Alternative Sigma Factor σB Is Not Essential for Listeria monocytogenes Surface Attachment

2005 ◽  
Vol 68 (2) ◽  
pp. 311-317 ◽  
Author(s):  
UTE SCHWAB ◽  
YUEWEI HU ◽  
MARTIN WIEDMANN ◽  
KATHRYN J. BOOR
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Single Cells ◽  
Foodborne Pathogen ◽  
Plate Count ◽  
Initial Surface ◽  
Wild Type ◽  
Surface Attachment ◽  
Steel Analysis ◽  
Static Conditions

Listeria monocytogenes is a foodborne pathogen frequently isolated from the food processing environment. Multiple lines of evidence suggested a possible role for the L. monocytogenes alternative transcription factor sigma B (σB) in surface attachment and biofilm formation. Therefore, through plate count and microscopic techniques, the L. monocytogenes 10403S strain and an otherwise isogenic ΔsigB strain were tested for attachment to stainless steel. Analysis of microscopic images revealed that after 72 h at 24°C under static conditions the tested L. monocytogenes strains attached uniformly to surfaces as single cells. Both strains were capable of rapid attachment (i.e., numbers of attached cells were essentially the same after either 5 min or 24 h of incubation). Numbers of attached ΔsigB cells were significantly lower than those of the wild-type strain after 48 and 72 h of incubation at 24°C (P = 0.001). Similar numbers of the ΔsigB strain attached to stainless steel regardless of temperature (24 or 37°C); however, ΔsigB cells attached at higher relative numbers in the presence of 6% NaCl after 48 and 72 h. Furthermore, in the presence of Pseudomonas fluorescens, similarly high numbers of wild-type and ΔsigB cells attached to the surfaces, forming mixed biofilms. Our data suggest that σB is not required for initial surface attachment of L. monocytogenes.

Behavior of Listeria monocytogenes in a Pseudomonas putida Biofilm on a Condensate-Forming Surface

2004 ◽  
Vol 67 (2) ◽  
pp. 322-327 ◽  
Author(s):  
ASHRAF N. HASSAN ◽  
DAWN M. BIRT ◽  
JOSEPH F. FRANK
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Pseudomonas Putida ◽  
Microscopic Observation ◽  
Pure Culture ◽  
Extracellular Polymeric Substances ◽  
Plate Count ◽  
Free Surfaces ◽  
Processing Plants ◽  
Humidity Chamber

Listeria monocytogenes has been isolated from condensate-forming surfaces in food processing plants. The objective of this research was to observe the behavior of L. monocytogenes on condensate-covered stainless steel with a Pseudomonas putida biofilm. L. monocytogenes–containing biofilms, either with or without added chicken protein, were incubated in a high humidity chamber at 12°C to allow formation of condensate. Samples were analyzed for attached and unattached L. monocytogenes and total plate count periodically for 35 days. Samples were also taken for microscopic observation of Listeria and bacterial extracellular polymeric substances (EPS). L. monocytogenes attached in significantly greater numbers (>3-log difference) to surfaces with preexisting P. putida biofilms than to Pseudomonas-free surfaces. L. monocytogenes survived in the presence or absence of P. putida with no added nutrients for 35 days, with numbers of survivors in the range of 3 to 4 log CFU/cm2 in the presence of P. putida and less than 2.9 log CFU/cm2 in pure culture. Attached and unattached L. monocytogenes were at similar levels throughout the incubation under all conditions studied. The addition of protein to the biofilms allowed growth of L. monocytogenes in pure culture during the first 7 days of incubation. Numbers of L. monocytogenes were not affected by the presence of P. putida when protein was present. Unattached L. monocytogenes were at levels of 3.6 to 6.7 log CFU/cm2 on the protein-containing surfaces. Microscopic observation of the condensate-covered biofilms indicated that L. monocytogenes formed microcolonies embedded within an EPS matrix over a 28-day period. This research demonstrates that L. monocytogenes can survive on condensate-forming stainless steel in low and high nutrient conditions, with or without the presence of Pseudomonas biofilm. The Listeria can detach and, therefore, have the potential to contaminate product.

scholarly journals Advanced understanding of prokaryotic biofilm formation using a cost-effective and versatile multi-panel adhesion (mPAD) mount

