Development and validation of the Sinonasal Endoscopic Score (SiNES) for chronic rhinosinusitis

BACKGROUND

Although there are several endoscopic grading systems for chronic rhinosinusitis (CRS), they are limited in their range and applicability. We developed a SiNonasal Endoscopic Score (SiNES) that builds upon the strengths of previous systems while addressing their limitations.

METHODS

The SiNES system was developed by consensus after multiple rounds of guided discussions. Face, content, and convergent validity were investigated. It was validated using an independent sample of 79 CRS individuals from two referral centres from September 2021 to February 2022. Each patient underwent a sinonasal endoscopy and filled PROM questionnaires. Three independent rhinologists graded endoscopic videos using the SiNES and modified Lund-Kennedy (MLK) scores. Inter-rater and test-retest reliability were assessed via the intraclass correlation coefficient (ICC). SiNES and MLK scores were correlated with PROMs using a Spearman correlation and canonical correlation analysis (CCA).

RESULTS

The SiNES system evaluates five anatomical spaces regarding edema, discharge, and scarring. Face, content, and convergent validity were deemed satisfactory by the study authors and an independent panel of Otolaryngologists. Inter-rater reliability was excellent for the SiNES and good for the MLK score. Test-retest reliability was excellent for both systems. Total SiNES was correlated with self-reported smell loss.

CONCLUSIONS

The SiNES system is an accurate and reliable grading framework applicable to all CRS subtypes. It can be utilized in clinical and research settings and improves upon previously published systems.

Horizontal flow aerated constructed wetlands for municipal wastewater treatment: The influence of bed depth

The influence of bed depth on the performance of aerated horizontal constructed wetlands was investigated at the pilot plant scale. Two horizontal flow subsurface constructed wetlands (HF) intensified units of different bed depth (HF1: 0.90 m and HF2: 0.55 m, 0.8 m and 0.5 m water level, respectively) were fitted with forced aeration, while a third one (HFc, 0.55 m bed depth, 0.5 m water level) was used as control and not aerated. The three HF units were operated in parallel, receiving the same municipal wastewater pre-treated in a hydrolytic up-flow sludge blanket anaerobic digester. Applied surface loading rates (SLR) ranged from 20 to 80 g biochemical oxygen demand (BOD5)/m2·d and from 3.7 to 6.7 g total nitrogen (TN)/m2·d, while it ranges from 6 to 23 g BOD5/m2·d and from 1.1 to 1.7 g TN/m2·d in the control unit. Removal of total suspended solids (TSS) and BOD5 was usually close to a 100 % in all units, whilst chemical oxygen demand (COD) removal was higher for the HF1 unit (97 % on average, range of 96-99 %) than for HF2 (92 %, 82-98 %) and HFc (94 %, 86-99 %). TN removal reached on average 33 % (16-43 %) in HFc, 37 % (10-76 %) in HF2 and 51 % (21-79 %) in HF1. High TN removal required a longer aeration time for nitrification and higher effluent recirculation ratio to enhance denitrification. The results indicate that artificial aeration and a high bed depth allows to increase the SLR by a factor of 4 in HF1 but only by a factor of 2 in HF2.

Knockdown of double-stranded RNases (dsRNases) enhances oral RNA interference (RNAi) in the corn leafhopper, Dalbulus maidis

The leafhopper Dalbulus maidis is a harmful pest that causes severe damage to corn crops. Conventional chemical pesticides have negative environmental impacts, emphasizing the need for alternative solutions. RNA interference (RNAi) is a more specific and environmentally friendly method for controlling pests and reducing the negative impacts of current pest management practices. Previous studies have shown that orally administered double-stranded RNA (dsRNA) is less effective than injection protocols in silencing genes. This study focuses on identifying and understanding the role of double-stranded ribonucleases (dsRNases) in limiting the efficiency of oral RNAi in D. maidis. Three dsRNases were identified and characterized, with Dmai-dsRNase-2 being highly expressed in the midgut and salivary glands. An ex vivo degradation assay revealed significant nuclease activity, resulting in high instability of dsRNA when exposed to tissue homogenates. Silencing Dmai-dsRNase-2 improved the insects' response to the dsRNA targeting the gene of interest, providing evidence of dsRNases involvement in oral RNAi efficiency. Therefore, administering both dsRNase-specific and target gene-specific-dsRNAs simultaneously is a promising approach to increase the efficiency of oral RNAi and should be considered in future control strategies.

Association between smoking and peri-implant diseases: A retrospective study

OBJECTIVES

To determine the association between tobacco and peri-implant diseases in a sample of patients who had received implant-supported restorations in a university dental clinic. Furthermore, the study aimed to investigate patient- and implant-related variables associated with peri-implant diseases.

MATERIALS AND METHODS

The present retrospective study analyzed data from 117 patients treated with implant-supported restorations from 2001 to 2013. A total of 450 implants were evaluated. Patients were selected from an electronic database, and patient- and implant-related variables were evaluated. Detailed information regarding the smoking history (i.e., smoking status, lifetime cumulative dose, duration of exposure, intensity of the habit, and smoking cessation) was recorded. The primary study outcome was peri-implant status [i.e., health (H), peri-implant mucositis (PM) and peri-implantitis (PI)]. Univariate and multinomial regression models comparing PM and PI versus peri-implant health were conducted.

RESULTS

A total of 117 subjects [55 (47%) females and 62 (53%) males] with a mean age at examination of 64.2 years (SD 11.6) and rehabilitated with 450 implants were included. The average number of implants per patient was 4.6 (SD 3.3) with a mean time in function of 8.0 years (SD 1.9). Fifty-six patients (47.9%) were non-smokers, 42 (35.9%) were former-smokers, and 19 (16.2%) were current-smokers. Thirty-nine subjects (33.4%) were H, whereas 41 (35%) and 37 (31.6%) exhibited PM and PI, respectively. At implant level, the corresponding values were 142 (31.6%), 230 (51.1%) and 78 (17.3%). In the multinomial regression model, significant associations for peri-implant diseases were observed for the mean number of implants per patient (p = .016), function time (p = .048), implants placed simultaneously with guided bone regeneration (p = .016), implant surface (p = .020), keratinized mucosa at the buccal aspect (p = .032), and access to interproximal hygiene (p < .001). In addition, ever smokers >23 pack-years exhibited a significantly higher risk for peri-implantitis (p = .002). Finally, the multinomial regression analysis revealed that subjects who had stopped smoking more than 21 years before the last examination presented a significantly lower risk of peri-implant diseases than a smoking cessation of ≤21 years (p = .028).

