Category Archives: Antibacterial

Research – FAO and the Republic of Korea join forces to reduce foodborne antimicrobial resistance


The Food and Agriculture Organization of the United Nations (FAO) and the Republic of Korea, through its Ministry of Food and Drug Safety (MFDS), today signed a new Framework Arrangement which establishes overarching terms and conditions that will govern the cooperation through voluntary contributions and facilitate future negotiations between MFDS and FAO.

The Arrangement focuses on food safety and standard setting, and contains a Contribution Arrangement which will help to simplify the implementation of individual projects.

The Republic of Korea will provide $10 million to help implement and monitor Codex Alimentarius international food standards, with the goal of containing and reducing foodborne antimicrobial resistance (AMR). AMR not only poses a major threat to human and animal health, but also has serious implications for food safety, food security and the economic wellbeing of millions of farming households.

The first project under the Arrangement will be implemented by the Joint FAO/WHO Centre on CODEX Food Standards and Zoonotic Diseases the FAO Division on Food Systems and Food Safety, and will focus on implementing Codex standards to support containment and reduction of foodborne AMR in six countries: Cambodia, Mongolia, Pakistan, Nepal, Bolivia and Colombia.

Signing on behalf of FAO, Deputy Director-General, Beth Bechdol, praised the Republic of Korea’s continuous interest and effort to increase cooperation with FAO and its deep commitment for the development of international food standards and to the Codex Alimentarius. “The COVID-19 pandemic has shown us how important it is to boost international food safety standards to ensure our food keeps travelling safely across borders, safeguarding food and nutritional security. We must transform our agri-food systems to make them more resilient and inclusive if we are to ensure a better food future for all.”

Since joining FAO as a recipient country in 1949, the Republic of Korea has transformed into a major G-20 economy and a dedicated FAO resource partner. The country is a long-standing Member and strong supporter of the Codex Alimentarius Commission, which sets international and regional standards, guidelines and codes of practice. The broad scope of Codex, which covers areas such as contaminants, nutrition, food hygiene, additives, antimicrobial resistance and pesticide and veterinary drug residues, makes it an essential tool to achieve food security and end hunger.

Jinseok Kim, Vice Minister of the MFDS welcomed the new Arrangement as a way to streamline and enhance the long-lasting cooperation between FAO and the Republic of Korea, and, in the years to come, as a basis for both parties to increase interventions within their joint areas of interest.

“Without global collaboration, we cannot overcome the difficulties due to the pandemic and I believe this is why we are here today: to work together,” Vice Minister Kim affirmed. “It is our responsibility to support other countries, and the most effective way to do this is through FAO, the key player in food safety in the UN.  It is essential to continue to move forward, and as of today Korea would like to play a leading role in world food safety.”

The Republic of Korea currently hosts the Codex ad hoc Intergovernmental Task Force on Antimicrobial Resistance (TFAMR), which is charged with developing science-based guidance on the management of foodborne antimicrobial resistance. The TFAMR is expected to complete its work in 2021.

In addition to hosting the TFAMR and supporting international standard development, the Republic of Korea leads by example in its own efforts to minimize and contain AMR in the food chain, and has expressed a desire to assist other countries in addressing AMR, by supporting the transition from standard-setting to the implementation of Codex guidance, with the collaboration and support of FAO.

Research – Antibacterial activity of sweet orange (Citrus sinensis) juice extract on selected bacteria


