Antimicrobial Resistance in Invasive Non-typhoid Salmonella from the Democratic Republic of the Congo: Emergence of Decreased Fluoroquinolone Susceptibility and Extended-spectrum Beta Lactamases Octavie Lunguya 1,2 , Veerle Lejon 3,4 , Marie-France Phoba 1,2 , Sophie Bertrand 5 , Raymond Vanhoof 5 , Youri Glupczynski 6 , Jan Verhaegen 7 , Jean-Jacques Muyembe-Tamfum 1,2 , Jan Jacobs 3 * 1 National Institute for Biomedical Research, Kinshasa, Democratic Republic of the Congo, 2 University Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo, 3 Department of Clinical Sciences, Institute of Tropical Medicine, Antwerp, Belgium, 4 Institut de Recherche pour le De ´veloppement, UMR 177 IRD-CIRAD INTERTRYP, Campus International de Baillarguet, Montpellier, France, 5 Institute of Public Health, Brussels, Belgium, 6 National Reference Laboratory for Monitoring of Antimicrobial Resistance in Gram-negative Bacteria, Cliniques Universitaires UCL de Mont-Godinne, Yvoir, Belgium, 7 University Hospital Leuven, Leuven, Belgium Abstract Background: Co-resistance against the first-line antibiotics ampicillin, chloramphenicol and trimethoprim/sulphamethox- azole or multidrug resistance (MDR) is common in non typhoid Salmonella (NTS). Use of alternative antibiotics, such as fluoroquinolones or third generation cephalosporins is threatened by increasing resistance, but remains poorly documented in Central-Africa. Methodology/Principal findings: As part of a microbiological surveillance study in DR Congo, blood cultures were collected between 2007 and 2011. Isolated NTS were assessed for serotype and antimicrobial resistance including decreased ciprofloxacin susceptibility and extended-spectrum beta-lactamase (ESBL) production. In total, 233 NTS isolates (representing 23.6% of clinically significant organisms) were collected, mainly consisting of Salmonella Typhimurium (79%) and Salmonella Enteritidis (18%). The majority of NTS were isolated in the rainy season, and recovered from children #2 years old. MDR, decreased ciprofloxacin susceptibility, azithromycin and cefotaxime resistance were 80.7%, 4.3%, 3.0% and 2.1% respectively. ESBL production was noted in three (1.3%) isolates. Decreased ciprofloxacin susceptibility was associated with mutations in codon 87 of the gyrA gene, while ESBLs all belonged to the SHV-2a type. Conclusions/Significance: Presence of almost full MDR among NTS isolates from blood cultures in Central Africa was confirmed. Resistance to fluoroquinolones, azithromycin and third generation cephalosporins is still low, but emerging. Increased microbiological surveillance in DR Congo is crucial for adapted antibiotic therapy and the development of treatment guidelines. Citation: Lunguya O, Lejon V, Phoba M-F, Bertrand S, Vanhoof R, et al. (2013) Antimicrobial Resistance in Invasive Non-typhoid Salmonella from the Democratic Republic of the Congo: Emergence of Decreased Fluoroquinolone Susceptibility and Extended-spectrum Beta Lactamases. PLoS Negl Trop Dis 7(3): e2103. doi:10.1371/journal.pntd.0002103 Editor: Stephen Baker, Oxford University Clinical Research Unit, Viet Nam Received December 10, 2012; Accepted January 24, 2013; Published March 14, 2013 Copyright: ß 2013 Lunguya et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This study was funded by Directorate General of Development Cooperation of the Belgian Government through Institutional Collaboration INRB-ITM (Project 2.01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors declare that they have no conflicting interests in relation to this work. * E-mail: vlejon@itg.be Introduction Non typhoid Salmonella (NTS) are among the leading causes of bacterial bloodstream infections in sub-Saharan Africa [1,2]. NTS bacteremia mainly affects immune compromised hosts and young children, in whom they are associated with high mortality rates up to 27% [3]. Usually, most cases of invasive non typhoid salmonellosis are due to either Salmonella enterica subsp. enterica serotype Typhimurium (further referred to as Salmonella Typhimurium), followed by Salmonella Enteritidis [2]. Resistance of NTS to the first line antibiotics ampicillin, chloramphenicol and trimethoprim/sulphamethoxazole (TMP-SMX) is usually high [4,5], also in the Democratic Republic of the Congo (DR Congo) [6–9]. Treatment of NTS therefore increasingly relies on fluoroquinolones or third generation cephalosporins but these treatment options are threatened by decreased susceptibility to fluoroquinolones (referred to as decreased ciprofloxacin susceptibility) and extended-spectrum beta-lacta- mases (ESBLs) respectively. In Central Africa, decreased ciprofloxacin susceptibility in NTS is poorly documented [8,10,11] and NTS resistance to third generation cephalosporins in NTS has not yet been described [7,10], in contrast to other regions in tropical Africa [12–15]. The present study describes the antimicrobial resistance profile of invasive NTS isolates recovered from bloodstream infections during a microbiological surveillance study in DR Congo over the PLOS Neglected Tropical Diseases | www.plosntds.org 1 March 2013 | Volume 7 | Issue 3 | e2103