Научная электронная библиотека

Монографии, изданные в издательстве Российской Академии Естествознания

2.2.1. Bactericidal activity of preparations

Healthcare and human welfare shall be the ultimate goal of envuronment protectiont. In this regard, one of the important tasks is to protect the human body from outside intrusion of unwanted microbes which cause various infectious diseases.

Currently, the spread of diseases such as tuberculosis, brucellosis requires regular disinfection of the various facilities of the national economy. The main obstacle in the implementation of these measures is a scarcity of effective disinfectants, low bactericidal power,toxicity of many available substances, as well as their corrosive action to metal surfaces.

Based on a comprehensive analysis of the literature data and the results of experimental works we have found new uses for the ammonium salts. They are used to create a number of new disinfectants [57–58].

Livestock farms pretty often fall into the poor state because of tuberculosis, brucellosis and other infectious diseases. At this present situation, there is a risk of the spread of infectious diseases among the population. The main pathways for the spread of these diseases are transportation facilities where significant numbers people have to be accumulated, problems of the livestock farms and other companies that are supplying the population with basic foodstuffs, the lack of treatment facilities for the disposal of sewage and other wastes, as well as and the absence in many places proper control bacteriological indicators that should be established by the Sanitary and Epidemiological Supervision.

The elimination of the nidus of infection and prevention of the possible cases of environmental pollution shall be the most important task at the Government level. Therefore, for the purpose of decontamination of railway, motorroad and water transport facilities, network of the disinfection and washing stations and veterinary service stations, premises and territories of the storage, processing, trade and utilization of raw materials of animal origin the studies on the development of disinfectants on the basis of the oil and gas industry wastes have been conducted.

The obstacle for the implementation of measures aimed at the decontamination of various not well facilities is the scarce of effective disinfectants, low bactericidal activity and toxicity of many preparations available.

Increased bactericidal activity of a mixture of ammonium persulfate and bisulfate against Staphylococcus aureus, Mycobacterium, Brucella and other cultures are known from studies by Akbasova with students [57, 58]. On the basis of ammonium persulfate and bisulfate salts they created the new disinfectants entitled as “Zhezpen-1” and “Zhezpen-2”. Bactericidal activity and the application of these preparations are described in works [57–59]. The authors on the base of production testing established their conformity with modern requirements for disinfectants, namely, they have a fairly high bactericidal action, odorless, easy soluble in water, transportable and decompose
in the environment without wastes damaging the environment. These preparations allow the replacement of those used in livestock farming for killing Mycobacterium tuberculosis and brucellosis in the external environment which are difficult to obtain toxic preparation such as, for example, alkali and chlorinated cresols, phenols, formalin and mixtures thereof with kreolina, glutaraldehyde, caustic and soda ash, peracetic acid, bleach, sodium hypochlorite and others.

Experimentally selected on the basis of the studies of bactericidal activity of the ratios of ammonium persulphate to the ammonium bisulfate in the preparation “Zhezpen” make 1:1,5–2,5 (Table 2.1). The bactericidal action of “Zhezpen” is based on the irregularity of the normal flow of redox processes in microorganisms causing their death.

For disinfection 0,1–4,0 % solutions of the preparation “Zhezpen-1” is used with its consumption as a spray 0,3 l/m2, and as solution of 0,5 l/m2 and 30 min exposure. It is harmless from the dermatological point of view, has a low toxic effect, the LD50 for white mice is 964 mg/kg of the body weight.

From Table 2.1 data it follows that ≥ 0,1 % solutions of the preparation have 100 % disinfectant capacity against Staphylococcus aureus culture. Relating to the mycobacteria (TB) culture ≥ 4,0 % solutions have the similar capacity and relating to Brucella culture the same ie true for ≥ 0,2 % solutions of the preparation.

