Assessment of antibacterial activity, modes of action, and synergistic effects of Origanum vulgare hydroethanolic extract with antibiotics against avian pathogenic Escherichia coli.

This study evaluates the antibacterial effectiveness of Origanum vulgare hydroethanolic extract, both independently and in combination with antibiotics, against Escherichia coli strains associated with avian colibacillosis-a significant concern for the poultry industry due to the rise of antibiotic-resistant E. coli. The urgent demand for new treatments is addressed by analyzing the extract's phytochemical makeup via High-Performance Liquid Chromatography (HPLC), which identified sixteen phenolic compounds. Antibacterial activity was determined through agar diffusion and the measurement of minimum inhibitory and bactericidal concentrations (MIC and MBC), showing moderate efficacy (MIC: 3.9 to 7.8 mg/mL, MBC: 31.2 to 62.4 mg/mL). Combining the extract with antibiotics like ampicillin and tetracycline amplified antibacterial activity, indicating a synergistic effect and highlighting the importance of combinatory treatments against resistant strains. Further analysis revealed the extract's mechanisms of action include disrupting bacterial cell membrane integrity and inhibiting ATPase/H+ proton pumps, essential for bacterial survival. Moreover, the extract effectively inhibited and eradicated biofilms, crucial for preventing bacterial colonization. Regarding cytotoxicity, the extract showed no hemolytic effect at 1 to 9 mg/mL concentrations. These results suggest Origanum vulgare extract, particularly when used with antibiotics, offers a promising strategy for managing avian colibacillosis, providing both direct antibacterial benefits and moderating antibiotic resistance, thus potentially reducing the economic impact of the disease on the poultry industry.

Degradation of veterinary antibiotics by the ozonation process: Product identification and ecotoxicity assessment.

The purpose of the study was to evaluate the effects of using of ozonation to remove antibiotics used, among others, in veterinary medicine, from the aqueous environment. The effect of this process on the degradation, mineralisation and ecotoxicity of aqueous solutions of ampicillin, doxycycline, tylosin, and sulfathiazole was investigated. Microbiological MARA® bioassay and two in silico methods were used for the ecotoxicity assessment. Ozonation was an effective method for the degradation of the antibiotics studied and the reduction in ecotoxicity of the solutions. However, after ozonation, the solutions contained large amounts of organic products, including compounds much less susceptible to ozonation than the initial antibiotics. Structures of 14, 12, 40 and 10 degradation products for ampicillin, doxycycline, tylosin, and sulfathiazole, respectively, were proposed. It was confirmed that ozone plays a greater role than hydroxyl radicals in the degradation of these antibiotics, with the exception of TYL. The use of ozonation to obtain a high degree of mineralisation is unfavourable and it is suggested to combine ozonation with biodegradation. The pre-ozonation will cause decomposition of antibiotic pharmacophores, which significantly reduces the risk of spread of antimicrobial resistance in the active biocenosis of wastewater treatment plants.

Occurrence profiling, risk assessment, and correlations of antimicrobials in surface water and groundwater systems in Southwest Nigeria.

The presence of antimicrobials in water has grown into a major global health concern. This study thus focused on the presence, ecological implications, and potential health risks associated with nine antimicrobials: five antibiotics (ampicillin, chloramphenicol, ciprofloxacin, metronidazole, and tetracycline) and four parabens (methylparaben, ethylparaben, propylparaben, and butylparaben) in surface water and groundwater samples collected from three Southwestern States in Nigeria (Osun, Oyo, and Lagos States). These antimicrobials were widely detected across the three States with ciprofloxacin being the most dominant having maximum average concentrations of 189 µg L-1 and 319 µg L-1 in surface water and groundwater respectively. The range of average concentrations of antibiotics in surface water are 47.3-235 µg L-1 (Osun), 27.9-166 µg L-1 (Oyo) and 52.1-159 µg L-1 (Lagos). For groundwater, it is 35.3-180 µg L-1 (Osun), 26.5-181 µg L-1 (Oyo) and 32.3-319 µg L-1 (Lagos). The average concentrations of all parabens were 32.4-153 µg L-1, 53.4-80.1 µg L-1, and 83.2-132 µg L-1 for surface water and 46.7-55.7 µg L-1, 53-117 µg L-1, and 62.4-118 µg L-1 for groundwater in Osun, Oyo, and Lagos States respectively. Methylparaben was most frequently detected paraben with average concentrations of 153 µg L-1 and 117 µg L-1 in surface water and groundwater respectively. The measured environmental concentrations of these antimicrobials pose a significant ecological risk while those of ciprofloxacin and ampicillin pose a high health risk to all population groups studied. The average concentrations of antibiotics investigated in this study exceeded their threshold values for Predicted No-Effect Concentrations (PNEC) associated with resistance selection, except for tetracycline.

