Isolation and antibiotic susceptibility of bacteria from foot infections in the patients with diabetes mellitus type I and type II in the district of Kancheepuram, Tamil Nadu, India

Background:Diabetic foot infections are important cause of morbidity and mortality among persons with diabetes mellitus. The reported prevalence rates in India range from 0.9–8.3%. Diabetes foot lesions are the leading cause of non-traumatic amputations worldwide. A study has been conducted to isolate and find the antibiotic susceptibility pattern of the bacteria from diabetic foot infections from the patients of Kancheepuram district, Tamil Nadu, India.Methods:Sixty patients previously diagnosed or newly diagnosed as diabetic, presented with lower extremity infection attending Tagore medical college and hospital and its peripheral centres were selected for the study. Various specimens (pus, wound exudates, or tissues biopsy) for microbiological studies were obtained from the infected region. The specimens were cultured on blood agar and MacConkey agar for aerobic / facultative anaerobic organisms and on Neomycin Blood Agar for anaerobic organism. The plates were then incubated at 37°C. For anaerobic culture the plates were incubated in the McIntosh anaerobic jar. Isolates obtained are identified by standard laboratory techniques.Results:The result showed that Pseudomonas aeruginosa (48.3%) is the predominant bacterium followed by Staphylococcus aureus (38%) and other bacteria. The anaerobic bacteria are also isolated from the diabetic foot ulcers. The Peptostreptococcus species (26.7%) are the predominant bacteria followed by other bacteria. Further the results showed that 22 patients (37%) showed the multi-bacterial infection and remaining 38 patients (63%) showed mono bacterial infection. The drugs like amikacin, cefepine, ciprofloxacin, cotrimoxazole and roxythromycin are sensitive to many gram positive bacterial isolates.Conclusion:The present study has given the data of various bacteria encountered in the diabetic foot ulcer in the district of Kancheepuram, Tamil Nadu, India and its antibiotic sensitivity pattern. The results clearly reveal that there is no definite aetiology in diabetic foot infections. Many patients presented the infection with the involvement of many bacteria. Further it is evident that many bacteria are multi drug resistant and thus complicating the management of diabetic foot infections.

Green synthesis of magnesium oxide nanoparticles and their antibacterial activity

1210-1215Nanotechnology has prospects of opening new avenues to fight and prevent diseases using atomic-scale tailoring of materials. As the nano revolution emerges, it is imperative to develop “nano‑naturo” links between nanotechnology and green domains of the nature. The present investigation describes the mangrove Rhizophora lamarckii’s property of synthesizing magnesium oxide nanoparticles . The newly synthesized magnesium oxide nanoparticle morphology is nanohexagonal and spherical. The particles range in dimensions between 20 and 50 nm and are crystalline in nature. The functional groups of the mangrove, amine, and alkane are found to act as reductants and stabilizers. The newly synthesized MgO nanoparticles are found to have potent antibacterial activity

Methylparathion- and carbofuran-induced mitochondrial dysfunction and oxidative stress in Helicoverpa armigera (Noctuidae: Lepidoptera)

The cotton bollworm, Helicoverpa armigera is a polyphagous pest of several crops in Asia, Africa, and the Mediterranean Europe. Organophosphate and carbamate insecticides are used on a large-scale to control Helicoverpa. Therefore, we studied the effect of methylparathion and carbofuran, an organophosphate and carbamate insecticide, respectively, on oxidative phosphorylation and oxidative stress in H. armigera larvae to gain an understanding of the different target sites of these insecticides. It was observed that state III and state IV respiration, respiratory control index (RCI), and P/O ratios were inhibited in a dose-dependent manner by methylparathion and carbofuran under invitro and in vivo conditions. Methylparathion and carbofuran inhibited complex II by ∼ 45% and 30%, respectively. Lipid peroxidation, H2O2 content, and lactate dehydrogenase (LDH) activity increased and glutathione reductase (GR) activity decreased in a time- and dose-dependent manner in insecticide-fed larvae. However, catalase activity was not affected in insecticide-fed larvae. Larval growth decreased by ∼ 64 and 67% in larvae fed on diets with sub-lethal doses of methylparathion and carbofuran. The results suggested that both the insecticides impede the mitochondrial respiratory functions and induced lipid peroxidation, H2O2, and LDH leak, leading to oxidative stress in cells, which contribute to deleterious effects of these insecticides on the growth of H. armigera larvae, along with their neurotoxic effects

Characterization of dihydrolipoamide dehydrogenase from the mitochondria of Helicoverpa armigera, a pest resistant to insecticides

Dihydrolipoamide dehydrogenase (DHLDH) was isolated from the mitochondria of Helicoverpa armigera, a destructive pest which has developed resistance to commonly used insecticides. The flavoenzyme was purified 17.98-fold to homogeneity with an overall yield of 10.53% by employing ammonium sulfate precipitation, hydroxylapatite chromatography and CM-Sephadex chromatography. The purified enzyme exhibited the specific activity of 18.7 U/mg and was characterized as a dimer with a subunit mass of 66 kDa. The enzyme showed specificity for nicotinamide adenine dinucleotide – hydrogen (NADH) and lipoamide, as substrates, with Michaelis-Menten constants (Km) of 0.083 mmol/L and 0.4 mmol/L, respectively. The reduction reaction of lipoamide by the enzyme could be explained by ping-pong mechanism. The spectra of DHLDH showed the maximum absorbance at 420 nm, 455 nm and 475 nm. The enzyme activity was strongly inhibited by mercurial and arsenical compounds. The N-terminal sequence of Ha-DHLDH showed homology with those of mammalian and arthropod DHLDH. Since H. armigera has developed high levels of resistance to commonly used insecticides, biochemical properties of the metabolic enzymes such as DHLDH, could be helpful to develop insecticidal molecules for the control of H. armigera, with a different mode of action