CONCLUSIONS

Smoke intensity was associated with an increased risk of the development of peri-implantitis. Moreover, the risk of peri-implant diseases might be similar in those subjects who had stopped smoking for more than 21 years with respect to never-smokers.

Use of Postoperative PET/CT in Altering Management in Adjuvant Head and Neck Radiation Therapy

PURPOSE/OBJECTIVE(S)

Routine clinical practice does not include postoperative positron emission tomography (PET)/CT prior to postoperative radiation therapy (PORT) for head and neck cancer. Besides logistical challenges in obtaining postoperative PET/CT within six weeks after surgery, interpreting PET/CT findings in the postoperative setting can also be difficult. However, given the potential for residual or rapidly recurrent disease, postoperative PET/CT may help identify the need for additional diagnostic evaluation or alter adjuvant therapy. There are limited data evaluating the utility of postoperative PET/CT prior to PORT for head and neck cancer. We sought to evaluate the use and clinical relevance of postoperative PET/CT prior to PORT.

MATERIALS/METHODS

In this retrospective, single-institution cohort study, we identified patients with head and neck cancer between 2013 and 2020 who received a postoperative PET/CT prior to PORT. We extracted electronic medical record data supplemented with manual chart review to collect patient and disease-related information. We measured the rates of additional diagnostic workup and treatment alterations as a result of postoperative PET/CT findings.

RESULTS

The cohort included 29 patients who received a postoperative PET/CT prior to PORT. The mean age at diagnosis was 60.8 years (standard deviation: 15.0 years) and 20 (69.0%) were male. Regarding primary site, 10 (34.5%) were oropharynx, 7 (24.1%) were salivary gland, and 6 (20.7%) were oral cavity. The mean time from surgery to postoperative PET was 40.9 days (standard deviation: 27.7 days), and the mean time from postoperative PET/CT to start of PORT was 22.4 days (standard deviation: 20.3 days). A total of 9 (31.0%) patients experienced a change in management as a result of the PET/CT findings. Six (66.7%) patients received a biopsy. All 9 patients had a change in their radiation treatment plan, either dose escalation, target change, or in one case, converting to palliative dosing. Six (66.7%) patients were recommended addition of chemotherapy as a result of additional workup, with 4 (44.4%) of those patients ultimately receiving chemotherapy. Three (33.3%) patients underwent re-resection prior to PORT.

CONCLUSION

In patients with head and neck cancer who received postoperative PET/CT prior to PORT, a meaningful proportion underwent additional diagnostic evaluation and/or experienced an alteration in adjuvant therapy as a result of the imaging findings. Interestingly, all patients with abnormal postoperative PET findings had changes in their radiation treatment plan, including at least boosting gross disease for patients in whom re-resection or chemotherapy was not pursued. Future work will seek to expand this cohort through 2022 when postoperative PET/CT became more routine at our institution and include oncologic outcomes. Additional studies are needed to identify appropriate candidates for postoperative PET/CT and determine the clinical impact of postoperative PET/CT.

In Vitro Activity of Cefiderocol Compared to Other Antimicrobials against a Collection of Metallo-Beta-Lactamase-Producing Gram-Negative Bacilli from Southern Spain

In this study, we aimed to comparatively evaluate the in vitro activity of cefiderocol versus other antimicrobials against a well-characterized collection of metallo-beta-lactamase (MBL)-producing Gram-negative bacilli (MBL-GNB) isolates from hospitals in Andalusia, Spain. We recovered 232 MBL-GNB from Andalusian hospitals, including 160 Enterobacterales and 72 nonfermenting Gram-negative bacilli belonging to 44 different clones (2015 to 2020). Cefiderocol and comparator MICs were determined with commercial methods (UMIC [Bruker] and EUMDROXF [Sensititre; Thermo Fisher], respectively). EUCAST breakpoints were used for all antimicrobials tested, and CLSI also was used for cefiderocol. Control strains used were E. coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. Cefiderocol showed potent in vitro activity against isolates tested, regardless of breakpoint (susceptibility rates, 85.3% for EUCAST versus 96.6% for CLSI, P < 0.001). MIC ranges for Enterobacterales and nonfermenting Gram-negative bacilli (NF-GNB) were ≤0.03 to 1 mg/L and 0.06 to 2 (IMP), 0.06 to 8 mg/L and 0.06 to 16 (VIM), 0.25 to 16 mg/L and 2 to 16 mg/L (NDM), respectively, and 0.25 to 8 mg/L for double MBL-producing Enterobacterales. By species, all cefiderocol-susceptible rates were over 90%, except Klebsiella oxytoca, Enterobacter cloacae, Escherichia coli, and Acinetobacter spp. Significant differences were observed comparing resistant isolates between Enterobacterales and NF-GNB by EUCAST (19.4% versus 4.2%, P < 0.01), but not by CLSI (4.4% versus 1.4%, P = 0.2). Cefiderocol was the most active antimicrobial tested. Cefiderocol showed excellent in vitro activity against MBL-GNB, especially NF-GNB; almost all isolates resistant to comparators were susceptible. IMPORTANCE This article demonstrates the efficacy of cefiderocol against a large collection of well-characterized metallo-beta-lactamase-producing isolates, some of them even producing double carbapenemases. Furthermore, cefiderocol activity is compared to other novel broad-spectrum antimicrobials with activity against carbapenemases.

Synergistic Effect of SOS Response and GATC Methylome Suppression on Antibiotic Stress Survival in Escherichia coli

The suppression of the SOS response has been shown to enhance the in vitro activity of quinolones. Furthermore, Dam-dependent base methylation has an impact on susceptibility to other antimicrobials affecting DNA synthesis. Here, we investigated the interplay between these two processes, alone and in combination, in terms of antimicrobial activity. A genetic strategy was used employing single- and double-gene mutants for the SOS response (recA gene) and the Dam methylation system (dam gene) in isogenic models of Escherichia coli both susceptible and resistant to quinolones. Regarding the bacteriostatic activity of quinolones, a synergistic sensitization effect was observed when the Dam methylation system and the recA gene were suppressed. In terms of growth, after 24 h in the presence of quinolones, the Δdam ΔrecA double mutant showed no growth or delayed growth compared to the control strain. In bactericidal terms, spot tests showed that the Δdam ΔrecA double mutant was more sensitive than the ΔrecA single mutant (about 10- to 102-fold) and the wild type (about 103- to 104-fold) in both susceptible and resistant genetic backgrounds. Differences between the wild type and the Δdam ΔrecA double mutant were confirmed by time-kill assays. The suppression of both systems, in a strain with chromosomal mechanisms of quinolone resistance, prevents the evolution of resistance. This genetic and microbiological approach demonstrated the enhanced sensitization of E. coli to quinolones by dual targeting of the recA (SOS response) and Dam methylation system genes, even in a resistant strain model.

