Eugenol, citral, and hexanal, alone or in combination with heat, affect viability, biofilm formation, and swarming on Shiga-toxin-producing Escherichia coli

Shiga toxin-producing Escherichia coli are pathogenic bacteria able to form biofilms both on abiotic surfaces and on food, thus increasing risks for food consumers. Moreover, biofilms are difficult to remove and more resistant to antimicrobial agents compared to planktonic cells. Bacteriophages, natural predators of bacteria, can be used as an alternative to prevent biofilm formation or to remove pre-formed biofilm. In this work, four STEC able to produce biofilm were selected among 31 different strains and tested against single bacteriophages and two-phage cocktails. Results showed that our phages were able to reduce biofilm formation by 43.46% both when used as single phage preparation and as a cocktail formulation. Since one of the two cocktails had a slightly better performance, it was used to remove pre-existing biofilms. In this case, the phages were unable to destroy the biofilms and reduce the number of bacterial cells. Our data confirm that preventing biofilm formation in a food plant is better than trying to remove a preformed biofilm and the continuous presence of bacteriophages in the process environment could reduce the number of bacteria able to form biofilms and therefore improve the food safety.

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Mixed Biofilm Formation by Shiga Toxin–Producing Escherichia coli and Salmonella enterica Serovar Typhimurium Enhanced Bacterial Resistance to Sanitization due to Extracellular Polymeric Substances†

Journal of Food Protection ◽

10.4315/0362-028x.jfp-13-077 ◽

2013 ◽

Vol 76 (9) ◽

pp. 1513-1522 ◽

Cited By ~ 48

Author(s):

RONG WANG ◽

NORASAK KALCHAYANAND ◽

JOHN W. SCHMIDT ◽

DAYNA M. HARHAY

Keyword(s):

Escherichia Coli ◽

Food Safety ◽

Foodborne Pathogens ◽

Shiga Toxin ◽

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Bacterial Resistance ◽

Salmonella Enterica Serovar Typhimurium ◽

E Coli ◽

Serovar Typhimurium

Shiga toxin–producing Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium are important foodborne pathogens capable of forming single-species biofilms or coexisting in multispecies biofilm communities. Bacterial biofilm cells are usually more resistant to sanitization than their planktonic counterparts, so these foodborne pathogens in biofilms pose a serious food safety concern. We investigated how the coexistence of E. coli O157:H7 and Salmonella Typhimurium strains would affect bacterial planktonic growth competition and mixed biofilm composition. Furthermore, we also investigated how mixed biofilm formation would affect bacterial resistance to common sanitizers. Salmonella Typhimurium strains were able to outcompete E. coli strains in the planktonic growth phase; however, mixed biofilm development was highly dependent upon companion strain properties in terms of the expression of bacterial extracellular polymeric substances (EPS), including curli fimbriae and exopolysaccharide cellulose. The EPS-producing strains with higher biofilm-forming abilities were able to establish themselves in mixed biofilms more efficiently. In comparison to single-strain biofilms, Salmonella or E. coli strains with negative EPS expression obtained significantly enhanced resistance to sanitization by forming mixed biofilms with an EPS-producing companion strain of the other species. These observations indicate that the bacterial EPS components not only enhance the sanitizer resistance of the EPS-producing strains but also render protections to their companion strains, regardless of species, in mixed biofilms. Our study highlights the potential risk of cross-contamination by multispecies biofilms in food safety and the need for increased attention to proper sanitization practices in food processing facilities.

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Single- and Dual-Species Biofilm Formation by Shiga Toxin-Producing Escherichia coli and Salmonella, and Their Susceptibility to an Engineered Peptide WK2

Microorganisms ◽

10.3390/microorganisms9122510 ◽

2021 ◽

Vol 9 (12) ◽

pp. 2510

Author(s):

Zhi Ma ◽

Xia Tang ◽

Kim Stanford ◽

Xiaolong Chen ◽

Tim A. McAllister ◽

...

