Research Article

Microbial Quality of Ready-To-Eat Shrimps from Three Selected Markets in Ibadan

Blessing Ndenum Peter1, Olufemi Bolarinwa Adedeji1, Reuben Chukwuka Okocha2,3*, Ekemini Moses Okon4

1Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, Ibadan, Nigeria; 2Landmark University SDG 14 (Life below Water), Omu-Aran, Kwara State, Nigeria; 3Department of Agriculture, Landmark University, Omu-Aran, Kwara State, Nigeria; 4Department of Animal Science and Aquatic Ecology, Faculty of Bioscience Engineering, Ghent University, Belgium.

Received | November 17, 2022; Accepted | June 15, 2023; Published | September 10, 2023

*Correspondence | Reuben Chukwuka Okocha, Department of Agriculture, Landmark University, P. M. B. 1001, Omu-Aran, Kwara State, Nigeria; Email: okocha.reuben@lmu.edu.ng

Citation | Peter BN, Adedeji OB, Okocha RC, Okon EM (2023). Microbial quality of ready-to-eat shrimps from three selected markets in ibadan. J. Anim. Health Prod. 11(3): 296-305.

DOI | http://dx.doi.org/10.17582/journal.jahp/2023/11.3.296.305

ISSN | 2308-2801

 

 

Copyright: 2023 by the authors. Licensee ResearchersLinks Ltd, England, UK.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).

INTRODUCTION

A significant proportion of the world’s food supply and income is contributed by seafood. Over the past 50 years, annual global consumption of seafood products per capita has more than doubled, from almost 10 kg in 1960 to over 20 kg in 2014 (FAO, 2016b). Seafood is a significant portion of a healthy diet. Seafood has high-quality protein and other indispensable nutrients with low saturated fatty acids and high Omega-3 fatty acids (Kakara et al., 2016). As a good protein source, seafood accounts for 14–16% of the animal-sourced protein consumed worldwide by over one billion people (Tidwell and Allan, 2012; Viglia et al., 2022).

The American Heart Association recommends consuming two servings of fish and shellfish per week to prevent coronary heart disease. Also, the United States Food and Drug Administration recommends that pregnant women or breastfeeding mothers consume 2 to 3 servings per week. They also suggest that children eat 1 to 2 servings per week at two years of age to promote development and growth (Centre for Disease Control and Prevention, 2018). However, seafood consumption is a potential source of human exposure to pathogenic microbes.

Infections of seafood can be due to pathogens, including parasites, viruses, and bacteria. These pathogens may have entered the food from different sources, such as production, harvesting, processing or transport to food handlers, including the consumers. In addition, these agents can be obtained from one of three sources: faecal contamination of the aquatic environment, the natural aquatic environment, and during the processing and preparation at homes, restaurants, retail stores, or industries. Similarly, a significant proportion of most food-borne diseases and outbreaks is caused by seafood allergy, which in sensitive people might be fatal (Mu et al., 1997; Heinitz et al., 2000; Fatma et al., 2006).

People most often find shrimps in marketplaces either frozen, uncooked or as products that have been cooked. In addition to fresh and prepared products, a ready-to-eat (RTE) product provides the consumer with a more convenient option. Ready-to-eat shrimp is a unique kind of primary domestic product made by specific communities of people and then sold in public places, such as supermarkets and traditional markets, to customers for immediate consumption. The current market trends demonstrate a fast-expanding demand for convenience items that are both ready-to-cook and ready-to-serve. The sophisticated consumer abroad, as well as the urban consumer at home, demand new type of value added, hygienically prepared, nutritious and attractively packed products (Gopakumar, 1997; Mohanbabu et al., 2008).

On the other hand, RTE goods provide a management challenge to the food safety authority in their ability to constantly monitor the foods’ quality and preparation (Jeyasanta et al., 2019). The appropriate handling of shrimp from the time it is captured and the time it is delivered to the consumer is an essential component in assuring the quality of the final product. This process ensures that the shrimp stays in good condition and is free of contaminants. Shrimp quality can also be affected by factors such as sanitation standards, the manner of handling, the amount of time held, and the temperature. As a result of the high degree of perishability of these foods, a drop in quality can arise very quickly after the catch (Dewi et al., 2011). Additionally, the presence of bacterial pathogens and the microbial load in seafood are essential indicators of the item’s quality and the potential threat to consumer health. (Rosmini et al., 2004; Mhango et al., 2010; Hosen and Afrose, 2019). Therefore, the screening of commercial marine fish for pathogenic microorganisms (bacteria, viruses and fungi) is of paramount importance (Geetha et al., 2014).

In addition, antibiotic administration to fish is a common practice in most aquaculture farms in the tropics. The World Health Organization has accepted 14 drugs, including seven antimicrobial agents (sulfadiazine/trimethoprim, oxytetracycline, flumequine, sarafloxacin, oxolinic acid, florfenicol and amoxicillin) employed in aquaculture. Also, two antibiotics used for human antibacterial therapies (fluoroquinolones and tetracyclines) are still approved for treating shrimp (Cabello, 2006). These antibiotics have been used in various production, processing, and value-addition chain settings across Nigeria. However, surveillance studies of antibiotics and antibiotic-resistant bacteria to ensure the wholesomeness of seafood and maintain human health and safety are limited in Nigeria.

