In principle, this procedure is similar to the definition of the IPC in the liquid "medium. Several Petri dishes are prepared with stepped antibiotic dilutions dissolved in the dinous medium. Add molten agar, the cups are cooled so that the culture of one or more bacteria is cooked on the surface of the medium and after Incubations in the thermostat for the required time determine the minimum concentration of the antibiotic, at which the growth of bacteria is suppressed. One of the advantages of this method before the titration method in the liquid medium is that different sections of the same cup can be sought with different types or strains of bacteria. As a result The MPC values \u200b\u200bfor several bacteria can be defined in one experiment (Fig. 2.2).

1. Determining the activity of antibiotics

Diffusion method in agar
This method is used to determine the concentration of the antibiotic in the solution. It consists next. The filter paper discs moistened with the test antibiotic solution are placed on the surface of the agar medium containing the diluted suspension of bacteria. After the corresponding incubation, the surface of the agar, which was initially translucent, purre due to the scattering of the light by the grew by bacteria. Translucent zones remain only around the filter paper disks, since the antibiotic diffuses in agar and suppresses the growth of bacteria. If the diameter of these zones is to determine under strictly standard conditions, it will be a function of a logarithm of the antibiotic concentration. Using known antibiotic concentrations, build a standard curve at which an antibiotic concentration can be determined in unknown solutions (Fig. 2.3). Sometimes instead of discs from filter paper use small hollow cylinders, put on the surface of the agar medium and the antibiotic solution containing a solution.

1. Factors affecting the definition

Activity of antibiotics
The activity of antibiotics in vitro depends on the definition conditions (Table 2.1). The definition of activity is influenced by such factors as the composition of the medium, the density of inoculum, the number of bacterial cells in Inoku Luma (the value of inoculum).

/

Table 2.1. Factors affecting the definition of antibiotic activity
Test organism
Composition of the medium (pH, ions, serum, antagonists)
The magnitude and density of inoculum (the heterogeneity of the population, the mechanisms of inactivation, the ingress of antagonist substances)
Incubation conditions (time, temperature, aeration)
A. The composition of the environment
Consider as an example an antibiotic that overwhelming the biosynthesis of one of the amino acids. If the antibiotic is experiencing in a medium without this amino acid, it seems that it has a very high activity, in other words, has a low MPK. When testing in a "medium containing amino acid, which he suppresses the synthesis and which bacterium can receive from the medium, the antibiotic will seem inactive.
In addition to these specific effects, there is often a less specific effect of the medium that is not directly related to the mechanism of action or with the chemical structure of the antibiotic. One particularly interesting case is the presence of serum in the medium. It is introduced on Wednesday when determining the IPC to create physiological conditions resembling conditions in the blood. Many antibiotics are binding to serum proteins (especially with albumin), as a result, the number of free antibiotic molecules that can penetrate bacterial cells decreases. The binding of an antibiotic with serum proteins usually correlates with the lipophobor of some substituents in its molecule.
Obviously, the conditions for determining the IPC in a liquid medium differ from the conditions in a dense medium, if only because agar is present in a dense medium. Agar, containing S03-RPYN, can adsorb the antibiotic, changing its diffusing ability, or adsorb dissolved oxygen and some components of the nutrient medium. It is not surprising, therefore, that the magnitude of the antibiotic IPC in relation to this bacteria depends on whether it is determined in a liquid or in a dense medium, even if these two media, with the exception of the presence or absence of agar, are identical in composition. It should also be remembered that cell physiology may vary depending on whether they are growing in a liquid or in the form of colonies on the surface of the dense medium.
A very strong effect on the activity of antibiotics is the pH of the medium. In addition to the secondary effects, as the effect of pH on the growth rate of microorganisms and, following
teshzyno, indirect effect on their susceptibility, the pH value has a very strong and direct effect on the ability of the drug to penetrate into the bacterial cell. For example, substances in a non-ionized form are better diffundated through a cellular steak and plasma membrane than substances in ionized form. Thus, the pH of the medium, determining the degree of ionization of the main or. Clear antibiotic, can directly affect the rate of its penetration into the bacteria and, therefore, effectiveness.
B. Density and magnitude of bacterial inoculum
Inoculum density is the number of sowing bacteria, referred to the volume in which they grow. It is usually expressed as the number of cells in 1 ml of culture. The value of inoculum is the total number of snowy bacteria. At the IPC, many antibiotics do not affect the variations in the density of the commonly used inoculum (103-106 bacterium / ml). Indeed, even at very low antibiotic concentrations, for example 0.01 μg / ml, the ratio of the number of antibiotic molecules to the number of bacterial cells remains very large (at a concentration of an antibiotic with mol. Weight 1000, equal to 0.01 μg / ml, in 1 ml of solution Contain ~ 1012 molecules). However, there are some exceptions. For example, often a lot of antibiotic molecules is adsorbed on the outer surface of the bacterial cell. If the density of bacteria is high, the number of free antibiotic molecules that can penetrate into the cell is very much reduced. In addition, a large number of antibiotic molecules is often needed to suppress the growth of one cell. As the bacteria grows, the enzymes can be synthesized and isolated on Wednesday, which can destroy the antibiotic (for example, p-lacta-maza acting on p-lactam antibiotics; see ch. 4). The amount of destroyed antibiotic is a function of the concentration of the enzyme in the nutrient medium and, therefore, depends on the value of inoculum.
At first glance, it seems that if the density of culture of bacteria is the same, it does not matter whether the activity of the antibiotic in small volumes is investigated, for example 0.25 ml and less in miniaturized systems, or in a volume of 10 ml in conventional laboratory test tubes. If all bacteria in the population are identical, there will be no difference in the results.
When the total number of bacteria in Inoculum is very large, the likelihood increases cells less susceptible to the antibiotic in the medium. The growth of all susceptible cells will be depressed, but less susceptible (in principle, it may even be a single cell) will multiply, and after incubation, it is formed for 18 hours

