Identification of the avian tracheal trematode Typhlocoelum cucumerinum (Trematoda: Cyclocoelidae) in a host-parasite-environment system: diagnosis, life cycle and molecular phylogeny.

Typhlocoelum cucumerinum is a tracheal parasite of birds widely distributed across the globe. Nevertheless, aspects of the biology of this cyclocoelid are still poorly understood. Herein, we report the finding of T. cucumerinum in definitive and intermediate hosts from an urban waterbody of Brazil. The parasite was initially detected during the necropsy of domestic Muscovy ducks (Cairina moschata) found dead in the locality. Coproparasitological tests in live animals revealed that 12/47 (25.53%) Muscovy ducks and 2/8 (25%) mallards (Anas platyrhynchos platyrhynchos) were infected with T. cucumerinum. Moreover, rediae and metacercariae morphologically similar to T. cucumerinum were found in 3/248 (1.33%) Biomphalaria straminea collected in the same waterbody frequented by the birds. The conspecificity between the adult and the larval stages was confirmed molecularly (100% similarity in Cox-1). Moreover, the phylogenetic position of T. cucumerinum was determined for the first time based on partial fragments of the 28S, Cox-1 and Nad-1 genes. The species grouped with other members of the subfamily Typhlocoelinae with sequences available, but the data obtained do not support the distinctiveness of the genera Typhlocoelum and Tracheophilus. Further studies involving a broader range of species can result in taxonomic rearrangements in Typhlocoelinae.

Causes of Fatal Cyathostomiasis in Brown Booby (Sula leucogaster) from Brazil: Identification of Pathogen and Implications for Management.

Fatal infection by Cyathostoma (Cyathostoma) phenisci (Nematoda: Syngamidae), was identified in 2 of 52 brown boobies (Sula leucogaster) collected on beaches in the state of Rio de Janeiro, Brazil, and admitted to the veterinary clinic for rehabilitation. Both infected birds were in poor physical condition, with atrophied pectoral muscles, and died soon after starting treatment. The parasitological and pathological examination of the carcasses revealed the presence of C. (C.) phenisci in the trachea, resulting in tracheitis, as well as severe parasitic granulomatous bronchopneumonia caused by eggs deposited in the lungs. In our opinion, these serious pathological changes were the primary cause of chronic respiratory illness. This is the first description of fatal cyathostomiasis in a fish-eating avian host caused by infection by a member of the subgenus Cyathostoma (Cyathostoma). Therefore, it is reasonable to consider C. (C.) phenisci to be a real threat to a wide range of their definitive hosts, and cyathostomiasis should be considered in the differential diagnosis for fish-eating marine birds, even in cases without respiratory signs. This is also the first record of the genus Cyathostoma in Brazil.

Range expansion of the tracheal mite Acarapis woodi (Acari: Tarsonemidae) among Japanese honey bee, Apis cerana japonica, in Japan.

Acarapis woodi, a parasitic mite of honey bees, was first detected in Japan in 2010. Infestation was mostly observed in the Japanese honey bee (Apis cerana japonica) and was rare in the European honey bee (Apis mellifera). By 2014, the mites had spread throughout central and eastern Japan. In the current study, we investigated the subsequent expansion of the mite to western Japan. Our research revealed that the mites were distributed across most of Japan by 2018, except for Wakayama and Kochi prefectures. Many small remote islands more than 20 km away from mainland Japan are still free of A. woodi, but bees on some of these islands were infested. About 40% of colonies of the Japanese honey bee in Japan were infested by the mites, and average mite prevalence of the infested colonies was about 50% during the 6-year study. There was no trend of decline in the infested colony proportion or in the mite prevalence. In addition, the observation of Japanese honey bee colonies by hobby beekeepers for two signs of mite infestation, K-wing and crawling bees, was an effective means for estimating infestation by tracheal mites.

An immunocompetent rat model of infection with Cryptosporidium hominis and Cryptosporidium parvum.

A major obstacle to developing vaccines against cryptosporidiosis, a serious diarrheal disease of children in developing countries, is the lack of rodent models essential to identify and screen protective immunogens. Rodent models commonly used for drug discovery are unsuitable for vaccine development because they either are purposefully immunodeficient or immunosuppressed. Here, we describe the development and optimization of an immunocompetent intratracheal (IT) rat model susceptible to infections with sporozoites of Cryptosporidium parvum and Cryptosporidium hominis - the primary causes of human cryptosporidiosis. A model suitable for screening of parasite immunogens is a prerequisite for immunogen screening and vaccine development.

