A case of meningitis due to Achromobacter xylosoxidans denitrificans 60 years after a cranial trauma

BACKGROUND

Achromobacter xylosoxidans (AX) is a non-fermentative aerobic gram-negative bacillus. It is an opportunistic pathogen and the causative agent of various infections. We report an original case of late posttraumatic meningitis due to AX denitrificans.

CASE REPORT

An 83-year-old man was hospitalized for acute headache, nausea and vomiting. The emergency brain computer tomography (CT) scan did not reveal any anomaly. In his medical history, there was an auditory injury due to a cranial trauma incurred in a skiing accident 60 years earlier. Cytobiochemical analysis of the cerebrospinal fluid (CSF) revealed increased levels of neutrophils and proteins. The CSF bacterial culture was positive: the Gram stain showed a gram-negative bacillus, oxidase + and catalase +, and the biochemical pattern using the API 20 NE strip revealed AX dentrificans. Late posttraumatic meningitis on a possible osteomeningeal breach was diagnosed even though the breach was not confirmed because the patient declined a second brain CT scan. The patient was successfully treated with meropenem.

CONCLUSIONS

This report demonstrates the importance of searching for unusual or atypical organisms when the clinician encounters meningitis in a particular context, as well as the importance of adequate follow-up of craniofacial traumas.

Sudden onset of pseudotuberculosis in humans, France, 2004-05

Cases of Yersinia pseudotuberculosis infection increased in France during the winter of 2004-05 in the absence of epidemiologic links between patients or strains. This increase represents transient amplification of a pathogen endemic to the area and may be related to increased prevalence of the pathogen in rodent reservoirs.

VEB-1 in Achromobacter xylosoxidans from cystic fibrosis patient, France

Multidrug-resistant Achromobacter xylosoxidans was recovered from the sputum of a patient with cystic fibrosis. The VEB-1 extended-spectrum β-lactamase was detected on a class 1 integron. This first report of a VEB-1–producing isolate in this population requires further investigation to determine its distribution.

Presumed pseudobacteremia outbreak resulting from contamination of proportional disinfectant dispenser

Reported here are the microbiological and epidemiological details of a presumed outbreak of aerobic gram-negative bacilli infections affecting 19 hematological patients, which was traced to contaminated disinfectant. Over a 5-month period, the following organisms were isolated from the blood cultures of 19 neutropenic patients: Pseudomonas fluorescens (n = 13), Achromobacter xylosoxidans (n = 12), Comamonas testosteroni (n = 2) or Stenotrophomonas maltophilia (n = 1). The affected patients were all treated with an expensive regimen of broad-spectrum antibiotic therapy. The same bacteria were recovered from environmental samples as well as from the water pipes of an apparatus for dispensing disinfectant (didecyldimethylammonium chloride). Genotyping results indicated that many of the clinical strains were identical to strains isolated from the apparatus. It was eventually discovered that the night staff was in the habit of disinfecting the blood-culture bottles before use, thereby contaminating the bottles with bacteria contained in the disinfectant. Contamination of the apparatus resulted from faulty maintenance.

Survey of Enterobacteriaceae producing extended-spectrum beta-lactamases in a Slovak hospital: dominance of SHV-2a and characterization of TEM-132

Eighty-five extended-spectrum beta-lactamase-producing Enterobacteriaceae from a Slovak hospital have been studied. SHV-2a was predominant, but other variants have been detected, namely, SHV-5, SHV-12, TEM-12, TEM-15, and TEM-132, which differed from TEM-1 by amino acid substitutions R164H, E240K, and I173V and had kinetic properties similar to those of TEM-28.

TEM-89 beta-lactamase produced by a Proteus mirabilis clinical isolate: new complex mutant (CMT 3) with mutations in both TEM-59 (IRT-17) and TEM-3

TEM-89 (CMT-3) is the first complex mutant beta-lactamase produced by a clinical strain of Proteus mirabilis (strain Pm 631). This new enzyme, which has a pI of 6.28, is derived from TEM-3 and has a single amino acid substitution also encountered in TEM-59 (inhibitor-resistant TEM beta-lactamase IRT-17): Ser-130 to Gly. TEM-89 hydrolyzed penicillins to the same extent that TEM-3 did but lost almost all hydrolytic activity for cephalosporins and, like TEM-59, was highly resistant to inhibitors.

