Viable Bacterial Counts Research Articles

ISOLATION AND IDENTIFICATION OF FUNGI AND BACTERIA FROM SOME SPOILED FRUITS AND VEGETABLES

Fruits and vegetables provide an ideal condition for the growth of microorganisms. They contaminate fruits and vegetable and made them insufficient for consumption. Many fungal and bacterial species are responsible for the spoilage of fruits and vegetables. In our present study, an investigation has been carried out to isolate and identify the fungal and bacterial species which are responsible for the spoilage of some fruits and vegetable particularly apple, grapes and tomato. Samples of contaminated fruits and vegetables were collected from three different markets (Tezpur Bazaar, Mission Chariali Bazaar and Poruwa Bazaar) and were immediately surface sterilized and studied.10 fungal isolates were found to be most commonly occurring in all of the samples, Similarly many isolates of bacteria were found to be common contaminants from the three samples. Biochemical tests and viable bacterial counts (10-2)/g of sample was also calculated.

Effects of toothbrush abrasion on surface and antibacterial properties of hydroxyapatite-tryptophan complex with gray titania.

Photocatalysts have attracted attention in the medical field for their antibacterial effects. However, typical photocatalysts are activated by ultraviolet rays, which may have adverse effects. Therefore, we focused on a new photocatalyst that is activated by visible light, hydroxyapatite (HAp), and amino acid complex with gray titania, and evaluated its antibacterial effects against Porphyromonas gingivalis and effect by toothbrushing. The test sample was a titanium alloy substrate, and four surface treatments were applied: (1) substrate only, (2) substrate with HAp complex, (3) substrate with HAp complex with gray titania, and (4) HAp-tryptophan complex with gray titania (TR). These surface treatments were evaluated with or without toothbrushing (8 total groups). Surface roughness (Sa), fluorescent X-ray analysis (XRF), and scanning electron microscopy (SEM) were used to evaluate surface properties. To investigate antibacterial effects, each sample was seeded with P. gingivalis, irradiated with red light, and total viable bacterial count was determined. For Sa measurement, TR showed no significant difference after toothbrushing. However, in XRF and SEM observation, TR exhibited peeling of the applied coating after toothbrushing. In the antibacterial test, TR showed a decrease in P. gingivalis under no toothbrushing condition. Conversely, with toothbrushing, the TR coating appeared to peel. However, no significant difference in P. gingivalis count was observed among all groups. HAp-tryptophan complex with gray titania coating showed an antibacterial effect against P. gingivalis when irradiated with visible light. However, toothbrushing can result in coat peeling and consequently reduce the antibacterial effect.

Counting bacteria in microfluidic devices: Smartphone compatible ‘dip-and-test’ viable cell quantitation using resazurin amplified detection in microliter capillary arrays

Viable bacterial cell counting is fundamental to analytical microbiology and agar plate colony counting remains common yet laborious and slow. Here, we demonstrate two methods for counting bacteria using commercially available microfluidic devices. We show that accurate viable cell counting is possible using simple and easy ‘dip and test’ arrays of microcapillaries. Colorimetric and fluorescent growth detection both permit viable cell counting in microcapillaries either by limiting dilution into multiple microfluidic compartments using a single endpoint measurement, or alternatively by quantifying growth kinetics. The microcapillary devices are compatible with conventional 96 well plates and multichannel pipettes, expanding each microplate row into 120 individual 1 or 2 μL samples. At limiting dilution, counting the proportion of positive compartments permitted accurate calculation of gram-negative and gram-positive bacteria (E. coli and S. saprophyticus) at concentrations down to as low as 10 CFU/mL with almost 1:1 agreement with agar plate colony counts over four orders of magnitude. A smartphone camera was sufficient to record endpoint images of resazurin growth detection both colorimetrically and fluorescently. Viable cell counting of E. coli and S. saprophyticus was also possible through recording growth kinetics and determining the time taken to detect resazurin conversion. However, only the limiting dilution method remained consistent in the presence of urine matrix, as some interference in growth rate was observed when bacteria were spiked into higher concentrations of normal urine to simulate urinary tract infection patient samples. However, with the limiting dilution counting method endpoint growth was always detected even in the presence of 90% urine matrix, suggesting that this method might permit bacterial pathogen counting directly in clinical samples without agar plating.

