[Staphylococcus saprophyticus isolated from urine culture in outpatients: epidemiology and antimicrobial susceptibility (Label Bio Elbeuf study - November 2007-July 2009)]. / Staphylococcus saprophyticus isolés d'examens cytobactériologiques urinaires en ville : épidémiologie et sensibilité aux antibiotiques (étude Label Bio Elbeuf - novembre 2007-juillet 2009).

OBJECTIVE: The aim of the study was to determine the distribution and the antibiotic susceptibility of Staphylococcus saprophyticus patterns isolated from urine culture in outpatients (population: 57,000, Elbeuf, Normandie, France). DESIGN: Prospective study from November 2007 to October 2009 in collaboration with three private medical laboratories. Determination of susceptibility to oxacillin by disk diffusion (cefoxitin, and moxalactam), automated method (Vitek BioMérieux 2) and mecA PCR's detection. Determination of the minimum inhibitory concentration by microbroth dilution for other antibiotics. RESULTS: Five thousand and fifty-one bacterial strains isolated, 91 strains of S. saprophyticus (1.8%), 89 in women (2.25%) and two in men (0.18%). S. saprophyticus represented 10.3% and 14.5% of isolates (women respectively aged between 11 and 30; 16 and 20 years); S. saprophyticus is isolated less frequently in winter. mecA PCR detection was positive for two strains. All strains tested were susceptible to ciprofloxacin and furans. Only one strain is resistant to cotrimoxazole. CONCLUSIONS: S. saprophyticus is found mostly in women between 11 to 30 years. Cotrimoxazole (after susceptibility testing) is efficient in case of S. saprophyticus's cystitis. Furans (probabilistic treatment) have to be reevaluated because of the potential for serious adverse effects.

Assessment of the bio-preparedness and of the training of the French hospital laboratories in the event of biological threat.

A national laboratory network 'Biotox-Piratox' was created in 2003 in France with the purpose of detecting, confirming and reporting potential biological and chemical threat agents. This network is divided into three levels: Level 1 is dedicated to the evaluation of risks (biological, chemical, radiological), to sampling and packing. Level 2 consists of university and military hospitals, who deal with biological specimens, and of environmental and veterinary laboratories, who deal with environmental and animal samples. Level 3 comprises national reference laboratories and the Jean Mérieux biosafety level (BSL)-4 laboratory in Lyon. This report presents the results of four bio-preparedness exercises to check critical points in the processing of samples. These exercises took place in 2007, 2009, 2010 and 2011. Each of them consisted of two parts. The first part was the identification of an unknown bacterial strain and its susceptibility to antibiotics used as a default in case of a bioterrorist event. The second part was the detection of Class III microorganisms, mainly by molecular techniques. The main lesson learnt in these exercises was that the key to successful detection of biological agents in case of a biological threat was standardisation and validation of the methods implemented by all the laboratories belonging to the network.

[Fecal carriage of third-generation cephalosporins-resistant Enterobacteriaceae in asymptomatic young adults: evolution between 1999 and 2009]. / Portage digestif d'entérobactéries résistantes aux céphalosporines de troisième génération dans une population d'adultes jeunes asymptomatiques : évolution entre 1999 et 2009.

OBJECTIVES: The aim of this work was to evaluate the fecal carriage of third generation cephalosporins resistant Enterobacteriaceae in nonhospitalized asymptomatic young adults. METHODS: A total of 517 normal fecal samples were spread onto plates agar containing cefotaxime. Isolated strains were identified and studied with agar disk diffusion antibiogram, minimal inhibition concentration in liquid medium and phenotypic and molecular study. Data were compared with a previous study realised in the same conditions in 1999. RESULTS: In 2009, the prevalence of cefotaxime resistant enterobacteria was 4.2%. Of these 22 Enterobacteriaceae, 11 harboured overexpressed cephalosporinase and 11 produced extended-spectrum-betalactamase (ESBL). Among ESBL, six E. coli produced CTX-M from group 1 (n=6), group 2 (n=1), group 9 (n=2), one E. coli produced SHV-12 and one Klebsiella pneumoniae produced CTX-M from group 1. All ESBL were multiresistant. In 1999, all the CTX resistant isolates recovered produced a cephalosporinase and no ESBL was found. CONCLUSIONS: This study highlights the increasing prevalence of fecal carriage of ESBL-producing enterobacteria in asymptomatic young patients in the community (0% in 1999 versus 2.1% in 2009; P<0.001). E. Coli with CTX-M from group 1 was the most frequent ESBL identified, while fecal carriage of Enterobacteteriaceae overproducing cephalosporinase was similar (2.1%).

