Spirochetes in Mosquitoes

1Institute of Vertebrate Biology, v.v.i., Academy of Sciences of the Czech Republic, Květná 8, 603 65 Brno, Czech Republic.
2Tomas Bata University, Faculty of Technology, Department of Environmental Protection and Engineering, náměstí T. G. Masaryka 275, 762 72 Zlin, Czech Republic.
3Institute of Public Health, Department of Bacteriology, Partyzánské náměstí 7, 702 00 Ostrava, Czech Republic.
4University of Illinois at Urbana-Champaign, WM Keck Centre for Comparative & Functional Genomics, Urbana, IL 61801, USA.
5Institute of Vertebrate Biology, v.v.i., Academy of Sciences of the Czech Republic, Květná 8, 603 65 Brno, Czech Republic; Masaryk University, Department of Experimental Biology, Section of Microbiology, Kotlářská 2, 611 37 Brno, Czech Republic. Electronic address: rudolf@ivb.cz.

Abstract

Growth temperature range, resistance to selective antibiotics, activities of 23 enzymes, protein fingerprints and fatty acids composition of the spirochaetal strain BR91, isolated from the Culex pipiens mosquito, were tested.

The spirochaetes were grown in BSK-H Complete liquid medium. The optimal in vitro growth temperature of the strain was 33 °C. Strain BR91 was sensitive to trimethoprim, nalidixic acid, 5-fluorouracil, and tolerated phosphomycin.

The strain produced acid and alkaline phosphatase, esterase (C4), esterase-lipase (C8), leucine arylamidase, naphthol-AS-BI-phosphohydrolase and α-fucosidase.

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) assay revealed several major proteins in the size range of 13-16 kDa, 22-30 kDa and 37-131 kDa. Fatty acid methyl ester (FAME) analysis showed that C₁₄:₀, C₁₆:₀, C₁₈:₁ ω9c and summed feature 5 (C₁₈:₂ ω6,9c and/or C₁₈:₀ anteiso) are major fatty acids.

This study highlights certain phenotypic differences between strain BR91 and the Lyme disease spirochaete Borrelia burgdorferi, and supports the hypothesis that strain BR91 represents a unique taxonomical entity in a system of spirochaetal species.

Culex pipiens; Enzyme activity; FAME; SDS-PAGE; Spirochaete

PMID: 24239193 [PubMed - indexed for MEDLINE] Free full text

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J Vector Ecol. 2010 Jun;35(1):50-5. doi: 10.1111/j.1948-7134.2010.00027.x.

Novel spirochetes isolated from mosquitoes and black flies in the Czech Republic.

Sikutová S1, Halouzka J, Mendel J, Knoz J, Rudolf I.

1Institute of Vertebrate Biology, v.v.i., Academy of Sciences of the Czech Republic, Kvetná 8, CZ-603 65 Brno, Czech Republic.

Abstract

During the years 1999-2002, a total of 4,898 individuals of 26 species of hematophagous insects (4,149 mosquitoes, 583 black flies, and 166 tabanid flies) was examined for the presence of spirochetes using dark-field microscopy.

There was an overall recovery of spirochetes from the midguts of Culicidae and Simuliidae of 23.5% and 11.4%, respectively. Spirochetes were not detected in Tabanidae.

Seven spirochetal strains have been successfully recovered from mosquitoes and black flies: BR149 (Culex pipiens), BR151 (Cx. pipiens), BR173 (Cx. pipiens), BR177 (Cx. pipiens), BR193 (Aedes cinereus), BR208 (Cx. pipiens), and BR231 (Simulium noelleri).

The strains have been adapted to laboratory conditions (BSK-H Complete medium).

Their preliminary determination based on 16S rRNA gene sequencing has shown that they differ from the Lyme disease spirochete Borrelia burgdorferi sensu lato as well as other members of the Order Spirochaetales indicating novel bacterial species in the Family Spirochaetaceae.

