Bacteria - Mold Bacteria Consulting Services

Salmonella food poisoning and symptoms

Salmonella food poisoning has been a growing concern in recent news. It has frequently lead to recalls of beef, salads and organic products and, even peanut butter products. Salmonella food poisoning occurs when one eats raw or undercooked foods such meat, poultry, eggs or egg products. Properly cooked food can get contaminated with Salmonella if it comes into contact with surfaces were not cleaned properly after being used to prepare raw meat and other foods. Unhygienic handling of food can result in food contamination. People can also be exposed to Salmonella through contact with contaminated pet foods or infected animals, including reptiles, amphibians, pocket pets (hedgehogs, rodents), birds, livestock, and dogs and cats.
The illness caused by Salmonella is called salmonellosis.

Symptoms and Signs of Salmonella food poisoning

Possible signs and symptoms Salmonella food poisoning may include:

Nausea
Vomiting
Abdominal cramps
Diarrhea
Fever
Chills
Headache
Blood in the stool

How long do the symptoms of Salmonella food poisoning last?

The symptoms of salmonellosis generally occur within 6 to 72 hours after eating contaminated food or drinking water containing the bacteria. The symptoms may last for 4 to 7 days.
Most people who become ill from Salmonella bacteria will recover fully after a few days.

In severe cases, salmonellosis can cause serious illness and sometimes death. People with weakened immune system such as seniors, infants or people undergoing medical treatment are at higher risk of serious illness. In rare cases, severe complications can occur where people may experience chronic symptoms, such as reactive arthritis three to four weeks later.

Treatment for Salmonella food poisoning

Treatment of salmonellosis include drinking plenty of liquids to replace the body fluids lost through diarrhea and vomiting. In severe cases, treatment involve administering the fluids intravenously.

We can help! For more information about our Salmonella, other bacteria or mold testing services, please contact Mold & Bacteria Consulting Laboratories, please call our Ontario, Mississauga Office at 905-290-9101 or the British Columbia, Burnaby Office at 604-435-6555.

Legionella pneumophila – Guidelines for Laboratory Interpretation

Lyn Gandham

Legionella pneumophila is a Gram negative, aerobic bacteria that is characterized as an opportunistic pathogen. It is the cause of Legionnaires’ Disease, a severe form of pneumonia and, it is the cause of Pontiac fever, a non-pneumonic form of L. pneumophila infection. Legionella spp.’s mode of transmission is through aerosols or aspiration of contaminated water.

The Public Health Agency of Canada has posted an informative pathogen safety data sheet on Legionella pneumophila which can be viewed at:

http://www.phac-aspc.gc.ca/lab-bio/res/psds-ftss/legionella-eng.php

Legionella spp. can be isolated from numerous places. Samples should be transported to the lab immediately and kept cool in sterile containers. Chlorinated water should be treated with sodium thiosulfate to neutralize the chlorine. Water samples should be brought to the lab ideally within a few hours of sampling and should be stored at room temperature (20 + 5°C) in the dark.

Examples of sampling areas:

A. Potable water (1 L in sterile container):

– Municipal water (hot water tanks), hoses, well water, faucets, water fountains, sinks, respiratory therapy equipment, showers, eye washers, bottled water or cooler water systems.

Note: Collect 2 water samples from shower heads, tap water faucets, respiratory therapy equipment, water fountains, etc. First a pre-flush or first draw sample by draining the first 1 L of water from the faucets or flush drains into a bottle. Allow the water to run for approximately 1 minute and collect the second draw of 1 L of water.

B. Non-potable water (250 mL in sterile container):

– Cooling towers, humidifiers, decorative fountains, HVAC systems, dire sprinkler systems, storage tanks, basin water, hot tubs, surface water from reservoirs, misters.

C. Swabs:

– Faucet aerators, condensate pan, shower heads, condenser coils.

D. Bulk samples:

– Sludge from the bottom of a condensate pan scraped off a cooling coil.

E. Legionella Air Sampling requires the following which can be provided by MBL Inc.:

Latex gloves
70% Isopropyl alcohol to sterilize sampler after every other sample
SKC QuickTake 30 pump with Andersen N-6 single stage Impactor
BCYE (Buffered Charcoal Yeast Extract) agar

Interpretation of Legionella results:

Table 1. The following chart can be used as a guideline for interpretation of Legionella spp. results received from the laboratory.

