Cleaning and sanitation in food processing environments for the prevention of biofilm formation, and biofilm removal

Author(s):  
D. Grinstead
Author(s):  
S. R. Warke ◽  
V. C. Ingle ◽  
N. V. Kurkure ◽  
P. A. Tembhurne ◽  
Minakshi Prasad ◽  
...  

Listeria monocytogenes, an opportunistic food borne pathogen can cause serious infections in immunocompromised individuals. L. monocytogenes is capable of producing biofilm on the surface of food processing lines and instruments.The biofilm transfers contamination to food products and impose risk to public health. In the present study biofilm producing ability of L. monocytogenes isolates were investigated phenotypically and genotypically by microtiter assay and multiplex PCR, respectively. Out of 38 L. monocytogenes isolates 14 were recovered from animal clinical cases, 12 bovine environment and 12 from milk samples. A total of 3 (21.42%) clinical, 2 (16.66%) environment and 3 (25%) milk samples respectively, revealed biofilm production in microtiter assay. Cumulative results showed that 23 (60.52%) out of 38 strains of L. monocytogenes were positive for luxS and flaA gene and 1 (2.63%) was positive only for the flaA gene.


Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 250 ◽  
Author(s):  
Daniel Rodríguez-Campos ◽  
Cristina Rodríguez-Melcón ◽  
Carlos Alonso-Calleja ◽  
Rosa Capita

Some strains of Listeria monocytogenes can persist in food-processing environments, increasing the likelihood of the contamination of foodstuffs. To identify traits that contribute to bacterial persistence, a selection of persistent and sporadic L. monocytogenes isolates from a poultry-processing facility was investigated for biofilm-forming ability (crystal violet assay). The susceptibility of sessile cells to treatments (five minutes) with sodium hypochlorite having 10% active chlorine (SHY: 10,000 ppm, 25,000 ppm, and 50,000 ppm) and benzalkonium chloride (BZK: 2500 ppm, 10,000 ppm, and 25,000 ppm) was also studied. All isolates exhibited biofilm formation on polystyrene. Persistent strains showed larger (p < 0.001) biofilm formation (OD580 = 0.301 ± 0.097) than sporadic strains (OD580 = 0.188 ± 0.082). A greater susceptibility to disinfectants was observed for biofilms of persistent strains than for those of sporadic strains. The application of SHY reduced biofilms only for persistent strains. BZK increased OD580 in persistent strains (2500 ppm) and in sporadic strains (all concentrations). These results indicate that the use of BZK at the concentrations tested could represent a public health risk. Findings in this work suggest a link between persistence and biofilm formation, but do not support a relationship between persistence and the resistance of sessile cells to disinfectants.


2018 ◽  
Vol 81 (4) ◽  
pp. 582-592 ◽  
Author(s):  
HYE RI JEON ◽  
MI JIN KWON ◽  
KI SUN YOON

ABSTRACT Biofilm formation on food contact surfaces is a potential hazard leading to cross-contamination during food processing. We investigated Listeria innocua biofilm formation on various food contact surfaces and compared the washing effect of slightly acidic electrolyzed water (SAEW) at 30, 50, 70, and 120 ppm with that of 200 ppm of sodium hypochlorite (NaClO) on biofilm cells. The risk of L. innocua biofilm transfer and growth on food at retail markets was also investigated. The viability of biofilms that formed on food contact surfaces and then transferred cells to duck meat was confirmed by fluorescence microscopy. L. innocua biofilm formation was greatest on rubber, followed by polypropylene, glass, and stainless steel. Regardless of sanitizer type, washing removed biofilms from polypropylene and stainless steel better than from rubber and glass. Among the various SAEW concentrations, washing with 70 ppm of SAEW for 5 min significantly reduced L. innocua biofilms on food contact surfaces during food processing. Efficiency of transfer of L. innocua biofilm cells was the highest on polypropylene and lowest on stainless steel. The transferred biofilm cells grew to the maximum population density, and the lag time of transferred biofilm cells was longer than that of planktonic cells. The biofilm cells that transferred to duck meat coexisted with live, injured, and dead cells, which indicates that effective washing is essential to remove biofilm on food contact surfaces during food processing to reduce the risk of foodborne disease outbreaks.


