Journal of Antimicrobial Chemotherapy最新文献

Background: Weight gain is common after antiretroviral initiation, especially among females, those of black race and lower baseline CD4, although this may potentially be due to lower baseline weight. Use of tenofovir disoproxil fumarate or efavirenz can suppress weight gain.

Methods: Data were pooled from the ADVANCE (n = 1053), NAMSAL (n = 613) and WHRI001 (n = 536) trials investigating first-line regimen. Week 96 weight and body mass index (BMI) was stratified by baseline CD4. Multivariable models of weight change and incident obesity (BMI ≥30 kg/m2) were adjusted for baseline CD4, age, sex, tenofovir disoproxil fumarate, efavirenz, baseline BMI and trial.

Results: Participants across all treatment arms experienced weight gain from baseline to week 96, with baseline CD4 count, baseline HIV RNA, tenofovir alafenamide and dolutegravir use, and female sex significant predictors. Mean unadjusted weight change was highest with CD4 < 100 (+8.6 kg; SD = 8.2) and lowest with CD4 ≥ 350 (+3.0 kg; SD = 6.5). This weight gain in CD4 < 100 was highest for participants on tenofovir alafenamide-inclusive treatment, such that absolute weight at week 96 was highest in the CD4 < 100 group. Although not statistically significant, obesity rate (BMI ≥ 30 kg/m2) in those taking TAF/FTC + DTG with CD4 < 100 overtook that seen in CD4 ≥ 350, despite lower baseline obesity prevalence. The unadjusted findings were corroborated in multivariable longitudinal models.

Conclusions: Participants with low CD4 may demonstrate significant 'overshoot' weight gain, in addition to 'return to health', with a trend towards increased risk of obesity when initiated on TAF/FTC + DTG. Use of tenofovir disoproxil fumarate and efavirenz were associated with smaller weight gains. Effective weight management strategies are needed, especially for individuals with low baseline CD4.

Background: Antimicrobial resistance is driven by inappropriate antimicrobial prescribing. The National Antimicrobial Prescribing Survey (NAPS) is an Australian-developed auditing platform to assist in the assessments of antimicrobial quality by antimicrobial stewardship programmes using consensus-based definitions. The NAPS has demonstrated to be transferable to other countries. Its adaptation to Portugal could improve knowledge about the quality of antimicrobial prescribing in the country.

Objectives: To translate, culturally adapt, and validate the Australian Hospital NAPS appropriateness assessment definitions of antimicrobial prescribing for Portugal.

Methods: International recommendations on translation and adaptation of instruments were followed. Two panels of experts participated in the process, using Zoom® for discussions and interviews, and Google Forms® for assessing vignettes. A native English-speaking person proficient in Portuguese conducted the back-translation. SPSS v.28 and Excel® were used for validity calculation.

Results: The Portuguese version was well accepted, its implementation being perceived as desirable and feasible by the experts. Validation process showed a Fleiss' κ score of 0.483 (95% CI, 0.415-0.551, P < 0.005) for appropriateness, and an average agreement with the Australian NAPS team of 0.8 and 0.9, respectively, for appropriateness and reasons for inappropriateness.

Conclusions: The Portuguese version of the Australian Hospital NAPS appropriateness assessment definitions of antimicrobial prescribing, the first to be translated from English, was deemed non-inferior to the original, was well accepted, considered to be desirable and feasible, and could inspire other countries, particularly other Portuguese-speaking countries, to adapt and validate them in their own contexts, reinforcing the possibility of transferring NAPS use beyond Australia.

Background: Clostridioides difficile infection (CDI), a leading cause of nosocomial deaths, is a microbiota-mediated disease. As such, the use of broader spectrum antibiotics, such as vancomycin and metronidazole, can prime the gastrointestinal tract to become more prone to CDI recurrences. Fidaxomicin, a narrow-spectrum antibiotic, has been demonstrated to be superior in preventing recurrence and in preserving the intestinal microbiota; however, widespread employment worldwide has been hindered due to high acquisition costs.

Objectives: To integrate the currently available guidelines on the management of CDI and to shed light on the timeliest employment of fidaxomicin.

Methods: An expert panel was gathered to obtain consensus using Delphi methodology on a series of statements regarding the management of CDI and on appropriate antibiotic use.

Results: Consensus was reached on 21 of the 25 statements addressing the management of CDI.

Conclusions: Delphi methodology was used to achieve consensus on the management of CDI, on the identification of patients at risk of recurrences or severe infection, and on the most appropriate use of fidaxomicin, with the final aim of fostering clinical practice application of treatment algorithms proposed by previous guidelines, in absolute synergy. It could be an important tool to promote more appropriate and cost-effective CDI treatments in European settings with limited resources, like Italy.

