Application Of Vancomycin Research Articles

P137 Efficiency of application of vancomycin in newborns in NICU

P137 Efficiency of application of vancomycin in newborns in NICU

Treatment for Staphylococcus aureus infection following open wedge high tibial osteotomy using antibiotic-impregnated calcium phosphate cement

This report describes a case of Staphylococcus aureus infection following open wedge high tibial osteotomy, which was successfully treated with by implant removal and replacement with antibiotic-impregnated calcium phosphate cement along with external fixation. The infection occurred 7 months after primary surgery and was treated by implant removal, debridement, external fixation, and application of vancomycin impregnated calcium phosphate cement to fill the defect. Subsequently, the infection resolved completely, and the osteotomy healed with no correction loss. Compared with conventional bone cement, calcium phosphate cement might be an optimal material for certain cases of infection after open wedge high tibial osteotomy because of its higher antibiotic retention, biocompatibility, osteoconductivity, and compatibility with heatlabile antibiotics. V.

Vancomycin removal during low-flux and high-flux extended daily hemodialysis in critically ill septic patients

To determine the extent of vancomycin removal and vancomycin pharmacokinetics in septic patients with AKI using daily hemodialysis with polysulphone high-flux and low-flux membrane. Five patients received 6 h daily dialysis with low-flux polysulphone membrane, four patients with high-flux polysulphone membrane. Vancomycin was administered over the last hour of dialysis. The maintenance dose was adjusted based on pre-hemodialysis serum concentrations. Patients were followed up for two days. Median percentage of vancomycin removal by low-flux membrane dialysis was 17% (8-38%) and by high-flux membrane dialysis was 31% (13-43%). Vancomycin clearance was only moderately higher in high-flux membrane dialysis (median 3.01 L/h, range 2.34-3.5 L/h) compared to low-flux dialysis (median 2.48 L/h, range 0.53-5.68 L/h) in the first day of the study. About two-fold higher vancomycin clearance in high-flux dialysis (median 3.62 L/h, range 1.37-5.07 L/h) was observed on the second day of the study than low-flux dialysis (median 1.74 L/h, range 0.75-30.94 L/h). Both high-flux and low-flux membrane dialysis remove considerable amounts of vancomycin in critically ill septic patients with AKI. Application of vancomycin after each dialysis was required to maintain therapeutic concentrations.

Intrawound Application of Vancomycin for Prophylaxis in Instrumented Thoracolumbar Fusions: Efficacy, Drug Levels, and Patient Outcomes

Intrawound Application of Vancomycin for Prophylaxis in Instrumented Thoracolumbar Fusions: Efficacy, Drug Levels, and Patient Outcomes

Intrawound Application of Vancomycin for Prophylaxis in Instrumented Thoracolumbar Fusions

A retrospective cohort study from a single institution of a consecutive series of spine surgery patients. To evaluate the safety and efficacy of adjunctive local application of vancomycin for infection prophylaxis in posterior instrumented thoracic and lumbar spine wounds compared to IV cephalexin alone. Cephalosporin resistant strains of staphylococcus (MRSA and coagulase negative staph) have diminished the efficacy of intravenous antibiotic prophylaxis for instrumented spine fusion. Intravenous vancomycin prophylaxis has not been shown to decrease wound infection rates compared to IV cephalosporins. Adjunctive application of vancomycin powder in wounds for instrumented spinal fusion surgery may decrease infection rates. Since 2000, 1732 consecutive thoracic and lumbar posterior instrumented spinal fusions have been performed with routine 24 hours of perioperative intravenous antibiotic prophylaxis with cephalexin. Since 2006, 911 of these instrumented thoracic and lumbar cases had 2 g of vancomycin powder applied to the wound before closure in addition to intravenous antibiotics. A retrospective review for infection rates and complications was performed. Oswestry and SF-36 outcomes instruments were completed before surgery, immediately after surgery, and at latest follow-up. The average follow-up is 2.5 years, range 1 to 7 years. Eight hundred twenty-one posterior instrumented thoracic and lumbar fusions were preformed using intravenous cephalexin prophylaxis with a total of 21 deep wound infections (2.6%). Coag negative staph was the most commonly isolated organism. Nine hundred eleven posterior instrumented thoracic and lumbar fusions have been performed with IV cephalexin plus adjunctive local vancomycin powder with two deep wound infections (0.2%). The reduction in wound infections was statistically significant (P < 0.0001). There were no adverse clinical outcomes or wound complications related to the local application of vancomycin. Adjunctive local application of vancomycin powder decreases the postsurgical wound infection rate with statistical significance in posterior instrumented thoracolumbar spine fusions.

