The outcome was sustained viral suppression. When trials included for the main predictors two arms (positive and negative), the effect size was described as a comparative index [odds ratio (OR)] and a standard meta-analytical procedure was applied. However, when trials did not report the outcome in separate study arms, the effect size was a non-comparative index (success rate) and comparisons between predictor-positive and -negative studies were performed by meta-regression.

Data involving 824 haemophilic HCV-infected patients treated with IFN plus ribavirin were collected from 18 articles (14 prospective cohort studies, 1 retrospective study and 3 randomized controlled trials). The higher rate of sustained viral response was observed in human immunodeficiency virus (HIV)-negative naive haemophiliacs treated with pegylated-IFN in combination with ribavirin (61%, ranging from 45% for genotype 1 to 79% for non-1 genotypes). Genotype 1 (OR, 0.15; 95% CI, 0.09–0.25) and co-infection with HIV (OR, 0.25; 95% CI, 0.08–0.81) were strong predictors of worse response to IFN therapy.

Our meta-analysis shows that the pattern of response to combination anti-HCV therapy of chronically HCV-infected haemophiliacs is similar to that achieved in the general HCV-infected population.

We selected subtype G viruses from patients with diverse amino acid combinations at codons 71 (A/T), 74 (T/S), 89 (I/L/M/V) and 90 (L/M). Viral protease genes were inserted into an HIV molecular clone (HXB2). PI drug susceptibilities of chimeric viruses were determined.

In isolates displaying 89I/V in combination with A71 or T74, a reversal to subtype G wild-type 89M was observed after growth in the absence of PI. The presence of 71T in one isolate and 74S in another allowed the persistence of 89I. Mutation 90M conferred intermediate but significant degrees of drug resistance to ritonavir and nelfinavir in subtype G viruses. The combination of 71T or 74S, 89I and 90M resulted in higher levels of resistance to those PIs.

Our results point to the hypothesis that 71T or 74S stabilizes 89I in the protease of subtype G, whose association was previously seen by Bayesian network analyses. The association of 89I with 90M may further increase the PI resistance of subtype G viruses when compared with 90M alone, highlighting novel mutational profiles for drug resistance in this non-B subtype.

The sensitivity of genotype (GT) 1 HCV NS5B clinical isolates from treatment-naive patients to nucleoside and non-nucleoside polymerase inhibitors was assessed. The genetic diversity at the population level, as well as that of their quasispecies, was correlated with the observed reduced sensitivity to inhibitors.

R1479 and NM107 (nucleoside analogues that have entered Phase 2 clinical trials as prodrugs R1626 and NM283, respectively) were similarly active across the tested clinical isolates. Resistance mutations to nucleoside analogues were not observed in any of the isolates. However, the activity of the non-nucleoside thumb II inhibitor NNI-1, palm I inhibitors NNI-2 and NNI-3, and palm II inhibitor HCV-796 was reduced across different isolates. This reduction in inhibitory activity for non-nucleoside inhibitors (NNIs) was, in most cases, correlated with the existence of known NNI resistance mutations in the NS5B polymerase population of the clinical isolates, as detected by population sequencing. Resistance mutations to NNIs were also observed at a low frequency within the clinical isolates' viral quasispecies that allowed for their rapid selection upon drug selective pressure.

The higher frequency of known NNI resistance mutations or polymorphisms known to affect their antiviral potency when compared with the lack of detection of resistance mutations to the nucleoside analogues suggests a potential for primary reduced responsiveness as well as faster development of clinically significant resistance.

A total of 40 DBSs were prepared from residual diagnostic specimens collected from HIV subtype B-infected persons and were stored with desiccant at 4°C. Total nucleic acids were extracted after 1 year using a modification of the Nuclisens assay. Resistance testing was performed using the ViroSeq HIV-1 assay and an in-house nested RT–PCR method validated for HIV-1 subtype B that amplifies a smaller (1 kb) pol fragment.

Using the ViroSeq assay, only 23 of the 40 (57.5%) DBS specimens were successfully genotyped; 22 of these specimens had plasma viraemia >10 000 RNA copies/mL. When the specimens were tested using the in-house assay, 38 of the 40 DBSs (95%) were successfully genotyped. Overall, resistance genotypes generated from the DBSs and plasma were highly concordant.

We show that drug resistance genotyping from DBSs stored at 4°C with desiccant is highly efficient but requires the amplification of small pol fragments and the use of an in-house nested PCR protocol with quality-controlled reagents. These findings suggest that 4°C may represent a suitable temperature for long-term storage of DBSs.

Phenotypic and genotypic methods were employed to identify plasmid-associated antibiotic and mercury resistance genes and to determine the organization of those genes in multidrug-resistant (MDR) A. salmonicida isolates.

