Welcome to the Microbiology Information

Cyclospora species are found in humans, insectivores and other animals; however Cyclospora cayetanensis is the only species of this genus found to infect humans.

The oocyst of Cyclospora cayetanensis are spherical in shape and are up to twice the size of Cryptosporidium oocyst, at 7.5 – 10um in diameter. The oocyst is surrounded by a 50nm thick wall and outer fibrillar (63nm) coat that contains complex carbohydrates and lipids which make the oocyst acid fast. Within the oocyst are two long oblong sporocyst that in turn contain two infectious sporozoites. Once ingested by the host, the oocyst excyst in the gastrointestinal tract freeing the sporozoites which then invade the epithelial cells of the small intestine. Inside these cells, the sporozoites undergo asexual multiplication and sexual development to form unsporulated non-infectious oocysts that rupture the host cell and are then excreted with the stool. In the environment, after 7 to 12 days and with temperatures between 22 and 32oC, sporulation occurs which results in division of the sporont into two sporocysts.

Cryptosporidium are protozoan that infects humans and non-human hosts. Fifteen species are infectious for non-human vertebrate host; however only seven of these (Cryptosporidium baileyi, Cryptosporidium canis, Cryptosporidium felis, Cryptosporidium hominis, Cryptosporidium meleagridis, Cryptosporidium muris and parvum) have been report to infect humans. The majority of species of Cryptosporidium appear to have some host specificity but are not strictly host specific.

Data has shown that Cryptosporidium hominis is common in humans whereas Cryptosporidium parvum is common in zoonotic species. The remaining species that have caused infections occurred mainly in patients with weak immune system.

Cryptosporidium species exists as a spherical oocyst (5um diameter) in the environment. The wall of the oocyst is made up of complex carbohydrates and lipids which surround four banana shaped sporozoites. This makes the oocyst extremely resistant to the environment.

After ingestion and exystation, the sporozoites stage enters into the host cells and begins a complex infection process. Asexual reproduction is followed by sexual reproduction where female macrogamonts and male microgamots develop and fertilisation occurs.

The resulting zygote zygote then develops a thick walled infectious oocyst that will exit the host or developed a thinned walled oocyst that will auto-infect the host.

Giardias are protozoan that inhabits the intestinal tracts of nearly all classes of vertebrates. Some species are commonly found more so in human’s and these are Giardia duodenalis which is sometimes referred to as Giardia intestinalis or Giardia lamblia. Zoonotic genotypes of Giardia duodenalis can be found in livestock, pets and some wildlife with some genotypes appearing to be host specific.

Giardia duodenalis exists as a cyst (12 x 5um), with a chitin-like wall making it resistant and protecting it from the harsh environment.

Infection of Giardia occurs in human when the cyst is transmitted through contaminated food, water or even human to human contact (faecal to oral due to poor hygiene).

Once the cyst is ingested, it opens (excystation) and releases two infectious non-encysted motile trophozoites. These trophozoites are bilaterally symmetrical, pear- shaped (12-15 by 6-8um) and binucleate. They have four pears of flagella along with a convex dorsal surface that allows attachment to the mucosa of the proximal small bowel of the host. The trophozoites multiply through asexual reproduction and some of the encyst are excreted when it passes through the bowels ready to infect another host.

In the USA, the E.coli outbreak in Spinach has claims its 4th victim on Friday 26th January. With evidence linking a death back in September the death toll could rise to 5.

The latest victim is 83 year old Elizabeth, “Betty” Howard of Richland, Wash., who died Friday of heart failure in a rehabilitation facility after close to a five month long battle with E. coli O157:H7, her son Darryl Howard said.

The other victim was June Dunning, 86, of Hagerstown, Md., who died in September 13, said Warren Swartz, Dunning’s son-in-law. She tested positive for E. coli O157:H7 at the hospital. But because the Maryland Dept. of Health lost culture samples from her illness, the state was unable to confirm the cause of her illness so she had not been officially included in the death toll.

However, the Centers for Disease Control and Prevention confirmed in a letter to Dunning’s family Thursday that microbiological tests on the two bags of spinach in her refrigerator were positive for a closely related and potentially fatal form of the bacteria, E. Coli 0146:H21.

The letter from Cheryl Bopp at CDC’s division of Food borne Diseases states that the E. coli strain found in Dunning’s spinach was “indistinguishable” from that found in a sample of spinach from Illinois “which also yielded the outbreak strain of E. coli O157:H7.”