Assessing the Risk of Legionella Infection through Showering with Untreated Rain Cistern Water in a Tropical Environment

In September 2017, two category-5 hurricanes Irma and Maria swept through the Caribbean Sea in what is now known as the region’s most active hurricane season on record, leaving disastrous effects on infrastructure and people’s lives. In the U.S. Virgin Islands, rain cisterns are commonly used for harvesting roof-top rainwater for household water needs. High prevalence of Legionella spp. was found in the cistern water after the hurricanes. This study carried out a quantitative microbial risk assessment to estimate the health risks associated with Legionella through inhalation of aerosols from showering using water from cisterns after the hurricanes. Legionella concentrations were modeled based on the Legionella detected in post-hurricane water samples and reported total viable heterotrophic bacterial counts in cistern water. The inhalation dose was modeled using a Monte Carlo simulation of shower water aerosol concentrations according to shower water temperature, shower duration, inhalation rates, and shower flow rates. The risk of infection was calculated based on a previously established dose–response model from Legionella infection of guinea pigs. The results indicated median daily risk of 2.5 × 10−6 to 2.5 × 10−4 depending on shower temperature, and median annual risk of 9.1 × 10−4 to 1.4 × 10−2. Results were discussed and compared with household survey results for a better understanding of local perceived risk versus objective risk surrounding local water supplies.

In vitro Tolerability of Biofilm-Forming Trimethoprim-/Sulfamethoxazole-Resistant Small Colony Variants of Staphylococcus aureus Against Various Antimicrobial Agents.

Trimethoprim-/sulfamethoxazole-resistant small colony variants (SCVs) of Staphylococcus aureus, which are selected by use of trimethoprim/sulfamethoxazole, are involved in intractable biofilm-forming infection. This study aimed to determine the biofilm formation ability in trimethoprim-/sulfamethoxazole-resistant SCVs of S. aureus and investigate the bactericidal activity of differential antimicrobial agents to its biofilm-forming S. aureus. Between 32 S. aureus wild type (WT) and 32 SCVs selected from its WT, the amount of formed biofilm was compared. Vancomycin, daptomycin, rifampicin, and minocycline were exposed to biofilm-forming S. aureus to determine viable bacterial counts and its susceptibility. The biofilm-producing quantify of SCVs was approximately twice that formed by its WT. Vancomycin and daptomycin reduce 4 logs the bacterial counts of biofilm-forming WT at 24 hours, but did not affect SCVs. Rifampicin and minocycline considerably decreased both WT and SCVs; however, both bacterial counts recovered to an initial number 48 hours later. These survival strains showed resistance to each drug, and rpoB mutation or tet38 mRNA overexpression was confirmed.

Toll-Like Receptor 4 Protects Against Clostridium perfringens Infection in Mice.

Toll-like receptor 4 (TLR4) has been reported to protect against Gram-negative bacteria by acting as a pathogen recognition receptor that senses mainly lipopolysaccharide (LPS) from Gram-negative bacteria. However, the role of TLR4 in Gram-positive bacterial infection is less well understood. Clostridium perfringens type A is a Gram-positive bacterium that causes gas gangrene characterized by severe myonecrosis. It was previously demonstrated that C. perfringens θ-toxin is a TLR4 agonist, but the role of TLR4 in C. perfringens infection is unclear. Here, TLR4-defective C3H/HeJ mice infected with C. perfringens showed a remarkable decrease in survival rate, an increase in viable bacterial counts, and accelerated destruction of myofibrils at the infection site compared with wild-type C3H/HeN mice. These results demonstrate that TLR4 plays an important role in the elimination of C. perfringens. Remarkable increases in levels of inflammatory cytokines, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and granulocyte colony-stimulating factor (G-CSF), were observed in C. perfringens-infected C3H/HeN mice, whereas the increases were limited in C3H/HeJ mice. Generally, increased G-CSF accelerates granulopoiesis in the bone marrow and the spleen to exacerbate neutrophil production, resulting in elimination of bacteria. The number of neutrophils in the spleen was increased in C. perfringens-infected C3H/HeN mice compared with non-infected mice, while the increase was lower in C. perfringens-infected C3H/HeJ mice. Furthermore, DNA microarray analysis revealed that the mutation in TLR4 partially affects host gene expression during C. perfringens infection. Together, our results illustrate that TLR4 is crucial for the innate ability to eliminate C. perfringens.