Keyword(s):

Escherichia Coli ◽

Stainless Steel ◽

Foodborne Pathogens ◽

Shiga Toxin ◽

Salmonella Enterica ◽

Biofilm Formation ◽

Single Species ◽

Protein Labeling ◽

Cross Contamination ◽

Temporal And Spatial

Shiga toxin-producing Escherichia coli (STEC) and Salmonella enterica are important foodborne pathogens capable of forming both single- and multi-species biofilms. In this study, the mono- and dual-species biofilms were formed by STEC O113:H21 and Salmonella enterica serovar Choleraesuis 10708 on stainless steel in the presence of beef juice over 5 d at 22 °C. The dual-species biofilm mass was substantially (p < 0.05) greater than that produced by STEC O113:H21 or S. Choleraesuis 10708 alone. However, numbers (CFU/mL) of S. Choleraesuis 10708 or STEC O113:H21 cells in the dual-species biofilm were (p < 0.05) lower than their respective counts in single-species biofilms. In multi-species biofilms, the sensitivity of S. Choleraesuis 10708 to the antimicrobial peptide WK2 was reduced, but it was increased for STEC O113:H21. Visualization of the temporal and spatial development of dual-species biofilms using florescent protein labeling confirmed that WK2 reduced cell numbers within biofilms. Collectively, our results highlight the potential risk of cross-contamination by multi-species biofilms to food safety and suggest that WK2 may be developed as a novel antimicrobial or sanitizer for the control of biofilms on stainless steel.

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Biofilm formation by Non-O157 Shiga toxin-producing Escherichia coli in monocultures and co-cultures with meat processing surface bacteria

Food Microbiology ◽

10.1016/j.fm.2021.103902 ◽

2022 ◽

Vol 102 ◽

pp. 103902

Author(s):

Yuan Fang ◽

Jeyachchandran Visvalingam ◽

Peipei Zhang ◽

Xianqin Yang

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Biofilm Formation ◽

Meat Processing

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Genotypic Characterization and Biofilm Formation of Shiga-toxin producing Escherichia coli

FEMS Microbiology Letters ◽

10.1093/femsle/fnw291 ◽

2016 ◽

pp. fnw291 ◽

Cited By ~ 3

Author(s):

C Picozzi ◽

D Antoniani ◽

I Vigentini ◽

R Foschino

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Biofilm Formation ◽

Genotypic Characterization

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Biofilm Formation by Shiga Toxin-Producing Escherichia coli on Stainless Steel Coupons as Affected by Temperature and Incubation Time

Microorganisms ◽

10.3390/microorganisms7040095 ◽

2019 ◽

Vol 7 (4) ◽

pp. 95 ◽

Cited By ~ 9

Author(s):

Zhi Ma ◽

Emmanuel W. Bumunang ◽

Kim Stanford ◽

Xiaomei Bie ◽

Yan D. Niu ◽

...

Keyword(s):

Escherichia Coli ◽

Stainless Steel ◽

Shiga Toxin ◽

Incubation Time ◽

Food Processing ◽

Biofilm Formation ◽

Crystal Violet Staining ◽

Plate Counts ◽

Air Liquid Interface ◽

Over Time

Forming biofilm is a strategy utilized by Shiga toxin-producing Escherichia coli (STEC) to survive and persist in food processing environments. We investigated the biofilm-forming potential of STEC strains from 10 clinically important serogroups on stainless steel at 22 °C or 13 °C after 24, 48, and 72 h of incubation. Results from crystal violet staining, plate counts, and scanning electron microscopy (SEM) identified a single isolate from each of the O113, O145, O91, O157, and O121 serogroups that was capable of forming strong or moderate biofilms on stainless steel at 22 °C. However, the biofilm-forming strength of these five strains was reduced when incubation time progressed. Moreover, we found that these strains formed a dense pellicle at the air-liquid interface on stainless steel, which suggests that oxygen was conducive to biofilm formation. At 13 °C, biofilm formation by these strains decreased (P < 0.05), but gradually increased over time. Overall, STEC biofilm formation was most prominent at 22 °C up to 24 h. The findings in this study identify the environmental conditions that may promote STEC biofilm formation in food processing facilities and suggest that the ability of specific strains to form biofilms contributes to their persistence within these environments.

