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TOPICAL USE OF BENZALKONIUM CHLORIDE IN TREATMENT OF CUTANEOUS LEISHMANIASIS

D. Dorostcar Moghaddam
Isfahan University of Medical Sciences, Hezar Jerib, Isfahan, Iran

Objective: The efficacy of topical paromomycin (PR) and methylbenzethonium chloride (MBCL) in cutaneous leishmaniasis management is well known. Because of local side effects due to MBCL. In the present study the antileishmanial effect of an ointment containing PR and benzalkonium chloride (BCL) were studied in experimentally infected mice.

Materials and methods: BALB/C mice were experimentally infected with the promastigotes of L. major. Seven days after the appearance of skin lesions, they were treated topically, twice daily for ten days with 15 percent PR and 2 percent BCL in SWP. Results were compared with 2 control groups.

Results: The average skin lesion size decreased from 23 to 2 mm after 10 days and disappeared in 29 days posttreatment in treated mice. No side effect and relapse was observed during and up to 90 days after treatment.

Conclusion: BCL increases the antileishmanial effect of paromomycin with no side effects in experimental mice. However, further studies will be needed in human cases for confirmation.

F 14

THE ADJUVANT EFFECT OF IL-12 AND BCG ON AUTOCLAVED LEISHMANIA MAJOR VACCINE IN EXPERIMENTAL CUTANEOUS LEISHMANIASIS

I.H. Hegazy, N.A. Hammouda, I.A. Rashwan, S.M. Ali
Department of Parasitology, Department of Immunology, Faculty of Medicine, Medical Research Institute Alexandria University, Egypt

Cutaneous leishmaniasis is a universal disease which causes skin ulceration and deformity. A reliable vaccine remains to be a possible practical means of control. The amastigotes multiply intracellulary in macrophages provoking a cell mediated type of immune response. IL-12 is the central cytokine of CMI. It is produced by sensitized macrophage, stimulates both Th 1 and Nk cells to secrete JFN-y which in turn activates the intracellular killing of Leishmania in macrophages via increased oxygen radicals.

This work aimed mainly at studying the adjuvant effect of IL-12 on autoclaved
L. major (ALM) vaccine, compared to that of BCG in L. major infection. The material included five groups of Swiss albino mice: the test group was infected after receiving ALM+ IL-12, a non-infected control group, and three other groups infected after receiving ALM+ BCG, IL-12 alone and BCG alone. L. major was cultured to provide promastigotes for vaccine and infection. The measured parameters included: the lesion size, type and progress, the parasite density and the level of IFN-y in serum.

The results showed that the best protection against challenge infection was obtained by ALM+IL-12 followed by ALM1BCG. The former is recommended for use as a vaccine with regards to its proved efficiency and known safety.

F 15

RESISTANCE OF S. TYPHIMURIUM TO ANTIBACTERIAL PREPARATIONS IN REPUBLIC BELARUS

T.I. Dmitrachenko, V.M. Semenov
Vitebsk State Medical University, Republic Belarus

Aim: To assess the resistance of S. typhimurium to antibacterial preparations.

Methods: The determination of antibiotic resistance was performed by serial dilutions method using Mueller-Hinton II broth and disk-diffusion method with the application of BBL disks produced by Becton Dickinson, USA. We have investigated 149 strains of S. typhimurium received from patients ill with salmonellosis hospitalized to 20 hospitals of 4 regions of Republic Belarus. Results were analyzed using NCCLS standards.

Results: It was indicated that S. typhimurium is resistant to the majority of the preparations tested. 89.3% of all isolates were resistant to ampicillin, 89.1% – to ampicillin/sulbactam, 85.3% – to chloramphenicol, 60.4% – to doxycyclin, and 47.7% – to co-trimoxazol. It is important that a number of S. typhimurium strains appeared to be resistant to cefalosporines of III-IV generation, e.g., 63.1% – to cefotaxim, 98.6% – to cefoperazon, 38.4% – to cefepim. It was revealed that Salmonella isolates resistant to cefotaxim were also resistant to ceftriaxon, aztreonam and ampicillin/sulbactam, but its sensitivity to ceftazidim was preserved. The prevalent patterns of antibiotic resistance among S. typhimurium strains were AM/SAM/SXT/D/GEN/CL/CTX (22.8%) and AM/SAM/SXT/D/CL/CTX (15.7%). About 49.9% of the investigated strains were resistant to 6-7 preparations. MIC90 for the majority of the preparations applied (ampicillin, ampicillin/sulbactam, cefotaxim, cefepim, cefoperazon, chloramphenicol, doxycyclin, co-trimoxazol) exceeded 64-128 µg/ml. MIC90 for meropenem and ciprofloxacin was less than 0.1 µg/ml.