[Real-time PCR for fast detection of plasmid-mediated qnr genes in extended spectrum beta-lactamase producing Enterobacteriaceae]. / Mise au point d'une technique de PCR en temps réel pour la détection rapide des gènes qnr chez des entérobactéries productrices de bêta-lactamases à spectre étendu.

AIM OF THE STUDY: To develop a fast and reliable real time PCR technique for detecting plasmid-mediated quinolone resistance genes qnrA, qnrB and qnrS. METHODS: A real-time PCR assay using SYBR Green I and Roche LightCycler(®) was developed to detect qnr genes. Detection of qnr genes was based on comparison of melting temperature differences with a positive control of each qnr genes. This assay was performed to study 138 isolates collected from diagnostic and screening samples in the Champagne-Ardenne region in 2004 (France). RESULTS: In optimized conditions, the three positive controls tested alone and with isolates confirmed the specificity of the PCR primers. Each PCR assay was able to test 30 strains in 60min for 1 qnr gene. Out of 138 isolates screened, 3.6 % isolates were positive for a qnrA1, 1.5 % for qnrS1 and no qnrB-like gene. Prevalence of qnr determinants was 5 % and reached 9.5 % in clinical isolates. CONCLUSION: Real-time PCR is a fast and reliable technique for screening of qnr-positive strains. This study shows a relatively high prevalence of qnr determinants (5 %) among ESBL-producing Enterobacteriaceae.

[Automation and consolidation of clinical biology: the HIA Begin experiment]. / Automatisation et consolidation en biologie clinique: l'expérience de l'hôpital d'instruction des armées Bégin.

Reorganization of hospital or private sector labs is a strong trend. Such process implies consolidation of tests on a minimum of analyzers, harmonization of equipment (limitation of number of suppliers), posts number reduction, and development of powerful software. Increase of productivity needs set up of automation systems, specially at the level of pre-analytical phase, in a way to limit manual steps. At the same moment, quality improvement generates a decreasing TAT (Turn-Around-Time), a strong reduction of errors, a better protection against biological hazards, and standardization of sample management and validation process. After giving some notions about consolidation and integration, our choices for a brand new and innovative solution are explained.

[Infectious aetiologies of travelers' diarrhoea]. / Les étiologies infectieuses des diarrhées du voyageur.

Traveler's diarrhoea (TD) occurs in 20 to 60% of European or North-American travelers in intertropical areas. Following return from endemic zone, malaria must always be evocated in front of febrile diarrhoea. Many causative infectious agents are involved in TD and their frequency may vary according to destination and seasons. The main agents involved in TD are Escherichia coli pathovars (especially enterotoxigenic and enteroaggregative E. coli) followed by enteroinvasive bacteria (Campylobacter spp., Shigella spp., Salmonella enterica), enteric viruses (norovirus, rotavirus) and protozoa (Gardia intestinalis, Cryptosporidium parvum et Entamoeba histolytica). The development of molecular biology methods as PCR may allow us to evaluate the relative frequency of these agents and especially of viral agents in TD. Protozoa and microsporidia are more frequently isolated in persistent and chronic TD, especially in compromised patients. A complete etiological research in routine microbiology laboratories is difficult and time-consuming, related to the high diversity of causative agents and the need for specific methods. Implementation of laboratory diagnosis is highly recommended when diarrhoea is associated with fever or presence of blood in stools, immunosuppression, antibiotic treatment (Clostridium difficile toxins) or in case of persistent/chronic diarrhoea. According to the high frequency of acquired antibiotic-resistance in enteric bacteria, an antibiogram must be performed for all causative bacterial agents.

[Campylobacter fetus bacteremia and cellulitis complicating a venous access port infection in an HIV infected patient]. / Bactériémie et dermohypodermite à Campylobacter fetus sur cathéter à chambre implantable au cours d'une infection par le VIH.