English

This study was aimed at determining the occurrence of Staphylococcus species in ready-to-eat (RTE) Rhynchophorus phoenicis (edible larvae) and Archachatina marginata (land snail) vended along Port Harcourt-Bayelsa route. Eighty samples from four locations were analysed employing standard techniques for proximate and microbiological analyses; virulence determination and antibiotic susceptibility. Data were statistically analyzed using ANOVA and t-test. The mean proximate results revealed the presence of protein (26.01/13.6%), lipid (18.9/3.88%), fibre (5.12/2.01%), ash (3.40/1.11%), moisture (13.47/59.5%) and carbohydrate (32.43/20.07%) for edible larvae/snail, respectively. Of the 80 samples examined, 33 (41.25%) and 52 (65.00%) had total viable bacterial counts and total staphylococcal counts above acceptable microbiological limits, respectively for RTE foods. Seven of the 81 characterized Staphylococcus produced the expected band of 950 bp with sea virulent genes while three produced expected bands of 550 bp with seb virulent genes. Three Staphylococcus aureus strains from edible larvae harboured both virulent genes. The virulent genes bearing Staphylococcus were 100% resistant to augmentin, ceftazidime and cloxacillin but showed varying resistance against ceftriaxone (57.14%), cefuroxime (28.57%), vancomycin (42.86%), oxacillin (42.86%) and cefoxitin (42.86%). The study showed that these RTE foods are potential sources of staphylococcal food poisoning in commuters; hence, food vendors need to conform to standard practice.   Key words: Edible larvae, land snail, staphylococcal enterotoxin A (sea), virulence.

Optimization and comparison of \u213d-aminobutyric acid (GABA) production by LAB in soymilk using RSM and ANN models

Backgroundℽ-Aminobutyric acid (GABA) is a non-proteinaceous amino acid. In the mammalian nervous system, GABA functions as an inhibitory neurotransmitter. The present study focused on screening and optimization of ℽ-aminobutyric acid (GABA) yield by lactic acid bacteria by using soymilk as basal media. Lactobacillus fermentum (Lb. fermentum) was isolated from sourdough. The qualitative confirmation of GABA production by Lb. fermentum was observed by detecting colored spots on thin layer chromatography plate (TLC) and comparing it with standard GABA spot. The GABA from bacteria is confirmed by its molecular mass using mass spectrophotometry analysis (MS analysis). Single variable experiments were conducted for various physical and nutritional parameters, and determined the GABA content produced from Lb. fermentum, viable bacterial count, and pH of the fermented soymilk medium. Experimental data were authenticated by using response surface method (RSM) and artificial neural network (ANN) model.ResultsThe results demonstrated that through single variable experiments, the yield of GABA and the viable bacterial cells increased in soymilk containing one percent of glucose, monosodium glutamate (MSG), and inoculum volume incubated at 37 °C, 48 h at pH 5. According to RSM results, the interaction of the highest concentration of MSG (1.5%) and mid glucose concentration (1.156%) yielded maximum GABA (5.54 g/L). The experimental data were in good agreement with two optimization models. The RSM models showed less error percentage than that of the ANN model.ConclusionThis study indicates that soymilk is the best basal substrate for GABA production and growth of Lb. fermentum compared to synthetic media. Lb. fermentum can be explored further by food and pharmaceutical industries for the development of functional foods and therapeutic purposes.

