Orv Hetil. 2002 May 26;143(21):1195-8.
[Borrelia burgdorferi Group: in-vitro antibiotic sensitivity]

[Article in Hungarian]

Henneberg JP, Neubert U.

Department of Dermatology, Ludwig-Maximilians-University, Munchen, Germany.

Failures in the antibiotic therapy of Lyme disease have repeatedly been demonstrated by post-treatment isolations of the infecting borreliae. Analyses of the antibiotic susceptibility patterns of borreliae may help to understand the causes of such treatment failures and to develop new therapeutic regimens. AIMS AND METHODS: The three subspecies of Borrelia burgdorferi known to be pathogenic for humans and to differ in their virulence and organ affinity possibly may also show divergent susceptibilities to some common antibacterial agents. In order to get real clues for such probable differences we compared the efficacy of six antimicrobial agents against 24 borrelial tick and skin isolates belonging to the three subspecies of B. burgdorferi sensu lato. RESULTS: In five comparative evaluations, some significantly different antibiotic sensitivity of the three borrelial species was found. The Borrelia burgdorferi sensu stricto isolates showed lower sensitivity to cephalosporin, tetracycline and ciprofloxacin as well as a higher sensitivity to erythromycin compared to the B. afzelii and B. garinii isolates. The B. garinii isolates proved to be more sensitive to penicillin in comparison to the B. burgdorferi s.s. and B. afzelii isolates. CONCLUSIONS: In the light of these data, treatment failures may be interpreted by serum and tissue levels of the antibiotic too low for an effective killing of the infecting Spirochetes. However, prolonged treatment regimens applying higher dosages of antibiotics, in order to get complete clearing of the infection, may be linked to aggravated side effects. PROPOSAL: Therefore, the combination of different antiborrelial agents with synergistic effect seems to be a meaningful alternative and should be included in future studies in vitro as well as in vivo.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12073540&dopt=Abstract antibiotic, antibiotics



SBHCS.com

Endovascular placement of vascular stent grafts in the aorta and peripheral vessels has become a prominent tool in the armamentaria of the vascular surgeon. Despite, several reports of stent graft infection, no current guidelines exist regarding the administration of antibiotics prior to episodes of potential bacterial seeding. We sought to clarify the role of prophylactic antibiotics in preventing stent graft infection after the parenteral administration of Staphylococcus aureus (S. aureus) at various intervals following device placement. A stent graft device was constructed from a 4 mm thin-walled polytetrafluoroethylene (PTFE) graft attached to the outside of a balloon expandable 394-Palmaz stent (Johnson and Johnson Interventional Systems, Warren, NJ). It was then inserted into the common iliac artery through an 11F peal-away sheath placed in the femoral artery. Sixty grafts were placed into 30 dogs. There were 5 groups of equal number (groups A-E). In group A, six dogs received intravenous injection of 3 cc x 104 CFU (colony forming units), biotype 31375 S. aureus, 1 day after stent graft implantation. An identically treated group B received antibiotic prophylaxis (1 gm cefazolin 30 minutes prior to bacterial challenge). Group C received bacterial injection 7 days after graft implantation with no antibiotic prophylaxis. Group D received bacterial injection 7 days after graft implantation with antibiotic prophylaxis. A control group E received no antibiotics and was not infected. All infected animals were sacrificed 7 days following bacterial challenge and the stent graft complex cultured. One half of the control group was sacrificed at 7 days and the other half at 14 days. The overall stent graft patency was 90%. Four of the six graft occlusions occurred in group A. Eleven of 12 (92%) dogs cultured S. aureus (biotype 31375) from the explanted stent graft complex. Two localized perforations occurred at the site of the infected complex. In group B, C, and D, no explanted graft complex cultured S. aureus. One graft occluded in group C and D. No stent graft in the control (group E) cultured S. aureus. A stent graft infection model can be consistently produced. In the canine model, the stent graft is more susceptible to infection in the early postoperative period and becomes less susceptible to bacterial seeding at one week after implantation. The authors recommend the use of prophylactic antibiotics in the prevention of endovascular graft infections in the early postoperative period during times when bacterial seeding may occur. They postulate that pseudointima formation during graft incorporation into the vessel wall may be responsible for the resistance to infection.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12075382&dopt=Abstract antibiotic, antibiotics



