Influence of Temperature, Source, and Serotype on Biofilm Formation of Salmonella enterica Isolates from Pig Slaughterhouses

2015 ◽  
Vol 78 (10) ◽  
pp. 1875-1878 ◽  
Author(s):  
FRANCESCA PIRAS ◽  
FEDERICA FOIS ◽  
SIMONETTA GIANNA CONSOLATI ◽  
ROBERTA MAZZA ◽  
RINA MAZZETTE
Keyword(s):  
Optical Density ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Cross Contamination ◽  
Meat Processing ◽  
Microtiter Plate Assay ◽  
Antimicrobial Resistance Profile ◽  
Density Values

Quantitative assessment of in vitro biofilm formation by 40 Salmonella enterica isolates isolated in pig abattoirs from animal and environmental sources (surfaces in contact and not in contact with meat) and classified in eight seroytpes was carried out by using a microtiter plate assay with spectrophotometric reading (optical density at 620 nm). Biofilm-forming ability was statistically correlated with the temperature of incubation (22 and 35°C), the source of the isolates, and the antimicrobial resistance profile. After incubation at 35°C, 9 isolates (22.5 %) were classified as weak biofilm producers. After incubation at 22°C, 25 isolates (62.5%) were classified as weak producers and 3 (7.5%) as moderate producers. The quantity of biofilm formed after incubation at 22°C was significantly higher (P < 0.01) than at 35°C. This result is notable because 22°C is a common temperature in meat processing facilities and in slaughterhouses. At 35°C, isolates detected from surfaces in contact with meat showed significantly higher (P < 0.1) optical density values compared to isolates from other samples, highlighting the risk of cross-contamination for carcasses and offal. No correlation was detected between quantity of biofilm and serotype or between biofilm formation and resistance to antimicrobials.

Evaluation of the Role of Staphylococci in the Pathomechanism of Conjunctivitis

2021 ◽  
Author(s):  
Ewa Jasińska ◽  
Agnieszka Bogut ◽  
Agnieszka Magryś ◽  
Alina Olender
Keyword(s):  
Antibiotic Resistance ◽  
Epithelial Cells ◽  
Biofilm Formation ◽  
Methicillin Resistance ◽  
Microtiter Plate ◽  
Host Cells ◽  
Diffusion Method ◽  
Microtiter Plate Assay ◽  
Low Prevalence

Abstract Purpose: Determination of the association between ica genes and phenotypic biofilm formation in staphylococcal isolates involved in conjunctivitis, their antibiotic resistance as well as detection of selected virulence characteristics: adhesion to epithelial cells and in vitro cytotoxicity.Methods: The study included 26 Staphylococcus aureus (SA) and 26 Staphylococcus epidermidis (SE) isolates. The presence of icaAD genes and ica operon was determined by the PCR assay. Phenotypic biofilm formation was verified using the microtiter plate assay. Antibiotic resistance was performed using the disc diffusion method. Staphylococcal ability to attach to host cells was assessed by flow cytometry. Cytotoxicity on epithelial cells was evaluated by LDH assay.Results: The ica genes were detected in 26.9% of SE and in 42.3% of SA isolates. Only 15.3% of isolates (SE) were positive for both the icaAD and the ica operon. Phenotypically, 19.2% of SE isolates were strong biofilm producers, among which three were both icaAD- and ica operon-positive. 26.9% of SA isolates were strong biofilm producers. Methicillin resistance (MR) was detected in 34.6% of SE and 26.9% of SA isolates. 75% of MR isolates were multidrug resistant. SA isolates adhered to host cells more extensively than SE. SA isolates released higher level of LDH than SE.Conclusions: Adherence abilities were commonly observed in staphylococci associated with conjunctivitis. However, low prevalence of isolates positive for a complete and functional ica locus and low prevalence of strong biofilm producers was detected. SA adhered to a greater extent to eukaryotic cells than SE and were more cytotoxic.

