Differences in antimicrobial activity of chlorine against twelve most prevalent poultry-associated Salmonella serotypes

Profiling and source tracking of the microbial populations and resistome present in fish products

Microorganisms in processing environments significantly impact the quality and safety of food products and can serve as potential reservoirs for antibiotic-resistant genes, contributing to public health concerns about antimicrobial resistance (AMR). Fish processing plants represent an understudied environment for microbiome mapping. This study investigated the microbial composition, prevalence of Listeria spp., and resistome structures in three catfish processing facilities in the southeastern United States. The 16S rRNA gene sequencing revealed that the observed richness and Shannon diversity index increased significantly from fish to fillet. Beta diversity analysis showed distinct clustering of microbial communities between fish, environment, and fillet samples. Fast expectation-maximization microbial source tracking (FEAST) algorithm demonstrated that the microbiota presents in the processing environment contributed 48.2 %, 62.4 %, and 53.7 % to the microbiota present on fillet in Facility 1 (F1), F2, and F3, respectively. Food contact surfaces made larger contributions compared to the non-food contact surfaces. The linear discriminant analysis of effect size (LEfSe) identified specific microbial genera (e.g., Plesiomohas, Brochothrix, Chryseobacterium and Cetobacterium) that significantly varied between Listeria spp. positive and negative samples in all three processing plants. The metagenomic sequencing results identified 212 antimicrobial resistance genes (ARGs) belonging to 72 groups from the raw fish and fish fillet samples collected from three processing plants. Although there was a significant decrease in the overall diversity of ARGs from fish to fillet samples, the total abundance of ARGs did not change significantly (P > 0.05). ARGs associated with resistance to macrolide-lincosamide-streptogramin (MLS), cationic antimicrobial peptides, aminoglycosides, and beta-lactams were found to be enriched in the fillet samples when compared to fish samples. Results of this study highlight the profound impact of processing environment on shaping the microbial populations present on the final fish product and the need for additional strategies to mitigate AMR in fish products.

Filter sterilized carcass rinsate for recovery of Salmonella species with various concentrations of cetylpyridinium chloride

Controlling Salmonella in poultry processing continues to be important to processors and consumers. Cetylpyridinium chloride (CPC) has proven to be effective in vitro in controlling Salmonella. This study evaluated the recovery of Salmonella after overnight storage in 4°C filter-sterilized carcass rinsate containing CPC from 0.44 to 909 ppm (μg/mL). Ten Salmonella serotypes (18 strains), of which 6 serotypes are commonly isolated from poultry products, were grown in Bacto-Tryptic Soy Broth overnight at 37°C. Serial dilutions of a CPC/propylene glycol solution were prepared in 24-well tissue culture plates containing filter-sterilized carcass rinsate. Approximately 107 cfu/mL of each Salmonella serotype was added to the appropriate wells. Inoculated plates were stored overnight at 4°C. After storage, triplicate plates of brilliant green agar with sulfapyridine (BGS) were surface inoculated with 10 μL of the contents for each well, streaked for isolation, and incubated at 37°C for 24 h. Three replications were conducted. The presence of typical colonies on BGS plates was recorded as growth and verified through biochemical and serological testing. Of the serotypes chosen, Salmonella Kentucky, Dublin, and Enteritidis were the least resistant to CPC with a median minimum inhibitory concentration (MIC) of 14.22 μg/mL (range from 3.55 to 56.88 μg/mL); S. Typhimurium demonstrated a median MIC of 114.00 μg/mL (range from 28.44 to 114.00 μg/mL). Residual CPC potentially remaining attached to a carcass or in the weep after processing could potentially alter which Salmonella serotype is recovered from a carcass rinse due to different growth patterns during regulatory testing, with a potential for more virulent strains not to be recovered.

Susceptibility of Campylobacter jejuni to Stressors in Agrifood Systems and Induction of a Viable-but-Nonculturable State

