Plate Count Research Articles

MICROBIAL CONTAMINATION IN MIXED SYRUP CONTAINING ERDOSTEIN AND CETIRIZIN STORED AT DIFFERENT STORAGE TEMPERATURE

Pharmaceutical services include drug dispensing activities, including drug compounding. Drug compounding is the process of mixing or changing ingredients to produce drugs that suit patient needs. Unmonitored storage conditions for compounded drugs in the community can affect the evaluation of the physical, chemical, and microbial contamination stability. The aim of this study was to determine the effect of storage temperature on the results of the evaluation of microbial contamination in compounding syrup pharmaceuticals, so it can provide education to the public about the storage patterns that have been carried out so far. Evaluation of microbial contamination in this study included contamination of the Total Yeast and Mold Count (TYMC) and Total Plate Count (TPC). The objective of this study was a mixture of Erdostein syrup and cetirizine tablets. The research materials used for the microbial contamination test were mineral water, sterile water, Plate Count Agar (PCA) media, and Potato Dextrose Agar (PDA). The results of the study in the form of TYMC and TPC on day 0 were 0 cfu/mL. After 7 days of storage, microorganisms, namely TYMC, grew at room temperature (<30°C) 4.98x102 cfu/mL and cold temperature (2-8°C) 2.2x102 cfu/mL. The TPC results at room temperature storage (<30°C) were 8.33x102 cfu/mL and at cold temperatures (2-8°C) were 3.67x102 cfu/mL ...

Hands-on learning for probiotic quality assessment: enhancing microbiology education through applied microbial counting techniques.

The microbial plate count continues to be an essential technique in food microbiology research and quality control. In food science education, this technique is often taught through traditional fact-based methods, requiring students to follow pre-established protocols. This approach may not fully engage students or enhance their problem-solving skills. Eighty-two final-year Food Science and Technology bachelor's students at the University of Milan were asked to combine their knowledge on general microbiology and microbial physiology for quality assessment of different probiotic products, including freeze-dried cells, fermented milk, and bacterial spore suspension. They were required to select the appropriate culture media, incubation conditions, and treatments based on flow cytometry cell quantification to optimize microbial plate counts and selectively count the different microbial species present in the probiotic formulations. The project aimed to bridge theoretical knowledge with practical applications, emphasizing the most appropriate procedure for viable and cultivable cell quantification, particularly relevant in probiotic formulation. Survey feedback indicated high satisfaction and relevance to future careers, with the majority finding the activity challenging yet engaging. The project demonstrated the effectiveness of combining different microbiological techniques in education, fostering a deeper understanding of the cultivability of probiotics and the role of selective agents.

Reduced Growth of Salmonella enterica and Listeria monocytogenes on Outdoor- Vs. Indoor-Grown Kale (Brassica oleracea var. acephala).

To compare the abilities of Salmonella enterica and Listeria monocytogenes to grow on kale (Brassica oleracea var. acephala) grown in an indoor vertical hydroponic system (IVHS) or outdoors. IVHS- and outdoor-grown kale was inoculated with L. monocytogenes and incubated at 4°C for 9 days or with S. enterica and incubated at 20°C for 24h. L. monocytogenes showed significant growth on the IVHS-grown kale after 6 days but was unable to grow on the outdoor-grown kale. S. enterica grew on both types of kale but to significantly greater numbers on the IVHS-grown kale (P<0.05). Plate counts of indigenous bacteria revealed that the outdoor-grown kale contained>2 log more culturable bacteria g-1 than the IVHS-grown kale. Analysis of 16S rRNA gene sequence libraries derived from the IVHS- and outdoor-grown kale revealed no significant differences in alpha diversity or community composition. The ability of the pathogens to grow on outdoor- or IVHS-grown kale do not appear to be related to the microbial population structures but to the levels of indigenous bacteria. We propose that the reduced bacterial cell density on the IVHS-grown kale is the result of reduced bacterial community productivity that supplies the pathogens with space and nutrients for growth.

