Microbial biofilms in seafood: A food-hygiene challenge

Mizan, Md. Furkanur Rahaman,Jahid, Iqbal Kabir,Ha, Sang-Do Elsevier 2015 FOOD MICROBIOLOGY Vol.49 No.-

<P><B>Abstract</B></P> <P>Seafood forms a part of a healthy diet. However, seafood can be contaminated with foodborne pathogens, resulting in disease outbreaks. Because people consume large amounts of seafood, such disease outbreaks are increasing worldwide. Seafood contamination is largely due to the naturally occurring phenomenon of biofilm formation. The common seafood bacterial pathogens that form biofilms are Vibrio spp., Aeromonas hydrophila, Salmonella spp., and Listeria monocytogenes. As these organisms pose a global health threat, recent research has focused on elucidating methods to eliminate these biofilm-forming bacteria from seafood, thereby improving food hygiene. Therefore, we highlight recent advances in our understanding of the underlying molecular mechanisms of biofilm formation, the factors that regulate biofilm development and the role of quorum sensing and biofilm formation in the virulence of foodborne pathogens. Currently, several novel methods have been successfully developed for controlling biofilms present in seafood. In this review, we also discuss the epidemiology of seafood-related diseases and the novel methods that could be used for future control of biofilm formation in seafood.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Bacterial biofilms contaminate seafood. </LI> <LI> Most <I>Vibrio</I> spp. form biofilms on seafood. </LI> <LI> Numerous factors affect biofilm formation on seafood. </LI> <LI> Use of novel biofilm-reducing methods could minimize seafood-borne diseases. </LI> </UL> </P>

Mechanisms and Control Strategies of Antibiotic Resistance in Pathological Biofilms

( Ying Luo ),( Qianqian Yang ),( Dan Zhang ),( Wei Yan ) 한국미생물생명공학회(구 한국산업미생물학회) 2021 Journal of microbiology and biotechnology Vol.31 No.1

Bacterial biofilm is a community of bacteria that are embedded and structured in a self-secreted extracellular matrix. An important clinical-related characteristic of bacterial biofilms is that they are much more resistant to antimicrobial agents than the planktonic cells (up to 1,000 times), which is one of the main causes of antibiotic resistance in clinics. Therefore, infections caused by biofilms are notoriously difficult to eradicate, such as lung infection caused by Pseudomonas aeruginosa in cystic fibrosis patients. Understanding the resistance mechanisms of biofilms will provide direct insights into how we overcome such resistance. In this review, we summarize the characteristics of biofilms and chronic infections associated with bacterial biofilms. We examine the current understanding and research progress on the major mechanisms of antibiotic resistance in biofilms, including quorum sensing. We also discuss the potential strategies that may overcome biofilm-related antibiotic resistance, focusing on targeting biofilm EPSs, blocking quorum sensing signaling, and using recombinant phages.