Degradation of Ampicillin with antibiotic activity removal using persulfate and submersible UVC LED: Kinetics, mechanism, electrical energy and cost analysis.

Effective water treatment to remove antibiotics and its activity from contaminated water is urgently needed to prevent antibiotic-resistant bacteria (ARB) emergence. In this study, we investigated degradation of Ampicillin (AMP), an extensively used ß-lactam antibiotic, using submersible Ultraviolet C Light Emitting Diode (λmax = 276 nm) irradiation source, and Persulfate (UVC LED/PS system). Pseudo first order rate constant (kobs) for degradation of AMP (1 ppm) by UVC LED/PS system was determined to be 0.5133 min-1 (PS = 0.2 mM). kobs value at pH 2.5 (0.7259 min-1) was found to be higher than pH 6.5 (0.5133 min-1) and pH 12 (0.1745 min-1). kobs value for degradation of AMP in deionized water spiked with inorganic anions (Cl-=0.5369 min-1,SO42-=0.4545 min-1, NO3-=0.1526 min-1, HCO3-=0.0226 min-1), in real tap water (0.1182 min-1) and simulated ground water (0.0372 min-1) were presented. Radical scavenging experiment reveal involvement of sulfate radical anion and hydroxyl radical in UVC LED/PS system. EPR analysis confirms the generation of sulfate radical anion and hydroxyl radical. Importantly, 74% reduction of total organic carbon (TOC) occurred within 60 min of AMP treatment by UVC LED/PS system. Seven degradation by-products were identified by high resolution mass spectrometry, and degradation pathways were proposed. Antibacterial activity of AMP towards Bacillus subtilis and Staphylococcus aureus was completely removed after UVC LED/PS treatment. ECOSAR model predicted no very toxic degradation by-products generation by UVC LED/PS system. Electrical Energy per order (EEo) and cost of UVC LED/PS system were determined to be 0.9351 kW/m3/order and ₹ 7.91/m3 ($ 0.095/m3 or € 0.087/m3), respectively. Overall, this study highlights, UVC LED/PS system as energy efficient, low-cost, and its potential to emerge as sulfate radical anion based advanced oxidation process (AOP) to treat water with antibiotics.

Bioassay-guided detection, identification and assessment of antibacterial and anti-inflammatory compounds from olive tree flower extracts by high-performance thin-layer chromatography linked to spectroscopy.

Olive trees are one of the most widely cultivated fruit trees in the world. The chemical compositions and biological activities of olive tree fruit and leaves have been extensively researched for their nutritional and health-promoting properties. In contrast, limited data have been reported on olive flowers. The present study aimed to analyse bioactive compounds in olive flower extracts and the effect of fermentation-assisted extraction on phenolic content and antioxidant activity. High-performance thin-layer chromatography (HPTLC) hyphenated with the bioassay-guided detection and spectroscopic identification of bioactive compounds was used for the analysis. Enzymatic and bacterial in situ bioassays were used to detect COX-1 enzyme inhibition and antibacterial activity. Multiple zones of antibacterial activity and one zone of COX-1 inhibition were detected in both, non-fermented and fermented, extracts. A newly developed HPTLC-based experimental protocol was used to measure the high-maximal inhibitory concentrations (IC50) for the assessment of the relative potency of the extracts in inhibiting COX-1 enzyme and antibacterial activity. Strong antibacterial activities detected in zones 4 and 7 were significantly higher in comparison to ampicillin, as confirmed by low IC50 values (IC50 = 57-58 µg in zone 4 and IC50 = 157-167 µg in zone 7) compared to the ampicillin IC50 value (IC50 = 495 µg). The COX-1 inhibition by the extract (IC50 = 76-98 µg) was also strong compared to that of salicylic acid (IC50 = 557 µg). By comparing the locations of the bands to coeluted standards, compounds from detected bioactive bands were tentatively identified. The eluates from bioactive HPTLC zones were further analysed by FTIR NMR, and LC-MS spectroscopy. Multiple zones of antibacterial activity were associated with the presence of triterpenoid acids, while COX-1 inhibition was related to the presence of long-chain fatty acids.

