scholarly journals Opportunistic feeding behaviour and Leishmania infantum detection in Phlebotomus perniciosus females collected in the human leishmaniasis focus of Madrid, Spain (2012–2018)

2021 ◽  
Vol 15 (3) ◽  
pp. e0009240
Author(s):  
Estela González ◽  
Ricardo Molina ◽  
Andrés Iriso ◽  
Sonia Ruiz ◽  
Irene Aldea ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Feeding Behaviour ◽  
Pcr Amplification ◽  
Blood Feeding ◽  
Control Measures ◽  
Its1 Region ◽  
Phlebotomus Perniciosus ◽  
High Infection ◽  
Human Leishmaniasis ◽  
Blood Source

Background An outbreak of human leishmaniasis due to Leishmania infantum has been registered in an urban area of southwestern Madrid, Spain, since 2010. Entomological surveys carried out in the municipalities of Fuenlabrada, Leganés, Getafe and Humanes de Madrid showed that Phlebotomus perniciosus is the only potential vector. In this work, an intensive molecular surveillance was performed in P. perniciosus females captured in the region between 2012 and 2018. Methodology/Principal findings A total of 1805 P. perniciosus females were analyzed for Leishmania infection, and 1189 of them also for bloodmeal identification. Eleven different species of vertebrate were detected by amplification and subsequent sequencing of the 359 bp cytb fragment. The most prevalent blood source identified was hare (n = 553, 46.51%), followed by rabbit (n = 262, 21.95%). Less frequent were cat (n = 45, 3.80%), human (n = 34, 2.90%), pig (n = 14, 1.20%), horse (n = 11, 0.93%), sheep (n = 3, 0.25%), rhea (n = 3, 0.25%), partridge (n = 1, 0.09%) and chicken (n = 1, 0.09%). The distribution of the blood meal sources varied between the different locations. Regarding L. infantum detection, PCR amplification of a fragment of kDNA, cpb gene and ITS1 region showed 162 positive specimens (8.97%). The highest infection rate was found in the municipality of Leganés (15.17%). Conclusions The results of this molecular survey in P. perniciosus, the only leishmaniasis vector in the outbreak occurred in southwestern Madrid region, showed its opportunistic blood-feeding behaviour, high infection rates and the differences between the different points. This study was an essential part of the intensive surveillance plan in the area and the results obtained have supported the implementation of control measures in the outbreak.

Detection of Leishmania infantum and identification of blood meals in Phlebotomus perniciosus from a focus of human leishmaniasis in Madrid, Spain

2013 ◽  
Vol 112 (7) ◽  
pp. 2453-2459 ◽  
Author(s):  
Maribel Jiménez ◽  
Estela González ◽  
Andrés Iriso ◽  
Elisa Marco ◽  
Ana Alegret ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Phlebotomus Perniciosus ◽  
Human Leishmaniasis ◽  
Blood Meals

Leishmania sp. detection and blood‐feeding behaviour of S ergentomyia minuta collected in the human leishmaniasis focus of southwestern Madrid, Spain (2012–2017)

2020 ◽  
Vol 67 (3) ◽  
pp. 1393-1400 ◽  
Author(s):  
Estela González ◽  
Ricardo Molina ◽  
Irene Aldea ◽  
Andrés Iriso ◽  
Ana Tello ◽  
...  
Keyword(s):  
Feeding Behaviour ◽  
Blood Feeding ◽  
Human Leishmaniasis

Intercistronic heterogeneity of the 16S–23S rRNA spacer region among Pseudomonas strains isolated from subterranean seeds of hog peanut (Amphicarpa bracteata)

Microbiology ◽  
2009 ◽  
Vol 155 (8) ◽  
pp. 2630-2640 ◽  
Author(s):  
J. T. Tambong ◽  
R. Xu ◽  
E. S. P. Bromfield
Keyword(s):  
Root Zone ◽  
Phylogenetic Analyses ◽  
Melting Curve ◽  
Pcr Amplification ◽  
23S Rrna ◽  
Melting Curve Analysis ◽  
Its1 Region ◽  
A Genome ◽  
Pure Cultures ◽  
Intercalating Dye

