Agricultural Research Management Information System

Home
Research Summary
Search
About Us
- ARMIS
- Brochure
Contact Us
Report
User Request
Data Input
Help
- Operation Manual
  - PDF
  - Video
- Program Area & Commodity
We have reached 37600 number of research entries at this moment.

- Logout

Research Detail

Home
Research
Detail

Comparative Microbiological Analysis of Raw Fishes and Sun-dried Fishes Collected from the Kawran Bazaar in Dhaka City, Bangladesh

Nur, I.T.
Department of Microbiology, Stamford University Bangladesh, 51 Siddeswari Road, Dhaka-1217, Bangladesh

Ghosh, B.K.
Department of Microbiology, Stamford University Bangladesh, 51 Siddeswari Road, Dhaka-1217, Bangladesh

Acharjee, M
Department of Molecular and Developmental Biology, Graduate School of Science and Technology, Shizuoka University, Oya 836, Suruga-ku, Shizuoka, 422-8529, Japan

Abstract/ Executive Summary:

Along with the raw fishes, dry fishes also have a huge contribution to meet up the demand for protein in our daily meals. The assay of microbiological quality is therefore needed to ensure public health safety. The present study has emphasized the existence of pathogenic bacteria in raw and dry fish. A total of 50 samples of raw fishes and sun-dried fishes has accumulated aseptically for microbiological quality analysis. Isolation of bacteria was done by the spread plate method. All the samples including both (raw and dry) fishes harbored bacteria and fungi up to 10⁶CFU/g. E. coliwas found in all samples as a specific pathogen. In case of raw fishes total viable count (TVC) and total coliform count (E. coli) were recorded up to 2.5x10⁶CFU/g and 5.2 x10⁴CFU/g respectively whereas a significant load of Salmonellaspp. was observed in almost all samples. Staphylococcus spp. and Pseudomonass pp. were present up to 5 x10²CFU/g and 1.8 x 10²CFU/g respectively. Likewise, total viable count (TVC), total coliform count (E. coli) and fungal load were recorded in dry fish up 3.50 x 105 CFU/g, 1.2 x103 CFU/g respectively. Fungal growth was observed in all experimental raw and dried fishes. For most of the pathogenic isolates, higher rates of resistance were found against Ceftriaxone, Penicillin, Nalidixic acid, Neomycin. On the other hand, most of the isolates were found to retain higher sensitivity against Imipenem, Ciprofloxacin, Tetracyclin and Amoxicillin. This data suggested that the dry fish harbored fewer bacteria than raw fish and the sun drying method is still a useful technique for the preservation of fish.

Keywords: Raw fishes, Dry fishes, Pathogen, Microbiological Quality

Location: Kawran bazaar in Dhaka city, Bangladesh

Start Date:

End Date:

Program Area: Quality and Nutrition

Commodity: Fish

Objectives:

The present study was designated to determine and compare the microbiological quality and the drug-resistant feature of the bacterial species among raw fishes and sun-dried fishes.

Methodology:

