Sarah Allam, Nader Mostafa, Ghada Kirrella, Nesreen Eleiwa, Mohammed Abu El-Magd


The present study was conducted to monitor the prevalence of salmonellae in fresh water fish in Gharbia governorate, Egypt. A total of 120 random samples of fresh water fish (Tilapia niloticus, Mugil cephalous and Clarias lazera, 40 of each) were analyzed bacteriologically for the presence of salmonella pathogens and were further identified using biochemical and serological tests. Positive samples were confirmed by polymerase chain reaction (PCR) through detection of common virulent genes invasion A (invA) and hyper-invasive locus (hilA). The obtained biochemical and serological results revealed presence of seven different serotypes including S. typhimurium which was the most frequent one followed by S. enteriditis, S. infantis , S. virchow, S. heidelberg, S. wingrove  and S. tsevie with a prevalence of 33.3%, 23%, 12.8%, 12.8%, 10.25%, 5% and 2.5%, respectively. The obtained molecular results revealed presence of the two virulent genes in all the detected serovars with a total prevalence rate of 100% for invA gene and 66.6% for hila gene. These results reflected a high prevalence of salmonella species in fresh water fish which act as a potential source of food borne infection and constitutes a major concern for public health.

Key words: fresh water fish; salmonella; serotypes; invA; hilA; PCR

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Food and Agriculture Organization (FAO). 2014. The State of World Fisheries and Aqua-culture 2014. Rome. 223.

El-Adawy M, El-Aziz M A, El-Shazly K, Ali N G, El-Magd M A. Dietary propionic acid enhances antibacterial and immunomodulatory effects of oxytetracycline on Nile tilapia, Oreo-chromis niloticus, Environmental Science and Pollution Research. DOI: 10.1007/s11356-018-3206-5 2018.

Raufu I, Lawan F, Bello H, et al. Occur-rence and antimicrobial susceptibility profiles of Salmonella serovars from fish in Maiduguri, sub-Saharah, Nigeria. The Egyptian J. Aqua. Res. 2014; 40 (1): 59–63.

Aberoumand, A. Estimation of microbio-logical variations in Minced Lean fish products. World J. Fish Mar. Sci. 2010; 2 (3): 204–7.

Wong M and Chen S. First detection of oqxAB in Salmonella spp. isolated from food. Antimicro. Agen. Chemothera. 2013; 57(1): 658–60.

McGuinness S, McCabe E and O'Regan E. Dolan, G. Duffy, C. Burgess, S. Fanning, T. Barry, and J. O'Grady. Development and vali-dation of a rapid real-time PCR based method for the specific detection of Salmonella on fresh meat. Meat Sci. 2009; 83: 555–62.

Kauffman G. Kauffmann white scheme. J. Acta. Path. Microbiol. Sci. 1974; 61:385-393.

Shanmugasamy M, Velayutham T and Ra-jeswar J. Inv A gene specific PCR for detection of Salmonella from broilers. Vet. World, 2011; 4 (12): 562–4.

Singh S, Singh H, Tewari S, Prejit N and Agarwal R. Characterization of virulence fac-tors among diverse Salmonella serotypes and sources. Adv. Anim. Vet. Sci., 2013; 1(2): 69–74.

Guo X, Chen J, Beuchat Land Brackett R. PCR detection of Salmonella enterica sero-type Montevideo in and on raw tomatoes using primers derived from hilA. Appl. Environ. Mi-crobiol. 2000; 66: 5248–52.

Abdelhamid A, Gawish M and Soryal K. Comparative study between desert cultivated and natural fisheries of mullet fish in Egypt, II-microbiological concern. J Agric Sci. 2007; 31(5):5681–7.

Moore B, Martinez E, Gay J, and Rice D. Survival of Salmonella enterica in freshwater and sediments, and transmission by the aquatic midge Chironomus tentans (chironomidae: dip-tera). Appl Environ Microbiol. 2003; 69:4556––60.

Food and Agriculture Organization (FAO). 2010. Expert Workshop on the applica-tion of biosecurity Measures to control Salmo-nella Contamınatıon in Sustainable aquaculture FAO Fisheries and Aquaculture Report No. 937 ISSN 2070-6987, Mangalore, India, 19–21 Jan-uary 2010.

Wang S, Chen J, and Fan J. Quality changes in fresh Tilapia and Milkfish during refrigerated (4 degree C) and frozen (-15 degree C) storage J. Food during Analysis, 1994; 2(4):311 –6.

El Bayomi R, Darwish W, Abd El-Moaty A, and Gad T. Prevalence, antibiogram, molecu-lar characterization and reduction trial of Sal-monella typhimurium isolated from different fish species.

Japanese Journal of Veterinary Research 2016; 64(Supplement 2): S181–6.

Falcão J, Dias A, Correa E, and Falcão D. Microbiological quality of ice used to refrig-erate food .J Food microb. 2002; 19(4): 269–76.

David O, Wandili S, Kakai R, and Wain-di E. Isolation of Salmonella and Shigella from fish harvested from the Winam Gulf of Lake Victoria, Kenya. J. Infect. Dev. Ctries. 2014; 3: 99–104.

World Health Organization (WHO). 1997. Microbial aspects of food hy-giene,technical Report Series, No. 598, pP.2l - 23. WHO, Geneva, Switzerland.

Bhatta D, Bangtrakulnonth A, Tishyadhigama P, et al. Serotyping, PCR, phage-typing and antibiotic sensitivity testing of Sal-monella serovars isolated from urban drinking water supply systems of Nepal. Lett. Appl. Mi-crobiol. 2007; 44: 588–94.

Maria A. Non typhoid Salmonella gastro-enteritis in pediatric patients from urban areas in the city of Mérida, Venezuela. J. Infect. Devel-oping Countries 2009; 3: 28–34.

Oliveira S, Rodenbusch C, Michae G, et al. Detection of virulence genes in Salmonella Enteritidis isolated from different sources. Braz. J. Microbiol. 2003; 34: 123–.

Tekale A. Detection and Virulence Gene Characterization of Salmonella Isolates from Fish by Conventional and Molecular Methods. J. Vet. Pub. Hlth. 2015; 13 (1): 43–6.

Fey A, Eichler S, Flavier S, et al. Estab-lishment of a real-time PCR-based approach for accurate quantification of bacterial RNA targets in water, using Salmonella as a model organism. Appl Environ Microbiol. 2004; 70: 3618–23.

Lesnick M, Reiner N, Fierer J, and Guin-ey D. 2001. The Salmonella spvB virulence gene encodes an enzyme that ADPribosylates actin and destabilizes the cytoskeleton of eu-karyotic cells. Mol Microbiol 39: 1464–70.

Pathmanathan S, Cardona-Castro N, Sanchez-Jimenez M, et al. Simple and rapid detection of Salmonella strains by direct PCR amplification of the hilA gene. J Med Microbi-ol. 2003; 52: 773–6.



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