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PubMed2002

Lack of correlation between Bartonella DNA detection within fleas, serological results, and results of blood culture in a Bartonella-infected stray cat population.

OBJECTIVE: To correlate the presence of different Bartonella species in the blood of a stray cat population trapped on a French military base with specific antibodies and species detected in cat fleas. METHODS: The prevalence of Bartonella bacteremia was investigated in 61 cats by plating frozen whole blood on blood agar plates. Identification of isolates and detection of Bartonella DNA from cat flea batches from ten cats was achieved by PCR amplification and sequencing. Antibody detection was performed by microimmunofluorescence. RESULTS: We obtained 38 isolates of Bartonella from blood. Sixteen were identified as B. clarridgeiae, 15 as B. henselae genotype/serotype Houston 1 (type I), and seven as B. henselae genotype/serotype Marseille (type II). B. henselae was detected in five fleas, and B. clarridgeiae in one flea. Sixty-one per cent of the cats had detectable antibodies against at least one species or serotype. Sixteen cats had antibodies against only one antigen. For each species, the distribution of bacteremia among the cats could not be correlated with either the distribution of infected fleas or the distribution of specific antibodies. CONCLUSIONS: The lack of correlation between Bartonella DNA detection within fleas, serological results, and results of blood culture is probably due to a lack of natural heterologous protection between species or serotypes. Cats suffer bacteremia with three Bartonella species and should therefore be considered the reservoirs of at least three human pathogens.

Animals↗
PubMed1999

Notes on the life-history of the rabbit flea Caenopsylla laptevi ibera Beaucournu & Marquez, 1987 (Siphonaptera: Ceratophyllidae) in eastern Spain.

The rabbit flea Caenopsylla laptevi ibera occurs in arid environments of central and eastern Spain. Although the fleas breed during the coolest, most humid part of the year, the larvae survive and grow in sand at only 50-60% relative humidity. At 22 degrees C and 80% relative humidity eggs hatch in six days and the cocoon stage is reached 10-11 days after hatching. Female fleas emerge from pupation at about 17 days after cocoon spinning; males emerge a little later at a mean of 20 days. Adult fleas are mainly found on the host Oryctolagus cuniculus. Measurements of burrow microclimate confirmed that in south-eastern Spain burrow humidity was adequate for the development of C. I. ibera larvae over most of the year. However, breeding may be restricted for at least part of the year, as the larvae of C. I. ibera apparently cannot complete development at 25 degrees C or above. In the laboratory, fleas can enter a prolonged quiescent period while in the cocoon. This is possibly a facultative, pre-pupal diapause and the likely mechanism that accounts for the disappearance of adult fleas from the field by spring and their reappearance each autumn.

Animals↗
PubMed2004

Ectoparasitic "jacks-of-all-trades": relationship between abundance and host specificity in fleas (Siphonaptera) parasitic on small mammals.

Animal species with larger local populations tend to be widespread across many localities, whereas species with smaller local populations occur in fewer localities. This pattern is well documented for free-living species and can be explained by the resource breadth hypothesis: the attributes that enable a species to exploit a diversity of resources allow it to attain a broad distribution and high local density. In contrast, for parasitic organisms, the trade-off hypothesis predicts that parasites exploiting many host species will achieve lower mean abundance on those hosts than more host-specific parasites because of the costs of adaptations against multiple defense systems. We test these alternative hypotheses with data on host specificity and abundance of fleas parasitic on small mammals from 20 different regions. Our analyses controlled for phylogenetic influences, differences in host body surface area, and sampling effort. In most regions, we found significant positive relationships between flea abundance and either the number of host species they exploited or the average taxonomic distance among those host species. This was true whether we used mean flea abundance or the maximum abundance they achieved on their optimal host. Although fleas tended to exploit more host species in regions with either larger number of available hosts or more taxonomically diverse host faunas, differences in host faunas between regions had no clear effect on the abundance-host specificity relationship. Overall, the results support the resource breadth hypothesis: fleas exploiting many host species or taxonomically unrelated hosts achieve higher abundance than specialist fleas. We conclude that generalist parasites achieve higher abundance because of a combination of resource availability and stability.

Animals↗
PubMed1995

Survival and reproduction of the cat flea (Siphonaptera: Pulicidae) fed human blood on an artificial membrane system.

Adult cat fleas, Ctenocephalides felis (Bouché), survive and reproduce when fed human blood through an artificial membrane system. When a dog hair substrate was included in cages with the fleas, mean adult mortality was 2.4 after 12 d of bloodfeeding. Egg production began after 3 d and was continuous for 12 d, ranging from 3 to 4 eggs per female per day. In cages without hair, mean adult mortality was 61.2% after 12 d of bloodfeeding. Egg production began after 2 d, reached a maximum of two eggs per female per day after 7 d, and decreased thereafter. No significant differences in egg hatch were seen in treatment groups sampled from 5 to 7 d after the onset of bloodfeeding. After 7 d, however, egg hatch for fleas maintained in cages without hair was significantly lower than in cages where fleas were maintained on dog hair. Adult emergence from these larvae did not differ significantly between the two groups. Egg hatch and adult emergence in both groups of fleas fed on human blood did not differ significantly from egg hatch and adult emergence in fleas fed on colony cats.