2.1 Study area and sample collection: The experiment was executed with a total of 50 samples on both raw fish (five samples of each raw fish type, n=25) and dry fish (five samples of each dry fish type, n=25) of the same species including Rupchada (Pomfret; Brama brama), Lote (Bombay duck; Harpadon neherreus), Chingri (Prawn; Penaeus monodon), Puti (Swamp barb; Puntius chola), Mola carplet (Amblyphryngodon microlepi). The samples were collected from Kawran bazar in Dhaka city using a sterile aseptic container together with ice for raw fishes. A total of 20 g of each raw and dried fish was homogenized with 180 g of sterile normal saline. The homogenized suspension was subjected to serial dilutions (10-fold) up to 10^-⁴ with normal saline (Nur et al., 2020). 2.2 Enumeration of total viable bacteria and fungus: A total of 0.1 mL of each sample was spread onto nutrient agar and Sabouraud dextrose agar (SDA) for enumerating total viable bacteria (TVB) and total fungal respectively. For TVB, plates were incubated at 37^oC. For the fungal assay, plates were incubated at 25^oC for 3 days (Acharjee et al., 2014). 2.3 Isolation of total coliform and fecal coliform: For enumeration of coliforms and fecal coliforms MacConkey agar and membrane fecal coliform agar (mFC) are used respectively. A total of 0.1 mL suspension was spread over MacConkey agar and mFC agar. For the isolation of Escherichia coli and Klebsiella spp., plates were incubated at 37^oC for 18-24 hrs. The presence of E. coli was further confirmed by the appearance of bluish-black colonies with green metallic sheen on eosin-methylene blue (EMB) agar (Acharjee et al., 2014). On the other hand, while for fecal coliforms, plates were incubated at 44.5^oC for 24 hrs. 2.4 Isolation of other pathogenic bacteriaFrom each of the 10^-³ dilution, 0.1 mL of suspension had was spread onto Xylose Lysine Deoxycholate (XLD) for the isolation of Shigella spp. and Salmonella spp. and Thiosulphate Citrate Bile Salt Sucrose (TCBS) agar plates for detecting the presence of Vibrio spp. For the isolation of Pseudomonas spp. and Staphylococcus spp., 0.1 mL from dilution 10^-³ of the sample was spread on cetrimide agar and MSA agar respectively. After the incubation at 37^oC for 24 hrs, characteristic colonies were observed. (Cappuccino and Sherman, 1996). Finally, a series of biochemical tests were performed following the standard methods to confirm the pathogenic identification (Cappuccino and Sherman, 1996). 2.5 Determination of antimicrobial susceptibility: All the isolates were tested to observe their antibiotic susceptibility pattern against the 10 antibacterial drugs (including first, second and third-generation drugs) by disc diffusion assay on Mueller-Hinton Agar (Difco, Detroit, MI) with antibiotic discs (Neo-Sensitabs, Rosco, Denmark) according to the modified Kirby-Bauer method (Bauer et al., 1966; Ferraro et al., 2001; Munshi et al., 2012). A single colony of each isolate was inoculated into 2 mL of Mueller-Hinton broth and incubated at 37°C for 4 hrs. The culture turbidity was then adjusted to a 0.5 McFarland standard. Sterile cotton swabs were dipped into the suspensions and spread evenly over the entire surface of Muller-Hinton agar. Antibiotic discs of appropriate concentrations (Neomycin 10μg, Chloramphenicol 10μg, Polymyxin B 30μg, ofloxacin 5μg, amoxicillin 10μg, ciprofloxacin 5 μg, cefpodoxime 30μg, nalidixic acid 30 μg, imipenem 10 μg, tetracycline 30 μg,) were placed aseptically over the surface at an appropriate spatial distance of 5 mm. Plates were then inverted and incubated at 37°C. After 24 hours, plates were examined and the diameters of the zones of inhibition were measured and interpreted as susceptible, intermediate, and resistant.

Source of Information: Food Research 4 (3) (2020) 846 -851

Article Link (Online Journal):

Funding Source:

1.

Budget:

Total Budget (Tk.) :

Achievement/Findings:

Our present study revealed that both raw fish and sun-dried fish may nurture various pathogenic microorganisms. The microbial stability of dried fish products depends upon their moisture content. To control the flies, insects, or pests, pesticide applied on the fish which is hazardous to the dry fish consumers, so fishermen should be aware of these things. The proper drying procedure is mandatory for achieving a high quality of dried fish. Very recently, the consumption of dry fish is not only popular to the Bangladeshi people but also getting its popularity to the people of Europe, the US, and the Middle East. To improve the quality and ensure consumer acceptance it is obvious to run a training session for the dried fish processors and dried fish traders. In order to minimize the existence of drug-resistant microflora in both raw and dry fish, the fish processing company should have to be more careful about the cross-contamination during the whole fish processing procedure. The government body should take necessary steps to improve the quality and safety of both raw and sun-dried fish produced in the coastal region of Bangladesh as well as to resist the frequent spreading of drug-resistant microflora.

Knowledge Management: Journal