Prevalence of Salmonella in poultry processing environments in wet markets in Penang and Perlis, Malaysia

Antibiotic-Resistant Salmonella Enteritidis in Raw Chicken Meat of Dhaka City, Bangladesh

Foodborne zoonotic Salmonella is transmitted through contaminated meat, milk, and eggs. This study is aimed at investigating the antimicrobial resistance (AMR) profile of Salmonella Enteritidis isolated from raw chicken meat in Dhaka City, Bangladesh. Two hundred raw chicken meat samples were aseptically collected from 20 retail markets located in Dhaka City, and the isolated Salmonella species were identified based on their morphological, cultural, biochemical, and molecular characterization by polymerase chain reaction (PCR). The primer sets of the InvA and Enteritidis-specific STM3098 gene were used for the PCR detection of Salmonella species and S. Enteritidis, respectively. The isolates were then screened for AMR phenotypically and the presence of the tetracycline resistance (TetA) gene. The prevalence of Salmonella species and S. Enteritidis was 22.5% (n = 45/200) and 18.5% (n = 37/200), respectively. However, the prevalence was constant across all the sample markets (p > 0.05). Tetracycline, amoxicillin, and ampicillin resistance was phenotypically present in all isolates (100%). Furthermore, approximately 70%, 49%, and 30% of S. Enteritidis showed resistance against erythromycin, amoxicillin/clavulanic acid, and ciprofloxacin, respectively. However, S. Enteritidis were sensitive to gentamicin (86.5%), meropenem (64.9%), ciprofloxacin (62.2%), and ceftriaxone (59.5%). The TetA gene, which causes AMR against tetracycline, was shown to be present in all phenotypically resistant Salmonella species. Multiple antibiotic resistance index (MARI) ranged between 0.3 and 0.8. Overall, multidrug resistant (MDR) Salmonella Enteritidis emerged in the chicken meat along with the presence of a resistance gene that is a threat to human health. Therefore, action must be taken to stop the spread of AMR.

Accumulation of microbial hazards and assessment of food hygiene associated with broiler chicken processing at open air food markets in Maputo, Mozambique

The burden of foodborne disease due to the consumption of animal-sourced foods is substantial in low- and middle-income countries (LMICs). Open air markets, while providing fresh and affordable foods, often have unhygienic practices that may contribute to contamination during the slaughter and processing of chicken meat. This study examines whether and how the common practice of rinse water (stored water used for rinsing broiler carcasses during processing) reuse leads to accumulation of pathogens, with potential cross contamination of chicken meat. To assess the accumulation of Campylobacter jejuni/coli, Salmonella spp., and the indicator of fecal contamination, Escherichia coli, in rinse water used during the slaughtering process at open air food markets in Maputo, Mozambique. We conducted a time-series study at three open air food markets. In a first experiment, we collected paired rinse water (N = 70), water used for chicken processing, and broiler chicken carcass (N = 60) samples from 10 vendors at 75-min intervals starting prior to any processing activity. In a second experiment, we collected 100, 50 mL rinse water samples, immediately before and after processing, from 10 vendors. Chicken processing activity and associated hygiene practices were captured through direct observation. Vendors processed 24 chickens per day, on average. In the first experiment, C. jejuni/coli and E. coli were detected in 30 % and 80 % of rinse water samples, respectively, prior to processing (baseline), and no Salmonella was detected. After the first carcass rinse, C. jejuni/coli and E. coli were detected in 100 % of samples, and Salmonella spp. was detected in 42 % of rinse water samples and 48 % of carcass samples. C. jejuni/coli showed an average 0.1 log10 copies (95 % CI 0.0, 0.2) increase in rinse water and carcass samples every 75 min. In the second experiment, no C. jejuni/coli or Salmonella spp. were detected in baseline rinse water samples, and E. coli were detected in 78 % of baseline rinse water samples. After processing the first carcass, C. jejuni/coli were detected in 100 % of remaining samples, Salmonella spp. were detected in 28 % of pre-final rinse and 36 % of post-final rinse samples, and E. coli were detected in 81 % of pre-final rinse and 100 % of post-final rinse samples. Our results reveal that consumers are at a high risk of purchasing chicken meat contaminated with human enteropathogens. Once contaminated, rinse water stays contaminated throughout the day. Low-cost and feasible interventions implemented at the carcass wash step are needed to reduce microbial hazards on chicken meat before purchase.

High prevalence of antibiotic-resistant Escherichia coli harbouring extended-spectrum beta-lactamase (ESBL) in raw chicken meat sold at retail in Klang Valley, Malaysia

Chicken is the most widely consumed meat in Malaysia as it is abundant, provides good nutrient and taste, and available at an affordable price. However, it is known to harbour various foodborne pathogens including faecal microorganism, Escherichia coli. There are various routes and factors that can cause contamination of E. coli in chicken. Furthermore, numerous reports have shown that over the past decades, the trends of antimicrobial resistance among foodborne pathogens have been increasing rapidly. Therefore, the present work aimed to assess the prevalence of E. coli contamination by examining various contributing factors and its antibiotic resistance in raw chicken meat sold in Klang Valley, Malaysia. Results showed that 74% of the samples were contaminated with E. coli with wet markets showing higher prevalence (17%) of E. coli than in hypermarkets. Univariate analysis within the same risk factor showed that packaging process, storage temperature, and antibiotics had significant effects on the prevalence of E. coli (∼ 6.097 log CFU/g). The E. coli loads were significantly influenced by market type and storage temperature as validated by Mann-Whitney tests. All E. coli isolates displayed multiple antibiotic resistance (MAR) index ranging from 0.33 to 1.00, and 35 E. coli isolates showed the highest MAR index (1.00), being resistant to 12 antibiotics. Furthermore, 90% of E. coli isolates contained extended-spectrum beta-lactamase genotypes that can subvert potent antibiotic, beta-lactam. The findings from the present work would help reduce the risk of foodborne illnesses by identifying the risk factors associated with E. coli prevalence in chicken and provide the basis to revise guidelines on antibiotic use in livestock to reduce antimicrobial resistance.

The effect of peanut skins as a natural antimicrobial feed additive on ileal and cecal microbiota in broiler chickens inoculated with Salmonella enterica Enteritidis

The consumption of poultry products contaminated with Salmonella species is one of the most common causes of Salmonella infections. In vivo studies demonstrated the potential application of peanut skins (PS) as an antimicrobial poultry feed additive to help mitigate the proliferation of Salmonella in poultry environments. Tons of PS, a waste by-product of the peanut industry, are generated and disposed in U.S. landfills annually. Peanut skins and extracts have been shown to possess antimicrobial and antioxidant properties. Hence, we aimed to determine the effect of PS as a feed additive on the gut microbiota of broilers fed a control or PS supplemented (4% inclusion) diet and inoculated with or without Salmonella enterica Enteritidis (SE). At hatch 160 male broilers were randomly assigned to 4 treatments: 1) CON-control diet without SE, 2) PS-PS diet without SE, 3) CONSE-control diet with SE, 4) PSSE-PS diet with SE. On d 3, birds from CONSE and PSSE treatments were inoculated with 4.2 × 109 CFU/mL SE. At termination (4 wk), 10 birds/treatment were euthanized and ileal and cecal contents were collected for 16S rRNA analysis using standard methodologies. Sequencing data were analyzed using QIIME2. No effect of PS or SE was observed on ileal alpha and beta diversity, while evenness, richness, number of amplicon sequence variants (ASV) and Shannon, as well as beta diversity were significantly (P < 0.05) affected in ceca. Similarly, more differentially abundant taxa between treatment groups were identified in ceca than in ileum. However, more microbiota functional changes, based on the PICRUST2 prediction, were observed in ileum. Overall, relatively minor changes in microbiota were observed during SE infection and PS treatment, suggesting that PS addition may not attenuate the SE proliferation, as shown previously, through modulation of microbiota in gastrointestinal tract. However, while further studies are warranted, these results suggest that PS may potentially serve as a functional feed additive for poultry for improvement of animal health.

