Occurrence of K1 and K2 serotypes and genotypic characteristics of extended spectrumβ-lactamases-producing Klebsiella pneumoniae isolated from selected hospitals in Malaysia

Objective:To determine the distribution,phenotypic and genetic background of extended spectrumβ-lactamases(ESBL)-producing Klebsiella(K.)pneumoniae clinical isolates associated with K1 and K2 serotypes in two selected hospitals in Malaysia.Methods:A total of 192 K.pneumoniae isolates were collected and subjected to antibiotic susceptibility,hypermucoviscosity test and multiplex PCR to detect the presence of K1-and K2-serotype associated genes.Multilocus sequence typing(MLST)was performed on ESBL-producing K.pneumoniae isolates presented with K1 and K2 serotypes,followed by phylogenetic analysis.Results:A total of 87 out of 192(45.3%)of the K.pneumoniae isolates collected were ESBL producers.However,only 8.3%(16/192)and 10.9%(21/192)of the total isolates were detected to carry K1-and K2-serotype associated genes,respectively.Statistical analysis showed that K1 and K2 capsular serotypes were not significantly associated with ESBL phenotype(P=0.196).However,they were significantly associated with hypervirulent,as demonstrated by the positive string test(P<0.001).MLST analysis revealed that ST23 as the predominant sequence type(ST)in the K1 serotype,while the ST in the K2 serotype is more diverse.Conclusions:Although the occurrence of ESBL-producing isolates among the hypervirulent strains was low,their coexistence warrants the need for continuous surveillance.MLST showed that these isolates were genetically heterogeneous.

Microbiology laboratory and the management of motherchild varicella-zoster virus infection

Varicella-zoster virus, which is responsible for varicella(chickenpox) and herpes zoster(shingles), is ubiquitous and causes an acute infection among children, especially those aged less than six years. As 90% of adults have had varicella in childhood, it is unusual to encounter an infected pregnant woman but, if the disease does appear, it can lead to complications for both the mother and fetus or newborn. The major maternal complications include pneumonia, which can lead to death if not treated. If the virus passes to the fetus, congenital varicella syndrome, neonatal varicella(particularly serious if maternal rash appears in the days immediately before or after childbirth) or herpes zoster in the early years of life may occur depending on the time of infection. A Microbiology laboratory can help in the diagnosis and management of mother-child infection at four main times:(1) when a pregnant woman has been exposed to varicella or herpes zoster, a prompt search for specific antibodies can determine whether she is susceptible to, or protected against infection;(2) when a pregnant woman develops clinical symptoms consistent with varicella, the diagnosis is usually clinical, but a laboratory can be crucial if the symptoms are doubtful or otherwise unclear(atypical patterns in immunocompromised subjects, patients with post-vaccination varicella, or subjects who have received immunoglobulins), or if there is a need for a differential diagnosis between varicella and other types of dermatoses with vesicle formation;(3) when a prenatal diagnosis of uterine infection is required in order to detect cases of congenital varicella syndrome after the onset of varicella in the mother; and(4) when the baby is born and it is necessary to confirm a diagnosis of varicella(and its complications), make a differential diagnosis between varicella and other diseases with similar symptoms, or confirm a causal relationship between maternal varicella and malformations in a newborn.

Dengue and falciparum malaria co-infection in travelers returning from Burkina Faso:Report of two cases in Northeastern Italy

Rationale: Malaria and dengue are the most prevalent vector-borne diseases in tropical countries. Plasmodium parasite and dengue virus(DENV) concurrent infection is possible and often under-recognized in geographical areas where these infections are both endemic.Patients concern and diagnosis: We describe the first two cases of Plasmodium falciparum and DENV-3 co-infection in travelers returning to northeastern Italy from Burkina Faso during 2013-2014.Interventions: Malaria infection in both patients was treated with mefloquine. Due to the persistence of symptoms despite of the antimalaria treatment, dengue was also investigated;the treatment of dengue was symptomatic.Outcomes: The patients were discharged in good general condition.Lessons: The need for surveillance of potential malaria and dengue co-infection in travelers returning to Europe from endemic areas is highlighted, as infection with Plasmodium does not exclude arboviral co-infection.

