Rickettsiae in the common pipistrelle Pipistrellus pipistrellus (Chiroptera: Vespertilionidae) and the bat soft tick Argas vespertilionis (Ixodida: Argasidae).

BACKGROUND: Increasing molecular evidence supports that bats and/or their ectoparasites may harbor vector-borne bacteria, such as bartonellae and borreliae. However, the simultaneous occurrence of rickettsiae in bats and bat ticks has been poorly studied. METHODS: In this study, 54 bat carcasses and their infesting soft ticks (n = 67) were collected in Shihezi City, northwestern China. The heart, liver, spleen, lung, kidney, small intestine and large intestine of bats were dissected, followed by DNA extraction. Soft ticks were identified both morphologically and molecularly. All samples were examined for the presence of rickettsiae by amplifying four genetic markers (17-kDa, gltA, ompA and ompB). RESULTS: All bats were identified as Pipistrellus pipistrellus, and their ticks as Argas vespertilionis. Molecular analyses showed that DNA of Rickettsia parkeri, R. lusitaniae, R. slovaca and R. raoultii was present in bat organs/tissues. In addition, nine of the 67 bat soft ticks (13.43%) were positive for R. raoultii (n = 5) and R. rickettsii (n = 4). In the phylogenetic analysis, these bat-associated rickettsiae clustered together with conspecific sequences reported from other host and tick species, confirming the above results. CONCLUSIONS: To the best of our knowledge, DNA of R. parkeri, R. slovaca and R. raoultii was detected for the first time in bat organs/tissues. This is also the first molecular evidence for the presence of R. raoultii and R. rickettsii in bat ticks. To our knowledge, R. parkeri was not known to occur in Asia. Our results highlight the need to assess rickettsial agents in a broader range of bat species and associated tick species.

Molecular detection of Coxiella (Gammaproteobacteria: Coxiellaceae) in Argas persicus and Alveonasus canestrinii (Acari: Argasidae) from Iran.

BACKGROUND: Coxiella burnetii and non-C. burnetii bacteria or endosymbiotic Coxiella-like were reported in various tick species. We aimed to detect C. burnetii within soft tick species, Argas persicus and Alveonasus canestrinii. METHODS: Argasid ticks were collected from different counties of Lorestan province, west of Iran. Partial fragments of 16S rRNA, IS1111 insertion sequence, com1, htpB, and icd genes related to Coxiella genus were sequenced. RESULTS: A partial 16S rRNA and com1 gene fragment as well as IS1111 was detected in four Ar. persicus and twelve Al. canestrinii pools. Moreover, partial htpB and icd gene was only detected in one pool of Ar. persicus. CONCLUSIONS: Detection of C. burnetii in tick samples was failed due to the occurrence of Coxiella-like endosymbionts and leads to misidentification. Thus, the house-keeping genes should be designated to distinguish C. burnetii within Coxiella-like endosymbionts.

Bats and ticks: host selection and seasonality of bat-specialist ticks in eastern Europe.

BACKGROUND: Parasites may actively seek for hosts and may use a number of adaptive strategies to promote their reproductive success and host colonization. These strategies will necessarily influence their host specificity and seasonality. Ticks are important ectoparasites of vertebrates, which (in addition to directly affecting their hosts) may transmit a number of pathogens. In Europe, three hard tick species (Ixodidae: Ixodes ariadnae, I. simplex and I. vespertilionis) and at least two soft tick species (Argasidae: Argas transgariepinus and A. vespertilionis) are specialized for bats. METHODS: Here we report data on the host range of these ticks and the seasonality of tick infestation on wild caught bats in south-east Europe. We collected 1803 ticks from 30 species of bats living in underground shelters (caves and mines) from Romania and Bulgaria. On the basis of tick-host associations, we tested several hypotheses on host-parasite evolutionary adaptations regulating host specificity, seasonality and sympatric speciation. RESULTS: We observed significant differences in host specificity and seasonality of abundance between the morphologically different bat specialist ticks (I. simplex and I. vespertilionis) likely caused by their host choice and their respective host-seeking behavior. The two highly generalist, but morphologically similar tick species (I. ariadnae and I. vespertilionis) showed temporal differences in occurrence and activity, thus exploiting significantly different host communities while occurring in geographical sympatry. CONCLUSIONS: We conclude that bat-specialist ticks show a wide range of adaptations to their hosts, with differences in specificity, seasonality of occurrence, the prevalence and intensity of infestation and all these contribute to a successful division of temporal niches of ticks sharing morphologically similar hosts occurring in geographical sympatry.