Persistence of Salmonella and Campylobacter on Whole Chicken Carcasses under the Different Chlorine Concentrations Used in the Chill Tank of Processing Plants in Sri Lanka

The persistence of non-typhoidal Salmonella and Campylobacter in chicken meat is a considerable public health risk and a future challenge. This study aimed to determine the prevalence of Salmonella and Campylobacter in poultry processing lines where different chlorine concentrations were used in the chill tank. The samples were collected from four types of processing plants in Sri Lanka, considering the chlorine concentration used in the chill tank, which ranged from 2 ppm to 50 ppm. Salmonella and Campylobacter were isolated from whole carcass washings, neck skin, and cecal samples. Subsequently, an antimicrobial susceptibility test was performed for the isolates. The results revealed the overall prevalence of Salmonella and Campylobacter was 78.25% and 63.5%, respectively. Positive percentages of Salmonella and Campylobacter were high in the carcasses compared to the neck skin and ceca. The Campylobacter counts on the whole carcasses were significantly low (p < 0.001), at higher chlorine concentrations ranging from 20 to 30 ppm and 40 to 50 ppm. The pathogen prevalence in the whole carcasses was 84.7% Campylobacter coli, 39.1% Campylobacter jejuni, 71.1% Salmonella Typhimurium, and 28.8% Salmonella Infantis. The highest resistance was observed for tetracycline (63.8%) in Salmonella, while it was for gentamicin (87.8%) in Campylobacter. The prevalence percentage of multidrug-resistant Campylobacter was 51.2%, while it was 2.12% for Salmonella. The persistence of multidrug-resistant Salmonella and Campylobacter on the post-chill carcasses was highlighted in the present study as a significant public health threat that has to be addressed urgently.

Hygienic status of beef butcher shop facilities and antibiotic resistance profile of Salmonella enterica in Ethiopia

The microbiological quality of meat is influenced by the conditions of hygiene prevailing during production and handling. Thus, this study aimed to assess the prevalence of Salmonella enterica and its antimicrobial resistance, load of hygiene indicator bacteria including E. coli (ECC), coliforms (CC), total coliform (TCC), Enterobacteriaceae (EB) and aerobic plate count (APC), and meat handler's food safety knowledge and hygiene practices in butcher shops in two cities, Addis Ababa and Hawassa in Ethiopia, during 2020 and 2021. A total of 360 samples of beef carcasses (n = 120), knives (n = 60), chopping boards (n = 60), weighing balance (n = 60), and personnel's hands (n = 60) were randomly collected for microbial analysis. Besides, 120 participants were selected to participate in a food safety knowledge and hygiene practices assessment. The S. enterica isolates were identified by agglutination test followed by qPCR targeting invA gene. Phenotypic antimicrobial resistance profiles of S. enterica were determined using disk diffusion assays as described in CLSI. The ECC, CC, TCC, EB, and APC populations were quantified by plating onto petrifilm plates. A structured questionnaire was used to determine food safety knowledge and hygiene practices of participants. Overall prevalence of S. enterica was 16.7% (95% CI, 8.3-26.7) and location seems to have no effect (p = 0.806). Only 20% of the S. enterica were resistant to ampicillin and tetracycline. However, the majority (80%) of S. enterica isolates were susceptible to the panel of 11 antimicrobials tested. The overall mean ± SD (log CFU/cm2) of ECC, CC, TCC, EB, and APC were 4.31 ± 1.15; 4.61 ± 1.33; 4.77 ± 1.32; 4.59 ± 1.38 and 5.87 ± 1.52, respectively. No significant difference (p = 0.123) in E. coli contamination was observed between samples of beef carcasses and chopping boards. The EB contamination showed no significant difference (p > 0.05) among sample sources. The APC contamination levels on beef carcass were significantly higher (p > 0.05) than other sample sources. A total of 56% (95% CI: 46.7 - 65.0) of the participants had poor knowledge and 65% (95% CI: 56.7 - 73.3) had poor hygiene practices towards food safety. This study highlighted the poor hygiene status of butcher facilities with a potential risk of beef safety. Thus, appropriate food safety control strategies and inspection is needed at retail establishments.

Salmonella serovars trend in poultry Malaysia from 2011 to 2020

Data and geographical trend of Salmonella serovars infecting poultry in Malaysia is limited. In this study, the trend of Salmonella serovars infection was presented for the past ten years from 2011 to 2020 and the predominant serovars were mapped based on geographical distribution. Analysis of passive surveillance data demonstrated a shift of Salmonella serovars that infected poultry in Malaysia. The Salmonella serovars varied within ten years of registered cases with the Veterinary Research Institute, Ipoh, Malaysia involving samples from live and dead birds. Total number of cases found from the year 2011 to 2020 were 391 cases, involving 73 Salmonella serovars with an additional one group of unclassified serovars known as Salmonella spp. Further analysis revealed that eight serovars were found predominant throughout the ten-year period. These included S. Albany, S. Braenderup, S. Brancaster, S. Corvallis, S. Enteritidis, S. Kentucky, S. Typhimurium and S. Weltevreden. Salmonella spp. (Salmonella that is incapable to be identified based on serotyping) were also one of the major groups observed throughout the years. This study could help the authorities to improvise policies for better disease control programs through the establishment of diagnostic tools for rapid Salmonella screening in poultry.

Rapid and sensitive detection of Salmonella in agro-Food and environmental samples: A review of advances in rapid tests and biosensors

Salmonella is as an intracellular bacterium, causing many human fatalities when the host-specific serotypes reach the host gastrointestinal tract. Nontyphoidal Salmonella are responsible for numerous foodborne outbreaks and product recalls worldwide whereas typhoidal Salmonella are responsible for Typhoid fever cases in developing countries. Yet, Salmonella-related foodborne disease outbreaks through its food and water contaminations have urged the advancement of rapid and sensitive Salmonella-detecting methods for public health protection. While conventional detection methods are time-consuming and ineffective for monitoring foodstuffs with short shelf lives, advances in microbiology, molecular biology and biosensor methods have hastened the detection. Here, the review discusses Salmonella pathogenic mechanisms and its detection technology advancements (fundamental concepts, features, implementations, efficiency, benefits, limitations and prospects). The time-efficiency of each rapid test method is discussed in relation to their limit of detections (LODs) and time required from sample enrichment to final data analysis. Importantly, the matrix effects (LODs and sample enrichments) were compared within the methods to potentially speculate Salmonella detection from environmental, clinical or food matrices using certain techniques. Although biotechnological advancements have led to various time-efficient Salmonella-detecting techniques, one should consider the usage of sophisticated equipment to run the analysis by moderately to highly trained personnel. Ultimately, a fast, accurate Salmonella screening that is readily executed by untrained personnels from various matrices, is desired for public health procurement.

Use of Essential Oils to Counteract the Phenomena of Antimicrobial Resistance in Livestock Species

Antimicrobial resistance is an increasingly widespread phenomenon that is of particular concern because of the possible consequences in the years to come. The dynamics leading to the resistance of microbial strains are diverse, but certainly include the incorrect use of veterinary drugs both in terms of dosage and timing of administration. Moreover, the drug is often administered in the absence of a diagnosis. Many active ingredients in pharmaceutical formulations are, therefore, losing their efficacy. In this situation, it is imperative to seek alternative treatment solutions. Essential oils are mixtures of compounds with different pharmacological properties. They have been shown to possess the antibacterial, anti-parasitic, antiviral, and regulatory properties of numerous metabolic processes. The abundance of molecules they contain makes it difficult for treated microbial species to develop pharmacological resistance. Given their natural origin, they are environmentally friendly and show little or no toxicity to higher animals. There are several published studies on the use of essential oils as antimicrobials, but the present literature has not been adequately summarized in a manuscript. This review aims to shed light on the results achieved by the scientific community regarding the use of essential oils to treat the main agents of bacterial infection of veterinary interest in livestock. The Google Scholar, PubMed, SciELO, and SCOPUS databases were used for the search and selection of studies. The manuscript aims to lay the foundations for a new strategy of veterinary drug use that is more environmentally friendly and less prone to the emergence of drug resistance phenomena.

Prevalence of multi-antimicrobial resistant non-typhoidal Salmonella isolated from filth flies at wet markets in Klang, Malaysia, and their survival in the simulated gastric fluid

Filth flies at wet markets can be a vector harbouring multiple antimicrobial-resistant (MAR) nontyphoidal Salmonella (NTS), and such strains are a significant threat to public health as they may cause severe infections in humans. This study aims to investigate the prevalence of antimicrobial-resistant NTS, especially Salmonella Enteritidis and S. Typhimurium harboured by filth flies at wet markets, and investigate their survival in the simulated gastric fluid (SGF). Filth flies (n = 90) were captured from wet markets in Klang, Malaysia, and processed to isolate Salmonella spp. The isolates (n = 16) were identified using the multiplex-touchdown PCR and assessed their antimicrobial susceptibility against 11 antimicrobial agents. Finally, three isolates with the highest MAR index were subjected to SGF survival tests. It was observed that 17.8 % of flies (n = 16/90) harbouring Salmonella, out of which 10 % (n = 9/90) was S. Enteritidis, 2.2 % (n = 2/90) was S. Typhimurium, and 5.6 % was unidentified serotypes of Salmonella enterica subsp. I. 43.8 % (n = 7/16) were confirmed as MAR, and they were observed to be resistant against ampicillin, chloramphenicol, kanamycin, streptomycin, and nalidixic acid. Three strains, F35, F75, and F85 demonstrated the highest MAR index and were able to survive (>6-log10) in the SGF (180 min), indicating their potential virulence and invasiveness. This study provides significant insights into the prevalence and severity of MAR nontyphoidal Salmonella harboured by filth flies in wet markets, which may help inform strategies for controlling the spread and outbreak of foodborne disease.