Factors affecting space use by laying hens in a cage-free aviary system: effect of nest lighting at pullet housing and of curtain nest color during laying

At 17 wk of age, 1,800 Lohman brown hens were housed in 8 pens of an experimental aviary system, specifically set up for the purposes of the present study, and kept until 26 wk without or with nest lighting (lights inside the nest 1.5 h before the lighting of the installation) for training in the nest use. Then, at 27 wk, 4 combinations of nest curtains were adopted to evaluate the effects on hens' distribution, that is, nests with red (RR) or yellow (YY) curtains at all tiers; nests with red and yellow curtains at the first and second tier, respectively (RY); or nests with yellow and red curtains at the first and second tier, respectively (YR). The use of enlightened compared to dark nests at housing increased the oviposition rate (P < 0.001) and decreased the rate of broken (P < 0.001) and dirty eggs (P < 0.05) from 27 to 45 wk, while increasing the rate of eggs laid inside the nests (P < 0.001). The presence of yellow nest curtains increased the rate of hens on the floor in pens YY and YR compared to pens RR and RY (35.3 and 35.5% vs. 34.1 and 33.3%, respectively; P = 0.05) and the rate of floor eggs in pens YR (2.23% vs. 1.63 and 1.65% in pens RR and RY; P < 0.05). In pens RY, a higher rate of eggs was always found on the second tier compared to the first one with the most inhomogeneous distribution compared to pens RR, YY, and YR (+10.8 vs. +3.4, +1.9, and +4.6 percentage points of eggs laid on the second tier compared to the first one, respectively). In conclusion, nest lighting at housing trained hens to the use of nests while improving egg production in terms of quantity and quality. The use of yellow curtains on nests moved hens between the different levels of the aviary but this was not associated with an increased nest use for laying.

Effect of the dietary supplementation with extracts of chestnut wood and grape pomace on performance and jejunum response in female and male broiler chickens at different ages

BACKGROUND

Recently, interest in the use of herbs and phytogenic compounds has grown because of their potential role in the production and health of livestock animals. Among these compounds, several tannins have been tested in poultry, but those from chestnut wood and grape-industry byproducts have attracted remarkable interest. Thus, the present study aimed to gain further insights into the mechanisms involved in the response to the dietary supplementation with extracts of chestnut wood or grape pomace. To this purpose, 864 broiler chickens were fed a control diet (C) or the same diet supplemented 0.2% chestnut wood (CN) extract or 0.2% grape pomace (GP) extract from hatching until commercial slaughtering (at 45 days of age) to assess their effects on performance, meat quality, jejunum immune response and whole-transcriptome profiling in both sexes at different ages (15 and 35 d).

RESULTS

Final live weight and daily weight gain significantly increased (P < 0.01) in chickens fed GP diets compared to CN and C diets. The villi height was lower in chickens fed the CN diet than in those fed the C diet (P < 0.001); moreover, a lower density of CD45⁺ cells was observed in chickens fed the CN diet (P < 0.05) compared to those fed the C and GP diets. Genes involved in either pro- or anti-inflammatory response pathways, and antimicrobial and antioxidant responses were affected by GP and CN diets. There was no effect of the dietary treatment on meat quality. Regarding sex, in addition to a lower growth performance, females showed a lower occurrence of wooden breast (16.7% vs. 55.6%; P < 0.001) and a higher occurrence of spaghetti meat (48.6% vs. 4.17%; P < 0.001) in pectoralis major muscles after slaughtering than those in males. Based on the results of whole-transcriptome profiling, a significant activation of some molecular pathways related to immunity was observed in males compared with those of females.

CONCLUSIONS

The GP supplementation improved chicken performance and promoted immune responses in the intestinal mucosa; moreover, age and sex were associated with the most relevant transcriptional changes.

Development of efficient RNAi methods in the corn leafhopper Dalbulus maidis, a promising application for pest control

BACKGROUND

The corn leafhopper Dalbulus maidis is the main vector of important stunting pathogens that affect maize production. Currently, there are no effective methods available to manage this pest without adverse impact on the environment. In this context, genomic-based technologies such as RNA interference (RNAi) provide a more environmentally friendly pest control strategy. Therefore, we aimed to assess the application of RNAi in D. maidis and determine the function of a candidate gene related to insect reproduction and propagation.

RESULTS

We have characterized the core RNAi genes and evaluated the functionality of the RNAi machinery. We assessed the potential of RNAi technology in D. maidis via injection or ingestion of double-stranded RNA (dsRNA) to adult females. We chose Bicaudal C (BicC) as a target gene due to its important role during insect oogenesis. Administration of dsRNA^BicC caused significant reductions in the transcript levels (fold changes up to 170 times) and ovipositions. Phenotypic analysis of the ovaries revealed alterations in oocyte development, providing additional confirmation for our results and supporting the idea that Dmai-BicC is a key player of D. maidis oogenesis.

CONCLUSION

This is, to our knowledge, the first report of efficient RNAi in D. maidis. We believe our findings provide a starting point for future control strategies against one of the most important maize pests in the Americas. © 2022 Society of Chemical Industry.