J Antimicrob Chemother. 2002 Jul;50 Suppl:13-7.
Pharmacokinetics and pharmacodynamics of oral beta-lactam antibiotics as a two-dimensional approach to their efficacy.

Auckenthaler R.

Unilabs SA and University of Geneva, Geneva, Switzerland. rauckenthalenilabs.ch

Pharmacokinetic and pharmacodynamic parameters are increasingly recognized as important determinants of the therapeutic efficacy of an antibiotic. For beta-lactam antibiotics, the most important determinant of the antimicrobial efficacy, and hence predictor of therapeutic efficacy, is the length of time that serum concentrations exceed the MIC. Dosing schedules for beta-lactam antibiotics should maintain serum concentrations above the MIC for the bacterial pathogen for at least 50% of the dosing interval to achieve therapeutic efficacy and prevent the development of resistance. This is a basic criterion for the clinical efficacy of beta-lactams. A combination of microbiological activity and pharmacokinetic characteristics was applied to calculate the time that serum antibiotic concentrations exceed the MIC for the major respiratory tract pathogens such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Streptococcus pyogenes and Klebsiella pneumoniae. In contrast with some other oral beta-lactam antibiotics, cefpodoxime 200 mg bd maintains serum concentrations above the MIC for each organism for at least 50% of the dosing interval and may therefore be an attractive choice for empirical therapy of community-acquired lower respiratory tract infections.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12077155&dopt=Abstract antibiotic, antibiotics



Acta Orthop Scand. 2002 Apr;73(2):199-205.
Release of netilmicin and vancomycin from cancellous bone.

Witso E, Persen L, Benum P, Bergh K.

Department of Orthopaedic Surgery, University Hospital, Norwegian University of Science and Technology, Trondheim. eivind.witsit-no

First, we studied the effect of the following variables used for netilmicin- and vancomycin-impregnation of cancellous bone: a) antibiotic concentration of the impregnation fluid, b) time used for impregnation, c) pH of the impregnation fluid, d) the degree of bone morselizing and e) antibiotic combination. An increase in the antibiotic concentration of the impregnation fluid increased the amount of antibiotics released from bone. In addition, the amount of vancomycin eluted was also dependent on the time used for impregnation. The fraction of the total amount of netilmicin and vancomycin released after 24 h was 80% and 30%, respectively. More netilmicin and vancomycin were eluted from bone impregnated with antibiotics at pH 7 than the amount eluted from bone impregnated at pH 3. More netilmicin was eluted from fine morselized bone than from coarse morselized bone. By combining netilmicin and vancomycin in the impregnation fluid, the release of vancomycin was reduced. Secondly, we analyzed if the release of antibiotics from bone was complete: 99.9% of the total amount of netilmicin adsorbed to the bone was released by elution during 6 weeks. Finally, after implantation of netilmicin-impregnated bone in rabbit femur condyle, we measured netilmicin and vancomycin in serum: peak serum values of netilmicin were 4.2 (3.7-4.7) mg/L 2-3 h postoperatively.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12079020&dopt=Abstract antibiotic, antibiotics



Genes Cells. 2002 Jul;7(7):629-38.
SsrA-mediated protein tagging in the presence of miscoding drugs and its physiological role in Escherichia coli.

Abo T, Ueda K, Sunohara T, Ogawa K, Aiba H.

Division of Biological Science, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.

