Bacteriological Quality and Public Health Implications of Selected Smoked Fish Sold in Port Harcourt Metropolis, Nigeria

INTRODUCTION  

Fish is an increasingly important source of high-quality protein and essential nutrients for human health. Many fish species inhabit freshwater lakes, rivers, and marine environments, serving as a major dietary component for millions of people worldwide. Fish is highly valued because of its easy digestibility, rich nutritional composition, and abundance of essential minerals, vitamins, and omega-3 fatty acids. In tropical regions, fish constitutes one of the most affordable and accessible sources of animal protein and is exceptionally rich in calcium, phosphorus, and B vitamins [1].

Despite its nutritional benefits, fish is one of the most highly perishable food products. Quality deterioration occurs rapidly during handling, processing, transportation, and storage, thereby limiting its shelf life [2]. The high moisture content and nutrient composition of fish make it particularly susceptible to microbial spoilage and contamination by pathogenic microorganisms. Fish may harbor a wide variety of bacteria, some of which are pathogenic to fish and humans, while others are opportunistic or saprophytic in nature [3]. Apart from causing diseases in fish, these microorganisms may also constitute serious public health hazards when contaminated fish products are consumed.

The safety of fish and fish products intended for human consumption is therefore of major concern in both aquaculture management and public health. Bacterial diseases are responsible for significant mortality in wild and cultured fish populations. The role of these microorganisms may vary from that of primary pathogens to opportunistic invaders in hosts with weakened immune systems [4]. Human infections associated with fish and aquatic environments are common and may depend on seasonal variations, dietary habits, the immune status of exposed individuals, and the extent of contact with contaminated fish products or environments [5]. Some bacterial species are facultatively pathogenic to both fish and humans and may be isolated from apparently healthy fish without visible signs of disease.

Determination of the bacterial microbiota of fish intended for human consumption is therefore an important indicator of fish quality and safety [6]. Among the bacterial pathogens associated with fish and fish products are Escherichia coli and Edwardsiella tarda, both of which are implicated in foodborne zoonotic infections. Escherichia coli is commonly found in the intestines of humans, animals, and fish. While many strains are harmless commensals, pathogenic strains such as enterotoxigenic E. coli (ETEC) can produce toxins that cause diarrhea and other gastrointestinal disorders [7]. The presence of E. coli in fish products is often regarded as an indicator of fecal contamination and poor hygienic practices during processing and handling.

Edwardsiella tarda, a Gram-negative bacterium belonging to the family Enterobacteriaceae, is the causative agent of edwardsiellosis, a serious fish disease reported worldwide [8]. In humans, infection with E. tarda has been associated with gastroenteritis, meningitis, cholecystitis, endocarditis, liver abscess, and osteomyelitis [9]. Consumption of contaminated or improperly processed fish products therefore represents a potential route of transmission of these pathogens to humans.

The widespread habit of consuming raw, lightly cooked, or improperly processed fish, combined with poor facilities for slaughtering, filleting, transportation, and storage, increases the risk of foodborne zoonotic infections [10]. Consequently, microbiological assessment of fish products is essential for ensuring consumer safety and maintaining acceptable public health standards.

To reduce spoilage and extend shelf life, fish is commonly preserved using methods such as chilling, freezing, salting, canning, drying, and smoking [11]. Among these methods, drying and smoking are particularly popular in developing countries because they are relatively inexpensive and accessible preservation techniques. Fish dehydration reduces water activity, thereby limiting microbial growth and enzymatic deterioration [12]. Traditionally, fish are disemboweled and air-dried under natural weather conditions. However, modern methods such as convection drying and solar drying have been introduced to improve drying efficiency and product quality [13].