Impedance Spectroscopy as a Tool for the Detection of Occlusal Noncavitated Carious Lesions

A total 302 teeth (148 molars and 154 premolars) corresponding to 152 patients aged ≥18 years were evaluated for caries using the ICDAS (International Caries Detection and Assessment System), fluorescence (DD, DIAGNOdent) and electrical impedance (IMS, CarieScan PRO) systems. Fissurotomy and intraoral radiographs were used as the gold standard. Accordingly, 27.5% (n=84) of the teeth were classified as sound, while 26.9% (n=81) had enamel involvement and 45.6% (n=138) presented carious lesions reaching the dentin. Sensitivity (Se), specificity (Sp), and the area under the curve (AUC) were, respectively, 90.7%, 87.8%, and 0.954 (IMS); 92.4%, 92.7%, and 0.954 (DD); and 79.0%, 72.3%, and 0.756 (ICDAS). With regard to Se and Sp, there were significant differences between ICDAS and DD (p<0.001) and between ICDAS and IMS (p=0.01), but not between IMS and DD (p=0.07). In relation to AUC, there were significant differences between ICDAS and DD (p<0.001), and between ICDAS and IMS (p<0.001), but not between IMS and DD (p>0.05). The correlations between fissurotomy and each method were 88.7% (IMS), 89.7% (DD), and 77.1% (ICDAS). Within the limitations of this study, clinically, the electrical system is not useful for differentiating between sound teeth and truly incipient caries lesions by itself. The fluorescence or electrical systems are recommended with the ICDAS to detect carious lesions in their early stages.

Effect of RecA inactivation and detoxification systems on the evolution of ciprofloxacin resistance in Escherichia coli

Background

Suppression of SOS response and overproduction of reactive oxygen species (ROS) through detoxification system suppression enhance the activity of fluoroquinolones.

Objectives

To evaluate the role of both systems in the evolution of resistance to ciprofloxacin in an isogenic model of Escherichia coli.

Methods

Single-gene deletion mutants of E. coli BW25113 (wild-type) (ΔrecA, ΔkatG, ΔkatE, ΔsodA, ΔsodB), double-gene (ΔrecA-ΔkatG, ΔrecA-ΔkatE, ΔrecA-ΔsodA, ΔrecA-ΔsodB, ΔkatG-ΔkatE, ΔsodB-ΔsodA) and triple-gene (ΔrecA-ΔkatG-ΔkatE) mutants were included. The response to sudden high ciprofloxacin pressure was evaluated by mutant prevention concentration (MPC). The gradual antimicrobial pressure response was evaluated through experimental evolution and antibiotic resistance assays.

Results

For E. coli BW25113 strain, ΔkatE, ΔsodB and ΔsodB/ΔsodA mutants, MPC values were 0.25 mg/L. The ΔkatG, ΔsodA, ΔkatG/katE and ΔrecA mutants showed 2-fold reductions (0.125 mg/L). The ΔkatG/ΔrecA, ΔkatE/ΔrecA, ΔsodA/ΔrecA, ΔsodB/ΔrecA and ΔkatG/ΔkatE/ΔrecA strains showed 4–8-fold reductions (0.03–0.06 mg/L) relative to the wild-type. Gradual antimicrobial pressure increased growth capacity for ΔsodA and ΔsodB and ΔsodB/ΔsodA mutants (no growth in 4 mg/L) compared with the wild-type (no growth in the range of 0.5–2 mg/L). Accordingly, increased growth was observed with the mutants ΔrecA/ΔkatG (no growth in 2 mg/L), ΔrecA/ΔkatE (no growth in 2 mg/L), ΔrecA/ΔsodA (no growth in 0.06 mg/L), ΔrecA/ΔsodB (no growth in 0.25 mg/L) and ΔrecA/ΔkatG/ΔkatE (no growth in 0.5 mg/L) compared with ΔrecA (no growth in the range of 0.002–0.015 mg/L).

Conclusions

After RecA inactivation, gradual exposure to ciprofloxacin reduces the evolution of resistance. After suppression of RecA and detoxification systems, sudden high exposure to ciprofloxacin reduces the evolution of resistance in E. coli.

Role of low-level quinolone resistance in generating tolerance in Escherichia coli under therapeutic concentrations of ciprofloxacin

BACKGROUND

Tolerance (including persistence) and resistance result in increased survival under antibiotic pressure.

OBJECTIVES

We evaluated the interplay between resistance and tolerance to ciprofloxacin under therapeutic and killing conditions to determine the contribution of low-level quinolone resistance (LLQR) mechanisms to tolerance. We also determined how the interaction between resistance (LLQR phenotypes) and tolerance was modified under SOS response suppression.

METHODS

Twelve isogenic Escherichia coli strains harbouring quinolone resistance mechanisms combined with SOS response deficiency and six clinical E. coli isolates (LLQR or non-LLQR) were evaluated. Survival (tolerance or persistence) assays were used to measure surviving bacteria after a short period (up to 4 h) of bactericidal antibiotic treatment under therapeutic and killing concentrations of ciprofloxacin [1 mg/L, EUCAST/CLSI breakpoint for resistance; and 2.5 mg/L, peak serum concentration (Cmax) of this drug].

RESULTS

QRDR substitutions (S83L in GyrA alone or combined with S80R in ParC) significantly increased the fraction of tolerant bacteria (2-4 log10 cfu/mL) after exposure to ciprofloxacin at clinically relevant concentrations. The impact on tolerant bacteria due to SOS response suppression (including persistence mediated by the tisB gene) was reversed by LLQR mechanisms at therapeutic concentrations. Furthermore, no reduction in the fraction of tolerant bacteria due to SOS response suppression was observed when S83L in GyrA plus S80R in ParC were combined.

CONCLUSIONS

Tolerance and quinolone resistance mutations interact synergistically, giving LLQR mechanisms an additional role in allowing bacterial survival and evasion of therapeutic antimicrobial conditions by a combination of the two strategies. At clinically relevant concentrations, LLQR mechanisms reverse further impact of SOS response suppression in reducing bacterial tolerance.

Bicaudal C is required for the function of the follicular epithelium during oogenesis in Rhodnius prolixus

The morphology and physiology of the oogenesis have been well studied in the vector of Chagas disease Rhodnius prolixus. However, the molecular interactions that regulate the process of egg formation, key for the reproductive cycle of the vector, is still largely unknown. In order to understand the molecular and cellular basis of the oogenesis, we examined the function of the gene Bicaudal C (BicC) during oogenesis and early development of R. prolixus. We show that R. prolixus BicC (Rp-BicC) gene is expressed in the germarium, with cytoplasmic distribution, as well as in the follicular epithelium of the developing oocytes. RNAi silencing of Rp-BicC resulted in sterile females that lay few, small, non-viable eggs. The ovaries are reduced in size and show a disarray of the follicular epithelium. This indicates that Rp-BicC has a central role in the regulation of oogenesis. Although the follicular cells are able to form the chorion, the uptake of vitelline by the oocytes is compromised. We show evidence that the polarity of the follicular epithelium and the endocytic pathway, which are crucial for the proper yolk deposition, are affected. This study provides insights into the molecular mechanisms underlying oocyte development and show that Rp-BicC is important for de developmental of the egg and, therefore, a key player in the reproduction of this insect.

