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

Abstract

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.