HEALTH ASSESSMENT OF CAPTIVE BEARDED VULTURES (GYPAETUS BARBATUS) IN CATALONIA (SPAIN).

Bearded vulture (Gypaetus barbatus) populations are declining worldwide primarily due to anthropogenic factors. A captive breeding program has been established in Spain, a country with one of the largest free-living populations in Europe, to further enhance the conservation efforts of this emblematic species. However, captive vulture populations can be exposed to different risks through food, such as drug residues and antimicrobial-resistant (AMR) bacteria. Health surveillance of species involved in captive breeding programs is important to face introduction of healthy animals in situ and to obtain baseline clinical data. The objective of this study was to assess the general health status of bearded vultures held in captivity in Catalonia (northeastern Spain) by carrying out hematologic, biochemical, toxicologic, and bacteriologic analyses. A total of 16 bearded vultures were sampled; the data obtained from one vulture, with a chronic tibiotarsal fracture, were excluded from the statistical analysis. Hematologic and biochemical parameters of the bearded vultures were mostly within the range of standard values as stated in previous studies. Basal feather and serum corticosterone levels were analyzed and described for the first time in this species. A total of 15 Escherichia coli isolates were obtained that were resistant to fluoroquinolones (80%), tetracycline (60%), trimethoprim and ampicillin (40%), sulfamethoxazole (33%), and colistin (20%), with 40% of them being multidrug resistant. Three of 15 isolates were carriers of the mcr-1 gene. Only the injured bird previously treated with enrofloxacin was positive for fluoroquinolone residues. Periodic monitoring for the presence of AMR bacteria would be recommended in captive breeding programs as a preventive action to establish future therapies.

Degradation of veterinary antibiotics by Fenton process: Products identification and toxicity assessment.

The aim of the work was primarily to determine the relationship between the doses of Fenton's reagents and the effectiveness of the ecotoxicity removal of aqueous solutions containing selected antibiotics. The degradation process of ampicillin, doxycycline, and tylosin in an acidic environment in the presence of H2O2 and FeSO4 was studied. The effect of reagent doses on the degree of degradation and identification of antibiotic transformation products was measured by the UPLC qTOF method. The degree of mineralisation was determined based on changes in the concentration of total organic carbon. The ecotoxicity of products was determined with commercial MARA® and MICROTOX® bioassays, as well as against unselected microorganisms from polluted rivers and wastewater treatment plant effluent. It was found that the complete degradation of antibiotics and the simultaneous elimination of the toxicity of the Fenton process products required the use of a precisely defined amount of reagents. When an insufficient dose of reactants was used, the post-reaction solutions contained antibiotic derivatives showing antimicrobial activity. On the other hand, the toxicity of the post-reaction solution against to microbiocenoses was observed when too high doses of H2O2 were used in the process. This effect resulted from the presence of unreacted reagent or other unidentified peroxides.

A low-cost, high-throughput microfluidic nano-culture platform for functional metagenomics.

Functional metagenomics is an attractive culture-independent approach for functional screening of diverse microbiomes to identify known and novel genes. Since functional screening can involve sifting through tens of thousands of metagenomic library clones, an easy high-throughput screening approach is desirable. Here, we demonstrate a proof-of-concept application of a low-cost, high-throughput droplet based microfluidic assay to the selection of antibiotic resistance genes from a soil metagenomic library. Metagenomic library members encapsulated in nanoliter volume water-in-oil droplets were printed on glass slides robotically, and cell growth in individual drops in the presence of ampicillin was imaged and quantified to identify ampicillin-resistant clones. From the hits, true positives were confirmed by sequencing and functional validation. The ease of liquid handling, ease of set-up, low cost, and robust workflow makes the droplet-based nano-culture platform a promising candidate for screening and selection assays for functional metagenomic libraries.