2022 ◽  
Author(s):  
Stefan Schulze ◽  
Heather Schiller ◽  
Jordan Solomonic ◽  
Orkan Telhan ◽  
Kyle Costa ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Cost Effective ◽  
Flow Chamber ◽  
Culture Conditions ◽  
Multiple Time ◽  
Wild Type ◽  
Surface Attachment ◽  
Flowing Liquid ◽  
Multiple Time Points ◽  
Static Conditions

Most microorganisms exist in biofilms, which comprise aggregates of cells surrounded by an extracellular matrix that provides protection from external stresses. Based on the conditions under which they form, biofilm structures vary in significant ways. For instance, biofilms that develop when microbes are incubated under static conditions differ from those formed when microbes encounter the shear forces of a flowing liquid. Moreover, biofilms develop dynamically over time. Here, we describe a cost-effective, 3D-printed coverslip holder that facilitates surface adhesion assays under a broad range of standing and shaking culture conditions. This multi-panel adhesion (mPAD) mount further allows cultures to be sampled at multiple time points, ensuring consistency and comparability between samples and enabling analyses of the dynamics of biofilm formation. As a proof of principle, using the mPAD mount for shaking, oxic cultures, we confirm previous flow chamber experiments showing that Pseudomonas aeruginosa wild type and a phenazine deletion mutant (Δ phz ) form biofilms with similar structure but reduced density in the mutant strain. Extending this analysis to anoxic conditions, we reveal that microcolony and biofilm formation can only be observed under shaking conditions and are decreased in the Δ phz mutant compared to wild-type cultures, indicating that phenazines are crucial for the formation of biofilms if oxygen as an electron acceptor is unavailable. Furthermore, while the model archaeon Haloferax volcanii does not require archaella for surface attachment under static conditions, we demonstrate that H. volcanii mutants that lack archaella are impaired in early stages of biofilm formation under shaking conditions. Importance: Due to the versatility of the mPAD mount, we anticipate that it will aid the analysis of biofilm formation in a broad range of bacteria and archaea. Thereby, it contributes to answering critical biological questions about the regulatory and structural components of biofilm formation and understanding this process in a wide array of environmental, biotechnological, and medical contexts.

Synergy between Nisin and Select Lactates against Listeria monocytogenes Is Due to the Metal Cations

2003 ◽  
Vol 66 (9) ◽  
pp. 1631-1636 ◽  
Author(s):  
JENNIFER CLEVELAND McENTIRE ◽  
THOMAS J. MONTVILLE ◽  
MICHAEL L. CHIKINDAS
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Resistant Strain ◽  
Foodborne Pathogen ◽  
Metal Cations ◽  
Resistant Mutant ◽  
Wild Type ◽  
Atp Levels ◽  
Potassium Lactate ◽  
Lactic Acids

Listeria monocytogenes, a major foodborne pathogen, has been responsible for many outbreaks and recalls. Organic acids and antimicrobial peptides (bacteriocins) such as nisin are produced by lactic acid bacteria and are commercially used to control pathogens in some foods. This study examined the effects of lactic acid (LA) and its salts in combination with a commercial nisin preparation on the growth of L. monocytogenes Scott A and its nisin-resistant mutant. Because of an increase in its activity at a lower pH, nisin was more active against L. monocytogenes when used in combination with LA. Most of the salts of LA, including potassium lactate, at up to 5% partially inhibited the growth of L. monocytogenes and had no synergy with nisin. Zinc and aluminum lactate, as well as zinc and aluminum chloride (0.1%), worked synergistically with 100 IU of nisin per ml to control the growth of L. monocytogenes Scott A. No synergy was observed when zinc or aluminum lactate was used with nisin against nisin-resistant L. monocytogenes. The nisin-resistant strain was more sensitive to Zn lactate than was wild-type L. monocytogenes Scott A; however, the cellular ATP levels of the nisin-resistant strain were not significantly affected. Changes in the intracellular ATP levels of the wild-type strain support our hypothesis that pretreatment with zinc lactate sensitizes cells to nisin. The similar effects of the salts of hydrochloric and lactic acids support the hypothesis that metal cations are responsible for synergy with nisin.

