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At least 19 recordsLinked to original sources

PubMed2006

Comparison of the activity of selamectin, imidacloprid and fipronil for the treatment of cats infested experimentally with Ctenocephalides felis felis and Ctenocephalides felis strongylus.

Twenty adult, domestic short hair cats were randomly allocated into four groups of five cats and housed in separated cages. Each cat was infested with 25 fleas Ctenocephalides felis felis and 25 Ctenocephalides felis strongylus and 2 days later (day 0) the cats in group 1, 2 and 3 received a spot on application of selamectin, imidacloprid or fipronil, respectively, while the cats in group four were not treated. The cats were combed 48 h later, the fleas were removed, counted and their subspecies were determined. All the cats were reinfested with the same number of the two subspecies of fleas on days 7, 14, 21, 29 and 35. The efficacy of each treatment was calculated 48 h after each infestation. The mean number of fleas on the control cats was 16.4 C. f. felis and 13.4 C. f. strongylus. The three treatments were effective for the first 31 days for C. f. felis and for the full 37 days for C. f. strongylus. Over the first 31 days, the efficacy of selamectin ranged from 89 to 100% and 85 to 100% against C. f. felis and C. f. strongylus, respectively, the efficacy of imidacloprid ranged from 76 to 100% and 92 to 100% and the efficacy of fipronil ranged from 98 to 100% and 97 to 100% against C. f. felis and C. f. strongylus. There were no significant differences between the control of C. f. felis and C. f. strongylus by the three products.

Animals↗

PubMed2006

Prevalence of Rickettsia felis in the fleas Ctenocephalides felis felis and Ctenocephalides canis from two Indian villages in Sao Paulo Municipality, Brazil.

We evaluated the presence of Rickettsia infection among fleas collected on domestic dogs in two Guarani Indian communities in the suburban area of São Paulo Municipality, Brazil. A total of 114 Ctenocephalides felis felis and 47 Ctenocephalides canis were collected from 40 dogs. A total of 41 C. felis felis (36.0%) and 9 C. canis (19.1%) fleas yielded expected bands by PCR, which were all shown by DNA sequencing to be indentical to the corresponding sequence of a fragment of the Rickettsia felis gltA gene deposited in GenBank. The overall prevalence of R. felis was 31.0% (49/161).

Animals↗

PubMed2000

Efficacy of selamectin against adult flea infestations (Ctenocephalides felis felis and Ctenocephalides canis) on dogs and cats.

Selamectin was evaluated in eight controlled studies (4 in dogs, 4 in cats) to determine the efficacy of a single topical unit dose providing the recommended minimum dosage of 6mgkg(-1) against Ctenocephalides felis felis and Ctenocephalides canis fleas on dogs and against C. felis on cats. In addition, the effect of bathing on the efficacy of selamectin against C. felis was evaluated. Identical studies were performed in Beagles and domestic shorthaired cats. For each study, animals were allocated randomly to treatments of 8-12 animals each. All studies (dog studies A, B, C, and D and cat studies A, B, C, and D) evaluated the efficacy of selamectin without bathing. In addition, study C in both dogs and cats evaluated efficacy with a shampoo bath at 24h after dosing, and study D evaluated the efficacy of selamectin with water soaking at 2h after dosing or with a shampoo bath at 2-6h after dosing. Dog study B evaluated efficacy against C. canis, whereas all other studies used C. felis. In each study, selamectin was administered on day 0 as a topical dose that was applied directly to the skin in a single spot at the base of the neck in front of the scapulae. Dogs and cats were infested with approximately 100 viable unfed C. felis or C. canis on days 4, 11, 18, and 27. On days 7, 14, 21, and 30, approximately 72h after infestation, a comb count of the number of viable fleas present on each animal was made. For C. felis and C. canis for dogs and cats, compared with controls, selamectin achieved significant reductions in geometric mean adult flea comb counts of > or =98.9% on days 7, 14, and 21 in all eight studies. On day 30, the reduction for C. felis remained at or above 98.0%. This included the dogs and cats that were soaked with water or bathed with shampoo at 2, 6, or 24h after treatment. There were no significant (P>0.05) differences between the flea counts from selamectin-treated animals in these studies, regardless of bathing status. On day 30, a significant reduction of 91.8% was achieved against C. canis on dogs. Thus, these studies demonstrated that a single topical unit dose of selamectin was highly effective against adult fleas on dogs and cats for at least 27 days.