Skin lesions in humans bitten by European pigeon tick Argas reflexus (Fab.) (Ixodida: Argasidae) massively occurring in the Upper Silesian conurbation of south-west Poland.

INTRODUCTION AND OBJECTIVE: The great number of pigeon populations in many European cities promotes the spread of the European pigeon tick (Argas reflexus), the bites of which cause local and systemic reactions. The aim was to study the occurrence of A. reflexus in several cities of Upper Silesia, and skin lesions caused by A. reflexus tick bites in humans. MATERIAL AND METHODS: The results of investigations carried out in 1995-2002 in five cities located in the Upper Silesian conurbation are presented. Specimens of A. reflexus were collected for one hour in attics and lofts inhabited by these ticks. A history of skin lesions caused by bites was taken from residents who had been infested by A. reflexus. The development of skin lesions was monitored for three months in two individuals who had been bitten several times by these arthropods. RESULTS: In the localities, 987 A. reflexus specimens were collected, including 334 females, 269 males, and 384 various nymphal stages. Within one hour, 38-109 ticks specimens were collected at the study sites. Cases of attacks by unengorged A. reflexus were reported in all the habitats located in the residential buildings; the ticks were also found in residents' flats and in staircases. Residents who had been repeatedly attacked by European pigeon ticks developed a strong inflammatory reaction to the components of tick saliva, and had purple papules with necrosis in the centre of the lesion. The tick bite areas exhibited scars and hyperpigmentation. CONCLUSIONS: Individuals attacked by A. reflexus several times are at risk of development of severe persistent local reactions to bites. Pigeon ticks, trophically associated with pigeons present abundantly in the Upper Silesian conurbation and other European urban habitats, pose a serious threat to public health.

Notes on maternal behaviour in soft ticks: Specifically observed in Argas (Argas) striatus Bedford, 1932 and Argas (Secretargas) transgariepinus White, 1846.

Maternal behaviour (carrying of larvae on the opisthosoma) in ticks has thus far only been observed in Antricola (Parantricola) marginatus and was considered a unique derived adaptation of this genus. The authors extend this observation to two additional argasid species, namely Argas (Argas) striatus and Argas (Secretargas) transgariepinus. In addition, brooding behaviour over eggs were observed with A. (S.) transgariepinus. Maternal behaviour may be an evolutionary adaptation to ecological challenges in habitats unsuited for larval survival and may be related to the presence of pulvilli in larvae. This adaptation might have been present in the ancestral tick lineage since pulvilli occur in all tick families, and may have been derived from a more ancient adaptation in chelicerates where maternal behaviour was common. Female A. (S.) transgariepinus also possess a unique area on their ventral abdomen that is absent in males and may be a unique adaptation for maternal behaviour in this species. Phylogenetic analysis of the 16S rRNA genes for both species indicate that they are unique lineages that group basal to other members of the Argas genus, supporting the possibility that they harbour ancestral traits for this group.

Mitochondrial gene heterogeneity of the bat soft tick Argas vespertilionis (Ixodida: Argasidae) in the Palaearctic.

BACKGROUND: Recently, a high degree of mitochondrial gene heterogeneity was demonstrated between conspecific ixodid ticks of bats in Eurasia. Argas vespertilionis is a soft tick species of mainly vespertilionid bats, also with a wide distribution in the Old World. The aim of this study was to investigate the morphology, mitochondrial gene heterogeneity and host range of A. vespertilionis in the Old World. RESULTS: Altogether 318 soft tick larvae were collected from 17 bat species (belonging to six genera) in seven countries. Based on the general morphology (setal arrangement) of 314 A. vespertilionis larvae, and the detailed measurements of fifteen larvae, only minor morphological differences (in dorsal plate size and the type of serrate setae) were observed between specimens from Europe and Vietnam. On the other hand, cytochrome c oxidase subunit 1 (cox1) and 16S rRNA gene sequence analyses of 17 specimens showed that A. vespertilionis from Europe is genetically different (with up to 7.5% cox1 and 5.7% 16S rRNA gene sequence divergence) from specimens collected in Vietnam, and their phylogenetic separation is well supported. CONCLUSION: In its evaluated geographical range, no larval phenotypic differences justify the existence of separate species under the name A. vespertilionis. However, phylogenetic analyses based on two mitochondrial markers suggest that it represents a complex of at least two putative cryptic species. The broad host range of A. vespertilionis might partly explain its lower degree of mitochondrial gene heterogeneity in comparison with ixodid bat tick species over the same geographical region of Eurasia.