Release of vancomycin from multilayer coated absorbent gelatin sponges

Wounds have the potential to become infected during any surgical procedure. Gelatin sponges that are commonly used to absorb blood during invasive surgeries would benefit tremendously if they released antibiotics. In this work, we have examined coating a commercial gelatin sponge with degradable polymer multilayer films containing vancomycin. The effect of the film on sponge absorption capabilities and the effect of the sponge on drug release kinetics were both examined. Application of vancomycin containing layer-by-layer assembled films to this highly porous substrate greatly increased drug loading up to approximately 880% compared to a flat substrate. Vancomycin drug release was extended out to 6 days compared to 2 days for film coated flat substrates. Additionally, the absorbent properties of the gelatin sponge were actually enhanced by up to 170% due to the presence of the vancomycin film coating. A comparison of film coated sponges with sponges soaked directly in vancomycin demonstrated the ability of the multilayer films to control drug release. Film released vancomycin was also found to remain highly therapeutic with unchanged antimicrobial properties compared to the neat drug, demonstrated by quantifying vancomycin activity against Staphylococcus aureus in vitro.

Auditory Function After Application of Ototopical Vancomycin and Mupirocin Solutions in a Murine Model

To determine whether mupirocin (440 µg/mL) and vancomycin otic drops (25 mg/mL) show evidence of ototoxicity in CBA/J mice immediately following a 7-day course of daily intratympanic (IT) injections and 1 month following treatment. Nonrandomized controlled trial. Academic hospital laboratory. Twenty CBA/J mice. Mean auditory brainstem response (ABR) thresholds increased in all drug- and saline-treated ears immediately after 7 days of IT injections but returned to baseline for most stimulus frequencies by 30 days later. This finding appeared to be correlated with the presence and subsequent resolution of tympanic membrane (TM) perforations and granulation tissue at the injection sites. Mupirocin-treated ears showed no significant difference in ABR thresholds compared to saline-treated ears. No significant differences were noted between vancomycin- and saline-treated ears, but there was a significant interaction between testing day and stimulus frequency (P < .001). Further analysis revealed that ABR thresholds at 32 kHz remained significantly elevated in vancomycin-treated mice despite the resolution of TM perforations and granulation tissue 30 days after completion of IT injections (95% confidence interval, -13.5 to -5.5, P < .01). Although IT application of mupirocin solution (440 µg/mL) caused no significant change in the ABR thresholds in a murine model, vancomycin solution (25 mg/mL) resulted in high-frequency threshold elevations in both the ear directly injected and the contralateral ear. Mupirocin solution may be beneficial in managing otitis externa and media caused by resistant pathogens. Further studies of ototopical vancomycin are needed to define parameters governing its safe use.

