Blood pressure cuff as a potential vector of pathogenic microorganisms: a prospective study in a teaching hospital.

OBJECTIVE: To investigate the potential role of blood pressure (BP) cuffs in the spread of bacterial infections in hospitals. DESIGN: A comprehensive, prospective study quantitatively and qualitatively evaluating the bacterial contamination on BP cuffs of 203 sphygmomanometers in use in 18 hospital units from January through March 2003. SETTING: A university hospital with surgical, medical, and pediatric units. RESULTS: A level of contamination reaching 100 or more colony-forming units per 25 cm(2) was observed on 92 (45%) of inner sides and 46 (23%) of outer sides of 203 cuffs. The highest rates of contamination occurred on the inner side of BP cuffs kept in intensive care units (ICUs) (20 [83%] of 24) or on nurses' trolleys (27 [77%] of 35). None of the 18 BP cuffs presumed to be clean (ie, those that had not been used since the last decontamination procedure) had a high level of contamination. Potentially pathogenic microorganisms were isolated from 27 (13%) of the 203 BP cuffs: 20 of these microorganisms were Staphylococcus aureus, including 9 methicillin-resistant strains. The highest rates of contamination with potentially pathogenic microorganisms were observed on cuffs used in ICUs and those kept on nurses' trolleys. For 4 patients with a personal sphygmomanometer, a genetic link was found between the strains isolated from the BP cuffs and the strains isolated from the patients. CONCLUSIONS: The results of this survey highlight the importance of recognizing BP cuffs as potential vectors of pathogenic bacteria among patients and as a source of reinfection when dedicated to a single patient, emphasizing the urgent need for validated procedures for their use and maintenance.

Mortality of aluminium reduction plant workers in France.

The mortality between 1950 and 1976 of 6455 French aluminium plant workers was analysed in order to assess occupational risks (especially lung cancer) associated with electrolysis, particularly with the Söderberg process. Mortality from all causes (SMR = 0.85), was lower in this cohort than in the French male population ('healthy worker effect'), and cancer mortality (SMR = 1.09) was only slightly higher. There was an excess of mortality from accidents (mainly non-occupational) in electrolysis workers (SMR = 1.38) and from cirrhosis of the liver in maintenance workers (SMR = 1.63). Among electrolysis workers, only those who had worked less than 10 years had a relative excess mortality from lung cancer (SMR = 1.94), but this did not seem to be associated with a particular electrolysis process. However a substantial underlying risk of lung cancer in Söderberg workers could not be excluded, although such a risk appeared unlikely for prebake workers.

Validation of diffusion methods for macrolide susceptibility testing of Helicobacter pylori.

Helicobacter pylori resistance to macrolides is increasing, and the need for susceptibility testing has become crucial. The only standardized method is agar dilution, which is not adapted to clinical practice. The present work aimed: (1) to optimize the technical conditions and to assess the reproducibility of the E-test and disk diffusion method for macrolides susceptibility testing of H. pylori, and (2) to assess the performances of these two phenotypic methods in detecting strains harboring a resistance mechanism to macrolides. We used 191 isolates collected in nine centers of France and Belgium. Phenotypic tests were performed on Mueller-Hinton agar supplemented with 10% horse blood, inoculated with a 2-day-old H. pylori suspension (10(8) CFU/ml), and incubated for 72 hr at 37 degrees C under microaerophilic conditions. The reproducibility studied on two randomly selected strains was better for disk diffusion than for the E-test for both clarithromycin and erythromycin. For a subset of 10 strains, the MICs of erythromycin and clarithromycin did not differ from more than one two-fold dilution when determined by E-test or agar dilution method. The breakpoints were for MICs: 1 mg/L for both clarithromycin and erythromycin and for inhibition diameters, 22 mm for clarithromycin and 17 mm for erythromycin. There was a 100% concordance between susceptibility to erythromycin and clarithromycin. However, the susceptible and resistant populations were better separated by testing erythromycin. Of 34 resistant strains, two lacked the A2142G and A2143G point mutations in 23S rRNA by PCR-RFLP. None of 15 tested sensitive strains were positive for one of these two point mutations. For clinical practice, we recommend to assess macrolide susceptibility of H. pylori by using one of these two phenotypic methods under the described technical conditions.

Typing of Staphylococcus epidermidis strains by random amplification of polymorphic DNA.