Intratracheal myiasis followed by tracheal-esophageal fistula: report of a rare case and literature review.

BACKGROUND: To enhance awareness of the clinical features and prevention of endotracheal myiasis. CASE PRESENTATION: A case of intratracheal myiasis is reported. A 61-year-old male patient with a history of laryngectomy was admitted to hospital due to tracheostomal hemorrhage of 3 h duration. Intratracheal myiasis was confirmed by bronchoscopy, and the patient underwent bronchoscopic intervention, which was complicated by a tracheal-esophageal fistula and resolved by endotracheal stenting. Twenty months after stent placement, the fistula had not healed. CONCLUSION: Intratracheal myiasis has serious complications and is difficult to treat. For post-tracheostomy patients, healthcare providers and caregivers should pay attention to the care and monitoring of wounds and maintenance of a tidy, clean living environment to prevent intratracheal myiasis.

Clinostomum poteae n. sp. (Digenea: Clinostomidae), in the trachea of a double-crested cormorant Phalacrocorax auritus Lesson, 1831 and molecular data linking the life-cycle stages of Clinostomum album Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 in Mississippi, USA.

Clinostomum spp. (Digenea: Clinostomidae) are a group of trematodes commonly found in the buccal cavity and oesophagus of a variety of piscivorous birds. The metacercariae, colloquially known as "yellow grubs," have been reported from a diverse group of freshwater fishes worldwide. In the catfish farming region of the southeastern USA, piscivorous birds present a continuous challenge for aquaculturists in the form of fish depredation and the introduction of trematodes into these static, earthen pond systems. Clinostomum spp. are commonly encountered in farm-raised catfish. While generally considered pests of minimal importance, heavy infections can result in unmarketable fillets. Of the piscivorous birds that frequent catfish aquaculture operations in the southeastern US, the double-crested cormorant (Phalacrocorax auritus Lesson) is one of the most damaging, although reports of Clinostomum spp. from P. auritus are limited. In this study, adult trematodes morphologically consistent with Clinostomum sp. were found in the trachea of a double-crested cormorant captured in Lowndes Co., Mississippi, USA. These specimens differed from other recognised Clinostomum spp. in several key morphological characters. Moreover, sequence data of mitochondrial cytochrome c oxidase subunit 1 gene (cox1), nicotinamide adenine dinucleotide dehydrogenase subunit 1 gene (nad1) and ribosomal internal transcribed spacer (ITS) regions did not match any known Clinostomum sp. for which sequence data are available. While genetically similar to C. marginatum and C. album Rosser, Alberson, Woodyard, Cunningham, Pote & Griffin, 2017 reported from the great egret Ardea alba L. in Mississippi, these adult clinostomids were larger in size and limited to the trachea, whereas both C. marginatum Rudolphi, 1819 and C. album are found in the oral cavity and esophagus. Given these distinct morphological and molecular characters we propose a new member of the genus, known hereafter as Clinostomum poteae n. sp. Additionally, larval stages in the life-cycle of C. album are morphologically and molecularly identified for the first time from ramshorn snails Planorbella trivolvis Say and fathead minnows Pimephales promelas Rafinesque.

Molecular methods indicate lack of spread of Acarapis woodi introduced to honey bees in western Norway.

The tracheal mite, Acarapis woodi, may be one of many factors contributing to the decline in honey bee (Apis mellifera) populations. Databases on the widespread distribution of A. woodi exist, but the data seem patchy. Norway is not listed as being infested, although there have been at least two separate introductions of the parasite. Investigations in 2003, 2006, and 2009 using standard microscopy methods indicated persistence of A. woodi in honey bees in this region. In 2013, we conducted another survey. Samples were sent in from 335 beehives belonging to 39 apiaries, and all were asked to complete a questionnaire. Analysis for A. woodi in the submitted samples was by PCR, with sequencing of positive results. The results described in this article indicate that this parasite still persists in some apiaries in this region, but at a low, and possibly decreasing, level, with positive results obtained from just two (5.1%) of the apiaries. Of the 17 beekeepers that answered the questionnaire, none reported symptoms of infestation with A. woodi. Sequencing of PCR products indicated a difference between the two A. woodi isolates. Our results were generally encouraging regarding the apparent lack of spread of A. woodi, within the County. Furthermore, the sequencing results may indicate two separate introductions rather than spread. Nevertheless, the scarcity of data, the vulnerability of honey bee populations globally, and the potential contribution of this parasite to reduced survival, indicate that the situation should be continued to be monitored. In addition, Norwegian beekeepers should be made aware of, and follow, restrictions regarding import and transport of bees, both nationally and internationally.

