Antimicrobial activity of lactic acid
bacteria on pathogens in foods
Prof.Dr. Dilek Heperkan
Istanbul Technical University,
Faculty of Chemical and Metallurgical
Engineering, Dept. of Food Engineering
Food Technology2014 21-23 July, Las Vegas
Microorganisms especially bacteria can be used for a number of beneficial purposes. Among them some are more prominent like Lactic acid bacteria (LAB) and bifidobacteria.
Lactic acid bacteria have been used as natural food-grade preservatives against a variety of undesirable microorganisms.
LAB has been used for production of fermented foods for many years. As a matter of fact fermented foods existed long before mankind discovered microorganisms.
During their activity in production of fermented foods their inhibitory potential on pathogenic bacteria have been recognised and they gained increasing interest in the scientific community.
Thus LAB has been used as a tool to produce antimicrobial compounds and to control undesirable microorganisms.
On the other hand, acute diarrhea due to the loss of normal intestinal microbiota, drug-resistant strains and chronic toxicity due to widespread use of antibiotics are well known negative effects of antibiotics.
The risks of toxic residues in foods, as well as contamination of soil and water due to the use of xenobiotics in food production chain are considered negatively by the public.
Lab producing a wide range of antimicrobial metabolites thus, the last two decades have seen pronounced advancements in using LAB and their metabolites for natural food preservation, as well as crop protection, and health protection.
EMERGING FOODBORNE PATHOGENS
Prof. Dr. İrfan EROL, DVM, Ph.D.
Turkish Representative of World Vet. Assoc.
Department of Food Hygiene and Technology
School of Veterinary Medicine
Despite advances in hygiene, consumer knowledge, food treatment and processing, foodborne diseases mediated by pathogenic microorganisms or microbial toxins still represent a significant treat to public health worldwide.
Globally, the WHO has estimated that approximately 1.5 billion episodes of diarrhea and more than 3 million deaths occurred in children under 5 years of age, and a significant proportion of these results from consumption of food mainly food of animal origin with microbial pathogens and toxins
Emerging & Reemerging Zoonotic Diseases
60 % of the human pathogens are zoonotic
75 % of emerging zoonotic
Emerging Foodborne Pathogens
those causing illnesses that have only recently appeared or been recognised in a population or that are well recognised but are rapidly increasing in incidence or geographic range
Emerging Foodborne Diseases
Extended to new vehicles of transmission
Started to increase rapidly in incidence or geographic range
Been widespread for many years but only recently identified through new or increased knowledge or methods of identification and analysis of the disease agent
Emerging Foodborne Diseases
Pose a threat to all persons; no matter on age, sex, lifestyle or socio-economic status etc.
Feel pain and death
Emerging Foodborne Diseases
Changes in environment (technology, climate, etc)
Mass production and globalisation of food supply
International travel and trade
Changing character of the population
Breakdown in public health
Emerging Foodborne Pathogens
Emerging foodborne bacteria
Salmonella (multidrug resistant strain)
E. coli O157:H7
S. aureus MRSA
Emerging foodborne viruses
Hepatit A and E
(Avian influenza, AI)
Emerging foodborne parasites
WHO Surveillance Programme for Control of Foodborne Infections and Intoxications in Europe 8th Report 1999-2000 Country Reports: Turkey
Salmonella serotype distribution in Turkey
(Erol et al., 2009)
S. Kentucky Spices
Some Important Campylobacter Outbreaks in the World
Quinolone- and fluoroquinolone-resistant Campylobacter jejuni in the United States, 1982–2001
Thermophilic Campylobacter spp. in turkey meat (n=270)
(Cakmak and Erol, 2009)
Thermophilic Camylobacter spp. 123 (45.5%)
C. jejuni 109 (40.3 %)
C. coli 11 ( 4.0 %)
Not typed 3
Antibiotic resistance profile of C. jejuni isolates in turkey meat (Cakmak and Erol, 2009)
E. coli O157:H7 isolates found in fecal samples of cattle and sheep at slaughter in Turkey (Erol et al., 2008)
Toxin profiles of 11 E. coli O157:H7 isolates within the PFGE groups in cattle in Turkey (Erol et al., 2008)
Some Important Listeria outbreaks in the World
Contamination level of turkey meat with
monocytogenes is 17.8 % (32/180)
(Ayaz and Erol 2008)
L. monocytogenes serotype distribution
44.9 % 1/2a
37.2 % 4b
9.0 % 1/2b
9.0 % 1/2c
Antibiotic resistance profiles of L. monocytogenes in turkey meat (n:24) (Ayaz and Erol, 2008)
Occurrence of Cryptosporidium spp. oocysts in Turkey
(Kursun and Erol, 2003)
It’s a global concern of the antibiotic resistance of major foodborne pathogens such as;
Salmonella Typhimurium DT 104
Staphylococcus aureus (MRSA)
Risk management Epidemiological evaluation /
Control of Foodborne Disease
From farm to table approach
Implementation of GMP and HACCP
Public Health Approach
Public health system
Epidemiology for earlier diagnosis
Early response to outbreaks
Provide to disease patterns changing
Public health lab. support for rapid and accurate diagnosis
Rapid communication links
Communication to public
Education on prevention and/or detection
Factors contributing to the global incidence of foodborne disease
Poor sanitary conditions
Changing demographics (increasing population of infants, elderly)
Inadequate public health infrastructure
Inadequate hygienic and technological conditions of food production
Inadequate cooking, reheating and storage conditions
Increasing tourism and international trade
Increasing animal movement and insufficient control of borders
Increasing international trade of animal and food
Inadequate legislation and official control system
Emerging/reemerging foodborne pathogens
Acquisition of virulence and antibiotic genes by nonpathogenic bacteria
Adaptation and enhanced survival of pathogens in food
Inadequate consumer education
outbreak in Turkey
Although there is a religious restriction on pork meat consumption, in January 2004 there was a big trichinellosis outbreak occurred by consuming çiğ köfte (raw ground meat ball-traditional food) in Izmir
542 people were affected and samples were found to be contaminated with T. britovi
One World One Health (OWOH)
The medical and veterinary professions have a common interest in many diseases, primarily zoonotic diseases such as BSE, SARS and, most recently, Avian Influenza (H5N1), have highlighted the need for interprofessional collaboration not just locally and nationally, but on a global scale.