2019 ◽  
Vol 85 (17) ◽  
Author(s):  
Jeyachchandran Visvalingam ◽  
Hui Wang ◽  
Tim C. Ells ◽  
Xianqin Yang

ABSTRACT This study investigated the microbial dynamics in multispecies biofilms of Escherichia coli O157:H7 strain 1934 (O157) or Salmonella enterica serovar Typhimurium ATCC 14028 (ST) and 40 strains of meat processing surface bacteria (MPB). Biofilms of O157 or ST with/without MPB were developed on stainless steel coupons at 15°C for up to 6 days. Bacteria in suspensions (inoculum, days 2 and 6) and biofilms (days 2 and 6) were enumerated by plating. The composition of multispecies cultures was determined by 16S rRNA gene sequencing. In suspensions, levels of O157 and ST were ∼2 log higher in single-species than in multispecies cultures on both sampling days. ST was 3 log higher in single-species than in multispecies biofilms. A similar trend, though to a lesser extent, was observed for O157 in biofilms on day 2 but not on day 6. No difference (P > 0.05) in bacterial counts was noted for the two MPB-pathogen cocultures at any time during incubation. Bacterial diversity in multispecies cultures decreased with incubation time, irrespective of the pathogen or culture type. The changes in the relative abundance of MPB were similar for the two MPB-pathogen cocultures, though different interbacterial interactions were noted. Respective fractions of ST and O157 were 2.1% and 0.97% initially and then 0.10% and 0.07% on day 2, and 0.60% and 0.04% on day 6. The relative proportions of facultative anaerobes in both multispecies cultures were greater in both suspensions and biofilms than in the inoculum. Citrobacter, Hafnia, Aeromonas, and Carnobacterium predominated in biofilms but not always in the planktonic cultures. IMPORTANCE Results of this study demonstrate that Salmonella enterica serovar Typhimurium and E. coli O157:H7 can integrate into biofilms when cocultured with bacteria from meat plant processing surfaces. However, the degree of biofilm formation for both pathogens was substantially reduced in the presence of the competing microbiota, with S. Typhimurium more greatly affected than E. coli O157:H7. The expression of extracellular determinants such as curli and cellulose appears to be less important for biofilm formation of the pathogens in multispecies cultures than in monoculture. In contrast to previous reports regarding food processing surface bacteria, data collected here also demonstrate that facultative anaerobes may have a competitive edge over strict aerobes in establishing multispecies biofilms. It would be important to take into account the presence of background bacteria when evaluating the potential persistence of a pathogen in food processing facilities.


2020 ◽  
Vol 48 (9) ◽  
pp. 030006052095298
Author(s):  
Yingxia Luo ◽  
Qixuan Yang ◽  
Bingkun Li ◽  
Yao Yao

Objective In recent years, the Emergency Care Research Institute has advised that endoscope cleaning is of considerable importance. In the present study, a quality control circle (QCC) was used to reduce the formation of biofilms in flexible endoscopes within one hospital in Guangdong Province, China. Methods During reprocessing of 235 flexible endoscopes in the urology surgical suite, adenosine triphosphate (ATP) detection was used to monitor the efficacy of biofilm removal. The internal and external parts of flexible endoscopes were used as sampling sites by means of the flushing and smudge methods, respectively. When the two results reached the standard of less than 500 relative light units/piece at the same time, endoscopic biofilm clearance was considered to be qualified. A QCC was established to implement a 10-step plan-do-check-act model. Results The baseline qualified rate (i.e., ATP monitoring pass rate) during reprocessing of 235 flexible endoscopes was 50%. During the study, the qualified rate increased to 85.29% after establishment of the QCC. During reprocessing of 150 flexible endoscopes in the following 6 months, the qualified rate remained at 90%. Conclusion Establishment of the QCC improved the removal of biofilm from flexible endoscopes in the urology surgical suite.


Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2762
Author(s):  
Bo-Kyung Jeon ◽  
Chang-Ha Lee ◽  
A Reum Kim ◽  
Seung Hyun Han ◽  
Hyun-Jung Kim ◽  
...  

Oral biofilms coat all surfaces in the oral cavity including the exposed dentin surface. This study aimed to investigate biofilm removal by acid etching procedures and the effects of the residual biofilm on dentin surfaces on composite–dentin adhesion. Dentin discs were assigned to five groups: no biofilm formation (C); biofilm formation and no surface treatment (BF); biofilm formation and acid etching (BF-E); biofilm formation and acid etching followed by chlorhexidine soaking (BF-EC); and biofilm formation and rubbing with pumice, followed by acid etching (BF-RE). Biofilms were formed on saliva-precoated dentin discs by soaking the discs in Streptococcus mutans (S. mutans) suspension. Biofilm removal from the dentin surface was evaluated quantitatively and qualitatively by confocal laser scanning microscopy and scanning electron microscopy, respectively. To compare the bond strength of the biofilm-coated dentin discs with the surface treatments, specimens were assigned to four groups: no biofilm formation and acid etching (C-E); BF-E; BF-EC; and BF-RE. Assessments of the micro-shear bond strength and subsequent failure modes were performed. BF-E and BF-EC did not remove the biofilm, whereas BF-RE partially removed the biofilm attached to the dentin (p < 0.05). The bond strength of BF-RE was significantly higher than those of BF-E and BF-EC, but lower than that of C-E (p < 0.05). In conclusion, mechanical biofilm removal is recommended before etching procedures to enhance adhesion to the biofilm-coated dentin.


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