Histoplasmosis in solid organ transplant recipients: 10 years of experience at a large transplant center in an endemic area.

BACKGROUND: Many clinical scenarios have been encountered by patients who developed histoplasmosis after receiving a solid organ transplant at a large transplant center in an endemic area. METHODS: Cases of posttransplantation histoplasmosis were identified by use of multiple methods, including reviews of microbiology test results, transplant databases, and billing codes. Data were obtained retrospectively. Descriptive statistics were used. RESULTS: During the 1997-2007 study period, 3436 patients received a solid organ transplant, and 38 patients were identified as having posttransplantation histoplasmosis. Of these 38 patients, 9 were excluded from our study because the diagnosis was solely clinical. Of the remaining 29 patients, 14 had posttransplantation histoplasmosis (incidence, 1 case per 1000 person-years); 14 showed histologic evidence of histoplasmosis in the recipient or donor tissue, which was encountered unexpectedly at the time of transplantation; and 1 had histoplasmosis before receiving the transplant. Of the 14 patients who developed histoplasmosis after transplantation, 5 were heart transplant recipients, 3 were lung transplant recipients, 3 were kidney transplant recipients, 1 was a liver transplant recipient, 1 was a pancreas transplant recipient, and 1 was a kidney-pancreas transplant recipient. The median time from transplantation to diagnosis was 17 months (interquartile range, 8.1-46 months), and the median time from onset of symptoms to diagnosis 3 weeks (interquartile range, 1.9-6.5 weeks). All recipients had disseminated disease. The most common treatment was amphotericin B and itraconazole. All were cured, or still on treatment, but symptom-free. Of the 14 patients who had an explanted organ or donor tissue that showed histologic evidence of histoplasmosis, 13 (93%) were lung transplant recipients, and 1 (7%) was a liver transplant recipient. None of these patients developed active histoplasmosis, but all received prophylactic treatment. Finally, 1 patient had histoplasmosis before transplantation; he was treated with itraconazole 3 months before and after transplantation, and he did well. CONCLUSIONS: In conclusion, posttransplantation histoplasmosis is rare (1 case per 1000 transplant-person-years; 95% confidence interval, 0.6-1.7), even in endemic areas. Prognosis is good but requires protracted therapy. Patients with latent infection did not develop posttransplantation histoplasmosis when prophylaxis was used.

Unsuitable distinction between viable and dead Staphylococcus aureus and Staphylococcus epidermidis by ethidium bromide monoazide.

AIMS: The DNA-intercalating dye ethidium bromide monoazide (EMA) has recently been used as a DNA binding agent to differentiate viable and dead bacterial cells by selectively penetrating through the damaged membrane of dead cells and blocking the DNA amplification during the polymerase chain reaction (PCR). We optimized and tested the assay in vitro using Staphylococcus aureus and Staphylococcus epidermidis cultures to distinguish viable from dead bacteria, with the goal of reducing false positive PCR results. METHODS AND RESULTS: Viable and heat-inactivated bacteria were treated with EMA or left untreated before DNA extraction. A real-time PCR assay for the detection of the tuf gene in each DNA extract was used. Our results indicated that EMA influenced viable bacteria as well as dead bacteria, and the effect of EMA depended on the EMA concentration and bacterial number. CONCLUSIONS: EMA is not a suitable indicator of bacterial viability, at least with respect to Staphylococcus species. SIGNIFICANCE AND IMPACT OF THE STUDY: Determining the viability of pathogens has a major impact on interpreting the results of molecular tests for bacteria and subsequent clinical management of patients. To this end, several methods are being evaluated. One of these methods--intercalating DNA of dead bacteria by EMA--looked very promising, but our study found it unsatisfactory for S. aureus and coagulase-negative Staphylococci.

In vitro effects of urokinase--prevention by different inhibitors.