실험실 일반 장비를 이용한 치과용 유니트 수관 모델 개발

윤혜영 ( Hye Young Yoon ),이시영 ( Si Young Lee ) 한국치위생과학회 2016 치위생과학회지 Vol.16 No.4

DUWL에 형성된 바이오필름 제거를 위한 효과적인 소독제의 제시와 새로운 소독제의 개발을 위해 DUWL의 실험실 모델의 확립이 필요하다. 따라서 본 연구에서는 실험실에서 쉽게 구할 수 있는 장비들로 실험실 모델을 제작하여, DUWL 바이오필름을 재현하기 위한 새로운 실험실 모델을 확립하고자 하였다. 사용 중인 DUWL을 통해 수집한 물에서 세균을 모은 후, R2A 액체 배지에서 10일 동안 배양시켰다. 10일 배양시킨 세균액을 -70℃에 보관하여 사용하였다. -70℃에 저장한 세균 stock은 R2A 액체배지에 5일 동안 회분 배양시킨 배양액은 모델에서 바이오필름을 형성시 키기 위해 사용되었다. 바이오필름 형성 모델은 실험실 내장비인 1 L 비커에 폴리우레탄 튜빙이 부착된 20 cm 유리막대를 꽂아서 제작하였다. 모델을 멸균시킨 후 R2A 액체배지 300 ml와 5일 동안 회분 배양한 세균액 50 ml을 넣고 stir plate에서 25℃로 배양시켰다. 배양 2일마다 R2A 액체배지를 교체해주었다. 임상의 상황과 유사한 조건에서 바이오필름을 형성하기 위해 와류상태는 오전 9시에서 오후 6시까지 적용시키고 그 이외의 시간에는(약 15시간) 정체상태로 배양시켰다. 바이오필름 형성은 4일 동안 진행하였으며, 그 후 바이오필름의 두께, 바이오필름을 구성하는 세균의 분포 및 형태학적 특징을 SEM과 CLSM을 사용하여 분석하였다. 4일 바이오필름 형성 후 평균 바이오필름 축적량은 4.68×104 CFU/cm2였고, 바이오필름의 두께는 10∼14 μm였다. 또한 바이오필름을 구성하는 세균들이 부분적으로 응집되어 덩어리를 이루고 있는 양상을 확인할 수 있었다. 본 연구에서 제작한 실험실 모델을 대상으로 차아염소산나트륨, 과산화 수소 그리고 클로르헥시딘과 같은 소독제의 효과를 확인하였다. 그 결과 적용된 소독제의 농도가 낮을수록 바이오필름 내 생존한 세균의 수가 많았다. 따라서 우리의 실험실 모 델에서 형성시킨 바이오필름은 소독제의 효과를 비교하기 위해 적절한 것으로 판단된다. 우리의 실험실 모델은 향후 DUWL 소독을 위한 새로운 방법의 개발을 위해 유용하게 사용될 것으로 예상된다. Water supplied through dental unit waterlines (DUWLs) has been shown to contain high number of bacteria. To reduce the contamination of DUWLs, it is essential to develop effective disinfectants. It is, however, difficulty to obtain proper DUWL samples for studies. The purpose of this study was to establish a simple laboratory model for reproducing DUWL biofilms. The bacteria obtained from DUWLs were cultured in R2A liquid medium for 10 days, and then stored at -70℃. This stock was inoculated into R2A liquid medium and incubated in batch mode. After 5 days of culturing, it was inoculated into the biofilm formation model developed in this study. Our biofilm formation model comprised of a beaker containing R2A liquid medium and five glass rods attached to DUWL polyurethane tubing. Biofilm was allowed to form on the stir plate and the medium was replaced every 2 days. After 4 days of biofilm formation in the laboratory model, biofilm thickness, morphological characteristics and distribution of the composing bacteria were examined by confocal laser microscopy and scanning electron microscopy. The mean of biofilm accumulation was 4.68×104 colony forming unit/cm2 and its thickness was 10∼14 μm. In our laboratory model, thick bacterial lumps were observed in some parts of the tubing. To test the suitability of this biofilm model system, the effectiveness of disinfectants such as sodium hypochlorite, hydrogen peroxide, and chlorhexidine, was examined by their application to the biofilm formed in our model. Lower concentrations of disinfectants were less effective in reducing the count of bacteria constituting the biofilm. These results showed that our DUWL biofilm laboratory model was appropriate for comparison of disinfectant effects. Our laboratory model is expected to be useful for various other purposes in further studies.

Biofilm formation in food processing plants and novel control strategies to combat resistant biofilms: the case of Salmonella spp.

Xinyi Pang,Xin Hu,Xueying Du,Chenglong Lv,육현균 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.12

Salmonella is one of the pathogens that cause many foodborne outbreaks throughout the world, representing an important global public health problem. Salmonella strains with biofilm-forming abilities have been frequently isolated from different food processing plants, especially in poultry industry. Biofilm formation of Salmonella on various surfaces can increase their viability, contributing to their persistence in food processing environments and cross-contamination of food products. In recent years, increasing concerns arise about the antimicrobial resistant and disinfectant tolerant Salmonella, while adaptation of Salmonella in biofilms to disinfectants exacerbate this problem. Facing difficulties to inhibit or remove Salmonella biofilms in food industry, eco-friendly and effective strategies based on chemical, biotechnological and physical methods are in urgent need. This review discusses biofilm formation of Salmonella in food industries, with emphasis on the current available knowledge related to antimicrobial resistance, together with an overview of promising antibiofilm strategies for controlling Salmonella in food production environments.