Antimicrobial Photodynamic Therapy Combined With Antibiotic in the Treatment of Rats With Third-Degree Burns.

Cationic porphyrin conjugate, protoporphyrin IX-methyl ethylenediamine derivative (PPIX-MED) has a potent photosensitive antibacterial effect on clinically isolated bacteria, including methicillin-resistant Staphylococcus aureus, (MRSA), Escherichia coli, and Pseudomonas aeruginosa. This study investigated (i) the PPIX-MED-mediated antimicrobial photodynamic effect on these three species in vitro and (ii) the effect of antimicrobial photodynamic therapy (aPDT) combined with the use of an antibiotic on the healing in vivo of third-degree burns of rats with the wounds infected by these bacterial species. PPIX-MED exerted a potent inhibitory effect on the growth of the three bacterial species by producing reactive oxygen species when photoactivated. PPIX-MED-mediated antimicrobial photodynamic therapy (PPIX-MED-aPDT) had high bacterial photoinactivation ability in vitro, with a minimum inhibitory concentration of 15.6 μM PPIX-MED against each of the three types of bacteria and minimum bactericidal concentrations of 31.25 μM against MRSA and E. coli and 62.5 μM against P. aeruginosa. In rats with third-degree burns infected by a mixture of these bacteria, the bactericidal efficiency of PPIX-MED–aPDT-combined-with-antibiotic treatment was higher than that of antibiotic or aPDT treatment alone. This was confirmed by analysis of viable bacterial counts in wound tissue and blood. Enzyme-linked immunosorbent assay revealed that aPDT-combined-with-antibiotic treatment resulted in an obvious reduction in tumor necrosis factor-alpha and interleukin-6 levels compared with the no-treatment control group and the other treatment groups. Immunohistochemistry revealed that the expression of basic fibroblast growth factor and CD31 (a marker of neovascularization), expressed in burn wound tissue was higher in the aPDT-combined-with-antibiotic treatment group than in the other groups. PPIX-MED–aPDT has a promising bactericidal effect both in vitro and in vivo, and PPIX-MED–aPDT-combined-with-antibiotic treatment enhanced the healing of infected third-degree burns in rats.

New Strategy of Reducing Biofilm Forming Bacteria in Oral Cavity by Bismuth Nanoparticles.

Objective Enterococcus faecalis and Streptococcus salivarius are the most important species in dental decay and producing biofilm. Treatment with chlorhexidine 2% mouthwash for 7 days is the best way to eliminate these bacteria. However, due to the ability of these bacteria to survive in harsh environments, increasing emergence of bacterial resistance against available antibiotics, and favorable properties of nanoparticles including broad spectrum antimicrobial activity and lower toxicity, we decided to evaluate reducing biofilm forming bacteria in oral cavity by bismuth nanoparticles. Materials and Methods This was a cross-sectional study of 40 samples isolated from the patients visiting dental clinics in Shiraz in 2019. Samples, which showed growth, were cultured on blood agar plates and incubated for the PCR procedure. Nanoparticle powder was dissolved in high-purity water, and the final concentration of bismuth nanoparticles (BiNPs) was measured with a spectrophotometer. Minimum inhibitory concentration (MIC) of BiNPs against E. faecalis and S. salivarius was determined by the microbroth dilution method according to methods for antimicrobial susceptibility tests. Also, bactericidal assays were conducted in a Mueller-Hinton broth medium and reported as the concentration of BiNPs that reduced the viable bacterial count by 99.9%. Statistical analysis was carried out using SPSS 21 and one-way analysis of variance, and P values less than 0.05 were considered significant. Results MICs of BiNP suspension against Streptococcus salivarius and Enterococcus faecalis were 2.5 and 5 μg/ml, respectively. Minimum bactericidal concentrations (MBC) of BiNP suspension against Streptococcus salivarius and Enterococcus faecalis were 5 and 10 μg/ml, respectively. Antibacterial activity of BiNPs was compared with chlorhexidine 2%. MICs of BiNPs against Streptococcus salivarius and Enterococcus faecalis were one-twentieth less than those of chlorhexidine. MBC of BiNPs against both pathogens was one-tenth less than those of chlorhexidine. Conclusion BiNPs were more effective than chlorhexidine, and MIC and MBC of bismuth nanoparticles are lower than those of chlorhexidine.

