There are two different microbial pathogens we are to discuss namely, Escherichia coli and Listeria monocytogenes that affect pregnant women and the unborn foetus upon eating (or coming into contacting) with infected meat. Listeria monocytogenes is a facultative anaerobic bacteria which causes the infection called Listeriosis. Escherichia coli is a bacteria that is commonly found in the lower intestine of warm blooded organisms, most E.coli strains are harmless, but some can cause serious food poisoning. Shiga toxin-producing E-coli (STEC) is a bacterium that can cause severe foodborne disease, its primary sources are raw or undercooked meat products, raw milk and faecal contamination of vegetables.
Diagnosis and Symptoms
A pathogenic microbial organism that can be found in raw meat, (uncooked vegetables and unpasteurized dairy products). Infection from the pathogen causes a diseases called Listeriosis. In pregnant woman the infection can start from the implantation of the foetus through birth. It can be devastating to the mother, sometimes leading to miscarriage/abortion and can be fatal to the unborn child.
Symptoms of the infected mother can be asymptomatic but the following are common: flu-like illness, fever, headache, backache, sore throat, muscle pains, vomiting, diarrhoea.
Diagnosis of listeria infection in pregnant women may be difficult due to the lack of GI symptoms normally associated with food-borne pathogens and non-specific symptoms of fever. Diagnosis can only be made by culturing the pathogenic micro-organism from blood, amniotic fluid, or spinal fluid. Vaginal or stool cultures are not helpful in diagnosis because some women are only carriers of the pathogen.
Escherichia Coli (E.coli)
E.coli is a bacteria that can be found naturally in GI and urinary tracts because it can be harmless and beneficial. Some strains of the bacteria can be pathogenic leading to serious infections in humans. One common infectious source of the pathogenic E.coli is an uncooked meat. This strain of E.coli may have severe effects such as miscarriage and low birth weight if its source infect a pregnant woman.
Symptoms during pregnancy: nausea, abdominal cramps, diarrhoea, vomiting, fatigue, dehydration, bloody urine, fever.
Stomach and kidney problems can be used as lead to the diagnosis of the pathogenic E.coli in pregnant woman. Continuous screening of the urine culture during pregnancy is the most common way in the diagnosis of the pathogenic strain of E.coli.
Sometimes listeria affects people in a minor way, so medication is not required. For more dire cases antibiotics are the most common treatment, ampicillin can be used alone or in conjunction with another antibiotic, often gentamicin. If septicaemia or meningitis occur, the individual will be given intravenous antibiotics and require up to six weeks of care and treatment.
For an antibiotic to be effective against listeria, it must penetrate into the host cell and maintain high intracellular concentration. It must bind to the penicillin-binding protein 3 (PBP3) of listeria which causes cell death.
In pregnant women, the antibiotic must cross the placenta in adequate concentration. Penicillin, ampicillin and amoxillin block several PBPs and do not penetrate intracellularly. High doses are generally used to assure adequate penetration of the umbilical cord and placenta. 6g or more a day is recommended of ampicillin for treatment during pregnancy. This dosage provides adequate intracellular penetration and crosses the placenta in adequate amounts.
Nitrofurantoin and cephalosporins can be used to treat pregnant women who have been infected with E. coli. Nitrofurantoin is a good choice of antibiotic because of its high urinal concentration. Cephalosporins are well tolerated and adequately treat the important organism.
Control of Disease
Listeria is a name of a bacteria found in soil and water and some animals, including poultry and cattle. It can be present in raw milk and foods made from raw milk. Pregnant women have high risk of being affected by this bacteria but it can be prevented by the following:
- Do not drink raw (unpasteurized) milk, and do not eat foods that are made from unpasteurized milk.
- Wash hands, knives, countertops and cutting boards after handling and preparing uncooked food.
- Rinse raw produce thoroughly under running tap water before eating.
- Keep uncooked meats, poultry and sea food separate from vegetables, fruits, and cooked food and ready to eat food.
- Thoroughly cook raw food from animal sources such as meat, poultry or sea food to a safe internal temperature.
- Persons in higher risk groups should heat hot dogs, cold nuts and deli meat before eating them.
The prevention of E.coli infection requires control measures at all stages of food chain, from agricultural production on the farm to processing, manufacturing and preparation of foods in both commercial establishments and household kitchens.
The number of cases of disease might be reduced by various mitigation strategies for ground beef. Good hygienic slaughtering practices reduce contamination of carcasses by faeces, but do not guarantee the absence of STEC from products.
Education in hygienic handling of food for workers at farms, abattoirs and those involved in food production is essential to keep microbial contamination to a minimum. The only effective method of eliminating STEC from foods is to introduce bactericidal treatment such as heating and irradiation.
Preventive measures for E. coli infection are similar to those recommended for other foodborne diseases, and also protect against foodborne diseases caused by STEC.
Most of severe diseases are caused by microorganisms, contamination can happen from slaughtering, handling, packaging, storage and transportation of food. Safety measures need to be taken in each and every step mentioned. Pregnant women and low immune system are the people that are at higher risk of these microorganisms. In the process of slaughtering, microbial contamination of carcass surfaces is unavoidable, while most of the micro floras transferred to the carcasses are non-pathogenic, there is possibility that pathogens such as E.coli and Listeria monocytogenes may be present and it presents one of the most critical safety challenges for the meat industry.