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BSL-4 agents are the most dangerous and often fatal. These microbes are typically exotic, are easily transmitted by inhalation, and cause infections for which there are no treatments or vaccinations. Examples include Ebola virus and Marburg virus, both of which cause hemorrhagic fevers, and smallpox virus. There are only a small number of laboratories in the United States and around the world appropriately equipped to work with these agents. In addition to BSL-3 precautions, laboratory workers in BSL-4 facilities must also change their clothing on entering the laboratory, shower on exiting, and decontaminate all material on exiting. While working in the laboratory, they must either wear a full-body protective suit with a designated air supply or conduct all work within a biological safety cabinet with a high-efficiency particulate air (HEPA)-filtered air supply and a doubly HEPA-filtered exhaust. If wearing a suit, the air pressure within the suit must be higher than that outside the suit, so that if a leak in the suit occurs, laboratory air that may be contaminated cannot be drawn into the suit ( [link] ). The laboratory itself must be located either in a separate building or in an isolated portion of a building and have its own air supply and exhaust system, as well as its own decontamination system. The BSLs are summarized in [link] .

A photo of a lab worker in a suit that completely covers them (including their face and hands).
A protective suit like this one is an additional precaution for those who work in BSL-4 laboratories. This suit has its own air supply and maintains a positive pressure relative to the outside, so that if a leak occurs, air will flow out of the suit, not into it from the laboratory. (credit: modification of work by Centers for Disease Control and Prevention)
Table labeled biosafety levels. The CDC classifies low risk microbes as BSL-1 and high risk microbes as BSL-4. Biosafety level-4 is used when microbes are dangerous and exotic, posing a high risk of aerosol-transmitted infections, which are frequently fatal without treatment or vaccines. Few labs at this level. Examples include ebola and Marburg viruses.  BSL-3 is used when microbes are indigenous or exotic and cause serious or potentially lethal diseases through respiratory transmission. Examples include Mycobacterium tuberculosis. BSL-2 is used when microbes are typically indigenous and are associated with diseases of varying severity. They pose moderate risk to workers and the environment. Examples include Staphylococcus aureus. BSL-1 is used when microbes are not knows to cause disease in healthy hosts and pose minimal risk to workers and environment.  Examples include nonpathogenic strains of Escherichia coli.
The CDC classifies infectious agents into four biosafety levels based on potential risk to laboratory personnel and the community. Each level requires a progressively greater level of precaution. (credit “pyramid”: modification of work by Centers for Disease Control and Prevention)
  • What are some factors used to determine the BSL necessary for working with a specific pathogen?

Sterilization

The most extreme protocols for microbial control aim to achieve sterilization : the complete removal or killing of all vegetative cells, endospores, and viruses from the targeted item or environment. Sterilization protocols are generally reserved for laboratory, medical, manufacturing, and food industry settings, where it may be imperative for certain items to be completely free of potentially infectious agents. Sterilization can be accomplished through either physical means, such as exposure to high heat, pressure, or filtration through an appropriate filter, or by chemical means. Chemicals that can be used to achieve sterilization are called sterilant s . Sterilants effectively kill all microbes and viruses, and, with appropriate exposure time, can also kill endospores.

For many clinical purposes, aseptic technique is necessary to prevent contamination of sterile surfaces. Aseptic technique involves a combination of protocols that collectively maintain sterility, or asepsis , thus preventing contamination of the patient with microbes and infectious agents. Failure to practice aseptic technique during many types of clinical procedures may introduce microbes to the patient’s body and put the patient at risk for sepsis , a systemic inflammatory response to an infection that results in high fever, increased heart and respiratory rates, shock, and, possibly, death. Medical procedures that carry risk of contamination must be performed in a sterile field , a designated area that is kept free of all vegetative microbes, endospores, and viruses. Sterile fields are created according to protocols requiring the use of sterilized materials, such as packaging and drapings, and strict procedures for washing and application of sterilants. Other protocols are followed to maintain the sterile field while the medical procedure is being performed.

