Search

Phage viruses shape the evolution and virulence of their bacterial hosts. The Salmonella enterica genome encodes several stress-inducible prophages. The Gifsy-1 prophage terminase protein, whose canonical function is to process phage DNA for packaging in the virus head, unexpectedly acts as a transfer ribonuclease (tRNase) under oxidative stress, cleaving the anticodon loop of tRNALeu. The ensuing RNA fragmentation compromises bacterial translation, intracellular survival, and recovery from oxidative stress in the vertebrate host. S. enterica adapts to this transfer RNA (tRNA) fragmentation by transcribing the RNA repair Rtc system. The counterintuitive translational arrest provided by tRNA cleavage may subvert prophage mobilization and give the host an opportunity for repair as a way of maintaining bacterial genome integrity and ultimately survival in animals.

The incidence of antimicrobial resistance (AMR) in the environment is often overlooked and leads to serious health threats under the One Health paradigm. Infection with extended-spectrum β-lactamase (ESBL) producing bacteria in humans and animals has been widely examined, with the mode of transmission routes such as food, water, and contact with a contaminated environment. The purpose of this study was to determine the occurrence and molecular characteristics of resistant Salmonella enterica (S. enterica) (n = 59) and Escherichia coli (E. coli) (n = 392) isolated from produce commodities collected from fresh markets and supermarkets in Bangkok, Thailand. In this study, the S. enterica isolates exhibited the highest prevalence of resistance to tetracycline (11.9%) and streptomycin (8.5%), while the E. coli isolates were predominantly resistant to tetracycline (22.5%), ampicillin (21.4%), and sulfamethoxazole (11.5%). Among isolates of S. enterica (6.8%) and E. coli (15.3%) were determined as multidrug resistant (MDR). The prevalence of ESBL-producing isolates was 5.1% and 1.0% in S. enterica and E. coli, respectively. A minority of S. enterica isolates, where a single isolate exclusively carried blaCTX-M-55 (n = 1), and another isolate harbored both blaCTX-M-55 and blaTEM-1 (n = 1); similarly, a minority of E. coli isolates contained blaCTX-M-55 (n = 2) and blaCTX-M-15 (n = 1). QnrS (11.9%) and blaTEM (20.2%) were the most common resistant genes found in S. enterica and E. coli, respectively. Nine isolates resistant to ciprofloxacin contained point mutations in gyrA and parC. In addition, the odds of resistance to tetracycline among isolates of S. enterica were positively associated with the co-occurrence of ampicillin resistance and the presence of tetB (P = 0.001), while the E. coli isolates were positively associated with ampicillin resistance, streptomycin resistance, and the presence of tetA (P

Wild birds pose unique food-safety risks to agriculture as they may carry multiple zoonotic pathogens, are difficult to exclude, and most are federally protected. As a result, the fresh produce industry regularly expresses concerns about these risks, and growers are sometimes instructed to not harvest crops around wild bird feces, potentially causing yield reductions and food waste. Farmers thus have financial incentives to reduce bird fecal contamination on their crops. However, existing bird deterrent methods can be expensive, have significant deleterious conservation implications, and/or are often ineffective. Thus, it is imperative to develop a holistic understanding of the true food-safety risks associated with wild bird communities and to inform growers and industry professionals about which birds, if any, represent substantive food safety concerns. Here, we evaluate the food-safety risks of wild birds, from the point of entering farms through harvest of the crop via three complementary approaches.

Genetic screening of pools of mutants can reveal genetic determinants involved in complex biological interactions, processes, and systems. We previously constructed two single-gene deletion resources for Salmonella enterica serovar Typhimurium 14028s in which kanamycin (KanR) and chloramphenicol (CamR) cassettes were used to replace non-essential genes. We have now used lambda-red recombination to convert the antibiotic cassettes in these resources into a tetracycline-resistant (TetR) version where each mutant contains a different 21-base barcode flanked by Illumina Read1 and Read2 primer sequences. A motility assay of a pool of the entire library, followed by a single-tube processing of the bacterial pellet, PCR, and sequencing, was used to verify the performance of the barcoded TetR collection. The new resource is useful for experiments with defined subsets of barcoded mutant strains where biological bottlenecks preclude high numbers of founder bacteria, such as in animal infections. The TetR version of the library will also facilitate the construction of triple mutants by transduction. The resource of 6197 mutants covering 3490 genes is deposited at Biological and Emerging Infections Resources (beiresources.org).

Background: In the context of pathogen surveillance, it is crucial to ensure interoperability and harmonized data. Several surveillance systems are designed to compare bacteria and identify outbreak clusters based on core genome MultiLocus Sequence Typing (cgMLST). Among the different approaches available to generate bacterial cgMLST, our research used an assembly-based approach (chewBBACA tool). Methods: Simulations of short-read sequencing were conducted for 5 genomes of 27 pathogens of interest in animal, plant, and human health to evaluate the repeatability and reproducibility of cgMLST. Various quality parameters, such as read quality and depth of sequencing were applied, and several read simulations and genome assemblies were repeated using three tools: SPAdes, Unicycler and Shovill. In vitro sequencing were also used to evaluate assembly impact on cgMLST results, for six bacterial species: Bacillus thuringiensis, Listeria monocytogenes, Salmonella enterica, Staphylococcus aureus, Vibrio parahaemolyticus and Xylella fastidiosa. Results: The results highlighted variability in cgMLST, which not only related to the assembly tools, but also induced by the intrinsic composition of the genomes themselves. This variability observed in simulated sequencing was further validated with real data for six of the bacterial pathogens studied. Conclusion: This highlights that the intrinsic genome composition affects assembly and resulting cgMLST profiles, and that variability in bioinformatics tools can induce a bias in cgMLST profiles. In conclusion, we propose that the completeness of cgMLST schemes should be considered when clustering strains. [ABSTRACT FROM AUTHOR]

1. Loop-mediated isothermal amplification (LAMP) assays were developed to detect Salmonella enterica subspecies enterica serotypes Enteritidis and Heidelberg in poultry farms. These serotype-specific methods were evaluated in comparison with PCR in the analysis of different Salmonella spp. serotypes from a culture collection and poultry farm samples.2. The results demonstrated the specific amplification of the genetic targets safA in all S. Enteritidis (n = 10) and ACF69659 in all S. Heidelberg (n = 36) isolates from the culture collection. The remaining isolates from other Salmonella spp. serotypes (n = 84) and bacterial species (n = 8) were negative in both LAMP assays.3. The methods detected DNAs from S. Enteritidis and S. Heidelberg after a single-step pre-enrichment in buffered peptone water of the poultry samples, which agreed with previously developed PCR methods to detect these same two serotypes.4. In conclusion, LAMP assays were useful for rapid serotype-specific detection, being suitable for surveillance purposes in resource-limited environments such as poultry farms. [ABSTRACT FROM AUTHOR]

Background: Typhoid fever remains a significant public health problem contributing to significant misapplication of antibiotics in Ghana. However, there is little data on the accuracy of the commonly used serology based rapid diagnostic Typhidot test kit (Typhidot RDT) for confirming typhoid fever. Methods: We conducted a study to assess the diagnostic accuracy of Typhidot RDT in seven clinical facilities across five regions in Southern Ghana. A total of 258 participants, clinically diagnosed with typhoid fever, were enrolled in this study. Blood and stool samples were obtained for culture, Typhidot and PCR assays. Disc diffusion antibiotic sensitivity was performed to determine the resistance pattern of Salmonella enterica isolates from positive blood and stool cultures. Results: Recovery of S. enterica isolates was higher from stool samples (14.7%) in comparison to blood samples (1.6%). The sensitivity and specificity of Typhidot compared to blood and stool cultures was 35% (19.94%—52.65%) and 45% (38.67%—51.45%), respectively. Compared to PCR, the Typhidot had a sensitivity and a specificity of 61% and 53%, respectively. Resistance phenotyping of isolates showed broad sensitivity to the front-line antibiotics used. Resistance to ampicillin (10%), cotrimoxazole (7%), azithromycin and ciprofloxacin (< 5%) was found in some isolates. Conclusions: These findings suggest sub-optimal performance of the Typhidot RDT for diagnosis of typhoid in Ghana with a higher chance for misdiagnosis and misapplication of antibiotics. The high proportion of isolates recovered from stool culture is consistent with the pathophysiology of bacterial shedding during the acute phase of infection, which provides a window of opportunity to control typhoid transmission. [ABSTRACT FROM AUTHOR]

