Growth Of Pseudomonas Research Articles

The Antibacterial Activity of Dayak Onion Ethanol Extract (Eleutherine Palmifolia (L.) Merr) and Red Ginger (Zingiber Officinale Rosc Var. Rubrum) on Growth Gi Tract Pathogen Bacteria

Antibiotic resistance in gastrointestinal bacterial infections can be overcome by alternatives using medicinal plants such as Dayak bulbs (Eleutherine palmifolia (L.) Merr) and red ginger rhizome (Zingiber officinale Rosc. Var. Rubrum). This study aims to examine the antibacterial activity of a combination of ethanol extracts of Dayak bulbs with red ginger rhizomes and the effectiveness of the extract combinations in inhibiting the growth of Pseudomonas sp. and Bacillus sp. This research is an experimental study with a completely randomized design (CRD) of one factor, namely a combination of ethanol extract of Dayak onion tubers and red ginger rhizomes with 4 variations of concentration 25, 50, 75, and 100 mg/mL at 2 ratios of the combination of 2:1 and 3:1 for 48 experimental units. Tests were carried out on bacteria Pseudomonas sp. and Bacillus sp. in vitro with agar diffusion technique (Kirby Bauer test), while the positive control was Chloramphenicol 30 μg / mL and the negative controls were sterile aquadest. Data analysis in this study used the ANOVA test. The results showed ethanol extract of dayak onion bulbs, red ginger rhizomes, and a combination of the two extracts have antibacterial activity so which can be inhibiting the growth of Pseudomonas sp. and Bacillus sp. The combination of ethanol extract from dayak onion bulbs and has the greatest antibacterial activity at a 3:1 combination of 56.95% against the growth of Pseudomonas sp. and 109.72% against the growth of Bacillus sp.

Physicochemical and microbiological analysis of goose meat

Temperature plays a crucial role in the storage of meat. Low temperature effectively slows down the growth rate of microorganisms and enzymatic activity that causes meat spoilage. Frozen storage of meat allows consumers to choose meat’s date of consumption during storage without losing its sensory quality. This work is committed to the effects of freezing and refrigeration on quality and safety of food. The study aims to determine whether different frozen storage temperatures and duration affect the quality of raw goose meat and its processing characteristics after thawing. This information could be a valuable contribution to the scientific literature concerning storage of meat. The focus was on goose meat and sausages. The meat was frozen in three independent runs for 3 and 6 months at -20°C and -70°C. The thawed meat was subjected to physicochemical and microbiological analyses and then turned into raw sausages. Frozen meat sausages showed significantly higher thiobarbituric acid (TBA) values after 2 and 4 weeks of the experiment, compared to the control group. Frozen storage also reduced the growth of Pseudomonas spp. and Enterobacteriaceae for all storage temperatures. Findings of the present study could be used to preserve quality and taste of products during meat processing.

Surfactant-enhanced bioremediation of petroleum-contaminated soil and microbial community response: A field study

Surfactant-enhanced bioremediation (SEBR) is frequently employed to clean up soil polluted with petroleum hydrocarbons, but few studies have focused on how surfactants affect microbial communities and different fractions of petroleum hydrocarbons, particularly in the field. Here, the surfactants sodium dodecyl benzene sulfonate (SDBS), alpha olefin sulfonate (AOS), Triton X-100 (TX-100), Tween80, and rhamnolipid were combined with the oil-degrading bacterium Pseudomonas sp. SB to remediate oil-contaminated soil in the laboratory. AOS gave the highest removal efficiency (65.1%) of total petroleum hydrocarbons (TPHs). Therefore, AOS was used in a field experiment with Pseudomonas sp. SB and the removal efficiency of TPHs and long-chain hydrocarbons C21–C40 reached 57.4 and 53.0%, respectively, significantly higher than the other treatments. During bioremediation the addition of Pseudomonas sp. SB significantly stimulated the growth of bacterial genera such as Alcanivorax, Luteimonas, Parvibaculum, Stenotrophomonas, and Pseudomonas and AOS further stimulated the growth of Sphingobacterium, Pseudomonas and Alcanivorax. This study validates the feasibility of surfactant-enhanced bioremediation in the field and partly reveals the mechanism of surfactant-enhanced bioremediation from the perspective of changes in different fractions of petroleum and microbial community dynamics.