Administration, Topical↗

PubMed2001

Seasonal occurrence of Ctenocephalides felis felis and Ctenocephalides canis (Siphonaptera: Pulicidae) infesting dogs and cats in an urban area in Cuernavaca, Mexico.

The seasonal occurrence of Ctenocephalides felis felis (Bouché and Ctenocephalides canis (Curtis) infestation on dogs and cats in Cuernavaca City in Mexico, was determined by examining 1,803 dogs and 517 cats at two veterinary clinics during 1995-1997. The overall flea infestation was 30.3 and 30.1% for dogs and cats, respectively. There were no significant differences (P > 0.05) in percentage of infestation among years for both hosts. The infestation was somewhat higher in spring, summer, and autumn than in winter, but no statistical differences was found among seasons (P > 0.05) for both pets. No relationship existed between percentage of flea infestation and temperature or rainfall among seasons. On dogs, 81.1% were infested with only C. felis felis, 16.8% with C. canis, and 2% had both flea species; whereas 92.3% of the cats were infested with C. felis felis and 7.7% with C. felis felis and C. canis. The cat flea was the most prevalent flea species found other than C. canis; no other species were found on the dogs and cats. It appeared that flea life cycle development continued throughout the year.

Animals↗

PubMed1998

Molecular identification of Rickettsia typhi and R. felis in co-infected Ctenocephalides felis (Siphonaptera: Pulicidae).

Rickettsia typhi and R. felis, 2 closely related rickettsial species, often have been identified in cat fleas, Ctenocephalides felis (Bouché) from the same geographical location. However, no fleas have been found to be naturally infected concurrently with both rickettsial species. To examine whether one rickettsial species can develop simultaneously with another species in the same flea host, cat fleas, naturally infected with R. felis, were allowed to feed on blood containing R. typhi (Ethiopian strain, 10(7) PFU/ml). Experimental controls consisted of uninfected cat fleas, fleas infected with only R. typhi; and fleas naturally infected with only R. felis. After 9 d at 28 degrees C, the fleas were examined by PCR amplification and subsequent restriction digest analysis and dot blot hybridization of PCR products. Results from these studies demonstrated that R. felis and R. typhi are capable of co-existing in the same flea host. Subsequent isolation of R. typhi from dually infected fleas by tissue culture indicated that R. typhi was viable and capable of being maintained in fleas naturally infected with R. felis. As more studies confirm the presence of R. felis and R. typhi in domestic pets and peridomestic vertebrates in urban areas, the ability of the individual cat fleas, which live on these animals, to support both rickettsial species could be an epidemiologically important consideration.

Animals↗

PubMed2002

Identification of Ctenocephalides felis fleas as a host of Rickettsia felis, the agent of a spotted fever rickettsiosis in Yucatań, Mexico.

In search for the vector of the recently recognized spotted fever rickettsiosis of the Yucatán, ticks, fleas, and lice were collected from vegetation and dogs in localities where seropositive persons had been found. The arthropods were examined by polymerase chain reaction (PCR) using primers for the genus-specific 17-kDa protein gene followed by restriction fragment length polymorphism (RFLP) and DNA sequencing. Eleven (20%) of 54 pools of Ctenocephalides felis fleas contained DNA of Rickettsia felis. None of 219 Amblyomma cajennense, 474 Rhiphicephalus sanguineus, 258 Boophilus sp. ticks, and 33 Poliplax species lice contained DNA of Rickettsia. The identity of the rickettsial DNA was confirmed as R. felis by PCR/RFLP for the citrate synthase and outer membrane protein A genes and by DNA sequencing. The results indicate that the host of R. felis in Yucatán is C. felis and suggest that the spotted fever rickettsiosis that has infected >5% of the population of the Yucatán and can present as a dengue-like illness is likely to be caused by R. felis.

Animals↗

PubMed2000

A comparison of jump performances of the dog flea, Ctenocephalides canis (Curtis, 1826) and the cat flea, Ctenocephalides felis felis (Bouché, 1835).

