Non-typhoidal Salmonella bloodstream infections in Kisantu, DR Congo: Emergence of O5-negative Salmonella Typhimurium and extensive drug resistance

Abstract

Background Non-typhoidal Salmonella (NTS) are a major cause of bloodstream infection (BSI) in sub-Saharan Africa. This study aimed to assess its longitudinal evolution as cause of BSI, its serotype distribution and its antibiotic resistance pattern in Kisantu, DR Congo. Methods As part of a national surveillance network, blood cultures were sampled in patients with suspected BSI admitted to Kisantu referral hospital from 2015-2017. Blood cultures were worked-up according to international standards. Results were compared to similar data from 2007 onwards. Results In 2015-2017, NTS (n = 896) represented the primary cause of BSI. NTS were isolated from 7.6% of 11,764 suspected and 65.4% of 1371 confirmed BSI. In children <5 years, NTS accounted for 9.6% of suspected BSI. These data were in line with data from previous surveillance periods, except for the proportion of confirmed BSI, which was lower in previous surveillance periods. Salmonella Typhimurium accounted for 63.1% of NTS BSI and Salmonella Enteritidis for 36.4%. Of all Salmonella Typhimurium, 36.9% did not express the O5antigen (i.e. variant Copenhagen). O5-negative Salmonella Typhimurium were rare before PLOS NEGLECTED TROPICAL DISEASES

High genetic similarity between non-typhoidal Salmonella isolated from paired blood and stool samples of children in the Democratic Republic of the Congo

“…Lastly, the date of onset of symptoms was not registered, nor was the occurrence of gastrointestinal symptoms. As to its strengths, blood cultures were systematically sampled based on harmonized indications and the hospital staff got the trust of the patient's families facilitating enrollment [ 14 , 15 ].…”

“…HSLK is the major sampling site of the microbiological surveillance network organized by the Institut National de Recherche Biomédicale (INRB), Kinshasa, DR Congo, and the Institute of Tropical Medicine, Antwerp, Belgium [4,14]. Over a 10-year period (2007-2017), NTS ranked first as a cause of BSI in children accounting for 63.8% of culture-confirmed BSI [14,15].…”

“…Blood cultures were collected and processed as previously described [4,15]. About 1 g of stool was suspended in 10 ml selenite broth (Oxoid, Basingstoke, UK and BD Difco TM , Becton, Dickinson and Company, Franklin Lakes, NJ, U.S.), and incubated at 36˚C for 18-24 hours.…”

“…cultures were systematically sampled based on harmonized indications and the hospital staff got the trust of the patient's families facilitating enrollment [14,15].…”

Invasive non-typhoidal Salmonella infections in sub-Saharan Africa: a systematic review on antimicrobial resistance and treatment

“…Gatifloxacin has been withdrawn from the market in many countries due to dysglycemia in elderly and diabetic patients, but this patient profile is uncommon in invasive NTS infections in sub-Saharan Africa [5]. Finally, the reporting of combined resistance patterns, e.g., MDR combined with C3G resistance and azithromycin resistance, should be promoted by the use of convened acronyms and definitions of extensive drug resistance (XDR) and pan drug resistance (PDR), as recently proposed by our research group [137]. These combined resistance patterns provide information about the antibiotic options left for treatment.…”