When the patients speak about "infection in the total hip or knee" they usually do not realize that this infection is a postoperative deep wound infection that developed around these joints. The absolute majority of these infections is caused by bacteria that landed in the operation wound during the total joint surgery. These bacteria are living with all of us in a close and innocent partnership, they cannot exist without us. Yet, when in contact with an artificial total joint, these bacteria change their character from a partner to an enemy.
All of us produce bacteria that cause our postoperative wound infections
Bacteria are everywhere around us, also in our clean operation wounds
The body's capability to destroy the bacteria, (some diseases, such as rheumatoid arthritis or HIV infection diminish the defense capability of the body)
how many bacteria are present in the operation wound (the more clean the air, the less bacteria will settle in the operation wound)
the character of the operation wound :clean or dirty(clean wound is a wound where there were no bacteria from the start, such as the operation wound done at the first time total joint replacement)
dirty wound is a wound where there are many bacteria already before the start of the operation, such as the operation through an already infected total joint)
the virulence of the bacteria. (Virulence= the capability of bacteria to cause infection by production of bacterial poisons.)Bacteria living in the hospital and not sensitive to ordinary antibiotic (synthetic penicillins) are especially virulent.
Bacteria living in hospitals are dangerous
Conclusion: If you wish to escape the contamination with bacteria resistant to antibiotics, limit your stay in the hospital to the shortest possible.
In patients not protected by prophylactic antibiotics there is a close correlation between the numbers of bacterial colonies in the operation room air and the rate of postoperative wound infections.The bacteria-carrying particles (mainly skin scales, but also droplets coming from mouths and noses) are generated by the operation room staff members & the patient. (Friberg 1998)
During moderate physical activity, every person sheds approximately 1000 bacteria carrying skin scales per minute! On these scales are bacteria, most staphylococcus, adherent. See picture. When the bacteria fall into suitable environment, such as an operation wound, the bacteria begin to multiply.
It then depends on whether in the operation wound's blood are antibiotics present, and whether the patient's white blood cells are sufficiently active. If the wound is unprotected then the bacteria multiply unrestricted and postoperative infection ensues, If the wound is protected, as it is in the majority of cases, the landed bacteria are killed and the wound heals without problems'
The more active the person is the more he / she sheds the bacteria carrying particles. The areas pumping most bacteria colonies in the air around a living human body are the neck, the arm pits, and the loins.
(Actually, studies demonstrated that naked people are shedding much less bacteria than people shrouded in conventional operation clothing. How about a naked surgeon?)
Living bacteria can travel in the air as colonies only, an individual bacterium is too small to survive in the air. The bacteria carrying skin scales are small, mean size is 12 micros ( one micro is one thousandth of a millimeter). They sediment as an invisible dust on all objects in the room where people are staying.The bacteriologists use different techniques to grow the bacteria.
However, bacterial causing chronic total joint infections are slow growers and must be identified by other methods. This is a very modern part of bacteriology. See the chapter: Bacteria Identification for details.
Skin bacteria:Staphylococcus albus (the white Staphylococcus) is spherical bacteria forming clusters. From that characteristic comes the name ( Staphyle - Greek for a bunch of grapes). S albus is the most frequent skin bacteria. It has been considered an innocent partner living on the skin surface of all of us and it has been found in about 30 % of all clean orthopedic operation wounds- all of these wounds healed without complications. This friendly coexistence between the people and the white Staphylococcus changed with the advent of total hip operations.When Staphylococcus albus colonizes the surfaces of total joints, it changes from doctor Jekyll to doctor Hyde. Once fixed to the surface of the total joint prosthesis, S. albus develops a slime cover and changes its characteristics: it develops resistance to antibiotics and causes slow, indolent infections around total joints.Other skin bacteria, some with long names, have been found only rarely as a cause of infections around total joints. It may seem curious that some of the bacteria living on our skin don't stand oxygen in the air we breathe. These bacteria are living deep in the sweat glands. Occasionally, also these anaerobe bacteria may cause infection around total joints.Staphylococcus aureus is a dangerous cousin of S. albus. His name "aureus" (Latin for golden) relates to the fact that the colonies of this bacterium have nice golden color. These bacteria cause serious infections, for example skin boils or dangerous infection of bones. These bacteria live occasionally on skin surface and in noses of certain persons, without causing them any troubles. Carriers of this bacterium may cause small epidemics of wound infection if they are shedding this bacterium in the hospital environment.
