To evaluate the virological response and to describe the resistance profiles in the case of failure after 6 months of first-line highly active antiretroviral therapy (HAART) in HIV-1-infected children living in resource-limited settings.

Ninety-seven HIV-1-infected children who started two nucleoside reverse transcriptase inhibitors (NRTIs) and one non-nucleoside reverse transcriptase inhibitor (NNRTI) (mainly zidovudine/lamivudine/nevirapine) in Mali were prospectively studied. Virological failure (VF) was defined as loss to follow-up, death or HIV-1 RNA viral load (VL) of >400 copies/mL at 6 months. When VL was >50 copies/mL, a genotypic resistance test was performed.

Among the 97 children, median age at antiretroviral initiation was 31 months and the majority were in WHO clinical (77.3%) and immunological (70.1%) stage III or IV. At month 6, 44% of children had VL > 400 copies/mL (61% VF). Among the children with detectable VL, 30/37 genotypic resistance tests were available, 8 with wild-type viruses and 22 with resistance mutations (73%): 19 M184V/I, 21 NNRTI mutations and only 3 thymidine analogue mutations (TAMs) (K70R, D67N and L210W in three distinct viruses). At failure, 6/8 children with wild-type viruses had a VL of <1000 copies/mL whereas 21/22 with resistant viruses had a VL of >1000 copies/mL.

Under NNRTI-based regimens, early detection of VF could allow the reinforcement of adherence when VL was <1000 copies/mL, because in most of these cases no resistance mutations were detected, or a change to a protease inhibitor-based regimen if VL was >1000 copies/mL. The low frequency of TAMs suggests that most NRTIs can be used in a second-line regimen after early failure.

It is debated whether a risk of protease inhibitor mutation selection in proviral DNA exists during intermittent HIV-1 viraemia thereby impacting long-term virological control.

Virologically controlled patients treated with lopinavir/ritonavir were included in a 48 week pilot trial during which lopinavir/ritonavir dosage was reduced if lopinavir concentration was >5000 ng/mL at inclusion. Serum lipids were longitudinally assessed and proviral DNA was quantified and sequenced in patients experiencing transient viraemia.

Thirty-three virologically suppressed patients while on a lopinavir/ritonavir-containing regimen were included, of whom 28 [20 males, mean age 44.6 years (SD 10.9)] completed the 48 week follow-up as scheduled. A significant decrease in lopinavir level was noted [mean C_min, 7363 ng/mL (min, 5118; max, 12 415) at baseline versus 4319 ng/mL (min, 1427; max, 8683) at week 48, P < 0.03]. A significant decrease in triglycerides was also observed [1.73 mmol/L (SD 1.08) at baseline versus 1.34 mmol/L (SD 0.91) at week 48, P = 0.03], whereas no significant change occurred for total, high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol. In the 15 patients with transient viraemia, analysis of proviral DNA for antiretroviral resistance showed that mutations had occurred when compared with baseline genotypes in three patients: I47M (n = 2) and M46I (n = 1). Selection of these mutations was not associated with virological failure as all three patients had a sustained virological response without treatment modification after a 3 year follow-up.

This pilot study evaluating the biochemical and virological impact of a reduced dosing of lopinavir/ritonavir suggests that lower exposure to lopinavir/ritonavir could be associated with a significant decrease in triglycerides during treatment, without occurrence of resistance mutations that might impact the virological response to treatment.

To assess the activity of mecillinam against two groups of Escherichia coli: (i) a selection of international isolates with mechanisms of resistance caused by the presence of defined β-lactamases; and (ii) isolates resistant to third-generation cephalosporins referred from across Wales.

Antibiotic susceptibility testing with mecillinam, meropenem, amoxicillin, co-amoxiclav, cefotaxime, piperacillin/tazobactam, ciprofloxacin, nitrofurantoin, trimethoprim and gentamicin was performed using the BSAC agar dilution method against 30 international strains of E. coli with known β-lactamase presence. Antibiotic susceptibility testing with mecillinam using the same method was performed against 325 regional isolates of E. coli resistant to third-generation cephalosporins.

The susceptibility results showed that the only antibiotics to which the 30 international isolates were consistently susceptible were mecillinam (100%) and meropenem (100%), irrespective of the presence of β-lactamases. Of the local isolates, 93.5% (304/325) were susceptible to mecillinam, having MICs < 8 mg/L.

Our results show that mecillinam has excellent in vitro activity against a range of E. coli exhibiting β-lactamase activity, some with the production of multiple β-lactamases. It is time to further evaluate the clinical utility of mecillinam in the treatment of infections caused by such organisms.

Solicited consultations constitute a substantial workload for infectious disease specialists (IDSs). The impact of physician adherence to recommendations on clinical outcomes following solicited IDS consultations has not been previously studied. The objectives of the study were to identify the factors associated with adherence and to determine whether adherence to recommendations was associated with better clinical outcomes.