Background: To clarify whether next-generation sequencing (NGS) can be useful for resistance assessment in virologically suppressed highly treatment-experienced (HTE) individuals with MDR HIV.

Methods: Ninety-one participants from the PRESTIGIO Registry were included. NGS was performed on HIV-DNA at 1%, 5% and 20% cut-offs; major drug resistance mutations (DRMs) were evaluated and compared with those detected in historical plasma genotypic resistance testing (h-GRT). APOBEC editing was also characterized.

Results: Participants had a complex and long treatment history [median 23 (IQR 21-25) years of ART exposure) and had been virologically suppressed since a median of 3 (IQR 2-5) years. Among all major DRMs detected by HIV-DNA NGS and/or h-GRT, 30% were exclusively found through NGS. The highest detection rate of historical major DRMs was reached with NGS set at 1%, but unusual substitutions and extensive APOBEC hypermutations suggest technical issues and poor clinical relevance in the 1%-5% interval. At NGS set at 5%, 67.2% of historical major DRMs were detected. The number of major DRMs detected exclusively by DNA-NGS as minority variants (frequency 5%-20%) was significantly higher in individuals who later experienced virological rebound compared with those who maintained virological control [median 2 (IQR 1-3) versus 1 (0-2), P = 0.030] and positively correlated with viraemia levels at rebound (rho = 0.474, P = 0.030).

Conclusions: In non-viraemic people with an MDR virus, HIV-1 DNA NGS set at 5% is an acceptable technical cut-off that might help to reveal mutations with a potential clinical relevance. Moreover, the number of minority resistance mutations additionally detected by NGS might be associated with loss of virological control.

Background: Transmitted drug resistance (TDR) is still a critical aspect for the management of individuals living with HIV-1. Thus, its evaluation is crucial to optimize HIV care.

Methods: Overall, 2386 HIV-1 protease/reverse transcriptase and 1831 integrase sequences from drug-naïve individuals diagnosed in north and central Italy between 2015 and 2021 were analysed. TDR was evaluated over time. Phylogeny was generated by maximum likelihood. Factors associated with TDR were evaluated by logistic regression.

Results: Individuals were mainly male (79.1%) and Italian (56.2%), with a median (IQR) age of 38 (30-48). Non-B infected individuals accounted for 44.6% (N = 1065) of the overall population and increased over time (2015-2021, from 42.1% to 51.0%, P = 0.002). TDR prevalence to any class was 8.0% (B subtype 9.5% versus non-B subtypes 6.1%, P = 0.002) and remained almost constant over time. Overall, 300 transmission clusters (TCs) involving 1155 (48.4%) individuals were identified, with a similar proportion in B and non-infected individuals (49.7% versus 46.8%, P = 0.148). A similar prevalence of TDR among individuals in TCs and those out of TCs was found (8.2% versus 7.8%, P = 0.707).By multivariable analysis, subtypes A, F, and CFR02_AG were negatively associated with TDR. No other factors, including being part of TCs, were significantly associated with TDR.

Conclusions: Between 2015 and 2021, TDR prevalence in Italy was 8% and remained almost stable over time. Resistant strains were found circulating regardless of being in TCs, but less likely in non-B subtypes. These results highlight the importance of a continuous surveillance of newly diagnosed individuals for evidence of TDR to inform clinical practice.

Objectives: Escherichia coli can cause infections in the urinary tract and in normally sterile body sites leading to invasive E. coli disease (IED), including bacteraemia and sepsis, with older populations at increased risk. We aimed to estimate the theoretical coverage rate by the ExPEC4V and 9V vaccine candidates. In addition, we aimed at better understanding the diversity of E. coli isolates, including their genetic and phenotypic antimicrobial resistance (AMR), sequence types (STs), O-serotypes and the bacterial population structure.

Methods: Blood and urine culture E. coli isolates (n = 304) were collected from hospitalized patients ≥60 years (n = 238) with IED during a multicentric, observational study across three continents. All isolates were tested for antimicrobial susceptibility, O-serotyped, whole-genome sequenced and bioinformatically analysed.

Results: A large diversity of STs and of O-serotypes were identified across all centres, with O25b-ST131, O6-ST73 and O1-ST95 being the most prevalent types. A total of 45.4% and 64.7% of all isolates were found to have an O-serotype covered by the ExPEC4V and ExPEC9V vaccine candidates, respectively. The overall frequency of MDR was 37.4% and ST131 was predominant among MDR isolates. Low in-patient genetic variability was observed in cases where multiple isolates were collected from the same patient.

