Brazilian artisanal cheeses are widely valued for their sensory quality and cultural relevance; however, their production frequently involves raw milk and extensive handling, conditions that may favor contamination by Staphylococcus aureus. This retrospective baseline study analyzed artisanal raw-milk cheeses collected between 2014 and 2016 in Southern and Southeastern Brazil and characterized the isolates regarding antimicrobial resistance, biofilm-forming ability, and the presence of virulence and resistance genes. A total of 147 cheese samples were collected from street vendors and markets in five Brazilian states; notably, 93% of the sampling and all S. aureus-positive samples were concentrated in Paraná, São Paulo, and Minas Gerais, Brazil. S. aureus was isolated using selective media and biochemical identification, followed by antimicrobial susceptibility testing according to CLSI guidelines. Molecular analyses were performed to detect enterotoxin genes, the tst gene, the mecA gene, and SCCmec types. Biofilm production was assessed using a microtiter plate assay. Thirteen samples (8.84%) were positive for S. aureus, yielding 25 isolates. Resistance to cefoxitin (FOX) was the most frequent phenotype (20%), followed by resistance to ampicillin, ciprofloxacin, chloramphenicol, and streptomycin (8% each). Two isolates were classified as multidrug-resistant (MDR). Genotypic analysis revealed one mecA-positive isolate (methicillin-resistant S. aureus [MRSA]; SCCmec nontypable), while four FOX-resistant mecA-negative isolates (including three SCCmec type II carriers) were classified as borderline-oxacillin-resistant S. aureus. Biofilm formation was observed among resistant isolates. Among the virulence genes investigated, only one isolate carried the sea gene, and none were positive for tstH. Although the prevalence of mecA-positive MRSA and enterotoxigenic strains was low, the detection of MDR, biofilm-producing S. aureus highlights potential risks to food safety and public health. These findings reinforce the importance of continuous surveillance, molecular monitoring of resistance determinants, and strict hygienic practices in artisanal cheese production.

Nontyphoidal Salmonella bacteria are an important global cause of gastrointestinal disease. In Australia, it is estimated that salmonellosis costs approximately 140 million Australian dollars per year in illness, pain and suffering, and other productivity losses. The Northern Territory (NT) of Australia is a sparsely populated tropical environment, with 31% of the population being Aboriginal Australians. We described the epidemiology of salmonellosis in the NT by analyzing routinely notified salmonellosis cases diagnosed between 2005 and 2024. We performed descriptive, univariate, and multivariate analyses. We used exact logistic regression to explore associations with severe disease (hospitalization or death). We performed negative binomial regression analysis to explore associations with length of hospitalization. There were 9628 salmonellosis notifications equating to a mean annual notification rate of 203 per 100,000 persons-the highest reported in the world; 51% of cases were male; 25.3% had severe disease (2432 hospitalizations and 18 deaths); and 50% were aged <5 years. The most commonly reported serotypes were S. Saintpaul (1125/9628, 11.7%), S. Virchow (1002/9628, 10.4%), and S. Typhimurium (936/9628, 9.7%). Aboriginal people were notified at 1.2 times (95% confidence interval [CI] 1.1-1.2, p < 0.001) the rate of non-Aboriginal people, were 3.7 times (95% CI 3.3-4.1, p < 0.001) more likely to experience severe disease, and were hospitalized for 1.6 times longer (95% CI 1.5-1.8, p < 0.001) than non-Aboriginal people. There was no difference in salmonellosis notification rates in 2005-2014 compared with 2015-2024; however, S. Typhimurium notifications decreased. The tropical climate, abundant wildlife, and contamination of the household environment with Salmonella contribute to high rates of salmonellosis in the NT. Credible interventions are needed to decrease the incidence of salmonellosis, particularly among young children exposed to contaminated tropical environments.

Toxoplasma gondii is a ubiquitous parasitic protozoan that can cause neurological and psychiatric disorders, potentially impacting human emotional behavior. This study aimed to explore serological and molecular evidence of T. gondii infection in opioid abusers in northern Iran. In this case-control study, opioid abusers who were referred to substance abuse rehabilitation centers in Mazandaran Province, northern Iran, were enrolled. Blood samples were collected from the participants to perform a serological assay to detect T. gondii IgG and IgM antibodies. A polymerase chain reaction (PCR) test was also conducted on buffy coats of the blood samples. The study comprised a total of 474 participants, with 239 individuals being opioid abusers and 235 healthy individuals serving as the control group. The results indicated that 163 opioid abusers (68.2%) were positive for T. gondii IgG, whereas 76 (31.8%) were negative. Among the control group, 63 individuals (26.8%) tested positive for T. gondii IgG, whereas 172 (73.2%) tested negative. This difference was statistically significant according to p = 0.01, odds ratio (OR) = 2.67, and 95% confidence interval (CI) = 1.03-4.15. In addition, 7.1% (17/239) of the case and 2.1% (5/235) of the control groups were PCR positive for Toxoplasma DNA. This difference was statistically significant (p = 0.01; OR = 2.96; 95%; CI = 0.94-7.01). In contrast, all of the participants were negative for T. gondii IgM antibodies. Our findings demonstrated that the sero-molecular prevalence of latent T. gondii infection in opioid abusers is significantly higher than that in healthy individuals. This suggests a potential correlation between T. gondii IgG antibody positivity and PCR results with opioid abuse.

