Demand for milk has increased in Malaysia due to the increased in awareness of healthy foods consumption.
Hence, research of milk is crucial to ensure that it is not contaminated with Escherichia coli. This study
evaluated the survival of Escherichia coli at different temperature and haemolysin activity of Escherichia
coli on blood agar. A total of 8 samples of raw fresh and pasteurized milk were collected from nearby farm
and market in Negeri Sembilan, Malaysia. After an overnight exposure to four different temperatures of
0
0C, 280C, 350C and 450C, the bacteriological test of milk was evaluated for the presence of Escherichia
coli. Overall, all raw fresh milk sampled exceeded the acceptable limit of bacterial count of 1 x 105 CFU/ml.
Raw fresh milk recorded the highest count at 35oC with 4.4 x 107 CFU/ml and the lowest at 0oC with 8.3 x
104 CFU/ml. The presence of Escherichia coli was detected in 7/20(35%) of the total raw fresh milk
samples. All pasteurized milk showed no presence of Escherichia coli due to the effectiveness of heat
treatment. Haemolysin test showed no haemolytic activity. Milk contaminated with Escherichia coli can
cause diarrheal, gastrointestinal diseases and urinary infection. Hence, it is important to study the survival
rate of Escherichia coli and its pathogenicity in milk to ensure public safety.
Smoked food was one of the most authentic dishes in Malaysian cuisines. However, local consumers were still unaware on the hygienic level of these smoked products. Nowadays, the smoked products were smoked in an open space that allowed the contamination of bacteria on the food. This study aimed to determine the occurrence and antibiotic resistance of Salmonella in the smoke catfish and meat at the local street stalls in Kuala Pilah, Negeri Sembilan by MPN-PCR methods. The microbial concentration of Salmonella sp. in smoked catfish was 2.4 x 10-8 MPN/g in smoked catfish and 2.9 x 10-7 MPN/g in smoked meat and were confirmed by culturing on selective agar of Salmonella Shigella agar. The prevalence of Salmonella sp. was found to be 68% in both samples by MPN-PCR approach. Salmonella sp. were 100% detected in smoked catfish followed by smoked meat by 44% respectively. All the positive isolates from MPN-PCR were continued with antibiotic susceptibility to determine the resistance level of Salmonella sp. towards selected antibiotics. As result, the isolates showed a multi-resistance patters from one to four antibiotics tested with MAR indices ranging from 0.25 to 1.00. The outcome indicated a high rate of foodborne pathogens which indicated the need to create the awareness on the safety and proper handling of smoked products to minimization of any potential health hazard caused by this foodborne pathogen.
This study aimed to determine the biofilm formation ability by Salmonella Typhi on cucumber, mango and guava surface, as well as to determine the relationship between time contact and biofilm formation. Crystal violet assay was performed to quantify the biofilm formation based on the value of optical density at 570 nm of the destaining crystal violet at the specific interval time. The result showed that the attachment of the bacterial cells on the fresh produce surface increased with the contact time. The readings of OD570at time 12 h for cucumber, mango and guava surfaces were 0.824, 0.683 and 0.598, respectively, indicating that the biofilm formation by Salmonella Typhi on different fresh produce surface varied with time. Since the result showed that Salmonella Typhi formed biofilm on fresh produce surfaces, hygienic practice from farm to fork including handling, processing, distribution and storage of the fresh produce should be of concern.
Escherichia coli is commonly found in the intestinal tract of human and warm-blooded animal.
Shiga toxin-producing Escherichia coli (STEC) serotype O157:H7 are pathogenic and able to
cause serious health problem to human. In this study, the detection of E. coli from raw coconut
milk was carried out by using the most-probable-number (MPN) and streaked plate methods.
A total of 125 samples were purchased randomly from five hypermarkets and 16 wet markets
in Kuala Pilah, Senawang and Seremban, West Malaysia areas. The samples that contaminate
with E. coli were found to be ranging from 2.4x107
MPN/ml. The results
revealed the presence of E. coli in fresh coconut milk from wet markets and hypermarkets in
Negeri Sembilan. Thus, the result showed high health risk and the need for improving hygienic
standard among food handlers. Therefore, public should be aware and always practice proper
food handling.
To date, cholera has cycle the world seven times through the seven pandemic cycles that has
affected tens of millions of people. The objective of this study was to determine the presence
and density as well as the antibiotic resistance profile of Vibrio cholerae isolated from catfish
(Pangasius hypohthalamus). From the combination of the Most Probable Number-Polymerase
Chain Reaction-plating on TCBS agar methods, V. cholerae was detected in 32 samples and
V. cholerae O139 was detected in 7 samples, with a density ranging between
A total of 87 market fish samples representing five types of fish were evaluated for the presence of Aeromonas spp. Of the samples examined, 69%, 55%, 11.5% and 2.3% harbored Aeromonas spp., A. veronii biovar sobria, A. hydrophila and A. caviae, respectively. The 60 isolated Aeromonas spp. strains were further examined for hemolytic activity, resistance to antimicrobial agents and presence of plasmids. Hemolytic activity varied widely among the isolated strains. Though all the isolates demonstrated resistance to three or more of the antibiotics tested, all were susceptible to ceptazidime. Thirty-four (56.7%) of the sixty isolates harbored plasmids, with sizes ranging from 2.3 to 15.7 kb. These results indicate that hemolytic, multiple antibiotic resistant and genetically diverse aeromonads are easily recovered from fish in this region.
