Methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to glycopeptides (GISA) in 63 French general hospitals.

Clinical isolates of methicillin-resistant Staphylococcus aureus (n = 1070) collected from 63 French general hospitals during June 2000 (n = 1070) were screened initially for reduced susceptibility to glycopeptides (GISA) on brain-heart infusion agar containing teicoplanin 6 mg/L. Glycopeptide MICs were determined for the 145 isolates that grew on the screening plates. Of the 1070 isolates, 1.4% were GISA on Mueller-Hinton agar, and 2.9% by Etest with a high inoculum, while 0.7% and 2.9% were GISA by vancomycin and teicoplanin population analysis profiles, respectively. Most isolates were resistant to gentamicin and rifampicin or fosfomycin or fusidic acid, as determined by disk diffusion. Pulsed-field gel electrophoresis of the 31 GISA isolates identified four clones, with dissemination of one predominant clone. In these French hospitals there was a low incidence of GISA and hetero-GISA.

A parent as a vector of Salmonella brandenburg nosocomial infection in a neonatal intensive care unit.

A newborn baby was admitted to the Neonatal Intensive Care Unit (NICU) of St Germain en Laye Hospital (France) because of premature birth. On day 12, he contracted gastroenteritis due to Salmonella brandenbourg. The salmonellosis led to a septic shock syndrome with a brief cardiopulmonary arrest. He was treated with intravenous ceftriaxone and gentamicin, and the evolution was favorable. Microbiological investigations revealed that the mother was the vector for this nosocomial infection. S. brandenbourg was isolated from the feces of the baby, despite recent recommendations on managing stool specimens from patients hospitalized for more than three days: according to these recommendations, these stools should be processed for viruses and Clostridium difficile toxin only.

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE) in Northern France: a five-year multicentre incidence study.

In order to measure the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and of Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE), and to evaluate the impact of the national guidelines for multidrug-resistant bacteria (MDRB) prevention in hospitals of Northern France, a multicentre study was conducted for three months every year starting in 1996, in volunteer hospital laboratories. All clinical specimens positive for MRSA and ESBLE were prospectively surveyed. During the five-year surveillance period, the overall proportion of MRSA was 38.4% in the 28,534 strains of S. aureus, and that of ESBLE was 11.4% in the 6121 strains of Klebsiella pneumoniae and 47.7% in the 2353 strains of Enterobacter aerogenes. The overall incidence rates of clinical specimens positive for MRSA, ESBL-K. pneumoniae and E. aerogenes were 0.84. 0.05 and 0.12/1000 hospital-days (HD), respectively. In the 23 hospitals that participated in the survey every year, the proportion and incidence of ESBLE decreased. Hence, despite recommendations as for isolation precautions, MRSA remains poorly controlled and requires more effective measures.

[Primary Neisseria meningitidis arthritis of the knee without meningitis: contribution of synovial fluid culture in blood-culture vial]. / Monoarthrite du genou à Neisseria meningitidis sans méningite: apport de la culture du liquide articulaire en flacon d'hémoculture.

INTRODUCTION: Primary meningococcal arthritis is a rare form of meningococcal disease. It occurs as an isolated acute purulent arthritis without meningitis, and presence of Neisseria meningitidis in articular fluid. We report a new case of typical primary meningococcal arthritis. EXEGESIS: A previously healthy 23-year-old female patient was admitted for purpuric lesions of the legs. At admission, conscience was normal and symptoms of meningitis were absent. During the 2nd day of hospitalisation, a warm and painful effusion in the right knee appeared. Aspiration from the right knee yielded a purulent fluid. N. meningitidis was isolated from a blood-culture vial inoculated with the synovial fluid, while blood cultures remained sterile. Anti-biotherapy was initiated as soon as microbiological diagnosis was established. The patient was symptom-free 1 month later. CONCLUSION: We emphasize the fact that agar cultures of the synovial fluid remained sterile, while N. meningitidis grew in a blood-culture vial. We suggest that diagnosis of primary meningococcal arthritis may be underestimated when inappropriate culture media are used.