Aerobic and facultative anaerobic Klebsiella pneumoniae strains establish mutual competition and jointly promote Musca domestica development.

The gut microenvironment in housefly harbors a rich and diverse microbial community which plays a crucial role in larval development. However, little is known about the impact of specific symbiotic bacteria on larval development as well as the composition of the indigenous gut microbiota of housefly. In the present study, two novel strains were isolated from housefly larval gut, i.e., Klebsiella pneumoniae KX (aerobe) and K. pneumoniae KY (facultative anaerobe). Moreover, the bacteriophages KXP/KYP specific for strains KX and KY were used to analyse the effects of K. pneumoniae on larval development. Our results showed that dietary supplementation with K. pneumoniae KX and KY individually promoted housefly larval growth. However, no significant synergistic effect was observed when the two bacterial strains were administered in combination. In addition, using high-throughput sequencing, it was demonstrated that the abundance of Klebsiella increased whereas that of Provincia, Serratia and Morganella decreased when housefly larvae received supplementation with K. pneumoniae KX, KY or the KX-KY mixture. Moreover, when used combined, K. pneumoniae KX/KY inhibited the growth of Pseudomonas and Providencia. When the abundance of both bacterial strains simultaneously increased, a balance in total bacterial abundance was reached. Thus, it can be assumed that strains K. pneumoniae KX and KY maintain an equilibrium to facilitate their development in housefly gut, by establishing competition but also cooperation with each other to maintain the constant composition of gut bacteria in housefly larvae. Thus, our findings highlight the essential role of K. pneumoniae in regulating the composition of the gut microbiota in insects.

Characterization of the Growth of Pseudomonas sp. strain DrY135 on Acrylamide

This study investigated the growth properties of a molybdenum-reducing bacteria previously isolated for its ability to break down amides. The bacterial growth range is 500–1000 mg/L, 6.5–8.0 pH, and 30–35 °C. The presence of hazardous heavy metals such as mercury, silver, and copper impeded this bacterium's development on acrylamide. The protracted lag phase seen when growing on acrylamide demonstrates the compound's severe growth inhibition. This bacterium has the potential to be an effective acrylamide bioremediation agent due to its greater tolerance for acrylamide than other acrylamide-degrading bacteria identified in the scientific literature. The influence of initial pH on bacterial growth at room temperature indicates that the optimal pH range lies between 6.5 and 8.0. The ideal temperature range for plant growth was between 30 and 35 oC. In a series of experiments utilizing a starting concentration of 1% (w/v) of various organic carbon sources, it was determined that glucose supported the most cellular growth on acrylamide, followed by sucrose, fructose, mannose, and citrate, in descending order of efficiency, whereas mannitol did not support growth. Doses of 300 and 500 mg/L of acrylamide stimulated the most rapid growth expansion, but concentrations of 1500 mg/L and above completely halted development. Copper (Cu), lead (Pb), cadmium (Cd), chromium (Cr), and mercury (Hg) were investigated at a concentration of 2 ppm. Mercury hindered growth by 71 percent, copper by 72 percent, and cadmium by 52 percent, according to our findings. There was a linear association between the acrylamide content and the delay before this bacterium began to develop. A lag time of one to three days was found when the acrylamide content grew from 100 to 1,500 mg/L. As quantities of acrylamide increased, so did the maximal growth rate, indicating an overall pattern of increasing toxicity.