A viable antibiotic strategy against microbial contamination in biotechnological production of polyhydroxyalkanoates from surplus whey

Abstract The study demonstrates the successful application of vancomycin for inhibiting growth of the contaminant Bacillus cereus in a polyhydroxyalkanoate (PHA) production process with Hydrogenophaga pseudoflava on whey. The minimum inhibiting concentration (MIC) of vancomycin for both strains was calculated in minimal medium H3 as well as in H3 medium supplemented with yeast extract. MIC for B. cereus was 0.57 μg mL −1 and 1.63 μg mL −1 in H3 and H3 plus yeast extract respectively. For H. pseudoflava , MIC amounted to 2.8 μg mL −1 in H3 medium and 6.88 μg mL −1 in H3 plus yeast extract. The effect of vancomycin on PHA production was minimal or negligible up to a vancomycin concentration of 1 μg mL −1 in both media. The specific PHA production rates of H. pseudoflava decreased with increasing antibiotics in a minimal medium but in media supplemented with yeast extract the specific PHB production rates increased as the antibiotics concentrations increased.

Focal injection of vancomycin combined with surgical debridement–dermatoplasty in the treatment of pseudo-epitheliomatous granuloma

Background Pseudo-epitheliomatous granuloma (PEG) can occur in some small skin wounds with secondary infections resulting from improper treatments. It is difficult to heal and can easily relapse. Objectives This study explores the clinical and pathological characteristics of PEG and effective treatments. Patients and methods Tissue specimens of PEG obtained from 11 patients (age range: 2–67 years) were sent for microbial examination and histological observation. The local lesions were treated by focal injection of vancomycin combined with surgical debridement–dermatoplasty. Results The diagnosis of PEG was based on histological examination, which revealed long epithelial peduncle encapsulated granulation tissue-like honeycomb in which more vessels, macrophages, lymphocytes and mast cells and less extracellular matrix were distributed. Bacteria such as Staphylococcus aureus, Bacillus pyocyaneus, ethylene-type Streptococcus, stool Streptococcus and F-citric acid Bacillus were found in the microbial culture of the specimens. They were tolerant to celbenin but sensitive to vancomycin. PEG could be cured by focal application of vancomycin combined with free skin or skin flap after thorough debridement. The relapse of PEG could be prevented by the therapy. Conclusion Focal injection of vancomycin combined with surgical debridement–dermatoplasty is an effective therapy for PEG.

A single-dose vancomycin application after standard protocol in peritoneal dialysis patients with recurrent peritonitis.