The ability of Salmonella enterica to biofilm formation in conditions of interspecific interaction with representatives of the intestinal microflora

2021 ◽  
pp. 75-80
Author(s):  
E.V. Matosova
Keyword(s):  
Optical Density ◽  
Intestinal Microbiota ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Intestinal Microflora ◽  
Gentian Violet ◽  
Density Measurement ◽  
Interspecific Interaction ◽  
E Coli

For effective distribution in the gastrointestinal tract, Salmonella must have the ability to form biofilms and compete for nutrients with the host microbiota. Objective: to characterize the ability of Salmonella enterica Typhimurium to biofilm formation under conditions of interspecific interaction in a multicultural biofilm with representatives of the intestinal microbiota in an in vitro experiment. Museum strains of the bacteria Salmonella enterica serovar Typhimurium, Lactobacillus acidophilus and Lactobacillus casei, Escherichia coli were used in the work. The process of interspecific interaction was modeled in a mixture of LB-broth with 0.85 % NaCl solution in a ratio of 1:3 at an initial bacterial concentration of 10³ CFU / ml in Petri dishes with a diameter of 65 mm at a temperature of +37 °C. The experimental results were evaluated within 12 days. The plate method was used to count the number of viable cells in biofilms. The optical density of the matrix of the biofilm stained with gentian violet was measured using spectrophotometry (wavelength 595 nm). To assess tinctorial properties, the bacterial samples were Gram-stained.. Enzymatic properties were assessed using Giss media and differential diagnostic media. All experiments were repeated 3 times. It was found that Salmonella enterica Typhimurium exhibit the ability to form biofilm. In the initial stages of biofilm formation, the bacteria of the intestinal microbiota suppress the development of Salmonella. In mature mixed biofilms, the growth of S. enterica and E. coli is mutually stimulated. By the end of the experiment, the dominance of Salmonella over the intestinal microbiota was noted. The results of the optical density measurement suggest the presence of species-specificity in bacterial interaction. Conclusion. Intestinal microbiota bacteria inhibit the growth of Salmonella bacteria in biofilms only in the initial stages. In mature mixed biofilms, the growth of E. coli and S. enterica is mutually stimulated, however, on the 12th day, Salmonella dominates over E. coli and Lactobacillus spp. (p > 0.05). English version of the article is available at URL: https://panor.ru/articles/ability-of-salmonella-enterica-to-biofilm-formation-under-conditions-of-interspecies-interaction-with-representatives-of-the-intestinal-microflora/72525.html

scholarly journals Analysis of the bacterial biofilm formation in different models of the in vitro culture

2021 ◽  
Vol 19 (1) ◽  
pp. 40-45
Author(s):  
Agnieszka Bogut ◽  
◽  
Agnieszka Magryś ◽  
Keyword(s):  
Biofilm Formation ◽  
Culture Media ◽  
Microtiter Plate ◽  
Bacterial Biofilm ◽  
Atmospheric Conditions ◽  
Experimental Conditions ◽  
Microtiter Plate Assay ◽  
Biofilm Production ◽  
Strain Type

Introduction. Microtiter plate assay (MPA) remains one of workhorses of in vitro biofilm research but it requires optimization of experimental conditions to fulfill the biofilm formation requirements of different bacterial pathogens. Aim. The aim was to determine the effect of TSB and RPMI1640 culture media and selected culture variables (O2 vs. 5% CO2, extended incubation time) on the biofilm production by bacteria commonly involved in biofilm-related infections: Enterococcus faecalis (EF), Escherichia coli (EC), Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), Klebsiella pneumoniae (KP). Material and methods. The investigation was performed using the MPA with crystal violet. Results. Statistically significant (p<0.05) increase in biofilm production between 24h and 72h time points was observed for EF (TSB o2, RPMIo2 and RPMIco2), EC (TSBo2), SA (TSBo2, TSBco2), KP (TSBo2, TSBco2), PA (RPMIco2, TSBco2). The TSB caused a significantly greater stimulation of biofilm production compared to RPM1640. It outcompeted RPMI1640 irrespective of the atmospheric conditions for SA and KP and under aerobic conditions for EF. Conclusion. Although the TSB provided the most optimal conditions for biofilm production, the process was influenced by the strain type, atmospheric conditions and period of cultivation which limits the ability to design a single universal model of the in vitro biofilm investigation.

scholarly journals The biofilm formation ability of Listeria monocytogenes isolated from meat, poultry, fish and processing plant environments is related to serotype and pathogenic profile of the strains

2012 ◽  
Vol 2 (1) ◽  
pp. 12 ◽  
Author(s):  
Domenico Meloni ◽  
Roberta Mazza ◽  
Francesca Piras ◽  
Sonia Lamon ◽  
Simonetta Gianna Consolati ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Target Genes ◽  
Microtiter Plate ◽  
Food Sources ◽  
Processing Plant ◽  
Pathogenic Potential ◽  
Microtiter Plate Assay ◽  
Processing Plants

