted. When he was readmitted a month later for the osteosynthesis material removal, clinical examination found a pus collection in the operated elbow. Specimen analysis showed a Gram positive stained bacilli identified as C.propinquum. The organism was resistant only to penicillin G and sulfamethoxazole-trimethoprim association. The patient was treated with ofloxacin [2g per day for 8 days] and gentamicin [160mg per day for 5 days] with clinical improvement. According to literature, infections due to C.propinquum are rare, occurring especially in patients with medical device or immunocompromised. Thus, this pathogen should be taken in consideration in such situations

Hospital acquired outbreak of methicillin-resistant staphylococcus aureus infection initiated by a health care worker

Methicillin-resistant Staphylococcus aureus [MRSA] has become an increasingly important pathogen leading to hospital acquired infections. This study was done to confirm an outbreak of MRSA suspected at Charles Nicolle Hospital. From 26 April to 11 June 2002, six patients hospitalized in the dermatologic ward at Charles Nicolle hospital of Tunisia have developed infections caused by MRSA. An investigation of the outbreak has been detected a nasal carriage nurse. This carrier received topical mupirocin treatment to decolonize the anterior nares and the outbreak was stopped without further incident. Typing of the MRSA strains by pulsed field gel electrophoresis demonstrated the same pulsotype shared by all isolates showing that MRSA isolates belonged to a single clonal type responsible of outbreak. Colonized nurse was the source of MRSA dissemination. This report illustrates the risk of nosocomial outbreak linked to cares delivered by the staff personnel. More sensibilisation and the respect of strict hygienic measures should be emphasized

[Evaluation of hand hygiene in healthcare staff of Charles Nicolle hospital of Tunis by questionnaire]

Known to be reservoir of bacteria, hands are implicated in bacteria cross-transmission which enhances nosocomial-acquired infection rates [NI] and outbreaks. Hand washing is then considered the first mean with authentic efficiency to prevent NI. To describe the situation of the hand hygiene at Charles Nicolle hospital of Tunis in order to identify problems that can oppose to the good execution of this practice. A descriptive transverse study performed in October 2006 where 600 questionnaires were distributed to healthcare staff of the hospital. Only 434 questionnaires were responded [158 doctors and 276 nurses]. Analysis of data obtained showed that hand washing was essentially practiced after each contact presumed to be contaminant for the healthcare person himself [80%] and was principally done with water and soap [82%]. Hydro-alcoholic solutions were rarely mentioned [17.1%]. The main reasons evoked for the non observance were unavailability of the necessary means [84.8%] and default of awareness [61.3%]. So, these results show a poor perception of the healthcare staff of on the importance of hand hygiene which they share the responsibility with healthcare managers. Thus, implication of all healthcare actors is necessary to ensure the good practice and mainly the observance of hand hygiene

[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

Self-medication with antibiotics in the ambulatory care setting within the Euro-Mediterranean region; results from the ARMed project

Anecdotal data from the southern and eastern Mediterranean region suggests that self-medication with antibiotics is commonly practiced in many countries. In order to provide proper information on the situation, we undertook short structured interviews in out-patients clinics or primary health centres in Cyprus, Egypt, Jordan, Lebanon, Libya, Tunisia and Turkey. A total of 2109 interviews were undertaken of which 1705 completed the full questionnaire. Self-medication was reported by 19.1% [<0.1% in Cyprus to 37% in Lebanon] of respondents. Intended self-medication ranged from 1.3% [95% CI 0%, 3%] in Cyprus to 70.7% [95% CI 64%, 77%] in Jordan. Upper respiratory tract symptoms were the most frequent reasons for which respondents indicated they would self-medicate. 48.4% of the whole group replied that they kept antibiotics at home, being highest in Lebanon [60%, 95% CI 51%, 69%]. We found a significant association between antibiotic hoarders and intended users of antibiotics for self-medication. Our data confirms that non-prescribed antibiotic use is high within ambulatory care in southern and eastern Mediterranean countries, being almost twice that reported in a similar European study. Corrective efforts are clearly required in the region to ensure proper use of antimicrobials so as to reduce pressure for antimicrobial resistance

[Spread of multidrug resistant acinetobacter baumannii in a teaching hospital]

A. baumannii is an important opportunistic pathogen widely distributed in the hospital environment and responsible for a variety of nosocomial infections especially in patients from intensive care units. We describe an outbreak of Acinetobacter baumannii [16 stains] in 3 intensive care units [I, II, III] at Charles Nicolle hospital of Tunis over a 5 month period [March to July 2005]. The antimicrobial susceptibility was determined by disc diffusion test and the genetic relatedness of isolates was done by Random Amplified Polymorphic DNA [RAPD] analysis. Two strains not related to the outbreak were used for the discrimination of the technique. Samples were collected from blood [44%], materials [31%], pus [6.5%], urines [6.5%] and respiratory tract [12.5%]. Antibiotic resistance pattern showed 2 different profiles. However, molecular typing of isolates revealed 3 distinct profiles [A, B, C] represented respectively by 8, 7 and one isolates. The major profile was the profile A found in 5 patients and in materials. It was appeared firstly in intensive care unit I. then in the 2 other units [II and Ill]. The profile B was observed also in the 3 units. However, the profile C was found in one patient in unit I. These data emphasize the need for active surveillance for multidrug-resistant Acinetobacter baumannii, and the value of molecular typing of strains in hospital settings to investigate spread of infection

