microorganisms ÍMDPIJ
Review
Human Infections by Wohlfahrtiimonas chitiniclastica:
A Mini-Review and the First Report of a Burn Wound Infection
after Accidental Myiasis in Central Europe
Martin Hladík1
, Břetislav Lipový1 , 2
, Yvona Kaloudova1
, Markéta Hanslianova 3
, Ivana Vítkova 4
,
Tereza Deissova 5
, Tomas Kempny1
, Martin Svoboda 6
, Zdenek Kala 6
, Pavel Brychta1
and Petra Borilova Linhartova 5
'7
'*
check for
updates
Citation: Hladík, M ; Lipový, B.;
Kaloudova, Y.; Hanslianova, M ;
Vítkova, I.; Deissova, T.; Kempny, T.;
Svoboda, M ; Kala, Z.; Brychta, P.;
et al. H u m a n Infections by
Wohlfahrtiimonas chitiniclastica: A
Mini-Review and the First Report of a
Burn Wound Infection after Accidental
Myiasis in Central Europe.
Microorganisms 2021, 9,1934.
https: / /doi.org/10.3390/
microorganisms9091934
Academic Editors: Dominic
Wichmann and Jörn Grensemann
Received: 24 August 2021
Accepted: 9 September 2021
Published: 11 September 2021
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4.0/).
1
Department of Burns and Plastic Surgery, Faculty of Medicine, Institution Shared with University Hospital
Brno, Masaryk University, Jihlavská 20, 625 00 Brno, Czech Republic; hladikm@gmail.com (M.H.);
bretalipovy@gmail.com (B.L.); kaloudova.yvona@fnbrno.cz (Y.K.); tomas.kempny@gmail.com (T.K.);
dr.brychta@seznam.cz (P.B.)
2
CEITEC-Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123,
612 00 Brno, Czech Republic
3
Department of Clinical Microbiology, Vyškov Hospital, Purkyňova 235/36, 628 01 Vyškov, Czech Republic;
hanslianova.marketa@nemvy.cz
4
Department of Clinical Microbiology and Immunology, University Hospital Brno, Jihlavská 20,
625 00 Brno, Czech Republic; vitkova.ivana@fnbrno.cz
5
Environmental Genomics Research Group, RECETOX, Faculty of Science, Masaryk University, Kamenice 5,
625 00 Brno, Czech Republic; tdeiss@mail.muni.cz
6
Department of Surgery, Faculty of Medicine, Institution Shared with University Hospital Brno, Masaryk
University, Jihlavská 20, 625 00 Brno, Czech Republic; svoboda.martin2@fnbrno.cz (M.S.);
kala.zdenek@fnbrno.cz (Z.K.)
7
Clinic of Maxillofacial Surgery, Faculty of Medicine, Institution Shared with the University Hospital Brno,
Masaryk University, Jihlavská 20, 625 00 Brno, Czech Republic
* Correspondence: petra.linhartova@recetox.muni.cz
Abstract: Wohlfahrtiimonas chitiniclastica are bacteria that cause rare infections, typically associated
with the infestation of an open wound with fly larvae. Here, we present a unique case report of the
first W. chitiniclastica isolation from a burn wound with accidental myiasis in a 63-year-old homeless
man and a literature review focused on human infections caused by these bacteria. So far, 23 cases of
infection with W. chitiniclastica have been reported; in 52% of these, larvae were found in the wound
area. Most of these cases suffered from chronic non-healing wound infections but none of these were
burn injuries. The overall fatality rate associated directly with W. chitiniclastica in these cases was
17%. Infections with parasitic larvae occur in moderate climates (especially in people living in poor
conditions); therefore, an infection with rare bacteria associated with accidental myiasis, such as
W. chitiniclastica, can be expected to become more common there. Thus, in view of the absence of
recommendations regarding the treatment of patients with accidental myiasis and, therefore, the risk
of infection with W. chitiniclastica or other rare pathogens, we provide a list of recommendations for
the treatment of such patients. The importance of meticulous microbial surveillance using molecular
biological methods to facilitate the detection of rare pathogens is emphasized.
