Central venous catheter related infections: Risk factors and the effect of glycopeptide antibiotics.

BACKROUND: We undertook a prospective study of all new central venous catheters inserted into patients in the intensive care units, in order to identify the risk factors and to determine the effect of glycopeptide antibiotics on catheter - related infections. METHODS: During the study period 300 patients with central venous catheters were prospectively studied. The catheters used were nontunneled, noncuffed, triple lumen and made of polyurethane material. Catheters were cultured by semiquantitative method and blood cultures done when indicated. Data were obtained on patient age, gender, unit, primary diagnosis on admission, catheter insertion site, duration of catheterization, whether it was the first or a subsequent catheter and glycopeptide antibiotic usage. RESULTS: Ninety-one (30.3%) of the catheters were colonized and infection was found with 50 (16.7%) catheters. Infection was diagnosed with higher rate in catheters inserted via jugular vein in comparison with subclavian vein (95% CI: 1.32-4.81, p = 0.005). The incidence of infection was higher in catheters which were kept in place for more than seven days (95% CI 1.05-3.87, p = 0.03). The incidence of infection was lower in patients who were using glycopeptide antibiotic during catheterization (95% CI: 1.49-5.51, p = 0.005). The rate of infection with Gram positive cocci was significantly lower in glycopeptide antibiotic using patients (p = 0.01). The most commonly isolated organism was Staphylococcus aureus (n = 52, 37.1%). CONCLUSION: Duration of catheterization and catheter insertion site were independent risk factors for catheter related infection. Use of glycopeptide antibiotic during catheterization seems to have protective effect against catheter related infection

In vivo release of vancomycin from biodegradable beads.

The current delivery system of antibiotics for the treatment of osteomyelitis uses polymethylmethacrylate (PMMA) beads as a local drug-release agent. The nonbiodegradable nature of the PMMA, however, necessitates a second operation to remove the beads. This article explores the alternative of using biodegradable polymers as antibiotic beads for a long-term drug release in vivo. To manufacture an antibiotic bead, lactide-glycolide copolymers were mixed with vancomycin. The mixture was compressed and sintered at 55 degrees C to form beads 8 mm in diameter. An in vivo animal model was proposed to characterize the elution rate of antibiotic over a 55-day period. Biodegradable beads released high concentrations of antibiotic (well above the breakpoint sensitivity concentration) in vivo for the period of time needed to treat bone infection; that is, 4-6 weeks. A bacterial inhibition test was also carried out to determine the relative activity of the released antibiotics. The diameter of the sample inhibition zone ranged from 8 to 18 mm, which is equivalent to 9.1 to 100% of relative activity. In addition, the antibiotic concentration of systemic blood was found to be very low. Antibiotic-impregnated biodegradable beads may have a potential role in the prevention and management of surgical infections. 2002 Wiley Periodicals, Inc

Cross-sectional study of consumption, compliance and awareness about antibiotic utilisation amongst the urban community in Kolkata.

A cross-sectional survey was conducted upon 500 respondents, comprising of 250 adults and 250 children who did consume antibiotics in the previous three months. Data were analysed to determine the patterns of utilisation, compliance and awareness regarding antibiotic medication amongst a selected urban population at Kolkata. Antibiotic consumption without prescription was evident amongst 41.2% of adults in comparison to that of 8.4% in children (P < 0.01). Compliance to daily dosage was observed in 40.8% of adults in comparison to 82.8% in children (P < 0.01). Awareness pattern regarding antibiotics were reported to have been more in the children group (16.4%) while compared to the adults (8%). The knowledge regarding antibiotic resistance remained more or less similar in both the groups. The study concludes that high over the counter (OTC) sale and inadequate compliance to antibitotic medication needs further intervention approach towards information, education and communication (IEC) to all concerned

The inventory of antibiotics in Russian home medicine cabinets.