Increasing the Quality of Blood Tofu in an Industrial Slaughterhouse of Thailand

Blood tofu, or cooked duck blood curd, is a Chinese delicacy in East Asia. Its quality and shelf-life are low due to microorganism contamination during production. Therefore, the present study was performed to investigate the role of sodium diacetate (SD), sodium chloride (NaCl), and polyethylene glycol 400 (PEG) combinations in increasing the quality of blood tofu. A total of 45 cooked duck blood curd samples were randomly divided into 3 groups with 3 replicates per group. The first two groups were used to investigate the effect of SD, NaCl, and PEG combinations on microbiological and physical analyses for non-inoculated samples. Another group was used to determine the effect of antimicrobial combinations on Lactobacillus plantarum, Pseudomonas fluorescens, Salmonella typhimurium, Escherichia coli, and Staphylococcus aureus in inoculated samples that were inoculated with these bacteria. All groups were treated with control-sterilized water, 0.15% SD (w/v) + 1.25% NaCl (w/v), 0.30% SD (w/v) + 1.25% NaCl (w/v), 0.15% SD (w/v) + 0.15% PEG (w/v), and 0.15% SD (w/v) + 1.25% NaCl (w/v) + 0.15% PEG (w/v). The results indicated that soaking cooked duck blood curd samples in antimicrobial agent combinations could reduce mesophile and psychrophile bacteria counts in non-inoculated samples. Additionally, 0.15% SD + 1.25% NaCl + 0.15% PEG combination had a higher reduction in mesophile and psychrophile counts, compared to soaking the samples in 0.30% SD + 1.25% NaCl, 0.15% SD + 1.25% NaCl and 0.15% SD + 0.15% PEG combinations. Similarly, this combination showed a significant decrease in lactic acid bacteria, Pseudomonas, Salmonella, Escherichia coli, and Staphylococcus aureus counts in inoculated samples. Furthermore, soaking the samples in 0.15% SD + 1.25% NaCl + 0.15% PEG combination did not negatively affect the samples’ physical quality. Soaking the samples in 0.15% SD + 1.25% NaCl + 0.15% PEG combination inhibited the growth of mesophile, psychrophile, and Pseudomonas in non-inoculated samples after storage for 10, 6, 10, and 8 days in a slaughter warehouse at 7℃, respectively, and extended shelf-life of samples for 16 days. Regarding physical quality changes, this treatment delayed the reduction of pH, hue, hardness, and chewiness of the samples after storage for 10, 8, 12, and 10 days, respectively. Thus, SD, NaCl, and PEG combination had a high preservative potential for cooked duck blood curd used in industrial slaughterhouses. Keywords: Blood curd, Duck, Organic acid salt, Polyethylene glycol, Quality changes

Microbiological and Sensorial Quality of Beef Meat (Longissimus dorsi) Marinated with Cinnamon Extract and Stored at Various Temperatures.

Meat spoilage caused by temperature abuse is a major problem for producers, retailers, and consumers that can generate large economic losses to industries. Microbial growth of Pseudomonas spp. is the main source of spoilage during storage. Cinnamon has antimicrobial properties that may potentially be used to reduce the spoilage caused by Pseudomonas. The objectives of this study were to determine the inhibitory effect of cinnamon extract (CE) against Pseudomonas aeruginosa (ATCC 27853) and evaluate the treatment of CE on meat quality during different storage temperatures (5 °C, 10 °C, 15 °C, and 25 °C). The anti-Pseudomonas result showed that 100% (w/v) CE concentration produced a 13.50 mm zone of inhibition in a disc diffusion assay. The minimum inhibitor concentration (MIC) of CE was noted at 25% (v/v), whereas the minimum bactericidal concentration (MBC) value was observed at 50% (v/v) concentration of CE. The time-kill showed the growth of P. aeruginosa decreased from 7.64 to 5.39 log CFU/mL at MIC concentration. Total phenolic content and IC50 value of the cinnamon extract was expressed as 6.72 ± 0.87 mg GAE/g extract and 0.15 mg/mL, respectively. When the meat was marinated with 50% (v/v) CE and stored at various temperatures, the total viable count (TVC) and growth of Pseudomonas spp. were lowered as compared to the control sample. However, the reduction in microbial count in all samples was influenced by the storage temperature, where the lowered microbial count was noted in the sample treated with CE and stored at 5 and 10 °C for 48 h. The pH of meat treated with or without CE ranged from pH 5.74 to 6.48. The sensory attributes of colour, texture, and overall acceptability have a significant difference, except for odour, between marinated meat and control. The results indicate that the use of cinnamon extract as the marination agent for meat could reduce the growth of Pseudomonas spp. and therefore assist in extending the shelf life of meat at 5 and 10 °C storage temperatures.

