Carbapenem resistance in the food supply chain

Parallel Detection of the Unamplified Carbapenem Resistance Genes blaNDM-1 and blaOXA-1 Using a Plasmonic Nano-Biosensor with a Field-Portable DNA Extraction Method

Antimicrobial resistance (AMR) is a rapidly growing global concern resulting from the overuse of antibiotics in agricultural and clinical settings. The challenge is exacerbated by the lack of rapid surveillance for resistant bacteria in clinical, environmental, and food supply settings. The increasing resistance to carbapenems, an important sub-class of beta-lactam antibiotics, is a major concern in the healthcare community. Carbapenem resistance (CR) has been found in the environment and food supply chain, where it has the potential to spread to pathogens, animals, and humans through direct or indirect contact. Rapid detection for preventative and control measures should be developed. This study utilized a gold nanoparticle-based plasmonic biosensor for the parallel detection of the CR genes blaNDM-1 and blaOXA-1. To explore the field portability, DNA was extracted using two methods: a commercial extraction kit and a boiling method. The results were compared between the two methods using a spectrophotometer and a cellphone application for RGB values to quantify the visual results. The results showed that the boiling method of extraction was more effective than extraction with a commercial kit for this analysis. The parallel detection of unamplified genes extracted via the boiling method is novel. When combined with other portable testing equipment, the approach has the potential to be an inexpensive, rapid, and simple on-site CR gene detection protocol.

Development and evaluation of a sensitive approach for detection and recovery of third-generation cephalosporin- and carbapenem-resistant Enterobacterales from ready-to-eat frozen stone fruit

Antimicrobial resistance (AMR) is a global public health threat, but the role of foods in its dissemination is poorly understood. We examined the incidence of foodborne bacteria carrying AMR genes considered high-priority research targets by the World Health Organization. Frozen, ready-to-eat, avocado, coconut, mango, and peach (n = 161) were tested for bacteria encoding extended-spectrum β-lactamases (ESBLs) and carbapenemases. Over 600 presumptive-positive isolates were recovered and analyzed with a pooled sequencing (Pool-seq) strategy. Coconut samples exhibited the highest bacterial loads and prevalence/diversity of AMR genes. Isolates harbouring the β-lactamase genes blactx-m, blatem, and blashv, identified in 14 coconut and 2 mango samples, were further characterized by whole-genome sequencing and antimicrobial susceptibility testing. The most common gene was blactx-m-15, detected in 20 unique strains. Two carbapenemase-producing strains were isolated from coconut: Enterobacter roggenkampii encoding blandm-1 and Escherichia coli encoding blandm-5. Subsequent quantitative PCR (qPCR) analysis of enrichments for blactx-m/blandm indicated a potentially higher prevalence of these genes than observed by colony screening. This study presents a practical method for recovering ESBL- and carbapenemase-producing bacteria from foods. Mapping their distribution in food products is crucial to assessing the role of foods in the global spread of AMR and developing effective public health interventions.

Metabolomics reveals the effect of vacuum packaging combined with moderate-temperature preservation on quality changes of tender ginger

Tender ginger is often used a fresh vegetable but hard to storage due to the delicate skin, high moisture content and prone to spoilage. In order to develop suitable preservation technology for tender ginger, the effects of vacuum packaging combined with different preservation temperatures (20-25 °C room temperature, 4 °C and 10 °C) on tender ginger shelf life were investigated. The results indicated that vacuum packaging combined with 4 °C (VP4) preservation could easily cause cold damage and postharvest physiological fluctuations. Vacuum packaging combined with 10 °C (VP10) inhibited moisture loss and physiological activities. Metabolomics analysis revealed 169 metabolites significantly differential regulated during VP10 preservation. The characteristic metabolites were primarily associated with amino acid, lipid and nucleotide metabolism. The metabolic pathways mainly involved linoleic acid metabolism; alanine, aspartate and glutamate metabolism; and purine metabolism. The above results indicated that VP10 effectively extended the preservation period of tender ginger with less damage.