Several Norovirus cases due to consumption of green onions have been reported during recent years but reports on red onions are not found. Onions are one of the major tastes in Malaysian food which are sometimes consuming raw especially the green onion. Viral contamination in onions can occur due to planting condition and not properly prepared food. This situation can pose the human health risk. A method was developed to detect the Norovirus that might present on different type of onions. In this study, 60 samples were collected from local market. Elution by Tryptose Phosphate Glycine broth and concentration steps using negatively charge filter were applied to enhance the detection of virus in food due to low copies of virus on food surface. The viral RNA was extracted using Qiagen Rneasy Mini kit before further detection using One-step RT-PCR. The total incidence of Norovirus in green onion and red onion was 13.33% (4/30) and 3.33 % (1/30) respectively. This is the first report of the detection of Norovirus in red and green onions in Malaysia. Based on the results, it is concluded that this method is reliable to detect Norovirus on onions and vegetables surface and hence can be applied in the laboratories for routine or food borne outbreak investigation.
This study was undertaken to characterize the antibiotic resistance and randomly amplified polymorphic DNA (RAPD) profiles of Vibrio parahaemolyticus isolates from raw vegetable samples. A total of 46 isolates of V. parahaemolyticus recovered from raw vegetables samples and were confirmed by PCR were analyzed in this study. Most of the isolates were resistant to nalidixic acid (93.48%) and were the least resistant towards imipinem (4.35%). The MAR index results also demonstrated high individual and multiple resistances to antibiotics among the isolates. From the RAPD analysis, the size for RAPD fragments generated ranged from 250 bp to 1,500 bp, with most of the strains contained three major gene fragments of 350, 1,000 and 1,350 bp. The RAPD profiles revealed a high level of DNA sequence diversity within the isolates. Antibiotic resistance and RAPD proved to be effective tools in characterizing and differentiating the V. parahaemolyticus strains.
Little is known on the biosafety level of Vibrio spp. in freshwater fish in Malaysia. The purpose of this study was to investigate the prevalence and concentration of Vibrio spp. and V. parahaemolyticus in
freshwater fish using the Most Probable Number-Polymerase Chain Reaction (MPN-PCR) method. The study was conducted on 150 samples from two types of freshwater fish commonly sold at hypermarkets, i.e. Pangasius hypophthalmus (catfish) and Oreochromis sp. (red tilapia). Sampling was done on the flesh, intestinal tract and gills of each fish. The prevalence of Vibrio spp. and V. parahaemolyticus was found to be 98.67% and 24% respectively with higher percentages detected in samples from the gills followed by the intestinal tract and flesh. Vibrio spp. was detected in almost all red tilapia and catfish samples. V. parahaemolyticus was detected in 25% of the catfish samples compared to 22.6% of red tilapia fish. The density of Vibrio spp. and V. parahaemolyticus in the samples ranged from 0 to 1.1x107 MPN/g. Although the maximum value was 1.1x107 MPN/g, most samples had microbial loads ranging from 0 to >104 MPN/g. The outcome on the biosafety assessment of Vibrio spp. and V. parahaemolyticus in freshwater fish indicates another potential source of food safety issues to consumers.
Salmonellosis outbreaks involving typhoid fever and human gastroenteritis are important diseases in tropical countries where hygienic conditions are often not maintained. A rapid and sensitive method to detect Salmonella spp., Salmonella Typhi and Salmonella Typhimurium is needed to improve control and surveillance of typhoid fever and Salmonella gastroenteritis. Our objective was the concurrent detection and differentiation of these food-borne pathogens using a multiplex PCR. We therefore designed and optimized a multiplex PCR using three specific PCR primer pairs for the simultaneous detection of these pathogens. The concentration of each of the primer pairs, magnesium chloride concentration, and primer annealing temperature were optimized before verification of the specificity of the primer pairs. The target genes produced amplicons at 429 bp, 300 bp and 620 bp which were shown to be 100% specific to each target bacterium, Salmonella spp., Salmonella Typhi and Salmonella Typhimurium, respectively.
Presence of Norovirus in food can cause viral gasteroenteritis. Recently, lots of reports relating to Norovirus in food have been published. Special attention must be paid to the raw foods as they are not subjected to further heat treatment. In this study, pegaga, kesum, tauge and ulam raja (popular salad vegetables in Malaysia) were investigated for Norovirus. A total of 32 samples from each type of salad vegetables were purchased from local market and analyzed using One-step RT-PCR (Reverse Transcriptase-Polymerase Chain Reaction) for both genogroups namely Norovirus Genogroup I and Genogroup II. Results showed that tauge had the highest contamination with Norovirus Genogroup I (15.6%) comparing to pegaga (9.4%), kesum (12.5%)
and ulam raja (0%). Samples were free from Norovirus Genogroup II. The study showed that raw vegetables are high-risk foods and can be contaminated with Norovirus.