Prevalence and characterisation of Salmonella Waycross and Salmonella enterica subsp. salamae in Nile perch (Lates niloticus) of Lake Victoria, Tanzania

Baniga, Zebedayo; Mdegela, Robinson H.; Barco, Lisa; Kusiluka, L.J.M.; Dalsgaard, Anders

doi:10.1016/j.foodcont.2019.01.006

Cited by 9 publications

(18 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The low prevalence of ESBL-producing E. coli in Nile perch from fishing grounds is likely due to the fact that these fish are commonly found and caught in deep water far away from the lake shore where fecal pollution is low compared with the shallow water near the shore of the lake (Baniga et al, 2019). Any occurrence of ESBL-producing E. coli in Nile perch caught offshore could be attributed to their eating habits feeding on other fish species, for example, tilapia and sardines, which are found in shallow water with higher fecal contamination levels.…”

Section: Discussionmentioning

confidence: 99%

“…We did not register how many Nile perch were on sale at each market. Details on sample collection, transport, and processing are provided by Baniga et al (2019). Nile perch samples were prepared by weighing intestines, gills, flesh, and fish surface mucus in a ratio of 1:9 to Buffered Peptone Water (BPW) (Oxoid Ltd., Hampshire, United Kingdom).…”

Section: Study Design Sample Collection and Processingmentioning

confidence: 99%

See 1 more Smart Citation

Genome-Based Analysis of Extended-Spectrum β-Lactamase-Producing Escherichia coli in the Aquatic Environment and Nile Perch (Lates niloticus) of Lake Victoria, Tanzania

et al. 2020

Self Cite

View full text Add to dashboard Cite

Extended-spectrum β-lactamase (ESBL)-producing bacteria constitute an emerging global health issue with food products being vehicles of transmission and the aquatic environments serving as potential reservoirs. This study aimed to characterize ESBLproducing Escherichia coli in Nile perch and water from Lake Victoria in Tanzania. A total of 180 samples of Nile perch and 60 water samples were screened for ESBL-producing E. coli on MacConkey agar supplemented with 2 µg/ml of cefotaxime and confirmed by bla CTX−M and bla TEM PCR. Antimicrobial resistance was determined by the disk diffusion method, and the ESBL-producing isolates were whole genome sequencing (WGS). ESBL-producing E. coli were detected in eight of the 180 analyzed Nile perch samples, and only one water sample was positive (1.7%, n = 60). Isolates were resistant to sulfamethoxazole-trimethoprim (100%), ampicillin/cloxacillin (100%), erythromycin 72.7% (8/11), tetracycline 90.9% (10/11), and nalidixic acid 63.6% (7/11). This mostly corroborates the resistance genes that they carried for sulfonamides (sul1 and sul2), trimethoprim (dfrA and dfrB), aminoglycosides [aac(3)-IId, strA, and strB], tetracycline [tet(B) and tet(D)], and fluoroquinolones (qepA4). They harbored plasmid replicon types IncF, IncX, IncQ, and Col and carried bla CTX−M−15 and bla TEM−1B genes generally found on the same contigs as the IncF plasmid replicon. Although epidemiologically unrelated, the strains formed three separate sequence type-phylogroup-serotypespecific clusters: C1, C2, and C3. Cluster C1 included five strains (3 to 13 SNPs) belonging to ST167, phylogroup A, and serotype O9:H21; the two C2 strains (11 SNPs) belong to ST156, phylogroup B1, and serotype ONT:H28; and C3 was made up of four strains (SNPs ranged from 4 to 17) of ST636, phylogroup B2, and serotype O45:H7. The common virulence gene gad was reported in all strains. In addition, strains in C2 and C3 possessed iss, lpfA, and nfaE virulence genes, and the vat gene was found only in C3. The present study reports the occurrence of multidrug-resistant ESBL-producing Frontiers in Microbiology | www.frontiersin.org February 2020 | Volume 11 | Article 108 Baniga et al.Genomics of ESBL-E. coli in Lake Victoria E. coli carrying plasmid-mediated ESBL genes in offshore water and Nile perch in Lake Victoria. Strains formed three clonal clusters of unknown origin. This study reveals that the Lake may serve as reservoir for ESBL-producing bacteria that can be transmitted by fish as a food chain hazard of One-Health concern.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Study Design Sample Collection and Processingmentioning

confidence: 99%

Genome-Based Analysis of Extended-Spectrum β-Lactamase-Producing Escherichia coli in the Aquatic Environment and Nile Perch (Lates niloticus) of Lake Victoria, Tanzania

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Fisheries are particularly concerned by pathogenic bacteria contamination in polluted waters. Their presence in fish may cause a potential risk of causing foodborne illnesses [11,12].…”

