Incorporation of probiotics in post-harvest wash treatments reduces Salmonella contamination and improves egg safety

Salmonella Enteritidis (SE) is a prevalent foodborne pathogen that is commonly transmitted through contaminated shell eggs. Therefore, decontamination of eggs is critical to food safety. Hence, this study determined the efficacy of incorporating probiotics in wash water to promote egg safety. Fresh eggs inoculated with a five-strain mix of SE (∼9 log CFU/egg) were washed using either a dip or spray method with one of the following treatments: Lactobacillus rhamnosus NRRL-B-442 (LR; ∼10 log CFU/ml), L. paracasei DUP 13076 (LP; ∼10 log CFU/ml), Hafnia alvei (HA; ∼10 log CFU/ml), chlorine (200 ppm), or tap water (Control). Eggs were sampled for surviving SE and probiotic populations immediately following wash and during refrigerated storage for 21 days. Three independent trials were conducted in a completely randomized design, and data were analyzed using GraphPad (Version 9.3.1) with significance set at P ≤ 0.05. Both dip and spray application of probiotics significantly reduced SE populations on eggshells and within internal contents throughout refrigerated storage (p ≤ 0.05). On the external surface SE populations in LP and LR groups were reduced to ∼4 log CFU/egg and ∼2 log CFU/egg on days 7 and 14 respectively, while ∼5.6 log CFU/egg and ∼4.8 log CFU/egg were still recovered from control and chlorine-treated samples. Similarly, only 10 % of probiotic-treated samples tested positive for SE in internal contents as opposed to 30-40 % positivity in the control and chlorine-treated samples. Overall, probiotic application by spraying or dipping significantly reduced SE populations on eggs (P ≤ 0.05) without impacting egg quality parameters including Haugh units and egg grade (P > 0.05). Although both washing modalities were effective, reduced water usage makes the spray method more environmentally friendly. Overall, incorporation of probiotics in wash water can be a safe, effective, and organic-friendly antimicrobial strategy to promote egg safety.

A Mini-Review on Multi-Hurdle Control of Salmonella Along Poultry Production Continuum

This mini-review presents common strategies for controlling Salmonella in poultry, addressing combined pre-harvest and post-harvest interventions to create a multi-hurdle approach. The goal is to highlight integrated approaches that enhance overall food safety and sustainability within the poultry industry. Current pre-harvest and post-harvest strategies are discussed, including industry practices and regulatory frameworks. Emphasis is placed on the implementation of biosecurity measures, vaccination, feed management, and environmental control in pre-harvest settings, as well as processing plant interventions such as antimicrobials for carcass decontamination, sanitation, and quality control measures. Pre-harvest strategies that have shown promise include enhanced biosecurity protocols, selective vaccinations for pathogenic Salmonella strains, and advanced feeding regimens. Post-harvest interventions, such as antimicrobial application for decontamination, have improved sanitation practices, and pathogen reduction technologies are also critical in reducing Salmonella prevalence. An integrated approach that combines both pre-harvest and post-harvest measures is essential for an effective Salmonella control program. Implementing a continuum of control strategies for Salmonella in poultry production is vital for ensuring food safety and protecting public health. Collaborative efforts between researchers, industry stakeholders, and policymakers are necessary to address emerging issues and enhance overall effectiveness.

Antimicrobial Coating Based on Tahiti Lemon Essential Oil and Green Banana Flour to Preserve the Internal Quality of Quail Eggs

This study evaluated the microbiological and internal quality of quail eggs stored for 21 days at room temperature (29.53 ± 1.36 °C) after being coated with green banana flour and Tahiti lemon essential oil (GBF/TAH). One hundred and sixty-two quail eggs were equally distributed into three treatments: (1) uncoated eggs, (2) eggs coated with green banana flour (GBF), and (3) eggs coated with GBF/TAH. The Haugh unit (HU) of the eggs was significantly lower in the third week for uncoated eggs (70.94 ± 1.63, grade A) compared to eggs coated with GBF/TAH (81.47 ± 2.38, grade AA). On the 21st day of storage, the eggs coated with GBF/TAH had significantly lower total counts of aerobic mesophilic bacteria in the shell and egg contents compared to the other treatments. GBF/TAH coating is an effective blending approach to reduce the microbial load of the shell and egg contents and preserve the sensory and internal quality of the eggs.