Interaction of plant cell signaling molecules, salicylic acid and jasmonic acid, with the mitochondria of Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera is a polyphagous pest in Asia, Africa, and the Mediterranean Europe. Salicylic acid (SA) and jasmonic acid (JA) are the cell signaling molecules produced in response to insect attack in plants. The effect of these signaling molecules was investigated on the oxidative phosphorylation and oxidative stress of H. armigera. SA significantly inhibited the state III and state IV respiration, respiratory control index (RCI), respiratory complexes I and II, induced mitochondrial swelling, and cytochrome c release in vitro. Under in vivo conditions, SA induced state IV respiration as well as oxidative stress in time- and dose-dependent manner, and also inhibited the larval growth. In contrast, JA did not affect the mitochondrial respiration and oxidative stress. SA affected the growth and development of H. armigera, in addition to its function as signaling molecules involved in both local defense reactions at feeding sites and the induction of systemic acquired resistance in plants

Effect of pyrethroids, permethrin and fenvalarate, on the oxidative stress of Helicoverpa armigera

The cotton bollworm, Helicoverpa armigera is a polyphagous pest of several crops in Asia, Africa, and the Mediterranean Europe. Pyrethroid insecticides are used to control noxious insects in agriculture, forestry, households and horticulture. Therefore, the effect of permethrin and fenvalarate was evaluated on the oxidative stress in H. armigera. Lipid peroxidation, H2O2 content, and lactate dehydrogenase (LDH) activity increased and glutathione reductase (GR) activity decreased in a time- and dose-dependent manner in insecticide-fed larvae. However, catalase activity was not affected in insecticide-fed larvae. Larval growth decreased by ~ 64 and 70% in larvae fed on diets with sub-lethal doses of permethrin and fenvalarate. The results suggested that both the insecticides induced lipid peroxidation, H2O2, LDH leak, and altered antioxidant enzymes leading to oxidative stress in cells, which contribute to deleterious effects of these insecticides on the growth of H. armigera larvae, along with their neurotoxic effects

Occurrence and distribution of black pod rot of Cocoa (Theobromae cocoa L.) in southern transition zone of Karnataka

Straminipile genus Phytophthora cause significant disease losses to global cocoa production. Phytopthtora palmivora is one of the major constraints in cocoa production causes significant pod losses. P. palmivora has a complex disease cycle involving several sources of primary inoculum and several modes of dissemination of secondary inoculum. This results in explosive epidemics during favorable environmental conditions. Highest severity of Seedling blight was observed in raised bed nurseries as compared to poly bag nurseries in Shivamogga district (59.26%) followed by Chikkamagluru (53.85%) of the state Karnataka , respectively. Further, the highest incidence of 72.00, 70.83 and 70.00% of black pod rot disease was recorded in Udupi, Dakshina Kannada and Shivamogga district followed by Chikkamagaluru (65.22%), Kodagu (64.00%) and Davanagere (55.56%) district respectively. Due to continuous rain fall or high moisture conditions and the crop was grown as intercrop with arecanut is vulnerable for the attack of pathogen due to the presence of pathogenic variability

Cloning and characterization of the Plasmodium falciparum adenylosuccinate synthetase gene

The cloning and deduced amino acid sequence of Plasmodium falciparum adenylosuccinate synthetase (PfADSS) are reported. PfADSS exhibited 67% homology with the human enzyme. On expression in Escherichia coli, enzymatically active ADSS was produced as deduced by functional complementation analysis. The PfADSS activity was inhibited by hadacidin, a known competitive inhibitor of this enzyme. Nucleotide sequence data are available at GenBank under accession number AF095282

Imidacloprid impedes mitochondrial function and induces oxidative stress in cotton bollworm, Helicoverpa armigera larvae (Hubner: Noctuidae)

Neonicotinoids have high agonistic affinity to insect nicotinic acetylcholine receptors (nAChR) and are frequently used as insecticides against most devastating lepidopteran insect pests. Imidacloprid influenced dose-dependent decline in the state III and IV respiration, respiration control index (RCI), and P/O ratios, in vitro and in vivo. The bioassay indicated its LD50 value to be 531.24 μM. The insecticide exhibited a dose-dependent inhibition on F0F1-ATPase and complex IV activity. At 600 μM, the insecticide inhibited 83.62 and 27.13% of F0F1-ATPase and complex IV activity, respectively, and induced the release of 0.26 nmoles/min/mg protein of cytochrome c. A significant dose- and time-dependent increase in oxidative stress was observed; at 600 μM, the insecticide correspondingly induced lipid peroxidation, LDH activity, and accumulation of H2O2 content by 83.33, 31.51 and 223.66%. The stress was the maximum at 48 h of insecticide treatment (91.58, 35.28, and 189.80%, respectively). In contrast, catalase and superoxide dismutase were reduced in a dose- and time-dependent manner in imidacloprid-fed larvae. The results therefore suggest that imidacloprid impedes mitochondrial function and induces oxidative stress in H. armigera, which contributes to reduced growth of the larvae along with its neurotoxic effect