Urinary Tract Infections in a Tunisian Orthopedic Institute: Major Strain Microbiological Profile

Background: Urinary Tract Infection (UTI) detected in the hospital and in the community is one of the most common reasons for consultation in everyday practice;it represents a major source of antibiotic consumption. This study’s objectives were to outline the microbiological profile of Tunisian patients with UTI and assess antibiotic resistance over the course of three years at the Orthopedic Institute. Methods: All strains identified in urine samples between January 1st, 2019, and December 31st, 2021, were included. Standard laboratory procedures were used to identify the bacterium. The Microscan Walkway 40 Plus was used to do biochemical assays and antibiotic susceptibility testing. The EUCAST criteria were used to interpret the findings. Results: A total of 1313 strains were isolated. The bacteriological study showed the predominance of enterobacteria (96.8%), especially E. coli (52.2%) and K. pneumoniae (19.3%). Overall resistance rates to antimicrobial agents were as follows: for hospital, E. coli strains were in descending order amoxicillin (73.05%), trimeth/sulfamethoxazole (46.9%), ofloxacin (40.3%), amoxicillin/clavulanic acid (35.05%) and gentamicin (20.5%). Our results showed low resistance to fosfomycin for E. coli 2.6% in hospitals while ≥12.1% for K. pneumoniae. Amikacin resistance remains medium-low for E. coli being ≥20% and 10% for K. pneumonia. Nitrofuran resistance has affected 1.06% of E. coli strains in hospital settings and 21.5% of K. pneumoniae. Extended Spectrum Beta-Lactamases (ESBLs) production was present in a number of enterobacteria (19.3% of K. pneumoniae and 14.4% of E. coli). Conclusion: The prevalence of E. coli and K. pneumoniae producers ESBLs in UTI is increasing. Rigorous surveillance of resistance rate is necessary to determine appropriate empirical treatment and limit the spread of multiresistant strains.

Prevalence of Some World Health Organization Priority Organisms from an Abattoir at Kwata, Anambra State, Nigeria

The abattoir is one of the important sectors in the food industry, therefore the need for close monitoring of everything concerning it to minimize microbial contamination. The aim of the study is to identify bacteria listed as WHO priority organisms associated with meat from Kwata abattoir in Awka, Anambra state. The study was carried out over a three (3) months period from September to December 2022. Thirteen samples were collected from the floor, table, water, meat, knife and soil in the abattoir. The samples were cultured using streak and spread plate methods on MacConkey and Cetrimide agar. The isolates were identified with the following biochemical tests: catalase, oxidase, citrate and indole tests. Ampiclox levofloxacin, gentamicin, ofloxacin impenem ceftraixone, cefixime, cefuroxime and nitrofurantoin were used for sensitivity test following Kirby Bauer disc diffusion method and biofilm formation was determined using the tube method. The 75 isolates obtained were identified as follows;29.3% E. coli, 26.7% Klebsiella spp., 16% Proteus spp., and 28% Pseudomonas spp. The result of antibiotics sensitivity test interpreted using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints showed that (98%) of the isolates were resistant to the antibiotics used. Test for biofilm formation with 52 isolates showed 31 strong, 12 moderate and 9 weak biofilm formers. The result of this study confirms the presence of bacteria contaminants within the WHO priority list in the abattoir, as such there is need for improved handling of animals. Slaughtering, cleaning and distribution of meat should be done using aseptic procedures. .

In Vitro Evaluation of the Antifungal Activity of Essential Oils of Thymus vulgaris and Cymbopogon citratus on Some Strains of Sclerotinia sclerotiorum, Agent Responsible for White Rot of Beans