The MDR phenotype was transferable via conjugation using Escherichia coli, Aeromonas hydrophila and Edwardseilla tarda as recipients. Antibiotic and mercury resistance genes were carried by a conjugative IncA/C plasmid. Three distinct antibiotic resistance cassettes were characterized; first a class I integron containing an aadA7 gene encoding for an aminoglycoside-3'-adenyltransferase, the second cassette showed 99.9% nucleotide sequence homology to a cassette previously identified in the Salmonella enterica IncA/C plasmid pSN254, containing floR, tetA, sulII and strA/strB sequences. The third cassette showed 100% nucleotide sequence similarity to a transposon-like element, containing a bla_CMY-2 β-lactamase in association with sugE and blc sequences. This element is known to be widely distributed among clinical and food-borne Salmonella and other Enterobacteriaceae throughout Asia and the United States. Mercury resistance was linked to the presence of a mer operon that showed 100% nucleotide sequence homology to the mer operon carried by plasmid pSN254.

Each MDR A. salmonicida isolate carried the same plasmid, which was related to plasmid pSN254. This is the first report of plasmid-mediated florfenicol-resistant A. salmonicida in North America. In addition, it is the first report of a plasmid-associated AmpC β-lactamase sequence in a member of the Aeromonadaceae.

pMLST was developed by selecting multiple target genes on the available complete IncI1 plasmid DNA sequences. Sixteen plasmids, all assigned to the IncI1 group by the PCR-based replicon typing method, were included in this study. They were analysed for β-lactamase genes and typed by restriction fragment length polymorphism (RFLP) and pMLST.

Sixteen plasmids identified in E. coli and Salmonella isolated from animals and humans in different countries carried bla_CMY-2, bla_CTX-M-15, bla_CTX-M-1, bla_CTX-M-14, bla_TEM-52, bla_SHV-12 or bla_TEM-1 β-lactamase genes. These plasmids were classified by RFLP in nine different groups corresponding to the nine sequence types determined by pMLST.

The pMLST method was suitable for rapid and easy subtyping of IncI1 plasmids. This study demonstrates that the pMLST method can contribute to the epidemiological description of circulation of specific resistance plasmids among β-lactamase producers isolated from animals and humans.

A total of 2035 E. coli and 1147 K. pneumoniae isolates collected between 1999 and 2005 were screened for qnrA, qnrB and qnrS by PCR and colony hybridization. β-Lactamase genes, genetic relatedness and transferability were examined by PCR, PFGE and conjugation, respectively.

The prevalence of qnr genes was 7.8% and 0.6% for K. pneumoniae and E. coli, respectively. The prevalence rates of qnrB2, qnrB4 and qnrS1 genes for K. pneumoniae were 2.3%, 3.6% and 2.8%, respectively, and for E. coli were 0.2%, 0% and 0.4%, respectively. The prevalence of qnrB4 in K. pneumoniae increased remarkably from 0% to 7.6% over the 7 study years. qnrA was not detected. Overall, the SHV-5-related, CTX-M-14, CTX-M-3, CMY-2, DHA-1 and IMP-8 β-lactamases were detected alone or in combination in 82.0% of qnr-positive K. pneumoniae isolates and 41.7% of qnr-positive E. coli isolates. Notably, all qnrB4-positive isolates possessed the DHA-1 enzyme, and the majority of the qnrB2-positive isolates (E. coli, 100%; K. pneumoniae, 80.8%) produced SHV-5-related β-lactamases. Genetic diversity was demonstrated by PFGE. Conjugation experiments revealed co-transfer of bla_SHV-12, bla_DHA-1 and bla_SHV-5 with qnrB2, qnrB4 and qnrS1, respectively.

qnr genes remained rare in E. coli but appeared to be increasing in K. pneumoniae in our hospital. Horizontal transfer may play a major role in the intra-hospital spread of qnr.

A PCR-based strategy was used to clone and express genes coding for Qnr-like PRPs in Enterococcus faecalis, Enterococcus faecium, Listeria monocytogenes, Clostridium perfringens, C. difficile, Bacillus cereus and B. subtilis in Escherichia coli DH10B. MIC values of nalidixic acid and fluoroquinolones were determined for reference strains and E. coli DH10B harbouring recombinant plasmids containing genes coding for PRPs.

Amino acid identity of Qnr-like PRPs in Gram-positive strains compared with that of the plasmid-mediated quinolone resistance determinants QnrA1, QnrB1 and QnrS1 was in the range of 16% to 22%. Recombinant plasmids coding for Qnr-like PRPs conferred reduced susceptibility to fluoroquinolones (in the range of 0.016 to 0.064 mg/L for ciprofloxacin) and nalidixic acid (from 6 to 12 mg/L), depending on the antimicrobial agent and PRP. The PRP from B. subtilis showed no protective effect.

The PRPs analysed conferred a reduced susceptibility phenotype in E. coli; the data provide further evidence of the possible roles in quinolone resistance of PRPs from different Gram-positive species. These Gram-positive species may constitute a reservoir for Qnr-like quinolone resistance proteins.

