[Monitoring of antibiotic resistance of gram negative anaerobes]. / Surveillance de la résistance aux antibiotiques des anaérobies stricts à Gram négatif.

MATERIAL AND METHOD: Using an agar reference method (Norma M11-A5, National Committee for Clinical and Laboratory Standards) the minimal inhibitory concentrations of nine antibiotics were determined for 376 anaerobic strains. The following strains were investigated: 254 Bacteroides fragilis group (including 143 B. fragilis), 122 other gram-negative anaerobes (Bacteroides spp., Prevotella, Fusobacterium, Porphyromonas, Suterella, Desulfomonas, Veillonella). RESULTS: In the B. fragilis group resistance rates were: coamoxyclav 2.8%, ticarcillin 27.5%, ticarcillin-clavulanic acid 1.9%, piperacillin-tazobactam 1.9%, cefoxitin 6.2%, imipenem 0.8%, clindamycin 28.3%, respectively. Based on previous studies, resistance to imipenem remained low in 2003 and was only observed for B. fragilis. Resistance to clindamycin was maintained around 25%. No metronidazole resistance was observed, but decreased susceptibility was found for B. fragilis, B. merdae and Prevotella, as in 4.3% of gram-negative anaerobes. DISCUSSION: This study confirms the high resistance rate of gram-negative anaerobes to clindamycin, the efficient activity of imipenem, beta-lactam/beta-lactamase inhibitor combinations and metronidazole. However, reduced metronidazole susceptibility seems to be increasing.

[Nasopharyngeal carriage of Streptococcus pneumoniae in healthy children, 2 to 24 months of age, in New-Caledonia]. / Etude du portage rhinopharyngé de Streptococcus pneumoniae chez les enfants sains âgés de 2 à 24 mois en Nouvelle-Calédonie.

OBJECTIVES: The aims of this study were to determine the prevalence of pneumococcal nasopharyngeal carriage in New-Caledonian children less than two years of age, to define risk factors for carriage, and to document the serotypes present in New Caledonia prior to the implementation of the conjugate pneumococcal vaccine. METHOD AND RESULTS: From August 2002 to April 2003, nasopharyngeal samples were collected on 1040 children less than two years of age during scheduled visits to dispensaries for routine immunization. Of the 1040 samples, 544 (52%) were positive for Streptococcus pneumoniae. The percentage of pneumococcal strains with reduced susceptibility to penicillin (PRSP) was 21%. Several risk factors for pneumococcal carriage were identified. These included the Province that the child lived in, the ethnic group, age, and having a sibling less than 6 years of age. Risk factors for carriage of PRSP carriage were similar but also included additional risk factors such as attendance at day care and a history of antibiotic treatment. The eight most frequent serotypes were 6B, 19F, 14, 23F, 6A, 19A, 11A, and 16F. These serotypes accounted for 60% of all strains detected. The most frequent serotypes of PRSP were 14, 9 V, 19F, 23F, and 6B. They were more often identified in european children and 80% were vaccine serotypes. However, overall 250/544 (46%) of all pneumococcal isolates were those included in the 7 serotype vaccine.

Infections following peripheral blood progenitor cell transplantation for lymphoproliferative malignancies: etiology and potential risk factors.

PURPOSE: We sought to describe the infections that occur after large-dose chemotherapy, which was followed by autologous peripheral blood progenitor cell transplantation, and to determine their risk factors. PATIENTS AND METHODS: We retrospectively analyzed the occurrence and the characteristics of infections in 277 consecutive patients who received intensive chemotherapy for non-Hodgkin's lymphoma (n = 207), Hodgkin's disease (n = 27), or multiple myeloma (n = 43) in a single institution. Conditioning regimens included total body irradiation in 47% of the cases. Infections occurring within the 30 days after transplant were defined as early infections, whereas infections after that time in patients who had achieved a neutrophil count greater than 1.0 x 10(9)/L (1,000 per microL) were considered as late infections. RESULTS: Within the first 30 days, 172 patients had unexplained fever (62%); infections were documented in 83 patients (30%), most commonly bacteremia (57 patients). Late infections occurred in 64 (26%) of 244 evaluable patients and consisted mainly of varicella zoster virus infections (n = 36) and pneumonia (n = 16). Administration of total body irradiation [odds ratio (OR) = 2.50; 95% confidence interval (CI) 1.4 to 4.5; P = 0.002) and previous use of fludarabine (OR 2.5; CI 1.2 to 5.2; P = 0.02) and a diagnosis of myeloma (OR 2.6; CI 1.2 to 5.6; P = 0.04) were significantly associated with late infections. CONCLUSIONS: This study confirms that infectious toxicity after peripheral blood progenitor cell transplantation is usually moderate, although bacteremia remains a serious problem. Late infections are encountered in about 25% of patients and are more common in those with myeloma, or those who received total body irradiation or fludarabine.