Action (see below)

Cooling tower

100

1,000

Domestic water

100

Humidifier

Action 1: Prompt cleaning and/or biocide treatment of the system.
Action 2: Immediate cleaning and/or biocide treatment. Take prompt steps to prevent employee exposure.

(Source: From OSHA Technical Manual (Section III: Chapter 7, Legionnaires’ Disease), which was adapted from George K. Morris, PhD, and Brian G. Shelton, Pathcon Technical Bulletin 1.3, Legionella in Environmental Samples: Hazard Analysis and Suggested Remedial Actions, June 1991)

For more information on Legionella testing or to find out about our other bacteria and mold testing services, please contact Mold & Bacteria Consulting Laboratories, call our Ontario, Mississauga Office at 905-290-9101 or the British Columbia, Burnaby Office at 604-435-6555.

Heterotrophic Plate Count: What is HPC and when is the right time to use it?

Lyn Gandham

Heterotrophs are a group of microorganisms (bacteria, moulds and yeasts) that use organic carbon sources to grow and can be found in all types of water. In fact, the majority of bacteria found in drinking water systems are considered heterotrophs. Heterotrophic plate count (HPC) is a method that measures colony formation on culture media of heterotrophic bacteria in drinking water. Thus the HPC test (also known as Standard Plate Count) can be used to measure the overall bacteriological quality of drinking water in public, semi-public and private water systems.

The Limitations of HPC:

As stated by the Health Canada guidelines on HPC testing, “HPC results are not an indicator of water safety and, as such, should not be used as an indicator of potential adverse human health effects.” The World Health Organization (WHO) states that methods such as coliform testing are better indicators than HPC to test the sanitary conditions of water.

The HPC method does not indicate the specific heterotrophic bacteria present or their sources. Instead, HPC testing indicates the culturable organisms present, which could be as low as 1% of the total bacteria present. There are several factors that affect the genera of bacteria and their level of presence recovered by HPC. These factors include the type of medium used to grow the bacteria, what temperature is used for incubation, how long the plates are incubated, where the water sample was collected, the time of year and the age of the sample. It is also important to note that the concentrations and types of bacteria that are recovered at the same sampling location can vary over time.

Typically high levels of HPC bacteria in a distribution or plumbing system result from bacterial regrowth where bacteria that resisted treatment grow or those that were injured during treatment recover.

How do we interpret HPC results?

For HPC, regulations set out by Health Canada are followed under the Canadian Drinking Water Quality Guidelines: “No maximum acceptable concentration (MAC) is specified for heterotrophic plate count (HPC) bacteria in water supplied by public, semi-public, or private drinking water systems. Instead, increases in HPC concentrations above baseline levels are considered undesirable.”

In other words, sudden increases in HPC above levels typically seen may indicate a change in the quality of raw water or, that bacterial regrowth has occurred in the distribution system or plumbing. When steady increases of HPC are seen over time, this indicates a gradual decline in raw water quality.

As stated by the National Primary Drinking Water Regulations established by the U.S. EPA a “lower concentration of heterotrophic bacteria in the drinking water is linked to a better maintenance of the treatment and distribution systems.” According to these regulations, treatment techniques should aim to control HPC concentrations in surface waters and groundwaters influenced by surface waters to less than 500 CFU/mL (using standard methods). Note: “This is not a health-based standard, but reflects the concern that at concentrations above 500 CFU/mL, heterotrophic bacteria can interfere with some total coliform and E. coli recovery methods.”

Importance of HPC counts:

High HPC counts indicate ideal conditions for bacterial regrowth and should be corrected. Bacterial regrowth can lead to pipe corrosion, encourage slime growth, increase the need for disinfectants, cause foul-tasting water, and harbour secondary respiratory pathogens (ex. Legionella). Thus, HPC can be used as a marker for the underlying causes of some aesthetic problems (WHO, 2002).

Does having a positive HPC results mean the overall water quality is poor?

No, not necessarily.

Unlike other indicators, such as Escherichia coli or total coliforms, low concentrations of HPC organisms will still be present after drinking water treatment. In general, water utilities can achieve heterotrophic bacteria concentrations of 10 colony-forming units (CFU) per millilitre or less in finished water.

What are the health effects associated with HPC levels?