From 2003 to 2004 in Barcelona, Spain, stool samples from 905 people involved in 132 acute gastroenteritis outbreaks and 226 food handlers related to the outbreaks were investigated.

In 31 outbreaks, 58 diners carrying one or more ESBL-PB were detected. In 10 outbreaks, two or more diners shared the same ESBL-PB, and in four of them, the strain was shared with the food handlers.

This study provides circumstantial evidence that foods can be a transmission vector for ESBL-PB, probably from two reservoirs, food animals and food handlers.

MICs were determined using Etest assay on Columbia agar supplemented with 5% horse blood. The presence of mutations in the quinolone-resistance-determining region (QRDR) of gyrA was searched for after PCR amplification and DNA sequencing using specific oligonucleotide primers.

Bartonella isolates from Australia were susceptible to rifampicin, tetracyclines, β-lactam and macrolide compounds but were resistant to vancomycin. We found heterogeneity of susceptibility for fluoroquinolones with ciprofloxacin being more effective (MICs from 0.06 to 0.5 mg/L) than ofloxacin (MICs from 0.5 to 4 mg/L). This heterogeneity was linked to a natural mutation Ser-83->Ala (Escherichia coli numbering) in the QRDR. Surprisingly, this mutation was also present in the QRDR of Bartonella henselae, Bartonella quintana and Bartonella bacilliformis.

Etest is a sensitive and reliable assay for evaluation of antibiotic susceptibility in the genus Bartonella. The higher sensitivity of this method allowed us to detect heterogeneity of susceptibility among fluoroquinolones that was associated with natural mutation in the QRDR of the DNA gyrase. Because a high level of resistance to fluoroquinolones due to a second mutation may be obtained easily in vitro, we believe that fluoroquinolone compounds should be avoided for the treatment of any Bartonella-related diseases.

The aim of this study is to investigate the significance of the four glutamic residues with regard to the potency, stability and functionality of enterocin AS-48.

Four genetically engineered variants of AS-48 were obtained by replacing each glutamic residue with alanine by site-directed mutagenesis. Each mutant peptide was purified from E. faecalis cultures. The activity of highly concentrated samples and the MIC were determined against nine bacterial strains by the spot-assay method. Structural studies were made with circular dichroism (CD) spectroscopy.

Occasional alterations to the net charge of AS-48 did not significantly affect its activity when high concentrations of bacteriocin were used. Nevertheless, according to the MIC values, three of the four mutated peptides showed weaker activity against the majority of the Gram-positive bacteria tested. CD spectroscopy showed that the derivatives were well structured, in a similar way to those of the native molecule, with no modifications in their helix content.

The spatial location of the Glu residues rather than their negative charge played a critical role in AS-48 target-cell specificity and bactericidal activity, because the replacement of Glu with Ala modify the interactions between neighbouring residues through their side chains and the interaction to the solvent affecting the protein stability and causing variations in the activity levels against identical organisms.

We examined the susceptibility of 190 clinical strains of methicillin-susceptible S. aureus (MSSA) and 304 strains of MRSA to two different classes of cationic antimicrobial peptides: LL-37 and human β-defensin-3 (hBD3). Out of the total 494 clinical strains, a random selection of 54 S. aureus strains was examined to establish the relationship between the net charge, or zeta potential, of each strain and its susceptibility to hBD3 or LL-37. To further confirm bacterial susceptibility to either hBD3 or LL-37, we concurrently measured: (i) percentage survival after in vitro bacterial exposure and (ii) MBCs for both MRSA and MSSA strains.

Of the 54 randomly selected S. aureus strains, those MRSA strains resistant to LL-37 showed significantly higher zeta potentials than those susceptible to LL-37 (P < 0.05). In contrast, there was no difference in bacterial zeta potentials for MRSA strains that showed either resistance or susceptibility to hBD3. In addition, resistance to LL-37, but not to hBD3, as determined by either percentage survival or MBC, was significantly elevated in highly methicillin-resistant strains of S. aureus when compared with MSSA strains (P < 0.01).

Clinical strains of MRSA, but not MSSA, that demonstrated an increased net charge also showed elevated resistance to LL-37, but not to hBD3.

A library of piperine-derived compounds was evaluated for their potential to inhibit ethidium bromide efflux in NorA-overexpressing S. aureus SA 1199B. The active compounds were then individually combined with ciprofloxacin to study the potentiation of ciprofloxacin’s activity.

Based on the efflux inhibition assay, a library of 200 compounds was screened. Three piperine analogues, namely SK-20, SK-56 and SK-29, were found to be the most potent inhibitors of the NorA efflux pump. These inhibitors acted in a synergistic manner with ciprofloxacin, by substantially increasing its activity against both NorA-overexpressing and wild-type S. aureus isolates. These analogues were 2- to 4-fold more potent than piperine at a significantly lower minimal effective concentration. Furthermore, these inhibitors also significantly suppressed the in vitro emergence of ciprofloxacin-resistant S. aureus.