The polymerase chain reaction was used to obtain randomly amplified polymorphic DNA profiles for typing of Staphylococcus epidermidis strains. Epidemiologically unrelated S. epidermidis isolates were screened with randomly amplified polymorphic DNA analysis. The discriminating ability of 45 randomly designed 10-mer primers was assessed. The highest discriminatory power was obtained with the 10-mer oligonucleotide OPAM-12. In typing a total of 13 unrelated S. epidermidis strains with OPAM-12, 11 different banding profiles were obtained reproducibly by agarose gel electrophoresis. The discriminatory power of the method with OPAM-12 was estimated using the D value of Hunter and Gaston (1988) to be 0.961. A reproducibility index of 1 was obtained after typing a total of 40 cultures including 12 triplicates and one quadruplicate of the 13 unrelated strains. Following the described procedure, the randomly amplified polymorphic DNA method provided a rapid, simple and reproducible alternative to other S. epidermidis typing systems.

Changes in microbial ecology and use of cloxacillin.

There is generally a positive correlation between antibiotic consumption and incidence of resistance to antibiotics used either for prophylaxis or therapy in human infections. This was not the case for two surgical wards in our hospital. A 15-year study showed that the incidence of methicillin-resistant Staphylococcus aureus (MRSA) was unrelated to cloxacillin consumption, and in fact fell after introduction into the two wards of an antibiotic policy based on cloxacillin. The two wards, a 90-bed orthopaedic unit and a 60-bed trauma unit, had an incidence of MRSA that has remained below the hospital average (23% in 1989, 32% in 1992). Before introduction of the policy the incidence of MRSA in 1977-1979 in the orthopaedic ward was 31%, and in the trauma ward 33%. In 1989 an investigation revealed no MRSA carriers in staff of either ward. In contrast, seven MRSA carriers were found among staff and patients of three other surgical units selected, because the percentage of MRSA isolated was above the average in our hospital. However, a different type of patient is found in these units, the treatment techniques differ and broader-spectrum antibiotics are used. In addition to the usual precautions regarding nursing care and isolation techniques, the best means of reducing MRSA epidemics is to reduce the reservoir of carriers. The fall in the MRSA infection rate in orthopaedic and traumatology wards can be explained by antibiotic policy but also by other infection control measures.

Genetic relationship between Escherichia coli strains isolated from the intestinal flora and those responsible for infectious diseases among patients hospitalized in intensive care units.

The exact origin of strains of Escherichia coli responsible for infectious diseases in intensive care units (ICUs) remains partly unknown. Our aim was to determine the nature of the link between strains from the intestinal flora of hospital staff, strains from the intestinal flora of patients hospitalized in ICUs and strains isolated from ICU patients with invasive diseases. For this purpose, 77 strains of E. coli were genetically characterized by exploring their entire genomes by random amplified polymorphism of DNA (RAPD), and by determining their phylogenetic position in ECOR (E. coli reference) groups, the virulence factors harboured (pap, sfa, afa, hly, aer and cnf) and their ability to mutate. The strains isolated from the intestinal flora of hospital staff were found to constitute a genetically heterogeneous population compared with the strains isolated from ICU carriers, which were highly clustered. The latter strains harboured numerous virulence factors, and 80% belonged to the group ECOR B2. The strains isolated from infected patients harboured fewer virulence factors than those from the ICU carriers, and only half belonged to ECOR B2. Moreover, these strains were more genetically related to strains from hospital staff than to strains from ICU carriers. Thus, the exogenous origin of the E. coli strains is probably almost as important as translocation from intestinal flora in ICUs. Moreover, a strong mutator phenotype had a minor, or no, role in the rapid adaptation to modifications in the ecological environment.

Identification of new phages to type Staphylococcus aureus strains and comparison with a genotypic method.

The aim of this study was to optimize the epidemiological monitoring of strains of Staphylococcus aureus, a major cause of hospital-acquired infections. From September to December 1998 47 S. aureus strains isolated from swabs taken from orthopaedic and trauma patients were in studied. Thirty-five isolates were sensitive to methicillin (MSSA) and 12 were methicillin-resistant (MRSA). Ten of the 47 isolates could not be phage-typed using the international set of typing phages: five of these isolates were MSSA and five were MRSA. These MRSA isolates, which were also not typeable by the phages currently recommended for phage-typing MRSA, were lysed by locally isolated experimental phages 584 and 1814. Phage 1814 lysed the gentamicin-resistant MRSA and phage 584 acted on the gentamicin-sensitive MRSA. Both new phages were inactive against the methicillin-sensitive isolates. Cloning of certain isolates was confirmed by macrorestriction genomic profiles obtained by pulsed-field gel electrophoresis analysis (PFGE). The results showed good discriminatory ability of antibiotic-resistance pattern phenotyping and phage-typing when the phages used were adapted to epidemic-associated MRSA strains.

