scholarly journals An approach on the use of predictive microbiology for biofilm formation

2020 ◽  
Vol 9 (8) ◽  
pp. e90985117
Author(s):  
Jaqueline da Silva Rumão ◽  
Christian Oliveira Reinehr

It is necessary to ensure food quality and safety during all stages of food production. The major challenge in the food sector is the control of microbial multiplication, as microorganisms are increasingly looking for alternatives, which involve their development, both in free form as in biofilm, to survive environmental attacks. Due to this concern, researchers use new strategies to understand the dynamics of microbial growth. In this context, predictive microbiology is gaining space in food microbiology. Therefore, the objective of the study was to verify whether the current predictive models are adequate to predict the growth of sessile cells, as well as planktonic cells. A bibliographic survey on the application of predictive microbiology in the evaluation of food safety control was carried out, and we concluded that, due to the scarcity of studies, it was not possible to state the adequacy of tertiary models in the control of biofilms during food production. We highlight the need for studies that can model the formation of biofilm of pathogens under different environmental factors.

2013 ◽  
Vol 76 (9) ◽  
pp. 1488-1499 ◽  
Author(s):  
SARAH FINN ◽  
JAY C. D. HINTON ◽  
PETER McCLURE ◽  
ALÉJANDRO AMÉZQUITA ◽  
MARTA MARTINS ◽  
...  

Salmonella can survive for extended periods of time in low-moisture environments posing a challenge for modern food production. This dangerous pathogen must be controlled throughout the production chain with a minimal risk of dissemination. Limited information is currently available describing the behavior and characteristics of this important zoonotic foodborne bacterium in low-moisture food production environments and in food. In our study, the phenotypes related to low-moisture survival of 46 Salmonella isolates were examined. Most of the isolates in the collection could form biofilms under defined laboratory conditions, with 57% being positive for curli fimbriae production and 75% of the collection positive for cellulose production, which are both linked with stronger biofilm formation. Biocides in the factory environment to manage hygiene were found to be most effective against planktonic cells but less so when the same bacteria were surface dried or present as a biofilm. Cellulose-producing isolates were better survivors when exposed to a biocide compared with cellulose-negative isolates. Examination of Salmonella growth of these 18 serotypes in NaCl, KCl, and glycerol found that glycerol was the least inhibitory of these three humectants. We identified a significant correlation between the ability to survive in glycerol and the ability to survive in KCl and biofilm formation, which may be important for food safety and the protection of public health.


2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.


Agriculture ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 156
Author(s):  
Simona Tarra ◽  
Giampiero Mazzocchi ◽  
Davide Marino

The restriction measures linked to the COVID-19 shock suddenly highlighted the vulnerability of most socioeconomic systems, including the food sector. In a context in which the limitation to the movement of people and goods has put the longer and more structured supply chains in serious difficulty, many experiences and initiatives have emerged as viable alternatives. The aim of the research was to understand if and how the Solidarity Purchasing Groups (SPG) of Rome have contributed to the resilience of the food system of the metropolitan city during the lockdown. The research was based on the results of a questionnaire administered to the SPGs of Rome during the first period of the pandemic (April–July 2020), enriched by some in-depth interviews carried out by the authors. What emerged was that, despite the limited extent in terms of products conveyed within the whole food system, the SPGs represented an important food supply channel during the lockdown period, for two main reasons: a greater flexibility and agility in moving and in handling goods and the possibility of remunerating local farms, contributing to the resilience of the local agri-food fabric. The analysis of the results confirms the strong vitality of such Food Movements in Rome and, at the same time, allows for the identification of a series of interventions that the institutions could adopt to favor the spread of a food environment more compatible with more sustainable and fairer forms of food production and distribution.


2010 ◽  
Vol 76 (7) ◽  
pp. 2122-2128 ◽  
Author(s):  
Mark Reuter ◽  
Arthur Mallett ◽  
Bruce M. Pearson ◽  
Arnoud H. M. van Vliet