Assessment of Food Safety Practices, Associated Factors and Microbial Contamination of Fried Nile Perch in Mwanza City Markets: A Cross-Sectional Study

Unsatisfactory hygienic practices can lead to food-borne pathogen contamination in fish and fishery products, posing serious health concerns for consumers. This study assessed the food safety practices, their associated factors, and microbial contamination levels of fried Nile Perch in Mwanza City across three markets: Kirumba, Butimba, and Nyakato. A cross-sectional study using a structured questionnaire examined the food safety practices of traders and processors, and their associated factors, including experience, income, and training. Standard methods for microbial analysis were conducted to determine the levels of coliforms, Escherichia coli, and Staphylococcus aureus. SPSS version 27 was used to compute the frequency and percentages. The factors and behaviours of fried Nile perch processors and traders were assessed using a 95% chi-square test. R software was employed to perform the Aligned Rank Transformation on market microbiological mean contamination. Tukey's Honest Significant Difference was employed for post hoc group comparisons. The results show that the transportation of raw fish at ambient temperature conditions showed a significant association across markets (X²=6.153, p=0.046), risking high levels of microbial contamination. Furthermore, tap water served as the predominant water source in the Butimba (88.9%), Kirumba (90%), and Nyakato (100%) marketplaces, despite the insufficient hand-washing facilities in the markets. Low income significantly affected the clear separation between storage and processing areas (X²=16.201, p=0.013), while insufficient training was related to inadequate temperature control (X²=6.032,p=0.014). Fried fish from all markets exceeded the safe limits of assessed microorganisms, with Nyakato having the highest levels of total plate count (9.53 log CFU/g), coliforms (8.74 log CFU/g), and S. aureus (5.51 log CFU/g), posing significant risks of food-borne illnesses upon consumption. Contamination levels differed significantly between markets (p&lt;0.05), despite similar activities across locations. Consumers should reheat fried Nile perch before consumption to avoid foodborne illnesses, and the government should offer formal training in food safety and environmental cleanliness to food safety operators to facilitate compliance with safety regulations.

Innovative zero-valent cobalt decoration on MIL-88 A(Fe)@β-CD for high-efficiency and reusable cr(VI) removal

Herein, the magnetic ZVCo-MIL-88 A(Fe)@β-CD composite was fabricated via post-synthetic decoration of MIL-88 A(Fe)@β-CD with ZVCo to produce a magnetic efficient adsorbent for Cr(VI) removal. The experimental findings denoted that the ZVCo decoration boosted the adsorption capability of MIL-88 A(Fe)@β-CD, where the adsorption % of Cr(VI) improved from 73.07 to 94.02% after its decoration with 10 wt% of ZVCo. Furthermore, the ZVCo decoration ameliorated the recycling feature of MIL-88 A(Fe)@β-CD since the removal % of Cr(VI) by MIL-88 A(Fe)@β-CD and ZVCo-MIL-88 A(Fe)@β-CD reached 27.24 and 84.98%, respectively. The optimization experiments of the Cr(VI) ions clarified that the higher adsorption % fulfilled 94.02% at pH = 3, using ZVCo-MIL-88 A(Fe)@β-CD dosage = 0.5 g/L, Cr(VI) concentration = 50 mg/L, and at room temperature. Notably, the concentration of the adsorbed Cr(VI) brings off the equilibrium stage within an hour, implying the fast adsorption property of ZVCo-MIL-88 A(Fe)@β-CD. The kinetic and isotherms assessments denoted the contribution of the physical and chemical adsorption pathways in adsorbing the Cr(VI) species onto ZVCo-MIL-88 A(Fe)@β-CD. In addition, the XPS spectra and zeta potential results supposed that the process inside the Cr(VI)/ZVCo-MIL-88 A(Fe)@β-CD system proceeded through reduction reaction, coordination bonds, electrostatic interactions, and pore-filling mechanisms.

Nano-coating with silicon dioxide to reduce the occurrence of bacterial contamination in a pig abattoir drinking system.