[Staphylococcus aureus resistant to methicillin. Survey of prevalence in Yvelines hospitals]. / Staphylococcus aureus résistants à la méticilline. Enquête de prévalence dans les hôpitaux des Yvelines.

During 2 months (01.01.95-28.02.95), we noted for each Staphylococcus aureus (SA) isolates, identification and susceptibility methods, hospital size, medical speciality, source, penicillin (P) and methicillin (M) susceptibility. For each non repetitive methicillin resistant SA we noted phenotype of aminoglycoside resistance of SA to 6 antistaphylococci drugs. We isolated 399 SA, SAP sensitives 6.5%, methicillin resistant SA (MRSA) 31.8%. MRSA in acute care unit 28.4%, non acute care unit 61.7%, surgery 28.6%, medicine 36.5%, orthopedics 34.5%, pédiatrics 4%, ICU 38.8%, others 10.3%. MRSA from wound 28.2%, respiratory tract 38.3% blood 22.5%, urine 58.5%, others 25.8% - MRSA kanamycin 1.7%, kanamycin tobramycin 36.2%, kanamycin, tobramycin, gentamicin 56.9% - MRSA erythromycin 79.5%, pefloxacin 91.3%, rifampicin 53.5%, acide fusidique 8.7%, fosfomycine 18.9%, TMP SMZ 5.5%. The proportion MRSA is equivalent among medical specialities predominant in urine cultures and respiratory tract. It should be better to carry on the survey for more than two months in each hospital.

Activity of CI-960 alone and in combination with amoxycillin against Listeria monocytogenes, and comparison with other quinolones.

In-vitro activity of CI-960 against seven strains of Listeria monocytogenes was compared to that of other fluoroquinolones. MICs/MBCs were: ciprofloxacin and sparfloxacin: 0.5-2/1-4 mg/L;PD 131628: 0.125-0.5/0.25-2 mg/L; CI-960: 0.06-0.25/0.25-0.5 mg/L. At 4 h, CI-960 (4 x MIC) reduced the inoculum (log10 cfu) by 2.88 +/- 0.61 compared with 1.78 +/- 0.48 for ciprofloxacin, 1.5 +/- 0.46 for sparfloxacin, and 1.35 +/- 0.47 for PD 131628 (P < 0.05). At 24 h, the bactericidal effects were similar (-4 log10 cfu). The amoxycillin/CI-960 (8 x MIC) combination was bactericidal, without emergence of resistant mutants.

Enzyme electrophoresis, sero- and subtyping, and outer membrane protein characterization of two Neisseria meningitidis strains involved in laboratory-acquired infections.

Two cases of laboratory-acquired infections due to Neisseria meningitidis were suspected to have occurred in two French hospitals. The first case occurred shortly, i.e., 3 days, after one strain had been handled by a laboratory technician, and the link between this strain and the strain causing meningitis was easily established. In the second case, infection occurred 3 weeks after 10 strains had been handled by a technician. In this case, it was necessary to use high-resolution markers in order to establish the link between the infecting strain and 1 of the 10 strains handled. The antigenic formulae of the two infecting strains (serogroup:serotype:subtype) were, respectively, C:NT:P1.12 and B:2a:P1.2. Outer membrane protein profile analysis and multilocus enzyme electrophoresis unequivocally confirmed the identity of the respective strains.

[Prevention of neonatal conjunctivitis. A comparative clinical and bacteriologic study of 2 eyedrops: silver nitrate and oxytetracycline chlorhydrate]. / Prévention des conjonctivites néonatales. Etude comparative clinique et bactériologique de deux collyres: nitrate d'argent et chlorhydrate d'oxytétracycline.