EFFECT OF TOPOGRAPHICALLY PATTERNED POLY(DIMETHYLSILOXANE) SURFACES ON Pseudomonas aeruginosa ADHESION AND BIOFILM FORMATION

Nano LIFE ◽  
2012 ◽  
Vol 02 (04) ◽  
pp. 1242004 ◽  
Author(s):  
JOHN F. LING ◽  
MARY V. GRAHAM ◽  
NATHANIEL C. CADY
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Lower Surface ◽  
Bacterial Attachment ◽  
Initial Surface ◽  
Direct Role ◽  
Surface Attachment ◽  
Bacterial Surface ◽  
Static Conditions

Bacterial pathogens, such as Pseudomonas aeruginosa, readily form biofilms on surfaces, limiting the efficacy of antimicrobial and antibiotic treatments. To mitigate biofilm formation, surfaces are often treated with antimicrobial agents, which have limited lifetime and efficacy. Recent studies have shown that well-ordered topographic patterns can limit bacterial attachment to surfaces and limit biofilm formation. In this study, nano and microscale patterned poly(dimethylsiloxane) surfaces were evaluated for their ability to affect adhesion and biofilm formation by Pseudomonas aeruginosa. Feature size and spacing were varied from 500 nm to 2 μm and included repeating arrays of square pillars, holes, lines and biomimetc Sharklet™ patterns. Bacterial surface adhesion and biofilm formation was assessed in microfluidic flow devices and under static conditions. Attachment profiles under static and fluid flow varied within topography types, sizes and spacing. Pillar structures of all sizes yielded lower surface attachment than line-based patterns and arrays of holes. This trend was also observed for biomimetic Sharklet™ patterns, with reduced bacterial attachment to "raised" features as compared to "recessed" features. Notably, none of the topographically patterned surfaces outperformed smooth surfaces (without topography) for resisting cell adhesion. Initial surface attachment patterns were indicative of subsequent biofilm formation and coverage, suggesting a direct role of surface topography in biofilm-based biofouling.

scholarly journals Increased ATPase Activity Is Responsible for Acid Sensitivity of Nisin-Resistant Listeria monocytogenes ATCC 700302

2004 ◽  
Vol 70 (5) ◽  
pp. 2717-2721 ◽  
Author(s):  
Jennifer Cleveland McEntire ◽  
George M. Carman ◽  
Thomas J. Montville
Keyword(s):  
Cell Death ◽  
Listeria Monocytogenes ◽  
Foodborne Pathogen ◽  
Spontaneous Mutant ◽  
Wild Type ◽  
Cell Cytoplasm ◽  
Acid Sensitivity ◽  
In The Wild ◽  
Increased Activity

ABSTRACT The growth of the foodborne pathogen Listeria monocytogenes can be controlled by nisin, an antimicrobial peptide. A spontaneous mutant of L. monocytogenes shows both resistance to nisin and increased acid sensitivity compared to the wild type. Changes in the cell membrane correlated with nisin resistance, but the mechanism for acid sensitivity appears unrelated. When hydrochloric or lactic acid is added to cultures, intracellular ATP levels drop significantly in the mutant (P < 0.01) compared to the results seen with the wild type. Characterization of the F0F1 ATPase, which hydrolyzes ATP to pump protons from the cell cytoplasm, shows that the enzyme is more active in the mutant than in the wild type. These data support a model in which the increased activity of the mutant ATPase upon acid addition depletes the cells' supply of ATP, resulting in cell death.

Growth and Survival of Attached Listeria on Lettuce and Stainless Steel Varies by Strain and Surface Type

2021 ◽  
Author(s):  
Lisa Gorski ◽  
Samarpita Walker ◽  
Kelly F Romanolo ◽  
Sophia Kathariou
Keyword(s):  
Stainless Steel ◽  
Listeria Monocytogenes ◽  
Fluorescent Protein ◽  
Foodborne Pathogen ◽  
Surface Growth ◽  
Growth And Survival ◽  
Abiotic Surfaces ◽  
Serotype 1 ◽  
Serotype 4B ◽  
Green Fluorescent

The foodborne pathogen Listeria monocytogenes lives as a saprophyte in nature and can adhere to and grows on surfaces as diverse as leaves, sediment, and stainless steel. To discern the mechanisms used by L. monocytogenes for attachment and growth on various surfaces, we studied interactions between the pathogen on lettuce and stainless steel. A panel of 24 strains (23 of Listeria monocytogenes and 1 L. innocua ) was screened for attachment and growth on lettuce at 4 o C and 25 o C and on stainless steel at 10 o C and 37 o C. Overnight growth of attached cells resulted in a 0 – 3 log increase on lettuce, depending on the strain and the temperature. Among the worst performing strains on lettuce were two from a large cantaloupe outbreak, indicating that factors important for interactions with cantaloupe may be different from those required on lettuce tissue. Strains that grew the best on lettuce belonged to serotypes 1/2a, 1/2b, and 4b and were from cheese, potatoes, and water/sediment near produce fields. Confocal microscopy of L. monocytogenes tagged with constitutively expressed green fluorescent protein indicated associations with the cut edges and veins of lettuce leaves. On stainless steel coupons, there was a 5 – 7 log increase at 10 o C after 7 d and a 4 – 7 log increase at 37 o C after 40 h. Statistically, surface growth on stainless steel was better for serotype 1/2a than for serotype 4b strains, even though certain serotype 4b strains grew well on the coupons. The latter included strains that originated from produce and water/sediment. Some strains were fit in both environments, while others showed variability between the two different surfaces. Further analysis of these strains should reveal molecular factors needed for adherence and surface growth of L. monocytogenes on different biotic and abiotic surfaces.

