==== Front Emerg Infect Dis Emerg Infect Dis EID Emerging Infectious Diseases 1080-6040 1080-6059 Centers for Disease Control and Prevention 37347900 23-0218 10.3201/eid2907.230218 Research Letter Research Letter Isolation of Elizabethkingia spp. from Diagnostic Specimens from Dogs and Cats, United States, 2019–2021 Isolation of Elizabethkingia spp. from Diagnostic Specimens from Dogs and Cats, United States, 2019–2021 Elizabethkingia spp. from Diagnostic Specimens from Dogs and Cats, United States, 2019–2021 Weese J. Scott Sobkowich Kurtis E. Poljak Zvonimir Bernardo Theresa M. University of Guelph, Guelph, Ontario, Canada Address for correspondence: J. Scott Weese, Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, ON N1G2W1, Canada; email: jsweese@uoguelph.ca 7 2023 29 7 14881489 2023 https://creativecommons.org/licenses/by/4.0/ Emerging Infectious Diseases is a publication of the U.S. Government. This publication is in the public domain and is therefore without copyright. All text from this work may be reprinted freely. Use of these materials should be properly cited. We retrospectively reviewed Elizabethkingia spp. culture and susceptibility results from 86 veterinary diagnostic laboratory results from US dogs and cats. We noted 26 E. menigoseptica, 1 E. miricola, and 59 unspeciated Elizabethkingia isolates from 9 US states (2–22 isolates per state). Elizabethkingia infections in animals might increase risks to humans. Keywords: Elizabethkingia bacteria zoonoses veterinary medicine infectious diseases dogs cats United States Canada ==== Body pmcElizabethkingia is a genus of environmental gram-negative bacteria that can cause severe opportunistic infections in humans. The 3 main Elizabethkingia species are E. meningoseptica, the most common cause of disease; E. miricola; and E. anophelis (1). Human infections are rare—5–10 infections are reported annually per state in the United States (2)—but mortality rates can be high, 24%–41% (1,3,4). Elizabethkingia infections have rarely been reported in domestic animals; 1 case was reported in a dog in Portugal (5), and 2 isolates were reported from horses in the United States (6). We describe Elizabethkingia spp. isolated from specimens from dogs and cats submitted to a US diagnostic veterinary laboratory for bacterial culture and susceptibility testing. We evaluated bacterial culture results from specimens from dogs and cats that were submitted to IDEXX Laboratories (https://www.idexx.com) in the United States during 2019–2021. Available metadata included year collected, state, county, animal species, animal age, anatomic sample site, and antimicrobial susceptibility. Isolates were identified by using MALDI Biotype matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (Bruker Corporation, https://www.bruker.com). Antimicrobial susceptibility was determined by using Clinical and Laboratory Standards Institute (CLSI) breakpoints for non-Enterobacterales bacteria (7). In all, we investigated 86 Elizabethkingia spp. isolates: 26 (30%) were E. meningoseptica, 1 was E. miricola, and 59 (69%) were only identified to the genus level. All isolates were from individual animals; 71 (83%) were from dogs and 15 (17%) were from cats. Twenty-one (24%) isolates were identified in 2019, 36 (42%) in 2020, and 29 (34%) in 2021. Isolates were from 9 states, each of which had 2 (South Carolina, Tennessee) to 22 (Washington) isolates (Table 1). The most common specimen sites were skin and soft tissue infection (25; 29%), abscesses (20; 23%), ears (12; 14%), lower respiratory tract (10; 12%), nasal (6; 7.0%), and surgical site infections (3; 3.5%). We also assessed antimicrobial susceptibility data (Table 2). Table 1 Elizabethkingia spp. isolated from diagnostic specimens from dogs and cats, United States, 2019–2021 State No. isolates Washington 22 Virginia 13 Pennsylvania 13 Oregon 11 Texas 11 Wisconsin 9 California 3 South Carolina 2 Tennessee 2 Table 2 Antimicrobial susceptibility of Elizabethkingia spp. isolated from 71 dog and 15 cat diagnostic specimens, United States, 2019–2021* Antimicrobial drug No. tested No. (%) susceptible Amikacin 84 13 (15) Amoxicillin 57 4 (7.0) Amoxicillin-clavulanic acid 57 5 (8.8) Cefotaxime 46 6 (13) Cefovecin 57 5 (8.8) Cefpodoxime 57 7 (12) Ceftazidime 86 6 (7.0) Ceftiofur 53 9 (17) Cephalexin 57 3 (5.3) Chloramphenicol 64 9 (14) Doxycycline 59 39 (66) Enrofloxacin 86 73 (85) Gentamicin 85 17 (20) Imipenem 86 7 (8.1) Marbofloxacin 86 75 (87) Trimethoprim/sulfamethoxazole 54 48 (89) *Antimicrobial susceptibility testing performed according to Clinical