The classification of bacteria:
Gram staining:Bacteriologists classify usually the bacteria into Gram- positive and Gram-negative. The Gram -positive bacteria are those that can be stained by a method developed by the Danish bacteriologist HC Gram. In many reports it is "gram-positive".
This distinction is important because the Gram positive bacteria have been sensitive to common antibiotics (such as Penicillins or Cephalosporins).Gram-positive bacteria,
such as Staphylococcus albus and aureus are spreading through air route, but also through direct contact with objects covered by the invisible dust of skin scales containing these bacteria. Staphylococcus albus and aureus are still causing the majority of infections around total joints.Gram-negative bacteria
do not stain with the Gram stain method. Many of these bacteria need wet environment for thriving. These bacteria do not travel through air, but are transported through direct contacts with (mostly wet) objects.Gram negative bacteria are often called gut bacteria, because many of them live in our bowels. The infections caused by these bacteria need treatment with special antibiotics, the results of treatment are usually less good.
BACTERIA CAUSING TOTAL JOINT INFECTIONSCHARACTERISTICS OF BACTERIAPER CENT OF ALL FINDINGSGram-positive bacteria76 % of it Staphylococcus - all strains56 %Gram-negative bacteria24 %
Living without the airAnother classification is based on the fact that some bacteria do not endure air atmosphere. The bacteriologists thus distinguish betweenaerobe bacteria i.e. bacteria living in oxygen containing atmosphere andAnaerobe bacteria, i.e. bacteria that die in the oxygen containing atmosphere.Some of the most dreaded infections (tetanus or gas gangrene , e.g.) are caused by anaerobe bacteria.One of the main principles of all surgery is to care for a good circulation in all tissues of the operative wound because tissues with bad circulation are good nourishing ground for anaerobe bacteria.Anaerobe skin bacteria may cause indolent infections around the total joints.BACTERIA CHARACTERISTICSPER CENT OF ALL FINDINGS IN INFECTED TOTAL JOINTSAerobe bacteria88 %Anaerobe bacteria12 %
(Garvin 1995)
From friend to foe - why?
The bacteria living as innocent partners on the surfaces of our bodies can cause fearful infection when they come in contact with the total joint prosthesis. Why?
Race for surface theory
The total joint prosthesis is a non-living object with no protection of its own against the colonization by bacteria. When a total joint prosthesis is placed into the human body, the body's cells hurry to get hold on the surface of the prosthesis.
Once the body cells colonize the surface of the total joint prosthesis they can protect this non living surface against the colonization attempts of the bacteria.
If any bacteria are present in the operation wound, and most often these bacteria are the skin bacteria, they hurry to get hold on the prosthesis surface too. Thus there develops a race - who will be first to colonize the surface, bacteria or body's cells.
By the long biological development, the bacteria evolved the capability to adhere to surfaces for their survival, not only on the human body, but everywhere in the nature. Bacteria have thus biological advantage against the body's cells in this race.
Once the bacteria attached themselves to the surface of the prosthesis they form a slime envelope that protects them against the action of antibiotics and the immune defense of the body. Moreover, adherence to a surface also changes the characteristics of the adhering bacteria, among others their resistance to antibiotics increases 100 to 1000 times
The minimum number of bacteria present on a plate is 1. Depending on how well the bacterial colony was isolated, there may be different kinds of bacteria present.
To destroy any microbes or bacteria that may be present in it.
No. Some amount of zinc may be present in fuel used in motor vehicle and as such zinc oxide may be present in air in traces. ( You have a lead free fuel available. )
Earths first life form may be non photosynthetic bacteria.
Cyanobacteria are larger than most bacteria, and may secrete a thick cell wall. More importantly, cyanobacteria may form large layered structure.
STatioNary Front :):
occluded
The word 'pense' is a form of the verb infinitive 'penser'. It's a singular form. It may be in the present or imperative. Within the present tense, it may be either indicative or subjunctive. As a command, it translates as [you] think. As a present indicative, it translates as I am thinking, do think, think, or he/she/it does think, is thinking, thinks. And as a present subjunctive, it translates as [that] I may think or think, [that] he/she/it may think or think.
Stationary
Argon may be present in trace amounts in the air breathed in and out, but because it is a noble gas it has no way of remaining there.
It is better to air dry as a towel may have other bacteria on it wich could lead to contamination.
The air in the lungs may become drier, and more bacteria may enter the trachea.