Characteristics and Dynamics of Salmonella Contamination along the Coast of Agadir, Morocco

Abstract

The occurrence of Salmonella enterica in the environment of tropical and desert regions has remained largely uninvestigated in many areas of the world, including Africa. In the present study, we investigated the presence of Salmonella spp. along 122 km of the coastline of Agadir (southern Morocco) in relation to environmental parameters. A total of 801 samples of seawater (243), marine sediment (279), and mussels (279) were collected from six sites between July 2004 and May 2008. The overall prevalence of Salmonella spp. was 7.1%, with the highest occurrence in mussels (10%), followed by sediment (6.8%) and seawater (4.1%). Only three serotypes were identified among the 57 Salmonella sp. strains isolated. S. enterica serotype Blockley represented 43.8% of all Salmonella strains and was identified in mussel and sediment samples. S. enterica serotype Kentucky (29.8%) was found almost exclusively in mussels, whereas S. enterica serotype Senftenberg (26.3%) was detected in sediment and seawater. Statistical analysis using generalized additive models identified seawater temperature, environmental temperature, rainfall, and solar radiation as significant factors associated with the presence of Salmonella. Rainfall was the only variable showing a linear positive effect on the presence of Salmonella in the sea, whereas the remaining variables showed more complex nonlinear effects. Twenty-eight (49.1%) Salmonella isolates displayed resistance to ampicillin (22 isolates), nalidixic acid (9 isolates), sulfonamide compounds (2 isolates), and tetracycline (1 isolate), with six of these isolates displaying multiple resistance to two of these antimicrobial agents. Pulsed-field gel electrophoresis analysis revealed homogenous restriction patterns within each serotype that were uncorrelated with the resistance pattern profiles.

Deniz Ürünlerinde Salmonella spp. ve Listeria monocytogenes Varlığının Kültürel Metotlar ve PCR İle Araştırılması

“…in Morocco [3] , in Spain [4] , in Vietnam [5] , in India [6] ; L. monocytogenes in Spain [7] , in USA [8] , in India [9] , in Denmark [10] , in Iran [11] . In Turkey the prevalence of these pathogens has not been extensively investigated.…”

Contribution of Dug-Out Wells to Salmonella Dissemination in Kwaebibirem District of Ghana

“…These activities disseminate Salmonella causing gastroenteritis and typhoid in the district (Attua et al, 2015). Not all Salmonellae serotypes found in the environments are the same as those isolated from humans (Setti et al, 2009) because some isolates are associated with animals (Levantes et al, 2012;Andoh et al, 2016). In this present study well water samples yielded Salmonella serovars commonly associated with human clinical disease (Abdulkadir et al, 2014).…”

Scientific Opinion on the minimum hygiene criteria to be applied to clean seawater and on the public health risks and hygiene criteria for bottled seawater intended for domestic use

“…In other studies from Spain, Morocco and Mexico, the proportion of seawater samples positive for Salmonella spp. varied from 2.3 to 4.1 % (Martinez- Urtaza et al, 2004;Setti et al, 2009;Simental and Martinez-Urtaza, 2008). Efstratiou et al (2009) showed that levels of either total coliforms or faecal coliforms adequately predicted the likelihood of the presence of Salmonella in seawater samples, although enterococci did not.…”