scholarly journals Recovery in Embryonated Eggs of Viable but Nonculturable Campylobacter jejuni Cells and Maintenance of Ability To Adhere to HeLa Cells after Resuscitation

1999 ◽  
Vol 65 (11) ◽  
pp. 5154-5157 ◽  
Author(s):  
J. M. Cappelier ◽  
J. Minet ◽  
C. Magras ◽  
R. R. Colwell ◽  
M. Federighi
Keyword(s):  
Surface Water ◽  
Campylobacter Jejuni ◽  
Hela Cells ◽  
Pathogenic Bacteria ◽  
Vbnc State ◽  
Adhesion Properties ◽  
Viable But Nonculturable

ABSTRACT The existence of a viable but nonculturable (VBNC) state has been described for Campylobacter jejuni as it had been for a number pathogenic bacteria. Three C. jejuni human isolates were suspended in surface water and subsequently entered the VBNC state. After starvation for 30 days, VBNC cells were inoculated in the yolk sacs of embryonated eggs. Culturable cells were detected in a large proportion of the embryonated eggs inoculated with VBNC C. jejuni cells. Recovered cells kept their adhesion properties.

scholarly journals Induction and Resuscitation of Viable but Nonculturable Corynebacterium diphtheriae

2021 ◽  
Vol 9 (5) ◽  
pp. 927
Author(s):  
Takashi Hamabata ◽  
Mitsutoshi Senoh ◽  
Masaaki Iwaki ◽  
Ayae Nishiyama ◽  
Akihiko Yamamoto ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Diphtheria Toxin ◽  
Pathogenic Bacteria ◽  
Corynebacterium Diphtheriae ◽  
Human Pathogen ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Environmental Survival ◽  
Reverse Transcription Quantitative Pcr ◽  
Morphological Differences

Many pathogenic bacteria, including Escherichia coli and Vibrio cholerae, can become viable but nonculturable (VBNC) following exposure to specific stress conditions. Corynebacterium diphtheriae, a known human pathogen causing diphtheria, has not previously been shown to enter the VBNC state. Here, we report that C. diphtheriae can become VBNC when exposed to low temperatures. Morphological differences in culturable and VBNC C. diphtheriae were examined using scanning electron microscopy. Culturable cells presented with a typical rod-shape, whereas VBNC cells showed a distorted shape with an expanded center. Cells could be transitioned from VBNC to culturable following treatment with catalase. This was further evaluated via RNA sequence-based transcriptomic analysis and reverse-transcription quantitative PCR of culturable, VBNC, and resuscitated VBNC cells following catalase treatment. As expected, many genes showed different behavior by resuscitation. The expression of both the diphtheria toxin and the repressor of diphtheria toxin genes remained largely unchanged under all four conditions (culturable, VBNC, VBNC after the addition of catalase, and resuscitated cells). This is the first study to demonstrate that C. diphtheriae can enter a VBNC state and that it can be rescued from this state via the addition of catalase. This study helps to expand our general understanding of VBNC, the pathogenicity of VBNC C. diphtheriae, and its environmental survival strategy.

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.

scholarly journals The Viable But Nonculturable State ofRalstonia solanacearum May Be Involved in Long-Term Survival and Plant Infection

2001 ◽  
Vol 67 (9) ◽  
pp. 3866-3872 ◽  
Author(s):  
Brian E. Grey ◽  
Todd R. Steck
Keyword(s):  
Pathogenic Bacteria ◽  
Physiological Status ◽  
Cupric Sulfate ◽  
Vbnc State ◽  
In Planta ◽  
Term Survival ◽  
Viable But Nonculturable ◽  
Plant Infection ◽  
Nonculturable State ◽  
Vbnc Bacteria