Discussion: The established resistance of S. typhimurium to cephalosporines of III and IV generations is of particular importance because these preparations are strongly recommend as reserve preparations for the treatment of patients with severe and generalized forms of bacterial intestinal infections.

F 16

PENICILLINASE-LIKE ACTIVITY OF POLYCLONAL IGG IN PATIENTS WITH SHIGELLOSIS

V.M. Semenov, I.V. Zhyltsou, I.I. Generalov
Vitebsk State Medical University, Republic Belarus

The investigation of b-lactamase-like activity of abzymes in patients ill with shigellosis is of great interest for the development of the new approaches to the overcoming of shigells antibiotic resistance.
We used the hydroxame method for the determination of ß-lactamase-like activity of IgG and the solution of ampicilline trihydras (1 mg/ml) as a substrate. The experiments performed with 67 specimens of IgG received from blood serum of patients ill with shigellosis revealed ß-lactamase-like activity in 33.82 ± 5.74% of all preparations. The detected levels of the catalytic activity varied from 103 ± 2.08% to 296 ± 2.39% of the substrate spontaneous disintegration level. The middle level of penicillinase activity of IgG samples was 141.96 ± 8.38%. The highest level of abzymes penicillinase-like activity was revealed in patients with Flexneri shigellosis (150.72 ± 20.38%), whereas the lowest level – in patients with Sonnei shigellosis (118.18 ± 4.69%). The average level of the catalytic activity at the overall group was 141.96 ± 8.38%. While adding the clavulanic acid solution (100 mg/ml) to the samples of IgG with the most significant penicillinase-like activity we noted the level of hydrolysis became equal to the level of substrate spontaneous disintegration or even below. Thus, the clavulanic acid inhibits the ß-lactamase-like activity of catalytic IgG, so we can suggest the existence of an “active site” in the molecular structure of abzymes which is responsible for the exhibiting of the catalytic activity. As a conclusion, polyclonal IgG capable of hydrolysing b-lactams may be revealed in 1/3 of patients ill with shigellosis. It may indicate the presence of “biologic” resistance to the antibiotics taking place in a number of patients.

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THE ANALYSIS OF SHIGELLA PLASMID PROFILE FROM THE POINT OF VISION OF THE NEW THEORY OF SHIGELLOSIS

I.V. Zhyltsou, V.M. Semenov, A.M. Kulba, T.I. Dmitrachenko
Vitebsk State Medical University, Republic Belarus

According to the new theory of shigellosis pathogenesis [Sansonetti P.J., 2001], all virulent shigella isolates should contain the large plasmid responsible for the exhibiting of invasive properties. The size of this plasmid must exceed 65-67 kb [Pechov A.P., 1996]. Hence, the information about the antibiotic resistance of shigella strains which do not contain the large plasmides should be analyzed cautiously.
We have performed the plasmid profile analysis of 116 shigella clinical isolates received from Vitebsk infectious hospital laboratory for the period from August 2000 to March 2001. 66 isolates were S. flexneri, and 50 S. sonnei. The modified Eckhardt method was used for the plasmides detection. It was revealed that 28 isolates only (24.14 ± 3.97%) contained the plasmides with the size exceeding or equal to 65 kb.
17 of them (60.71 ± 9.23%) was S. flexneri, and 11 (39.29 ± 9.23%) S. sonnei. There were no significant differences between the antibiotic resistance of isolates containing and not containing large plasmides. Nevertheless, S. sonnei isolates with the large plasmides were reliably more sensitive to chloramphenicol than the strains without these plasmides (p < 0.05).
One may conclude that only 1/4 of shigella strains from Vitebsk region contains the large plasmides, which play the significant role in the pathogenesis of invasive diarrheas. There are some differences between the antibiotic resistance of shigella isolates containing and not containing large plasmides. Hence, we may suggest while determining the regional levels of shigella antibiotic resistance with the purposes of development of long time strategy of routing antibacterial therapy to take simultaneously the plasmide content of the corresponding isolates.