scholarly journals Formation and Resuscitation of Viable but NonculturableSalmonella typhi

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Bin Zeng ◽  
Guozhong Zhao ◽  
Xiaohong Cao ◽  
Zhen Yang ◽  
Chunling Wang ◽  
...  
Keyword(s):  
Large Population ◽  
Animal Experiments ◽  
Salmonella Typhi ◽  
Total Cell ◽  
Tween 20 ◽  
Vbnc State ◽  
Carbon And Nitrogen ◽  
Cell Counts ◽  
Atomic Force ◽  
Plate Counts

Salmonella typhiis a pathogen that causes the human disease of typhoid fever. The aim of this study was to investigate the viable but nonculturable (VBNC) state ofS. typhi. Some samples were stimulated at 4°C or −20°C, while others were induced by different concentrations of CuSO4. Total cell counts remained constant throughout several days by acridine orange direct counting; however, plate counts declined to undetectable levels within 48 hours by plate counting at −20°C. The direct viable counts remained fairly constant at this level by direct viable counting. Carbon and nitrogen materials slowly decreased which indicated that a large population of cells existed in the VBNC state and entered the VBNC state in response to exposure to 0.01 or 0.015 mmol/L CuSO4for more than 14 or 12 days, respectively. Adding 3% Tween 20 or 1% catalase enabled cells to become culturable again, with resuscitation times of 48 h and 24 h, respectively. The atomic force microscope results showed that cells gradually changed in shape from short rods to coccoids, and decreased in size when they entered the VBNC state. Further animal experiments suggested that resuscitated cells might regain pathogenicity.

scholarly journals Retention of Virulence in a Viable but Nonculturable Edwardsiella tarda Isolate

2006 ◽  
Vol 73 (4) ◽  
pp. 1349-1354 ◽  
Author(s):  
Meng Du ◽  
Jixiang Chen ◽  
Xiaohua Zhang ◽  
Aijuan Li ◽  
Yun Li ◽  
...  
Keyword(s):  
Morphological Changes ◽  
Large Population ◽  
Edwardsiella Tarda ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Cell Counts ◽  
Nonculturable State ◽  
Plate Counts ◽  
Temperature Upshift ◽  
Viable But Nonculturable State

ABSTRACT Edwardsiella tarda is pathogen of fish and other animals. The aim of this study was to investigate the viable but nonculturable (VBNC) state and virulence retention of this bacterium. Edwardsiella tarda CW7 was cultured in sterilized aged seawater at 4�C. Total cell counts remained constant throughout the 28-day period by acridine orange direct counting, while plate counts declined to undetectable levels (<0.1 CFU/ml) within 28 days by plate counting. The direct viable counts, on the other hand, declined to ca. 109 CFU/ml active cells and remained fairly constant at this level by direct viable counting. These results indicated that a large population of cells existed in a viable but nonculturable state. VBNC E. tarda CW7 could resuscitate in experimental chick embryos and in the presence of nutrition with a temperature upshift. The resuscitative times were 6 days and 8 days, respectively. The morphological changes of VBNC, normal, and resuscitative E. tarda CW7 cells were studied with a scanning electron microscope. The results showed that when the cells entered into the VBNC state, they gradually changed in shape from short rods to coccoid and decreased in size, but the resuscitative cells did not show any obvious differences from the normal cells. The VBNC and the resuscitative E. tarda CW7 cells were intraperitoneally inoculated into turbot separately, and the fish inoculated with the resuscitative cells died within 7 days, which suggested that VBNC E. tarda CW7 might retain pathogenicity.

scholarly journals Survival Strategy of Erwinia amylovora against Copper: Induction of the Viable-but-Nonculturable State

2006 ◽  
Vol 72 (5) ◽  
pp. 3482-3488 ◽  
Author(s):  
M�nica Ordax ◽  
Ester Marco-Noales ◽  
Mar�a M. L�pez ◽  
Elena G. Biosca
Keyword(s):  
Pathogenic Bacteria ◽  
Erwinia Amylovora ◽  
Control Plant ◽  
Viable Cell ◽  
Epifluorescence Microscopy ◽  
Survival Strategy ◽  
Vbnc State ◽  
Tetrazolium Chloride ◽  
Viable But Nonculturable ◽  
Cell Counts