Conclusions: Our results highlight the predominance of MDR O25b-ST131 E. coli isolates across diverse geographic areas. These findings provide further baseline data on the theoretical coverage of novel vaccines targeting E. coli associated with IED in older adults and their associated AMR levels.

The similarity of current definitions of 'cross-resistance' and 'co-resistance' continues to cause confusion both in the scientific community as well as in understanding policies and in particular when looking at resistance from a risk assessment perspective. Further, lack of harmonized definitions of these terms in the regulatory space is challenging for interpretation. The purpose of this article is to: (i) provide an overview of the ambiguity in existing terminology related to cross-resistance, co-resistance and co-selection; (ii) emphasize the challenges created by the use of poor terminology in research and scientific literature; and (iii) propose a clear set of harmonized definitions that could be put into use through international regulatory agencies and institutions, such as the World Health Organization, Food and Drug Administration, European Medicines Agency, Center for Disease Control, Committee for Veterinary Medicinal Products, World Organization for Animal Health/Office International des Epizooties and the Food and Agriculture Organization of the United Nations.

Objectives: This study aimed to explore the prevalence of macrolide resistance and the underlying resistance mechanisms in Haemophilus influenzae (n = 2556) and Haemophilus parainfluenzae (n = 510) collected between 2018 and 2021 from Bellvitge University Hospital, Spain.

Methods: Antimicrobial susceptibility was tested by microdilution. Whole-genome sequencing was performed using Illumina MiSeq and Oxford Nanopore technologies, and sequences were examined for macrolide resistance determinants and mobile genetic structures.

Results: Macrolide resistance was detected in 67 H. influenzae (2.6%) and 52 (10.2%) H. parainfluenzae strains and associated with resistance to other antimicrobials (co-trimoxazole, chloramphenicol, tetracycline). Differences in macrolide resistance existed between the two species. Acquired resistance genes were more prevalent in H. parainfluenzae (35/52; 67.3%) than in H. influenzae (12/67; 17.9%). Gene mutations and amino acid substitutions were more common in H. influenzae (57/67; 85%) than in H. parainfluenzae (16/52; 30.8%). Substitutions in L22 and in 23S rRNA were only detected in H. influenzae (34.3% and 29.0%, respectively), while substitutions in L4 and AcrAB/AcrR were observed in both species. The MEGA element was identified in 35 (67.3%) H. parainfluenzae strains, five located in an integrative and conjugative element (ICE); by contrast, 11 (16.4%) H. influenzae strains contained the MEGA element (all in an ICE). A new ICEHpaHUB8 was described in H. parainfluenzae.

Conclusions: Macrolide resistance was higher in H. parainfluenzae than in H. influenzae, with differences in the underlying mechanisms. H. parainfluenzae exhibits co-resistance to other antimicrobials, often leading to an extensively drug-resistant phenotype. This highlights the importance of conducting antimicrobial resistance surveillance.

Background: With the increasing prevalence of antibiotic resistance, real-world data on the optimal empirical second-line therapy for Helicobacter pylori are still limited.

Objectives: To evaluate the real-world efficacy of various second-line therapies for H. pylori.

Patients and methods: This was a retrospective population-based cohort study of all H. pylori-infected patients who had received the second-line treatment after the failure of primary clarithromycin triple therapy in Hong Kong between 2003 and 2018. The retreatment success rates of different second-line therapies were evaluated.

Results: A total of 7591 patients who received second-line treatment were included. Notably, the most commonly prescribed regimen was still clarithromycin triple therapy, but the frequency of use had decreased from 59.5% in 2003-06 to 28.7% in 2015-18. Concomitant non-bismuth quadruple therapy had emerged as the commonest regimen (from 3.3% to 43.9%). In a validation analysis, the sensitivity and specificity of retreatment-inferred second-line treatment failure were 88.3% and 97.1%, respectively. The overall success rate of second-line therapies was 73.6%. Bismuth quadruple therapy had the highest success rate of 85.6%, while clarithromycin triple therapy had the lowest success rate of 63.5%. Specifically, bismuth/metronidazole/tetracycline quadruple, metronidazole/tetracycline triple, levofloxacin/metronidazole/tetracycline quadruple, rifabutin/amoxicillin triple and amoxicillin/levofloxacin triple therapies had relatively higher success rates over 80%. Age, treatment duration, baseline conditions and first-line treatment used were associated with success rate.

Conclusions: Bismuth quadruple therapy was the most effective second-line regimen for H. pylori in this real-world study. Despite a very low success rate, clarithromycin-containing triple therapies were still commonly used as second-line regimens.