Comparative in vitro activities of teicoplanin, vancomycin, oxacillin, and other antimicrobial agents against bacteremic isolates of gram-positive cocci

Comparison of shunt infection incidence in high-risk subgroups receiving antibiotic-impregnated versus standard shunts

BACKGROUND

Shunt infection is a morbid complication of CSF shunting. Though antibiotic-impregnated shunt (AIS) systems decrease shunt infections by preventing bacterial colonization following device implantation, their effectiveness in populations at high risk for infection has recently been disputed. We set out to determine whether the categorical switch to AIS systems at our institution has resulted in a decreased incidence of shunt infection in high-risk pediatric patients.

METHODS

We retrospectively reviewed the records from all pediatric patients undergoing CSF shunt procedures at The Johns Hopkins Hospital over a 10-year period between January 1997 and December 2007. During the 5.75 years prior to October 2002, all CSF shunts included standard, non-AIS catheters. During the 4.25 years after October 2002, all CSF shunts included AIS catheters. High-risk subgroups were defined a priori as prematurity (<35 weeks gestational age), shunts placed immediately post-meningitis, conversion of external ventricular drains (EVD) to shunt, and replacement of nosocomial shunt infection in patients requiring prolonged hospital stay (>1 month).

RESULTS

A total of 544 pediatric patients underwent 1,072 shunt placement procedures (502 AIS, 570 non-AIS). Of patients with non-AIS catheters, 64 (11.2%) experienced shunt infection, whereas only 16 (3.2%) patients with AIS catheters experienced shunt infection (p<0.001). AIS versus non-AIS was associated with decreased shunt infection in premature neonates [three (5.5%) vs. seven (20.0%), p=0.030], acutely following bacterial meningitis [two (5.7%) vs. nine (25.0%), p=0.043], when converting EVD to shunts [zero (0%) vs. four (13.3%), p=0.030], and in patients with prolonged hospital stay>1 month [three (5.3%) vs. 12 (18.5%), p=0.022]. Staphylococcus aureus was the most common infectious agent for both non-AIS (81.3%) and AIS (75.0%) systems.

CONCLUSION

The introduction of AIS catheters into our institutional practice has reduced the incidence of shunt infection in pediatric populations at highest risk for infection. AIS catheters are effective instruments to prevent peri-operative colonization of CSF shunt components.

Synergistic activity of vancomycin and teicoplanin alone and in combination with streptomycin against Enterococcus faecalis strains with various vancomycin susceptibilities

The synergy between two glycopeptides, vancomycin (Vm) and teicoplanin (Tec) and streptomycin (Sm) was studied by time-kill method. Five clinical vanB resistant Enterococcus faecalis (ENC) isolates with variable Vm-susceptibility were used. Different concentrations of Vm, Tec and Sm representing therapeutic concentrations were combined. Antibacterial activity was related to the concentrations of Vm and Sm, and Vm susceptibility to ENC. For strains with Vm MIC up to 64 mg/l, synergy was achieved with higher concentrations of Vm and Sm, while all combinations of Tec and Sm were synergistic against all strains except ENC 29. For ENC 29 with Vm MIC of 512 mg/l and Tec MIC of <1 mg/l, none of the combinations was synergistic. The significance of these in vitro results needs further investigation in vivo.

European survey of glycopeptide susceptibility in Staphylococcus spp

OBJECTIVE: To reassess the relative potencies of teicoplanin and vancomycin following several years of clinical usage. METHODS: The glycopeptide susceptibilities of clinical isolates of staphylococci collected from 70 hospitals in 1995 were determined using NCCLS (National Committee for Clinical Laboratory Standards) methods. RESULTS: In total, 2885 isolates of Staphylococcus aureus and 1480 isolates of coagulase-negative staphylococci were collected. S. aureus was significantly less susceptible to vancomycin (MIC50 1 mg/L) than teicoplanin (MIC50 0.5 mg/L), but the reverse was the case for S. haemolyticus and S. epidermidis. No S. aureus isolate was resistant (>/=32 mg/L) to either glycopeptide, but nine isolates of coagulase-negative staphylococci had an MIC of teicoplanin of 32 mg/L. Respiratory isolates of S. aureus were less susceptible to glycopeptides than those from other sites. Staphylococci from Belgium and Italy were less susceptible to teicoplanin than isolates from other countries. CONCLUSIONS: This European survey shows that in 10 years of clinical use there have been no major changes in the susceptibility of staphylococci to the glycopeptides.