Well-Plate를 사용한 치과용 유니트 수관 바이오필름 모델 확립

윤혜영 ( Hye Young Yoon ),이시영 ( Si Young Lee ) 한국치위생과학회 2017 치위생과학회지 Vol.17 No.4

DUWL에 형성한 바이오필름을 효율적으로 제거할 수 있는 새로운 소독제는 개발되어야 하며, 실험실에서 소독제의 효과를 확인하기 위해 DUWL 바이오필름 시료는 필요하다. 이 연구의 목적은 well plate를 사용하여 간단하고 재현 가능한 DUWL 바이오필름 모델을 개발하는 것이다. 사용중인 4대의 DUWL에서 배출된 1 L의 물을 여과지에 여과시켜 세균을 얻었다. 여과지를 PBS (pH 7.4) 용액 20 ml에 현탁시킨 후, 현탁액을 R2A 액체배지에 접종하고 25℃에서 10일 동안 배양하였다. 10일 배양한 세균 배양액을 -70℃에 보관하였고 매 실험에 사용하였다. 세균배양액을 R2A 배지에서 5일 동안 회분 배양하였다. 12-well plate에 회분 배양한 세균 배양액과 멸균한 폴리우레탄 튜빙 조각을 넣고 정체된 상태로 25℃에서 바이오필름을 형성시켰다. R2A 액체배지는 2일마다 2 ml씩 교체해주었다. 폴리우레탄 내 형성된 바이오필름의 축적량을 확인하기 위해 폴리우레탄 튜빙 조각을 내면에서 수집한 바이오필름을 R2A 고체배지에 도말하였다. 도말한 R2A 고체배지는 25℃에서 7일 배양하고 CFU/㎠를 계산하였다. 그리고 바이오필름의 두께와 구성 세균의 형태 및 분포를 확인하기 위해 CLSM과 SEM을 사용하였다. 4일 동안 배양시킨 바이오필름의 평균 축적량은 1.15×10⁷ CFU/㎠였다. 바이오필름은 구균, 짧은 길이의 간균, 그리고 중간길이의 간균을 포함하고 있었고 폴리우레탄 튜빙 내면에 넓게 분포하고 있었다. 바이오필름 두께는 위치에 따라 차이가 있지만 2∼7 μm였다. 이 연구에서 제작된 DUWL 바이오필름 model은 DUWL에서 수집된 모든 세균을 사용하여 세균의 다양성을 확보했고 또한 실험실에서 쉽게 구할 수 있는 well-plate를 사용했기 때문에 비용 효율적이고 재현이 간단하다. 본 연구의 DUWL 바이오필름 모델은 새로운 소독방법을 개발하는 데 유용하게 사용될 수 있다. The water discharged from dental unit waterlines (DUWLs) is heavily contaminated with bacteria. The development of efficient disinfectants is required to maintain good quality DUWL water. The purpose of this study was to establish a DUWL biofilm model using well-plates to confirm the effectiveness of disinfectants in the laboratory. Bacteria were obtained from the water discharged from DUWLs and incubated in R2A liquid medium for 10 days. The bacterial solution cultured for 10 days was made into stock and these stocks were incubated in R2A broth and batch mode for 5 days. Batch-cultured bacterial culture solution and polyurethane tubing sections were incubated in 12-well plates for 4 days. Biofilm accumulation was confirmed through plating on R2A solid medium. In addition, the thickness of the biofilm and the shape and distribution of the constituent bacteria were confirmed using confocal laser microscopy and scanning electron microscopy. The average accumulation of the cultured biofilm over 4 days amounted to 1.15×10⁷ CFU/㎠. The biofilm was widely distributed on the inner surface of the polyurethane tubing and consisted of cocci, short-length rods and medium-length rods. The biofilm thickness ranged from 2 μm to 7 μm. The DUWL biofilm model produced in this study can be used to develop disinfectants and study DUWL biofilm-forming bacteria.

Extracellular matrix-degrading enzymes as a biofilm control strategy for food-related microorganisms

김주성,임민철,김세민,이주영 한국식품과학회 2023 Food Science and Biotechnology Vol.32 No.12

Biofilm is one of the major problems in food industries and is difficult to be removed or prevented by conventional sanitizers. In this review, we discussed the extracellular matrix-degrading enzymes as a strategy to control biofilms of foodborne pathogenic and food-contaminating bacteria. The biofilms can be degraded by using the enzymes targeting proteins, polysaccharides, extracellular DNA, or lipids which mainly constitute the extracellular polymeric substances of biofilms. However, the efficacy of enzymes varies by the growth medium, bacterial species, strains, or counterpart microorganisms due to a high variation in the composition of extracellular polymeric substances. Several studies demonstrated that the combined treatment using conventional sanitizers or multiple enzymes can synergistically enhance the biofilm removal efficacies. In this review, the application of the immobilized enzymes on solid substrates is also discussed as a potential strategy to prevent biofilm formation on food contact surfaces.

Synergistic bactericidal action of phytic acid and sodium chloride against Escherichia coli O157:H7 cells protected by a biofilm

Kim, N.H.,Rhee, M.S. Elsevier Science Publishers 2016 International journal of food microbiology Vol.227 No.-