ABSTRACT Copper compounds, widely used to control plant-pathogenic bacteria, have traditionally been employed against fire blight, caused by Erwinia amylovora. However, recent studies have shown that some phytopathogenic bacteria enter into the viable-but-nonculturable (VBNC) state in the presence of copper. To determine whether copper kills E. amylovora or induces the VBNC state, a mineral medium without copper or supplemented with 0.005, 0.01, or 0.05 mM Cu2+ was inoculated with 107 CFU/ml of this bacterium and monitored over 9 months. Total and viable cell counts were determined by epifluorescence microscopy using the LIVE/DEAD kit and by flow cytometry with 5-cyano-2,3-ditolyl tetrazolium chloride and SYTO 13. Culturable cells were counted on King's B nonselective solid medium. Changes in the bacterial morphology in the presence of copper were observed by scanning electron microscopy. E. amylovora entered into the VBNC state at all three copper concentrations assayed, much faster when the copper concentration increased. The addition of different agents which complex copper allowed the resuscitation (restoration of culturability) of copper-induced VBNC cells. Finally, copper-induced VBNC cells were virulent only for the first 5 days, while resuscitated cells always regained their pathogenicity on immature fruits over 9 months. These results have shown, for the first time, the induction of the VBNC state in E. amylovora as a survival strategy against copper.

Oxidative stress and inflammation contribute to lung toxicity after a common breast cancer chemotherapy regimen

2002 ◽  
Vol 283 (2) ◽  
pp. L336-L345 ◽  
Author(s):  
Amir M. Abushamaa ◽  
Thomas A. Sporn ◽  
Rodney J. Folz
Keyword(s):  
Breast Cancer ◽  
Oxidative Stress ◽  
Lung Injury ◽  
Inflammatory Response ◽  
Chemotherapeutic Agents ◽  
Total Cell ◽  
Lung Toxicity ◽  
High Dose ◽  
Cell Counts ◽  
Cellular Inflammatory Response

Delayed pulmonary toxicity syndrome after high-dose chemotherapy (HDC) and autologous hematopoietic support occurs in up to 64% of women with advanced-stage breast cancer. Using a similar, but nonmyeloablative, HDC treatment regimen in mice, we found both immediate and persistent lung injury, coincident with marked decreases in lung tissue glutathione reductase activity and accompanied by increases in lung oxidized glutathione, bronchoalveolar lavage (BAL) lipid peroxidation, and BAL total cell counts. Most interestingly, at 6 wk, BAL total cell counts had increased fourfold, with lymphocyte cell counts increasing >11-fold. A single supplemental dose of glutathione prevented early lung injury at 48 h but showed no lung-protective effects at 6 wk, whereas single doses of other thiol-sparing agents (Ethyol and glutathione monoethyl ester) showed no benefit. These data suggest that this HDC regimen results in acute and persistent lung toxicity, induced in part by oxidative stress, that culminates with an acute lung cellular inflammatory response. Continuous glutathione supplementation and/or attenuation of the delayed pulmonary inflammatory response may prove beneficial in preventing lung toxicity after the use of these chemotherapeutic agents.

Biofilm Formation and Sporulation by Bacillus cereus on a Stainless Steel Surface and Subsequent Resistance of Vegetative Cells and Spores to Chlorine, Chlorine Dioxide, and a Peroxyacetic Acid–Based Sanitizer

2005 ◽  
Vol 68 (12) ◽  
pp. 2614-2622 ◽  
Author(s):  
JEE-HOON RYU ◽  
LARRY R. BEUCHAT
Keyword(s):  
Stainless Steel ◽  
Relative Humidity ◽  
Bacillus Cereus ◽  
Chlorine Dioxide ◽  
Biofilm Formation ◽  
Total Cell ◽  
Stainless Steel Surface ◽  
Peroxyacetic Acid ◽  
Vegetative Cells ◽  
Cell Counts