Many bacteria can become viable but nonculturable (VBNC) in response to stressors commonly identified in agrifood systems. Campylobacter is able to enter the VBNC state to evade unfavorable environmental conditions, but how food processing can induce Campylobacter jejuni to enter this state and the potential role of foods in inducing the VBNC state in C. jejuni remains largely unknown. In this study, the culturability and viability of C. jejuni cells were investigated under chlorine treatment (25 ppm), aerobic stress (atmospheric condition), and low-temperature (4°C) conditions that mimicked food processing. In addition, the behaviors of C. jejuni cells in ultrahigh-temperature (UHT) and pasteurized milk were also monitored during refrigerated storage. The numbers of viable and culturable C. jejuni cells in both the pure bacterial culture and food matrices were separately determined by propidium monoazide (PMA)-quantitative PCR (qPCR) and plating assay. The C. jejuni cells lost their culturability but partially retained their viability (1% to 10%) once mixed with chlorine. In comparison, ~10% of C. jejuni cells were induced to enter the VBNC state after 24 h and 20 days under aerobic and low-temperature conditions, respectively. The viability of the C. jejuni cells remained stable during the induction process in UHT (>10%) and pasteurized (>10%) milk. The number of culturable C. jejuni cells decreased quickly in pasteurized milk, but culturable cells could still be detected in the end (day 21). In contrast, the number of culturable C. jejuni cells slowly decreased, and they became undetectable after >42 days in UHT milk. The C. jejuni cells responded differently to various stress conditions and survived in high numbers in the VBNC state in agrifood systems. IMPORTANCE The VBNC state of pathogens can pose risks to food safety and public health because the pathogens cannot be detected using conventional microbiological culture-based methods but can resuscitate under favorable conditions to develop virulence. As a leading cause of human gastroenteritis worldwide, C. jejuni can enter the VBNC state to survive in the environment and food-processing chain with high prevalence. In this study, the effect of food-processing conditions and food products on the development of VBNC state in C. jejuni was investigated, providing a better understanding of the interaction between C. jejuni and the agroecosystem. The knowledge elicited from this study can aid in developing novel intervention strategies to reduce the food safety risks associated with this microbe.

Quality and Processability of Modern Poultry Meat

The poultry meat industry has gone through many changes. It moved from growing dual-purpose birds (meat and egg production) taking ~110 days to reach 1.2 kg 100 years ago, to developing specialized meat breeds that grow to 2.5 kg within ~40 days. It also moved from selling ~80% whole birds to mostly selling cut up and further processed products in the Western world. This necessitated building large, centralized processing plants, capable of processing 15,000 birds per hr on a single line (60 years ago only 2500), that require higher bird uniformity (size, color, texture). Furthermore, consumer demand for convenient products resulted in introducing many cut-up fresh poultry (some companies have 500 SKU) and further processed products (chicken nuggets did not exist 50 years ago). Those developments were possible due to advancements in genetics, nutrition, medicine, and engineering at the farm and processing plant levels. Challenges keep on coming and today a rise in myopathies (e.g., so called woody breast, white striping, spaghetti meat), requires solutions from breeders, farmers, and processing plants, as more automation also requires more uniformity. This review focuses on the changes and challenges to the processing industry segment required to keep supplying high quality poultry to the individual consumer.

The Prevalence of Salmonella and Campylobacter on Broiler Meat at Different Stages of Commercial Poultry Processing

In poultry processing, Salmonella and Campylobacter contaminations are major food safety concerns. Peracetic acid (PAA) is an antimicrobial commonly used in commercial poultry processing to reduce pathogen prevalence so as to meet the USDA-FSIS performance standards. The objective of this study was to determine the prevalence of Salmonella and Campylobacter on broiler meat in various steps of commercial poultry processing in plants that use PAA. Post-pick, pre-chill, post-chill, and drumstick chicken samples were collected from three processing plants and mechanically deboned meat (MDM) was collected from two of the three plants. Each plant was sampled thrice, and 10 samples were collected from each processing step during each visit. Among the 420 samples, 79 were contaminated with Salmonella and 155 were contaminated with Campylobacter. Salmonella and Campylobacter contamination on the post-pick samples averaged 32.2%. Significant reductions in Salmonella and Campylobacter were observed in pre-chill to post-chill samples, where the prevalence was reduced from 34% and 64.4% to nondetectable limits and 1.1%, respectively (p < 0.001). Salmonella and Campylobacter remained undetectable on the drumstick samples in all three processing plants. However, the prevalence of Salmonella and Campylobacter on MDM was similar to the post-pick prevalence, which suggests substantial cross-contamination from post-chill to MDM.