Keywords: Wohlfahrtiimonas chitiniclastica; burn wound infection; myiasis
1. Introduction
Wohlfahrtiimonas chitiniclastica was first described in 2008 by Toth et al. [1]. These
bacteria are strictly aerobic gram-negative, straight short rods (1.5-2.0 x 0.5-1.0 um) that are
non-motile, non-spore-forming, which grow at p H 5.0-10.5 and temperatures of 28-37 °C,
and are capable of causing both local skin/soft tissues infections (SSTIs) and sepsis. W.
chitiniclastica is catalase and oxidase-positive, and indole, urease and H2S negative. It has a
Microorganisms 2021, 9,1934. https://doi.org/10.3390/microorganisms9091934 https: / /www.mdpi.com/journal/microorganisms
Microorganisms 2021, 9,1934 2 of 11
strong chitinase activity, which leads to discussions about whether or not its presence can
be symbiotic and play a role in the larval metamorphosis [1,2].
The presence of W. chitiniclastica was associated with fly larvae infestation in open
wounds; nevertheless, an infection with this bacterium is very rare in humans [2]. In
the last decade, rare pathogens have begun to emerge as causes of the development of
infectious complications. To date, there is no report about a W. chitiniclastica infection in a
b u m wound [3].
This paper describes the first isolation worldwide of W. chitiniclastica from a burn
wound with accidental myiasis (interestingly in a patient from Central Europe) and reviews
available information on W. chitiniclastica-caused infections in humans. In addition, a set of
recommendations for care of a patient with accidental myiasis and, therefore, a possible
infection with W. chitiniclastica and other rare pathogens, is proposed.
2. Case Report
We describe the case of a 63-years-old man who was transferred to the Department
of Burns and Plastic Surgery of the University Hospital Brno, Czech Republic, with deep
burns in the region of thorax and abdomen, covering 5% of the total body surface area
(TBSA). His vitals on admission showed a body temperature of 37.2 °C, blood pressure
of 163/87 m m H g , and a heart rate of 98/min. O n admission, the patient suffered from
massive cutaneous myiasis, pediculosis of the head, and phlegmon of the thorax. The
patient lived in poor and unhygienic conditions (homeless/staying in shelters for homeless
people overnight). He admitted to tobacco and alcohol abuse; he also had hepatitis A in
the past. He reported that his bums were the result of an injury that happened two weeks
prior, when his shirt caught fire while smoking a cigarette. Right after the injury, first
aid was provided by the shelter employee. For the next two weeks, however, the wound
was left unattended. The wound showed signs of accidental myiasis, redness, and edema
(Figure 1).
Figure 1. The wound on admission after removal of maggots with signs of redness and edema (a), in
detail (b).
The maggot infestation was immediately mechanically removed, and swabs were
taken for microbiological analysis. Local therapy included Octenisept® (Schulke & Mayr
G m b H , Norderstedt, Germany) for antisepsis and Flamazine® cream 1% w/w (Smith &
Nephew Pharmaceuticals Ltd., Hessle Road, Hull, UK) for wound-bed preparation; at
the same time, systemic oral therapy with amoxicillin, clavulanic acid (1 g every 8 h) and
metronidazole (500 mg every 8 h) was initiated. Dressings were changed every 2 days;
Microorganisms 2021, 9,1934 3 of 11
no maggots were observed after the first infestation removal and the wound bed was
prepared for closure. Staphylococcus aureus, Streptococcus pyogenes, and W. chitiniclastica
were isolated from the initial swab, all susceptible to amoxicillin and clavulanic acid. O n
day 7, debridement under general anesthesia was performed and defects were finally
covered with split-thickness skin grafts on 3% TBSA (Figure 2).
Figure 2. Wound bed preparation with granulation tissue (a,b), the process of split-thickness skin
graft transplantation (c).
The next series of swabs revealed only coagulase-negative Staphylococcus in a single
spot; hence, the systemic therapy with amoxicillin and clavulanic acid continued for 8 days.
A l l skin defects were completely healed, and the patient was discharged to our outpatient
care and long-term care ward for intensive rehabilitation (Figure 3).
Figure 3. Complete burn wound closure on the discharge of the patient.