A prospective study was conducted on 621 patients, aged ≥ 18 years, hospitalized in a university-affiliated hospital in France, who received an IDS consultation between December 2007 and June 2008. The main outcome was early clinical improvement, and the secondary outcomes were length of stay and in-hospital mortality.

Adherence to the IDS's recommendations was 88.2% (548/621) for antimicrobial treatment and 72.2% (317/439) for diagnostic or monitoring tests. In a multivariable analysis, independent factors of adherence to therapeutic recommendations were a community-acquired infection [adjusted odds ratio (OR), 1.8; 95% confidence interval (CI), 1.1–3.0] and discontinuation or non-use of antibiotic treatment (adjusted OR, 9.7; 95% CI, 1.2–80.3). Adherence to recommendations for antibiotic treatment was associated with a higher rate of early clinical improvement (60.7% versus 43.9%, P = 0.01), shorter median length of stay (20 days versus 23 days, P = 0.03) and comparable in-hospital mortality (7.7% versus 5.5%, P = 0.50).

Factors associated with non-adherence must be anticipated by IDSs during consultations, because non-adherence leads to worse clinical outcomes. Further studies are needed to identify the interventions that could improve physician adherence to recommendations made during solicited consultations.

Pooled analysis of the TORO comparative clinical trial data sets showed a significantly higher incidence rate (IR) of bacterial pneumonia (BP) among patients treated with enfuvirtide-containing combination antiretroviral therapy (ENF-cART) than in those treated with other cART regimens.

To examine the possible impact of ENF-cART on the risk of BP.

From the French Hospital Database on HIV, we selected two groups of patients among cART-treated patients who were prescribed a new cART regimen during the period 2001–2006, when their CD4 counts were <350 cells/mm³. The ENF-cART and cART groups consisted of 1220 and 9374 patients, respectively. Poisson regression models were used to quantify the relationship between ENF-cART therapy and the risk of BP.

At baseline the median CD4 counts were 100 and 211 cells/mm³ and the median plasma viral load (pVL) values were 60 276 and 2702 copies/mL in the ENF-cART and cART groups, respectively. The respective BP IRs were 0.65 [95% confidence interval (CI) 0.25–1.06] and 0.31 (95% CI 0.25–0.38) cases per 100 person-years. After adjustment for age, the HIV transmission group, the time period, co-trimoxazole prophylaxis, and stratified CD4 cell counts and pVL values, we found that the BP risk ratio was not increased by enfuvirtide treatment (relative rate 1.39; 95% CI 0.46–4.13). In contrast, lower CD4 cell counts and higher pVL values were significantly associated with a higher risk of BP.

ENF-cART is not associated with a significantly higher risk of BP than other cART regimens, although the value of the adjusted risk and the upper limit of the CI do not allow us to exclude a small increased risk.

The emergence of oseltamivir-resistant viruses raised the global threat with regard to influenza virus infection. To develop alternative antiviral agents against influenza virus infection is significant and urgent.

A neutralization test was applied as a screening assay and a plaque reduction assay was used for confirmation. Expression plasmids for viral ribonucleoproteins (RNPs) and a plasmid that allowed expression of a pseudoviral reporter RNA were transfected into cells to investigate the effects of a novel antiviral compound on viral RNA synthesis.

BPR2-D2 was identified as a novel inhibitor against influenza virus from a hit obtained from high throughput screening of 20 000 or more compounds. BPR2-D2 exhibited an excellent antiviral efficacy for the oseltamivir-resistant virus (EC₅₀ ranging from 0.021 to 0.040 µM). No resistant virus was produced throughout 20 passages in the presence of BPR2-D2, whereas oseltamivir-resistant virus was generated at passage 8 using the same experimental system. A molecular target other than neuraminidase (NA) was found because BPR2-D2 inhibited the synthesis of viral RNA that was driven by influenza viral RNP in a transfection assay. BPR2-D2 also exhibited a broad antiviral spectrum against various strains of influenza A and influenza B viruses.

BPR2-D2 was identified as a novel inhibitor of influenza virus. It may target viral RNPs that are responsible for viral RNA synthesis. Targeting different molecules compared with NA allows BPR2-D2 to inhibit oseltamivir-resistant viruses.

Fluoroquinolones have a potential role in shortening tuberculosis (TB) treatment duration. They are currently used in the treatment of other infections. This has raised concerns about development of mycobacterial resistance. The current study evaluates the sale of fluoroquinolones (among other antibacterials) in Moshi, Tanzania, a country with one of the highest burdens of TB in the world.

