The established practice of sending blood cultures in an aerobic-anaerobic pair of bottles has been questioned in recent years, and this study was conducted to evaluate the routine use of an anaerobic bottle in the BACTEC blood culture set at the University of Malaya Medical Centre, Kuala Lumpur, from January to December 2004. A total of 11,663 paired blood culture sets were received, of which 3326 were from pediatric patients and 8337 were from adult patients. The overall positive isolation rate was 15%; the positive isolation rate on excluding the anaerobic bottles was 13%. Overall, there were significantly more organisms isolated from the aerobic bottle (p<0.05); however, the best yield was obtained on using the paired aerobic-anaerobic bottles. Among the positive blood culture sets, organisms were isolated from the anaerobic bottle alone in 15.2% of the pediatric sets and in 18.1% of the adult sets. Organisms that grew more frequently in the anaerobic bottle were anaerobes and some facultative anaerobes; however, the difference was not statistically significant except for anaerobes in the adult sets. We recommend that when culturing blood, an aerobic-anaerobic pair of bottles be used rather than an aerobic-aerobic pair, to optimize the recovery of a wider spectrum of organisms, including obligatory anaerobes.
Flavonoids are polyphenols that are important organic chemicals in plants. The health benefits of flavonoids that result in high commercial values make them attractive targets for large-scale production through bioengineering. Strategies such as engineering a flavonoid biosynthetic pathway in microbial hosts provide an alternative way to produce these beneficial compounds. Escherichia coli, Saccharomyces cerevisiae and Streptomyces sp. are among the expression systems used to produce recombinant products, as well as for the production of flavonoid compounds through various bioengineering approaches including clustered regularly interspaced short palindromic repeats (CRISPR)-based genome engineering and genetically encoded biosensors to detect flavonoid biosynthesis. In this study, we review the recent advances in engineering model microbial hosts as being the factory to produce targeted flavonoid compounds.
Toxinotype of Clostridium perfringens (CP) isolates collected from the Bernam River, Selangor River and Tengi Canal between April 2007 and January 2008 were determined by Polymerase Chain Reaction (PCR) using published primers. All the 147 isolates were toxinotype Type A, harbouring the alpha toxin gene. In addition, 5 of the isolates also had the enterotoxin (CPE) gene.
Assessment of amino acid decarboxylase activity can be conducted using tubed broth or plated agar. In this study, the test was carried out in microtitre plates containing lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final concentration of 6.0 x 10(7) cfu/ml and incubated at 35ºC. The absorbance of the culture broth was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A'(570) between 0 hour and a specified incubation time was determined statistically. Positive decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae in less than 6 hours. The current method is suitable for immediate producers of amino acid decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be used for screening aliquots of food materials for amino acid decarboxylase activities.
Burkholderia pseudomallei infections are prevalent in Southeast Asia and northern Australia and often misdiagnosed. Diagnostics are often neither sensitive nor rapid, contributing up to 50% mortality rate. In this 2018 pilot study, we enrolled 100 patients aged 6 months-79 years from Kapit Hospital in Sarawak, Malaysia, with symptoms of B. pseudomallei infection. We used three different methods for the detection of B. pseudomallei: a real-time polymerase chain reaction (PCR) assay, a rapid lateral flow immunoassay, and the standard-of-care bacterial culture-the gold standard. Among the 100 participants, 24 (24%) were positive for B. pseudomallei by one or more of the detection methods. Comparing the two individual diagnostic methods against the gold standard-bacterial culture-of any positive test, there was low sensitivity for each test (25-44%) but high specificity (93-98%). It seems clear that more sensitive diagnostics or a sensitive screening diagnostic followed by specific confirmatory diagnostic is needed for this disease.