S.E. OMONIGHO

Food safety remains a critical public health concern globally, with dairy products repeatedly implicated in food-borne illness outbreaks. This study aimed to detect enteric pathogens in dairy products sold in Benin City, Edo State. Dairy product samples comprising of branded (Hollandia, Nana, Cedaa, and Super Yogo) and locally processed (Nono milk, Kindoromo, Wara, and Maishanu) products were purchased for this study. Enumeration and isolation of bacteria was done using serial dilution and pour plate techniques on selective agar. Bacterial isolates were identified based on cultural, morphological and biochemical characteristics. The pH and total titratable acidity of samples were determined using a pH meter and acid/base titration method respectively, while antibiotic susceptibility testing was performed using the Kirby-Bauer disc diffusion method. The total heterotrophic bacteria count of the samples ranged from 4.8±0.26 to 8.6±0.26 ×10⁸ CFU/ml, while colony counts on MacConkey agar, Salmonella-Shigella agar, and Eosin methylene blue agar ranged from 0.80±0.485 to 6.67±1.53 ×10⁷ CFU/ml; 1.13±0.31 to 6.87±0.61 ×10⁴ CFU/ml and 5.07±0.64 to 7.0±0.40 ×10³ CFU/ml respectively. Six bacterial isolates were identified in this study, which include: Escherichia coli1 , Escherichia coli 2 , Salmonella sp.1 , Salmonella sp.2 , Enterobacter aerogenes and Serratia marcescens with Escherichia coli1 , Escherichia coli2 , Salmonella sp 1 and Salmonella sp 2. having the highest frequency of occurrence of 33.33% each. The pH values of dairy samples ranged from 3.82±0.01 to 6.96±0.03, while total titratable acidity ranged from 0.17±0.02 to 1.86±0.02 mg/l. Most isolates were resistant to antibiotics used, with resistance indices ranging from 0.1 to 0.8, with Enterobacter aerogenes and Salmonella sp.2 recording the highest resistance index of 0.8, indicating multidrug resistance pattern. This study revealed that dairy products (especially in locally processed dairy products) sold in Benin City showed the enteric bacteria which may possibly be pathogenic with high multidrug resistance profiles, underscoring the need for improved hygiene practices, enforcement of pasteurization standards, and stringent microbiological monitoring in the dairy value chain.

Actinomycetes are gram-positive bacteria with high guanine + cytosine content of over 55% in their DNA. They belong to the order Actinomycetales and form an important segment of the microflora of most natural environments. Soils, manures and composts, freshwater bodies such as lakes and river bottoms contain an abundance of these organisms. Actinomycetes are aerobic, spore forming organisms with a distinctive feature of possessing filamentous hyphae that do not normally undergo fragmentation. Due to their phenotypic similarities to fungi, actinomycetes are also known as ray fungi (Chaudhary et al., 2013). Actinomycetes provide an excellent resource for the isolation and identification of therapeutically important secondary metabolites such as, antibiotic, antifungal, antiviral, anticancer, enzyme, immunosuppressant and other industrially useful compounds (Dhawane and Zodpe, 2017). These microbial compounds have been a source of life saving environment for many bacterial and fungal infections. Some effective antibiotics manufactured from actinomycetes includes: penicillin, streptomycin, tetracycline, erythromycin, amphotericin and vancomycin. These microbial natural products are notable not only for their potent therapeutic activities but also for the fact that they frequently pose desirable pharmacokinetic properties required for clinical development (Khasabuli and Kibera, 2014). Antibiotics of actinomycetes origin have a wide variety of chemical structure, including aminoglycosides, β-lactams, antracyclines, tetracycline, nucleosides, peptides, polyenes and actinomycins. Secondary metabolites isolated from soil actinomycetes have also been proven to be potent inhibitors of numerous plant pathogens (Agadagba, 2014). 1 A large number of actinomycetes have been isolated and screened from soil in the past several decades, accounting for 70 80% of relevant secondary metabolites available commercially. It has been estimated that approximately one-third of the thousands of naturally occurring antibiotics have been obtained from actinomycetes (Chaudhary et al., 2013). More than 70% of these antibiotics are attributed to two genera viz., Streptomyces and Micromonospora (Rai et al., 2018). The richness and diversity of actinomycetes present in any specific soil, is greatly influenced by the soil type, geographical location, cultivation and organic matter amongst other factors (Agadagba, 2014). According to the World Health Organization, over-prescription and the improper use of antibiotics has led to the generation of antibiotic resistance in many bacterial pathogens (Kumar et al., 2010). Serious infections caused by microorganisms that have acquired resistance to commonly used antibiotics have become a major global healthcare problem in the 21st century (Jarallah and Rahaman, 2014). Some antibiotics like penicillin, erythromycin, and methicillin which used to be very effective treatment against infectious diseases are now less effective because pathogens are now more resistant to such antibiotics. Antibiotic resistant pathogens such as methicillin and vancomycin resistant strains of Staphylococcus aureus and others cause an enormous threat to the treatment of serious infections. These drug resistant strains emerge more quickly than the rate of discovery of new drugs and antibiotics (Kumar et al., 2010). Also, increase in fungal infection happens because the available antifungal drugs are not very effective in treating fungal diseases. Fungal diseases are often difficult to diagnose and treat because antifungal drugs are often not very effective in the setting of impaired immunity (Casadevall et al., 2002). Candida albicans can develop resistance to antimycotic drugs such as fluconazole which is often used to treat candidiasis. The frequency of multiazole-resistant 2 3 strains belonging to Candida species other than Candida albicans is increasing (Hitchcock et al., 1993)

Milk is the fresh lacteal secretion from the mammary glands of mammals used in nourishing their young. It also serves as a significant food source for humans of all ages. However, milk can be easily contaminated by microorganisms and toxic substances such as aflatoxins during the stages of milking, processing, storage and transportation. The aim of this study was to isolate and characterize moulds from raw cow milk and its locally processed products, sold in open markets in Benin City. A total of 16 samples were obtained from two markets (Aduwawa and Oluku) in Benin City, Edo state. All samples were serially diluted and inoculated on Potato dextrose agar (PDA) using the pour plate technique. Pure cultures were obtained, and fungal isolates were identified based on the cultural and morphological characteristics. The pH of each sample was determined using an electronic pH meter (PH-98108) and the moisture contents of the samples were determined according to the method of AOAC. Fungal counts obtained in this study ranged from 0.10 ± 1.00 to 0.90 ± 0.30x10 3 Cfu/ml. Fungi isolated in this study include: Aspergillus niger, Aspergillus flavus, Penicillium digitatum, Rhizopus nigricans, Curvulavia lunata, Fusarium oxysporium, Cladosporium sp, and Penicillium sp. The most occurring fungi were Penicillium sp. and Aspergillus niger (23%) and the least occurring fungi (7.7%) were Rhizopus nigricans and Curvulavia lunata. Mean pH values of the samples ranged from 4.10 ± 0.30 to 6.20 ± 0.80 while the moisture content ranged from 6.00 ± 0.40% to 20.00 ± 0.70%. This study revealed the presence of mycotoxigenic moulds such as Aspergillus flavus and Aspergillus niger in locally processed milk products sold in open markets in Benin City. This may have resulted from unhygienic conditions during processing and storage of the milk products, and poor sanitary conditions of the milk handlers as well.