Effect of RecA inactivation on quinolone susceptibility and the evolution of resistance in clinical isolates of Escherichia coli

BACKGROUND

SOS response suppression (by RecA inactivation) has been postulated as a therapeutic strategy for potentiating antimicrobials against Enterobacterales.

OBJECTIVES

To evaluate the impact of RecA inactivation on the reversion and evolution of quinolone resistance using a collection of Escherichia coli clinical isolates.

METHODS

Twenty-three E. coli clinical isolates, including isolates belonging to the high-risk clone ST131, were included. SOS response was suppressed by recA inactivation. Susceptibility to fluoroquinolones was determined by broth microdilution, growth curves and killing curves. Evolution of quinolone resistance was evaluated by mutant frequency and mutant prevention concentration (MPC).

RESULTS

RecA inactivation resulted in 2-16-fold reductions in fluoroquinolone MICs and modified EUCAST clinical category for several isolates, including ST131 clone isolates. Growth curves and time-kill curves showed a clear disadvantage (up to 10 log10 cfu/mL after 24 h) for survival in strains with an inactivated SOS system. For recA-deficient mutants, MPC values decreased 4-8-fold, with values below the maximum serum concentration of ciprofloxacin. RecA inactivation led to a decrease in mutant frequency (≥103-fold) compared with isolates with unmodified SOS responses at ciprofloxacin concentrations of 4×MIC and 1 mg/L. These effects were also observed in ST131 clone isolates.

CONCLUSIONS

While RecA inactivation does not reverse existing resistance, it is a promising strategy for increasing the effectiveness of fluoroquinolones against susceptible clinical isolates, including high-risk clone isolates.

Learning latent dynamics for partially observed chaotic systems

This paper addresses the data-driven identification of latent representations of partially observed dynamical systems, i.e., dynamical systems for which some components are never observed, with an emphasis on forecasting applications and long-term asymptotic patterns. Whereas state-of-the-art data-driven approaches rely in general on delay embeddings and linear decompositions of the underlying operators, we introduce a framework based on the data-driven identification of an augmented state-space model using a neural-network-based representation. For a given training dataset, it amounts to jointly reconstructing the latent states and learning an ordinary differential equation representation in this space. Through numerical experiments, we demonstrate the relevance of the proposed framework with respect to state-of-the-art approaches in terms of short-term forecasting errors and long-term behavior. We further discuss how the proposed framework relates to the Koopman operator theory and Takens' embedding theorem.

Effect of dietary supplementation with yeast cell wall extracts on performance and gut response in broiler chickens

Background

The dietary supplementation of yeast cell wall extracts (YCW) has been found to reduce pathogenic bacteria load, promote immunoglobulin production, prevent diseases by pro-inflammatory responses, and alter gut microbiota composition. This study evaluated growth and slaughter results, health, gut morphology, immune status and gut transcriptome of 576 male chickens fed two diets, i.e. C (control) or Y (with 250-500 g/t of YCW fractions according to the growth period). At 21 and 42 d the jejunum of 12 chickens per diet were sampled and stained with hematoxylin/eosin for morphometric evaluation, with Alcian-PAS for goblet cells, and antibodies against CD3+ intraepithelial T-cells and CD45+ intraepithelial leukocytes. The jejunum sampled at 42 d were also used for whole-transcriptome profiling.

Results

Dietary YCW supplementation did not affect final live weight, whereas it decreased feed intake (114 to 111 g/d; P ≤ 0.10) and improved feed conversion (1.74 to 1.70; P ≤ 0.01). Regarding the gut, YCW supplementation tended to increase villi height (P = 0.07); it also increased the number of goblet cells and reduced the density of CD45+ cells compared to diet C (P < 0.001). In the gut transcriptome, four genes were expressed more in broilers fed diet Y compared to diet C, i.e. cytochrome P450, family 2, subfamily C, polypeptide 23b (CYP2C23B), tetratricopeptide repeat domain 9 (TTC9), basic helix-loop-helix family member e41 (BHLHE41), and the metalloreductase STEAP4. Only one gene set (HES_PATHWAY) was significantly enriched among the transcripts more expressed in broilers fed diet Y. However, a total of 41 gene sets were significantly over-represented among genes up-regulated in control broilers. Notably, several enriched gene sets are implicated in immune functions and related to NF-κB signaling, apoptosis, and interferon signals.

Conclusions

The dietary YCW supplementation improved broiler growth performance, increased gut glycoconjugate secretion and reduced the inflammatory status together with differences in the gut transcriptome, which can be considered useful to improve animal welfare and health under the challenging conditions of intensive rearing systems in broiler chickens.

Suppression of the SOS response modifies spatiotemporal evolution, post-antibiotic effect, bacterial fitness and biofilm formation in quinolone-resistant Escherichia coli

Background

Suppression of the SOS response has been proposed as a therapeutic strategy for potentiating quinolones against susceptible, low-level quinolone-resistant (LLQR) and resistant Enterobacteriaceae.

Objectives

To monitor the functionality of the SOS response in the evolution towards clinical quinolone resistance and study its impact on the evolution of spatiotemporal resistance.

Methods

An isogenic collection of Escherichia coli (derived from the strain ATCC 25922) carrying combinations of chromosomally and plasmid-mediated quinolone resistance mechanisms (including susceptible, LLQR and resistant phenotypes) and exhibiting a spectrum of SOS activity was used. Relevant clinical parameters such as mutation rate, mutant prevention concentration (MPC), bacterial fitness, biofilm formation and post-antibiotic effect (PAE) were evaluated.

Results

Inactivating the SOS response (recA deletion) led to a decrease in mutation rate (∼103 fold) in LLQR compared with WT strains at ciprofloxacin concentrations of 1 mg/L (the EUCAST breakpoint for resistance) and 2.5 mg/L (Cmax), as well as a remarkable delay in the spatiotemporal evolution of quinolone resistance. For all strains, there was an 8-fold decrease in MPC in RecA-deficient strains, with values for LLQR strains decreasing below the Cmax of ciprofloxacin. Inactivation of the SOS response reduced competitive fitness by 33%-50%, biofilm production by 22%-80% and increased the PAE by ∼3-4 h at sub-MIC concentrations of ciprofloxacin.

