Molecular detection of Rickettsia felis, Bartonella henselae, and B. clarridgeiae in fleas from domestic dogs and cats in Malaysia

The presence of Rickettsia felis, Bartonella henselae and B. clarridgeiae in 209 fleas (Ctenocephalides felis) obtained from domestic cats and dogs in several locations in Malaysia was investigated in this study. Using a polymerase chain reaction specific for the citrate synthase (gltA) and 17-kD antigenic protein (17kD) genes of rickettsiae, we detected R. felis DNA in 6 (2.9%) fleas. For detection of bartonellae, amplification of the heme-binding protein (pap31) and riboflavin synthase (ribC) genes identified B. henselae and B. clarridgeiae DNA in 24 (11.5%) and 40 (19.1%) fleas, respectively. The DNA of B. henselae and B. clarridgeiae was detected in 10 (4.8%) fleas. Two B. henselae genogroups (Marseille and Houston-1) were detected in this study; genogroup Marseille (genotype Fizz) was found more often in the fleas. The findings in this study suggest fleas as potential vectors of rickettsioses and cat-scratch disease in this country.     

Rickettsia, Ehrlichia, Anaplasma, and Bartonella in ticks and fleas from dogs and cats in Bangkok

Flea and tick specimens (5-10 fleas or ticks) on dogs and cats from various sites in Bangkok were tested by polymerase chain reaction and DNA sequencing to detect DNA of bacteria Rickettsia (gltA and 17?kDa genes), Anaplasmataceae (16S rRNA gene), and Bartonella (pap31 and its genes). We confirmed that Rickettsia sp. related to Rickettsia felis was detected in 66 of 98 (67.4%) flea specimens from dogs, whereas 8 Bartonella henselae and 2 Bartonella clarridgeiae were detected in 10 of 54 (18.5%) flea specimens from cats. Further, this work provides the first evidence of 10 Ehrlichia canis (3.3%), 7 Anaplasma platys (2.3%), and 2 Wolbachia spp. (0.66%) in 304 Rhipicephalus sanguineus tick specimens in Thailand.     

Rickettsia felis and Bartonella spp. in fleas from cats in Albania

Fleas can serve as vectors for bacterial pathogens like Bartonella and Rickettsia species, which have been isolated worldwide. However, the knowledge of the epidemiology of vector-borne diseases in general and thus on flea-borne diseases in Albania is limited. Therefore, from 78 free-roaming cats in Tirana, Albania, fleas (371 Ctenocephalides felis and 5 Ctenocephalides canis) were collected to examine them for the presence of Rickettsia and Bartonella species. Ten of the 371 C. felis (2.7%) were positive for Rickettsia felis, and 24 (6.5%) for Bartonella spp. (B. henselae and B. clarridgeiae). In total, fleas from 15 cats (19.2%) were positive for either one or the other of the pathogens. The results of this study provided evidence for the presence of R. felis (causing flea-borne spotted fever) and Bartonella spp. (causing cat scratch disease) in Albania. Thus, these infectious diseases should be considered as differential diagnoses when febrile symptoms are presented, especially after contact with cats or their fleas.     

Rickettsia felis and Bartonella henselae in fleas from Lebanon

A total of 155 fleas collected in 2009 in Lebanon from 16 cats (104 Ctenocephalides felis specimens, 1 C. canis specimen) and 2 dogs (50 C. canis specimens) were tested for the presence of Rickettsia spp. and Bartonella spp. using molecular methods, including real-time quantitative polymerase chain reaction (PCR), regular PCR, and sequencing of amplified PCR products. Rickettsia felis, the agent of the emerging flea-borne spotted fever in humans, was identified in 17 (16%) C. felis cat fleas. Bartonella henselae, an agent of cat scratch disease, was identified in three (2.9%) C. felis. Our results emphasize the potential risk of these emerging flea-borne infections in Lebanon.     