Table 2.2. Factors affecting the activity of some antibiotics

pouution of bacteria with high density. Significant variability of the magnitude of the IPC with a change in the number of inoculated cells typically indicates a high frequency of mutants resistant to an antibiotic (ch. 4). The frequency of the appearance of stable mutants is non-etinakov for different antibiotics. In the case of antibiotics used in the clinic, it varies from 10 ~ 7 to 10-10.
This section describes not all factors that may affect the activity of the antibiotic with respect to a certain bacterium (Table 2.2). Therefore, in order to use the suppression of the growth of bacteria to quantify the activity of antibiotics and obtain data that can be reproduced in different laboratories, it is necessary that all the conditions be accurately defined and as standardized.

(POPPY)- This is an alveolar concentration of inhalation anesthetic, which prevents the movement of 50% of patients in response to a standardized stimulus (for example, skin cut).The poppy is a useful indicator, because it reflects the partial pressure of anesthetic in the brain, allows you to compare the power of various anesthetics and is a standard for experimental studies (Table 7-3). However, it should be remembered that the poppy is a statistically averaged value and its value in practical anesthesiology is limited, especially at stages accompanied by a rapid change in alveolar concentration (for example, under induction). The values \u200b\u200bof the poppy of various anesthetics are folded. For example, a mixture of 0.5 poppy nitrogen zakisi (53%) and0.5 MA poppy gatalon (0.37%) causes the depression of the CNS approximately comparable to depression arising under action 1 of the interfluran (1.7%). In contrast to the depression of the CNS, the degree of myocardium depression in different anesthetics with the same poppy is not equivalent: 0.5 poppy gatalon causes a more pronounced oppression of the pump function of the heart than 0.5 poppy nitrogen zakisi.

Fig. 7-4. There is a direct, although not strictly linear relationship between the power of anesthetic and its grease-rimine. (From: Lowe H. J., Hagler K. Gas Chromatography in Biology and Medicine. Churchill, 1969. Reproduced with changes, with permission.)

Mac represents only one point on the "dose-effect" curve, namely, ED 50 (ED 50%, or 50% effective dose, is the dose of the drug, which causes the expected effect in 50% of patients. Note. per.).Mac has a clinical value if anesthetic is known for the "Dose Effect" curve. It can be estimated that 1.3 poppy of any inhalation anesthetic (for example, for halotan 1.3 x 0.74% \u003d 0.96%) prevents movement in surgical stimulation in 95% of patients (i.e. 1.3 Mac - Approximate equivalent of ED 95%); At 0.3-0.4 Mac occurs awakening (poppy wake).

Mac changes under the influence of physiological PI pharmacological factors (Table 7-4.). The poppy practically does not depend on the type of living being, his Iola and the duration of anesthesia.