Current progress in valorization of food processing waste and by-products for pectin extraction

Food processing waste and by-products such as peel of citrus fruit, melon, mango, pineapple, etc. and fruit pomace can be utilized for manufacturing of several high-value products. Valorization of these waste and by-products for extraction of pectin, can help offset growing environmental concerns, facilitate value-addition of by-products and their sustainable uses. Pectin has many applications in food industries such as gelling, thickening, stabilizing, and emulsifying agent, and as a dietary fibre. This review elaborates on various conventional and advanced, sustainable pectin extraction techniques, and paints a comparative picture between them considering extraction efficiency, quality, and functionality of the pectin. Conventional acid, alkali, and chelating agents-assisted extraction have been profusely used for pectin extraction, but advanced extraction technologies e.g., enzyme, microwave, supercritical water, ultrasonication, pulse electric field and high-pressure extraction are preferred due to less energy consumption, better quality product, higher yield, and minimal or no generation of harmful effluent.

Recent progress in pectin extraction and their applications in developing films and coatings for sustainable food packaging: A review

Perishable foods like fruits and vegetables, meat, fish, and dairy products have short shelf-life that causes significant postharvest losses, which poses a major challenge for food supply chains. Biopolymers have been extensively studied as sustainable alternatives to synthetic plastics, and pectin is one such biopolymer that has been used for packaging and preservation of foods. Pectin is obtained from abundantly available low-cost sources such as agricultural or food processing wastes and by products. This review is a complete account of pectin extraction from agro-wastes, development of pectin-based composite films and coatings, their characterizations, and their applications in food packaging and preservation. Compared to conventional chemical extraction, supercritical water, ultrasound, and microwave assisted extractions are a few examples of modern and more efficient pectin extraction processes that generate almost no hazardous effluents, and thus, such extraction techniques are more environment friendly. Pectin-based films and coatings can be functionalized with natural active agents such as essential oils and other phytochemicals to improve their moisture barrier, antimicrobial and antioxidant properties. Application of pectin-based active films and coatings effectively improved shelf-life of fresh cut-fruits, vegetables, meat, fish, poultry, milk, and other food perishable products.

Effect of Radiant Catalytic Ionization and Ozonation on Salmonella spp. on Eggshells

Three Salmonella enterica strains were used in the study (serovars: S. enteritidis, S. typhimurim and S. virchow). This study evaluated the efficacy of radiant catalytic ionization (RCI) and ozonation against Salmonella spp. on eggshell (expressed as log CFU/egg). The egg surface was contaminated three different bacterial suspension (10³ CFU/mL, 10⁵ CFU/mL and 10⁸ CFU/mL) with or without poultry manure. Experiments were conducted at 4 °C and 20 °C in three different time period: 30 min, 60 min and 120 min. Treatment with RCI reduced Salmonella numbers from 0.26 log CFU/egg in bacterial suspension 10⁸ CFU/mL, 4 °C and 20 °C, with manure for 30 min to level decrease in bacteria number below the detection limit (BDL) in bacterial suspension 10⁵ CFU/mL, 20 °C, with or without manure for 120 min. The populations of Salmonella spp. on eggs treated by ozonizer ranged from 0.20 log CFU/egg in bacteria suspension 10⁸ CFU/mL, 20 °C, with manure for 30 min to 2.73 log CFU/egg in bacterial suspension 10⁵ CFU/mL, 20 °C, with manure for 120 min. In all treatment conditions contamination with poultry manure decrease effectiveness the RCI and ozonation. In summary, RCI technology shows similar effectiveness to the ozonation, but it is safer for poultry plant workers and consumers.