Detection of Rickettsia felis and Rickettsia typhi and seasonal prevalence of fleas collected from small mammals at Gyeonggi Province in the Republic of Korea

Fleas were collected from live-captured small mammals to identify flea-borne pathogens, host associations, and seasonal prevalence of flea species, as part of the 65th Medical Brigade rodent-borne disease surveillance program at 20 military installations and training sites, Gyeonggi Province, Republic of Korea, 2005-2007. A total of 1251 fleas were recovered from 2833 small mammals. Apodemus agrarius, the striped field mouse, accounted for 93.1% (2,637/2,833) of all small mammals captured, followed by Crocidura lasiura (3.1%), Mus musculus (1.3%), Microtus fortis (0.7%), Myodes regulus (0.7%), Micromys minutus (0.5%), Rattus norvegicus (0.4%), Tscherskia triton (0.1%), Apodemus peninsulae (< 0.1%), Rattus rattus (< 0.1%), and Mogera robusta (< 0.1%). A total of 6/11 species of mammals captured were infested with fleas with infestation rates ranging from a high of 26.3% (A. agrarius and M. regulus) to a low of 5.3% (M. fortis). Flea indices among infested mammals were highest for R. norvegicus (2.50), followed by C. lasiura (2.20), A. agrarius (1.71), M. regulus (1.20), M. musculus (1.0), and M. fortis (1.0). The predominant flea species collected were Stenoponia sidimi (56.5%), followed by Ctenophthalmus congeneroides (38.3%) and Rhadinopsylla insolita (3.9%). The minimum field infection rates [number of positive pools/total number of fleas (600)] for Rickettsia typhi and for Rickettsia felis were 1.7% and 1.0%, respectively.     

Cortisol determination in hair and faeces from domestic cats and dogs

The present study explored the feasibility of a hair cortisol assay in domestic cats (Felis silvestris catus) and dogs (Canis familiaris) as a valid and reliable alternative to existing non-invasive techniques for monitoring the hypothalamic-pituitary-adrenal (HPA) axis activity. To this aim, 56 new hair growth samples and 870 faecal samples from 27 domestic cats and 29 domestic dogs were collected and cortisol content was assessed. A significant positive association was observed in both species between the concentrations of cortisol determined in hair and faeces. This finding is discussed in the light of the existing knowledge of hair physiology and in the perspective of its application to studies on chronic stress.     

First molecular detection of Rickettsia felis in fleas from Algeria

Fleas collected in Algeria in the district of Oran between July and September 2003 were tested by polymerase chain reaction for the presence of Rickettsia spp. DNA using primers amplifying gltA and OmpA genes. Two gltA sequences identical to those of an emerging pathogen, Rickettsia felis, were detected including i) R. felis California 2 in Ctenocephalides canis from rodents and ii) R. felis RF2125 in Archeopsylla erinacei from hedgehogs.     

Bartonella clarridgeiae, B. henselae and Rickettsia felis in fleas from Morocco

A total of 554 fleas were collected in the Moroccan Casablanca and Tiznit regions from domesticated animals and ruminants between August 2007 and October 2008 and were tested for the presence of Rickettsia spp. and Bartonella spp. using molecular methods. For the first time in Morocco, we found Rickettsia felis, the agent of flea-borne spotted fever in Ctenocephalides felis; B. henselae, an agent of cat scratch disease; and Bartonella clarridgeiae, a cat pathogen and potentially a human pathogen.     

Rickettsia mooseri infection in the fleas Leptopsylla segnis and Xenopsylla cheopis