Conclusions

Our data indicate that suppression of the SOS response affects key bacterial traits and is a promising strategy for reversing and tackling the evolution of antibiotic resistance in E. coli, including low-level and resistant phenotypes at therapeutic quinolone concentrations.

Effect of breast myopathies on quality and microbial shelf life of broiler meat

To evaluate the impact of emerging myopathies on meat quality and microbial shelf life, 48 normal, 48 white striped (WS), and 48 wooden breasts (WB) were stored for 11 d at 4°C aerobically and analyzed at 24, 72, 120, 168, 216, and 264 h post-mortem. Normal breasts showed lower (P < 0.001) redness index (-0.88 vs. -0.41 and -0.43) and cooking losses (22.0 vs. 23.8 vs. 26.9%) than those of WS and WB meat. Normal and WS breasts exhibited higher protein content than that in WB meat (23.9 and 23.2 vs. 21.4%; P < 0.001). Normal meat also had a lower ether extract content than that in WB meat (1.09 vs. 1.88%; P < 0.001), with intermediate values for WS meat. Normal breasts exhibited higher saturated fatty acid (FA) rate (31.3 vs. 28.0% of total FA on average) and lower unsaturated FA rate (68.7 vs. 72.0%) than those in WS and WB meat (P < 0.001). Differences were mainly due to polyunsaturated FA (30.5% in normal vs. 35.3 and 35.4% in WS and WB meat; P < 0.001). Normal breasts had higher initial total viable count (TVC) and a shorter TVC lag phase than those of WS and WB meat (46.3 vs. 85.2 and 77.8 h). The microbial shelf life threshold (7 log10 CFU TVC/g) was achieved first in normal (130 h) and then in WS (149 h) and WB (192 h) meat. TVC and Pseudomonas spp. counts were significantly higher in normal than those in the affected breasts between 72 and 216 h of storage. Enterobacteriaceae spp. and lactic acid bacteria counts were significantly higher in normal meat, lower in WB meat, and intermediate in WS meat until 216 h. All differences in microbial targets across meat types disappeared by 264 h of storage. Further studies are necessary to elucidate the factors and the mechanisms that may modulate microbial growth and composition during storage in broiler breast meat affected by myopathies.

Microbiological diagnostics of bloodstream infections in Europe-an ESGBIES survey

OBJECTIVES

High-quality diagnosis of bloodstream infections (BSI) is important for successful patient management. As knowledge on current practices of microbiological BSI diagnostics is limited, this project aimed to assess its current state in European microbiological laboratories.

METHODS

We performed an online questionnaire-based cross-sectional survey comprising 34 questions on practices of microbiological BSI diagnostics. The ESCMID Study Group for Bloodstream Infections, Endocarditis and Sepsis (ESGBIES) was the primary platform to engage national coordinators who recruited laboratories within their countries.

RESULTS

Responses were received from 209 laboratories in 25 European countries. Although 32.5% (68/209) of laboratories only used the classical processing of positive blood cultures (BC), two-thirds applied rapid technologies. Of laboratories that provided data, 42.2% (78/185) were able to start incubating BC in automated BC incubators around-the-clock, and only 13% (25/192) had established a 24-h service to start immediate processing of positive BC. Only 4.7% (9/190) of laboratories validated and transmitted the results of identification and antimicrobial susceptibility testing (AST) of BC pathogens to clinicians 24 h/day. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry from briefly incubated sub-cultures on solid media was the most commonly used approach to rapid pathogen identification from positive BC, and direct disc diffusion was the most common rapid AST method from positive BC.

CONCLUSIONS

Laboratories have started to implement novel technologies for rapid identification and AST for positive BC. However, progress is severely compromised by limited operating hours such that current practice of BC diagnostics in Europe complies only partly with the requirements for optimal BSI management.

Rafting behaviour of seabirds as a proxy to describe surface ocean currents in the Balearic Sea

Spatio-temporal variability of surface geostrophic mesoscale currents in the Balearic Sea (western Mediterranean) is characterized from satellite altimetry in combination with in-situ velocity measurements collected, among others, by drifting buoys, gliders and high-frequency radar. Here, we explore the use of tracking data from living organisms in the Balearic Sea as an alternative way to acquire in-situ velocity measurements. Specifically, we use GPS-tracks of resting Scopoli’s shearwaters Calonectris diomedea, that act as passive drifters, and compare them with satellite-derived velocity patterns. Results suggest that animal-borne GPS data can be used to identify rafting behaviour outside of the breeding colonies and, furthermore, as a proxy to describe local sea surface currents. Four rafting patterns were identified according to the prevailing driving forces responsible for the observed trajectories. We find that 76% of the bird trajectories are associated with the combined effects of slippage and Ekman drift and/or surface drag; 59% are directly driven by the sea surface currents. Shearwaters are therefore likely to be passively transported by these driving forces while resting. The tracks are generally consistent with the mesoscale features observed in satellite data and identified with eddy-tracking software.

Predictors of outcome in patients with severe sepsis or septic shock due to extended-spectrum β-lactamase-producing Enterobacteriaceae

PURPOSE

There are few data in the literature regarding sepsis or septic shock due to extended-spectrum β-lactamases (ESBL)-producing Enterobacteriaceae (E). The aim of this study was to assess predictors of outcome in septic patients with bloodstream infection (BSI) caused by ESBL-E.

METHODS

Patients with severe sepsis or septic shock and BSI due to ESBL-E were selected from the INCREMENT database. The primary endpoint of the study was the evaluation of predictors of outcome after 30 days from development of severe sepsis or septic shock due to ESBL-E infection. Three cohorts were created for analysis: global, empirical-therapy and targeted-therapy cohorts.

RESULTS

367 septic patients were analysed. Overall mortality was 43.9% at 30 days. Escherichia coli (62.4%) and Klebsiella pneumoniae (27.2%) were the most frequent isolates. β-lactam/β-lactamase inhibitor (BLBLI) combinations were the most empirically used drug (43.6%), followed by carbapenems (29.4%). Empirical therapy was active in vitro in 249 (67.8%) patients, and escalation of antibiotic therapy was reported in 287 (78.2%) patients. Cox regression analysis showed that age, Charlson Comorbidity Index, McCabe classification, Pitt bacteremia score, abdominal source of infection and escalation of antibiotic therapy were independently associated with 30-day mortality. No differences in survival were reported in patients treated with BLBLI combinations or carbapenems in empirical or definitive therapy.