Escherichia coli ST117: exploring the zoonotic hypothesis

Extraintestinal pathogenic Escherichia coli (ExPEC) can lead to severe infections, with additional risks of increasing antimicrobial resistance rates. Genotypic similarities between ExPEC and avian pathogenic E. coli (APEC) support a possible role for a poultry meat reservoir in human disease. Some genomic studies have been done on the ST117 lineage which contaminates poultry meat, carries multidrug resistance, can be found in the human intestinal microbiota, and causes human extraintestinal disease. This study analyzed the genomes of 61 E. coli from Brazilian poultry outbreaks focusing on ST117, to further define its possible zoonotic characteristics by genotypic and phylogenomic analyses, along with 1,699 worldwide ST117 isolates originating from human, animal, and environment sources. A predominance of ST117 was detected in the Brazilian isolates (n = 20/61) frequently carrying resistance to critical antibiotics (>86%) linked to IncFII, IncI1, or IncX4 replicons. High similarities were found between IncX4 from Brazilian outbreaks and those from E. coli recovered from imported Brazilian poultry meat and human clinical cases. The ST117 phylogeny showed non-specificity according to host and continent and an AMR index score indicated the highest resistance in Asia and South America, with the latter statistically more resistant and overrepresented with resistance to extended-spectrum beta-lactamases (ESBL). Most ST117 human isolates were predicted to have a poultry origin (93%, 138/148). In conclusion, poultry is a likely source for zoonotic ExPEC strains, particularly the ST117 lineage which can also serve as a reservoir for resistance determinants against critical antibiotics encoded on highly transmissible plasmids.

IMPORTANCE

Certain extraintestinal pathogenic Escherichia coli (ExPEC) are particularly important as they affect humans and animals. Lineages, such as ST117, are predominant in poultry and frequent carriers of antibiotic resistance, presenting a risk to humans handling or ingesting poultry products. We analyzed ExPEC isolates causing outbreaks in Brazilian poultry, focusing on the ST117 as the most detected lineage. Genomic comparisons with international isolates from humans and animals were performed describing the potential zoonotic profile. The Brazilian ST117 isolates carried resistance determinants against critical antibiotics, mainly on plasmids, in some cases identical to those carried by international isolates. South American ST117 isolates from all sources generally exhibit more resistance, including to critical antibiotics, and worldwide, the vast majority of human isolates belonging to this lineage have a predicted poultry origin. As the world's largest poultry exporter, Brazil has an important role in developing strategies to prevent the dissemination of multidrug-resistant zoonotic ExPEC strains.

Presence of carbapenem resistance in hybrid Escherichia coli pathovars from ready-to-eat fresh-cut fruits in Accra, Ghana

AIM

This study reports the presence of carbapenem-resistant Escherichia coli hybrid pathovars and its prevalence in 200 fresh-cut fruits from Accra.

METHODS AND RESULTS

Standard culture methods were used to quantify microbial indicators and E. coli on fresh-cut fruits retailed in formal and informal outlets in Accra. The Kirby-Bauer disc diffusion method was used to determine the antibiotic resistance profile of E. coli, while multiplex PCR was employed to identify the virulence and carbapenem-resistance genes. Escherichia coli prevalence in cut fruits was 17%, with pawpaw, watermelon, and mixed fruit having higher prevalence than pineapple. Of the 34 E. coli isolates from fresh-cut fruits, 44% showed broad resistance to beta-lactam antibiotics, while 5.9% showed carbapenem resistance. The study identified virulence genes associated with all E. coli isolates, including stx1, stx2, escV, and ipaH, of which 97% were hybrid pathovars bearing genes for Shiga toxin-producing E. coli/enteropathogenic E. coli/enteroinvasive E. coli. The carbapenemase gene, blaIMP, was associated with both carbapenem-resistant E. coli phenotypes identified.

CONCLUSION

Despite a low-carbapenem-resistance prevalence observed among E. coli isolates, hypervirulent hybrid strains of E. coli is present in fresh-cut fruits in the sampling area, posing a potential public health risk to fresh-cut fruit consumers.

Carbapenem-resistant Enterobacterales in wastewater resources and healthy carriers: A survey in Iran

