1. The virulence of pathogenic bacteria is called virulence. Generally, the greater the virulence of pathogenic bacteria is, the stronger the pathogenicity is. The virulence of the same kind of pathogenic bacteria varies with the number of strains and the size of pathogenicity. Its virulence can be divided into strong, weak and non-toxic strains. The determination of virulence of bacteria is particularly important in microbial experimental research, especially in the determination of vaccine titer, serum titer and bacterial toxin, In food toxicology research, the virulence of bacteria (or toxins) used in the experiment must be determined in advance. The determination of microbial virulence is carried out by infecting susceptible animals with decreasing doses of materials (living microorganisms or toxins). In each experiment, attention should be paid to the species, age and weight of experimental animals, test materials and doses, The route of infection and other factors will directly affect the results of virulence test. The route of infection and animal weight are particularly important. Generally, they should be specified. There are two units commonly used to express the virulence of microorganisms: minimum lethal dose (m.l.d) and median lethal dose (LD50).
(1) the minimum lethal dose can make a specific animal infected with the virus, This method is relatively simple, but sometimes there may be errors e to the indivial differences of experimental animals.
(2) the median lethal dose (LD50) is the amount of viable microorganisms or toxins required for half of experimental animals to die after infection within a certain period of time, The animals with the same body weight were divided into several groups, and the number of animals in each group was equal. Then the same group of animals were infected with the same amount of test materials. The amount of test materials used by each group of animals had a certain difference, (3) the minimum amount of infection and the minimum amount of infection (m.i.d) are the effects of pathogenic microorganisms on the experimental objects (experimental animals, chicken embryos, chicks, chicks and chicks), ID50 is the number of pathogens that can infect half of the test subjects.
(4) LD50 is calculated according to the method introced by reed and Muench. It includes adhesion structures on the cell surface, such as cilia, outer membrane, hydrolases, toxic metabolites, including lipopolysaccharide, protein and so on
2. Hello! HPV is the abbreviation of human papillomavirus in English. This virus only infects human beings. It has an incubation period of 2 weeks to 8 months, with an average of 3 months. It has a strong affinity for skin and mucous membrane. At present, it is reported that there are more than 200 subtypes, and more than 100 subtypes have been determined by international scientific research virus laboratories; According to its pathogenicity, it can be divided into two types: high risk type and low risk type. At present, the main means to detect HPV are PCR typing technology and HC2 quantitative technology. Among them, the application of this technology is the pre cancer screening of women's cervix. If you find HPV positive for the first time, the clinic will recommend you to test again every six months or a year. If the same subtype of HPV is positive for more than two consecutive times, it can be called HPV positive persistent infection. High risk HPV positive persistent infection should be paid attention to, because its 3-10 years of persistent positive infection will lead to cancer (such as cervical cancer, vulvar cancer, penile cancer, anal cancer, etc.), it is best to intervene in advance to remove the virus, block precancerous lesions. At present, China's traditional Chinese medicine and pure Chinese medicine preparations have advantages in this respect, which has attracted international attention
the above is my understanding, and I hope I can help you. Thank you, also thank the network know to provide such a good communication platform!
3. The virus should not be able to reproce itself, right? If the invading virus is the first generation, then the second generation will come out after the death of the host.
4. The differences between influenza and viral influenza are as follows:
1. Viral influenza has obvious characteristics of group onset, most people have onset in a short time, or several people in a family have onset; Influenza is more sporadic, and there are few or no patients with fever at the same time
The symptoms of nasal runny nose of viral cold were more obvious than those of pharynx; But influenza is tonsil or pharynx swelling and pain is more obvious. If accompanied by diarrhea or conjunctival congestion, it tends to be virus infection There was no purulent secretion in simple viral cold, and purulent sputum was an important evidence of bacterial infection The onset of viral cold was sudden, and the symptoms of systemic poisoning were mild or severe; Bacterial infection, the onset can be acute or slow, systemic poisoning symptoms are relatively serious. If the fever is not high at the beginning, and the condition worsens after 2-3 days, it is mostly influenza The white blood cell count was generally lower or normal in virus infected patients, and the percentage of neutrophils was slightly higher in early stage. The total number of leukocytes and percentage of neutrophils were higher in bacterial infection. Therefore, if the clinical blood test is not done, it is difficult to determine whether the pathogen is a virus or influenza
5. No bleeding, no infection
human skin is not only the surface layer, there are cuticle, fat and so on (professionals say)! Generally you are not fresh bleeding wound will not be infected, specific you can go to check the grade of AIDS lesions< As for symptoms, almost no one will show them!