Bongkrekic acid (BKA) poisoning is a rare but highly lethal foodborne illness caused by the mitochondrial toxin produced by Burkholderia gladioli pv. cocovenenans. Historically concentrated in Indonesia and China, recent outbreaks in Africa and North America underscore its global public health relevance. A comprehensive literature search was conducted in PubMed and China National Knowledge Infrastructure, supplemented by manual searches. A total of 91 studies were included. Outbreaks are mainly linked to traditional fermented foods such as tempe bongkrek, rice noodles, and corn products, with case fatality rates ranging from 30% to 100%. BKA irreversibly inhibits adenine nucleotide translocase, leading to profound mitochondrial dysfunction and multiorgan failure. Clinically, poisoning progresses rapidly from gastrointestinal symptoms to severe hepatic, renal, and neurological damage. Liquid chromatography-tandem mass spectrometry remains the gold standard for confirmation, while immunoassays and molecular tools provide rapid screening in outbreak settings. Despite advances in detection and mechanistic understanding, prevention is hindered by the toxin's heat stability and its association with traditional food practices. Enhanced surveillance, point-of-care diagnostics, and targeted public education in high-risk regions are urgently needed.

Listeria monocytogenes is a significant foodborne pathogen that poses serious risks to public health and the food industry. In humans, infections can lead to severe clinical outcomes, including gastroenteritis, septicemia, meningitis, encephalitis, and pregnancy-related complications such as stillbirths and spontaneous miscarriages. Contamination of meat and meat products has been associated with numerous outbreaks and sporadic cases worldwide. The detection and identification of L. monocytogenes involve traditional microbiological and biochemical methods, as well as advanced molecular techniques, including the polymerase chain reaction and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This review provides a comprehensive overview of the microbiological characteristics, global prevalence, and antibiotic resistance profiles of L. monocytogenes . The emergence of multidrug-resistant strains underscores the importance of ongoing surveillance, effective antimicrobial stewardship, and rigorous adherence to food safety measures. Integrated efforts across the meat production and processing chain, combined with rapid diagnostic tools and public health interventions, are crucial to reducing the risk of listeriosis and ensuring the safety of meat products globally.

Antibiotic resistance remains a global public health concern, and the prevalence of Enterobacteriaceae species that harbor antibiotic resistance genes (ARGs) is on the rise. The aim of this study was to assess the distribution of extended-spectrum beta-lactamase (ESBL)/AmpC-producing Enterobacteriaceae in vegetables cultivated on irrigated farms in Lagos, Nigeria. A total of 257 samples, including vegetable samples, irrigation water, and soil, were collected from five farms within the city. Standard microbiological and molecular biology methods were used for the isolation and characterization of bacterial genera within Enterobacteriaceae and the detection of ARGs. Antibiotic susceptibility testing was conducted using the Kirby-Bauer disc diffusion method, and ESBL production was determined by the double-disk synergy test. Fifty-eight bacterial strains were isolated from the samples, of which 52 (90%) belonged to the family Enterobacteriaceae . Ten genera from this family were represented among obtained isolates, with Klebsiella species and Escherichia fergusonii being most prevalent. In total, 85% and 52% of these isolates were resistant to amoxicillin–clavulanic acid and ceftazidime, respectively. Sixty-five percent of these isolates were multidrug-resistant (MDR), with 56% and 46% testing positive for ESBL and AmpC production, respectively. Some of the MDR isolates had Multiple Antibiotic Resistance Index (MARI) ranging from 0.4 to 0.8. bla SHV was the dominant ESBL encoding gene detected, while bla AmpC was detected in only 4% of isolates. Plasmids ranging in size from 2.6 to 20.35 kb were detected in some of the MDR Enterobacteriaceae isolates. The presence of MDR Enterobacteriaceae in the food chain is of public health significance, highlighting the need for continuous surveillance.