This study carried out at the Saint-Germain-en-Laye Hospital maternity ward included all the neonates delivered between February and September 1989 who exhibited no abnormal manifestations during their stay in the ward, except for ocular symptoms in some subjects. Nine hundred neonates were enrolled. Each day, one of two eyedrop preparations for the prevention of neonatal ocular infections was selected at random. Investigators were blinded to the preparation used. Study subjects were evaluated twice, between D1 and D7 (900 infants) and between D15 and D30 (407 infants). Ocular findings were classified as follows: normal, minimally abnormal (isolated swelling of the eyelids, clear discharge), or frankly abnormal (conjunctivitis, purulent discharge). A bacteriologic study was performed in all patients with minimally abnormal or abnormal findings. Between D1 and D7, ocular symptoms were significantly (p less than 0.05) more prevalent in neonates treated with silver nitrate than in neonates treated with oxytetracycline hydrochloride. This difference was no longer present between D15 and D30. Bacteriologic studies recovered no gonococci. One enfant in the oxytetracycline group had bacteriologically confirmed Chlamydia trachomatis ocular infection. The other organisms recovered were mainly Staphylococcus aureus and non-hemolytic streptococci. In inclusion, no currently available eyedrop preparation offers complete protection against C. trachomatis but tolerance is considerably better with oxytetracycline hydrochlorate than with silver nitrate.

[Enterobacteriaceae isolated in nine general hospitals of the Ile-de-France in 1988 and 1989: susceptibility to beta-lactam antibiotics according to the length of hospitalisation]. / Sensibilité aux bêtalactamines en fonction de la durée d'hospitalisation des entérobactéries isolées dans neuf hôpitaux généraux d'Ile-de-France en 1988 et 1989.

Susceptibility to beta-lactam antibiotics of strains of Enterobacteriaceae consecutively isolated in nine general hospitals during a period of 2 months (march and april) has been studied by the disk-agar diffusion method. The separation between susceptible and resistant strains was based on the measure of the inhibition zones centered by 2 disks: cephalothin and ticarcillin. Enterobacteriaceae were divided in 2 groups: strains isolated during the first 48 h of hospitalisation or isolated after. Fifty one per cent of the strains were isolated during the first 48 h: they did not belong to the residential flora of these hospitals. Klebsiella, Proteus indole positive, Providencia, Enterobacter, Serratia were more frequently isolated after 48 h of hospitalisation. Susceptible strains of Klebsiella, Proteus indole positive, Providencia, Serratia were more rarely isolated after 48 h of hospitalisation. E. coli whatever the duration of hospitalisation, is the less frequent susceptible bacterium.

Prospective multicenter study of vascular-catheter-related complications and risk factors for positive central-catheter cultures in intensive care unit patients.

To determine the incidence rate of complications associated with vascular catheters in intensive care unit patients and to analyze risk factors for a positive vascular culture, we performed a multicenter study of intensive care unit patients at eight French hospitals. During the study period, 865 intravenous catheters were inserted in 566 patients; 362 (41.8%) were peripheral catheters, and 503 (58.2%) were central catheters. Local complications (i.e., infiltration) occurred significantly more often with peripheral than with central catheters (P less than 0.001); in contrast, fever and bacteremia were significantly more often associated with central than with peripheral catheters (P less than 0.01 and P less than 0.05, respectively). The culture of the vascular-catheter tip was positive for 24% of central catheters (32 of 1,000 catheters days) and for 9% of peripheral catheters (21 of 1,000 catheters days). Staphylococcus epidermidis was the most common microorganism isolated from both peripheral and central catheters, followed by Staphylococcus aureus and Pseudomonas aeruginosa. No significant risk factor associated with positive cultures for peripheral catheters was found by univariate analysis. In contrast, the purpose of the cannula (nutrition and monitoring of central venous pressure), the insertion site (jugular), the dressing type (semipermeable transparent dressing), the antiseptic used to prepare the insertion site (povidone iodine), and routine changing of the intravenous administration set were significantly associated with positive cultures of central catheters. Three factors, duration of catheterization, use of a semipermeable transparent dressing, and the jugular insertion site, were found to be independently associated with positive cultures of central catheters by multivariate analysis.

Alteration of PBP 3 entails resistance to imipenem in Listeria monocytogenes.