Microorganisms 2021, 9,1934 4 of 11
2.1. Pathogen Identification
As a part of the microbiological examinations, swabs from the patient's burn areas
were transferred to culture media suitable for both aerobic and anaerobic growth; blood
agar (Merck KGaA, Darmstadt, Germany), McConkey agar (selective medium for growth
of gram-negative bacteria; Pronadisa, Conda Laboratories, Madrid, Spain) and blood agar
with N a C l addition (selective agar for staphylococci; Merck KGaA, Germany) were used
for aerobic culture and V L agar (Bio-Rad Laboratories Chemical Division, Richmond, C A ,
USA) was used for anaerobic culture. The inoculated culture media were then incubated
for 18-24 h at 35-37 °C; blood agar and chocolate agar (OXOID CZ, Brno, Czech Republic)
in the atmosphere with elevated CO2 concentration, V L agar in the anaerobic atmosphere,
and the remaining media in a normal atmosphere. The growth of the W. chitiniclastica strain
on the culture media and the morphology of the individual colonies are shown in Figure 4.
Figure 4. Wohlfahrtiimonas chitiniclastica colonies on blood agar (Merck KGaA, Germany) and nonselective
chromogenic agar (UriSelect, Bio-Rad Laboratories, Hercules, CA, USA) (left, center).
Microscopic view of the morphology of W. chitiniclastica (right). Olympus BX40 microscope, Olympus
Czech group, s.r.o., magnification 100 x. The specimen is stained according to Gram.
The colonies were then identified using the MALDI-TOF Biotyper (Bruker Daltonics,
GmbH, Leipzig, Germany) and software M A L D I T O F MS, version 3.1.
In addition, bacterial D N A obtained from the culture of W. chitiniclastica was isolated
by the QIAamp BiOstic Bacteremia D N A Kit (QIAGEN Redwood City, C A , USA). D N A
was analyzed by the 16S r R N A Sanger sequencing method (SEQme s.r.o., Dlouhá 176
26,301 Dobris, Czech Republic), forward primer S'-AYTGGGYDTAAAGNG-S' and reverse
primer 500B4-CCGTCAATTYYTTTRAGTTT-3' were used. A 98% match of the specified
sequence with the sequence of W. chitiniclastica D S M 18,708 strain S5 16S r R N A was found
using the basic local alignment search tool (BLAST) provided by the National Center for
Biotechnology Information (NCBI) [4] (Figure 5).
• Ignatzschineria larvae (NR 025382.1)
• Ignatzschineria ureiclastica (NR 116121.1)
-Ignatzschineria indica (NR 116120.1)
•Wohlfahrtiimonas populi (NR 159162.1)
Wohlfahrtiimonas larvae (NR 133893.1)
r •patient's isolate
* •Wohlfahrtiimonas chitiniclastica (NR 042554.1)
Figure 5. Neighbor-joining phylogenetic tree of partial 16S rRNA gene sequences. Sequences from GenBank are shown
with taxonomic names (sequence ID). Query_57927 is the sequence of the patient's isolate.
Microorganisms 2021, 9,1934 5 of 11
2.2. Antimicrobial Susceptibility Profile of W. chitiniclastica
The susceptibility of W. chitiniclastica to antibiotics was established by determining
the minimum inhibitory concentration using the MicroScan WalkAway M I C instrument
(Beckman Coulter, Brea, C A , USA). Susceptibilities were evaluated using a disc diffusion
method according to the E U C A S T standard-PK/PD (non-species related) breakpoints
(EUCAST Clinical Breakpoints Tables, v.10.0, January 2020). The W. chitiniclastica strain
was sensitive to the tested antibiotics, including the amoxicillin/clavulanate used in the
therapy (Table 1).
Table 1. Susceptibility of the isolated Wohlfahrtiimonas chitiniclastica according to the EUCAST
Clinical Breakpoints.
Antibiotic MIC Value (mg/L) Interpretation
Amoxicillin/clavulanic acid <2.0 S
Piperacillin/tazobactam <4.0 S
Cefotaxime 1.0 S
Ceftazidime <0.5 S
Cefepime <0.5 S
Ciprofloxacin 0.25 S
Levofloxacin 0.5 S
Ofloxacin 0.25 S
Imipenem <1.0 S
Meropenem <0.5 s
S: sensitive; MIC: minimum inhibition concentration.
