Reversibility of antimicrobial resistance in respiratory isolates in HIV-positive Cambodian children after 36 months of HAART

Abstract number: 1733_237

Kalavsky E., Beno P., Shahum A., Benca J., Seng Duong L., Augustinova A., Havlikova Z., Liskova A., Krcmery V.

Objective: Aim of this study was to assess, if restauration of the immune system after 36 months treatment with HAART in cambodian children has an impact on antibiotic resistance and its reversibility.

Methods: Study participants were HIV positive cambodian children treated with HAART stavudine, lamivudine and nevirapine or efavirenz. Respiratory tract isolates (nose, pharyngeal, ear svabs) from 32 cambodian previously ART naive children 3–11 years old were assessed every 3 months within 36 months of HAART.

Results: Analysing relationship between duration of HAART, and colonisation with any specific resistance pattern, MRSA appeared to emerge after 6–12 months of HAART in comparison to pre-HAART period (was 90–93% after 9–12 months vs 50% in HAART naive, P < 0.01). Presence of multiresistant Klebsiella, and Enterobacter spp. was high already at baseline and in first months of HAART and the proportion of multiresistant Gram-negative bacteria (MR GNB) decreased later to 0 and 20% (P < 0.02). Susceptibility of both Gram-negative and Gram-positive bacteria showed biphasic but increasing tendency. Proportion of MR GNB decreased from 21/23 (90%) in the first 6 months of HAART, to 0–11% in those receiving HAART for 15–18 months and to 20–50% after 33 months of HAART. Reversibility of MR in GNB took 15–18 months. However, the baseline of resistance in GNB were relatively high. Proportion of MRSA increased from 50–55% in first 6 months to 93–85.7% after 9–18 months but than decreased to 20–33% after 36 months of HAART. Emergence of MRSA was slower. Reversibility of MR in Staphylococcus aureus was longer and took approximately 24–30 months. Ratio of Gram-positive to Gram-negative decreased from 1:3.9 (HAART naive) to 1:1.1 (30–36 month of HAART).

Conclusion: Reversibility of resistance among isolates from respiratory system was probably due to the reconstitution of their immune system due to the HAART and therefore less exposition with therapeutic ATB. In MRSA, the reversibility of resistance took 15–21 months and was slower than in MR Gram-negative bacilli (Klebsiella, Enterobacter) where the increase of susceptibility (and the decrease of resistance) took 9–12 months. Prophylactic administration of cotrimoxazol 3x weekly did not affect the reversibility of resistance and seems to be less promotive for antibiotic resistance.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
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