The objective of this study was to inventory the stock of antimicrobials in the home medicine cabinets (HMCs) of the general population in Russia and to find out for which indications people report that they would use antibiotics without a physician's recommendation. The research was performed in 9 Russian cities by physicians who visited households. An inventory of antibiotics in HMCs was made, and respondents were asked about instances in which they would choose automedication with antibiotics. We found that 83.6% of families had antibiotics for systemic use in HMCs. The most common antibiotics in HMCs were trimethoprim-sulfamethoxazole (46.3% of HMCs), ampicillin (45.1%), chloramphenicol (32.7%), erythromycin (25.5%), and tetracycline (21.8%). The major indications for automedication with antibiotics were acute viral respiratory tract infections (12.3% of total indications), cough (11.8%), intestinal disorders (11.3%), fever (9%), and sore throat (6.8%). According to this study, antibiotics are widely stocked among the general population in Russia, and people use antibiotics in an uncontrolled and imprudent manner

The use of first- and second-line outpatient antibiotics under the Saskatchewan Drug Plan.

The Saskatchewan Drug Plan proposed de-listing several second-line antibiotics from its formulary for reasons of potential overuse and expense. This study evaluated the use of second-line antibiotics as initial and secondary courses of therapy depending on the patient's prior use of other antibiotics and other factors. A total of 637,607 courses of therapy dispensed to Plan members for selected antibiotics between July 1989 and June 1990 were evaluated. Second-line antibiotics were used in 5.0% of all initial courses of therapy. This use was correlated with patient characteristics that may warrant use of second-line antibiotics as initial therapy: age, rural residence, the use of bronchodilators or inhaled steroids, and the number of prior courses of antibiotic therapy. The potential savings from de-listing second-line antibiotics from the formulary are limited because of their use in only 5% of all initial courses of therapy. Savings would be further reduced by administrative costs and physician time required to process prior authorisation requests, and the costs of treating any additional antibiotic treatment failures that may result from reduced access

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

Penetration of antibiotics into the pancreas in rats: an effect of acute necrotizing pancreatitis.

BACKGROUND: Penetration of antibiotics into the pancreas is considered to be an important criterion in determining the most appropriate antibiotic treatment during severe acute pancreatitis. Our study investigated pancreatic penetration of five antibiotics in rats with and without acute necrotizing pancreatitis (ANP) (non-pancreatitis rats (NR), pancreatitis rats (AP)). METHODS: ANP was induced by intraductal bile acid injection, and 3 h later the antibiotic was administered. In both NR and AP the antibiotic concentrations were evaluated in blood and pancreatic tissue 90 min after antibiotic administration. RESULTS: The tissue/serum (T/S) ratios for NR were 16% with amikacin, 24% with amoxycillin/clavulanic acid, 27% with piperacillin, 59% with ofloxacin, and 108% with cefoperazone. The ratios for AP were 7%, 23%, 26%, 52%, and 70%, respectively. T/S ratios were similar for NR and AP except for amikacin, for which the T/S ratio was lower in AP than in NR (P = 0.02). Pancreatic tissue concentrations of antibiotics with high penetration rates (cefoperazone and ofloxacin) were sufficient to inhibit most of the pathogens expected during acute pancreatitis. The concentrations of the other antibiotics were less than the minimal inhibitory concentrations (MIC) for common potential pathogens in pancreatic infection. CONCLUSIONS: Cefoperazone and ofloxacin showed the best pancreatic penetration of the five antibiotics tested. The high concentrations of these antibiotics in the pancreatic tissue would have enabled efficient antibacterial activity against most of the potential pathogens causing pancreatic infection. An early stage of acute necrotizing pancreatitis did not have a major effect on the pancreatic concentrations of the antibiotics

Infective Endocarditis.