At an international meeting of experts in Geneva, Switzerland, it was concluded that heterotrophic bacteria in drinking water is not a health concern to the general public. However, some bacteria present in a heterotrophic population are opportunistic pathogens that could infect individuals with weakened immune systems.

“Heterotrophic bacteria belonging to the following genera have been associated with opportunistic infections: Acinetobacter, Aeromonas, Chryseobacterium (Flavobacterium), Klebsiella, Legionella, Moraxella, Mycobacterium, Serratia, Pseudomonas, and Xanthomonas. These organisms have been mainly associated with nosocomial (hospital acquired) infections, including wound infections, urinary tract infections, post-operative infections, respiratory infections, and infections in burn patients.”

What methods can be used to measure HPC?

There are 3 methods used for routine testing of heterotrophic bacteria:

Pour plate method (least desirable method because embedded colonies are slower growing and microaerobic environment is not ideal for growth and, bacteria could undergo heat shock during plating).
Spread plate method (heat shock is eliminated by using solidified agar but only a small volume (0.1-0.5 mL) can be tested).
Membrane filtration method (most flexible method because volumes upto 10L can be tested, heat shock is eliminated by membrane filter, and it is ideal for HPC less than 10 CFU/mL but multiple dilutions may be required to count colonies on filter).

Here at MBL, we use membrane filtration to measure heterotrophic plate count. If you need to determine the level of heterotrophic bacteria, fecal coliforms, E.coli, total coliforms, Legionella or other type of bacteria in water call our Mississauga office at 905-290-9101 or our toll free number at 1-866-813-0648.

References:

Health Canada (1996) Guidelines for Canadian Drinking Water Quality, 6th edn. Minister of Public Works and Government Services Canada, Ottawa, Ontario

Heterotrophic plate counts and drinking-water safety: The significance of HPCs for water quality and the human health. Edited by J. Bartram, J. Cotruvo, M.Exner, C. Fricker, A. Glasmacher.

Guidelines for Canadian Drinking Water Quality: Guideline Technical Document: Heterotrophic Plate Count (Prepared by the Federal-Provincial-Territorial Committee on Drinking Water of the Federal-Provincial-Territorial Committee on Health and the Environment (February 2006).

For access to the BC Drinking Water Protection Act and the BC Drinking Water Protection Regulation, please refer to the following website: http://www.health.gov.bc.ca/protect/dw_index.html

Guidance on the Use of Heterotrophic Plate Counts in Canadian Drinking Water Supplies (Document for Public Comment Prepared by the Federal-Provincial-Territorial Committee on Drinking Water – Consultation period ended May 27, 2011).

US EPA (1989) 40 CFR Parts 141 and 142 Drinking Water; National Primary Drinking Water Rules and Regulations; filtration, disinfection; turbidity, Giardia lamblia, viruses, Legionella, and heterotrophic bacteria; final rule. US Environmental Protection Agency. Fed. Regist. 54(124), 27486–27541.

US EPA (2001) National Primary Drinking Water Standards. EPA 816-F-01-007, March, US Environmental Protection Agency, Washington, DC (www.epa.gov/safewater).

Listeria: How to avoid food poisoning caused by Listeria

Lyn Gandham

Public awareness of the bacterium Listeria, an opportunistic pathogen, has been on the rise in recent years as the number of reported cases of listeriosis continues to grow. Listeriosis is an infection caused by the bacterium Listeria monocytogenes. The number of reported cases in Canada rose from 85 in 2003 to 239 in 2008.

In 2008, a widespread outbreak of listeriosis originated from a Maple Leaf Foods Bartor Road facility in North York, Ontario which caused infection in 57 people and took the lives of 23 of them (Table 1). In other words, 40% of the people affected in this outbreak died of this serious illness. 119 meat products produced by Maple Leaf Foods Bartor Road plant were recalled. It is believed that contamination with L. monocytogenes likely occurred during packaging.

Table 1. Listeria monocytogenes outbreak 2008

Province	Confirmed Cases	Deaths where Listeriosis was the underlying or contributing cause*
Ontario	41	16
BC	5	2
Alberta	2	1
Saskatchewan	2	1
Manitoba	1	0
Quebec	5	2
New Brunswick	1	1
Total	57	23

*As recorded on death certificate or as assessed by attending physician.