Quantifying Enteropathogen Contamination along Chicken Value Chains in Maputo, Mozambique: A Multidisciplinary and Mixed-Methods Approach to Identifying High Exposure Settings

BACKGROUND

Small-scale poultry production is widespread and increasing in low- and middle-income countries (LMICs). Exposure to enteropathogens in poultry feces increases the hazard of human infection and related sequela, and the burden of disease due to enteric infection in children < 5 y in particular is substantial. Yet, the containment and management of poultry-associated fecal waste in informal settings in LMICs is largely unregulated.

OBJECTIVES

To improve the understanding of potential exposures to enteropathogens carried by chickens, we used mixed methods to map and quantify microbial hazards along production value chains among broiler, layer, and indigenous chickens in Maputo, Mozambique.

METHODS

To map and describe the value chains, we conducted 77 interviews with key informants working in locations where chickens and related products are sold, raised, and butchered. To quantify microbial hazards, we collected chicken carcasses (n = 75 ) and fecal samples (n = 136 ) from chickens along the value chain and assayed them by qPCR for the chicken-associated bacterial enteropathogens C. jejuni/coli and Salmonella spp.

RESULTS

We identified critical hazard points along the chicken value chains and identified management and food hygiene practices that contribute to potential exposures to chicken-sourced enteropathogens. We detected C. jejuni/coli in 84 (76%) of fecal samples and 52 (84%) of carcass rinses and Salmonella spp. in 13 (11%) of fecal samples and 16 (21%) of carcass rinses. Prevalence and level of contamination increased as chickens progressed along the value chain, from no contamination of broiler chicken feces at the start of the value chain to 100% contamination of carcasses with C. jejuni/coli at informal markets. Few hazard mitigation strategies were found in the informal sector.

DISCUSSION

High prevalence and concentration of C. jejuni/coli and Salmonella spp. contamination along chicken value chains suggests a high potential for exposure to these enteropathogens associated with chicken production and marketing processes in the informal sector in our study setting. We identified critical control points, such as the carcass rinse step and storage of raw chicken meat, that could be intervened in to mitigate risk, but regulation and enforcement pose challenges. This mixed-methods approach can also provide a model to understand animal value chains, sanitary risks, and associated exposures in other settings. https://doi.org/10.1289/EHP11761.

Limiting the spillover of zoonotic pathogens from traditional food markets in developing countries and a new market design for risk-proofing

Traditional food markets are age-old systems that primarily serve the food supply needs of society's less affluent sectors, often operating with minimal infrastructure. These markets are prevalent in low and middle-income countries. However, their hygienic conditions are frequently suboptimal, potentially fostering the emergence and spread of presumptive zoonotic diseases. The recent emergence of zoonotic or potentially zoonotic diseases and their possible links to traditional food markets underscore the need for focused attention on this overlooked issue. The socioeconomic characteristics of traditional food markets reveal that despite the risk of zoonotic pathogen spread, these markets play a crucial role for large segments of the population. These individuals rely on such markets for their livelihood, food, and nutrition. Therefore, a comprehensive set of measures addressing various aspects of traditional food markets is necessary to manage and mitigate the risks of potential zoonotic disease emergence. In this article, we explore various facets of traditional food markets, paying special attention to the risks of zoonotic diseases that urgently require stakeholder attention. We also propose a new market design to prevent the risk of zoonotic spillover and advocate for the development of a Market Hygiene Index for these markets.

Multidrug-Resistant Salmonella Species and Their Mobile Genetic Elements from Poultry Farm Environments in Malaysia

The prevalence and persistent outbreaks of multidrug-resistant (MDR) Salmonella in low-income countries have received growing attention among the public and scientific community. Notably, the excessive use of antibiotics in chicken feed for the purpose of treatment or as prophylaxis in the poultry industry have led to a rising rate of antimicrobial resistance. Therefore, this study aimed to determine the presence of antimicrobial-resistant Salmonella species and its mobile genetic elements from soil and effluent samples of 33 randomly selected poultry farms in Selangor, Malaysia. Salmonella species were isolated on selective media (CHROMagar™ Salmonella). VITEK® 2 system was used to identify the isolates and their antimicrobial susceptibility. Subsequently, eight isolates were subjected to the whole genome sequencing (WGS). Based on the results, Salmonella spp. was detected in 38.1% (24/63) of samples, with the highest resistance to ampicillin (62.5%), followed by ampicillin/sulbactam (50.0%) and ciprofloxacin (45.8%). Meanwhile, the identified serovars were Salmonella enterica subspecies enterica serovar Weltevreden (S. Weltevreden), S. Jedburgh, and S. Brancaster. The most prevalent resistance genes detected include qnrS1, blaTEM-176, dfrA14, and tet(A). The IncX1 plasmid, with encoded resistance genes, was also detected in four isolates. Furthermore, mutations in the quinolone resistant-determining regions (QRDR) were discovered, specifically in the gyrA, gyrB, and parC genes. In short, surveillance such as continuous monitoring of antimicrobial resistance and emerging trends in resistance patterns through farm environmental samples could provide information to formulate public health interventions for effective infection prevention and disease control.

Integrative and Conjugative Element-Mediated Azithromycin Resistance in Multidrug-Resistant Salmonella enterica serovar Albany

We identified an erm42-carrying integrative and conjugative element, ICE_erm42, in 26.4% of multidrug-resistant Salmonella enterica serovar Albany isolates recovered from human salmonellosis between 2014 and 2019 in Taiwan. ICE_erm42-carrying strains displayed high-level resistance to azithromycin and the element could move into the phylogenetically distant Vibrio cholerae via conjugation.

Prevalence and antimicrobial resistance of Salmonella enterica serovars Enteritidis and Typhimurium isolated from retail chicken meat in Wasit markets, Iraq

Background and Aim: Food poisoning caused by Salmonella enterica serovars is the most common type of foodborne illness. Tainted chicken meat is a major vector for spreading these serovars throughout the food supply chain. Salmonella isolates that developed resistance to commonly used antimicrobials pose a noteworthy risk to public health, yet there has been a lack of data on this issue in Iraq. Therefore, it is crucial to address these serious public health challenges with an adequate database on the occurrence and antibiotic resistance of these serovars. This study aimed to determine the frequency of occurrence of Salmonella enterica serovars Enteritidis and Typhimurium (S. Enteritidis and S. Typhimurium), antimicrobial resistance (AMR), and prevalence of multidrug resistance among S. Enteritidis and S. Typhimurium isolated from poultry meat collected in Wasit Province in Iraq. Materials and Methods: A total of 150 raw and frozen poultry meat samples were gathered from retail markets in various locales across the Wasit Governorate in Iraq. Salmonella spp. were successfully cultured and identified using the technique recommended by ISO 6579:2002, with minor modifications. The multiplex polymerase chain reaction approach was used to confirm Salmonella spp. (S. Enteritidis and S. Typhimurium). A disk diffusion test was performed to determine the susceptibility to particular antimicrobial agents, and 12 different antimicrobial agents were evaluated. Results: Only 19 of the 150 (12.7%) samples tested positive for Salmonella (16% and 11% were isolated from raw and frozen chicken meat, respectively). S. Enteritidis accounted for 63.2%, whereas S. Typhimurium accounted for 36.8%. Nalidixic acid resistance was the most common (73.7%), followed by sulfamethoxazole-trimethoprim (63.2%) and tetracycline (63.2%), but gentamicin and ciprofloxacin (up to 15.8%) only had modest resistance. Antibiogram of S. Enteritidis and S. Typhimurium yield 13 antibiotypes. Among the 19 Salmonella isolates, 12 of 19 (63.2%) established resistance to no less than three categories of antimicrobials. Conclusion: This study highlighted the necessity of limiting the utilization of antibiotics in animal production by providing vital information regarding the frequency and AMR of Salmonella at markets in Wasit Province. Therefore, risk assessment models could use these data to lessen the amount of Salmonella passed on to humans in Iraq from chicken meat. Keywords: antimicrobial resistance, chicken, food poisoning, serovars.

