Species status of Neisseria gonorrhoeae: Evolutionary and epidemiological inferences from multilocus sequence typing

This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited - Copyright @ 2007 Bennett et al; licensee BioMed Central Ltd.Background: Various typing methods have been developed for Neisseria gonorrhoeae, but none provide the combination of discrimination, reproducibility, portability, and genetic inference that allows the analysis of all aspects of the epidemiology of this pathogen from a single data set. Multilocus sequence typing (MLST) has been used successfully to characterize the related organisms Neisseria meningitidis and Neisseria lactamica. Here, the same seven locus Neisseria scheme was used to characterize a diverse collection of N. gonorrhoeae isolates to investigate whether this method would allow differentiation among isolates, and to distinguish these three species. Results: A total of 149 gonococcal isolates were typed and submitted to the Neisseria MLST database. Although relatively few (27) polymorphisms were detected among the seven MLST loci, a total of 66 unique allele combinations (sequence types, STs), were observed, a number comparable to that seen among isolate collections of the more diverse meningococcus. Patterns of genetic variation were consistent with high levels of recombination generating this diversity. There was no evidence for geographical structuring among the isolates examined, with isolates collected in Liverpool, UK, showing levels of diversity similar to a global collection of isolates. There was, however, evidence that populations of N. meningitidis, N. gonorrhoeae and N. lactamica were distinct, with little support for frequent genetic recombination among these species, with the sequences from the gdh locus alone grouping the species into distinct clusters. Conclusion: The seven loci Neisseria MLST scheme was readily adapted to N. gonorrhoeae isolates, providing a highly discriminatory typing method. In addition, these data permitted phylogenetic and population genetic inferences to be made, including direct comparisons with N. meningitidis and N. lactamica. Examination of these data demonstrated that alleles were rarely shared among the three species. Analysis of variation at a single locus, gdh, provided a rapid means of identifying misclassified isolates and determining whether mixed cultures were present.This study is funded by the Wellcome Trust and European Unio

The epidemiology of diarrhoeal disease in children at Queen Elizabeth Central Hospital, Blantyre, Malawi, 1994-1997

Diarrhoeal disease (DD) is a leading cause of childhood morbidity and mortality in developing countries throughout the world. To begin to understand the burden of DD at Queen Elizabeth Central Hospital (QECH), its seasonality and age distribution, we reviewed inpatient and outpatient records for cases of gastroenteritis between 1994 and 1997. Annually, DO. accounted for an average of 7,300 attendances to the; Under 5's rehydration clinic, 1219 paediatric admissions (12% of all hospitalisations) and 183 deaths in hospitalised children (19% of total). A distinct seasonal pattern was identified with monthly peaks for DD occurring between October to January. Over 75% children (inpatients and outpatients) were below two years of age. During the study period, an increase in the number of outpatient attendances for DD was observed. In contrast, the number of children with a more severe outcome, hospitalisation or death, declined during the study period. This is likely to be explicable by the increasing and appropriate use of oral rehydration therapy. We conclude that DD is a substantial cause of morbidity and mortality in Malawian children. Further studies of the patterns of DD at QECH will be necessary to assess the impact ofDD control programmes

Concentrations of trace metals (lead, iron, copper and zinc) in crops harvested in some oil prospecting locations in Rivers State, Nigeria