PMID: 20618647 [PubMed - indexed for MEDLINE]

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KEYWORDS:

Ann Agric Environ Med. 2009 Dec;16(2):273-6.

What is the percentage of pathogenic borreliae in spirochaetal findings of mosquitolarvae?

Nejedla P1, Norek A, Vostal K, Zakovska A.

1Department of Animal Physiology and Immunology, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, CZ-61137 Brno, Czech Republic.

Abstract

In this study, larvae (1,179 ex.) of mosquito genera Culex were examined for the presence of spirochaetes by Dark Field Microscopy (DFM) at the locality of Blansko (Czech Republic) in of 2004-2008.

DFM spirochaete positive samples (25.4 %) were investigated by nested PCR; only 4 samples were positive for the presence of Borrelia burgdorferi sensu lato, which is 0.3 % of the total examined samples.

We can conclude that only a low percentage of pathogenic borreliae are presented in mosquito larvae, while the spirochaete of undefined genera infect larvae in high amounts.

PMID: 20047261 [PubMed - indexed for MEDLINE] Free full text

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Ann Agric Environ Med. 2008 Dec;15(2):225-30.

Ribotyping and whole-cell protein analysis of spirochetes isolated from arthropods in the Czech Republic.

Bunková L1, Svec P, Halouzka J, Rudolf I, Nemec M.

1Department of Lipids, Tensides and Cosmetics Technology, Faculty of Technology, Tomas Bata University-Zlin, Namesti T. G. Masaryka 275, Zlin, Czech Republic. bunkova@ft.utb.cz

Abstract

In the presented work, six Borrelia burgdorferi sensu lato isolates were recovered from Ixodes ricinus ticks and one strain of spirochete with uncertain taxonomic position isolated from Culex pipiens mosquito collected in the Valtice area (South Moravia, Czech Republic), as well as representative type strains, were further characterized by ribotyping and whole-cell protein fingerprinting.

The ribotype patterns obtained with HindII and EcoRV ribotype patterns showed good correlations with the recently proposed genotypes and grouped each genospecies in a well-separated cluster.

The whole-cell protein profiles of genospecies were more heterogeneous than the ribotype patterns.

The non-identified spirochetal strain was clearly separated from the Borrelia isolates in both methods thus proving their good capacity to characterize Borrelia burgdorferi sensu lato strains.

PMID: 19061259 [PubMed - indexed for MEDLINE] Free full text

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Folia Biol (Krakow). 2007;55(3-4):143-6.

Ticks and mosquitoes as vectors of Borrelia burgdorferi s. l. in the forested areas of Szczecin.

Kosik-Bogacka DI1, Kuźna-Grygiel W, Jaborowska M.

1Department of Biology and Medical Parasitology, Pomeranian Medical University, Powstancow Wielkopolskich Av. 72, 70-111 Szczecin, Poland. kodan@sci.pam.szczecin.pl

Abstract

The aim of the study was to determine the infection level of adult forms and larvae of ticks and mosquitoes with Borrelia burgdorferi in the forested areas of Szczecin.

A total of 1699 ticks Ixodes ricinus, including 1422 nymphs, 277 adult forms and 2862 mosquito females representing the genera Aedes (89.6%) and Culex (10.4%) were collected between the years 2004 and 2005.

A further 3746 larvae and 1596 pupae of Culex pipiens pipiens were colleted from water bodies.

Borrelia burgdorferi s. l. was detected in the arthropods by the method of indirect immunofluorescence assay (IFA).

A positive immunological reaction was detected in 16.6% of the adult forms and in 16.5% of the nymphs of Ixodes ricinus.

Spirochetes were also detected in 1.7% of mosquito females, 3.2% of larvae and in 1.6% of pupae of Culex pipiens pipiens. The results of the present study confirm that contact with ticks constitutes the main risk of contracting Lyme disease, although mosquitoes play a role as vectors as well.

PMID: 18274258 [PubMed - indexed for MEDLINE]

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Ann Agric Environ Med. 2006;13(2):345-8.

