Escherichia coli

Escherichia coli, /ˌɛʃəˈrɪkiə ˈkoʊlaɪ/; commonly abbreviated E. coli; named after Theodor Escherich) is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but some, such as serotype O157:H7, can cause serious food poisoning in humans, and are occasionally responsible for product recalls. The harmless strains are part of the normal flora of the gut, and can benefit their hosts by producing vitamin K2, and by preventing the establishment of pathogenic bacteria within the intestine.

E. coli bacteria are not always confined to the intestine, and their ability to survive for brief periods outside the body makes them ideal indicator organisms to test environmental samples for fecal contamination. The bacterium can also be grown easily, and its genetics are comparatively simple and easily manipulated or duplicated through a process of metagenics, making it one of the best-studied prokaryotic model organisms, and an important species in biotechnology and microbiology.

E. coli was discovered by German pediatrician and bacteriologist Theodor Escherich in 1885, and is now classified as part of the Enterobacteriaceae family of gamma-proteobacteria.

Diversity

As more is known about certain organisms, such as genetic information, the taxonomic classification of species is changed to reflect the advance in knowledge, however in the case of Escherichia coli due to its medical importance, this has not occurred (namely split into several genera/species) and remains one of the most diverse bacterial species: only 20% of the genome is common to all strains. In fact, from the evolutionary point of view, the members of genus Shigella (dysenteriae, flexneri, boydii, sonnei) are actually E. coli strains "in disguise" (i.e. E.coli is paraphyletic to the genus).

A strain of E. coli is a sub-group within the species that has unique characteristics that distinguish it from other E. coli strains. These differences are often detectable only at the molecular level; however, they may result in changes to the physiology or lifecycle of the bacterium. For example, a strain may gain pathogenic capacity, the ability to use a unique carbon source, the ability to take upon a particular ecological niche or the ability to resist antimicrobial agents. Different strains of E. coli are often host-specific, making it possible to determine the source of faecal contamination in environmental samples. For example, knowing which E. coli strains are present in a water sample allows researchers to make assumptions about whether the contamination originated from a human, another mammal or a bird.

A common subdivison system of E.coli, but not based on evolutionary relatedness, is by serotype, which is based on major surface antigens (O antigen: part of lipopolysaccharide layer; H: flagellin; K antigen: capsule), e.g. O157:H7) (NB: K-12, the common laboratory strain is not a serotype.)

New strains of E. coli evolve through the natural biological process of mutation and through horizontal gene transfer. Some strains develop traits that can be harmful to a host animal. These virulent strains typically cause a bout of diarrhoea that is unpleasant in healthy adults and is often lethal to children in the developing world. More virulent strains, such as O157:H7 cause serious illness or death in the elderly, the very young or the immunocompromised.

E. coli is the type species of the genus and the neotype strain is ATCC 11775, also known as NCTC 9001,[22] which is pathogenic to chickens and has a O1:K1:H7 serotype. However, in most studies either O157:H7 or K-12 MG1655 or K-12 W3110 are used as a representative E.coli.

Biology and biochemistry

E. coli is Gram-negative, facultative anaerobic and non-sporulating. Cells are typically rod-shaped, and are about 2.0 micrometres (μm) long and 0.5 μm in diameter, with a cell volume of 0.6 – 0.7 (μm)3. It can live on a wide variety of substrates. E. coli uses mixed-acid fermentation in anaerobic conditions, producing lactate, succinate, ethanol, acetate and carbon dioxide. Since many pathways in mixed-acid fermentation produce hydrogen gas, these pathways require the levels of hydrogen to be low, as is the case when E. coli lives together with hydrogen-consuming organisms, such as methanogens or sulphate-reducing bacteria.

Optimal growth of E. coli occurs at 37°C (98.6°F) but some laboratory strains can multiply at temperatures of up to 49°C (120.2°F). Growth can be driven by aerobic or anaerobic respiration, using a large variety of redox pairs, including the oxidation of pyruvic acid, formic acid, hydrogen and amino acids, and the reduction of substrates such as oxygen, nitrate, dimethyl sulfoxide and trimethylamine N-oxide.