Evidence of in vivo transfer of a plasmid encoding the extended-spectrum beta-lactamase TEM-24 and other resistance factors among different members of the family Enterobacteriaceae

The epidemiological study of several multidrug-resistant Enterobacteriaceae isolated from five patients demonstrated in vivo dissemination of a 100-kb plasmid encoding the extended-spectrum beta-lactamase TEM-24 from a clonal strain of Enterobacter aerogenes to different strains of Klebsiella pneumoniae, Escherichia coli, Proteus vulgaris, Proteus mirabilis, and Serratia marcescens.

[Lung disease due to Mycobacterium xenopi excluding AIDS. Apropos of 8 cases]

Between 1994 and early 1999, Mycobacterium xenopi was isolated in 11 HIV-negative patients seen at the Respiratory Disease Department of the Dijon University Hospital. Eight of these patients met the criteria of lung infection. Clinical and radiological features simulated pulmonary tuberculosis which delayed diagnosis until the germ was identified. Treatment is considered to be mandatory though it is difficult to manage and often disappointing. In spite of long-term medical care, sometimes associated with surgery, outcome is currently determined by the underlying disease rather than by Mycobacterium xenopi infection.

[A three-dimensional model for in vitro study of the association of three antibiotics. Application to the activity of piperacillin, tazobactam and amikacin against five strains of enterobacteria as a function of their phenotype of beta-lactam resistance]

We described an in vitro 3-dimensional model to study the bactericidal activity of piperacillin (P), tazobactam (T) and amikacin (A) in combination against 5 strains of enterobacteria with different resistance patterns of beta-lactam antibiotics. A synergy was defined by calculation of sigma FBCP,T,A = BCp/MBCp + BCT/MBCT + BCA/MBCA and classic sigma FBCs for each double combination. The therapeutic value of each antibiotic was estimated by comparison of its bactericidal concentrations alone and in double or triple combination.

Bactericidal activity of cefodizime on Enterobacteriaceae in an in-vitro model simulating plasma pharmacokinetics in humans

An in-vitro dialysis model was employed to assess the feasibility of once-daily dosing of cefodizime in the treatment of infections caused by various Enterobacteriaceae: Escherichia coli, Klebsiella pneumoniae, Morganella morganii, Serratia marcescens, Providencia stuartii and Enterobacter cloacae. This model simulated the concentrations of cefodizime detected in human blood after an intravenous (i.v.) bolus injection of 1 g or 2 g of the antibiotic. Validation of the model was undertaken to confirm its utility. Based on the data obtained with this model, once-daily dosing with 1 g cefodizime (i.v.) should be effective against infections due to the commonest Gram-negative bacteria (E. coli, K. pneumoniae, M. morganii). For infections caused by Enterobacteriaceae strains that produce large quantities of Class I beta-lactamases, twice-daily (P. stuartii or S. marcescens) or four times daily (E. cloacae) administration of 1 g cefodizime may be required.

Imipenem resistance in clinical isolates of Proteus mirabilis associated with alterations in penicillin-binding proteins

Two strains of Proteus mirabilis, IpR1 and IpR2, resistant to both imipenem and mecillinam, but susceptible to other beta-lactams were isolated from blood cultures of patients who had been treated with imipenem. Strain IpR1 was isolated in the same sample as a P. mirabilis IpS1 which was susceptible to imipenem and mecillinam. Strains IpR1 and IpR2 did not produce a beta-lactamase and their outer membrane protein profiles were similar to those of IpS1 and P. mirabilis ATCC 29906. Electrophoretic profiles of penicillin-binding proteins (PBPs) showed a decrease in PBP 1A of strains IpR1 and IpR2 compared with IpS1 and ATCC 29906. Competition experiments revealed a decrease in affinity of PBP 2 for imipenem from strain IpR1. These findings suggest that imipenem resistance in P. mirabilis might result from altered PBPs, as reported for Acinetobacter baumanii and Pseudomonas aeruginosa.