Animals↗
PubMed1993

Characterization of allergens of the cat flea, Ctenocephalides felis: detection and frequency of IgE antibodies in canine sera.

Flea allergens, fractionated by polyacrylamide gel electrophoresis and transferred to nitrocellulose, were identified using 20 flea-allergic dog sera in an enhanced chemiluminescent assay for canine IgE antibodies. At least 15 different flea components in the molecular weight range of 14-150 K bound IgE and every serum demonstrated a different pattern of binding. Three of the components with apparent molecular weights of 25, 40 and 58 K were each bound by at least 40% of the sera. No reactivity was seen when normal dog sera were used. These results demonstrate a greater number of flea allergens and a far greater diversity of the IgE antibody response to flea allergens than has previously been described, and suggest that immediate hypersensitivity may be an important mechanism in the pathogenesis of canine flea allergy.

Allergens↗
PubMed2001

[Bartonella henselae infection in domestic cat and dog fleas].

We studied on the infection of domestic cat and dog fleas with Bartonella henselae by polymerase chain reaction (PCR). A total of 62 fleas (36 Ctenocephalidis felis from cats, 24 C. felis from dogs and 2 Ctenocephalidis canis from dogs), stored in 70% ethanol, were analyzed by PCR for B. henselae specific DNA. Of the 62 fleas, C. felis from cats and dogs were positive for B. henselae specific DNA in 12 of the 36 (33.3%) and in 5 of the 24 (20.8%), respectively, and C. canis from dogs was positive in 2 of the 2 (100%). Our results demonstrated that pet fleas were infected with B. henselae, and suggest that flea transmission of B. henselae between cats or dogs may occur, and direct transmission of B. henselae from pet fleas to human may cause cat scratch disease.

Animals↗
PubMed1995

Disinfestation of experimentally infested cat fleas, Ctenocephalides felis, on cats and dogs by oral lufenuron.

In vivo efficacy of orally administered lufenuron, an insect growth regulator, in disinfesting cat fleas was evaluated, using flea-free cats and dogs which were purchased and infested every 10 days with cat fleas from a colony kept in our laboratory. Lufenuron was orally administered as a single dose of 15, 30, or 60 mg/kg to cats, and 5, 10 or 20 mg/kg to dogs. In cats, adult flea emergence was intensively prevented for 30 days by dosing of 15 mg/kg of lufenuron and 40 days by 30 or 60 mg/kg. The average egg hatch rate in 15 mg/kg group was, however, significantly higher than those in 30 mg/kg or more, suggesting necessity to dose 30 mg/kg to cats to prevent development of cat fleas effectively. In dogs, a lower dose of the drug, 10 mg/kg seemed to be sufficient for the complete prevention of flea development.

Administration, Oral↗
PubMedDate not supplied

[Natural infection by Yersinia pestis, in fleas from plague foci in the northeast of Brazil].

Three different containment transport processes of fleas were evaluated as an approach to the bacteriologic isolation of Yersinia pestis. The three methods employed were: live fleas in glass tubes containing pieces of wrapped filter paper; dead fleas in saline solution; and macerated fleas in Cary-Blair culture medium. The two latter methods were almost equal and superior to the first method. A total of 29512 flea pools, from plaque foci in Northeast Brazil collected during 1966 to 1982 were evaluated by the three methods. Among these samples, 236 (0.80%) flea pools were positive with regard to bacteriological cultivation and/or infection of susceptible animals.

Animals↗
PubMed2001

Laboratory techniques for rearing the fleas (Siphonaptera: Ceratophyllidae and Pulicidae) of California ground squirrels (Rodentia: Sciuridae) using a novel nest box.

Three species of fleas, Oropsylla montana (Baker), Hoplopsyllus anomalus (Baker), and Echidnophaga gallinacea (Westwood), occur seasonally on the California ground squirrel, Spermophilus beecheyi (Richardson). Few studies have focused on the biology and ecology of these fleas despite their importance in the epidemiology of sylvatic plague. To best duplicate a natural parasite-host relationship in the laboratory, a novel nest box was developed that facilitated housing wild-caught S. beecheyi, was conducive to rearing fleas, and met modern standards for laboratory animal hygiene. This flexible system allowed adult fleas with different feeding strategies to be colonized successfully while providing sufficient flea eggs for both colony maintenance and biological research. The techniques described could be adapted to work with other species of rodents and their fleas.