Interrelationships of Dictyocaulus spp. in Wild Ruminants with Morphological Description of Dictyocaulus cervi n. sp. (Nematoda: Trichostrongyloidea) from Red Deer, Cervus elaphus.

Lungworms from the genus Dictyocaulus cause parasitic bronchitis (dictyocaulosis) characterized by coughing and severe lung pathology in both domestic and wild ruminants. In this study we investigated the interrelationships of Dictyocaulus spp. from European bison (Bison bonasus L.), roe deer (Capreolus capreolus), and red deer (Cervus elaphus) by nucleotide sequence analysis spanning the 18S RNA gene (small subunit [SSU]) and internal transcribed spacer 2 (ITS2) regions of the ribosomal gene array as well as the mitochondrial cytochrome c oxidase subunit 1 (cox1). Molecular analyses of sequence data obtained partly with novel primers from between 10 and 50 specimens from each host were carried out. Bayesian inference analysis revealed that each host species was infected with different genotypes. Analysis of cox1 sequence data showed a diverse genetic background and high evolutionary potential of Dictyocaulus taxa. Data from lungworms of European bison revealed a distinct genotype of Dictyocaulus viviparus, whereas Dictyocaulus capreolus was only found in roe deer. In contrast, red deer were infected with a taxon with unique SSU, ITS2, and cox1 sequences. These results indicate the occurrence of a novel genotype from red deer, which differs significantly from the National Center for Biotechnology Information reference sequence of Dictyocaulus eckerti. The molecular evidence was consistent with a morphological study with description and imaging of Dictyocaulus cervi n. sp. recovered from red deer. Dictyocaulus cervi n. sp. can be distinguished from D. eckerti on the basis of the absence of cervical papillae, the occurrence of a single ring of 4 symmetrical submedian cephalic papillae, length of the tail in females, morphometry of the female reproductive system, and measurements of gubernacula in males. In conclusion, our findings further strengthen the idea that the genetic complexity and diversity among Dictyocaulus lungworms infecting wildlife ruminants is larger than previously believed and warrants further investigation.

Body condition is negatively associated with infection with Syngamus trachea in the ring-necked pheasant (Phasianus colchicus).

The role that parasites play in regulating animal populations is debated, however recent research hints at their pervasiveness among free-living animal populations. Parasites exert both direct and indirect effects on host populations, and can act to regulate populations. The Ring-necked pheasant is an important game-bird species in the UK, and large numbers of birds are released annually. The impact of the ubiquitous tracheal nematode, Syngamus trachea on pheasant populations through effects on host condition was assessed on two pheasant estates in the south west of England. Pheasants infected with S. trachea demonstrated a significant reduction in host condition compared with uninfected controls, with as few as one pair of worms per bird. Although there was no difference in worm burden between sexes, analysis of regression slopes revealed there was a significant difference between sexes in the magnitude of the effect of increasing worm burden on host condition, with detectable effects observed in hosts with one and three pairs of worms for males and females respectively. The observed reductions in host condition in birds with even sub-clinical infections could be the cause of poor reproductive success and survival of pheasants post-release.

Trichomonas gallinae: Prevalence and molecular characterization from pigeons in Minoufiya governorate, Egypt.

Trichomonas gallinae infects the upper digestive tract of pigeons. It is transmitted from mother to young squabs by feeding crop milk. Generally, infection resulted in severe mortalities in young birds. In this study, we examined 3315 pigeons of different ages from the Minoufiya governorate for the clinical infection by T. gallinae. The infection was confirmed in infected birds by microscopical examination of oral swabs, histopathological examination, and PCR of the ITS1/5.8S/ITS2 gene. The prevalence was 63 (1.9%). The parasite was found in 35 (2.04%) from Ashmoun, 15 (1.66%) from Minoof, 8 (1.6%) from Quesna, and 5 (2.5%) from El-Shohada birds. The infection was mainly detected in squabs 60 (1.8%). The sequence of T. gallinae ITS1/5.8S/ITS2 gene from Egypt has high nucleotide sequence identity (up to100%) to T. gallinae from pigeon of USA, Austria, Canada, and Spain. The sequence belongs to genotype B of T. gallinae. Histopathological examination presented the parasites in crop, liver, larynx, and trachea as poorly eosinophilic bodies with severe inflammatory cell infiltration. This is the first study to present the prevalence and genotype of T. gallinae from Minoufiya governorate, Egypt.