Microbiological Profile and Hygienic Quality of Foodstuffs Marketed in Collective Catering in Central Morocco

Food hygiene is important both for its impact on the health of citizens and also for the cost of the infections that it can generate. In Morocco, it has become a concern of authorities. This work, realized for the first time in the center of Morocco, is aimed at describing the microbiological quality of foodstuffs marketed in collective catering in central Morocco. This study was conducted retrospectively from January 2015 to December 2019 in Fez city, central Morocco. The samples collected by the competent authority during official control from restaurants and food outlets were analyzed. Non-conformity was chosen as an indicator of food quality according to the official Moroccan standards. The samples were presented according to several variables: year/month/season, category/subcategory, communes, and establishment. The statistical processing of the results was done by SPSS 25. The Chi2 statistical test was calculated to determine a relationship between non-conformity and the type of analyzed matrix (year, season, and food category). The test was considered statistically significant for a p value < 0.05. A total of 2223 food samples were investigated, with an annual average of 445 samples. Overall, the rate of non-compliance during 2015-2019 was 31%, reaching its maximum in 2017 (36.4%) and its minimum in 2018 (27.5%).This rate varies by food type. Juices/drinks and meat products are the most contaminated with 71.7% and 58.1%, respectively, followed by milk and derivatives with 43.2%, seasoning sauces with 28.6%, pastries and pastry creams with 21.4%, and 14.4% for ready meals. The main causes of food non-conformity were fecal contamination germs with 67% positive fecal coliforms and 15% of total coliforms followed by total germs (7%), Staphylococcus aureus (5%), yeasts and molds (3%), sulfite-reducing anaerobes (2%), and Salmonella (1%). Given the obtained results, improving the hygienic quality of foods is necessary to ensure better consumer safety.

Peanut Skins as a Natural Antimicrobial Feed Additive To Reduce the Transmission of Salmonella in Poultry Meat Produced for Human Consumption

ABSTRACT

Salmonella is the leading cause of bacterial foodborne zoonoses in humans. Thus, the development of strategies to control bacterial pathogens in poultry is essential. Peanut skins, a considerable waste by-product of the peanut industry is discarded and of little economic value. However, peanut skins contain identified polyphenolic compounds that have antimicrobial properties. Hence, we aim to investigate the use of peanut skins as an antibacterial feed additive in the diets of broilers to prevent the proliferation of Salmonella Enteritidis (SE). One hundred sixty male hatchlings (Ross 308) were randomly assigned to (i) peanut skin diet without SE inoculation (PS); (ii) peanut skin diet and SE inoculation (PSSE); (iii) control diet without SE inoculation (CON); and (iv) control diet with SE inoculation (CONSE). Feed intake and body weights were determined at weeks 0 and 5. On days 10 and 24 posthatch, three birds per pen (24 total) from each treatment group were euthanized, and the liver, spleen, small intestine, and ceca were collected. The weights of the liver, spleen, and ceca were recorded. Organ invasion was determined by counting SE colonies. Each pen served as an experimental unit and was analyzed by using a t test. Performance data were analyzed in a completely randomized design by using a general linear mixed model to evaluate differences. There were no significant differences (P > 0.05) in weekly average pen body weight, total feed consumption, bird weight gain, and feed conversion ratio between the treatment groups. There were no significant differences in SE CFU per gram for fecal, litter, or feed between the treatment groups CONSE and PSSE. However, for both fecal and litter, the PSSE treatment group tended (P ≤ 0.1) to have a lower Salmonella CFU per gram compared with the CONSE treatment group. The results indicate that peanut skins may have potential application as an antimicrobial feed additive to reduce the transmission or proliferation of SE in poultry environments or flocks.

HIGHLIGHTS

Potential Applications of Essential Oils for Environmental Sanitization and Antimicrobial Treatment of Intensive Livestock Infections

The extensive use of antibiotics has contributed to the current antibiotic resistance crisis. Livestock infections of Salmonella spp, Clostridium spp. and E. coli antimicrobial-resistant bacteria represent a public threat to human and animal health. To reduce the incidence of these zoonoses, essential oils (EOs) could be effective antibiotic alternatives. This study aims at identifying EOs safe for use, effective both in complementary therapy and in the environmental sanitization of intensive farming. Natural products were chemo-characterized by gas chromatography. Three S. Typhimurium, three C. perfringens and four E. coli strains isolated from poultry and swine farms were used to assess the antimicrobial properties of nine EOs and a modified GR-OLI (mGR-OLI). The toxicity of the most effective ones (Cinnamomum zeylanicum, Cz; Origanum vulgare, Ov) was also evaluated on porcine spermatozoa and Galleria mellonella larvae. Cz, Ov and mGR-OLI showed the strongest antimicrobial activity; their volatile components were also able to significantly inhibit the growth of tested strains. In vitro, Ov toxicity was slightly lower than Cz, while it showed no toxicity on G. mellonella larvae. In conclusion, the study confirms the importance of evaluating natural products to consolidate the idea of safe EO applications in reducing and preventing intensive livestock infections.

Risk factors associated with Salmonella prevalence, its antibiotic resistance, and egg antibiotic residues in the layer farming environment

Background and Aim:

Human salmonellosis with non-typhoidal Salmonella remains a global public health concern related to the consumption of contaminated eggs and egg-based products. This study aimed to examine the prevalence of Salmonella, antimicrobial-resistant Salmonella, and egg antibiotic residues concerning risk factors associated with Salmonella contamination in eggs, the layer farming environment, and laying hens kept in battery-cage closed-housing systems.

Materials and Methods:

This study used a repeated cross-sectional design to collect 488 samples from eggs, laying hens, and the farm environment on one laying farm for Salmonella detection according to ISO 6579:2002/AMD 1:2007. Salmonella-positive samples were further tested for serotype and antimicrobial susceptibility using the disk diffusion test. The layer farm contact person was interviewed at the sampling time to evaluate the risk factors associated with Salmonella contamination using logistic regression analysis. For each month, 24 eggs (144 eggs in total) were also randomly sampled from the collection egg area at the farm for antibiotic residue detection using the European Four Plate Test.

Results:

The highest Salmonella prevalence rates were in the samples from the layer pen floors, followed by the egg sizing machine (ESM) and eggshells at 65.5%, 52.5%, and 15%, respectively. Salmonellaenterica serovar Corvallis was the dominant serovar (48.38%), followed by Mbandaka (37.76%), Braenderup (14.29%), and Typhimurium (4.08%). Rodent presence at the farm and the frequency of changing the disinfectant foot dip were significant factors related to Salmonella contamination on the pen floors (odds ratio [OR]=22.5, 95% confidence interval [CI]=2.11-240.48, p=0.01; OR=24, 95% CI=2.78-206.96, p=0.004, respectively). Hand-washing before sorting and cleaning the ESM were the significant factors (OR=13, 95% CI=1.2-140.73, p=0.04). The most resistant Salmonella isolates were resistant to oxytetracycline. One isolate of S. enterica Typhimurium was resistant to cefotaxime, enrofloxacin, and oxytetracycline. The antibiotic residues in the egg yolks were streptomycin, enrofloxacin, and tetracycline at prevalence rates of 36.11%, 11.81%, and 7.64%, respectively. Streptomycin was the most abundant residue in the albumen and yolk, followed by tetracycline.

Conclusion:

Salmonella prevalence in layer farming with a closed-housing system is related to effective biosecurity and hygiene issues, such as rodent control, clean farm equipment, and good worker hygiene. In addition, eggs’ antibiotic residues may be related to treating antimicrobial-resistant Salmonella isolates and medicated feed with inappropriate antibiotic withdrawal time.

Alphitobius diaperinus Panzer (Insecta, Coleoptera) in a single house of a broiler production facility as a potential source of pathogenic bacteria for broilers and humans

Pest infestation in any stage can lead to a quality reduction in the finished products. This study aimed to detect Escherichia coli, Salmonella spp., Campylobacter spp., and Staphylococcus aureus in Alphitobius diaperinus adults, and in samples from broiler swabs, administered water and feed collected in a single house from a broiler production facility in central Italy. Three samplings were carried out, each collecting ninety adult beetles for microbial detection in the external, fecal and internal content; ten cloacal swab samples; and one sample of both administered feed and water. Microbiological cultures and biochemical identification were performed on suspected cultures and confirmed by species-specific PCRs. A. diaperinus was abundantly found near the windows, under the manger and in the corners of the facility. Salmonella enterica serovar Cholerasuis was found at the external surface of the beetles, while Staphylococcus xylosus and E. coli in the fecal content. The latter microrganism together with Staphylococcus lentus, S. xylosus and other staphylococcal species were detected in the internal microbiota. E. coli and Campylobacter spp. were observed in cloacal swabs, and S. xylosus in one feed sample. The study findings support evidence for Salmonella spp. and E. coli, and remark that adherence with sanitation rules and biosecurity procedures are required.