The present in vitro study investigated dose-, time- and temperature-dependent effects of two-chain urokinase plasminogen activator (u-PA, urokinase) on normal citrated plasma. When 10 micrograms/ml u-PA were added to pooled normal plasma and incubated for 30 min at an ambient temperature (25 degrees C), alpha 2-antiplasmin decreased to 8% of the control value. Incubation on ice yielded a decrease to 45% of control, whereas alpha 2-antiplasmin was fully consumed at 37 degrees C. Fibrinogen and plasminogen fell to 46% and 39%, respectively, after a 30 min incubation at 25 degrees C. Thrombin time prolonged to 190% of control. Various inhibitors were studied with respect to their suitability and efficacy to prevent these in vitro effects. Aprotinin exhibited a good protective effect on fibrinogen at concentrations exceeding 500 KIU/ml plasma. Its use, however, was limited due to interferences with some haemostatic assays. We could demonstrate that L-Glutamyl-L-Glycyl-L-Arginyl chloromethyl ketone (GGACK) and a specific polyclonal anti-u-PA-antibody (anti-u-PA-IgG) effectively inhibited urokinase-induced plasmin generation without interfering with haemostatic assays. The anti-u-PA-antibody afforded full protection of alpha 2-antiplasmin at therapeutic levels of u-PA. It is concluded that u-PA in plasma samples from patients during thrombolytic therapy may induce in vitro effects which should be prevented by the use of a suitable inhibitor such as GGACK or specific anti-u-PA-antibody.

Influence of acute myocardial infarction and rt-PA therapy on circulating fibrinogen.

In 12 patients treated with 100 mg rt-PA/3 h for acute myocardial infarction (AMI), serial fibrinogen levels were measured with the Clauss clotting rate assay ("functional fibrinogen") and with a new enzyme immunoassay for immunologically intact fibrinogen ("intact fibrinogen"). Levels of functional and "intact fibrinogen" were strikingly different: functional levels were higher at baseline; showed a more pronounced breakdown during rt-PA therapy; and a rebound phenomenon which was not seen for "intact fibrinogen". The ratio of functional to "intact fibrinogen" was calculated for each individual patient and each time point. The mean ratio (n = 12) was 1.6 at baseline, 1.0 at 90 min, and increased markedly between 8 and 24 h to a maximum of 2.1 (p < 0.01), indicating that functionality of circulating fibrinogen changes during AMI and subsequent thrombolytic therapy. The increased ratio of functional to "intact fibrinogen" seems to reflect a more functional fibrinogen at baseline and following rt-PA infusion. This is in keeping with data that the relative amount of fast clotting "intact HMW fibrinogen" of total fibrinogen is increased in initial phase of AMI. The data suggest that about 20% of HMW fibrinogen are converted to partly degraded fibrinogen during rt-PA infusion. The rebound phenomenon exhibited by functional fibrinogen may result from newly synthesized fibrinogen with a high proportion of HMW fibrinogen with its known higher degree of phosphorylation. Fibrinogen- and fibrin degradation products were within normal range at baseline. Upon infusion of the thrombolytic agent, maximum median levels of 5.88 micrograms/ml and 5.28 micrograms/ml, respectively, were measured at 90 min.(ABSTRACT TRUNCATED AT 250 WORDS)

Overexpression of marA, soxS, or acrAB produces resistance to triclosan in laboratory and clinical strains of Escherichia coli.

Triclosan (Irgasan) is a broad spectrum antimicrobial agent used in handsoaps, toothpastes, fabrics, and plastics. It inhibits lipid biosynthesis in Escherichia coli, probably by action upon enoyl reductase (FabI) (McMurry, L.M., Oethinger, M. and Levy, S.B. (1988) Nature 394, 531-532). We report here that overexpression of the multidrug efflux pump locus acrAB, or of marA or soxS, both encoding positive regulators of acrAB, decreased susceptibility to triclosan 2-fold. Deletion of the acrAB locus increased the susceptibility to triclosan approximately 10-fold. Four of five clinical E. coli strains which overexpressed marA or soxS also showed enhanced triclosan resistance. The acrAB locus was involved in the effects of triclosan upon both cell growth rate and cell lysis.

Studies on the functionality of fibrinogen during rt-PA therapy: results of three different methods of fibrinogen determination.