A recently discovered source for infection of slaughter pigs, and thus entry for bacteria into the food chain, is the installed drinking equipment in lairage pens of pig abattoirs. To mitigate this, nano-coating of stainless steel, currently used in human medicine fields as well as in other parts of the food chain, appears as promising technology. In this study, silicon dioxide nano-coating was applied to six drinkers and installed for one and three months in a lairage of a pig abattoir, while results were compared with those of drinkers that had not been nano-coated. Laboratory examination of eight sample types related to the drinkers was conducted for total aerobic plate count, Enterobacteriaceae count, Pseudomonas spp. count, Salmonella presence, pathogenic Yersinia enterocolitica presence, Listeria monocytogenes presence and methicillin-resistant Staphylococcus aureus presence. The nipple drinker, which the pigs take into their mouth for drinking, was then examined using scanning electron microscopy and elemental analysis. The nano-coating did not produce statistically significant reductions in the loads or presence of these bacteria compared to the same but uncoated drinking equipment used under the same conditions. Further studies should focus on the implementation of combined methods, such as nano-coating and sanitary treatment, as well as modifications to the coating itself, to produce meaningful reductions of the bacterial loads on/in abattoir lairage drinking equipment.

Chemical and microbiological assessment of early wine fermentation phase can predict yeast cell viability during post-fermentation process.

The management of post-fermentation phase is essential for the protection of wine oxidation. The prolonged contact of yeast lees and wine can help to limit this problem, although off-flavours can originate. It is known that some cellular components (mannoproteins, lipids, glutathione, etc.) released into the wine influence oxygen protection; however, still active cells could contribute to maintaining protection against oxidation. To date, in the literature there is a lack of data that evaluates cell viability, especially in the post-fermentation phase, particularly using methods different by plate count that identifies only a small part of the viable population. The aim of the work was to investigate the yeast viability of 12 wine Saccharomyces cerevisiae strains during 45days after the fermentation in natural grape juice. The major fermentation parameters were measured at early phase (40h) and at the end of the process, and were correlated with total and viable cells in the post-fermentation phase. Contrary to what has been observed in the literature, this work demonstrates that cell viability in the post-fermentation phase is very high and dependent on the yeast strain. A predictive model that can estimate viability in the post-fermentation phase, based on parameters measured at the early fermentation phase, was successfully set up. This approach can be adopted by wineries or winemakers as it uses fermentation data (sugar and nitrogen residues, ethanol and glycerol production, total cell count) obtained through simple chemical and microbiological analyses.

Microbial indicators for water quality in recirculating shower technology.

Recirculating showers save up to 70-80% of the water and energy use of conventional showers, but water quality in these systems are not studied very well due to the technology's early stages. The aim of this study was to provide an overview of information available on which microorganisms were investigated and at which densities. Based on this platform we further aimed at identifying key microbial indicators and pathogens for monitoring water quality in these systems by integrating data from the top five waterborne outbreaks with findings from studies on (1) microbial investigations in reuse projects involving shower effluents or combined bathroom streams, (2) shower water effluents, and (3) biofilms in conventional showers. Outbreak data were extracted from the National Outbreak Reporting System (NORS) and a systematic literature review, supplemented with additional references found within the papers. Escherichia coli, Total Coliforms, enterococci as faecal indicator bacteria and the heterotrophic plate count were reported in shower effluents at variable, but generally high concentrations, indicating these organisms to be relevant as indication of faecal bacterial contamination and as general microbial densities in recirculating showers. Pseudomonas aeruginosa was abundant in conventional shower biofilms, detectable in shower effluents at concentrations in the range of 2-4 logs CFU/100mL and ranked among the top five etiological agents of waterborne outbreaks. Consequently, P. aeruginosa is considered as a significant reference pathogen for assessing water quality in recirculating shower systems. A diverse range of Legionella species, particularly Legionella pneumophila, are the primary cause of waterborne outbreaks, and persist in conventional shower biofilms. Therefore, we consider it to be significant as an indicator species in monitoring water quality. Staphylococcus aureus, Mycobacterium spp., and fungi such as Candida albicans could serve as supplementary microbial parameters. Trace organisms such as protozoa (Cryptosporidium spp. and Giardia spp.) and model viruses are also recommended for assessing treatment efficacy. In conclusion, while further research is required to validate these findings, this review critically evaluates relevant pathogens, creating the basis for future microbial water quality assessments in recirculating showers.

