Carbapenems are beta-lactam antimicrobial agents with a broad
in vitro spectrum against Gram-negative, many Gram-positive and anaerobic bacteria
(Zhanel et al., 2007). They are considered as one of the most critically important antimicrobials for human treatment. Worldwide, the emergence and global spread of microorganisms with acquired carbapenemases is of great concern. The reservoirs for such organisms are increasing, not only in hospitals, but also in the community and environment. Recent studies have highlighted the presence of such organisms in livestock, companion animals and wildlife
(Abraham et al., 2014). The detection of carbapenemase producing
Escherichia coli,
Salmonella spp. (
VIM-1 producers) and
Acinetobacter spp. (producing
OXA-23 and
NDM-1) in livestock animals (poultry, cattle and swine) and their environment have been reported
(Fischer et al., 2012, 2013;
Poirel et al., 2012; Zhang et al., 2013). In addition, the isolation of
NDM-1 producing
E. coli,
OXA-48 in
E. coli and
K. pneumoniae or
OXA-23 in
Acinetobacter spp. from companion animals (cats, dogs or horses) has also been observed
(Smet et al., 2012; Shaheen et al., 2013; Stolle et al., 2013).
Carbapenems are the last sort drugs against MDR, ESBL producing Gram-negative bacterial spp. and their prescription is increasing in humans due to the increased prevalence of ESBL and other multi resistant organisms
(Papp-Wallace et al., 2011; Patel and Bonomo, 2013;
Woodford et al., 2014). Considering the close contact between humans and their pets and the potential for cross-species transmission, the emergence of carbapenem resistance in companion animals is a public health concern. The discovery of carbapenem resistance in companion animals could possibly be linked to their widespread use in humans or may be through environment. it may also be attributed to their use in veterinary practice and even though carbapenems are not registered for use in animals in any major jurisdiction, off-label veterinary use of this critical ‘last-line’ antimicrobial class has been reported in dogs for the treatment of urinary tract infection (UTI) and postoperative infection caused by multidrug-resistant
E. coli (Gibson et al., 2008). Since these drugs are not currently licensed, for use in Veterinary sector, resistance to carbapenems is not routinely evaluated in animal isolates, so it seems likely that its prevalence is underestimated. The great increase and spread of carbapenemase producing enterobacteriacea from human sources and its recent isolation from animals may reflect an emerging problem in human and veterinary medicine, as interspecies transmission may occur between humans and companion animals within the same household
(Johnson et al., 2008; Livermore, 2012;
Meletis, 2016).
Previous research works conducted in our institute have identified a high prevalence of MDR, ESBL producing Gram-negative bacteria among the companion animals like dogs
(Paulson et al., 2019). Since no studies have been conducted so far in Kerala in this regard, we have envisaged a pilot study to detect the prevalence of major carbapenemase encoding genes among the companion animals in Kerala. In the present study, out of 100 samples collected from dogs with different clinical ailments, 44 Gram-negative isolates could be obtained which includes 30
E. coli, 11
K. pneumoniae and 3
P. aeruginosa based on cultural, morphological and biochemical characteristics.
Polymerase chain reaction assays were standardised to detect the presence of common carbapenemase in animals which includes
NDM-1,
KPC,
OXA-181,
OXA-48,
VIM and
IMP. The highest prevalence obtained was that for
NDM in 23 isolates (52.27%; 18
E. coli, 3
K. pneumoniae, 2
P. aeruginosa) followed by
OXA-181 in 10 (22.73%; 7
E. coli, 2
K. pneumoniae, 1
P. aeruginosa),
KPC in 8 (18.18%; 7
E. coli, 1
K. pneumoniae)
OXA-48 in 6 (13.64%; 1
E. coli, 4
K. pneumoniae, 1
P. aeruginosa) and
VIM in 2 (4.55%; 2
E. coli) (Fig 1,2,3,4 and 5). None of the isolates revealed positive amplicons for
IMP genes. As per
Bartolini et al., (2014), NDM and
KPC were the predominant carbapenemase conferring resistance among Gram negative bacterial spp. isolated from human and reported now worldwide, emerging as a health crisis in treatment (
Diene and Rolain, 2014). In the present study we recorded a high prevalence of
NDM followed by
OXA-181 in dogs. This is in accordance with other studies in companion animals where the most detected carbapenemase were
NDM and
OXA (Smet et al., 2012; Shaheen et al., 2013; Stolle et al., 2013; Gonzalez-Torralba et al., 2016).The results are pointing to an impending threat in the therapy of clinical infections in both human and veterinary sector. Hence, there is an urgent need to curb the irrational and excessive use of antibiotics in both human and veterinary sector. The already established national policies and guidelines might be the beginning to combat this problem. Regular and systematic screening using modern molecular and culture-based methods on the prevalence of carbapenem resistance is required because of the variety of bacterial species and the different genetic elements involved. Transmission of resistance bacteria/genetic elements between animals and humans in either direction to be investigated thoroughly for an evidence-based public health risk assessment
(Daniel-Haardt et al., 2018). The present study could be a pilot one in the state in this regard.