Efficacy of pectin-based caproic acid, caprylic acid, linalool, and cuminaldehyde coatings in reducing Salmonella Heidelberg on chicken eggs

Among the animal derived food products, contamination of poultry eggs, and egg shell surface is one of the major causes for foodborne salmonellosis in the United States. As a means of reducing the pathogen transfer to the internal egg contents, polysaccharide-based coatings containing antimicrobial phytochemicals could potentially serve as a biocontrol strategy for shelled egg products. The current study investigated the efficacy of four GRAS (Generally Recognized as Safe)-status plant-derived compounds, namely, caproic acid (CAO), caprylic acid (CAY), linalool (LIN) and cuminaldehyde (CUM), as pectin-based coating treatments, individually or in combination, for reducing Salmonella Heidelberg (SH) on shell eggs. A three-strain mixture of SH (~8.0 log CFU in 50 μL inoculum) was spot-inoculated on surface sterilized white-shelled eggs. Eggs were evenly coated with either pectin-based treatments of CAO (1%), CAY (1%), LIN (1%) and CUM (1%), individually, or a combination of 4 phytochemicals (COMB- each phytochemical at 0.5% v/v level of inclusion). The treated eggs were stored at 4°C and SH counts were enumerated on days 0, 1, 3, 5, 7, 14, and 21 of storage. The study was replicated thrice, 3 eggs/treatment/day time point, and the data were analyzed using two-way ANOVA with significance tested at p < 0.05. On day 0, pectin-coated control eggs had ~7.6 log CFU of SH/egg. At the end of refrigerated storage (day 21), pectin-based coating of CAO and CAY at 1% level reduced SH by 2.0–2.5 log CFU/egg (P < 0.05) when compared to controls. In addition, the CUM and LIN based coatings produced 3.0 log and 3.9 log reduction, respectively, in SH counts on eggs by day 21 of storage. Among the treatments with phytochemical combinations, COMB1 [pectin (2%) + Caprylic acid, caproic acid and cuminaldehyde (each at 0.5% level)] was found to be most effective, reducing SH counts to 2.5–3.3 log CFU/egg from day 0 through day 14, and by the end of storage period (day 21), a 3.5 log CFU reduction/egg (p < 0.05) compared to untreated controls. Morphological studies of treated eggs using atomic force microscopy (AFM) have shown that the roughness of eggs can be influenced by a combination of various compounds. Results indicate the potential efficacy of the aforesaid phytochemicals in reducing SH on shell eggs; however, further studies investigating their industrial feasibility and effects on sensory attributes of eggs are warranted.

Combination of cassava starch biopolymer and essential oils for coating table eggs

This work aimed to evaluate the eggshell microbiota and the internal egg quality after coatings with cassava starch biopolymer enriched with different essential oils during 35 days of storage at 20°C. A total of 369 brown table eggs were used and distributed in the following treatments: uncoated eggs, coated with cassava starch + Ginger essential oil (CS+GIN), cassava starch + Lemongrass essential oil (CS+LEM), and cassava starch + Tahiti lemon essential oil (CS+TAH). The count of total aerobic mesophilic bacteria on coated eggshells at 0 and 35 days of storage were similar to each other (mean 0.70 ± 0.37 and 0.91 ± 0.22 log10 CFU/mL) and significantly lower compared to uncoated eggs (2.21 ± 0.17 and 3.17 ± 0.22 log10 CFU/mL), in that order. On the 35th day, coated eggs showed similar Haugh unit (HU) values between them (mean 70.61 ± 5.35; classified as A - high quality) and significantly higher than uncoated eggs (51.60 ± 4.28; classified as B - average quality). Cassava starch coatings added with essential oils preserved the internal quality of the eggs during storage for 5 weeks at 20°C, reducing the eggshell microbiota and effectively keeping it at low levels during storage.