Isolation of Borrelia afzelii from overwintering Culex pipiens biotype molestus mosquitoes.

Zákovská A1, Capková L, Serý O, Halouzka J, Dendis M.

1Department of Comparative Animal Physiology and General Zoology, Faculty of Science, Masaryk University, Kotlarska 2, CZ-611 37 Brno, Czech Republic. alenazak@sci.muni.cz

Abstract

A total of 662 samples (winter period: 469; summer period: 193 specimens) of female mosquitoes of the genus Culex, Aedes and Anopheles were collected during the period March 2000-April 2001 from the locality of Vysoke Myto (Eastern Bohemia, Czech Republic).

They were examined by dark field microscopy for the presence of spirochetes.

The motile spirochetes were observed in 4.2 % of all species of investigated mosquitoes.

One spirochetal strain out of the 8 isolation attempts (BRZ14) was obtained (cultivation rate was 12.5 %) and the spirochetal strain was then successfully cultivated and identified using PCR for the presence of Borrelia burgdorferi s.l., and subsequently with the RFLP as genomospecies Borrelia afzelii.

This strain was derived from overwintering Culex (Culex) pipiens biotype molestus female mosquitoe.

This is apparently one of the sporadic cases of the occurrence of pathogenic borreliae in haematophagous arthropods, other than Ixodes ricinus complex ticks.

PMID: 17199258 [PubMed - indexed for MEDLINE] Free full text

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Folia Biol (Krakow). 2006;54(1-2):55-9.

Borrelia burgdorferi sensu lato infection in mosquitoes from Szczecin area.

Kosik-Bogacka DI1, Kuźna-Grygiel W, Górnik K.

1Chair and Department of Biology and Medical Parasitology, Pomeranian Medical University, Powstańców Wielkopolskich 72, 70-111 Szczecin, Poland. kodan@sci.pam.szczecin.pl

Abstract

The aim of the study was to determine the level of infection in mosquitoes with spirochetes Borrelia burgdorferi sensu lato in the woody areas of Szczecin.

The mosquitoes were collected from May to September 2003. The spirochetes, Borrelia burgdorferi s. l., present in mosquitoes were detected in mosquitoes with indirect immunofluorescence assay (IFA) using rabbit anti-Borrelia burgdorferi antibodies and goat anti-rabbit IgG marked with fluorescein isocyanate (FITC).

A total of 1557 females and 58 males were collected. They represented the genera Aedes (63%) and Culex (37%).

The infection level of the mosquitoes from the area studied amounted to 1.7%. The results of the present study confirm the potential of these arthropods to spread Lyme borreliosis.

PMID: 17044261 [PubMed - indexed for MEDLINE]

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J Chromatogr B Analyt Technol Biomed Life Sci. 2004 Sep 5;808(2):249-54.

Characterization of spirochetal isolates from arthropods collected in South Moravia, Czech Republic, using fatty acid methyl esters analysis.

Cechová L1, Durnová E, Sikutová S, Halouzka J, Nemec M.

1Department of Microbiology, Faculty of Science, Masaryk University Brno, Tvrdého 14, 60200 Brno, Czech Republic. lejka@sci.muni.cz

Abstract

Aim of this study was to evaluate cellular fatty acid analysis for characterization of spirochetes.

Strains were isolated from arthropods collected in South Moravia, Czech Republic.

Fatty acid methyl esters (FAME) profile was determined for five Borrelia burgdorferi sensu lato (s.l.) strains isolated from Ixodes ricinus ticks, one "Spironema culicis" strain recovered from mosquito Culex pipiens and seven spirochetal strains (not identified yet) isolated from mosquitoes and black flies.

Analysis was performed using a gas chromatography column in conjunction with Microbial Identification System Sherlock (MIDI Inc., Newark, DE, USA).

Results obtained on the basis of cluster analysis of FAME profiles showed, that the B. burgdorferi sensu lato isolates could be well separated from other spirochetal isolates.