[In vitro antibacterial activity of piperacillin-tazobactam in combination with netilmicin or amikacin against Enterobacteriaceae resistant to amoxicillin]

The antibacterial in vitro activity of piperacillin and tazobactam (in a concentration ratio of 8/1) was studied in combination with netilmicin or amikacin by a microtiter checkerboard assay against 162 strains of Enterobacteriaceae. These strains were selected for their resistance pattern to beta-lactam antibiotics and their beta-lactamases were characterized by the mean of isoelectric focusing in comparison with reference strains. A comparison of the MICs of piperacillin, alone and in combination, assessed the efficacy of tazobactam as beta-lactamase inhibitor, particularly when a TEM-1 beta-lactamase was produced. When the strains were sensitive to the aminoglycosides (111 netilmicin-sensitive ones and 131 amikacin-sensitive ones), we observed 55% of synergistic effects and 45% of additions with the combinations piperacillin-tazobactam-netilmicin or amikacin. A synergistic effect was usually encountered with P. mirabilis, P. vulgaris, M. morganii and with the strains of E. coli, E. cloacae and S. marcescens which produced a cephalosporinase only. Among the 51 strains that were intermediate or resistant to netilmicin, 8 ones were inhibited by piperacillin-tazobactam-netilmicin at therapeutic levels (3 synergisms, 5 additions). Among the 31 strains that were intermediate or resistant to amikacin, 24 ones (18 synergisms, 6 additions) were inhibited by piperacillin-tazobactam-amikacin at therapeutic concentrations. In most of the cases, the combination of piperacillin-tazobactam with an aminoglycoside enhanced the antibacterial activity of these agents by decreasing the concentrations necessary to inhibit the strains.

[Uptake of ofloxacin by Escherichia coli]

The uptake of ofloxacin by Escherichia coli NIHJ-JC2 was determined by a sensitive and convenient method using high-performance liquid chromatography (HPLC) with a fluorometric detection (sensitivity level: 1 ng/ml). Concentrations of ofloxacin were measured in bacteria after contact with 5 micrograms/ml of antibiotic for 1, 2, 3, 5, 10, 20 and 30 min. Ofloxacin uptake was rapid, 70% of broth concentration occurring within the first min and 96% after 5 min; then it reached a plateau which was 1.16 times as high as the broth concentration.

[Comparative study of the antibacterial activity of cefpodoxime against enterobacteria producing beta lactamases]

Cefpodoxime proxetil (RU 51 807) is the oral prodrug of cefpodoxime (RU 51 763), a third generation cephalosporin. The antibacterial activity of cefpodoxime was compared with the activities of amoxicillin in combination with clavulanic acid (AUG), cefaclor (CCl), cefuroxime (CXM) and cefotaxime (CTX), against species of Enterobacteriaceae showing a resistance pattern against ampicillin (AMP), ticarcillin (TIC), cefalothin (CFT) and cefotaxime (CTX) respectively. For strains AMP and TIC R, CFT and CTX S, MICs 90% of cefpodoxime were 1 mg/l (E. coli), 0.5 (K. pneumoniae), 0.06 (P. mirabilis), 0.5 (Shigella sp.) and 1 (Salmonella sp.); they were 4 to 16 times as high for AUG -CCL -CXM and 4 to 16 times as low for CTX. For K. pneumoniae AMP and TIC R, CFT I/R and CTX S, similar résults were obsereved for the 5 beta-lactam antibiotics, but with an activity 10 times as low. Among the species AMP R, TIC S, CFT R and CTX S, cefpodoxime was active against P. rettgeri, P. stuartii, C. diversus, E. aerogenes and Y. enterocolitica (MICs 90% ranging from 2 to 4 mg/l; from 0.12 to 1 mg/l for CTX) and less active or inactive against P. vulgaris, E. cloacae, S. marcescens, M. morganii and E. coli (MICs 90% ranged from 16 to 32 mg/l; from 1 to 4 mg/l for CTX).(ABSTRACT TRUNCATED AT 250 WORDS)

[Nosocomial Staphylococcus epidermidis and Staphylococcus aureus septicemias in neonates]

Sixteen neonates developed staphylococcal septicemia (S. epidermidis in 10 cases and S. aureus in six). Two infections were due to maternofetal contamination and four to contaminated foreign material. Clinical symptoms included non-specific evidence of neonatal bacterial infection and, in S. aureus infections, suggestive skin or bone localizations. Fifteen patients recovered without sequelae and one died as a result of S. aureus septicopyemia. In view of the patterns of resistance to antimicrobial agents exhibited by S. aureus and S. epidermidis, the vancomycin-amikacin combination seems the most appropriate treatment in neonatal staphylococcal septicemias. However, the fosfomycin-cefotaxim combination can be proposed for the treatment of staphylococcal infections with osteoarticular or meningeal involvement.