Detailed observations on the acquisition and propagation of experimental Rickettsia mooseri infection in two species of fleas are presented. Rickettsia mooseri infection became detectable by means of the direct fluorescent antibody test about 2 days earlier in Leptopsylla segnis than in the putative vector, Xenopsylla cheopis. By the 6th day after the infective feeding, the entire lining and the lumen of the midgut in L. segnis contained masses of rickettsiae and the agent was being passed in the feces of the flea, whereas in X. cheopis these events did not occur until the 8th day. Basic behavioral differences in the two species of flea may explain these discrepancies and also influence their ability to serve as vectors of murine typhus. As a semisessile flea and sustained feeder, L. segnis only rarely attaches to a second individual and thus has an opportunity to acquire a heavy dose of rickettsiae, if feeding on a rickettsemic host. X. cheopis, in contrast, feeds rapidly and intermittently, even on man, and generally leaves its host soon thereafter, later returning to the same or another host to feed again. While L. segnis may not be as efficient a vector as X. cheopis regarding the intramurine cycle or transmission to man of murine typhus, the dense accumulation of infective feces on certain sites on the fur of the host raises the possibility of air-borne infection to man or rodent. Infection with R. mooseri had no effect on the survival of X. cheopis and L. segnis. Furthermore, no visible cytopathological effect was found in the paraffin-embedded sections of infected fleas.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

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.     

Detection of Rickettsia parkeri and Candidatus Rickettsia andeanae in Amblyomma maculatum Gulf Coast ticks collected from humans in the United States

Rickettsia parkeri, a spotted fever group (SFG) rickettsia recently found to be pathogenic to humans, causes an eschar-associated febrile illness. The R. parkeri rickettsiosis, Tidewater spotted fever, has been misdiagnosed as Rocky Mountain spotted fever due to serologic cross reactivity and the lack of specific diagnostic methods. Candidatus Rickettsia andeanae, also a SFG rickettsia, is a recently described agent of unknown pathogenicity originally identified in ticks collected from domestic animals during a fever outbreak investigation in northern Peru. Among 37 Amblyomma maculatum (collected from humans (n=35) and questing (n=2)) obtained from the southern United States during 2000-2009, nine and four A. maculatum nucleic acid preparations were found positive for R. parkeri and Candidatus R. andeanae, respectively, by newly developed genus- and species-specific quantitative real-time polymerase chain reaction assays. In addition Rickettsia felis was found in two A. maculatum nucleic acid preparations.     

Zoonotic Bartonella species in fleas and blood from red foxes in Australia

Bartonella are arthropod-borne, fastidious, Gram-negative, and aerobic bacilli distributed by fleas, lice, sand flies, and, possibly, ticks. The zoonotic Bartonella species, Bartonella henselae and Bartonella clarridgeiae, which are the causes of cat scratch disease and endocarditis in humans, have been reported from cats, cat fleas, and humans in Australia. However, to date, there has been no report of B. henselae or B. clarridgeiae in Australian wild animals and their ectoparasites. B. henselae and B. clarridgeiae were detected in fleas (Ctenocephalides felis) from red foxes (Vulpes vulpes), an introduced pest animal species in Australia, and only B. clarridgeiae was detected in blood from one red fox. Phylogenetic analysis of the ribosomal intergenic spacer region revealed that the B. henselae detected in the current study were related to B. henselae strain Houston-1, a major pathogenic strain in humans in Australia, and confirmed the genetic distinctness of B. clarridgeiae. The identification and characterization of Bartonella species in red foxes in the Southwest of Western Australia suggests that red foxes may act as reservoirs of infection for animals and humans in this region.     

A focus of dogs and Rickettsia massiliae-infected Rhipicephalus sanguineus in California

A recurrent focus of Rhipicephalus sanguineus infestation was investigated in a suburban area of southern California after reports of suspected Rocky Mountain spotted fever in two dogs on the same property. Abundant quantities of Rh. sanguineus were collected on the property and repeatedly from each dog, and Rickettsia massiliae DNA was detected by polymerase chain reaction (PCR). Whole blood and serum samples from four dogs were tested by using PCR and microimmunofluorescent assay for antibodies against spotted fever group rickettsiae. Serum samples from all four dogs contained antibodies reactive with R. massiliae, R. rhipicephali, R. rickettsii, and 364D Rickettsia but no rickettsial DNA was detected by PCR of blood samples. Serum cross-absorption and Western blot assays implicated R. massiliae as the most likely spotted fever group rickettsiae responsible for seropositivity. To our knowledge, this is the first detection of R. massiliae in ticks in California.     

Arbovirus isolations from mosquitoes collected during 1988 in the Senegal River basin.