Intercistronic heterogeneity of the 16S–23S rRNA internal transcribed spacer regions (ITS1) was investigated in 29 strains of fluorescent pseudomonads isolated from subterranean seeds of Amphicarpa bracteata (hog peanut). PCR amplification of the ITS1 region generated one or two products from the strains. Sequence analysis of the amplified fragments revealed an ITS1 fragment of about 517 bp that contained genes for tRNAIle and tRNAAla in all 29 strains; an additional smaller ITS1 of 279 bp without tRNA features was detected in 15 of the strains. The length difference appeared to be due to deletions of several nucleotide blocks between the 70 bp and 359 bp positions of the alignment. The end of the deletions in the variant ITS1 type coincided with the start of antiterminator box A, which is homologous to box A of other bacteria. Phylogenetic analyses using the neighbour-joining algorithm revealed two major phylogenetic clusters, one for each of the ITS1 types. Using a single specific primer set and the DNA-intercalating dye SYBR Green I for real-time PCR and melting-curve analysis produced highly informative curves with one or two recognizable melting peaks that readily distinguished between the two ITS1 types in pure cultures. The assay was used to confirm the presence of the variant ITS1 type in the Pseudomonas community in total DNA from root-zone soil and seed coats of hog peanut. Heterogeneity of the ITS1 region between species has potential for studying molecular systematics and population genetics of the genus Pseudomonas, but the presence of non-identical rRNA operons within a genome may pose problems.

scholarly journals Odour of domestic dogs infected with Leishmania infantum is attractive to female but not male sand flies: evidence for parasite manipulation

2020 ◽  
Author(s):  
Monica E. Staniek ◽  
James G.C. Hamilton
Keyword(s):  
Visceral Leishmaniasis ◽  
Leishmania Infantum ◽  
Feeding Activity ◽  
Blood Feeding ◽  
Human Infection ◽  
T Test ◽  
Domestic Dogs ◽  
Lutzomyia Longipalpis ◽  
Sand Flies ◽  
Paired T Test

AbstractGlobally visceral leishmaniasis (VL) causes thousands of human deaths every year. In South America, the etiologic agent, Leishmania infantum, is transmitted from an infected canine reservoir to human hosts by the blood-feeding activity of the sand fly vector, predominantly, Lutzomyia longipalpis. Previous evidence from model rodent systems have suggested that the odour of infected hosts is altered by the parasite making them more attractive to the vector leading to an increased biting rate and improved transmission prospects for the pathogen. However, the effect of Le. infantum infection on the attractiveness of naturally infected dogs which are integral to human infection, has not been assessed.Hair collected from infected and uninfected dogs residing in a VL endemic city in Brazil. was entrained to collect the volatile chemical odours present in the headspace. Female and male Lu. longipalpis sand flies were offered a choice of infected or uninfected odour in a series of behavioural experiments. Control experiments established that female and male Lu. longipalpis were equally attracted to uninfected dog odour, female Lu. longipalpis were significantly more attracted to infected dog odour than uninfected dog odour in all 15 experimental replicates (average 45.7±0.87 females attracted to infected odour; 23.9±0.82 to uninfected odour; paired T-test, P=0.000). Male Lu. longipalpis did not significantly prefer either infected or uninfected odour (average 36.1±0.4 males to infected odour; 35.7±0.6 to uninfected odour; paired T-test, P=0.722). A significantly greater proportion of females chose the infected dog odour compared to the males (paired T-test, P=0.000).The results show that dogs infected with Le. infantum are significantly more attractive to blood-feeding female than male sand flies. This is strong evidence for parasite manipulation of the host odour in a natural transmission system and indicates that infected dogs may have a disproportionate significance in maintaining infection in canine and human infection.Author SummaryVisceral leishmaniasis (VL) is a disease caused by the Protist parasite Leishmania infantum. In Brazil and other South and Central American countries, the parasite is transmitted by the blood-feeding activity of infected female Lutzomyia longipalpis sand flies. The disease leads to thousands of human cases and deaths every year. Domestic dogs are the reservoir of infection for humans therefore understanding the effect of infection on dogs is important in developing an understanding of the epidemiology of the disease. Although previous studies on rodent models of Le. infantum infection have shown that infected Golden Hamsters are more attractive to Lu. longipalpis the attractiveness of naturally infected dogs to the insect vector has not been previously been investigated. In this study we showed that the odour of infected dogs is significantly more attractive to female sand flies which can transmit the pathogen than to male sand flies which do not. This clear-cut difference in attraction of female and males suggests that the females are preferentially attracted by parasite infected hosts and may lead to enhanced infection and transmission opportunities for the parasite.

