Ticks are important vectors of various pathogenic protozoa, bacteria and viruses that cause serious and life-threatening illnesses in humans and animals worldwide. Estimating tick-borne pathogen ...prevalence in tick populations is necessary to delineate how geographical differences, environmental variability and host factors influence pathogen prevalence and transmission. This study identified ticks and tick-borne pathogens in samples collected from June 2016 to December 2017 at seven sites within the Coastal, Sudan and Guinea savanna ecological zones of Ghana.
A total of 2016 ticks were collected from domestic animals including cattle, goats and dogs. Ticks were morphologically identified and analysed for pathogens such as Crimean-Congo haemorrhagic fever virus (CCHFV), Alkhurma haemorrhagic fever virus (AHFV), Rickettsia spp. and Coxiella burnetii using polymerase chain reaction assays (PCR) and sequence analysis.
Seven species were identified, with Amblyomma variegatum (60%) most frequently found, followed by Rhipicephalus sanguineus sensu lato (21%), Rhipicephalus spp. (9%), Hyalomma truncatum (6%), Hyalomma rufipes (3%), Rhipicephalus evertsi (1%) and Rhipicephalus (Boophilus) sp. (0.1%). Out of 912 pools of ticks tested, Rickettsia spp. and Coxiella burnetii DNA was found in 45.6% and 16.7% of pools, respectively, whereas no CCHFV or AHFV RNA were detected. Co-infection of bacterial DNA was identified in 9.6% of tick pools, with no statistical difference among the ecozones studied.
Based on these data, humans and animals in these ecological zones are likely at the highest risk of exposure to rickettsiosis, since ticks infected with Rickettsia spp. displayed the highest rates of infection and co-infection with C. burnetii, compared to other tick-borne pathogens in Ghana.
House flies (Musca domestica) are worldwide agricultural pests with estimated control costs at $375 million annually in the U.S. Non-target effects and widespread resistance challenge the efficacy of ...traditional chemical control. Double stranded RNA (dsRNA) has been suggested as a biopesticide for M. domestica but a phenotypic response due to the induction of the RNAi pathway has not been demonstrated in adults. In this study female house flies were injected with dsRNA targeting actin-5C or ribosomal protein (RP) transcripts RPL26 and RPS6. Ovaries showed highly reduced provisioning and clutch reductions of 94-99% in RP dsRNA treated flies but not in actin-5C or GFP treated flies. Gene expression levels were significantly and specifically reduced in dsRNA injected groups but remained unchanged in the control dsGFP treated group. Furthermore, injections with an Aedes aegypti conspecific dsRNA designed against RPS6 did not impact fecundity, demonstrating species specificity of the RNAi response. Analysis of M. domestica tissues following RPS6 dsRNA injection showed significant reduction of transcript levels in the head, thorax, and abdomen but increased expression in ovarian tissues. This study demonstrates that exogenous dsRNA is specifically effective and has potential efficacy as a highly specific biocontrol intervention in adult house flies. Further work is required to develop effective methods for delivery of dsRNA to adult flies.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Recently, the BG-Sentinel® trap (BGS) trap has been reconfigured for increased durability during harsh field conditions. We evaluated the attractiveness of this redesigned trap, BG-Sentinel 2® ...(BGS2), and its novel granular lure cartridge system relative to the original trap and lure. Granular lures containing different combinations of lactic acid, ammonia, hexanoic acid, and octenol were also evaluated. Lure cartridges with all components except octenol trapped significantly more Aedes albopictus than lures containing octenol. This new granular lure combination and original BG-Lure® system were paired with BGS and BGS2 traps to compare relative attractiveness of the lures and the traps. All evaluations were conducted under field conditions in a suburban neighborhood in northeastern Florida from July to October 2014. Overall, the average numbers of Ae. albopictus collected by BGS or BGS2 were similar regardless of the lure type (i.e., mesh bag versus granules) (P = 0.56). The functionality and durability of both trap models are discussed.
The Aedes mosquito vectors of dengue virus (DENV) and chikungunya virus (CHIKV) are attracted to specific host cues that are not generated by traditional light traps. For this reason multiple ...companies have designed traps to specifically target those species. Recently the standard trap for DENV and CHIKV vectors, the BG-Sentinel (BGS) trap, has been remodeled to be more durable and better suited for use in harsh field conditions, common during military operations, and relabeled the BG-Sentinel 2 (BGS2). This new trap was evaluated against the standard Centers for Disease Control and Prevention (CDC) light trap, Zumba Trap, and BG-Mosquitito Trap to determine relative effectiveness in collecting adult Aedes aegypti and Ae. albopictus. Evaluations were conducted under semifield and field conditions in suburban areas in northeastern Florida from May to August 2014. The BGS2 trap collected more DENV and CHIKV vectors than the standard CDC light trap, Zumba Trap, and BG-Mosquitito Trap, but attracted fewer species, while the BG-Mosquitito Trap attracted the greatest number of mosquito species.
