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In this study out of 130 different clinical specimens, 70 Acinetobacter baumannii were collected from hospitalized patients. Then; all the isolates were characterized using biochemical tests and confirmed by using the Vitek II compact system. All isolates of Acinetobacter baumannii were subjected to the disc diffusion method to determine it's a susceptibility to 8 types of antibiotic disc, and the result showed these bacteria were resistant to Cefepime, Imipenem, trimethoprim, Piperacillin, tetracycline, Amikacin, ampicillin-sulbactam and levofloxacin. According to bacterial susceptibility test, all isolated were showed highly resistance to Trimethoprim (88.57%) and the lower resistance to tetracycline (47.14%). Minimum inhibitory concentration was determined only for levofloxacin resistant isolates of Acinetobacter baumannii using the broth dilution method. MIC shows these bacteria were resistant to levofloxacin in concentration ranging between 32µg/100µl to 128µg/100µl. The relation between adeIK and levofloxacin resistance was calculated by determining gene expression using real-time PCR. The result showed the mean value of adeI and adeK before exposing bacteria to levofloxacin was 2.3 and 0.42 respectively while the mean value of adeI and adeK after exposing bacteria to levofloxacin was 3.15 and 3.29 respectively. This study indicates that adeI has a non-significant role (p-value=0.11) in providing resistance to levofloxacin, while adeK plays a significant role (p-value= 0.008) in providing resistance to levofloxacin.

Introduction: Antimicrobial resistance (AMR) is a global health challenge, and antimicrobial susceptibility testing (AST) is vital for guiding treatment. Although widely used, the Kirby-Bauer method depends on skilled interpretation, which can be time-intensive and error-prone. This study explored the potential of an artificial intelligence (AI)-driven progressive web app (PWA) to automate the analysis of Kirby-Bauer test images, thereby enhancing accuracy and efficiency. Methodology: Images of Kirby-Bauer test results were annotated to train the Faster R-CNN ResNet-50 to detect agar plates, inhibition zones, and antibiotic discs. MobileNetv2 was used for antibiotic disc classification. A Human-in-the-Loop (HITL) approach enabled technicians to correct errors and improve model performance through retraining. The PWA, built with VueJS and Python-PHP, provided real-time analysis aligned with the Clinical and Laboratory Standards Institute (CLSI) and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) standards. Results: The application achieved 92.95% accuracy for inhibition zone detection and 96.92% accuracy for antibiotic disc identification, with a performance improvement of 99.28% following HITL corrections. The measurements closely aligned with those of the technicians in 89.54% of the cases. The system processed up to 50 images per hour, supporting reliable and rapid AST workflow. Conclusions: The AI-powered “Disc Diffusion Reader” demonstrated high accuracy and efficiency, by reducing interpretation variability in the AST workflows. Its scalability and adaptability, particularly in low-resource settings, make it a valuable tool for combating AMR. Continuous retraining and validation will ensure sustained reliability, and highlight the potential of AI-driven solutions in modern microbiology.

The use of disc diffusion susceptibility tests to determine the antibacterial activity of engineered nanoparticles (ENPs) is questionable because their low diffusivity practically prevents them from penetrating through the culture media. In this study, we investigate the ability of such a test, namely the Kirby-Bauer disc diffusion test, to determine the antimicrobial activity of Au and Ag ENPs having diameters from 10 to 40 nm on Escherichia coli cultures. As anticipated, the tests did not show any antibacterial effects of Au nanoparticles (NPs) as a result of their negligible diffusivity through the culture media. Ag NPs on the other hand exhibited a strong antimicrobial activity that was independent of their size. Considering that Ag, in contrast to Au, dissolves upon oxidation and dilution in aqueous solutions, the apparent antibacterial behavior of Ag NPs is attributed to the ions they release. The Kirby-Bauer method, and other similar tests, can therefore be employed to probe the antimicrobial activity of ENPs related to their ability to release ions rather than to their unique size-dependent properties.