The present work was aimed to the study of the antifungal activity of essential oils of two aromatic plants against three strains of Sclerotinia sclerotiorum responsible for white rot of bean. The two essential oils (EO) of the studied plants: Thymus vulgaris (HET) and Cymbopogon citratrus (HEC), used at different concentrations: C1 (0.75 ml/ml), C2 (1.5 ml/ml) and C3 (3 ml/ml) presented significant inhibitory activities on the three tested fungal strains namely Bia 1, Bia 2, and Njo 2. Two control treatments (T-: containing no antifungal substance and T+: synthetic fungicide) were also used. The antifungal activity here is related to the inhibition of mycelial growth especially with high concentrations of essential oils. Thus, against S. sclerotiorum, HET showed the highest activity comparable to that of T+ (100% inhibition) at all concentrations on the Bia 1 and Bia 2 strains and at concentration C3 on the Njo 2 strain compared to that of HEC, which certainly inhibited the mycelial growth of the different strains considerably (with a maximum of 78.15% on the Njo 2 strain) but not completely. According to their sensitivity, the Bia 2 strain showed a higher sensitivity to essential oils than the others while the Njo 2 strain was more aggressive. On the basis of MIC50 and MIC90 obtained on the Njo 2 strain, the HET turns out to be the most efficient with respective lower values of (1.73 and 23.34 ml/ml) against (4.76 and 26.03 ml/ml) for the HEC. These EO could thus be exploited as biodegradable antifungal substances, likely to control white rot of bean.

多重PCR检测万古霉素耐药的肠球菌

目的检测2005～2007年澳大利亚墨尔本地区万古霉素耐药的肠球菌基因。方法用多重PCR检测肠球菌4种耐药基因(vanA,vanB,vanC1和vanC2),鉴定4种肠球菌E.faecalis(粪肠球菌),E.faecium(屎肠球菌),E.gallinarum(母鸡肠球菌)和E.casseliflavus(产黄肠球菌)。结果vanA基因扩增阳性可见732bp条带;vanB基因为635bp条带;vanC1基因为822bp条带;vanC2/3基因为439bp条带。粪肠球菌基因扩增见941bpDNA条带,屎肠球菌为550bpDNA条带。3年回顾性研究中,最常见的万古霉素耐药基因是vanB型(84.9%),菌种是屎肠球菌(76.3%)。2007年还出现2株同时含有vanA和vanB耐药基因的屎肠球菌菌株。结论万古霉素耐药的肠球菌菌株逐年增多,多重PCR检测万古霉素耐药的肠球菌,简便迅速,有利于准确及时地发出报告。

Serological diagnosis of Epstein-Barr virus infection: Problems and solutions

Serological tests for antibodies specific for Epstein-Barr virus(EBV) antigens are frequently used to define infection status and for the differential diagnosis of other pathogens responsible for mononucleosis syndrome. Using only three parameters [viral capsid antigen(VCA) Ig G, VCA Ig M and EBV nuclear antigen(EBNA)-1 Ig G],it is normally possible to distinguish acute from past infection: the presence of VCA Ig M and VCA Ig G without EBNA-1 Ig G indicates acute infection, whereas the presence of VCA Ig G and EBNA-1 Ig G without VCA Ig M is typical of past infection. However, serological findings may sometimes be difficult to interpret as VCA Ig G can be present without VCA Ig M or EBNA-1 Ig G in cases of acute or past infection, or all the three parameters may be detected simultaneously in the case of recent infection or during the course of reactivation. A profile of isolated EBNA-1 Ig G may also create some doubts. In order to interpret these patterns correctly, it is necessary to determine Ig G avidity, identify anti-EBV Ig G and Ig M antibodies by immunoblotting, and look for heterophile antibodies, anti-EA(D) antibodies or viral genome using molecular biology methods. These tests make it possible to define the status of the infection and solve any problems that may arise in routine laboratory practice.

H pylori infection and other risk factors associated with peptic ulcers in Turkish patients: A retrospective study