Virulence and antimicrobial resistance profile of non-typhoidal Salmonella enterica serovars recovered from poultry processing environments at wet markets in Dhaka, Bangladesh

The rapid emergence of virulent and multidrug-resistant (MDR) non-typhoidal Salmonella (NTS) enterica serovars is a growing public health concern globally. The present study focused on the assessment of the pathogenicity and antimicrobial resistance (AMR) profiling of NTS enterica serovars isolated from the chicken processing environments at wet markets in Dhaka, Bangladesh. A total of 870 samples consisting of carcass dressing water (CDW), chopping board swabs (CBS), and knife swabs (KS) were collected from 29 wet markets. The prevalence of Salmonella was found to be 20% in CDW, 19.31% in CBS, and 17.58% in KS, respectively. Meanwhile, the MDR Salmonella was found to be 72.41%, 73.21%, and 68.62% in CDW, CBS, and KS, respectively. All isolates were screened by polymerase chain reaction (PCR) for eight virulence genes, namely invA, agfA, IpfA, hilA, sivH, sefA, sopE, and spvC. The S. Enteritidis and untyped Salmonella isolates harbored all virulence genes while S. Typhimurium isolates carried six virulence genes, except sefA and spvC. Phenotypic resistance revealed decreased susceptibility to ciprofloxacin, streptomycin, ampicillin, tetracycline, gentamicin, sulfamethoxazole-trimethoprim, amoxicillin-clavulanic acid, and azithromycin. Genotypic resistance showed a higher prevalence of plasmid-mediated blaTEM followed by tetA, sul1, sul2, sul3, and strA/B genes. The phenotypic and genotypic resistance profiles of the isolates showed a harmonic and symmetrical trend. According to the findings, MDR and virulent NTS enterica serovars predominate in wet market conditions and can easily enter the human food chain. The chi-square analysis showed significantly higher associations among the phenotypic resistance, genotypic resistance and virulence genes in CDW, CBS, and KS respectively (p < 0.05).

Live bird market in Bangladesh: Regulatory systems and operations

Objective:

In developing countries, such as Bangladesh, the live bird market (LBM) is a vital location for the trading of live poultry. The study was carried out in nine LBMs located around Bangladesh to ascertain the present regulations and procedures governing their operation. Additionally, the responsibilities and levels of engagement of the stakeholders were determined.

Materials and Methods:

The data were gathered through the use of a semi-structured interview guide. Thematic analysis was used to code the interview transcripts iteratively.

Results:

The findings indicated that the government was directly and indirectly involved in the leasing process of the markets. A market in this country is divided into numerous sectors, including LBM, fish market, vegetable market, and grocery stores. A market’s hygienic condition is highly dependent on market authority’s decisions. In some markets, market officials conducted routine sanitary inspections. Veterinarians played a little role in the inspection procedure.

Conclusion:

There is no adequate, functional monitoring system to ensure that LBMs adhere to cleanliness and adequate and functional biosecurity. Biosecurity enhancements, effective cleaning programs, and regular monitoring by relevant authorities are critical for LBMs in Bangladesh.

Prevalence and antimicrobial resistance phenotypes of Salmonella species recovered at various stages of broiler operations in Hathazari, Bangladesh

Background and Aim: Dissemination of multidrug-resistant (MDR) Salmonella through food chains has serious health implications, with higher rates of morbidity and mortality. Broiler meat remains a major reservoir of Salmonella contamination. The lack of proper hygiene in local broiler operations has, therefore, prompted this research into the assessment of Salmonella contamination in local shops and associated antimicrobial resistance (AMR) phenotypes. Materials and Methods: A total of 55 broiler samples including skin, meat, and swab samples from chopping and dressing sites were included in the study. The samples were collected from broiler shops in Hathazari, Bangladesh, and screened for the presence of Salmonella strains using culture-based methods. The isolates were biochemically characterized and further tested for AMR to eight common antibiotics using the disk diffusion technique. Results: Salmonella contaminations were identified in 29% (16/55) of the broiler samples. Swab samples collected from the chopping sites appeared to be contaminated in higher proportions (33%) than those collected from the dressing areas (25%). On the other hand, the skin samples (50%) were detected with a higher percentage of contamination than the meat samples (25%). All Salmonella isolates showed resistance toward at least one of the eight antibiotics used. Although none of the isolates was resistant to all antibiotics, 18.75% showed resistance to a maximum of seven antibiotics. Resistance to nalidixic acid was most prevalent (87.5%), followed by sulfamethoxazole-trimethoprim (81.25%), erythromycin (81.25%), tetracycline (75%), streptomycin (56.25%), ampicillin-clavulanic acid (50%), chloramphenicol (43.75%), and cefotaxime (18.75%). The resistance patterns of the isolates were found to be highly diverse. The most frequently observed pattern was the following: Ampicillin-clavulanic acid-sulfamethoxazole-trimethoprim-nalidixic acid-tetracycline-chloramphenicol-streptomycin-erythromycin. Conclusion: The relatively high prevalence of MDR strains in the samples underlies an urgent need for surveillance and control measures concerning hygiene and antibiotic use in local broiler operations.

Prevalence, Serovars, and Factors Associated with Salmonella Contamination of Chicken Carcasses Sold in Outlets of the Informal Market in Gauteng Province, South Africa

ABSTRACT

Salmonella has been linked to many foodborne illnesses and epidemics in both humans and animals. This cross-sectional study determined the prevalence, serovars, and factors associated with Salmonella contamination of chickens slaughtered in informal market outlets in Gauteng Province, South Africa. A total of 151 chicken carcasses were randomly collected from 47 outlets. Standard bacteriological and molecular methods were used to isolate, identify, and determine the serovar of Salmonella isolates. The prevalence of Salmonella in carcass swabs, cloacal swabs, and carcass drips was 29.1% (44 of 151), 27.2% (41 of 151), and 43.7% (66 of 151), respectively, and the differences were statistically significant (P = 0.004). Only 5 (township locations of outlet, throughput, carcass evisceration, location of carcass for sale, and outlet sanitation) of 10 factors investigated for the contamination of carcasses by Salmonella were statistically significantly (P < 0.05) associated with the isolation of Salmonella. Of the 268 isolates of Salmonella, 157 (58.6%) were typeable using a limited molecular PCR technique, and nine serovars were identified. The predominant Salmonella enterica serovars were Bovismorbificans (31.0%), Enteritidis (7.5%), and Hadar (6.7%). The five important factors found to be significantly associated with the isolation of Salmonella at these outlets offer opportunities for the reduction of Salmonella contamination. There is a need for further investigation of the probable causes of the predominant isolation of Salmonella serovar Bovismorbificans in chickens and its potential implications for human infections in South Africa. It is concluded that chickens purchased from the informal market in Gauteng Province can be a source for salmonellosis in humans if improperly cooked before consumption.

Characterization of Salmonella Isolates Recovered from Stages of the Processing Lines at Four Broiler Processing Plants in Trinidad and Tobago

This cross-sectional study determined the prevalence, characteristics, and risk factors for contamination of chicken with Salmonella at four operating broiler processing plants in Trinidad. Standard methods were used to isolate and characterize the Salmonella isolates. The overall prevalence of Salmonella at the four processing plants was 27.0% (107/396). The whole carcass enrichment (WCE) method yielded a statistically significantly (p = 0.0014) higher frequency of isolation (53.9%; 97/180) than the whole carcass rinse (35.0%; 63/180) and neck skin methods (42.2%; 38/90). S. enterica serotypes Enteritidis, Javiana, and Infantis were the predominant serotypes isolated accounting for 20.8%, 16.7% and 12.5%, respectively, of the serotyped isolates. Risk factors included the use of over 100 contract farmers (OR 4.4), pre-chiller (OR 2.3), addition of chlorine to chiller (OR 3.2), slaughtering sick broilers (OR 4.4), and flocks with >50% mortality. Multi-drug resistance was detected in 12.3% (14/114) of the isolates of Salmonella. Resistance was high to kanamycin (85.7%) and doxycycline (74.6%) but low to amoxicillin-clavulanic acid (2.4%) and sulphamethoxazole-trimethoprim (0.8%). The occurrence of resistant Salmonella in chickens processed at commercial broiler processing plants has implications for salmonellosis and therapeutic failure in consumers of improperly cooked contaminated chickens from these plants in the country.