ABSTRACT The role of the dormant-like viable but nonculturable (VBNC) condition in the etiology of bacterial infection was examined using a plant system. The plant-pathogenic bacterium Ralstonia solanacearum was first shown to enter into the VBNC state both in response to cupric sulfate when in a saline solution and when placed in autoclaved soil. To determine if the VBNC condition is related to pathogenesis, the physiological status of bacteria recovered from different regions of inoculated tomato plants was determined at different stages of infection. The fraction of in planta bacteria that were VBNC increased during infection and became greater than 99% by the late stage of disease. The possibility that soil-dwelling VBNC bacteria may resuscitate and infect plants was also examined. When tomato seeds were germinated in sterile soil that contained VBNC but no detectable culturable forms of R. solanacearumcells, resuscitation was observed to occur in soil adjacent to plant roots; these resuscitated bacteria were able to infect plants. This is the first report of R. solanacearum entering the VBNC state and of resuscitation of any VBNC plant-pathogenic bacteria and provides evidence that the VBNC state may be involved in explaining the persistent nature of some infections.

scholarly journals Viable but Nonculturable Bacteria: Food Safety and Public Health Perspective

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Md. Fakruddin ◽  
Khanjada Shahnewaj Bin Mannan ◽  
Stewart Andrews
Keyword(s):  
Public Health ◽  
Food Safety ◽  
Pathogenic Bacteria ◽  
Disease Outbreaks ◽  
Human Pathogens ◽  
Vbnc State ◽  
Public Health Perspective ◽  
Viable But Nonculturable ◽  
Vbnc Bacteria ◽  
Adverse Environmental Conditions

The viable but nonculturable (VBNC) state is a unique survival strategy of many bacteria in the environment in response to adverse environmental conditions. VBNC bacteria cannot be cultured on routine microbiological media, but they remain viable and retain virulence. The VBNC bacteria can be resuscitated when provided with appropriate conditions. A good number of bacteria including many human pathogens have been reported to enter the VBNC state. Though there have been disputes on the existence of VBNC in the past, extensive molecular studies have resolved most of them, and VBNC has been accepted as a distinct survival state. VBNC pathogenic bacteria are considered a threat to public health and food safety due to their nondetectability through conventional food and water testing methods. A number of disease outbreaks have been reported where VBNC bacteria have been implicated as the causative agent. Further molecular and combinatorial research is needed to tackle the threat posed by VBNC bacteria with regard to public health and food safety.

Evaluation of Propidium Monoazide and Quantitative PCR To Quantify Viable Campylobacter jejuni Biofilm and Planktonic Cells in Log Phase and in a Viable but Nonculturable State

2015 ◽  
Vol 78 (7) ◽  
pp. 1303-1311 ◽  
Author(s):  
BRENDA MAGAJNA ◽  
HEIDI SCHRAFT
Keyword(s):  
Quantitative Pcr ◽  
Campylobacter Jejuni ◽  
Viable Cell ◽  
Propidium Monoazide ◽  
Vbnc State ◽  
Planktonic Cells ◽  
Viable But Nonculturable ◽  
Cell Counts ◽  
Routine Monitoring ◽  
Novel Method

Despite being considered fragile and fastidious, Campylobacter jejuni remains the leading cause of bacterial gastroenteritis in the developed world. C. jejuni survives stresses by forming biofilms or entering a viable but nonculturable (VBNC) state. To investigate the number of viable cells in samples exposed to low nutrient and temperature stress, a novel method, propidium monoazide quantitative PCR (PMAqPCR), was compared with BacLight biovolume analysis and conventional plate counting for the enumeration of C. jejuni–removed biofilm cells and separately grown planktonic cells in late log phase (24 h). There were no significant differences between viable cell counts obtained using PMAqPCR and those from plate counts or BacLight biovolume analyses for each sample, confirming that this method provides results consistent with those from accepted enumeration methods (P > 0.05). To induce a VBNC state, C. jejuni planktonic cells and dislodged and washed biofilm cells were separately incubated in phosphate-buffered saline at 4°C for up to 60 days. Even when cells exposed to stress were provided with enrichment in Bolton broth before plating, treated biofilm cells lost culturability by day 10, whereas their planktonic counterparts remained culturable to day 60. The nonculturable biofilm cells remained viable in high numbers to day 60, and viable cell counts from the PMAqPCR (6.15 log cells per ml) were not significantly different from those obtained using the BacLight assay (6.98 log cells per ml) (P > 0.05), confirming that this novel method is also reliable for cells exposed to stress for extended periods. PMAqPCR shows promise for analysis where C. jejuni exists in biofilms or in the VBNC state. Adopting PMAqPCR in routine monitoring, in conjunction with improved biofilm cell collection methods, will allow for more accurate enumeration of viable and potentially virulent cells, leading to improved sanitation and reduced incidence of infection.