Microbiological Quality of Dried Bombay Duck (Harpodon Nehereus) Samples Obtained from North-Eastern Bangladesh (Sylhet District)

This research was selected to assess the microbial and sensory quality of dried Bombay duck (loitta) in Sylhet district. Fourty eight (48) samples of dried Bombay duck (loitta) were collected from eight Upazila dried fish markets in Sylhet district in each of the eight upazilas during September 2022 to February 2023, the study collected 48 samples from two markets in each of the eight upazilas. Microbiological analyses included Aerobic Plate Count (APC), Total Coliform Count (TCC), presence of Escherichia coli &amp; Salmonella spp., and sensory evaluation. Results revealed that aerobic plate counts showed the highest (log 5.69 ± 0.2) in Gowainghat upazila markets and the lowest (log 3.453 ± 0.2) in Sylhet sadar market. Total Coliform counts (ranged from 21 ± 1 to 80 ± 3 MPN/g) of the samples analyzed remained within permissible limits. The prevalence of Escherichia coli was found the highest in Gowainghat (67%) and the lowest in Sylhet Sadar and South Surma (17%), and the prevalence of Salmonella spp. was found the highest in Companiganj and Fenchuganj (67%) and the lowest in Sylhet Sadar (17%). Sensory examination favored samples from South Surma. Presence of pathogenic bacteria suggests unsanitary processing conditions. Dried fish quality varied significantly among upazilas, emphasizing the need for improved hygiene and sanitation practices to ensure safe, high-quality dried loitta production. J. Asiat. Soc. Bangladesh, Sci. 50(1-2): 101-111, June-December 2024

Impurity profiling of synthetic cyclic peptides based on orthogonality between hydrophilic-interaction and reversed-phase liquid chromatography.

Owing to their high selectivity and low toxicity, synthetic cyclic peptides hold promise as bioactive therapeutics. The corresponding impurity analysis typically relies on reversed-phase high-performance liquid chromatography (RP-HPLC), which, however, often provides inaccurate results because of the abundance of chemically similar impurities. To bridge this gap, hydrophilic-interaction liquid chromatography (HILIC), a technique orthogonal to RP-HPLC, was herein used with an ultraviolet detector to analyze the impurities of four cyclic peptides. Each of these peptides comprises nine amino acids (both natural and nonnatural) and features neutral, acidic, basic, or zwitterionic residues incorporated at positions 3 and 6. Three polymer-based HILIC columns (acidic, basic and zwitterionic) were newly employed, and seven mobile phases were used to investigate the effects of additives and pH. Derringer's desirability functions based on five criteria (purity, impurity factor, peak symmetry factor, theoretical plate number, and retention time) were employed to identify optimal screening conditions. Ammonium acetate was identified as an effective additive, and polymeric selectors with vinylpyridine and phosphoryl choline residues were shown to be effective irrespective of the peptide features. Optimized HILIC conditions were established for each peptide, and the corresponding impurity elution profiles were compared with those obtained by RP-HPLC using a column filled with octadecylsilyl-functionalized silica. RP-HPLC and HILIC were revealed to be mutually orthogonal, i.e., most impurities with small RP-HPLC retention times had large HILIC retention times, and vice versa. The results help make the purity evaluation of synthetic peptides more accurate, thus paving the way for their efficient purification.

Optimized Design of a Triangular Shear Piezoelectric Sensor Using Non-Dominated Sorting Genetic Algorithm-II(NSGA-II)

A new piezoelectric sensor with a triangular shear structure was designed to conduct the deformation monitoring of geotechnical bodies in mining airspace. Firstly, a three-dimensional sensor model was developed to analyze the impact of structural parameters on resonant frequency and voltage, utilizing both finite element and experimental methods. Secondly, the NSGA-II genetic algorithm was employed to optimize the sensor’s structural parameters, focusing on resonant frequency and voltage, resulting in a Pareto optimal solution set. For the first time, the optimal parameter combination was selected by minimizing the difference method (the height of the mass block was 10.6 mm, the thickness of the piezoelectric plate was 3.29 mm, the height of the piezoelectric plate was 8.1 mm, and the height of the central column was 19 mm). The optimized sensor exhibited a 4.14% increase in resonant frequency and a 9.11% increase in voltage. Finally, the prototype was fabricated, and the effectiveness and feasibility of the design were verified through experiments. The findings indicate the sensor’s promising potential for monitoring geotechnical deformation in mining airspace regions.