In the present study, the relationships between serotype, pathogenic profile and <em>in vitro</em> biofilm formation of 106 <em>Listeria monocytogenes</em> strains, having no epidemiological correlation and isolated from different environmental and food sources, were analyzed. The quantitative assessment of the <em>in vitro</em> biofilm formation was carried out by using a microtiter plate assay with spectrophotometric reading (OD620). The isolates were also submitted to serogrouping using the target genes <em>lmo0737</em>, <em>lmo1118, ORF2819, ORF2110, prs</em>, and to the evaluation of the presence of the following virulence genes: <em>prfA, hlyA, rrn, inlA, inlB, iap, plcA, plcB, actA</em> and <em>mpl</em>, by multiplex PCRs. The 62% of the strains showed weak or moderate <em>in vitro</em> ability in biofilm formation, in particular serotypes 1/2b and 4b, frequently associated with sporadic or epidemic listeriosis cases. The 25% of these isolates showed polymorphism for the <em>actA</em> gene, producing a fragment of 268-bp instead of the expected 385-bp. The deletion of nucleotides in this gene seems to be related to enhanced virulence properties among these strains. Strains belonging to serotypes associated with human infections and characterized by pathogenic potential are capable to persist within the processing plants forming biofilm.

scholarly journals Salmonella enterica Serovar Typhimurium Swarming Mutants with Altered Biofilm-Forming Abilities: Surfactin Inhibits Biofilm Formation

2001 ◽  
Vol 183 (20) ◽  
pp. 5848-5854 ◽  
Author(s):  
Joe Robert Mireles ◽  
Adam Toguchi ◽  
Rasika M. Harshey
Keyword(s):  
Polyvinyl Chloride ◽  
Salmonella Enterica ◽  
Biofilm Formation ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Microtiter Plate ◽  
Wild Type ◽  
Swarming Motility ◽  
Microtiter Plate Assay ◽  
Serovar Typhimurium ◽  
Transposon Mutants

ABSTRACT Swarming motility plays an important role in surface colonization by several flagellated bacteria. Swarmer cells are specially adapted to rapidly translocate over agar surfaces by virtue of their more numerous flagella, longer cell length, and encasement of slime. The external slime provides the milieu for motility and likely harbors swarming signals. We recently reported the isolation of swarming-defective transposon mutants of Salmonella enterica serovar Typhimurium, a large majority of which were defective in lipopolysaccharide (LPS) synthesis. Here, we have examined the biofilm-forming abilities of the swarming mutants using a microtiter plate assay. A whole spectrum of efficiencies were observed, with LPS mutants being generally more proficient than wild-type organisms in biofilm formation. Since we have postulated that O-antigen may serve a surfactant function during swarming, we tested the effect of the biosurfactant surfactin on biofilm formation. We report that surfactin inhibits biofilm formation of wild-type S. enterica grown either in polyvinyl chloride microtiter wells or in urethral catheters. Other bio- and chemical surfactants tested had similar effects.

scholarly journals The Anti-Biofilm Activity of Oregano Essential Oil Against Dental Plaque-Forming Streptococcus mutans In Vitro and In Vivo

2020 ◽  
Vol 24 (3) ◽  
Author(s):  
Fatemeh Hejazinia ◽  
Leila Fozouni ◽  
Nasrin Sadat Azami ◽  
Seyedgholamreza Mousavi
Keyword(s):  
Essential Oil ◽  
Elementary School Students ◽  
Streptococcus Mutans ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
School Students ◽  
Microtiter Plate Assay ◽  
Oregano Essential Oil

Background: The oral and dental infections that are mainly caused by bacterial biofilms are among the most prevalent human infections worldwide. Objectives: The present study aimed to investigate the in vitro and in vivo inhibitory and anti-biofilm effects of oregano essential oil on the Streptococcus mutans isolates obtained from elementary school students. Methods: This experimental study was conducted on 150 samples collected from the buccal and lingual surfaces of the posterior teeth of elementary school students. S. mutans strains were identified using conventional microbiological and biochemical tests, and biofilm formation was assessed using the microtiter plate assay. The minimum inhibitory concentration (MIC) of the oregano essential oil against the isolates was determined using the broth microdilution method. In addition, the effective constituents of the essential oil were measured via gas chromatography-mass spectroscopy. The in vitro and in vivo anti-biofilm activities of the oregano essential oil were also evaluated using the modified microtiter plate assay and on the tooth surfaces of male NMRI mice, respectively. Results: The frequency of S. mutans was 15.3%, 87% of which were capable of biofilm formation. The MIC of the oregano essential oil was 50 µl/ml against the S. mutans isolates, and 82% of the isolates did not grow at the concentrations of ≥ 512 µl/ml. However, none of the isolates were capable of biofilm formation at the MIC and sub-MIC concentrations of the essential oil. Limonene and myrcene were the most effective constituents of the essential oil. Furthermore, a significant correlation was observed between treatment with the oregano essential oil and biofilm formation by the streptococci isolates (P = 0.05). Conclusions: According to the results, the presence of biofilm and incidence of dental caries were significantly correlated. Moreover, the essential oil of oregano and its main constituents had potent anti-biofilm and antibacterial properties and could be utilized for the production of new plant-based mouthwashes.