We recommended method used in this study as a useful tool for preliminary identification of spirochetes isolated from ticks and dipterans.

PMID: 15261818 [PubMed - indexed for MEDLINE]

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Ann Agric Environ Med. 2004;11(1):105-8.

The prevalence of spirochete Borrelia burgdorferi sensu lato in ticks Ixodes ricinus and mosquitoes Aedes spp. within a selected recreational area in the city of Szczecin.

Kosik-Bogacka D1, Kuźna-Grygiel W, Bukowska K.

1Department of Biology and Medical Parasitology, Pomeranian Medical University, 70-111 Szczecin, Al. Powstánców Wielkopolskich 72, Poland. kodan@sci.pam.szczecin.pl

Abstract

The aim of this study was to determine the prevalence of spirochete Borrelia burgdorferi s.l. in ticks Ixodes ricinus and mosquitoes Aedes spp. within the Bukowa Forest, collected between 2000 and 2001.

The study covered 215 ticks (193 nymphs and 22 adults) and 947 mosquitoes female of the genus Aedes.

Spirochetes of Borrelia burgdorferi s.l. were detected in the arthropods studied with the method of indirect immunofluorescence assay (IFA).

Positive readings of the immunological reaction were stated in 17.7 % of the collected nymphs and adult forms of Ixodes ricinus, and in 0.8 % of mosquito females of the genus Aedes.

The number of B. burgdorferi observed in a view field (400 x) of microscopic preparations of all infected mosquitoes and about 10 % of the infected ticks, ranged from 1-10.

This number in 50 % of the nymphs was from 11-50 spirochetes. View fields of the preparations of the other 50 % of nymphs and adult forms featured more then 50 spirochetes.

The observed low values of the prevalence and infection intensity of female mosquitoes Aedes spp. compared to ticks suggest that the former do not pose a serious epidemiological threat in the spreading of Lyme disease.

PMID: 15236506 [PubMed - indexed for MEDLINE] Free full text

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Ann Agric Environ Med. 2002;9(2):257-9.

Positive findings of Borrelia burgdorferi in Culex (Culex) pipiens pipiens larvae in the surrounding of Brno city determined by the PCR method.

Zákovská A1, Nejedla P, Holíková A, Dendis M.

1Department of Comparative Animal Physiology and General Zoology, Faculty of Science, Masaryk University, Brno, Czech Republic. alenazak@sci.muni.cz

Abstract

After first finding Borrelia in the midgut of imago mosquitoes, we concentrated on the presence of Borrelia in mosquito development stages--larvae of the third or fourth instar.

In the summer season in the years of 2000-2001 a total of 439 Culex (Culex) pipiens pipiens larvae were collected from a barrel of rainwater in the Obrany holiday area of Brno city (East Moravia, Czech Republic).

The larvae midgut was observed under dark-field microscopy.

Ten DFM positive samples (2.28%) were further analysed using the single-tube nested PCR method for the presence of flagellum DNA sequence specific for Borrelia burgdorferi sensu lato, of which 5 were positive.

Borrelian positivity of Culex (C.) pipiens pipiens larvae was 1.14%.

One spirochete isolated strain in BSK-H medium was obtained. PCR detection for borrelian DNA of the isolated strain was negative.

From these results we can conclude that a low percentage Borreliae can be also found in mosquito larvae and are likely to survive into imago stage.

PMID: 12498597 [PubMed - indexed for MEDLINE] Free full text

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Ann Agric Environ Med. 2002;9(1):55-7.

Detection of Borrelia burgdorferi sensu lato in mosquitoes (Culicidae) in recreational areas of the city of Szczecin.

Kosik-Bogacka D1, Bukowska K, Kuźna-Grygiel W.

1Department of Biology and Medical Parasitology, Pomeranian Medical University, 70-111 Szczecin, al. Powstancow Wielkopolskich 72, Poland. kodan@sci.pam.szczecin.pl

Abstract

The mosquitoes were caught within the period of their highest activity, i.e. June August 2001, in recreational areas of the city of Szczecin.