However, the microbial load of shrimp and related products is not frequently monitored in Nigeria. As a result, consumers are unaware of the risk of ready-to-eat seafood purchased in Ibadan seafood markets. Also, there is a need to identify the critical control point in the distribution chain of shrimps and its products using the Hazard Analysis Critical Control Points (HACCP) principle. This study, therefore, aims to determine the microbial quality of ready-to-eat shrimps available in Ibadan. Precisely, this study will (i) determine the microbial quality of ready-to-eat shrimps sold in selected markets in Ibadan; (ii) identify the microbial content associated with ready-to-eat shrimps commonly consumed by people in Ibadan; (iii) determine the susceptibility pattern of the isolates identified.

MATERIALS AND METHODS

Study Location

This study was carried out including three selected markets (Alesinloye, Eleyele and Bodija) in Ibadan, Nigeria, with longitude 7˚ 2’ and 7˚ 40’ E and latitudes 3˚ 35’ and 4˚ 10’ N. A total of 80 ready-to-eat (RTE) shrimp samples were purchased from three selected markets in Ibadan (Figure 1) as follows; Aleshinloye (n=15), Eleyele (n=15), and Bodija (n=50). The shrimp (ready-to-eat) were sourced directly from the markets that public consumers often patronise. The retail vendors were randomly selected at the different markets. All collected samples had their exoskeletons intact.

 

Sample Collection and Preparation

A total of eighty (80) samples of unbranded Ready–To–Eat shrimp were purchased from three open markets in Ibadan (50 from Bodija, 15 from Alesinloye and 15 from Eleyele). These were fried samples with no information on the ingredients or recipe used. During collection, all the shrimp samples were packed into individual sterile polythene bags and placed on ice packs. These samples were transported to the Food and Meat Hygiene Laboratory, Department of Veterinary Public Health and Preventive Medicine, the University of Ibadan, for microbiological studies. The samples were immediately processed for microbial quality assessment. The shrimps were then aseptically blended, homogenised using a sterile waring laboratory blender, and kept in sterile sampling bottles. For each sample, 25g was suspended in 225ml of buffered Peptone water, homogenised using a stomacher (Laboratory Blender), inoculated in different media, and incubated at 37˚C for 24-48 hours. In addition, an aliquot of 0.1ml of the pre-enrichment broth was inoculated onto each of the prepared Agar Plates.

Microbial Isolation and Purification of Isolates

Bacterial and Fungal Isolation: A modified method of bacterial and fungal isolation by Kusumaningrum & Zainurib, (2015), was adopted. The homogenates were diluted one at a time, and each successive dilution was used to inoculate the culture. Nutrient agar was used for the Total Aerobic Plate Count, Sabouraud Dextrose Agar was used for the fungal count, Mannitol Salt agar was used for the isolation of Staphylococcus aureus, Eosin Methylene Blue agar was used for the coliform count, Bacillus cereus medium and Xylose Lysine Deoxyribose agar were used for the bacterial count, and so on. Agar plate preparations (for isolation of Shigella and Salmonella). The homogenates were diluted serially from 10-3 to 10-5 times, and 0.2 millilitres of each dilution was used to inoculate media plates consisting of Nutrient agar (to determine the total number of aerobic plate counts) and MacConkay agar (to determine the total number of coliform counts).

After each incubation period at 37oC for 24–48 hours, colony counts were obtained from plates containing the proper dilutions. For easy identification, the cultural aspects of the colonies were also documented. After the incubation period, the number of colonies was determined using a colony counter. Finally, a total count was given regarding colony-forming units (CFU) per gramme of material, abbreviated as CFU/g. By repeatedly subculturing the isolates on the proper medium, pure cultures of the isolates were acquired for characterisation. The morphological properties of the colonies, microscopy, and the results of several biochemical tests, such as the sugar fermentation test, the oxidase test, the indole test, and the catalase test, were used to make a preliminary determination of the identity of the bacterial isolates.

Fungal Identification: The distinct mycelia section from each isolate on sabouraud dextrose agar based on colour, pigment production were cut using a sterile mounted lancet blade and placed on a clean glass slide, teased and moistened. A drop of Lactophenol Cotton Blue (LCB) was added (Kusumaningrum & Zainurib, 2015), and a cover slip was placed to be viewed at different magnifications using a light microscope.

Bacterial Identification: The identification methods by Buchanan & Gibbons, (1985); Garrity et al. (2004); Krieg et al. (2004) were employed in this study. Briefly, all the isolates were primarily identified from their staining reactions using Gram’s technique. Further test conducted were biochemical studies which employed Catalase test, Indole test, Oxidase test, Sugar fermentation test and Triple sugar test.