Integrated genome-based assessment of safety and probiotic characteristics of Lactiplantibacillus plantarum PMO 08 isolated from kimchi.

Lactiplantibacillus plantarum PMO 08 has been used as a probiotic starter culture for plant-based fermented beverages, with various health-promoting effects such as cholesterol-lowering and anti-inflammatory activities. This study aimed to analyze the genome sequence of Lp. plantarum PMO 08 and identify its safety and probiotic characteristics at the genomic level. For this, complete genome sequencing was conducted to investigate the genes associated with risk and probiotic characteristics by using Pacbio combined with Illumina HiSeq. This bacterial strain has one circular chromosome of 3,247,789 bp with 44.5% G + C content and two plasmids of 50,296 bp with 39.0% G + C content and 19,592 bp with 40.5% G + C content. Orthologous average nucleotide identity analysis showed that PMO 08 belongs to the Lp. plantarum group with 99.14% similarity to Lp. plantarum WCFS1. No deleterious genes were determined in the virulence factor analysis, and no hemolysin activity or secondary bile salt synthesis were detected in vitro test. In the case of antibiotic resistance analysis, PMO 08 was resistant to ampicillin in vitro test, but these genes were not transferable. In addition, the strain showed same carbohydrate utilization with Lp. plantarum WCFS1, except for mannopyranoside, which only our strain can metabolize. The strain also harbors a gene for inositol monophosphatase family protein related with phytate hydrolysis and have several genes for metabolizing various carbohydrate which were rich in plant environment. Furthermore, in probiotic characteristics several genes involved in phenotypes such as acid/bile tolerance, adhesion ability, and oxidative stress response were detected in genome analysis. This study demonstrates that Lp. plantarum PMO 08 harbors several probiotic-related genes (with no deleterious genes) and is a suitable probiotic starter for plant-based fermentation.

Assessment of antibiotic resistance changes during the Covid-19 pandemic in northeast of Iran during 2020-2022: an epidemiological study.

BACKGROUND: The coronavirus disease 2019 seems to change antibiotic resistance pattern. Certain conditions in the Covid-19 era may be contributing to the rise of antimicrobial resistance (AMR). Due to the limited information on the impact of Covid-19 on antimicrobial resistance (AMR), the purpose of this research was to investigate the trend in antimicrobial resistance changes of E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii in Hasheminezhad hospital. This hospital was a Corona center in Mashhad at the onset of this epidemic. METHODS: 1672 clinical samples were collected between January 21, 2020 and January 30, 2022from patients hospitalized at Hasheminezhad Hospital in Mashhad, Conventional microbiological procedures for identifying gram-negative bacteria and antibiotic susceptibility testing were used, according to the clinical and laboratory standards institute (CLSI) 2021. The two years of the pandemic, from the initial stage of the outbreak until the 6th peak, (January 2020 to and January 2022) were divided into 9 periods according to the seasons. RESULTS: Highest resistance rates were seen in E. coli (615 samples), K. pneumoniae (351 samples), P. aeruginosa (362 samples) and A. baumannii (344 samples) to Ampicillin (89.6%), Ampicillin (98%), Imipenem (91.8%), and Ceftazidime (94.6%), respectively. The largest change in antibiotic resistance was seen between Summer 2020 and Summer 2021 for K. pneumoniae with about a 30% rise in antibiotic resistance to Ceftriaxone. CONCLUSIONS: All 4 species evaluated in this study, have shown rising AMR rates during the first year of the pandemic in the northeast of Iran. This study revealed that E. coli, P. aeruginosa, K. pneumoniae, and A. baumannii strains in Northern Iran have a higher level of antibiotic resistance than what was measured in similar studies conducted before the pandemic. This will further restrict treatment choices and jeopardize global public health.

Assessment of the In Vitro Cytotoxic Profile of Two Broad-Spectrum Antibiotics-Tetracycline and Ampicillin-On Pharyngeal Carcinoma Cells.