The Aedes mosquito vectors of dengue virus (DENV) and chikungunya virus (CHIKV) are attracted to specific host cues that are not generated by traditional light traps. For this reason multiple ...companies have designed traps to specifically target those species. Recently the standard trap for DENV and CHIKV vectors, the BG-Sentinel (BGS) trap, has been remodeled to be more durable and better suited for use in harsh field conditions, common during military operations, and relabeled the BG-Sentinel 2 (BGS2). This new trap was evaluated against the standard Centers for Disease Control and Prevention (CDC) light trap, Zumba Trap, and BG-Mosquitito Trap to determine relative effectiveness in collecting adult Aedes aegypti and Ae. albopictus. Evaluations were conducted under semifield and field conditions in suburban areas in northeastern Florida from May to August 2014. The BGS2 trap collected more DENV and CHIKV vectors than the standard CDC light trap, Zumba Trap, and BG-Mosquitito Trap, but attracted fewer species, while the BG-Mosquitito Trap attracted the greatest number of mosquito species.
Paraiotonchium autumnale (Nickle) (Tylenchida: Iotonchiidae) causes parasitic sterilization in female Musca autumnalis DeGeer (Diptera: Muscidae). In addition to sterilization, P. autumnale causes ...physiological and behavioural changes within its host. However, there have been no records of reduced host lifespan in this system. Studies were conducted in 2009 and 2010 with wild M. autumnalis collected as larvae from cow dung pats from Browns Valley, California, USA. Field-collected larvae were reared to adulthood and flies of the same eclosion dates were caged together, regardless of whether or not they were parasitized. Dead flies were collected daily, and parasitism status was confirmed by dissection. Due to the very different effects of P. autumnale-parasitism on male versus female face flies, flies were analysed separately by sex. Kaplan-Meier analysis revealed a non-significant difference in longevity between non-parasitized and parasitized flies for female and male flies in 2009. In 2010, however, significant differences (P < 0·05) were found between parasitized and non-parasitized female and male flies. In 2010, the median time to death for non-parasitized female flies was 20 days and 15 days for parasitized females. The 2010 median survival time for non-parasitized male flies was 33 days and 15 days for parasitized males. This is a parasite-mediated cost to the host that has not been recorded previously. Based on our results and results from another published study we suggest that the potential for sterilizing parasites to alter host longevity is condition dependent.
The wing beat frequencies (WBF) and flight durations of the face fly, Musca autumnalis De Geer (Diptera: Muscidae), were evaluated at 1, 3, 5, 7, 11, and 14 days post-eclosion. For flight tests, ...flies were tethered magnetically using magnetic primer paint. WBF were measured stroboscopically. The average WBF for one-day-old flies was significantly lower compared with the average WBF of all other age groups for both female and male face flies. Based on our results, male and female face flies require more than 24 hours post eclosion to reach a WBF of over 167 beats per second and continuously fly for more than 10 minutes. Age was a significant factor towards WBF. The present study is the first to report laboratory descriptions of face fly flight capabilities. The benefits of the magnetic paint tether (MagPaT) method are discussed. Nous avons évalué les fréquences de battement des ailes (WBF) et la durée du vol chez la mouche faciale, Musca autumnalis De Geer (Diptera: Muscidae), 1, 3, 5, 7, 11 et 14 jours après l’éclosion. Durant les essais en vol, les mouches étaient retenues magnétiquement à l'aide d'une peinture d'apprêt magnétique. Les fréquences de battement des ailes ont été mesurées par stroboscopie. La WBF moyenne des mouches d'un jour est significativement inférieure à celles des moyennes des autres groupes d’âge de mouches faciales femelles et mâles. D'après nos résultats, il faut aux mouches faciales mâles et femelles plus de 24 heures après l’éclosion pour atteindre une WBF supérieure à 167 battements par seconde et pour voler continuellement plus de 10 minutes. L’âge est un facteur significatif en ce qui a trait à la WBF. Notre étude est la première à décrire en laboratoire les capacités de vol des mouches faciales. Nous discutons des avantages à utiliser la méthode de rétention avec une peinture d'apprêt magnétique.
Parasites have become increasingly recognized as important natural enemies with a potential to regulate host populations. Parasites-induced reductions in host fecundity and host survival both impact ...the mean rate of reproduction in host population. However in order to assess a parasite's potential to control host populations, it is important to understand which components of host fitness are affected by parasites in addition to the differences in reproductive output between parasitized and non-parasitized individuals. I present a study focused on a host-parasite relationship where the parasite, Paraiotonchium autumnale (Nickle), parasitically sterilizes females face flies (Musca autumnalis DeGeer). Face flies are economically significant pest of cattle. In past studies, P. autumnale's potential to control face fly populations have largely been based on surveys of parasitized flies in natural populations. With laboratory and field studies, I investigate factors other than reduced host fecundity that may be important details of the relationship and elucidate P. autumnale's potential to control M. autumnalis populations.
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