[Post-antibiotic diarrheas: role of Klebsiella oxytoca]. / Diarrhée post-antibiotique: rôle de Klebsiella oxytoca.

From May 1989 to January 1991, 20 patients were investigated for antibiotic-associated acute diarrhea. Colonoscopy or rectosigmoidoscopy was performed in each patient. Cultures of colonic mucosal biopsies were carried out using conventional culture grounds (cystine-lactose-electrolyte-deficient). The aim of this study was to investigate the role of a gram negative bacillus: Klebsiella oxytoca. Among the 20 patients with antibiotic-associated acute diarrhea, 11 had bloody and mucus diarrhea and colitis ranging from a right-sided hemorrhagic to diffuse acute ulcerative or erosive colitis, 7 had a grossly normal colonic appearance, while 2 had mucus diarrhea and pseudomembranous colitis. Of colonic biopsies cultures obtained from 36 control patients, 15 had a normal colonic appearance, 15 had ulcerative or crohn's colitis, 6 had well-tolerated amoxicillin therapy. Klebsiella oxytoca was never found in the 36 control patients; Klebsiella oxytoca was noted among 8/11 patients with mucus-discharging and bloody diarrhea. These results suggest that antibiotic-associated, non pseudomembranous colitis is frequently associated with Klebsiella oxytoca infection, which may be the cause of this type of colitis.

[Use of the API 20E system for rapid identification of Enterobacteriaceae (six hours) (author's transl)]. / Utilisation du système API 20E pour l'identification rapide (six heures) des Enterobacteriaceae.

The authors propose a modification of the method of use of the API 20E system permitting more rapid identification of Enterobacteriaceae within six hours (3 hours preculture and 3 hours incubation on an API 20E plate) it was possible to identify correctly 67% of 192 strains studied at species level and 75.5% studied at generic level. One may note four mistakes (2.1%) of which 3 were minor, (species within the same genus). The construction of a base of numerical data adapted to the technic within six hours would no doubt permit us to reduce the percentage undetermined.

Erythromycin ethyl succinate: diffusion through interstitial dermal fluid.

Erythromycin is widely used in dermatology. There are few studies of its diffusion in the skin. The diffusion of erythromycin ethyl succinate (EES) in dermal fluid has now been investigated by the suction blister method. Suction blister fluid (SBF) and blood samples were collected from 10 volunteers before administration of 1 g EES and 10 times during the following 24 h. The median peak serum level was 2.05 micrograms/ml and in SBF it was 0.34 microgram/ml. The median ratio of the areas under curves (f SBF/f serum) was 43%. In all subjects EES concentrations in SBF between the second and twelfth hours exceeded 0.1 g/ml. The results show good diffusion of EES through normal skin from the second to the twelfth hours after oral administration.

Plasmids in Listeria monocytogenes in relation to cadmium resistance.

One hundred and seventy-three unrelated Listeria monocytogenes strains isolated from humans, animals, the environment, and food were analyzed for the presence of plasmids. Extrachromosomal DNA was found in 28% of the strains. Plasmid DNA was extracted more frequently from L. monocytogenes serogroup 1 strains (35%) than from serogroup 4 strains (15%). Among strains from food and the environment, 40% and 29%, respectively, harbored plasmids, whereas only 13% of the strains from humans and animals with listeriosis bore plasmids. We also investigated the susceptibility of 90 strains to seven antibiotics and four heavy-metal salts. No antibiotic resistance could be detected, but 95.3% of the plasmid-positive strains and only 12.7% of the plasmid-negative strains were resistant to cadmium. The plasmid-determined genetic basis of cadmium resistance was proven by conjugation between strains of L. monocytogenes and by cure of the plasmid. This is the first time that plasmids of L. monocytogenes have been shown to be associated with cadmium resistance.

Formation of planar optical waveguides in the new nonlinear gadolinium calcium oxoborate, Ca(4)GdO(BO(3))(3), crystal by 2-MeV He(+) implantation.