Rapid evaluation of optimal growth substrates and improvement of industrial production of Bifidobacterium adolescentis based on the automatic feedback feeding method

This study aimed to improve the industrial production of Bifidobacterium adolescentis strain Z25 by establishing a method that could rapidly evaluate proliferation efficiency in response to different carbon, and nitrogen sources, inorganic salts, trace elements. Notably, glucose, yeast extract, fish peptone, Mg were the optimum substrates for high-efficient proliferation of the strain. The inorganic salts were not required in a pH-controlled culture. Both batch culture and automatic feedback feeding culture methods were optimized and compared. The maximum proliferation efficiency was achieved when the carbon-nitrogen ratio was equivalent to the carbon-nitrogen consumption ratio at the point of growth rate inhibition and the osmotic pressure of the medium was lower than 550 mOsm kg−1. Within a certain concentration range, the maximum biomass was positively correlated with the concentration of Mg2+. The automatic feedback feeding method was more conducive for a high-density bifidobacterial culture. Finally, at the optimum pH of 5.5 and the initial medium osmotic pressure of 312 ± 6 mOsm kg−1, the viable bacterial count reached (1.6 ± 0.1) × 1010 CFU mL−1 after 15 h with a feed liquid containing 320 g L−1 glucose, a 20-fold increase compared to the yield obtained with the original culture method and MRS medium.

Marginal Adaptation and Microbial Leakage at Conometric Prosthetic Connections for Implant-Supported Single Crowns: An In Vitro Investigation

Encouraging clinical results were reported on a novel cone-in-cone coupling for the fixation of dental implant-supported crowns (Acuris, Dentsply Sirona Implants, Mölndal, Sweden). However, the presence or absence of a microgap and a potential bacterial leakage at the conometric joint has not yet been investigated. A misfit and a resulting gap between the conometric components could potentially serve as a bacterial reservoir that promotes plaque formation, which in turn may lead to inflammation of the peri-implant tissues. Thus, a two-fold study set-up was designed in order to evaluate the bidirectional translocation of bacteria along conometrically seated single crowns. On conometric abutments filled with a culture suspension of anaerobic bacteria, the corresponding titanium nitride-coated (TiN) caps were fixed by friction. Each system was sterilized and immersed in culture medium to provide an optimal environment for microbial growth. Positive and negative controls were prepared. Specimens were stored in an anaerobic workstation, and total and viable bacterial counts were determined. Every 48 h, samples were taken from the reaction tubes to inoculate blood agar plates and to isolate bacterial DNA for quantification using qrt-PCR. In addition, one Acuris test system was subjected to scanning electron microscopy (SEM) to evaluate the precision of fit of the conometric coupling and marginal crown opening. Throughout the observational period of one week, blood agar plates of the specimens showed no viable bacterial growth. qrt-PCR, likewise, yielded a result approaching zero with an amount of about 0.53 × 10−4 µg/mL DNA. While the luting gap/marginal opening between the TiN-cap and the ceramic crown was within the clinically acceptable range, the SEM analysis failed to identify a measurable microgap at the cone-in-cone junction. Within the limits of the in-vitro study it can be concluded that the Acuris conometric interface does not allow for bacterial translocation under non-dynamic loading conditions.

The effect of different decontaminants on green vegetable foods collected from Iraqi stores.