The conversion of soluble fibrinogen to insoluble fibrin is a crucial event in the process of haemostasis. In the present study three different methods were used for the determination of plasma fibrinogen levels in 12 patients with acute myocardial infarction during rt-PA therapy. Two methods were based on fibrin formation and thus measured 'functional' fibrinogen: a clotting rate assay according to the Clauss method and a photometric polymerization rate assay. Thirdly, fibrinogen antigen was measured with a new enzyme immunoassay (EIA) for immunologically intact fibrinogen. The levels of functional and intact fibrinogen were strikingly different: 4.1 g/l (Clauss) and 3.6 g/l (photometric) vs 2.6 g/l (EIA) at baseline, 2.2 g/l (54% of preinfusion value) and 2.1 g/l (59%) vs 2.1 g/l (81%) at 90 min, 5.7 g/l (146%) and 4.5 g/l (130%) vs 2.7 g/l (106%) at 72 h. The rebound phenomenon exhibited by functional fibrinogen (130-150%) was not observed for levels of intact fibrinogen. A ratio was calculated of functional (Clauss method) to intact fibrinogen (EIA) for each individual patient and each time point. The mean ratio (n = 12 patients) was 1.6 at baseline, 1.0 at 90 min, and increased markedly between 8 and 24 h to a maximum of 2.1 (P less than 0.01). Our data indicate that the 'functionality', i.e. the clotting rate per unit concentration of circulating fibrinogen, changed during acute myocardial infarction and subsequent thrombolytic therapy. This is in keeping with data from literature that the relative amount of fast clotting high molecular weight (HMW) fibrinogen of total fibrinogen was increased in the initial phase of acute myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Fluoroquinolone resistance of Escherichia coli at a cancer center: epidemiologic evolution and effects of discontinuing prophylactic fluoroquinolone use in neutropenic patients with leukemia.

The aim of the present study was to investigate the epidemiologic evolution of fluoroquinolone resistance of E. coli clinical isolates from patients admitted to a hematology-oncology service where fluoroquinolone prophylaxis during neutropenia was recommended as the standard of care for many years but was then discontinued in a trial conducted in patients with acute leukemia. Fluoroquinolones had been shown to decrease the incidence of gram-negative bacteremia in cancer patients with neutropenia, yet it was thought that the emergence of resistance in Escherichia coli and other gram-negative bacteria may have caused a progressive lack of efficacy of fluoroquinolone prophylaxis. Epidemiologic surveillance of fluoroquinolone resistance of E. coli clinical isolates at our cancer center since 1992 showed a continuing influx of new clones not previously observed in the population of cancer patients, an increase in the number of cancer patients per year colonized and/or infected by fluoroquinolone-resistant E. coli (1992-1994, 10-16 patients; 1995-1997, 24-27 patients), and a resistance rate of >50% among E. coli bloodstream isolates of hematology-oncology patients. A 6-month fluoroquinolone prophylaxis discontinuation intervention trial in 1998 suggested that despite increasing resistance among E. coli isolates, fluoroquinolone prophylaxis in acute leukemia patients was still effective in the prevention of gram-negative bacteremia (incidence rates, 8% during the pre-intervention period vs. 20% after discontinuation; p<0.01). The resumption of fluoroquinolone prophylaxis in acute leukemia patients thereafter decreased the incidence of gram-negative bacteremia to the pre-intervention level (9%; p=0.03), while the proportion of in vitro fluoroquinolone resistance in E. coli bacteremia isolates again increased (from 15% during the intervention period to >50% in the post-intervention period). Relative rates of resistance thus were a poor indicator of the potential clinical benefits associated with fluoroquinolone prophylaxis in cancer patients.

Thyroid growth stimulating activity in highly purified IgG-fractions of patients with nonimmune thyroid diseases.

Two different proliferation assays have been used to measure the proliferative potential of IgG-fractions from 57 patients with nontoxic goiter of an iodine-deficient area: primary human thyroid epithelial cells (TEC) and the thouroughly investigated FRTL-5 cell line. IgG-fractions from patients with nontoxic goiter (n = 30), nontoxic recurrent goiter (n = 8), toxic-nodular goiter (n = 15) and carcinoma of the thyroid (n = 4) were highly purified on DEAE-Sepharose and additionally Protein A-Sepharose in some cases. The two proliferation assays gave contradictory results: primary cultures of human thyroid epithelial cells (TEC) could not be stimulated by any of the patient's IgG-fractions nor by bTSH. The FRTL-5 cells, however, were stimulated with 10 microU/ml bTSH by 326% +/- 96% (range: 222% - 497%, p less than 0.001). In one experimental series, 72% of all patients exceeded mean + 2 SD of normal controls, when the stimulation index was referred to the effect of bTSH (NTG: 77%, Rec. G.: 88%, Tox. G.: 53%, Ca. thyroid: 75%). With a different method of calculation - stimulation index referred to the basal value - the number of patients above mean + 2 SD of normal controls decreased to 30% (NTG: 33%, Rec. G.: 12.5%, Tox. G.: 33%, Ca. thyroid: 25%). Statistical analysis, however, of results of different patient groups compared to the normal control group failed to show any significance.