Nitrous oxide

Physical properties

Nitrogen approach (N 2 O, "funny gas") is the only inorganic compound from inhalation anesthetics used in the clinical practice (Table 7-3). Nitrogen is colorless, actually does not smell, does not flamm and does not explode, but it supports burning like oxygen. In contrast to all other inhalation anesthetics at room temperature and atmospheric pressure, nitrogen is gas (all liquid inhalation anesthetics using evaporators are converted into a vapor state, so they are sometimes called vapor-forming anesthetics. Note. per.).Under pressure, nitrogen is stored as a liquid, because its critical temperature is above room (see ch. 2). Nitrogen approach is a relatively inexpensive inhalation anesthetic.

Influence on the body

A. Cardiovascular system.Nitrogen stimulates the sympathetic nervous system, which explains its effect on blood circulation. Though in vitro.anesthetic causes myocardial depression, in practice, blood pressure, cardiac output and heart rate do not change or slightly increase due to increasing the concentration of catecholamines (Table 7-5).

Table 7-3.. Properties of modern inhalation anesthetics

1 The presented MAC values \u200b\u200bare calculated for people aged 30-55 years and expressed as a percentage of one atmosphere. When used in highlands to achieve the same partial pressure, a higher concentration of anesthetic in the inhaled mixture should be used. * If the poppy\u003e 100%, then for achieving 1.0 poppy, hyperbaric conditions are needed.

Myocardial depression may have clinical importance for CHA and Hypovolemia: arising arterial hypotension increases the risk of myocardial ischemia.

Nitrogen rushing causes a narrowing of the pulmonary artery, which increases the pulmonary vascular resistance (LSS) and leads to an increase in pressure in the right of atrium. Despite the narrowing of the vessels of the skin, the total peripheral vascular resistance (OPS) changes slightly.

Table 7-4.Factors affecting poppy

Factors	Influence on Mak.	Notes
Temperature
Hypothermia	↓
Hypertermia	↓	If\u003e 42 ° С
Age
Young
Senile	↓
Alcohol
Acute intoxication	↓
Chronic consumption
Anemia
Hematocrit< 10 %	↓
PAO 2.
< 40 мм рт. ст.	↓
Paco 2.
\u003e 95 mm Hg. Art.	↓	Due to a decrease in pH in the CES
Function of thyroid gland
Hyperthyroidism	Does not affect
Hypothyroidism	Does not affect
Arterial pressure
Hell CP.< 40 мм рт. ст.	↓
Electrolytes
Hypercalcemia	↓
Hypernamentia		Due to a change in the composition of the CSZH
Hyponatremia	↓
Pregnancy	↓
Medications
Local anesthetics	↓	In addition to cocaine
Opioids	↓
Ketamine	↓
Barbiturates	↓
Benzodiazepines	↓
Verapamil	↓
Lithium preparations	↓
Sympatolithic
Metyldop	↓
Reserpine	↓
Klonidin	↓
Sympathomimetics
Amphetamine
Chronic use	↓
Acute intoxication
Cocaine
Ephedrine

Since nitrogen rushes increases the concentration of endogenous catecholamines, its use increases the risk of arrhythmias.

B. Respiratory system.Nitrogen rushing increases the frequency of respiration (i.e. causes Tahipne) and reduces respiratory volume as a result of the stimulation of the central nervous system and, possibly, the activation of pulmonary stretching receptors. The total effect is a slight change in the minute volume of respiratory and Paco 2 alone. Hypoxic drive, i.e., an increase in ventilation in response to arterial hypoxemia, mediated by peripheral chemores-charters in carotid tanks, is significantly inhibited using nitrogen oxide even in low concentration. This may lead to serious complications arising from the patient in the postoperative wakenation chamber, where it is not always possible to quickly identify hypoxemia.

B. Central nervous system.Nitrogen rushing increases cerebral blood flow, causing some increase in intracranial pressure. Nitrogen rushing also increases oxygen consumption by a brain (CMRO 2). Nitrogen at concentrations less than 1 poppy provides adequate anesthesia in dentistry and when performing small surgical interventions.

G. Nervous muscular conductivity.Unlike other inhalation anesthetics, nitrogen does not cause a noticeable muscle relaxation. On the contrary, in high concentration (when used in hyperbaric chambers), it causes the rigidity of the skeletal muscles. Nitrogen rushing, most likely, does not provoke malignant hyperthermia.

