Myiasis of the Tracheostomy Wound Caused bySarcophaga(Liopygia)argyrostoma(Diptera: Sarcophagidae): Molecular Identification Based on the Mitochondrial Cytochrome c Oxidase I Gene: Fig. 1.

Abstract

Wound myiasis is the infestation of open wounds of mammalian hosts caused by larvae of various species of flies. This kind of myiasis can be a serious problem for immobilized patients with open wounds. Here, we identify a dipteran larva found in the tracheostomy wound of a child affected by a severe spinal muscular atrophy. The collected larva was dissected and microscopically analyzed. DNA was extracted from part of the larva and used for the molecular identification. A 487 bp fragment, including part of 5.8 S, the internal transcribed spacer 2 (ITS2), and part of 28S, was amplified using a novel PCR assay to be cloned and sequenced. The barcode region of cytochrome oxidase I (COI) was also cloned and sequenced after PCR amplification. The larva, designated as SASI1, was identified as a third instar of Sarcophaga sp. The COI sequencing confirmed a low similarity with Sarcophaga ruficornis (F.) (95%), yet COI showed a 100% similarity with Sarcophaga argyrostoma (Robineau-Desvoidy, 1830) species. Therefore, SASI1 was identified as a S. argyrostoma larva on the basis of its COI barcode. This is one of the rare cases of myiasis of tracheostomy wound and the first caused by S. argyrostoma.

Wound Myiasis Caused bySarcophaga (Liopygia) Argyrostoma(Robineau-Desvoidy) (Diptera: Sarcophagidae): Additional Evidences of the Morphological Identification Dilemma and Molecular Investigation

“…The robustness of the coxI gene as a diagnostic marker to lay the groundwork for identification of these three species of Sarcophaga has been demonstrated [ 21 , 26 ]. Sarcophaga argyrostoma has been identified using a coxI sequence in an elderly patient with an external ophthalmomyiasis (with 97% identity) [ 6 ] and very recently in a tracheotomized child's surgical wound (with an identity of 100%) [ 8 ]. In the present study, the involvement of S. argyrostoma in the wound myiasis is confirmed with 99% identity.…”

“…This is the third case in Europe [ 4 , 8 ]. Cases of myiasis caused by Sarcophaga species are apparently few, but it must be underlined that cases of myiasis often remain unrecorded or that, more frequently, identification is partial, that is, at genus level [ 27 – 31 ].…”

“…The most distinctive characters available in literature for Sarcophaga (Liopygia) spp. identification, that is, Sarcophaga argyrostoma [ 8 , 10 , 16 , 17 ], Sarcophaga crassipalpis [ 18 ], and Sarcophaga cultellata [ 3 ], were considered. In particular, the presence/absence of spines/warts on the t2 interband area, the number of lobes on the anterior spiracles, the shape of the posterior spiracles, and cephalo-skeleton were compared ( Table 1 ).…”

“…Among them, in the Mediterranean countries, three Sarcophaga species belonging to the same subgenus (Liopygia) share the same ecological niche: Sarcophaga (Liopygia) crassipalpis Macquart, 1839 , Sarcophaga (L.) argyrostoma Robineau-Desvoidy, 1830, and Sarcophaga (L.) cultellata Pandelle, 1986 [ 3 ]. These species are included in the category of “nosocomial myiasis agents” because they have been found in wound myiasis affecting hospital patients who are immobilized, often old, and poorly cared [ 4 – 8 ]. Flies are attracted by the smell of fresh or infected and untreated wounds and lay eggs (or larvae as in the case of Sarcophaga ), which then develop in necrotic or injured tissues and sometimes cause or exacerbate a wound [ 9 ].…”

A Rare Case of Tracheostomal Myiasis in a Child

“…[2][3][4][5][6][7] In a massive internet search using PubMed/Medline services, authors could find only 3 cases reported in children on the cited subject. 6,8,9 Myiasis is classified as specific (obligate), semi-specific (facultative), and accidental (pseudomyiasis). 2 Open wounds and bodily orifices that emit odors of natural secretions are major factors in susceptibility to myiasis, as they provide a favorable environment for attraction and oviposition of flies.…”