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.

Emergence of fluoroquinolone-resistant Escherichia coli at a cancer center.

Prophylactic treatment with fluoroquinolones of patients with profound neutropenia has been found to be useful for preventing gram-negative bacteremia and has become a standard preventive-therapy strategy in many cancer centers, but the development of bacterial resistance is a cause of concern. During the past few years, we have observed an increasing number of patients with leukemia from whom fluoroquinolone-resistant strains of Escherichia coli were isolated. The increase was significant in this patient population, and among patients with other underlying diseases, the rates of isolation of such strains per number of discharges were significantly lower and did not increase. Most of the leukemia case patients (16 of 19) had been pretreated with an oral quinolone (ofloxacin), with cumulative doses until the first isolation of a resistant E. coli strain ranging from 0 to 97.8 g (median, 14.4 g). Repeated isolation of such strains was seen in 8 of 17 patients during a follow-up period of > or = 4 weeks and in 1 of 6 patients during a follow-up period of > or = 16 weeks. Ten patients developed bacteremia (mortality, 1 of 10). On the basis of the number of patients with leukemia admitted to the hematology-oncology service, the incidence of bacteremia caused by fluoroquinolone-resistant E. coli increased from < 0.5% in 1988-1989 and 0.8% in 1990-1991 to 4.5% in 1992-1993 (P < 0.01). MICs for nine isolates obtained from cultures of blood from different patients ranged between 8 and 16 microgram/ml (ciprofloxacin and PD 131628), 8 and 32 microgram/ml (ofloxacin and BAY Y 3118), and 16 and 32 microgram/ml (sparfloxacin) and indicated resistance to trimethoprim-sulfamethoxazole, ampicillin, doxycycline, and chloramphenicol. Of nine isolates obtained from cultures of blood from different patients and that were subjected to genomic DNA typing by pulsed-field gel electrophoresis of XbaI digests, seven were typeable. Among these, four different genotypes were identified, suggesting both the independent development and the horizontal spread of resistant clones of E. coli.

Ochrobactrum anthropi bacteremia: report of four cases and short review.

Ochrobactrum anthropi, formerly "Achromobacter" CDC group Vd, is a nonfermentative, nonfastidious gram-negative bacillus, that only recently has been given attention as a potential human pathogen. Over a 2-year period, we observed four patients with multiple blood cultures that were positive for the organism. The patients had acute leukemia as underlying disease, and presented with clinical and microbiologic features consistent with catheter-related bacteremia. In three of the patients the infection initially appeared to be unrelated to chemotherapy-associated profound neutropenia and occurred early after, or was the reason for, hospital admission. The antimicrobial susceptibility of the isolates varied: unlike previously reported cases, resistance in some of our isolates included aminoglycosides, newer fluoroquinolones, and trimethoprim-sulfamethoxazole. Despite in vitro susceptibility to imipenem in initial isolates, treatment of two patients with this agent obviously failed to eradicate the organism, and the patients either relapsed with bacteremia shortly after discontinuation of treatment or remained persistently febrile and bacteremic. O. anthropi appears to be increasingly recognized as a human opportunist pathogen associated with intravascular catheters and unpredictable multiple antibiotic resistance.

In vitro activities of the lichen secondary metabolites vulpinic acid, (+)-usnic acid, and (-)-usnic acid against aerobic and anaerobic microorganisms.

Secondary metabolites of different species of lichen were tested for their activities against a variety of microbial species. While gram-negative rods and fungi were not inhibited by these compounds, Staphylococcus aureus, Enterococcus faecalis, Enterococcus faecium, and some anaerobic species (Bacteroides and Clostridium species) were susceptible at the concentrations tested. Vulpinic acid generally was less active than usnic acid, regardless of its stereochemistry. The susceptibility to usnic acid was not impaired in clinical isolates of S. aureus resistant to methicillin and/or mupirocin.

Autotransfusion--bacterial contamination during hip arthroplasty and efficacy of cefuroxime prophylaxis. A randomized controlled study of 40 patients.