Animals↗
PubMed2001

Systemic activity of the avermectins against the cat flea (Siphonaptera: Pulicidae).

Ivermectin has potent systemic activity against numerous species of nematodes and arthropods, but there are some important species in these two groups, such as the cat flea, Ctenocephalides felis (Bouché), that appear to be refractory to it. In an effort to determine if the lack of systemic activity against C. felis is specific to ivermectin, or if it is a class-wide phenomenon, 20 avermectin derivatives were tested in an artificial membrane flea feeding system at concentrations of 20, 10, and 1 microg/ml. Results showed that ivermectin had LC90 and LC50 values against fleas of 19.1 and 9.9 microg/ml, respectively. Only four of the other 19 compounds evaluated possessed both LC90 and LC50 values more potent than ivermectin and even then the advantage was modest. Among those four compounds was a two-fold increase in potency relative to ivermectin when the LC90 values were considered (range, 9.2-10.3 microg/ml) and a two- to eight-fold increase when the LC50 values were examined (range, 1.23-5.26 microg/ml). Neither the possession nor the number of oleandrosyl sugars on the macrocyclic backbone were relevant for additional flea activity because among these four compounds were two disaccharides, a monosaccharide and an aglycone. Also, bond disposition between C-22 and 23 did not contribute to increase in activity because these molecules comprise members with either single or double bonds. One of these avermectin analogs was scaled-up and tested subcutaneously in a dog at >100 times the commercial ivermectin dosage and zero efficacy was observed against the flea. We conclude that even the best in vitro avermectin does not have the in vivo potential to become a commercial oral or subcutaneous flea treatment for companion animals.

Animals↗
PubMed2003

Wolbachia endosymbionts in fleas (Siphonaptera).

Intracellular endosymbionts, Wolbachia spp., have been reported in many different orders of insects and in nematodes but not previously in fleas. This is the first conclusive report of Wolbachia spp. within members of the Siphonaptera. Using nested polymerase chain reaction (PCR) targeting of the 16S ribosomal RNA gene, we screened for Wolbachia spp. in fleas collected from 3 counties in Georgia and 1 in New York. The prevalence of Wolbachia spp. detected varied among the 6 different species screened: 21% in the cat flea Ctenocephalides felis (n = 604), 7% in the dog flea C. canis (n = 28), 25% in Polygenus gwyni (n = 8), 80% in Orchopeas howardi (n = 15), 94% in Pulex simulans (n = 255), and 24% in the sticktight flea Echidnophaga gallinacea (n = 101). Wolbachia spp. infection in fleas was confirmed by sequencing positive PCR products, comparing sequenced 16S ribosomal DNA (rDNA) with Wolbachia spp. sequences in GenBank using BLAST search, and subjecting sequence data to phylogenetic analysis. For further confirmation, 16S rDNA-positive samples were reamplified using the wsp gene.

Animals↗
PubMed1991

Mass flea outbreak at a child care facility: case report.

Cat fleas, Ctenocephalides felis Bouchet, were collected at a Mississippi child care facility after reports of large numbers of adult fleas occurring on children and personnel. One building yielded 161 (99 percent) of the fleas collected. Urticarial lesions due to flea bites occurred on the legs of six children. Flea presence was due to cats occupying the crawl space. Fleas were eradicated by eliminating entry of cats and using residual insecticides throughout the facility.

Animals↗
PubMed1975

[Serological study of nontriturated fleas following preliminary cultivation of the plague microbe].

Under experimental conditions there was shown a possibility of serological study of nontriturated fleas for the presence of Past. pestis. Hottinger's broth with gentian-violet ((0.0003%) sodium sulfite (0.03%) and a surfactant--O (see article)-7 (3%) served as the growing medium. After the nontriturated fleas were grown for 48 hours at 37 degrees C the capsular antigen was detected with the aid of the passive hemagglutination and antibody neutralization tests. Detection of the capsular antigen in the growing medium pointed to the presence of Past. pestis in the fleas. To test the serological method of study the nontriturated fleas, the insects were collected in the colonies of Rhombomys opimus Licht. at the epizootic territory. The collected fleas were divided into portions (each portion contained not more than 20 fleas). Half of the portions of each collection was studied after trituration by the usual bacteriological method, and another--by serological method without trituration of the insects. In examining the parallel portions (a total of 2400 portions, about 32 000) it appeared that positive results were obtained by both methods with about the same frequency.

Animals↗
PubMed1975

Insecticide susceptibility of some vector fleas and mosquitoes in Burma.

