Isolation, drug resistance and molecular characterization of Salmonella isolates in northern Morocco

Mohammed Abid,Said Barrijal,Christa Wildemauwe,Amine Laglaoui,Sanae Ammari,Sophie Bertrand,Latifa En-Nanei

doi:10.3855/jidc.104

Abstract

The objective of this investigation was to assess the methods for the characterization of Salmonella isolates and to identify relationships of Salmonella isolates from human and food sources in northern Morocco. Several Salmonella serotypes were isolated from human and food samples and were characterized using conventional culture methods, biochemical, serological, antimicrobial testing, and phage typing. Molecular analyses such as enterobacterial repetitive intergenic consensus (ERIC)-PCR, macrorestriction profiling by pulsed-field gel electrophoresis (PFGE), and virulence gene analysis were also performed. Sixteen Salmonella strains were isolated in our laboratory, serotyped and identified as S. Kottbus, S. Indiana, S. London, S. Typhi, S. Hadar, S. Corvallis, S. Mbandaka, S. Ouakam, S. Tm var. cop., S. Virchow, and S. Altona. The most common resistance profiles for the isolates was ATCFATSCGKSSS, belonging to phage type PT20, ATASCSS associated with strains DT104L/ad and ATATSS for isolates that were not typeable. The PFGE patterns were different for each Salmonella serotype. All strains were negative for the virulence gene spvR. To our knowledge, this is the first molecular characterization of Salmonella in food and humans from Morocco. Comparison of molecular techniques for differentiating between human and food isolates of Salmonella in north of Morocco shows that ERIC typing and PFGE were more discriminating than the other techniques used in this study.

Highlights

Salmonella infections occur worldwide in both developed and developing countries and are a major contributor to morbidity and economic costs [1]
We investigated the suitability of enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprinting to discriminate among Salmonella isolates
The AMX, TIC, AMP, SPE, CHL, STR, SSS profiles were typically associated with phage type DT104L/ad and the AMX, TIC, CEF, F, AMP, TMP, SPE, CHL, GEN, KAN, STR,SSS,SXT profiles were associated with phage type PT20

Summary

Introduction

Salmonella infections occur worldwide in both developed and developing countries and are a major contributor to morbidity and economic costs [1]. Salmonella can colonize and cause disease in a variety of food-producing and non-food-producing animals. Within this genus, more than 2,500 serovars have been described [5,6]. All serovars may be regarded as potential human pathogens, the majority of infections are caused by a very limited number of serovars. Since these pathogens are transmitted primarily through contaminated food or water, the presence of strains in food animals and in raw meat products has important public health implications [6,7]

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Discussion

Conclusion