D. Kidneys.Nitrogen rinse reduces the renal blood flow due to increasing renal vascular resistance. This reduces the speed of glomerular filtration and diuresis.

Table 7-5.Clinical pharmacology of inhalation anesthetics

	Nitrous oxide	Galotan	Methoxy fluorane	Eneflyuran	Isoflu-Ran.	Desflu-Ran.	Sevo-Fluorane
The cardiovascular system
Arterial pressure	±	↓↓	↓↓	↓↓	↓↓	↓↓	↓
Heart rate	±	↓				± or
OPS	±	±	±	↓	↓↓	↓↓	↓
Cardiac output 1.	±	↓	↓	↓↓	±	± or ↓	↓
Breath system
Respiratory volume	↓	↓↓	↓↓	↓↓	↓↓	↓	↓
Breathing rate
Paco 2 alone	±
PACO 2 with load
CNS.
Brain blood flow
Intracranial pressure
Metabolic Brain Needs 2		↓	↓	↓	↓↓	↓↓	↓↓
Causes	↓	↓	↓		↓	↓	↓
Nervous muscular conductivity
Non-polarizing unit 3.
Kidney
Renal blood flow	↓↓	↓↓	↓↓	↓↓	↓↓	↓	↓
Speed \u200b\u200bof glomerular filtration	↓↓	↓↓	↓↓	↓↓	↓↓	?	?
Diuresis	↓↓	↓↓	↓↓	↓↓	↓↓	?	?
Liver
Bleeding in the liver	↓	↓↓	↓↓	↓↓	↓	↓	↓
Metabolism 4 O.	,004 %	15-20%	50%	2-5 %	0,2 %	< 0, 1 %	2-3 %

Note:

Increase;

↓ - decrease; ± - no changes; ? - Unknown. 1 Ha Background of IVL.

2 Metabolic brain needs increase if the enflurane causes convulsions.

Anesthetics are most likely to have a depolarizing block, but this effect has no clinical value.

4 Part of the anesthetic entered into blood, which is subjected to metabolism.

E. liver.Nitrogen rushing reduces blood flow in the liver, but to a lesser extent than other inhalation anesthetics.

J. Gastrointestinal tract.In some works, it is proved that nitrogen rushing causes nausea and vomiting in the postoperative period as a result of activation of the chemoreceptor trigger zone and the dump center in the oblong brain. In the studies of other scientists, on the contrary, no connection was found between nitrogen and vomiting.

4. Essence of concepts: antibiotic, probiotic (eubiotic).

5. The essence of concepts: bactericidal and bacteriostatic action.

6. The essence of the concepts: means of choice (preparations of the first row, fixed assets) and reserve agents (preparations of the second row, alternative means).

7. The essence of the concepts is the minimum inhibitory (overwhelming) concentration and minimum bactericidal concentration.