Occurrence

Most healthy individuals exposed to Listeria are usually at low risk of infection because our immune systems are strong enough to clear the bacterium from our bodies. Some healthy individuals and children can become infected but, they rarely become seriously ill. In fact, according to the Public Health Agency of Canada, of the 11 to 13 million annual cases of food-related illness in Canada, listeriosis cases are in the low hundreds. However, although this infection is rare, it causes serious health effects to those at risk and is responsible for ¼ of the deaths of all reported foodborne illnesses. The population at highest risk for listeriosis are infants, the elderly, pregnant women, and people with weakened immune symptoms.

Health Effects and Treatment

Most foodborne related bacteria, such as Salmonella cause infection within 12-72 hours after eating contaminated food. However, Listeria is unusual in that it can take 3 to 70 days (with a median of 3 weeks) for a mild or invasive infection to start. Once an infection occurs in humans, 1 out of 5 people die. Another difficulty when dealing with Listeria is that early symptoms of listeriosis can easily be mistaken for the flu. Generally, listeriosis is not diagnosed until laboratory reports of L. monocytogenes have been cultured from blood, cerebrospinal fluid or amniotic fluid.

The most common symptoms of listeriosis are:

Sepsis (blood stream infection): infection results in high fever and very ill appearance. Infection of the heart valves and other organs can occur.
Infection of the central nervous system (typically meningitis): results in high fever, intense headaches, neck stiffness, altered consciousness and convulsions.
Miscarriage, still birth or premature delivery of a newborn. The infected pregnant mother may have a mild flu-like illness however; it can affect newborns by penetrating the endothelial layer of the placenta. If the baby is infected at the time of birth, it can develop a blood stream infection or meningitis.

Antibiotics such as ampicillin, ciprofloxacin and azithromycin are usually given intravenously to treat listeriosis. In spite of treatment however, 20-30% of cases results in death.

Disease Transmission

The majority of listeriosis cases reported are foodborne and result from eating food contaminated with L. monocytogenes. Listeria has been found in uncooked meats such as cold cuts/deli meats and hot dogs, raw and smoked fish, raw vegetables, fresh fruit such as cantaloupes, unpasteurized (raw) milk, unpasteurized dairy products and soft cheeses like feta, Brie or Camembert. Listeria can also be found in soil, stream water, sewage, and plants. Vegetables and plants can become contaminated with Listeria from soil, water or manure-based fertilizers. Farm animals that appear healthy can carry Listeria to contaminate meats and dairy products.

Listeria monocytogenes can grow in temperatures from 4ºC (refrigerator temp) to 37ºC (body’s internal temp).

Prevention

Everyone has a role to play in ensuring the consumption of safe foods. Manufacturers of foods such as the Maple Leaf Foods Bartor Road plant must go above and beyond to ensure the necessary measures are taken to prevent another outbreak. From the CEO to the night janitor, all involved have a part to play. Ensuring proper sanitation and removal of all possible sources of Listeria growth and, monitoring and auditing of safe practice procedures must be performed daily. Manufacturers of food processing equipment are responsible for the proper design of food processing equipment that will enable thorough cleaning and disinfection as well as efficient and complete disassembly and assembly for effective cleaning.

Preventing Listeria growth requires effective sanitation of food contact surfaces. The four main types of sanitizers used in the meat industry are hot water, chlorine, iodophors and quatnerary ammonia. Quaternary ammonia and iodophors are the most effective when combined with post-processing steam and heat treatments. Alcohol alone is also effective against Listeria. Increasing the duration of contact time on food contact surfaces will improve sanitization procedures.

Precautionary measures need to be taken when preparing foods likely to contain Listeria such as ensuring raw vegetables are thoroughly washed before eaten. Those especially at risk should avoid consumption of refrigerated pâtés, smoked seafood, unpasteurized milk and milk products. Risks groups should also avoid eating luncheon meats, deli-meats and hot dogs unless they are steaming hot. Listeria can even survive and grow in vacuum-packed products. Thus, refrigerated foods in the home should be kept below 4 ºC to discourage Listeria growth.

The fluids from packages such as hot dogs contain more Listeria than hot dogs themselves. Steps should therefore be taken to avoid the fluid from coming into contact with other foods, cutting boards, utensils, dishes and food preparation surfaces. Hand washing can greatly reduce the spread of contamination.