Antibiotic Sensitivity Tests

The antibiotic sensitivity tests were performed using the Kirby-Bauer method (Disc Diffusion Technique) with reference to the Clinical and Laboratory Standards Institute (CLSI, 2012). The sensitivity discs were specifically designed and contained appropriate concentrations of different Gram-positive antibiotics; ceftazidime(30µg), cefuroxime(30µg), gentamicin(10µg), ceftriaxone(30µg), erythromycin(5µg), cloxacillin(5µg), ofloxacin(5µg), augmentin(30µg). And Gram-negative antibiotics; ceftazidime(30µg), cefuroxime(30µg), gentamicin(10µg), cefixime(5µg), ofloxacin(5µg), augmentin(30µg), nitrofurantoin(300µg), and ciproflaxaciline(5µg).

Pure isolates were closely streaked onto the surface of Muller –Hinton Agar plates. The plates were then incubated at 37˚C for 18-24 hours. Following incubation, they were observed for the inhibition zone surrounding each disc.

Statistical analysis

Bacterial counts were measured in colony-forming units using two different dilutions (10-3 and 10-5), the average of which was used for the final analysis. Bacterial counts were log10 transformed (because they were positively skewed) to make them approximately normally distributed during analysis. Total bacterial and coliform counts were presented as mean (95% Confidence Interval) and compared by location. Bacterial and fungal isolates were presented as proportions and their corresponding 95% confidence interval (CI). The isolated organisms’ proportions were compared by location and presented as bar charts with 95% CI error bars. The statistical significance was set at a 2-tailed p-value of 0.05 or less. Data analysis was done with STATA version 14.2 for Windows (StataCorp, College Station, TX, USA).

RESULTS

Total bacterial and coliform counts

The mean total bacterial and coliform counts were 6.40 log CFU/g and 6.24 log CFU/g, respectively. However, the total bacterial count was significantly lower in ready-to-eat shrimp sourced from Alesinloye [6.29 (6.24 – 6.33) log CFU/g] compared to those from Eleyele [6.43 (6.40 – 6.46) log cfu/g] and Bodija [6.43 (6.41 – 6.46) log CFU/g]. Similarly, the total coliform count was significantly lower in ready to eat shrimp obtained from Alesinloye [6.14 (6.07 – 6.21) log CFU/g] compared to those from Eleyele [6.25 (6.21 – 6.30) log CFU/g] and Bodija [6.27 (6.23 – 6.31) log CFU/g] (Table 1).

 

Table 1: Total bacteria and coliform counts (log CFU/g) from ready-to-eat shrimp in Ibadan

Locations	Total bacteria count (95%CI) *	Total coliform count (95%CI) *
Eleyele	6.43 (6.40 – 6.46) b	6.25 (6.21 – 6.30) b
Alesinloye	6.29 (6.24 – 6.33) a	6.14 (6.07 – 6.21) a
Bodija	6.43 (6.41 – 6.46) b	6.27 (6.23 – 6.31) b
Total/average	6.40 (6.38 – 6.43)	6.24 (6.22 – 6.27)

*Log CFU/ml; Values with different superscripts in the same column differ significantly (p < 0.05)

 

Prevalence of bacterial organisms isolated from ready to eat shrimp in Ibadan

Of the 80 ready-to-eat shrimps sampled for the study, E. coli was isolated from 52 (65.5%), Salmonella spp. from 68 (85.0%), Shigella spp. from 52(65.5%), Bacillus spp. from 52(65.5%), Staphylococcus aureus from 56 (70.0%) and Staphylococcus epidermidis from 43 (53.8%) (Table 2).

 

Table 2: Proportion of bacteria organisms isolated from ready to eat Shrimp in Ibadan

Organisms	No. Isolated (%)	95% CI
E. coli	52 (65.5)	53.5 - 75.3
Salmonella spp.	68 (85.0)	75.2 - 92.0
Shigella spp.	52 (65.5)	53.5 - 75.3
Bacillus spp.	52 (65.5)	53.5 - 75.3
Staphylococcus aureus	56 (70.0)	58.7 - 79.7
Staphylococus epiderdimis	43 (53.8)	42.2 - 65.0

 

Prevalence of fungal organisms isolated from ready to eat shrimp in Ibadan

The prevalence of fungal organisms isolated from ready-to-eat shrimp is presented in Table 3. The most and least frequently isolated fungi were Rhizopus spp. (70.0%, 95% CI: 58.7% – 79.7%) and Trichophyton spp. (12.5%, 95% CI: 6.2% – 21.8%) respectively. Other pathogenic fungi isolated were Aspergillus Niger (50.0%, 95% CI: 38.6% – 61.4%), Aspergillus fumigatus (38.8%, 95% CI: 28.1% – 50.3%), Aspergillus flavus (25.0%, 95% CI: 16.0% – 35.9%), Penicillium spp. (20.0%, 95% CI: 11.9% – 30.4%), Candida spp. (16.3%, 95% CI: 9.0% – 26.2%) and Mucor spp. (28.8%, 95% CI: 19.2% – 40.0%) (Table 3).