Spirochetes, Borrelia burgdorferi sensu lato were detected in mosquitoes with the aid of the method of indirect immunofluorescence (IFA) using rabbit anti-Borrelia burgdorferi antibodies and goat anti-rabbit IgG marked with fluorescein isothiocyanate (FITC).

A total of 639 mosquito females representing genera Aëdes (99.1%) and Culex (0.9%) were collected.

The mean value of the infection rate of mosquitoes from the area studied was 1.25%.

The highest infection rate was recorded in June (3.2%), while the lowest -- in July (0.6%).

All mosquitoes infected with Borrelia burgdorferi spirochetes belonged to the genus Aëdes.

The results of the present study confirm a potential role of those arthropods in epidemiology of Lyme borreliosis.

PMID: 12088398 [PubMed - indexed for MEDLINE] Free full text

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Infection. 1999;27(4-5):275-7.

Isolation of Borrelia afzelii from overwintering Culex pipiens biotype molestus mosquitoes.

Halouzka J1, Wilske B, Stünzner D, Sanogo YO, Hubálek Z.

1Institute of Vertebrate Biology, Academy of Sciences of the Czech Republic, Brno.

Abstract

During the years 1995-1996, a total of 1,743 overwintering Culex pipiens biotype molestus female mosquitoes were tested for the presence of spirochetes in several localities in South Moravia, Czech Republic.

The spirochetes were observed in 5% of the mosquitoes investigated. One of the five isolated strains of spirochetes (BR-84) was identified as Borrelia afzelii.

The potential role of mosquitoes in the ecology and epidemiology of Lyme disease (LD) borreliae should be further investigated.

PMID: 10885843 [PubMed - indexed for MEDLINE]

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Folia Parasitol (Praha). 1998;45(1):67-72.

Investigation of haematophagous arthropods for borreliae--summarized data, 1988-1996.

Hubálek Z1, Halouzka J, Juricová Z.

1Institute of Landscape Ecology, Academy of Sciences of the Czech Republic, Brno, Czech Republic. zhubalek@brno.cas.cz

Abstract

Blood-sucking arthropods, collected in South Moravia, Czech Republic, were examined by darkfield microscopy for borreliae from 1988 to 1996.

Among host-seeking ixodid ticks (8481 Ixodes ricinus (L.), 372 Dermacentor reticulatus (Fabr.), 167 Haemaphysalis concinna Koch), borreliae were only observed in adult (23.2%), nymphal (17.2%) and larval (6.3%) I. ricinus.

The prevalence of borreliae in I. ricinus did not vary considerably among habitats except for lower values in agroecosystems, xerothermic oak woods and grasslands. The frequency of intensity of spirochaetal infection (log10 counts of borreliae per tick) in I. ricinus approximated the negative binomial distribution.

The proportions of host-seeking female and nymphal ticks containing > 100 borreliae were 5.0% and 1.7%, respectively. Among preimaginal ticks (749 I. ricinus, 222 D. reticulatus, 82 H. concinna) parasitizing free-living forest birds and small mammals, borreliae were detected in 6.1% of larval and 10.3% of nymphal I. ricinus, and in one larval H. concinna; 3.2% of the birds and 19.4% of the mammals carried infected ticks.

Among 3464 female mosquitoes (Culicidae) of 6 species, 4.1% contained spirochaetes: 1.4% of Aedes vexans Meig., 1.3% of A. cantans (Meig.), 2.2% of A. sticticus (Meig.), 2.2% of Culex pipiens pipiens L. and 5.9% of C. p. molestus Forskal.

Borreliae were also detected in 8.4% of 142 fleas (Siphonaptera, largely Ctenophthalmus agyrtes Heller and Hystrichopsylla talpae Curtis) collected from small mammals.