scholarly journals Motility and Chemotaxis in Agrobacterium tumefaciens Surface Attachment and Biofilm Formation

2007 ◽  
Vol 189 (22) ◽  
pp. 8005-8014 ◽  
Author(s):  
Peter M. Merritt ◽  
Thomas Danhorn ◽  
Clay Fuqua
Keyword(s):  
Agrobacterium Tumefaciens ◽  
Biofilm Formation ◽  
Bacterial Species ◽  
Wild Type ◽  
Swarming Motility ◽  
Surface Attachment ◽  
Directed Motility ◽  
Suppressor Mutants ◽  
Static Conditions ◽  
Specific Deletion

ABSTRACT Bacterial motility mechanisms, including swimming, swarming, and twitching, are known to have important roles in biofilm formation, including colonization and the subsequent expansion into mature structured surface communities. Directed motility requires chemotaxis functions that are conserved among many bacterial species. The biofilm-forming plant pathogen Agrobacterium tumefaciens drives swimming motility by utilizing a small group of flagella localized to a single pole or the subpolar region of the cell. There is no evidence for twitching or swarming motility in A. tumefaciens. Site-specific deletion mutations that resulted in either aflagellate, flagellated but nonmotile, or flagellated but nonchemotactic A. tumefaciens derivatives were examined for biofilm formation under static and flowing conditions. Nonmotile mutants were significantly deficient in biofilm formation under static conditions. Under flowing conditions, however, the aflagellate mutant rapidly formed aberrantly dense, tall biofilms. In contrast, a nonmotile mutant with unpowered flagella was clearly debilitated for biofilm formation relative to the wild type. A nontumbling chemotaxis mutant was only weakly affected with regard to biofilm formation under nonflowing conditions but was notably compromised in flow, generating less adherent biomass than the wild type, with a more dispersed cellular arrangement. Extragenic suppressor mutants of the chemotaxis-impaired, straight-swimming phenotype were readily isolated from motility agar plates. These mutants regained tumbling at a frequency similar to that of the wild type. Despite this phenotype, biofilm formation by the suppressor mutants in static cultures was significantly deficient. Under flowing conditions, a representative suppressor mutant manifested a phenotype similar to yet distinct from that of its nonchemotactic parent.

scholarly journals Flagellar Motility Is Critical for Listeria monocytogenes Biofilm Formation

2007 ◽  
Vol 189 (12) ◽  
pp. 4418-4424 ◽  
Author(s):  
Katherine P. Lemon ◽  
Darren E. Higgins ◽  
Roberto Kolter
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Early Stage ◽  
Food Contamination ◽  
Initial Surface ◽  
Flagellar Motility ◽  
Surface Attachment ◽  
Abiotic Surfaces ◽  
Biofilm Development

ABSTRACT The food-borne pathogen Listeria monocytogenes attaches to environmental surfaces and forms biofilms that can be a source of food contamination, yet little is known about the molecular mechanisms of its biofilm development. We observed that nonmotile mutants were defective in biofilm formation. To investigate how flagella might function during biofilm formation, we compared the wild type with flagellum-minus and paralyzed-flagellum mutants. Both nonmotile mutants were defective in biofilm development, presumably at an early stage, as they were also defective in attachment to glass during the first few hours of surface exposure. This attachment defect could be significantly overcome by providing exogenous movement toward the surface via centrifugation. However, this centrifugation did not restore mature biofilm formation. Our results indicate that it is flagellum-mediated motility that is critical for both initial surface attachment and subsequent biofilm formation. Also, any role for L. monocytogenes flagella as adhesins on abiotic surfaces appears to be either minimal or motility dependent under the conditions we examined.