Sampling of Listeria

Testing for Listeria is typically done using a swab, environmental sponge or the Microbial-Vac system((R)). Food contact surfaces (dairy board, stainless steel) or other non-food contact areas suspected of Listeria growth (such as brick, doorways, hall drains, floors, equipment panels, and aprons) can be tested. Specimens for sampling can also be taken from solid foods (such as cheese). Water from sources containing chlorine must be collected in a pre-sterilized bottle containing sodium thiosulfate. Samples must be collected and delivered to the laboratory as soon as possible.

Sample Handling and Storage

Optimal temperature conditions during transport and storage is below 4˚C. The holding time between collection and analysis must not exceed 48 h for water samples. All samples must be labeled according to the chain of custody.

Test Methods

Here at MBL we detect and enumerate Listeria spp. in environmental samples by the 3M^TM petrifilm technique. 3M^TM petrifilm plates are a thin, film, dehydrated, version of the conventional petri dish agar plate. Once a result is positive for Listeria spp., a confirmation step is performed. Benefits of this method are:

It is a cost effective tool for the detection of environmental Listeria.
Its quantitative results allow identification of hot spots in plant and you can track Listeria over time.
Rapid turnaround time of results from sample collection; as little as 2-4 business days. Other methods of Listeria testing can take up much longer because of the increased number of steps and longer incubation times.
It is safer and more reliable than other methods because it does not require an enrichment step which would increase exposure to potentially pathogenic Listeria and, it requires no culture transfers.

For more information on our Listeria testing or for a complete list of microbiological tests performed at Mold & Bacteria Consulting Laboratories, please call our Ontario, Mississauga Office at 905-290-9101 or the British Columbia, Burnaby Office at 604-435-6555.

References

“Controlling Listeria Contamination in Your Meat Processing Plant”. Government of Ontario. 27 February 2007.

Health Canada. Sept 2006. MFLP-11: Enumeration of Listeria Species in environmental Samples using 3M Petrifilm environmental Listeria plates.

Maple Leaf Foods assessing Listeria-killing chemical. ctv.ca (ctvglobemedia). 2008-10-12.

Pagotto, Franco, Karine Hébert and Jeff Farber. Feb 2011. Isolation of Listeria monocytogenes and other Listeria spp.from foods and environmental samples.

Can Mold, Yeast, and Non-specific Bacteria Cause Bladder Problems?

Jackson Kung'u

Question: I love your blog and hope you can answer this mold question.

I worked at a beauty salon for 1 1/2 years. I started to have back to back urinary tract infections (Escherichia coli). I’ve had these infections a couple of times in my 40+ years on earth but nothing like I was experiencing this time around. It felt like someone lined my bladder with vicks vapor rub and added some pins. The antibiotics I was prescribed made the pain worse. A client of mine (she came every week and spent a long time under the dryer) was experiencing the same thing. About 2 weeks after the bladder pain started, I started having difficulty breathing (I was diagnosed with moderate lung obstruction) and I was placed on an inhaler. I then noticed a fungal rash on my arms I had to treat with Monistat (it cleared up in 6 days). My symptoms started in early June after a flood in the shop which I suspect could have caused mold growth. Dehumidifiers were bought in and ran all day for a couple of days. By August I had to leave because it was just too difficult to breath, take a flight of stairs etc. My urologist couldn’t find the cause of the pain and an internal view of my bladder found nothing. Can mold, yeast, and non-specific bacteria found in these reports cause bladder problems? The pain got significantly better a week after I left. The pain went away completely after about 2 months away from the salon.

The owner decided to have an air quality test for mold done because a girl that rented the room prior to me complained of breathing difficulties only when she was at work. I attached the mold report for you to look at.

Thanks!

Answer: Escherichia coli (E. coli in short) is a bacterium commonly found in the lower digestive tract of warm-blooded animals including humans. Most E. coli strains are harmless, but some strains, such as serotype O157:H7, can cause serious food poisoning. E. coli is also a common cause of urinary tract infections. Infection occurs when E. coli from the digestive tract find their way into the urethra and begin to multiply. The bacterium can move to the bladder and multiply there causing infection of the bladder. I have looked at the lab report that you had attached. The molds reported are unlikely to cause infection. A possible fungal infection of the bladder especially when one has been using antibiotics is Candida infection (candidiasis). Candida can infect other areas of the body including the mouth, throat, skin, scalp, genitals, fingers, nails, bronchi, lungs, and the gastrointestinal tract.