Campylobacter fetus subspecies fetus is an opportunist Gram-negative bacillus, which is known to be a cause of systemic infections, mainly in immunocompromised patients. We report a C. fetus bacteremia and cellulitis complicating a venous access port infection in a patient with acquired immunodeficiency syndrome (AIDS). This bacillus seems to have a predilection for the vascular endothelium and its isolation is difficult. Physicians should be aware of C. fetus infection in patients with vascular devices. Microbiologists should accurately isolate this organism from clinical specimens by modifying incubation techniques and performing molecular biology. The prognosis seems to be improved by a prolonged betalactam antibiotic regimen, especially amoxicilline plus clavulanic acid. In HIV infected patients, quinolones that were successful in our case, should be used with caution because of increasing resistance to antibiotics.

[Community-acquired urinary tract infections in 15 to 65 years old female patients in France. Susceptibility of E. coli according to history: AFORCOPI-BIO network 2003]. / Infections urinaires communautaires de la femme de 15 à 65 ans: sensibilité aux antibiotiques de E. coli en fonction des antécédents: étude AFORCOPI-BIO 2003.

OBJECTIVES: A multicenter study was implemented in order to determine the distribution and antibiotic susceptibility patterns of strains isolated from 15 to 65 year old female patients with community-acquired urinary tract infections. PATIENTS AND METHODS: From October to December 2003, 11 French private laboratories consecutively collected 420 clinical strains with medical data. Minimal inhibitory concentrations of antibiotics on E. coli were determined using the agar dilution method in a coordinating center and interpretation followed the recommendations of the Comité de l'antibiogramme de la Société française de microbiologie. RESULTS: Escherichia coli was the most prevalent pathogen (80%) followed by Proteus mirabilis (4%), Klebsiella spp (2%), other Enterobacteriaceae (4%), Enterococcus spp (3%), Staphylococcus aureus (2%), Staphylococcus saprophyticus (2%), and Streptococcus agalactiae (2%). The susceptibility of E. coli strains was 61% for amoxicillin (AMX), 93% for nalidixic acid (NAL), 97% for norfloxacin (NOR) and ciprofloxacin (CIP), 77% for cotrimoxazole (SXT), 99% for fosfomycin, gentamicin and cefotaxime. The susceptibility of E. coli was lower in case of previous treatment with beta-lactam antibiotics for AMX (84 vs 95% p=0.02) and SXT (62 vs 81% p=0.02). In the same way, previous treatment with quinolones was associated with decreased susceptibility for NAL (84 vs 95% p=0.02) and SXT (62 vs 81% p=0.02). CONCLUSIONS: In 2003, fluoroquinolones, third generation cephalosporins, aminoglycosides, and fosfomycin kept a good activity on E. coli collected from community-acquired urinary tract infections in 15 to 65 years old female patients in France.

Occurrence of qnrA-positive clinical isolates in French teaching hospitals during 2002-2005.

Bacteria harbouring the novel qnrA plasmid-mediated mechanism of quinolone resistance have been described in different countries, but the frequency of their occurrence has not been investigated. In total, 1,468 clinical isolates of Enterobacteriaceae with quinolone resistance or extended-spectrum beta-lactamase (ESBL) phenotypes were collected from eight teaching hospitals in France during 2002-2005 and screened for qnrA. Overall, 28 isolates (22 Enterobacter cloacae, three Klebsiella pneumoniae, one Citrobacter freundii, one Klebsiella oxytoca and one Proteus mirabilis) were positive for qnrA, representing 1.9% of all isolates, 3.3% of ESBL-producing isolates (22% of the E. cloacae isolates) and 0% of non-ESBL-producing isolates. The prevalence of qnrA among consecutive ESBL-producing isolates in 2004 from the eight hospitals was 2.8% (18/639). Of the qnrA-positive isolates, 100% were intermediately-resistant or resistant to nalidixic acid, and 75% to ciprofloxacin. Twenty-one of the 22 qnrA-positive E. cloacae isolates were obtained from two hospitals in the Paris area, and molecular typing and plasmid content analysis showed clonal relationships for five, three and two isolates, respectively. The qnrA genetic environment was similar to that of the In36 integron. The remaining two isolates had qnrA variants (30 and 29 nucleotide differences, respectively, compared with the original sequence) and an unknown genetic environment. The ESBL gene associated with qnrA was bla(SHV-12) in most of the isolates, but bla(PER-1) and bla(SHV-2a) were found in two isolates. In France, it appears that qnrA-positive isolates are predominantly E. cloacae isolates producing SHV-12, and may be associated with the dissemination of an In36-like integron.