BACKGROUND: We have shown recently that read-through of a normal stop codon by a suppressor tRNA in specific genes possessing a Rho-independent terminator leads to SsrA-mediated tagging of extended proteins in Escherichia coli cells. Miscoding antibiotics such as kanamycin and streptomycin reduce translational fidelity by binding to the 30S ribosomal subunit. The aim of the present study was to address how miscoding antibiotics affect the read-through of stop codons and SsrA-mediated protein tagging. RESULTS: Miscoding antibiotics caused translational read-through of stop codons when added to the culture medium at sublethal concentrations. Under the same conditions, the drugs enhanced SsrA-mediated tagging of bulk cellular proteins, as observed in cells carrying an ochre suppressor tRNA. Translational read-through products generated from the crp gene in the presence of the antibiotics was efficiently tagged by the SsrA system, presumably because the ribosome reached the 3' end of the mRNA defined by the terminator hairpin. The SsrA-defective cells were more sensitive to the miscoding antibiotics compared to the wild-type cells. CONCLUSION: We conclude that the SsrA system contributes to the survival of cells by dealing with translational errors in the presence of low concentrations of miscoding antibiotics.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12081641&dopt=Abstract antibiotic, antibiotics



Infez Med. 2001 Dec;9(4):193-211.
[Role of parenteral cephalosporins for outpatients treatment of infections]

[Article in Italian]

Esposito S, Mazzei T, Novelli A.

Clinica Malattie Infettive, Seconda Universit degli Studi di Napoli.

OPAT (Outpatient Parenteral Antibiotic Therapy) arose in the early !980s in the USA and later in many other countries from the primary consideration that outpatient treatment is more cost-effective than hospitalisation. Currently, several thousand patients undergo OPAT programmes all over the world and several different bacterial infections are included in the list of treatable diseases, especially those requiring long-term parenteral treatment such as osteomyelitis and soft tissue infections. All injectable antibiotics are suitable for OPAT according to their microbiological spectrum, although clearly some pharmacological properties make one antibiotic more preferable than another. Beta-lactams represent more than half of the antibiotic world market and two-thirds of them are cephalosporins. Such a widespread use of cephalosporins is certainly due to their wide antibacterial spectrum and good tolerability. Among third-generation cephalosporins, covering the majority of micro-organisms responsible for community-acquired infections, ceftriaxone is the only one with an 8-hour half-life, thereby permitting a single daily dose, which represents a great advantage when undertaking an OPAT programme. Analysis of antibiotic consumption used for OPAT therapies, based on data collected from the International OPAT Registry project, with the participation of many countries (USA, Canada, Britain, Argentina, etc.) including Italy, shows that ceftriaxone is the most widely used antibiotic for home therapy, clearly due to the above-mentioned properties.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12087207&dopt=Abstract antibiotic, antibiotics [PubMed - in process]



Therapie. 2002 Jan-Feb;57(1):39-47.
[Evaluation of the impact of individual antibiotic order forms on consumption of antibiotics]

[Article in French]

Labarere J, Martin S, Fourny M, Mallaret MR, Pavese P, Allenet B, Stahl JP, Calop J, Francois P.

Laboratoire GPSP, Faculte de Medecine, La Tronche. Jlabarerhu-grenoble.fr

The aim of the study was to assess the impact of an individual patient order form which concerned the 21 most costly antibiotics in a university hospital. Antibiotics expenditures were monitored from 1995 to 1999 and were expressed in 1999 French Francs per 100 patient days (p.d.). The time series were analyzed by auto-regressive models. The trend of antibiotics expenditures which were concerned by the individual patient order form was a yearly increase of 50 FF/100 p.d. (p < 0.01). The individual patient order form had no significant impact on global antibiotics expenditures but there were some differences across departments: antibiotics costs decreased 1.293 FF/100 p.d. (p = 0.02) in intensive care departments. Monitoring antibiotics consumption should be continued in order to increase power of analysis and to assess the impact of the implementation of guidelines.


Source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12090146&dopt=Abstract antibiotic, antibiotics