Introduction: Many microorganisms present on human skin can cause various diseases. One preventive measure is the use of cosmetics with antibacterial properties. These include everyday body care products and specialized ones designed to limit bacterial growth. This study aims to assess the antimicrobial efficacy of various cosmetics against selected bacteria and yeasts naturally found on the skin.Materials and methods: The study used clinical strains of: Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecium, Candida albicans, and reference strains of: Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, and Acinetobacter baumannii ATCC 19606. Five commercially available antibacterial cosmetics were tested. Effectiveness was assessed by the reduction in bacterial numbers, expressed as log colony-forming units (CFU)×cm-3, and the size of the growth inhibition zone, expressed in mm.Results: Our research found that the highest antibacterial efficacy was achieved by the face gel and antiperspirant. The gel caused an average reduction in bacterial numbers by 4.73 log CFU×cm-3. The mattifying powder and creams were less effective. In the disc-diffusion method, the antiperspirant most frequently showed the largest inhibition zone, while the regenerating cream showed the smallest.Conclusion: The use of antibacterial cosmetics limits the growth of microorganisms, which is crucial for maintaining body hygiene and alleviating symptoms of skin diseases.

NADESs represent a modern class of extraction media that align with the principles of green chemistry. They are considered non-toxic and biodegradable, but relatively little is known about their biological activity. This study investigated the antioxidant, antibacterial, and antifungal properties of 40 NADESs. The systems were developed from primary (PRIM) based on choline chloride (ChCl), and specialized (HEVO) plant-derived metabolites, particularly based on thymol and menthol. Their antioxidant activity was evaluated using spectrophotometric tests. The antimicrobial activity was evaluated by the disk diffusion method. The data obtained were analyzed using principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA). NADESs based on PRIM exhibited negligible antioxidant activity and relatively low antimicrobial activity. By contrast, NADESs containing HEVO, particularly thymol-based systems, indicated significant antioxidant activity, with stronger activity observed at higher molar proportions of thymol. In the 1,8-cineole:thymol system, ABTS activity ranged from 167.37 ± 24.17 to 861.25 ± 33.03 mg Trolox equivalents/mL NADES (molar ratios 9:1 and 1:9, respectively). The 1,8-cineole:thymol system (1:9) also showed strong antimicrobial activity, with a maximum inhibition zone of 39.33 ± 2.52 mm against Staphylococcus aureus. In summary, NADESs based on HEVO exhibit significantly stronger biological activity than those containing only PRIM.

The present study investigates the antimicrobial and preservative potentials of turmeric extracts for food industry. Turmeric extracts prepared in n-hexane, water, chloroform and ethanol were applied to meals as preservatives and antibacterial agent. The samples were assessed microbiologically (total bacterial, total fungal and total coliform counts) and organoleptically (color, odor, taste) at day zero and after 15 days intervals. Meals autoclaved for shorter time (5 min) and treated with combination of 1 % or 2 % turmeric extract preserved for longer period. These results were comparable with samples autoclaved for longer period (15 min) with out turmeric extract. The antibacterial activities of different turmeric extracts were also tested against Escherichia coli, Staphylococcus aureus, Salmonella typhi and Candida albicans by disc diffusion method. Water extracted samples of turmeric stored at room temperature inhibited the growth of Escherichia coli and Salmonella typhi while aqueous extract autoclaved at 121 °C for 30 min reduced the growth of Escherichia coli and Staphylococcus aureus. Methanol extracted samples stored at room temperature or autoclaved at 121 °C was effective to control the growth of all microbes under study. Chloroform and n-hexane extracts (stored at room temperature) showed weak activity against all tested microbes.