Jump performances of Ctenocephalides canis and Ctenocephalides felis felis have been measured and compared on unfed young imagos. The mean length of the C. felis felis jump was 19.9+/-9.1cm; minimum jump was 2cm, and the maximum was one 48cm. The C. canis jump was significantly longer (30.4+/-9.1cm; from 3 to 50cm). For height jump evaluation, grey plastic cylindric tubes measuring 9cm in diameter were used. Their height was increasing from 1 to 30cm by 1cm. Groups of 10 fleas of the same species were deposited on the base of the tube. The number of fleas which succeeded in jumping above the tube was recorded. The mean height jump carried out by 50% of fleas was calculated after linearisation of the curves: it was 15.5 and 13.2cm for C. canis and C. felis, respectively. The highest jump was 25 for C. canis and 17cm for C. felis.

Animals↗

PubMed1998

Development and evaluation of a PCR-based assay for detection of Haemobartonella felis in cats and differentiation of H. felis from related bacteria by restriction fragment length polymorphism analysis.

The 16S rRNA gene of Haemobartonella felis was amplified by using universal eubacterial primers and was subsequently cloned and sequenced. Based on this sequence data, we designed a set of H. felis-specific primers. These primers selectively amplified a 1,316-bp DNA fragment of the 16S rRNA gene of H. felis from each of four experimentally infected cats at peak parasitemia. No PCR product was amplified from purified DNA of Eperythrozoon suis, Mycoplasma genitalium, and Bartonella bacilliformis. Blood from the experimental cats prior to infection was negative for PCR products and was greatly diminished or absent 1 month after doxycycline treatment. The overall sequence identity of this fragment varied by less than 1.0% among experimentally infected cats. By taking into consideration the secondary structure of the 16S rRNA molecule, we were able to further verify the alignment of nucleotides and quality of our sequence data. In this PCR assay, the minimum detectable number of H. felis organisms was determined to be between 50 and 704. The potential usefulness of restriction enzymes DdeI and MnlI for distinguishing H. felis from closely related bacteria was examined. This is the first report of the utility of PCR-facilitated diagnosis and discrimination of H. felis infection in cats.

Anaplasmataceae↗

PubMed2001

Comparison of the activity of selamectin, imidacloprid and fipronil for the treatment of dogs infested experimentally with Ctenocephalides canis and Ctenocephalides felis felis.

Twenty-four beagles were randomly allocated into four groups of six and housed in separate cages. Each dog was infested with 25 Ctenocephalides canis and 25 Ctenocephalides felis felis and two days later (day 0) the dogs in groups 1, 2 and 3 received a spot-on application of selamectin (6 mg/kg), imidacloprid (10 mg/kg), or fipronil (6-7 mg/kg), respectively, while the dogs in group 4 were not treated. The dogs were combed 48 hours later, the fleas were removed, counted and their species were determined. All the dogs were reinfested with the same number of the two species of fleas on days 7, 14, 21, 28 and 35, and the efficacy of the treatments was calculated 48 hours after each infestation. The mean numbers of fleas on the control dogs were 19.8 C. canis and 14.7 C. felis felis. The three treatments were effective for the full 35 days of the trial; over the first 28 days, the efficacy of selamectin ranged from 81 to 100 and 92 to 99 per cent against C. felis felis and C canis, respectively, the efficacy of imidacloprid ranged from 98 to 100 per cent and the efficacy of fipronil was 100 per cent against both species. There were no significant differences between the three treatments.

Administration, Cutaneous↗

PubMed2001

Establishment of the cat flea (Ctenocephalides felis felis) on the ferret (Mustela putorius furo) and its control with imidacloprid.

As the ferret, Mustela putorius furo L. (Carnivora: Mustelidae), is becoming increasingly popular as a pet animal and as it is susceptible to the cat-flea, Ctenocephalides felis felis Bouché (Siphonaptera: Pulicidae), an experimental model was established for evaluating insecticidal treatments on this host. A high establishment rate (76.7-91.8%) was recorded when 60 unfed adult C. felis were placed on ferrets. This provided an adequate infestation for chemotherapeutic evaluation without causing undue discomfort to the host. Twelve ferrets were allocated to two groups matched for sex and individual ability to sustain a flea population. One group was treated topically with an imidacloprid spot-on formulation at a dose rate of 10 mg/kg body-weight on Day 0. All ferrets were infested with C. felis on Days -1, 7, 14, 21 and 28, and flea counts were performed 8 and 24 h post-treatment and one day after each subsequent infestation. Fleas were removed at all but the 8 h count (when they were returned to their host). Flea burdens were reduced by 95.3% (P < 0.001) within 8 h of treatment and 100% efficacy was recorded at 24 h. At 1, 2, 3 and 4 weeks post-treatment, protection against re-infestation was 92.9% (P < 0.001), 55.7% (P < 0.02), 18.3% (NS) and 7.4% (NS), respectively. Thus, at this dose rate, imidacloprid gave excellent efficacy against a resident C. felis population and provided a high level of residual activity for at least one week after treatment.