A newly identified class of compounds derived from a natural amide, piperine, is more potent than the parent molecule in potentiating the activity of ciprofloxacin through the inhibition of the NorA efflux pump. These molecules may prove useful in augmenting the antibacterial activities of fluoroquinolones in a clinical setting.

More than 700 methicillin-susceptible and methicillin-resistant strains covering >90% of all registered European MRSA spa types within the SeqNet network were studied.

All 513 MRSA strains tested were recognized as methicillin-resistant: among these, 96 MRSA strains were from an institutional collection, each presenting a unique spa type. None of the 211 methicillin-susceptible strains were detected as positive.

The new growth-based rapid MRSA assay was shown to detect without exception all MRSA strains of large collections of strains comprising highly diverse genetic backgrounds, indicating that such a phenotypic test might be potentially more likely to cope with new strains.

We defined the biocompatibility index (BI) by measuring the antibacterial activity against the test organisms Escherichia coli and Staphylococcus aureus and, in parallel, the cytotoxicity on cultured murine fibroblasts. The antiseptic agents tested were benzalkonium chloride (BAC), cetylpyridinium chloride (CPC), chlorhexidine digluconate (CHX), mild silver protein (MSP), octenidine dihydrochloride (OCT), polyhexamethylene biguanide (PHMB), povidone iodine in solution [PVP-I(s)], povidone iodine in ointment [PVP-I(o)], silver nitrate (AgNO₃), silver (I) sulfadiazine (SSD) and triclosan (TRI). Assays were carried out for 30 min of exposure at 37°C in the presence of cell culture medium containing 10% fetal bovine serum. The resulting dimensionless BI was defined as the ratio of the concentration at which 50% of the murine fibroblasts are damaged and the microbicidal effect producing at least 3 log₁₀ (99.9%) reduction.

The resulting rank ordering of BI for the ratio of fibroblast cytotoxicity to E. coli toxicity was OCT > PHMB > CHX > PVP-I(o) > PVP-I(s) > BAC > CPC > TRI > MSP and that to S. aureus was OCT > PHMB > CHX > CPC > PVP-I(o) > BAC > PVP(s) > TRI > MSP. OCT and PHMB were the most suitable agents with a BI greater than 1.

The BI presented may be a useful tool to evaluate antiseptic agents for use in clinical practice.

J774 macrophages and rat embryo fibroblasts were exposed for up to 24 and 72 h to telavancin (5–90 mg/L). The following studies were performed: measurement of ¹⁴C-labelled telavancin cellular uptake and subcellular distribution (cell fractionation), determination of pericellular membrane integrity (lactate dehydrogenase release), electron microscopy with morphometric analysis of changes in lysosome size and determination of total phospholipid and cholesterol content.

The uptake of telavancin proceeded linearly as a function of time and concentration in both cell types (clearance rate of ~10 mL/g of protein/h). Efflux (macrophages) was ~5.7-fold slower. Telavancin subcellular distribution was superimposable on that of a lysosomal marker (N-acetyl-β-hexosaminidase). It did not cause an increase in the release of lactate dehydrogenase and did not induce significant increases in total phospholipid or cholesterol content. It caused only mild morphological lysosomal alterations (similar to vancomycin and much less than oritavancin by morphometric analysis).

Telavancin is taken up by eukaryotic cells and localizes in lysosomes, causing mild morphological alterations without evidence of lipid metabolism alterations. These data support our observations that telavancin is active against intracellular S. aureus.

We propose a new theoretical framework for analysis of agar diffusion assays. MIC was determined by this technique for a number of antibiotics and analysis was carried out using both the existing free diffusion and the new dissipative diffusion models.

A theory for analysis of antibiotic diffusion in solid media is described, in which we consider possible interactions of the test antibiotic with the solid medium or partial antibiotic inactivation during diffusion. This is particularly relevant to the analysis of diffusion of hydrophobic or amphipathic compounds. The model is based on a generalized diffusion equation, which includes the existing theory as a special case and contains an additional, dissipative term.

Analysis of agar diffusion experiments using the new model allows significantly more accurate interpretation of experimental results and determination of MICs. The model has more general validity and is applicable to analysis of other dissipative processes, for example to antigen diffusion and to calculations of substrate load in affinity purification.

Candida albicans was grown in protein [bovine serum albumin (BSA) or casein (CSN)] as a sole nitrogen source, in ammonium sulphate (AS) as a nitrogen source, or in both protein and AS.