Occurrence and Concentrations of Residues of Tetracyclines, Polyether Ionophores, and Anthelmintics in Livers of Chickens Sold in the Informal Market in Gauteng Province, South Africa

ABSTRACT

The occurrence, concentrations, and variables associated with tetracycline, polyether ionophore, and anthelmintic residues in the livers of chickens sold in the informal market in South Africa were determined. Ultrahigh-performance liquid chromatography-tandem mass spectrometry was used to simultaneously analyze for four tetracyclines, five polyether ionophores, and six anthelmintic residues. The study determined the presence of residues in liver samples at both the limit of quantifications (LOQ) and concentrations over the maximum residue limit (MRL), i.e., noncompliant. Doxycycline (tetracycline group) was detected in 24 (24.5%) of 98 chicken livers, and 15 (15.3%) of the 98 were noncompliant. Mean ± standard deviation (SD) concentrations of 919.04 ± 1,081.30 ppb (LOQ) and 1,410.57 ± 108.89 ppb (MRL) were obtained. Maduramicin was detected in 27 (27.6%) of 98 chicken livers, and 19 (19.4%) of 98 were noncompliant. The mean ± SD for LOQ was 117.96 ± 84.56 ppb, and MRL was 153.21 ± 76.29 ppb. The concentrations of residues of doxycycline and maduramicin in chicken livers varied significantly across townships. Lasalocid was found in 31 (31.6%) of 98 samples, of which 5 (5.1%) had concentrations above the MRL. The mean ± SD concentration of lasalocid was 62.90 ± 170.84 ppb for samples in which lasalocid was quantified and 310.16 ± 356.68 ppb for noncompliant samples. Detectable concentrations of praziquantel, closantel, and rafoxanide (anthelmintics) residues were found in 3 (3.1%), 1 (1.0%), and 2 (2.0%) of 98 chicken livers, respectively. The presence of residues of three classes of veterinary drugs in chicken livers poses food safety implications to consumers and indicates a need for enhanced regulatory enforcement in controlling these drugs in South Africa.

The Role of Peridomestic Rodents as Reservoirs for Zoonotic Foodborne Pathogens

Although rodents are well-known reservoirs and vectors for a number of zoonoses, the functional role that peridomestic rodents serve in the amplification and transmission of foodborne pathogens is likely underappreciated. Clear links have been identified between commensal rodents and outbreaks of foodborne pathogens throughout Europe and Asia; however, comparatively little research has been devoted to studying this relationship in the United States. In particular, regional studies focused on specific rodent species and their foodborne pathogen reservoir status across the diverse agricultural landscapes of the United States are lacking. We posit that both native and invasive species of rodents associated with food-production pipelines are likely sources of seasonal outbreaks of foodborne pathogens throughout the United States. In this study, we review the evidence that identifies peridomestic rodents as reservoirs for foodborne pathogens, and we call for novel research focused on the metagenomic communities residing at the rodent-agriculture interface. Such data will likely result in the identification of new reservoirs for foodborne pathogens and species-specific demographic traits that might underlie seasonal enteric disease outbreaks. Moreover, we anticipate that a One Health metagenomic research approach will result in the discovery of new strains of zoonotic pathogens circulating in peridomestic rodents. Data resulting from such research efforts would directly inform and improve upon biosecurity efforts, ultimately serving to protect our food supply.

The Occurrence of Antimicrobial-Resistant Salmonella enterica in Hatcheries and Dissemination in an Integrated Broiler Chicken Operation in Korea

Positive identification rates of Salmonella enterica in hatcheries and upstream breeder farms were 16.4% (36/220) and 3.0% (6/200), respectively. Among the Salmonella serovars identified in the hatcheries, S. enterica ser. Albany (17/36, 47.2%) was the most prevalent, followed by the serovars S. enterica ser. Montevideo (11/36, 30.6%) and S. enterica ser. Senftenberg (5/36, 13.9%), which were also predominant. Thirty-six isolates showed resistance to at least one antimicrobial tested, of which 52.8% (n = 19) were multidrug resistant (MDR). Thirty-three isolates (enrofloxacin, MIC ≥ 0.25) showed point mutations in the gyrA and parC genes. One isolate, S. enterica ser. Virchow, carrying the blaCTX-M-15 gene from the breeder farm was ceftiofur resistant. Pulsed-field gel electrophoresis (PFGE) showed that 52.0% S. enterica ser. Montevideo and 29.6% S. enterica ser. Albany isolates sourced from the downstream of hatcheries along the broiler chicken supply chain carried the same PFGE types as those of the hatcheries. Thus, the hatcheries showed a high prevalence of Salmonella isolates with high antimicrobial resistance and no susceptible isolate. The AMR isolates from hatcheries originating from breeder farms could disseminate to the final retail market along the broiler chicken supply chain. The emergence of AMR Salmonella in hatcheries may be due to the horizontal spread of resistant isolates. Therefore, Salmonella control in hatcheries, particularly its horizontal transmission, is important.

Prevalence of Salmonella enterica Isolated from Food Contact and Nonfood Contact Surfaces in Cambodian Informal Markets

ABSTRACT

The lack of hygiene and sanitation practices and insufficient infrastructure in Cambodian informal markets may increase the risk of food contamination, specifically raw vegetables, which in turn may increase the chances of contracting a foodborne disease. The aims of this study in informal markets in Cambodia were (i) to quantify the prevalence of Salmonella enterica based upon differences in season of the year (rainy versus dry), surface types (food contact surfaces versus nonfood contact surfaces), and location of vendors within the market (inside versus outside) and (ii) to characterize S. enterica serotype prevalence. A total of 310 samples were screened for S. enterica prevalence following the U.S. Department of Agriculture guidelines, and results were confirmed by PCR assay. Whole genome sequencing was used to determine the serotype for each isolate in silico using SeqSero 1.0 on draft genomes. A total of 78 samples were confirmed positive for S. enterica. During the dry season, S. enterica was more prevalent on food contact surfaces than on nonfood contact surfaces (estimated probability of detection [confidence interval]: 0.41 [0.25, 0.59] and 0.17 [0.08, 0.32], respectively; P = 0.002), but no differences were apparent in the rainy season. No differences in S. enterica prevalence were found based on location within the market (P = 0.61). Sixteen S. enterica serotypes were detected across multiple surfaces. The most common S. enterica serotypes were Rissen (18 isolates), Hvittingfoss (11), Corvallis (10), Krefeld (8), Weltevreden (6), and Altona (6). Accurate data on the prevalence of S. enterica in informal markets are crucial for the development of effective surveillance and implementation of suitable intervention strategies at the domestic level, thus preventing foodborne illness.

HIGHLIGHTS

Prevalence of Salmonella enterica on poultry processing equipment after completion of sanitization procedures

Salmonella is a poultry-borne pathogen that causes illness throughout the world. Consequently, it is critical to control Salmonella during the process of converting broilers to poultry meat. Sanitization of a poultry processing facility, including processing equipment, is a crucial control measure that is utilized by poultry integrators. However, prevalence of Salmonella on equipment after sanitization and its potential risk to food safety has not been evaluated thoroughly. Therefore, the objective of this study was to evaluate the persistence of Salmonella on poultry processing equipment before and following cleaning and sanitization procedure. A total of 15 locations within 6 commercial processing plants were sampled at 3 time points: (A) after processing; (B) after cleaning; and (C) after sanitization, on 3 separate visits for a total of 135 samples per plant. Salmonella-positive isolates were recovered from samples using the United States Department of Agriculture MLG 4.09 conventional method. Presumptive Salmonella colonies were subjected to biochemical tests for confirmation. Salmonella isolates recovered after sanitization were serotyped and tested for the presence of specific virulence genes. A completely randomized design with a 6 × 3 × 15 factorial arrangement was utilized to analyze the results for Salmonella prevalence between processing plants. Means were separated using Fishers protected least significant difference when P ≤ 0.05. For Salmonella prevalence between processing plants, differences (P < 0.0001) were observed in the 6 plants tested where the maximum and minimum prevalence was 29.6 and 7.4%, respectively. As expected, there was a difference (P < 0.0001) in the recovery of Salmonella because of sampling time. Salmonella prevalence at time A (36%) was significantly higher, whereas there was no difference between time B (12%) and C (9%). There was a location effect (P < 0.0001) for the prevalence of Salmonella with the head puller, picker, cropper, and scalder having a significantly higher prevalence when compared with several other locations. At sampling time C, a trend toward a difference (P = 0.0899) was observed for Salmonella prevalence between the 6 plants, whereas significant differences were observed because of location (P = 0.0031). Five prominent Salmonella enterica serovars were identified, including Kentucky, Schwarzengrund, Enteritidis, Liverpool, and Typhimurium with S. Kentucky being the most prevalent. PCR analysis of 8 Salmonella virulence genes showed that the invA, sipB, spiA, sseC, and fimA were detected in all isolates, whereas genes carried on plasmids and/or fimbriae varied remarkably among all isolates. This study established Salmonella prevalence and persistence in poultry processing facilities after antimicrobial application through sanitization procedures which could result in contamination of poultry carcasses and food safety risks because of poultry meat.