[Bactericidal activity of daptomycin and vancomycin alone or in combination with tobramycin, netilmicin or ampicillin against enterococcus]

The in vitro bactericidal activity of daptomycin and vancomycin alone or in combination was studied against enterococci in a microtiter checkerboard assay and by kill-kinetic experiments. Daptomycin was more active than vancomycin and was bactericidal. Better Fractional Bactericidal Concentration indices were observed with combinations of vancomycin with aminoglycosides, but in kill-kinetic studies, the combinations of 4 MICs of daptomycin with 4 mg/l of tobramycin or netilmicin produced the more lethal effect; these combinations were even more lethal than ampicillin and aminoglycosides in the same conditions. While vancomycin and ampicillin were antagonistic, synergistic FBC indices were observed with daptomycin and ampicillin in combination, but at 4 MICs of each antibiotic, the combination was less bactericidal than ampicillin alone. The bactericidal effect obtained with daptomycin in combination with aminoglycosides suggest that further evaluation of these combinations in enterococcal endocarditis could have a clinical interest if this bactericidal effect was confirmed by in vivo studies.

[Treatment with a cefotaxime-fosfomycin combination of staphylococcal or enterobacterial meningitis in adults]

Thirty-two patients were included in this trial: 22 with staphylococcal meningitis (including 5 methicillin-resistant) and 10 with enterobacterial meningitis. Mean duration of treatment was 14.5 and 15.9 days respectively. The combination was synergistic in vitro against 10 of the 12 strains of Staphylococcus and 5 of the 6 strains of Enterobacteriaceae studied. Bacteriological sterilization occurred in all cases which could be evaluated, and clinical recovery was obtained in 95.2% of patients with staphylococcal meningitis (4 unrelated deaths) and 100% of patients with enterobacterial meningitis (2 deaths). Bactericidal power of the cerebro-spinal fluid, often less than 1/8, was not correlated with effectiveness against Staphylococci. Mean CSF concentrations of cefotaxime, desacetylcefotaxime and fosfomycin on the 2nd and 15th days of treatment were 4, 3.5 and 39.8 mg/l and 2.2, 2.1 and 28.0 mg/l, respectively. Clinical and biological acceptability was satisfactory. There were three cases of superinfection or colonization, by Pseudomonas and Enterobacter.

Biliary tract excretion of ofloxacin in man

This study examined the biliary tract excretion of ofloxacin in 6 post-cholecystectomy patients with a T-tube inserted into the common duct (group A) and 6 patients during cholecystectomy (group B). The patients were given 7 oral doses of ofloxacin 200mg with a 12-hour interval between each dose. Blood and common duct bile samples were collected in group A at various time intervals after the first and the seventh dose. Blood, gallbladder wall, and gallbladder and common duct bile were collected in group B during operation, 6 hours after the seventh dose. Assays were performed by use of high performance liquid chromatography (HPLC). In group A, mean serum Cmax and half-life were 2.6 mg/L and 7.6 hours after the first dose, and 5.3 mg/L and 8 hours after the seventh dose, respectively. Mean common duct bile Cmax and half-life were 6.5 mg/L and 7.5 hours after the first dose, and 12.0 mg/L and 14 hours after the seventh dose, respectively. In group B, mean concentrations (mg/L) were 2.6 in blood, 5.3 in gallbladder wall, 24.6 in gallbladder bile and 10.1 in common duct bile, 6 hours after the seventh dose. These data suggest that ofloxacin may be suitable for the treatment of biliary tract infections.

