The tet(X) gene encodes a flavin-dependent monooxygenase that confers resistance to all clinically relevant tetracycline antibiotics including tigecycline. It has only previously been identified in environmental and non-human pathogenic bacteria. To investigate levels of multidrug resistance in Bo, Sierra Leone, a molecular epidemiological study was conducted using an antimicrobial resistance determinant microarray (ARDM), PCR and DNA sequencing. The study found that 21% of isolates from Mercy Hospital (Bo, Sierra Leone) were tet(X)-positive, all of which originated from urinary specimens. Use of molecular epidemiological surveillance tools has provided the first evidence of tet(X)-containing multidrug-resistant Gram-negative hospital isolates in a hospital in Sierra Leone.

ABSTRACT We describe the results of a molecular epidemiological survey of 15 carbapenemase-encoding genes from a recent collection of clinical isolates from Mercy Hospital in Bo, Sierra Leone. The most salient findings revealed that (i) 60% of the isolates harbored multiple carbapenemase genes; (ii) the bla DIM-1 gene, which has previously only been reported in The Netherlands, is also circulating in this environment; and (iii) bla OXA-51-like and bla OXA-58 genes, which were thought to reside exclusively in Acinetobacter species, can also be found in members of the Enterobacteriaceae.