Cells grown in BSA or CSN were 4- to 16-fold less susceptible to amphotericin B and nystatin than those grown in AS. Similar results were observed for cycloheximide, but not for fluconazole or caspofungin, and were observed for many C. albicans clinical isolates. The results were observed in two different media, and in broth and on agar. Cells grown under these nitrogen-poor conditions have a reduction in ergosterol sterol levels and a reduction in overall sterol synthesis. Quantitative real-time reverse transcription–polymerase chain reaction analysis shows that some genes involved in sterol biosynthesis are induced under nitrogen-limiting conditions, consistent with the lower sterol levels.

The results demonstrate that nitrogen source has a significant effect on polyene susceptibilities. As these nitrogen-limiting conditions mimic oral nitrogen availability, they suggest that in vitro polyene susceptibilities may overestimate the in vivo susceptibilities to polyene drugs in the mouth.

Germinated conidia of A. fumigatus were exposed to 1–10x MIC of amphotericin B for 1 and 4 h and to 2.5–40x MIC of voriconazole for 4 and 24 h. After removal of the drug by washing, similar numbers of exposed and control germlings were inoculated into Pedi-BacT culture bottles. CO₂ production was automatically monitored until the bottles signalled positive. The difference in time for positive signals in drug-exposed and control bottles was used to calculate the PAFE.

The killing rate of amphotericin B against germlings was both concentration- and time-dependent, as has been previously found for actively growing hyphae. Similarly, voriconazole showed fungicidal effect after 24 h of exposure, but not after 4 h. Amphotericin B induced a long concentration- and time-dependent PAFE, whereas voriconazole resulted in a short and dose-independent PAFE that was significantly longer after 24 h than after 4 h of exposure.

An automated method is presented for the determination of PAFE on filamentous fungi using quantifiable numbers of germinated conidia. In contrast to previous results obtained from conidia, this method could demonstrate a PAFE of amphotericin B on Aspergillus that shared characteristics similar to that on Candida spp.

To determine the in vitro susceptibility of Prototheca isolates to conventional antifungal agents and to essential oils.

Twenty P. zopfii isolated from milk during these outbreaks, six P. zopfii isolated from fresh water and two Prototheca sp. reference strains were submitted to antifungal susceptibility testing by broth microdilution assay following the CLSI guidelines for yeasts.

The tested isolates were shown to be resistant to fluconazole and caspofungin. A wide range of voriconazole MICs was observed. In contrast, amphotericin B, itraconazole and posaconazole appeared active with MICs ≤ 1 mg/L. Bergamot and tea tree oils seemed to exert an interesting activity against this yeast-like alga.

Difficulties in treating animals with conventional drugs and the potent in vitro activity of essential oils demonstrated here raise the interest in further investigations on the therapeutic use of these non-conventional natural products.

Five Shigella spp., 6 Salmonella spp. and 318 E. coli were isolated from stool specimens obtained from 367 children with or without acute diarrhoea. Isolates were differentiated using standard laboratory procedures and tested using a breakpoint microbroth dilution method for their susceptibility to 18 antimicrobials and by disc diffusion for their susceptibility to chloramphenicol.

Although the salmonellae showed an acceptable resistance pattern, E. coli isolates and the closely related shigellae were highly resistant. About 91% and 81% of E. coli isolates from patients or controls, respectively, were resistant to ampicillin (MICs ≥ 8 mg/L), 88% and 76% to trimethoprim/sulfamethoxazole (MICs ≥ 80/4 mg/L) and 46% and 41% to chloramphenicol (inhibition zones ≤ 12 mm). Resistance to β-lactam antibiotics or chloramphenicol was observed more frequently among isolates obtained from infants when compared with older children (1–4 years of age).

Enteric bacteria from children in urban Northern Ghana are highly resistant to antibiotics used in that area. Therefore, new antibiotics should be introduced for the treatment of infections caused by these bacteria. Additionally, the establishment of a surveillance of the prevalence of the main bacterial infectious agents and their antimicrobial resistance is desirable.

According to the classical cure criteria, animals were classified as treated not cured (TNC = 76.4%), treated cured (TC = 12.5%) and dissociated (DIS = 11.1%) using parasitological [fresh blood examination (FBE), blood culture (BC) and blood PCR] and serological methods [conventional serology (CS-ELISA) and non-conventional serology (NCS-FC-ALTA)]. Tissues were also evaluated by PCR.

FBE was able to detect patent parasitaemia in only 18.1% of TNC and therapeutic failure was detected in 79.1% and 97.2% of TNC by BC and blood PCR, respectively. CS-ELISA should not be used before 3 months after treatment since it may lead to false-negative results. At 3 months after treatment with benznidazole, NCS-FC-ALTA was more efficient for categorizing the groups of treated mice. In the TNC group, although a decreased frequency of PCR-positive tissue was observed in several host tissues, increased positivity was also observed, despite the T. cruzi genotype combination. All TC animals presented at least two positive tissue-PCR results.