Several drying methods are employed to preserve fish and prevent bacterial and fungal spoilage, including smoking, air drying, and sun drying. Studies comparing hot-air drying, freeze-drying, sun-drying, and solar-conduction drying have shown variations in product quality and browning characteristics among the methods [14]. Prior to drying, fish are often salted to enhance flavor and facilitate osmotic dehydration. In some traditional practices, the head and backbone are removed before the fish flesh is folded and salted for several weeks [13]. However, many local vendors still rely on traditional sun-drying methods that expose fish directly to environmental contaminants such as dust, insects, and airborne microorganisms [15].

Smoking is another widely used preservation method that involves exposing fish to smoke generated from burning wood or charcoal at temperatures ranging from approximately 40°C to 90°C [16]. In many parts of Nigeria, including Bayelsa State and Rivers State, fish smoking is commonly carried out using local kilns fueled with firewood [16]. Although smoking helps reduce microbial load and moisture content, smoked fish may still become contaminated during cooling, handling, packaging, transportation, and marketing, particularly where hygiene standards are poor.

Smoked fish is widely consumed in Nigeria, especially in Port Harcourt metropolis, where it serves as a staple food item sold in markets, roadside outlets, and restaurants. The increasing demand for smoked fish in the area, coupled with inadequate sanitation and improper handling practices among vendors, increases the likelihood of microbial contamination and foodborne infections. Organisms of public health importance such as Salmonella spp., Escherichia coli, and Staphylococcus aureus, have been reported in smoked fish products and may pose serious health risks to consumers.

In many local markets, smoked fish is often processed and displayed under unhygienic conditions using rudimentary equipment and without strict adherence to food safety regulations. Poor packaging, exposure to flies and dust, contaminated water sources, and frequent human handling may contribute significantly to bacterial contamination of smoked fish products. These practices compromise product quality and increase the risk of transmitting pathogenic microorganisms to consumers.

Despite the widespread consumption of smoked fish in Port Harcourt metropolis, there is limited scientific information regarding its bacteriological quality and associated public health risks. The absence of adequate data may hinder the ability of regulatory agencies to establish effective monitoring systems and implement evidence-based food safety interventions. Therefore, it is important to evaluate the bacterial quality of smoked fish sold within Port Harcourt metropolis, identify potential pathogenic organisms associated with the products, and assess their implications for public health. Findings from such studies will contribute to improved food safety awareness, better hygienic handling practices, and strengthened regulatory control measures aimed at protecting consumers.

MATERIALS AND METHODS

Research design

This study employed a cross-sectional descriptive laboratory-based design to assess the bacteriological quality and safety of smoked fish sold in selected markets within Port Harcourt metropolis, Rivers State, Nigeria. Smoked fish specimens, including catfish (Clarias gariepinus), mackerel (Scomber spp.), shiny-nose (Polydactylus quadrifilis), sardine (Clupea pilchardus), and panla hake, were purchased from fish vendors at Rumuokoro and Mile III markets. Standard microbiological techniques were used for bacterial isolation, enumeration, and identification. In addition, questionnaires and direct observations were employed to evaluate the hygiene practices of fish vendors. The bacteriological findings were subsequently compared with observed hygiene practices to determine possible public health implications associated with smoked fish consumption.

Study Area

This study was conducted in Port Harcourt, the capital city of Rivers State, Nigeria. Geographically, Port Harcourt is located at approximately latitude 4.824°N and longitude 7.034°E along the Bonny River in the Niger Delta region. The city is one of the major commercial and industrial centers in southern Nigeria due to its strategic role in the oil and gas industry, agriculture, and fish trade. Port Harcourt has an estimated urban population of approximately 3.8 million people as of 2025, making it one of the most densely populated cities in the Niger Delta region. The study focused on Rumuokoro and Mile III markets because of their high commercial activities and large volume of fish trade.

Ethical Considerations

Ethical approval for this study was obtained from the Health Research Ethics Committee of Rivers State Hospitals Management Board (RSHMB/RSHREC/2025/086). Informed consent was obtained from all participating fish vendors before sample collection and administration of questionnaires. Information regarding fish type, smoking duration, purchase time, packaging methods, and hygiene practices was obtained through interviews and direct observations.

