Wohlfahrtiimonas chitiniclastica Bacteremia Associated with Myiasis, United Kingdom

To the Editor: We report the identification of Wohlfahrtiimonas chitiniclastica bacteria in a sample of blood obtained from a patient in Surrey, United Kingdom. We highlight the importance of recognizing unusual bacteria that are associated with the larvae of parasitic flies as a potential causative agent of severe infection in patients with myiasis in the United Kingdom and possibly worldwide.

sequencing. Two W. chitiniclastica reference isolates were in the MALDI-TOF database at time of testing; scores matched to our isolate were 2.264 and 2.200, indicating a match to species level. We could not isolate W. chitiniclastica from swab specimens of superficial lesions or ear swab specimens.
Blood culture samples grew a mixture of Proteus mirabilis, Providencia rettgeri, and Staphylococcus aureus. The patient made good clinical recovery and was later discharged to a local rehabilitation unit.
Previous case reports from Argentina and the south of France of bacteremia caused by Wohlfahrtiimonas spp. involved homeless persons with histories of alcohol abuse, 1 of whom was infested with insect larvae (1,2). One of these patients died from sepsis. W. chitiniclastica is known to colonize at least 2 species of flies but is not reported in Lucilia sp. This bacterium has been isolated from larvae of the fly Wohlfahrtia magnifica, a serious parasite of livestock in eastern Europe, the Mediterranean, and Central Asia (3), but this fly is not usually seen in the United Kingdom. W. chitiniclastica has also been isolated in China from Chrysomya megacephala oriental latrine flies, a screwworm species common in tropical and subtropical regions that is a facultative cause of myiasis (4,5). A study from South Korea reported a new Wohlfahrtiimonas sp. isolated from the larval gut of Hermetia illucens, the black soldier fly, although this fly is not pathogenic (6).
L. sericata is a blowfly that is common across much of the world. Although it usually feeds on dead or necrotic tissue, it can invade healthy tissue and is the cause of sheep blowfly strike (i.e., cutaneous myiasis) in otherwise healthy livestock. This organism has a role in forensic investigations and is used in health care settings for larval debridement of necrotic tissue from wounds and ulcers (5). The woman in our study had myiasis (i.e., infestation) with some invasion of healthy tissue and tissue damage from enzymes secreted by the larvae.
In this case, use of MALDI-TOF mass spectrometry enabled rapid identification of a rare bacterial species (7) in a patient with myiasis; slower molecular methods were previously required for such diagnoses. Without local availability of this technology, considerably more time would have been required for the diagnosis. Previous lack of identification of this species may be due to the former shortage of W. chitiniclastica isolates in the MALDI-TOF database.
This case demonstrates association of W. chitiniclastica with myiasis, although the pathogenic role in this clinical situation is uncertain. It is difficult to ascribe the clinical symptoms solely to bacteremia caused by this organism because multiple organisms were isolated. The cultures might have been heavily contaminated, but this would still highlight an association between L. sericata and W. chitiniclastica. Although we did not test the extracted fly larvae for W. chitiniclastica, we believe it is likely that the bacteremia originated from the patient's inner ear infestation. L. sericata may be a vector for this microorganism in the United Kingdom, and possibly worldwide, given this fly's widespread habitat. To the Editor: New Delhi metallo-β-lactamase (NDM) is an example of a successful antimicrobial drug resistance determinant and has become one of the most clinically significant carbapenemases. The gene bla NDM was first described in India in 2009. Its dispersion is epidemiologically linked to the Indian subcontinent, from which increased international transmission has been detected in nosocomial, community, and environmental isolates (1). Currently, the main acquired carbapenemases around the world are Klebsiella pneumoniae carbapenemase (KPC), oxacillinase-48 (OXA-48), and NDM. KPC is broadly detected and endemic to some areas; OXA-48 has been widely disseminated throughout European countries and has been reported in other regions. NDM is reported almost worldwide but did not successfully spread in most countries of Europe except the United Kingdom and recently, France, as has been found in Enterobacteriaceae (2) and in nonfermenting gram-negative bacilli, with progression toward rapid global prevalence.

Response to Detection of New Delhi Metallo-β-Lactamase-Producing Bacteria, Brazil Leonardo Neves Andrade, Ana Lúcia Costa Darini
NDM producers were detected most recently in South America (3). However, an increase in cases of NDM-producing bacteria has been noted. Carvalho-Assef et al. (4) described characterization of NDM in Brazil, in Providencia rettgeri isolated from a tissue sample excised from a patient in a hospital in Rio Grande do Sul state in southern Brazil, in 2013. Reports by Carvalho-Assef et al. (5) and Rozales et al. (6) have highlighted that P. rettgeri and isolates from the Enterobacter cloacae complex, clonally and nonclonally related, have been increasingly detected in the southern region of Brazil. In addition, retrospective studies have shown that NDM-1-producing Enterobacter have been present in Brazil since 2012 and have also been detected in Rio Grande do Sul (5). NDM-1-producing Morganella morganii (6), Escherichia coli, Klebsiella pneumoniae (7), Acinetobacter baumannii (8), and Citrobacter freundii (J. Campos, et al., https://www.escmid.org/escmid_library/ online_lecture_library/?search=1&current_page=1&search_ term=Citrobacter+freundii+NDM) have also been reported. Initial reports from Brazil also indicate that NDM producers have displayed characteristics such as co-resistance (5,9,10) and heteroresistance (11), but to date, occurrence in the community has not been reported. NDM producers were originally detected in the southern and southeastern regions of Brazil and have since moved into the northern states.
Brazil is a country of extremes that has industrialized and nonindustrialized regions, and this situation converges with social, economic, and infrastructure problems (e.g., sanitation and health care public services). This scenario is similar to the initial conditions that contributed to worldwide dissemination of NDM from the Indian subcontinent. Successful and widespread international high-risk clones and epidemic plasmids have been detected in Brazil and could have a critical role in rapid national expansion of NDM-encoding genes and NDM producers. Brazil is under imminent threat of national spread and prevalence of NDM.