Our results confirm that NSC-FC-ALTA and blood PCR are the most suitable methods to early detect therapeutic failure in acute murine T. cruzi infection. Additionally, our data show that BC positivity is highly dependent upon the T. cruzi genotype combination. Moreover, our findings demonstrated that PCR tests performed on tissues from animals considered cured after benznidazole treatment still detected T. cruzi DNA, most probably indicating residual infection.

Fifty patients received a single oral dose of 400 mg as an antimicrobial prophylaxis regimen for a short urological procedure under spinal anaesthesia. Serum and cerebrospinal fluid (CSF) were sampled at different time intervals post-drug intake and patients were divided into five groups, as follows: group I: 0.5–1 h; group II: 1–2 h; group III: 2–4 h; group IV: 4–6 h; and group V: 6–8 h. Concentrations of moxifloxacin were estimated after analysis by an HPLC system. Bactericidal activity of CSF samples of groups III and IV was assessed by a microdilution technique against two penicillin-resistant isolates of Streptococcus pneumoniae with MICs of moxifloxacin of 0.19 and 0.125 mg/L, respectively.

Mean CSF concentrations of moxifloxacin of groups I, II, III, IV and V were 0.19, 0.87, 3.00, 4.07 and 1.82 mg/L, respectively. The mean bactericidal activity of CSF of group III was 8 and that of group IV was 4.

Single oral intake of 400 mg moxifloxacin is accompanied by good penetration through healthy meninges within 2–6 h post-dose and reached adequately high levels in human CSF exerting satisfactory bactericidal activity against penicillin-resistant S. pneumoniae. These results render novel perspectives for a role of moxifloxacin in CNS infections.

Ganciclovir pharmacokinetics was intensively studied in two lung transplant recipients under valganciclovir 450 mg every 48 h over one dosing interval. In vitro experiments using blank whole blood spiked with ganciclovir further investigated exchanges between plasma and erythrocytes.

Ganciclovir disposition was characterized by apparent total body clearance of 3.3 and 5.8 L/h, terminal half-life of 16.9 and 14.1 h, and apparent volume of distribution of 60.3 and 104.9 L in Patients 1 and 2, respectively. The observed sieving coefficient was 1.05 and 0.96, and the haemofiltration clearance was 3.3 and 3.1 L/h. In vitro experiments confirmed rapid efflux of ganciclovir from red blood cells into plasma, increasing the apparent efficacy of haemofiltration.

A valganciclovir dosage of 450 mg every 48 h appears adequate for patients under CRRT requiring prophylaxis for CMV infection, providing concentration levels in the range reported for 900 mg once daily dosing outside renal failure.

HIV-1-infected children received efavirenz capsules or tablets in accordance with manufacturer's dosing recommendations. Plasma was collected at regular visits and analysed by HPLC. The therapeutic range of efavirenz was defined as 1.0–4.0 mg/L.

Thirty-three children were included. Median (range) age, body weight, dose and dose/kg were 8.2 (2.1–16.7) years, 24 (12–62) kg, 300 (200–800) mg and 13.3 (9.7–22.5) mg/kg, respectively. Median (range) efavirenz plasma concentration at first sampling was 2.8 (0.13–11.6) mg/L. Plasma concentrations were not dependent on age (P = 0.97) or dose/kg (P = 0.87). A total of 307 efavirenz plasma concentrations were determined. Forty-five samples (14.7%) contained >4.0 mg/L, and 27 samples (8.8%) contained <1.0 mg/L. Eight children (24%) reported persistent adverse events probably caused by efavirenz [concentration problems (5), sleep disorder (1), psychotic reaction (1) and seizure (1)]; six discontinued efavirenz for this reason. A non-significant trend existed towards a higher proportion of toxic efavirenz plasma concentrations (>4.0 mg/L) in subjects who reported efavirenz adverse events: 25.9% versus 12.8% (P = 0.23; t-test). Viral load was <50 copies/mL in all 27 subjects who continued efavirenz, despite occasional subtherapeutic efavirenz plasma concentrations in 12 children. The occasional subtherapeutic levels suggest that temporal non-adherence was present.

Efavirenz as part of highly active antiretroviral therapy was highly effective in children able to tolerate the drug. Therapeutic drug monitoring (TDM) as part of toxicity management may prevent discontinuation in a subset of patients. Temporal non-adherence occurs frequently. TDM may allow initiation of adherence interventions before viral load becomes detectable.

Thirty-five Thai patients with full HIV RNA suppression were switched from stavudine/didanosine to tenofovir/lamivudine while receiving saquinavir/ritonavir 1600/100 mg once daily. Patients were assessed at the time of switch and 24 and 48 weeks after for lipids, liver enzymes, lactate, mitochondrial DNA content and limb/total fat mass by dual energy X-ray absorptiometry (DEXA) scanning.