3. Review and Discussion
Myiasis (from the Greek myia, which means fly, and iasis, disease) is defined as an
infestation of humans or other vertebrates with a larval stage of an insect. The term was
first used by F. W. Hope in 1840, who used it to distinguish diseases caused by the larvae
of dicotyledons from other parasitic insects [5]. Such larvae are usually detected in necrotic
tissue (benign myiasis), but can also affect fully viable tissue (malignant myiasis). In the
past, myiasis was almost exclusively described in tropical or subtropical climates [6]. In
recent years, it has also been found in temperate climates [6].
Two principal types of myiasis can be distinguished, controlled and accidental. Controlled
myiasis is a therapeutic procedure using sterile larvae for selective debridement of
necrotic tissue and facilitation of the wound-healing phase. This methodology is mainly
used in the treatment of non-healing wounds. Larvae can also be used for reducing the
bioburden of gram-positive strains of bacteria. In modern times, this method was first
approved for use in 2004 by the Food and Drug Administration [7].
Accidental myiasis usually arises as a manifestation of parasitic larvae in non-healing
wounds in high-risk groups of patients (alcohol addiction, homelessness, poor hygiene,
tobacco use, chronic vascular diseases, immunocompromisation, non-compliant patients,
low socioeconomic status, etc.). Our patient had almost all of these risk factors (he was a
homeless, alcohol and tobacco abuser with poor living conditions). His burns were not
treated and covered with any dressings for 2 weeks prior to hospitalization (hence the
notion of non-compliancy). In accidental myiasis, the larvae are not sterile and, therefore,
can act as a vector for a variety of potentially pathogenic microorganisms, such as W.
chitiniclastica or Ignatzschineria indica.
Accidental myiasis causing bacteremia or sepsis can be potentially lethal. So far, there
is no uniform therapeutic concept or methodology for sanitizing the primary larval burden.
In the case of cavital myiasis, surgical intervention involving incision and drainage, or
the excision of infected tissue may be necessary. In the case of cutaneous myiasis, manual
debridement with removal of the larvae is needed; in the case of deeper penetration with
larvae, their primary asphyxiation with petroleum jelly or similar material is a suitable
method for their eradication.
Microorganisms 2021, 9,1934 6 of 11
Burn patients are highly susceptible to infections in the area of the skin defect; infectious
complications account at present for the majority of mortality and morbidity in
these patients. Immediately after thermal trauma, any b u m area is sterile as a result of the
heat on the superficial microorganisms. However, the necrotic tissue in the wound bed
represents an excellent growth medium for microorganisms, especially for bacteria with a
short generation time. Burn wound infections are relatively diverse, ranging from cellulitis
and impetigo to invasive wound infections requiring prompt antimicrobial treatment with
early debridement [8]. In our patient, we used manual debridement with the removal of
larvae and antiseptic treatment.
In the course of thermal trauma therapy, both quantitative and qualitative changes
in microbial colonization occur in the burn area (as well as in the other parts of the
body). While etiologically, gram-positive cocci (S. aureus, coagulase-negative Staphylococci,
Streptococcus sp., etc.) predominated the burn wound in the first week of hospitalization,
the predominance of gram-negative rods (mainly representatives of Enterobacteriacae sp.,
Pseudomonas aeruginosa, Acinetobacter baumannii, etc.) begins to manifest from the second
week of hospitalization onwards [9]. Rare viral, bacterial, and yeast infections in burn
patients occur mostly as a result of the encounter with microorganisms of exogenous
origin [10]. The burn wound infection in our patient with minor burns was of polymicrobial
etiology; interestingly, W. chitiniclastica was cultured from the burn wound, which was also
confirmed by the sequencing analysis. It should be mentioned that W. chitiniclastica was
cultured on blood agar in an elevated CO2 concentration, which falls within a standard set
of culture conditions; therefore, no special culture is necessary.
W. chitiniclastica can be found in Wohlfahrthia magnifica (Diptera, Sarcophagidae) a
parasitic flesh fly native to continental Europe, Asia and the Mediterranean, Lucilia sericata
(green bottle fly) in the Americas, Chrysomya megacephala (oriental latrine fly), Hermetia
illucens (black soldier fly), and Musca domestica L. (housefly) [7,11,12]. Although most
reports of W. chitiniclastica infections have been associated with the larvae of parasitic flies,
this bacterium has also been isolated in retail frozen chicken meat, arsenic-affected soils in
Bangladesh, and in cow [13-15].