Improving animal and human health globally through collaboration among all the health sciences, especially between the veterinary and human medical professions to address critical needs.
Membrane filtration systems are especially used when the sample like drinking water or fruit j uices which can easily pass through the filter and contain really small amount of microorganisms less than 1 CFU/ ml.
About coliform bacteria and why do we do this test:
Coliform bacteria are present in the environment and feces of all warm-blooded animals and humans. Coliform bacteria are unlikely to cause illness. However, their presence in drinking water indicates that disease-causing organisms (pathogens) could be in the water system. Most pathogens that can contaminate water supplies come from the feces of humans or animals. Testing drinking water for all possible pathogens is complex, time-consuming, and expensive. It is easy and inexpensive to test for coliform bacteria. If testing detects coliform bacteria in a water sample, water services search for the source of contamination and restore safe drinking water. There are three groups of coliform bacteria. Each is an indicator of drinking water quality and each has a different level of risk. Total coliform is a large collection of different kinds of bacteria. Fecal coliform are types of total coliform that exist in feces. E. coli is a subgroup of fecal coliform. Labs test drinking water samples for total coliform. If total coliform is present, the lab also tests the sample for fecal coliform or E. coli, depending on the lab testing method. Total coliform bacteria are common in the environment (soil or vegetation) and are generally harmless. If a lab detects only total coliform bacteria in drinking water, the source is probably environmental and fecal contamination is unlikely. However, if environmental contamination can enter the system, pathogens could get in, too. It is important to find and resolve the source of the contamination. Fecal coliform bacteria are a subgroup of total coliform bacteria. They exist in the intestines and feces of people and animals. The presence of fecal coliform in a drinking water sample often indicates recent fecal contamination. That means there is a greater risk that pathogens are present. E. coli is a subgroup of the fecal coliform group. Most E. coli bacteria are harmless and exist in the intestines of people and warm-blooded animals. However, some strains can cause illness. The presence of E. coli in a drinking water sample usually indicates recent fecal contamination. That means there is a greater risk that pathogens are present. Note: E. coli outbreaks receive a lot of media coverage. A specific strain of E. coli bacteria known as E. coli O157:H7 causes most of those outbreaks. When a drinking water sample is reported as “E. coli present,” it does not mean that O157:H7 is present. However, it does indicate recent fecal contamination. Boiling or disinfecting contaminated drinking water destroys all forms of E. coli, including O157:H7.
Producing Safe Food is Our Top Priority!
• Consumer protection and trust
– Consumers must be able to trust the brands they buy and the food they
– Food safety is absolutely critical to that trust
• Business survival/self-interest
– Our brands are our most important asset
– History is replete with brands and businesses being destroyed because
• Industry responsibility
– Moral obligation to produce food as safe as practical
– Industry pledge not to make safety a competitive issue eat of a lapse in food safety
Why is Food Safety our Top Priority?
• It is a cost of doing business
• The changing global food safety landscape demands more diligence, flexibility, and speed than ever before.
• The cost impact of not doing food safety right is higher than it’s ever been.
• The benefits of doing food safety right contributes directly to the bottom line – and not just in cost avoidance.
• Consumer and regulatory scrutiny are at an all time high.
• World class companies that win in the marketplace have world class food safety principles.
Causes of Foodborne Contamination
• Food Products can become contaminated via several routes:
– Naturally occurring (raw foods)
– Underprocessing/improper processing
• Spoilage organisms
• Chemical contaminants
– Intentional contamination
• Economic adulteration (e.g melamine)