Forty-eight weeks after the switch, there were significant reductions in lipids and lactate, but no change in liver enzymes. There was reversal of lipoatrophy, as shown by rises in limb fat mass (+0.38 kg, P = 0.006) and total fat mass (+0.69 kg, P = 0.02) on DEXA scan. Patients perceived weight improvement, but did not report reversal of lipoatrophy of individual body parts. The mitochondrial DNA/nuclear DNA ratio rose (+1.06, P < 0.0001).

After the nucleoside reverse transcriptase inhibitor switch, reversal of mitochondrial toxicity was consistent with switch studies of mainly Caucasian patients, although the peripheral mononuclear cell mitochondrial DNA rise exceeded previous reports.

To evaluate the impact of a first-line lopinavir/ritonavir alone or standard triple combination on HIV-1 shedding in the genital tract.

HIV-1-infected men enrolled in the Monark randomized trial were eligible for the present study after 48 weeks of a first-line lopinavir/ritonavir alone or in combination with zidovudine and lamivudine. Single-paired samples of blood and semen were collected at week 48. Blood plasma HIV-RNA and seminal plasma HIV-RNA were measured at week 48. Lopinavir and ritonavir concentrations were measured in blood and in semen at week 48 by high-performance liquid chromatography.

Ten patients were included: five of them received lopinavir/ritonavir monotherapy and five received a triple combination. At week 48, all patients had blood plasma HIV-RNA <1.7 log₁₀ copies/mL. Median lopinavir and ritonavir concentrations were within the expected therapeutic target range in blood plasma (4896 and 130.5 ng/mL, respectively), whereas both lopinavir and ritonavir were undetectable in all seminal plasma samples (<30 ng/mL). All 10 patients had undetectable seminal plasma HIV-RNA at week 48 (<2.3 log₁₀ copies/mL).

No local viral production was evident in semen, despite the local absence of therapeutic antiretroviral drug concentrations in the five patients receiving lopinavir/ritonavir alone.

Efficacy was examined comparing time to virological failure, CD4 recovery and clinical progression. Tolerability was examined comparing time to treatment discontinuation for any reason and for toxicity. Survival analysis was conducted using the Kaplan–Meier method, and standard and weighted Cox regression models.

A total of 1550 antiretroviral-naive patients starting a two-nucleoside reverse transcriptase inhibitor regimen plus either efavirenz (n = 1159) or lopinavir/ritonavir (n = 391) were included in the study. At baseline, patients starting lopinavir/ritonavir had higher HIV-1 RNA and lower CD4+ cell counts. There was no difference in the adjusted hazards of virological failure [efavirenz versus lopinavir/ritonavir hazard ratio (HR) = 0.93, 95% confidence interval (CI): 0.77–1.12, P = 0.43], CD4 recovery (HR = 1.11, 95% CI: 0.95–1.30, P = 0.19) and clinical progression (HR = 0.71, 95% CI: 0.39–1.31, P = 0.27). There was an increased risk of discontinuation for any reason or for toxicity for lopinavir/ritonavir (HR = 2.10, 95% CI: 1.40–3.15, P = 0.0003). CD4 recovery with both drugs was also similar in the lowest CD4 strata. A higher risk of early hypertriglyceridaemia was associated with lopinavir/ritonavir-based regimens.

Our study suggests similar virological efficacy for efavirenz- or lopinavir/ritonavir-based first-line antiretroviral regimens, but an increased risk of discontinuation because of toxicity in case of lopinavir/ritonavir-based therapy. Immunological outcome appeared similar with both regimens.

Twenty-one HIV-infected patients with suppressed HIV replication (<50 copies/mL) for at least 6 months and without previous failure while receiving a protease inhibitor-based regimen started lopinavir/ritonavir monotherapy. Follow-up was performed within the OK pilot clinical trial during the first 2 years and according to routine clinical practice during the 3rd and 4th years.

Fourteen patients (67%) remain on monotherapy and with RNA <50 copies/mL (intention-to-treat analysis, with missing patients scored as failures). Five patients (24%) had virological rebound and all of them were successfully re-suppressed by adding two nucleosides. No major protease inhibitor mutations were found.

Our data support the long-term efficacy and safety of lopinavir/ritonavir monotherapy for the maintenance of HIV suppression, a finding that must be confirmed in larger studies.

PI-experienced patients with virological failure receiving fosamprenavir/ritonavir as the sole PI for at least 3 months and with detectable fosamprenavir plasma levels were included. The impact of baseline protease mutations on virological response (VR, i.e. decrease in plasma HIV-1 RNA between baseline and month 3) was analysed using the Mann–Whitney test. Mutations with prevalence >10% and P value <0.10 were retained. The Jonckheere–Terpstra test was used to select the combination of mutations most strongly associated with VR. The association between score and VR was assessed by multivariate backward regression.