scholarly journals Genotypic and virulence characteristics of Listeria monocytogenes recovered from food items in Lebanon

2016 ◽  
Vol 10 (07) ◽  
pp. 712-717 ◽  
Author(s):  
Nathaline Haidar-Ahmad ◽  
Kohar Annie B Kissoyan ◽  
Sukayna M Fadlallah ◽  
Rima El-Hajj ◽  
Majd Saleh ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Food Selection ◽  
Pcr Amplification ◽  
Food Products ◽  
Microtiter Plate ◽  
Pathogenic Potential ◽  
Microtiter Plate Assay ◽  
Imported Food

Introduction: Listeria monocytogenes is the agent of listeriosis, a life threatening foodborne disease for immunocompromised patients and pregnant women. This bacterium is not routinely screened for in Lebanon and there is lack of data about the prevalent strains and their potential pathogenicity. To that purpose, this study was undertaken to characterize L. monocytogenes from various food products, by assessing the in vitro biofilm forming ability, detecting their virulence potential, and characterizing them at the strain level. Methodology: Fifty-nine isolates were obtained from the Lebanese Agriculture Research Institute (LARI). They were collected in 2012-2013 from local and imported food products in the Lebanese market. Biofilm formation was measured using the Microtiter Plate Assay. PCR amplification was performed for three main virulence genes; hly, actA, and inlB. Pulsed field gel electrophoresis (PFGE) and BIONUMERICS analysis were carried out. Results: Lebanese isolates from cheese and raw meat showed higher biofilm formation than imported and Lebanese seafood isolates. A total of 100% of the isolates were PCR positive for hly and actA genes and 98.3% for inlB gene. PFGE analysis demonstrated the prevalence of 13 different subtypes with 100% similarity. Detected subtypes were grouped into 6 clusters of 90% genomic similarity. Clustered subtypes were particular to the country of origin. Conclusion: This study highlights the presence of L. monocytogenes in the Lebanese food market with high pathogenic potential and stresses the importance of enhanced surveillance and the implementation of strict regulations on local and imported food. Future investigations may be conducted on a larger food selection.

scholarly journals Effect of sodium chloride and temperature on biofilm formation and virulence of Flavobacterium columnare isolated from striped catfish (Pangasianodon hypophthalmus)

2020 ◽  
Vol 12 (3) ◽  
Author(s):  
Nguyen Thi Kim My ◽  
Tu Thanh Dung ◽  
Channarong Rodkhum ◽  
Dong Thanh Ha
Keyword(s):  
Biofilm Formation ◽  
In Vitro Study ◽  
Microtiter Plate ◽  
Flavobacterium Columnare ◽  
Immersion Method ◽  
Microtiter Plate Assay ◽  
Pangasianodon Hypophthalmus ◽  
Striped Catfish

This research was conducted to investigate the biofilm formation ability at various salt concentrations and temperatures of Flavobacterium columnare isolated from striped catfish (Pangasianodon hypophthalmus) at Can Tho University. Microtiter plate assay and the in vivo challenge were used to test the virulence of this strain of F. columnare for 10 days by immersion method at different salt concentrations (0, 3, 6, 9, 12 and 15 ppt). Results showed that biofilm formation of F.columnare was inhibited at 3 and 6 ppt and stronger reductions were recorded at 9, 12 and 15 ppt. In the same trend, the higher temperature the lower biofilm formation, the highest biofilm formation was at 25°C treatment, then it was reduced at 28 and 31°C and at 35°C the formed biofilm was greatly reduced. Interestingly, there were no statistically significant differences between 28 and 31°C (P>0.05). The virulent study found that 100% fish died after 1 day post challenge at 0 ppt. There were 10% and 25% of fish died at 3 and 6 ppt respectively. No dead fish was found at 9 and 12 ppt. In conclusion, biofilm formation was inhibited at 3 ppt, was almost controlled at 9, 12 and 15 ppt and was also mostly reduced at 31°C at least in the in-vitro study. Furthermore, the virulence of this bacterial strain was controlled 90% at 3 ppt and completely controlled (100%) at 9, 12 and 15 ppt.