Strains that possess flagella can swim and are motile. The flagella have a peritrichous arrangement.

E. coli and related bacteria possess the ability to transfer DNA via bacterial conjugation, transduction or transformation, which allows genetic material to spread horizontally through an existing population. This process led to the spread of the gene encoding shiga toxin from Shigella to E. coli O157:H7, carried by a bacteriophage.

Role in disease

Virulent strains of E. coli can cause gastroenteritis, urinary tract infections, and neonatal meningitis. In rarer cases, virulent strains are also responsible for haemolytic-uremic syndrome, peritonitis, mastitis, septicaemia and Gram-negative pneumonia.

Laboratory diagnosis

In stool samples microscopy will show Gram negative rods, with no particular cell arrangement. Then, either MacConkey agar or EMB agar (or both) are inoculated with the stool. On MacConkey agar, deep red colonies are produced as the organism is lactose-positive, and fermentation of this sugar will cause the medium's pH to drop, leading to darkening of the medium. Growth on Levine EMB agar produces black colonies with greenish-black metallic sheen. This is diagnostic of E. coli. The organism is also lysine positive, and grows on TSI slant with a (A/A/g+/H2S-) profile. Also, IMViC is {+ + – -} for E. coli; as it's indole-positive (red ring) and methyl red-positive (bright red), but VP-negative (no change-colourless) and citrate-negative (no change-green colour). Tests for toxin production can use mammalian cells in tissue culture, which are rapidly killed by shiga toxin. Although sensitive and very specific, this method is slow and expensive.

Typically diagnosis has been done by culturing on sorbitol-MacConkey medium and then using typing antiserum. However, current latex assays and some typing antisera have shown cross reactions with non-E. coli O157 colonies. Furthermore, not all E. coli O157 strains associated with HUS are nonsorbitol fermentors.

The Council of State and Territorial Epidemiologists recommend that clinical laboratories screen at least all bloody stools for this pathogen. The American Gastroenterological Association Foundation (AGAF) recommended in July 1994 that all stool specimens should be routinely tested for E. coli O157:H7.[citation needed] It is recommended that the clinician check with their state health department or the Centers for Disease Control and Prevention to determine which specimens should be tested and whether the results are reportable.

Other methods for detecting E. coli O157 in stool include ELISA tests, colony immunoblots, direct immunofluorescence microscopy of filters, as well as immunocapture techniques using magnetic beads. These assays are designed as screening tool to allow rapid testing for the presence of E. coli O157 without prior culturing of the stool specimen.

Vaccination

Researchers have actively been working to develop safe, effective vaccines to lower the worldwide incidence of E. coli infection. In March 2006, a vaccine eliciting an immune response against the E. coli O157:H7 O-specific polysaccharide conjugated to recombinant exotoxin A of Pseudomonas aeruginosa (O157-rEPA) was reported to be safe in children two to five years old. Previous work had already indicated that it was safe for adults.A phase III clinical trial to verify the large-scale efficacy of the treatment is planned.

In 2006 Fort Dodge Animal Health (Wyeth) introduced an effective live attenuated vaccine to control airsacculitis and peritonitis in chickens. The vaccine is a genetically modified avirulent vaccine that has demonstrated protection against O78 and untypeable strains.

In January 2007 the Canadian bio-pharmaceutical company Bioniche announced it has developed a cattle vaccine which reduces the number of O157:H7 shed in manure by a factor of 1000, to about 1000 pathogenic bacteria per gram of manure.

In April 2009 a Michigan State University researcher announced that he has developed a working vaccine for a strain of E. coli. Mahdi Saeed, professor of epidemiology and infectious disease in MSU's colleges of Veterinary Medicine and Human Medicine, has applied for a patent for his discovery and has made contact with pharmaceutical companies for commercial production.

Former Vic top cop Sir Ken bugged

Phones of the Deputy Commissioner, who was ordered to take annual leave after giving notice of his resignation last month, were bugged following a stand-off with the Chief Commissioner, over Simon Overland's suspicions that he was leaking information to the press.