scholarly journals Assessment of the insecticidal activity of oral afoxolaner against Phlebotomus perniciosus in dogs

Parasite ◽  
2019 ◽  
Vol 26 ◽  
pp. 63
Author(s):  
Nadège Perier ◽  
Wilfried Lebon ◽  
Leon Meyer ◽  
Noua Lekouch ◽  
Nesrine Aouiche ◽  
...  
Keyword(s):  
Untreated Control ◽  
Exposure Period ◽  
Blood Feeding ◽  
Treated Group ◽  
Control Group ◽  
Untreated Control Group ◽  
Phlebotomus Perniciosus ◽  
Post Exposure ◽  
Insecticidal Efficacy ◽  
Healthy Dogs

Twelve healthy dogs were included in this laboratory efficacy study. Six dogs were randomly allocated based on body weight to an untreated control group and six to an afoxolaner (NexGard®) treated group. In the treatment group, afoxolaner was administered orally on Day 0 in accordance with label instructions. On Days 1, 14 and 28, each dog was exposed to 60 unfed female and 10 male Phlebotomus perniciosus sandflies for 1 h. At the end of each exposure period, sandflies were counted and assessed for viability and feeding status. There was no statistical difference in mortality (0.0–5.4%), nor in feeding proportion (61.6–78%) between the control and the treated groups at all 1-h post-exposure assessments. After collection, live fed and unfed sandflies were kept for viability assessments at 48 and 72 h post-exposure. In the untreated control group, the average percentages of live, fed, female sandflies after exposure, on Days 1, 14 and 28, ranged from 51% to 74% at 48 h and from 46% to 57% at 72 h, demonstrating model robustness over the 28 days of the study. Significantly fewer live fed sandflies were recorded for the afoxolaner treated group (p < 0.01). The insecticidal efficacy was 100%, 95.9% and 75.2% at 48 h post Days 1, 14 and 28 exposures, respectively, and 100%, 100% and 86.3% at 72 h post Days 1, 14, and 28 exposures, respectively. A single administration of oral afoxolaner (NexGard®) to dogs significantly killed P. perniciosus sandflies 48 and 72 h after blood feeding for 1 month.

scholarly journals First Report of Canine Infection by Leishmania (Viannia) guyanensis in the Brazilian Amazon

2020 ◽  
Vol 17 (22) ◽  
pp. 8488
Author(s):  
Francisco J. A. Santos ◽  
Luciana C. S. Nascimento ◽  
Wellington B. Silva ◽  
Luciana P. Oliveira ◽  
Walter S. Santos ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Blood Collection ◽  
Wild Mammals ◽  
First Report ◽  
Transmission Cycle ◽  
First Choice ◽  
Human Leishmaniasis ◽  
Leishmania Spp ◽  
Canine Infection