Introduction: Miang is one of the post-fermented teas made in Northern Thailand. Although lactic acid bacteria are involved in fermentation of Miang, details are still not clear. This study investigated the diversity of Lactobacillaceae bacteria, related to fermentation of Miang. Probiotic potential of isolated Lactobacillaceae bacteria was examined. Methods: Lactobacillaceae bacteria were isolated from 52 Miang samples collected from three provinces in northern Thailand and identified by MALDI-TOF MS. Hemolytic activity, antibiotic susceptibility, antimicrobial activity and tolerance to gastrointestinal juice were examined for probiotic potential of isolates. Results: A total of 1,181 Lactobacillaceae bacteria strains were isolated from Miang. The most abundant isolates were Lactiplantibacillus pentosus. Besides Lactiplantibacillus plantarum , Levilactobacillus brevis , Paucilactobacillus suebicus , Lacticaseibacillus pantheris , and Secundilactobacillus collinoides were also found with frequency. Of these isolates, 450 with a high score for MALDI-TOF identification were then screened for probiotic ability. Most isolates were resistant to aminoglycosides and clindamycin. Then, 35 isolates were tested for their antimicrobial activity against pathogens using the well diffusion method, and 31 isolates exhibited inhibition zones against Staphylococcus aureus , Staphylococcus epidermidis , Salmonella enterica serovar Typhimurium, S. enterica serovar Enteritidis, Listeria monocytogenes , Propionibacterium acnes , and Streptococcus mutans. All 31 isolates were non-hemolytic and readily tolerated simulated gastric juice at pH 3 and simulated intestinal juice at pH 8. Discussion: Miang contains lactic acid bacteria that could potentially be used as probiotics. [ABSTRACT FROM AUTHOR]

A unique species of pine, Cedrus deodara is known for its wood oil. Its traditional therapeutic use is mainly antibacterial and anti-inflammatory. The aim of this study was to investigate the antibacterial properties of Cedrus deodara essential oil (CDEO) obtained from the crushed wood. The antimicrobial activity of CDEO was evaluated against Gram-negative (G-) bacteria which included Pseudomonas aeruginosa CCM 1595, Salmonella enterica subs. enterica CCM 3807 and Gram-positive (G+) bacteria Yersinia enterocolitica CCM 5671. Listeria monocytogenes CCM 4699, Staphylococcus aureus subs. aureus CCM 2461 and Streptococcus consellatus CCM 4043 in vitro and in situ. The best antimicrobial activity for the disc diffusion method ranged from 4.67 to 9.67 mm and the minimum inhibitory concentration ranged from 1.48 to 5.44 mg.mL-1. The most effective antimicrobial effect was found against S. aureus and L. monocytogenes. The vapour phase used showed the best antimicrobial effect against P. aeruginosa in the kiwifruit model and L. monocytogenes in the banana model at a lower CDEO concentration of 62.5 µg.L-1 and against P. aeruginosa in the potato model and Y. enterocolitica in the cucumber model at a higher CDEO concentration of 500 µg.L-1. CDEO showed good antimicrobial activity against bacteria on vegetable and fruit model and may be a new preservative for storage of vegetables and fruits. [ABSTRACT FROM AUTHOR]

Salmonella enterica subspecies enterica serovar Choleraesuis (S. Choleraesuis) is a nontyphoidal Salmonella pathogen that causes swine paratyphoids. S. Choleraesuis is a zoonotic pathogen transmitted to humans via contaminated food and causes sepsis. Here, we report a rare case of pyelonephritis caused by S. Choleraesuis in a Japanese patient with a carcinoma of unknown primary origin. On the day of admission, the patient was diagnosed with pyelonephritis associated with ureteral stent obstruction. He had no history of raw pork consumption or gastrointestinal symptoms. Gram-negative rods were isolated from urine and blood cultures, identified as Salmonella enterica subsp. enterica using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The serological typing results were O7: -: 1 and 5; however, the serotypes could not be determined. The isolate was identified as S. Choleraesuis using multilocus sequence typing, nucleotide sequence analysis of the fliC gene, and biochemical examination. Four days after a 14-day course of intravenous piperacillin-tazobactam (9 g/day), the patient showed relapse of the condition. Subsequently, the patient was treated with intravenous ceftriaxone (2 g/day) and oral amoxicillin (1000 mg/day) for 14 days each; recurrence was not observed. This novel case of pyelonephritis with bacteremia was caused by S. Choleraesuis in Japan. Conventional testing methods could not identify the serotypes; however, the case highlights the importance of adopting advanced diagnostic techniques based on molecular biology to ensure accurate pathogen identification. [ABSTRACT FROM AUTHOR]

The European Union (EU) regulations mandate 10% of all food packaging to be reusable by 2030. United States (U.S.) exporters of specialty crops face new challenges in ensuring microbiological food safety using reusable packaging. A novel antimicrobial formulation consisting of ammonium carboxylate salt of capric acid and L-arginine (GS-2) was recently developed as a spray coating chemical for food packaging materials. In this study, we evaluated the antimicrobial efficacy of GS-2 against microbial strains representing three foodborne bacterial pathogens (Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica), one fungal spoilage organism (Aspergillus niger), and one surrogate viral pathogen (murine norovirus) on three reusable plastic materials (acrylonitrile butadiene styrene, high-density polyethylene, and polypropylene) and one cardboard packaging material, respectively. Different chemical concentrations, exposure times, and storage conditions were individually evaluated for the relative antimicrobial efficacies of GS-2 against these microorganisms. Our results showed that GS-2 was highly effective for inactivating bacterial pathogens on both plastic and cardboard surfaces. For instance, 3% GS-2 achieved a >5 log CFU/in2 reduction in E. coli O157:H7, L. monocytogenes, and S. enterica on tested plastic surfaces at an exposure time of 60 min. However, its efficacy against A. niger and murine norovirus was less optimal, resulting in a ≤1 log CFU/in2 reduction on all tested surfaces. Based on our study, GS-2 demonstrated a strong potential as an antibacterial coating reagent for reusable food packaging materials to minimize pathogen contamination and ensure the safety of the specialty crops. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Agona (S. Agona) has been increasingly recognised as a prominent cause of gastroenteritis. This serovar is a strong biofilm former that can undergo genome rearrangement and enter a viable but non-culturable state whilst remaining metabolically active. Similar strategies are employed by S. Typhi, the cause of typhoid fever, during human infection, which are believed to assist with the transition from acute infection to chronic carriage. Here we report S. Agona's ability to persist in people and examine factors that might be contributing to chronic carriage. A review of 2233 S. Agona isolates from UK infections (2004–2020) and associated carriage was undertaken, in which 1155 had short-read sequencing data available. A subset of 207 isolates was selected from different stages of acute and persistent infections within individual patients. The subset underwent long-read sequencing and genome structure (GS) analysis, as well as phenotyping assays including carbon source utilisation and biofilm formation. Associations between genotypes and phenotypes were investigated to compare acute infections to those which progress to chronic. GS analysis revealed the conserved arrangement GS1.0 in 195 isolates, and 8 additional GSs in 12 isolates. These rearranged isolates were typically associated with early, convalescent carriage (3 weeks– 3 months). We also identified an increase in SNP variation during this period of infection. We believe this increase in genome-scale and SNP variation reflects a population expansion after acute S. Agona infection, potentially reflecting an immune evasion mechanism which enables persistent infection to become established. Author summary: The persistence of non-typhoidal Salmonella following acute gastroenteritis is a significant challenge for public health but the causes that lead to such chronic infections are understudied. This study aimed to investigate the ability of Salmonella Agona (S. Agona), the fourth most common non-typhoidal Salmonella serovar in the UK, to persist in humans and transition from acute illness to chronic infection. A phylogenomic analysis of 2233 S. Agona isolates (from all reported UK infections during 2004 to 2020) revealed there were no specific lineages that were responsible for persistent infection. A subset of 207 isolates underwent genotype and phenotypic analysis to explore within-patient changes and compare acute infections to those which progress to chronic. Key findings revealed increases in single nucleotide polymorphism and genomic structure variation during the early stages of persistent infection, indicating either population expansion after acute infection or a population bottleneck during transition to persistent infection. [ABSTRACT FROM AUTHOR]

Salmonella enterica ser. Typhimurium is a common pathogen that poses a considerable public health threat, contributing to severe gastrointestinal diseases and widespread foodborne illnesses. The virulence of S. Typhimurium is regulated by quorum sensing (QS) and the type III secretion system (T3SS). This study investigated the inhibitory effects and anti-QS activity of epigallocatechin gallate (EGCG), which is a bioactive ingredient found in green tea, on the virulence of S. Typhimurium. In vitro bacterial experiments demonstrated that EGCG inhibited the production of autoinducers, biofilm formation, and flagellar activity by downregulating the expression of AI-1, AI-2, Salmonella pathogenicity islands (SPI)-1, SPI-2, and genes related to flagella, fimbriae, and curli fibers. In a mouse model of S. Typhimurium-induced enteritis, EGCG considerably reduced intestinal colonization by S. Typhimurium and alleviated intestinal damage. In conclusion, EGCG protects the intestines of mice infected with S. Typhimurium by inhibiting QS-induced virulence gene expression, demonstrating its potential as a therapeutic agent for controlling S. Typhimurium infections. [ABSTRACT FROM AUTHOR]