Prevalence and characteristics of Salmonella isolates recovered from retail raw chickens in Shaanxi Province, China

In this study, we evaluated the prevalence of Salmonella in retail raw chickens in Shaanxi Province, China, on a monthly basis. In addition, we studied the antibiotic susceptibility, serotype, and genotype of Salmonella isolates and explored their relationships with sampling time, location, market type, and chicken type. The results showed that Salmonella was more prevalent in chickens sampled during the spring and summer than during the autumn and winter. Thirty-nine serotypes were identified from 406 Salmonella isolates, of which Salmonella typhimurium (16.7%) was the most prevalent. Other prevalent serotypes included S. thompson (12.8%), S. essen (9.1%), S. infantis (6.9%), S. rissen (5.7%), and S. enteritidis (5.4%). Approximately 71.4% of the 406 isolates were resistant to 3 or more antibiotics, 11.8% to 12 or more, and 1.7% to all 14 antibiotics tested. The most frequently detected resistance was to trimethoprim/sulfamethoxazole (82.0%), followed by nalidixic acid (71.9%) and tetracycline (59.4%). The frequencies of resistance to ampicillin, chloramphenicol, and amoxicillin/clavulanic acid were moderately high (∼50% each). Resistance to kanamycin, ceftiofur, streptomycin, gentamicin, and ciprofloxacin was less common (<40% each). Serotype distribution and antibiotic susceptibility of Salmonella isolates were related to sampling time, location, chicken type, and market type. Isolates recovered from the same sampling time, market type, location, and chicken type commonly exhibited identical or similar genotypes and antibiotic resistance profiles. However, DNA profiles and antibiotic resistance phenotypes of isolates within some serotypes were diverse. Our results revealed that multiple Salmonella subtypes with antibiotic resistance were prevalent in retail raw chickens in Shaanxi Province. Our study findings provide information for developing preventive measures against contamination of retail foods with Salmonella.

Distribution of Salmonella Serovars in Humans, Foods, Farm Animals and Environment, Companion and Wildlife Animals in Singapore

We analyzed the epidemiological distribution of Salmonella serovars in humans, foods, animals and the environment as a One-Health step towards identifying risk factors for human salmonellosis. Throughout the 2012-2016 period, Salmonella ser. Enteritidis was consistently the predominating serovar attributing to >20.0% of isolates in humans. Other most common serovars in humans include Salmonella ser. Stanley, Salmonella ser. Weltevreden, Salmonella ser. Typhimurium and Salmonella ser. 4,5,12:b:-(dT+). S. Enteritidis was also the most frequent serovar found among the isolates from chicken/chicken products (28.5%) and eggs/egg products (61.5%) during the same period. In contrast, S. Typhimurium (35.2%) and Salmonella ser. Derby (18.8%) were prevalent in pork/pork products. S. Weltevreden was more frequent in seafood (19.2%) than others (≤3.0%). Most isolates (>80.0%) from farms, companion and wildlife animals belonged to serovars other than S. Enteritidis or S. Typhimurium. Findings demonstrate the significance of a One-Health investigative approach to understand the epidemiology Salmonella for more effective and integrated surveillance systems.

Viability of Salmonella Typhimurium biofilms on major food-contact surfaces and eggshell treated during 35 days with and without water storage at room temperature

Salmonella is one of the main foodborne pathogens that affect humans and farm animals. The Salmonella genus comprises a group of food-transmitted pathogens that cause highly prevalent foodborne diseases throughout the world. The aim of this study was to appraise the viability of Salmonella Typhimurium biofilm under water treatment at room temperature on different surfaces, specifically stainless steel (SS), plastic (PLA), rubber (RB), and eggshell (ES). After 35 D, the reduction of biofilm on SS, PLA, RB, and ES was 3.35, 3.57, 3.22, and 2.55 log CFU/coupon without water treatment and 4.31, 4.49, 3.50, and 1.49 log CFU/coupon with water treatment, respectively. The d_R value (time required to reduce bacterial biofilm by 99% via Weibull modeling) of S. Typhimurium without and with water treatment was the lowest on PLA (176.86 and 112.17 h, respectively) and the highest on ES (485.37 and 2,436.52 h, respectively). The viability of the S. Typhimurium on ES and the 3 food-contact surfaces was monitored for 5 wk (35 D). The results of this study provide valuable information for the control of S. Typhimurium on different surfaces in the food industry, which could reduce the risk to consumers.

Three-Year Longitudinal Study: Prevalence of Salmonella Enterica in Chicken Meat is Higher in Supermarkets Than Wet Markets from Mexico

Worldwide, chicken meat is considered one of the main sources of Salmonella enterica in humans. To protect consumers from this foodborne pathogen, international health authorities recommend the establishment of continuous Salmonella surveillance programs in meat. However, these programs are scarce in many world regions; thus, the goal of the present study was to perform a longitudinal surveillance of S. enterica in chicken meat in Mexico. A total of 1160 samples were collected and analyzed monthly from 2016 to 2018 in ten chicken meat retailers (supermarkets and wet markets) located in central Mexico. The isolation and identification of S. enterica was carried out using conventional and molecular methods. Overall, S. enterica was recovered from 18.1% (210/1160) of the chicken meat samples. Remarkably, during the three years of evaluation, S. enterica was more prevalent (p < 0.0001) in supermarkets (27.2%, 158/580) than in wet markets (9.0%, 52/580). The study was 3.8 times more likely (odds ratio = 3.8, p < 0.0001) to recover S. enterica from supermarkets than wet markets. Additionally, a higher prevalence (p < 0.05) of this pathogen was observed during the spring, summer, autumn, and winter in supermarkets compared with wet markets. Moreover, the recovery rate of S. enterica from supermarkets showed a gradual increase from 20.78% to 42% (p < 0.0001) from 2016 to 2018. Interestingly, no correlation (p > 0.05) was observed between the S. enterica recovery rate in chicken meat and reported cases of Salmonella infections in humans. Higher levels of S. enterica in chicken meat retailed in supermarkets are not unusual; this phenomenon has also been reported in some European and Asian countries. Together, these results uncover an important health threat that needs to be urgently addressed by poultry meat producers and retailers.

Salmonella in native "village" chickens (Gallus domesticus): prevalence and risk factors from farms in South-Central Peninsular Malaysia

Village chicken or Ayam Kampung, common to Southeast Asian countries, has always been regarded as superior in comparison to commercial broiler chicken in terms of wholesomeness and health benefits. The current study investigates the prevalence and risk factors of Salmonella among village chicken flocks from the central and southern states of Peninsular Malaysia. A total of 35 village flocks were sampled from Selangor (n = 19), Melaka (n = 10), Johor (n = 4), and Negeri Sembilan (n = 2). In total, 1,042 samples were collected; these included cloacal swabs (n = 675), eggs (n = 62), pooled drinking water (n = 175), pooled feeds (n = 70), and pooled flies (n = 60). Isolation of Salmonella from cloacal swabs, poultry drinking water, and feeds was carried out according to the protocols and recommendations of the World Organization for Animal Health (OIE) terrestrial manual. The prevalence of Salmonella at an individual bird-level was 2.5% (17/675, 95% CI: 1.6 to 4.0). All eggs screened were negative; in the case of environmental samples, however, Salmonella was detected in 5.14% (9/175), 7.14% (5/70), and 5.0% (3/60) for water, feed, and flies, respectively. A total of 34 isolates and 8 Salmonella serotypes were identified. Weltevreden (20.6%) was the most common, followed by Typhimurium and Agona (17.6%), Albany and Enteritidis (8.8%), Molade (5.9%), Corvallis and Schleissheim (2.9%), and others grouped as Salmonella spp. (11.8%). Multivariable logistic regression models revealed that Salmonella positivity among flocks could be strongly predicted by storage of feeds (uncovered feeds; OR = 10.38; 95% CI: 1.25 to 86.39; p = 0.030) and uncovered water tanks (uncovered tank; OR = 6.43; 95% CI: 1.02 to 40.60; p = 0.048). The presence of Salmonella in village chickens in the study area was lower than that of commercial chickens in Malaysia.