Questions & Answers

who is the father of microbiology
kasia Reply
how microbial proteins are used to diagnose infectious diseases
Gift Reply
microbes are cultured on industrial scale and then their secretions are extracted...I think that's called downstream processing
Chaitanya
in which language is the following sentence in omne vivum ex vivo
Chetan Reply
What are the five types of serological tests used to identify microorganism in the laboratory?
Prudence Reply
what is mycobacteria
Taslim Reply
what is gram staining
Nankya Reply
microbiology?
Bekka
It's technique to differentiate bacterial species.The method is discovered by Hans Christian Gram. The bacteria is differentiated as gram positive and gram negative on the basis of peptidoglycan layer which is present in cell wall. The gram positive have peptidoglycan layer.
shamali
What is study of morphology ? and it's classification
Maryam
taxonomy
Kamaluddeen
define the microbes
Saro
word microbes from microns.
Jayeeta
who is the father of microbiology?
Deborah
Antonie van Leeuwenhoek.
shamali
what makes a student to forget what he or she has been taught with easily and how can he or she cope up with it
Samson Reply
to be in touch with subject will help to cope up with the learning life long and also interest matters for subject
shriya
Constant review. And don't worry if you do forget something you always have the option to study it again. Each time you study a certain topic the more it make sense and the more it becomes something natural rather than brute memorization.
Abdi
the cause are many 1.lack of interest . 2. poor attitude to the subject. how can he cope up 1. falling in love with the subject . 2. making it part of you at all times and having determination
Ikilai
understanding the concept and relating whatever course of study with something in his/her day to day activities (i.e in which you are more conversant with in your life).
Kamaluddeen
how many types of cross matching method
umesh
which disease is caused by vicera zoster virus
Timaka Reply
chicken pox
Osuoha
Patients with disseminated herpes zostermay present with severe abdominal pain that results from visceral involvement of varicella-zoster-virus infection. In immunocompetent individuals herpes zoster usually is a localised illness, affecting the skin of one or two adjacent dermatomes.
Kamaluddeen
Actually, it is severe abdominal pain thanks
Osuoha
what causes inflammation of the lung?
Samson
what causes the fungi infection of the vigina
Estar Reply
what causes the fungi infection of the vagina?
Estar
poor hygiene of the area and unprotected sex with infected partner
Kamaluddeen
poor hygiene,some times having sex with infected person or when normal flora enters in the vagina
Ikilai
unprotected sex and poor hygiene are the major but keep in mind that there are some other minor causes also
Samson
what brings about dirt in blood
Sumaiyah Reply
So many factors might be the cause viz. Defects of blood capillaries and certain organs like the liver, the kidneys e.t.c
MOHAMMED
with the above any infection of the body easily enters the bloodstream.
MOHAMMED
there may be fevers which cause septicemia
Ikilai
even taking drug, and eating junk foods .
Ikilai
drinking contaminated water and taking drugs which contains chemical and afterwards they gets absorbed in yo the blood stream
Samson
write a essay about gene library's
anaparthi Reply
Structure of bacteria
Maggy Reply
Outline the classification of viruses according to morphology, nucleic acid, type of diseases, antigenic reaction
chilufya Reply
who is da father of microbiology
Mukomya Reply
Lucie pasture
Felicity
Father of microbiology is Anton von Leuuwenhoek
Anshika
mean Luice pasture the father of microbiology
Felicity
Luice pasture is the father of industrial microbiology
Anshika
who is the father of surgery
Talemwa
father of surgery is Sushruta
Agyekum
sushruta is the father of surgery
Ven.phumie
he Anthony van Lee wen hock
Ikilai
who is the father of medical microbiology
Naveen
he is Anthony van Lee wen hock
Ikilai
Anthony van Lee wen hook
Kamaluddeen
where would we be without microbes
Jessa Reply
nowhere because our body alone also contain billions of microbes.
Edward
in the dreams
Abid
Bangladeshi people's body contain thrice the amount of microbes than regular people.
IamTheMegaExploder
sure?
Kamaluddeen
yah
Kamran
why it was like that
Mمهazn
no where
Mukomya
cocci which are arranged in pairs are called?
umesh
diplococci
vijaya
Cocci are bacterias
Anshika
fimbriae is an organ of ?
umesh
what is the choma like vrius?
PRALHAD
Vibrio cholarea
Kamaluddeen
outline the classification of viruses
chilufya
Fimbriae z an organ of bacteria
Maggy
Antoni van Leeuwenhoek, the father of micro biology
Yang

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Source:  OpenStax, Microbiology. OpenStax CNX. Nov 01, 2016 Download for free at http://cnx.org/content/col12087/1.4
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