 

Table 3: Proportion of fungal organisms isolated from ready to eat Shrimp in Ibadan

Organisms	No. Isolated (%)	95% CI
Aspergillus niger	40 (50.0)	38.6 - 61.4
Aspergillus fumigatus	31 (38.8)	28.1 - 50.3
Aspergillus flavus	20 (25.0)	16.0 - 35.9
Penicillum spp.	16 (20.0)	11.9 - 30.4
Rhizopus spp.	56 (70.0)	58.7 - 79.7
Trichophytum spp.	10 (12.5)	6.2 - 21.8
Candida spp.	13 (16.3 )	9.0 - 26.2
Mucor spp.	23 (28.8)	19.2 - 40.0

 

Prevalence of bacterial organisms isolated from ready to eat shrimp by location

Figures 2-4 compared the proportion by location of some gram-negative and gram-positive bacteria isolated from ready-to-eat shrimp. The proportions of Shigella spp., Salmonella spp., E. coli, Bacillus spp., Staphylococcus aureus, and Staphylococcus epidermidis isolated from ready to eat shrimp did not differ significantly by location (p > 0.05). However, the percentage of E. coli and Salmonella spp. isolated was highest in shrimp sourced from Eleyele (80.0% and 86.7%, respectively), followed by Bodija (62.0% and 86.0%, respectively) and Alesinloye (60.0% and 80.0%, respectively) (Fig. 2). For Shigella spp., the highest isolation proportion was observed in Alesinloye followed by Bodija and Eleyele, while Bacillus spp. the proportion isolated was the same in Eleyele and Alesinloye (73.3%) but higher than in Bodija (60.0%). For Staphylococcus aureus, the proportion isolated from shrimp was highest in Bodija (74.0%), followed by Eleyele (66.7%) and Alesinloye (60.0%), while for Staphylococcus epidermidis prevalence was highest in Eleyele (73.3%), followed by Alesinloye (53.3%) and Bodija (48.0%).

 

Prevalence of fungal organisms isolated from ready to eat shrimp by location

Figures 5 -8 compared the proportion by location of some fungi isolated from ready-to-eat shrimp. The proportions of Rhizopus spp., Trichophytum spp., Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Penicillum spp., Candida spp. and Mucor spp. isolated from ready-to-eat shrimp was not significantly different by location (p > 0.05). However, the proportion of Aspergillus niger and Aspergillus fumigatus isolated was highest in Bodija (54.0% & 42.0%), respectively. The ratio of Penicillium spp. isolated was the same in all three locations (20.0%), while the isolation rate for Aspergillus flavus was highest in Alesinloye (33.3%). For Rhizopus spp., the proportion of isolation was the same in Eleyele and Alesinloye (33.3%) but higher than in Bodija (24.0%) while for Trichophyton spp., it was highest and lowest in Bodija (14.0%) and Alesinloye (6.7%), respectively.

 

Antibiotic sensitivity test results

All the Salmonella and Shigella isolates were sensitive to ceftazidime, cefuroxime, ofloxacin, and ciprofloxacin but resistant to gentamicin, cefixime, augmentin, and nitrofurantoin. All Bacillus isolates were sensitive to gentamicin, erythromycin, and ofloxacin but resistant to ceftazidime, cefuroxime, ceftriaxone, cloxacin, and augmentin. All Staphylococcus aureus isolates were sensitive to gentamicin, ceftriaxone, erythromycin, and cloxacin but resistant to ceftazidime, cefuroxime, ofloxacin and augmentin. In contrast, Staphylococcus epidermidis isolates were sensitive to ceftazidime, gentamicin, ceftriaxone, and erythromycin but resistant to cefuroxime, cloxacin, ofloxacin, and augmentine. E. coli was sensitive to ciprofloxacin, ofloxacin, ceftazidime, and cefuroxime but resistant to, cefixime, gentamycin, augmentin, and nitrofurantoin (Figure 9).

 

DISCUSSION

The mean total bacterial count of 6.40 log CFU/g and coliform count of 6.24 log CFU/g, reported in this study, are higher than the minimum permissible limit of the International Commission on Microbiological Specification for Foods (2005). This result suggested a maximum microbial count of less than 5.0 log CFU/g and a coliform level of less than 2.0 log CFU/g of shellfish for consumer safety. Our values in this study were also considerably higher than those obtained by Oranusi and Nubi, (2016), who found microbial counts ranging from 4.11 to 5.75 log CFU/g from ready-to-eat shrimp was selected from three vending sites along Lagos-Shagamu expressway. Ehigiator et al., (2008) also obtained values ranging from 2.03 to 5.08 log CFU/g in prawns from Ovie River in Edo State.

The extremely high counts might result from pollutants from shrimp flora that were not eliminated by the processing methods, or they could be due to post-process contamination that originated from the processing environment, water, utensils, and food employees (Chukwu et al., 2013). The discovery of coliforms in the shrimp samples suggests that the items may have been tainted with animal or human faeces, which might be a probable explanation for their contamination. Coliforms are considered indicator organisms because the presence of these organisms suggests that other intestinal pathogens could also be present. Because the samples are frequently packaged and organised with bare hands in white cellophane or hawked in tiny bowls for clients using forks or toothpicks to select, contamination with coliforms might be caused by the staff (food processors and vendors). The water used for processing and cleaning utensils is another potential source of coliform contamination in samples (Reilly et al., 2007; Zambuchini et al., 2008). The market environment at Bodija, Aleshinloye, and Eleyele could contribute to coliform contamination. Also, animals in their flocks are a typical scene in these markets as the animals are moved to nearby markets for sale. Therefore, the practical application of sound and hygienic shrimp-processing practices and HACCP is essential to prevent contamination from coliform.