Multidrug resistance (MDR) considered as global crisis facing poultry industry. Migratory birds play very important role in the dissemination of antimicrobial resistant pathogen during their fly way specially to poultry farms. Therefore, 750 samples from migratory birds and 300 samples from broiler chicken farms and its environment were collected during the winter seasons of five years (2019 to 2023). The samples were subjected to the isolation of Salmonella enterica and Escherichia coli with the detection of antimicrobial resistance (phenotypic and genotypic) with insight to the genetic similarity between the isolates from migratory birds and broiler chickens' farms. Different members of Enterobacteriaceae were isolated; Salmonella enterica, Escherichia coli, Citrobacter, Enterobacter, Klebsiella, Proteus, Providencia, Serratia, Hafnia. 298 (28.4%) of S. enterica strains belonging to 27 serovars. S. Typhimurium, S. Kentucky, S. Enteritidis and S. Shangani were the common 4 serotypes between migratory birds and farms. Meanwhile, we found 489 (46.6%) isolates of E. coli belonging to 24 serogroups and O91, O128, O26, O125, O55, O103 and O159 were the common 7serogroups between migratory birds and farms samples. The majority of Salmonella (91.6%; 274 out of 298) and E. coli (92%; 450 out of 489) were MDR. The MDRI range of Salmonella and E. coli was 0.08- 1.The genetic similarity between the isolates of migratory birds and broiler chicken farms were detected by ERICPCR and hot map. This study suggests the continuous applications of surveillance programs for migratory birds and biosecurity measures in poultry farms. [ABSTRACT FROM AUTHOR]

Non-typhoidal Salmonella (NTS) is one of the top causes of diarrhea worldwide. Ceftriaxone is commonly recommended as the initial treatment option for Salmonella infections due to its antibacterial effectiveness. The objective of this study was to investigate the molecular epidemiological characteristics of NTS and to compare the phenotypic and genotypic profiles of antimicrobial resistance in multidrug-resistant Salmonella strains by sequencing 329 NTS strains collected from a county-level hospital between 2018 and 2021. Multi-locus sequence typing (MLST), antimicrobial resistance genes and plasmid types were identified by BacWGSTdb 2.0 webserver. Phylogenetic analysis of all NTS strains was carried out using Snippy and Gubbins software. The transferability of ceftriaxone resistant plasmids was confirmed through plasmid conjugation assays, and verified by S1-PFGE-Southern blot assays. The predominant serotypes among all NTS strains were Typhimurium (161/329), Enteritidis (49/329) and London (45/329). The most common sequence type observed was ST34 (86/329), followed by ST19 (72/329) and ST11 (47/329). The antimicrobial resistance of Salmonella to a wide range of antimicrobials showed an overall increase. Out of these 37 (11.24%) ceftriaxone-resistant strains, with the majority of them (33/37) being blaCTX−M. The predominant plasmid types identified were IncHI2 (14/21) and IncI1 (6/21), ranging in size from 70 kb to 360 kb. The conjugation efficiency was calculated with the high conjugation efficiency of 1.1 × 10− 5 to 9.3 × 10− 2. The strains varied widely, ranging from 3 to 45,024 single nucleotide polymorphisms (SNPs). There are close linkages observed among the predominant lineage, with an average of 78 SNPs between each pair of ST34 strains. The findings contribute to our understanding of the transmission and resistance mechanisms of multidrug-resistant Salmonella, thereby facilitating the development of effective control strategies. [ABSTRACT FROM AUTHOR]

The Chilean Technical Manual for Milk Dietary Service (SEDILE) was evaluated to determine its effectiveness in ensuring the microbiological safety and vitamin D adequacy of a commercially available powdered infant formula (PIF) used in SEDILE. The evaluation focused on whether adherence to the manual's guidelines positively influenced these factors. Both the PIF and the reconstituted PIF (RIF) were found to be free from Cronobacter sakazakii and Salmonella enterica contamination, with levels of total coliforms and Escherichia coli within acceptable limits. Moreover, the vitamin D content in the formula was within the expected range. These findings suggest that following the Chilean Technical Manual for SEDILE contributes to the microbiological safety and nutritional adequacy of RIF in dietary services. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Gallinarum (S. Gallinarum) is an avian-specific pathogen responsible for fowl typhoid, a severe systemic disease with high mortality in chickens. This disease poses a substantial burden to the poultry industry, particularly in developing countries like China. However, comprehensive genome datasets on S. Gallinarum are lacking. Here, we present the most extensive S. Gallinarum genome dataset, comprising 574 well-collated samples. This dataset consists of 366 genomes sequenced in our laboratory and 208 publicly available genomes, collected from various continents over the past century. Using in silico prediction, we categorized S. Gallinarum into three distinct biovars. Regarding antimicrobial resistance, 238 strains (41.5%) carried antimicrobial resistance genes (ARGs) with a total of 635 records, while 232 strains (40.4%) exhibited multi-drug resistance. Mobile genomic elements (MGEs) serve as critical drivers for ARGs. Our dataset includes 5,636 MGEs records, with most MGEs belonging to prophages and plasmids. This dataset expands our understanding of the genomic characteristics of S. Gallinarum, providing valuable resources for future genomic studies to improve disease management. [ABSTRACT FROM AUTHOR]

This study evaluated the biological characteristics of seaweeds Turbinaria ornata, Ulva lactuca, and Gracilaria crassa. Among the seaweeds tested, ethyl acetate extract of Ulva lactuca exhibited the highest antibacterial activity against Salmonella enterica, Staphylococcus aureus, and Pseudomonas aeruginosa. The phytochemical analysis of ULME and ULEA showed the presence of most of the tested phytochemicals, whereas only amino acids, tannins, glycosides, and carbohydrates were detected by ULHE. The DPPH scavenging property of U. lactuca exerted the maximum antioxidant property of 62.54% (ULME), 75.64% (ULEA), and 39.55% (ULHE), whereas the alpha amylase inhibitory property (µg/mL) of ULME, ULEA, and ULHE was, respectively, 80.99, 51.15, and 49.23. ULME, ULEA, and ULHE exhibited the greatest alpha-glucosidase inhibition, with IC50 values (g/mL) of 116.12, 45.59, and 170.10 correspondingly. ULEA also showed potent mosquito-larvicidal effects against Aedes aegypti larvae with the maximum lethal concentration values with LC50 and LC90 values (mg/mL) being 11.55 and 65.97, respectively. FTIR analysis of ULME, ULHE, and ULEA were found to have various functional groups, including alkanes, carboxylic acids, alkenes, alkynes, aldehydes, amides and alkanes, ketones, and aromatics, while HPLC revealed a strong peak at 4.760 retention time. In conclusion, Ulva lactuca, particularly its ethyl acetate extract, demonstrates significant antibacterial, antioxidant, and enzyme-inhibitory properties, highlighting its therapeutic and biotechnological potential. Its diverse phytochemicals and effective mosquito-larvicidal activity further support its broad application prospects. [ABSTRACT FROM AUTHOR]

This study developed a postbiotic fermentation solution for fresh oyster preservation with the use of food waste soy whey. Lactiplantibacillus plantarum 299V was able to proliferate in soy whey within 24 h without any supplementation. Pacific oysters (Magallana gigas) were immersed in the postbiotic fermentation solution and stored at 4 °C for 12 days. Pathogenic bacteria Vibrio parahaemolyticus and Salmonella enterica introduced by bioaccumulation were suppressed to levels below the detection limit (<2 log CFU/g) within 4 days. The spoilage-related microbial parameters and chemical parameters were maintained at low levels across the 12 days. Sensory evaluation revealed that the product had a positive effect on most of the participants (>60%). Overall, the postbiotic fermentation solution reported in this study enhanced the shelf life and safety of oysters in a sustainable way and could also be recognized as an innovative probiotic vehicle with potential implications for human health promotion. [ABSTRACT FROM AUTHOR]

Swine paratyphoid infection is caused by the swine-adapted Salmonella enterica serovar Choleraesuis. Infected individuals remain healthy carriers, and if the infection occurs at the end of the fattening period, it could pose a threat to human health. The present work aimed to assess antimicrobial susceptibility of S. enterica serovar Choleraesuis serotypes isolated from domestic pigs in central-western Albania, and to assess the presence and circulation of antibiotic-resistant paratyphoid Salmonella in Albania. Increasing mortality was reported in 6 farrow-to-finish pig farms located in the western and central parts of the country from December 2022 to April 2023. Post-mortem examination revealed macroscopic lesions in different organs indicating Salmonella infection. Four serovars Choleraesuis were isolated out of 24 different Salmonella spp. Multi-drug resistance (MDR), extensively drug-resistant (XDR), and Pan Drug Resistance (PDR) was calculated. Three out of four isolates showed MDR, and one out of four showed XDR. All S. enterica serovar Choleraesuis isolates showed resistance to at least two antimicrobials. Three isolates were observed to display MAR index values >0.2 indicating high-risk contaminated sources with frequent use of antibiotics. The predominant antimicrobial resistance was observed for amoxicillin, oxytetracycline, sulfamethoxazole, trimethoprim, spiramycin, colistin sulpha, and doxycycline. The findings emphasize the importance of strict biosecurity measures in affected pig farms, and prevention and control of S. enterica serovar Choleraesuis in the farm sanitary programs in Albania. [ABSTRACT FROM AUTHOR]