According to the results of production tests in various farms of the agriculture complex of the country “Zhezpen-1” is recommended for wide introduction as a germicide for sanitation and disinfection of vehicles and livestock facilities. Combination of “Zhezpen-1” with the cationic surfactant of penazolin 10–16 B resulted in a new composition which has not only enhanced germicidal capacity but also has cleaning and tanning capacity for the tissue surfaces exposed to purulonecrotic decay

In this composition under the name of “Zhezpen-2” the optimal weight ratios of the components (NH4)2S2O8:NH4НSO4:penazolin = 1:(1,5–2,5):0,02 [59].

For disinfecting solutions used drug “Zhezpen 2” in concentrations of 0,5–3,0 wt. %, Wherein the content of the penazolin is 0,02–0,04 wt %. In this concentration range the penazolin exhibits enhanced surface activity” it maximally lowers the surface tension of solutions to form stable foam and is an effective inhibitor of the corrosion of metals, has drying effect on the surface of animals’ tissue and exhibits antiseptic properties.

“Zhezpen-2” preparation as the “Zhezpen-1” preparation, is harmless from the dermatological point of view, it has low toxicity LD50 = 960–230 mg/kg (white rats, intraperitoneally).

Table 2.1

Characteristics of Bactericidal Properties of “Zhezpen-1”
preparation (30 minutes exposure)*

٭Note: + presence of bacteria growth; – absence of bacteria growth (with each concentration of the Disinfectant 4 parallel testing have been made).

Penazolin 10–16 B which is a part of this preparation, is a good foaming agent in acidic medium, in this connection it is possible to use disinfectant “Zhezpen-2” as the foam, which will allow considerably reduce the flow rate per unit area of the disinfected area to 0,2 l/m2.

At the present time, on the basis of the ammonium persulfate and bisulfate another new antibacterial composition “Bactericide” has been developed that has the lower corrosion and higher bactericidal capacity. “Bactericide” is a mixture of ammonium persulfate, bisulfate and a surfactant – alkylimidazoline [60].

To determine the possibility of using the surfacant alkyl imidazoline as inhibitory additive the studies have been conducted to identify the change of its surface-active properties depending on the salt composition of the solution, concentration of surfactants and temperature.

Table 2.2

Characteristics of Bactericidal Properties of “Bactericide”. Preparation

Tables 2.2 and 2.3 shows the data to determine the bactericidal capacity and optimal ratio of the components in the composition of the proposed agent “Bactericide”, in which a sufficiently high disinfecting capacity is observed.

Previously conducted studies on the chemical compatibility of the components that make up the proposed disinfectant “Bactericide”. Compatibility was determined based on analysis of the content of the active substances (ADV): ammonium persulfate and bisulfate in solutions containing and not containing the surfactant additives.

Experimental data suggest that the solutions containing ≥ 0,1 % of the “Bactericide” preparation have 100 % disinfectant capacity against Staphylococcus aureus cultures. Concerning the mycobacteria (TB) culture solution with a concentration of ≥ 3,5 % has the similar capacityactivity and in respect of Brucella culture ≥ 0,5 % solutions of this preparation have the same capacity (Tables 2.2 and 2.3).

It is determined that the content of the active compound in the presence of alkylimidazoline is not reduced, i.e. the components are chemically compatible. Determination of the active compound was conducted during 24 hours with sampling for analysis after every 8 hours from the moment the alkylimidazoline additives had been added.

Table 2.3

Optimum ratios of Components
in Composition of Proposed Disinfectant “Bactericide”

The findings indicate a high enough bactericidal power of the “Bactericide” preparation and the absence of influence on alkylimidazoline disinfectant capacity of the ammonium salts.

Using a thermal method, the functional connection of the freezing point of the solutions and the concentration of the preparation was determined (Picture 2.2).

Picture 2.2. Functional Connection of Temperature of the “Bactericide” Preparation Water Solutions and its Concentration (wt %.)

As can be seen from the experimental data shown in Picture 2.2, with the increase of the “Bactericide” preparation concentrations in the solutions there is the decrease in temperature of their freezing. For example, 0,5 % solution has a freezing point of –12,8 °C, and 7,0 % solution – 14,4 °C. The bactericidal efficiency of the preparation remains at the sub-zero temperatures, which is one of its advantages over other known disinfectants as their solutions freeze at temperatures below –5 °C.