 

The bacteria isolated from ready-to-eat shrimp in this study were Bacillus spp., Shigella spp., Salmonella spp., E. coli, Staphylococcus aureus and Staphylococcus epidermidis. In contrast, the fungal organisms isolated were Rhizopus spp. and Trichophytum spp., Aspergillus fumigatus, Aspergillus flavus, Penicillium spp., Candida spp. and Mucor spp. The presence of Staphylococcus aureus and S. epidermidis in the shrimp selected for this study indicates the possible contamination of the samples from personnel because both organisms are found in the normal flora of humans. Furthermore, shrimp samples could have been cross-contaminated from equipment and contact surfaces. Enterotoxin-producing strains of S. aureus are known to cause food poisoning (Le Loir et al., 2003; Oranusi et al., 2007). There is, therefore, a need to control ready-to-eat shrimp from S. aureus contamination. In addition, the presence of entero-bacterial organisms, such as Salmonellae and E. coli showed that some of the shrimp samples were contaminated by faeces (Oranusi et al., 2007). Salmonellae are the infectious organisms that cause salmonellosis, which is frequently linked to the intake of foods and drinks that have been contaminated (Heinitz et al., 2000; Phan et al., 2005). The presence of E. coli in some of the shrimps is evidence that the shrimps were contaminated with faeces and may affect the consumer’s health. Evidence shows that the pathogenic strains of E. coli, notably E. coli O157: H7, are responsible for outbreaks of food-borne infections (CDC, 2014). Over the past few years, there has been a significant increase in focus placed on the production, processing, packing, transportation, and storage of food. Because of this, foods can get contaminated with infectious or toxigenic bacteria if they are not produced and kept in the appropriate circumstances and/or if any damage occurs. As a result, they can become a source of disease transmission to humans. In Brazil, staphylococcal food poisoning epidemics have been observed and examined for several years (Carmo, 1995).

It is well-established that certain fungal species produce spores and are widespread environmental contaminants; this could be why those spores were found in the shrimp samples. Most Bacillus and fungal species are either food spoilage organisms or opportunistic pathogens. Therefore, they need to be controlled to reduce the likelihood of engaging in activities that result in food spoilage. Mycotoxins are known to be produced by fungi such as Aspergillus species when favourable conditions are present; these mycotoxins are a concern in ready-to-eat foods. Shrimp should not be taken lightly because these products are stored for days before being sold. In addition, these products are nutritionally rich enough to support the proliferation of these fungi in growth and possibly the production of mycotoxins. Particularly in the immunocompromised population, certain species of Rhizopus and Mucor have been linked to acting as opportunistic agents that cause infections (Kirk et al., 2008). Mycotoxins are known to be produced by certain species of fungi, such as Aspergillus. Moreover, A. flavus is a species that produces aflatoxin, which has been linked to human carcinogenicity, mutagenicity, and teratogenicity (Zhang et al., 2015). The fungus, A. fumigatus, is the most common pathogen that causes infections in humans, followed by the bacteria A. flavus, A. niger, A. terreus, and A. nidulans (Morgan et al., 2005).

According to Adebayo-Tayo and Okpo (2010), the occurrence of Penicillium sp. and Aspergillus sp. could be because, during storage, the shellfish, such as the shrimp samples, are susceptible to reabsorb moisture from the environment, which then supports the growth of microorganisms in addition to the contamination during processing and handling. Therefore, the occurrence of indicators and other organisms investigated in this study is of particular concern. Also, the greatest threat associated with shrimp used for food preparation, eating purposes and other human consumption may be due to contamination by human excrement (Okonko et al., 2009). Therefore, it is essential to do microbiological testing on shrimp and other types of seafood before they are prepared and packed for human consumption to lessen the risk of infection (Fagade et al., 2005).

Most organisms discovered on these shrimps are the microbes often found in soil and water. But an organism, S. aureus, found in shrimp, is a pathogenic organism that is important to public health. The pathogens isolated in this current study are comparable to the microorganisms reported by Olawale et al. (2005). They found nine bacterial genera and two fungal genera in a study that was very similar to this one, which included E. coli and S. auerus. The findings of this study are in agreement with the findings of Adesokan et al. (2005), who reported the presence of E. coli and Bacillus sp. among other organisms, and Bankole et al. (2004); Bankole et al. (2005), who reported the presence of S. aureus, S. epidermidis, Bacillus sp., E. coli, Shigella sp., Salmonella sp., and A. flavus. The finding that the organisms Bacillus sp. and A. flavus were present in the contamination of some non-carbonated orange drinks is comparable to the findings that Fagade et al. (2005) obtained from a study on the microbiological qualities of certain non-carbonated orange drinks. In that study, the researchers found that the same organisms were present in the contamination of the drinks.