The OPI launched its extraordinary investigation into Sir Ken after receiving a complaint from Mr Overland, shortly after the chief asked Sir Ken to stand down.

Sir Ken has been using his wife's phone since being ordered on leave, for fear his phones were being tapped.

The Herald Sun understands there has been an audit of Sir Ken's phone records and emails.

Sir Ken has backers within the State Government, arising from anger at a perceived belief that Mr Overland was too close to the former Labor government.

Senior police sources have confirmed with the newspaper that the OPI launched its surveillance at the request of police chief commissioner Simon Overland.

Communications of Sir Ken and his close associates have been intercepted for weeks, the report says.

The ministerial staffers targeted in the operation have reportedly been identified as supporters of Sir Ken.

Ombudsman George Brouwer is also believed to have launched an investigation into the OPI probe of Sir Ken and whether it has abused its powers in doing so.

Sir Ken last month revealed he would leave Victoria Police in August, but just days later Mr Overland ordered him out of the force with immediate effect.

Police Association secretary Sen-Sgt Greg Davies wanted to know what crime Sir Ken was suspected of committing that would have led to his phones being bugged.

"It would be very nice to know what major offence, that would carry at least seven years in prison, has triggered the ability to get a warrant to intercept his phone, that the OPI or anyone else believes Ken Jones committed," he said.

Sen-Sgt Davies said if it was true Sir Ken's phone was being bugged, the community may never know why.

"Just as with Noel Ashby and Paul Mullett, we will never know what offence he has supposed to have committed," he said.

It's understood that the OPI has been monitoring communications of Sir Ken, his wife, and close friends for weeks.

The OPI has also reportedly focused on the communications of one or more people working in sensitive government positions, who are identified as Sir Ken's supporters.

Victoria Police refused to comment last night.

Kids turned away in Malaysia Solution

Some migrant women are forced to stay inside or travel in groups to avoid being singled out by police and RELA, the paramilitary corps.

While men are asked for a cash bribe when stopped, some police allegedly sexually harass and abuse women.

This is the frightening scenario awaiting refugees who will soon be sent from Australia to Kuala Lumpur under the federal government's controversial refugee swap.

Malaysian opposition MP and foreign affairs spokesman Liew Chin Tong - who has called for a ban on the use of the rattan cane - said sexual harassment and abuse of female refugees was rampant.

"One member of parliament told the story of Chinese women caught and molested in police custody. This exists; it's a real threat and it's part of the systematic culture of abuse that exists behind closed doors," Mr Tong said.

It is inevitable that will occur again unless we break the people smuggler's business model.'

The government hopes the plan will erase a 'pull factor' for people smugglers, persuading them not to send children in boats.

Mr Bowen was responding to documents obtained by the ABC which show Malaysia was demanding tough new conditions for the proposed refugee swap deal which the minister says will be signed within weeks.

The proposal involves Australia sending up to 800 asylum seekers to the back of the queue in Malaysia in exchange for 4000 processed refugees.

FBI Raids El Cajon Home of Suburban 'Suicide Kit' Seller

Sharlotte Hydorn, the San Diego County woman who sells so-called suicide kits out of her home, describes a federal raid on her home earlier this week and explains that she just wants to give terminally ill patients the chance to die at home peacefully.

“You can embarrass me and say that I’m murderous and I’m making suicide kits and I’m killing people,” Hydron said Thursday from the yard of her home in unincorporated El Cajon. “Good luck to you in your last days, honey.”

On Wednesday, federal agents served this search warrant at Hydorn's home and seized materials used to make so-called suicide kits that she began marketing in 2002.

The 91-year old widow said agents with guns served a warrant Wednesday and searched the home for evidence in the investigation of mail fraud, wire fraud, tax evasion, the sale of adulterated material and mis-branded medical devices.

Agents took several computers, letters and other paperwork and a special sewing machine Hydorn said.