Sample Collection

A total of 60 specimens were used in this study. These comprised 40 fish samples and 20 environmental swab samples. The fish samples consisted of 20 fresh fish and 20 smoked (dried) fish obtained from five vendors in Rumuokoro Market and Mile 3 Market, Port Harcourt. The fish species sampled included catfish (Clarias gariepinus), mackerel (Scomber spp.), shiny-nose (Polydactylus quadrifilis), sardine (Clupea pilchardus), and hake (“panla”). The samples were randomly selected from the vendors, placed in sterile zip-lock bags, stored in ice packs, and transported to the Microbiology Laboratory for analysis. In addition, 20 environmental samples were collected by swabbing the hands of the five fish vendors (n = 5), cutting knives (n = 5), smoking trays (n = 5), and cutting boards (n = 5). All specimens were transported to the laboratory and processed within the shortest possible time.

Sample Preparation and Laboratory analysis

The fish samples were aseptically swabbed using sterile cotton swab sticks. Each swab stick was transferred into a test tube containing 9 mL of sterile normal saline and homogenized for approximately 30 seconds. Similarly, swab specimens collected from vendors’ hands, cutting knives, smoking trays, and cutting boards were inoculated into 9 mL sterile normal saline and thoroughly homogenized.

Serial ten-fold dilutions were prepared using sterile dilution tubes containing 9 mL of sterile normal saline. One milliliter (1 mL) of the homogenized sample was aseptically transferred into the first dilution tube and mixed properly. Subsequently, 1 mL was transferred from the first dilution tube into the next dilution tube. This procedure was repeated serially to obtain the required dilution levels.

Using sterile pipettes, 0.1 mL aliquots from the 10⁻³ dilution tubes were aseptically inoculated onto freshly prepared and dried Nutrient Agar plates for Total Heterotrophic Bacterial Count (THBC) and MacConkey Agar plates for Total Coliform Count (TCC). The inoculum was evenly spread using a sterile bent glass rod. All inoculations were carried out in duplicate.

The inoculated plates were incubated at 37°C for 24 hours. After incubation, visible colonies were counted and the average colony count was recorded. The bacterial load was calculated as colony-forming units per gram (CFU/g) using the formula:

CFU/g=       Average Colony Count × Dilution Factor

Volume Plated

The total bacterial population was expressed as colony-forming units per gram (CFU/g). This procedure was repeated for all samples analyzed.

Isolation of bacteria

Pure cultures of bacterial isolates were obtained by repeated subculturing on freshly prepared Nutrient Agar plates. Selective and differential media including MacConkey Agar, Cetrimide Agar, Eosin Methylene Blue (EMB) Agar, Mannitol Salt Agar, and Salmonella–Shigella Agar, were used for further isolation and characterization of bacterial isolates.

The isolates were preserved on agar slants and stored at 4°C until further identification. Identification of bacterial isolates was based on colonial morphology, Gram staining reaction, microscopic examination, and biochemical tests.

Identification materials, reagents, and procedures described were adopted for the characterization and confirmation of discrete bacterial colonies obtained from the culture media [17].

Total Heterotrophic Bacterial Count and Total Coliform Count

Serial dilutions of the samples were prepared depending on the level of contamination for the determination of Total Heterotrophic Bacterial Count (THBC) and Total Coliform Count (TCC). Nutrient Agar, MacConkey Agar, and Eosin Methylene Blue (EMB) Agar plates were used for bacterial enumeration.

The inoculated plates were incubated at 37°C for 24–48 hours, after which visible colonies were counted and recorded. The microbial counts obtained were compared with acceptable microbiological standards for food products as described in previous studies [18].