The carbapenem-resistant Enterobacterales (CRE) pose a pressing public health concern. Here, we investigated the frequency of CRE bacteria, carbapenemase-encoding genes, and the molecular epidemiology of carbapenemase-resistant Escherichia coli in wastewater resources and healthy carriers in Iran. Out of 617 Enterobacterales bacteria, 24% were carbapenem-resistant. The prevalence of CRE bacteria in livestock and poultry wastewater at 34% and hospital wastewater at 33% was significantly higher (P ≤ 0.05) than those in healthy carriers and municipal wastewater at 22 and 17%, respectively. The overall colonization rate of CRE in healthy individuals was 22%. Regarding individual Enterobacterales species, the following percentages of isolates were found to be CRE: E. coli (18%), Citrobacter spp. (24%), Klebsiella pneumoniae (28%), Proteus spp. (40%), Enterobacter spp. (25%), Yersinia spp. (17%), Hafnia spp. (31%), Providencia spp. (21%), and Serratia spp. (36%). The blaOXA-48 gene was detected in 97% of CRE isolates, while the blaNDM and blaVIM genes were detected in 24 and 3% of isolates, respectively. The B2 phylogroup was the most prominent group identified in carbapenem-resistant E. coli isolates, accounting for 80% of isolates. High prevalence of CRE with transmissible carbapenemase genes among healthy people and wastewater in Iran underscores the need for assertive measures to prevent further dissemination.

Bioactive Compounds from Plant Origin as Natural Antimicrobial Agents for the Treatment of Wound Infections

The rising prevalence of drug-resistant bacteria underscores the need to search for innovative and nature-based solutions. One of the approaches may be the use of plants that constitute a rich source of miscellaneous compounds with a wide range of biological properties. This review explores the antimicrobial activity of seven bioactives and their possible molecular mechanisms of action. Special attention was focused on the antibacterial properties of berberine, catechin, chelerythrine, cinnamaldehyde, ellagic acid, proanthocyanidin, and sanguinarine against Staphylococcus aureus, Enterococcus spp., Klebsiella pneumoniae, Acinetobacter baumannii, Escherichia coli, Serratia marcescens and Pseudomonas aeruginosa. The growing interest in novel therapeutic strategies based on new plant-derived formulations was confirmed by the growing number of articles. Natural products are one of the most promising and intensively examined agents to combat the consequences of the overuse and misuse of classical antibiotics.

Defying the odds: Determinants of the antimicrobial response of Salmonella Typhi and their interplay

Salmonella Typhi, the invasive serovar of S. enterica subspecies enterica, causes typhoid fever in healthy human hosts. The emergence of antibiotic-resistant strains has consistently challenged the successful treatment of typhoid fever with conventional antibiotics. Antimicrobial resistance (AMR) in Salmonella is acquired either by mutations in the genomic DNA or by acquiring extrachromosomal DNA via horizontal gene transfer. In addition, Salmonella can form a subpopulation of antibiotic persistent (AP) cells that can survive at high concentrations of antibiotics. These have reduced the effectiveness of the first and second lines of antibiotics used to treat Salmonella infection. The recurrent and chronic carriage of S. Typhi in human hosts further complicates the treatment process, as a remarkable shift in the immune response from pro-inflammatory Th1 to anti-inflammatory Th2 is observed. Recent studies have also highlighted the overlap between AP, persistent infection (PI) and AMR. These incidents have revealed several areas of research. In this review, we have put forward a timeline for the evolution of antibiotic resistance in Salmonella and discussed the different mechanisms of the same availed by the pathogen at the genotypic and phenotypic levels. Further, we have presented a detailed discussion on Salmonella antibiotic persistence (AP), PI, the host and bacterial virulence factors that can influence PI, and how both AP and PI can lead to AMR.

Occurrence and characterization of NDM-5-producing Escherichia coli from retail eggs

The New Delhi Metallo-β-lactamase (NDM) producing Enterobacterales has been detected from diverse sources but has rarely been reported in retail eggs. In this study, 144 eggshell and 96 egg content samples were collected in 2022 from Guangdong province and were screened for NDM-producing strains. Four Escherichia coli strains (ST3014, ST10, ST1485, and ST14747) recovered from two (1.39%, 2 of 144) eggshells and two (2.08%, 2 of 96) egg content samples were identified as blaNDM-5-positive strains. Oxford Nanopore MinION sequencing and conjugation assays revealed that the blaNDM-5 gene was carried by IncX3 (n = 1), IncI1 (n = 1), and IncHI2 (n = 2). The IncI1-plasmid-carrying blaNDM-5 displayed high homology with one plasmid pEC6563-NDM5 from the human clinic, while the IncHI2 plasmid harboring blaNDM-5 shared highly similar structures with plasmids of animal origin. To the best of our knowledge, this is the first report on the identification of blaNDM-5-positive bacteria in retail eggs. NDM-producing E. coli could be transmitted to humans by the consumption of eggs or direct contact, which could pose a potential threat to human health.