8. The concept of concepts sensitivity and resistance of the pathogen, an additional libeotic effect.

9. Determinants of selective toxicity of chemotherapeutic agents.

10. The essence of the difference in pharmacodynamic and chemotherapeutic properties.

11. Basic principles of rational chemotherapy.

12. Indications for combined antibiotic therapy.

13. Principles of combined antibiotic therapy.

14. Principles of the classification of antibiotics.

15. Basic mechanisms of action of antibiotics.

16. Name the side effects of antibiotics caused by their allergenic action.

17. Name side effects and complications of antibiotic therapy associated with pharmacodynamic effect.

18. Name side effects and complications of antibiotic therapy associated with chemotherapeutic effects.

19. Mechanisms for the development of microorganisms to antibiotics.

20. Ways to overcome the resistance of microorganisms to antibiotics.

21. Causes of non-efficiency of antimicrobial therapy.

22. Name the groups of antibiotics inhibiting the synthesis of the cell wall.

31. Classification of cephalosporins (specify highly active drugs).

32. Name the most active antibiotics of the group of monobactam and carbapenes.

48. Name chemotherapeutic preparations with high antipsevdomonade activity.

49. Indications for the purpose of tetracycline.

50. Indications for the purpose of chloramphenicol.

59. Side effects of chloramphenicol.

60. Side effects of macrolides.

77. Call the drugs of 8-oxychinoline derivatives.

89. Complications for nitrofurantoin therapy.

90. Side effects of Furazolidone.

91. Difference in the antibacterial acid spectrum: nodidix, oxolin and pipemeida.

93. The distinction and similarity of the pharmacokinetic properties of acids: nodidix, oxolin and pipemeida.

101. Pharmacokinetic properties of fluoroquinolones.

102. Indications for appointment of fluoroquinolones.

103. The side effects of fluoroquinolones.

104. Contraindications for appointment of fluoroquinolones.

142. Name the funds used in Zhiydiase (giardiasis).

147. Features of therapy of toxoplasmosis in the threat of fetal infection.

157. Name the inhibitors of RNA synthesis and late viral proteins.

185. Indications for the use of ribavirin.

194. The side effects of Ganziklovir.

195. Side Effects of Zidovudine.

196. The side effects of aminoadamantanes.

234. The duration of the standard tuberculosis treatment.

235. What depends on and how does the duration of the treatment of tuberculosis change?

236. "Short" course of treatment of tuberculosis recommended by WHO. His substantiation and duration.

237. What is the difference between the standard and "short" (recommended WHO) course of treatment of tuberculosis?

238. Principles of combining anti-tuberculosis funds.

239. Name the combined drugs for the treatment of tuberculosis.

240. Rifampicin, Rifabutin. Comparative characteristics of their antimicobacterial action.

241. Side effects of isoniazid.

242. Side effects of etcutol.

7. The essence of the concepts is the minimum inhibitory (overwhelming) concentration and minimum bactericidal concentration.

Minimum inhibiting concentration (MIC)- minimum concentration of chemotherapeutic or antiseptic substance causing Full suppressionnoticeable with naked eye Heostthis microorganism on media under standard conditions of experience.

Measured in μg / ml or in units. actions. It is established by sowing a tested culture on dense or liquid media containing various concentrations of the drug.

Minimum bactericidal concentration (MBK)- the minimum concentration of chemotherapeutic or antiseptic agent causing Full deathbacteria in standard experience conditions.

Measured in μg / ml or units. actions. It is established by sowing a tested culture on dense or liquid nutrient media containing different concentrations of the drug. To distinguish between MIC from sterile zones or transparent tubes, it is made on the medium without a drug (the appearance of growth indicates a static action, the absence of it is on a zeal).

MBK and MICs are used in chemotherapy and antiseptics to select efficient drugs and doses for this patient.

8. The concept of concepts sensitivity and resistance of the pathogen, an additional libeotic effect.

Sensitivity of the pathogen- the absence of the mechanisms of resistance to xs; In this case, the reproduction of the pathogen is suppressed by an average therapeutic dose that exceeds the minimum inhibitory concentration of 2-4 times.

Resistant pathogen- the presence of mechanisms of resistance to xc; The growth of the pathogen is not suppressed by the concentration of the drug that has the toxic effect in vivo.

Old-proteic effect- persistent inhibition of the vital activity of bacteria after their short-term contact with the antibacterial preparation.

9. Determinants of selective toxicity of chemotherapeutic agents.

1) HS accumulates in microbial cells in concentrations many times large than in mammalian cells

2) Xs act on the structures that are available only in the microbial cell (cell wall, DNA girase II type) and are absent in the mammalian cell

3) Xc act on biochemical processes flowing exclusively in microbial cells and missing mammalian cells.

10. The essence of the difference in pharmacodynamic and chemotherapeutic properties.

1. Pharmacodynamic therapy operates at the level of architecture of functional systems, its effects are usually reversible. For chemotherapy, agents are most valuable with the most irreversible action.

2. Pharmacodynamic agents cause a gradual response of the body system, for chemotherapeutic means the most desirable effects "all or nothing".

3. Chemotherapy has a etiotropic strategy aimed at the destruction of the pathogen or on transformed organism cells, and pharmacodynamic therapy can be both etiotropic and pathogenetic.

11. Basic principles of rational chemotherapy.

1. The pathogen must be sensitive to ab

The "best sentence" rule is reference tables, taking into account regional population features of antibacterial sensitivity.