A planar waveguide composed of the new nonlinear material, Ca(4)GdO(BO(3))(3) (GdCOB), is reported. This crystal belongs to the calcium oxoborate family. It has attractive nonlinear properties that can be of great interest in integrated optics applications. We used a method of He(+) implantation to fabricate waveguides in GdCOB crystals by creating a buried layer of lowered refractive index a few micrometers beneath the surface. Both TE and TM modes were observed. Therefore, according to the Y cut of the crystal, refractive-index values of n(x) , n(y) , and n(z) were obtained. Index profiles were reconstructed by an improved inverse WKB method. The profiles showed a steplike index behavior, indicating that the guiding region obtained was of good optical quality.

[Fosfomycin resistance in Staphylococcus saprophyticus and other species of coagulase-negative staphylococci]. / La résistance à la fosfomycine chez Staphylococcus saprophyticus et chez les autres espèces de staphylocoques coagulase négative.

Susceptibility of 121 isolates of coagulase-negative staphylococci to two antimicrobial agents, novobiocin and fosfomycin, was determined using the agar dilution method. Isolates included 45 strains of Staphylococcus saprophyticus, 26 strains of S. cohnii and S. xylosus, 24 strains of S. epidermidis and 26 strains of S. hominis, S. capitis, S. warneri and S. auricularis . The minimal inhibitory concentration average of fosfomycin for S. saprophyticus differed (p less than 0.001) from that other for novobiocin-resistant staphylococci (S. cohnii and S. xylosus) and for S. epidermidis (p less than 0.001). Out of 45 isolates of S. saprophyticus, 42 were resistant to fosfomycin. The results were very heterogeneous with regard to fosfomycin for all of the other coagulase-negative staphylococci. Resistance to fosfomycin, like resistance to novobiocin, could be used as a presumptive test for the identification of S. saprophyticus.

[Antibiotic therapy of pneumopathies in intensive care and protected distal bronchial samples]. / Antibiothérapie des pneumopathies en réanimation et prélèvement bronchique distal protégé (PBDP).

Bacteriology was performed on 57 specimens collected by the Wimberley protected catheter bronchoscopy technique (PCB) from 42 ventilated patients with severe head trauma hospitalized in the neurosurgical intensive care unit to determine the etiology of their pneumopathy. All patients had a nasotracheal tube upon arrival at the intensive care unit. For each sample, smears were examined and cultures under aerobic and anaerobic conditions as well as with CO2 were performed. In 34 (59%) of the 57 cases, examination of smears allowed rapid diagnosis and appropriate chemotherapy. In 47 (82%) cases, culture was positive, with a single pathogen being recovered in half of cases. The most prevalent organisms among the 75 species isolated were S. aureus (38%), P. aeruginosa (15%), Klebsiella (12%), Haemophilus (8%), and Pneumococcus (9%). Consistency with positive cultures of blood or pleural effusion samples was recorded in 92% of cases. Narrow spectrum antibiotic therapy can be chosen according to the results of PCB bacteriology and rapid automated antibiotic sensitivity testing obtained within 24 hours. PCB is therefore recommended in pulmonary infections in intensive care units.

[Cloxacillin concentration in suction fluid following flash antibiotic therapy during insertion of a hip prosthesis]. / Concentrations de cloxacilline dans les liquides de Redon après antibiothérapie flash au cours de mise en place de prothèse de hanche.

Since 1982 we have administered cloxacillin intraoperatively during total hip replacement. 1 g cloxacillin is injected intravenously at induction of anesthesia, followed by 1g every hour until the end of the procedure or a total of 6 g. In our study, cloxacillin concentrations were determined in the fluid collected from the deep suction catheter inserted at the end of the surgical procedure. Fluid samples were collected 2 h, 4 h, 6 h, 8 h and 24 hours after the last injection of cloxacillin. Serum samples were taken 2 h, 6 h and 24 hours after the last injection. Cloxacillin was assayed using an agar-diffusion microbiologic method. 18 patients were studied. Each had received 3 to 5 g cloxacillin over 3 to 5 hours. Mean suction catheter fluid concentrations were to 69.7 micrograms/ml, 37.6 micrograms/ml, 24.2 micrograms/ml, 15.5 micrograms/ml, and 6.8 micrograms/ml respectively in the samples collected 2 h, 4 h, 6 h, 8 h and 24 hours after the last injection of cloxacillin. Mean serum concentrations were 34.1 micrograms/ml, 4.2 micrograms/ml, and 0 microgram/ml respectively 2 h, 6 h and 24 hours after the last injection. Our results indicate that cloxacillin concentrations within the hip joint are probably effective against staphylococci for 8 to 12 hours.