scholarly journals Increased Listeria monocytogenes Dissemination and Altered Population Dynamics in Muc2-Deficient Mice

2021 ◽  
Vol 89 (4) ◽  
Author(s):  
Ting Zhang ◽  
Jumpei Sasabe ◽  
Karthik Hullahalli ◽  
Brandon Sit ◽  
Matthew K. Waldor
Keyword(s):  
Population Dynamics ◽  
Listeria Monocytogenes ◽  
Systemic Disease ◽  
Foodborne Pathogen ◽  
Major Constituent ◽  
Infection Model ◽  
Wild Type ◽  
Content Type ◽  
Oral Infections ◽  
Founding Population

ABSTRACT The mucin Muc2 is a major constituent of the mucus layer that covers the intestinal epithelium and creates a barrier between epithelial cells and luminal commensal or pathogenic microorganisms. The Gram-positive foodborne pathogen Listeria monocytogenes can cause enteritis and also disseminate from the intestine to give rise to systemic disease. L. monocytogenes can bind to intestinal Muc2, but the influence of the Muc2 mucin barrier on L. monocytogenes intestinal colonization and systemic dissemination has not been explored. Here, we used an orogastric L. monocytogenes infection model to investigate the role of Muc2 in host defense against L. monocytogenes. Compared to wild-type mice, we found that Muc2−/− mice exhibited heightened susceptibility to orogastric challenge with L. monocytogenes, with higher mortality, elevated colonic pathology, and increased pathogen burdens in both the intestinal tract and distal organs. In contrast, L. monocytogenes burdens were equivalent in wild-type and Muc2−/− animals when the pathogen was administered intraperitoneally, suggesting that systemic immune defects related to Muc2 deficiency do not explain the heightened pathogen dissemination observed in oral infections. Using a barcoded L. monocytogenes library to measure intrahost pathogen population dynamics, we found that Muc2−/− animals had larger pathogen founding population sizes in the intestine and distal sites than observed in wild-type animals. Comparisons of barcode frequencies suggested that the colon becomes the major source for seeding the internal organs in Muc2−/− animals. Together, our findings reveal that Muc2 mucin plays a key role in controlling L. monocytogenes colonization, dissemination, and population dynamics.

Aerobic Plate Counts and ATP Levels Correlate with Listeria monocytogenes Detection in Retail Delis

2015 ◽  
Vol 78 (4) ◽  
pp. 825-830 ◽  
Author(s):  
SUSAN R. HAMMONS ◽  
MATTHEW J. STASIEWICZ ◽  
SHERRY ROOF ◽  
HALEY F. OLIVER
Keyword(s):  
Listeria Monocytogenes ◽  
Foodborne Pathogen ◽  
Fold Increase ◽  
The United States ◽  
Plate Count ◽  
Relative Light Unit ◽  
Atp Level ◽  
Atp Levels ◽  
Level Increase ◽  
Aerobic Plate Count

Listeria monocytogenes is a foodborne pathogen that causes an estimated 1,591 cases of illness and 255 deaths annually in the United States, the majority of which are attributed to ready-to-eat deli meats processed in retail delis. Because retail delis distribute product directly to consumers, rapid methods to validate cleaning and sanitation are needed to improve retail food safety. This study investigated the relationships among ATP levels, standard aerobic plate count (APC), and L. monocytogenes presence in fully operational delis. Fifteen full-service delis were concurrently sampled for ATP, APC, and L. monocytogenes during preoperational hours once monthly for 3 months. Fifteen additional delis were recruited for 6 months of operational sampling (n = 30). A 1-log increase in APC was equivalent to a 3.3-fold increase in the odds of detecting L. monocytogenes (P &lt; 0.001) and a 1.9-log increase in L monocytogenes population (P = 0.03). An ATP level increase of 1 log relative light unit correlated to a 0.22-log increase in APC (P &lt; 0.001). A preoperational ATP level mean increase by 1 log relative light unit increased the odds of detecting L. monocytogenes concurrently fourfold. A 0.5-log increase in mean ATP level during preoperational sampling corresponded to a 2% increase in the predicted L. monocytogenes prevalence during operation (P &lt; 0.01). Additionally, 10 statistically representative sites were identified and recommended for use in sanitation monitoring programs. Our data support the use of ATP as a rapid method to validate effective cleaning and sanitation to reduce L. monocytogenes in retail delis.

Sign in / Sign up

Export Citation Format

Share Document