2. AB must compare therapeutic concentration in the focus.

3. Preferably adequate dosing mode, depending on:

ü pathogen

ü Dynamics of the clinical course of infection

ü Localization of infection

ü The duration and nature of the flow of infection (acute, chronic or bacterianesis)

4. Optimal duration of antimicrobial chemotherapy (example: Streptococcal pharyngitis healing for 10 days, acute uncompressed gonoxococcal urethritis for 1-3 days, sharp low cystitis in 3 days).

To prevent adverse reactions, the development of superinfection or resistance, the duration of treatment must correspond to the trace agent eradication period.

5. Accounting patient factors:

ü Allergianamnez, immunocompetence

ü liver and kidney function

ü tolerability AB during oral administration; compliance

ü heaving condition

ü Age, gender, pregnancy or child feeding, oral contraceptives

ü Side Effects

6. Combined antibiotic therapy.

1 "St. Petersburg State Pediatric Medical University" Ministry of Health of Russia

Relevance

In ophthalmological practice, the choice of antibacterial drug, as in other cases of antimicrobial therapy, is primarily dependent on the causative agent and its sensitivity to antibiotics. The antibacterial drug used should have a bactericidal effect and have a low minimal overwhelming concentration (IPC). This is especially important in modern conditions with constantly increasing resistance of microorganisms to antibiotics. The purpose of the drug in doses that cannot have a detrimental effect on the microorganism can contribute to the further development of microflora resistance.

The IPC is the smallest concentration of the antibacterial drug, which causes the suppression of microflora with a noticeable eye growth. It is the IPC that allows you to most accurately characterize the degree of sensitivity of the microorganism to the antibiotic. The lower the PCA of the drug, the higher the sensitivity to the microflora it. Only the knowledge of the IPC makes it possible to solve the question: does the antibiotic achieves the localization of the pathogen localization zones at a concentration sufficient to suppress this microorganism? It should also be noted that antibacterial drugs (fluoroquinolones and aminoglycosides) are most widely used in ophthalmological practice: dose-dependent drugs, i.e. The death rate of microorganisms increases in direct proportion to their concentration. In the scientific literature, there are data on the slower achievement of the Floxacin MPC in the wicking of the anterior chamber of the eye compared to Levofloxacin. It is also proved that after a single instillation of Levofloxacin, its concentration has repeatedly exceeds the IPC for all microorganisms that cause infectious eye diseases. However, new antibacterial drugs are constantly being introduced into clinical practice, and in the existing literature there are practically no information about the IPC, i.e. On the antimicrobial efficiency of the entire spectrum of modern antibiotics used in ophthalmology, which served as a reason for conducting our research.

goal

Determine the IPC of modern antibiotics for the most common microflora.

Material and methods

To determine the IPC of antibiotics, we used HI COMB MIC TEST (Certificate of the Ministry of Health of the Russian Federation 2003/1664 dated December 23, 2003). The test consists of strips to which the discs impregnated with not one, but a number of decreasing concentrations of the same antibiotic. When performing the study, we first took the contents of the conjunctival cavity for sowing on a simple agar. Next, they allocated the pure culture of the microorganism and sowed it to the corresponding solid nutrient medium in a cup of Petri in the form of a lawn. Then Petri dishes were incubated in a thermostat at a temperature of 37º for 24 hours. At the same time, the microflora delay in the form of an ellipse was formed around the test strips, which allows to determine the IPC of the antibacterial preparation. The IPC was determined by a digital scale on a test strip in the minimum diameter of the ellipsed microflora growth zone. We have defined the MPC of the most common in the clinical practice of antibacterial drugs - Ciprofloxacin (Cipromed, Sentiss), Ofloxacin (Floxal, Baush & Lomb), Levofloxacin (Signicef, Sentiss), Moxifloxacin (Vigamox, Alcon), Gatifloxacin (Zimar, Allergan) and Tobramycin (Tobrakhin , Alcon).

results

Total examined 105 patients aged 2 months. Up to 7 years old with various inflammatory diseases of the front eye of the eye: acute and chronic conjunctivitis, blufurokonjunctivitis, wall-cutting stenosis, complicated chronic dacryocystitis, as well as bacterial keratitis. In the crops of children separated from the conjunctival cavity, epidermal (43.9%) and golden staphylococci (22.9%), streptococci (15.1%), as well as gram-negative microflora (18.1%) were found.