Background and Objectives: In spite of the fact that antibiotics are considered to be the cornerstone of modern medicine, their use in the treatment of cancer remains controversial. In the present study, the main objective was to examine the effects of two antibiotics-tetracycline and ampicillin-on the viability, morphology, migration, and organization and structure of the nuclei and the actin fiber network of pharyngeal carcinoma cells-Detroit-562. Materials and Methods: In order to determine the viability of the cells, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method was applied after the cells were stimulated with five concentrations of tetracycline and ampicillin (10, 25, 50, 75, and 100 µM) for 72 h. A scratch assay was used to assess the migration ability of the cells. For the visualization of the nuclei and actin fibers, 4,6-diamidino-2-phenylindole (Dapi) and Rhodamine-Phalloidin were used. Results: There are different effects of tetracycline and ampicillin. Thus, tetracycline: (i) exhibited a concentration-dependent cytotoxic effect, decreasing cell viability to approximately 46%; (ii) inhibits cellular migration up to 16% compared to 60% for control cells; and (iii) induces changes in cell morphology as well as apoptotic changes in the nucleus and F-actin fibers. In contrast, in the case of ampicillin, an increase in viability up to 113% was observed at 10 µM, while a decrease in viability up to approximately 94% was observed at the highest concentration tested (100 µM). Conclusions: The results indicated a different effect regarding the impact on pharyngeal carcinoma cells. Thus, tetracycline has a concentration-dependent cytotoxic effect, while in the case of ampicillin a slight stimulation of cell viability was observed.

Microbiological assessment of marine and estuarine ecosystems using fecal indicator bacteria, Salmonella, Vibrio and antibiotic resistance pattern.

Marine and estuarine environments are often affected by microbiological contamination that adversely affects their use and severely impacts human health. To examine the influence of anthropogenic activities, this study used two different ecosystems in Agadir Bay, to compare fecal indicator bacteria (FIB) and bacterial pathogen profiles over two years. Vibrio target pathogens were detected at a high frequency (49.3%), while a low percentage (5.5%) was noted for Salmonella. Apart from those mentioned above, several other pathogenic bacteria were detected such as Cronobacter sakzakii, Pseudomonas fluorescens, and Aeromonas hydrophila. We also investigated the antimicrobial resistance of the pathogenic bacteria isolated. Salmonella strains were sensitive to all the antibiotics used, except ampicillin, amoxicillin + Ac clavulanic and chloramphenicol. And Vibrio strains were resistant to ampicillin, cephalothin, amikacin, and ciprofloxacin. This study highlights the limitations of FIB in assessing the microbiological quality and the importance of environmental surveys in understanding the distribution of pathogens.

Simultaneous pharmacokinetic/pharmacodynamic (PKPD) assessment of ampicillin and gentamicin in the treatment of neonatal sepsis.

OBJECTIVES: This study aimed to simultaneously investigate the pharmacokinetics of ampicillin and gentamicin, currently the WHO standard of care for treating neonatal sepsis. METHODS: Pharmacokinetic data were collected in 59 neonates receiving ampicillin and gentamicin for suspected or proven sepsis in the NeoFosfo trial (NCT03453177). A panel of 23 clinical Escherichia coli isolates from neonates with sepsis, resistant to either ampicillin, gentamicin or both, were tested for susceptibility using chequerboards. Pharmacokinetic/pharmacodynamic (PKPD) modelling and simulations were used to compare single-agent (EUCAST MIC) and combination (chequerboard MIC) target attainment with standard dosing regimens. RESULTS: A model was established that simultaneously estimated parameters of a one-compartment ampicillin model and a two-compartment gentamicin model. A common clearance for both drugs was used (6.89 L/h/70 kg) relating to glomerular filtration (CLGFR), with an additional clearance term added for ampicillin (5.3 L/h/70 kg). Covariate modelling included a priori allometric weight and post-menstrual age scaling of clearance. Further covariate relationships on renal clearance were postnatal age and serum creatinine.Simulation-based PKPD assessments suggest good Gram-positive (MIC ≤ 0.25 mg/L) cover. However, less than one-quarter of neonates were predicted to receive efficacious coverage against Enterobacterales (MIC ≤ 2 mg/L). The benefit of the ampicillin/gentamicin combination was limited, with only 2/23 E. coli clinical strains showing FIC index < 0.5 (synergy) and most in the range 0.5-1 (suggesting additivity). Simulations showed that feasible dosing strategies would be insufficient to cover resistant strains. CONCLUSIONS: PKPD simulations showed ampicillin and gentamicin combination therapy was insufficient to cover Enterobacterales, suggesting the need for alternative empirical treatment options for neonatal sepsis.