In vitro bactericidal activity of sulbactam plus ampicillin against methicillin-resistant Staphylococcus aureus

By a microtiter checkerboard method, the in vitro bactericidal activity of sulbactam/ampicillin was tested against three groups of Staphylococcus aureus strains: group PR (penicillin-resistant through the production of penicillinase; methicillin-susceptible both at 30 degrees C in medium containing 5% NaCl and at 35 degrees C in medium without NaCl; n = 10); group MR1 (methicillin-resistant under the former conditions but not under the latter; n = 15); and group MR2 (methicillin-resistant under both sets of conditions; n = 20). Sulbactam/ampicillin was synergistic against all strains (fractional bactericidal index, less than or equal to 0.10). Moreover, there was a linear relation in each group between the different concentrations of the two antibiotics required for bactericidal activity. Thus, an equation of bactericidal synergy could be formulated for the combination. The bactericidal activity of sulbactam/ampicillin was assessed against one strain of each group and against a reference strain (S. aureus ATCC 6538 P) in an in vitro model simulating the kinetics of both antibiotics in human blood after intravenous administration of 2 g of ampicillin and 1 g of sulbactam. The observed rate of killing was approximately 99% except with the MR2 strains, against which the combination was bacteriostatic.

[Inhibition of cephalosporinase of enterobacteria by ceftriaxone]

Resistance of ceftriaxone, cefotaxime and cefmenoxime to inactivation by the chromosomal constitutive cephalosporinases of Enterobacter cloacae P99, Morganella morganii GN 1510 and Serratia liquefaciens 132 was determined using high performance liquid chromatography. The inhibitory properties of ceftriaxone against the same cephalosporinases were studied by determining the residual amount of cephalothin used as the substrate. With a 1:50 cephalosporinase-cephalosporin ratio, ceftriaxone was less resistant to hydrolysis than cefotaxime of cefmenoxime but showed stronger inhibitory properties.

[Fosfomycin-cefotaxime combination in severe staphylococcal infections in newborn infants]

Clinical and bacteriological effectiveness of the fosfomycin-cefotaxime combination is reported in four cases of serious staphylococcal infections in neonates (1 meningitis, 2 osteomyelitis, 1 superinfection of congenital varicella). Owing to the strong synergistic effect of this combination on methicillin-resistant staphylococcal strains, the authors suggest that the fosfomycin-cefotaxime combination should be considered for anti-staphylococcal therapy in neonates with deep tissue and/or methicillin-resistant infections.

Cefotaxime in combination with other antibiotics for the treatment of severe methicillin-resistant staphylococcal infections

Methicillin-resistant staphylococci (M-R staphylococci) represent 30% of the staphylococcal strains isolated in our hospital and pose important therapeutic problems. In a preliminary in vitro checkerboard study the bactericidal effect of various cephalosporins (cephalothin, cefamandole, cefotaxime and cefoperazone) in combination with other antibiotics (netilmicin, amikacin, vancomycin and fosfomycin) was studied on ten M-R staphylococcal strains. The combinations of cefoperazone with amikacin, cephalothin with vancomycin and of the four cephalosporins with fosfomycin were synergistic on the ten strains (FBC indexes less than or equal to 0.75). According to the CSF and bone levels achieved by these antibiotics and their bactericidal concentrations in combination, the combination of cefotaxime and fosfomycin was the most interesting, a concentration of less than or equal to 2 mg/l cefotaxime being bactericidal on five homogeneous M-R Staphylococcus aureus when combined with 4 mg/l of fosfomycin. This combination of cefotaxime (25 mg/kg, i.v. infusion over 30 min) and fosfomycin (50 mg/kg, i.v. infusion over three hours) three to four times daily was used to treat 16 patients: three patients with meningitis, six with bone and joint infections and seven with persistent bacteremia. The FBC indexes were less than or equal to 0.625 for the 12 strains studied. All the patients were cured without relapses. The concentrations of cefotaxime, desacetyl cefotaxime and fosfomycin in the CSF during meningitis three hours after the end of the infusion on the second day of treatment were 8.76, 6.82 and 58.0 mg/l, respectively, for patient one and 2.0, 0.53 and 31.0 mg/l, respectively, for patient two.(ABSTRACT TRUNCATED AT 250 WORDS)

Bactericidal activity of cefotaxime and fosfomycin in cerebrospinal fluid during the treatment of rabbit meningitis experimentally induced by methicillin-resistant Staphylococcus aureus