Incidence of foodborne illness due to bacterial contamination of fresh produce continue to exist despite continuous research on processing interventions to mitigate the problem. In this study, we combined atmospheric cold plasma treatments with an antimicrobial solution containing specific organic acids generally recognized as safe (GRAS) by the FDA and tested its antimicrobial efficacy against Salmonella enterica inoculated on tomato surfaces. Tomato surfaces were inoculated with at 5.6 log CFU/g of Salmonella by spotting 0.1 mL of 7 log CFU/ml Salmonella onto the tomato stem scars, and by dipping whole tomatoes into a solution of 7 log CFU/ml Salmonella for 3 min to achieve 4.1 log CFU/g. Antimicrobial efficacy of the organic acid‐based sanitizer + cold plasma treatments for 30, 60, 120, 180, and 360 s, were investigated, and significant bacterial inactivation was achieved above 120 s treatments. At 120 s, surviving populations of aerobic mesophilic bacteria recovered on the tomatoes surfaces averaged < 2 logs/g while yeast and mold survival averaged < 1 CFU/g. Treatment combination with this organic acid‐based sanitizer + cold plasma for 120 s resulted in a 4.9 log reduction of Salmonella on the stem scar area and a 3.9 log reduction on the smooth peel surface. Similarly, populations of aerobic mesophilic bacteria recovered on treated tomato surfaces averaged < 0.3 log CFU/g. The results of this study indicate that combining an organic acid‐based sanitizer with cold plasma treatments for ≥ 120 s can inactivates significant populations of Salmonella to enhance the microbial safety of tomato surfaces designated for fresh‐cut salad. [ABSTRACT FROM AUTHOR]

Sprouts are popular due to their high nutritional content, including vitamins, minerals, antioxidants, and enzymes. However, the conditions favorable for sprouting, such as warm and humid environments, are also ideal for the growth of bacteria, including food‐borne pathogens. Here, we analyzed the growth and developed predictive models of locally isolated and commercial strains of Salmonella enterica and Listeria monocytogenes in alfalfa sprouts under various constant temperatures, ranging from 5°C to 25°C. Our findings indicated that these pathogens could grow at 5°C in sprouts, albeit with a low growth rate. A rapid increase in concentration occurred at temperatures of 10°C and above. The fitted models demonstrated high performance, with R2 values ranging from 0.964 to 0.997 and RMSE values ranging from 0.15 to 0.51, respectively. Based on the fitted values, bias factor (Af) values varied between 1.01 and 1.06, with all accuracy factor (Bf) values at 1.00. Acceptable prediction zone (APZ) values ranged from 81.8% to 100%. Validation of the models under dynamic temperature conditions for specific strains showed acceptable performance. This study enhances our understanding of S. enterica and L. monocytogenes growth in alfalfa sprouts. The findings of this study could be used to improve the risk assessment of these pathogens in alfalfa sprouts. [ABSTRACT FROM AUTHOR]

Simple Summary: Salmonella enterica subsp. enterica infections critically affect cattle health, producing high rates of morbidity and mortality in calves and reducing the performance of adult cows. Some European countries implemented surveillance and control programs decades ago, but in Italy, there is no national control program for dairy cows. This study describes an outbreak of Salmonella Bredeney in a dairy herd and the consequent control strategies applied. Control strategies included sample collection visits to the farm in order to identify the prevalence of Salmonella spp. and assess biosecurity levels. In this outbreak, there was a higher prevalence in calves and this condition was associated with poor biosecurity practices. Subsequently, the practitioner and farmer were provided with a health management plan to reduce the prevalence and control the outbreak. During the follow-up period, monitoring and testing revealed repeated negative results, indicating adequate control over the outbreak. The procedures undertaken in this project made it possible to collect useful data for the definition of measures for the management of outbreaks of salmonellosis in dairy cows. Salmonellosis in dairy cattle represents an increasing problem for both animal and public health. Nevertheless, in Italy, there is no control plan in place on dairy farms. The aim of this study was to describe a Salmonella Bredeney outbreak that occurred on a dairy farm and the measures that were adopted to control the outbreak. Management consisted in identifying the spread of infection and assessing the environmental contamination of Salmonella spp. and the associated risk factors. After the farm visit, laboratory investigations showed that 48% of rectal swabs collected from calves and 33% of environmental samples were positive for S. Bredeney, and a poor biosecurity level was detected. The farmer and practitioner were provided with a health management plan to control the spread of Salmonella spp., followed by a monitoring period and a follow-up visit in which all samples resulted negative. The results demonstrated the efficacy of indirect prophylaxis measures in reducing the circulation of Salmonella spp., leading to the extinction of the outbreak. Collaboration with farmers, practitioners, and public health veterinarians and the introduction of measures reported in the health management plan constitute a possible model for the management of Salmonella spp. outbreaks in dairy herds, even in complex farm situations. [ABSTRACT FROM AUTHOR]

The list of standard abbreviations for JDS is available at adsa.org/jds-abbreviations-24. Nonstandard abbreviations are available in the Notes. Endemic infectious diseases remain a major challenge for dairy producers worldwide. For effective disease control programs, up-to-date prevalence estimates are of utmost importance. The objective of this study was to estimate the herd-level prevalence of bovine leukemia virus (BLV), Salmonella enterica ssp. enterica serovar Dublin (Salmonella Dublin), and Neospora caninum in dairy herds in Alberta, Canada, using a serial cross-sectional study design. Bulk tank milk samples from all Alberta dairy farms were collected 4 times, in December 2021 (n = 489), April 2022 (n = 487), July 2022 (n = 487), and October 2022 (n = 480), and tested for antibodies against BLV, Salmonella Dublin, and N. caninum using ELISA. Herd-level apparent prevalence was calculated as positive herds divided by total tested herds at each time point. A mixed-effect modified Poisson regression model was employed to assess the association of prevalence with region, herd size, herd type, and type of milking system. Apparent prevalence of BLV was 89.4%, 88.7%, 86.9%, and 86.9% in December, April, July, and October, respectively, whereas for Salmonella Dublin apparent prevalence was 11.2%, 6.6%, 8.6%, and 8.5%, and for N. caninum apparent prevalence was 18.2%, 7.4%, 7.8%, and 15.0%. For BLV, Salmonella Dublin, and N. caninum , a total of 91.7%, 15.6%, and 28.1% of herds, respectively, were positive at least once, whereas 82.5%, 3.6%, and 3.0% of herds were ELISA positive at all 4 times. Compared with the north region, central Alberta had a high prevalence (prevalence ratio [PR] = 1.13) of BLV antibody-positive herds, whereas south Alberta had a high prevalence (PR = 2.56) of herds positive for Salmonella Dublin antibodies. Furthermore, central (PR = 0.52) and south regions (PR = 0.46) had low prevalence of N. caninum -positive herds compared with the north. Hutterite colony herds were more frequently BLV positive (PR = 1.13) but less frequently N. caninum -positive (PR = 0.47). Large herds (>7,200 L/d milk delivered ∼>250 cows) were 1.1 times more often BLV positive, whereas small herds (≤3,600 L/d milk delivered ∼≤125 cows) were 3.2 times more often N. caninum positive. For Salmonella Dublin, Hutterite colony herds were less frequently (PR = 0.07) positive than non-colony herds only in medium and large strata but not in small stratum. Moreover, larger herds were more frequently (PR = 2.20) Salmonella Dublin-positive than smaller herds only in non-colony stratum but not in colony stratum. Moreover, N. caninum prevalence was 1.6 times higher on farms with conventional milking systems compared with farms with an automated milking system. These results provide up-to-date information of the prevalence of these infections that will inform investigations of within-herd prevalence of these infections and help in devising evidence-based disease control strategies. [ABSTRACT FROM AUTHOR]

The search for synergies between natural products and commercial antibiotics is a promising strategy against bacterial resistance. This study determined the antimicrobial capacity of Nerol (NE) and Tannic Acid (TA) against 14 pathogenic bacteria, including ESKAPE pathogens. TA exhibited the lowest Minimum Inhibitory Concentrations (MICs) at 162.5 µg/mL against Pasteurella aerogenes and 187.5 µg/mL against Acinetobacter baumannii (WHO priority 1). NE showed its lowest MIC of 500 µg/mL against both Pasteurella aerogenes and Salmonella enterica. A total of 35 combinations of NE and 13 of TA with eight commercial antibiotics were analyzed. For NE, combinations with Streptomycin and Gentamicin were effective against Salmonella enterica, Bacillus subtilis, and Streptococcus agalactiae, with antibiotic MIC reductions between 75.0 and 87.5%. TA showed six synergies with Chloramphenicol, Ampicillin, Erythromycin, and Streptomycin against Acinetobacter baumannii, Streptococcus agalactiae, and Pasteurella aerogenes, with MIC reductions between 75.0 and 93.7%. Additionally, 31 additive effects with antibiotics for NE and 8 for TA were found. Kinetic studies on these synergies showed complete inhibition of bacterial growth, suggesting that natural products enhance antibiotics by facilitating their access to targets or preventing resistance. Given their safety profiles recognized by the EPA and FDA, these natural products could be promising candidates as antibiotic enhancers. [ABSTRACT FROM AUTHOR]