Plants have potentials to be developed into many new drugs yet to be discovered because of the countless chemical compositions in them. The investigation is targeted at the antibacterial activity of sweet orange juice extract on some bacteria using ethanol and ethyl ethanoate solvent to extract juice. Ditch method was used for the sensitivity testing against Escherichia coliStaphylococcus aureusKlebsiella pneumoniae and Neisseria gonorrheae with a dilution factor of 10-10 for inoculation from pure culture of each selected bacteria. Disc method was used to test streptomycin, ciprofloxacin, gentamycin and penicillin G against test organisms as positive controls. There was no significant difference in the effect of different concentrations of the same extract on test organisms. However, there was a significant difference in the ethyl ethanoate and alcohol extracts. The ethyl ethanoate extract showed minimum inhibitory concentration at 300 mg/ml on E. coli (31.5 ± 0.5 mm); Ngonorrheae (21 ± 0.0 mm) at 200 mg/ml; Saureus (22 ± 0.0 mm) and Kpneumoniae (37 ± 3.0 mm) at 100 mg/ml; while ethanol extract at 100 mg/ml on E. coli (23.5 ± 1.5 mm) and Kpneumoniae (25 ± 5.0 mm);  N. gonorrheae (13.5 ± 1.0 mm) and S. aureus (12.5 ± 2.5 mm) at 300 mg/ml and 200 mg/ml respectively. The zones of inhibition exhibited by streptomycin ranges from Ngonorrheae (14-24 mm) E. coli; ciprofloxacin varies from 15- 21 mm on K. pneumoniae and S. aureus respectively. Gentamycin ranges from 14-20 mm on N. gonorrheae and S. aureus respectively; and penicillin G on N. gonorrheae (14 mm) and Saureus (28 mm). It can be concluded that sweet orange juice of ethyl ethanoate extract was more effective than the ethanol extract and the positive control.

Research – Bacteria Broadly-Resistant to Last Resort Antibiotics Detected in Commercial Chicken Farms


Resistance to last resort antibiotics in bacteria is an emerging threat to human and animal health. It is important to identify the source of these antimicrobial resistant (AMR) bacteria that are resistant to clinically important antibiotics and evaluate their potential transfer among bacteria. The objectives of this study were to (i) detect bacteria resistant to colistin, carbapenems, and β-lactams in commercial poultry farms, (ii) characterize phylogenetic and virulence markers of E. coli isolates to potentiate virulence risk, and (iii) assess potential transfer of AMR from these isolates via conjugation. Ceca contents from laying hens from conventional cage (CC) and cage-free (CF) farms at three maturity stages were randomly sampled and screened for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae, carbapenem-resistant Acinetobacter (CRA), and colistin resistant Escherichia coli (CRE) using CHROMagar™ selective media. We found a wide-spread abundance of CRE in both CC and CF hens across all three maturity stages. Extraintestinal pathogenic Escherichia coli phylogenetic groups B2 and D, as well as plasmidic virulence markers iss and iutA, were widely associated with AMR E. coli isolates. ESBL-producing Enterobacteriaceae were uniquely detected in the early lay period of both CC and CF, while multidrug resistant (MDR) Acinetobacter were found in peak and late lay periods of both CC and CF. CRA was detected in CF hens only. blaCMY was detected in ESBL-producing E. coli in CC and CF and MDR Acinetobacter spp. in CC. Finally, the blaCMY was shown to be transferrable via an IncK/B plasmid in CC. The presence of MDR to the last-resort antibiotics that are transferable between bacteria in food-producing animals is alarming and warrants studies to develop strategies for their mitigation in the environment. View Full-Text

Research – Prevalence, Concentration, and Antimicrobial Resistance Profiles of Salmonella Isolated from Florida Poultry Litter

Journal of Food Protection


For over a decade, Salmonella contamination has increasingly led to outbreaks of foodborne illness associated with fresh produce. The use of untreated animal manures, or biological soil amendments of animal origin, to amend agricultural soils holds a risk of contamination from foodborne pathogens, such as Salmonella. This study was conducted to determine the prevalence, concentration, serotypes, and antimicrobial resistance profiles of Salmonella in poultry litter from Florida farms. Litter pH, total Kjeldahl nitrogen, total ammonia nitrogen, total phosphorus (P2O5), total potassium (K2O), moisture content, total solids, total ash, organic matter, and aerobic plate count (APC) were also measured. Litter samples (n = 54) were collected from 18 broiler farms across three seasons (spring, summer, and winter). Salmonella concentrations were enumerated using a most-probable-number (MPN) method, and antimicrobial susceptibility testing was performed. The prevalence of Salmonella in litter samples was 61.1%, with a geometric mean of 0.21 ± 20.7 MPN/g. Across all seasons, Salmonella concentrations were not influenced by the chemical, physical, or microbial properties measured. Recovered Salmonella isolates (n = 290) were grouped into serogroups O:4 (43.1%), O:7 (26.9%), O:8 (11.0%), O:1,3,10,19 (7.9%), and O:9,46 (7.2%). Serotyping Salmonella isolates (n = 47) resulted in 12 serotypes, with the most common being Typhimurium (27.7%), Kentucky (17.0%), Enteritidis (14.9%), and Mbandaka (14.9%). Antimicrobial resistance to tetracycline (29.8%), sulfisoxazole (23.4%), and streptomycin (14.9%) was observed. No isolates were resistant to more than two antimicrobial agents. This study provides valuable information for future risk assessments for the use of poultry litter as an untreated biological soil amendment of animal origin.