CONCLUSIONS

BSI due to ESBL-E in patients who developed severe sepsis or septic shock was associated with high 30-day mortality. Comorbidities, severity scores, source of infection and antibiotic therapy escalation were important determinants of unfavorable outcome.

Molecular insights into fosfomycin resistance in Escherichia coli

Objectives

Fosfomycin activity in Escherichia coli depends on several genes of unknown importance for fosfomycin resistance. The objective was to characterize the role of uhpT , glpT , cyaA and ptsI genes in fosfomycin resistance in E. coli.

Methods

WT E. coli BW25113 and null mutants, Δ uhpT , Δ glpT , Δ cyaA , Δ ptsI , Δ glpT-uhpT , Δ glpT-cyaA , Δ glpT-ptsI , Δ uhpT-cyaA , Δ uhpT-ptsI and Δ ptsI-cyaA , were studied. Susceptibility to fosfomycin was tested using CLSI guidelines. Fosfomycin mutant frequencies were determined at concentrations of 64 and 256 mg/L. Fosfomycin in vitro activity was tested using time-kill assays at concentrations of 64 and 307 mg/L (human C max ).

Results

Fosfomycin MICs were: WT E. coli BW25113 (2 mg/L), Δ glpT (2 mg/L), Δ uhpT (64 mg/L), Δ cyaA (8 mg/L), Δ ptsI (2 mg/L), Δ glpT-uhpT (256 mg/L), Δ glpT-cyaA (8 mg/L), Δ glpT-ptsI (2 mg/L), Δ uhpT-cyaA (512 mg/L), Δ uhpT-ptsI (64 mg/L) and Δ ptsI-cyaA (32 mg/L). In the mutant frequency assays, no mutants were recovered from BW25113. Mutants appeared in Δ glpT , Δ uhpT , Δ cyaA and Δ ptsI at 64 mg/L and in Δ uhpT and Δ cyaA at 256 mg/L. Δ glpT-ptsI , but not Δ glpT-cyaA , Δ uhpT-cyaA or Δ uhpT-ptsI , increased the mutant frequency compared with the highest frequency found in each single mutant. In time-kill assays, all mutants regrew at 64 mg/L. Initial bacterial reductions of 2-4 log 10 cfu/mL were observed for all strains, except for Δ uhpT-ptsI , Δ glpT-uhpT and Δ uhpT-cyaA . Only Δ glpT and Δ ptsI mutants were cleared using 307 mg/L.

Conclusions

Fosfomycin MIC may not be a good efficacy predictor, as highly resistant mutants may appear, depending on other pre-existing mutations with no impact on MIC.

High clinical inflammatory activity prior to the development of secondary progression: a prospective 5-year follow-up study

Objective: To study if there are different patterns of clinical activity - measured by the annual exacerbation rate (AER) - among relapsing-remitting multiple sclerosis (RRMS), "early" secondary multiple sclerosis (SPMS) and "late" SPMS. Methods: A prospective 5-year follow-up study in 80 MS patients has been carried out, calculating the AER and the mean expanded disability status scale (EDSS) change rate (MCR). Results: A significant difference on the AER, among RRMS, early SPMS and late SPMS, has been found. Conclusions: The SPMS has a high clinical inflammatory activity before and during its transformation from a RRMS. Multiple Sclerosis (2002) 8, 59-63

Clinical and ultrasound features of benign, borderline, and malignant invasive mucinous ovarian tumors

OBJECTIVE

To compare clinical and sonographic features of benign, borderline, and malignant invasive mucinous ovarian tumors (MOTs).

MATERIALS AND METHODS

Retrospective observational multicenter study comprising 365 women (mean age: 46.1 years) with a histologically confirmed benign, borderline or malignant invasive MOT. Clinical data (patient's age, patient's complaints), tumor markers (CA-125 and CA-1 9.9), and sonographic data (tumor size, bilaterality, morphology -unilocular, multilocular, unilocular-solid, multilocular-solid and solid-, and IOTA color score) were reviewed and compared among these three groups. Women with ultrasound evidence on intra-abdominal disease spread were excluded.

RESULTS

Three hundred seventy-eight MOTs (14 women had bilateral lesions) were analyzed. Histologically, 287 tumors were benign, 51 were borderline, and 40 were malignant. No difference in patient's mean age was observed. Women with borderline or invasive tumors were less frequently asymptomatic. Tumors were larger in case of invasive lesions. Borderline and invasive tumors showed solid components and exhibited IOTA color score 3 or 4, more frequently than benign lesions (p < 0.001). However, the authors discovered that 16 out of 51 (31.4%) of borderline tumors and six out of 40 (15.0%) of invasive cancers had no solid components and a color score 1 or 2, and were considered as a benign lesion by the sonolo- gist. On the other hand, 96 out of 287 (33.4%) benign mucinous cystadenoma exhibited solid components and/or a color score of 3 or 4.

CONCLUSIONS

In spite of statistical differences, the authors observed significant overlapping in ultrasound features among benign, borderline, and invasive ovarian mucinous tumors that renders a difficult accurate preoperative discrimination among these lesions.

Hydrolytic anaerobic reactor and aerated constructed wetland systems for municipal wastewater treatment - HIGHWET project

The HIGHWET project combines the hydrolytic up-flow sludge bed (HUSB) anaerobic digester and constructed wetlands (CWs) with forced aeration for decreasing the footprint and improving effluent quality. The HIGHWET plant in A Coruña (NW of Spain) treating municipal wastewater consists of a HUSB and four parallel subsurface horizontal flow (HF) CWs. HF1, HF2 and HF3 units are fitted with forced aeration, while the control HF4 is not aerated. All the HF units are provided with effluent recirculation, but different heights of gravel bed (0.8 m in HF1 and HF2, and 0.5 m in HF3 and HF4) are implemented. Besides, a tobermorite-enriched material was added in the HF2 unit in order to improve phosphorus removal. The HUSB 76-89% of total suspended solids (TSS) and about 40% of chemical oxygen demand (COD) and biological oxygen demand (BOD). Aerated HF units reached above 96% of TSS, COD and BOD at a surface loading rate of 29-47 g BOD₅/m²·d. An aeration regime ranging from 5 h on/3 h off to 3 h on/5 h off was found to be adequate to optimize nitrogen removal, which ranged from 53% to 81%. Average removal rates of 3.4 ± 0.4 g total nitrogen (TN)/m²·d and 12.8 ± 3.7 g TN/m³·d were found in the aerated units, being 5.5 and 4.1 times higher than those of the non-aerated system. The tobermorite-enriched HF2 unit showed a distinct higher phosphate (60-67%) and total phosphorus (54%) removal.

