Associations of HIV status and the abundance of blaCTX-M and vanB resistance genes in stool samples of Ghanaian individuals.

BACKGROUND

A cross-sectional study was performed to investigate associations of enteric colonization with resistant bacteria in Ghanaian individuals who were tested positive and negative for the human immunodeficiency virus (HIV).

METHODS

Abundance of the ESBL-(extended spectrum beta-lactamase-)type resistance-mediating gene blaCTX-M and the vancomycin resistant enterococci-(VRE-)associated genes vanA and vanB genes was associated with available clinical and epidemiological data on the study participants.

RESULTS

In terms of enteric carriage of ESBL-positive bacteria with CTX-M-type beta-lactam resistance genes, being HIV-positive (93.3% vs. 83.3%, P = 0.003) and having low CD4+ T-lymphocyte counts <200 cells/µL (microliter) (96.8% vs. 91.2%, P = 0.009) were identified as risk factors. Enteric carriage of ESBL-positive bacteria with CTX-M-type resistance genes was associated with poor immunological status in terms of lower CD4+ T-leukocyte counts, lower CD4+/CD8+ ratios, higher viral replication, as well as with immune activation. For VRE, a non-significant trend for more VRE in control individuals without known HIV infection (6% vs. 2.5%, P = 0.089) was observed.

CONCLUSIONS

An association of ESBL colonization and immunological status was recorded. No such association was detected for VRE, suggesting different determinants of local VRE epidemiology.