ABSTRACT The microaerophilic human pathogen Campylobacter jejuni is the leading cause of food-borne bacterial gastroenteritis in the developed world. During transmission through the food chain and the environment, the organism must survive stressful environmental conditions, particularly high oxygen levels. Biofilm formation has been suggested to play a role in the environmental survival of this organism. In this work we show that C. jejuni NCTC 11168 biofilms developed more rapidly under environmental and food-chain-relevant aerobic conditions (20% O2) than under microaerobic conditions (5% O2, 10% CO2), although final levels of biofilms were comparable after 3 days. Staining of biofilms with Congo red gave results similar to those obtained with the commonly used crystal violet staining. The level of biofilm formation by nonmotile aflagellate strains was lower than that observed for the motile flagellated strain but nonetheless increased under aerobic conditions, suggesting the presence of flagellum-dependent and flagellum-independent mechanisms of biofilm formation in C. jejuni. Moreover, preformed biofilms shed high numbers of viable C. jejuni cells into the culture supernatant independently of the oxygen concentration, suggesting a continuous passive release of cells into the medium rather than a condition-specific active mechanism of dispersal. We conclude that under aerobic or stressful conditions, C. jejuni adapts to a biofilm lifestyle, allowing survival under detrimental conditions, and that such a biofilm can function as a reservoir of viable planktonic cells. The increased level of biofilm formation under aerobic conditions is likely to be an adaptation contributing to the zoonotic lifestyle of C. jejuni.


2020 ◽  
Vol 69 (6) ◽  
pp. 830-837
Author(s):  
Raimunda Sâmia Nogueira Brilhante ◽  
José Alexandre Telmos Silva ◽  
Géssica dos Santos Araújo ◽  
Vandbergue Santos Pereira ◽  
Wilker Jose Perez Gotay ◽  
...  

Introduction. Cryptococcus species are pathogens commonly associated with cases of meningoencephalitis in individuals who are immunosuppressed due to AIDS. Aim. The aim was to evaluate the effects of the antiretroviral darunavir alone or associated with fluconazole, 5-flucytosine and amphotericin B against planktonic cells and biofilms of Cryptococcus species. Methodology. Susceptibility testing of darunavir and the common antifungals against 12 members of the Cryptococcus neoformans/Cryptococcus gattii species complex was evaluated by broth microdilution. The interaction between darunavir and antifungals against planktonic cells was tested by a checkerboard assay. The effects of darunavir against biofilm metabolic activity and biomass were evaluated by the XTT reduction assay and crystal violet staining, respectively. Results. Darunavir combined with amphotericin B showed a synergistic interaction against planktonic cells. No antagonistic interaction was observed between darunavir and the antifungals used. All Cryptococcus species strains were strong biofilm producers. Darunavir alone reduced biofilm metabolic activity and biomass when added during and after biofilm formation (P<0.05). The combination of darunavir with antifungals caused a significant reduction in biofilm metabolic activity and biomass when compared to darunavir alone (P<0.05). Conclusion. Darunavir presents antifungal activity against planktonic cells of Cryptococcus species and synergism with amphotericin B. In addition, darunavir led to reduced biofilm formation and showed activity against mature biofilms of Cryptococcus species. Activity of the antifungals against mature biofilms was enhanced in the presence of darunavir.


2013 ◽  
Vol 57 (10) ◽  
pp. 4877-4881 ◽  
Author(s):  
César de la Fuente-Núñez ◽  
Fany Reffuveille ◽  
Kathryn E. Fairfull-Smith ◽  
Robert E. W. Hancock

ABSTRACTThe ability of nitric oxide (NO) to induce biofilm dispersion has been well established. Here, we investigated the effect of nitroxides (sterically hindered nitric oxide analogues) on biofilm formation and swarming motility inPseudomonas aeruginosa. A transposon mutant unable to produce nitric oxide endogenously (nirS) was deficient in swarming motility relative to the wild type and the complemented strain. Moreover, expression of thenirSgene was upregulated by 9.65-fold in wild-type swarming cells compared to planktonic cells. Wild-type swarming levels were substantially restored upon the exogenous addition of nitroxide containing compounds, a finding consistent with the hypothesis that NO is necessary for swarming motility. Here, we showed that nitroxides not only mimicked the dispersal activity of NO but also prevented biofilms from forming in flow cell chambers. In addition, anirStransposon mutant was deficient in biofilm formation relative to the wild type and the complemented strain, thus implicating NO in the formation of biofilms. Intriguingly, despite its stand-alone action in inhibiting biofilm formation and promoting dispersal, a nitroxide partially restored the ability of anirSmutant to form biofilms.


2015 ◽  
Vol 61 (11) ◽  
pp. 827-836 ◽  
Author(s):  
Rossana de Aguiar Cordeiro ◽  
Rosana Serpa ◽  
Francisca Jakelyne de Farias Marques ◽  
Charlline Vládia Silva de Melo ◽  
Antonio José de Jesus Evangelista ◽  
...  