Host finding of the pigeon tick Argas reflexus.

The medically and veterinary important feral pigeon tick Argas reflexus (Ixodida: Argasidae) Fabricius usually feeds on pigeons, but if its natural hosts are not available, it also enters dwellings to bite humans that can possibly react with severe allergic reactions. Argas reflexus is ecologically extremely successful as a result of some outstanding morphological, physiological, and ethological features. Yet, it is still unknown how the pigeon tick finds its hosts. Here, different host stimuli such as living nestlings as well as begging calls, body heat, smell, host breath and tick faeces, were tested under controlled laboratory conditions. Of all stimuli tested, only heat played a role in host-finding. The heat stimulus was then tested under natural conditions within a pigeon loft. The results showed that A. reflexus is able to find a host over short distances of only a few centimetres. Furthermore, it finds its host by random movements and recognizes a host only right before direct contact is made. The findings are useful for the control of A. reflexus in infested apartments, both to diagnose an infestation and to perform a success monitoring after disinfestation.

Efficacy of abamectin against the fowl tick, Argas (Persicargas) persicus (Oken, 1818) (Ixodoidea: Argasidae).

Abamectin, in aqueous solutions of dose rates 0.0625, 0.125, 0.25, 0.5, and 1 mL/L, was sprayed on different feeding stages of the tick Argas (P.) persicus. The results revealed a marked increase of immobile and dead male or female ticks following a single treatment with the above doses, particularly the higher ones, and during the 5 weeks after treatment. Abamectin seriously decreased the percentage of fed ticks as well as that of oviposition and hatching. A decrease in the amount of emitted coxal fluid was observed also following treatment. Although the amount of ingested blood increased following abamectin treatment, digestion remained similar. The study also revealed that spraying a dose of 0.5 mL/L of abamectin in fowl shelters, i.e., floor, walls, ceiling, etc., is sufficient to eradicate A. persicus population.

Asthenes dorbignyi (Passeriformes: Furnariidae) host of Argas neghmei (Acari: Argasidae).

Argas neghmei Kohls & Hoogstraal is a Neotropical tick species parasite of poultry and man in the arid western of the southern cone of America in Argentina and Chile. Males, females and nymphs of an argasid were collected from 20 to 22 of June, 2007 in nests of Creamy-breasted Canastero, Asthenes dorbignyi (Reinchenbach) (Passeriformes: Furnariidae) at about 7 km S of La Poma (24 degrees 46'S, 66 degrees 12'W) and a male tick at 24 degrees 48'S, 66 degrees 10'W on Nov 27, 2008, Salta province, Argentina. Scanning electron microscope micrographies and sequences of 16S rDNA confirmed that the ticks found were A. neghmei. Development in breeding areas of A. dorbignyi is probably a source of infestation for animal premises and houses. However, the role of other unknown wild birds may also contribute to the invasion of A. neghmei in chicken houses or residences.

Characterization of anti-hemostatic factors in the argasid, Argas monolakensis: implications for the evolution of blood-feeding in the soft tick family.

To date, the only anti-hemostatic factors characterized for softs ticks are for Ornithodoros moubata and Ornithodoros savignyi, ticks that feeds mainly on mammals. This includes thrombin (ornithodorin and savignin), fXa (TAP and fXaI) and platelet aggregation (disagegin and savignygrin) inhibitors that belong to the BPTI-Kunitz protein family. This raises the question on how well anti-hemostatic factors will be conserved in other soft tick genera that feeds on other vertebrates such as birds. We characterized the anti-hemostatic factors from Argas monolakensis, a soft tick that feeds mainly on Californian gulls. The main anti-clotting factor (monobin) is an ortholog of ornithodorin and savignin and shows similar slow tight-binding kinetics. The main anti-platelet activities are apyrase and fibrinogen receptor antagonists (monogrins). The monogrins are orthologs of disagregin and savignygrin and like savignygrin presents the RGD integrin-recognition motif on the BPTI substrate-binding presenting loop. This implies that the anti-hemostatic factors evolved in the ancestral soft tick lineage and has been maintained in soft tick species from two distinct genera with different host preferences. The Argas derived anti-hemostatic factors bind to mammalian targets with affinities similar to that observed for their orthologs in the Ornithodoros genus. This cross-reactivity could have facilitated the switching of soft ticks from avian to mammalian hosts and can explain in part the ability of Argas ticks, to feed on humans, thereby remaining a possible health risk.