Twelve isolates of B. burgdorferi sensu lato have been identified to genospecies: 6 strains from I. ricinus (4 Borrelia garinii Baranton et al., 1 B. afzelii Canica et al. and 1 B. lusitaniae Le Fleche et al.), 1 strain from A. vexans (B. afzelii), 2 strains from C. agyrtes (B. afzelii), and 3 strains from host rodents (B. afzelii).

PMID: 9516997 [PubMed - indexed for MEDLINE]

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Med Vet Entomol. 1998 Jan;12(1):103-5.

Isolation of the spirochaete Borrelia afzelii from the mosquito Aedes vexans in the Czech Republic.

Halouzka J1, Postic D, Hubálek Z.

1Institute of Landscape Ecology, Academy of Sciences of the Czech Republic.

Abstract

During the years 1993-1995, a total of 3580 culicine mosquitoes of six species were collected in South Moravia, Czech Republic, and examined by dark-field microscopy for the presence of borreliae.

Females of Aedes cantans, Ae. sticticus, Ae. vexans, Culex pipiens and Cx pipiens biotype molestus (but not Ae. geniculatus or Culiseta annulata) harboured spirochaetes, the frequencies ranging from 0.7% to 7.8%.

One isolate (BR-53) from Ae. vexans was identified as Borrelia afzelii genospecies.

The potential role of mosquitoes in the epidemiology of Lyme borreliosis should be investigated.

PMID: 9513946 [PubMed - indexed for MEDLINE]

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Eur J Epidemiol. 1997 Dec;13(8):951-7.

Distribution of Borrelia burgdorferi sensu lato genomic groups in Europe, a review.

Hubálek Z1, Halouzka J.

1Institute of Landscape Ecology, Academy of Sciences of the Czech Republic, Brno. zhubalek@brno.cas.cz

Abstract

The survey is based on a total of 1263 records (738 isolations and 525 molecular DNA detections) of five Borrelia burgdorferi s.l. genomic groups available from 26 European countries: B. burgdorferi sensu stricto, B. afzelii, B. garinii, B. valaisiana (= VS116) and B. lusitaniae (= PoTiB2).

It shows the geographic distribution, the source (ixodid ticks 802 records, fleas 2 records, mosquitoes 2 records, wild mammals 66 records, human patients 391 records) and the association of the genomic groups with particular clinical manifestations of Lyme borreliosis in humans (B. afzelii significantly prevails in skin lesions whereas B. garinii is more often associated with neuroborreliosis).

The most frequent genomic groups in Europe are B. garinii (501 records) and B. afzelii (469 records). They occur across the continent and islands, whereas the third frequent genomic group, B. burgdorferi s.s. (201 records), has only rarely been isolated in eastern Europe. The remaining genomic groups, i.e. B. valaisiana (85 records) and B. lusitaniae (7 records) have only been isolated from, or detected in, Ixodes ricinus ticks in a few European countries.

PMID: 9476827 [PubMed - indexed for MEDLINE]

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Rev Sci Tech. 1994 Dec;13(4):1175-99.

Nematocera (Ceratopogonidae, Psychodidae, Simuliidae and Culicidae) and control methods.

Braverman Y1.

1Kimron Veterinary Institute, Beit Dagan, Israel.

Abstract

The biology, veterinary importance and control of certain Nematocera are described and discussed. Culicoides spp. (family Ceratopogonidae) transmit the arboviruses of bluetongue (BT), African horse sickness (AHS), bovine ephemeral fever (BEF) and Akabane.

Some other arboviruses have been isolated from these species, while fowl pox has been transmitted experimentally by Culicoides.

These insects are vectors of the parasitic protozoans Leucocytozoon caulleryi and Haemoproteus nettionis, and the parasitic nematodes Onchocerca gutturosa, O. gibsoni and O. cervicalis.

They also cause recurrent summer hypersensitivity in horses, ponies, donkeys, cattle and sheep. Farm animals can die as a result of mass attack by Simulium spp., which are also vectors of Leucocytozoon simondi, L. smithi and the filariae O. gutturosa, O. linealis and O. ochengi.