AIM: To identify and evaluate the relative impact of H pylori infection and other risk factors on the occurrence of gastric ulcer (GU), duodenal ulcer (DU) and gastritis in Turkish patients. METHODS: A total of 4471 patients (48.3% female) out of 4863 attended the Samatya hospital in Istanbul (June 1999 - October 2003) were included. The records of H pylori status (CLO-test), endoscopic f indings of GU, DU and gastritis, personal habits (smoking, alcohol intake) and medication [non-steroidal anti-inflammatory drugs (NSAIDs), aspirin intake] were analyzed using multi-way frequency analysis. RESULTS: We have found that GU in the presence of H pylori had significant association with aspirin (P = 0.0001), alcohol (P = 0.0090) and NSAIDs (P = 0.0372). DU on the other hand had significant association with aspirin/ smoking/NSAIDs (P = 0.0259), aspirin/alcohol (P = 0.0002) and aspirin/smoking (P = 0.0233), also in the presence of H pylori. In the absence of H pylori GU had significant association with alcohol/NSAIDs (P = 0.0431), and NSAIDs (P = 0.0436). While DU in the absence of H pylori had significant association with smoking/alcohol/ NSAIDs (P = 0.0013), aspirin/NSAIDs (P = 0.0334), aspirin/alcohol (P = 0.0360). CONCLUSION: In the presence of H pylori, aspirin, alcohol and NSAIDs intake act as an independent risk factors that had an augmenting impact on the occurrence of GU and only together on the occurrence of DU in Turkish patients.

Isolation and identification of bioactive antibacterial components in leaf extracts of Vangueria spinosa(Rubiaceae)

Objective:The column chromatographic fraction of ethyl acetate(EA1,EA2,EA3,EA4 and EA5) leaf extracts of Vangueria spinosa(V.spinosa) were screened for antibacterial activity and phytochemical analysis.Methods:EA3 fraction was isolated and identified by column chromatography,thin layer chromatography,spectral data analysis and phytochemical screening were used for analysis.Results:EA3 fraction was significantly active at 4 to 64 mg/L against Staphylococcus aureus,Escherichia coli,Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.1250 mg/mL.The active fraction(EA3) revealed the presence of flavonoid with retention factor value(R_f) of 0.39.The active antibacterial agent in the most potent fraction(EA3) was isolated and identified as flavonoid(-)-epicatechin-3-O-β-glucopyranoside by thin layer chromatography(TLC) and phytochemical screening.EA1 and EA2 show inhibitory activity at 4 to 64 mg/L against Staphylococcus aureus only where as fraction EA4 and EA5 do not shows any inhibitory activity within that range of concentration against any bacteria.Conclusions:The results support the ethnomedicinal use of leaf of V.spinosa for the treatment of bacterial diseases.

Isolation and identification of antibacterial components in seed extracts of Argemone mexicana L.(Papaveraceae)

Objective:The column chromatographic fractions of chloroform(CH1,CH2,CH3) seed extracts of Argemone mexicana(A.mexicana) were screened for antibacterial activity and phytochemical analysis.Methods:CH3 fraction was isolated and identified by column chromatography,thin layer chromatography,spectral data analysis and phytochemical screening were used for analysis. Results:CH3 fraction was significantly active at 4 to 64 mg/mL against Staphylococcus aureus, Escherichia coli,Klebsiella pneumoniae and Pseudomonas aeruginosa with minimum inhibitory concentration of 1.5625 to 3.125 mg/mL.The active fraction(CH3) revealed presence of alkaloid with retention factor value of 0.44.The active antibacterial agent in the most potent fraction (CH3) was isolated and identified as N-demethyloxysanguinarine by thin layer chromatography (TLC) and phytochemical screening.The CH1 and CH2 fractions did not show inhibitory activity. Conclusions:The results support the ethnomedicinal use of seeds of A.mexicana for treatment of bacterial diseases.

Seroprevalence of Helicobacter pylori infection among students of a Nigerian University

Objective:To investigate the seroprevalence of Helicobacter pylori(H.pylori) infection among the undergraduate students of Nasarawa state University,Keffi,Nigeria.Methods:A total of 200 serum samples were collected from undergraduate students of Nasarawa State University, Keffi,and 100μL of each serum was aseptically transferred to the specimen well of an H.pylori antigen kit(Clinotech USA).The 2 distinctive red lines apearing in the control and test regions of the kit after 10 minufes indicated positive reaction.Results:Of the 200 students sampled, 108(54%) were seropositive.Analysis of seroprevalence of H.pylori revealed the correlation between infection prevalence and age.The infection prevalence was 45.5%among students aged 18-20,rose to the peak of 85.7%adults aged 31-40,dropped to 66.7%among those 41-50 years old,and continuously went down to 28.6%in the 51-year-old and above populaion.There was a statistically significant difference(using Chi-square) with respects to gender,age and type of infection(symptomatic or asymptomatic seropositive infection)(P【0.0S).Conclucions: Community Health Personnel should be aware of this microorganism as a potential cause of illness in children.Furthermore,the mode of transmission and possible means of controlling the bacterial infection among students or a community is of public health concern and requires further study.