[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

[Community-acquired pneumonia due to panton-valentine producing staphylococcus aureus: first description in Tunisia]

Community-acquired pneumonia clue to Panton-Valentine producing S. aureus is a serious infection recently described. Many cases have been reported worldwide. We report here the first case in Tunisia. Our patient is a previously healthy fourteen-year-old girl hospitalized for bilateral hypoxemic pneumonia. The clinical course had violently deteriorated two hours later, marked by massive hemoptysis that lead to rapid degradation of her hemodynamic state and death. Toxicologic research and blood cultures were negatives. A post- mortem pleural specimen culture yielded a meticillin-resistant Staphylococcus aureus strain that carried the Panton-Valentine leucocidin genes. Community-acquired pneumonia due to Panton-Valentine producing Staphylococcus aureus is a serious affection unrecognized in our country. Thus, this pathogen must imperatively be included in the spectrum of those responsibles for pulmonary infections in children and young adults

[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

[Methicillin resistant staphylococcus aureus: Phenotypic and genotypic studies]

Staphylococcus aureus is a human opportunistic pathogen. Its important pathogenicity and the increasingly rate of resistance to methicillin ate the main causes of morbidity and mortality. In order to evaluate the epidemiologic situation of Methicillin Resistant S. aureus [MRSA] at Charles Nicolle hospital. A four years retrospective study [January 1999-December 2002] was conducted. 65 non redundant MRSA isolates were collected. Identification was based on morphology, culture and biochemical characters. Antibiotic susceptibility was determined by disk diffusion method. Resistance to methicillin was confirmed by mec A PCR. Molecular typing was performed by Random Amplified Polymorphic DNA using ERIC-IR. Despite a perfect biotypic similarity between strains, ERIC-IR PCR revealed 7 genotypes. The combination of phenotypic methods and RAPD fingerprinting were easy to perform routinely for MRSA typing. However, phylogenetic relationship between strains needs more investigations

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

[Virological diagnosis and follow-up of HIV infection]

Human immunodeficiency virus [HIV] is a retrovirus infecting approximatively 40 millions people worldwide. HIV is characterized by a great variability with epidemiological, diagnostic and therapeutic implication. This course of infection goes through three stages [acute infection, clinical latency and AIDS] with the evolution of virological markers [anti-HIV antibodies, p24 antigenemia, plasma RNA and prevail DNA]. Direct virological diagnosis is mainly based on molecular tools allowing viral genome detection and amplification with specific primary and nucleic probes, besides p24 antigenic detection, and more rarely culture. Antigenic properties of viral proteins elicit in infected patients antibody synthesis, which is detected using serology [ELISA and Western blot tests]. The follow-up of infected patients is carried out with plasma HIV-1 RNA quantization and phenotypic or genotypic characterization of variant isolated. Virological testes are prescribed according of clinical presentation [screening, acute infection, newborn from HUIV-infected mother]. Most of these virological tools are available in Tunisia, allowing both diagnosis of HIV infection and monitoring of infected individuals. Regarding diagnostic tests indication and interpretation, multidisciplinary concentration is hopeful in order to optimize patient management

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

[Detection of DNA human cytomegalovirus of a molecular methods: hybrid capture DNA CMV by immunocompromised]

Human cytomegalovirus [HCMV], a member of the beta-virus herpes family, is a ubiquitous human pathogen. After a primary infection, HCMV establishes life latency. HCMV rarely causes symptomatic disease in an immunocompetent host, however, it is a major cause of infectious morbidity and mortality in immunocompromised individuals and developing fetuses. The HCMV genome consists of 240 kbp of double stranded DNA. Early diagnosis molecular of CMV infection is important. The objective of this study was to develop a molecular methods: Quantitative Hybrid capture for the detection of DNA CMV. We present results for 200 immunocompromised collected from 1999 to 2003 [122 men and 78 women, whom mean age was 35 years]. Our results showed that 25% of women and 36% of men were positif for hybrid capture DNA CMV.This simple test [cold probe] provide quantitative and fast results. Also the efficacity of anti-CMV therapy can be followed. More over. in contrary with pp65- antigenemia assay and CMV PCR, this test can be managed on biopsy sample

[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

Epidemiologie des septicemies a bacilles gram negatif: donnees d'un hopital Tunisien [1996 - 1998]

Gram negative bacilli [GNB] septicemia are among the most serious infections encountered in the hospital since they generally occur on debilitated patients and are due to the multi-drug resistant bacteria. A retrospective study relating to 195 septicemia was carried out with an aim studying epidemiologic profile, predisposing factors, entry sites for micro-organisms, responsible GNB and their antibiotic susceptibility. GNB septicemia were mainly frequent in intensive care units [34%] and surgery [31%]. Previous antibiotherapy, invasive procedures and surgical acts were the principal predisposing factors. The entry sites for micro-organisms remained unknown in 1/3 of the cases. The most common source of septicemia was the urinary tract infections. E. coli was the most frequent isolated bacteria [26%] in the community acquired spticemia whereas klebsiella enterobacter serratia [KES], acinetobacter and pseudomonas were mainly encountred in nosocomial infections. Imipenem remained the most active betalactamin on GNB [2% of resistance] with amikacin [16% of resistance] among aminoglycosides. The rate of mortality was 18%. Hospitalization wards [intensive care units, surgery], entry sites unknown, septic shock syndrome were the main factors of prognosis. The development of immunology and molecular biology should improve the outcome of these infection but the preventive measures remain the most effective