The misuse of antibiotics has led to high levels of drug-resistance in specific pathogens, promoting the search of molecules from different natural sources or the design of novel drug candidates. Medicinal and edible plants are a rich source of bioactive compounds, in particular those of polyphenol class. In the present work, we screen the antimicrobial properties of an aqueous extract prepared from the leaves of Ugni molinae (Turz) against a panel of pathogenic bacteria strains formed by Helicobacter pylori (ATCC 43504), Listeria monocytogenes (ATCC 7644), Staphylococcus aureus (ATCC 9144), Escherichia coli (ATCC 11775), and Salmonella enterica (ATCC 13076). Preliminary fast HPLC-micro fractionation allows the identification of potential urease inhibitors using high throughput urea-phenol microplate assay. Afterwards, preparative fractionation by Centrifugal Partition Chromatography (CPC) allow to select the specific bioactive fractions. A combination of antimicrobial tests, enzyme assays and molecular docking resulted in the identification by HPLC-MS/MS of two quercetin-O-(6"-O-galloyl)-hexosides as the most dominant compounds in the active CPC-fractions. These bioactive compounds were quercetin-3-O-(6"-O-galloyl)-8-galactopyranoside (hyperin 6"-gallate) and quercetin-3-O-ß-D-(6"-O-galloyl)- ß-glucopyranoside (tellimoside). The molecular docking evaluation revealed that hyperin-6"-gallate enter the binding site of urease and bind in through pi-cation, pi-pi, and H-bond interactions. In concordance with the in-silico assay, the CPC fraction containing this compound has the lowest values of IC50 for Jack bean (0.41 ± 0.08 µg/mL) and Helicobacter pylori (0.28 ± 0.08 µg/mL) ureases, respectively. Moreover, Label-Free Microscale Thermophoresis (MST) analysis suggest that this flavonoid forms a complex with urease, even inducing protein aggregation. In conclusion, Ugni molinae leaves has potent anti-urease flavonoids that can contribute to significantly reduce the acclimation of H. pylori in the acidic environmental of gastric mucosa. [ABSTRACT FROM AUTHOR]

Around 450 species of blueberries of the genus Vaccinium are known, of which some have gained preferential breeding, such as the 'Biloxi' variety. Some little studied species, such as Vaccinium leucanthum Schltdl. located in Mexico, could be a potential source of bioactive compounds. In this study, the phenolic compounds (chlorogenic acid content, hyperoside, phenols, flavonoids, tannins and total anthocyanins content) as well as the potential biological activity (antioxidant, antimicrobial, xanthine oxidase converting enzyme inhibition and angiotensin I inhibition) of Vaccinium leucanthum Schltdl. were studied, making a comparison with the Biloxi variety, which is the most widely cultivated one. The extract of V. leucanthum showed the highest content of flavonoids (4.853 ± 0.341 mg QE/g DW), total anthocyanins (0.303 ± 0.008 mg CGE/g DW), petunidin-3-glucoside (6.92 ± 0.12 mg PGE/g DW), malvidin-3-glucoside (11.80 ± 0.10 mg MGE/g DW) and hyperoside (5.137 ± 0.100 mg HE/g DW). It should be noted that V. leucanthum showed the same total tannin content and the same efficacy in the inhibition of Angiotensin I-converting enzyme as 'Biloxi', as well as the same antibacterial effect against the enterobacteria Salmonella choleraesuis ATCC 12022, Escherichia coli ATCC 12792and Shigella flexneri ATCC 10708. These findings demonstrate that V. leucanthum extracts could be an important source of preservatives as well as nutraceutical compounds for use in foods and medicines. [ABSTRACT FROM AUTHOR]

Investigating the quality of bee products obtained across different geographical regions and analyzing their antimicrobial activity is of significant interest to various scientific disciplines. This study focuses on comparing the antimicrobial activity of honey and propolis samples from different areas of Alba County, Romania. The quality parameters of five samples of two types of bee products (honey and propolis) were assessed. Then, the samples were tested to comparatively determine their antimicrobial properties against 12 species of bacteria (Escherichia coli, Salmonella typhimurium, Salmonella enteritidis, Salmonella anatum, Salmonella choleraesuis, Pseudomonas aeruginosa, Pseudomonas fluorescens, Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Bacillus subtilis, and Listeria monocytogenes) and 7 fungal strains (Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium chrysogenum, Rhizopus stolonifer, Fusarium oxysporum, and Alternaria alternata). Of the bacterial strains, the most sensitive to the action of honey samples were the two strains of Staphylococcus followed by P. fluorescens. The two strains of Pseudomonas and L. monocytogenes were the most sensitive to the activity of propolis. Of the fungal strains, F. oxysporum was the most sensitive to the actions of both honey and propolis, followed by P. chrysogenum in the case of honey samples and the two Aspergillus strains in the case of propolis. These findings indicate that bee products are rich sources of bioactive compounds exhibiting strong antimicrobial properties and significant potential for the development of new phytopharmaceutical products. [ABSTRACT FROM AUTHOR]

Adding essential oils in an edible coating could be an alternative for the food industry to control foodborne pathogens. In 2014, EFSA published a report highlighting the risk associated with Salmonella spp. and Norovirus in fresh and frozen berries. This study aimed to evaluate the efficacy of an edible coating (RP-7) with carvacrol and citral on reducing the population of Salmonella enterica, Escherichia coli O157:H7, Listeria monocytogenes, and murine Norovirus (MNV-1) in frozen strawberries and blueberries. Before evaluating the efficacy, the best method for applying the coating on fruit was studied. The immersion method was selected, with an optimal drying time of 45 min. After this, the berries were frozen and stored for one, two, three, four, and eight weeks at −18 °C. In strawberries, all bacteria were reduced to below 0.7 log cfu/strawberry in the eighth week, and the MNV-1 infectivity showed a reduction of nearly 2 logarithmic units. In blueberries, S. enterica and E. coli O157:H7 were reduced to 0.8 log cfu/blueberries within a week, and MNV-1 achieved a reduction of 0.8 logarithmic units at the end of the assay. The application of RP-7 affected the studied microorganisms in frozen strawberries and blueberries. [ABSTRACT FROM AUTHOR]

The food industry constantly seeks new starter cultures with superior characteristics to enhance the sensory and overall quality of final products. Starting from a collection of Algerian dairy (goat and camel) lactic acid bacteria, this work focused on the exploration of the technological and probiotic potential of Weissella cibaria (VR81 and LVT1) and Lactiplantibacillus plantarum R12 strains isolated from raw camel milk and fermented milk, respectively. These bioactive strains were selected for their high performance among ten other LAB strains and were used as starter cultures to develop a novel and nutritionally enhanced dairy-like plant-based yogurt using quinoa (Chenopodium quinoa Willd) as a raw matrix. The strains were evaluated for their antagonistic effects against Listeria innocua, Listeria ivanovii, Staphylococcus aureus, Escherichia coli, Salmonella enterica, and Pseudomonas aeruginosa, resilience to acidic and osmotic challenges, and tolerance to gastrointestinal mimicking conditions (i.e., pepsin and bile salt). Their aggregation and adhesion profiles were also analyzed. Furthermore, L. plantarum and W. cibaria were tested in single and co-culture for the fermentation and biocontrol of quinoa. The strains exhibited probiotic properties, including a high potential for biocontrol applications, specifically against L. innocua and P. aeruginosa (20 mm diameter zone with the neutralized cell-free supernatant), which disappeared after protease treatment, suggesting that bioactive peptides might be responsible for the observed antimicrobial effect. Additionally, they demonstrated resilience to acidic (pH 2) and osmotic challenges (1M sucrose), tolerance to gastro-intestinal conditions, as well as good aggregation and adhesion profile. Furthermore, the strains were able to produce metabolites of interest, such as exopolysaccharide (yielding up to 4.7 mg/mL) and riboflavin, reaching considerable production levels of 2.5 mg/L upon roseoflavin selection. The application of W. cibaria and L. plantarum as primary starters (both in single and co-culture) for fermenting quinoa resulted in effective acidification of the matrix (ΔpH of 2.03 units) and high-quality beverage production. in vivo challenge tests against L. innocua showed the complete inhibition of this pathogen when L. plantarum was included in the starter, either alone or in combination with W. cibaria. Both species also inhibited Staphylococcus and filamentous fungi. Moreover, the co-culture of mutant strains of L. plantarum R12d and W. cibaria VR81d produced riboflavin levels of 175.41 µg/100 g in fermented quinoa, underscoring their potential as starters for the fermentation, biopreservation, and biofortification of quinoa while also displaying promising probiotic characteristics. [ABSTRACT FROM AUTHOR]