Activists have long argued about a person's right to take his or her life, and what exactly it means to assist. In the late 1990s, Michigan doctor Jack Kevorkian brought the debate into American homes by airing his assist of a suicide on "60 Minutes." Now that debate, and its ethical implications, is being rekindled by the increasing use of helium hood kits.

"Until recently nobody would have thought, 'Gosh, we have to define the word assisting,' because it was just kind of, like, duh," said Rita Marker, executive director of Patients Rights Council. "But now someone says, what does assisting really mean?"

In 1994, Oregon became the first state to enact a law that lets terminally ill people end their lives with a physician's assistance, with voters approving the policy twice. Physician-assisted suicide is also legal in Washington and Montana. Oregon law mandates multiple doctor consultations and looks at possible psychological evaluation before such a suicide can happen. The state says 65 Oregonians took their lives under the law in 2010.

Neighbors and friends, however, said she is not motivated by money. They noted she was driven to start the business following her husband’s protracted battle with cancer, before his death in the 1970s.

Jim Christensen, who lives next door to Hydorn, said he believes she sells the kits out of compassion.

He saw the FBI raid as overstepping. “To me, it’s not the government’s business to poke its nose into this issue … It should be up to the individual how they die and the way they go out.”

He and others in the neighborhood, set in a hilly, unincorporated area of El Cajon, near Fuerte Elementary School, said they only learned the full scope of Hydorn’s business in recent weeks.

“She just seemed like a nice lady who was enjoying retirement,” said resident Frank Obregón.

The kit is promoted online and sold under the name of Hydorn’s company, The Gladd Group. Orders are handled through a Rancho San Diego business address.

Derek Humphry, who wrote the book “Final Exit,” a how-to guide for the terminally ill, recently said he believes Hydorn is the only person in nation who sells such a kit.

Medical ethicists and others say Hydorn has no way of knowing if her customers are terminally ill. Many may suffer from depression and need a therapist.

Two weeks ago, Hydorn told the San Diego Union-Tribune in an interview that she is not 'a death merchant,' claiming that the bags are solely meant to be used by terminally ill people.

“I’m not killing people. This is my chance to try to help them,” she said.

Earlier this month, the state Senate in Oregon voted to crack down on companies selling plastic hoods or other items that could aid in suicide.

State Sen. Floyd Prozanski (D-Eugene) sponsored the legislation after reading about the suicide of Nick Klonoski, whose mother and father are both U.S. district court judges. Klonoski killed himself more than four months ago using one of Hydorn’s kits, which he bought online. Klonoski’s family said at a Senate hearing last month that he was not terminally ill.

Union and Patrick to resume negotiations

SYDNEY — Australian wharves were returning to normal Friday, after dock workers called off work bans that had prompted some port operations to shut down and had threatened to hurt exporters.

The Maritime Union of Australia (MUA) said employees at Sydney's port Botany had gone back to work Friday and those in Brisbane would return later in the day. Workers in Fremantle were to vote on the matter later Friday.

The development comes after Patrick Stevedores decided to shut down ports where the union had imposed work restrictions, which included bans on overtime and which were to last about one week.

The dispute follows months of negotiations over pay and safety conditions.

"Patrick has chosen to escalate this dispute by unilaterally closing down its container terminals, which was never intended by the MUA," the union's national secretary Paddy Crumlin said.

The MUA said it would consult with Patrick to resolve the dispute.

"Patrick owns the decision to shut down the ports but in any event the union has determined that work should resume in an effort to undo the damage of Patrick's decisions," MUA deputy national Secretary Mick Doleman said.

We've rejected their written offer for arbitration earlier this week, we're inviting them back to the negotiating table," the spokesman told AAP.

"We're certainly optimistic that they'll be back at the negotiating table, we would think hopefully next week.

The MUA had planned a week of work restrictions in the three states from Wednesday after negotiations over a pay dispute stalled.

But the action was called off after Patrick refused to pay its workers for the work restriction days and denied them access to the wharfs.

Union officials met with members on Friday morning to encourage them to return to work, with national secretary Paddy Crumlin describing it as "a tough sell".

"They have been hurt at the way the company treated them in the media, and are frustrated and angry," Mr Crumlin told AAP.