scholarly journals Effect of S-PRG Eluate on Biofilm Formation and Enzyme Activity of Oral Bacteria

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Masahiro Yoneda ◽  
Nao Suzuki ◽  
Yosuke Masuo ◽  
Akie Fujimoto ◽  
Kosaku Iha ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Composite Resin ◽  
Fusobacterium Nucleatum ◽  
Microtiter Plate ◽  
Oral Bacteria ◽  
Gelatin Film ◽  
Glass Ionomer ◽  
Microtiter Plate Assay ◽  
Substrate Hydrolysis ◽  
Adherence Ability

Recently, the antibacterial activity of a composite resin containing prereacted glass ionomer (S-PRG) filler was revealed. We examined the effect of an S-PRG eluate on various biologic activities ofStreptococcus mutansandPorphyromonas gingivalis. Adherence ability ofS. mutanswas evaluated by microtiter plate assay; protease and gelatinase activities ofP. gingivaliswere examined by synthetic substrate hydrolysis and gelatin film spot assay, respectively. Coaggregation ofP. gingivaliswithFusobacterium nucleatumwas also examined. S-PRG eluate was found to suppress streptococcal adherence. S-PRG eluate inhibited the protease and gelatinase activities ofP. gingivalisand the coaggregation betweenP. gingivalisandF. nucleatum. These results indicate that S-PRG eluate suppresses streptococcal adherence and inhibits the protease and coaggregation activities ofP. gingivalis. These findings may prompt research into novel strategies for preventing caries and periodontitis.

scholarly journals Antibiofilm and antivirulence potential of silver nanoparticles against multidrug-resistant Acinetobacter baumannii

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Helal F. Hetta ◽  
Israa M. S. Al-Kadmy ◽  
Saba Saadoon Khazaal ◽  
Suhad Abbas ◽  
Ahmed Suhail ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Antibacterial Activity ◽  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Microtiter Plate ◽  
Diffusion Method ◽  
Resistance Pattern ◽  
Infection Model ◽  
The Impact

AbstractWe aimed to isolate Acinetobacter baumannii (A. baumannii) from wound infections, determine their resistance and virulence profile, and assess the impact of Silver nanoparticles (AgNPs) on the bacterial growth, virulence and biofilm-related gene expression. AgNPs were synthesized and characterized using TEM, XRD and FTIR spectroscopy. A. baumannii (n = 200) were isolated and identified. Resistance pattern was determined and virulence genes (afa/draBC, cnf1, cnf2, csgA, cvaC, fimH, fyuA, ibeA, iutA, kpsMT II, PAI, papC, PapG II, III, sfa/focDE and traT) were screened using PCR. Biofilm formation was evaluated using Microtiter plate method. Then, the antimicrobial activity of AgNPs was evaluated by the well-diffusion method, growth kinetics and MIC determination. Inhibition of biofilm formation and the ability to disperse biofilms in exposure to AgNPs were evaluated. The effect of AgNPs on the expression of virulence and biofilm-related genes (bap, OmpA, abaI, csuA/B, A1S_2091, A1S_1510, A1S_0690, A1S_0114) were estimated using QRT-PCR. In vitro infection model for analyzing the antibacterial activity of AgNPs was done using a co-culture infection model of A. baumannii with human fibroblast skin cell line HFF-1 or Vero cell lines. A. baumannii had high level of resistance to antibiotics. Most of the isolates harbored the fimH, afa/draBC, cnf1, csgA and cnf2, and the majority of A. baumannii produced strong biofilms. AgNPs inhibited the growth of A. baumannii efficiently with MIC ranging from 4 to 25 µg/ml. A. baumannii showed a reduced growth rate in the presence of AgNPs. The inhibitory activity and the anti-biofilm activity of AgNPs were more pronounced against the weak biofilm producers. Moreover, AgNPs decreased the expression of kpsMII , afa/draBC,bap, OmpA, and csuA/B genes. The in vitro infection model revealed a significant antibacterial activity of AgNPs against extracellular and intracellular A. baumannii. AgNPs highly interrupted bacterial multiplication and biofilm formation. AgNPs downregulated the transcription level of important virulence and biofilm-related genes. Our findings provide an additional step towards understanding the mechanisms by which sliver nanoparticles interfere with the microbial spread and persistence.

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