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Dual-Serotype Biofilm Formation by Shiga Toxin-Producing Escherichia coli O157:H7 and O26:H11 Strains

Applied and Environmental Microbiology ◽

10.1128/aem.01137-12 ◽

2012 ◽

Vol 78 (17) ◽

pp. 6341-6344 ◽

Cited By ~ 11

Author(s):

Rong Wang ◽

Norasak Kalchayanand ◽

James L. Bono ◽

John W. Schmidt ◽

Joseph M. Bosilevac

Keyword(s):

Escherichia Coli ◽

Food Safety ◽

Potential Risk ◽

Shiga Toxin ◽

Biofilm Formation ◽

Escherichia Coli O157 ◽

Content Type ◽

E Coli

ABSTRACTEscherichia coliO26:H11 strains were able to outgrow O157:H7 companion strains in planktonic and biofilm phases and also to effectively compete with precolonized O157:H7 cells to establish themselves in mixed biofilms.E. coliO157:H7 strains were unable to displace preformed O26:H11 biofilms. Therefore,E. coliO26:H11 remains a potential risk in food safety.

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Biofilm formation by LEE-negative Shiga Toxin–Producing Escherichia coli strains

Microbial Pathogenesis ◽

10.1016/j.micpath.2021.105006 ◽

2021 ◽

pp. 105006

Author(s):

Vélez María Victoria ◽

Colello Rocío ◽

Etcheverría Silvina ◽

Etcheverría Analía Inés ◽

Padola Nora Lía

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Biofilm Formation

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Biofilm-Forming Abilities of Shiga Toxin-Producing Escherichia coli Isolates Associated with Human Infections

Applied and Environmental Microbiology ◽

10.1128/aem.02983-15 ◽

2015 ◽

Vol 82 (5) ◽

pp. 1448-1458 ◽

Cited By ~ 25

Author(s):

Philippe Vogeleer ◽

Yannick D. N. Tremblay ◽

Grégory Jubelin ◽

Mario Jacques ◽

Josée Harel

Keyword(s):

Escherichia Coli ◽

Shiga Toxin ◽

Biofilm Formation ◽

Food Industry ◽

Enzymatic Digestion ◽

Human Infection ◽

Genetic Determinants ◽

Independent Manner ◽

Content Type ◽

Human Infections

ABSTRACTForming biofilms may be a survival strategy of Shiga toxin-producingEscherichia colito enable it to persist in the environment and the food industry. Here, we evaluate and characterize the biofilm-forming ability of 39 isolates of Shiga toxin-producingEscherichia coliisolates recovered from human infection and belonging to seropathotypes A, B, or C. The presence and/or production of biofilm factors such as curli, cellulose, autotransporter, and fimbriae were investigated. The polymeric matrix of these biofilms was analyzed by confocal microscopy and by enzymatic digestion. Cell viability and matrix integrity were examined after sanitizer treatments. Isolates of the seropathotype A (O157:H7 and O157:NM), which have the highest relative incidence of human infection, had a greater ability to form biofilms than isolates of seropathotype B or C. Seropathotype A isolates were unique in their ability to produce cellulose and poly-N-acetylglucosamine. The integrity of the biofilms was dependent on proteins. Two autotransporter genes,ehaBandespP, and two fimbrial genes,z1538andlpf2, were identified as potential genetic determinants for biofilm formation. Interestingly, the ability of several isolates from seropathotype A to form biofilms was associated with their ability to agglutinate yeast in a mannose-independent manner. We consider this an unidentified biofilm-associated factor produced by those isolates. Treatment with sanitizers reduced the viability of Shiga toxin-producingEscherichia colibut did not completely remove the biofilm matrix. Overall, our data indicate that biofilm formation could contribute to the persistence of Shiga toxin-producingEscherichia coliand specifically seropathotype A isolates in the environment.

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