Corynebacterium JK: surgical infections in non-immunosuppressed patients.

Infection caused by Corynebacterium JK (CJK) has been recently described in immunocompromised patients. To evaluate the frequency of CJK infection among surgical and trauma intensive care patients, all patients with CJK isolations at clinical sites were reviewed. The criteria used were the presence of bacterial infection symptoms, isolation from significant sites and the efficiency of a vancomycin treatment. Eight patients were studied; 3 of them were considered infected, while 5 were judged only colonized. It is concluded that CJK infections can be a clinical problem in surgical trauma patients.

Protection of mice by a pseudodiffuse strain of Staphylococcus aureus possessing polyvalent capsular type antigen.

Staphylococcus aureus strain MC31 showed pseudodiffuse growth in serum-soft agar and reacted with immune rabbit sera to strains Smith diffuse (capsular type A), NS58D (type B) and NS41D (type C) but not with strain NS68D (type D) in serum-soft agar. Immunisation of mice with 300 micrograms of cell-surface polysaccharide extracted from strain MC31 protected against lethal infection by strain MC31 and the strains of capsular types A, B and C. Immune rabbit serum prepared against strain MC31 passively protected mice against challenge infection with the homologous strain, but approximately 30 times more anti-MC31 serum was required to protect against infection with the strains of capsular types A, B and C. Absorption of the passive protective activity of immune sera raised against the three capsular type strains required at least 10 times the quantity of MC31 cell-surface polysaccharide than the quantity of cell-surface polysaccharide from the homologous capsular strain. Electronmicrographs of strain MC31 treated with ferritin-labelled antisera to the three capsular strains showed only small amounts of ferritin granules around the cell wall.

Comparative in vitro activity of penicillin G, levofloxacin, moxifloxacin, telithromycin, pristinamycin, quinupristin-dalfopristin and linezolid against ofloxacin-intermediate and -resistant Streptococcus pneumoniae.

Screening by ofloxacin disk was carried out on 1158 strains of Streptococcus pneumoniae in order to investigate the in vitro bacteriostatic activity of penicillin G, levofloxacin, moxifloxacin, telithromycin, linezolid, pristinamycin and quinupristin-dalfopristin against ofloxacin-intermediate and -resistant S. pneumoniae strains. It was concluded that these new antimicrobial agents could be useful for the treatment of pneumococcal infections caused by penicillin-sensitive and -resistant S. pneumoniae, and would represent a valid therapeutic option for patients allergic to beta-lactams, should they prove to be potent in vivo.

Resistance of bacteria in urinary tract infections.

Bacterial infection of the urinary tract is a common health problem in young women but also the most common nosocomial infection (>33%) contributing to the mortality of patients, and increasing the duration and cost of hospitalization. Escherichia coli is the most predominant organism and its prevalence varies in different studies. The high consumption of inappropriately prescribed antibiotics, combined with multiple pathology and frequent use of invasive devices, is a major factor contributing to high levels of resistance. There is a serious decrease in susceptibility of E. coli strains to amoxycillin, due to the presence of R-TEM enzymes, to cotrimoxazole and trimethoprim. Nitrofurantoin and fosfomycin-trometamol remain highly active against urinary Enterobacteriaceae, with over 90% of E. coli being susceptible. Knowledge of the most likely causative organisms and the prevalence of resistance pathogens to antimicrobial agents is essential to select antibiotics and to establish guidelines for the empirical treatment of urinary tract infections.

[Peritonitis with Mycobacterium avium complex in a patient with alcoholic cirrhosis]. / Infection du liquide d'ascite à Mycobacterium avium complex chez un malade ayant une cirrhose alcoolique.