Detection of Salmonella pathogenicity island and Salmonella plasmid virulence genes in Salmonella Enteritidis originated from layer and broiler farms in Java Island

OBJECTIVE

The incidence of salmonellosis in humans and animals is still high due to the occurrence of virulence factors in Salmonella enterica which play a role in the process of infection in the host and the spread of disease and most of the S. enterica can infect humans and animals. The present study was aimed to identify Salmonella Enteritidis and detect virulence genes related to Salmonella pathogenicity islands (SPIs) and Salmonella plasmid virulence (Spv).

MATERIALS AND METHODS

A total of 27 S. Enteritidis archive isolates belonging to the National Veterinary Drug Assay Laboratory (NVDAL) were used in this study. The bacteria were collected in 2016 and 2017 from samples of the cloaca and fecal swabs from layer and broiler farms in five provinces of Java Island. Isolates were cultured in specific media, biochemical tests and Gram staining. Detection of S. Enteritidis and virulence genes was done by polymerase chain reaction (PCR) method.

RESULTS

Identification of serovar showed 100% (27/27) isolates were positive for the sdfI gene (304 bp). The result confirmed that all strains were S. Enteritidis. PCR based detection of virulence genes showed that 100% of isolates had virulence genes in SPI-1 to SPI-5, namely, invA, ssaQ, mgtC, spi4D, and pipA genes. All the isolates (27/27) were also positive to spvB gene-based PCR.

CONCLUSION

All the isolates of S. Enteritidis in this study carry virulence genes related to SPI-1 to SPI-5 and plasmid virulence. The existence of virulent genes indicates that the S. Enteritidis strain examined in this study is highly virulent and poses a potential threat of worse disease outcome in humans and animals.

Occurrence and Phenotypic and Molecular Characterization of Antimicrobial Resistance of Salmonella Isolates from Food in Tunisia

HIGHLIGHTS

Multidrug-resistant Salmonella isolates have been recovered from food in Tunisia. Salmonella isolates from food are resistant to fluoroquinolones and cephalosporins. Surveillance of the antimicrobial susceptibility of foodborne bacteria is needed in Tunisia.

Salmonellosis: Serotypes, prevalence and multi-drug resistant profiles of Salmonella enterica in selected poultry farms, Kwara State, North Central Nigeria

Salmonellosis is a major threat facing the poultry industry globally. This study was conducted to investigate the level of Salmonella contaminations and determine the resistance pattern of isolates obtained from selected poultry farms in Kwara State, a transition state between southern and northern regions of Nigeria. A total of 900 samples were collected between January and August 2017, from the poultry environment, apparently including healthy and dead birds. Salmonella was isolated and identified using standard bacteriological methods. All presumptive Salmonella isolates were serotyped and tested for antimicrobial susceptibility using 11 different antimicrobials. A total of 58 (6.4%) Salmonella isolates were obtained, and the isolation rate was only statistically significant (p < 0.05) in live birds. The isolates comprised of 13 serovars. The three predominant serovars, Salmonella enterica ser. 6.7:d:- (29.0%), Salmonella Agama (28.0%) and Salmonella Typhimurium (16.0%), were isolated from all three sample types. Rare serovars like Salmonella Albany, Salmonella Colindale, Salmonella Istanbul, Salmonella Larochelle, Salmonella Nigeria and Salmonella Orion were also isolated in this study. A high frequency of resistance was generally observed with all the isolates exhibiting a total of (100%) resistance to ampicillin, cefotaxime and ceftazidime. This study documents the first predominant isolation of S. enterica ser. 6.7:d:- and S. Agama from chickens. It also documents the high frequency of fluoroquinolone and cephalosporins resistance of the isolates indicating the presence of selective pressure in the environment. Controls and targeted interventions against Salmonella and the frequent occurrence of antimicrobial resistance in chickens should be initiated to prevent the spread of this organism.

Detection of invA gene of Salmonella from milkfish (Chanos chanos) at Sidoarjo wet fish market, Indonesia, using polymerase chain reaction technique

Aim:

The study aimed to detect the invA gene in Salmonella isolated from milkfish in the Sidoarjo wet fish market.

Materials and Methods:

A total of 84 samples were prepared in enrichment media and isolated on the surface of Salmonella Shigella Agar. Salmonella growth produces transparent colonies with blackish color in the middle due to H₂S gas formation. Samples were identified as Salmonella based on macroscopic colony morphology. Presumptive Salmonella sp. was put on Bismuth Sulfite Agar media. Salmonella was determined based on the results of the biochemical test that has been carried out using Microbact identification kits from negative gram staining.

Results:

The results of this study indicate that 32 of 84 samples (38.09%) were Salmonella bacteria. Furthermore, the invA gene detection was carried out using the polymerase chain reaction technique. Electrophoresis results showed four positive samples contained invA gene with a length of 284 bp.

Conclusion:

Results in this study indicate that contamination of milkfish with Salmonella needs strict hygienic measures to prevent their transmission to human.

Prevalence and serotypes of Salmonella spp. on chickens sold at retail outlets in Trinidad

BACKGROUND

This cross-sectional study determined the prevalence of Salmonella spp. and their serotypes on dressed chicken sold at retail outlets in Trinidad. The study also investigated the risk factors for contamination of dressed carcasses by Salmonella spp. at cottage poultry processor outlets where chickens are slaughtered and processed for sale.

METHODS

A total of 133 dressed, whole chickens and 87 chicken parts from 44 cottage poultry processors and 36 dressed, whole chickens and 194 chicken parts from 46 supermarket outlets were randomly collected throughout the country. Isolation and identification of Salmonella spp. were performed using standard bacteriological techniques. Serotyping was performed by a regional reference laboratory.

RESULTS

The prevalence of Salmonella spp. in chicken carcasses sampled from cottage poultry processors and supermarkets was 20.5% and 8.3% respectively (p <0.001). The frequency of isolation of Salmonella spp. at cottage poultry processors was 22.4%, 23.0%, 7.1%, and 10.0% for non-chilled whole chicken, non-chilled chicken parts, chilled whole chicken and chilled chicken parts respectively. Fresh, non-chilled chicken (22.6%) yielded a higher frequency of isolation of Salmonella spp. than chilled chickens (8.3%). For supermarket samples, the frequency of isolation of Salmonella spp. was 19.0%, 8.1%, 0.0% and 7.6% for chilled whole chickens, chill chicken parts, frozen whole chicken and frozen chicken parts respectively. The swab method of sampling yielded a statistically significantly (p = 0.029) higher frequency (3.2%) of Salmonella spp. than the rinse method (1.6%). The predominant serotypes isolated were Kentucky (30.9%) and Javiana (22.7%). Use of chilled water-bath to cool carcasses was the only risk factor significantly (p = 0.044) associated with isolation of Salmonella spp.

CONCLUSION

Raw chicken carcasses purchased from cottage poultry processors pose a significantly higher risk of contamination with Salmonella spp. than those sold at supermarkets.

The study of effect of didecyl dimethyl ammonium bromide on bacterial and viral decontamination for biosecurity in the animal farm

Aim:

The aim of this study was to determine the effectiveness of the fourth-generation quaternary ammonium compounds, didecyl dimethyl ammonium bromide (DDAB), on the efficacy of bacterial and viral decontamination against pathogens commonly found in livestock industry including Salmonella infantis (SI), Escherichia coli, and avian influenza virus (AIV).

Materials and Methods:

The DDAB was prepared at 500, 250, and 125 parts per million (ppm) for absent and present organic material. Meanwhile, 5% of fetal bovine serum in DDAB solution sample was used to mimic the presence of organic material contamination. 400 µl of each DDAB concentration was mixed with 100 µl of each pathogen (SI, E. coli, and AIV) and then incubated at room temperature or 4°C at various time points (5 s, 30 s, 1 min, 5 min, 10 min, 15 min, and 30 min). The activity of DDAB treatment was stopped using 500 µl of FBS. Each treatment sample was titrated on either deoxycholate hydrogen sulfide lactose agar plates or Madin-Darby canine kidney cells for bacteria and AIV, respectively. Each treatment was conducted in triplicates, and the pathogen inactivation was considered effective when the reduction factor was ≥3 log₁₀.

Results:

Our current study revealed that the DDAB inactivated SI, E. coli, and AIV under the various concentrations of DDAB, organic material conditions, exposure temperature, and exposure timing. In addition, the comparison of bactericidal and virucidal efficacy indicated that bacteria were more susceptible to be inactivated by DDAB as compared to viruses. However, DDAB showed marked inactivated differences in the absence or presence of organic materials.

Conclusions:

The DDAB may be a potential disinfectant for inactivating bacteria and viruses, especially enveloped viruses, in livestock farms. It can be useful as a disinfectant for biosecurity enhancement on and around animal farm.