A Novel Dirofilaria Species Causing Human and Canine Infections in Hong Kong

To, Kelvin Kai-Wang; Wong, Samson S. Y.; Poon, Rosana W.S.; Trendell-Smith, Nigel J.; Ngan, Antonio H. Y.; Lam, W.K. Jacky; Tang, Thomas; AhChong, Ah Kian; Kan, Joshua Chi Hang; Chan, Konan; Yuen, Kwok‐Yung

doi:10.1128/jcm.01590-12

Cited by 60 publications

(63 citation statements)

References 30 publications

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“…4 As a common amphixenosis, this disease is now receiving widespread attention, and increasing numbers of cases have been reported in recent years. [5][6][7][8][9] In some areas, disease is present in up to 30% of human serum samples. 10 Because of the wide epidemic range and multiple hosts, heartworms are now considered to be among the most harmful Dirofilaria nematodes infecting man and other mammals.…”

Section: Introductionmentioning

confidence: 99%

Intraspecific Genetic Variation and Phylogenetic Analysis of Dirofilaria immitis Samples from Western China Using Complete ND1 and 16S rDNA Gene Sequences

Liang

Zhong

et al. 2014

The American Society of Tropical Medicine and Hygiene

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Abstract. Dirofilaria immitis (heartworm) is the causative agent of an important zoonotic disease that is spread by mosquitoes. In this study, molecular and phylogenetic characterization of D. immitis were performed based on complete ND1 and 16S rDNA gene sequences, which provided the foundation for more advanced molecular diagnosis, prevention, and control of heartworm diseases. The mutation rate and evolutionary divergence in adult heartworm samples from seven dogs in western China were analyzed to obtain information on genetic diversity and variability. Phylogenetic relationships were inferred using both maximum parsimony (MP) and Bayes methods based on the complete gene sequences. The results suggest that D. immitis formed an independent monophyletic group in which the 16S rDNA gene has mutated more rapidly than has ND1.

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Section: Introductionmentioning

confidence: 99%

Intraspecific Genetic Variation and Phylogenetic Analysis of Dirofilaria immitis Samples from Western China Using Complete ND1 and 16S rDNA Gene Sequences

Liang

Zhong

et al. 2014

The American Society of Tropical Medicine and Hygiene

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“…PCR products were purified and sequenced as described previously (12). All statistical analyses were performed using PASW Statistics 18 and VassarStats (http://vassarstats.net/).…”

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confidence: 99%

Use of Nasopharyngeal Aspirate for Diagnosis of Pneumocystis Pneumonia

Wong

et al. 2013

J Clin Microbiol

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Quantitative PCR on nasopharyngeal aspirate (NPA) can achieve high sensitivity and specificity in diagnosing Pneumocystis pneumonia (PCP) compared to microscopic examination of bronchoscopic specimens in a population with low HIV prevalence. Since NPA is a minimally invasive procedure, it is ideal as a screening test for PCP. C urrently, microbiological confirmation of Pneumocystis pneumonia (PCP) requires the identification of Pneumocystis cysts or trophozoites using microscopy. Bronchoscopic specimens are preferred because Pneumocystis resides mainly in the alveolar space (1). However, both transbronchoscopic bronchoalveolar lavage and sputum induction pose significant risk to the patient (2-4). Upper respiratory tract specimens are not recommended because of low sensitivity when traditional microscopic examination is used (5). PCR has higher sensitivity than microscopic examination in the detection of Pneumocystis (6) and may overcome the problem of low sensitivity associated with microscopic examination of upper respiratory tract specimens. In this study, we sought to determine whether nasopharyngeal aspirate (NPA) specimens could be used for the diagnosis of PCP.Patients of the Hong Kong West Cluster Hospitals with bronchoscopic specimens (bronchoalveolar lavage fluid [BALF] or bronchial aspirate) submitted to our laboratory for Pneumocystis examination from 1 January 2010 to 31 March 2012 were identified using the laboratory information system. In our laboratory, Pneumocystis cysts were visualized with methenamine silver stain by using standard procedures (7). With this method, Pneumocystis trophozoites or sporozoites could not be detected. Archived NPA specimens from these patients collected during the same hospitalization were retrieved. Only the earliest NPA specimen was tested if multiple specimens were available from the same patient. NPA specimens were collected as described previously (8). Clinical and laboratory data were obtained using the clinical management system. Patients without archived NPA specimens were excluded. A patient was considered to have definite PCP if Pneumocystis was identified in the bronchoscopic specimen by microscopic examination (9). This study has been approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster.DNA was extracted from 200 l of NPA specimens and from other fungi using the QIAamp DNA kit (Qiagen, Hilden, Germany) and DNeasy plant minikit (Qiagen, Hilden, Germany), respectively, according to the manufacturer's instructions (10). Real-time quantitative PCR (qPCR) targeting a 124-bp fragment of the mitochondrial large subunit rRNA (mt LSU rRNA) gene of Pneumocystis jirovecii was performed as described previously (11). Plasmid suspensions were used as standards for quantification and positive controls (Fig. 1).We verified the positive results from the mitochondrial (mt) large-subunit (LSU) rRNA qPCR (LSU-qPCR) by a conventional PCR targeting the mitochondrial small-subunit rRNA (mt SSU rRNA) gene of P. jiro...

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“…10 In 2012, To et al 11 reported a case series of three patients who had diseases caused by a novel Dirofilaria species in Hong Kong. This species was found in 3% of stray dogs' blood samples in Hong Kong.…”

Section: Discussionmentioning

confidence: 99%