Biofilm formation by Bacillus cereus 038-2 on stainless steel coupons, sporulation in the biofilm as affected by nutrient availability, temperature, and relative humidity, and the resistance of vegetative cells and spores in biofilm to sanitizers were investigated. Total counts in biofilm formed on coupons immersed in tryptic soy broth (TSB) at 12 and 22°C consisted of 99.94% of vegetative cells and 0.06% of spores. Coupons on which biofilm had formed were immersed in TSB or exposed to air with 100, 97, 93, or 85% relative humidity. Biofilm on coupons immersed in TSB at 12°C for an additional 6 days or 22°C for an additional 4 days contained 0.30 and 0.02% of spores, respectively, whereas biofilm exposed to air with 100 or 97% relative humidity at 22°C for 4 days contained 10 and 2.5% of spores, respectively. Sporulation did not occur in biofilm exposed to 93 or 85% relative humidity at 22°C. Treatment of biofilm on coupons that had been immersed in TSB at 22°C with chlorine (50 μg/ml), chlorine dioxide (50 μg/ml), and a peroxyacetic acid–based sanitizer (Tsunami 200, 40 μg/ml) for 5 min reduced total cell counts (vegetative cells plus spores) by 4.7, 3.0, and 3.8 log CFU per coupon, respectively; total cell counts in biofilm exposed to air with 100% relative humidity were reduced by 1.5, 2.4, and 1.1 log CFU per coupon, respectively, reflecting the presence of lower numbers of vegetative cells. Spores that survived treatment with chlorine dioxide had reduced resistance to heat. It is concluded that exposure of biofilm formed by B. cereus exposed to air at high relative humidity (≥97%) promotes the production of spores. Spores and, to a lesser extent, vegetative cells embedded in biofilm are protected against inactivation by sanitizers. Results provide new insights to developing strategies to achieve more effective sanitation programs to minimize risks associated with B. cereus in biofilm formed on food contact surfaces and on foods.

scholarly journals Total Cell Counts of the Bone Marrow of Normal Albino Rats from 1 to 50 Weeks of Age

Blood ◽  
1959 ◽  
Vol 14 (4) ◽  
pp. 409-414 ◽  
Author(s):  
WILLIAM T. BURKE ◽  
CHARLES HARRIS
Keyword(s):  
Bone Marrow ◽  
Cell Population ◽  
Normal Values ◽  
Age Groups ◽  
Considerable Change ◽  
Total Cell ◽  
Albino Rats ◽  
Cell Counts ◽  
Total Cell Population ◽  
Femoral Bone Marrow

Abstract A method is described by which the total nucleated cell count of femoral bone marrow of the rat can be estimated and cell population expressed in terms of differential counts. Normal values of total nucleated cell counts and the cellular distributions are given for seven age groups. These data indicate considerable change in bone marrow total cell population in rats one to 10 weeks of age.

scholarly journals Peptide-Based Formulation from Lactic Acid Bacteria Impairs the Pathogen Growth in Ananas Comosus (Pineapple)

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 457 ◽  
Author(s):  
Gabriela N. Tenea ◽  
Daniela Olmedo ◽  
Clara Ortega
Keyword(s):  
Significant Proportion ◽  
High Capacity ◽  
Total Cell ◽  
Ananas Comosus ◽  
Street Vending ◽  
E Coli ◽  
Cell Counts ◽  
Total Cell Density

Worldwide, street vending commerce has grown exponentially, representing in some countries, including Ecuador, a significant proportion of food consumed by the urban population. Pineapple is one of the common fruits sold as ready-to-eat slices by ambulant vendors in the street or on public transport at risk of contamination by various microorganisms. Previously, we selected Lactobacillus plantarum UTNCys5-4 and Lactococcus lactis subsp. lactis Gt28 strains producing peptides with high capacity to inhibit pathogen growth in vitro. In this study, the effect of different edited formulations containing a mixture of Cys5-4/Gt28 peptides was evaluated in vitro and ex vitro against a pathogenic cocktail containing E. coli (2), Salmonella (2) and Shigella (1). The growth of bacterial cocktail co-inoculated with cell-free supernatant containing peptides (formulation T1) and precipitated peptides (formulation T6), in a ratio of Cys5-4/Gt28:1:1 (v/v), results in a decrease of total cell viability with 1.85 and 1.2 log CFU/mL orders of magnitude at 6 h of incubation. About the same decrease (1.9 log CFU/g) was observed when pineapple slices artificially inoculated with the pathogenic cocktail were coated with T1 formulation, indicating the capacity to diminish simultaneous pathogens in situ, thus demonstrating its great biological control and protection. However, the E. coli cell counts reduced by 2.08 log CFU/g while Salmonella and Shigella cell counts reduced by 1.43 and 1.91 log CFU/g, respectively, at 5 days of refrigeration. In the untreated pineapple slices, the total cell density was maintained during storage, suggesting the adaptation of the pathogens to the fruit matrix. The peptide-based formulation exerted a bacteriolytic mode of action inducing pathogenic cell death. The results indicate that coating pineapple slices with peptide-based formulation is a promising approach to protect them from further contamination by microbial spoilage as well as an alternative to increase the food safety.