Administration, Topical↗

PubMed2000

Dose selection of selamectin for efficacy against adult fleas (Ctenocephalides felis felis) on dogs and cats.

Selamectin, a novel avermectin, was evaluated in two controlled studies (one in Beagles, one in domestic shorthaired cats) to determine an appropriate topical dose for efficacy against adult Ctenocephalides felis felis (C. felis) fleas on dogs and cats for 1 month. For each study, animals were allocated randomly to four treatments. One treatment consisted of the inert formulation ingredients (vehicle) administered as a negative control, and the other three treatments consisted of a single topical dosage of 3, 6, or 9mgkg(-1) of selamectin. In each study, selamectin was administered as a topical dose applied to the skin in a single spot at the base of the neck in front of the scapulae. Dogs and cats were infested with 100 viable unfed C. felis (50 males and 50 females) on days 4, 11, 18, and 27. Seventy-two hours (+/-2h) after each infestation, on days 7, 14, 21, and 30, a comb count to determine the number of viable fleas present on each animal was performed. Efficacy of selamectin on day 30 was used to select an appropriate dose. For dogs and cats, percentage reductions in geometric mean flea comb counts for the three selamectin treatments ranged from 94. 6 to 100% on days 7, 14, and 21, compared with the negative-control treatment. On day 30, reductions in flea comb counts were 81.5, 94.7, and 90.8% for dogs, and 79.8, 98.0, and 96.2% for cats treated with selamectin at 3, 6, or 9mgkg(-1), respectively. For day 30 flea comb counts for dogs and cats, analysis of variance showed that the three selamectin treatments resulted in significantly (P< or =0.05) lower counts than did the negative-control treatment. For dogs and cats, geometric mean flea counts for selamectin administered at a dosage of 3mgkg(-1) were significantly (P< or =0.05) higher than those for the 6 and 9mgkg(-1) treatment dosages combined. There were no significant differences in flea counts between the 6 and 9mgkg(-1) treatments. This analysis was confirmed by linear-plateau modeling. Thus, the optimal dose of selamectin for efficacy against adult fleas for both dogs and cats, as estimated by the turning point (plateau) in the dose response curve, was 6mgkg(-1).

Administration, Topical↗

PubMed2000

Efficacy of selamectin administered topically to pregnant and lactating female dogs in the treatment and prevention of adult roundworm (Toxocara canis) infections and flea (Ctenocephalides felis felis) infestations in the dams and their pups.

The efficacy of selamectin in the treatment and prevention of naturally acquired Toxocara canis infections and experimentally induced flea (Ctenocephalides felis felis) infestations in dams and their suckling pups was evaluated by administering selamectin to the adult females only, approximately 40 and 10 days before parturition and 10 and 40 days after parturition. Unit doses of the commercial formulation of selamectin were administered to the dams to provide at least the minimum recommended dosage of 6mgkg(-1) (range, 6-12mgkg(-1)). Dams and their pups were housed in carpeted environments able to support the flea life cycle. Flea infestations were established initially by experimental infestation before treatment administration and by repeated re-infestation of dams at approximately weekly intervals throughout the study, which was completed 45 days after parturition. There were no adverse drug experiences related to treatment with selamectin and no treatment-related mortalities. Percentage reductions in geometric mean T. canis faecal egg counts for the selamectin-treated dams, compared with those receiving the negative-control treatment (vehicle only) were 99.7% at the end of the study (P=0.0001). Geometric mean faecal egg counts in pups from selamectin-treated females were reduced by > or =96% on the 24th and 34th days after birth (P=0.0001), and the number of adult worms recovered from the gastrointestinal tract of pups from selamectin-treated dams was reduced by 98.2% (P=0.0001), compared with that for pups from dams treated with the vehicle only. Percentage reductions in geometric mean flea counts for selamectin-treated dams and their pups, compared with vehicle-treated dams and their pups, were > or =99.8% (P=0.0001) and 100% (P=0.0001), respectively, throughout the study. Thus, selamectin administered topically at a minimum unit dosage of 6mgkg(-1) to dams with naturally acquired T. canis infections and experimentally induced C. felis infestations was safe and highly effective in the treatment, control, and prevention of adult T. canis infection and C. felis infestation affecting both the dams and their pups.