[Dermatological aspects in the risk of biological warfare]. / Aspects dermatologiques du risque biologique provoqué

The possible cutaneous manifestations of infectious biological warfare are multiple and vary depending on the agent used. An ulcerous and/or necrotic syndrome and/or regional lymphadenitis syndrome are possible with anthrax, tularaemia, bubonic plague and emission of trichotecene mycotoxins. A vesiculo-pustular syndrome with fever is provoked by smallpox, melioidosis and glanders. A purpural and/or haemorrhagic syndrome is seen during haemorrhagic fever viruses and septicaemic plague. These cutaneous manifestations are excellent markers that orient and alert when they occur in a context of a situation at risk, when several cases are observed in a usually non-exposed population and with extra-dermatological syndromes. They permit the early initiation of treatment.

[Utility and limitations of laboratory diagnosis of amebiasis]. / Intérêt et limites du diagnostic au laboratoire de l'amibiase en 2004.

Entamoeba histolytica is an invasive and pathogenic protozoan parasite that causes amebiasis. It must be distinguished from Entamoeba dispar, a nonpathogenic commensal parasite of the human gut lumen that is morphologically identical to Entamoeba histolytica. Diagnosis of amoebic colitis currently requires combination of microscopic examination of stool specimens with another technique allowing positive identification of the two species. Stool culture followed by zymodem analysis is considered as gold standard but is not applicable in routine practice. Detection of specific Entamoeba histolytica antigens in stools is a fast, sensitive technique that should be considered as the method of choice. Stool PCR is a highly sensitive and specific technique but high cost make it unsuitable for use in endemic areas where economic conditions are difficult. The utility of serologic tests in distinguishing Entamoeba dispar from Entamoeba histolytica is controversial. However serology is still considered as the method of choice for diagnosis of extraintestinal amebiasis. Circulating Gal/GalNac lectin antigens can be detected in the serum of 96% of patients with untreated amoebic liver abscess. In the future this method should allow early diagnosis and treatment of extraintestinal amoebiasis in patients who have not yet developed detectable serum antibodies.

A plasmid-mediated CMY-2 beta-lactamase from an Algerian clinical isolate of Salmonella senftenberg.

Multiresistance to antibiotics including beta-lactams, e.g. cefoxitin, was transferred by conjugation to Escherichia coli strain C1a from a clinical isolate of Salmonella senftenberg recovered from stools of an Algerian child. The susceptibility pattern to beta-lactams was similar to the profile mediated by an AmpC-type beta-lactamase. By biochemical analysis, typical AmpC-type enzyme substrate and inhibition profiles were obtained. Finally, an ampC plasmid-encoded beta-lactamase gene was cloned and sequenced. Its deduced amino acid sequence confirmed its identity as a class C beta-lactamase. It showed 99.5% sequence identity with the plasmid-mediated beta-lactamase CMY-2. The differences in the amino acid sequences of the two enzymes were located in the signal peptide.

Effect of beta-lactam antibiotics on the in vitro development of resistance in Pseudomonas aeruginosa.

OBJECTIVE: To investigate whether stepwise selection of resistance mutations may mirror the continued bacterial exposure to antibiotics that occurs in the clinical setting. METHODS: We examined the in vitro development of resistance to a number of commonly used antibiotics (cefepime, cefpirome, ceftazidime, cefotaxime, piperacillin and imipenem) in Pseudomonas aeruginosa, a significant nosocomial pathogen. Stepwise resistance was assessed by serial passage of colonies located nearest to the inhibition zone on antibiotic-containing gradient plates. RESULTS: The lowest frequencies of spontaneous resistance mutations were found with cefepime and imipenem; these drugs also resulted in the slowest appearance of resistance of spontaneous resistance mutations. In five wild-type P. aeruginosa strains, cefepime-selected isolates required a mean of 30 passages to reach resistance; resistance occurred more rapidly in strains selected with other cephalosporins. P. aeruginosa strains that produced beta-lactamase or non-enzymatic resistance generally developed resistance more rapidly than wild-type strains. For most strains, resistance to all antibiotics except imipenem correlated with increased levels of beta-lactamase activity. Cross-resistance of cephalosporin-selected resistant mutants to other cephalosporins was common. Cephalosporin-resistant strains retained susceptibility to imipenem and ciprofloxacin. CONCLUSIONS: From our in vitro study, we can conclude that the rate of development of resistance of P. aeruginosa is lower with cefepime compared with other cephalosporines.

Bacillus thuringiensis serotype H34 isolated from human and insecticidal strains serotypes 3a3b and H14 can lead to death of immunocompetent mice after pulmonary infection.