94 EFFECTS OF 6- OR 12-HOUR CULTURE IN A Micro Q STRAW INCUBATOR ON DEVELOPMENT OF IN VITRO-PRODUCED BOVINE EMBRYOS

2016 ◽  
Vol 28 (2) ◽  
pp. 177
Author(s):  
C. R. Looney ◽  
J. H. Pryor ◽  
M. Snyder ◽  
A. Ilercil ◽  
C. R. Long
Keyword(s):  
Embryo Transfer ◽  
Uv Light ◽  
Tween 20 ◽  
Treatment Groups ◽  
Cell Counts ◽  
Stage 4 ◽  
Embryo Stage ◽  
Transfer Services ◽  
In Transit

Transporting in vitro-produced (IVP) embryos can be challenging when an embryo transfer destination is more than 6 h away or electricity is not available on site to unload embryos for transfer. The objective of this study was to determine if development rates would be compromised for Day 6.5 IVP embryos when placed in warmed Vigro holding medium (Vetoquinol, Pullman, WA, USA) loaded and plugged into 1/4 cc straws (Professional Embryo Transfer Services, Canton, TX, USA) for a period of either 6 or 12 h in a 38.5°C Micro Q straw block incubator (Micro Q iQ1T 64). Bovine oocytes were shipped and matured in transit from a commercial abattoir (DeSoto Biosciences, Seymour, TN, USA), fertilized (IVF = Day 0) with frozen-thawed semen, and cultured in Bovine Evolve (Zenith Biotech, Guilford, CT, USA) supplemented with 4 mg mL–1 BSA (Probumin, EMD Millipore, Norcross, GA, USA) under oil in a 5% CO2, 5%O2, 90% N2 humidified incubator (Pryor et al. 2011 Theriogenology 75, 24–33). Cleavage rates of 87.7% (664/757) from three replicates produced 273 (36.0%) viable embryos on Day 6.5 post-IVF, which were evenly distributed by IETS stage (4–7) and grade (1 and 2) into three treatment groups (0 = control, 6 or 12 h straw incubation) before in vitro culture for an additional 24 h. For each replicate, the average embryo stage was calculated by multiplying the number of embryos in each treatment by their IETS stage and dividing by total embryos per group. The change in stage for each treatment was calculated by subtracting the initial average stage from the final average stage on Day 8. Grade 1 and 2 embryos at stage 6–8 were counted and used to calculate total viable rates. Day 8 (post-IVF) embryos were fixed in cold methanol, washed in PBS/0.1%Tween 20, mounted in 10 μg mL–1 Hoechst 33342/glycerol and viewed under UV light to count nuclei. Percentage data were transformed using arcsine square root function before analysis, and means were compared using a one-way ANOVA and Tukey’s HSD. Although viability decreased with increasing time in straw incubation, there were no statistical differences between control, 6 and 12 h treatments for total viable rates (90.8, 80.3, and 70.8%, respectively). Average embryo stage on Day 8 for control, 6 and 12 h (7.0 ± 0.66, 6.6 ± 0.24, and 6.2 ± 0.30 s.e.m., respectively) was not different, but tended to be higher in control (P = 0.08). The change in stage, however, was different between control and 12 h (1.46 ± 0.33 and 0.66 ± 0.24, respectively; P < 0.05). Likewise, cell numbers were greater in control and 6 h embryos compared with 12 h straw incubation (149.8 ± 9.14, 138.7 ± 7.94, and 101.8 ± 5.29; n = 47, 50, and 46, respectively P < 0.01). In conclusion, 6.5 day IVP embryos held in warm Vigro holding medium for 12 h in 1/4 cc straws fail to develop at the same rate and incurred lower cell counts than either control or 6 h treatments. Further research to evaluate pregnancy rates following transfer and utilising different incubation or media and/or temperature is warranted to further evaluate the utility of in straw incubation for extended periods of time.

