Non-albicans Candida species are emerging in the nosocomial environment, with the multidrug-resistant (MDR) species Candida auris being the most notorious example. Consequently, rapid and accurate species identification has become essential. The objective of this study was to evaluate five commercially available chromogenic media for the presumptive identification of C. auris Two novel chromogenic formulations, CHROMagar Candida Plus (CHROMagar) and HiCrome C. auris MDR selective agar (HiMedia), and three reference media, CandiSelect (Bio-Rad), CHROMagar Candida (CHROMagar), and Chromatic Candida (Liofilchem), were inoculated with a collection of 9 genetically diverse C. auris strains and 35 strains from closely related comparator species. After 48 h of incubation, the media were evaluated for their ability to detect and identify C. auris All media had the same limitations in the differentiation of the more common species Candida dubliniensis and Candida glabrata Only on CHROMagar Candida Plus did C. auris colonies develop a species-specific coloration. Nevertheless, the closely related pathogenic species Candida pseudohaemulonii and Candida vulturna developed a similar appearance as C. auris on this medium. CHROMagar Candida Plus was shown to be superior in the detection and identification of C. auris, with 100% inclusivity for C. auris compared to 0% and 33% for the reference media and HiCrome C. auris MDR selective agar, respectively. Although C. vulturna and C. pseudohaemulonii can cause false positives, CHROMagar Candida Plus was shown to be a valuable addition to the plethora of mostly molecular methods for C. auris detection and identification.
Langat (LGT) virus, initially isolated in 1956 from ticks in Malaysia, is a naturally occurring nonpathogenic virus with a very close antigenicity to the highly pathogenic tick-borne encephalitis (TBE) Western subtype virus and TBE Far Eastern subtype virus. NS3, the second largest viral protein of LGT virus, is highly conserved among flaviviruses and contains a characteristic protease moiety (NS3 pro). NS3 pro represents an attractive target for anti-protease molecules against TBE virus. We report herein a purification method specially designed for NS3 pro of LGT using a strategy for proper refolding coupled with the enzymatic characterisation of the protein. Different p-nitroanilide substrates, defined on canonic sequences for their susceptibility to Ser-protease, were applied to the proteolytic assays of the protein. The highest values were obtained from substrates containing an Arg or Lys (amino acid) residue at the P1 position. This purification method will facilitate the future development of reliable testing procedures for anti-proteases directed to NS3 proteins.
The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.
A modified version of the standard 2-site sporozoite enzyme-linked immunosorbent assay (ELISA) using 3,3',5,5'-tetramethylbenzidine (TMB) as the substrate chromogen solution was adapted for rapid detection and identification of Plasmodium falciparum and P. vivax circumsporozoite (CS) proteins. The TMB-ELISA was evaluated using sporozoites from experimentally infected mosquitoes and laboratory colonized uninfected mosquitoes. Our data indicate comparable sensitivity levels between the TMB-ELISA and the standard ELISA, i.e., 50 P. falciparum or P. vivax sporozoites/50 microliters of test solution. Reactions inherent to the method were specific and background reactivity was minimal. The TMB-ELISA is rapid (1 hr), simple, uses a minimal amount of monoclonal antibodies, and is suitable for use in a wide range of laboratories.