Unraveling the effect of the combination of modified atmosphere packaging and ε-polylysine on the physicochemical properties and bacterial community of greater amberjack (Seriola dumerili).

The combined effect of ε-polylysine (PL) and modified atmosphere packaging (MAP; 60% CO2/40% N2) on the bacterial community of greater amberjack filets and their physicochemical properties was evaluated at 4°C. The total viable counts (TVC), psychrotrophic bacterial count, sensory index, texture analysis, and total volatile basic nitrogen (TVB-N) revealed that PL, MAP, and MAP + PL treatment delayed the deterioration of greater amberjack filets. These treatment groups also showed decreased accumulation of biogenic amines. High-throughput 16S rRNA gene sequencing results indicated that these treatments suppressed the growth of Pseudomonas in greater amberjack filets. Furthermore, the MAP + PL treatment group was observed to be more effective than the PL and MAP groups, extending the shelf life of greater amberjack filets by 6 days. This investigation showed that the combination of PL and MAP has the potential to retain the quality and extend the shelf life of greater amberjack.

Effect of protective cultures on spoilage bacteria and the quality of vacuum-packaged lamb meat

Protective cultures, as natural antimicrobials, have the ability to suppress the growth of spoilage bacteria and can potentially be used to extend the shelf-life of fresh meat and help reduce food waste. As there have been limited reports on the application of this approach in fresh red meat, the aim of this study was to evaluate the potential and practicality of this approach for red meat shelf-life extension based on the antimicrobial efficacy and quality impact of selected protective cultures. Two protective cultures (one containing Lactobacillus sakei and the other containing Staphylococcus carnosus and L. sakei) were applied to chill-stored (4 °C) vacuum-packaged lamb meat to determine their effects on spoilage bacteria as well as non-microbiological meat quality over a 20-day storage period. These protective cultures dominated the microbiota throughout storage and effectively suppressed the growth of common meat spoilage bacteria, Brochothrix thermosphacta, Pseudomonas spp., and Enterobacteriaceae. Meat color (measured in CIE L*a*b* color space) changed slightly in culture-treated samples in the later stage of storage, but the changes were not unacceptable based on previously reported thresholds for consumer acceptability. The mixed culture containing additional S. carnosus exhibited a slightly stronger inhibitory effect against the spoilage bacteria but also caused more changes in meat color. Protective culture addition did not significantly affect meat pH, texture, or microstructure. Overall, these results demonstrated the potential of biopreservation using protective cultures for fresh red meat shelf-life extension.

Effects of various logistics packaging on the quality and microbial variation of bigeye tuna (Thunnus obesus).