Penetration of teicoplanin into heart valves and subcutaneous and muscle tissues of patients undergoing open-heart surgery

Penetration of teicoplanin into serum, heart valves, and subcutaneous and muscle tissues was determined in 22 patients undergoing open-heart surgery. Each patient received 12 mg of teicoplanin per kg of body weight as a 30-min intravenous infusion preoperatively. Within 10 h, serum concentrations of teicoplanin declined from 43.1 to 2.8 microg/ml. Teicoplanin concentrations in subcutaneous tissues reached their peak of 9.2 microg/g after 2 to 3 h and decreased slowly to 2.3 microg/g after 9 to 10 h. Concentrations in muscle decreased from 8.7 microg/g to nondetectable levels. Teicoplanin concentrations in cardiac valvular tissue reached their peak of 6.1 microg/g and decreased thereafter to 1.7 microg/g. Teicoplanin concentrations in heart valves were high enough to inhibit methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci, which are known to cause postoperative wound infections and infective endocarditis.

Teicoplanin in cardiac surgery: intraoperative pharmacokinetics and concentrations in cardiac and mediastinal tissues

The concentrations of teicoplanin in the sera and mediastinal and heart tissues of 23 patients undergoing cardiac surgery were measured after two regimens of teicoplanin administration. Intraoperative pharmacokinetic parameters were also obtained. Patients were randomized into two groups. Those in group 1 were given teicoplanin at 6 mg x kg(-1) intravenously at the time of induction of anesthesia. Patients in group 2 were given teicoplanin at 12 mg x kg(-1) during the same period. The maximum concentration in serum (71 +/- 20 and 131 +/- 44 mg x l(-1)), the minimum concentration in serum (3.6 +/- 1.3 and 6.8 +/- 2.1 mg x l(-1)), the area under the concentration-time curve (AUC) from 0 to 12 h (108 +/- 20 and 217 +/- 38 microg x h x ml(-1)), and the AUC from 0 h to infinity (154 +/- 36 and 292 +/- 77 microg x h x ml(-1)) were twice as high after 12-mg x kg(-1) injections as after 6-mg x kg(-1) injections. No differences in mean residence time (9.7 +/- 4.9 and 8.4 +/- 2.7 h) or terminal half-life (8.5 +/- 3.8 and 7.5 +/- 2.3 h) were observed. Teicoplanin penetrated mediastinal and heart tissues but not sternal bone, where the antibiotic was detectable in only 1 of 13 patients in group 1 and 2 of 10 patients in group 2. In group 1, 7 of 13 patients had teicoplanin concentrations in tissue that were lower than the MIC for 90% of the strains of potential pathogens tested (MIC90) that cause infection after cardiac surgery. All of the patients in group 2 but one had teicoplanin concentrations in tissue (other than in sternal bone) far in excess of the MIC90 for the potential pathogens. In conclusion, the 12-mg x kg(-1) regimen of teicoplanin is followed by a significant increase in teicoplanin concentrations in heart and mediastinal tissues and should be preferred to the 6-mg x kg(-1) regimen if teicoplanin is selected for antimicrobial prophylaxis in open heart surgery.

Comparative study on the antibacterial activity of phytochemical flavanones against methicillin-resistant Staphylococcus aureus

Differently substituted flavanones were isolated from Leguminosae and their antibacterial activity was comparatively studied against methicillin-resistant Staphylococcus aureus (MRSA). The minimum inhibitory concentrations (MICs) of phytochemical flavanones to clinical isolates of MRSA were determined by a serial agar dilution method. The structure-activity relationship has indicated that 2',4'- or 2',6'-dihydroxylation of the B ring and 5,7-dihydroxylation of the A ring in the flavanone structure are important for significant anti-MRSA activity and that substitution with a certain aliphatic group at the 6- or 8-position also enhances the activity. Among the thirteen flavanones tested, tetrahydroxyflavanones with these structural characteristics isolated from Sophora exigua and Echinosophora koreensis showed intensive activity to inhibit the growth of all MRSA strains at 3.13-6.25 micrograms/ml. The present hydroxyflavanones would be useful in the phytotherapeutic strategy against MRSA infections.