Sir, Peritonitis remains the major cause of catheter removal in peritoneal dialysis (PD) patients suffering from recurrent attacks, despite appropriate antibiotic therapy. Bacteria such as coagulase-negative staphylococci (CNS) from the exit site of the catheter and contaminated dialysis fluids can grow into microcolonies in biofilms on the surface of the catheter [1,2]. In the preliminary study, we evaluated the outcome of administration of a single-dose intracatheterial vancomycin just after primary response to the treatment of the last peritonitis attack with cefazolin in continuous ambulatory PD patients with recurrent peritonitis. Among 166 patients who underwent routine PD, six cases with recurrent peritonitis attacks were treated with initial empiric antibiotic therapy consisting of intraperitoneal cefazolin given in each exchange for gram-positive organisms. The characteristics and data regarding peritonitis attacks are given in Table ​Table1.1. Six patients had three to five peritonitis attacks with intervals of ∼1–7 weeks following the completion of a standard 2- or 3-week course of antimicrobial therapy. Four cases out of six had no history of peritonitis, tunnel or exit-site infection before. One patient (fourth case in the table) had exit-site infection. For S. aureus positive culture, the patient received mupirocin pomade and Sodium Fusidate (1 g/day per oral for 7 days). After therapy, exit-site infection completely resolved, and the two cultures taken afterwards were negative. Then, she also had a peritonitis attack with S. aureus on 21 February 2006. The other patient (third case in the table) had a culture-negative peritonitis attack on 1 May 2006. They were treated with cefazolin. The wives of the two male patients (one having diabetic retinopathy) helped during the dialysis exchanges, and the remaining patients were on their own. Six patients and the two assistants (wives) were negative for nasal carriage state. However, prophylactic mupirocin was given to all patients, but the peritonitis attacks recurred. None of the patients had tunnel infection. After complete resolution of peritonitis by cefazolin alone in the last attack, 50 cc peritoneal dialysate was mixed with 2 g vancomycin after drainage of the entire peritoneal fluid and left in the catheter lumen for 8 h. Then, without drainage, a normal dialysis session was carried out. During the mean follow-up of 25 ± 0.8 months, none of the six patients had recurrence peritonitis. Table 1 Characteristics of peritoneal dialysis patients with recurrent gram-positive peritonitis Many episodes of peritonitis appear to be unrelated to obvious causes. Bacterial biofilm formation on the dialysis catheter represents a concern for PD patients in terms of our ability to eradicate the infection [2]. However, there is sometimes no clear relationship between biofilms and clinical peritonitis. Indeed, one exception may occur in patients with multiple episodes of peritonitis who were likely to have stable biofilms, positive biofilm cultures and a high incidence of catheter loss. Recently, examination by electron microscopy of catheters of patients who experienced PD peritonitis revealed biofilm formation; however, no biofilm formation was found in PD catheters removed from patients without infection [3]. The risk associated with administering cefazolin continuously (in every PD bag) is that the organisms survive and continue dividing in biofilms. Our current antimicrobial protocols may not permit adequate dosing to penetrate the biofilm and be a reason for recurrent episodes of peritonitis. To evaluate the differences in the antibiotic sensitivity patterns of CNS, minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentration (MBEC) assays were compared in CNS isolates from patients with PD-associated peritonitis in a study [4]. In the PD effluent sample from patients with repeat infection, the rate of first-generation cephalosporin (FGC) or gentamicin or both resistances was higher. MBEC results were higher than those with standard MIC assays. Although no vancomycin resistance was observed with MIC assays, a small number of cases were identified with MBEC assays. There was no resistance when a vancomycin/rifampin 1:1 combination was used. All patients with repeat infections had high degrees of FGC resistance, and infection cycles were terminated when their treatment protocol included vancomycin. In conclusion, we assume that adequate antibiotic levels will be achieved within the catheter-contained biofilm with a single dose of vancomycin of 2 g at the end of the treatment course that will prevent recurrent peritonitis and catheter loss. These results are difficult to compare because patient numbers are small. In our opinion, this observation should be confirmed by other investigators. Conflict of interest statement. None declared.

Osteitisbehandlung an Unterschenkeln mit Knochenersatzmaterial als lokalem Antibiotikumträger

A seriously injured tsunami victim with complicated osteomyelitis is presented. The patient was treated with a new resorbable bone substitute, which can be loaded with different antibiotics. The successful treatment is illustrated by the clinical, radiological and histological features. Bilateral open fractures of the lower leg with open elbow fracture led to a bilateral amputation of the lower legs and the right arm because of a beginning sepsis. The following intramedullary osteitis with multiresistant Pseudomonas aeruginosa, Escherichia coli and Enterococcus faecium was treated with the bone substitute PerOssal combined with systemic and local application of vancomycin and systemic application of ceftazidime and meropenem. This case report illustrates the concept of an additional local antibiotic treatment of osteomyelitis by a bone substitute also functioning as a drug delivery system.

Enterocolitis caused by Clostridium difficile. Analysis of 15 cases in adults

Each of 48 patients with suspected Clostridium difficile enterocolitis after treatment with antibiotics underwent a faecal test in which a Clostridium difficile culture was set up and a cytotoxin test carried out. The detection of Clostridium difficile was positive in 15 cases. Diarrhoea with varying severity was present in all patients, most frequently after medication with the newer cephalosporins. Nine patients also underwent rectoscopy: a typical pseudo-membranous colitis was seen only in 5 of these and a "non-specific" enterocolitis in only 4. Management in 12 patients involved discontinuance of the antibiotic followed by oral vancomycin therapy for an average of 7 days. A female patient suffered a recurrence but responded to a repeat application of vancomycin. The possibility of Clostridium difficile enterocolitis should always be kept in mind when diarrhoea with unclear aetiology occurs during antibiotic therapy. The cytotoxin test and culture identification of Clostridium difficile are suitable routine methods for confirming the diagnosis. In severe cases, treatment should commence without waiting for the microbiological results.