Administration, Topical↗

PubMed2005

Isolation and properties of methanesulfonate-degrading Afipia felis from Antarctica and comparison with other strains of A. felis.

Three novel strains of methylotrophic Afipia felis were isolated from several locations on Signy Island, Antarctica, and a fourth from estuary sediment from the River Douro, Portugal. They were identified as strains of the alpha-2 proteobacterium A. felis by 16S rRNA gene sequence analysis. Two strains tested were shown to contain the fdxA gene, diagnostic for A. felis. All strains grew with methanesulfonate (and two strains with dimethylsulfone) as sole carbon substrate. Growth on methanesulfonate required methanesulfonate monooxygenase (MSAMO), using NADH as the reductant and stimulated by reduced flavin nucleotides and Fe(II). Polymerase chain reaction amplification of DNA from an Antarctic strain showed a typical msmA gene for the alpha-hydroxylase of MSAMO, and both Antarctic and Portuguese strains contained mxaF, the methanol dehydrogenase large subunit gene. This is the first report of methanesulfonate-degrading bacteria from the Antarctic and of methylotrophy in Afipia, and the first description of any bacterium able to use both methanesulfonate and dimethylsulfone. In contrast, the type strain of A. felis DSM 7326(T) was not methylotrophic, but grew in defined mineral medium with a wide range of single simple organic substrates. Free-living Afipia strains occurring widely in the natural environment may be significant as methylotrophs, degrading C(1)-sulfur compounds, including the recalcitrant organosulfur compound methanesulfonate.

Afipia↗

PubMed2006

Prevalence of Rickettsia felis in Ctenocephalides felis and Ctenocephalides canis from Uruguay.

Our aim was to determine the presence of Rickettsia spp. in 66 fleas from Uruguay. Rickettsial DNA was amplified using gltA and ompB PCR primers. Rickettsia spp. were found in 41% of the fleas (25 Ctenocephalides felis and 2 Ctenocephlides canis). Sequences resulted in the identification of Rickettsia felis and four genotypes closely related to this species (Rickettsia sp. TwKM03, California 2, Hf187, and RF2125). The presence of R. felis in fleas from Uruguay in was demonstrated. This is the second species of Rickettsia identified in Uruguay in the past 2 years using molecular approaches, and it is helping to clarify the etiology of rickettsial diseases in the region.

Animals↗

PubMed2002

Vertical transmission of Rickettsia felis in the cat flea (Ctenocephalides felis Bouché).

Rickettsia felis can be maintained in cat fleas by vertical transmission for up to 12 generations without the benefit of an infected host. Horizontal transmission or the acquisition of R. felis by fleas feeding on cats or artificially infected meals were not demonstrated in this study. Horizontal transmission of R. felis by the ingestion of feces or eggs by flea larvae was not detected. We also tested for and found no evidence to support horizontal transmission by contact among positive fleas and negative fleas.

Animals↗

PubMed2006

Polygenic detection of Rickettsia felis in cat fleas (Ctenocephalides felis) from Israel.

The presence of Rickettsia felis, an emerging bacterial pathogen, was investigated in 79 cat flea (Cteno-cephalides felis) pools from Israel (5 to 20 fleas each) by polymerase chain reaction (PCR) and sequencing of 5 different genes. Amplified targets included both metabolic (gltA and fusA) and surface antigen (ompA, ompB, and the 17-kDa antigen) genes. R. felis DNA was detected in 7.6% of the flea pools. Two genotypes similar in their housekeeping gene sequences but markedly different in their surface antigenic genetic milieus were characterized. This is the first detection of this flea-transmitted rickettsia within its vector in Israel and the Middle East. Although no clinical case has been reported in human beings in Israel to date, these findings suggest that this infection is prevalent in Israel.

