Presse Med. 2000 Sep 23;29(27):1497-503.
[Sensitivity to antibiotics of bacteria from nosocomial infections. Evolution in resuscitation services of military hospitals]

[Article in French]

Garrabe E, Cavallo JD, Brisou P, Chapalain JC, Coue JC, Courrier P, Granic G, Herve V, Koeck JL, Morillon M, Claude JD, Rouby Y, Teyssou R.

Service de Biologie medicale, HIA Begin, Saint-Mande.

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 "Comite Francais de l'Antibiogramme de la Societe Francaise 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.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11045115&dopt=Abstract antibiotic, antibiotics



Br J Biomed Sci. 2000;57(3):185-91.
Clinical and community strains of Klebsiella pneumoniae: multiple and increasing rates of antibiotic resistance in Abha, Saudi Arabia.

Bilal NE, Gedebou M.

Department of Clinical Microbiology and Parasitology, College of Medicine and Medical Sciences, King Khalid University, Abha, Saudi Arabia.

Klebsiella pneumoniae is the most commonly isolated bacterial species in a maternity hospital in Saudi Arabia. Here, 380 strains isolated in 1997 and 480 strains in 1999 were studied for their resistance antibiograms, using the standardised disc diffusion test. Of 16 antibiotics tested, four in 1997 and six in 1999 were ineffective against > 50% of the respective isolates, and resistance rates to 11 antibiotics increased over the two-year period (P = 0.05-< 0.0001). With resistance rates of < 20%, imipenem, ciprofloxacin, gentamicin and cefotaxime were more effective in 1997; only imipenem and ciprofloxacin remained as effective in 1999. In addition, 105 community strains were tested and > 50% were resistant to four antibiotics. Resistance rates to most antibiotics were lower than those of clinical strains (P = 0.0285-< 0.0001). Imipenem resistance was detected among both clinical and community isolates. Multiresistance was 64.5% in 1997 and 79.2% in 1999 (P < 0.0001), and 83.8% in community strains in 1999. Using the double-disc synergy test, extended-spectrum beta-lactamase (ESBL) was detected in 27.5% of ceftazidime-resistant clinical strains isolated in 1999. Among the clinical strains, seven (65%) and 11 (67.9%) resistance antibiograms occurred frequently in 1997 and 1999, respectively. Such frequency was not observed among community isolates. These findings confirm the alarmingly high rates of multiresistance and the emergence of ESBL-producing strains, highlighting the urgent need to restrict over-the-counter availability of antibiotics, and increase awareness in the local medical community.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11050768&dopt=Abstract antibiotic, antibiotics



J Antimicrob Chemother. 2000 Sep;46 Suppl 1:59-62; discussion 63-5.
Ecological antibiotic policy.

Hoiby N.

Department of Clinical Microbiology, Rigshospitalet, University of Copenhagen, Denmark. hoibnet.uni2.dk

Development of resistance to antibiotics is a major problem worldwide. The normal oropharyngeal flora, the intestinal flora and the skin flora play important roles in this development. Within a few days after the onset of antibiotic therapy, resistant Escherichia coli, Haemophilus influenzae and Staphylococcus epidermidis can be detected in the normal flora of volunteers or patients. Horizontal spread of the resistance genes to other species, e.g. Salmonella spp., Staphylococcus aureus and Streptococcus pneumoniae, occurs by conjugation or transformation. An ecologically sound antibiotic policy favours the use of antibiotics with little or no impact on the normal flora. Prodrug antibiotics which are not active against the bacteria in the mouth and the intestine (before absorption) and which are not excreted to a significant degree via the intestine, saliva or skin are therefore preferred. Prodrugs such as pivampicillin, bacampicillin, pivmecillinam and cefuroxime axetil are favourable from an ecological point of view. Experience from Scandinavia supports this, since resistance to mecillinam after 20 years of use is low (about 5%) and stable.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11051626&dopt=Abstract antibiotic, antibiotics



J Fam Pract. 2000 Oct;49(10):907-13.
Back-up antibiotic prescriptions for common respiratory symptoms. Patient satisfaction and fill rates.

Couchman GR, Rascoe TG, Forjuoh SN.

Department of Family Medicine, Scot & White Memorial Hospital and Clinic, USA. gcouchmawmail.sw.org

BACKGROUND: In recent years much has been written about the overuse of antibiotics, especially for common respiratory illnesses. One approach to this issue is the use of a back-up prescription, only to be filled if a patient's condition deteriorates or fails to improve. The purpose of our study was to determine patient satisfaction, prescription fill rates, and correlates of these outcomes among patients receiving back-up antibiotic prescriptions. METHODS: In our observational study we obtained survey data from 28 physicians and 2 physician extenders in 3 family practice clinics and their patients presenting with complaints of common respiratory symptoms. We computed patient satisfaction and fill rates of back-up antibiotic prescriptions. Agreement between the perceived need of patients for antibiotics before the office visit and the subjective rating of their physicians of the clinical necessity to prescribe antibiotics for these patients was assessed using the kappa statistic. Finally, we determined correlates of satisfaction and the rate of filling back-up prescriptions. RESULTS: Of the 947 patients enrolled in the study, 46.6% received no antibiotic prescriptions, 30.2% received back-up antibiotic prescriptions, and 23.2% were given immediate-fill prescriptions for an antibiotic. Patients' self-reported satisfaction and fill rates for back-up antibiotic prescriptions were 96.1% and 50.2%, respectively. CONCLUSIONS: Our findings indicate that patients were very satisfied with a back-up antibiotic prescription. The fact that half of the patients chose not to fill these prescriptions suggests a potential health care cost savings.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11052163&dopt=Abstract antibiotic, antibiotics



Anal Chem. 2000 Oct 15;72(20):4957-64.
Rapid antibiotic susceptibility testing via electrochemical measurement of ferricyanide reduction by Escherichia coli and Clostridium sporogenes.