Paediatric cataract surgery

Bilateral congenital cataract is the most common cause of treatable childhood blindness. Nuclear cataract is usually present at birth and is non-progressive, while lamellar cataract usually develops later and is progressive. Prompt surgery has to be performed in cases with dense congenital cataract: if nystagmus has developed, the amblyopia is unfortunately irreversible. A treatment regime based on surgery within 2 months of life, combined with prompt optical correction of the aphakia and occlusion therapy with frequent follow-up, have been successful in both unilateral and bilateral cases. The surgery ought to include anterior and posterior capsulorexis in all children at the present time. Intraocular lens implantation has been safely performed below the age of 1 year and has also been successfully performed in bilateral cases. Anterior dry vitrectomy should be performed in preschool children to avoid visual axis opacification. Visual axis opacification is the most common complication found after cataract surgery in children. Secondary glaucoma is by far the most sight-threatening complication and is, unfortunately, common in the newborn so lifelong follow-up is essential in these cases.

Release of Vancomycin and Teicoplanin from a Plasticized and Resorbable Gelatin Sponge: in Vitro Investigation of a New Antibiotic Delivery System with Glycopeptides

The aim of this study was to evaluate the efficacy of sustained release of vancomycin and teicoplanin from a resorbable gelatin glycerol sponge, in order to establish a new delivery system for local anti-infective therapy. 60 plasticized glycerol gelatin sponges containing either 10 or 20% gelatin (w/v) were incubated in vancomycin or teicoplanin solution at 20 degrees C for either 1 or 24 h. In vitro release properties of the sponges were investigated over a period of 1 week by determining the levels of vancomycin and teicoplanin eluted in plasma using fluorescent polarization immunoassay. The rate constant and the half-life for the antibiotic release of each group were calculated by linear regression assuming first order kinetics. Presoaking for 24 h was associated with a significant increase in the total antibiotic release in all groups opposed to 1 h of incubation, except for the 10% sponges presoaked in teicoplanin. Doubling the gelatin content of the sponges from 10 to 20% significantly increased the total release of antibiotic load only in teicoplanin-containing sponges after 24 h incubation. In all corresponding groups investigated, release of vancomycin was more prolonged compared to teicoplanin, which allowed a gradual release beyond 5 days. The half-life (h +/- SEM) of both types of vancomycin-containing sponges was significantly prolonged by 24 h incubation in comparison to 1 h incubation (29.1 +/- 5.9 vs 5.9 +/- 1.0; p < 0.001, 30.0 +/- 2.1 vs 11.1 +/- 1.9; p < 0.001). However, neither doubling the gelatin content of the sponges nor a prolonged incubation was associated with a significantly prolonged delivery of teicoplanin. This study demonstrated a better diffusion-controlled release of vancomycin-impregnated glycerol gelatin sponges compared to those pretreated with teicoplanin. The plasticized glycerol gelatin sponge may be a promising carrier for the application of vancomycin to infected wounds for local anti-infective therapy.

The Efficacy of Intravitreal Piperacillin/Tazobactam in Rabbits with Experimental Staphylococcus epidermidis Endophthalmitis: A Comparison with Vancomycin