and Laboratory Standards Institute guidelines (7) at IDEXX Laboratories (https://www.idexx.com). We assessed clustering at the county level over time. We noted 19 counties that had multiple isolates; 4 pairs of isolates at the county level were from specimens submitted within the same month, and another pair of isolates was submitted from a single county in subsequent months. Although reports of Elizabethkingia spp. infections in animals have been limited, our data indicate that this bacterium is rare but extant in clinical specimens from dogs and cats in the United States. Noninvasive infections predominated; skin infections, abscesses, and wound infections accounted for >50% of isolates. The distribution of infection sites is consistent with an environmental opportunist, for which infection would develop after environmental contamination of compromised sites, particularly after skin barrier damage. Those animal infections contrast with human infections, in which meningitis and bacteremia are most common (1,3). Whether those differences are because of a true difference in disease distribution or because human data are biased due to more testing of high-risk populations, such as infants and immunocompromised persons, publication biases toward reporting severe disease, or both, remains unclear. Isolates were from multiple states. Geographic distribution of infection in humans is not well reported in the United States; however, Wisconsin was the site of a notable high incidence outbreak in humans during 2015–2016 (8). Further study of geographic patterns in humans and domestic animals is warranted. Most isolates appeared to be from sporadic infections. In a few instances, 2 isolates were from the same county in the same or subsequent months. Because clinic-level data were not available, whether those isolates were from the same clinics or had any epidemiologic links is unclear. Therefore, although clustering in clinics is possible, as seen in human healthcare facilities, we could not determine whether any of these infections were linked. Because clinical data were not available, we could not determine whether Elizabethkingia was the cause of disease or was a clinical contaminant. The zoonotic risks posed by animals with Elizabethkingia spp. infections are unknown; however, 2 equine-origin E. anopheles isolates clustered within a clade of human isolates in 1 instance (6), and another instance had a similar overlap between isolates from a frog and a human (9). Those findings are not unexpected for infections that likely originate in the environment but do not clarify whether zoonotic transmission can occur once an animal has a clinical infection. Elizabethkingia isolates tend to have intrinsic resistance to multiple antimicrobial drugs (10). The high prevalence of susceptibility to potentiated sulfonamides (89%) and fluoroquinolones (85%–87%) for samples from dogs and cats in this study is consistent with human data (10), as would be expected if a common environmental source was involved. Although rare, Elizabethkingia spp. were identified in dogs and cats in multiple US states. Because Elizabethkingia is an environmental pathogen, human and animal exposures presumably are from similar environmental sources. Thus, an understanding of infections in animals might have relevance for assessing risks to humans and for identifying potential animal health risks. Acknowledgments The authors thank IDEXX Laboratories for providing the data and supporting Dr. Bernardo’s IDEXX Chair in Emerging Technologies and Preventive Healthcare. Dr. Weese is a professor at the Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada, director of the University of Guelph Centre for Public Health and Zoonoses, and chief of infection control at the Ontario Veterinary College Health Sciences Centre. His primary research interests include emerging infectious diseases in animals, zoonotic diseases, antimicrobial resistance, and antimicrobial stewardship. Suggested citation for this article: Weese JS, Sobkowich KE, Poljak Z, Bernardo TM. Isolation of Elizabethkingia spp. from diagnostic specimens from dogs and cats, United States, 2019–2021. Emerg Infect Dis. 2023 Jul [date cited]. https://doi.org/10.3201/eid2907.230218 ==== Refs References 1. Dziuban EJ, Franks JL, So M, Peacock G, Blaney DD. Elizabethkingia in children: a comprehensive review of symptomatic cases reported from 1944 to 2017. Clin Infect Dis. 2018;67 :144–9. 10.1093/cid/cix1052 29211821 2. US Centers for Disease Control and Prevention. 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