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M Meyran

Publications and source records attributed to M Meyran.

At least 37 records · Page 2Linked to original sources
PubMed1994

Interactions of ceftibuten with extended-spectrum beta-lactamases: a bacteriological and enzymatic analysis.

The authors analysed the antibacterial activity of ceftibuten, cefotaxime, ceftazidime and aztreonam against Klebsiella pneumoniae strains, including those which produced novel extended-spectrum beta-lactamases. These molecules were also tested for their susceptibility to cell-free extracts of the corresponding beta-lactamases. Both approaches showed that ceftibuten was not hydrolysed by the CTX-1/TEM-3, SHV-2 and SHV-3 beta-lactamases, while cefotaxime, ceftazidime and aztreonam were hydrolysed. Nevertheless all compounds were substrates for the SHV-4 and SHV-5 beta-lactamases, and the organisms which produced these beta-lactamases showed increased MICs.

Ceftibuten↗
PubMed1993

[Severe infections caused by methicillin-resistant Staphylococcus aureus. 62 cases].

A French multicentre study was conducted in 15 Infectious Diseases departments; 347 cases of severe staphylococcal infections were collected during one year (October 1989 to October 1990): Two-hundred and fifty-eight strains were analysed with complementary bacteriological studies, including 62 strains of methicillin-resistant Staphylococcus aureus. Epidemiological, clinical and therapeutic aspects were investigated. Nosocomial infection was responsible for 90 percent of the cases, and previous antibiotic therapy was reported in 74 percent. An invasive procedure was incriminated in 43 patients (69 percent); intravenous catheter (38 percent), mechanical ventilation (31 percent), surgery (22 percent), prosthetic device (20 percent). Thirty-nine patients were treated with glycopeptides either alone or in combination with beta-lactams, aminoglycosides, fucidic acid, fosfomycin, rifampicin, quinolones or synergistines, showing the great diversity in the choice of antibiotics in methicillin-resistant S. aureus infections. More than 90 percent of these strains were resistant to gentamicin and quinolones, 80 percent of clindamycin and 70 percent to rifampicin. No resistance to glycopeptides (vancomycin or teicoplanin) was observed. Prognosis was severe, with a mortality rate of 35 percent, justifying educational and prophylactic measures in at risk medical departments.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Realities of immunizations in the armed forces: necessity of continued adaptation of vaccinations against cerebrospinal meningitis, typhoid and hepatitis A].

The history of military medicine has always been closely linked with that of vaccinations. Doctors of Armed Forces, doctors of collectivities, have contributed to vaccination progresses in large amounts. But evolutions are often rapid here: epidemiological modifications, improvements in the existing vaccines or creation of new vaccines, diversification of military specificities. Three recent modifications in the vaccination schedule of the Armed Forces show this necessary adaptation: Systematization of the meningococcal A + C vaccination during the incorporation, because of the modification of the disease's epidemiological profile: increase of the frequency in serogroup C with a mortality increase (9 cases of death out of 10 observed between 1991 and 1992). Cancellation of antityphoïd vaccination for recruits serving in home country. Indeed the disease has become rare in France, and this is often due to imported cases (3 cases in the Armed Forces in 1992). Introduction in 1994 of vaccination against viral hepatitis A, systematic under the age of 25 years and after a serological selection above for servicemen having to serve overseas or for outside operations. These 3 examples show the necessity to have updated and adaptable vaccination schedules.

Bacterial Vaccines↗
PubMed1993

[Evaluation of rapid screening tests in the diagnosis of urinary infections].

Bacterial urine examination is the main bacterial examination used in microbiology laboratories. The comparative interest of urine aspect associated with rapid screening tests (catalase, leucocyte esterase, nitrite) and different urine examination methods (Gram stain of sediment, direct examination on Malassez cell and on centrifuged urine pellet) are evaluated for negative predictive value of urinary tract infection. In out-patient, the association urine aspect-leucocyte esterase has the best negative predictive value for urinary tract infection (99.4%). Either in outpatients or in hospitalized patients, the association Gram stain of sediment-leukocyturia evaluation has the best negative predictive value for urinary tract infection (100%). This data allows in our population to give back negative results without culture.

Bacteriological Techniques↗
PubMed1993

[Importance of bacterial vaccines].