Background: To investigate the efficacy of intravitreal piperacillin/tazobactam in rabbit eyes with experimental S. epidermidis endophthalmitis and to compare the outcomes with intravitreal vancomycin application. Material and Methods: Twenty-four New Zealand white albino rabbits were divided into three equal groups (n = 8 in each), and the right eyes received 0.1-ml intravitreal injections of S. epidermidis suspension. The left eyes served as uninfected controls and were injected with 0.1 ml of saline solution. The right eyes of rabbits in group 1 were treated with intravitreal injection of 250 µg/0.1 ml piperacillin/tazobactam 24 h after intravitreal inoculation of S. epidermidis whereas group 2 eyes received intravitreal 1 mg/0.1 ml vancomycin. Group 3 eyes received no treatment and served as infected controls. Clinical examination of the eyes in each group was performed on the 1st, 3rd and 6th day after the inoculation of S. epidermidis. On the 6th day, 0.1-ml vitreous aspirates were obtained for microbiological analysis, and then the eyes were enucleated for histopathological evaluation. Results: There were no statistically significant differences in mean clinical scores between the groups on the first day after S. epidermidis inoculation (p > 0.05). On the 6th day, the mean clinical score of group 3 was significantly higher (p < 0.001), but the mean clinical scores of groups 1 and 2 were similar (p = 0.812). The mean logarithmic value of colony-forming units per milliliter of groups 1, 2 and 3 were 0.6 ± 1.3, 0.5 ± 1.5 and 5.3 ± 0.7, respectively. Mean histopathological scores of the groups were 8.3 ± 0.9, 7.5 ± 1.3 and 15.6 ± 1.2, respectively. Group 3 eyes had significantly more colony-forming units per milliliter and a higher histopathological score (for each, p < 0.001), and there were no statistically significant differences in microbiological and histopathological scores between groups 1 and 2 (for each, p > 0.05). Conclusion: Intravitreal application of 250 µg/0.1 ml piperacillin/tazobactam seems to be approximately equally effective with intravitreal 1 mg/0.1 vancomycin application in the treatment of experimental S. epidermidis endophthalmitis. Therefore, intravitreal piperacillin/tazobactam may be an alternative therapeutic option in the treatment of S. epidermidis endophthalmitis.

Linezolid Treatment of Skeletal Methicillin-Resistant Staphylococcus aureus Infection

To investigate the role of linezolid in the treatment of skeletal methicillin-resistant Staphylococcus aureus (MRSA) infections in a university clinic for trauma surgery with regard to treatment results, side effects, practicability, and costs. Data were recorded retrospectively in a single center over a 1-year period. Four patients with MRSA osteitis/infected pseudarthrosis of the upper extremity following prolonged fracture treatment were administered linezolid, after therapy with established antibiotics such as vancomycin had failed. In two patients with vertebral osteitis due to progressive spondylodiscitis, linezolid was used as the only effective antibiotic with oral availability, when intravenous application was technically impossible (central venous line complications/vena cava thrombosis). Adequate surgical treatment (debridement, stabilization, osteosynthesis) was performed in all patients. Linezolid was administered for a mean of 2.2 months (1.5–3 months). Side effects of intravenous or oral linezolid treatment were not seen. One patient died after 6 weeks (heart failure). Mean follow-up time was 17.4 months (13–24 months). MRSA arthritis after 12 months was observed in one patient. A second critically ill patient was diagnosed with MRSA infection of a prosthetic hip 15 months later. Reinfection was excluded in four patients. High daily costs also of oral linezolid application compete with advantages of an early ambulatory treatment. Linezolid is a potent antibiotic that should be left to skeletal MRSA infection after stabilization and debridement if (1) vancomycin treatment has failed and (2) intravenous application of vancomycin is not possible.