Anti-infective treatment in intensive care: the role of glycopeptides

Antibiotics are used in 80% of patients in the ICU, encouraging nosocomial infections with resistant organisms. If the antibiotic susceptibilities of the pathogen are known, a narrow-spectrum antibiotic is preferable to preserve the patient's resistance to colonization. However, treatment is often empirical and broad-spectrum combinations are commonly used. Gram-positive bacteraemia is associated with invasive monitoring or intravascular catheters. If the device cannot be removed easily, the glycopeptides are the only agents likely to be active against most strains of the commonest pathogen, the coagulase-negative staphylococcus. Long-stay patients are susceptible to infection with enterococci and methicillin-resistant Staphylococcus aureus, which are often resistant to all the usual agents other than glycopeptides. Vancomycin is long established, but is nephrotoxic, requires serum monitoring, must be administered as an infusion and can cause red man syndrome. Teicoplanin can be given as a single daily bolus without similar side-effects or monitoring. In deep-seated staphylococcal infection, the usual dose of teicoplanin is adequate if given in combination with other agents, but it may need to be doubled if used as monotherapy. Monitoring of the levels in the serum is helpful to ensure an adequate dose in patients with renal failure or in drug abusers, but is not needed to prevent toxicity.

Teicoplanin: 10 years of clinical experience

The teichomycin antibiotics have been discovered and chemically purified in the late 1970s. Teicoplanin, one of the major derivatives of this group, has been introduced into clinical use in 1984. In Germany, teicoplanin was licensed in 1988 and now ranks among the antimicrobial agents most frequently used in intensive care units. Due to its reduced rate of side effects compared to vancomycin, its longer serum half-life and a simplified mode of application, teicoplanin has become the glycopeptide of choice in many hospitals. The present review summarizes in vitro activity data, pharmacokinetics, and clinical experience with teicoplanin, with special consideration of currently recommended doses and serum levels.

Flavanones with potent antibacterial activity against methicillin-resistant Staphylococcus aureus

With the therapeutic concept of using the defensive ability of plants against microbial infections, phytoalexin, an antimicrobial phytochemical was studied for its ability to inhibit the growth of methicillin-resistant Staphylococcus aureus (MRSA). Extracts from Sophora exigua (Leguminosae) were fractionated by serial chromatography and the anti-MRSA activity of each fraction was determined by the agar-plate method. Among the active isolates, 5,7,2',6'-tetrahydroxy-6-isoprenyl-8-lavandulyl-4'-methox yflavanone (exiguaflavanone D) completely inhibited the growth of all the MRSA strains examined at the concentration of 1.56-6.25 micrograms mL-1, and 5, 2',6'-trihydroxy-8-lavandulyl-7-methoxy-flavanone (exiguaflavanone B) inhibited at a concentration of 50 micrograms mL-1. This former compound is expected to be a phytotherapeutic agent for MRSA infections as an alternative to conventional antibiotics with unwanted side-effects or the appearance of antibiotic-resistant bacteria.

Comparative activity of teicoplanin and vancomycin against 400 penicillin susceptible and resistant Streptococcus pneumoniae. The French Study Group

The MICs of teicoplanin and vancomycin were determined for 400 penicillin-susceptible and -resistant strains of Streptococcus pneumoniae isolated during a multicenter study in 1992. Teicoplanin displayed a four-fold better activity than vancomycin, with modal MICs of these agents being 0.06 and 0.25 micrograms/ml, respectively. These data warrant further studies with teicoplanin in the treatment of pneumococcal infections.

Comparative in vitro activities of teicoplanin, daptomycin, ramoplanin, vancomycin, and PD127,391 against blood isolates of gram-positive cocci

The in vitro activities of teicoplanin, daptomycin, ramoplanin, and PD127,391, a new quinolone, were compared with that of vancomycin. Teicoplanin showed the lowest MICs against Enterococcus faecalis. Ramoplanin was slightly more active than the other peptide antibiotics against oxacillin-resistant Staphylococcus aureus. The MICs of the four peptide antibiotics were similar for the oxacillin-susceptible S. aureus. Daptomycin had good activity against staphylococci but was the least active agent against E. faecalis. The MICs of vancomycin against all isolates were in general higher than those of the new antibiotics, with the exceptions of the MICs of daptomycin against E. faecalis and teicoplanin against oxacillin-resistant Staphylococcus epidermidis. PD127,391 was the most active agent against all staphylococcal isolates.