40 patients undergoing primary hip arthroplasty, given autologous processed blood transfusion, were randomized a receive no antibiotic prophylaxis (group A, n 20) or cefuroxime (1.5 g single injection; group B, n 20). Bacterial contamination at various steps in the autotransfusion procedure was assessed in liquid and solid culture media. The operation field and the wound drainage blood were never contaminated either of the groups but some of the suction tips were. Parts of the Vacufix blood collection bags of group A contained bacteria, but none in group B. Processed red blood cell concentrates in both groups showed bacterial growth. Greater blood loss did not increase the contamination rate in general. Isolated bacteria included the species Staphylococcus epidermidis, coagulase-negative staphylococci and Propionibacteria in both groups, but with different cell counts. In addition, Corynebacterium bovis et minutissimum and Moraxelle were identified in group A. In conclusion, autologous blood transfusion was a safe procedure. If contamination occurred, the bacterial count was low, and the bacteria of low pathogenicity. Antibiotic prophylaxis with cefuroxime reduced this contamination of suction tips and collection bags and limited the transfer of autologous blood products.

gyrA mutations in high-level fluoroquinolone-resistant clinical isolates of Escherichia coli.

Double mutations in the quinolone resistance determining region of the gyrase A gene (gyrA) have recently been reported to be associated with high-level resistance to fluoroquinolones in clinical isolates of Escherichia coli. We examined the type and frequency of such mutations in a large number of clinical isolates that were obtained from ten different geographical locations and had been genotypically characterized by pulsed field gel electrophoresis (PFGE) of chromosomal DNA digests. Of 36 isolates with ofloxacin MICs > or = 4 mg/L that represented at least 24 distinct genotypes, 35 had double mutations at amino acid codons 83 and 87 of gyrA, while two isolates with ofloxacin MICs of 0.5 and 4 mg/L, respectively, each had a single mutation at codon 83. Mutations at codon Ser-83 were uniform, resulting in substitution by Leu. The additional mutations at amino acid codon 87 in the 35 double-mutants were diverse, resulting in Asp-87 substitutions by residues Asn (23 isolates), Gly (7 isolates), Tyr (4 isolates), or His (1 isolate) without a discernable correlation with fluoroquinolone MICs or with phenotypic resistance to chemically unrelated antibacterial agents. Maximal differences between MICs of double-mutants with the same amino acid substitution were eight-fold. The changes of amino acid residues at codon Asp-87 differed between individual patient isolates with the same genotype (and similar MICs), suggesting that the amino acid codon 87 mutations (and possibly the development of high-level fluoroquinolone resistance) might have occurred after the transmission and sharing of a precursor strain carrying the Ser-83-->Leu mutation.

Non-target gene mutations in the development of fluoroquinolone resistance in Escherichia coli.

Mutations in loci other than genes for the target topoisomerases of fluoroquinolones, gyrA and parC, may play a role in the development of fluoroquinolone resistance in Escherichia coli. A series of mutants with increasing resistance to ofloxacin was obtained from an E. coli K-12 strain and five clinical isolates. First-step mutants acquired a gyrA mutation. Second-step mutants reproducibly acquired a phenotype of multiple antibiotic resistance (Mar) and organic solvent tolerance and showed enhanced fluoroquinolone efflux. None of the second-step mutants showed additional topoisomerase mutations. All second-step mutants showed constitutive expression of marA and/or overexpressed soxS. In some third-step mutants, fluoroquinolone efflux was further enhanced compared to that for second-step mutants, even when the mutant had acquired additional topoisomerase mutations. Attempts to circumvent the second-step Mar mutation by induction of the mar locus with sodium salicylate and thus to select for pure topoisomerase mutants at the second step were not successful. At least in vitro, non-target gene mutations accumulate in second- and third-step mutants upon exposure to a fluoroquinolone and typically include, but do not appear to be limited to, mutations in the mar or sox regulons with consequent increased drug efflux.

A fatal infection with Alternaria alternata and Aspergillus terreus in a child with agranulocytosis of unknown origin.

Alternaria alternata and Aspergillus terreus were isolated from cutaneous nodules in a 5-year-old girl with agranulocytosis of unknown origin. Histopathological examination supported the diagnosis of an infection with two opportunistic moulds. Aspergillus terreus was also isolated from the secretions of the maxillary sinuses of the patient. In spite of antimycotic therapy, the child eventually died from respiratory failure.

Colonization and infection with fluoroquinolone-resistant Escherichia coli among cancer patients: clonal analysis.