Rat fleas and mosquitoes are insect vectors of public health importance in Burma. Plague is endemic in Central Burma and DDT has been the principal insecticide used for its control to date. Dengue haemorrhagic fever, recently introduced and transmitted by Aedes aegypti, has been spreading to major towns since 1971. The rodents, Rattus rattus, R. exulans, Bandicota bengalensis, Mus musculus, as well as shrews were commonly caught during routine trapping in the country. Rattus norvegicus, prevalent in Rangoon City, is not found in Central Burma. The rat fleas, Xenopsylla cheopis and X. astia, were found to be infesting these rodents, the former being the principal vector of plague. Insecticide susceptibility tests have been carried out periodically in plague endemic areas and Rangoon since 1966 and it is now observed that rat fleas in most of these endemic towns and Rangoon Port are no longer susceptible to DDT. Subsequent rechecks in towns where fleas became resistance to DDT show that fleas are persistently resistant to the insecticide. Aedes aegypti is found to be highly prevalent both in rural and urban areas of almost every major town and townships below 900 meters. Insecticide susceptible tests on this mosquito in limited areas show that the mosquito is generally resistant to DDT but susceptible to other insecticides. With the development of DDT resistance in fleas, it is now necessary to change to an effective insecticide in the control of plague in Burma.

Aedes↗
PubMed1992

Studies on flea fauna in El Fayoum Governorate, Egypt.

This paper dealt with the studies of flea fauna as collected on the rodent hosts over one year. The collected rodents (499) in a descending order of abundance in the collection were Rattus rattus, R. norvegicus, Mus musculus, Gerbillus pyramidum and Arvicanthis niloticus. The collected fleas in a descending order in the collection were X. cheopis, P. irritans, N. jasciatus, C. felis, L. segnis and E. gallinacea. The total flea index reached the maximum (0.76) in May and it was zero in December and January. The highest number of fleas was on R. norvegicus and A. niloticus and the lowest was on G. pyramidum. The highest number of rodents and their flea ectoparasites was during the Spring and the lowest was during Autumn. The medical importance of the collected fleas and the whole results were discussed.

Animals↗
PubMedDate not supplied

[Species composition and population dynamics of fleas on the small suslik in stable foci of plague on the Ergenin ridge].

The paper presents results of investigations of fleas from Citellus pygmaeus obtained during epizootological surveys in 1972-1974 (the Ergenin ridge, Kalmyk ASSR). The most high number of the main species of fleas of C. pygmaeus was observed in the first year of epizootic on the background of great abundance of the host (over 30 specimens per 1 hectare). In the following years the decrease in the number of C. pygmaeus was accompanied by the fall in the fleas number. The distribution of different species of fleas in a microbiotope is uneven in various periods. In all periods in nests fleas of N. setosa were dominant while fleas of C. tesquorum were most abundant on the host. In burrows there was noted a change of dominant species: in the period of intensive epizootic of 1972 they were Ct. pollex and C. tesquorum, in 1973 during a slump of epizootic--C. tesquorum and N. setosa and in 1974 when epizootic was not discovered at all--N. setosa.

Animals↗
PubMedDate not supplied

[Epizootological role of fleas in the Gorno-Altai natural plague focus (a review)].

Epizootological role of fleas in the Gorno-Altai natural plague focus (Sailugemsk focus) and numerous data on the flea viability are analyzed and generalized. Information concerning the flea natural infectivity with Yersinia pestis altaica is represented. Ecological peculiarities of some flea species parasitizing the main host, Mongolian pika Ochotona pallasi, and nature of their interrelations with Y. pestis are investigated. It is shown that the flea taxocenosis provides the permanent all year-round circulation of Y. pestis in the Gorno-Altai natural focus. Certain combinations of structural elements of the flea taxocenosis have a dominant significance in determination the circulation process at different phases of the annual epizootic cycle.

Animals↗
PubMedDate not supplied

[Seasonal dynamics of a flea number (Siphonaptera) on the common shrew (Sorex araneus) in the north part of the Novgorod oblast].

In the course of 5-year stationary investigations of the common shrew Sorex araneus in the north part of the Novgorod oblast, 12 flea species have been recorded on this host. Among them, Palaeopsylla soricis and Doratopsilla dasycnema are specific parasites of small insectivores, including the common shrew. Hystrichopsylla talpae is a polyxenous species, parasitizing both rodents and insectivores. Other 9 flea species are not common parasites of S. araneus and apparently have come to this host from other mammal species inhabiting the forest biotopes in the area of investigation. P. soricis and D. dasycnema have similar phenology of parasitism. These fleas appear in spring (April), are present during summer and autumn and disappear in winter. During a year, the abundance of these species shows three pikes, which correspond to three generations: spring (April), summer (June-July) and autumn (September-October) generation. The first species dominates in spring (April-May) and in the autumn-winter period, while the second species predominates in summer. These two species comprise over 90% of total number of fleas collected and determine general dynamics of the flea number on the shrews; during the year the flea number has a sinusoidal increasing from spring to autumn and minimum in winter.

Animals↗