South Asian Journal of Research in Microbiology

Aim: To determine the microbiological quality of zobo drink preserved with scent leaves.

Methods: The zobo drink and scent leaves were prepared and evaluated using standard microbiological techniques.

Results: Twenty three (23) bacteria species and fourteen (14) fungi species were identified from zobo drink preserved with scent leaves samples. This reveals the major bacterial species to be Enterobacter spp, Staphylococcus aureus, Bacillus spp, and Micrococcus spp. and fungi species to be Aspergillus niger, Rhizopus spp and Penicillium spp. The bacterial and fungal counts decreased as the days increased with day 1 having the highest bacterial and fungal counts at 1.41x105 (cfu/ml) and 3.1x104 (cfu/ml) respectively. The control samples were generally higher than the counts recorded on the bacterial and fungal counts. Zobo + scent leaves (ZSC) recorded the highest bacterial count at 1.41x105 (cfu/ml), while the least was recorded for (ZSA) at 1.01x106 (cfu/ml). Zobo + Scent (ZSC) recorded the highest fungal counts at 3.1x104 (cfu/ml), while the least was recorded for ZSA at 1.2x105 (cfu/ml). From this study, Bacillus spp and Staphylococcus aureus were the most frequently occurring bacterial isolates with a high percentage occurrence of 8(21.6%) and 6(16.2%), while Penicillium spp was the most frequently occurring fungal isolate.

Conclusion: The association of these microorganisms with foods such as the commercial zobo drinks may be as a result of poor hygiene or poor sanitary condition. The microbial counts showed that among the zobo drink preserved with scent leaves samples, zobo + scent leaves (ZSC) is the most predisposed product to microbial population due to the high microbial counts recorded. Therefore, the result revealed that the samples of zobo drink were directly and indirectly contaminated with high levels of pathogenic bacteria, but can be reduced by the addition of scent leaves as a preservative.

Aims: one of the most important foodborne microorganisms is the Gram’s positive environmental wide spread Listeria spp. As the Listeria may be considered a public health concern so there is in needing to rapid, precise and reliable diagnosis of the organism in consumed food. The present study aimed to survey the presence of Listeria spp. among two popular consuming Egyptian white soft cheese using advanced biochemical, antibiotic susceptibility and molecular techniques.

Methodology: Listeria spp. was investigated in 155 samples of two white soft cheeses (70 kareish cheese and 85 Damietta cheese) collected from street vendors and retail markets in Giza. The existence of Listeria spp. was tested through cultural and the identification was confirmed biochemically by Vitek2 compact system as well as molecular identification via diplex real time PCR using species specific primers.

Results: The results of the study revealed the isolation of two Listeria spp. in a total number of 22 from155 samples (14.19%); 14 isolate out of 70 (20%) Kareish cheese while 8 isolates out of 85 (9.4%) Damietta cheese's samples. The 22 Listeria spp. isolates were differentiated into L. innocua 15 (68.18%), and L. monocytogenes 7 (31.81%) also their antimicrobial susceptibility was declared using advanced Vitek-2 compact system. The two Listeria spp. isolates were definitely confirmed by using diplex DNA hybridization real PCR technique.

Conclusion: Soft raw milk based cheese is a popular food in Egypt and looked on as a risk for foodborne bacteria contamination. The data of this study pointed out that there is a potential risk of infection with Listeria, especially the public health concern L. monocytogenes. The current study presented Vitek-2 compact system as advanced technique for not only for identification and differentiation of Listeria strains but also for their antimicrobial susceptibility. Furthermore the using of diplex real PCR technique gives a chance for quick and precise identification.

This work aimed to characterize the bacterial and fungal concentrates present in the wastewater thrown by the Ogbe slaughterhouse. Bacterial and fungal concentrates from Ogbe slaughterhouse wastewater were evaluated at two seasons. Results obtained showed total heterotrophic bacterial count (2.0×10⁵-2.1×10⁵ cfu/mL) and total fungal count (1.5×10⁵-2.0×10⁵ cfu/mL). Bacterial isolates such as Acinetobacter sp. (0.50-3.65%), Citrobacter sp. (3.00-9.13%), Escherichia sp. (2.50-13.69%), Klebsiella sp. (2.50-14.16%), Proteus sp. (2.00-9.13%), and Staphylococcus sp. (11.00-13.69%) were higher in dry season than rainy season. Bacillus sp. (9.13-23.00%), Enterobacter sp. (0.00-3.00%), Micrococcus sp. (6.85-7.50%), Pseudomonas sp. (12.84-25.00%), Salmonella sp. (4.57-5.00%), Serratia sp. (0.00-1.50%) and Streptococcus sp. (4.57-13.00%) were higher in rainy season than dry season. Mould isolates such as Absidia sp., Aspergillus sp., Fusarium sp., Cladosporium sp., Penicillium sp., and Rhizopus sp., were observed in the present study. Apart from Penicillium sp., the percentage occurrence of all the observed mould isolates in wastewater for the seasons were higher than their respective control. Candida sp., Saccharomyces sp., and Torulopsis sp, were among the yeast isolated from wastewater generated from Ogbe abattoir in this study.  The observed isolates become important when their potential risk as pathogens as well as the intensified environmental health hazards they pose to humans living within the abattoir environment are considered.