P-2230. Light Transmission-based Quantitation of Bacterial Growth on an Agar Plate

Abstract Background The growth of microorganisms in liquid culture is usually evaluated by measuring light transmission and calculating optical density (OD). We have developed a new thin-film transistor image sensor (1000 x 1000 pixels) to measure light transmission through agar plates (Figure 1). Similar to OD in liquid culture, cells grown on the surface of agar plates scatter light and reduce the intensity of transmitted light as the cells grow. This device captures a single image every 5 minutes, enabling in-depth time-lapse studies of cell growth when combined with digital image analysis. Here we present proof-of-concept studies to apply this growth monitoring system for quantitative growth assessment. Figure 1. Schematic representation of the bacterial growth monitoring system. Methods Escherichia coli cells were spread on a plate count agar plate and the growth was monitored over 745 min using the device. The optical density was calculated in the same way as OD of liquid culture: OD = -log10(I/I0) where I0 and I represent the intensity of incident light and transmitted light, respectively. The intensity of I0 and I was measured pixel by pixel; I0 was defined as the average of the first ten frames; I was defined as the average of the three consecutive frames (n-1, n, n+1) to reduce noise. The pixel size is 100 x 100 μm. Figure 2. Quantitative evaluation of E. coli colony growth on an agar plate. (A) The last (149th) frame was binarized at the threshold of OD 0.02 to extract colony contours. The circled and numbered colonies were analyzed in (B). The numbers along the horizontal and vertical axes represent the pixel positions. (B) The OD values of the central pixels of the colonies were tracked over time. Results Colony contours were extracted from the binary image, at the threshold of OD 0.02, of the last (149th) frame (Figure 2A). Five colonies with the highest and lowest OD were selected and the OD values of their central pixels were plotted over time, showing distinct modes of increase (Figure 2B). Next, one colony (#3) was chosen to analyze whether the OD correlated with colony size. One axis represents the OD of its central pixel. The other represents the number of pixels that showed OD 0.02 or more in the 20 x 20 pixel area surrounding the central pixel. As shown in Figure 3, after approximately 550 min, the cell growing area began to expand in correlation with the continued increase in OD. The binarized images, at the indicated time points, also showed the area expansion. Cell growth Figure 3. Cell growth in a single pixel and colony expansion in a wider area. The colony #3 in Figure 2 was analyzed. Shown are the OD of the central pixel (light green) and the number of the pixels that showed OD 0.02 or more in the 20 x 20 pixel area surrounding the central pixel (dark green). The binarized images, at the indicated time points, also showed the area expansion. Conclusion The light transmission-based growth monitoring system enabled us to quantitatively evaluate growth on the agar plate. The pixel-by-pixel analysis provided detailed information on the colony formation and growth. This system can be used in a broad spectrum of microorganism research and inspection. Disclosures Masakazu Nakajima, B. Engineering, CarbGeM Inc.: Board Member|CarbGeM Inc.: Ownership Interest

P-1489. Shaken Not Stirred: Novel Antibiotic Cocktails to Combat Pan-Drug Resistant Klebsiella pneumoniae

Abstract Background K. pneumoniae producing Metallo-Beta-Lactamases (MBL) confers resistance to a large spectrum of beta-lactam antibiotics which is a cause for significant concern. Novel combinatorial therapies can be an effective option for treating MBL Gram-negatives. The present study assessed the synergistic potential of Polymyxin B combinatorial strategies to combat the rising tide of PDR Gram-negative strains which have emerged worldwide. Methods K. pneumoniae producing blaNDM-5, blaCTX-M-55 and mcr-1 was exposed to an array of therapeutic regimens in a Hollow Fiber Infection Model (HFIM) over 9 days. These regimen arms included Polymyxin B (fCss = 4 mg/L), Aztreonam (fCss = 21 mg/L) + Avibactam (fCss = 5.5 mg/L), Aztreonam (fCss = 21 mg/L) + Avibactam (fCss = 5.5 mg/L) + Polymyxin B (fCss = 4 mg/L). Bacterial plate counts were taken throughout the experiment. Samples were also fixed and imaged under a Scanning Electron Microscope. Results Closely mirroring the growth control, Polymyxin B monotherapy did not inhibit the growth of K. pneumoniae S200. The clinical combination of aztreonam + avibactam demonstrated initial bactericidal activity with 6 log fold reduction (total count 1.6 log10 CFU/mL) over 24h followed by rapid recovery as the counts bounced back to 6.07 log10 CFU/mL by 48h. Reversion experiments demonstrated complete regrowth to 9.53 log10 CFU/mL by the 216h time point. In contrast, the addition of polymyxin B to the β-lactam/β-lactamase inhibitor combination resulted in prolonged marked bactericidal activity with 6.05 log fold reduction within 24h and eventually below the detectable limits over 168h.This was supported by tracking the evolution of salient phenotypic alterations using SEMs over 216h that showed filamentation in response to aztreonam containing regimens and lack of viable cells as well as overwhelming presence of cellular debris in Polymyxin B combination arm at 24 and 168h. Conclusion The results of the present study suggest that despite the intrinsic mcr-1 and blaNDM-5 resistance mechanisms our novel antibiotic cocktails show significant promise. Novel therapeutic options that enhance combinatorial pharmacodynamics are necessary to combat the urgent threat of MBL Gram-negative strains which are resistant to all antibiotics. Disclosures All Authors: No reported disclosures