Synergistic Interaction Between Paired Combinations of Natural Antimicrobials Against Poultry-Borne Pathogens

Natural antimicrobials (NAM) are promising candidates for the successful control of poultry-borne bacteria, carrying potent antimicrobial activity (AMA) against a wide range of multidrug-resistant pathogens. Individual activities of carvacrol, eugenol, trans-cinnamaldehyde, oregano, and thymol, along with the combined activity of paired compounds, were examined using broth microdilution and checkerboard techniques. The characteristic interactions between the compounds were calculated using an improved method, based on combination index (CI) values. The bacteria examined herein were selected due to their known genetic resistance to at least one antibiotic. Our results indicated that thymol was most effective, exhibiting the lowest minimum inhibitory concentration (MIC) value against Salmonella pullorum, Escherichia coli, and Klebsiella pneumoniae, establishing the order of antimicrobial efficacy as: thymol > oregano > carvacrol > trans-cinnamaldehyde > eugenol. In the interaction study, the paired combination of carvacrol and thymol showed synergistic effects and was highly effective in reducing the antibiotic resistance of all the evaluated pathogens. Notably, all CI values were <1.0 in evaluations of S. pullorum, indicating the absence of antagonism between eugenol and thymol (or oregano). In K. pneumoniae, majority of CI values, which had a few concentration points, were smaller than 1.0, indicating a synergistic effect between eugenol and carvacrol (oregano or thymol), and trans-cinnamaldehyde and carvacrol. In E. coli, apart from some concentration points, some CI values were smaller than 1.0, demonstrating a synergistic effect between eugenol and carvacrol, and thymol and carvacrol (eugenol or oregano). It is therefore of great significance to investigate and illuminate the minimal effect concentration of these five components when they are used in combination as feed additives. Moreover, the improved evaluation method of this study provides a precise and extensive means to assess the synergistic effects of NAM.

Decontamination of Salmonella enterica spp. on shell eggs by Allium cepa L. dry scales extracts

Salmonellae are a major global diarrheal diseases agent and are commonly found in a variety of foods. However, eggs appear to be one of the most important sources of infection ultimately leading to salmonellosis. Here we investigate a potential utilization of onion (Allium cepa L.) dry scales extracts and decoction for disinfection of eggshells contaminated with Salmonella enterica spp. Antimicrobial activity was screened by a microplate dilution method against 32 environmental and 1 reference Salmonella strains, at 106 and 103 CFU/ml starting cell concentration. Also, the efficacy of egg submersion treatment was tested. At high contamination level of 106 Salmonella cells per ml, extracts exhibited MIC and MBC values in the range of 0.08-2.50 mg/ml and 0.31-10.0 mg/ml, respectively. Ethanol extract had the most potent antibacterial activity followed by methanol, ethyl-acetate and acetone extracts. Pure decoction had MIC and MBC in the range of 250-500 mg/ml. When testing a lower level of contamination (103 CFU/ml) which is more similar to real life levels, MIC and MBCs were 8 to 14 times lower. Submersion of artificially contaminated eggs in ethanol extracts and decoctions resulted in the complete elimination of Salmonella after 8 minutes of exposure. Thus, a reduction of a minimum of 3.71 log units was achieved during the 8 minutes of treatment. Having in mind natural levels of Salmonella eggshell counts are far lower it can be implied that such treatment could be highly effective in practical application. Results show that tested onion dry scale decontamination solutions are an efficient, cost-effective and eco-friendly options for eggshell decontamination, and are especially promising for use in organic egg production.