Vancomycin-resistantEnterococcus faecalisin Serbia

To the Editor: First isolated in France (1), vancomycin-resistant enterococci (VRE) have become pathogens of major importance, particularly in the United States (2). Infections due to VRE are still uncommon in most European countries (3). We report the first isolation of high-level vancomycin-resistant Enterococcus faecalis in Serbia. A 55-year-old woman was admitted to the Clinic for Cardiovascular Diseases, Belgrade, on April 1, 2002, for aortobifemoral bypass surgery. Three weeks after she was admitted to the hospital, an infection developed in the surgical wound and treatment with sulfamethoxazole-trimethoprim (160/800 mg q 12 h) was empirically introduced. Bacteriologic analysis of the wound swab sample showed a methicillin-resistant strain of Staphylococcus aureus, a multiresistant strain of Acinetobacter sp., a commonly susceptible strain of Enterococcus sp., and a VRE strain. According to the results of susceptibility testing, imipenem (1 g q 6 h) was added to the patient’s treatment protocol. VRE were not isolated from subsequent wound samples or any other sample submitted for microbiologic analysis. The patient was discharged at the end of the 14-day treatment period. The isolate was identified as E. faecalis by biochemical characterization, as recommended by Facklam and Collins (4) and confirmed by API 20 Strep (bioMerieux, Marcy-l’Etoile, France). Susceptibility testing, performed by the disk diffusion method, showed that the isolate was resistant to vancomycin, teicoplanin, gentamicin, streptomycin, tetracycline, and ciprofloxacin, while susceptible to ampicillin, amoxicillin, amoxicillin and clavulanic acid, and imipenem. Resistance to vancomycin, teicoplanin, gentamicin, and streptomycin was confirmed by the broth dilution method, according to the National Committee for Clinical Laboratory Standards (NCCLS) recommendations (5). The obtained MICs were 256 μg/mL for vancomycin, 64 μg/mL for teicoplanin, >4,000 μg/mL for gentamicin, and >2,000 μg/mL for streptomycin. This phenotype, with high-level resistance to vancomycin and teicoplanin, is typical for the vanA genotype (2). The strain was subsequently genotyped by pulsed-field gel electrophoresis, using previously described methods (6). The presence of the vanA gene was confirmed by polymerase chain reaction assay, according to a previously described procedure (7). E. faecium EF228 was used as the positive control. The enterococci are among the most frequent causes of nosocomial infections, particularly in intensive care units, and present a major therapeutic challenge (2). While the emergence of VRE strains in the United States is probably associated with extensive use of vancomycin, the occurrence of VRE in Europe is possibly due to application of avoparcin (glycopeptide analog) as a growth promoter in animal husbandry (3). However, avoparcin has not been used in Serbia, and vancomycin application has been restricted to hospitalized patients and quite limited due to its high cost. Thus, emergence of VRE strains in Serbia has not been likely. The origin of this VRE isolate is unknown: the strain may have been imported or may have originated from the hospital environment. The first prospective pan-European VRE surveillance study (January–April 1997) showed VanA-VRE strains in only eight European countries, with isolates numbering from one to four per country (3). No epidemiologic relations were established among the VanA isolates, and only 2 out of 18 isolates (11%) were identified as E. faecalis (3). Since our patient-case had no history of travel outside Serbia, we assumed that the VRE isolate originated from the hospital environment. However, a study investigating the occurrence of VRE strains in Belgrade, the capital of Serbia, detected no such isolates in five different hospitals (8). Although the study did not analyze samples from the Clinic for Cardiovascular Diseases, it did include samples from the Clinic for General Surgery, which is located within the same building. The susceptibility of 191 isolates of enterococci to vancomycin was tested by agar dilution method according to NCCLS recommendations. Of the 191 isolates, 159 were classified as susceptible and 32 as intermediately susceptible. This report of the first isolation of VRE in Serbia, as well as the previously shown presence of enterococci displaying intermediary susceptibility to vancomycin, provides the rationale for future active screening for VRE in hospital environments in the region.

Colonic fermentation as affected by antibiotics and acidic pH: Application of an in vitro model.