During August and September 1988, we collected adult mosquitoes from 14 locations in the Senegal River basin to search for evidence of Rift Valley fever (RVF) viral activity one year after the 1987 outbreak, which occurred along the Senegal-Mauritania border. More than 62,000 specimens representing 18 species in seven genera were collected with carbon dioxide-baited, solid-state Army miniature light traps and sheep-baited traps. Twenty virus isolations from Culex, Aedes, and Anopheles mosquitoes were recovered from six locations: Fanaye Diery (11), Bode (four), Matam (two), Diongui (one), Ndialene (one), and Ngoui (one). Species yielding viral isolates were Anopheles pharoensis (eight), Culex tritaeniorhynchus (three), Cx. univitattus gr. (three), Cx. antennatus (two), Cx. poicillipes (two), Ae. hirsutus (one), and An. gambiae (one). Viruses were identified by complement fixation, and virus and plaque-reduction neutralization testing as Ngari (Bunyavirus, Bunyaviridae) (n = 15), Babanki (Alphavirus, Togaviridae) (n = 3), Bagaza (Flavivirus, Flaviviridae) (n = 1), and Bangui (Bunyavirus-like) (n = 1). No evidence of any RVF viral activity in the Senegal River Basin was detected in the mosquitoes tested.     

Ticks and associated pathogens collected from domestic animals in the Netherlands

Following an outbreak of autochthonous canine babesiosis in the Netherlands, a request made to veterinarians and the public to collect ticks from companion animals resulted in 4298 ticks submitted between July 2005 and October 2006 to our center. Ticks were identified as Ixodes ricinus adults (2907/4298, 67.6%), Ixodes sp. nymphs (529/4298, 12.3%) and Ixodes sp. larvae (385/4298, 9.0%), I. hexagonus adults (328/4298, 7.6%), Dermacentor reticulatus (72/4298, 1.7%), and several other exotic tick species such as Amblyomma flavomaculatum (formerly Aponomma flavomaculatum), Hyalomma marginatum rufipes, Rhipicephalus sanguineus, and R. turanicus (55/4298, 1.3%). Eight localities were surveyed for the presence of local D. reticulatus, a tick not indigenous to the Netherlands, based on multiple submissions of D. reticulatus ticks from these areas. D. reticulatus was collected from the vegetation in six of these localities, confirming the presence of populations of this tick in the Netherlands. Adult I. ricinus (n=251), I. hexagonus (n=237), and D. reticulatus (n=344) ticks were selected at random and subsequently screened by polymerase chain reaction (PCR) and reverse line blot (RLB) hybridization for the presence of Borrelia, Babesia, Theileria, Anaplasma, Ehrlichia, and Rickettsia species. I. ricinus ticks were infected with Rickettsia helvetica (24.7%), spirochetes belonging to the Borrelia burgdorferi sensu lato group (7.2%), the Ehrlichia-like "Schotii" variant (2.4%), Anaplasma phagocytophilum (1.6%), Babesia sp. (EU1) (1.2%), Babesia divergens (0.4%), and Babesia microti (0.4%). A. phagocytophilum (5.9%) and R. helvetica (0.8%) were also detected in adult I. hexagonus ticks. Spotted fever group Rickettsiae, previously reported as Rickettsia sp. DnS14/RpA4 (14.0%), and Borrelia burgdorferi sensu lato (0.3%) were detected in the D. reticulatus ticks, which appeared to be free from B. canis infection. We concluded that a much broader spectrum of ticks and tick-borne pathogens is present in the Netherlands than previously thought, including several potential zoonotic pathogens.     