In situ imaging of genes of pathogenic bacteria can profile cellular heterogeneity, such as the emergence of drug resistance. Fluorescence in situ hybridization (FISH) serves as a classic approach to image mRNAs inside cells, but it remains challenging to elucidate genomic DNAs and relies on multiple fluorescently labeled probes. Herein, we present a dead Cas12a (dCas12a)-labeled polymerase chain reaction (CasPCR) assay for high-contrast imaging of cellular drug-resistant genes. We employed a syncretic dCas12a-green fluorescent protein (dCas12a–GFP) to tag the amplicons, thereby enabling high-contrast imaging and avoiding multiple fluorescently labeled probes. The CasPCR assay can quantify quinolone-resistant Salmonella enterica in mixed populations and identify them isolated from poultry farms. [ABSTRACT FROM AUTHOR]

Typhoidal Salmonella enterica serovars, such as Typhi and Paratyphi A, cause severe systemic infections, thereby posing a significant threat as human-adapted pathogens. This study focuses on cytolysin A (ClyA), a virulence factor essential for bacterial dissemination within the human body. We show that ClyA is exclusively expressed by intracellular S. Paratyphi A within the Salmonella-containing vacuole (SCV), regulated by the PhoP/Q system and SlyA. ClyA localizes in the bacterial periplasm, suggesting potential secretion. Deletion of TtsA, an essential Type 10 Secretion System component, completely abolishes intracellular ClyA detection and its presence in host cell supernatants. Host cells infected with wild-type S. Paratyphi A contain substantial ClyA, with supernatants capable of lysing neighboring cells. Notably, ClyA selectively lyses macrophages and erythrocytes while sparing epithelial cells. These findings identify ClyA as an intracellularly induced cytolysin, dependent on the SCV environment and secreted via a Type 10 Secretion System, with specific cytolytic activity. Typhoidal Salmonella enterica strains cause serious infections in humans. Here, Krone et al show that the bacterial protein cytolysin A is secreted intracellularly where it selectively kills specific cell types and helps to establish bacterial infection. [ABSTRACT FROM AUTHOR]

This study explored the molecular epidemiology and resistance mechanisms of 271 non-duplicate Salmonella enterica (S. enterica) strains, isolated mainly from adults (209/271) in a tertiary hospital in Hangzhou between 2020 and 2021. Through whole-genome sequencing and bioinformatics, the bacterial strains were classified into 46 serotypes and 54 sequence types (ST), with S. Enteritidis, S. 1,4,[5],12:i:-, and S. Typhimurium being the most prevalent serotypes and ST11, ST34, and ST19 the most common STs. The strains isolated from adults were primarily S. Enteritidis (59/209), while from children were mainly S. 1,4,[5],12:i:- (20/62). Worryingly, 12.55% strains were multi-drug resistant (MDR), with resistance rates to cefepime (FEP), ceftazidime (CAZ), ceftriaxone (CRO) and cefotaxime (CTX) of 7.38%, 9.23%, 15.87% and 16.24%, respectively, and resistance rates to levofloxacin (LEV) and ciprofloxacin (CIP) of 8.49% and 19.19%, respectively. It is worth noting that the resistance rates of CRO and CTX in children reached 30.65%. A total of 34 strains carried extended-spectrum β-lactamase (ESBL) genes, dominated by blaCTX-M-65 (13/34) and blaCTX-M-55 (12/34); it is notable that one strain of S. Saintpaul carried both blaCTX-M-27 and blaCTX-M-55. The resistance mechanism to cephalosporins was mainly due to ESBL genes (20/43), and other genes included AmpC and β-lactamase genes. The strains resistant to quinolones mainly carried qnrS1 (27/53), and others included qnrB6, aac(6′)-Ib-cr, and mutations in gyrA and parC. One strain did not carry common quinolone resistance genes but had a parC (p.T57S) mutation to cause CIP resistance. This research provides vital insights into the molecular epidemiology and resistance mechanisms of clinical S. enterica, implicating possible infection control strategies. [ABSTRACT FROM AUTHOR]

Simple Summary: Salmonella enterica serovar Pullorum (S. Pullorum) is a formidable pathogen within the poultry industry and constitutes a substantial threat to global poultry production. Pullorum disease eradication and antibiotic treatment are two main strategies for controlling this disease. Therefore, understanding the prevalence and resistance characteristics of S. Pullorum is important for its control. The objective of this study was to determine the antigenic types and genotype characteristics of S. Pullorum isolates from China, and to clarify the relationship between antibiotic resistance and resistance genes. In this study, all the isolates tested were of standard antigenic types, with ST92 the predominant genotype, and 92.5% of the isolates displayed multidrug resistance. Our analysis of virulence genes indicated that the isolates expressed numerous factors associated with secretion systems. These data provide valuable information for the prevention and control of S. Pullorum infections in the poultry industry. Pullorum disease, caused by Salmonella enterica serovar Pullorum (S. Pullorum) infection, is a major pathogenic threat to the poultry industry. In this study, 40 S. Pullorum isolates from seven provinces of China were comprehensively analyzed in terms of antigenic type and antimicrobial susceptibility, and their drug-resistance genes and virulence genes were identified with whole-genome sequencing (WGS). We show that all these isolates were standard antigenic types, with ST92 the predominant genotype (92.5%). Disk diffusion assays revealed high resistance rates to streptomycin (92.5%), ciprofloxacin (82.5%), and ampicillin (80%), and the resistance rates to streptomycin, gentamicin, ampicillin, and cefotaxime were higher in isolates from sick chickens than in those from healthy chickens. In addition, gyrA mutations and eight acquired resistance genes were identified, with aac(6′)-Iaa the most prevalent, followed by blaTEM1β, sul2, and the GyrA S83F mutation. The resistance phenotypes to streptomycin, ampicillin, and ciprofloxacin correlated strongly with the presence of the aac(6′)-Iaa resistance gene, blaTEM1β resistance gene, and gyrA mutations, respectively. Analysis of the virulence genes showed that the isolates expressed numerous factors associated with secretion systems, including SPI-1 and SPI-2. Overall, this study extends our understanding of the epidemiology and antibiotic resistance of S. Pullorum in China. [ABSTRACT FROM AUTHOR]

The pervasive environmental metal contamination has led to selection of heavymetal resistance genes in bacteria. The pco and sil clusters are located on a mobile genetic element and linked to heavy-metal resistance. These clusters have been found in Salmonella enterica serovars isolated from human clinical cases and foods of animal origin. This may be due to the use of heavy metals, such as copper, in animal feed for their antimicrobial and growth promotion properties. The sil cluster can be found alone or in combination with pco cluster, either in the chromosome or on a plasmid. Previous reports have indicated that sil, but not pco, cluster contributes to copper resistance in S. enterica Typhimurium. However, the role of the pco cluster on the physiology of non-typhoidal S. enterica remains poorly understood. To understand the function of the pco gene cluster, a deletion mutant of pcoABCD genes was constructed using allelic exchange mutagenesis. Deletion of pcoABCD genes inhibited growth of S. enterica in high-copper medium, but only under anaerobic environment. Complementation of the mutant reversed the growth phenotype. The survival of S. enterica in RAW264.7 macrophages was not affected by the loss of pcoABCD genes. This study indicates that the acquired pco cluster is crucial for copper detoxification in S. enterica, but it is not essential for intracellular replication within macrophages. [ABSTRACT FROM AUTHOR]

As one of the biggest ports, the aquatic ecology of Shanghai Port has a significant impact on the health of surrounding residents and aquatic animals. Therefore, this study explored the composition and distribution of bacteria, pathogens, and ARGs at Shanghai Ports by high-throughput sequencing. The results showed that the bacterial community was dominated by the Proteobacteria at the phylum level. With the refinement of classification level, the main composition of bacteria in different samples shows significant differences. In contrast, there was no significant difference in the composition and distribution of pathogens among the samples. It indicates that pathogens and ARGs have steady community composition at Shanghai Port. Pseudomonas aeruginosa and Salmonella enterica could be regarded as candidate indicator pathogens. macB, tetA (58), and evgS were the main ARGs, and they showed a close relationship with Mycobacterium tuberculosis, Magnaporthe oryzae, Streptococcus pneumonia, Xanthomonas oryzae, and Vibrio cholerae in different sites and layers. This may lead to the transfer of ARGs between different pathogens, resulting in more threatening pathogens. The results showed that the pathogens and ARGs present posed a risk of transmission and were potentially harmful to residents in the environment. They can spread to any other ports in the world through the transmission of ballast water, posing a threat to humans and local ecology. In order to keep human health, it is necessary to pay more attention to the water environment of ports and increase the monitoring. Furthermore, it is essential to strengthen the supervision of external source pollution input due to the special features of the port. [ABSTRACT FROM AUTHOR]

Ozone is a molecule that has gained increasing interest in recent years by food industries for sanitization of food-grade surfaces. Compared to chemical sanitizers such as chlorine, hydrogen peroxide, or peracetic acid, ozone shows undeniable advantages, such as the absence of by-products that should affect human health or the possibility of generating it when needed. Therefore, the aim of this paper was the assessment of the resistance to ozonized water of two pathogenic bacteria (Listeria monocytogenes, Salmonella) and of three airborne food-spoiling fungi (Aspergillus brasiliensis, Hyphopichia burtonii, and Penicillium nordicum) inoculated on stainless steel tiles and treated in static conditions with 1 to 6 mg L−1 (pathogens) or 8.5 mg L−1 (filamentous fungi). Ozonized water gave different results based on the tested microorganisms: pathogenic bacteria proved markedly more sensible to ozone than filamentous fungi, even if great differences were observed at inter- and intra-specific levels for both categories of microorganisms. Nevertheless, the non-linear inactivation kinetics of the studied strains made the calculation of a punctual F-value difficult, so in industrial practice, adequate tailoring of the treatments to be applied, based on the registered extrinsic factors and the industrial bio-burden, would be appropriate. [ABSTRACT FROM AUTHOR]