Geographical distribution of the incidence of gastric cancer in Bhutan

AIM: To estimate the prevalence of gastric cancer(GC) in a cohort of patients diagnosed with GC and to compare it with patients diagnosed with all other types of gastro-intestinal(GI) cancer during the same period.METHODS: Between 2008 and 2013,five-year period,the medical records of all GI cancer patients who underwent medical care and confirm diagnosis of cancer were reviewed at the National Referral Hospital,Thimphu which is the only hospital in the country where surgical and cancer diagnosis can be made. Demographic information,type of cancer,and the year of diagnosis were collected.RESULTS: There were a total of 767 GI related cancer records reviewed during the study period of which 354(46%) patients were diagnosed with GC. There were 413 patients with other GI cancer including; esophagus,colon,liver,rectum,pancreas,gall bladder,cholangiocarcinoma and other GI tract cancers. The GC incidence rate is approximately 0.9/10000 per year(367 cases/5years per 800000 people). The geographic distribution of GC was the lowest in the south region of Bhutan 0.3/10000 per year compared to the central region 1.4/10000 per year,Eastern region 1.2/10000 per year,and the Western region 1.1/10000 per year. Moreover,GC in the South part was significantly lower than the other GI cancer in the same region(8% vs 15%; OR = 1.8,95%CI: 1.3-3.1,P = 0.05). Among GC patients,38% were under the age of 60 years,mean age at diagnosis was 62.3(± 12.1) years with male-to-female ratio 1:0.5. The mean age among patients with all other type GI cancer was 60 years(± 13.2) and male-tofemale ratio of 1:0.7. At time of diagnosis of GC,342(93%) were at stage 3 and 4 of and by the year 2013; 80(23%) GC patients died compared to 31% death among patients with the all other GI cancer(P = 0.08).CONCLUSION: The incidence rate of GC in Bhutan is twice as high in the United States but is likely an underestimate rate because of unreported and undiagnosed cases in the villages. The high incidence of GC in Bhutan could be attributed to the high prevalence of Helicobacter pylori infection that we previously reported. The lowest incidence of GC in Southern part of the country could be due to the difference in the ethnicity as most of its population is of Indian and Nepal origin. Our current study emphasizes on the importance for developing surveillance and prevention strategies for GC in Bhutan.

Fungal contamination of crude herbal remedies as a possible source of mycotoxin exposure in man

Objective:The documented evidence of toxigenic fungi and their toxic metabolites on medicinal plants,coupled with the ability of these toxins to resist decomposition and temperature treatments necessitated this study,with a view of surveying for a possible carry over into the final medicinal products.As such popular indigenous crude herbal preparations widely consumed for various ailments in south-western Nigeria,were screened for fungal contamination,mycoflora enumeration,flora mycotoxin productibility,detection and quantification of a potent human carcinogen(aflatoxin). Methods:Fungal contamination was assessed on acidified potato dextrose agar using the plate count method, while mycotoxin detection,extraction and quantification were achieved by the thin - layer chromatography and chemical confirmation techniques.Mycoflora were characterized by standard procedures.Results:The total plate count ranged from 1.80×10~4 CFU/ML to 1.1×10~5 CFU/ML and 2.00×10~3 CFU/ML to 1.38×10~5 CFU/ML for water and dry gin extracted preparations respectively.The mycoflora consisted of six genera(Aspergillus,Penicillium,Fusarium, Mucor,Alternaria and Rhizopus).Thirty-four percent(34%) of the potential toxigenic species(Aspergillus, Penicillium and Fusarium) produced mycotoxins in culture,while further characterization indicated production of aflatoxin Bl(42%),ochratoxin A(50%) and penicillic acid(8%) by the mycotoxigenic strains respectively. The aflatoxin content of the herbal medicines ranged between 0.004μg/kg and 0.345μg/kg.Conclusion:The study confirmed the carry over of the fungal contaminants and their toxic metabolites into the final herbal medicines in quantities that exceeded some of the available limits.The implication of this is that the chronic exposure to mycotoxins particularly aflatoxins as a result of long term consumption of these preparations,could lead to impaired growth, nutritional interference,immunologic suppression and hepatocellular carcinoma in the consumers.

