--- title: Antimicrobial Resistance in Bacteria date: 2012-07-12T15:56:00-07:00 author: admin canonical_url: "https://marlerclark.com/foodborne-illnesses/listeria/antimicrobial-resistance-in-bacteria" section: Resource Library --- [Foodborne Illnesses](/foodborne-illnesses) / [Listeria](https://marlerclark.com/foodborne-illnesses/listeria) / # Antimicrobial Resistance in Bacteria ### Antimicrobial resistance is increasing in foodborne pathogens. Antimicrobial resistance in bacteria is an emerging and increasing threat to human health. Physicians are increasingly aware that antimicrobial resistance is increasing in foodborne pathogens and that, as a result, patients who are prescribed antibiotics are at increased risk for acquiring antimicrobial-resistant foodborne infections. Indeed, “increased frequency of treatment failures for acute illness and increased severity of infection may be manifested by prolonged duration of illness, increased frequency of bloodstream infections, increased hospitalization, or increased mortality.” *L. monocytogenes*, in general, is considered vulnerable to a wide range of antibiotics that have bactericidal effects against Gram-positive bacteria, including, tetracyclines, erythromycin, ampicillin, and gentamicin. However, most strains of *L. monocytogenes* exhibit native resistance to cefotaxime, cefepime, fosfomycin, oxacillin, and licosamides. Recently, antibiotic resistance among *L. monocytogenes* isolated from foods and the environment has increased, particularly for those antibiotics commonly used to treat listeriosis. Therefore, monitoring changes in the antibiotic resistance of *L. monocytogenes* due to the continuing emergence of resistant strains is needed. The use of antimicrobial agents in the feed of food animals is estimated by the FDA to be over 100 million pounds per year. It is estimated that 36% to 70% of all antibiotics produced in the United States are used in a food animal feed or in prophylactic treatment to prevent animal disease. While antibiotics are commonly and broadly used in animal production, there is a lack of substantial research on the impacts to human health and benefits to the food industry. Additionally, there is high variability with policies around their use. The unnecessary use of antibiotics in feed for food animals, on animals prophylactically to prevent disease, and in humans must be reduced. European countries have reduced the use of antibiotics in animal feed and have seen a corresponding reduction in antibiotic-resistant illnesses in humans. Researchers have found that *Listeria monocytogenes* have varying resistance to certain antibiotics, depending on the strain. Many of these strains with resistance genes are isolated from food samples and food production areas. *Listeria innocua,* another similar species also found in food environments, more commonly displays antibiotic resistance and can be valuable for research. There is concern that *L. monocytogenes* strains will continue to acquire antibiotic resistance from shared genetic materials and environmental persistence, making severe illness harder to treat. This is especially concerning when the antibiotic resistance is seen in foods that are considered ready-to-eat (RTE) and thus less likely to have a control step before consumption. This research study discovered: > In the present study, *Listeria* isolates from RTE meat products displayed higher overall antimicrobial resistance (31.3%) than those from the environment (13.4%). Similarly, Kovacevic et al. indicated that antibiotic resistance was more commonly observed for *L. monocytogenes* in RTE foods than in processing environment samples, describing a co-selection phenomenon in which repeated exposure to sub-lethal concentrations of some antimicrobials (i.e. ciprofloxacin) may produce derivative strains possessing increased tolerance to the respective selective agent as well as increased tolerance to other antibiotics. [ Next: The Economic Impact of Listeria Infections › ](https://marlerclark.com/foodborne-illnesses/listeria/the-economic-impact-of-listeria-infections) ### More information about Listeria [August 23, 2023 ###### Listeria outbreak: Three die after drinking contaminated milkshakes Three people have died, and three others are in hospital after drinking milkshakes contaminated with listeria bacteria in the US state of Washington, health officials say. Marler Clark, the Listeria ... ](https://marlerclark.com/news_events/listeria-outbreak-three-die-after-drinking-contaminated-milkshakes) [July 12, 2023 ###### 2011 Listeria outbreaks linked to cantaloupes: A history A total of 148 persons infected with any of the five outbreak-associated strains of Listeria monocytogenes were reported to the CDC from 28 states. The number of infected persons identified ... ](https://marlerclark.com/news_events/2011-listeria-outbreak-linked-to-cantaloupes-a-history) [March 26, 2023 ###### Listeria linked to yogurt prompts recall Clio Snacks of Piscataway, New Jersey, is voluntarily recalling 581 cases of its Strawberry Granola & Greek Yogurt Parfait Bar due to potential contamination with Listeria monocytogenes, an organism which ... ](https://marlerclark.com/news_events/listeria-linked-to-yogurt-prompts-recall) [November 20, 2022 ###### Enoki Mushrooms recalled again As of November 15, 2022, two people infected with the outbreak strain of Listeria have been reported from two states. Sick people’s samples were collected from October 5, 2022, to October 8, 2022. ... ](https://marlerclark.com/news_events/enoki-mushrooms-recalled-again) [1. View all ](/news_events/outbreaks?illness=listeria&year=all) ## All Listeria Resources [###### Listeria Food Poisoning ](https://marlerclark.com/foodborne-illnesses/listeria/about-listeria) [###### The Incidence of Listeria Infections ](https://marlerclark.com/foodborne-illnesses/listeria/the-incidence-of-listeria-infections) [###### The Prevalence of Listeria in Food and the Environment ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-prevalence) [###### Transmission of and Infection with Listeria ](https://marlerclark.com/foodborne-illnesses/listeria/transmission-of-and-infection-with-listeria) [###### Who is Most at Risk of Becoming Ill with Listeria? ](https://marlerclark.com/foodborne-illnesses/listeria/who-is-most-at-risk-for-becoming-ill-with-listeria) [###### What Are the Symptoms of Listeria Infection? ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-symptoms-risks) [###### Complications of Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/complications-of-listeria-infection) [###### How is Listeria Infection Diagnosed? ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-diagnosis) [###### Treatment for Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-treatment) [###### Antimicrobial Resistance in Bacteria ](https://marlerclark.com/foodborne-illnesses/listeria/antimicrobial-resistance-in-bacteria) [###### The Economic Impact of Listeria Infections ](https://marlerclark.com/foodborne-illnesses/listeria/the-economic-impact-of-listeria-infections) [###### Preventing Listeria Infection ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-prevention) [###### Listeria References ](https://marlerclark.com/foodborne-illnesses/listeria/listeria-references) ### Other foodborne illnesses [E. coli](https://marlerclark.com/foodborne-illnesses/e-coli) [Salmonella](https://marlerclark.com/foodborne-illnesses/salmonella) [Hepatitis A](https://marlerclark.com/foodborne-illnesses/hepatitis-a) [Reactive Arthritis](https://marlerclark.com/foodborne-illnesses/reactive-arthritis) [Guillain-Barre Syndrome](https://marlerclark.com/foodborne-illnesses/guillain-barre-syndrome) [Irritable Bowel Syndrome](https://marlerclark.com/foodborne-illnesses/irritable-bowel-syndrome) [Norovirus](https://marlerclark.com/foodborne-illnesses/norovirus) [Botulism](https://marlerclark.com/foodborne-illnesses/botulism) [Campylobacter](https://marlerclark.com/foodborne-illnesses/campylobacter) [Shigella](https://marlerclark.com/foodborne-illnesses/shigella) [Cyclospora](https://marlerclark.com/foodborne-illnesses/cyclospora) [Hemolytic Uremic Syndrome](https://marlerclark.com/foodborne-illnesses/hemolytic-uremic-syndrome)