Rhinella marina (Amphibia: Bufonidae) Versus Rhabdias paraensis (Nematoda: Rhabdiasidae): Expanding the View on a Natural Infection.

Amphibian and reptile lungs are frequently infected with Rhabdias parasites, and this condition ultimately leads to reduced survival, performance, and growth because of granulomatous inflammation, nodule formation, and nematodal pneumonia onset. Here we investigate the histopathological features of naturally infected Rhinella marina by the lung nematode Rhabdias paraensis. A total of 10 host animals were captured in peridomiciliar areas in the eastern Brazilian Amazon, and anatomic-histological analyses were performed on both the infected and non-infected lungs of these amphibians. Helminths were usually found within the secondary and primary septa of infected lungs whereas parasites were not detected within vessels or adhering to tissues. In addition, we observed discrete erythrocytes, diapedesis foci, few granulocytes and erythrocytes in the interseptal spaces, discrete cell infiltration, and a small number of melanomacrophages, and no granulomas or cysts were observed. New aspects related to changes in tissue and helminth-host interactions are discussed for the relationship of R. paraensis × Rhi. marina from the Amazon region.

Geographical distribution of Angiostrongylus vasorum in foxes (Vulpes vulpes) in the Republic of Ireland.

The reported incidence of the metastrongylid nematode Angiostrongylus vasorum, that infects dogs and other canids, is increasing worldwide outside recognized endemic foci. This apparent expansion of the parasite's range is causing concern to veterinary clinicians as the disease caused in dogs can be life threatening and its treatment is not straightforward. The red fox is thought to be a reservoir host for dogs. To investigate the spatial distribution of infection in foxes in Ireland, the hearts and lungs of 542 foxes from all over Ireland were examined. The incidence of infection was found to be 39·9% [95% confidence interval (CI) 35·7-44·1] with positive samples occurring in each of the country's 26 counties. This report confirms that the parasite is endemic in Ireland and the overall prevalence is the second highest in Europe. This is the first survey of A. vasorum infection in Irish foxes and highlights the potential exposure of the Irish dog population to high risk of cross-infection. Additionally, Crenosoma vulpis was found in seven of the foxes, a parasite not previously reported in the Irish fox.

Spatial distribution of infectious stages of the nematode Syngamus trachea within pheasant (Phasianus colchicus) release pens on estates in the South West of England: Potential density dependence?

The spatial distribution of the infectious stages of parasites with a direct life cycle is one of the most important factors influencing infectious disease dynamics, and acquisition rates will generally increase as the contact time between parasite and host increases. For animal species that are constrained by feeding opportunities, one might expect disease patterns to be highly skewed within confined systems. The aim of the present study was to identify to what extent, if any, eggs of avian parasites are aggregated within the release pen, and to evaluate what effect, if any, this aggregation had on the distribution of the adult stages within the host species. The abundance of Syngamus trachea eggs were highly aggregated within pens, with high levels of contamination driven by a combination of feeder placement, soil moisture and host-mediated heterogeneities in immuno-competence. The log mean and log variance of egg abundance was highly linear (R(2)=0.97-0.99), with an estimated slope (b) of between 1.79 and 1.97 for individual sites, and 2.11 when sites were combined, which indicated aggregation relative to an estimated Poisson slope of unity. Although the placement of feeders and environmental moisture could be contributing to parasite aggregation, density-dependent processes appear to be ensuring the population does not become too over or under-dispersed, in order to maintain the transmission-virulence equilibrium. To the best of our knowledge, this is the first paper to explicitly demonstrate the high spatial aggregation of eggs around feeding sites and the first to suggest possible density-dependent regulatory mechanisms stabilising disease dynamics between S. trachea and ring necked Pheasants (Phasianus colchicus).

Infection by Toxoplasma gondii, a severe parasite in neonates and AIDS patients, causes impaired anion secretion in airway epithelia.

