Irina S. Khokhlova

Publications (129) View all

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  Available from: Irina S. Khokhlova

  Dataset: Kiffner2013-Sex-biased parasitism is not universal-Suppl

  Christian Kiffner, Michal Stanko, Serge Morand, Irina S Khokhlova, Georgy I Shenbrot, Anne Laudisoit, Herwig Leirs, Hadas Hawlena, Boris R Krasnov
• Article: Energy expenditure for egg production in arthropod ectoparasites: the effect of host species.

  Irina S Khokhlova, Laura J Fielden, Joseph B Williams, A Allan Degen, Boris R Krasnov
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  ABSTRACT: SUMMARY We studied the energy cost of egg production in two flea species (Parapulex chephrenis and Xenopsylla ramesis) feeding on principal (Acomys cahirinus and Meriones crassus, respectively) and auxiliary (M. crassus and A. cahirinus, respectively) rodent hosts. We predicted that fleas feeding on principal as compared with auxiliary hosts will (a) expend less energy for egg production; (b) produce larger eggs and (c) live longer after oviposition. Both fleas produced more eggs and spent less energy per egg when exploiting principal hosts. Parapulex chephrenis produced larger eggs after exploiting auxiliary hosts, while the opposite was true for X. ramesis. After oviposition, P. chephrenis fed on the auxiliary hosts survived for a shorter time than those fed on the principal hosts, while in X. ramesis the survival time did not differ among hosts. Our results suggested that one of the proximate causes for lower reproductive performance and subsequent lower abundance of fleas on auxiliary hosts is the higher energy cost of egg production. However, in some species, lower offspring number may be compensated to some extent by their size, although this compensation may also compromise their future reproduction via decreased survival. In addition, the reproductive strategy of exploitation of low profitable (i.e. auxiliary) hosts may differ between flea species.
  Parasitology 05/2013; · 2.96 Impact Factor
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  Available from: Irina S. Khokhlova

  Article: Sex-biased parasitism is not universal: evidence from rodent-flea associations from three biomes.

  Christian Kiffner, Michal Stanko, Serge Morand, Irina S Khokhlova, Georgy I Shenbrot, Anne Laudisoit, Herwig Leirs, Hadas Hawlena, Boris R Krasnov
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  ABSTRACT: The distribution of parasites among individual hosts is characterised by high variability that is believed to be a result of variations in host traits. To find general patterns of host traits affecting parasite abundance, we studied flea infestation of nine rodent species from three different biomes (temperate zone of central Europe, desert of Middle East and tropics of East Africa). We tested for independent and interactive effects of host sex and body mass on the number of fleas harboured by an individual host while accounting for spatial clustering of host and parasite sampling and temporal variation. We found no consistent patterns of the effect of host sex and body mass on flea abundance either among species within a biome or among biomes. We found evidence for sex-biased flea infestation in just five host species (Apodemus agrarius, Myodes glareolus, Microtus arvalis, Gerbillus andersoni, Mastomys natalensis). In six rodent species, we found an effect of body mass on flea abundance (all species mentioned above and Meriones crassus). This effect was positive in five species and negative in one species (Microtus arvalis). In M. glareolus, G. andersoni, M. natalensis, and M. arvalis, the relationship between body mass and flea abundance was mediated by host sex. This was manifested in steeper change in flea abundance with increasing body mass in male than female individuals (M. glareolus, G. andersoni, M. natalensis), whereas the opposite pattern was found in M. arvalis. Our findings suggest that sex and body mass are common determinants of parasite infestation in mammalian hosts, but neither of them follows universal rules. This implies that the effect of host individual characteristics on mechanisms responsible for flea acquisition may be manifested differently in different host species.
  Oecologia 05/2013; · 3.41 Impact Factor
• Article: Effects of Bartonella on feeding and reproductive performance of fleas.

  Danny Morick, Boris R Krasnov, Irina S Khokhlova, Ricardo Gutiérrez, Laura J Fielden, Yuval Gottlieb, Shimon Harrus
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  ABSTRACT: Numerous pathogens are transmitted from one host to another by hematophagous insect vectors. The interactions between a vector-borne organism and its vector vary in many ways, most of which are yet to be explored and identified. These interactions may play a role in the dynamics of the infection cycle. One way to evaluate these interactions is by studying the effect of the tested organism on the vector. In this study, we tested the effect of infection with Bartonella species on fitness-related variables of fleas using Bartonella sp. OE 1-1, Xenopsylla ramesis fleas and Meriones crassus jirds as a model system. Feeding parameters including blood meal size and metabolic rate during digestion as well as reproductive parameters including fecundity, fertility and life span were compared between experimentally Bartonella-infected and uninfected fleas. In addition, the developmental time, sex ratio and body size of F1 offspring fleas were compared between the two groups. Most tested parameters did not differ between infected and uninfected fleas. However, F1 males produced by Bartonella-positive females were significantly smaller than F1 males produced by Bartonella-negative female fleas. The findings in this study suggest that bartonellae are well adapted to their flea vectors, and by minimally affecting their fitness evolved to better spread themselves in the natural environment.
  Applied and environmental microbiology 03/2013; · 3.69 Impact Factor
• Article: Aggregative structure is the rule in communities of fleas: null model analysis

  Boris R. Krasnov, Georgy I. Shenbrot, Irina S. Khokhlova
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  ABSTRACT: We used null models to examine patterns of species co-occurrences in 59 communities of fleas parasitic on small mammals from 4 biogeographic realms (Afrotropics, Nearctic, Neotropics, and Palaearctic). We compared frequencies of co-occurrences of flea species across host species with those expected by chance, using a null model approach. We used 4 tests for non-randomness to identify pairs of species (within a community) that demonstrate significant positive or negative co-occurrence. The majority of flea communities were non-randomly assembled. Patterns of flea co-occurrences on the same host species indicated aggregation but not segregation of flea species (except for the flea community of Madagascar). Although only a small fraction of species pairs were associated significantly (264 of 10, 943 species pairs according to the most liberal criterion), most of these associations were positive (except for 2 negatively associated species pairs). Significantly associated pairs were represented mainly by non-congeneric species. The degree of non-randomness of the entire flea community was similar among biogeographic regions, but the strength of pair-wise association varied geographically, being the highest in the Afrotropics and the lowest in the European region of the Palaearctic.
  Ecography 02/2011; 34(5):751 - 761. · 4.19 Impact Factor