scholarly journals Antimicrobial Efficacy and Spectrum of Phosphorous-Fluorine Co-Doped TiO2 Nanoparticles on the Foodborne Pathogenic Bacteria Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1786
Author(s):  
György Schneider ◽  
Bettina Schweitzer ◽  
Anita Steinbach ◽  
Botond Zsombor Pertics ◽  
Alysia Cox ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Campylobacter Jejuni ◽  
Food Industry ◽  
Pathogenic Bacteria ◽  
Antibacterial Activities ◽  
Tio2 Nps ◽  
E Coli ◽  
Foodborne Pathogenic Bacteria ◽  
And Staphylococcus Aureus ◽  
Co Doped

Contamination of meats and meat products with foodborne pathogenic bacteria raises serious safety issues in the food industry. The antibacterial activities of phosphorous-fluorine co-doped TiO2 nanoparticles (PF-TiO2) were investigated against seven foodborne pathogenic bacteria: Campylobacter jejuni, Salmonella Typhimurium, Enterohaemorrhagic E. coli, Yersinia enterocolitica, Shewanella putrefaciens, Listeria monocytogenes and Staphylococcus aureus. PF-TiO2 NPs were synthesized hydrothermally at 250 °C for 1, 3, 6 or 12 h, and then tested at three different concentrations (500 μg/mL, 100 μg/mL, 20 μg/mL) for the inactivation of foodborne bacteria under UVA irradiation, daylight exposure or dark conditions. The antibacterial efficacies were compared after 30 min of exposure to light. Distinct differences in the antibacterial activities of the PF-TiO2 NPs, and the susceptibilities of tested foodborne pathogenic bacterium species were found. PF-TiO2/3 h and PF-TiO2/6 h showed the highest antibacterial activity by decreasing the living bacterial cell number from ~106 by ~5 log (L. monocytogenes), ~4 log (EHEC), ~3 log (Y. enterolcolitca, S. putrefaciens) and ~2.5 log (S. aureus), along with complete eradication of C. jejuni and S. Typhimurium. Efficacy of PF-TiO2/1 h and PF-TiO2/12 h NPs was lower, typically causing a ~2–4 log decrease in colony forming units depending on the tested bacterium while the effect of PF-TiO2/0 h was comparable to P25 TiO2, a commercial TiO2 with high photocatalytic activity. Our results show that PF-co-doping of TiO2 NPs enhanced the antibacterial action against foodborne pathogenic bacteria and are potential candidates for use in the food industry as active surface components, potentially contributing to the production of meats that are safe for consumption.

scholarly journals Induction of Viable but Nonculturable Escherichia coli O157:H7 in the Phyllosphere of Lettuce: a Food Safety Risk Factor

2011 ◽  
Vol 77 (23) ◽  
pp. 8295-8302 ◽  
Author(s):  
Laura-Dorina Dinu ◽  
Susan Bach
Keyword(s):  
Escherichia Coli ◽  
Food Safety ◽  
Low Temperature ◽  
Cell Density ◽  
Prolonged Storage ◽  
Potential Hazard ◽  
Vbnc State ◽  
Viable But Nonculturable ◽  
Content Type ◽  
E Coli

