Evaluation of the different methods to detect Salmonella in poultry feces samples

Aptamer-modified paper-based analytical devices for the detection of food hazards: Emerging applications and future perspective

Food analysis plays a critical role in assessing human health risks and monitoring food quality and safety. Currently, there is a pressing need for a reliable, portable, and quick recognition element for point-of-care testing (POCT) to better serve the demands of on-site food analysis. Aptamer-modified paper-based analytical devices (Apt-PADs) have excellent characteristics of high portability, high sensitivity, high specificity, and on-site detection, which have been widely used and concerned in the field of food safety. The article reviews the basic components and working principles of Apt-PADs, and introduces their representative applications detecting food hazards. Finally, the advantages, challenges, and future directions of Apt-PADs-based sensing performance are discussed, to provide new directions and insights for researchers to select appropriate Apt-PADs according to specific applications.

Occurrence and distribution of Salmonella serovars associated with human infection isolated from irrigation waters and food-producing animals in southern Italy: eleven-year monitoring (2011-2021)

Salmonella is one of the main zoonotic agents causing foodborne diseases in Europe. The main reservoirs of the infection are represented by domestic and wild animals, and the infection occurs by direct contact or following the consumption of contaminated food or water. The study aimed to evaluate the presence of Salmonella spp. in food-producing animals and irrigation waters in southern Italy and the serovar distribution. From 2011 to 2021, a total of 473 samples from 6 different animal species (bovine, buffalo, goat, ovine, swine, poultry, and wild boars) and 313 irrigation water samples were collected and analyzed. The overall percentage of positive samples was 56.87% in organs, 50.85% in feces, and 20.45% in irrigation waters. By animal species, the most frequently detected serovar was Salmonella Typhimurium in bovine (17.39%), in buffalo (13.10%) and swine (28.21%), and S. Kentucky (24.78%) in poultry. The subspecies diarizonaeIIIb was frequently detected in goats (40.00%) and ovine (83.33%), while salamaeII (14.12%) and diarizonaeIIIb (11.76%) were frequently isolated in wild boars. In the irrigation water samples, the most frequently detected serovar was S. Napoli (25%). Results revealed that, although in Europe, control strategies aimed at preventing the spread of Salmonella have been implemented, the prevalence of this pathogen in food-producing animals and irrigation waters is high. Considering the risk to public health associated with the contamination of products or foods, more stringent control interventions are needed at primary production and along the food chain.

Prevalence of Salmonella infection in village chickens and determination of the tetracycline resistance genes in the Salmonella isolates in the Sistan region, Iran

Recently, an increasing number of multi drug resistant Salmonella species have been emerged due to overuse of antibiotics in veterinary and human medicine which has adverse consequences on public health. The present study was conducted with the aim of investigating the prevalence of Salmonella infection in village chickens in Sistan region and determining the prevalence of the antibiotic resistance genes in Salmonella isolated from these birds. In this study, 100 chickens were randomly selected from five counties of Sistan region. A cloacal swab sample was taken from each bird and also information about age, gender, breed, proximity with other birds, proximity with waterfowl, proximity with livestock, and receiving different antibiotics especially tetracycline were obtained using a questionnaire. Conventional culture methods used for Salmonella detection and isolation. Then, amplification of invA gene by PCR was used to confirm Salmonella colonies. Finally, 27 samples were confirmed to be infected with Salmonella by both culture and PCR methods. Disk diffusion method was used to determine the sensitivity to 4 antibiotics including; tetracycline, gentamicin, cefepime, and difloxacin. The results of the present study showed that proximity to waterfowl (OR = 0.273) significantly mitigates the risk of Salmonella infection. For the isolates, the highest resistance was recorded against cefepime and the highest susceptibility was to difloxacin. The presence proportion of tetA and tetB in tetracycline resistant isolates was higher than that in susceptible ones but this difference was not statistically significant.

One-Pot Synthesis of Enzyme and Antibody/CaHPO4 Nanoflowers for Magnetic Chemiluminescence Immunoassay of Salmonella enteritidis

In this study, through a bioinspired strategy, the horseradish peroxidase (HRP) and antibody (Ab) were co-embedded into CaHPO₄ to prepare HRP-Ab-CaHPO₄ (HAC) bifunctional hybrid nanoflowers by one-pot mild coprecipitation. The as-prepared HAC hybrid nanoflowers then were utilized as the signal tag in a magnetic chemiluminescence immunoassay for application in the detection of Salmonella enteritidis (S. enteritidis). The proposed method exhibited excellent detection performance in the linear range of 10-10⁵ CFU/mL, with the limit of detection (LOD) of 10 CFU/mL. This study indicates great potential in the sensitive detection of foodborne pathogenic bacteria in milk with this new magnetic chemiluminescence biosensing platform.