The vaccines presently developed in laboratories are more numerous than the ones in current use. This acceleration of research efforts was made possible by a genuine biotechnological revolution which opened new avenues for vaccine preparation, with techniques such as the selection of relevant antigens and the use of subunit vaccines. Genetic engineering plays an increasing part in the development and production of both live and inactivated vaccines.

Bacterial Vaccines↗
PubMed1993

[Antibiotic sensitivity of 140 strains of Shigella isolated in 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.

Ampicillin↗
PubMed1992

A collaborative study of the in-vitro sensitivity to RP 59500 of bacteria isolated in seven hospitals in France.

The in-vitro activity of RP 59500 was determined against 1051 recent clinical bacterial isolates. The susceptibility to RP 59500 was determined with an agar dilution technique for all the isolates, while MICs and MBCs were determined for 82 selected strains in broth. Isolates of both Staphylococcus aureus and coagulase-negative staphylococci appeared to be potentially susceptible to RP 59500, independent of susceptibility to methicillin or MLS resistance. (S. aureus: methicillin-sensitive, MIC90, 1.0 mg/L; methicillin-resistant, MIC90 1.0 mg/L; coagulase-negative staphylococci: methicillin-sensitive, MIC90 0.5 mg/L). Lancefield group A, B, C and G streptococci (MIC50 0.5 and MIC90 1.0 mg/L) and Streptococcus pneumoniae (MIC50 0.5 and MIC90 1.0 mg/L) appeared to be susceptible to RP 59500. Some Streptococcus spp. and enterococci as well as Listeria monocytogenes were inhibited by a higher concentration of RP 59500 (enterococci: MIC90 4 mg/L, range 0.125-16 mg/L). Comparatively low MICs were seen when Legionella spp., Neisseria gonorrhoeae and Gardnerella vaginalis were tested. Broth dilution MIC/MBC determinations showed no evidence of tolerance, as MIC values were within two dilutions of MBC values. RP 59500 might be a useful compound in the treatment of infections caused by a range of Gram-negative and Gram-positive bacteria, including those resistant to methicillin and/or macrolides.

Coagulase↗
PubMed1992

Resistance to cefotaxime and seven other beta-lactams in members of the family Enterobacteriaceae: a 3-year survey in France.

During the second quarter each of 1988, 1989, and 1990, a French collaborative study group, including 12 university hospital laboratories, surveyed the resistance to beta-lactams of clinical isolates from hospitalized patients: consecutively, 10,641, 10,692, and 9,382 isolates were tested. The distribution of bacterial species over time was similar in each laboratory. The susceptibilities of microorganisms to amoxicillin, ticarcillin, cephalothin, cefoxitin, cefotaxime (CTX), ceftazidime (CAZ), aztreonam (ATM), and imipenem (IPM) were measured by the disk diffusion method in accordance with the recommendations of the Antibiogram Committee of the French Society for Microbiology. Five reference strains were included for quality control. Extended-spectrum beta-lactamases were detected by the synergistic effect of the combination of clavulanic acid-amoxicillin with CTX, CAZ, and ATM in the double-diffusion test. A synergistic effect with CTX, CAZ, and ATM was detected for 1.5% of all strains, mainly those of Klebsiella pneumoniae (13.3%). For this species, the synergy test enabled the detection of roughly 50% of the resistant strains misclassified as susceptible on the basis of interpretative standards. Extended-spectrum beta-lactamases disseminated in 1990 in most enterobacterial species but at a low frequency. Important variations in the percentages of resistant strains were observed in terms of bacterial species, hospitals, and wards. However, when the total number of strains was considered, the percentages of resistance to newer beta-lactams remained low.

Anti-Bacterial Agents↗
PubMed1992

[Thyroid teratoma in adults].

A new case of thyroid teratoma is reported in an adult and the heighten other cases of the literature are reviewed. This pathology, rather frequent and always benign in infants, is distinguished in adults by a malignant metastatic course for 14 cases of 19. The reported case, the second one in a male adult, remains a benign one after 14 years.

Adolescent↗
PubMed1992

[Rapid diagnosis of malaria. The microwave furnace].

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.

Animals↗
PubMed1992

[Spread in hospital units of a Pseudomonas aeruginosa phenotype producing a beta-lactamase highly inducible by clavulanic acid in vitro].