All tested antibacterial drugs of the IPC for epidermal staphylococcus turned out to be the highest. The lowest IPC for the epidermal staphylococcus was levofloxacin and moxifloxacin - 0.544 and 0.551 μg, respectively. The maximum IPC is fixed by us in Tobramycin (8,623 μg), i.e. This drug turned out to be the least effective in terms of Staphylococcus Epidermidis. Despite the fact that Gatifloxacin is relatively recently used in clinical practice, its IPC turned out to be quite high - 1.555 μg. The IPC of Ciprofloxacin and Opleloxacin was small - 1.023 and 1.191 μg, respectively.

The IPC of all antibacterial drugs for golden staphylococcus turned out to be less than for epidermal. In this case, the lowest IPC was levofloxacin (0.020 μg), i.e. For the treatment of infections caused by gold staphylococcus, this drug turned out to be the most efficient. MCP Moxifloxacin (0.202 μg) and offlsacin (0.240 μg) also turned out to be small, but 10 times higher than the IPC of Levofloxacin. The highest IPC is fixed by us in the preparation of Tobramycin (5.115 μg).

The following streptococcis were allocated from the conjunctival cavity: Streptococcus Pneumoniae, Streptococcus Viridans and Streptococcus Haemolyticus. The smallest IPC for all streptococci dedicated in children was Moxifloxacin - only 0.006 μg. MPK Levofloxacin was also small, but significantly exceeded MPK Moxifloxacin - 0.135 μg. The high IPC was recorded at Ciprofloxacin (1.246 μg) and the largest - in Tobramycin (6,460 μg).

The group allocated in children of gram-negative microorganisms was a cynic chopstick, Enterobacter Brevis, Klebsiella Pneumonia, as well as Serratia Marcencens. The lowest MPK for gram-negative microflora was at Ciprofloxacin - 0.034 μg. Low indicators of the IPC, i.e. High efficiency, also noted at Levofloxacin - 0.051 μg. The IPC of Oplexacing and Gatifloxacin was significantly greater and almost the same - 0.096 and 0.102 μg. The highest IPC was again recorded in Tobramycin (7,050 μg). (See crisp)

Conclusion

Thus, levofloxacin was the most effective antibacterial drug in relation to the most frequently allocated in children of microflora. The IPC of this drug for streptococci and gram-negative microorganisms also turned out to be small, which makes it possible to recommend a drug based on 0.5% levofloxacin Signicef \u200b\u200bfor the treatment of all inflammatory diseases of the eye of bacterial nature.

For the therapy of inflammatory eye diseases caused by streptococci, Moxifloxacin is preferable, since its IPC for streptococci turned out to be the smallest. Ciprofloxacin MPK for all gram-negative microflora turned out to be the lowest, which confirms the generally accepted high efficiency of this drug. The highest IPC for all dedicated microorganisms was in Tobramycin.

Source page: 26

Table of contents of the topic "Methods for determining sensitivity to antimicrobial means. Side effects of antibiotic therapy.":

Methods for determining sensitivity to antimicrobial means. Minimum inhibiting concentration (MIC). Method of serial dilutions in liquid media.

The criteria of activity of this or that drug are minimum inhibiting concentration (Mick) - the smallest concentration of the drug, which is inhibiting the growth of test culture and minimum bactericidal concentration (MBK) - the smallest concentration of the drug, which causes a bactericidal effect.

Method of serial dilutions in liquid media

Method of serial dilutions in liquid media Allows you to install minimal inhibiting concentration (Mick) I. minimal bactericidal concentric (MBK) The drug for the dedicated pathogen. Studies can be performed in different volumes of the nutrient medium (1-10 ml). Use liquid nutrient media corresponding to the food needs of the causative agent. In test tubes (usually eight) prepare a series of double dilutions of the drug on the nutrient medium. The concentration is reduced by 128 to 0.06 μg / ml, respectively (base concentration may vary depending on the activity of the drug). The final volume of the medium in each tube is 1 ml. Control serves a test tube containing a pure nutrient medium. In each test tube, 0.05 ml of a physiological solution containing 106 / ml microbial cells are brought. The tubes are incubated for 10-18 hours at 37 ° C (or before the appearance of bacterial growth in the control tube). Upon expiration of the specified period, the results are taken into account by changing the optical density of the medium visually or nephowerometric. You can also use a modified method using a medium supplemented with glucose and indicator. The growth of microorganisms is accompanied by a change in the pH of the medium and, accordingly, the color of the indicator.