Teicoplanin versus vancomycin for prophylaxis of experimental Enterococcus faecalis endocarditis in rats

Teicoplanin was compared with vancomycin for the prophylaxis of experimental Enterococcus faecalis endocarditis in rats. Single intravenous doses of teicoplanin (7 mg/kg of body weight) or vancomycin (15 mg/kg) were given 30 min before bacterial challenge. Two strains of E. faecalis (309 and 1209) isolated from patients with endocarditis were tested. Bacterial inocula ranged from 10(4) (i.e., the inoculum infecting 90% of the control rats [ID90]) to 10(7) CFU/ml. The MICs and MBCs of teicoplanin and vancomycin were, respectively, 0.25 to greater than 128 mg/liter and 2 to greater than 128 mg/liter for strain 309 and 0.5 to greater than 128 mg/liter and 0.5 to greater than 128 mg/liter for strain 1209. Vancomycin prevented endocarditis only in 60% (strain 309) and in 87% (strain 1209) of rats challenged with the smallest bacterial-inoculum size (ID90), whereas teicoplanin prevented endocarditis in 100% of rats challenged with the same inoculum (strain 309; P = 0.05), in 87% of rats challenged with 10 times the ID90 (strain 309; P = 0.02), and in 95% of rats challenged with 100 times the ID90 (strain 1209; P = 0.0003). The combination of teicoplanin plus gentamicin (4 mg/kg) extended the protection to inocula 100 times the ID90 (strain 309; 96% of sterile animals) and 1,000 times the ID90 (strain 1209; 100% of sterile animals). Prevention of endocarditis was likely to be due to a prolonged inhibition of bacterial growth by sustained levels of teicoplanin in serum and not to bacterial killing. Indeed, teicoplanin did not exhibit any bactericidal activity either in vitro (time-kill curves) or in vivo (serum bactericidal activity). Teicoplanin proved to be superior to vancomycin in the prophylaxis of experimental E. faecalis endocarditis in rats.

Susceptibility of Staphylococcus species and subspecies to teicoplanin

Twenty-four Staphylococcus species and their subspecies were examined for their susceptibilities to teicoplanin by disk diffusion (30-micrograms disk) and agar dilution for the determination of MICs. Moderately susceptible and resistant clinical strains were further tested for their susceptibilities to oxacillin and vancomycin. Teicoplanin resistance was not observed in the reference strains of the various Staphylococcus species isolated from healthy volunteers or animals. However, the novobiocin-resistant species Staphylococcus saprophyticus, Staphylococcus cohnii, Staphylococcus xylosus, Staphylococcus arlettae, Staphylococcus kloosii, and Staphylococcus gallinarum were less susceptible to teicoplanin (MIC, 2 to 8 micrograms/ml) than most of the novobiocin-susceptible species were (MIC, 0.5 to 4 micrograms/ml). Clinical isolates of coagulase-negative species were generally less susceptible to teicoplanin than were reference strains. Seven percent of the Staphylococcus epidermidis clinical strains were moderately susceptible (MIC, 16 micrograms/ml) to teicoplanin. Of these strains, 70% were oxacillin resistant. For Staphylococcus haemolyticus strains, 11% were resistant (MIC, greater than 16 micrograms/ml) and 21% were moderately susceptible to teicoplanin. Of these strains, 95% were oxacillin resistant, No strains of S. epidermidis or S. haemolyticus were intermediate or resistant to vancomycin. Teicoplanin appears to be less active in vitro against oxacillin-resistant S. haemolyticus. However, teicoplanin is an effective antimicrobial agent against many Staphylococcus species.

Treatment of bone, joint, and vascular-access-associated gram-positive bacterial infections with teicoplanin