Ertl P, Robello E, Battaglini F, Mikkelsen SR.

Department of Chemistry, University of Waterloo, Ontario, Canada.

Electrochemical measurement of respiratory chain activity allows rapid and reliable screening for antibiotic susceptibility in microorganisms. Chronoamperometry and chronocoulometry of suspensions of aerobically cultivated E. coli combined with the non-native oxidant potassium hexacyanoferrate(III) (ferricyanide) yield signals for reoxidation of the reduction product ferrocyanide that are much smaller if the E. coli has been incubated briefly with an effective antibiotic compound. Chronocoulometric results, obtained following 20-min incubation with antibiotic and 2-min measurement in assay buffer containing 50 mM ferricyanide and 10 mM succinate, at +0.50 V vs Ag/AgCl at a Pt working electrode, were compared with traditional disk diffusion susceptibility testing, which requires overnight incubation on agar plates; the results show significantly lower accumulation of ferrocyanide in all cases in which growth inhibition was observed in the disk diffusion assay. A range of antibiotic compounds (13) were examined that possess different mechanisms of action. Quantitative determination of IC50 values for penicillin G and chloramphenicol yielded values that were 100-fold higher than those obtained by standard turbidity methods after 10-h incubation; this is likely a result of the very brief (10 min) exposure time to the antibiotics. Addition of 5 microM 2,6-dichlorophenolindophenol, a hydrophobic electron-transfer mediator, to the assay mixture allowed susceptibility testing of a Gram-positive obligate anaerobe, Clostridium sporogenes. This rapid new assay will facilitate clinical susceptibility testing, allowing appropriate treatment virtually as soon as a clinical isolate can be obtained.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11055715&dopt=Abstract antibiotic, antibiotics



Appl Environ Microbiol. 2000 Nov;66(11):4615-9.
Natural antibiotic resistance of bacteria isolated from larvae of the oil fly, Helaeomyia petrolei.

Kadavy DR, Hornby JM, Haverkost T, Nickerson KW.

School of Biological Sciences, University of Nebraska, Lincoln, Nebraska 68588-0666, USA.

Helaeomyia petrolei (oil fly) larvae inhabit the asphalt seeps of Rancho La Brea in Los Angeles, Calif. The culturable microbial gut contents of larvae collected from the viscous oil were recently examined, and the majority (9 of 14) of the strains were identified as Providencia spp. Subsequently, 12 of the bacterial strains isolated were tested for their resistance or sensitivity to 23 commonly used antibiotics. All nine strains classified as Providencia rettgeri exhibited dramatic resistance to tetracycline, vancomycin, bacitracin, erythromycin, novobiocin, polymyxin, colistin, and nitrofurantoin. Eight of nine Providencia strains showed resistance to spectinomycin, six of nine showed resistance to chloramphenicol, and five of nine showed resistance to neomycin. All 12 isolates were sensitive to nalidixic acid, streptomycin, norfloxacin, aztreonam, cipericillin, pipericillin, and cefotaxime, and all but OF008 (Morganella morganii) were sensitive to ampicillin and cefoxitin. The oil fly bacteria were not resistant to multiple antibiotics due to an elevated mutation rate. For each bacterium, the number of resistant mutants per 10(8) cells was determined separately on rifampin, nalidixic acid, and spectinomycin. In each case, the average frequencies of resistant colonies were at least 50-fold lower than those established for known mutator strain ECOR 48. In addition, the oil fly bacteria do not appear to excrete antimicrobial agents. When tested, none of the oil fly bacteria produced detectable zones of inhibition on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, or Candida albicans cultures. Furthermore, the resistance properties of oil fly bacteria extended to organic solvents as well as antibiotics. When pre-exposed to 20 microg of tetracycline per ml, seven of nine oil fly bacteria tolerated overlays of 100% cyclohexane, six of nine tolerated 10% xylene, benzene, or toluene (10:90 in cyclohexane), and three of nine (OF007, OF010, and OF011) tolerated overlays of 50% xylene-50% cyclohexane. The observed correlation between antibiotic resistance and organic solvent tolerance is likely explained by an active efflux pump that is maintained in oil fly bacteria by the constant selective pressure of La Brea's solvent-rich environment. We suggest that the oil fly bacteria and their genes for solvent tolerance may provide a microbial reservoir of antibiotic resistance genes.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11055901&dopt=Abstract antibiotic, antibiotics



J Antimicrob Chemother. 2000 Nov;46(5):811-4.
Bactericidal effect of antibiotics on Bartonella and Brucella spp.: clinical implications.

Rolain JM, Maurin M, Raoult D.

Unite des Rickettsies CNRS UPRES-A 6020, Faculte de Medecine, Universite de la Mediterranee, 27 Boulevard Jean Moulin, 13385 Marseille Cedex 05, France.

The species Bartonella and Brucella are phylogenetically closely related bacteria, both of which can produce chronic infections in humans that are difficult to cure with antibiotics. MICs of antibiotics for both species correlate poorly with the in vivo efficacy of the antibiotics. In this study we have determined MBCs of several antibiotics for this group of pathogens. Only the aminoglycosides were bactericidal, and this correlates well with the usefulness of these antibiotics for the therapy of human brucellosis and chronic Bartonella spp. infections such as endocarditis. Our data indicate that current clinical experience in treating brucellosis may help to define better the optimum antibiotic therapy for Bartonella-related diseases.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11062204&dopt=Abstract antibiotic, antibiotics