<P>The food industry must prevent the build-up of strong Escherichia coli O157:H7 biofilms in food processing environments. The present study examined the bactericidal action of phytic acid (PA), a natural extract from rice bran and the hulls/peels of legumes, against E. coli O157:H7 biofilms. The synergistic bactericidal effects of PA plus sodium chloride (NaCl) were also examined. E. coli O157:H7 biofilms were allowed for form on stainless steel coupons by culture in both rich (tryptic soy broth, TSB) and minimal (M9) medium at 22 degrees C for 6 days. Bacterial cells within biofilms grown in M9 medium were significantly more resistant to PA than those grown in TSB (p < 0.05); thus M9 medium was selected for further experiments. The anti-biofilm effect of PA was significantly increased by addition of NaCl (2-4%) (p < 0.05); indeed, the combination of 0.4% PA plus 3-4% NaCl completely inactivated E. coli O157:H7 biofilms without recovery (a > 6.5 log CFU/cm(2) reduction). Neither PA nor NaCl alone were this effective (PA, 1.6-2.7 log CFU/cm(2) reduction; NaCl, < 0.5 log CFU/cm(2) reduction). Confocal laser scanning microscopy images of propidium iodide-treated cells showed that PA (0.4%) plus NaCl (2-4%) had marked membrane permeabilizing effects. These results suggest that a sanitizer that combines these two naturally occurring antimicrobial agents may be useful to food safety managers who encounter thick biofilm formation in food processing environments. (C) 2016 Elsevier B.V. All rights reserved.</P>

Biofouling control potential of tannic acid, ellagic acid, and epigallocatechin against Pseudomonas aeruginosa and reverse osmosis membrane multispecies community

Muhammad Faisal Siddiqui,오현석,Miles Rzechowicz,Harvey Winters,Tzyy Haur Chong,Anthony G. Fane 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.30 No.-

Exploring novel biological strategies to mitigate membrane biofouling is of great worth in order to allowsustainable performance of membrane systems for wastewater treatment. Here, the optimal biofilmprevention potential of three phenolic compounds, viz. tannic acid (TA), ellagic acid (EA), andepigallocatechin (EG) on polystyrene microtiter plate, glass surface, and reverse osmosis (RO) membranecoupons was investigated using Pseudomonas aeruginosa PAO1 and RO multispecies community. Biofilmformation was qualitatively and quantitatively assessed by crystal voilet assay and confocal microscopy[bacterial cells and the components of extracellular polymeric substances (EPS)]. The three phenoliccompounds had different optimal concentrations (TA 100 mg/L, EA 200 mg/L, and EG 200 mg/L) forbiofilm control. Biofilm control was correlated with a reduction in EPS. The three phenolic compoundshad no dispersal effect on 24 h-old PAO1 biofilms. Phenolic compounds also reduced multispeciesbiofilm formation of RO community. The data present strong evidence for the application of thesephenolic compounds for the prevention of biofouling in an industrial setting.

식품공정환경에서의 Listeria monocytogenes의 바이오필름

윤현선 ( Hyun Sun Yun ),김세헌 ( Sae Hun Kim ),전우민 ( Woo Min Jean ) 한국유가공기술과학회 2009 Journal of Dairy Science and Biotechnology (JMSB) Vol.27 No.2

Listeria monocytogenes is a major concern in food processing environments because it is ubiquitous and can easily contaminate food during processing. Contaminated food and the surfaces in food facilities can serve as reservoirs of L. monocytogenes, which can lead to the serious foodborne illness listeriosis in consumers. L. monocytogenes can adhere to materials commonly used in food processing equipment and form biofilms. In the biofilm mode, L. monocytogenes is significantly more resistant to disinfection or sanitizers than its planktonic counterparts. Many researchers have studied the effects of surface materials on bacterial adhesion and the formation of biofilms. Recent studies have focused on preventing the establishment of L. monocytogenes in niches in the food plant environments.

Aqueous-based continuous antimicrobial finishing of polyester fabrics to achieve durable and rechargeable antibacterial, antifungal, and antiviral functions

Jianchuan Wen,AdorrahLe D. Khan,Jake B. Sartorelli,Nancy Goodyear,Yuyu Sun 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.107 No.-

This study reports an aqueous-based continuous finishing strategy to introduce durable and rechargeableantibacterial, antifungal, and antiviral functions onto polyester fabrics. A series of water-soluble acyclicN-halamine precursors, poly(methacrylamide-co-acrylic acid) (PMAs), were synthesized and finishedonto poly(ethylene terephthalate) (PET) fabrics by crosslinking with poly(ethylene glycol)-basedwater-soluble epoxy resins through a simple continuous dip-pad-dry-cure procedure. Amide groups inthe PMA on the finished PET were converted to stable N-halamines by treating with diluted chlorinebleach. The influences of reaction conditions on the finishing were evaluated, and the finished PET fabricswere characterized with Fourier transform infrared (FT-IR) spectroscopy, iodometric titration, water contactangle evaluation, fluorescence microscopy, scanning electron microscopy (SEM), and energy dispersiveX-ray spectrometry (EDS) analysis. The N-halamine finished PET fabrics provided potent and rapidbiocidal efficacies against Gram-positive bacteria, Gram-negative bacteria, fungi, and viruses, and inhibitedthe formation of bacterial and fungal biofilms. Moreover, the finishing did not negatively affect thephysical and mechanical properties of the PET, making the new process attractive for a broad range ofrelated functional finishing of synthetic fabrics.