Venezuelan equine encephalomyelitis (VEE) and Rift Valley fever (RVF) have been isolated from simuliids, and vesicular stomatitis virus New Jersey strain has been replicated in Simulium vittatum.

Simuliids are well known as vectors of O. volvulus, the cause of human onchocercosis (river blindness).

The family Psychodidae includes the genera Phlebotomus and Lutzomyia (subfamily Phlebotominae), vectors of Leishmania spp. in humans, dogs and other mammals.

Vesicular stomatitis virus Indiana strain has been regularly isolated from phlebotomine sandflies.

Mass attack by mosquitoes can also prove fatal to farm animals.

Mosquitoes are vectors of the viruses of Akabane, BEF, RVF, Japanese encephalitis, VEE, western equine encephalomyelitis, eastern equine encephalomyelitis and west Nile meningoencephalitis, secondary vectors of AHS and suspected vectors of Israel turkey meningoencephalitis.

The viruses of hog cholera, fowl pox and reticuloendotheliosis, the rickettsiae Eperythrozoon ovis and E. suis, and the bacterium Borrelia anserina are mechanically transmitted by mosquitoes.

These insects also induce allergic dermatitis in horses.

They transmit several filarial worms of both animals and humans, and are of great medical importance as vectors of major human diseases, including malaria, yellow fever, dengue fever and many more diseases caused by arboviruses.

PMID: 7711309 [PubMed - indexed for MEDLINE]

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Cesk Epidemiol Mikrobiol Imunol. 1994 Mar;43(1):32-5.

[Variations in the occurrence of Borrelia in the tick, Ixodes ricinus (L.) in the Olomouc District].

[Article in Czech]

Chmela J1.

1Okresní hygienická stanice, Olomouc.

Abstract

Examinations of 1,998 ticks Ixodes ricinus in the district of Olomouc revealed 182 cases of borrelia, i.e. in 9.1% ticks.

Prevalence in males is 10.7%, in females 12.8% and in nymphs 7.0%.

A certain coincidence was observed between mosquito incidence, in particular during the first half of the year, and borrelia prevalence in ticks in the course of the following year, with prevalence variations manifested in tick imagos only.

A hypothesis is formulated that mosquitos feeding on larger animals, who are often attacked by nymphs of I. ricinus ticks, can increase the infection rate in the hosts by borrelia transmission and thus participate in the increase of tick imago prevalence during subsequent years.

PMID: 8168165 [PubMed - indexed for MEDLINE]

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Med Vet Entomol. 1990 Apr;4(2):221-6.

Vector roles of Fennoscandian mosquitoes attracted to mammals, birds and frogs.

Jaenson TG1.

1Department of Zoology, Uppsala University, Sweden.

Abstract

1. Mosquitoes were sampled with five suction traps, from May to October 1983, at a forest site in south-central Sweden.

2. Twenty-three species of mosquitoes were identified among the total of 3108 females collected: 4% of them in an unbaited trap, 3% in a trap baited with two frogs, 24% with a guinea-pig, 28% with a hen and 40% in a trap baited with a rabbit.

3. The dominant species of Culicidae trapped were 39% Aedes communis (De Geer), 21% Ae. cinereus Meigen, 14% Coquillettidia richiardii (Ficalbi), 8% Ae. punctor (Kirby) and 4% Culiseta morsitans (Theobald).

4. Aedes annulipes (Meigen), Ae. cantans (Meigen), Ae. cinereus, Ae. communis and Ae. punctor were mostly attracted to the rabbit, whereas Culiseta morsitans, Culex pipiens L. and/or Cx torrentium Martini were strongly ornithophilic.

5. Based on these and previously published data the ecological and behavioural potential of the mosquitoes to transmit Sindbis, Inkoo, Tahyna and Batai viruses, tularaemia (caused by Francisella tularensis) and Ixodes-borne borreliosis (caused by Borrelia burgdorferi) in Fennoscandia is discussed.