Succinic acid (SA), a dicarboxylic acid of industrial importance, can be efficiently produced by metabolically engineered Mannheimia succiniciproducens. Although the importance of magnesium (Mg2+) ion on SA production has been evident from our previous studies, the role of Mg2+ ion remains largely unexplored. In this study, we investigated the impact of Mg2+ ion on SA production and developed a hyper-SA producing strain of M. succiniciproducens by reconstructing the Mg2+ ion transport system. To achieve this, optimal alkaline neutralizer comprising Mg2+ ion was developed and the physiological effect of Mg2+ ion was analyzed. Subsequently, the Mg2+ ion transport system was reconstructed by introducing an efficient Mg2+ ion transporter from Salmonella enterica. A high-inoculum fed-batch fermentation of the final engineered strain produced 152.23 ± 0.99 g/L of SA, with a maximum productivity of 39.64 ± 0.69 g/L/h. These findings highlight the importance of Mg2+ ions and transportation system optimization in succinic acid production by M. succiniciproducens. [ABSTRACT FROM AUTHOR]

Objective: To investigate the diagnostic value of metagenomic next-generation sequencing (mNGS) in detecting pathogens from joint infection (JI) synovial fluid (SF) samples with previous antibiotic exposure. Methods: From January 2019 to January 2022, 59 cases with suspected JI were enrolled. All cases had antibiotic exposure within 2 weeks before sample collection. mNGS and conventional culture were performed on SF samples. JI was diagnosed based on history and clinical symptoms in conjunction with MSIS criteria. The diagnostic values, including sensitivity, specificity, positive/negative predictive values (PPV/NPV), and accuracy, were in comparison with mNGS and culture. Results: There were 47 of the 59 cases diagnosed with JI, while the remaining 12 were diagnosed with non-infectious diseases. The sensitivity of mNGS was 68.1%, which was significantly higher than that of culture (25.5%, p<0.01). The accuracy of mNGS was significantly higher at 71.2% compared to the culture at 39.0% (p <0.01). Eleven pathogenic strains were detected by mNGS but not by microbiological culture, which included Staphylococcus lugdunensis, Staphylococcus cohnii, Finegoldia magna, Enterococcus faecalis, Staphylococcus saprophytics, Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Acinetobacter pittii, Brucella ovis, andCoxiella burnetii. Antibiotic therapy was adjusted based on the mNGS results in 32 (68.1%) patients, including 12 (25.5%) and 20 (42.6%) patients, in whom treatment was upgraded and changed, respectively. All JI patients underwent surgery and received subsequent antibiotic therapy. They were followed up for an average of 23months (20-27 months), and the success rate of treatment was 89.4%. Out of the 33 patients who had positive results for pathogens, reoperation was performed in 1 case (3.03%), while out of the 14 cases with negative results for both mNGS and cultures, reoperation was performed in 4 cases (28.6%). Conclusions: mNGS has advantages over conventional culture in detecting pathogens in SF samples from JI patients previously treated with antibiotics, potentially improving clinical outcomes. [ABSTRACT FROM AUTHOR]

Epigenetic mechanisms can generate bacterial lineages capable of spontaneously switching between distinct phenotypes. Currently, mathematical models and simulations propose epigenetic switches as a mechanism of adaptation to deal with fluctuating environments. However, bacterial evolution experiments for testing these predictions are lacking. Here, we exploit an epigenetic switch in Salmonella enterica, the opvAB operon, to show clear evidence that OpvAB bistability persists in changing environments but not in stable conditions. Epigenetic control of transcription in the opvAB operon produces OpvABOFF (phage-sensitive) and OpvABON (phage-resistant) cells in a reversible manner and may be interpreted as an example of bet-hedging to preadapt Salmonella populations to the encounter with phages. Our experimental observations and computational simulations illustrate the adaptive value of epigenetic variation as an evolutionary strategy for mutation avoidance in fluctuating environments. In addition, our study provides experimental support to game theory models predicting that phenotypic heterogeneity is advantageous in changing and unpredictable environments. [ABSTRACT FROM AUTHOR]

The present study investigated the microbiological safety of the increasingly popular plant‐based milk alternatives. No (10/27) or only very low microbial counts (17/27) were detected in the tested products. These were mainly identified as spore formers via MALDI‐ToF‐MS. Three products contained Bacillus cereus group isolates, which were able to form considerable amounts of enterotoxins and exhibited cytotoxicity towards CaCo‐2 cells. Preliminary tests showed good growth of B. cereus, Listeria monocytogenes, and Salmonella enterica in all tested products (maximum bacterial counts: 5 × 1012 cfu/mL). These experiments also revealed strain‐, time‐, and temperature‐, but especially product‐specific enterotoxin production of B. cereus. In propagation and persistence tests according to DIN EN ISO 20976‐1:2019‐09, rapid bacterial proliferation was also detected in all products. B. cereus generally showed lower bacterial counts (106–107 cfu/mL) compared to L. monocytogenes and S. enterica (108–109 cfu/mL), but was detectable in a larger number of products over the test period of 6 weeks. pH values decreased (20/27) over time and visual and/or olfactory alterations (24/27) were observed. The present study provides information on the occurrence, growth and persistence of pathogenic bacteria in plant‐based drinking milk alternatives. It also points out that the accompanying changes in pH, odor, and appearance are not necessarily recognizable to the consumer. Practical Application: The present study contributes to the understanding of the microbial risk related to plant‐based drinking milk alternatives. It is crucial that the manufacturer ensures that particularly spore formers have been effectively eliminated from the products. Among them, especially toxin‐producing bacteria can pose a risk to the consumer, as these products promote proliferation and persistence of the bacteria. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovar Typhimurium, which is a common foodborne pathogen, causes both intestinal and systemic infections in hosts. Salmonella has a complex pathogenic mechanism that involves invasive capacity and intracellular survivability, which hampers research on virulence of Salmonella. The virulence of Salmonella is primarily studied through Salmonella pathogenicity islands (SPIs). However, there are also genes outside these SPIs that significantly impact virulence. Macrophage survival gene msgA is positioned at a region independent of the SPIs and conserved in Salmonella. However, there has been limited research on msgA to date. This study aims to investigate the virulent function of msgA to deepen our understanding of Salmonella virulence. Proteomic and RT-qPCR analyses reveal that MsgA influences multiple metabolic pathways and the expression of SPIs. The depletion of msgA led to the significantly reduced invasive capacity and intracellular survivability, and thus the decreased virulence of Salmonella. In conclusion, our study suggests that MsgA is an important regulator that mainly regulates virulence. Further research into the function of MsgA will enhance the understanding of Salmonella pathogenesis and promote the application of Salmonella for medical treatment. [ABSTRACT FROM AUTHOR]

Aims The increasing prevalence of AmpC β-lactamase (AmpC)- and extended-spectrum β-lactamase (ESBL)- producing food pathogens is a serious public health concern. AmpC- and ESBL-producing Salmonella species pose a high risk of food contamination. This study aimed to investigate changes in the prevalence of Salmonella among food handlers in Japan from 2006 to 2021 using 100 randomly selected isolates from 2006, 2012, 2018, and 2021 with different serotypes and antimicrobial resistance patterns. Methods and results The average Salmonella isolation rate was 0.070% (19 602/27 848 713). Serotyping revealed that the most common serotypes were Enteritidis in 2006, Infantis in 2012, Agoueve/Cubana in 2018, and Schwarzengrund in 2021. Antimicrobial susceptibility testing showed that Salmonella isolates exhibited the highest resistance to streptomycin (<40%), followed by tetracycline (<20%–40%). Moreover, 6% of the Salmonella isolates produced cephalosporinases with the bla CMY-2, bla CTX-M-14, and bla TEM genes. The annual incidence of cephalosporin resistance has increased. Plasmid conjugation assays revealed that cephalosporin-resistant Salmonella spp. transmitted their resistance to Escherichia coli. Additionally, plasmid genome analysis showed that the insertion sequence IS 26 was encoded in the upstream and downstream regions of bla CTX-M-14 and qnrS1 in the IncHI1 plasmid, which could be transmitted to other bacteria. Conclusions The tested Salmonella isolates showed high resistance to specific antibiotics, with differences in resistance depending on the serotype. Further increase and spread of transmissible cephalosporin-resistant strains should be noted. [ABSTRACT FROM AUTHOR]

