Backgound: Dengue vector control using chemical insecticides for a long time on the same target encourages the rapid development of a resistant dengue vector population of Aedes aegypti. Therefore, ...an alternative method is needed in the form of the use of plant-based insecticides, Lansium domesticum or duku has been proven to contain secondary metabolites that have the potential as insecticides. This study was conducted to measure the activity of enzyme esterase and glutathione S-transferase, as well as to observe the concentration of inorganic substances such as Fe, Mg, Na, and K in Ae. aegypti larvae exposed to L. domesticum extract using methanol as the solvent and fractionation using hexane, butanol, and ethyl acetate as the solvents. Methods: This study used Ae. aegypti larvae and L. domesticum leaves extract and fraction. Esterase activity was measured using a spectrophotometer at λ = 490 nm and obtained as light absorption per minute per mg protein. GST activity was measured using a spectrophotometer at λ = 340 nm and expressed as light absorption per minute per mg protein. Inorganic substance level was evaluated by the absorbance of the atoms using an atomic absorption spectrophotometer which was analyzed at certain wavelengths of each atom according to Beer's law equation Results: The results showed LD50 and LD90 of the crude extract of L. domesticum were 2200ppm and 3200ppm after 24 hours of observation. Crude extract and the fraction of L. domesticum leaf influenced the development of Ae. Aegypti. It reduced the activity of the esterase enzyme. Meanwhile, it increased the GST enzyme activity of Ae. aegypti larvae as well as affects the levels of inorganic substances in Ae. aegypti larvae. Conclusion: Thus, L. domesticum as a plant-based insecticide is an alternative to control the vector whose target is more selective and safe.
Background. The clinical and microbiological characteristics of nontyphoidal Salmonella (NTS) meningitis in South Africa, where human immunodeficiency virus (HIV) prevalence is high (approximately ...15% in persons ≥15 years of age), were reviewed. Methods. From 2003 through 2013, 278 cases were identified through national laboratory-based surveillance. Clinical information (age, sex, outcome, Glasgow Coma Scale GCS, and HIV status) was ascertained at selected sites. Isolates were serotyped; susceptibility testing and multilocus sequence typing on Salmonella enterica serovar Typhimurium isolates was performed. Multivariable logistic regression was used to determine factors associated with mortality outcome, using Stata software, version 13. Results. Where age was ascertained, 139 of 256 (54.3%) patients were <15 years. Males represented 151 of 267 (56.6%). Mortality outcome was recorded for 112 of 146 (76.7%) enhanced surveillance patients; 53 of 112 (47.3%) died. Death was associated with GCS ≤13 (adjusted odds ratio OR, 18.7; 95% confidence interval CI, 3.0–118.5; P= .002) on multivariable analysis. Where data were available, all 45 patients aged >15 years were HIV infected, compared with 24 of 46 (52.2%) patients aged <5 years. Neonates were less likely to be HIV infected than infants aged 2–12 months (OR, 4.8; 95% CI, 1.1–21.1; P= .039). Salmonella Typhimurium represented 106 of 238 (44.5%) serotyped isolates: 65 of 95 (68.4%) were ST313 vs ST19, respectively, and significantly associated with HIV-infected patients (P= .03) and multidrug resistance (OR, 6.6; 95% CI, 2.5–17.2; P< .001). Conclusions. NTS meningitis in South Africa is highly associated with HIV in adults, with neonates (irrespective of HIV status), and with Salmonella Typhimurium ST313. GCS is the best predictor of mortality: early diagnosis and treatment are critical. Focused prevention requires further studies to understand the sources and transmission routes.
Ceramic waste materials from the production of titles has increased over the years. Preliminary studies on the properties of ceramics showed that this material can be incorporated into asphalt ...mixtures as aggregates. Laboratory tests were conducted to evaluate the feasibility of utilizing ceramic materials from tile manufacturing firms. A study was undertaken to look into the performance of crushed ceramics that were incorporated in asphalt mixtures to replace the conventional granite aggregates from sizes 5.0 mm down including the 75 micron filler. The replacement was done proportionally with a 0, 20, 40, 60, 80, and 100% percent by weight of granite aggregates. The outcome of the study showed that the performance of recycled ceramic aggregates in hot mix asphalt (HMA) reached an optimum at about 20% which means there is a great potential for the use of it in asphalt mixtures. The Marshall stability showed an increment of about 25% while the resilient modulus strength improved by 13.5% as compared with the control specimen. All samples were analyzed at various proportions of ceramic–granite aggregate combination and were observed that a 20% use of 5 mm down ceramic aggregates blended with granite aggregates produce higher strength HMA.
Background. A total of 720 Vibrio cholerae O1 strains were recovered for investigation from an outbreak of cholera in South Africa between November 2008 and April 2009. Methods. Strains were ...characterized by serotype testing. Antimicrobial susceptibility testing. Genetic diversity of 248 strains was investigated using pulsed-field gel electrophoresis (PFGE) analysis. Extended characterization was performed on 90 strains. Molecular analysis included: polymerase chain reaction (PCR) identification of ctxA and tcpA genes, sequencing the ctxAB gene, and investigation of molecular mechanisms conferring antimicrobial resistance. Results. The majority of strains were characterized as serotype Ogawa. Strains showed multidrug resistance. Approximately 1.0% of strains displayed extended-spectrum β-lactamase (ESBL) activity. Strains showed very similar PFGE patterns. Ninety strains selected for extended characterization showed the following results: Strains possessed the cholera toxin (CT) and all were PCR positive for the tcpA-El Tor variant. Sequencing of the ctxB gene matched the B-1 allele. Strains harbored the SXT element. Strains that displayed ESBL activity possessed a 140-kilo-base-pair plasmid that produced the TEM-63 β-lactamase. Nalidixic acid-resistant strains harbored mutations in GyrA (Ser83-Ile) and ParC (Ser85-Leu). Conclusions. These data highlight the rapid development of antimicrobial resistance and spread of V. cholerae O1 El Tor variants expressing the classical CT within South Africa.
Candida auris
is an invasive healthcare-associated fungal pathogen. Cases of candidemia, defined as illness in patients with
Candida
cultured from blood, were detected through national ...laboratory-based surveillance in South Africa during 2016–2017. We identified viable isolates by using mass spectrometry and sequencing. Among 6,669 cases (5,876 with species identification) from 269 hospitals, 794 (14%) were caused by
C. auris
. The incidence risk for all candidemia at 133 hospitals was 83.8 (95% CI 81.2–86.4) cases/100,000 admissions. Prior systemic antifungal drug therapy was associated with a 40% increased adjusted odds of
C. auris
fungemia compared with bloodstream infection caused by other
Candida
species (adjusted odds ratio 1.4 95% CI 0.8–2.3). The crude in-hospital case-fatality ratio did not differ between
Candida
species and was 45% for
C. auris
candidemia, compared with 43% for non–
C. auris
candidemia.
C. auris
has caused a major epidemiologic shift in candidemia in South Africa.
Electronic surveillance for antimicrobial resistance was established in 2013 for public sector laboratories and released annually. This article reports susceptibility data on ESKAPE pathogens for ...2016.
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