Emergence of OXA-48 and OXA-181 Carbapenemases among Enterobacteriaceae in South Africa and Evidence of In Vivo Selection of Colistin Resistance as a Consequence of Selective Decontamination of the Gastrointestinal Tract

Abstract

This study reports on the emergence of OXA-48-like carbapenemases among isolates of Enterobacteriaceae in South Africa. In addition, the emergence during therapy of a colistin-resistant OXA-181-producing Klebsiella pneumoniae isolate was documented following selective digestive tract decontamination with oral colistin, which is therefore strongly discouraged. CASE REPORTS

First report of OXA-181 and NDM-1 from a clinical Klebsiella pneumoniae isolate from Nigeria

“…In Africa, the bla OXA-181 gene has only been reported in Angola (Kieffer et al, 2016) and South Africa (Brink et al, 2013). However, it has also been detected together with the NDM-1 and VIM-2 carbapenemase genes in a surveillance rectal swab isolate obtained from a patient in Canada who had previously been hospitalized in Nigeria (Walkty et al, 2015).…”

Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemase-producing isolates of Klebsiella pneumoniae in South Africa

“…Resistance to the clinically significant carbapenem antibiotics by enzymatic hydrolysis has been described in Enterobacteriaceae worldwide, and recently the class D β-lactamase, OXA-48 and its variants have been detected more frequently. [4] While the bla OXA-181 gene has previously been identified in several clonally unrelated K. pneumoniae isolates from SA, India, Singapore, the Netherlands and New Zealand, [4][5][6][7][8][9][10][11][12] this is the first report describing an outbreak of bla OXA-181 in SA. To our knowledge this is the first identification of a bla OXA-181 -producing K. oxytoca isolate.…”

“…[3] OXA-48 was first described in the environmental bacterium Shewanella spp., and more recently there have been several reports of this enzyme, mainly in K. pneumoniae isolates, from countries in the Middle East, Europe, and northern and southern Africa. [4][5][6][7] OXA-181, a variant of OXA-48, was first identified in K. pneumoniae isolated from a Tanzanian patient. [7] It differs by just four amino acid substitutions in the active site, yet still confers the same levels of enzymatic hydrolysis of carbapenems as OXA-48.…”

“…A subsequent report indicates that such organisms had recently been detected in other local institutions. [6] This outbreak report serves as the first description and characterisation of a single outbreak of carbapenemresistant K. pneumoniae in a haematology unit of a local hospital in Cape Town, South Africa (SA), during the month of May 2012.…”

Role of infection control in combating antibiotic resistance

“…Some studies have demonstrated emergence of resistance during CRE decolonisation regimens (which usually include colistin), [30][31][32] and this, allied to limited evidence of its efficacy, strongly suggests that decolonisation for multiresistant Gram-negative bacteria should not be attempted. If active screening for CRE carriage is carried out, the main intervention for carriers consists of isolation/cohorting and enhanced infection control measures.…”