6. The data support the hypothesis that Sindbis virus, which is enzootic in bird populations in Fennoscandia, is vectored between birds by Cx pipiens/torrentium and Cs. morsitans, and that abundant Aedes spp., particularly Ae. cinereus, which feed on both birds and mammals, are primary link vectors from infective birds to man and other mammals.

PMID: 1983455 [PubMed - indexed for MEDLINE]

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J Clin Microbiol. 1988 Aug;26(8):1482-6.

Ticks and biting insects infected with the etiologic agent of Lyme disease, Borreliaburgdorferi.

Magnarelli LA1, Anderson JF.

1Department of Entomology, Connecticut Agricultural Experiment Station, New Haven 06504.

Abstract

Members of 18 species of ticks, mosquitoes, horse flies, and deer flies were collected in southeastern Connecticut and tested by indirect fluorescent-antibody staining methods for Borrelia burgdorferi, the etiologic agent of Lyme disease.

An infection rate of 36.2% (116 tested), recorded for immature Ixodes dammini, exceeded positivity values for all other arthropod species.

Prevalence of infection for hematophagous insects ranged from 2.9% of 105 Hybomitra lasiophthalma to 14.3% of seven Hybomitra epistates.

Infected I. dammini larvae and nymphs coexisted with infected Dermacentor variabilis (American dog tick) immatures on white-footed mice (Peromyscus leucopus), but unlike I. dammini, none of the 55 adult American dog ticks collected from vegetation harbored B. burgdorferi.

Groups of 113 field-collected mosquitoes of Aedes canadensis and 43 Aedes stimulans were placed in cages with uninfected Syrian hamsters. Of these, 11 females of both species contained B. burgdorferi and had fed fully or partially from the hamsters.

No spirochetes were isolated from the hamsters, but antibodies were produced in one test animal.

PMID: 3170711 [PubMed - indexed for MEDLINE] PMCID: PMC266646 Free PMC Article

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J Infect Dis. 1987 Oct;156(4):694-5.

Experimental infections of mosquitoes with Borrelia burgdorferi, the etiologic agent of Lyme disease.

Magnarelli LA, Freier JE, Anderson JF.

NO ABSTRACT

PMID: 3624914 [PubMed - indexed for MEDLINE]

[Summary by LB- Mosquitoes can feed on infected blood and spirochetes can survive

in mosquitoes for 6 days, during feeding and re-feeding.

Spirochetes were detected in 82 mosquitoes within 48 hours of feeding.

Within 3 weeks spleens and kidneys of hamsters were infected by mosquito fed blood.]

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Bull Soc Pathol Exot Filiales. 1985;78(4):512-25.

[Etiologic and epidemiologic questions posed by erythema chronicum migrans and Lyme disease. Apropos of 4 cases at the Regional Hospital Center, Rennes].

[Article in French]

Doby JM, Chastel C, Couatarmanac'h A, Cousanca C, Chevrant-Breton J, Martin A, Legay B, Guiguen C.

Abstract

The authors give 4 observations, made in Rennes (France), of 3 cases contracted in France and 1 in Canada, cases they think to be related, for 3 at least, to the infectious entity described by American authors under the name of Lyme disease.

If 1 of these cases was limited to an erythema chronicum migrans, the 3 others showed a beginning evolution towards a classical Lyme disease. In 2 of these 3 last cases, the infection was perhaps cut short by a quickly applied therapy by antibiotics.

They discuss the different hypotheses about the negative Borrelia serologic reactions in 3 of the 4 cases.

A possible arboviral aetiology is evocked.

In only one of the 4 cases, a tick-bite can be asserted, the role in the the transmission of this kind of arthropods being strictly excluded in 2 of the 3 other cases (transmission likely by a mosquito and by a biting fly (tabanid?)).

The authors put the question of the possibility of transmission, for erythema chronicum migrans and Lyme disease, by arthropods other than ticks.

PMID: 4075471 [PubMed - indexed for MEDLINE]