In the 73 patients included, the median baseline HIV-1 RNA was 4.6 log₁₀ copies/mL (range: 2.7–6.9) and the mean decrease at month 3 was –1.07 ± 1.40 log₁₀ copies/mL. Ninety per cent of the patients were infected by HIV-1 subtype B variants. Two fosamprenavir/ritonavir mutation scores were constructed: score A (L10F/I/V + L33F + M36I + I54L/M/V/A/T/S + I62V + V82A/F/C/G + I84V + L90M) was based only on mutations associated with a worse VR, whereas score B (L10FIV + L33F + M36I + I54L/M/V/A/T/S + A71V – V77I – N88S + L90M) also took into account favourable mutations. Both scores were independent predictors of VR, however, co-administration of tenofovir was associated with a worse VR and the presence of the N88S protease mutation and co-administration of enfuvirtide with a better VR.

These clinically validated mutation scores should be of interest for the clinical management of PI-experienced patients. The fosamprenavir/ritonavir score A was introduced in the 2006 ANRS algorithm along with isolated mutations I50V and V32I + I47V.

The aim of this study was to evaluate the efficacy and safety of polymyxins and ampicillin/sulbactam for treating infections caused by carbapenem-resistant Acinetobacter spp. and to evaluate prognostic factors.

This was a retrospective review of patients from two teaching hospitals who had nosocomial infections caused by carbapenem-resistant Acinetobacter spp. from 1996 to 2004. Diagnosis of infection was based on CDC criteria plus the isolation of Acinetobacter from a usually sterile site or from bronchoalveolar lavage. Urinary tract infections were not included. Data on demographic and clinical features and treatment were collected from medical records. Prognostic factors associated with two outcomes (mortality during treatment and in-hospital mortality) were evaluated.

Eighty-two patients received polymyxins and 85 were treated with ampicillin/sulbactam. Multiple logistic regression analysis revealed that independent predictors of mortality during treatment were treatment with polymyxins, higher Acute Physiological and Chronic Health Evaluation II (APACHE II) score, septic shock, delay in starting treatment and renal failure. On multivariate analysis, prognostic factors for in-hospital mortality were older age, septic shock and higher APACHE II score.

This is the first study comparing current therapeutic options for infections due to carbapenem-resistant Acinetobacter. The most important finding of the present study is that ampicillin/sulbactam appears to be more efficacious than polymyxins, which was an independent factor associated with mortality during treatment.

A 6 month (1 August 2006–31 January 2007), prospective cohort study of non-ICU patients with Gram-negative bacteraemia in a tertiary-care hospital was performed. Inadequate empirical antibiotic therapy was defined as no antibiotic or starting a non-susceptible antibiotic within 24 h after the initial positive blood culture.

Two hundred and fifty non-ICU patients had Gram-negative bacteraemia. The mean age was 56.4 (±16.1) years. The predominant bacteria in monomicrobial infections were Escherichia coli (24%), Klebsiella pneumoniae (18%) and Pseudomonas aeruginosa (8%). Sixty-one (24%) patients had polymicrobial bacteraemia. Seventy patients (28%) required ICU transfer and 35 (14%) died. Seventy-nine (31.6%) received inadequate empirical antibiotic therapy. These patients were more likely to have a hospital-acquired infection [odds ratio (OR) = 1.99, 95% confidence interval (CI) = 1.11–3.56, P = 0.02] and less likely to have E. coli monomicrobial bacteraemia [OR 0.40 (95% CI 0.19–0.86), P = 0.02]. There were no differences in occurrence of sepsis [72 (91.1%) patients with inadequate versus 159 (93.0%) with adequate therapy; P = 0.6], ICU transfer [20 (25.3%) versus 50 (29.2%); P = 0.5], post-bacteraemia length of stay (median = 6.8 versus 6.1 days; P = 0.09) or death [11 (13.9%) versus 24 (14.0%); P = 1.0].

Nearly one-third of the non-ICU patients with Gram-negative bacteraemia received inadequate empirical antibiotic therapy. There was no difference in adverse outcomes between patients receiving inadequate or adequate therapy in this study.

Measures of process of care were identified from a literature review. Forty sets of medical notes were reviewed by two independent doctors and the inter-rater reliability determined using observed percentage agreement and the kappa statistic. These measures were collected weekly and fed back to doctors in order to stimulate improvement.

Four process measures were identified and were grouped together to create a ‘day 3 bundle’: antibiotic plan, review of the diagnosis, adaptation to microbiology and intravenous–oral switch. The inter-rater agreement was ≥80% for all measures. Data collection was feasible and was easily sustained over several weeks. The reassessment of antibiotic prescriptions around day 3 was better documented using real-time feedback of the measures to the medical team.

Our measures of care are suitable for the reassessment of empirical inpatient antibiotic prescriptions, with good inter-rater reliability. This quality intervention should be part of a more comprehensive and multifaceted plan to improve antibiotic use in hospitals.