Welcome to the Microbiology Information

Now here is an interesting question, can you eat moldy cheese? Well it depends on the type of cheese and the type of mould that’s on it. You see, soft cheeses such as camembert, Brie, Blue Vein and so forth are mould ripen cheese so it normal for the mould to be present.

On the other hand, cheeses such as cheddar, mozzarella, and parmesan are cheese that is not normal to have moulds. So the question remains, can you eat moldy cheese? Of course you can as long as the mould is limited to a small area and it is removed. You will need to be able to cut away at least a 1 cm chunk under and around the mould because it may have penetrated farther in than you can see.

Always throw any cheese that’s very very moldy. It’s safest to chuck them, as some moulds can produce toxins that can damage your liver, kidneys and immune system.

Here is some interesting news by a team of scientists. They have found bacteria living almost three kilometres underground, dining on sulfur in a world of steaming water and radioactive rock - completely independent of the sun.

The organisms, which have been there for millions of years, will probably survive as long as the planet does, drawing energy from the stygian world around them.

Found in water spilling out of a fissure in a South African goldmine in 2003, they are among the most primitive life forms described, researchers reported in yesterday’s issue of the journal Science.

What is unusual is that their underground home contains no nutrients traceable to photosynthesis, the sunlight-harnessing process that fuels all life on earth’s surface. Such a community is an oddity on this planet - and is of interest to people looking for life on other ones.

“There is an organism that dominates that environment by feeding off an essentially inexhaustible source of energy, radiation,” said Tullis Onstott, a geoscientist at Princeton University who led the team.

“The bottom line is: water plus rocks plus radiation is enough to sustain life for millennia.”

The research was mainly done by Li-Hung Lin, of National Taiwan University.

Professor Li-Hung descended three times to the fissure in East Driefontein Gold Mine, south-west of Johannesburg, to get samples. It was 2.7 kilometres underground, and the temperature of the rock was 50 degrees.

The surfaces of other rocky bodies in the solar system are all too cold, too hot, too dry or too toxic to support the kind of life known on earth. But their subterranean environments are likely to be more hospitable and stable. More important, many may contain the shortlist of ingredients that seem to be all the South African microbes need.

“This is a very nice potential model of the habitability of Mars, Jupiter’s Europa and other moons,” said Steven D’Hondt, an astrobiologist at the University of Rhode Island.

“The sorts of ecosystems you could get there could certainly be something like this.”

Mars is known to have both subsurface water and uranium. The findings of Professor Onstott’s team suggest that even without volcanos to warm the Martian environment, organisms that evolved in a more temperate time might survive there.

“This really increases the likelihood that we will find life beneath the surface of Mars,” Professor Onstott said.

For more than 20 years microbiologists have retrieved colonies of bacteria living hundreds thousands of metres below ground. Most of the environments contained carbon-based molecules from decayed plants or animals. The energy in those molecules’ chemical bonds was all traceable to the sun.

The microbes from the South African mine appear to exist outside this food chain.

Source: SMH

In most languages, sentences only make sense if the words are placed in the right order. Now, MIT researchers and an IBM colleague have used grammatical principles to help their search for new antimicrobial medicines.

After identifying “grammatical” patterns in naturally occurring antimicrobial peptides, the researchers custom-designed molecules that proved extremely effective in killing microbes, including anthrax bacteria. The research could lead to new medicines to combat deadly drug-resistant bacteria.

“In the last 40 years, there have been only two new classes of antibiotic drugs discovered and brought to the market,” said graduate student Christopher Loose, lead author of a paper on the work that appears in the Oct. 19 issue of Nature. “There is an incredible need to come up with new medicines.”

Loose, research associate Kyle Jensen and Professor Gregory Stephanopoulos of the Department of Chemical Engineering are focusing their attention on antimicrobial peptides, or short strings of amino acids. Such peptides are naturally found in multicellular organisms, where they play a role in defense against infectious bacteria.

The researchers’ newly designed peptides were shown to be effective against dangerous microbes such as Bacillus anthracis (anthrax) and Staphyloccus aureus, a bacteria that spreads in hospitals and is frequently drug-resistant. The peptides may also be less likely to induce drug resistance in these bacteria, according to the researchers.