Teicoplanin, a glycopeptide antibiotic, was evaluated for safety and efficacy in the treatment of vascular-access-associated bacteremias and of bone and joint infections due to susceptible gram-positive organisms. Of 35 patients enrolled, 26 had osteomyelitis, 8 had vascular-access-associated bacteremias, and 1 had a joint infection. A total of 38 gram-positive isolates were identified: 23 Staphylococcus aureus and 6 coagulase-negative staphylococcus and 9 streptococcus isolates. After at least 6 months of follow-up, 17 patients were evaluable for efficacy: 10 of 14 (71%) with osteomyelitis and 3 of 3 with vascular-access-associated bacteremias had full resolution of their infections. Inadequate debridement, the presence of metal, and inadequate dosing were likely causes of two failures and two relapses in patients with osteomyelitis. For all but two organisms, teicoplanin MICs were less than or equal to 2 micrograms/ml. Patients who responded had median peak and trough serum bactericidal levels at serum dilutions of 1:64 and 1:16; trough levels of teicoplanin in serum were greater than 30 micrograms/ml. Patients did not respond as expected to daily doses of 4 mg/kg of body weight, which consequently were increased to greater than or equal to 15 mg/kg. Audiology testing of 20 patients found 2 with a mild loss of high-frequency hearing; 1 patient complained of tinnitus. Patients tolerated peak levels in serum as high as 127 micrograms/ml and trough levels of 49 micrograms/ml. However, 5 of 18 patients (28%) whose daily dose was greater than or equal to 12 mg/kg developed drug fever and rash and had teicoplanin discontinued. Further study of the antibiotic at such higher doses is needed.

Teicoplanin. A review of its antibacterial activity, pharmacokinetic properties and therapeutic potential

Teicoplanin is a glycopeptide antibiotic with a molecular structure which is related to that of vancomycin. Gram-positive bacteria such as staphylococci (including methicillin-resistant strains), streptococci, enterococci and many anaerobic Gram-positive bacteria are susceptible to teicoplanin in vitro. Teicoplanin has an exceptionally long half-life, allowing once-daily intramuscular or intravenous administration. Teicoplanin is clinically and bacteriologically effective against a wide variety of Gram-positive infections such as septicaemia, endocarditis, skin and soft tissue infections and infections associated with venous catheters. The drug is equally efficacious against methicillin-resistant and -susceptible staphylococci. Adverse effects with teicoplanin are generally limited to local effects or hypersensitivity reactions. While teicoplanin has the potential for ototoxicity and nephrotoxicity, the incidence appears to be quite low when recommended serum concentrations are maintained. Teicoplanin is a valuable alternative to vancomycin, and providing controlled comparative studies prove equivalent safety and efficacy between the 2 glycopeptides the more easily administered teicoplanin should become the preferred antibacterial agent.

Resistance to vancomycin and teicoplanin: an emerging clinical problem

Vancomycin and teicoplanin are glycopeptides active against a wide range of gram-positive bacteria. For 30 years following the discovery of vancomycin in 1956, vancomycin resistance was not detected among normally susceptible bacteria recovered from human specimens. Since 1986, however, bacteria resistant to vancomycin or teicoplanin or both have been described. Strains of the genera Leuconostoc, Lactobacillus, Pediococcus, and Erysipelothrix seem inherently resistant to glycopeptides. Species and strains of enterococci and coagulase-negative staphylococci appear to have acquired or developed resistance. There are at least two categories of glycopeptide resistance among enterococci, characterized by either high-level resistance to vancomycin (MIC, greater than or equal to 64 mg/liter) and teicoplanin (MIC, greater than or equal to 8 mg/liter) or lower-level vancomycin resistance (MIC, 32 to 64 mg/liter) and teicoplanin susceptibility (MIC, less than or equal to 1 mg/liter). The two categories appear to have similar resistance mechanisms, although genetic and biochemical studies indicate that they have arisen independently. Among coagulase-negative staphylococci, strains for which vancomycin MICs are up to 20 mg/liter or teicoplanin MICs are 16 to 32 mg/liter have been reported, but cross-resistance between these glycopeptides varies. The selective advantage accorded to glycopeptide-resistant bacteria and the observation that high-level resistance in enterococci is transferable suggest that such resistance may be expected to increase in incidence. Clinicians and microbiologists need to be aware of this emerging problem.

Percentages and distributions of teicoplanin- and vancomycin-resistant strains among coagulase-negative staphylococci

The activities of teicoplanin and vancomycin against 362 coagulase-negative staphylococci were determined by an agar dilution method. At the 4- and 32-micrograms/ml breakpoint levels of the National Committee for Clinical Laboratory Standards, 23.2% of the strains were intermediate and 1.7% were resistant to teicoplanin, in contrast to less than 0.3% intermediate to vancomycin. Resistant strains belonged to the species Staphylococcus epidermidis (74%) and S. haemolyticus (19%).