A mutant with decreased susceptibility to imipenem (IpR) was selected in vitro from a susceptible clinical isolate of Listeria monocytogenes (IpS). IpR exhibited decreased susceptibility to penicillin G (4 x MIC) and imipenem (16 x MIC) and increased susceptibility to cefotaxime (0.25 x MIC). Electrophoretic profiles of membrane proteins and penicillin-binding proteins (PBPs) were identical in the two strains; each strain had five PBPs with molecular masses of ca. 97, 83.3, 81, 77.1, and 42.6 kilodaltons. A decreased affinity of PBP 3 for penicillin G and imipenem (10-fold) was observed in IpR. In contrast, the affinity of PBP 3 for cefotaxime in IpR was increased twofold and correlated with the decreased MIC of this drug. From these findings and competition experiments with different beta-lactam antibiotics, we conclude that the alteration of PBP 3 is responsible for the decreased susceptibility of IpR to penicillin and imipenem and that PBP 3 might be an essential target of beta-lactam antibiotics in L. monocytogenes.

In vitro bactericidal activity of amoxicillin, gentamicin, rifampicin, ciprofloxacin and trimethoprim-sulfamethoxazole alone or in combination against Listeria monocytogenes.

The in vitro bactericidal activity of amoxicillin, gentamicin, rifampicin, ciprofloxacin and trimethoprim-sulfamethoxazole alone or in combination was determined against seven strains of Listeria monocytogenes by the killing curve method. Amoxicillin plus gentamicin was the most rapidly bactericidal combination, whereas trimethoprim-sulfamethoxazole was less bactericidal at 6 h but as bactericidal at 24 h. The combination of trimethoprim-sulfamethoxazole with either amoxicillin, ciprofloxacin or rifampicin did not result in antagonism, but the combinations were no more active than trimethoprim-sulfamethoxazole alone. The interaction of amoxicillin with rifampin was fairly antagonistic (1 log10 difference). The combination of amoxicillin and ciprofloxacin, although producing antagonism during the first 6 h, was more active at 24 h than amoxicillin alone and prevented the regrowth observed with ciprofloxacin alone. Ciprofloxacin and rifampicin interacted antagonistically during the first 6 h, and the combination was not very bactericidal (3 log10) but prevented the emergence of mutants, as observed with each drug alone, when used at concentrations greater than the MICs for the strain tested. These regimens merit evaluation in in vivo models of Listeria monocytogenes meningitis.

Inducible, transferable resistance to vancomycin in Enterococcus faecium, D399.

Enterococcus faecium D399 was isolated from the blood and peritoneal abscess of a patient with intraabdominal sepsis. The patient had not been treated with vancomycin, but the strain was found to be resistant with a MIC of 1000 mg/l. Resistance was inducible and transferable (probably by conjugation) to JH2-2, and correlated with induction of synthesis of a 39 kDa protein. This mechanism appears to be identical to that previously described for E. faecalis A256, suggesting that dissemination of this form of glycopeptide resistance has already occurred. The resistance phenotype of D399, however, differed somewhat from that found in other enterococcal strains with inducible resistance.

Interaction between piperacillin and pefloxacin or amikacin on the selection of resistant mutants of Pseudomonas aeruginosa.

Pseudomonas aeruginosa mutants were selected with piperacillin, pefloxacin, amikacin and the combinations pefloxacin-piperacillin and amikacin-piperacillin. With amikacin and the piperacillin-amikacin combination no mutants were selected. With piperacillin (1-32 x MIC) mutants resistant to carboxypenicillins, ureidopenicillins, monobactam and cephalosporins were selected. With pefloxacin, three different types of mutant were observed which showed different patterns of cross-resistance to pefloxacin, sulphonamides, imipenem, piperacillin and other beta-lactam antibiotics. With the pefloxacin-piperacillin association, mutants similar to one of the types selected by pefloxacin alone and resistant to both of the selective antibiotic were predominantly obtained. No mutants were selected with this combination if one of the antibiotics was used at a concentration equal to its MIC for the wild type strain and the other at concentrations above 4 x MIC. Since the association of piperacillin and pefloxacin was only moderately bactericidal against the predominantly cross-resistant mutant selected, the concentration of these antibiotics may have to be carefully controlled to prevent the emergence of such mutants.