Antibiotic resistance determinants and genetic analysis of Salmonella enterica isolated from food in Morocco.
Antimicrobial-resistant non-typhoidal Salmonella (NTS) are an important cause of infection in Africa, but there is a lack of information on their molecular mechanisms of resistance and epidemiology. This study contributes to fill this gap through the characterization by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), plasmid profiling and analysis of antibiotic-resistance determinants of 94 Salmonella enterica strains isolated from food in Morocco. PFGE revealed considerable heterogeneity among the strains, showing 32 pulsotypes. MLST of strains representative of the different serovars evidenced 13 sequence types (STs), three of which were newly identified (ST1694, ST1768 and ST1818) and nine not previously reported in Morocco. Thirty-four strains harbored from one to four plasmids, of IncI1 group in S. Mbandaka, IncFIIA in S. Typhimurium, IncL/M in S. Hadar and S. Blockley. For the first time in Morocco an intact Salmonella Genomic Island 1 (SGI1) carrying the resistance genes aadA2, floR, tetG, blaPSE-1 and sul1 was detected in S. Typhimurium DT104. In serovar Hadar resistance to ampicillin, tetracycline and streptomycin was associated to blaTEM-1, tetA and strA genes respectively, whereas one mutation in gyrA (Asp87Asn) and one in parC (Thr54Ser) genes conferred resistance to nalidixic acid. These findings improve the information on foodborne Salmonella in Morocco, evidencing the presence of MDR strains potentially dangerous to humans, and provide useful data for future studies.
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy. Electronic address: murgiam@uniss.it.
Manuela
M
Murgia
Laboratoire de microbiologie et d'hygiène des aliments et des eaux, Institut Pasteur in Morocco, 1 place Louis Pasteur, Casablanca 20100, Morocco. Electronic address: brahim.bouchrif@pasteur.ma.
Brahim
B
Bouchrif
Laboratoire de microbiologie et biologie moléculaire, Institut Pasteur in Morocco, 1 place Louis Pasteur, Casablanca 20100, Morocco. Electronic address: mohammed.timinouni@pasteur.ma.
Mohammed
M
Timinouni
Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354 (MBC-03), Riyadh 11211, Saudi Arabia. Electronic address: aqahtani@kfshrc.edu.sa.
Ahmed
A
Al-Qahtani
Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354 (MBC-03), Riyadh 11211, Saudi Arabia. Electronic address: drahdal@gmail.com.
Mohammed N
MN
Al-Ahdal
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy. Electronic address: pcappuc@uniss.it.
Pietro
P
Cappuccinelli
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy; Department of Infection and Immunity, King Faisal Specialist Hospital and Research Centre, P.O. Box 3354 (MBC-03), Riyadh 11211, Saudi Arabia. Electronic address: rubino@uniss.it.
Salvatore
S
Rubino
Department of Biomedical Sciences, University of Sassari, V. le San Pietro 43/B, 07100 Sassari, Italy. Electronic address: biancap@uniss.it.
Bianca
B
Paglietti
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D016521:Electrophoresis, Gel, Pulsed-Field; D005516:Food Microbiology; D044404:Genomic Islands / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D009018:Morocco; D058885:Multilocus Sequence Typing; D009268:Nalidixic Acid / Q000494:pharmacology; D010957:Plasmids / Q000235:genetics; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D009268:Nalidixic Acid
Antibiotic-resistance determinants; MLST; PFGE; Salmonella