Antimicrobial peptides act by attaching to bacterial membranes and punching holes in them, an attack that is general to many different types of bacteria and is difficult for them to defend against. “There’s no quick easy mutation fix for a bacteria to get around this non-specific membrane attack,” said Loose.

The peptides are generally short, consisting of about 20 amino acid building blocks. The molecules naturally fold into a helix, with positively charged areas running along one side of the helix and hydrophobic (water-resisting) areas along the other side. The charged ends allow the peptides to latch onto the bacteria by attracting the negative charges of the bacterial membrane, while the hydrophobic ends punch holes in the membrane.

Because there are 20 naturally occurring amino acids, there are about 1026 possible peptide sequences of length 20. Some of those kill microbes with varying levels of effectiveness; the overwhelming majority have no effect.

With such a mind-boggling number of possible combinations, it is extremely difficult to find effective antimicrobial peptides by using traditional methods such as testing random sequences or slightly tweaking naturally existing peptides. “Designing them from scratch is quite difficult,” said Loose.

Instead, the researchers decided to take a more strategic approach, based on grammatical patterns in the peptide sequences.

At its essence, a “grammar” is a simple rule that describes the allowed arrangements of words in a given language. As it applies to peptides, the sequence can be thought of as a sentence, while the individual amino acids are the words. For example, the sequence QxEAGxLxKxxK, where x is any amino acid and Q, E, A, etc. are specific amino acids, is a pattern that occurs in more than 90 percent of a certain class of insect antimicrobial proteins known as cecropins.

In this case, the researchers, led by Jensen and Isidore Rigoutsos of IBM Research (Rigoutsos is also a visiting lecturer in the Department of Chemical Engineering), used a pattern discovery tool to find about 700 grammatical patterns in the sequences of 526 naturally occurring antimicrobial peptides.

To design their new peptides, the researchers first came up with all possible 20-amino acid sequences in which each overlapping string of 10 amino acids conformed to one of the grammars. They then removed any peptides that had six or more amino acids in a row in common with naturally occurring peptides. Then, they threw out sequences that were very similar to each other and chose 42 peptides to test.

About half of the peptides displayed significant antimicrobial activity against two common strains of bacteria — Escherichia coli and Bacillus cereus. That is a much higher success rate than one would expect from testing randomly generated sequences, and much higher than the success rate for peptides with the same amino acids as the designed sequences, but in a shuffled order.

“We’ve been able to focus our shotgun approach so that half of the time, we get a hit,” said Loose.

In further tests, two of the designed peptides showed very high effectiveness against two types of especially dangerous bacteria, S. aureus and anthrax.

The researchers have already begun using their technique to further refine the most effective peptides by tinkering with the sequences and altering traits like charge and hydrophobicity. They hope this process will eventually lead to new, more effective antimicrobial medicines.

The research was funded by the Singapore-MIT Alliance, the National Institutes of Health and the Fannie and John Hertz Foundation.

Source: WebWire - Anne Trafton

Did you know that infections with thermophilic Campylobacter are now generally considered to be the main cause of bacterial enteritis in many developed countries. The infections mainly result from the consumption of contaminated and unheated or only weakly heated food such as poultry.

Human pathogenic campylobacter such as campylobacter jejuni and campylobacter coli are highly infectious and therefore rapid microbiological diagnostics in foods is especially important. Nevertheless, the detection of these species is time-consuming and requires trained personnel.

To simplify the detection of these bacteria MERCK KGaA has developed Singlepath Campylobacter, an immunochromatographic rapid test, which, in a single working process within 20 minutes after 48 h of incubation of the food sample in Bolton broth, specifically detects these bacteria.

A study was conducted for the targeted detection of Campylobacter specie. in natural and in “spiked” food samples were evaluated.

The overall results to date show that the rapid test Singlepath Campylobacter is suitable for the routine examination of food samples for Campylobacter. Die Specificity and sensitivity of the rapid test (in comparison with biochemical culture methods) were measured at 98% and 100%. Singlepath Campylobacter can therefore be considered to be very safe

In comparison with another alternative method, the VIDAS Campylobacter. Singlepath has the advantages of a much shorter detection time, simpler handling and a more attractive price.

This means for routine examinations a clear decrease in operating costs. Occasional false-negative or false-positive results can never be completely excluded with biological material and do not reduce the applicability of the tested method.