Assessment of three SERS approaches for studying E. Coli O157:H7 susceptibility to ampicillin.

Antibiotic resistant bacteria pose an increasing threat to global public health, and it is essential that effective detection methods for identifying these organisms. This study assesses the ability of three different analytical approaches that were developed using surface-enhanced Raman spectroscopy (SERS) to differentiate between antibiotic sensitive and resistant bacteria based on their responses to ampicillin exposure, using Escherichia coli O157:H7 as a model bacterium. The approaches tested in this study included a conventional SERS approach of mixing a droplet of bacterial culture with gold nanoparticles, extracellular matrix analysis, and in situ mapping of bacterial cells on a filter membrane. All three of the SERS techniques were able to differentiate between the sensitive and resistant bacterial strains based on peak intensity changes associated with compounds released by the bacteria in response to antibiotic exposure, with extracellular matrix analysis and filter mapping both observed to be more effective than the conventional approach. However, there were significant differences between the spectra obtained from the different techniques and the potential advantages and disadvantages of each approach should be considered when used in the future. This study shows that SERS can be an effective technique for rapid and efficient assessment of ampicillin sensitivity in E. coli, and more work should be done to explore these analytical approaches with other types of bacterial samples.

Comparación de antibióticoterapia en la apendicitis complicada en pediatría / Comparison of antibiotic therapy in complicated appendicitis in pediatrics

INTRODUCCIÓN. La apendicitis aguda es una patología pediátrica quirúrgica que en su fase complicada requiere uso de antibióticos en el postoperatorio; encontrar la mejor opción como experiencia local, fue necesario. OBJETIVO. Comparar un esquema de antibioticoterapia triple vs un doble respecto a variables: demográficas, clínicas y de costos en pacientes pediátricos con apendicitis complicada. MATERIALES y MÉTODOS. Estudio analítico transversal. Población de 133 pacientes y una muestra de 93, operados por apendicitis complicada; 58 recibieron ampicilina + metronidazol + gentamicina y 35 ceftriaxona + metronidazol. Se comparó las variables: estadía hospitalaria, complicaciones y costo monetario de cada esquema. Se realizó en la Unidad de Cirugía Pediátrica del Hospital de Especialidades Carlos Andrade Marín, en el periodo enero de 2017 a octubre de 2018. Los datos fueron analizados con R-Studio 1.8.366 para Windows. RESULTADOS. No hubo diferencia estadística con respecto a: estadía hospitalaria (p=0,261); complicaciones como infección del sitio quirúrgico (p=0,196), re-intervención quirúrgica (p=0,653) y costo (p=0,059). CONCLUSIÓN. Se comparó el esquema de antibioticoterapia triple vs un doble, utilizados en apendicitis complicada en pediatría. No se encontró diferencias estadísticamente significativas en este reporte preliminar, con la diferencia de que con el esquema doble la frecuencia de administración fue menor y se evitó la exposición a los efectos colaterales de los aminoglicósidos.

INTRODUCTION. Acute appendicitis is a pediatric surgical pathology that in its complicated phase requires the use of antibiotics during the postoperative period; finding the best option as local experience was a must. OBJECTIVE. Compare a triple vs a double antibiotic therapy scheme respect demographic, clinical and cost variables in pediatric patients whit complicated apendicitis. MATERIALS AND METHODS. Cross-sectional analytical study. Population of 133 patients and sample of 93, with complicated appendicitis; 58 received ampicillin + metronidazole + gentamicin and 35 ceftriaxone + metronidazole. The following variables were compared; hospital stay, complications and monetary cost of each scheme. It was performed in the Pediatric Surgery Unit of the Hospital of Specialties Carlos Andrade Marin, during january 2017, through october 2018. The data were analyzed with R-Studio 1.8.366 for Windows. RESULTS. There was no statistical difference regarding hospital stay (p=0.261); complications such as surgical site infection (p=0.196), re-surgical intervention (p=0.653); nor cost (p=0.059). CONCLUSION. Triple vs. Double antibiotic therapy scheme used in complicated appendicitis in pediatrics was compared. No statistically significant differences were found in this preliminary report, how ever with the double scheme the frequency of administration was lower and exposure to side effects of aminoglycosides was avoided.