[Informative capacity of 8 serological tests in the diagnosis of human brucellosis]. / Capacité informative de huit tests sérologiques dans le diagnostic de la brucellose humaine.

Assessment of the informative value of 8 immunological tests: sero-agglutination (Wright and Rose Bengale), indirect immunosorbent assay, counter immuno electrophoresis, ELISA IgG, IgM and IgA, and particle counting immunoassay (PACIA) has been performed among the results of serum of 209 patients. The patients were divided in four groups: 71 who already had brucellosis, 18 Yersinia infections, 12 Tularemia and 108 free of desease. The informative capacities of a positive result of counter immuno electrophoresis (Protein antigen Brucellin-INRA Tours-Nouzilly) is higher than others reactions and can be proposed as a confirmatory test of brucellosis. Among others techniques, 4 were found to be more sensitive: Elisa IgA (se = 97.6) and IgG (se = 90.1), IFI (se = 91.5) and Rose Bengale (se = 85.9) and can be proposed as screening test for medical diagnosis or epidemiological survey. Many cross-reactions were observed specially with Yersinia enterocolitica even with new serological methods.

Pseudomonas aeruginosa from cystic fibrosis patients: study using whole cell RAPD and antibiotic susceptibility.

Pseudomonas aeruginosa is the most important bacterial pathogen in lung disease of cystic fibrosis patients. Different morphotypes of the bacterium are frequently recovered in sputum samples of these patients. We developed a whole cell Randomly Amplified Polymorphic DNA (RAPD) technique in order to establish the relatedness between morphotype, genotype and antibiotic susceptibility. Six cystic fibrosis patients already colonized by P. aeruginosa were investigated by collecting three successive sputum samples (before and after antibiotic treatment, and one month later) and selecting 10 isolates per morphotype. 250 isolates of P. aeruginosa were recovered from 16 of 18 sputum samples. Five patients carried a single RAPD type strain four of which showed at least two morphotypes; one patient carried two RAPD types strains. No patients carried the same strain. These results confirmed other studies previously published in showing stability of the chronic colonization with a single strain. Antibiotype differences were not associated with differences of RAPD profiles and no relation was found between antibiotype and morphotype.

Second-harmonic generation in He+-implanted gadolinium calcium oxoborate planar waveguides.

What is believed to be the first investigation of second-harmonic generation (SHG) in Ca(4)GdO (BO(3))(3) waveguides is reported. A planar waveguide was formed by 2-MeV-helium implantation. We cut the sample to achieve type I noncritical phase matching of an 823-nm fundamental wave for fundamental light propagating along the y axis and polarized along the z crystallophysic axis of the crystal. SHG was achieved with a relatively low pumping power of a cw Ti:sapphire laser. The results indicate that the nonlinearity of the material remains in the guiding region after ion implantation.

Epidemiology of Staphylococcus aureus in patients with cystic fibrosis.

Seven hundred and thirty-four isolates of Staphylococcus aureus, recovered from the sputum of 238 cystic fibrosis patients in six French hospitals, were characterized by esterase electrophoretic typing, capsular polysaccharide serotyping and phage typing and tested against 14 antibiotics for sensitivity. Thirty-four esterase electrophoretic types were found with a genotypic diversity coefficient of 0.91. Five hundred and forty-eight (78.7%) isolates produced capsular polysaccharide and 350 (50.3%) were type 8. Four hundred and sixty isolates (66.6%) were phage typable and 202 (28.2%) were lysed by group III bacteriophages. No esterase electrophoretic type, capsular type or phage type was specific to cystic fibrosis. Isolates belonged to a wide range of types, similar to strains acquired outside hospitals. Eighty-five patients had three or more consecutive isolates over at least 6 months. The ability of S. aureus to persist for long periods of time has been demonstrated in 73% of them. Methicillin-resistance was encountered among 73 strains (9.8%) which were also multiresistant. Two hundred and eighty-nine (39.9%) strains were sensitive to all antibiotics tested except to penicillin. Pristinamycin and co-trimoxazole were the most effective antibiotics. These results could contribute to the elaboration of a rational approach to the prophylaxis and therapy of respiratory staphylococcal infections in cystic fibrosis patients.