P-356. Reduction of high-touch surface aerobic bacteria and fungi colony counts with the implementation of ActivePure continuous disinfection technology

Abstract Background As hospitals nationwide rebound from the effects of the COVID pandemic, reduced staffing and increased hospital-acquired infections (HAIs) are still challenges. Surface disinfection plays a pivotal role in the prevention of HAIs. To improve high-touch surface disinfection and remove the dependence on the human factor, ActivePure continuous disinfection technology devices were installed in the Medical Intensive Care Unit (MICU) HVAC system at Ochsner LSU Health Shreveport in October 2023. ActivePure is a novel technique that kills microbes in the environment by using an advanced photocatalytic oxidation particle. Methods A prospective study was conducted in the 19-bed MICU. Two weeks before device activation, 50 high-touch surface samples and 10 reservoir samples were collected by sterile sponge in situ and plated onto Nutritive (tryptic soy) agar for total aerobic microbial counts, Selective (Sabouraud dextrose) agar for total fungal counts, selective (MeReSa) agar for total MRSA counts, and CHROMagar selective for Carbapenem-Resistant Acinetobacter baumannii (CRAB). All agar plates were incubated at 30°C or 37°C (as applicable) for 48-96 hours. For evaluation, serial dilution plate counts were used to calculate the CFU per sponge for each media type. The detection limit was 10 CFU/sponge for each evaluation. After 4 weeks post-activation, 50 high-touch surface samples and 10 reservoir samples from the same pre-activation sample locations were collected and evaluated via the same methods, and the same was repeated at 9 weeks post-activation. Routine cleaning and disinfection protocols were unchanged during the entire study period. Figure 2 Results The mean aerobic bacterial and fungi surface CFUs were reduced over 99.78% (Fig 1). The mean MRSA surface CFUs were reduced by 99.99% and the mean CRAB surface CFUs were reduced by 99.75% (Fig 2). There was a 94% reduction in surfaces with greater than 500 CFUs/100cm2 of MRSA. There was a 100% reduction in reservoirs with greater than 500 CFUs/100cm2 of CRAB and 80% reduction in reservoirs with greater than 10 CFUs/100cm2 of CRAB. Conclusion The ActivePure continuous disinfection technology devices significantly reduced total aerobic bacteria, including MRSA, difficult-to-treat CRAB, and fungi surface colony counts on high-touch surfaces. Disclosures Kimberly Trosch, RN, BSN, ActivePure Technologies: Full time employee Daniel Marsh, n/a, ActivePure Medical: Advisor/Consultant

Corynebacteria from the respiratory microbiota modulate inflammatory responses and associate with a reduced pneumococcal burden in the lungs