Concentrations of the trace metals lead, iron, copper and zinc were estimated in  crops harvested in some oil prospecting locations in Rivers State, Nigeria. The   locations were; Agbada-Aluu (AA), Ebocha (EB), Idu Ekpeye (IE), Obagi (OB) and Trans Amadi Layout (TA), with the Teaching and Research Farm of Rivers State University of Science and Technology, Port Harcourt as control. Crops investigated were cassava (Manihot esculenta), cocoyam (Colocasia esculenta), okra (Hibiscus esculentus), pumpkin leaves (Telfairia occidentalis) and waterleaf (Talinum  traingulare). Results of the mean lead concentrations were from 1.1μg/g in cocoyam to 9.1 μg/g in okro, showing higher trends in the industrialized areas. While cocoyam had the lowest lead concentration, the concentration rest of the crops did not differ significantly from one another. Crops from locations TA, OB, IE and EB had  significantly higher concentrations of lead, although IE, AA and TF were not  significantly different from one another. Mean concentrations of iron were between 40 μg/g in cassava from TF, and 651 μg/g in pumpkin leaves from TA - the industrial base of Rivers State - reflecting a high level of pollution from the various industries in that location. Differences in concentration of iron in crops showed pumpkin leaves to have the highest level of iron, followed by the other green  vegetables – waterleaf and okra - although no significant differences occurred between okra, cocoyam and cassava. Copper concentrations were between 4.4 μg/g in cocoyam from locations TF and 23 μg/g in pumpkin leaves from TA. Pumpkin leaves had the highest concentrations of copper, followed by okra, then waterleaf, with cocoyam and cassava having the least significant levels. Zinc concentrations in crops were between 29 μg/g in cocoyam from TF to 240 μg/g in pumpkin leaves from EB. Pumpkin leaves and okra contained the highest levels of the metal,  followed by waterleaf, then cassava and finally cocoyam. In terms of location, TA, OB and EB had the highest concentrations in crops, the least occurring in TF and AA. These results reflect higher concentrations of metals in crops from the  industrialized locations, with the green vegetables, particularly pumpkin leaves, having the highest uptake, while cocoyam invariably had the least. These findings give cause for concern, particularly as heavy metals are bio-accumulative in the system and portend a serious health risk to man and animals.Key Words: Trace metals, concentrations, food crops, oil prospecting locations Des concentrations de métaux en traces (plomb, fer, cuivre et zinc) ont été  évaluées dans des cultures récoltées dans certains endroits de prospection de pétrole dans l’Etat de Rivers State, Nigeria. Ces endroits étaient Agbada-Aluu (AA), Ebocha (EB), Idu Ekpeye (IE), Obagi (OB) et Trans Amadi Layout (TA), avec la ferme d’enseignement et de recherche de l’Université des Sciences et Technologie de Rivers State, avec Port Harcourt comme contrôle. Les cultures qui ont fait l’objet d’analyse étaient le manioc, (Manihot esculenta), la patate douce (Colocasia  esculenta), le gombo, (Hibiscus esculentus), les feuilles de courge (Telfairia  occidentalis) et un légume hydrophile (Talinum traingulare). Les résultats de la moyenne des concentrations de plomb se situaient entre 1,1μg/g dans la patate douce et 9,1 μg/g dans le gombo, ce qui montre de plus hautes tendances dans les régions industrialisées. Alors que la patate douce avait la plus faible concentration, le reste des cultures ne différaient pas considérablement l’une de l’autre. Les  cultures provenant des régions TA, OB, IE et EB avaient des concentrations  nettement supérieures en plomb, tandis que celles de IE, AA et TF ne différaient pas beaucoup l’une et de l’autre. Les concentrations moyennes de fer se situaient entre 40μg/g dans le manioc de TF, et 651 μg/g dans les feuilles de courge de TA – la base industrielle de Rivers State– ce qui reflète un niveau élevé de pollution des différentes industries de cette région. Des différences de concentration de fer dans les cultures ont montré que les feuilles de courge ont la plus haute teneur en fer, suivies par les autres légumes verts – le légume hydrophile et le gombo – bien qu’aucune grande différence ne se soit produite entre le gombo, la patate douce et le manioc. Des concentrations de cuivre se situaient entre 4,4 μg/g dans la patate douce des régions TF et 23 μg/g dans les feuilles de courge des régions TA. Les feuilles de courge avaient les plus hautes concentrations de cuivre, suivies par le gombo, puis le légume hydrophile, tandis que la patate douce et le manioc avaient les niveaux les plus bas. Les concentrations de zinc dans les cultures se situaient entre 29 μg/g dans la patate douce  de TF et 240 μg/g dans les feuilles de courge de EB. Les feuilles de courge et le gombo contenaient les niveaux les plus élevés de ce métal, puis le légume hydrophile, ensuite le manioc et finalement la patate douce. En ce qui concerne le lieu, TA, OB et EB avaient les concentrations les plus hautes dans les cultures, les concentrations les plus basses se trouvaient dans TF et AA. Ces résultats reflètent des concentrations de métaux plus élevées dans les  cultures des régions  industrialisées, tandis que les légumes verts -particulièrement les feuilles de courgeavaient la plus haute assimilation, et la patate douce avait  invariablement la plus faible. Ces résultats suscitent des appréhensions,  particulièrement parce que les métaux lourds sont bio-cumulatifs dans le système et qu’ils présagent de sérieux risques sanitaires pour les hommes et les animaux.Mots-clés: Métaux en traces, concentrations, denrées alimentaires, endroits de prospection de pétrole

