Seventy five random samples were collected (25 raw milk, 50 local different made soft cheeses) from different supermarkets in Tripoli- Libya. The Objectives of this study were: (i)- to clear the incidence rate and count of coliforms as an indicator microorganisms for fecal contamination in raw milk and locally made soft cheese samples manufactured by traditional methods and (ii)- to make comparison between the most famous two conventional methods used for counting of such group of microorganisms. Coliforms were recovered from all the raw milk samples using the two methods (most probable number using liquid lauryl sulphate broth and sold plating method using violet red bile agar). The mean count for the former media was 28x106 while for the later one was 15x106 cfu/ml. For cheese samples (locally made Ricotta and Maasora), positive samples were 78% (39 samples) using MPN method, while 76% (38 samples) using sold plating media VRBA. The mean coliform count for positive samples using MPN was 18x107 cfu/g, while for VRBA plates the mean count for positive samples was 21x106 cfu/g. all counts were higher using MPN than VRBA for the same sample in both raw milk and cheese samples, although, clear difference in count between the two methods was recorded in cheese than that in raw milk, conditions that may affect the count in both raw milk and cheese were discussed. Factors that may limit
Hesham Taher Naas(1-2007)

Abstract This study aimed to evaluate the antibacterial activity of flavonoids extracted from two Libyan brown algae namely Cystoseira compressa and Padina pavonica using microwave-assisted extraction method against pathogenic bacteria isolated from meat, meat products, milk and dairy products (Staphylococcus aureus subsp. aureus (5 isolates), Bacillus cereus (3 isolates), Bacillus pumilus (1 isolate), Salmonella enterica subsp. enteric (4 isolates) and Enterohaemorrhagic Escherichia coli O157 (EHEC O157) (4 isolates)). All of these isolates were muti-drug resistant with high MAR index. The results showed that C. compressa extract exhibited better and stronger antibacterial activities against the seventeen tested isolates with inhibition zones diameter ranged from 14 - 22 mm compared to P. pavonica extract which showed positive effect against 9 isolates with low inhibition zone ranged from 11 - 16.5 mm. Flavonoids extracted from C. compressa also displayed the best spectrum of bactericidal effect with a ratio MBC/MIC ≤ 4 obtained on all susceptible tested bacterial strains. Flavonoids and proanthocyanidins significantly contributed to the antibacterial properties. The mode of action of these active extracts is under investigation.
Hesham Taher Naas(1-2017)

The objective of this study was to determine the antimicrobial activity of proteolytic, meat-tenderizing enzymes (papain and bromelain) against E. coli and L. monocytogenes at three different temperatures (5, 25 and 35°C). Two overnight cultures of E. coli JM109 and L. monocytogenes were separately suspended in 1% peptone water and exposed to a proteolytic enzyme (papain or bromelain) at three different temperatures. Bromelain concentrations (4 mg/ml) and (1 mg/ml) tested at 25°C against E. coli and L. monocytogenes, respectively, were the most effective concentrations tested reducing populations by 3.37 and 5.7 log CFU/ml after 48 h, respectively. Papain levels of (0.0625 mg/ml) and (0.5 mg/ml) were the most effective concentration tested at 25°C against E. coli and L. monocytogenes, respectively, reducing populations by 4.94 and 6.58log CFU/ml after 48h, respectively. Interestingly, the lower papain concentration tested (0.0625 mg/ml) was more effective than the higher concentration (0.5 mg/ml) against E. coli at all three temperatures. As expected, the temperature was directly related to enzyme efficacy against both E. coli and L. monocytogenes.
Hesham Taher Naas(1-2013)