The airway epithelia initiate and modulate the inflammatory responses to various pathogens. The cystic fibrosis transmembrane conductance regulator-mediated Cl(-) secretion system plays a key role in mucociliary clearance of inhaled pathogens. We have explored the effects of Toxoplasma gondii, an opportunistic intracellular protozoan parasite, on Cl(-) secretion of the mouse tracheal epithelia. In this study, ATP-induced Cl(-) secretion indicated the presence of a biphasic short-circuit current (Isc) response, which was mediated by a Ca(2+)-activated Cl(-) channel (CaCC) and the cystic fibrosis transmembrane conductance regulator. However, the ATP-evoked Cl(-) secretion in T. gondii-infected mouse tracheal epithelia and the elevation of [Ca(2+)]i in T. gondii-infected human airway epithelial cells were suppressed. Quantitative reverse transcription-PCR revealed that the mRNA expression level of the P2Y2 receptor (P2Y2-R) increased significantly in T. gondii-infected mouse tracheal cells. This revealed the influence that pathological changes in P2Y2-R had on the downstream signal, suggesting that P2Y2-R was involved in the mechanism underlying T. gondii infection in airways. These results link T. gondii infection as well as other pathogen infections to Cl(-) secretion, via P2Y2-R, which may provide new insights for the treatment of pneumonia caused by pathogens including T. gondii.

Effects of different inoculation routes on the parasitic sites of Cryptosporidium baileyi infection in chickens.

Cryptosporidiosis is prevalent in domesticated, caged, and wild birds. Cryptosporidium baileyi, an ascendant species of avian Cryptosporidium, is an important pathogen. It causes respiratory disease in chickens, especially chickens younger than 50 days. In this study, SEM, histological, semi-quantitative PCR, and nested PCR techniques were used to explore the impact of different inoculation routes on sites of C. baileyi infection in chickens. Results showed that inoculation with sporozoites or oocysts via the rectum was an effective means of causing infection. This may provide an important reference for the development of the transfection system of C. baileyi in chickens. Numerous endogenous stages of C. baileyi were observed in the bursas of Fabricius (BF) and cloacas of chickens inoculated with sporozoites or oocysts via the rectum, but no parasite was seen in the tracheas of any of these chickens. In chickens infected with oocysts via the crop, the number of parasites in the BF was approximately 23-fold more than in the trachea. All blood samples collected after inoculation were negative for C. baileyi. These data show that C. baileyi was not transferred by blood circulation between the BF and respiratory tract. Different routes of inoculation were here found to distinctly affect sites of parasitism in chickens. These findings may facilitate further understanding of the biology of C. baileyi and efforts to control avian cryptosporidiosis.

Molecular determination and genotyping of Cryptosporidium spp. in fecal and respiratory samples of industrial poultry in Iran.

OBJECTIVE: To identify the genotypes of prevalent Cryptosporidia in broiler chickens in Lorestan province, Iran. METHODS: A total of 1 000 fecal and 1 000 trachea samples were collected from chickens. Smears from both fecal and tracheal samples were stained with modified Ziehl-Neelsen method and nested PCR-RFLP according to amplification of 18S rRNA gene using Ssp I and Vsp I restriction enzymes and DNA sequencing. RESULTS: From the examined chickens 0.7% was positive for Cryptosporidium. Infection was present in 0.5% fecal samples and also in 0.5% trachea. Only 0.3% of simultaneous infections in fecal and tracheal samples were observed. Nested PCR of our isolates demonstrated Cryptosporidium baileyi. CONCLUSIONS: In our work, low rate of Cryptosporidium baileyi infection was detected, but in critical situations and our poor management circumstances, cryptosporidiosis occurs in serious feature especially in immune suppressed individuals.

Pathological and histological findings associated with the feline lungworm Troglostrongylus brevior.

Troglostrongylus brevior is a neglected feline lungworm species, which has been increasingly reported in the Mediterranean area, although scant data are available on the respiratory alterations it causes in cats. Therefore, we describe the gross and histological lesions of a 20-week old kitten that succumbed due to the onset of a fulminant respiratory failure. At necropsy, a catarrhal exudate was observed in the airways, along with nematodes in the trachea and bronchi. The lungs were processed for histological examination and serial pulmonary sections were performed. A total of 14 nematodes were collected, being all morphologically and molecularly identified as T. brevior. Lungworms were histologically localized within the bronchial lumen, surrounded by an eosinophilic infiltrate. The presence of T. brevior in the airways has been histologically documented for the first time and its life-threatening potential is discussed.