Despite improvements in antibiotic regimens, patients with infective endocarditis (IE) have a high risk of valve replacement and death. Effective initial treatment depends on two steps: 1) diagnosis of the infecting organism, enabling specific antibiotic therapy, and 2) complete characterization of the anatomic extent of infection. Identification of the infecting organism requires culturing of blood prior to the initiation of antibiotics. Whenever possible, at least three sets of blood cultures should be obtained over 6 to 24 hours and held for 4 weeks if necessary to detect unusual or fastidious organisms. Transesophageal echocardiography (TEE) is usually necessary either to confirm the diagnosis or, most importantly, to identify the local complications of infection, many of which mandate surgery. Despite widespread availability, TEE remains under-used, both for the prevention of unnecessary antibiotic therapy in patients at very low risk for the disease and for the recognition of patients likely to benefit from early surgery. The selection of optimal antibiotic therapy depends on microbiologic data to establish the sensitivities of the specific causative organism. Short courses of antibiotic therapy and outpatient administration of intravenous antibiotics are useful in selected cases

Antibiotic-resistant fecal Escherichia coli in healthy children. Induced by the use of antibiotics?

OBJECTIVE: To determine the rate of antibiotic resistance of fecal E. coli from healthy children and to infer if it is acquired environmentally or induced by antibiotic use. MATERIAL AND METHODS: Cross sectional study in children from schools and day care centers in Leon, Mexico. Prior antibiotic use (60 days) was questioned to the parents. A single fecal sample was cultured and an isolated colony suggestive of E. coli was submitted to biochemical identification and testing of disk susceptibility to 12 antibiotics. RESULTS: Four hundred fifty-six isolates were studied from children of 10 institutions, with ages ranging from 3 to 72 months (mean, 42.41). Use of antibiotics was referred in 242 children (53.07%). The antibiotics more commonly used were trimethoprim/sulfa, ampicillin, and penicillin (34, 20.5, and 18%). The highest rate of resistance was found for tetracycline, ampicillin, and trimethoprim/sulfa (64.4, 52.63, and 46.05%). The resistance to ciprofloxacin, amikacin, gentamicin, and ceftriaxone was less than 5%. Resistance to five or more antimicrobials was found in 93 isolates (20.39%); this rate was higher in isolates from children who received antibiotics (59/242, 24.38% vs. 34/214, 15.89%) (p = .025; OR 1.71, IC 95% 1.04-2.81). CONCLUSIONS: The study suggests that saprophyte bacteria acquires resistance through both, use of antibiotics and from the environment. These results support the concept that antimicrobial resistance must be considered as a public health problem

Differences in neutrophil death among beta-lactam antibiotics after in vitro killing of bacteria.

Antibiotic therapy is an essential treatment for gram-negative bacterial infections. Antibiotic-induced endotoxin release and subsequent production of inflammatory cytokines reportedly depend on the type of antibiotic action. This study examined the effects of various beta-lactam antibiotics on cell death of human polymorphonuclear neutrophils (PMNs) cocultured with Escherichia coli (E. coli) in vitro. E. coli morphology after antibiotic treatment was determined. PMNs and E. coli were cocultured with antibiotics for 0, 4, or 12 h. Levels of endotoxin and cytokines (TNF-alpha, IL-1beta, and IL-6) in the supernatants were measured. The filtrates of antibiotic-treated E. coli supernatants were cocultured with PMNs for 0, 4, or 12 h. In all experiments, ampicillin (ABPC), cefazolin sodium (CEZ), cefoperazone sodium (CPZ), latamoxef sodium (LMOX), imipenem (IPM), and polymyxin B sulfate (PLB) were used at 30 microg/mL. PMNs were isolated from healthy volunteers. PMN cell death was assessed by flow cytometry and light microscopy. ABPC, CEZ, CPZ, and LMOX, which induce bacterial filament formation with lysis, caused PMN necrosis when cocultured with E. coli. In contrast, IPM, which induces bacterial spheroplast formation with lysis, caused PMN apoptosis. Levels of endotoxin, TNF-alpha and IL-6 in the supernatants with IPM and PLB were significantly lower than in those with other beta-lactam antibiotics. The filtrates of IPM- and PLB-treated E. coli supernatants induced PMN apoptosis, whereas those treated with other beta-lactam antibiotics increased PMN necrosis. Beta-lactam antibiotics have different impacts on the types of PMN cell death after E. coli killing. Underlying mechanisms and the clinical relevance of IPM-induced PMN apoptosis in severe gram-negative infection warrant further investigation