Affordable automated phenotypic antibiotic susceptibility testing method based on a contactless conductometric sensor.

User-friendly phenotypic antibiotic susceptibility testing (AST) methods are urgently needed in many fields including clinical medicine, epidemiological studies and drug research. Herein, we report a convenient and cost-effective phenotypic AST method based on online monitoring bacterial growth with a developed 8-channel contactless conductometric sensor (CCS). Using E. coli and V. parahaemolyticus as microorganism models, as well as enoxacin, florfenicol, ampicillin, kanamycin and sulfadiazine as antibiotic probes. The minimum inhibitory concentration (MIC) determination was validated in comparison with standard broth microdilution (BMD) assay. The total essential agreements between the CCS AST assays and the reference BMD AST assays are 68.8-92.3%. The CCS has an approximate price of $9,000 (USD). Requiring neither chemical nor biotic auxiliary materials for the assay makes the cost of each sample < $1. The MICs obtained with the automated CCS AST assays are more precise than those obtained with the manual BMD. Moreover, in 72 percent of the counterpart, the MICs obtained with the CCS AST assays are higher than that obtained with the BMD AST assays. The proposed CCS AST method has advantages in affordability, accuracy, sensitivity and user-friendliness.

Beta-lactams susceptibility testing of penicillin-resistant, ampicillin-susceptible Enterococcus faecalis isolates: a comparative assessment of Etest and disk diffusion methods against broth dilution.

This study aimed to evaluate the accuracy of disk diffusion and Etest methods, compared to that of the broth dilution reference method for identifying beta-lactam susceptibilities of Penicillin-Resistant, Ampicillin-Susceptible Enterococcus faecalis (PRASEF) isolates. Fifty-nine PRASEF and 15 Penicillin-Susceptible, Ampicillin-Susceptible E. faecalis (PSASEF) clinical nonrepetitive isolates were evaluated. The effectiveness of five beta-lactams (ampicillin, amoxicillin, imipenem, penicillin, and piperacillin) was tested. All antimicrobial susceptibility tests were performed and interpreted according to the Clinical and Laboratory Standards Institute guidelines. Interpretative discrepancies, such as essential agreement, categorical agreement, and errors, were assessed. The acceptability was ≥ 90% for both categorical agreement and essential agreement. Etest proved to be an accurate method for testing beta-lactam susceptibilities of the emerging PRASEF isolates, disk diffusion presented poor performance, particularly for imipenem and piperacillin.

Management Patterns in Pediatric Complicated Sinusitis.

OBJECTIVES: Sinusitis is a common pediatric illness that can be complicated by periorbital or intracranial extension. Patients can be managed with antimicrobials alone or in conjunction with surgical intervention. This article examines management patterns and outcomes in pediatric patients presenting with complicated sinusitis. STUDY DESIGN: Case series with chart review. SETTING: Tertiary care pediatric hospital. SUBJECTS AND METHODS: An evaluation of 168 pediatric patients with complicated sinusitis with periorbital complications presenting at a single institution from 2008 to 2018 was performed. Demographics, disease characteristics, in-hospital management, and outcomes were recorded and analyzed. RESULTS: The most common complication was orbital cellulitis, seen in 49% of children. Surgical intervention occurred in 49% of patients, with 36% receiving medical therapy followed by surgery (MTS). Chandler I patients underwent surgical intervention 30% of the time, Chandler II patients 29%, and Chandler III patients 83%. Nineteen percent of initially nonoperative patients started on ampicillin-sulbactam required MTS vs 57% of those started on other antibiotic regimens (P = .01). Twelve percent of initially nonoperative Chandler I to II patients started on ampicillin-sulbactam needed MTS vs 40% started on other antibiotic regimens. Hospital charges for operative patients were $45,056 vs $14,311 for nonoperative patients (P < .01). Hospital charges for patients with surgery followed by medical therapy (SMT) were $45,563 vs $44,393 for MTS (P = .92). CONCLUSION: Nonoperative early stage patients started on ampicillin-sulbactam had a lower risk of MTS. MTS did not cost significantly more than SMT, and there were no significant outcome differences seen.