Bigeye tuna (Thunnus obesus) is an economically valuable ocean fish species. It is susceptible to contamination during storage and transportation. Having proper transportation packaging and stable temperature during transportation are critical to prevent quality deterioration. However, the influence of packaging on retaining freshness in transit remains unknown. Here, the impact of different transportation packaging on the quality and microbiological variation of bigeye tuna during the logistics process was investigated by measuring physical-chemical indexes and microbial diversity. It turned out that aluminum foil paper (AFP) group had minimum temperature fluctuation, exhibited preferable water retaining capacity and color protection effect. AFP packaging could efficiently prevent TVB-N increase and microbial growth. After 40 h, the TVB-N value was 21.28 mg/100 g and microbial total plate count was 3.53 lg CFU/g, which was within the acceptable range. Temperature fluctuations and packaging materials had a major effect on the microbial community structure of bigeye tuna. Chitinophagaceae, Acinetobacter, and Knoellia were dominant in the AFP group, while Pseudomonas, Acinetobacter, and Macrococcus were dominant in the expanded polystyrene foam (EPSF) and European logistics (EUL) groups. AFP packaging could effectively slow down the growth and reproduction of Pseudomonas, restraining the growth of microorganisms and preserve the quality of bigeye tuna. This study provides insights into understanding the effects of packaging material on maintaining quality during logistics transportation.

Comparison of composting factors, heavy metal immobilization, and microbial activity after biochar or lime application in straw-manure composting

Composting is an efficient way of disposing agricultural solid wastes as well as passivating heavy metals (HMs). Herein, equivalent (3%) biochar (BC) or lime (LM) were applied in rice straw and swine manure composting, with no additives applied as control group (CK). The results indicated that both the additives increased NO3­-N content, organic matter degradation, humus formation, and HM immobilization in composting, and the overall improvement of lime was more significant. In addition, the additives optimized the bacterial community of compost, especially for thermophilic and mature phase. Lime stimulated the growth of Bacillus, Peptostreptococcus, Clostridium, Turicibacter, Clostridiaceae and Pseudomonas, which functioned well in HM passivation via biosorption, bioleaching, or promoting HM-humus formation by secreting hydrolases. Lime (3%) as additive is recommended in swine manure composting to promote composting maturity and reduce HM risk. The study present theoretical guidance in improving composting products quality for civil and industrial composting.

Exploring the dynamic of microbial community and metabolic function in food waste composting amended with traditional Chinese medicine residues

The aim of this study was to explore the dynamic of microbial community and metabolic function in food waste composting amended with traditional Chinese medicine residues (TCMRs). Results suggested that TCMRs addition at up to 10% leads to a higher peak temperature (60.5 °C), germination index (GI) value (119.26%), and a greater reduction in total organic carbon (TOC) content (8.08%). 10% TCMRs significantly induced the fluctuation of bacterial community composition, as well as the fungal community in the thermophilic phase. The addition of 10% TCMRs enhanced the abundance of bacterial genera such as Acetobacter, Bacillus, and Brevundimonas, as well as fungal genera such as Chaetomium, Thermascus, and Coprinopsis, which accelerated lignocellulose degradation and humification degree. Conversely, the growth of Lactobacillus and Pseudomonas was inhibited by 10% TCMRs to weaken the acidic environment and reduce nitrogen loss. Metabolic function analysis revealed that 10% TCMRs promoted the metabolism of carbohydrate and amino acid, especially citrate cycle, glycolysis/gluconeogenesis, and cysteine and methionine metabolism. Redundancy analysis showed that the carbon to nitrogen (C/N) ratio was the most significant environmental factor influencing the dynamic of bacterial and fungal communities.

