Detection of Bacillus cereus in formula milk and ultra high temperature (UHT) treated milk products

Ultra high temperature (UHT) treated milk products and formula milk are known to be frequently contaminated with Bacillus cereus. Presence of B. cereus in these milk products is of particular concern considering the majority of consumers are infants and children. Possible sources of contamination are contaminated raw milk, cross-contamination during processing, under-processing and mishandling of milk products. This study was conducted to detect the presence of B. cereus in both formula milk (n=12) and UHT milk (n=20) sold in selected retail markets. The approach consisted of enumerating by MPN/g followed by PCR assay aimed at detecting gyrB gene in B. cereus, that encode for the subunit B protein of DNA gyrase (topoisomerase type II). Contamination level of B. cereus in both types of samples examined ranged from 1100 MPN/g. The contamination level of B. cereus was found to be highest in full cream UHT milk (> 1100 MPN/g) and formula milk (> 1100 MPN/g). The PCR analysis showed that 41.7% (5/12) formula milk and 30% (6/20) UHT milk samples were detected with B. cereus, respectively. This is the first report of such study demonstrating the presence of B. cereus in formula milk from Malaysia. Therefore, constant surveillance of these milk products would reduce the potential risk of B. cereus-linked outbreaks

Performance of a pilot-scale biofilters and constructed wetland with ornamental plants in greywater treatment

Partially treated black water from septic tanks and grey water from households in Kuching City were polluting the Sarawak River. A pilot scale ecological sanitation was implemented where blackwater was held in septic tanks and greywater was channeled to a grease trap, biofilters and a constructed wetland before discharge. The objectives of this study were to evaluate the efficiency of the biofilters and the constructed wetland with two species of terrestrial ornamental plants in greywater treatment. For the combined system, results indicated that the influent dissolved oxygen of below 1 mg/L improved to 3.4-4.6 mg/L. Removal of biochemical oxygen demand (BOD ) and chemical oxygen demand (COD) were the highest (99 and 95%). 5 Influent fecal coliform (FC) of 4.0x105 CFU/100mL dropped to 6.3x102 CFU/100mL at the effluent. More than 80% of ammonia-nitrogen (NH -N), total nitrogen (TN) and total suspended solids (TSS) were removed. Reactive 4 phosphorus (RP) and total phosphorus (TP) removals were 64 and 61% respectively. The biofilters contributed most of the total removal of BOD , COD, FC and NH -N. However, the wetland and biofillters were equally 5 4 efficient in TSS removal. The removal efficiency of the wetland in decreasing order was NO -N>FC> 3 TSS>BOD >TN>COD>NH -N>RP>TP and all removals exceeded 55% with the exception of P (38-39%). Both 5 4 species of plants grown on the wetland contained significantly higher weight and P content than the control. Tissue P content of F. microcarpa was significantly higher than S. campanulatum indicating F. microcarpa as a better accumulator of P. This indicates that constructed wetland with F. microcarpa could be potentially implemented in urban housing areas to reduce river pollution

Treatment of domestic wastewater in Kuching City - ecological sanitation

In Kuching, partially treated black water from septic tanks and grey water are discharged into stonn water drains and subsequently into the rivers. Discharge from households was the main pollution source of the Sarawak River. The option of urban ecological sanitation was explored by the Sarawak Government. Ecological sanitation involves separating wastewater at source and recycling of the nutrients. A pilot project of ecological sanitation was implemented. Grey water from selected households were clmmeled to a grease trap and then pumped to biofilters before flowing through a constructed wetland with two species of ornamental plants before discharge. The objective of this study was to deternline the efficiency of the biofilters and the constructed wetland. Results of six months of sampling indicated that there was significant improvement in water quality in terms of dissolved oxygen (DO), total suspended solids (TSS), reactivephosphorus (RP), total-phosphorus (TP), anunonia-nitrogen (AN), total nitrogen (TN), biochemical oxygen demand (BODs), chemical oxygen demand (COD) and fecal coliform counts. The influent DO of below 1 mg/L improved to 3.4 - 4.6 mglL in the effluent. Removals of BODs and COD were the highest .with means of 99 and 95% respectively. Removal of nitrogen were also high, 86% (AN) and 81 % (TN) respectively. Total removal of TSS was 81 %. Removal of phosphorus, though not as high were 64 (RP) and 61 % (TP). The biofilter contributed most of the total removal especially organic matter (97% for BODs and 92% for COD) followed by nitrogen (78% for AN, 62% for TN) and then phosphorus (66% for RP and 61 % for TP). The wetland contributed 53% of total removal ofTSS and 22-41 % of nutrients and 46% of the total increase in DO. The fecal coliform count in the influent was reduced by 99 % after the biofilter treatment. In teffilS of BODs, COD and TSS, the effluent complied with the effluent standard A of Environmental Quality Act 1974 (Sewage and Industrial Effluents). Furthermore, WQI indicated that the effluent quality of water improved from Class V to Class II. Therefore, this cost effective method of urban sanitation is highly recommended

Presence of Bacillus cereus s.l. from ready-to-eat cereals (RTE) products in Sarawak