Effects of rice protein coating enriched with essential oils on internal quality and shelf life of eggs during room temperature storage

The effectiveness of rice protein coatings enriched with essential oils on maintaining interior quality of fresh eggs was evaluated during storage at 20°C for 6 wk. Egg quality was assessed by weight loss, Haugh unit (HU), albumen pH, and yolk index (YI) in uncoated eggs (control treatment) and eggs coated with rice protein concentrate at 8% enriched or not with different essential oils (1%): tea tree (Melaleuca alternifolia), copaíba (Copaifera langsdorffii), or thymo (Thymus vulgaris). The HU and YI were higher in coated eggs (P < 0.001). Data were submitted to variance analysis, and the statistical models included the effects of treatments (coating types), storage periods (weeks), and interaction (treatments by storage periods). Weight loss increased (P < 0.001) during long-term storage. Uncoated eggs showed the highest weight loss (5.43%), whereas coatings of rice protein alone (4.23%) or enriched with tea tree (4.10%), copaíba (3.90%), and thymo (4.08%) solutions were effective in preventing weight lost (P < 0.001). The coating use preserved the internal quality of the eggs for up to 3 wk longer than uncoated eggs in terms of HU, YI, and pH. Uncoated eggs had the worst (P < 0.001) HU (58.46), albumen pH (9.48), and YI (0.33) after 6 wk of storage. In conclusion, the use of coatings based on rice protein concentrate enriched with different essential oils influences the internal quality of eggs during storage and may be an effective alternative for increasing the shelf life of commercial eggs.

Effect of dietary supplementation with phytogenic blend on growth performance, apparent ileal digestibility of nutrients, intestinal morphology, and cecal microflora of broiler chickens

The effects of dietary supplementation with phytogenic blend (PB) of Aerva lanata, Piper betle, Cynodon dactylon, and Piper nigrum on growth performance, ileal nutrient digestibility, intestinal morphology, and cecal microflora were determined in a 42-day broiler feeding trial. A total of 192 broilers were assigned to 4 dietary treatments (6 replicates and 8 birds/replicate): basal diet, basal diet supplemented with antibiotic (chlortetracycline), 1% and 2% PB, respectively. The body weight gain (BWG) of starter chicks increased linearly (P = 0.023) as dietary supplementation levels of PB increased. At grower phase, broilers fed diet supplemented with 1% PB had similar BWG with the antibiotic group, but other treatments had reduced (P = 0.0001) BWG. Dietary supplementation with 1% PB resulted in the highest (P < 0.0001) BWG during the study. Feed intake was not affected by the treatments during the starter, finisher, and overall rearing periods. Broilers fed diet supplemented with 1% PB had the best (P < 0.0001) feed conversion ratio during the study. Overall, broilers fed only basal diet had the highest (P = 0.0450) mortality. Ileal organic matter (OM) digestibility increased linearly (P = 0.044) with broilers fed diet supplemented with PB, but reduced with antibiotic group. Dietary supplementation with 1% PB had the highest (P = 0.0402) ileal digestibility of tryptophan. In the duodenum, broilers fed diet supplemented with PB had longer (P = 0.0006) villi heights than the birds fed only basal diet, but similar with antibiotic group. Broilers fed diet supplemented with PB had longer (P = 0.0064) villi height in the jejunum than the antibiotic group. Bifidobacterium concentration of the cecum content showed a slight increase (P = 0.053) with increasing supplementation levels of PB. In conclusion, the current study shows that dietary supplementation with PB improves growth performance, intestinal morphology, and apparent ileal digestibility of OM and tryptophan in a dose-dependent manner with the best response at 1% inclusion level.

Efficacy of plant-derived antimicrobials for controlling Salmonella Schwarzengrund on dry pet food