In vitro synergy and enhanced murine brain penetration of saquinavir coadministered with mefloquine.

Highly active antiretroviral therapy has substantially improved prognosis in human immunodeficiency virus (HIV). However, the integration of proviral DNA, development of viral resistance, and lack of permeability of drugs into sanctuary sites (e.g., brain and lymphocyte) are major limitations to current regimens. Previous studies have indicated that the antimalarial drug chloroquine (CQ) has antiviral efficacy and a synergism with HIV protease inhibitors. We have screened a panel of antimalarial compounds for activity against HIV-1 in vitro. A limited efficacy was observed for CQ, mefloquine (MQ), and mepacrine (MC). However, marked synergy was observed between MQ and saquinavir (SQV), but not CQ in U937 cells. Furthermore, enhancement of the antiviral activity of SQV and four other protease inhibitors (PIs) by MQ was observed in MT4 cells, indicating a class specific rather than a drug-specific phenomenon. We demonstrate that these observations are a result of inhibition of multiple drug efflux proteins by MQ and that MQ also displaces SQV from orosomucoid in vitro. Finally, coadministration of MQ and SQV in CD-1 mice dramatically altered the tissue distribution of SQV, resulting in a >3-fold and >2-fold increase in the tissue/blood ratio for brain and testis, respectively. This pharmacological enhancement of in vitro antiviral activity of PIs by MQ now warrants further examination in vivo

Genotype analysis of Escherichia coli strains isolated from children and chickens living in close contact

Escherichia coli isolates from rectal swabs from 62 chickens and stools from 42 children living in close contact with chickens on the same farms in Kiambu district, Kenya, were compared for their genetic relatedness. Antibiotic susceptibility profiles broadly categorized isolates from the children and from the chickens into two separate clusters: the majority (144; 85.5%) of the E. coil isolates from children were multidrug resistant, while the majority (216; 87.1%) of the E. coli isolates from chickens were either fully susceptible or resistant only to tetracycline. Sixty- and 100- to 110- MDA plasmids were found to encode the transferable resistance to co- trimoxazole and tetracycline. HindIII restriction endonuclease digestion of the 60- and 100- to 110-MDA plasmids produced four distinct patterns for isolates from children and three distinct patterns for isolates from chickens. XbaI digestion of genomic DNA followed by pulsed-field gel electrophoresis (PFGE) analysis produced 14 distinct clusters. There were six distinct PFGE clusters among the isolates from children, while among the isolates from chickens there were seven distinct clusters. Only one PFGE cluster contained isolates from both children and chickens, with the isolates displaying an approximately 60% coefficient of similarity. This study showed that although several different genotypes of E. coli were isolated from children and chickens from the same farms, the E. coli strains from these two sources were distinct

Transoral laser surgery for laryngeal carcinoma: has Steiner achieved a genuine paradigm shift in oncological surgery?