Antibiotic Susceptibility Testing for the Isolates

Antibiotic susceptibility testing of bacterial isolates was carried out using the modified Kirby–Bauer disc diffusion method in accordance with the guidelines of the Clinical and Laboratory Standards Institute (CLSI).

Briefly, 0.1 mL of standardized bacterial culture was inoculated into 20 mL of sterile molten Mueller–Hinton agar cooled to approximately 45°C. The contents were mixed thoroughly by gentle rotation and aseptically poured into sterile Petri dishes. The plates were allowed to solidify before the application of antibiotic discs.

Commercially prepared antibiotic discs (Rapid Labs®) were aseptically placed on the surface of the inoculated agar using sterile forceps. The discs were gently pressed to ensure adequate contact with the agar surface. A maximum of eight antibiotic discs were placed equidistantly on each plate. All tests were carried out in duplicate.

The plates were incubated at 37°C for 24 hours. After incubation, the diameters of zones of inhibition were measured in millimeters using a transparent ruler, and the mean values were recorded.

Interpretation of susceptibility patterns was performed using the inhibitory zone diameter standards [17]. The bacterial isolates were classified as susceptible, intermediate, or resistant to the tested antibiotics.

RESULT

Total Heterotrophic Bacteria and Total Coliform Count

Bacterial species isolated from samples obtained from Vendor 1 included Klebsiella spp., Escherichia coli, Staphylococcus spp., Bacillus spp., Pseudomonas spp. and Salmonella spp. Among the isolates, Bacillus spp. and Klebsiella spp. were the most frequently occurring organisms, accounting for 30% and 26% of the total isolates, respectively. Escherichia coli and Staphylococcus spp. each constituted 17% of the isolates, while Salmonella spp. and  Pseudomonas spp. were the least frequently isolated organisms, each representing 5% of the total isolates. The distribution of bacterial isolates is presented in Figure 1.

The Total Heterotrophic Bacteria Count (THBC) for samples obtained from Vendor 1 ranged from 2.05 × 10⁴ CFU/g to 8.0 × 10⁵ CFU/g, while the Total Coliform Count (TCC) ranged from 3.4 × 10⁴ CFU/g to 9.7 × 10⁵ CFU/g. Fresh mackerel recorded the highest heterotrophic bacterial load, whereas the cutting board sample had the lowest heterotrophic bacterial count. Similarly, fresh shiny nose-fish recorded the highest coliform count, while the hand swab sample exhibited the lowest coliform count, as seen in Table 1.

Bacteria isolated fromvendor 2 in rumuokoro ,market include Proteus spp, Shigella sp, Streptobacillus sp, Escherichia coli, Staphylococcus spp. Bacillus spp, Pseudomonas spp, and Salmonella spp. were predominant organisms isolated. Bacillus spp showed the highest occurrence of 22% of isolates from this vendor. Proteus sp and Salmonella sp showed 17% each, Pseudomonas sp shows 13%, while Escherichia coli, Staphylococci and Shigella sp showed percentage of occurrence of 9% . This result is as shown in figure 2.

The Total Heterotrophic Bacteria Count (THBC) of samples obtained from Vendor 2 at Rumuokoro Market ranged from 1.06 × 10⁵ to 1.00 × 10⁶ CFU/g. The highest Total Coliform Count (TCC) recorded was 3.19 × 10⁶ CFU/g. Fresh panla and smoking tray samples exhibited the highest microbial loads among the samples analyzed. The results are presented in Table 2.

The bacteria isolated from Vendor 3 included Bacillus spp., Proteus spp., and Pseudomonas spp., which were the predominant organisms. Bacillus spp. had the highest occurrence at 18.6%, while Proteus spp. and Pseudomonas spp. each accounted for 14.3% of the total isolates. Shigella spp., Salmonella spp., and Klebsiella spp. followed closely, each representing 11% of the isolates. Escherichia coli and Staphylococcus spp. each occurred at 7.7%, whereas Citrobacter spp. recorded the least occurrence at 4.3%. This distribution of bacterial isolates is as shown in Figure 3.