Salmonella enterica is a major human pathogen that is responsible for 23,000 hospitalizations annually in the United States. Contact with contaminated pet food and infected companion animals can transmit salmonellosis to humans. Recent multistate human outbreaks of salmonellosis linked to commercial contaminated dry dog foods underscore the need for controlling the pathogen in pet foods for protecting pet and public health. In this study, the efficacy of five Generally Recognized as Safe (GRAS) status, plant-derived antimicrobials (PDAs), namely trans-cinnamaldehyde (TC), carvacrol (CR), thymol (TY), eugenol (EG), and caprylic acid (CA) applied as a vegetable oil or chitosan based antimicrobial spray on dry pet food for reducing Salmonella Schwarzengrund was investigated. Three hundred gram portions of a commercial dry dog food were inoculated with a two-strain mixture of nalidixic acid (NA) resistant S. Schwarzengrund (~6 log CFU/g), followed by a spray treatment with 0%, 0.5%, 1% or 2% of TC, CR, TY, EG or CA in combination with 5% vegetable oil or 1% chitosan as a carrier. The control and treated dog food samples were stored at 25 °C for 28 days. On days 0, 1, 3, 5, 7, 14, 21, and 28, Salmonella on pet food was enumerated by serial dilution and plating on xylose lysine desoxycholate (XLD) agar. All PDAs at 1% and 2% applied in vegetable oil or chitosan reduced S. Schwarzengrund by at least ~2 log CFU/g on day 3 of storage when compared to control (P < 0.05). No significant reductions in Salmonella were observed on feed sprayed with only vegetable oil or chitosan (P > 0.05). Overall, 2% TC in vegetable oil or chitosan was the most effective treatment, where at least 3 to 3.5 log CFU/g reduction in bacterial populations was observed during storage (P < 0.05). Results suggest that the aforementioned PDAs could potentially be used as an antimicrobial spray to reduce S. Schwarzengrund on dry dog food. However, further studies on the acceptance of PDA-treated dry food by dogs are needed.

Edible Coatings Fortified With Carvacrol Reduce Campylobacter jejuni on Chicken Wingettes and Modulate Expression of Select Virulence Genes

Campylobacter jejuni, a leading cause of foodborne disease in humans, associate primarily with consumption of contaminated poultry and poultry products. Intervention strategies aimed at reducing C. jejuni contamination on poultry products could significantly reduce C. jejuni infection in humans. This study evaluated the efficacy of gum arabic (GA) and chitosan (CH) fortified with carvacrol (CR) as an antimicrobial coating treatment for reducing C. jejuni on chicken wingettes. Aforementioned compounds are generally recognized as safe status compounds obtained from gum arabic tree, crustaceans and oregano oil respectively. A total of four separate trials were conducted in which wingettes were randomly assigned to baseline, saline control (wingettes washed with saline), GA (10%), CH (2%), CR (0.25, 0.5, or 1%) or their combinations. Each wingette was inoculated with a cocktail of four wild-type strains of C. jejuni (∼7.5 log10 cfu/sample). Following 1 min of coating in aforementioned treatments, wingettes were air dried (1 h) and sampled at 0, 1, 3, 5, and 7 days of refrigerated storage for C. jejuni and total aerobic counts (n = 5 wingettes/treatment/day). In addition, the effect of treatments on wingette color was measured using a Minolta colorimeter. Furthermore, the effect of treatments on the expression of C. jejuni survival/virulence genes was evaluated using real-time quantitative PCR. Results showed that all three doses of CR, CH or GA-based coating fortified with CR reduced C. jejuni from day 0 through 7 by up to 3.0 log10 cfu/sample (P < 0.05). The antimicrobial efficacy of GA was improved by CR and the coatings reduced C. jejuni by ∼1 to 2 log10 cfu/sample at day 7. Moreover, CH + CR coatings reduced total aerobic counts when compared with non-coated samples for a majority of the storage times. No significant difference in the color of chicken wingettes was observed between treatments. Exposure of pathogen to sublethal concentrations of CR, CH or combination significantly modulated select genes encoding for energy taxis (cetB), motility (motA), binding (cadF), and attachment (jlpA). The results suggest that GA or CH-based coating with CR could potentially be used as a natural antimicrobial to control C. jejuni in postharvest poultry products.