In 1995, we isolated a strain of Bacillus thuringiensis serotype H34 from severe human tissue necrosis. This bacterium was able to induce myonecrosis in immunosuppressed mice after cutaneous infection. Its potential pathogenicity for immunocompetent hosts was investigated in a mouse model of pulmonary infection. Mice infected intranasally by a suspension containing 10(8) spores died within 8 h in a clinical toxic-shock syndrome. In the same conditions, infection with a mutant without crystalline toxin, with the supernatant from a culture containing 10(8) bacteria ml(-1) and by the insecticidal strain serotypes 3a3b or H14 led to identical results. Lower inocula simply induced a local inflammatory reaction with bacterial persistence observed during the course of 10 days.

[Rapid diagnosis of malaria. The microwave furnace]. / Diagnostic rapide du paludisme. Le four à micro-ondes.

Thick blood is a well known method for malaria diagnosis, very faithful and sensitive, but it could not be used in emergency because it had to dry for many hours. Micro-wave over allows a quick drying (two minutes). Do it can now be used in emergency.

[Antibiotic sensitivity of 140 strains of Shigella isolated in Djibouti]. / Etude de la sensibilité aux antibiotiques de 140 souches de shigelles isolées à Djibouti.

Shigellae are the most frequently isolated invasive bacteria in Djibouti. 140 clinical strains collected during an eight months period have been studied for their in vitro susceptibility to antibiotics mainly used in treatment and prophylaxis by measure of MIC (agar dilution) for all antibiotics except for trimethoprim-sulfamethoxazole, trimethoprim and sulfamethoxazole (disk diffusion on lysed horse blood medium). Characterization of beta-lactamase is carried out for all strains resistant to amoxicillin and for all S. sonnei. The overall prevalence of resistance to amoxicillin is 41.7% (penicillinase TEM-1, OXA-1 and OXA-3 alone or associated) to tetracyclines 97.1% and to trimethoprim-sulfamethoxazole 51.4%. This prevalence is particularly high for amoxicillin with S. flexneri and for trimethoprim-sulfamethoxazole with S. sonnei. All strains of S. sonnei have a low level chromosomal cephalosporinase without phenotypic expression. Among 68 strains sensitive to trimethoprim-sulfamethoxazole, 39 are resistant to sulfamethoxazole alone. All strains are sensitive to nalidixic acid and fluoroquinolones. These data allows us to recommend fluoroquinolones for treatment and prophylaxis of shigellosis in Djibouti.

[Fever of unknown origin (FUO) in the camps of Rwandan refugees in the Goma region of in Zaire (September 1994)]. / Les fièvres d'origine indéterminée (FOI) dans les camps de réfugiés rwandais de la région de Goma au Zaïre (septembre 1994).

After the outbreaks of cholera, dysenteriae, meningitidis of which the rwandese refugees have been the victims in August and September 1994 in the camps of the Goma's area (Zaïre), the medical teams were confronted with a great number of fevers of unknown origin. In order to explore the possible etiologies, we have conducted a cases/controls study (n = 96). Clinically, the cases occur more frequently than controls headache (p < 0.001), splenomegaly (p = 0.02) and neutropeny (p < 0.001) Serologically, it has been constated non significantly difference between cases and controls, but prevalence of HIV-1 infections (19 and 6%) and arbovirus (23 and 10%) infections are very high. Arbovirosis could explain, partially or associated with HIV and tuberculosis, the presence of these fevers undeterminated more than malaria or typhus epidemic.

[Antibiotic sensitivity of aerobic gram-negative bacilli isolated from severe infections in 1992: results of a French multicenter study. Groupe d'Etude d'Infections à bacilles à Gram Négatif (GEIGN)]. / Sensibilité aux antibiotiques des bacilles à Gram négatif aérobies isolés d'infections sévères en 1992: résultats d'une étude multicentrique française. Groupe d'Etude d'Infections à bacilles à Gram Négatif (GEIGN).