Escherichia coli with high-level fluoroquinolone resistance were isolated from feces and/or various body sites of 16 cancer patients who were on oral fluoroquinolone prophylaxis. Population analysis of fecal isolates in 11 patients showed that fluoroquinolone-resistant E. coli was the only aerobic gram-negative bacillus present and exhibited a relatively homogenous fluoroquinolone MIC distribution. Molecular typing by pulsed field gel electrophoresis of chromosomal DNA digests or by random amplified polymorphic DNA fingerprinting confirmed the clonal nature of gastrointestinal tract colonization with E. coli. Genotyping of ten colonies picked from the same fecal culture demonstrated identical strains in four of four patients examined. Identical genotypes from the same patient were isolated over prolonged periods of time in 12 of 12 cases examined, with one patient (with the longest follow-up of 14 months) who lost his initial genotype and became persistently colonized with a new genotype. In the 11 patients who developed infection due to fluoroquinolone-resistant E. coli, molecular typing also indicated that fecal colonization was associated with, and presumably preceded infection due to an indistinguishable genotype of fluoroquinolone-resistant E. coli.

Association of organic solvent tolerance and fluoroquinolone resistance in clinical isolates of Escherichia coli.

Fluoroquinolone resistance in Escherichia coli is principally caused by two kinds of mutation: those affecting the target proteins of the drugs, i.e. DNA gyrase and topoisomerase IV, and those affecting regulatory genes such as marA, soxS or robA. Recently, overexpression of the latter genes was linked to increased organic solvent tolerance in E. coli. Among 138 clinical fluoroquinolone-resistant and -susceptible clinical isolates of E. coli we found a high association between fluoroquinolone resistance and organic solvent tolerance. This finding suggests that E. coli may undergo an adaptive response to extrinsic substances other than quinolones, while mutating to fluoroquinolone resistance.

Overexpression of the marA or soxS regulatory gene in clinical topoisomerase mutants of Escherichia coli.

The contribution of regulatory genes to fluoroquinolone resistance was studied with clinical Escherichia coli strains bearing mutations in gyrA and parC and with different levels of fluoroquinolone resistance. Expression of marA and soxS was evaluated by Northern blot analysis of isolates that demonstrated increased organic solvent tolerance, a phenotype that has been linked to overexpression of marA, soxS, and rob. Among 25 cyclohexane-tolerant strains detected by a screen for increased organic solvent tolerance (M. Oethinger, W. V. Kern, J. D. Goldman, and S. B. Levy, J. Antimicrob. Chemother. 41:111-114, 1998), we found 5 Mar mutants and 4 Sox mutants. A further Mar mutant was detected among 11 fluoroquinolone-resistant, cyclohexane-susceptible E. coli strains used as controls. Comparison of the marOR sequences of clinical Mar mutants with that of E. coli K-12 (GenBank accession no. M96235) revealed point mutations in marR in all mutants which correlated with loss of repressor function as detected in a marO::lacZ transcriptional assay. We found four other amino acid changes in MarR that did not lead to loss of function. Two of these changes, present in 20 of the 35 sequenced marOR fragments, identified a variant genotype of marOR. Isolates with the same gyrA and parC mutations showed increased fluoroquinolone resistance when the mutations were accompanied by overexpression of marA or soxS. These data support the hypothesis that high-level fluoroquinolone resistance involves mutations at several chromosomal loci, comprising structural and regulatory genes.

Influence of hemodilution on cefuroxime levels and bacterial contamination of intra- and postoperative processed wound blood during hip replacement.

MATERIALS AND METHODS: In a prospective randomized study we investigated the effect of hemodilution on cefuroxime levels and bacterial contamination of processed shed blood during hip arthroplasty. 10 patients received cefuroxime 1,5 g as single shot prophylaxis before (group A), 10 after hemodilution (15 ml/KG) (group B). Cefuroxime levels in serum 1 h after administration, at the end of operation, after 12 h and in drainage-blood after 12 h were assessed by HPLC. Bacteriological study was performed from collecting bags (Vacufix), wound drainage blood and processed red blood cell concentrates, using pour plate technique and broth culture enrichment. RESULTS AND DISCUSSION: Mean concentrations of cefuroxime were higher in group B than group A, but differed not significantly. No bacterial contamination was found in collecting bags and wound drainages in both groups. Processed red cell concentrates in group B showed no growth. In group A, however, 3/10 were contaminated with < or = CFU/ml of coagulase-negative Staphylococcus, Staphylococcus epidermidis and Propionibacterium acnes. The differences between groups did not reach the level of statistical significance and could not be related to lower cefuroxime levels. No wound infection occurred in either group.