Antimicrobial peptide S100A12 (calgranulin C) inhibits growth, biofilm formation, pyoverdine secretion and suppresses type VI secretion system in Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen and is the major cause of corneal infections in India and worldwide. The increase in antimicrobial resistance among Pseudomonas has prompted rise in significant research to develop alternative therapeutics. Antimicrobial peptides (AMPs) are considered as potent alternatives to combat bacterial infections. In this study, we investigated the role of S100A12, a host defense peptide, against PAO1 and an ocular clinical isolate. Increased expression of S100A12 was observed in corneal tissues obtained from Pseudomonas keratitis patients by immunohistochemistry. S100A12 significantly inhibited growth of Pseudomonas in vitro as determined from colony forming units. Furthermore, recombinant S100A12 reduced the corneal opacity and the bacterial load in a mouse model of Pseudomonas keratitis. Transcriptome changes in PAO1 in response to S100A12 was investigated using RNA sequencing. The pathway analysis of transcriptome data revealed that S100A12 inhibits expression of genes involved in pyoverdine synthesis and biofilm formation. It also impedes several important pathways like redox, pyocyanin synthesis and type 6 secretion system (T6SS). The transcriptome data was further validated by checking the expression of several affected genes by quantitative PCR. Our study sheds light on how S100A12 impacts Pseudomonas and that it might have the potential to be used as therapeutic intervention in addition to antibiotics to combat infection in future.

The Effect of Syringic Acid and Phenoxy Herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) on Soil, Rhizosphere, and Plant Endosphere Microbiome.

The integration of phytoremediation and biostimulation can improve pollutant removal from the environment. Plant secondary metabolites (PSMs), which are structurally related to xenobiotics, can stimulate the presence of microbial community members, exhibiting specialized functions toward detoxifying, and thus mitigating soil toxicity. In this study, we evaluated the effects of enrichment of 4-chloro-2-methylphenoxyacetic acid (MCPA) contaminated soil (unplanted and zucchini-planted) with syringic acid (SA) on the bacterial community structure in soil, the rhizosphere, and zucchini endosphere. Additionally, we measured the concentration of MCPA in soil and fresh biomass of zucchini. The diversity of bacterial communities differed significantly between the studied compartments (i.e., unplanted soil, rhizospheric soil, and plant endosphere: roots or leaves) and between used treatments (MCPA or/and SA application). The highest diversity indices were observed for unplanted soil and rhizosphere. Although the lowest diversity was observed among leaf endophytes, this community was significantly affected by MCPA or SA: the compounds applied separately favored the growth of Actinobacteria (especially Pseudarthrobacter), while their simultaneous addition promoted the growth of Firmicutes (especially Psychrobacillus). The application of MCPA + SA together lead also to enhanced growth of Pseudomonas, Burkholderia, Sphingomonas, and Pandoraea in the rhizosphere, while SA increased the occurrence of Pseudomonas in leaves. In addition, SA appeared to have a positive influence on the degradative potential of the bacterial communities against MCPA: its addition, followed by zucchini planting, significantly increased the removal of the herbicide (50%) from the soil without affecting, neither positively nor negatively, the plant growth.

Investigation of the relationship between microbiota dynamics and volatile changes in chilled beef steaks held under high-oxygen packaging enriched in carbon dioxide

Carbon dioxide (CO2) plays an important bacteriostatic role in high-oxygen modified atmosphere packaging (HiOx-MAP). This study aimed to explore the influence of CO2 on the volatile organic compounds (VOCs) profile in HiOx-MAP beef steaks and assess the changes in VOCs associated with microbiota dynamics during 20-days of chilled storage. Compared to control MAP (CMAP: 50% O2/50% N2), CO2-enriched MAP (TMAP: 50% O2/40% CO2/10% N2) rendered steaks with desirable appearance and odor freshness during storage through inhibiting bacterial growth and reducing the accumulation of acetoin, 2-ethyl-1-hexanol, 1,3-butanediol, diacetyl and 2-heptanone (P < 0.05). 1-Octen-3-ol and 2-ethyl-1-hexanol were main VOCs in TMAP steaks and were positively related to Brochothrix thermosphacta levels. Acetoin and 2-ethyl-1-hexanol could be used as potential spoilage indicators in CMAP steaks, which were positively related to B. thermosphacta and Pseudomonas levels. Overall, the desirable odor freshness of TMAP steaks was mainly attributed to the CO2-inhibitory effect on the off-odor VOCs production correlated with B. thermosphacta, Pseudomonas and Serratia growth.