For Vendor 3 (Rumuokoro Market), the Total Heterotrophic Bacterial Count (THBC) ranged from 2.0 × 10⁵ to 1.30 × 10⁶ CFU/g, while the Total Coliform Count (TCC) ranged from 1.3 × 10⁵ to 1.60 × 10⁶ CFU/g. The fresh panla and knife samples exhibited the highest microbial counts (Table 3).

Escherichia coli was the predominant bacterial species isolated from Vendor 4, accounting for 22% of the total isolates. Bacillus spp. and Staphylococcus spp. were the second most frequently isolated organisms, each representing 17% of the isolates. Proteus spp. and Salmonella spp. followed, with an occurrence rate of 13% each. Klebsiella spp. and Pseudomonas spp. were the least frequently isolated organisms, each accounting for 9% of the total isolates. The distribution of bacterial isolates is presented in Figure 4.

For Vendor 4 (Mile III Market), Total Heterotrophic Bacterial Counts (THBC) ranged from 3.0 × 10⁵ to 1.17 × 10⁶ CFU/g, while Total Coliform Counts (TCC) ranged from 1.3 × 10⁵ to 9.0 × 10⁵ CFU/g. Higher microbial counts were observed in panla and mackerel fish, particularly among fresh samples. These elevated counts may suggest contamination resulting from handling, storage, or environmental exposure after smoking. The microbial count distribution is shown in Table 4.

Staphylococcus spp. were the predominant organisms isolated from Vendor 5 (Mile III Market), accounting for 33% of the total isolates. Salmonella spp. followed with 25%, while Shigella spp. constituted 20% of the isolates. Pseudomonas spp. and Escherichia coli each accounted for 11% of the total isolates, representing the least frequently isolated organisms.This result is presented in Figure 5.

For Vendor 5 at Mile III Market, the Total Heterotrophic Bacterial Count (THBC) ranged from 1.2 × 10⁴ to 3.55 × 10⁵ CFU/g, while the Total Coliform Count (TCC) ranged up to 3.20 × 10⁶ CFU/g. Fresh catfish samples recorded the highest heterotrophic bacterial and coliform counts, whereas the dried fish samples exhibited comparatively lower microbial loads (See table 5).

Antibiotic susceptibility

 The Gram-negative bacterial isolates exhibited varying susceptibility patterns to the antibiotics tested. Ofloxacin (67.2%) showed the highest level of susceptibility, followed by Pefloxacin (53.1%) and Streptomycin (50.0%). Conversely, the highest resistance was observed against Cefuroxime (67.2%), Ceftriaxone (50.0%), Gentamicin (46.9%), Ceporex (45.3%), and Augmentin (45.3%). A notably high proportion of isolates demonstrated intermediate susceptibility to Ciprofloxacin (75.0%) and Ceftazidime (42.2%), suggesting reduced effectiveness of these antibiotics against some isolates.

The Gram-positive bacterial isolates exhibited varying susceptibility patterns to the tested antibiotics. Gentamicin (CN) demonstrated the highest activity, with 73.5% of isolates being susceptible, followed by Cefuroxime (CEF, 64.0%) and Levofloxacin (LEU, 63.6%). Amoxicillin (AMX) also showed appreciable activity, with 56.8% susceptibility. In contrast, high levels of resistance were observed against Streptomycin (54.1%) and Rifampicin Disc (RD, 50.0%). A large proportion of isolates exhibited intermediate susceptibility to Ciprofloxacin (83.8%), Erythromycin (76.5%), and Azithromycin (55.6%), indicating reduced effectiveness of these antibiotics against some Gram-positive isolates.