Pseudomonas aeruginosa strains belonging to the serogroup O:11 exhibiting susceptibility to ticarcillin (TIC) and resistance to the ticarcillin-clavulanic acid (CA) combination were found in 19 inpatients over a 14 month period. Mean inhibition diameters obtained using the agar diffusion method were 21.75 mm around the TIC disks (75 micrograms) and 15.96 mm around the TIC+CA disks (75 + 10 micrograms). With control PaO:11 strains, these diameters were 25.27 and 25 mm, respectively. MIC for ticarcillin determined using the checkerboard method rose to 64 mg with CA levels of 16 mg/l or more. CA exhibited dose-dependent antagonism on TIC killing curves when TIC levels approximated the MIC; this effect was no longer present with higher TIC levels. In the crude bacterial extract, a betalactamase of the cephalosporinase type was detected in the absence of induction and increased threefold after exposure to cefoxitin (100 mg/l) and fourfold after exposure to CA (5 mg/l). All these PaO:11 strains exhibited the same antimicrobial resistance phenotype with decreased susceptibility to ureidopenicillins and resistance to aminoglycosides and fluoroquinolones. The induction of a chromosome-encoded cephalosporinase by CA proved useful as an epidemiologic marker. Nosocomial spread of this phenotype was likely the result of selection due to use of antimicrobials.

Anti-Bacterial Agents↗
PubMed1991

[In vitro activity of tazobactam and piperacillin combination against 224 strains of Pseudomonas aeruginosa according to the production of beta-lactamase].

Piperacillin (PIP) alone and combined with 4 mg/l, 8 mg/l of tazobactam (TAZ) were tested by MIC determination on Mueller-Hinton agar against 224 clinical strains of P. aeruginosa: "wild type" (BLA-), 32 producing a constitutive cephalosporinase (CEP), 41 producing the PSE-1 type beta-lactamase, 7 PSE-2, 8 PSE-3, 9 PSE-4, 13 TEM-1, 24 TEM-2, 13 OXA-1, 22 OXA-2, 5 OXA-3. The combination with 8 mg/l was more effective than that one with 4 mg/l. Combinations of PIP-TAZ 8 mg/l reduced the MICs of PIP for the resistant strains (MICs greater than 64 mg/l) to the susceptible ot the moderately susceptible range (MICs less than or equal to 64 mg/l) for 31% of the CEP producing strains, 63% of the PSE-1, 15% of the PSE-2, none of the PSE-3, 34% of the PSE-4, 39% of the TEM-1, 30% of the TEM-2, 23% of the OXA-1, 14% of the OXA-2, 27% of the OXA-3, TAZ is the first beta-lactamase inhibitor effective against the constitutive cephalosporinase of P. aeruginosa; it is also very effective against the most frequently found PSE-1 beta-lactamase in P. aeruginosa.

Cephalosporinase↗
PubMed1991

[Comparative activities of 15 beta-lactam antibiotics against 590 strains of Klebsiella pneumoniae according to the production of beta-lactamase].

In October 1988, all non repetitive strains of K. pneumoniae isolated in 17 hospitals have been studied. Among these 590 strains: 451 (76%) only produce the specific beta-lactamase of the species SHV-1 (pI 7,7) or SHV-1 type (pI 7,1), while 74 (12.5%) produce a TEM-1 or TEM-2 type beta-lactamase, and 65 (11%) an extended broad spectrum beta-lactamase: 22 CTX-1, 5 SHV-2, 4 SHV-3, 26 SHV-4, 8 SHV-5. The minimum inhibitory concentrations of the following antibiotics were performed by a liquid micro dilution technic: amoxicillin (AMX), amoxicillin + clavulanic acid (CL), 5 mg/l, ticarcillin (TIC), piperacillin (PIP), cefazolin (CEZ), cefamandole (CFM), cefoperazone (CFP), cefotaxime (CTX), cefotaxime + clavulanic acid 5 mg/l, cefotaxime + sulbactam (SUL) 5 mg/l, cefpirome (CPI), ceftazidime (CAZ), azthreonam (AZT), latamoxef (MOX), cefoxitin (FOX), cefotetan (CTT), temocillin (TMO), imipenem (IMI). The "wild" strains with SHV-1 beta-lactamase are resistant to AMX and have a decreased susceptibility to TIC and PIP, but are susceptible to other antibiotics. The TEM producing strains are more resistant to PIP and TIC, have a decreased susceptibility to CEZ and CFM but are susceptible to other antibiotics. For the extended broad-spectrum beta-lactamase producing strains, the MIC of penicillin antibiotics (AMX, TIC, PIP) are very high and also the MIC of CEZ, CFM and CFP. The MIC of CTX are higher for CTX-1 or SHV-4 producing strains, than for SHV-2, SHV-3, or SHV-5 producing strains. The combination with CL is more efficacious than the one with SUL to reduce the MIC of CTX in susceptibility area.(ABSTRACT TRUNCATED AT 250 WORDS)

