Prevalence, antimicrobial susceptibility test and associated factors of Salmonella and Shigella in ready-to-eat fruit juices and salads in Mekelle, northern Ethiopia.

BACKGROUND: Food borne diseases is a challenging problem nowadays. Salmonella and Shigella species are great concern of food-born outbreaks. Thus, this study was aimed to assess the prevalence, antimicrobial susceptibility test and associated factors of Salmonella and Shigella species in fruit juices and salads. METHODS: A community based cross sectional study design was carried out on 50 juice houses from December to March 2020 in Mekelle. One hundred fifty samples were collected aseptically from the juice houses for laboratory analysis. Information related to risk factors was obtained using a structured questionnaire. In the laboratory, samples were homogenized using peptone water and incubated overnight for enrichment. Then, Salmonella and Shigella species were isolated on Salmonella-Shigella agar and Xylose Lysine Deoxycholate agar. Disc diffusion method was used to perform antimicrobial susceptibility test. Using SPSS (version 22) package, descriptive statistics and Chi square test (χ2) were used to analyze the data, and p < 0.05 was considered as statistically significant. RESULT: The overall prevalence of Salmonella and Shigella species was 41/150 (27.33%; 95% CI: 20.20 - 34.46) with 33 (22%) Salmonella spp. and 8(5.33%) Shigella spp. Antimicrobial susceptibility tests of both Salmonella and Shigella spp.showed high resistance against ampicillin (100%), tetracycline (63.6 and 62.5%, respectively) and amoxicillin-clavulanic acid (100%). Accessibility of fruits to flies and dust had statistical association (p = 0.021) with occurrence of Salmonell a and/or Shigella spp. CONCLUSION: The overall prevalence of Salmonella and Shigella spp. was found to be significant. The resistant rate of isolates against ampicillin, tetracycline and amoxicillin-clavulanic acid was high. Storage sites for fruits should be inaccessible to flies and dust. Therefore, routine monitoring of juice houses should be promoted and regular evaluation of bacterial resistance pattern should be done for selective antimicrobial therapy. Furthermore, consistent training of juice makers on food safety and hygiene should be implemented by the concerned body.

Field-based investigation on phytoremediation potentials of Lemna minor and Azolla filiculoides in tropical, semiarid regions: Case of Ethiopia.

This study investigated the concurrent accumulation of eight heavy metals by two floating aquatic macrophytes (Lemna minor and Azolla filiculoides) cultivated in ambient media and blended wastewaters in the semiarid regions of Ethiopia. Both species accumulated heavy metals in varying degrees with a significant concentration gradient within the immediate water media. Highest bioconcentration factor (BCF) was determined for Mn and Fe in both plants. Results revealed that L. minor was high phytoaccumulator for Fe, Mn, Zn, and Co but moderate for Cd, Cu, Ni, and Cr. On the other hand, A. filiculoides was a high accumulator for Fe, Mn, Zn, and Cu, but its potency was moderate for Co, Cr, and Ni, but lower for Cd. Both species exhibited significant difference in accumulating Co, Zn, and Mn (p < 0.05). In general, the BCFs for both plants were comparable within the same treatment. In this study, stronger associations between the heavy metal concentrations in the plant tissues and in the grown water media were observed for A. filiculoides.