Bacillus cereus is a soil inhabitant gram positive bacterium, and is known to cause severe food poisoning. The objective of this study was to isolate and identify the presence of Bacillus cereus s.l. from selected ready to eat cereals purchased randomly from local supermarkets in Kuching and Kota Samarahan, Sarawak. The result showed that four of the 30 food samples were detected to be contaminated by B. cereus s.l.. Our findings suggested that it is important for the public to be aware of the safety of RTE cereals consumption, as it is possible that B. cereus s.l. may be present in high count number and pose hazardous health effects to the consumers

Assessment of the characteristic of nutrients, total metals, and fecal coliform in Sibu Laut River, Sarawak, Malaysia

The concentrations of nutrients (nitrogen and phosphorus), total metals, and fecal coliform (FC) coupling with chlorophyll-a (chl-a), 5-day biochemical oxygen demand (BOD5) and other general environmental parameters were evaluated at the sub-surface and near-bottom water columns of 13 stations in the Sibu Laut River during low and high slack waters. The results indicated that inorganic nitrogen (mainly nitrate) was the primary form of nitrogen whereas organic phosphorus was the major form of phosphorus. The abundance of total heavy metals in Sibu Laut River and its tributaries was in the order of Pb\Cu\Zn\Cd. Fecal coliform concentration was relatively low along Sibu Laut River. The shrimp farm effluents contributed a substantial amount of chl-a, BOD5, nutrients, and FC to the receiving creek except for total metals. Nevertheless, the influence was merely noticeable in the intake creek and amended rapidly along Selang Sibu River and brought minimal effects on the Sibu Laut River. Besides, the domestic sewage effluents from villages nearby also contributed a substantial amount of pollutants

Characterization of Escherichia coli isolated from cultured catfish by antibiotic resistance and RAPD analysis

Antibiotic susceptibility and genetic diversity of E. coli isolated from cultured catfish and their surrounding environment were determined. The levels of resistance of the E. coli isolates towards six different antibiotics tested differed considerably. Though the isolates displayed resistance towards some of the antibiotics tested, none of the isolates showed resistant towards norfloxacin, sulphametoxazole/trimethoprim and chloramphenicol. RAPD-PCR analysis using single primer and primers combination clustered the E. coli isolates into 3 and 5 groups, respectively. The results of this study suggest that the E. coli isolates from the catfish and their surrounding environment derived from a mixture of sensitive and resistant strains with diverse genetic contents. The use of the RAPD analysis is sufficiently discriminatory for the typing of the E. coli isolates

Epidemiological study of human intestinal parasites in Sarawak, East Malaysia: A review

Intestinal parasitic infections are endemic in rural settings and may account for asymptomatic infections to various health complications. These infections are a cause of concern for communities of lower economic status, especially in developing countries. In Sarawak, indigenous populations residing in geographically inaccessible areas are socially and economically disadvantaged. Through close association with nature, these populations are prone to intestinal parasitism. Currently, scattered information has led to a continual state of neglect at each level of parasitic infection control. This urges for a review of their distribution and transmission based on previous reports to understand the pattern of the diseases in the state which can further address the improvement of mass controlling programs. A literature search was conducted to collect previous reports on human intestinal parasites in Sarawak, East Malaysia from PubMed (Medline), SCOPUS, ScienceDirect and Web of Science from January 2019 to March 2021. Extrapolating the current data in Sarawak which is still considered limited, further interdisciplinary strategies are demanded to give insights in the epidemiology and true prevalence of intestinal parasites in Sarawak. This review addresses for redirection of attitude towards intestinal parasitic infections where it should be given with ample attention by rural populations. In tandem to that, improvement of rural livelihood such as standard of living and sanitation in Sarawak should be accredited as part of the efforts to reduce the number of intestinal parasitic infections in the state. As a control measure, mass deworming should be reconsidered especially to the rural populations

Diversity of Leptospira spp. in Rats and Environment from Urban Areas of Sarawak, Malaysia

Various prevalence studies on Leptospira in animals and humans, as well as environmental samples, had been conducted worldwide, includingMalaysia. However, limited studies have been documented on the presence of pathogenic, intermediate, and saprophytic Leptospira in selected animals and environments. This study was therefore conducted to detect Leptospira spp. in rats, soil, and water from urban areas of Sarawak using the polymerase chain reaction (PCR) method. A total of 107 rats, 292 soil samples, and 324 water samples were collected fromApril 2014 to February 2015. Pathogenic Leptospira was present in 5.6% (6/107) of rats, 11.6% (34/292) of soil samples, and 1.9% (6/324) of water samples. Intermediate Leptospira was present in 2.7% (8/292) of soil samples and 1.9% (6/324) of water samples. Saprophytic Leptospira was present in 10.3% (11/107) of rats, 1.4% (4/292) of soil samples, and 0.3% (1/324) of water samples. From this study, 76 Leptospira spp. were isolated. Based on DNA sequencing, the dominant Leptospira spp. circulating in urban areas of Sarawak are pathogenic Leptospira noguchii, intermediate Leptospira wolffii serovar Khorat, and saprophytic Leptospirameyeri, respectively.Overall, this study provided important surveillance data on the prevalence of Leptospira spp. from rats and the environment, with dominant local serovars in urban areas of Sarawak