BackgroundCertain species from the normal respiratory tract microbiota have recently been proposed to positively influence human health. Corynebacterium propinquum and C. pseudodiphtheriticum (Corynebacteria) are two Gram-positive species that frequently colonize the upper respiratory tract and strongly associate with a reduced incidence of respiratory tract infections. The specific role of Corynebacteria during respiratory health and disease is, however, largely uncharacterized.MethodRespiratory tract epithelial cells NCI-H292 and BALB/cByJ mice were inoculated with Corynebacteria (C. propinquum 2018M3 and 2019M4, and C. pseudodiphtheriticum 2019M8 and 2020M12) alone or with subsequent challenge with Streptococcus pneumoniae (pneumococci). The inflammatory response and the bacterial burden of both species over time were determined by Western blot, luciferase assay, cytokine bead array, flow cytometry and viable plate counts on blood agar plates.ResultsClinical isolates of Corynebacteria were well tolerated by human cells and mice. Corynebacteria induced a transient inflammatory response during healthy conditions in the absence of known pathogens. Pre-exposure or nasal priming with Corynebacteria did not affect subsequent acquisition of pneumococci but were associated with a modulated inflammatory response in vitro and in vivo as well as with a reduced pneumococcal burden in the respiratory tract of mice. This indicates that the presence of C. propinquum or C. pseudodiphtheriticum may protect against severe pneumococcal infections.ConclusionsIn this study, we delineate the role of Corynebacteria from the normal microbiota that epidemiologically associate with respiratory health. We show that the presence of Corynebacteria modulates the inflammatory response to pneumococci and associate with faster decrease in pneumococcal burden, primarily in the lower respiratory tract. Our data indicate that Corynebacteria has potential to protect against severe pneumococcal infections.

CuO/Cu2O Coatings via Plasma Electrolytic Oxidation on Ti–4.5Cu Alloy: A Synergistic Approach to Antibacterial Properties and Cytocompatibility

In this article, plasma electrolytic oxidation (PEO) is applied to Ti–4.5Cu alloy to prepare a Cu2O/CuO containing coating to improve the antimicrobial properties and cytocompatibility. Scanning electron microscopy and X‐ray photoelectron spectroscopy are used to characterize the surface microstructure as well as the elemental valence states, and electrochemical tests and inductively coupled plasma spectroscopy are used to determine the corrosive properties and Cu‐ion release behavior, and the antimicrobial properties are evaluated by plate counting method and the cytotoxicity is evaluated by methylthiazolyldiphenyl‐tetrazolium bromide (MTT) method. In the results, it is shown that PEO treatment significantly improves the hardness, hydrophilicity, roughness, corrosion resistance, and accelerated Cu‐ion release. In the plate counting method results, it is shown that the antimicrobial capacity of Ti–4.5Cu alloys is significantly increased to &gt;99.9% after the PEO treatment due to multiple effects of the release of Cu ions and the formation of Cu2O and CuO. Furthermore, PEO treatment promotes the proliferation of L929 cells while the surface morphology after sandblasting has a further value‐added effect on cell adhesion. It is concluded that Cu ion and the surface morphology play a decisive role in the adhesion and proliferation of the cells.

Tailoring and characterization of bioactive graft material for alveolar bone preservation and regeneration in fresh extraction sockets of dog model

The objective of this study was to tailor an osteoinductive scaffold for alveolar bone regeneration and around immediately placed implants in extraction sockets of dogs. Tailored amorphous multiporous bioactive glass (TAMP -BG) was prepared and characterized for bioactivity and response of human alveolar bone marrow mesenchymal stem cells (hABMSCs). Extraction sockets of twenty-two male mongrel dogs received TAMP-BG in the right side around implant in the distal socket of the mandibular fourth premolar (P4), while the adjacent empty mesial socket of the same tooth was filled with the same graft. Autologous bone chips were used in the left side. Animals were euthanized at 1, 2, 4, 8 &12 weeks for histological and SEM analyses. SEM/EDX, FTIR and XRD analyses displayed formation of a bioactive hydroxycarbonated apatite layer. TAMP-BG significantly increased proliferation and migration of hABMSCs. Histologically, at the 1st week, advanced bone healing was shown in TAMP-BG group. At four weeks bone density was significantly higher forTAMP-BG (92.71% ± 1.71) versus control (62.92% ± 2.02) (P = 0.0001).At eight weeks, significant increase in width of buccal plate and height of lingual bony plate was observedfor TAMP-BG grafted implant.The socket orifice width significantly decreased for autologous bone from 1 to 12 weeks (P < 0.001), while it significantly increased for TAMP-BG (P = 0.03). We conclude that TAMP-BG can provide a preservative dynamic microenvironment following extraction up to three months which can be attributed to its unique physico-chemical characteristics.