Mr Crumlin also accused Patrick of running "megaphone diplomacy" and blamed the breakdown in negotiations on new management.

A spokeswoman for Patrick said that any agreement reached would need to include productivity offsets.

"We've been negotiating now for eight months, there's been in excess of 25 meetings, we are hopeful and optimistic that (we) will reach an outcome," the spokeswoman said.

"At this point we believe that the company and Maritime Union obviously remain some way apart."

The union has not accepted Patrick's offer of a four per cent pay rise over three years with an additional one per cent annually if "internationally recognised safety, productivity and efficiency targets" are met.

The work bans commenced on Australian wharves Wednesday, and an industry body said it had already begun to slow down some container ships or force them to consider diverting to New Zealand.

Shipping Australia said disruption on the docks could not have come at a worse time given exporters were already battling against a soaring Aussie dollar and given economic uncertainty in Europe and Japan.

G8 summit to pledge £12bn for Arab spring states

Arab transition to democracy are to be offered as much as £12bn in aid, loans and debt relief as a result of pledges being compiled at the G8 group of nations summit on Friday. The money will come from international financial institutions and members of the G8.

Leaders of both Egypt and Tunisia, the two chief recipients of the aid, will speak to leaders of the G8, currently chaired by the French on the second day of its summit in Deauville, and stress that they need money urgently to ensure their shift to democracy is smooth and not hampered by economic crisis.

Both countries have been severely hit by falling economic growth, high inflation, high youth unemployment and loss of tourism, on which both depend. Tunisia has been especially hit by the continuing war in neighbouring Libya.

Tunisia, the electoral commission is insisting elections are deferred from the summer to October to allow more time to prepare a workable electoral roll, a move that is disputed by the interim government.

Egypt, some of the groups responsible for the initial protests that led to the overthrow of Mubarak in February are calling for a second day of rage in Cairo on Friday to protest at the way in which the army appears to be dominating the transition process. Many groups, including the Muslim Brotherhood, have warned against further demonstrations.

The £12bn ($20bn) figure, although impressive-sounding, will have to be examined carefully to see how much represents grants as opposed to loans. The money will predominantly come from the International Monetary Fund, the World Bank, the US and the EU. Both the UK and France have offered bilateral sums: France offered Egypt up to $250m a year in development aid on Thursday and David Cameron set aside £110m over four years for political and economic development.

Britain and France have agreed to send ground attack helicopters to the region in a move that will intensify the attacks on the Libyan regime's command and control sites. Britain will send as many as eight Apache helicopters. Sarkozy has tried to persuade the US to deploy A-10 attack aircraft and AC-130 gunships in Libya.

The draft declaration by the G8 will urge Muammar Gaddafi to declare a ceasefire and agree to a political solution, officials said. The Arab Union meeting this week also called for a ceasefire, but did not call for Gaddafi to stand aside.

Russia's ambassador to France, Alexander Orlov, said the Nato coalition has gone too far.

Mladic due back in Belgrade court

EU’s most wanted war crimes fugitive was arrested on Thursday in a northern Serbian village after 16 years on the run. The Bosnian Serb wartime army commander is facing international war crimes charges, including the slaughter of 8,000 Muslim men and boys in the Bosnian town of Srebrenica during Bosnia’s 1992—95 war.

Thursday’s extradition hearing was adjourned due to what Mladic’s lawyer claimed was his poor health.

Serbian war crimes prosecutors claim the health issue appears to be Mladic’s tactic to delay his extradition to the U.N. tribunal in the Hague, Netherlands.

“What’s important is that his identity has been established,” said deputy war crimes prosecutor Bruno Vekaric. “It now depends on his defense whether they will launch appeals, but a maximum deadline for his extradition is a week.”

Meanwhile, a photo portrait of Mladic during his arrest in the village of Lazarevo, 60 miles (100 kilometers) northeast of Belgrade, was obtained by The Associated Press. It shows him looking much older than in 2002 when he was last seen in Belgrade.