ABSTRACTEscherichia coliO157:H7 continues to be an important human pathogen and has been increasingly linked to food-borne illness associated with fresh produce, particularly leafy greens. The aim of this work was to investigate the fate ofE. coliO157:H7 on the phyllosphere of lettuce under low temperature and to evaluate the potential hazard of viable but nonculturable (VBNC) cells induced under such stressful conditions. First, we studied the survival of six bacterial strains following prolonged storage in water at low temperature (4°C) and selected two strains with different nonculturable responses for the construction ofE. coliO157:H7 Tn7gfptransformants in order to quantitatively assess the occurrence of human pathogens on the plant surface. Under a suboptimal growth temperature (16°C), bothE. coliO157:H7 strains maintained culturability on lettuce leaves, but under more stressful conditions (8°C), the bacterial populations evolved toward the VBNC state. The strain-dependent nonculturable response was more evident in the experiments with different inoculum doses (109and 106E. coliO157:H7 bacteria per g of leaf) when strain BRMSID 188 lost culturability after 15 days and strain ATCC 43895 lost culturability within 7 days, regardless of the inoculum dose. However, the number of cells entering the VBNC state in high-cell-density inoculum (approximately 55%) was lower than in low-cell-density inoculum (approximately 70%). We recorded the presence of verotoxin for 3 days in samples that contained a VBNC population of 4 to 5 log10cells but did not detect culturable cells. These findings indicate thatE. coliO157:H7 VBNC cells are induced on lettuce plants, and this may have implications regarding food safety.

scholarly journals Probiotic and Antioxidant Potential of Lactobacillus reuteriLR12 and Lactobacillus lactisLL10 Isolated from Pineapple Puree and Quality Analysis of Pineapple-Flavored Goat Milk Yoghurt during Storage

2020 ◽  
Vol 8 (10) ◽  
pp. 1461 ◽  
Author(s):  
Naif Abdullah Al-Dhabi ◽  
Mariadhas Valan Arasu ◽  
Ponnuswamy Vijayaraghavan ◽  
Galal Ali Esmail ◽  
Veeramuthu Duraipandiyan ◽  
...  
Keyword(s):  
Pathogenic Bacteria ◽  
Radical Scavenging Activity ◽  
Starter Culture ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Goat Milk ◽  
Quality Analysis ◽  
Scavenging Activity ◽  
Bacterial Strains ◽  
Adhesion Properties

In recent years, studies have focused on the therapeutic properties of probiotics to eliminate pathogenic microorganisms associated with various diseases. Lactobacilli are important probiotics groups that have been found to possess many health-promoting activities. This study was carried out to isolate LactobacillusreuteriLR12 and L. lactisLL10 from pineapple puree. The invitro analysis to evaluate probiotic characteristics of the isolated bacteria included survival in bile and acid tolerance. The cell-free supernatant of L. reuteri LR12 was effective against various pathogenic bacteria and fungi compared with L. lactisLL10. These two bacterial strains have strong anti-biofilm activity (100%) against Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus. The bacterial strains exhibited adhesion properties to HT-29 cells (human colorectal adenocarcinoma). These bacteria showed DPPH- (2,2-diphenyl-1-picryl-hydrazyl-hydrate) free radical scavenging activity, scavenging of hydroxyl radical activity, superoxide radical scavenging activity, and reducing power activity in the range of 72% ± 3%to 89.3% ± 1.7%, 64% ± 2.7%to 66.8% ± 1.5%, 59.8% ± 4.1% to 63.8% ± 2.1%, and 60.4% ± 1.8%to 66.1% ± 3.3%, respectively. Pineapple puree was used as the starter culture with milk for 2 days for yogurt preparation. Pineapple puree increased flavor and showed the physicochemical properties of yogurt. The finding of the sensory evaluation revealed no significant change compared with the control, except the appearance of yogurt. These findings show that Lactobacilli and pineapple puree have potential use in various probiotic preparations for the fermentation industry.

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