Before highly active antiretroviral therapy were available, disseminated Mycobacterium avium complex infection was common in adults with HIV. Diagnosis was often made by blood culture in these immunocompromised patients. Although Mycobacterium avium complex disease can involve any organ of the body, infection of serosal surfaces is very rare. Mycobacterium avium complex peritonitis is rare and usually occurs in immunocompetent patients with chronic ambulatory peritoneal dialysis. We report a case of Mycobacterium avium complex peritonitis in a patient with alcoholic cirrhosis with no evidence of HIV infection. Diagnosis was made by culture of a lymphocytic ascites which showed Mycobacterium avium complex at 4 weeks. Interestingly, blood and hepatic cultures remained negative. At three months, marked improvement occurred with antimycobacterial treatment, so that orthotopic liver transplantation could be performed.

[Comparison of various characters and antigenic structure in S. aureus strains cultivated in hospitalized patients and in healthy carriers]. / Comparaison des divers caractères et de la structure antigénique de souches de S. aureus, isolées chez des malades hospitalisés et des porteurs sains.

A comparison has been done between various characters of 170 non epidemic strains cultivated from hospitalized patients and 29 strains originated from healthy carriers without any hospital contact and antibiotic treatment since 6 months. Following characters have been tested: M.I.C. of 13 antibiotics, heterogenous methicillin resistance, enzymatic antibiotic resistance, macrolide inducible or constitutive type resistance, mercuric chloride susceptibility; phage types; enzymes and toxins production. Antigenic structure has been studied, in particular production of protein A, A beta teichoc acid and type antigens. Significant differences have been observed between hospital and healthy carriers strains; these later strains are antibiotic susceptible, produce few toxins and enzymes, are not frequently phage typable. Their antigenic structure shows also significant differences: A beta-teichoic acid is less frequently detected; type antigens are less frequent and different. Role of these surface antigens in virulence is discussed.

Tonsillar diffusion kinetics of amoxycillin after oral administration of 1 g to adults.

Although amoxycillin is widely used to treat pharyngo-tonsillitis, the kinetics of tonsillar diffusion have rarely been studied. The aim of this work was to study the kinetics of amoxycillin diffusion in the tonsils of adults, by measuring tonsillar concentrations 1.5, 3, 6 and 12 h after oral administration of 1 g of amoxycillin (Clamoxyl dispersible tablet, 1 g) relative to concomitant serum levels by using an HPLC method and a microbiological technique. At enrollment, the 20 patients were randomly divided into four groups of five, corresponding to the time intervals (1.5, 3, 6 or 12 h) between the third amoxycillin intake and the start of surgery. The results given by the two assay methods correlated well (r = 0.92-0.99). Amoxycillin showed excellent penetration into the tonsils, with both tonsillar and serum concentrations exceeding the MIC for most pathogens encountered in this setting (including Streptococcus pyogenes), even 12 h after repeated dosing with 1 g of amoxycillin.

[Evaluation of a rapid technique for antibiotic sensitivity testing using an MS-2 automate and blood culture medium]. / Evaluation d'une technique rapide d'antibiogramme réalisée à partir des bouillons d'hémocultures avec un automate MS-2.

The authors propose a rapid method for studying antibiotic sensitivity of bacteria isolated from blood cultures. An MS-2 automate is used directly with bacteria collected after centrifugation. With the exception of the sensitivity of Gram-positive cocci to the combination of sulfamethoxazole-trimethoprime and to Penicillin G and of Gram-negative bacillus to beta lactamines, the results were comparable to those obtained after isolation of bacteria on gel medium. Various causes for error are discussed.

[Comparison of the results of antibiograms obtained from blood culture broth and after isolation on agar media with the Autobac 1]. / Comparaison des résultats d'antibiogrammes obtenus à partir des bouillons d'hémocultures et après isolement sur milieu gélosé avec l'appareil autobac 1.

The authors compare the results of antibiotic sensitivity tests performed within 4 hours with the aid of the Autobac 1 machine, using blood culture medium and following isolation on agar plates. There was concordance in about 90 p. cent of cases. The first test is not suitable for sensitivity to trimethoprim and the beta-lactamines, as was already observed in the study using the MS-2 machine. The authors discuss the various sources of error and compare the results obtained from the two machines.