Control of human filarial vector,Culex quinquefasciatus Say 1823(Diptera:Culicidae)through bioactive fraction of Cayratia trifolia leaf

Objective:To investigate the mosquito larvicidal activity of Cayratia trifolia(L.)Domin(Vitaceae:Vitales)(C.trifolia)which is distributed in many parts of India with medicinal properties as vector control is facing threat due to the emergence of resistance to synthetic insecticides.Methods:Young and mature leaves of C.trifolia were investigated for larvicidal activity against3rd instars larvae of Culex quinquefasciatus in different seasons throughout the year.The active fractions were extracted using six different solvents in a non-polar to polar fashion viz petroleumether,benzene,chloroform:methanol(1:1 v/v),acetone,absolute alcohol and distilled water.Dose dependent mortality was recorded against each solvent extract.Determination of LD_(50)and LD_(90)were executed through log-probit analysis using the most bioactive fraction.The fluctuations in mortality were statistically co-related through ANOVA analyses concerning different seasons and types of leaves as random variables.Justification of larvicidal activity was established through student's t-test.Costing effects were evaluated on the non-target water fauna under laboratory conditions.Thin layer chromatographic techniques were performed for phytochemical analysis and categorization of chemical personality of the active fractions using the most effective solvent extract following standard methods.Results:Significant variations in mortality rate were noted with respect to the type of leaves(mature and senescence),concentration of leaf extract and between seasons.The water extract among all the solvent extracts was found to induce cent percent mortality at 50 mg/L in test mosquito species within 24 h with a LD_(50)and LD_(90)value of 10.70 mg/L and 27.64 mg/L respectively.No significant mortality was recorded in non-target water population.Chromatographic analyses of the water extract revealed the presence of steroids,triterpene glycosides,essential oil,phenolics and diterpenes as secondary phytochemicals.Conclusions:Water extract of C.trifolia leaf promised as a cost effective and potent larvicidal agent against Culex quinquefasciatus.

Association of hepatitis C virus infection and diabetes in central Tunisia

AIM:To investigate hepatitis C virus(HCV) seroprevalence in Tunisian patients with diabetes mellitus and in a control group.METHODS:A cross-sectional study was conducted to determine the HCV seroprevalence in 1269 patients with diabetes(452 male,817 female) and 1315 nondiabetic patients,attending health centers in Sousse,Tunisia.HCV screening was performed in both groups using a fourth-generation enzyme immunoassay.RESULTS:In the diabetic group,17(1.3%) were found to be HCV-infected compared with eight(0.6%) in the control group,although the difference was not significant(P=0.057).Quantitative PCR was performed in 20 patients.Eleven patients were positive and showed HCV genotype 1b in all cases.CONCLUSION:Frequency of HCV antibodies was low in patients with diabetes and in the control group in central Tunisia,with no signifi cant difference between the groups.

Early gastric cancer:A challenge in Western countries

Early gastric cancer(EGC)is an invasive carcinoma involving only the stomach mucosa or submucosa,independently of lymph node status.EGC represents over 50%of cases in Japan and in South Korea,whereas it accounts only for approximately 20%of all newly diagnosed gastric cancers in Western countries.The main classification systems of EGC are the Vienna histopathologic classification and the Paris endoscopic classification of polypoid and non-polypoid lesions.A careful endoscopic assessment is fundamental to establish the best treatment of EGC.Generally,EGCs are curable if the lesion is completely removed by endoscopic resection or surgery.Some types of EGC can be resected endoscopically;for others the most appropriate treatment is surgical resection and D2 lymphadenectomy,especially in Western countries.The favorable oncological prognosis,the extended lymphadenectomy and the reconstruction of the intestinal continuity that excludes the duodenum make the prophylactic cholecystectomy mandatory to avoid the onset of biliary complications.

