Extended-spectrum β-lactamase (ESBL) is an enzyme produced by Gram-negative bacteria (family Enterobacteriaceae), which is a threat to health in the fields of human and veterinary medicine globally. The production of this enzyme by these bacteria confers resistance to cephalosporin and monobactam, but not to cephamycin or carbapenem, and it is inhibited by β-lactamase inhibitors such as clavulanate, sulbactam, and tazobactam. Resistance caused by ESBL is often associated with resistance to other groups of antibiotics commonly used in human medicine. As a result, there is growing concern that ESBL producing bacteria in companion animals can potentially spread directly through resistant pathogens from animals to humans or indirectly through resistance genes. One approach to promote human and animal health is to limit antibiotic resistance, especially that in animals living in close proximity to humans. ESBL-producing Escherichia coli has been well documented in humans, livestock, wild animals, and non-clinical isolates, but the role of companion animals is not well known in terms of the spread of resistance.
The ESBL test, a combination of Vitek-2 and an advanced expert system, is an automated system that is used to show the phenotype of the isolates tested and able to determine the sensitivity or resistance of an isolate to an antibiotic. It is hoped that this method can rapidly detect the presence of antibiotic resistance, enabling administration of the appropriate treatment to prevent the spread of antibiotic resistance.
This study aimed to assess the presence of extended-spectrum β-lactamase-producing E. coli in companion dogs in animal clinics in Surabaya, Indonesia. Pets, especially dogs, are attracting attention as a potential source of the spread of ESBL-producing Enterobacteriaceae due to their physical closeness and frequent close contact with their owners. The present study revealed the prevalence of ESBL-producing E. coli isolated from companion dogs to be 9.41%. In surveillance studies of sick dogs and cats across Europe, 1.6% carried ESBL-producing Enterobacteriaceae in feces, most of which contained blaCTX-M, but only included 2 E. coli ST131 isolates, suggesting that domesticated animals may be a source of transmission of ESBL in general, but may not be the main source of epidemic clones. The findings may raise public health concerns because the gut microbiome of these animals can form a reservoir for resistance genes encoding ESBL/AmpC, which can be transmitted to humans. The food chain is also a source of transmission, but transmission resulting from close contact between humans and animals on farms could also occur. Veterinarians are occupationally exposed to animals, and there are also opportunities where humans come into contact with animals in domestic situations such as on farms, zoos, or by owning pets.
Research on the frequency of multidrug-resistant E. coli in dogs and cats in Poland showed a prevalence of 66.8% in the isolates studied. In other studies, the prevalence of ESBL-producing strains in clinical isolates of Enterobacteriaceae originating from dogs and cats ranged from 3.1% to 54.4%, whereas in healthy animals, a rate as high as 20% were reported. The above reports are in agreement with the findings of the present study on companion dogs in Surabaya, Indonesia, which reported a prevalence rate of 9.41%.
Research conducted at a veterinary clinic at the University of Zurich, Switzerland, during 2012-2016
identified ESBL-producing Enterobacteriaceae with a prevalence rate of 20.8% in clinical samples of dogs and cats. This rate is much higher than those found in similar studies of companion animals in the United Kingdom (7%), the Netherlands (2%), France (3.7%), and Europe (1.6%).
The automated Vitek-2 compact system (bioMerieux, Marcy l’Etoile, France) is a bacterial identification and semi-automatic resistance testing system that enables the rapid determination of minimum inhibitory concentration by analyzing the kinetics of bacterial growth with antimicrobials on test cards. In a comparative study with the Clinical and Laboratory Standards Institute method in detecting ESBL, Vitek-2 showed a sensitivity of 100% and specificity of 99.3-100%, while disk diffusion methods and Etest also showed similar results.
The use of Vitek-2 for detection of ESBL producing E. coli showed sensitivity and specificity of 98.5% and 98.9%, respectively. This is in accordance with the findings of this study that observed 100% sensitivity for ESBL-producing E. coli isolated from companion dogs using the automated Vitek-2 system. From several previous reports and the results of the study, Vitek-2 compact can be used as a reliable tool for detecting ESBL-producing Enterobacteriaceae.
The presence of ESBL-producing E. coli from companion dogs as proven using Vitek-2 is clearly a source of zoonotic bacterial infections that can emerge and affect humans. Bacterial zoonotic diseases can be transferred from animals to humans in various ways, including through animal bites and scratches or zoonotic bacteria originating from animal feed can reach humans through the direct fecal–oral route, contaminated pet food products, inappropriate food handling, and inadequate cooking. Thus, in the One Health concept, humans who are close to pets would be able to contract zoonotic pathogenic bacteria and spread them to other humans in the community. So this finding should be used as evidence of the dangers posed by bacteria that come from companion dogs that exist near our society.
Corresponding Author: Prof. Dr. Mustofa Helmi Effendi, drh., DTAPH
Detailed information from this research can be viewed on our article at:
Kristianingtyas L, Effendi MH, Witaningrum AM, Wardhana DK, Ugbo EN (2021) Prevalence of extended-spectrum ß-lactamase-producing Escherichia coli in companion dogs in animal clinics, Surabaya, Indonesia, Int J One Health, 7(2): 232-236.