Eucalyptus citriodora (lemon eucalyptus) is a medicinal plant commonly used as an antiseptic agent to prevent infection and promote healing. The aim of this exploration was to investigate for the first time the antibacterial mode of action of a gas chromatography-mass spectrometry chemically characterized E. citriodora essential oil (EO) obtained by microwave-assisted hydrodistillation. First, the chemical investigation revealed citronellal (30.67%) and citronellol (19.14%) as the major components. E. citriodora EO represented remarkable antibacterial properties, as demonstrated by significant zone of inhibition in the disc-diffusion test against all tested bacterial pathogens, including Listeria innocua ATCC 33090, L. monocytogenes ATCC 13932, Proteus mirabilis ATCC 25933, Salmonella typhimurium ATCC 700408, and Pseudomonas aeruginosa ATCC 27853. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values confirmed these findings showing antibacterial efficacy at low concentrations ranging 5.75-92 µg/mL for MICs and 11.5-184 µg/mL for MBCs. These results were comparable with gentamicin. The MICindex revealed that E. citriodora EO has bactericidal effects. We evaluated the antibacterial properties of E. citriodora EO and determined its mode of action using advanced tests with P. aeruginosa as a typical pathogen. The time-kill test revealed dose-dependent inhibitory effects on the cell proliferation of P. aeruginosa, affecting its membrane permeability based on the time and concentration of the EO. E. citriodora EO also caused damage to the cell membrane, resulting in leakage of cellular constituents, including RNA and DNA. Anti-quorum sensing activity was tested by inhibiting biofilm formation, showing that E. citriodora EO effectively inhibited biofilm formation. The UV-visible investigation on the release of cellular materials absorbed at 260 nm showed significant leakage of cytoplasmic substances, including proteins, DNA, and RNA, indicating devastation to bacterial cell membrane integrity. In addition, the use of E. citriodora EO significantly inhibited P. aeruginosa adhesion on 304 L stainless-steel surface, making it more suitable for applications requiring better wetting ability and surface interactions, particularly in food production. [Figure: see text].

Foodborne botulism is a rare but highly lethal disease. The botulinum neurotoxin (BoNT) that causes botulism is produced by Clostridium botulinum (C. botulinum) and other clostridia. In this study, we characterized C. botulinum strains isolated during food poisoning events in Sichuan Province from 1990 to 2024 by analyzing whole-genome sequencing data. Statistical analyses of the geographical distribution food sources of strains suggested that the primary sources of contamination were associated with specific regions and food types. The isolates were further compared with reference strains using average nucleotide identity analysis to reveal their genetic diversity and evolutionary relationships. Among the eight strains, five strains belonged to Group I, and the other three strains belonged to Group II. All strains belonging to Group I (SC001, SC002, SC003, SC006, and SC009) were assigned to five totally different recognized ST types (ST-2 to ST-51). In addition, analysis of BoNTs subtypes demonstrated that the types of BoNTs causing botulism in Sichuan were mainly types A, B, and E. Among them, some rare subtypes of BoNT reported for the first time in China, such as BoNT/B4, BoNT/E12, and BoNT/A5(B3), and no specific subtypes were predominant in the botulism incidents. This study is critical for disease surveillance and early warning systems, while also providing a basis for food safety regulation, clinical diagnosis, and treatment in the future.

Klebsiella quasipneumoniae is a recently described species that can be differentiated from Klebsiella pneumoniae. However, in clinical settings, they are frequently misidentified as K. pneumoniae. In this study, our objective was to conduct genomic characterization and bioinformatics analysis of K. quasipneumoniae subsp. quasipneumoniae (KpII-A) isolated from a sample obtained from a retail fish market in Assam, India. Notably, this particular isolate was identified as K. pneumoniae when identified using BD Pheonix™ M50 (BD Difco, USA). This represents a serious pitfall of conventional microbiological methods for distinguishing between K. pneumoniae and K. quasipneumoniae. In this connection, identifying differences in nuclear gene content is key to avoid misidentification. The isolate was confirmed to be KpII-A using species identification by Mash Screen and whole-genome sequencing by the Illumina platform. We report the draft genome sequence of this strain, comprising of 53 contigs with an average GC content of 58.11%. The annotation revealed 5,095 protein coding sequences, 69 tRNA genes, and 4 rRNA genes. The isolated strain acknowledges the presence of oqxA, oqxB, fosA, and blaOKP-A-3 antimicrobial resistance genes (ARGs). Additionally two phage genomes were detected in contigs 3 and 19 of the bacterial genome. Based on the multilocus sequence typing and genome sequencing, the isolate was identified as a novel sequence type, ST5655, within the species K. quasipneumoniae under the phylogroup KpII-A. The presence of antimicrobial resistance genes in KpII-A, isolated from retail fish samples, raises concerns regarding transmission across barriers in ecological niches and possible transmission to consumers. Given that fish may serve as a potential vehicle for ARG transmission, our findings are highly relevant and paramount to human health. Moreover, our study supports the robustness of the sequence-based microbial identification.