Antimicrobial substances such as vancomycin or metronidazole suppress normal gut flora, thereby preventing physiological fermentation of colonic substrates that may promote mucosal inflammation. This study was designed to establish an in vitro model of microbial metabolism in the colon under control and disturbed conditions (acidic pH) to investigate specific effects of vancomycin and metronidazole on the production of short chain fatty acids (SCFA), which play a pivotal role in maintaining homeostasis in the colon. The experiments were carried out with the colon simulation technique (Cositec) representing an in vitro model for the semi-continuous incubation of defined colon contents. Inocula and fermentable substrates were sampled from cecal contents of fistulated pigs. Disturbed microbial metabolism was generated by reduction of pH in the fermentation vessels from 6.7 to 5.8 and 5.1. In general, application of either vancomycin or metronidazole resulted in a significant decrease of SCFA production rates indicating substantial disturbance of the homeostasis of microbial metabolism. With low doses of vancomycin acetate and butyrate production rates were reduced and with high doses of the antibiotic propionate production was inhibited to a greater extent. Treatment with metronidazole inhibited butyrate production almost completely. Similarly, low pH caused a reduction in total SCFA production, which was mainly due to respective decrease of acetate synthesis. Metronidazole effects were not consistently changed at low pH. The Cositec system provides an excellent facility to test the effects of different antibiotics under defined conditions. In this study, both vancomycin and metronidazole affected microbial metabolism to a considerable extent. Both substances may thus be responsible for disturbances of colon function in vivo.

Bacterial growth based on reductive dechlorination of trichlorobenzenes.

An anaerobic mixed bacterial culture was enriched for bacteria dechlorinating 1,2,3- and 1,2,4-trichlorobenzene (TCB) to dichlorobenzenes by exclusive use of non-fermentable substrates and the application of vancomycin. Growth and dechlorination occurred in a purely synthetic medium with formate or hydrogen, acetate, and TCB. Neither acetogenesis nor methanogenesis was detected in the culture. Repeated subculturing maintaining high dechlorinating activities was also achieved when only hydrogen and TCB were supplied. This indicated that reductive dechlorination of TCB was the primary energy conservating process. The number of dechlorinating bacteria was strictly limited by the amount of TCB supplied in the medium. In addition, the dechlorinating activity could be maintained only in the presence of TCB. A most probable number analysis showed that the dechlorinating species amounted to at least 6 x 10(5) cells per ml at a total cell number of about 2 x 10(6) cells per ml. Vitamin B12 significantly stimulated the dechlorinating activity.

Early Infectious Complications after High-Dose Therapy and Autologous Blood Stem Cell Transplantation

Background: Only few data have been published regarding the frequency and type of infectious complications after high-dose therapy (HDT) and autologous blood stem cell transplantation (ASCT). The purpose of this study was to evaluate early infectious complications after this type of treatment and to identify predictive factors. Patients and Methods: The clinical data of 100 patients (50 with hematologic neoplasms, 50 with solid tumors) treated with 133 HDT-courses in a single institution were analyzed retrospectively. For 34 courses CD34+ cells were positively enriched. Results: In 86% of the courses fever occurred during neutropenia. In response to an empirical antibiotic therapy with ceftazidime and either vancomycin or flucloxacillin the patients defervesced after a median of 3 days. No invasive fungal infection was diagnosed. There was no infection-related death. Comparing hematologic neoplasms and solid tumors, a significant difference in the duration of fever was found: median 4 vs. 2 days. We observed a correlation between the duration of fever and the duration of morphin needing mucositis. Apart from a group of ‘myeloablative’ busulfan- and/or TBI-containing regimens we separated two different aggressive groups of HDT-regimens using duration of severe neutropenia and morphine-needing mucositis. A multivariate analysis demonstrated that the type of HDT-regimen is a predictive factor for the number of fever days and freedom from infection. The diagnosis (hematologic neoplasia vs. solid tumor) is predictive only for pneumonia/ pneumonitis. Conclusion: Early infectious complications after HDT and ASCT are usually not severe. The application of first-line vancomycin and amphotericin B is generally not necessary. The type of HDT-regimen has to be considered in further prospective investigations of predictive infection-related factors.