A national study through a 'Farm-to-fork' Approach to determine Salmonella dissemination along with the Lebanese poultry production chain

This cross-sectional study was conducted to determine the prevalence of Salmonella at different stages of the broiler production chain and layer flocks in addition to their antibiotic resistance profile and molecular patterns. Over a period of 3 years, different sample matrices were collected from Lebanese farms, slaughterhouses and retail markets. Out of 672 Salmonella serotyped, 514 were analysed for antimicrobial resistance and 214 for clonality using Pulsed-field gel electrophoresis (PFGE). The results highlighted an important prevalence of Salmonella, 30% in farms, 35.8% in slaughterhouses and 22.4% at retail level. A large diversity of serotypes was identified with predominance among Salmonella Infantis (32.9%), Salmonella Enteritidis (28.4%) and Salmonella Kentucky (21.4%). High resistance to nalidixic acid was revealed in all the isolates. The most prominent resistance was exhibited in S. Kentucky and S. Infantis. The latter was resistant to tetracycline (99%), streptomycin (88.2%) and remarkable multi-drug resistance (MDR) (89.7%). All S. Kentucky isolates were resistant to ciprofloxacin, MDR (62.4%) and 6% were resistant to extended-spectrum cephalosporin (ESCs). One persistent clone of S. Enteritidis was found common between poultry and humans. Similar genomic profiles were detected between farms, slaughterhouses and retail suggesting the dissemination of identical clones throughout the food chain possibly due to weak barriers preventing such transmission.

Application of a catalytic oxidation method for the simultaneous determination of total organic carbon and total nitrogen in marine sediments and soils

This study presents the application of a simultaneous method for the determination of total organic carbon (TOC) and total nitrogen (TN) in marine sediments and soils, using a data set of 206 samples collected from coastal lagoonal/marine sedimentary environments and certified reference materials (CRMs). TOC and TN were determined using the high temperature (720°C) catalytic (Pt/Al₂O₃) oxidation method and the detection of TOC and TN was performed using an infrared or a chemiluminescence detector, respectively. Results from the abovementioned TOC method were compared with the results from the widely used Wakley-Black titration method, while TN results with these from elemental analysis. Analytical quality control experiments were performed using CRM samples. Method characteristics such as range of measurement, calibration, method detection limit (MDL), limit of quantification (LOQ), repeatability and reproducibility, were calculated. The precision and the accuracy of the methods are also discussed. Comparison of the two TOC methods of 206 data set yields a regression line of correlation coefficient with R² = 0.985. Additional different levels of TOC concentrations of low <1%, moderate 1–5% and high 5–40% level were examined indicating very good correlations. The lowest correlation coefficient was observed in low concentrations TOC<1% (R² 0.825), mainly as a result of the limitation of titration method. The evaluation of TN results indicated that the catalytic oxidation method and the elemental analysishave a significant good correlation with R² = 0.977. The results of precision and accuracy, as well as the calculated MDL and LOQ show that this is a reliable method. Moreover, it requires a small amount of the analyzed sample and the total analysis time is 10 min. Therefore, it can be easily applied for the fast and precise simultaneous determination of TOC and TN in sediment and soil samples.

Research Note: Identification and characterization of Salmonella spp. in mechanically deboned chickens using pulsed-field gel electrophoresis

Salmonella is one of the common foodborne bacteria, causing 80.3 million illnesses every year worldwide. This study was conducted to isolate and identify Salmonella enterica serovars from poultry samples responsible for causing foodborne poisoning in the Mississippi area, United States. A total of 55 S. enterica serovars—Enteritidis (6), Oranienburg (1), Schwarzengrund (8), Heidelberg (4), Kentucky (22), 4, [5], 12:i:- (1), Montevideo (2), Infantis (9), and multi serotypes (2)—were isolated from approximately 110 poultry samples. Through pulsed-field gel electrophoresis (PFGE) analysis, 8 to 13 bands were obtained. The profiles showed >90% similarity in strains within the same type. Consequently, PFGE could be a useful tool to determine chromosomal similarity (clonality of strains) that can be used to trace down epidemiologic sources and geographical origins of Salmonella.

Antimicrobial resistance associated with the use of antimicrobial processing aids during poultry processing operations: cause for concern?

Antimicrobial resistance has become a global issue and a threat to human and animal health. Contamination of poultry carcasses with meat-borne pathogens represents both an economic and a public health concern. The use of antimicrobial processing aids (APA) during poultry processing has contributed to an improvement in the microbiological quality of poultry carcasses. However, the extensive use of these decontaminants has raised concerns about their possible role in the co-selection of antibiotic-resistant bacteria. This topic is presented in the current review to provide an update on the information related to bacterial adaptation to APA used in poultry processing establishments, and to discuss the relationship between APA bacterial adaptation and the acquisition of a new resistance phenotype to therapeutic antimicrobials by bacteria. Common mechanisms such as active efflux and changes in membrane fluidity are the most documented mechanisms responsible for bacterial cross-resistance to APA and antimicrobials. Although most studies reported a bacterial resistance to antibiotics not reaching a clinical level, the under-exposure of bacteria to APA remains a concern in the poultry industry. Further research is needed to determine if APA used during poultry processing and therapeutic antimicrobials share common sites of action in bacteria and encounter similar mechanisms of resistance.