In recent years, the search for drugs to treat systemic and opportunistic mycoses has attracted great interest from the scientific community. This study evaluated the in vitro inhibitory effect of the antituberculosis drugs isoniazid and ethionamide alone and combined with itraconazole and fluconazole against biofilms of Cryptococcus neoformans and Cryptococcus gattii. Antimicrobials were tested at defined concentrations after susceptibility assays with Cryptococcus planktonic cells. In addition, we investigated the synergistic interaction of antituberculosis drugs and azole derivatives against Cryptococcus planktonic cells, as well as the influence of isoniazid and ethionamide on ergosterol content and cell membrane permeability. Isoniazid and ethionamide inhibited both biofilm formation and viability of mature biofilms. Combinations formed by antituberculosis drugs and azoles proved synergic against both planktonic and sessile cells, showing an ability to reduce Cryptococcus biofilms by approximately 50%. Furthermore, isoniazid and ethionamide reduced the content of ergosterol in Cryptococcus spp. planktonic cells and destabilized or permeabilized the fungal cell membrane, leading to leakage of macromolecules. Owing to the paucity of drugs able to inhibit Cryptococcus biofilms, we believe that the results presented here might be of interest in the designing of new antifungal compounds.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Mark Fenton ◽  
Ruth Keary ◽  
Olivia McAuliffe ◽  
R. Paul Ross ◽  
Jim O'Mahony ◽  
...  

New antibacterial agents are urgently needed for the elimination of biofilm-forming bacteria that are highly resistant to traditional antimicrobial agents. Proliferation of such bacteria can lead to significant economic losses in the agri-food sector. This study demonstrates the potential of the bacteriophage-derived peptidase,CHAPK, as a biocidal agent for the rapid disruption of biofilm-forming staphylococci, commonly associated with bovine mastitis. PurifiedCHAPKapplied to biofilms ofStaphylococcus aureusDPC5246 completely eliminated the staphylococcal biofilms within 4 h. In addition,CHAPKwas able to prevent biofilm formation by this strain. TheCHAPKlysin also reducedS. aureusin a skin decolonization model. Our data demonstrates the potential ofCHAPKas a biocidal agent for prevention and treatment of biofilm-associated staphylococcal infections or as a decontaminating agent in the food and healthcare sectors.


Author(s):  
N.A. Shurduba ◽  
◽  
D.V. Gruznov ◽  

The article presents data on studies of the stability of staphylococcal biofilms. Staphylococcus grows predominantly as biofilm on virtually any type of industrial surface, causing contamination of food and water, corrosion of the metal surface and obstruction of the equipment. In particular, in the processing meat and dairy industry, biofilm formation can contribute to food spoilage and the transfer of pathogenic microorganisms, increasing the possibility of cross-contamination, which can be associated with a serious risk to consumer health. Staphylococci are often isolated from products of animal origin, but it turned out that in the state of biofilm they are more stable and viable than planktonic cells, especially after insufficiently effective disinfection. In this regard, commonly used means and modes of rehabilitation of technological surfaces of meat and dairy processing enterprises must be improved.


Author(s):  
Kevin Morgan ◽  
Terry Marsden ◽  
Jonathan Murdoch

With its rolling hills, small farms, diverse products, and high-quality foodstuffs, Tuscany easily conjures up a world of diversification and localization. In fact, so many of the region’s products are seen as world class—notably its wines, olive oils, cheeses, and processed meats—that it is tempting to see this region as the prime example of an Interpersonal World (in Salais and Storper’s terms). Yet, Tuscany’s perceived success in this world of food is a recent phenomenon. Until the 1990s the region was thought to be rather ‘backward’ in character, mainly due to its inability to adopt conventional industrial approaches to food production and processing. While some effort was made to shift Tuscany on to a more industrialized development path during the 1960s and 1970s, by the early 1990s this was widely regarded as having failed. Out of this failure, however, came the search for a new development model, one that could work with, rather than against, the region’s core assets—notably, its localized variety in foodstuffs and environmental features. Thus, a distinctively Tuscan approach to the agri-food sector is explicitly identified in the recent Rural Development Plan (RDP) drawn up by the Tuscan regional government. The document states that the strategy elaborated in the plan is aiming at ‘strengthening the ‘‘Tuscan model’’ of agricultural and rural development’. The plan goes on to identify key characteristics of the model, including the presence of small and mediumsized farms, the existence of quality products, the diversification of agricultural production, the provision of adequate marketing networks, and the enhancement of the environment and the agricultural landscape (Regione Toscana, 2000). It is tempting to imagine that the consolidation of a diversified and localized world of food production in Tuscany owes much to the implementation of this model by governmental authorities in concert with other actors in the food sector. However, it will be argued below that the emergence of a new world of food in Tuscany owes as much to happenstance as it does to the conscious agency of differing institutions and organizations.


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