Pectin or chitosan coating fortified with eugenol reduces Campylobacter jejuni on chicken wingettes and modulates expression of critical survival genes

Campylobacter jejuni infection in humans is strongly associated with the consumption of contaminated poultry products. With increasing consumer demand for minimally processed and natural product, there is a need for novel intervention strategies for controlling C. jejuni. Antimicrobial coatings are increasingly being used for preventing food contamination due to their efficacy and continuous protection of product. This study investigated the efficacy of pectin and chitosan coating fortified with eugenol to reduce C. jejuni on chicken wingettes. Pectin, chitosan, and eugenol are generally recognized as safe status compounds derived from berries, crustaceans, and cloves respectively. Each wingette was inoculated with a mixture of 4 wild-type strains of C. jejuni (approximately 10⁷ CFU/sample) and randomly assigned to controls, pectin (3%), chitosan (2%), eugenol (0.5, 1, or 2%), or their combinations. Following 1 min of coating, wingettes were air-dried, vacuum sealed, and sampled on 0, 1, 3, 5, and 7 d of refrigerated storage for C. jejuni and aerobic counts (n = 5 wingettes/treatment/d). In addition, the effect of treatments on wingette color and expression of C. jejuni survival/virulence genes was evaluated. All 3 doses of eugenol or chitosan significantly reduced C. jejuni and aerobic bacteria from 0 d through 7 d. Incorporation of 2% eugenol in chitosan improved coating efficiency and reduced C. jejuni counts by approximately 3 Log CFU/sample at the end of 7 d of storage (P < 0.05). Similarly, the antimicrobial efficacy of pectin was improved by 2% eugenol and the coating reduced C. jejuni by approximately 2 Log CFU/sample at 7 d of storage. Chitosan coating with 2% eugenol also showed greater reductions of total aerobic counts as compared to individual treatments of eugenol and chitosan. No significant difference in the color of chicken wingettes was observed between treatments. Exposure of C. jejuni to eugenol, chitosan, or combination significantly modulated select genes encoding for motility, quorum sensing, and stress response. Results demonstrate the potential of pectin or chitosan coating fortified with eugenol as a postharvest intervention against C. jejuni contamination on poultry products.

Correlations among Resistances to Different Antimicrobial Compounds in Salmonella Strains from Hen Eggshells

Persistence of antibiotic-resistant Salmonella in the food chain may depend on strain tolerance to other antimicrobials and also on biofilm formation capacity. Yet, there is limited information on sensitivity of antibiotic-resistant Salmonella to other antimicrobials, such as phenolic compounds, chemical preservatives, or antimicrobial peptides. This study aimed at correlating antimicrobial resistance and biofilm formation capacity in antibiotic-resistant, biocide-tolerant Salmonella strains from hen eggshells. A collection of 21 strains previously selected according to their antibiotic resistance and biocide tolerance phenotypes were used for the present study. Strains were inspected for their biofilm formation capacity and for their sensitivity to (i) phenolic compounds (carvacrol, thymol), (ii) chemical preservatives (sodium lactate, trisodium phosphate), and (iii) cationic antimicrobials (polymyxin B, lysozyme-EDTA). Biofilm formation capacity was not correlated with antimicrobial resistances of the planktonic Salmonella. Polymyxin B and the lysozyme-EDTA combinations showed significant ( P < 0.05) positive correlations to each other and to sodium lactate. Significant ( P < 0.05) positive correlations were also observed for benzalkonium chloride and cetrimide with carvacrol, thymol, and trisodium phosphate, or between hexadecylpyridinium chloride and carvacrol. Antibiotic resistance also correlated positively with a higher tolerance to other antimicrobials (cefotaxime, ceftazidime, and ciprofloxacin with carvacrol, thymol, and trisodium phosphate; netilmicin with thymol and trisodium phosphate; tetracycline with carvacrol and thymol). These results must be taken into consideration to ensure a proper use of antimicrobials in the poultry industry, at concentrations that do not allow coselection of biocide-tolerant, antibiotic-resistant Salmonella.