Biochar enhanced polycyclic aromatic hydrocarbons degradation in soil planted with ryegrass: Bacterial community and degradation gene expression mechanisms

Biochar and ryegrass have been used in the remediation of polycyclic aromatic hydrocarbons (PAHs)-contaminated soils; however, the effects of different biochar application levels on the dissipation of PAHs, bacterial communities, and PAH-ring hydroxylating dioxygenase (PAH-RHDα) genes in rhizosphere soil remain unclear. In this study, enzyme activity tests, real-time quantitative polymerase chain reaction (PCR), and high-throughput sequencing were performed to investigate the effects of different proportions of rape straw biochar (1%, 2%, and 4% (w/w)) on the degradation of PAHs, as well as the associated changes in the soil bacterial community and PAH-RHDα gene expression. The results revealed that biochar enhanced the rhizoremediation of PAH-contaminated soil and that 2% biochar-treated rhizosphere soil was the most effective in removing PAHs. Furthermore, urease activity, abundance and activity of total bacteria, and PAH-degrading bacteria were enhanced in soil that was amended with biochar and ryegrass. Additionally, the activity of 16S rDNA and PAH-RHDα gram-negative (GN) genes increased with increasing biochar dosage and had a positive correlation with the removal of PAHs. Biochar changed the rhizosphere soil bacterial composition and α-diversity, and promoted the growth of Pseudomonas and Zeaxanthinibacter. In addition, the relative abundance of Pseudomonas was positively correlated with PAH removal. These findings imply that rape straw biochar can enhance the rhizoremediation of PAH-contaminated soil by changing soil bacterial communities and stimulating the expression of PAH-RHDα GN genes. The 2% of rape straw biochar combined with ryegrass would be an effective method to remediate the PAH-contaminated soil.

Role of inhaled antibiotics in children and adolescents with cystic fibrosis: Experience from the tertiary care center

Introduction:Cystic fibrosis (CF) remains under-diagnosed in Pakistan. CF population has increased tendency for Pseudomonas aeruginosa (Pa) infection and it is one of the leading causes of mortality. Utilizing inhaled antibiotics (IAs) for the treatment of Pa infection has been well established in the literature. There is limited data available on CF in Pakistan, especially regarding the efficacy of IAs. The aim of this study is to investigate the role of IAs on Pa infection in children and adolescents with CF.Methodology:CF patients enrolled between January 2012 and December 2019 were selected as part of this retrospective cohort study. CF patients from 2 to 18 years of age who cultured Pa on any respiratory sample and who had never been Pa-free in at least two sputum cultures in the previous 12 months were included. Patients were divided into an IA group and a noninhaled antibiotic (NIA) group based on the treatment they received. Follow-up was done between 3 and 6 months posttherapy on Pseudomonas growth in the sputum. The number of pulmonary exacerbations were documented for 6 months follow-up.Results:Eighty-one children with CF were enrolled during the study period, of which 39 were in the IA group and 42 were in the NIA group. There was no significant difference in their demographics and initial clinical characteristics. The mean pulmonary exacerbations after 6 months were lower in the IA group as compared to the NIA group (1.102 ± 0.50 vs. 2.45 ± 0.89: P = 0.001). Follow-up between 3 and 6 months showed greater Pseudomonas colonization in the IA group versus the NIA group (53.84% vs. 92.85%: P = 0.001).Conclusion:IAs in combination with airway clearance therapy and oral or IV antibiotics are an effective regimen for children with CF.