This study investigates the antifungal and antibacterial activities of extracts of Trema orientalis linn. Blume. The selected isolates used in the study includes Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi, Streptococcus faecalis, Shigella dysenteriae, Proteus mirabilis, Haemolytic Streptococcus viridian, Aspergillus niger, Candida albicans ,and Aspergillus flavus.  The antibiogram profile of the organism was obtained using the disc diffusion method. Tannin, flavonoid, Terpenoid, Saponin, and cardiac glycosides were found present in T. orientalis. The antibiotic sensitivity test reveals the presence of multiple antibiotic resistant bacteria. The agar well diffusion method was used to assay the antibiotic activities of the extract. The extracts were prepared from T. orientalis using Methanol and petroleum ether as extraction solvents.  The antibacterial assay shows the efficacy of the methanol and petroleum ether extracts except on S. aureus ATCC 43300 and Shigella dysenteriae. The highest zones of inhibition by methanol and petroleum ether extracts were recorded on Salmonella typhi of 22.003 ± 0.003 mm and 32.002 ± 0.002 mm, respectively. The fungal isolates were susceptible to the extracts with the zones 11.67±0.33 mm and 13.67±0.33 mm. The results of the sensitivity test compared well with that of the antimicrobial test. The Minimum Inhibitory Concentration ranged between 3.125- 25.00 mg/mL. T. Orientalis contains bioactive compounds that has antimicrobial effects. The leaf of Trema orientalis has broad - spectrum activity, hence T. Orientalis methanol and Petroleum ether extracts is recommended for  exploration as source of antimicrobial agents.

Roselle (Hibiscus sabdariffa) grows abundantly in some parts of Nigeria and the plant has high nutritional value to all ages. Over the years, Nigeria has depended on imported wines to satisfy the demands for wine consumption by her citizens and this has placed huge economic burden on her economy. Hence, the need to exploit the commercial availability of Hibiscus sabdariffa for wine production. This study was aimed at comparative evaluation of red wine produced from Hibiscus sabdariffa L. and Citrus sinensis juice using Saccharomyces cerevisiae isolated from palm wine and brands of commercial wine. The Roselle calyx extract and sweet orange juice in the ratio of 3:1 was inoculated with the palm wine yeast and allowed to ferment for 14 days at 28±2°C. Physicochemical and microbiological parameters of the fermenting ‘must’ were monitored at intervals using standard methods. Culturable microorganisms was not detected in the ‘must’ at Day 0, but only yeast cells which have a mean count of 2.77 x 10⁴ Cfu/ml and 2.25 x 10⁴ Cfu/ml were present in the fermenting ‘must’ at Day 7 and 14, respectively. There were significant differences (p<0.05) among the parameters monitored in this study except pH and specific gravity (SG) of the fermenting ‘must’. The data obtained demonstrated that there was a decline in pH, reducing sugar, and SG of the fermenting ‘must’ which ranged from 3.8-3.5, 23-2.10 g/L and 1.08-1.00 ^oBrix % w/w, respectively. However, this study reported increase in alcohol content (0 - 10.87% v/v), titratable acidity (0.45 - 0.68 g/mL), and temperature (26.0 - 30.7°C) during the fermentation of the ‘must’. The wine produced had a bright red colour, pH of 3.5, alcohol content of 10.87% v/v, SG of 1.00 ^oBrix % w/w, and titratable acidity (TA) of 0.68%. The outcome of this study indicated that the wine produced is slightly more preferable than some commercialized brands of wine based on sensory scores. Since, the alcoholic beverage developed during fermentation process is in generally of acceptable quality as a good table wine thus, it can be concluded that our wine is a good product recommendable.