Section: Microbiological Analyses Of Tilapia Samplesmentioning

confidence: 99%

“…Penetration and establishment of pathogenic bacteria such as Escherichia coli and Salmonella spp. in different fish tissues and organs, such as digestive tract, gills, and muscle have been reported in polluted aquatic environments [11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Microbiological quality assessment of fresh tilapia marketed in the Federal District and of the ice used for its conservation

Ferreira

Monteiro²,

Sousa³

et al. 2022

Sci. Plena

View full text Add to dashboard Cite

Tilapia (Oreochromis niloticus) is the most cultivated and consumed freshwater fish in Brazil. The present study aimed to evaluate the microbiological quality of ice and fresh tilapia samples commercialized in the Federal District. Tilapia samples were tested for counts of mesophilic and psychrotrophic bacteria, determination of total and thermotolerant coliforms, Staphylococcus aureus counts and presence of Salmonella. Ice samples were analyzed for determination of total coliforms and thermotolerant coliforms and presence of Escherichia coli. Of the 20 samples of fresh tilapia analyzed, ten samples (50%) presented Salmonella (genetically confirmed through the presence of the invA gene) and, therefore, were unfit for consumption. S. aureus was found in 11 samples (55%), and one sample of fillet presented S. aureus counts (3.15 CFU/g) above the limit allowed by Brazilian legislation (3 log CFU/g). S. aureus colonies were confirmed by detection of CoA gene in molecular analysis. Of the 14 ice samples analyzed, 12 samples (85.7%) were unfit for use in fish conservation due to the presence of total coliforms and 9 ice samples (64.3%) were also contaminated with thermotolerant coliforms. E. coli was isolated from 6 ice samples (42.9%) and confirmed in the molecular analysis through the amplification of the MalB gene. In conclusion, the high contamination of tilapia samples with Salmonella and of the ice used for its conservation with coliforms and E. coli indicates the need for better hygienic practices in the tilapia production chain, to increase its quality and microbiological safety.

show abstract

“…The relative contribution of seafood including fish to the global epidemiology of human salmonellosis is very low and mostly limited to S. Weltevreden in Asia; a serovar which is also an enterica subspecies 9 , 10 . In a recent study, we identified S. Waycross of subspecies enterica and the serovar 42:r- of subspecies Salamae from Nile perch ( Lates niloticus ) and water sampled far off the shores of Lake Victoria containing low levels of fecal contamination 11 .…”

Section: Introductionmentioning

confidence: 99%

Salmonella Salamae and S. Waycross isolated from Nile perch in Lake Victoria show limited human pathogenic potential

Hounmanou

Baniga

García

et al. 2022

Sci Rep

Self Cite

View full text Add to dashboard Cite

Non-enterica subspecies of Salmonella enterica are rarely associated with human infections. Paradoxically, food safety legislations consider the entire genus Salmonella as pathogenic to humans. Globally, large amounts of seafoods are rejected and wasted due to findings of Salmonella. To inform better food safety decisions, we investigated the pathogenicity of Salmonella Salamae 42:r- and Salmonella Waycross isolated from Nile perch from Lake Victoria. Genome-wide analysis revealed absence of significant virulence determinants including on key Salmonella pathogenicity islands in both serovars. In epithelial cells, S. Salamae showed a weak invasion ability that was lower than the invH mutant of S. Typhimiurium used as negative control. Similarly, S. Salamae could not replicate inside macrophages. Moreover, intracellular replication in S. Waycross strains was significantly lower compared to the wild type S. Typhimurium. Our findings suggest a low pathogenicity of S. Salamae reinforcing the existing literature that non-enterica subspecies are avirulent. We propose that food legislations and actions taken on findings of Salmonella are revisited to avoid wasting valuable sea- and other foods.

show abstract

Prevalence and characterisation of Salmonella Waycross and Salmonella enterica subsp. salamae in Nile perch (Lates niloticus) of Lake Victoria, Tanzania

Cited by 9 publications

References 36 publications

Genome-Based Analysis of Extended-Spectrum β-Lactamase-Producing Escherichia coli in the Aquatic Environment and Nile Perch (Lates niloticus) of Lake Victoria, Tanzania

Genome-Based Analysis of Extended-Spectrum β-Lactamase-Producing Escherichia coli in the Aquatic Environment and Nile Perch (Lates niloticus) of Lake Victoria, Tanzania

Microbiological quality assessment of fresh tilapia marketed in the Federal District and of the ice used for its conservation

Salmonella Salamae and S. Waycross isolated from Nile perch in Lake Victoria show limited human pathogenic potential

Contact Info

Product

Resources

About