The purpose of this study was to evaluate the therapeutic effect of cefotaxime (CTX) and fosfomycin (FOS), alone or in combination, in an experimental meningitis, with cerebrospinal fluid (CSF) concentrations of the two antibiotics reproducing those obtained in human CSF during bacterial meningitis. With a dose of 50 mg/kg of CTX and 100 mg/kg of FOS injected i.v. (CTX over 0.5 h and FOS over 3 h), CSF concentrations were comparable to those observed in man. In a series of five rabbits per treatment group, the bacterial population was counted before and after treatment (two doses with a six-hour interval) with CTX, FOS or CTX + FOS (CTX over 0.5 h before the end of FOS infusion). By the 12th hour of treatment, the percentage of bacteria surviving in CSF compared to the initial population was 4.35% for CTX, 0.20% for FOS and 0.19% for CTX + FOS. Thus, it seemed that CTX + FOS was not more active than FOS alone. In another series of four rabbits per group, the bactericidal effect was followed at T0, T6, T12, T24 and T48 after treatment (two doses with a six-hour with a six-hour interval). With CTX, a variable drop in bacterial count from one rabbit to the other occurred during the first 12 h, and then a bacteriostasis followed. With FOS, a quick bactericidal effect was observed during the first 12 h, becoming slower during the following 36 h (0.03% of bacteria surviving at the 48th hour). With CTX and FOS in combination, a quick bactericidal effect was achieved, remaining steady over a 48-hour period (0.001% of bacteria surviving at the 48th hour).

Treatment of severe staphylococcal infections with cefotaxime and fosfomycin in combination

In a prospective study, 23 severe staphylococcal infections (9 meningitis, 10 bone and joint infections, 3 septicaemia, 1 superinfection of a congenital varicella) were treated with cefotaxime and fosfomycin in combination. There was a synergistic effect of the combination for 14 of the 17 strains tested. Three hours after the end of the infusion, mean CSF concentrations of cefotaxime and fosfomycin were respectively at day 2 3.2 mg/l and 31.4 mg/l, at day 4 2.9 mg/l and 33.9 mg/l. All the patients with meningitis or acute bone and joint infections recovered satisfactorily without relapses. Two superinfections were observed (one systemic candidosis and one septicaemia due to Pseudomonas aeruginosa). Clinical tolerance was good and treatment was discontinued for side effects in only three patients.

[HPLC study of the inhibition of enterobacterial cephalosporinases by cefmenoxime]

High performance liquid chromatography (HPLC) has shown that cefmenoxime and cefotaxime are stable to the cephalosporinase of Enterobacter cloacae P99 , Morganella morganii GN 1510 and Serratia liquefaciens 132. They are significantly resistant to hydrolysis by 100 cephalosporinase units (cephalosporinase production of 10(12) bacterial). Cefmenoxime and cefotaxime are also inhibitors of cephalosporinase at the concentration of 5.10-10 micrograms per 10-10 unit of enzyme.

[In vitro evaluation of moxalactam on enterobacteria producing beta-lactamases]

We have studied strains of enterobacteria which are resistant to first generation cephalosporins, in relation to their cephalosporinase production. Therefore, this is not an epidemiological study. For these selected strains, if a difference in MIC greater than or equal to 2 base 2 logarithms is considered to be significant, Moxalactam appears as more potent than cefotaxim. An appropriate study shows that these findings are related to the production of cephalosporinase. If very little cephalosporinase is produced, cefotaxim is more potent, implying better accession to the lethal target of the bacteria. Conversely, when cephalosporinase production is higher, Moxalactam is more potent. Moxalactam can be shown to be more resistant to hydrolysis by cephalosporinases.

[Combination between fosfomycin and oxacillin or cefotaxime against methicillin-resistant Staphylococci and Enterococci]

The resistance of Gram positive cocci to oxacillin and cephalosporins do not appear to be in relation with the synthesis of a beta-lactamase, thus fosfomycin (FOS) could enhance the action of beta-lactam antibiotics by blocking another stage of the peptidoglycan synthesis. When FOS is combined with oxacillin (OXA) or cefotaxime (CTX) against fosfomycin sensitive strains (25 S. aureus 4-16 mg/l, 20 S. epidermidis 2-32 mg/l and 20 Enterococci 16-64 mg/l) one can see a dramatic synergistic effect of these two combinations. Respectively with S. aureus, S. epidermidis and Enterococci, FIC indices are 0.17-0.39 and 0.43 for FOS-OXA and 0.29-0.47 and 0.29 for FOS-CTX. If one considers the CSF concentrations of these three antibiotics, the combination of fosfomycin with oxacillin or cefotaxime may be used in the treatment of meningitis due to methicillin resistant Staphylococci.