Trained pharmacy assistants registered the sale of fluoroquinolones during February and March 2009 to outpatients in Moshi in all 14 pharmacies that are authorized to sell antibacterials for systemic use. The sale of all antibacterials of the Anatomical Therapeutic Chemical (ATC) J01 class was expressed in defined daily doses (DDDs) per 1000 inhabitants per day (DID). The availability of fluoroquinolones in drug outlets that are not authorized to sell antibacterials for systemic use was assessed in 15 randomly selected outlets in Moshi.

The sale of antibacterials to outpatients in Moshi by authorized pharmacies was 4.99 DID. The sale of fluoroquinolones was 0.62 DID (12% of total antibacterial sales). Ciprofloxacin was available in all 15 unauthorized drug outlets.

The substantial sales of fluoroquinolones by authorized pharmacies and the wide availability of fluoroquinolones in unauthorized drug outlets in Moshi constitute a challenge to the use of fluoroquinolones in TB treatment in Tanzania. Control of antibacterial use in Tanzania requires the implementation of surveillance systems for antibacterial use and resistance, and adequate restriction of antibacterial sales to authorized pharmacies only.

The worldwide rapid increase in antibiotic-resistant bacteria has made efforts to prolong the lifespan of existing antibiotics very important. Antibiotic resistance often confers a fitness cost in the bacterium. Resistance may thus be reversible if antibiotic use is discontinued or reduced. To examine this concept, we performed a 24 month voluntary restriction on the use of trimethoprim-containing drugs in Kronoberg County, Sweden.

The intervention was performed on a 14 year baseline of monthly data on trimethoprim resistance and consumption. A three-parameter mathematical model was used to analyse the intervention effect. The prerequisites for reversion of resistance (i.e. fitness cost, associated resistance and clonal composition) were studied on subsets of consecutively collected Escherichia coli from urinary tract infections.

The use of trimethoprim-containing drugs decreased by 85% during the intervention. A marginal but statistically significant effect on the increase in trimethoprim resistance was registered. There was no change in the clonal composition of E. coli and there was no measurable fitness cost associated with trimethoprim resistance in clinical isolates. The frequency of associated antibiotic resistances in trimethoprim-resistant isolates was high.

A lack of detectable fitness cost of trimethoprim resistance in vitro together with a strong co-selection of other antibiotics could explain the rather disappointing effect of the intervention. The result emphasizes the low possibility of reverting antibiotic resistance once established and the urgent need for the development of new antibacterial agents.

The protease inhibitors lopinavir and atazanavir are both recommended for treatment of HIV-infected patients. Considerable inter-individual variability in plasma concentration has been observed for both drugs. The aim of this study was to evaluate which demographic factors and concomitant drugs are associated with lopinavir and atazanavir plasma concentration.

Data from the Liverpool TDM (therapeutic drug monitoring) Registry were linked with the UK Collaborative HIV Cohort (CHIC) study. For each patient, the first measurement of lopinavir (twice daily) or atazanavir [once daily, ritonavir boosted (/r) or unboosted] plasma concentration was included. Linear regression was used to evaluate the association of dose, gender, age, weight, ethnicity and concomitant antiretroviral drugs or rifabutin with log-transformed drug concentration, adjusted for time since last intake.

Data from 439 patients on lopinavir (69% 400 mg/r, 31% 533 mg/r; 3% concomitant rifabutin) and 313 on atazanavir (60% 300 mg/r, 32% 400 mg/r, 8% 400 mg) were included. Multivariable models revealed the following predictors for lopinavir concentration: weight (11% decrease per additional 10 kg; P = 0.001); dose (25% increase for 533 mg/r; P = 0.024); and rifabutin (116% increase; P < 0.001). For atazanavir the predictors were dose (compared with 300 mg/r: 40% increase for 400 mg/r, 67% decrease for 400 mg; overall P < 0.001) and efavirenz (32% decrease; P = 0.016) but not tenofovir (P = 0.54).

This analysis confirms that efavirenz decreases atazanavir concentrations, and there was a negative association of weight and lopinavir concentrations. The strong impact of rifabutin on lopinavir concentration should be studied further.

To analyse the oxidative and nitrosative stress response in Candida albicans generated by fluconazole at subinhibitory concentrations, and the functional consequences of such a response for the interaction with phagocytic cells.

The C. albicans CAI-4 strain carrying transcriptional fusions of the TRR1p, YHB1p and GRE2p genes to the Renilla reniformis luciferase LUC gene was pre-treated with subinhibitory concentrations of fluconazole and incubated with oxidants (diamide and hydrogen peroxide) or with the myelomonocytic cell line HL-60.

Fluconazole induced oxidative and nitrosative stress in a time- and dose-dependent manner as determined using oxidative- and nitrosative-specific gene reporters. At subinhibitory concentrations, fluconazole was able to induce protection in vitro to subsequent challenges with oxidants in both liquid and solid media, and also induced partial protection against the oxidative-mediated killing mechanisms of the myelocytic HL-60 cells.