Acromegaly in dogs and cats

Acromegaly is an endocrine disease that leads to elevated production and secretion of growth hormone (GH). It can occur in adult and aged cats and is usually associated with neoplasms, such as functional pituitary macroadenoma of somatotropic cells. In dogs it is usually related to an increase in serum progesterone that induces production of GH by the mammary glands. The main clinical signs are related to insulin resistance and the anabolic effect induced by GH: polyuria, polydipsia, polyphagia, increased tissue growth, weight gain, prognathism, and other changes. The condition can be diagnosed from clinical signals and imaging associated to measurement of serum concentrations of GH and insulin-like growth factor 1 (IGF-1, also known as somatomedin C). The main therapeutic modalities are radiotherapy, hypophysectomy, and several drugs such as somatostatin analogs, dopaminergic agonists and GH receptor antagonists. The present review aims to provide a relevant animal model of acromegaly with an update on the therapeutic approach that may help clinicians to consider the GH axis–IGF-1 system, its pathogenesis and the clinical signs induced by this hormonal disorder.     

Seroprevalence of Rickettsia typhi and Rickettsia conorii infection among rodents and dogs in Egypt

A serological survey of 1813 rodent and 549 dog sera, collected from 1979 to 1986 from animals in 16 Egyptian Governorates were tested for antibody to Rickettsia typhi and Rickettsia conorii by the indirect fluorescent antibody test. Only three of 82 (4%) sera from Rattus rattus collected near Aswan had antibody to R. conorii. The prevalence of R. typhi antibody in dog sera was only 0.4% (n = 549) while 25% (n = 547) of Rattus norvegicus and 11% (n = 1138) of R. rattus had measurable antibodies. Among the other rodents, antibody was demonstrated in only 2% (n = 45) of Arvicanthis spp., and 1% (n = 83) of Acomys spp. Collectively, rodents captured in the Nile Delta had a higher prevalence (mean 24% (n = 787] than those captured in the Nile Valley (mean 4% (n = 650]. Antibody to R. typhi was detected in rodents collected in all port cities: ismailiya, 13%; Port Said, 9%; Suez, 9%; Safaga, 16%; Quseir, 32% and Alexandria, 34%. These data showed evidence of R. typhi infection among rodents in widespread geographic localities of Egypt and suggested that infected rodents may be a source of human infections.     

A sero-epidemiological study of Rickettsia typhi infection in dogs from Soria province, central Spain

Data relating to Rickettsia typhi infection in Spain are scarce. The seroprevalence of canine infection with this species has now been investigated, in dogs from the central province of Soria. The results of indirect immunofluorescence assays indicated that nine (12.3%) of the 73 dogs checked were carrying antibodies against R. typhi. The gender, age and breed of the dog, and whether it was used for hunting, shepherding, guarding or simply as a pet, apparently had no significant affect on the probability of it being seropositive. Being infested with fleas or having a history of such infestation was, however, significantly associated with seropositivity. The present results confirm that dogs may be infected with R. typhi and indicate their potential usefulness as sentinels in epidemiological studies of the pathogen. The results of wide-scale, serological studies of dogs may allow the geographical distribution of R. typhi to be mapped relatively simply.     

Prevalence of Bartonella species and 16s rRNA gene types of Bartonella henselae from domestic cats in Thailand.

Prevalence of Bartonella infection among 275 cats in 9 sites from 4 geographical regions (northern area: Chiang Mai; central area: Kanchanaburi, Ratchaburi, and Bangkok; northeastern area: Khon Kaen, Roi Et, Ubon Ratcharthani, and Nakhonratchasima; southern area: Songkhla) of Thailand was investigated. Overall, Bartonella species were isolated from 27.6% (76 of 275) of the cats. The isolation rate varied from 12.8% (5 of 39) in Songkhla (southern area) to 50.0% (26 of 52) in Khon Kaen (northeastern area). Bartonella henselae and B. clarridgeiae were isolated from 82.9% (63 of 76) and 11.8% (9 of 76) of the Bartonella-positive cats, respectively. Coinfection with both species was found in 5.3% (4 of 76) of the bacteremic cats. Of the 67 bacteremic cats from which B. henselae was isolated, 48 (71.6%) and 13 (19.4%) were infected with only Type I and Type II, respectively. Coinfection with both types was observed in 9.0% (6 of 67) of the B. henselae-positive cats. To our knowledge, this is the first report on the presence of Bartonella infection in domestic cats from Thailand, which constitute a large reservoir of Bartonella infection in this country.