Mladic is alleged to have led the forces that attacked the Bosnian town of Srebrenica, a UN-declared safe area, in the summer of 1995. In early July that year, more than 8,000 Bosnian Muslim men and boys were executed by Serbian forces, and the town's women and children were driven out of the area. Mladic has been on the run since 1995, when he was indicted by the UN war crimes tribunal in The Hague.

The arrest of Mladic, the most-wanted man in Europe for the alleged massacre of thousands of Muslim men and boys, was announced Thursday by Serbian President Boris Tadic.

The extradition process began that day, but Mladic's lawyer said the judge cut short the questioning because the suspect's "poor physical state" left him unable to communicate.

The BBC has reported that doctors are assessing whether Mladic is well enough to attend his scheduled hearing.

Serbian war crimes prosecutors said the health issue is only a delaying tactic.

What's important is that his identity has been established," said deputy war crimes prosecutor Bruno Vekaric. "It now depends on his defense whether they will launch appeals, but a maximum deadline for his extradition is a week.

Broadcast of live betting odds:Australian sports gambling promotion threat

Meeting of state and federal ministers in Canberra agreed that the promotion of live odds during the broadcast of sport events had to be curtailed.

Governments are concerned that promotion, including commentary by sporting role models, is becoming insidious in live sports coverage," the Select Council on Gambling Reform stated in their communique following the talks.

Under the plan, which has backing from the responsible ministers at the state and federal levels, broadcasters would not be able to promote live odds and gaming websites. The arrangement will cover all sports with the exception of horse racing, which has been excluded due to its long-standing connection with the pastime.

Senator Stephen Conroy, the communications minister, said that the Government would discuss the proposed rules with broadcasters, with a particular focus on how the restrictions would operate.

"The particular concern of all the ministers was the practice by commentators reading out odds and encouraging people to get on," he said.

Conroy said that the government did not wish to override existing commercial arrangements between broadcasters and betting agencies. Networks will have twelve months to alter their practices voluntarily; otherwise, the Government will introduce retrospective legislation to ban the activity.

The peak body representing commercial free-to-air networks, Free TV Australia, said in a statement that it would negotiate over the terms of the ban. But the body's chief executive Julie Flynn insisted that any proposal must also cover other forms of media.

During cricket broadcasts, for example, commentators which include former Australian captains break away from ball-by-ball coverage to give up-to-date odds from a gambling agency to reflect the current state of the match.

Advertisement: Story continues below

"We are concerned that this can significantly influence vulnerable and young people and normalize gambling behaviour," the statement said.

If the gambling industry and television networks do not voluntarily halt such promotion by the end of June next year, legislation to ban it will be introduced to parliament. The proposed restrictions will apply to all sports with the exception of horse racing.

The Australian government also announced a review of existing online gambling laws.

Senator Stephen Conroy, the government minister for broadband, communications and the digital economy, said there would be no new contracts allowed for in-game betting, including odds on scoreboards at sporting events.

Commonwealth wants the measure compulsory while the states want a voluntary system, and some want compensation for lost tax revenue system.

Community Services Minister Jenny Macklin foreshadowed a constitutional showdown on the issue.

Ms Macklin said that in February it had been made "very clear" the Commonwealth had constitutional power to legislate on the issue and override the states.

She said legislation will be drafted in conjunction with independent Andrew Wilkie, who has made mandatory limits a condition of his support for the minority government, for operation by 2014.

"I would prefer to get an agreement with the states and territories and I do think today is a very significant step forward," Ms Macklin said after a meeting of the Council of Australian Governments.

"It is the first time all of us - the states, the territories, and the Commonwealth - have agreed that pre-commitment technology is a very helpful tool for people who are gambling on the poker machine.''

Victorian Gaming Minister Michael O'Brien said after the talks his state would install the technology needed for pre-commitment on all poker machines, but make its use voluntary.

"Ministers noted that members do not agree on whether such technology should be used on a voluntary or mandatory basis," the council's communique stated.

"Ministers asked senior officials to do further work on developing the required functionality for pre-commitment and a timetable for implementation.