The presence of Bacillus spp. and Aspergillus flavus in this shrimp sample is also comparable with Ehigiator et al. (2014) in a study of bacteria and fungi load of raw processed shrimp from different meat shops in the Benin metropolis. According to the findings of the study, the same organisms were present. It was discovered that locally smoked prawns had microorganisms that were either pathogenic, cause food poisoning or deterioration, or are of epidemiological importance.

Antimicrobial resistance is a worldwide public health concern that has drawn attention in the recent time. Existence of antibiotic resistance amongst the bacterial isolates may have public health implication in shrimp consumers. While the bacterial isolates from the shrimps were multidrug resistant, the resistance of the isolates to antibiotics could be explained by the possibility of the massive use of these compounds in aquaculture, several of which are non-biodegradable (Gufe et al., 2019). This study also revealed the effectiveness of the existing and readily available drugs to control both gram-positive and gram-negative bacterial pathogens in aquaculture. However, there is need to be aware of the potential hazards of indiscriminate use of drugs in aquaculture systems, which has been largely reported (Okocha et al., 2018).

CONCLUSION

This study demonstrated the presence of highly pathogenic agents such as Salmonella and Shigella species in ready-to-eat shrimps samples from Ibadan. The mean total bacterial and coliform counts were 6.40 log CFU/g and 6.24 log CFU/g, respectively. This study concluded that ready-to-eat shrimps in Ibadan are not safe, wholesome and fit for human consumption because of the high loads of bacteria. The bacterial and fungal organisms isolated from the shrimps indicate contamination from personnel and the environment. The isolated multidrug resistant bacteria pose high risk to human, animal, and the environment. Strict rules and monitoring activities combined with food safety training for stakeholders on various aspects of good hygiene practices are recommended.

FUNDING

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

acknowledgements

The authors express their gratitude to the Department of Veterinary Public Health and Preventive Medicine, University of Ibadan, for providing the required facility and Landmark University for defraying the article processing charges.

CONFLICT OF INTEREST

The authors declare no conflict of interest.

novelty statement

The study provided current data on the microbial load of shrimps which is not routinely checked in Ibadan.

authors contribution

Olufemi Bolarinwa Adedeji conceived, designed and supervised the study; Blessing Ndenum Peter performed the research, analysed and interpreted the data; Reuben Chukwuka Okocha and Ekemini Moses Okon analysed and interpreted the data, writing - review and editing.

REFERENCES

Adebayo-Tayo B.C, Okpo MA (2010). Microbiological, proximate and heavy metal concentration in Penaeus sp.(shrimp) and Calllinectes sp.(crab) from creeks in Niger delta Nigeria. Afr. J. Food Agric. Nutr. Dev, 10(8), 3047-3064.

Adesokan IA, Ogunbanwo ST, Odetoyinbo BB (2005). Microbiological quality of selected brands of beer in Nigeria. In the Book of Abstract of the 29th Annual Conference & General Meeting (Abeokuta 2005) on Microbes As Agents of Sustainable Development, organised by Nigerian Society for Microbiology (NSM), University of Agriculture, Abeokuta, from (p. 21).

Bankole MO, Oladimeji DS, Omemu AM (2005). Microorganisms associated with the palms of food-vendors in Abeokuta Metropolis. In the Book of Abstract of the 29th Annual Conference & General Meeting (Abeokuta 2005) on Microbes As Agents of Sustainable Development, organised by Nigerian Society for Microbiology (NSM), University of Agriculture, Abeokuta, from (pp. 6-1).

Bankole MO, Sangokoya OA, Adeitan AA (2004). The microbiological analysis of spoilt canned foods sold and meant for sale in the markets. Book Abstract., (67): 62.

Buchanan RE, Gibbons NE (1985). Bergey’s manual of determinative bacteriology, 8-Ed, New York: Springer.

Beshiru A, Igbinosa EO (2018). Characterisation of extracellular virulence properties and biofilm-formation capacity of Vibrio species recovered from ready-to-eat (RTE) shrimp, Microbial Pathogenesis. https://doi.org/10.1016/j.micpath.2018.04.015

Cabello FC (2006). Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment. Environ. Microbiol. 8: 1137–1144. https://doi.org/10.1111/j.1462-2920.2006.01054.x

Carmo LS, Dias RS, Anunciação LLC, Bergdoll MS (1995). Staphylococcal food poisoning in Minas Gerais state (Brazil). Arq. Brasil. Med. Vet. 47: 113-122.

Center for Disease Control and Prevention (CDC). (2014). Multistate Outbreak of Shiga toxinproducing Escherichia coli O157:H7 infections linked to ground beef (Final Update). http://www.cdc.gov/ecoli/2014/O157H7-05 14/index.html. Accessed August 14, 2022.

Centre for Disease Control (CDC) (1999). An outbreak of food borne infections associated with consumption of oysters and clams harvested from Long Island Sound occurred among residents of Connecticut, New Jersey, and New York. MMWR 48(03) Accessed on 11 July, 2022.

