Spatially structured genetic diversity of the Amerindian yam (Dioscorea trifida L.) assessed by SSR and ISSR markers in Southern Brazil

Dioscorea trifida L. (Dioscoreaceae) is among the economically most important cultivated Amerindian yam species, whose origin and domestication are still unresolved issues. in order to estimate the genetic diversity maintained by traditional farmers in Brazil, 53 accessions of D. trifida from 11 municipalities in the states of São Paulo, Santa Catarina, Mato Grosso and Amazonas were characterized on the basis of eight Simple Sequence Repeats (SSR) and 16 Inter Simple Sequence Repeats (ISSR) markers. the level of polymorphism among the accessions was high, 95 % for SSR and 75.8 % for ISSR. the SSR marker showed higher discrimination power among accessions compared to ISSR, with D parameter values of 0.79 and 0.44, respectively. Although SSR and ISSR markers led to dendrograms with different topologies, both separated the accessions into three main groups: I-Ubatuba-SP; II-Iguape-SP and Santa Catarina; and III-Mato Grosso. the accessions from Amazonas State were classified in group II with SSR and in a separate group with ISSR. Bayesian and principal coordinate analyzes conducted with both molecular markers corroborated the classification into three main groups. Higher variation was found within groups in the AMOVA analysis for both markers (66.5 and 60.6 % for ISSR and SSR, respectively), and higher Shannon diversity index was found for group II with SSR. Significant but low correlations were found between genetic and geographic distances (r = 0.08; p = 0.0007 for SSR and r = 0.16; p = 0.0002 for ISSR). Therefore, results from both markers showed a slight spatially structured genetic diversity in D. trifida accessions maintained by small traditional farmers in Brazil.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ São Paulo, Luiz de Queiroz Coll Agr, Dept Genet, BR-13400970 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Biol Sci, BR-09972270 São Paulo, BrazilUniv Calif Davis, Dept Plant Sci MS1, Sect Crop & Ecosyst Sci, Davis, CA 95616 USAUniversidade Federal de São Paulo, Dept Biol Sci, BR-09972270 São Paulo, BrazilFAPESP: 2007/04805-2Web of Scienc

Asymptomatic genital infection among pregnant women in Sagamu, Nigeria.

Background: Untreated genital tract infections in pregnancy may be associated with adverse effects on foetal and maternal health leading to poor pregnancy outcome.Aim: The aim of this study is to determine the prevalence and microbial isolates associated with asymptomatic genital infectionsin pregnancy.Methodology: This was a cross-sectional study on 252 pregnant women attending their first antenatal clinic. Data on socio-demographic characteristics of study participants was recorded. Microbial culture was carried out on High Vaginal and Endocervical swab samples. Statistical analysis was done using IBM-SPSS Windows version 20.Results: The prevalence of asymptomatic genital infection was 44.8%. Multiparity had statistically significant association with increased prevalence of the condition. Candida albicans and Staphylococcus aureus were the most predominant microbial isolates. Erythromycin and Levofloxacin were the most sensitive antibiotics against the bacterial isolates.Conclusion: This prevalence of asymptomatic genital infectionsis high in pregnant women in Sagamu. It is recommended that routine screening and treatment of these infections should be included in the antenatal clinic services offered to pregnant women so as to prevent the adverse foetal and maternal effects associated with asymptomatic genital infections in pregnancy.Keywords: Genital infection, Pregnancy, Asymptomatic, Sagamu

Vacuum Assisted Vaginal Deliveries in Sagamu

A retrospective review of all cases of vacuum assisted vaginal deliveries at the Olabisi Onabanjo University Teaching Hospital, Sagamu, between January 1990 and December 2001 is presented. During the study period there were 4962 deliveries and assisted vaginal deliveries by vacuum was 223, giving an incidence of 4.53%. Primiparous patients accounted for 57.4% of the cases. The commonest indication was delayed second stage (87%). The mean birth weight of babies was 3.13 Kg + 0.51 SD. One hundred and fifty two (68.2%) babies had Apgar scores of seven and more at the fifth minute of birth. The commonest fetal injury was scalp abrasion and cervical laceration was the commonest maternal complication. Key Words: Vacuum, Delivery, Vagina. Nig. Medical Practitioner Vol. 45(3) 2004: 38-4

Asymptomatic Urinary Tract Infection among Pregnant Women in Sagamu, Nigeria

A cross-sectional study involving 201 pregnant women with no symptoms and/or clinical signs of urinary tract infection who attended antenatal booking clinic of Olabisi Onabanjo University Teaching Hospital, Sagamu Nigeria. The two hundred and one pregnant women were examined for asymptomatic bacteriuria, 34 (16.9%) had positive urine culture for significant bacteriuria and 12 (5.9%) had candiduria. There were statistically significant associations between bacteriuria and age (p=0.018), educational level (p=0.019) and occupation (p=0.008). The most prevalent bacterial isolate was Staphylococcus aureus (47.1%) and least cultured isolate was Escherichia coli (5.9%). Cotrimoxazole and ofloxacin were the most sensitive antimicrobial agents while Nitrofurantoin was the least sensitive. The prevalence of asymptomatic bacteriuria among women attending antenatal care in Sagamu is still high (16.9%) and this underscores the need for routine antenatal screen for all pregnant women at least on the first antenatal visit.Keywords: Urinary tract infection, Asymptomatic bacteriuria, Pregnant women, Age, Educational level, Occupation, Sagamu

Promiscuous arbuscular mycorrhizal symbiosis of yam (Dioscorea spp.), a key staple crop in West Africa

Yam (Dioscorea spp.) is a tuberous staple food crop of major importance in the sub-Saharan savannas of West Africa. Optimal yields commonly are obtained only in the first year following slash-and-burn in the shifting cultivation systems. It appears that the yield decline in subsequent years is not merely caused by soil nutrient depletion but might be due to a loss of the beneficial soil microflora, including arbuscular mycorrhizal fungi (AMF), associated with tropical "tree-aspect" savannas and dry forests that are the natural habitats of the wild relatives of yam. Our objective was to study the AMF communities of natural savannas and adjacent yam fields in the Southern Guinea savanna of Benin. AMF were identified by morphotyping spores in the soil from the field sites and in AMF trap cultures with Sorghum bicolor and yam (Dioscorea rotundata and Dioscorea cayenensis) as bait plants. AMF species richness was higher in the savanna than in the yam-field soils (18-25 vs. 11-16 spp.), but similar for both ecosystems (29-36 spp.) according to the observations in trap cultures. Inoculation of trap cultures with soil sampled during the dry season led to high AMF root colonization, spore production, and species richness (overall 45 spp.) whereas inoculation with wet-season soil was inefficient (two spp. only). The use of D. cayenensis and D. rotundata as baits yielded 28 and 29 AMF species, respectively, and S. bicolor 37 species. AMF root colonization, however, was higher in yam than in sorghum (70-95 vs. 11-20%). After 8 months of trap culturing, the mycorrhizal yam had a higher tuber biomass than the nonmycorrhizal controls. The AMF actually colonizing D. rotundata roots in the field were also studied using a novel field sampling procedure for molecular analyses. Multiple phylotaxa were detected that corresponded with the spore morphotypes observed. It is, therefore, likely that the legacy of indigenous AMF from the natural savanna plays a crucial role for yam productivity, particularly in the low-input traditional farming systems prevailing in West Africa