[Evaluation of a rapid technic for antibiotic sensitivity testing: reproducibility of minimal inhibitory concentrations routinely estimated with the use of Abbott MS-2 autoanalyzer]. / Evaluation d'une technique rapide d'antibiogramme: reproductibilité des concentrations minimales inhibitrices estimées en routine à l'aide de l'automate Abbott MS-2.

The inter-system reproducibility of the MIC results obtained from the MS-2 automated system of antibiotic sensitivity testing was assessed by a two-stage study. In the first stage, a total of 168 MICs were calculated by the automated system from 134 diverse bacterial strains, selected from routine antibiotic sensitivity testing for their "intermediate" sensitivity to one or more antibiotics. The antibiotic sensitivities were repeated using the same machine, in the same laboratory, on another suspension of the same bacteria. The results of antibiotic sensitivity reported as "intermediate" on the first test were compared to those of the second test; only 19 p. cent of the responses remained "intermediate" and the MICs were comparable between the two tests; 50 p. cent became sensitive and 31 p. cent became resistant (MIC not calculated). In the second stage, 4 strains with stable intermediate sensitivity to 8 antibiotics, as shown by 2 routine sensitivity tests, were tested 33, 48, 44, and 39 times respectively against these antibiotics using various suspensions of the same strain. 394 results were obtained: 92 intermediate results with a MIC (24.4 p. cent), 219 sensitive results (56.3 p. cent) and 83 resistant results (20.2 p. cent). The range of values for the MIC calculated by the automatic system was small, so the MICs are reproducible; but, for 5 of the 8 antibiotics, the responses were both "S" and "R". This suggests that the so-called "Intermediate" zone is in fact a zone of uncertainty where the majority of the MIC results are erroneous.

[Pneumococcal antibiotic resistance in 1999. Results from 19 registries for 1999]. / Résistance du pneumocoque aux antibiotiques. Résultats portant sur 19 observatoires pour l'année 1999.

BETA-LACTAM RESISTANCE: Among the 9956 strains of Streptococcus pneumoniae isolated in adults, 39% had some degree of penicillin resistance (reduced susceptibility), but there were relatively few strains highly resistant to penicillin: 10%. Among the 4422 strains isolated in children, the overall rate of penicillin resistance was higher (51%) with 15% highly resistant strains. For amoxicillin, the rate of reduced susceptibility was 25% while 1.4% were amoxicillin-resistant. For ceftaxime the respective figures were 21% and 0.3% OTHER ANTIBIOTIC FAMILIES: Important reduction in the susceptibility of all strains, more pronounced for peni-R strains, for macrolides, cotrimoxazole, tetracyxine and chloramphenicol. Very rare resistance to rifampicin and intact susceptibility to vancomycin. CHILDREN VERSUS ADULTS: The rate of reduced susceptibility to beta-lactams was higher in children: 31% versus 23% for amoxicillin and 21% versus 14% for cefotaxime. However there were only a few rare strains that were amoxicillin and cefotaxime resistant. Unlike what was observed in adults, there were major differences by site of sampling; strains isolated from purulent middle ear fluid exhibited the strongest resistance.

Automated detection of nosocomial infections: evaluation of different strategies in an intensive care unit 2000-2006.

The aim of this study was to evaluate seven different strategies for the automated detection of nosocomial infections (NIs) in an intensive care unit (ICU) by using different hospital information systems: microbiology database, antibiotic prescriptions, medico-administrative database, and textual hospital discharge summaries. The study involved 1,499 patients admitted to an ICU of the University Hospital of Lyon (France) between 2000 and 2006. The data were extracted from the microbiology laboratory information system, the clinical information system on the ward and the medico-administrative database. Different algorithms and strategies were developed, using these data sources individually or in combination. The performances of each strategy were assessed by comparing the results with the ward data collected as a national standardised surveillance protocol, adapted from the National Nosocomial Infections Surveillance system as the gold standard. From 1,499 patients, 282 NIs were reported. The strategy with the best sensitivity for detecting these infections using an automated method was the combination of antibiotic prescription or microbiology, with a sensitivity of 99.3% [95% confidence interval (CI): 98.2-100] and a specificity of 56.8% (95% CI: 54.0-59.6). Automated methods of NI detection represent an alternative to traditional monitoring methods. Further study involving more ICUs should be performed before national recommendations can be established.