Aims Characterize global genomic features of 86 genomes of Salmonella Gallinarum (SG) and Pullorum (SP), which are important pathogens causing systemic infections in poultry. Methods and results All genomes harbored efflux pump encoding gene mdsA and gold tolerance genes golS and golT. Aminoglycoside (aac(6′)-Ib, aadA5, aph(6)-Id, aph(3′')-Ib, ant(2′')-Ia), beta-lactam (bla TEM-1, bla TEM-135), efflux pump (mdsB), fosfomycin (fosA3), sulfonamide (sul1, sul2), tetracycline [ tet(A) ], trimethoprim (dfrA17), acid (asr), and disinfectant (qacEdelta1) resistance genes, gyrA, gyrB , and parC quinolone resistance point mutations, and mercury tolerance genes (mer) were found in different frequencies. Additionally, 310 virulence genes, pathogenicity islands (including SPI-1, 2, 3, 4, 5, 6, 9, 10, 12, 13, and 14), plasmids [IncFII(S), ColpVC, IncX1, IncN, IncX2, and IncC], and prophages (Fels-2, ST104, 500465-1, pro483, Gifsy-2, 103 203_sal5, Fels-1, RE-2010, vB_SenS-Ent2, and L-413C) were detected. MLST showed biovar-specific sequence types, and core genome MLST showed country-specific and global-related clusters. Conclusion SG and SP global strains carry many virulence factors and important antimicrobial resistance genes. The diverse plasmids and prophages suggest genetic variability. MLST and cgMLST differentiated biovars and showed profiles occurring locally or worldwide. [ABSTRACT FROM AUTHOR]

Among sixty-eight pseudomonads, isolate QCS59 from the rhizosphere of H. schimperi was selected based on its siderophore level. Production was optimal in Kings B supplemented with 2% peptone and 0.5% fructose at pH 6.5 and 25 °C for 72 h. Additionally, the threshold potential of iron was found at a concentration of 10 µM. After purification, the acidified siderophore presented a maximum absorption peak of 360 nm, while the neutral form presented a maximum of 414 nm, confirming its pyoverdine (PVD) nature. Furthermore, a major peak appeared at a retention time (RT) of 27.5 min during RP-HPLC, confirming its homogeneity. Interestingly, it demonstrated effective antibacterial activity, especially against Escherichia coli ATCC 8739, with a minimum inhibitory concentration (MIC) of 6.3 µg/mL and a minimum bactericidal concentration (MBC) of 12.5 µg/mL. At ½ the MIC value, it inhibited 82.1% of well-established biofilms of Salmonella enterica. There was an increase in malondialdehyde (MDA) and antioxidative enzymes, especially catalase (CAT) in the treated bacteria because of the peroxidation of membrane lipids and oxidative stress, respectively. SEM proved cellular lysis and surface malformation in most of the treated bacteria. This study concludes that QCS59 siderophore is a promising antibacterial candidate for treating wastewater bacteria and skin pathogens. [ABSTRACT FROM AUTHOR]

The effects of juice pH, type of acidulant, and post-treatment refrigeration on the high-pressure processing (HPP) inactivation of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in acid beverages were evaluated. Inoculated apple, orange, and grape juices (at their original pH and adjusted to pH 4.00, 4.50, and 5.00) were treated at 550 MPa for 1 min at 5 °C. In addition, inoculated model solutions acidified to a pH of 5.00 with acetic, citric, malic, and tartaric acids were treated at 400 MPa for 1 min at 5 °C. The effect of refrigerated storage for 24 h after treatment on pathogen inactivation in both experiments was also assessed. A greater than 5-log reduction of the three pathogens inoculated was achieved in all juices immediately after HPP at the juices' original pH, and of L. monocytogenes under all experimental conditions. Refrigerated storage for 24 h after HPP treatment improved the inactivation of E. coli O157:H7, to >5-log reduction, at pH 4.00 in apple juice and of Salmonella in the three juices at pH 4.00. The type of acidulant did not significantly (p > 0.01) affect E. coli or Salmonella inactivation in acidified model solutions but a greater than 5-log reduction after HPP was only achieved for L. monocytogenes when acetic acid was used. The effectiveness of HPP for pathogen inactivation depended largely on product pH and the target pathogen of concern. [ABSTRACT FROM AUTHOR]

Salmonella enterica serovars are zoonotic bacterial that cause foodborne enteritis. Due to bacteria's antibiotic resistance, using bacteriophages for biocontrol and treatment is a new therapeutic approach. In this study, we isolated, characterized, and analyzed the genome of vB_SenS_TUMS_E19 (E19), a broad host range Salmonella bacteriophage, and evaluated the influence of E19 on liquid eggs infected with Salmonella enterica serovar Enteritidis. Transmission electron microscopy showed that the isolated bacteriophage had a siphovirus morphotype. E19 showed rapid adsorption (92% in 5 min), a short latent period (18 min), a large burst size (156 PFU per cell), and a broad host range against different Salmonella enterica serovars. Whole-genome sequencing analysis indicated that the isolated phage had a 42 813 bp long genome with 49.8% G + C content. Neither tRNA genes nor those associated with antibiotic resistance, virulence factors, or lysogenic formation were detected in the genome. The efficacy of E19 was evaluated in liquid eggs inoculated with S. Enteritidis at 4 and 25 °C, and results showed that it could effectively eradicate S. Enteritidis in just 30 min and prevented its growth up to 72 h. Our findings indicate that E19 can be an alternative to a preservative to control Salmonella in food samples and help prevent and treat salmonellosis. [ABSTRACT FROM AUTHOR]

Copyright of Farmacia is the property of Societatea de Stiinte Farmaceutice Romania and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Salmonella infections are a serious global health concern, particularly in developing countries, and are further exacerbated by the emergence of antibiotic resistance. San‐Huang‐Xie‐Xin‐Tang (SHXXT), a traditional herbal medicine with potent anti‐inflammatory properties, has recently gained attention as an alternative treatment. Our study emphasizes on the importance of precise timing in accordance with traditional Chinese medicine principles. A mouse infection model was established while different administration times of SHXXT were recorded for the body weight, clinical scores, bacterial counts in blood, and organs. Additionally, cytokine levels, fatty acids, and amino acids in the serum were also monitored. We found that administering SHXXT 1 day after Salmonella enterica subsp. enterica serovar Typhimurium (S. Typhimurium) infection (T1 group) leads to positive outcomes. This includes restoration of body weight, improved clinical scores, and reduced bacterial counts in blood and vital organs. Interferon‐gamma levels remained consistently high across all treatment groups 6 days post‐infection. However, the T1 group showed exclusive suppression of serum levels of tumor necrosis factor‐alpha (TNF‐α) and interleukin‐1 beta (IL‐1β). The timing of administration significantly influenced serum fatty acid concentrations, countering Salmonella‐induced disruptions, aligning with TNF‐α and IL‐1β levels. SHXXT had also restored amino acid profiles disrupted by the infection, with notable effects when administered at the correct timing. Our research highlights SHXXT's potential in treating S. Typhimurium infection, emphasizing the importance of precise timing in line with traditional Chinese medicine principles for effective treatment at different disease stages. [ABSTRACT FROM AUTHOR]

This study examined the prevalence and antibiotic resistance pattern of bla CTX-M extended-spectrum β-lactamase positive Salmonella species isolated from a hospital in Weifang. Salmonella strains were isolated from hospitalized patients from January 2018 to April 2023. Whole-genome sequencing was performed by Illumina platform. CTX-M-producing Salmonella were identified by Comprehensive Antibiotic Research Database (CARD). Strain susceptibility to six antimicrobial agents was assessed by BD Phoenix™ M50 System. MLST analysis confirmed sequence types and additionally, serotypes were determined by SeqSero2. Genetic environments of bla CTX-M genes were analyzed by Isfinder and BLASTn. Single nucleotide polymorphisms were used to construct a phylogenetic tree to analyze homology. A total of 34 CTX-M-producing Salmonella were detected. The most prevalent serotype was Salmonella enterica subsp. enterica 1,4,[5],12:i:- (14/34, 41.18%), belonging to ST34, followed by Salmonella Enteritidis (10/34, 29.41%), belonging to ST11. The highest resistance rate was detected to ampicillin (97.06%), followed by ceftriaxone (94.12%) and ceftazidime (58.83%). In CTX-M-producing Salmonella five types of bla CTX-M genes were identified, the most prevalent was bla CTX-M-55 (47.06%, 16/34), followed by bla CTX-M-14, bla CTX-M-65, bla CTX-M-125, and bla CTX-M-27 at 26.47% (9/34), 11.77% (4/34), 8.82% (3/34), and 5.88% (2/34), respectively. Apart from bla CTX-M, 40 antibiotic resistance genes were also detected, conveying resistance to multiple drugs and the most frequent genes were namely, mcr-1.1, aph(6)-Id, aph(3″)-Ib, oqxAB, qnrB6, qnrS1. According to genetic environment analysis, the insertion sequence IS Ecp1 was prevalent upstream of the bla CTX-M gene. Our study demonstrates that multiple resistance genes are carried by clinical isolates of Salmonella spp. however, the dominant ESBL genotype is CTX-M-55, that is associated with IS Ecp1. [ABSTRACT FROM AUTHOR]