DISCUSSION

The results of this study reveal a concerning level of bacteriological contamination in smoked fish sold within the Port Harcourt Metropolis. The Total Heterotrophic Bacterial Count (THBC), which ranged from 2.05 × 10⁴ to 1.30 × 10⁶ CFU/g, and the Total Coliform Count (TCC), which reached up to 3.19 × 10⁶ CFU/g, indicate poor microbiological quality of the products. These values exceed acceptable limits for ready-to-eat (RTE) foods as recommended by the International Commission on Microbiological Specifications for Foods (ICMSF), which generally stipulates aerobic counts not exceeding 10⁵ CFU/g and absence of coliforms in RTE foods due to their association with faecal contamination and poor hygiene [18].

When compared with previous studies, the microbial loads observed in this study are consistent with findings from other developing regions. Similarly high bacterial loads (10⁵–10⁷ CFU/g) in smoked fish sold in Ghana and attributed the contamination to poor handling practices, exposure to environmental contaminants, and use of polluted water sources have been reported [19]. Other studies reported elevated coliform counts in smoked catfish from southeastern Nigeria, reinforcing the widespread challenge of inadequate hygiene in fish processing and marketing in the region [20]. In contrast, significantly lower microbial counts have been reported in commercially processed smoked fish in developed countries, where strict hygienic standards, regulated processing conditions, and cold-chain maintenance are routinely enforced [21]. This disparity underscores the critical role of food safety regulation in ensuring microbiological quality.

The higher bacterial loads observed in fresh smoked fish compared to dried samples suggest that contamination is more likely to occur during post-processing handling rather than during smoking itself. The recovery of high microbial loads from contact surfaces such as knives, bowls, hands, and storage containers further supports the role of poor hygiene practices in cross-contamination. It has been noted that smoked fish becomes re-contaminated during marketing through exposure to contaminated surfaces and improper handling [19].

The identification of pathogenic bacteria in the samples presents a more serious public health concern. Escherichia coli was frequently isolated, indicating possible faecal contamination of the fish products or processing environment. Although many strains of E. coli are harmless, pathogenic strains can cause severe gastrointestinal illness. The presence of E. coli in food products is widely regarded as an indicator of poor sanitary conditions and has been consistently associated with contaminated water and inadequate hygiene practices in food handling environments [20, 22].

Similarly, the isolation of Salmonella spp. is of significant concern because of its well-documented role in foodborne gastroenteritis. Its presence in ready-to-eat foods indicates a critical failure in hygiene control during processing and handling. The occurrence of Salmonella in this study is consistent with other studies that  identified Salmonella spp. in smoked fish from Nigerian markets, highlighting its persistence in traditional food systems [20].

Staphylococcus spp. were also isolated from several samples, suggesting contamination from human handlers. This finding is consistent with a study on ready-to-eat foods vended in Owerri, Nigeria that reported that Staphylococcus aureus contamination in food products is strongly associated with poor personal hygiene and direct handling without proper sanitation measures [22]. The presence of Staphylococcus spp. in ready-to-eat foods is particularly important due to its ability to produce heat-stable enterotoxins that are not destroyed during reheating.

The isolation of Klebsiella spp., Proteus spp., and Pseudomonas spp. further indicates environmental contamination. These organisms are commonly found in soil, water, and decaying organic matter, and their presence suggests inadequate sanitation and exposure of products to contaminated environments. Their detection aligns with findings from previous studies in tropical regions, where environmental contamination plays a major role in food spoilage and bacterial transmission.

The antibiotic susceptibility profiles revealed a worrying pattern of antimicrobial resistance among both Gram-negative and Gram-positive isolates. Among Gram-negative bacteria, Ofloxacin showed the highest activity (67.2%), followed by Pefloxacin (53.1%) and Streptomycin (50.0%). In contrast, high resistance rates were observed against Cefuroxime (67.2%), Ceftriaxone (50.0%), Gentamicin (46.9%), Ceporex (45.3%), and Augmentin (45.3%). The high resistance to β-lactam antibiotics suggests widespread reduced susceptibility among isolates commonly associated with food contamination.