Green vegetable foods are highly contaminated with bacteria and in order to reduce viable bacterial count in this important type of foods and make it less harmful; this research used different types of decontaminants in certain acceptable concentrations. Twenty five bundles of green vegetable foods had been collected from vegetable shops and peddlers in Baghdad, samples had been washed three times and treated with 0.1% potassium permanganate, 10% sodium chloride (table salt), 5% acetic acid (apple vinegar), and 2 Parts Per Million (PPM) of sodium hypochlorite separately, then the soaked water had been inoculated on nutrient agar and incubated for a viable bacterial count. It had been found that these substances have clear effect in bacterial reduction and this may help in reducing the harmful effect of pathogenic ones for human health 0.1% potassium permanganate was the most effective decontaminant, followed by 5% acetic acid, 10% table salt, while 2 ppm of sodium hypochlorite exhibited less effectiveness. Using of different types of decontaminants in certain concentrations that have a lower harmful effect on health and on plant structure with green vegetable foods helps in bacterial reduction and contributes in preventing their harmful effect.

Hematological analysis of blood cells and isolation of pathogenic microorganisms from second-degree flame burn patient with the prevalence of multidrug resistance traits

Burns are traumatic injuries that can occur in the home or workplace. It is a type of injury to flesh or skin caused by heat, electricity, chemicals, or radiation. The aims of this study to identified drug resistance traits of microorganisms, which is lead to wound infection after burn injury and causes hematological imbalanced of blood cells that are lead to the immune response against these pathogenic strains. The patient was burned by flame and seriously injured, with 24% tissue damaged. The whole blood was collected for complete blood count and peripheral blood film to analyze the components and morphological shape of blood cells. In addition, the wound samples were collected from wound infected sites to isolation and identification of microbial contamination as well as the study of antimicrobial susceptibility and resistance traits of microbes which are intensively involved in wound infection along with skin tissue damage. Among the complication period, the patient was seriously infected by pathogenic bacteria with viable bacterial count with log 107 colony-forming unit (CFU)/mL. The predominant pathogens were Escherichia coli, Klebsiella spp., Pseudomonas spp. and Staphylococcus spp. Most of the pathogens were found as drug-resistant, notably against second- and third-line antibiotics. The serious complication of microbial infection during the wound healing period was lead to increase white blood cells range along with terribly lower than the normal range of hemoglobin at 6.8 g/dl. Furthermore, the abnormal morphology of red blood cells was noted as an iron deficiency complication of the patient. Bacterial infection of the postburn patient is alarming for quick treatment. Most of the pathogens are rarely sensitive against most commercial antibiotics. Hence, bacterial colonization is the main threat for the burn-injured patient, which prohibits the immune response against in vivo infection.

Effect of dental acid etchant-mediated photodynamic therapy on bacterial reduction and microshear bond strength of composite to dentin - An in vitro study.

Objective:The objective of this study was to assess the effect of dental acid etchant (DAE)-mediated photodynamic therapy on bacterial reduction and microshear bond strength of composite to dentin.Materials and Methods:Eighty permanent third molars after sample preparation were exposed to a cariogenic challenge with Streptococcus mutans. After incubation, specimens were randomly divided into four groups (n = 20): Group I – DAE, Group II – low-level laser (LLL), Group III – diode laser + methylene blue (MB + L), and Group IV – diode laser + DAE (DAE + L). Half of the specimens from each group were selected for bacterial reduction assessment and the other half for microshear bond strength. All the samples for assessment of bacterial reduction (before and after intervention) were seeded onto the surface of mitis-salivarius-bacitracin medium. After incubation, the viable bacterial count was determined in colony-forming unit/mL. For microshear bond strength assessment, samples were subjected to various treatment modalities and then bonding and debonding procedure was performed for blocks of composite and values were recorded.Results:Significant reductions in S. mutans were observed in all the groups – Group I (DAE) 68.50%, Group II (LLL) 55.90%, Group III (MB + L) 88.60%, and Group IV (DAE + L) 87% with comparable bacterial reduction between Group III (MB + L) and Group IV (DAE + L). Furthermore, a significant difference in bond strength values was seen in Group III (MB + L) 10.99 MPa and Group IV (DAE + L) 17.99 MPa whereas an insignificant difference was found between Group I (DAE) 20.74 MPa, Group II (LLL) 18.27 MPa, and Group IV (DAE + L).Conclusion:DAE caused a comparable reduction in bacterial count to MB-assisted PDT and also there was no adverse effect on bond strength values. PDT can be performed while acid etchant containing MB dye is being applied in the cavity, thus reducing operative time and enhancing cavity disinfection.