Despite the fact that W. magnifica is the most likely vector of this myiasis in the Czech
Republic, another possible vector, a new invasive representative of the order Diptera,
Clogmia albipunctata, has been also reported in the geographical area where our patient
resided [16]. The identification of the vector was not performed in our case. Although it is
not important for clinical practice, it may be perceived as a limitation of this paper from
the epidemiological perspective. If a particular vector overpopulation occurs in a certain
area, we can potentially expect an increased risk of rare pathogen infections, including W.
chitiniclastica. For this reason, we would also like to recommend the determination of the
vector, where possible, in any future cases of myiasis, especially if a rare pathogen is identified.
This can be performed, for example, by inserting the larvae into a fixation solution
and if a rare pathogen is determined, cooperation with entomologists can be initiated.
Most reports of W. chitiniclastica infections originate from subtropical or tropical
regions [2,11,17-32] (see the literature review in Table 2). Nevertheless, an infection with
bacterium was also reported from northern Europe [18]. Similarly, our case did not occur
in subtropical or tropical conditions either, but in a moderate climate in the autumn with
relatively low day temperatures (the mean temperature at our patient's place of residence
between the accident and hospitalization was 14.13 ± 3.75 °C). This supports the notion
that living conditions are extremely important for the development of W. chitiniclastica.
Microorganisms 2021, 9,1934 7 of 11
Table 2. Review of the literature of case reports; human infections caused by Wohlfahrtiimonas chitiniclastica.
Year
[Ref.]
Country
Sex/age
Years
Culture Site Anatomic Localization
Associated
Myiasis
Antibiotics Outcome Associated Bacteria
2009 [2] France F/60 Blood culture Scalp (head) Yes ceftriaxon Survived -
2011 [17] Argentina M/70 Blood culture Inguinal regions No
ciprofloxacin +
ampicillin-sulbactam and later
ceftazidime + amikacin
Died
2014 [18] Estonia M/64 Resected bone Right foot N o amoxicillin-clavulonate Survived M Y O D
2015 [19] India M/43 Ulcer swab Right lower limb ulcer No
cefoperazone-sulbactam followed
by cefpodoxime (outpatient care)
Survived
2015 [20] U S A M/26 Ulcer swab Right leg N o cefpodoxime Survived P R V U , K L P N , M S S A
2015 [21] U K F/82 Blood culture
Excoriations of head,
face, and neck
Yes
cefuroxime, metronidazole,
clarithromycin, topical
chloramphenicol, fucidic acid
followed by flucloxacillin
(outpatient care)
Survived PRMI, PRRE, M S S A
2016 [22] U S A
F/69
M/72
F/Ulcer swab
M/blood culture
F/Sacral decubitus
M/Right foot and
umbilical wound
F/No
M/Yes
F/ceftaroline fosamil,
meropenem,
amoxicillin-clavulonate
(outpatient care)
M/piperacilline-tazobactam,
vancomycin, clindamycin
F/Survived
M / D i e d
F/Blood culture: A N S U
Urine: P R M I
Decubitus: M S S A ,
AEspp., STspp., B A F R
M / E S C O
2016 [23] South Africa M/17 Blood culture Right shoulder wound N o ceftriaxone Survived
2017 [24] Germany
F/78
M/43
M/71
M/79
F/78 Swabs from ulcers
M/43 Swabs from ulcers
M/71 Swabs from ulcers
M/79 Swab from ulcer
F/78 Leg ulcer
M/43 Leg ulcer
M/71 Leg ulcer
M/79 Leg ulcer
No
No
No
No
F/78 no antibiotic treatment
M/43 no antibiotic treatment
M/71 no antibiotic treatment
M/79 cefuroxime followed by
levofloxacin and clindamycin
F/78 Survived
M/43 Survived
M/71 Survived
M/79 Survived
F/78 PRMI, M S S A ,
S E M A , M O M O
M/43 P R M I
M/71 PRMI, PRST, PSAE
M/79: ESCO
2017 [25] U S A F/41
Blood culture and
decubitus swab
Ischial decubitus or
lower extremity bilateral
excoriations
No
vancomycin, cefepim,
metronidazole
Died due to other
disease
Blood culture: P R M I
Swab: M Y L N , E N F A
E N F A , BAspp.