Chukwu OO, Chukwuedo AA, Otalike P, Chukwu ID, Echeonwo NO, Bitrus JG., Akubo SI (2013). Studies on food-borne bacteria in commercially hawked ready to eat fish in Jos and its environments. African J. Food Sci., 7: 71 – 75. https://doi.org/10.5897/AJFS2013.0977

Dewi RS, Nurul Huda G, Ahmad R (2011). Changes in the physiological properties, microstructure and sensory characteristics of shark dendeng using different drying methods. American J. Food Technol., 6:149- 157. https://doi.org/10.3923/ajft.2011.149.157

Ehigiator FAR, Akise OG, Eyong MM (2014). Bacteria and fungi load of raw processed shrimp from different meat shops in Benin metropolis. Nigerian J. Agricult. Food Environ., 10(3): 1-7.

Ehigiator OA, Anyata BU (2008). Saturated hydraulic conductivity in a tropical alfisol in Southwest Nigeria. Environ. Res. J., 2(2): 70-75.

Emmett R, Akkersdyk S, Yeatman H, Meyer BJ (2013). Expanding awareness of docosahexaenoic acid during pregnancy. Nutrients. 5:1098-1109. https://doi.org/10.3390/nu5041098

Fagade OE, Ogunjobi AA, Oyelade AA (2005). Microflora of Non-carbonated orange drink. In the Book of Abstract of the 29th Annual Conference & General Meeting (Abeokuta 2005) on Microbes As Agents of Sustainable Development, organised by Nigerian Society for Microbiology (NSM), UNAAB, from (p. 16).

FAO, Food and Agriculture Organization of the United Nations, (2016b). The State of World Fisheries and Aquaculture 2016: Contributing to food security and nutrition for all. FAO, Rome, 200 pp.

Fatma AC, Aliye S1 Burcu K (2006). Occurrence of Vibrio spp. and Aeromonas spp. in shellfish harvested off Dardanelles cost of Turkey. Food Control. 17: 648–65. https://doi.org/10.1016/j.foodcont.2005.04.014

Garrity GM, Bell JA, Lilburn TG (2004). Outline of The Prokaryotes. Bergey’s manual of systematic bacteriology, 2nd edn. New York: Springer.

Geetha S, Rao V, Muddula N, Ram Sai Reddy N, Ramesh Babu K (2014). Screening of pathogenic microorganisms from commercially important marine fishes of Visakhapatnam fishing harbour, east coast of India. Int. Res. J. Environ. Sci., 3 (11): 47-51. https://www.gettyimages.com/detail/photo/shrimp-royalty-free-image/184857664?adppopup=true. Accessed 13 september 2021.

Gopakumar K (1997). Product development for overseas market penetration prospects for India. Seafood Export J. 28(2):25-30.

Gufe C, Hodobo TC, Mbonjani B, Majonga O, Marumure J, Musari S, Jongi G, Makaya PV, Machakwa J (2019). Antimicrobial profiling of bacteria isolated from fish sold at informal market in Mufakose, Zimbabwe. Int. J. Microbiol. https://doi.org/10.1155/2019/8759636.

Heinitz ML, Ruble RD, Wagner DE, Tatini SR (2000). Incidence of Salmonella in fish and seafood. J. Food Prot. 63: 579–592 https://doi.org/10.4315/0362-028X-63.5.579.

Hosen Z, Afrose S (2019). Microbial Quality of Common Restaurant Foods: Food Safety Issue in Bangladesh. J. Food Nutr. Sci., 7(4): 56. https://doi.org/10.11648/j.jfns.20190704.11

International Commission on the Microbiological Specifications for Foods (ICMSF) (2005). Fish and fish products, In Microorganisms in foods 6: Microbial ecology of food commodities, ed. ICMSF, 174–249. New York: Kluwer Academic/Plenum Publishers.

Jeyasanta KI, Sathish N, Patterson J (2019). Microbiological, biochemical and organoleptic quality of marine shrimp ready-to-eat (RTE) value added products purchased from self-help group. Food Nutrit. OA.; 2(2):115.

Kakara RR, Geetha S, Muddula Krishna N, Govinda Rao V, Ramesh Babu K (2016). Microbial assessment of commercially important crabs from Visakhapatnam fishing harbour, east coast of India. Europina J. Experimen. Biol., 6 (4): 57-61.

Kirk P.M., Cannon PF, Minter DW, Stalpers JA (2008). Dictionary of the Fungi.(10thedn). Wallingford, UK.

Krieg NR, Staley JT, Brown DR, Hedlund BP, Paster BJ, Ward NL, Ludwig W, Whitman WB. Ed. Bergey’s manual of systematic bacteriology, 2nd edn, vol. 4. The Bacteroidetes, Spirochaetes, Tenericutes(Mollicutes), Acidobacteria, Fibrobacteres, Fusobacteria, Dictyoglomi, Gemmatimonadetes, Lentisphaerae, Verrucomicrobia, Chlamydiae, and Planctomycetes. Eds, New York: Springer.

Kusumaningrum HP, Zainurib M (2015). Detection of Bacteria and Fungi Associated with Penaeus monodon Postlarvae Mortality Procedia. Environ. Sci. 23: 329 – 337. https://doi.org/10.1016/j.proenv.2015.01.048

Loir Y., Baron F, Gautier M. (2003). Staphylococcus aureus and food poisoning. Genet. Molecul. Res. 2 (1): 63-76.