Transoral laser microsurgery applies to the piecemeal removal of malignant tumours of the upper aerodigestive tract using the CO2 laser under the operating microscope. This method of surgery is being increasingly popularised as a single modality treatment of choice in early laryngeal cancers (T1 and T2) and occasionally in the more advanced forms of the disease (T3 and T4), predomi- nantly within the supraglottis. Thomas Kuhn, the American physicist turned philosopher and historian of science, coined the phrase ‘paradigm shift’ in his groundbreaking book The Structure of Scientific Revolutions. He argued that the arrival of the new and often incompatible idea forms the core of a new paradigm, the birth of an entirely new way of thinking. This article discusses whether Steiner and col- leagues truly brought about a paradigm shift in oncological surgery. By rejecting the principle of en block resection and by replacing it with the belief that not only is it oncologically safe to cut through the substance of the tumour but in doing so one can actually achieve better results, Steiner was able to truly revolutionise the man- agement of laryngeal cancer. Even though within this article the repercussions of his insight are limited to the upper aerodigestive tract oncological surgery, his willingness to question other peoples’ dogma makes his contribution truly a genuine paradigm shift

PSK4 COST-EFFECTIVENESS OF TOPICAL CALCIPOTRIOL/BETAMETHASONE DIPROPIONATE TWOCOMPOUND PRODUCT IN A SCOTTISH CARE MODEL

Aprovada pel gerent de l'Institut Municipal d'Hisenda el 01-07-200

Prevalence of Group A beta-haemolytic Streptococcus isolated from children with acute pharyngotonsillitis in Aden, Yemen.

OBJECTIVES: To estimate the prevalence of Group A beta-haemolytic streptococcus (GAS) and non-GAS infections among children with acute pharyngotonsillitis in Aden, Yemen, to evaluate the value of a rapid diagnostic test and the McIsaac score for patient management in this setting and to determine the occurrence of emm genotypes among a subset of GAS isolated from children with acute pharyngotonsillitis and a history of acute rheumatic fever (ARF) or rheumatic heart disease (RHD). METHODS: Group A beta-haemolytic streptococcus infections in school-aged children with acute pharyngotonsillitis in Aden, Yemen, were diagnosed by a rapid GAS antigen detection test (RADT) and/or GAS culture from a throat swab. The RADT value and the McIsaac screening score for patient management were evaluated. The emm genotype of a subset of GAS isolates was determined. RESULTS: Group A beta-haemolytic streptococcus pharyngotonsillitis was diagnosed in 287/691 (41.5%; 95% CI 37.8-45.3) children. Group B, Group C and Group G beta-haemolytic streptococci were isolated from 4.3% children. The RADT had a sensitivity of 238/258 (92.2%) and specificity of 404/423 (95.5%) against GAS culture. A McIsaac score of ≥4 had a sensitivity of 93% and a specificity of 82% for confirmed GAS infection. The emm genotypes in 21 GAS isolates from children with pharyngitis and a history of ARF and confirmed RHD were emm87 (11), emm12 (6), emm28 (3) and emm5 (1). CONCLUSION: This study demonstrates a very high prevalence of GAS infections in Yemeni children and the value of the RADT and the McIsaac score in this setting. More extensive emm genotyping is necessary to understand the local epidemiology of circulating strains

Stem cells of the lower limb: Their role and potential in management of critical limb ischemia.

Peripheral arterial occlusive disease (PAOD) contributes to decreased exercise tolerance, poor balance, impaired proprioception, muscle atrophy and weakness, with advanced cases resulting in critical limb ischemia (CLI) where the viability of the limb is threatened. Patients with a diagnosis of CLI have a poor life expectancy due to concomitant cardio and cerebrovascular diseases. The current treatment options to avoid major amputation by re-establishing a blood supply to the limb generally have poor outcomes. Human skeletal muscle contains both multipotent stem cells and progenitor cells and thus has a capacity for regeneration. Phase I and II studies involving transplantation of bone marrow-derived progenitor cells into CLI limbs show positive effects on wound healing and angiogenesis; the increase in quiescent satellite cell numbers observed in CLI muscle may also provide a sufficient in vivo source of resident stem cells. These indigenous cells have been shown to be capable of forming multiple mesodermal cell lineages aiding the repair and regeneration of chronically ischemic muscle. They may also serve as a repository for autologous transplantation. The behavior and responses of the stem cell population in CLI is poorly understood and this review tries to elucidate the potential of these cells and their future role in the management of CLI