Subinhibitory concentrations of fluconazole protect against oxidants and killing mediated by phagocytes.

The emergence of oseltamivir-resistant viruses raised the global threat with regard to influenza virus infection. To develop alternative antiviral agents against influenza virus infection is significant and urgent.

A neutralization test was applied as a screening assay and a plaque reduction assay was used for confirmation. Expression plasmids for viral ribonucleoproteins (RNPs) and a plasmid that allowed expression of a pseudoviral reporter RNA were transfected into cells to investigate the effects of a novel antiviral compound on viral RNA synthesis.

BPR2-D2 was identified as a novel inhibitor against influenza virus from a hit obtained from high throughput screening of 20 000 or more compounds. BPR2-D2 exhibited an excellent antiviral efficacy for the oseltamivir-resistant virus (EC₅₀ ranging from 0.021 to 0.040 µM). No resistant virus was produced throughout 20 passages in the presence of BPR2-D2, whereas oseltamivir-resistant virus was generated at passage 8 using the same experimental system. A molecular target other than neuraminidase (NA) was found because BPR2-D2 inhibited the synthesis of viral RNA that was driven by influenza viral RNP in a transfection assay. BPR2-D2 also exhibited a broad antiviral spectrum against various strains of influenza A and influenza B viruses.

BPR2-D2 was identified as a novel inhibitor of influenza virus. It may target viral RNPs that are responsible for viral RNA synthesis. Targeting different molecules compared with NA allows BPR2-D2 to inhibit oseltamivir-resistant viruses.

Slow-growing and non-dividing bacteria exhibit tolerance to many antibiotics. However, membrane-active agents may act against bacteria in all growth phases. We sought to examine whether the novel porphyrin antibacterial agents XF-70 and XF-73, which have rapid membrane-perturbing activity against Staphylococcus aureus, retained antistaphylococcal activity against growth-attenuated cells.

The killing kinetics of XF-70, XF-73 and various comparator agents against exponential phase cultures of S. aureus SH1000 were compared with effects on cells held at 4°C, non-growing cultures expressing the stringent response induced by mupirocin and bacteria in the stationary phase. Biofilms of S. aureus SH1000 were generated with the Calgary device to examine the activities of XF-70 and XF-73 under a further system exhibiting diminished bacterial growth.

Cold culture, stringent response and stationary phase cultures remained susceptible to XF-70 and XF-73, which caused ≥5 log reductions in viability over 2 h. During this period the most active comparator agents (chlorhexidine and cetyltrimethylammonium bromide) only promoted a 3 log drop in viability. XF-70 and XF-73 were also highly active against biofilms, with both agents exhibiting low biofilm MICs (1 mg/L) and minimum biofilm eradication concentrations (2 mg/L).

XF-70 and XF-73 remained highly active against various forms of slow-growing or non-dividing S. aureus. The results support the hypothesis that membrane-active agents may be particularly effective in eradicating slow- or non-growing bacteria and suggest that XF-70 and XF-73 could be utilized to treat staphylococcal infections where the organisms are only dividing slowly, such as biofilm-associated infections of prosthetic devices.

To further understand the mechanism of intermediate-level glycopeptide resistance, resulting from multiple endogenous mutations, in both laboratory-derived and clinically isolated Staphylococcus aureus.

Laboratory-derived S. aureus strains were generated under selection using a variety of cell-wall-active antibiotics. Complete sequences of 27 genes, including 17 two-component histidine kinase sensors, were then compared with those of their susceptible parent strain. Further genetic analysis was performed on 125 clinical S. aureus isolates and 42 geographically diverse isolates of vancomycin-intermediate S. aureus (VISA).

Selective pressure using imipenem resulted in single point mutations leading to amino acid substitutions in two genes: vraS, encoding a two-component histidine kinase sensor; and SA1702 (also called yvqF, located immediately upstream of vraS), encoding a conserved hypothetical protein. The accumulation of the mutation in two distinct proteins—MsrR, a peptide methionine sulphoxide reductase regulator, and TcaA, a teicoplanin-resistance-associated protein—correlated with further increases in the glycopeptide MIC. The prevalence of YvqF/VraSR mutants among 125 clinical isolates along with the corresponding teicoplanin MICs was as follows: 0% (0/39), ≤1 mg/L; 48.6% (17/35), 2 mg/L; 72.7% (24/33), 4 mg/L; 93.8% (15/16), 8 mg/L; and 100% (2/2), 16 mg/L. Genetic analysis of 42 VISA isolates also identified the predominant amino acid substitutions in YvqF/VraS: 9 isolates (21.4%) revealed mutations in YvqF, followed by 7 isolates with mutations in VraS (16.7%).

Our findings provide novel insights into the high prevalence and genetic diversity of YvqF/VraSR mutants among clinical S. aureus isolates with reduced susceptibility to teicoplanin.