scholarly journals Hydrophilic Silver Nanoparticles Loaded into Niosomes: Physical–Chemical Characterization in View of Biological Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1177 ◽  
Author(s):  
Federica Rinaldi ◽  
Elena del Favero ◽  
Johannes Moeller ◽  
Patrizia Nadia Hanieh ◽  
Daniele Passeri ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Human Serum ◽  
Nile Red ◽  
Chemical Characterization ◽  
Entrapment Efficiency ◽  
Tween 20 ◽  
Biological Applications ◽  
Force Microscopy ◽  
Atomic Force ◽  
New Perspective

Silver nanoparticles (AgNPs) are widely used as antibacterial agents and anticancer drugs, but often their low stability limits their mass production and broad applications. The use of niosomes as a carrier to protect and envelop AgNPs gives a new perspective to solve these problems. In this study, AgNPs were functionalized with sodium 3-mercapto-1-propanesulfonate (3MPS) to induce hydrophilic behavior, improving loading in Tween 20 and Span 20 niosomes (NioTw20 and NioSp20, respectively). Entrapment efficiency was evaluated by UV analyses and is around 1–4%. Dimensions were investigated by means of dynamic light scattering (DLS) (<2RH> = 140 ± 4 nm and <2RH> = 251 ± 1 nm respectively for NioTw20 + AgNPs and NioSp20 + AgNPs) and were compared with those by atomic force microscopy (AFM) and small angle X ray scattering (SAXS) analyses. Stability was assessed in water up to 90 days, and both in bovine serum and human serum for up to 8 h. In order to characterize the local structure of niosomes, SAXS measurements have been performed on Tween 20 and Span 20 empty niosomes and loaded with AgNPs. The release profiles of hydrophilic probe calcein and lipophilic probe Nile Red were performed in HEPES buffer and in human serum. All these features contribute to conclude that the two systems, NioTw20 + AgNPs and NioSp20 + AgNPs, are suitable and promising in the field of biological applications.

scholarly journals Persistent Sputum Cellularity and Neutrophils May Predict Bronchiectasis

2011 ◽  
Vol 18 (4) ◽  
pp. 221-224 ◽  
Author(s):  
Nicole Drost ◽  
Liesel D’silva ◽  
Ryan Rebello ◽  
Ann Efthimiadis ◽  
Frederick E Hargreave ◽  
...  
Keyword(s):  
Cell Count ◽  
Roc Curves ◽  
Total Cell ◽  
Total Cell Count ◽  
High Resolution Computed Tomography ◽  
Predictive Values ◽  
Retrospective Survey ◽  
Cell Counts ◽  
Airway Diseases ◽  
Computed Tomography Scans

BACKGROUND: Quantitative cell counts in sputum provide an accurate assessment of the type and severity of bronchitis.OBJECTIVE: To examine whether sputum cell counts could identify bronchiectasis in patients with recurrent bronchitis.METHODS: A retrospective survey of a clinical database (January 2004 to January 2005) of quantitative cell counts from sputum selected from expectorate in patients with obstructive airways diseases was used to identify predictors of bronchiectasis using ROC curves. This was prospectively evaluated (February 2005 to April 2008) using high-resolution computed tomography scans of thorax that were independently scored by a radiologist who was blinded to the clinical details.RESULTS: The retrospective survey identified 41 patients with bronchiectasis among 490 patients with airway diseases. Total cell count of 60×106/g or greater of the selected sputum with predominant neutrophils on two occasions had a sensitivity of 86.7%, a specificity of 87.5%, and positive and negative predictive values of 93% and 78%, respectively, to identify bronchiectasis. In the prospective study, 10 of 14 (71%) patients who met these criteria were identified to have bronchiectasis. Both total cell count and the percentage of neutrophils correlated with radiographic bronchiectasis severity.CONCLUSIONS: Persistent or recurrent intense sputum cellularity with neutrophilia is suggestive of bronchiectasis.

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