The Efficacy of Posttreatment with Synthetic C-Reactive Protein in Murine Bacterial Peritonitis via Activation of FcγRI-Expressing Kupffer Cells

Pretreatment with synthetic C-reactive protein (CRP), a functional CRP peptide, has the potential to augment macrophage phagocytosis by bacterial challenge. However, the posttreatment is clinically ideal. We investigated the efficacy of posttreatment with synthetic CRP on murine cecal ligation and puncture (CLP), focusing on liver macrophages. Mice received CLP, and 1 h later, synthetic CRP or saline was intraperitoneally administered. Posttreatment with synthetic CRP increased the murine survival after CLP. It reduced viable bacterial counts in the liver 24 h after CLP with an increase in the number of Kupffer cells but not monocyte-derived liver macrophages. Posttreatment with synthetic CRP increased the phagolytic activity of Kupffer cells against Escherichia coli (E. coli) as well as capsulated Klebsiella pneumoniae at 3 h after CLP. Synthetic CRP therapy augmented TNF production by E. coli-phagocytosing Kupffer cells, resulting in an increase in tissue TNF levels in the liver at 24 h. Kupffer cells substantially expressed FcγRI, which is a ligand of CRP, and their FcγRI expression was further increased after CLP. In contrast, synthetic CRP therapy affected neither the phagocytic function of monocyte-derived liver macrophages (showing a weak FcγRI expression) nor their TNF production. Depletion of Kupffer cells in mice inhibited these beneficial effects of synthetic CRP in CLP mice. Conclusion: Posttreatment with synthetic CRP effectively improves murine bacterial peritonitis via the activation of phagocytosis of FcγRI-expressing Kupffer cells.

Assessment of Physico-Chemical and Microbiological Quality of Drinking Water in Three Upazilas of Noakhali District in Bangladesh

This study was driven for analyzing the drinking water quality of three upazillas at Noakhali district in Bangladesh. Nine different areas drinking water samples were collected from three upazilas (sadar-upazila, kabirhat upazila, Chatkhil upazila). Physical & chemical parameters of the collected samples like pH, electrical conductivity, salt, TDS, chloride-ion, iron content were measured and microbial parameters like Total Viable Bacterial Count (TVBC), Most Probable Number (MPN) of coliforms, E. coli, Pseudomonas, Klebsiella, Enterobacter aerogenes were also detected. All the parameters were compared with WHO drinking water quality standard ranges to understand the condition of drinking water in these areas. This study showed the pH of Chatkhil upazila was comparatively lower (6.18) than other upazilas. Electrical conductivity was also lower (252.1 μS/cm) in Chatkhil than other upazilas. Salt volume was comparatively higher (554.33 ppm) in sadar upazila sample than in others. TDS of all upazila samples were in an acceptable range. Chloride-ion was very much higher (7326.33 mg/L) in upazila-sadar. Iron content was mostly (3 mg/L) in Chatkhil upazila. Total bacterial load was comparatively higher (7.13 × 106 CFU/mL) in Kabirhat upazila. Most Probable Number (MPN) of Coliforms were comparatively higher (24.67 number of coliforms/100mL) in upazila-sadar than others. This study also showed the water samples that were collected almost all were contaminated by E. coli bacteria without supply water in upazila-sadar. As a result, water was not suitable for drinking. Water purification is very urgently needed for saving people from water-borne diseases. So necessary steps should immediately be taken for purifying the sources of drinking water.