Amino Acid Sequence↗

PubMed2000

Evaluation of the effects of selamectin against adult and immature stages of fleas (Ctenocephalides felis felis) on dogs and cats.

The adulticidal, ovicidal, and larvicidal effects of selamectin against flea (Ctenocephalides felis felis) infestations on dogs and cats were evaluated in a series of seven controlled and masked studies (three in cats, four in dogs). Animals were randomly allocated to treatment with either selamectin at a minimum dosage of 6mgkg(-1) in the commercial formulation or one of two negative-controls (0.9% NaCl solution or the vehicle from the commercial formulation). Treatments were administered topically in a single spot on the skin at the base of the neck in front of the scapulae. Speed of kill, measured by flea comb counts at 12h intervals during the 48h immediately following a single treatment on day 0, was evaluated in two studies. One study was in dogs and the other in cats, and each animal was infested with approximately 100 unfed viable adult fleas prior to treatment. Reductions in geometric mean flea counts for selamectin compared with saline were >98% between 24 and 36h after treatment in dogs, and between 12 and 24h after treatment in cats (P< or =0.0006). Efficacy in reducing flea egg hatch and larval development was evaluated in four studies, in which dogs and cats were treated once on day 0 and then repeatedly infested with approximately 600 fleas. Flea eggs were collected approximately for 72h after each infestation, on days 3, 7, 14, 21, and 30, counted, and cultured to determine their hatchability and subsequent larval development. Compared with the vehicle, selamectin was highly effective in reducing flea egg hatch (>92% in cats) and larval development (> or =95% for dogs and cats), and emergence of adults (97.8-100% for dogs, 85.6-100% for cats) for 30 days. Effects of exposure to hair coat debris were investigated in a study with dogs treated once on day 0 and repeatedly infested with 100 adult fleas. Debris (dander, flea faeces, hair, scales) was collected on days 1, 7, 14, 21, and 30 and added to normal flea eggs or larvae for incubation. Compared with debris from vehicle-treated dogs, debris from selamectin-treated dogs was highly effective in preventing egg hatch (>96%), in killing larvae (>98%) and in preventing larval development to adults (>99%) (P</=0.0033). Selamectin was shown to be highly effective in the treatment and control of flea infestations (C. felis) on dogs and cats. The adulticidal, ovicidal, and larvicidal effects of selamectin will be important in interrupting the flea life cycle by preventing the introduction and establishment of new flea infestations in a household environment.

Administration, Topical↗

PubMed2003

Comparison of the activity of selamectin, fipronil, and imidacloprid against flea larvae (Ctenocephalides felis felis) in vitro.

The activity of selamectin, fipronil and imidacloprid against larval cat fleas (Ctenocephalides felis felis) was evaluated in an in vitro potency assay system. One hundred microliters of each compound at various concentrations in acetone were added to glass vials (1.5 by 3 cm) to which had been previously added 20 mg of sand and 10 mg of flea feces. Vials were then ball milled to allow the acetone to evaporate. Selamectin and fipronil were tested at 0.001, 0.003, 0.005, 0.01, 0.03, 0.05, 0.11, 0.3, and 0.5 microg of active compound per tube. Imidacloprid was tested at 0.01, 0.03, 0.05, 0.1, 0.3, 0.5, 1.0, 3.0, and 5.0 microg of active compound per tube. Thirty first instar C. felis larvae were added to each vial. The number of larvae remaining alive in each vial was determined once daily for 72 h. With selamectin, reductions of >/=93.5% were achieved at 24 h after exposure at doses of >/=0.3 microg. In contrast, at 24 h neither fipronil nor imidacloprid reached 90% reduction, even at the highest doses tested (0.5 microg for fipronil and 5.0 microg for imidacloprid). Selamectin was significantly (P</=0.05) more potent than imidacloprid and fipronil at levels >/=0.03 microg. A similar pattern of activity was observed at both 48 and 72 h, but higher percentages of larvae were killed for each of the compounds as the incubation time increased. At 72 h selamectin was significantly (P</=0.05) more potent than imidacloprid at levels of 0.01-0.1 microg and significantly (P</=0.05) more potent than fipronil at levels of 0.003-0.01 microg. Therefore, selamectin was more potent than either fipronil or imidacloprid in killing flea larvae in this in vitro assay system.

Animals↗