Mosquito larvicidal activity of some common spices and vegetable waste on Culex quinquefasciatus and Anopheles stephensi

Objective:To investigate the larvicidal activities of crude and chlor of orm:methanol(1:1 v/ v) extracts of some common spices(Cuminum cyminum,Allium sativum,Zingiber offinale, Curcuma longa) and vegetable waste(Solanum tuberosum germinated tuber) against Anopheles stephensi and Culex quinquefasciatus mosquito larvae.Methods:Larval mortality of above mosquito species were observed after 24,48 and 72 h of exposure to five concentrations of aqueous extract(0.1%,0.2%,0.3%,0.4%and 0.5%) and four concentrations(25,50,75 ppm) of chlor of orm:methanol(1:1 v/v) extract.The lethal concentration of individual spices or vegetable waste was determined by log-probit analysis(at 95%confidence level) and effect of crude and chlor of orm:methanol(1:1 v/v) extracts were recorded on non target organisms.Results: Relative mortality rate of both larval mosquito species were recorded in the following sequences: Cuminum cyminum】 Allium sativum】Zingiber offinale,Curcuma longa 】 Solanum tuberosum germinated tuber for crude extract,and efficacy of chlor of orm:methanol(1:1 v/v) extract were as follows:Curcuma longa 】 Zingiber offinale 】 Solanum tuberosum germinated tuber 】 Cuminum cyminum】 Allium sativum.Conclusions:Crude and chlor of orm:methanol(1:1 v/v) extract of Cuminum cyminum,Allium sativum,Zingiber offinale,Curcuma longa and Solanum tuberosum germinated tuber can be recommended effectively in mosquito control programmes at very low concentrations.No mortality and other abnormalities were noticed on non target organisms and further studies are needed to investigate the chemical structure of active principal which are responsible for larvicidal activity.

Effects of Carbon Source on Growth Characteristics and Lipid Accumulation by Microalga <i>Dictyosphaerium</i>sp. with Potential for Biodiesel Production

Sustainability and eco-friendliness have both engendered research on alternative replacement of fossil fuel. This study was aimed at determining the effects of varying levels of glucose (10 ~ 40 g/L), and glycerol (0.25 ~ 1.0 mL/L) on the heterotrophic and mixotrophic growth and lipid production by Dictyosphaerium sp. The microalga was cultivated in 2000 mL amber-coloured bottles each containing 1000 mL of a sterile modified BG-11 medium at pH of 7.3. Each bottle was inoculated with a one-week-old pure culture of the isolate (inoculum ratio = 15%) and incubated in the dark at room temperature (30°C ± 2°C) for 10 d. Dictyosphaerium sp. showed the ability to grow heterotrophically and mixotrophically on glucose and on glycerol as a sole carbon substrates. Biomass productivity and specific growth rates did not vary when the initial medium glucose was varied. Lipid accumulation was not dependent on the initial medium glycerol contents. The mean lipid content and productivity of the organism in the present study were high enough to be utilised for industrial processes. Growth and lipid accumulations were better in mixotrophic cultures than both heterotrophic and autotrophic. However, both were better than autotrophic. The percentage compositions of the major fatty acids from Dictyosphaerium sp. grown under different culture conditions show at least five components each. The carbon skeletons eluted ranged from C14 to C22. Oleic acid was a major component of all the fatty acids, which confirm the suitability of the use of the oil for biodiesel production.

Hepatitis delta virus: A fascinating and neglected pathogen

Hepatitis delta virus(HDV) is the etiologic agent of the most severe form of virus hepatitis in humans. Sharing some structural and functional properties with plant viroids, the HDV RNA contains a single open reading frame coding for the only virus protein, the Delta antigen. A number of unique features, including ribozyme activity, RNA editing, rolling-circle RNA replication, and redirection for a RNA template of host DNA-dependent RNA polymerase Ⅱ, make this small pathogen an excellent model to study virus-cell interactions and RNA biology. Treatment options for chronic hepatitis Delta are scarce and ineffective. The disease burden is perhaps largely underestimated making the search for new, specific drugs, targets, and treatment strategies an important public health challenge. In this review we address the main features of virus structure, replication, and interaction with the host. Virus pathogenicity and current treatment options are discussed in the light of recent developments.