2017 [11] Malaysia F/47 Blood culture - No cefoperazone
Died due to other
disease
2018 [26] U S A M/37 Blood culture
Left lower extremity
ulcer
Yes
piperacilline-tazobactam,
vancomycin, clindamycin later
cefepime
Survived PRST, IGIN
2018 [27] Japan M/75 Blood culture Left shoulder lesion Yes
vancomycin, cefepime,
metronidazole
Survived
M O M O , STspp., BAspp.,
P R M I
Microorganisms 2021, 9,1934 8 of 11
Table 2. Cont.
Year
[Ref.]
Country
Sex/age
Years
Culture Site Anatomic Localization
Associated
Myiasis
Antibiotics Outcome Associated Bacteria
2018 [28] U S A M/57 Blood culture Right ankle gangrene Yes Not stated Died P R A C , C N S
2019 [29] Australia M/54 Blood culture Right foot wound Yes
piperacilline-tazobactam +
meropenem, ciprofloxacin
(outpatient care)
Survived M O M O
2019 [30] U S A
M/63
F/87
M/blood culture
F/swab
M/Right foot ulcer
F/Left lower extremity
wound
Yes
Yes
M/vancomycin+
piperacilin/tazobactam
F/unknown
M / D i e d
F/unknown
M / P R R E
F/-
2020 [31] U S A M/82 Blood culture Right lower extremity Yes
vancomycin and cefepim, later
daptomycin and ceftriaxon
Survived IGIN, M R S A
2021 [32] U S A M/70 Blood culture
Ulcer of left temporal
region
Yes levofloxacin Survived MSSA, PRMI
M Y O D : Myroides odoratimimus, P R V U : Proteus vulgaris, K L P N : Klebsiella pneumoniae, M S S A : Staphylococcus aureus, PRMI: Proteus mirabilis, PRRE: Providencia rettgeri, A N S U : Anaerobiospirilum succinicproducens,
AEspp.: Aeromonas spp., BAFR: Bacteroides fragilis, ESCO: Escherichia coli, S E M A : Serratia marsescens, M O M O : Morganella morganii, PSAE: Pseudomonas aueruginosa, M Y I N : Myroides injenensis. ENFA: Enterococcus
faecalis, BAspp.: Bacteroides spp., P R A C : Propionibacterium acnes, C N S : coagulase negative staphylococci, PRST: Providencia stuartii, IGIN: Ignatzschineria indica, M R S A : methicillin-resistant Staphylococcus aureus,
STspp.: Streptococcus spp.
Microorganisms 2021, 9,1934 9 of 11
The spectrum of infections in the total of the 23 reported patients ranges from wound
infection (43% of all reported patients) to bacteremia or bloodstream infection (61% of
all reported patients). In some cases, the infection might have resulted in septic shock;
however, we are not aware of any reported case of burn wound or other acute wound
infection. Most reported cases described secondary infections in patients with non-healing
wounds (34% of patients reported). Although infection with W. chitiniclastica is generally
considered to be associated with maggot infestation, no larvae were identified in the wound
area in 48% of the described cases.
The mortality associated with this type of infectious complication depends on the
host condition and immunological status, but also on the level of invasiveness/severity of
the infection itself and, of course, the quality of care. The overall fatality rate reported in
previous studies was 26%; however, death clearly associated with W. chitiniclastica infection
was reported only in 17% of patients (all of w h o m had an invasive infection). Only six
patients (26%) described in the literature suffered from a monobacterial W. chitiniclastica
infection; the remaining 17 (74%) were infected with multiple pathogens. This was also the
case of our patient who presented with multiple pathogens (besides W. chitiniclastica, S.
aureus, and S. pyogenes were also detected in the b u m wound).
Since infection with W. chitiniclastica is very rare, no standardized antimicrobial protocol
for its treatment has been established so far. The most commonly used antibiotics
in the treatment of such infections include beta-lactams (mainly amoxicillin-clavulonate,
cefuroxime, ceftriaxone, or cefepime) or fluoroquinolones (ciprofloxacin, levofloxacin).