Wastewater treatment plants can act as a reservoir of antibiotic-resistant bacteria, antibiotic-resistance genes, and antibiotic residues. The study aims to investigate the status of the microorganism present in a built wastewater pretreatment plant (WWPTP) during degradation of cephalosporin antibiotics by NaOH at pH around 10.00–13.00 discharged from a drug manufacturing plant. The resistance phenomena of the in situ bacteria present in WWPTP were investigated by a modified disc diffusion technique below the detectability of the analytical procedure (0.05 ppm) with the treatment strategy set in the laboratory. Four different cephalosporins (Cefadroxil, Cefaclor, Ceftriaxone, and Cefepime) were used to prepare the antibiotic discs for the experiments against two common bacterial strains named s taphylococcus aureus (ATCC 29213) and Escherichia coli (ATCC 25922). These two bacteria were cultured and evaluated in different pH environments (pH @ 6.00 and pH @ 11.00) with variable treated cephalosporins (high and low concentration), LOQ level cephalosporins (0.1 ppm). There was no stressor effect found against these strains based on bacterial growth and zone of inhibition (ZOI) on Muller Hinton Agar (MHA) media. For instance, the standard bacterial strains were susceptible in presence of LOQ level or NaOH treated cephalosporin antibiotics solution. The same experiment was repeated with the mostly native microorganism found during wastewater pretreatment executed in situ into the WWPTP. The laboratory-developed pretreatment method effectively degrades cephalosporins, reducing their concentration to a level (e.g., LOQ) where they no longer constitute a primary stressor for resistance.

The possibilities of the practical utilization of essential oils (EOs) from various plant species in the food industry have attracted the attention of the scientific community. Following our previous studies, the antifungal activities of three further commercial EOs, Melaleuca armillaris subsp. armillaris (rosalina; REO), Melaleuca quinquenervia (niaouli; NEO), and Abies alba (fir; FEO), were evaluated in the present research in respect to their chemical profiles, over four different concentrations, 62.5 μL/L, 125 μL/L, 250 μL/L, and 500 μL/L. The findings revealed that the major compounds of REO, NEO, and FEO were linalool (47.5%), 1,8-cineole (40.8%), and α-pinene (25.2%), respectively. In vitro antifungal determinations showed that the inhibition zones of a Penicillium spp. mycelial growth ranged from no inhibitory effectiveness (00.00 ± 00.00 mm) to 16.00 ± 1.00 mm, indicating a very strong antifungal activity which was detected against P. citrinum after the highest REO concentration exposure. Furthermore, the in situ antifungal efficacy of all EOs investigated was shown to be dose-dependent. In this sense, we have found that the highest concentration (500 µL/L) of REO, NEO, and FEO significantly reduced (p < 0.05) the growth of all Penicillium strains inoculated on the bread, carrot, and potato models. These results indicate that the investigated EOs may be promising innovative agents in order to extend the shelf life of different types of food products, such as bread, carrot and potato.

Antimicrobial in vitro and in situ efficacies of Cymbopogon citratus essential oil (lemongrass, LGEO) against 17 spoilage microorganisms (bacteria, yeasts and fungi) were evaluated. Additionally, its chemical composition, and antioxidant and antibiofilm activities were investigated. The LGEO exhibited a strong antioxidant activity (84.0 ± 0.1%), and its main constituents were citral (61.5%), geraniol (6.6%) and 1,8-cineole (6.4%). An in vitro antimicrobial evaluation revealed the lowest inhibition zone (1.00 ± 0.00 mm) in Pseudomonas fluorescens, and the highest inhibition zone (18.00 ± 2.46 mm) in Candida krusei. The values for the minimal inhibitory concentration were determined to be the lowest for Salmonella enteritidis and the highest for C. albicans. Furthermore, the concentration of ≥250 µL/L of LGEO suppressed the growth of Penicillium aurantiogriseum, Penicillium expansum, Penicillium chrysogenum and Penicillium italicum. The changes in the molecular structure of the biofilms produced by Pseudomonas fluorescens and Salmonella enteritidis, after their treatment with LGEO, confirmed its action on both biofilm-forming bacteria. Moreover, an in situ antimicrobial activity evaluation displayed the most effective inhibitory effectiveness of LGEO against Micrococcus luteus, Serratia marcescens (250 µL/L) and Penicillium expansum (125, 250 and 500 µL/L) growing on a carrot. Our results suggest that LGEO, as a promising natural antimicrobial agent, can be applied in the innovative packaging of bakery products and different types of vegetables, which combines commonly used packing materials with the addition of LGEO.