Synergistic effect and disinfection mechanism of combined treatment with ultrasound and slightly acidic electrolyzed water and associated preservation of mirror carp (Cyprinus carpio L.) during refrigeration storage

This study evaluated the synergistic effects and disinfection mechanism of ultrasound (US, 200 W and 30 kHz) and slightly acidic electrolysed water (SAEW, 60 mg/L and pH of 6.2) treatment and the associated preservation of mirror carp during refrigeration storage (4 °C). US and SAEW alone and US combined with SAEW (US + SAEW) showed the lower water loss of fish. Fish treated with US + SAEW exhibited significantly lower degrees of lipid oxidation and protein degradation (P < 0.05). Microbiological results showed that US + SAEW inhibited the growth of Pseudomonas and activity of endogenous enzymes; also, US + SAEW decreased the relative activities of 2,3,5-triphenyl tetrazolium chloride-dehydrogenase (TTC-dehydrogenase) and ATP-ase in Pseudomonas by 65.89% and 10.26%, respectively. The combination of US + SAEW destroyed the cellular membrane and aggravated the leakage of nucleic acid and protein of Pseudomonas, and effectively inhibited the activity of antioxidant enzyme. This study reports a new industrial method for preserving refrigerated fish.

Synthesis and characterization of new functionalized chitosan and its antimicrobial and in-vitro release behavior from topical gel

Recently, chitosan and its derivatives have been gaining more attention due to their high integration into various biomedical applications. Herein, a new chitosan derivative was prepared by linking the chitosan (Cs) with a novel heterocyclic compound, Benzoimidazolyl-thiadiazole (BzimTD) to form Cs-BzimTD. The synthesis of the new chitosan derivative was confirmed by Fourier-Transform Infrared (FT-IR) spectroscopy, proton nuclear magnetic resonance (1H NMR), thermogravimetric (TGA-DTG) analysis, elemental analysis, and UV–Visible spectrophotometer. Data showed the high efficacy of functionalized Cs-BzimTD to inhibit the growth of pathogenic microbes, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans, with inhibition zones of 15.3 ± 0.6 – 9.2 ± 0.3 mm. Also, Cs-BzimTD was applied in a topical gel formulation by using two different polymers, Carbopol 940 (CP) and Carboxymethyl Cellulose (CMC) to form three gel formulations: Cs-BzimTD-CP, Cs-BzimTD-CMC, and Cs-BzimTD-CP-CMC. The new gels were checked for physical appearance, viscosity, Cs-BzimTD release, pH, spread-ability, and drug content. The results showed that all formulations were clear, transparent, and homogeneous with non-irritant pH values for skin (6.4 – 6.8). The spread-ability was found in the range of 7.1 – 9.4 g.cm/s. The Cs-BzimTD-CP formula showed the maximal Cs-BzimTD content percentage (86.5%) and the Cs-BzimTD release varied from 89.9 to 81.6% after 8 h depending on the gel formulation, with a maximum release achieved for Cs-BzimTD-CMC.

Effects of sorbitol, vacuum packaging and SVC treatment on the microbiota changes and quality of Russian sturgeon (Acipenser gueldenstaedti)

The effects of 10% sorbitol solution (w/v), vacuum packaging and sous-vide cooking (SVC) treatment on the microbial community composition and quality of Russian sturgeon fillets stored at 4 °C were researched over 12 days in this study. The combination of sorbitol solution and SVC had a beneficial effect on maintaining the quality of Russian sturgeon fillets during refrigerated storage. The fillets were on the verge of spoilage on the 12th day of storage, and compared with the control group, there was a 6-day lag period. In addition, the sorbitol solution and SVC can effectively reduce the growth of Pseudomonas , the main microbial group in the final storage period. The results showed that 10% sorbitol solution (w/v) and SVC treatment can extend the shelf life of Russian sturgeon fillets at 4 °C mainly due to their inhibitory effects on the main spoilage bacteria. • Sous-vide cooking effectively slow down microorganisms growth of Russian sturgeon. • 10% sorbitol solution (w/v) prolong the shelf life of sturgeon fillets. • SVC and sorbitol effectively inhibit the increase of the abundance of Pseudomonas. • Sorbitol had no bad effect on the elasticity and hardness of sturgeon fillets. • The sturgeon fillets treated with SVC and sorbitol have good biosafety.