OBJECTIVES: Antibiotic susceptibility of 649 gram-negative bacilli involved in severe infections and isolated in 18 teaching hospitals from January to December 1992 was evaluated. METHODS: Minimal Inhibitory Concentrations were determined by agar dilution method for piperacillin, piperacillin+ tazobactam and imipenem, and by a microdilution method for 11 other antibiotics (amoxicillin, amoxicillin + clavulanic acid, cefotaxime, ceftazidime, aztreonam, ticarcillin, ciprofloxacin, fosfomycin, tobramycin, gentamicin, amikacin). Criteria of Comité Français de l'Antibiogramme de la Société Française de Microbiologie were followed for interpretation. Betalactamases were identified by isoelectric focusing and overproduction of cephalosporinase was defined by the resistance phenotype. The main species isolated were Escherichia coli (45%), Pseudomonas aeruginosa (14%), Klebsiella pneumoniae (7.8%), Salmonella spp. (7.5%), Enterobacter cloacae (4%) and Klebsiella oxytoca (4%). Most of the strains were isolated from blood culture (72.3%), respiratory tract (11.4%) and intraabdominal infections (8.6%). Most of the enterobacteria isolates were susceptible to imipenem, aztreonam, amikacin and ciprofloxacin (percentages of susceptibility were respectively 99.3, 98, 98.3 and 96.3); in most of cases clavulanic acid did not entirely restore sensitivity to amoxicillin of penicillinase-producing strains. Among 89 P. aeruginosa strains, 82% were susceptible to imipenem and ceftazidime, 81% to the association piperacillin + tazobactam and 51% to ticarcillin. Resistance rates are very high for Acinetobacter baumannii except for imipenem. CONCLUSION: Production of TEM-type penicillinase and over-production of the chromosomal cephalosporinase are the most widely observed mechanisms of resistance (respectively 22% and 9% of 649 strains). Prevalence of extended spectrum betalactamases was low (1%) and essentially observed for K. pneumoniae.

[Sensitivity to antibiotics of bacteria from nosocomial infections. Evolution in resuscitation services of military hospitals]. / Sensibilité aux antibiotiques des bactéries d'infections nosocomiales. Evolution dans les services de réanimation des hôpitaux des armées.

OBJECTIVE: The aim of this study, conducted in the French Military hospitals, was to monitor the course of the antimicrobial sensibility of bacteria isolated from nosocomial infection in intensive care units. PATIENTS AND METHODS: A prospective study has been conducted from January to December 1998 in all the intensive care units of the French Army. All the non-repetitive strains isolated from nosocomial infection were collected and sent to a reference centre. Antimicrobial susceptibility was determined by the agar dilution method. Beta-lactamase were identified by iso-electro-focalisation. Antibiotics choice and interpretative criteria were those of the "Comité Français de l'Antibiogramme de la Société Française de Microbiologie". RESULTS: A total of 849 strains are included in this study. Pseudomonas aeruginosa was the most frequently isolated bacterium (20%) followed by Escherichia coli (19%) Staphylococcus aureus (15%), coagulase-negative Staphylococci (CoNS) (11%) and Enterococci (7%). Imipenem was the most effective antibiotic against enterobacteriaceae (336 isolates; 100% susceptibility). Gentamicin (92%), amikacin (92%) third generation cephalosporins (83%), aztreonam (83%) and ciprofloxacin (78%) were also very effective. Resistance to III generation cephalosporins was correlated with an extended spectrum beta-lactamase (BLSE) in 36% of cases. This BLSE could be associated with an over production of the constitutive cephalosporinase. The most frequent species producing BLSE were Enterobacter aerogenes (75% of BLSE) and Klebsiella pneumoniae (17%). Among the 172 P. aeruginosa isolated, antimicrobial susceptibility were respectively: 71% for imipenem, 62%: tobramycin, 60%: amikacin 59%: ciprofloxacin 59% piperacillin + tazobactam, 55% piperacillin, 53%: ceftazidime and 44% for ticarcillin. Seventy per cent of the 96 CoNS and 50.2% of the 126 S. aureus isolated were resistant to methicillin. A strain of S. aureus and 2 CoNS strains had intermediate resistance to teicoplanin. Twenty per cent of the 59 Enterococci strains isolated were resistant to aminopenicillins (10/11 strains of E. faecium), and 9% presented a high level of resistance to gentamicine. One strain of E. faecium was resistant to vancomycin. CONCLUSION: The evolution of the susceptibility to antibiotics in intensive care units reflects the antibiotic pressure and level of cross-transmission. High rates of meticillin-resistance among staphylococci, of resistance to beta-lactams antibiotics among P. aeruginosa and of ciprofloxacin among Enterobacteriaceae are shown in this study. The implementation of appropriate strategies for surveillance and prevention is necessary.