RESUMO
Background & objectives: Previously there were reports from all over India about the changing spectrum of severe manifestations of Plasmodium falciparum malaria. Consequently, the present retrospective study was conducted to compare the severity of malaria caused by P. falciparum and P. vivax during 2007–08 and 2017–18. Methods: The present study was conducted on the patients admitted with severe malaria in a classified malaria ward of a tertiary care hospital in Bikaner, Rajasthan (Northwest India) during 2007–08 and 2017–18. It included adult patients of both sexes belonging to all age groups. The diagnosis was done by peripheral blood film (PBF), rapid diagnostic test (RDT), and validated by polymerase chain reaction (PCR). All patients were treated with intravenous oral quinine. The specific individual malaria complications registered in 2007–08 and 2017–18 were treated by following the standard WHO protocol. Results: In 2007–08, severe manifestations caused by P. falciparum were dominated by thrombocytopenia (25.98%) followed by jaundice (24.39%), multi-organ dysfunction (MODS) (16.66%), severe anemia (16.17%), cerebral malaria (5.39%), bleeding manifestation (3.92%) and shock (0.49%). While in the same year, P. vivax associated clinical spectrum of complications were observed to be dominated by thrombocytopenia (26.47%) followed by jaundice (25.00%), MODS (14.70%), severe anemia (5.88%), cerebral malaria (5.88%), renal failure (4.41%), bleeding manifestation (2.45%), shock (0.98%) and acute respiratory distress syndrome (ARDS) (0.49%). However, in 2017–18, the clinical spectrum of malaria complications caused by both species has changed. Relative to P. falciparum infections, P. vivax individual complications like thrombocytopenia (51.78%) (p<0.001) followed by jaundice (19.13%) (p<0.001) and severe anemia (4.22%) (p<0.05) were found to have increased significantly. Interpretation & conclusion: Over the last decade there is an apparent spatial and temporal shift in the clinical manifestations of severe malaria caused by the both Plasmodium species. As evident from the patient’s data from 2007–08 and 2017–18, the severity is more inclined towards Plasmodium vivax than Plasmodium falciparum malaria. Moreover, individual P. falciparum-associated complications were decreased significantly in the Bikaner region of Rajasthan, India
RESUMO
Bacteria have evolved various mechanisms to extract utilizable substrates from available resources and consequently acquire fitness advantage over competitors. One of the strategies is the exploitation of cryptic cellular functions encoded by genetic systems that are silent under laboratory conditions, such as the bgl (β-glucoside) operon of E. coli. The bgl operon of Escherichia coli, involved in the uptake and utilization of aromatic β-glucosides salicin and arbutin, is maintained in a silent state in the wild type organism by the presence of structural elements in the regulatory region. This operon can be activated by mutations that disrupt these negative elements. The fact that the silent bgl operon is retained without accumulating deleterious mutations seems paradoxical from an evolutionary view point. Although this operon appears to be silent, specific physiological conditions might be able to regulate its expression and/or the operon might be carrying out function(s) apart from the utilization of aromatic β-glucosides. This is consistent with the observations that the activated operon confers a Growth Advantage in Stationary Phase (GASP) phenotype to Bgl+ cells and exerts its regulation on at least twelve downstream target genes.