The American cutaneous (CL) and visceral leishmaniasis (VL) are zooanthroponoses transmitted by sand flies. Brazil records thousands of human leishmaniasis cases annually. Dogs are reservoirs of Leishmania infantum, which causes VL, but their role in the transmission cycle of CL is debatable. Wild mammals are considered reservoirs of the aetiological agents of CL (Leishmania spp.). Objective: To describe the aetiology of leishmaniasis in dogs in an endemic area for CL and VL in the Amazon, Brazil. Methods: Clinical evaluation and blood collection of 40 dogs from the villages Ubim (20) and Socorro (20), city of Tomé-Açu, state of Pará, were carried out. The DNA extracted from the blood was used for PCR with Leishmania-specific primers targeting the hsp70-234 gene sequence. Products were sequenced (ABI3500XL), and the sequences were aligned, edited (BioEdit), and analyzed (Blastn). Results: Of the 34 amplified samples, 21 were sequenced, namely Leishmania infantum (12), L. guyanensis (5), L. braziliensis (3), and Leishmania sp. (01). Conclusion: Given the diversity of circulating pathogens, elucidation of the role of the dog in the Leishmania spp. cycle in Amazonian villages is imperative to the surveillance of CL in the region. We present the first report in Brazil, confirmed by sequencing, of canine infection by L. guyanensis, a species highly resistant to treatment in humans, with the drug of first choice (Glucantime®).

scholarly journals Infection of dogs by Leishmania infantum elicits a general response of IgG subclasses

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. I. Olías-Molero ◽  
I. Moreno ◽  
M. J. Corral ◽  
M. D. Jiménez-Antón ◽  
M. J. Day ◽  
...  
Keyword(s):  
Leishmania Infantum ◽  
Vaccine Development ◽  
Parasitic Infection ◽  
Igg Subclasses ◽  
Human Populations ◽  
Igg Subclass ◽  
Diagnosis And Prognosis ◽  
Source Of Infection ◽  
Human Leishmaniasis ◽  
General Response

Abstract Leishmania infantum is the etiological agent of zoonotic visceral leishmaniasis. In endemic areas, canine infections are considered the main source of infection for human populations. Therefore, any control of human leishmaniasis must include the control of canine infections. Chemotherapy of leishmaniasis is inadequate and canine immunoprophylaxis has important limitations. Reports on the response of infected dogs are abundant but no clear picture of immune events has emerged. To shed some light on these shortcomings the specific IgG subclass response was followed in 20 Beagle dogs experimentally infected with L. infantum using monoclonal antibodies (MAb) specific for canine IgG1, IgG2, IgG3 and IgG4, along with ELISA and flow cytometry. Results showed that parasitic infection elicits a general response of all IgG subclasses, with a predominant IgG1 response and without any evidence of IgG1/IgG2 dichotomy. These findings suggest that the inconsistent results reported previously could be related to the lack of specific reagents and not to the actual differences in the immune response of infected animals. Differential IgG subclass reactivity in ELISA and cytometry and the analysis of the reacting antigens could facilitate the diagnosis and prognosis of the disease and provide a useful tool for adequate therapeutics and vaccine development against leishmaniasis.

scholarly journals Investigations on Mediterranean kala azar IX—Feeding experiment with phlebotomus perniciosus and other species on animals infected with leishmania infantum

1935 ◽  
Vol 116 (801) ◽  
pp. 516-542 ◽  
Keyword(s):  
Small Proportion ◽  
Leishmania Infantum ◽  
Short Form ◽  
Chinese Hamster ◽  
Large Majority ◽  
Feeding Experiment ◽  
Phlebotomus Perniciosus ◽  
Short Forms ◽  
Feeding Experiments ◽  
Kala Azar

In the present paper it is intended to analyse the results of feeding experiments with Phlebotomus perniciosus on animals infected with various strains of Leishmania infantum carried out during 1930, 1931, 1932 and 1933. In a previous paper (1931) the results of feeding experiments carried out on a Chinese hamster from June 18 to October 22, 1930, were discussed. Only 330 sandflies infected by feeding on a Chinese hamster inoculated with Catania strains of L. infantum were included, and the results obtained appeared fairly uniform but for one point. A large majority of sandflies had an infection in which flagellates described as "long forms" predominated and only a small proportion (5%) were infected with "short forms" Proboscis infections ( i. e ., infections in the epipharynx) were observed mainly among the latter. The "short form infections" were observed from September 20 till the end of the sandfly season in 1930.

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