6. Humidity (RH%) and its calculation formula: 1. The definition of humidity is stipulated in metrology, and humidity is defined as "the quantity of object image state". Humidity in daily life refers to relative humidity, expressed as RH%. In a word, it is the percentage of saturated water vapor (saturated water vapor pressure) when the water vapor content (water vapor pressure) in the gas (usually air) is the same as that in the air. 2、 There are 20 or 30 humidity measurement methods in principle. But humidity measurement is always one of the famous problems in the field of world metrology. A seemingly simple quantity involves a rather complex physical-chemical theoretical analysis and calculation. Beginners may ignore many factors that must be paid attention to in humidity measurement, thus affecting the rational use of sensors. The common humidity measurement methods are: dynamic method (double pressure method, double temperature method, split flow method), static method (saturated salt method, sulfuric acid method), dew point method, wet and dry bulb method and electronic sensor method. 3、 Absolute humidity, relative humidity and dew point humidity have a close relationship with life for a long time, but it is difficult to express them by quantity. The expression methods of humidity include absolute humidity, relative humidity, dew point, the ratio of moisture to dry gas (weight or volume), etc. Absolute humidity refers to the mass of water vapor per cubic meter of air. Relative humidity (RH) refers to the degree of water vapor saturation in the air, which is 100% RH. When the absolute humidity is constant, the higher the temperature is, the smaller the relative humidity is. When the water content in the air is not saturated, the ratio of the actual water content to the saturated water content is the relative humidity. When the relative humidity reaches 100%, the water will not evaporate naturally. The higher the temperature is, the more water it can hold, and the lower the temperature is. If there is not enough water in the air, condensation will occur. Condensation is a phenomenon of condensation on a relatively low temperature object when the air humidity reaches a certain degree of saturation. Humidity is universal, and condensation is only a special phenomenon when the humidity reaches a certain degree. 4、 The relative humidity can be calculated according to the following formula: the symbols are: ρ W – absolute humidity, g / m3 ρ w. Max – maximum humidity, unit: g / m3, e – vapor pressure, unit: Pascal, e – saturated vapor pressure, unit: Pascal, s – specific humidity, unit: g / kg, s – maximum specific humidity, unit: g / kg, relative humidity less than 30% is low humidity. Low humidity and low temperature can accelerate the heat dissipation of the body. At this time, the heat radiation in the body is absorbed by the water vapor in the air. People feel cold, causing capillary contraction, pale skin, low metabolism of the body, blood circulation and cell metabolism disorders in the tissue, causing tissue nutrition disorder and frostbite. When the indoor relative humidity is less than 10% ~ 15%, the dry air will dehydrate the nasal cavity, trachea and bronchial mucosa, rece the elasticity, mucus secretion, cilia movement and resistance, so that the inhaled st accumulating bacteria can not be removed quickly, and it is easy to ince and aggravate respiratory system diseases. Dry air can also lead to dehydration of epidermal cells, accelerated keratinization, reced sebum secretion, leading to rough wrinkling and cracking. In addition, if the air is too dry, it will make the st fly and worsen people's living conditions. In dry season, the incidence rate of diphtheria, influenza, pertussis, meningitis and other diseases also increased significantly, and the number of attacks of asthma and bronchitis increased significantly. The main reason is that the dry air accelerates the propagation of influenza virus and Gram-positive bacteria with strong pathogenicity, and spreads with st, causing epidemic disease. When the room temperature is moderate, the change of relative humidity has little effect on human body. When the temperature is 15. When the relative humidity changes 50%, the effect on human body is only equivalent to the indoor temperature change of 1 ℃.
7. Judge according to the "+" or "-" after the model
when the model is shown as "-", it means that it is negative, that is, it is not infected
when the model is shown as "+", it means that it is positive, that is, it is infected with this type of virus
extended data:
when the model is displayed as "+", it will be displayed as infection, and the harm to people after infection will be different:
1. Asymptomatic: Most HPV infection does not proce any clinical symptoms, but also can disappear by itself, and will not ince any health problems
2, lead to skin diseases: flat warts, filamentous warts and other skin diseases are the culprit of HPV virus, some skin low-risk HPV virus in patients with low resistance can ince such deformities
3, lead to condyloma acuminatum: skin high-risk HPV infection and external genital low-risk HPV infection can lead to genital warts, often manifested as condyloma acuminatum, it is understood that HPV infection caused by genital warts accounted for 15-20% of sexually transmitted diseases
4, leading to cancer: Women's cervical cancer has been confirmed to be directly related to HPV infection, after research, 99.7% of cervical cancer is caused by HPV infection. HPV can also ince tonsil cancer, oral cancer, laryngeal cancer, intranasal cancer, esophageal cancer and so on
8. There are two calculation formulas for relative humidity, which are as follows:
1, the percentage of actual water vapor density D1 in unit volume of air and saturated water vapor density D2 at the same temperature, that is, Rh = D1 / D2 x 100%
The ratio of actual air water pressure P1 and saturated water pressure P2 at the same temperature, that is, Rh = P1 / P2 x 100%
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extended data:
Application of relative humidity:
1. Prevention of cold:
(1) low relative humidity accelerates the propagation of influenza virus and Gram-positive bacteria with strong pathogenicity, and causes epidemic disease with st diffusion
(2) low relative humidity can decrease the resistance of respiratory system and ince and aggravate respiratory diseases (1) when the relative humidity is below 65%, mold can not develop normally (2) if the relative humidity drops below 45% and lasts for a long time, the paper will be brittle e to drying, causing physical decay. Therefore, it is a strict requirement for calligraphy and painting preservation to keep the lower limit of 50% relative humidity
reference source: Network - relative humidity
9. The problem is not very clear, for you to briefly describe the steps of the transformation experiment of Griffith pneumococci: 1, the non-toxic R-type live bacteria were injected into mice, the mice did not die. 2. The mice died of septicemia when the S-type bacteria were injected into the mice. 3. The S-type bacteria killed by heating were injected into mice, and the mice did not die. 4. After mixing the nontoxic R-type live bacteria with the S-type bacteria killed by heating, the mice were injected into the body and died of sepsis. The conclusion is: among the S-type bacteria killed by heating, there is a "transformation factor", which transforms R-type bacteria into S-type bacteria. In both cases, the mice did not die. After high temperature heating, the bacteria were inactivated, the enzyme was permanently inactivated, only DNA but no cells for transformation, and the mice did not die. The first step of this question seems to be useless, because no matter what bacteria add DNA, it's useless after high temperature heating... Because DNase is a protein macromolecule, it can't penetrate the capsule composed of polysaccharide, even if it can penetrate the capsule, it can't penetrate the cell membrane, so we really need to do it, The bacterial cells in this experiment must be treated as competent cells before they can absorb DNA enzymes. Diplococcus pneumoniae is a kind of bacteria with spearhead shape and often arranged in pairs. 5-1. 5 μ m in diameter. Gram staining was positive, but the aged bacteria were often negative. After artificial culture, the capsule graally disappeared, and the colony changed from smooth type (s type) to rough type (R type). Facultative anaerobes often reside in the nasopharyngeal cavity of normal people, most of them are not pathogenic, only some of them are pathogenic, causing lobar pneumonia, peritonitis, pleurisy, otitis media, mastoiditis and sepsis. On the nutrient agar medium containing blood, small, gray, transparent or translucent flat colonies were formed at 37 ℃ for 24 hours. After 2-3 days of culture, e to the proction of autolyase, the bacteria autolyzed and the depression appeared in the center of the colony. Bile, bile salts or other active substances can accelerate the action of autolytic enzymes and make bacteria dissolve in a short time. Its capsular polysaccharide antigen is closely related to pathogenicity, and its components are complex. According to the different antigen of capsular polysaccharide, it can be divided into several serotypes. Among them, type I-III has stronger pathogenicity, type III has the strongest pathogenicity and thick capsule, which can be used as the basis for the identification of this bacterium. In various types of pneumococci, many genetic markers can be transferred, and intraspecific and intrageneric interactions have been demonstrated. Micrococcus pneumoniae under the microscope can be used as antibiotic treatment for eye diseases infected by Micrococcus pneumoniae.
10. Some women often backache, leucorrhea is not normal, sometimes bloody, sometimes purulent. Go to the hospital test leucorrhea shows that white blood cells have a plus sign or two plus signs, but also did not find the presence of mold or trichomonal vaginitis. After taking a lot of anti-inflammatory drugs, the patient didn't get much effect, so the doctor suggested that the patient should have a high-risk HPV test, and the test results showed that the high-risk subtype 16 was positive. What does this index mean
What is the meaning of HPV high-risk subtype 16 positive?
3. The harm of high-risk human papillomavirus?
1. In addition to external genital warts, high-risk HPV can cause external genital cancer, cervical cancer and high-grade cervical intraepithelial neoplasia. The main virus subtypes are HPVl6, 18, 31, 33, 35, 45, 51, 52, 56, 58 and hpv61
High risk HPV mainly infects human through direct or indirect contact with contaminated materials or sexual transmission. After the virus invades the human body, it stays in the skin and mucous membrane of the infected site, and does not proce viremia. Within 1-2 months after the appearance of the infection focus, the corresponding antibodies against the infection virus were proced in the blood. At this time, if the blood was taken for examination, the results would be positive, and the positive rate was about 50-90%. 15 types of high-risk HPV, especially 16 and 18 types, mainly lead to high cervical intraepithelial neoplasia and cervical cancer What is the meaning of HPV high-risk subtype 16 positive?
Fourth, the meaning of HPV high-risk subtype 16 positive?
don't worry too much. If you only report high-grade lesions of squamous epithelial cells, it is likely to be in the CIN stage of irregular proliferation, and whether it worsens to in situ carcinogenesis needs further diagnosis. However, the 16 subtype HPV is indeed the killer of cervical cancer. It is suggested to follow the doctor's advice and visit again in time. If it is confirmed that it belongs to CIN3 stage or has early in situ canceration, then certain surgical treatment is necessary, and the effect is usually very good. But remember, don't delay. Cervical cancer is characterized by a long incubation period, some can grow to 20 years. However, the stage of malignant transformation is relatively short, and the faster one will evolve into invasive cancer in 3-6 months