These findings are consistent with a study that documented increasing resistance to β-lactam antibiotics among foodborne Escherichia coli and Klebsiella isolates in Nigeria [23]. Although phenotypic ESBL production was not assessed in this study, the observed resistance pattern may suggest the presence of β-lactam resistance mechanisms, which require further molecular confirmation.

Although fluoroquinolones such as Ofloxacin and Ciprofloxacin showed relatively better activity, reduced susceptibility was still observed among several isolates. This is consistent with findings  of the study prevalence and antimicrobial resistance of Salmonella isolated from poultry in Ghana who reported increasing fluoroquinolone resistance among foodborne pathogens in West Africa, likely linked to the misuse of these antibiotics in both human and veterinary medicine [24].

Gentamicin retained moderate effectiveness against several Gram-negative isolates; however, resistance was still observed in some cases, limiting its reliability. The presence of resistance to commonly used antibiotics highlights the growing challenge of antimicrobial resistance in foodborne pathogens and its implications for public health.

Among Gram-positive isolates, Gentamicin (73.5%), Cefuroxime (64.0%), and Levofloxacin (63.6%) demonstrated the highest levels of susceptibility. However, Streptomycin and Rifampicin showed relatively high resistance rates. The frequent intermediate susceptibility observed for Ciprofloxacin, Erythromycin, and Azithromycin suggests reduced antibiotic effectiveness and possible emerging resistance trends among Gram-positive bacteria.

The presence of multidrug-resistant organisms in ready-to-eat smoked fish is of serious public health importance. Consumption of contaminated food products may lead to infections that are difficult to treat due to limited therapeutic options. In addition, foodborne bacteria may serve as reservoirs of antimicrobial resistance genes, facilitating their transfer to human microbiota and contributing to the broader global burden of antimicrobial resistance [23,24].

Overall, the findings of this study highlight the need for improved hygienic practices during fish processing and marketing, regular microbiological monitoring of ready-to-eat foods, and strict adherence to food safety regulations. Public health education for food vendors and enforcement of sanitation standards are essential to reduce the risk of foodborne infections and limit the spread of antimicrobial-resistant bacteria within the community.

CONCLUSION

This study evaluated the bacteriological quality and safety of commonly smoked fish sold in the Port Harcourt Metropolis, with emphasis on samples obtained from Rumuokoro and Mile III markets as well as associated vending environments. The findings revealed consistently high Total Heterotrophic Bacterial Counts (THBC) and Total Coliform Counts (TCC), with maximum values of 1.30 × 10⁶ CFU/g and 3.19 × 10⁶ CFU/g, respectively, exceeding recommended limits for ready-to-eat foods.

A range of pathogenic bacteria, including Escherichia coli, Salmonella spp., Staphylococcus aureus, Klebsiella spp., Bacillus spp., Pseudomonas spp., and Shigella spp., were isolated from both fish samples and contact surfaces. The presence of these organisms indicates poor hygienic practices and potential contamination during post-processing handling, storage, and vending.

Antibiotic susceptibility testing further revealed a high prevalence of multidrug-resistant (MDR) isolates, with notable resistance to commonly used antibiotics such as ampicillin and cephalosporins, as well as reduced susceptibility to fluoroquinolones and aminoglycosides.

Overall, the study demonstrates that smoked fish sold in the study area may pose a public health risk due to microbial contamination and the presence of antibiotic-resistant pathogens. The findings highlight the need for improved hygiene practices among vendors, better handling and storage conditions, and strengthened food safety monitoring by relevant regulatory authorities.

Acknowledgement: The authors thank the laboratory Staff of the department Department of Medical Microbiology, Faculty of Medical Laboratory Science, for their support throughout this study.

Conflict of Interest:
The authors declare no conflict of interest.

Financial Disclosure: The authors declared that this study has received no financial support.

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