Bulent Salih Alten

Prof. Dr. Bulent Salih Alten

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Research Focus & Metrics

Academic Career Length

27Years (2000-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 February 2016 in PLOS Neglected Tropical Diseases
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BABulent Salih Alten
Bulent Salih Alten
Carla MaiaCarla Maia
Carla Maia
MAMaria Odete Afonso
Maria Odete Afonso
LCLenea Campino
Lenea Campino
MJMaribel Jiménez
Maribel Jiménez
LGLuigi Gradoni
Luigi Gradoni
The recent geographical expansion of phlebotomine vectors of Leishmania infantum in the Mediterranean subregion has been attributed to ongoing climate changes. At these latitudes, the activity of sand flies is typically seasonal; because seasonal phenomena are also sensitive to general variations in climate, current phenological data sets can provide a baseline for continuing investigations on sand fly population dynamics that may impact on future scenarios of leishmaniasis transmission. With this aim, in 2011–2013 a consortium of partners from eight Mediterranean countries carried out entomological investigations in sites where L. infantum transmission was recently reported. A common protocol for sand fly collection included monthly captures by CDC light traps, complemented by sticky traps in most of the sites. Collections were replicated for more than one season in order to reduce the effects of local weather events. In each site, the trapping effort was left unchanged throughout the survey to legitimate inter-seasonal comparisons. Data from 99,000 collected specimens were analyzed, resulting in the description of seasonal dynamics of 56,000 sand flies belonging to L. infantum vector species throughout a wide geographical area, namely P. perniciosus (Portugal, Spain and Italy), P. ariasi (France), P. neglectus (Greece), P. tobbi (Cyprus and Turkey), P. balcanicus and P. kandelakii (Georgia). Time of sand fly appearance/disappearance in collections differed between sites, and seasonal densities showed variations in each site. Significant correlations were found between latitude/mean annual temperature of sites and i) the first month of sand fly appearance, that ranged from early April to the first half of June; ii) the type of density trend, varying from a single peak in July/August to multiple peaks increasing in magnitude from May through September. A 3-modal trend, recorded for P. tobbi in Cyprus, represents a novel finding for a L. infantum vector. Adults ended the activity starting from mid September through November, without significant correlation with latitude/mean annual temperature of sites. The period of potential exposure to L.infantum in the Mediterranean subregion, as inferred by adult densities calculated from 3 years, 37 sites and 6 competent vector species, was associated to a regular bell-shaped density curve having a wide peak center encompassing the July-September period, and falling between early May to late October for more than 99% of values. Apparently no risk for leishmaniasis transmission took place from December through March in the years considered. We found a common pattern of nocturnal females activity, whose density peaked between 11 pm and 2 am. Despite annual variations, multiple collections performed over consecutive years provided homogeneous patterns of the potential behavior of leishmaniasis vectors in selected sites, which we propose may represent sentinel areas for future monitoring. In the investigated years, higher potential risk for L. infantum transmission in the Mediterranean was identified in the June-October period (97% relative vector density), however such risk was not equally distributed throughout the region, since density waves of adults occurred earlier and were more frequent in southern territories. Recent projections on global warming indicate a constant rise of temperatures in the Mediterranean subregion in the near-mid future. While this phenomenon already caused geographical expansion of several arthropod-borne diseases, it is likely to affect also temporal parameters of seasonally transmitted diseases such as leishmaniasis, a protozoan infection spread by the bite of phlebotomine sand flies. Phenology of sand flies consists in the periods of emergence of adults and their disappearance from collections following an activity period during warm months, which can be characterized by peaks of abundance. Current phenological observations can be important for continuing investigations on sand fly dynamics that may impact on leishmaniasis transmission in the future. With this aim, partners from eight Mediterranean countries identified sites with documented Leishmania infantum transmission by six different vector species and performed multiannual trappings. From the high number of 56,000 specimens collected throughout an area spanning from Portugal at west to Georgia at east, the current seasonal dynamics of Mediterranean vectors was obtained. Both, period of adults emergence and type of density trend were found to be significantly correlated with latitude or mean annual temperature of trapping sites. At the southernmost latitudes, vector activity started as early as begin of April and ended by late November, showing that the no-risk period of potential exposure to L. infantum lasted only 4 months.

1 October 2013 in Antiviral Research
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CACigdem Alkan
Cigdem Alkan
LBLaurence Bichaud
Laurence Bichaud
XLXavier de Lamballerie
Xavier de Lamballerie
BABulent Salih Alten
Bulent Salih Alten
EGErnest A. Gould
Ernest A. Gould
Remi CharrelRemi Charrel
Remi Charrel
Sandfly-borne phleboviruses may cause a transient febrile illness (sandfly fever) or more severe neuroinvasive disease. In the Old World, they are vectored by phlebotomine flies, which are widely distributed in the Mediterranean basin, North Africa, the Indian subcontinent, the Middle East and central Asia. High seroprevalence rates have been recorded in humans and domestic animals in areas where sandflies are present. Most published studies have focused on phlebovirus infections of travelers and of soldiers stationed in endemic areas, but the health impact on local populations should not be underestimated, as seroprevalence studies indicate massive circulation of these viruses, even if disease is seldom documented. Except for Toscana virus, which shows a marked neurotropism and is a leading cause of aseptic meningitis in endemic regions, phlebovirus infections are inadequately considered by physicians and are generally underestimated. However, several properties of these viruses suggest that they will extend their geographic range. First, changes in the areas occupied by sandflies as a result of climate change have a direct impact on the epidemiology of associated human and animal diseases. Second, phleboviruses exhibit a high mutation rate, and their tri-segmented genome is prone to reassortment and recombination. Third, distinct virus strains can be transmitted by the same arthropod species. Recent studies have documented the distribution of sandfly-borne phleboviruses in Western Europe, but data for Eastern Europe, the Middle East and Africa are very limited. With the goal of filling knowledge gaps and planning new research programs, we have examined available information and present it as a comprehensive review, with a specific focus on understudied regions. We also discuss the need to conduct studies aimed at developing new antiviral drugs and vaccines.