Comparative analysis of zygotic developmental genes in Rhodnius prolixus genome shows conserved features on the tracheal developmental pathway

Most of the in-depth studies on insect developmental genetic have been carried out in the fruit fly Drosophila melanogaster, an holometabolous insect, so much more still remains to be studied in hemimetabolous insects. Having Rhodnius prolixus sequenced genome available, we search for orthologue genes of zygotic signaling pathways, segmentation, and tracheogenesis in the R. prolixus genome and in three species of Triatoma genus transcriptomes, concluding that there is a high level of gene conservation. We also study the function of two genes required for tracheal system development in D. melanogaster - R. prolixus orthologues: trachealess (Rp-trh) and empty spiracles (Rp-ems). From that we see that Rp-trh is required for early tracheal development since Rp-trh RNAi shows that the primary tracheal branches fail to form. On the other hand, Rp-ems is implied in the proper formation of the posterior tracheal branches, in a similar way to D. melanogaster. These results represent the initial characterization of the genes involved in the tracheal development of an hemimetabolous insect building a bridge between the current genomic era and V. Wigglesworth's classical studies on insects' respiratory system physiology.

Monotherapy versus combination therapy for sepsis due to multidrug-resistant Acinetobacter baumannii: analysis of a multicentre prospective cohort

BACKGROUND

Treatment of multidrug-resistant Acinetobacter baumannii (MDRAB) infection presents a challenge because of the scarcity of available options. Even though combination therapy (CT) is frequently used in clinical practice, data are needed to support its use instead of monotherapy (MT).

METHODS

A prospective observational study was conducted in 28 Spanish hospitals. Patients with sepsis caused by MDRAB, defined according to strict criteria, and who received active antibiotic treatment (according to in vitro susceptibility testing) for at least 48 h, were included. The main outcome variable was all-cause 30 day mortality after initiation of targeted therapy. Multivariate analysis, including a propensity score (for receiving CT), was performed by Cox regression.

RESULTS

One hundred and one patients were included in the analysis; 68 (67.3%) received MT and 33 (32.7%) received CT. Pneumonia was the most common infection (50.5%), 68.6% of cases being associated with mechanical ventilation. Colistin (67.6%) and carbapenems (14.7%) were the most common drugs used in MT; colistin plus tigecycline (27.3%) and carbapenem plus tigecycline (12.1%) were the most frequent combinations. Crude 30 day mortality was 23.5% and 24.2% for the MT and CT groups, respectively (RR = 1.03; 95% CI 0.49-2.16; P = 0.94). Multivariate analysis of 30 day survival showed no trend towards reduced 30 day mortality with CT (HR = 1.35; 95% CI 0.53-3.44; P = 0.53). Subgroup analysis showed similar results.

CONCLUSIONS

Our data do not support an association of CT with reduced mortality in MDRAB infections. More data for specific types of infection and combinations are needed.

Foundry sands as low-cost adsorbent material for Cr (VI) removal

The potential of foundry sands, industrial waste from the iron foundry industry, was evaluated for the removal of Cr (VI) using discontinuous assays. Chemical foundry sands are composed of fine silica sand, furanic resins as binder, chemical catalyst and residual iron particles. The influence ofpH, agitation rate and metal concentration on the removal process was investigated. Kinetic and equilibrium tests were conducted to determine Cr (VI) removal from aqueous solutions at a temperature range of 25-55 degrees C. Cr (VI) removal of 40-100% for a range of pH 6-1.6 was obtained. This removal was attributed to the presence of a large number of protonated silanol and aluminol groups. Cr (VI) adsorption in foundry sands follows a pseudo-second-order kinetic reaction (Ho model, r2 > 0.999) reaching kinetic constants of 0.341, 0.551, 0.775 and 0.920 g/mg h at 25, 35, 45 and 55 degrees C, respectively. The adsorption data were fitted to the Langmuir adsorption isotherm model (r > 0.99) obtaining adsorption capacities (q(max)) of 1.99, 2.40, 2.50, and 3.14 mg Cr (VI)/g sand at 25, 35, 45 and 55 degrees C, respectively. Calculated Gibbs free energy change (deltaG0), adsorption energy (E) and activation energy (E(a)) values indicate that a physisorption mechanism governs Cr (VI) adsorption process in foundry sands.

Impact of qnrA1, qnrB1 and qnrS1 on the efficacy of ciprofloxacin and levofloxacin in an experimental pneumonia model caused by Escherichia coli with or without the GyrA mutation Ser83Leu

OBJECTIVES

The aim of this study was to evaluate the impact of qnrA1, qnrB1 and qnrS1 on the in vivo efficacies of ciprofloxacin and levofloxacin in an experimental model of pneumonia caused by Escherichia coli.

METHODS

Two isogenic groups of E. coli transformants, based on two ATCC 25922 strains, with or without the GyrA mutation Ser83Leu, and carrying qnrA1, qnrB1 or qnrS1, were used in an experimental pneumonia model. The efficacies of ciprofloxacin (40 mg/kg/day) and levofloxacin (50 and 150 mg/kg/day) were evaluated.

RESULTS

For the pneumonia caused by the parental strains lacking qnr genes, both fluoroquinolones significantly (P<0.05) reduced the bacterial lung concentration by >7 log10 cfu/g against E. coli ATCC/pBK and between 5.09 and 6.34 log10 cfu/g against E. coli ATCC-S83L/pBK. The presence of any qnr genes in the strains of both isogenic groups diminished the reduction of bacterial lung concentration with any therapy (P<0.05). Furthermore, all therapeutic schemes reduced the percentage of positive blood cultures in both isogenic groups (P<0.05). Finally, the survival results suggest a higher mortality with the strains expressing qnr genes.

CONCLUSIONS

The presence of qnrA1, qnrB1 and qnrS1 in E. coli reduced the efficacy of ciprofloxacin and levofloxacin in a murine pneumonia model.