Antimicrobial effects of nitric oxide in murine models of Klebsiella pneumonia

RationaleInhalation of nitric oxide (NO) exerts selective pulmonary vasodilation. Nitric oxide also has an antimicrobial effect on a broad spectrum of pathogenic viruses, bacteria and fungi. ObjectivesThe aim of this study was to investigate the effect of inhaled NO on bacterial burden and disease outcome in a murine model of Klebsiella pneumonia. MethodsMice were infected with Klebsiella pneumoniae and inhaled either air alone, air mixed with constant levels of NO (at 80, 160, or 200 parts per million (ppm)) or air intermittently mixed with high dose NO (300 ppm). Forty-eight hours after airway inoculation, the number of viable bacteria in lung, spleen and blood was determined. The extent of infiltration of the lungs by inflammatory cells and the level of myeloperoxidase activity in the lungs were measured. Atomic force microscopy was used to investigate a possible mechanism by which nitric oxide exerts a bactericidal effect. Measurements and main resultsCompared to control animals infected with K. pneumoniae and breathed air alone, intermittent breathing of NO (300 ppm) reduced viable bacterial counts in lung and spleen tissue. Inhaled NO reduced infection-induced lung inflammation and improved overall survival of mice. NO destroyed the cell wall of K. pneumoniae and killed multiple-drug resistant K. pneumoniae in-vitro. ConclusionsIntermittent administration of high dose NO may be an effective approach to the treatment of pneumonia caused by K. pneumoniae.

The effects of thermal treatment on the bacterial community and quality characteristics of meatballs during storage.

Thermal treatment is a widely applied food processing technology in the meat industry due to its convenience. However, the interpretation of the changes in the bacterial community and quality properties in the thermal processed meat products have not been well established. Therefore, the effects of thermal treatment on the quality characteristics and bacterial communities in meatballs during storage at 4°C were investigated, which will provide a more comprehensive understanding of the influence of thermal treatment on the meat quality. Thermal treatment (121°C, 15 min) decreased the initial total viable bacterial counts by 2.1 log CFU/g and the diversity of the initial bacterial communities in meatballs. Compared with the thermal treatment group, a significantly more rapidly increasing trend of total volatile basic nitrogen and a decreasing trend of pH were observed in the control group. At the end of storage, the bacterial community was dominated by Streptococcus, Acinetobacter and Pseudomonas in the thermal treatment meatballs, whereas Pseudomonas, Pantoea, and Serratia. dominated the bacterial community of the control group. Besides, the predicted metabolic pathways revealed high levels of carbohydrate, amino acid, and lipid metabolism in the control group. This finding could contribute to a deep understanding of the influence of thermal treatment on the meat quality. Moreover, these results could provide a theoretical foundation for the development of alternative and novel nonthermal processing technologies for use in the meat industry.

옻나무 추출물의 젖산균 혼합 발효를 통한 고농도 γ-aminobutyric acid(GABA) 생산

Higher production of GABA by co-fermentation lactic acid bacteria with R. verniciflura extract. The pH and acidity of the RV extract were 4.49 and 0.13%, respectively. The soluble solid and polyphenol contents were 0.52% and 5.77 mg/g, and the reducing sugar content was 3.9 mg/g. The RV extract (15%, v/v) was mixed with sucrose (5%) and yeast extract (1%). The mixture was fermented for 2 days at 25°C in the presence of Leuconostoc citreum S5. The second fermentation step involved the use of, Monosodium glutamate (5%, precursor) and skimmed milk (5%). The second fermentation was carried out by Lactobacillus plantarum EJ2014 at 30°C over a period of 7 days. The pH of the co-fermented RV extract was 4.75 and the acidity was 0.99%. The viable bacterial count for Leuc. citreum S5 and L. plantarum EJ2014 were 4.10 log CFU/mL and 8.68 log CFU/mL, respectively. The complete bio-conversion of MSG produced GABA (24.56 mg/mL). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2’-azino-bis (ABTS) radical scavenging activity of the co-fermented RV decreased (from 3.89 mg/mL to 2.03 mg/mL (IC50 values) for DPPH; from 16.03 mg/mL to 5.07 mg/mL (IC50 values) for ABTS). In conclusion the novel co-fermentation of RV extract could provide multi-functional ingredients, including GABA and probiotics.