1 January 2009 in International Journal for Parasitology
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Milena SvobodováMilena Svobodová
Milena Svobodová
BABulent Salih Alten
Bulent Salih Alten
LZLenka Zídková
Lenka Zídková
Vit DvorakVit Dvorak
Vit Dvorak
JHJitka Hlavačková
Jitka Hlavačková
PVPetr Volf
Petr Volf

1 December 2006 in Journal of Vector Ecology
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OKOzge Erisoz Kasap
Ozge Erisoz Kasap
BABulent Salih Alten
Bulent Salih Alten
We measured reproductive and population parameters of adult sand flies, Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae), in environmental chambers maintained at temperatures of 15, 18, 20, 25, 28, and 32° C. Based on cohorts of adults at each temperature regime, horizontal life tables were constructed using established laboratory colonies initiated from specimens collected in Sanliurfa Province, southeastern Anatolia, Turkey. The fecundity and longevity of the insects were both highly variable, depending on the temperature. At 15° C, all of the cohort females died before laying eggs, so the construction of a life table for this temperature regime was not possible. Within a range of 18 to 32° C, the longevity of adult P. papatasi increased as the temperature decreased; at 15° C, the mean survival times of females and males were 19.04±6.94 days (9–35) and 17.84±7.11 days (9–33), respectively. While the highest number of eggs was found in the cohort at 28° C (44.08±7.79), this was only 3.60±1.55 in the cohort at 32° C and 2.8±0.9 in the cohort at 18° C. This result showed that extreme temperatures negatively affect the fecundity of this species. The cohort reared at 28° C exhibited the highest intrinsic rates of population increase (rm) for P. papatasi. The rm ranged from 0.098 at 28° C to 0.007 at 18° C. The cohort placed at 28° C was found to be significantly different (P<0.01) from the other cohorts producing the fewest progeny in terms of net reproductive rate, R0, (15.87). The values for mean generation time (T) were estimated to vary from 36 days to 271 days depending on temperature. Principal Component Analysis (PCA) confirmed results from the previous studies that the cohort at 28° C orientated and clustered as a distinct group along the first two PCs.

1 March 2015 in Acta Tropica
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FGFiliz Gunay
Filiz Gunay
BABulent Salih Alten
Bulent Salih Alten
FSFatih Simsek
Fatih Simsek
AAAdnan Aldemir
Adnan Aldemir
YLYvonne-Marie Linton
Yvonne-Marie Linton
As a precursor to planned arboviral vector incrimination studies, an integrated systematics approach was adopted using morphology and DNA barcoding to examine the Culex fauna present in Turkey. The mitochondrial COI gene (658bp) were sequenced from 185 specimens collected across 11 Turkish provinces, as well as from colony material. Although by morphology only 9 species were recognised, DNA barcoding recovered 13 distinct species including: Cx. (Barraudius) modestus, Cx. (Culex) laticinctus, Cx. (Cux.) mimeticus, Cx. (Cux.) perexiguus, Cx. (Cux.) pipiens, Cx. (Cux.) pipiens form molestus, Cx. (Cux.) quinquefasciatus, Cx. (Cux.) theileri, Cx. (Cux.) torrentium, Cx. (Cux.) tritaeniorhynchus and Cx. (Maillotia) hortensis. The taxon formerly identified as Cx. (Neoculex) territans was shown to comprise two distinct species, neither of which correspond to Cx. territans s.s. These include Cx. (Neo.) impudicus and another uncertain species, which may be Cx. (Neo.) europaeus or Cx. (Neo.) martinii (herein=Cx. (Neo.) sp. 1). Detailed examination of the Pipiens Group revealed Cx. pipiens, Cx. pipiens f. molestus and the widespread presence of the highly efficient West Nile virus vector Cx. quinquefasciatus for the first time. Four new country records are reported, increasing the Culex of Turkey to 15 recognised species and Cx. pipiens f. molestus. A new taxonomic checklist is provided, annotated with respective vector competencies for transmission of arboviruses.

12 May 2014 in Journal of Vector Ecology
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JMJolyon Medlock
Jolyon Medlock
KHKayleigh M. Hansford
Kayleigh M. Hansford
WBWim Van Bortel
Wim Van Bortel
HZHerve Zeller
Herve Zeller
BABulent Salih Alten
Bulent Salih Alten