Antibiotic Susceptibility Profile of Gram-Negative Bacteria Isolated From Pond Catfish in Ketu Adie-Owe, Ado-Odo Local Government Area of Ogun State, Nigeria

The increasing number of fish ponds in Nigeria is driven by the demand for fish and fishery products. Catfish, specifically Clarias gariepinus, is popular for cultivation due to its economic significance. However, bacterial infections pose a threat to the health of catfish in these ponds, resulting in the need for antibiotic usage. This study is aimed to assess the antibiotic susceptibility pattern of Gram-negative bacteria isolated from pond catfish. This study involved isolating bacteria from the catfish skin and intestine, analyzing their biochemical characteristics, and conducting antimicrobial susceptibility testing. Fungi present in the catfish samples were also identified. The Gram-negative isolates were subjected to antibiotic susceptibility testing, revealing the prevalence of multidrug-resistant strains. The findings contribute to the understanding of antibiotic resistance in aquaculture and highlight the need for appropriate management strategies. The bacterial load in different catfish samples was examined through total plate counts and dilution effects. The results revealed variations in colony counts and CFU/ml values among the samples, with the highest bacterial load observed in the skin of large catfish. The bacterial load observed in the skin of catfish ranged from 4.7 X 103 CFU/ml to 9.8 X 103 CFU/ml, while the bacterial load observed in the intestine of catfish ranged from 3.1 X 103 CFU/ml to 5.4 X 103 CFU/ml. Biochemical testing identified specific organisms, including Enterobacter cloacae, Aeromonas hydrophila, Klebsiella pneumoniae, Citrobacter brakii, Citrobacter freundii, and Enterobacter aerogenes. Varying resistance patterns emphasize the need for careful antibiotic use and infection control in catfish aquaculture. Therefore, continuous monitoring and preventive measures are recommended.

Microbial Level and Microbiota Change of Laver in Dried Laver Processing Line During Production Seasons

To understand better the high microbial load in dried laver (Porphyra yezoensis or nori), this study analyzed the aerobic plate count (APC), coliform count, temperature change, and microbiota of processing water, laver materials, and food contact surface (FCS) samples from three processing plants during the dried laver processing season from December 2023 to April 2024. The seawater used for the first washing had a low microbial load (APCs &lt; 1–2.85 log CFU/g; coliform &lt; 1 log CFU/g) and was dominated by Proteobacteria, Firmicutes, and Bacteroidota. The microbial load of fresh laver (4.21–4.76 log CFU/g) remained unchanged after seawater washing, but significantly increased after continuous shredding, sponge dehydration, first drying, and with the seasonal temperature rise. The microbiota of laver before drying was vulnerable between processing steps and seasons, but consistently shifted back to fresh laver microflora and was dominated by Flavobacteriaceae after drying. The FCSs (except for the curtain), which had a high microbial load (APCs 5.25–8.26 log CFU/g; coliform 1.52–4.84 log CFU/g) with similar microbiota to seawater, caused the secondary contamination of laver during processing. This study revealed the microbial proliferation of laver and seawater microflora in the continuous processing line with high nutrients and with the seasonal processing water temperature rise caused by the local weather, highlighting the need for routine cleaning and sanitizing, better washing of fresh laver, and low temperature control for future dried laver production.

Films from Starch Inclusion Complexes with Bioactive Compounds as Food Packaging Material

Abstract Natural polymers are an alternative to plastics in food packaging applications due to their biodegradability, and starch is a promising candidate due to its abundance and low cost. Furthermore, amylose has the ability to form inclusion complexes with bioactive compounds, ensuring their stability; nevertheless, this property has not been exploited in food packaging applications. In the present study, films from starch inclusion complexes with bioactive compounds (carvacrol and ascorbic acid) were developed and tested as food packaging material. The formation of starch inclusion complexes resulted in films with enhanced tensile strength, without compromising their flexibility, water vapor permeability, and transparency. Fresh minced meat was packaged in films from starch inclusion complexes with bioactive compounds and refrigerated for 4 days. Films from starch inclusion complexes with ascorbic acid had the highest antioxidant activity, resulting in the most appealing color properties, while films from starch inclusion complexes with carvacrol had the highest antimicrobial activity, resulting in smaller increases in aerobic plate and psychrotrophic count. Consequently, the formation of starch inclusion complexes with bioactive compounds is a promising technology for the development of biodegradable, active food packaging materials.