The situation is further complicated by the fact that, as mentioned above, many of the
cases described in the literature are not monopathogenic infections; therefore, all pathogens
present in the wound must be taken into consideration. Therefore, we recommend the
following when encountering a patient with accidental myiasis (and with an increased
possibility of infection with W. chitiniclastica or other rare pathogens):
1. Larvae should be removed from the wound (cutaneous myiasis); non-invasive removal
of larvae is possible by occlusion or suffocation using petroleum jelly, beeswax,
or liquid paraffin. Over the course of several hours, the larvae either leave the wound
or die and can be removed more easily from the wound [33]. Surgical removal of
larvae requires repeated debridement with an application of antiseptic agents. In
the case of cavitary myiasis, surgical debridement, incision or even excision of the
infected tissue may be necessary [6]. The larvae should be also preserved for potential
future identification;
2. Microbiological analysis focusing on the bacteria typically associated with accidental
myiasis should be performed (e.g., Proteus mirabilis, Ignatzschineria indica, Providencia
rettgeri, Morganella morganii, and Staphylococcus aureus). For the identification of rare
pathogens, especially W. chitiniclastica, M A L D I - T O F M S or 16S r R N A sequencing
are recommended [17,22,24] because the use of the VITEK 2 system often leads to
misclassification: for example, W. chitiniclastica was incorrectly classified as Acinetobacter
Iwoffii, Comamonas testosteroni or Rhizobium radiobacter [18,20,25]. As no data are
available on the performance of other systems, a study evaluating the performance of
other methods with respect to the identification of W. chitiniclastica can be valuable
for clinical practice;
3. The choice of antimicrobial therapy should be tailored to the overall microbiological
findings; management should also be based on the severity of the infectious
complication.
4. Conclusions
Accidental myiasis is no longer the domain of only subtropical or tropical regions;
with climate change, the likelihood of its occurrence, especially in people with low socioeconomic
status, increases in temperate climates as well. In individuals with unsterile
parasitic larvae infestation, infection by rare pathogens, such as W. chitiniclastica, can be
suspected. To minimize the impact of potential septic complications on the patient, the
Microorganisms 2021, 9,1934 10 of 11
rapid and accurate identification of microorganisms using molecular-biological methods,
followed by effective antimicrobial therapy, is necessary.
Author Contributions: Conceptualization, M.H. (Martin Hladik), B.L. and P.B.L.; methodology, B.L.
and P.B.L.; validation, M.H. (Martin Hladik), B.L. and P.B.L.; formal analysis, M.H. (Martin Hladik),
B.L. and P.B.L.; investigation, M.H. (Martin Hladik), B.L., T.D. and P.B.L.; resources, M.H. (Martin
Hladik) and B.L.; data curation, B.L., P.B.L. and M.H. (Marketa Hanslianova); writing—original draft
preparation, M.H. (Martin Hladik), B.L., P.B.L. and M.H. (Marketa Hanslianova); writing—review
and editing, M.H. (Martin Hladik), B.L., Y.K., M.H. (Marketa Hanslianova), I.V., T.D., T.K., M.S., Z.K.,
PB. and P.B.L.; supervision, B.L. and P.B.L.; project administration, B.L.; funding acquisition, B.L. All
authors have read and agreed to the published version of the manuscript.
Funding: The study was supported by the Ministry of Health of the Czech Republic, grants No.
NV19-05-00214 and No. NU20-05-00166. This project has received funding from the European
Union's Horizon 2020 research and innovation program under grant agreement No 857560. A l l
rights reserved.
Institutional Review Board Statement: The Ethics Committee for Multicentre Clinical Trials of the
University Hospital Brno approved this publication (18-091220/EK, 9 December 2020). All the
procedures performed in this case presentation were in accordance with the ethical standards of the
institutional and/or national research committee and with the 1964 Helsinki Declaration and its later
amendments or comparable ethical standards. Informed consent was obtained from the patient.
Informed Consent Statement: Informed consent was obtained from the subject involved in the study.
Data Availability Statement: Data supporting presented results are available upon request.
Conflicts of Interest: The authors declare no conflict of interest.
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