[Biological aspects of Argas (Persicargas) miniatus Kock, 1844, (Ixodoidea; Argasidae) larvae in Gallus gallus]. / Aspectos biológicos de larvas de Argas (Persicargas) miniatus Koch, 1844, (Ixodoidea: Argasidae) em Gallus gallus.

The aim of the present study was to describe the biological aspects of larvae of Argas miniatus at 27+/-1 masculineC and 80+/-5% and in environmental condition. Domestic fowls with age lower than one week were infested with approximately 700 larvae of A. miniatus 15 days posthatching. The period of larval fixation varied from 3 to 7 days in four repetitions. Approximately 90% of larvae were recovered in the 4th and 5th day after attachment. The mean weight increased approximately 81.37 times the initial weight of the unfed larvae. The mean larval mortality in controlled conditions and laboratory environment were 6.35% and 13.97%, respectively. Molting period varied from 4 to 9 days in controlled condition, while in the environment conditions the interval varied from 5 to 15 days. The larval longevity was 120 days, in both conditions. Unfed larvae maintained at 27+/-1 masculineC and 80+/-5% and environment condition were capable to attach from 6 to 60 days and 8 to 45 days, respectively.

The new locality of Argas reflexus Fabricius, 1794 in Warsaw, Poland.

The new locality of Argas reflexus in Warsaw, Poland is recorded. The ticks occur in the lof of apartment blocks, inhabited by pigeons. When the birds were removed by cleaning services, the ticks began to look for a new host and penetrate the flats. Some of the lodgers had been bitten by tick larvae and nymphs.

Anaphylactic shock to Argas reflexus bite.

Anaphylaxis is a severe, life-threatening allergic reaction, affecting both children and adults. The occurrence of anaphylaxis is not as rare as generally believed (1.21% to 15.04% of the US population). Often the cause of this reaction remain unknown, mainly due to the difficulty in defining the outbreaking causes. Herein, we describe an interesting case of a patient, who developed an anaphylactic reaction after the bite of a pigeon tick. During the last 2 years, in wintertime, the patient often came to the emergency room for general rash and swelling, hypotension and tachycardia preceded by itching and general distress. Notably, the symptoms manifested themselves as night fell. In two particular occasions the patient reached the hospital in a state of shock. After another episode of general swelling, the patient was invited to examine her domestic environment. She brought us some parasites, collected at home, particularly on the bed. A morphological examination by entomologists proved these parasites to belong to Argas reflexus (Arg.r.), one of the 31 species of soft ticks. The presence of specific IgE to a protein secreted by the Arg.r. salivary glands was in favour of immediate-type systemic reaction, as supposed by the clinical history.

[The pigeon tick, Argas reflexus, and hazard for human health]. / La zecca del piccione Argas reflexus (Acari: Argasidae) ed i rischi per la salute umana.

The massive presence of the pigeon (Columba livia f. domestica) in urban areas not only is cause of serious aesthetic damages as decline of squares, of churches, of statues and buildings, but often creates many hygienic and medical problems. The pigeon, in fact, can transmit a great number of pathogenic agents and also be infested by several ectoparasites. Among these, Argas reflexus (Acari: Argasidae), the well known pigeon tick, is the most important ectoparasite that can involve also human health. Buildings infested by A. reflexus and attacks by this tick species to man are frequently reported, with an increasing interest for human health. In fact the pigeon tick bites can induce anaphylactic reactions for the presence of allergens, and as vector, the tick can also transmit some pathogens. This review deals with actual knowledge on the distribution, eco-biology, vector competence, prevention and control of A. reflexus in Italy.

[Argas reflexus (Fabricius, 1794) as a cause of acarosis in people]. / Argas reflexus (Fabricius 1794) przyczyna akarozy u ludzi.

The studies were carried out between 1997-1999 within the administrative district of Torun. Forty sports pigeon breeders together with their pigeonswere understudy annually. The collected material allowed noticing the following issues: in 1997 and 1998 the Argas reflexus (Fabricius, 1794) was present in dovecotes (individuals) and t he breeds' owners were pricked. In 1998 numerous specimens of the A. reflexus were obtained from the material from the sanitary-epidemiological station. The specimens were collected from the bodies of the people, family members and from their flat located on the highest third floor of the old house. In the mite-infected dovecotes and in the old houserooms, the following steps were suggested: mechanical cleansing, whitewashing, disinfecting, and triple disinsecting, with fourteen-day-long intervals. The people with the symptoms of acariosis were subjected to treatment with calcium, anti-allergic, and anti-fever mixtures, and, in some cases, cortisone ointments were applied. In spite of a considerable growth in the symptoms, the used methods turned out to be successful in all the studied cases.