Amoxicillin↗
PubMed1991

[In vitro antibacterial activity of a new fluoroquinolone, temafloxacin, against hospital isolates. Results of a multicenter study].

Minimal inhibitory concentrations (MICs) of temafloxacin (TMF) was determined by agar dilution for 2,510 bacterial strains isolated in 1989 in 9 university hospitals. Activity of TMF against nalidixic acid (NAL) susceptible (S) Enterobacteriaceae was close to that of other fluoroquinolones (FQ) (mode MIC: 0.06 micrograms/l); like for other FQ, this activity was reduced against NAL intermediate (mode 1) and resistant (R) (mode 4) Enterobacteriaceae. MICs of TMF against P. aeruginosa were between 0.12 and 128 (mode 0.5-1). TMF had also a good activity against NAL S A. baumannii (mode MIC: 0.06-0.12) but this activity is reduced against NAL R Acinetobacter (mode MIC: 16). TMF was highly active against Haemophilus mode MIC: less than or equal to 0.008), Gonococci (mode MIC: 0.008-0.032), Meningococci (mode MIC: 0.08) and B. catarrhalis (mode MIC: 0.016). TMF showed better activity to other fluoroquinolones against methicillin susceptible Staphylococci (mode MIC: 0.06); the resistant strains (mode MIC: 8) are usually methicillin resistant. Comparatively to the currently available FQ, TMF is so more effective against Enterococci (mode MIC: 1), Streptococci (mode MIC: 0.5-1) and Pneumococci (mode MIC: 0.5). Finally, for the anaerobic bacteria, TMF is more active against C. perfringens (mode MIC: 0.5) than against B. fragilis (mode MIC: 2).

4-Quinolones↗
PubMed1991

[In vitro antibacterial activity of a new oral cephalosporin, ceftibuten. Results of a multicenter study].

Minimal inhibitory concentration (MIC) of ceftibuten (CBT) were evaluated by agar dilution for 1,416 bacterial strains isolated in 5 hospitals. For Enterobacteriaceae, MIC 50 and 90% were respectively (micrograms/ml): (I) Naturally non beta-lactamase producing species: E. coli 0.12-0.5, Shigella 0.06-0.12 and Salmonella 0.03-0.12, P. mirabilis 0.16-0.03. (II) Chromosomal penicillinase producing species: K. pneumoniae 0.03-0.5 and K. oxytoca 0.03-0.06. (III) Chromosomal cephalosporin producing species: E. cloacae and C. freundii 1- greater than 128: S. marcescens 0.25-2; indole + Proteus 0.06-0.12. Activity of CBT was not modified on plasmid mediated penicillinase producing strains; however, CBT was inactive on cephalosporinase hyperproducing strains, and its activity was variably reduced on broad spectrum beta-lactamases producing strains. CBT was inactive on P. aeruginosa (MIC greater than or equal to 32) and on A. baumannii (8- greater than 128). Haemophilus and Gonococci, regardless on beta-lactamase production status, were very susceptible to CBT (MIC 50 and 90%: 0.06-0.5 and 0.016-0.06); it is the same situation for Meningococci; B. catarrhalis was generally inhibited by 0.03 to 2 (strains susceptible to penicillin G) and 0.12 to 16 (strains resistant to penicillin G). CBT was inactive on Staphylococci. Enterococci and Streptococci B were generally resistant; Streptococci A, C, G were inhibited by low concentrations: 0.06 to 1 (MIC 50 and 90%: 0.25-0.5), whereas MIC for other Streptococci 0.12 to 128 (MIC 50 and 90%: 8-128) and for Pneumococci were 0.25 to 16 (4-8). These antibacterial properties particularly against Enterobacteriaceae placed CBT in excellent position among oral cephalosporins.

Acinetobacter↗