Mhango M, Mpuchane SF, Mpuchane BA (2010). Incidence of indicator organisms, opportunistic and pathogenic bacteria in fish. African J. Food, Agricult. Nutrit. Develop., 10(10). https://doi.org/10.4314/ajfand.v10i10.62898

Mohanbabu BA, Nath KG, Ramya BS (2008). Value added products from macrobrachium rosenbergii. J. Dairy., Foods Home Sci., 27(3and4): 230-233.

Morgan J, Wannemuehler KA, Marr KA, Hadley S, Kontoyiannis DP, Walsh TJ, Warnock DW (2005). Incidence of invasive aspergillosis following hematopoietic stem cell and solid organ transplantation: interim results of a prospective multicenter surveillance program. Med. Mycol., 43(Supplement_1): S49-S58. https://doi.org/10.1080/13693780400020113

Mu DT, Huang YW, Gates KW, Wu WH (1997). Effect of trisodium phosphate on Listeria monocytogenes attached to rainbow trout (Oncorhynchus mykiss) and shrimp (Penaeus spp.) during refrigerated storage. J. Food Safety., 17(1): 37-46. https://doi.org/10.1111/j.1745-4565.1997.tb00174.x

Okonko IO, Ogun AA, Adejoye OD, Ogunjobi AA, Nkang AO, Adebayo-Tayo BC (2009). Hazards analysis critical control points (HACCP) and Microbiology qualities of Sea-foods as affected by Handler’s Hygiene in Ibadan and Lagos, Nigeria. African J. Food Sci., 3(1): 035-050.

Okocha RC, Olatoye IO, Adedeji OB (2018). Food safety impacts of antimicrobial use and their residues in aquaculture. Public Health Rev. 39(21). https://doi.org/10.1186/s40985-018-0099-2.

Olawale AK, Oluduro AO, Famurewa O (2005). Evaluation of microbiological and sanitary standards of canteens and eateries in Osun State Polytechnic, Iree. In the Book of Abstract of the 29th Annual Conference & General Meeting (Abeokuta 2005) on Microbes As Agents of Sustainable Development, organised by Nigerian Society for Microbiology (NSM), UNAAB, Abeokuta, from (p. 19).

Oranusi S, Nubi FE (2016). Microbiological safety evaluation of ready to eat shrimps and snails sold along Lagos-Shagamu Expressway, Nigeria. Covenant J. Physic. Life Sci.

Oranusi S, Galadima M, Umoh, Nwanze P (2007). Food safety evaluation in boarding schools in Zaria, Nigeria, using the HACCP system. Scient. Res. Essay. 2 (10): 426 – 433.

O’Reilly CE, Bowen AB, Perez NE, Sarisky JP, Shepherd CA, Miller MD, Outbreak Working Group. (2007). A waterborne outbreak of gastroenteritis with multiple etiologies among resort island visitors and residents: Ohio, 2004. Clin. Infect. Dis., 44(4): 506-512. https://doi.org/10.1086/511043

Oshilim AO, Orogu JO (2020). Microbiological evaluation of daily use handkerchief. Pharm. Innov., 9: 08-11.

Phan TT, Khai LTL, Ogasawara N, Tam NT, Okatani AT, Akiba M, Hayashidani H (2005). Contamination of Salmonella in retail meats and shrimps in the Mekong Delta, Vietnam. J. Food Protect., 68(5): 1077-1080. https://doi.org/10.4315/0362-028X-68.5.1077

Ramesh Babu K, Govinda Rao V, Krishna NM, Geetha S, Kakara RR (2017). Assessment of bacteriological quality in selected commercially important shrimps of Visakhapatnam, East Coast of India. Int. J. Microbiol. Biotechnol., 2(2): 102-105.

Rosmini MR, Signorini ML, Schneider R, Bonazza JC (2004). Evaluation of two alternative techniques for counting mesophilic aerobic bacteria in raw milk. Food Cont., 15(1): 39-44. https://doi.org/10.1016/S0956-7135(03)00005-7

Tidwell JH, Allan G (2012). The role of aquaculture. Aquacult. Prod. Syst., 3-14. https://doi.org/10.1002/9781118250105.ch1

Viglia S, Brown MT, Love DC, Fry J, Neff RA, Hilborn R (2022). Wild caught Alaska sockeye salmon: A case study of the food energy water nexus for a sustainable wild catch fishery. J. Clean. Prod., 133263. https://doi.org/10.1016/j.jclepro.2022.133263

Zambuchini B, Fiorini D, Verdenelli MC, Orpianesi C, Ballini R (2008). Inhibition of microbiological activity during sole (Solea solea L.) chilled storage by applying ellagic and ascorbic acids. LWT-Food Sci. Technol., 41(9): 1733-1738 https://doi.org/10.1016/j.lwt.2007.11.004.

Zhang J, Zheng N, Liu J, Li FD, Li SL,Wang JQ (2015). Aflatoxin B1 and aflatoxin M1 induced cytotoxicity and DNA damage in differentiated and undifferentiated Caco-2 cells. Food Chem. Toxicol., 83: 54-60. https://doi.org/10.1016/j.fct.2015.05.020