In October Caroline Smith DeWaal, food safety director of the Center for Science in the Public Interest, had sent a public letter to the CDC asking that Dunning be included in the death toll because of the strong circumstances linking her death to the others.

The outbreak was traced to pre-washed, bagged spinach from processor Natural Selection Foods of San Juan Bautista, Calif., sold by Dole. It sickened 199 people in 26 states, according to the Food and Drug Administration (FDA).

Howard became ill after eating a turkey sandwich with spinach on it. She had been living independently in her own home until she became ill with the O157:H7 strain of the virus. She went into the hospital on Sept. 7 several days after eating the sandwich and never returned home.

“E. coli is like running the blood through razor blades. It devastates every part of the body,” her son said. He said his mother worked for years as a secretary at the Department of Energy’s Hanford (Wash) Nuclear site.

Howard’s medical bills in the rehabilitation center where she died were paid for by the Dole company’s insurer, her lawyer, William Marler said.

Dunning became ill after eating spinach salad on August 28 of last year. On September 2nd she was hit with “horrible, bloody liquid diarrhea,” Swartz said. She went into the hospital and never came home.

On September 6 doctors told the family that they’d gotten results back from the stool sample they’d taken when Dunning first entered the hospital and that she had E. coli O157:H7.

“We said ‘What’s that? It sounds like something from Mars,” Swartz said. “The doctor said ‘It’s very rare and in over 30 years of practice I’ve never seen it.’ “The infectious disease doctor told them that it came from hamburger.

“We said she doesn’t eat hamburger, she loves vegetables,” Swartz said.

Dunning fell into a coma that evening and died on Sept. 13.

Born in Catford, England, she married an American and moved to the United States after the end of her husband’s 20-year-career in the U.S Army, her son-in-law said.

After her death, Swartz looked up E. coli on the Internet and realized that there was a nationwide outbreak associated with spinach. In their refrigerator Swartz found a half-eaten bag of pre-washed Dole baby spinach with the same use-by date and lot number implicated in the outbreak.

He and his wife Corinne turned the bags over to the Maryland Dept. of Health and Mental Hygiene, which passed them along to the CDC, he said.

Other deaths related to the outbreak include Ruby Trautz, 81, of Omaha, Kyle Allgood, 2, of Chubbuck, Idaho, and Marion Graff, 77, of Manitowoc, Wisc.

Source

On the December 21, 2006 in Albany NY, the New York State Agriculture Commissioner Patrick H. Brennan issued a warning to consumers in the Allegany County, New York area not to consume “unpasteurized” raw farm milk from the Gerald E. Snyder farm due to possible Listeria Monocytogenes contamination. Due to potential pathogenic concerns, pasteurization of raw milk is mandatory in 99% all milk sold.

The Snyder farm located at RD #1 1444 Randolph Rd., Alfred Station, New York 14803 holds a Department permit to legally sell raw milk at the farm. Although sample are taken monthly and tested by the Department to determine if the raw milk is free of pathogenic bacteria, it is still inadequate and the frequency should be increase to at least weekly testing.

A routine sample of the milk, taken by an inspector from the Division of Milk Control and Dairy Services on December 11, 2006, was subsequently tested by the Department’s Food Laboratory and discovered to be contaminated with Listeria monocytogenes.

On December 15, 2006, the producer was notified of a preliminary positive test result and volunteered to suspend raw milk sales until the sample results were confirmed.

Test results were confirmed on December 20, 2006 and the producer is prohibited from selling raw milk until subsequent sampling of the environment as well as packaged product indicates it is free of pathogens.

Listeria contaminated product could cause Listeriosis, a disease that usually causes mild flu-like symptoms in healthy individuals; however in weakened immuno-compromised individuals, meningitis and blood poisoning can occur. Pregnant women are also considered a high-risk group, as Listeriosis can also result in stillbirths.

It is important to note that raw milk does not provide the protection of pasteurization, which eliminates all pathogenic bacteria, including Listeria, salmonella, E.coli and so forth. Producers who sell raw milk to consumers must have a permit to do so from the Department, must sell directly to consumers on the farm where the milk is produced and must post a notice at the point of sale indicating that raw milk does not provide the protection of pasteurization. Farms with permits to sell raw milk are inspected by the Department monthly.