  • Prevalence and concentration of Salmonella in Florida poultry litter were examined.
  • Serovars Typhimurium, Kentucky, Enteritidis, and Mbandaka were most common.
  • Antimicrobial resistance to tetracycline, sulfisoxazole, and streptomycin was seen.
  • Multidrug-resistant Salmonella isolates were not observed.

Research – Innovative Antimicrobial Chitosan/ZnO/Ag NPs/Citronella Essential Oil Nanocomposite—Potential Coating for Grapes – Antimicrobial


New packaging materials based on biopolymers are gaining increasing attention due to many advantages like biodegradability or existence of renewable sources. Grouping more antimicrobials agents in the same packaging can create a synergic effect, resulting in either a better antimicrobial activity against a wider spectrum of spoilage agents or a lower required quantity of antimicrobials. In the present work, we obtained a biodegradable antimicrobial film that can be used as packaging material for food. Films based on chitosan as biodegradable polymer, with ZnO and Ag nanoparticles as filler/antimicrobial agents were fabricated by a casting method. The nanoparticles were loaded with citronella essential oil (CEO) in order to enhance the antimicrobial activity of the nanocomposite films. The tests made on Gram-positive, Gram-negative, and fungal strains indicated a broad-spectrum antimicrobial activity, with inhibition diameters of over 30 mm for bacterial strains and over 20 mm for fungal strains. The synergic effect was evidenced by comparing the antimicrobial results with chitosan/ZnO/CEO or chitosan/Ag/CEO simple films. According to the literature and our preliminary studies, these formulations are suitable as coating for fruits. The obtained nanocomposite films presented lower water vapor permeability values when compared with the chitosan control film. The samples were characterized by SEM, fluorescence and UV-Vis spectroscopy, FTIR spectroscopy and microscopy, and thermal analysis.

Research – Effectiveness of a Novel, Rechargeable, Polycationic N-halamine Antibacterial Coating on Listeria Monocytogenes Survival in Food Processing Environments


The goal of this research was to evaluate the efficacy of a novel rechargeable non-leaching polycationic N-halamine coating applied to stainless steel (STEEL) food contact surfaces to reduce Listeria monocytogenes contamination on ready-to-eat (RTE) foods. For this purpose, four L. monocytogenes strains were inoculated onto the charged (C; chlorine-activated) or uncharged (NC) N-halamine coated STEEL coupon surfaces (intact vs. scratched). After inoculation, test surfaces were incubated under different temperatures (2, 10, and 25°C) for different exposure times (0, 48, and 72 h). L. monocytogenes transfer from coated adulterated surfaces to ready to eat meat (beef sausages and roast beef) was also tested at 2 °C. Results showed that both intact-C and scratched-C coated surfaces showed significant reductions at any temperature; however, in presence of organic material, they were more effective in reducing L. monocytogenes at 2 °C and 10 °C than at 25 °C (p < 0.05). In contrast, INTACT-NC and SCRATCHED-NC increased their reduction capability at 25 °C (p < 0.05) decreasing the magnitude of difference of L. monocytogenes reduction with INTACT-C and SCRATCHED-C at the same temperature. Overall, higher L. monocytogenes reduction was observed for INTACT-C and SCRATCHED-C (≈ 4.1 ± 0.19 log CFU/cm2) than INTACT-NC and SCRATCHED-NC (≈ 2.3 ± 0.19 log CFU/cm2) at any temperature (p < 0.05). Additionally, the combination of the surface condition and chlorine presence on the N-halamine coating exposed for 2 h at 2 °C in presence of organic load (50 % meat purge) did not significantly affect the coating bactericidal efficacy. Regarding L. monocytogenes transfer to RTE meat, an overall reduction of ≈ 3.7 logs CFU/g was observed in sausages and roast beef. These findings suggest that a novel rechargeable N-halamine coating on STEEL surfaces has considerable potential to inactivate L. monocytogenes.