Ozone-Based Interventions To Improve the Microbiological Safety and Quality of Poultry Carcasses and Parts: A Review

HIGHLIGHTS

Ozone treatment achieved microbial population reductions. Gaseous ozone was most commonly used on poultry parts. Carcasses were treated exclusively with aqueous ozone or ozonated water. Ozone treatment can extend poultry product shelf life without significant quality effects.

Fluoroquinolone-Resistant Salmonella enterica, Campylobacter spp., and Arcobacter butzleri from Local and Imported Poultry Meat in Kumasi, Ghana

Salmonella and Campylobacter are important gastroenteric pathogens. Arcobacter butzleri is an emerging enteric pathogen. Data on the frequencies of these poultry-associated pathogens on meat products sold in sub-Saharan Africa are scarce. This study aimed to analyze the frequency of Salmonella, Campylobacter, and Arcobacter antibiotic resistance and underlying mechanisms of resistance to fluoroquinolones in locally produced and imported poultry sold in urban Ghana. Chicken meat was collected and cultured on standard media. Bacterial strains were identified by biochemical methods and by mass spectrometry. Antibiotic susceptibility was tested by disk diffusion. Ciprofloxacin-resistant strains were assessed for molecular mechanisms of resistance. Among 200 samples, comprising 34% (n = 68) from the Ghanaian poultry industry and 66% (n = 132) from imports, 9% (n = 17) contained Salmonella, 11% (n = 22) Campylobacter, and 26.5% (n = 53) A. butzleri. Higher overall contamination frequencies were found in local meat. Most common Salmonella serovars identified were Kentucky (n/N = 5/16; 31%) and Poona (n/N = 4/16; 25%). Campylobacter were C. coli (n/N = 10/19; 53%) and C. jejuni (n/N = 9/19; 47%). Resistance to fluoroquinolones was high with 63% (n = 10), 75% (n = 15), and 52% (n = 25) in Salmonella, Campylobacter, and Arcobacter, respectively. A link between Salmonella Kentucky [sequence type (ST) 198] and a ciprofloxacin minimum inhibitory concentration of 16 μg/mL was found. Salmonella Poona-ST308 revealed transferable qnrB2 fluoroquinolone resistance genes. Markedly high frequencies of resistant Salmonella, Campylobacter, and Arcobacter predominant in locally produced meat represent a probable transmission reservoir for human infections. These findings highlight the need for implementation of surveillance systems that focus on food hygiene, use of antibiotics in animal husbandry, and continuous monitoring of the quality of meat products from imports.

Risk Assessment for Salmonellosis in Chicken in South Korea: The Effect of Salmonella Concentration in Chicken at Retail

Salmonellosis caused by chicken consumption has been a critical issue in food safety worldwide, including in Korea. The probability of illness from consumption of chicken was simulated in study, based on the recipe of Dakgalbi, a commonly eaten chicken dish in Korea. Additionally, the processing stage at slaughterhouses to decrease Salmonella concentration in broilers was modeled to explore its effect on the likelihood of illness. A Monte Carlo simulation model was created using @RISK. Prevalence of Salmonella in chickens at the retail stage was found to be predominantly important in determining the probability of illness. Other than the prevalence, cooking temperature was found to have the largest impact on the probability of illness. The results also demonstrated that, although chlorination is a powerful tool for decreasing the Salmonella concentration in chicken, this effect did not last long and was negated by the following stages. This study analyzes the effects of variables of the retail-to-table pathway on the likelihood of salmonellosis in broiler consumption, and also evaluates the processing step used to decrease the contamination level of Salmonella in broilers at slaughterhouses. According to the results, we suggest that methods to decrease the contamination level of Salmonella such as chlorination had little effect on decreasing the probability of illness. Overall, these results suggest that preventing contamination of broiler with Salmonella must be a top priority and that methods to reduce the concentration of Salmonella in broilers at slaughterhouses hardly contribute to safe consumption of Salmonella-contaminated chicken.