So far there has been no illnesses reported by the Department to be associated with product from the Snyder Farm.

Source

According to the Sydney Morning Herald, the source of the Legionella outbreak has been linked to the Royal Automobile Club (RAC) building in Macquarie Street. The link is still to be confirmed.

It is interesting what they said a few days ago when the possible source could have been eliminated as the infection occurred around the New Year period. Since then the regular cleaning would have eliminated the source. It looks like there going to be a surge of Legionlla testing this year.

Anyhow here’s what they write:

“Seven cases of the potentially fatal disease have been reported in NSW this month, including six patients who were in the Circular Quay area on New Year’s Eve.

Outbreaks are usually associated with readings above 1,000.”

One of the 25 cooling towers near Sydney’s Circular Quay has been disinfected and will be sterilised after low risk traces of the bacteria causing legionnaires’ disease were discovered.

Seven cases of the potentially fatal legionnaires’ disease have been reported in NSW this month, including six patients who were in the Circular Quay area on New Year’s Eve.

The results from tests on another 21 towers in the area will be known in the next two days, while the remaining three cooling units will be tested early this week.

Professor Mark Ferson from NSW Health said the overall results would provide authorities with a much clearer indication of the role played by the Circular Quay towers in the outbreak, but he doubted there was a link.

“That may help us but it’s actually quite uncommon to find a proven link between a cooling tower and an outbreak of legionnaires’ disease,” Prof Ferson said.

“I don’t think we know yet whether the two events are related.”

The towers were tested by an independent laboratory last week, with the unit at Customs House registering a reading of 200 colony-forming units per millilitre, a category considered by the Department of Health to be of low risk to public health.

Outbreaks are usually associated with readings above 1,000.

Three new cases were reported this weekend, with one man in his 50s in intensive care at a Sydney hospital, although his case is not believed to be linked with Circular Quay.

The two other patients, a woman in her 40s and a man in his 50s, have both told authorities they were in Circular Quay on December 31.

Four other men who were in the same area on New Year’s Eve were diagnosed with the disease earlier last week.

Source: SMH

Here is another recall for 2007 where a number of Florette brand ready-to-eat salads are being recalled from the shelves of Irish and UK supermarkets because of salmonella contamination. As a precaution, consumers are being warned not to eat any Florette watercress and Florette spinach, watercress and rocket salads purchased between January 5th and 10th 2007.

The Food Safety Authority says it has asked a number of Irish retailers to withdraw the products from sale which it says the salmonella contamination poses a risk to consumers’ health.

Here’s what the Food standards agency says:

“The Food Standards Agency has today been informed that Soleco UK Ltd has withdrawn watercress products, including watercress and spinach, and watercress and rocket mixed salad, from sale at branches of Budgens, Co-op, and a number of convenience stores, because of possible salmonella contamination.

The affected batches are:

Florette’s brand is sold through a number of convenience stores in the UK. No other batches or products are known to be affected.

Salmonella can cause diarrhea and sickness. People who have already bought any of the potentially affected products should throw them away and take the packaging to their retailer.

According to Lisa Finneran from the DAILY PRESS (NEWPORT NEWS, VA.), the rise of Drug-Resistant Staphylococcus Infections is growing worst each day. She writes:

“Kathleen Jaeger thought she had survived the worst condition of her life: a breast cancer diagnosis, chemotherapy and a double mastectomy.

Although the community-contracted bacterium is resistant to many drugs, there are some older drugs in the penicillin family that can successfully combat the bug.”

Source

Eggs are a healthy and nutritious food, and should be a part of any regular diet. But the use of raw eggs in foods is always a risky proposition. Numerous investigations around the world where outbreaks in the use of raw eggs in foods have link them as a possible source of infection. In the majority of these outbreaks Salmonella isolated from clinical specimens matched Salmonella from food samples made with the raw eggs.

Some eggs carry low levels of pathogenic bacteria on their surface, such as Salmonella, which can multiply to harmful levels if left in an environment conducive to growth. Examples of such environments include raw egg based sauces (hollandaise, mayonnaise) and desserts (mousse, tiramisu). Only a few live cells of the salmonella bacterium can cause an infection.

In all these products raw eggs can be substituted for commercially produced sauces or pasteurized egg products that are free from harmful bacteria. This minimizes the risk of infection and the risk of getting a bad reputation if your businesses are involved!