Serological study of feline leishmaniasis and molecular detection of Leishmania infantum and Leishmania braziliensis in cats (Felis catus)

Abstract

<jats:p>Abstract Blood samples and swabs from ocular conjunctiva and mouth were obtained from 64 cats. Of 64 serum samples, 19 were positive for Leishmania antibodies by ELISA (29.80%). Eight cats were positive by PCR (12.5%) in swab samples from mouth and/or ocular mucosa. Poor kappa agreement between serological and molecular results (k = 0.16) was obtained. From five positive PCR samples one was L. braziliensis and four were L. infantum. Phylogenetic analysis performed with the five isolates of Leishmania, showed that samples of L. infantum isolated from the cats were phylogenetically close to those isolated from domestic dogs in Brazil, while the L. braziliensis is very similar to the one described in humans in Venezuela. The study demonstrated that, despite high seropositivity for Leishmania in cats living in the study region, poor agreement between serological and molecular results indicate that positive serology is not indicative of Leishmania infection in cats. Parasite DNA can be detected in ocular conjunctiva and oral swabs from cats, indicating that such samples could be used for diagnosis. Results of phylogenetic analyzes show that L. infantum circulating in Brazil is capable of infecting different hosts, demonstrating the parasite's ability to overcome the interspecies barrier.</jats:p>

Epidemiological and diagnostic aspects of feline leishmaniasis with emphasis on Brazil: a narrative review

“…Some studies use molecular analyses only to discriminate parasite species after a positive serological or parasitological test result, using cPCR (Coelho et al 2010(Coelho et al , 2011aOliveira et al 2015b;Madruga et al 2018;Marcondes et al 2018;Rocha et al 2019;Costa-Val et al 2020), qPCR (Vides et al 2011;Sobrinho et al 2012;Benassi et al 2017) and less frequently PCR-RFLP (PCR-restriction fragment length polymorphism) (Dahroug et al 2010;Metzdorf et al 2017). In Brazil, the most prevalent species diagnosed by molecular methods both domestic and wild cats is L. infantum (Coelho et al 2010;Dahroug et al 2010;Vides et al 2011;Sobrinho et al 2012;Metzdorf et al 2017).…”

“…In blood samples from dogs, it is well established that kDNA has better sensitivity compared to nuclear DNA and, for this reason, has been widely used for the detection of parasite DNA in these animals (Lachaud et al 2002). kDNA has also been widely used as a target for diagnosis and species identification for cats in Brazil (Silva et al 2008;Coelho et al 2011a;Morais et al 2013;Metzdorf et al 2017;Benassi et al 2017;Coura et al 2018;Pedrassani et al 2019;Costa-Val et al 2020). However, it is necessary to pay attention to the selection of the best primers for a better performance of molecular diagnosis (Lachaud et al 2002;Spada et al 2020).…”

“…L. infantum, on the other hand, has been reported in 12 of the 27 states of Brazil, with a lesser number in regions not endemic for VL (Savani et al 2004;Braga et al 2014b;Benassi et al 2017;Pedrassani et al 2019), and mostly in endemic regions (Fig. 1) (Silva et al 2008;Coelho et al 2010;Coelho et al 2011a;Vides et al 2011;Sobrinho et al 2012;Morais et al 2013;Silva et al 2014;Sousa et al 2014;Metzdorf et al 2017;Coura et al 2018;Marcondes et al 2018;Rocha et al 2019;Costa-Val et al 2020;Berenguer et al 2020;Silva et al 2020).…”

“…Since then, the importance of the cat in the epidemiology of the disease has become the target of other studies that have reported the presence of the protozoan infecting cats in other Brazilian states (Table 1). The prevalence of FeL in Brazil is estimated to be between 7 and 8% diagnosed via molecular and serological methods, with the most common species being Leishmania braziliensis, L. infantum, and Leishmania amazonensis (Schubach et al 2004;Souza et al 2005;Figueiredo et al 2009;Coura et al 2018;Asfaram et al 2019;Carneiro et al 2020;Costa-Val et al 2020).…”

“…Regarding the geographical location of these species, it was seen that L. braziliensis was restricted to the southeastern region of Brazil, reported both in endemic (Schubach et al 2004) and non-endemic areas (Figueiredo et al 2009) of the state of Rio de Janeiro and in endemic municipalities in the state of Minas Gerais (Costa-Val et al 2020). L. amazonensis has been reported in cats from endemic municipalities in the Midwest, Mato Grosso do Sul state (Souza et al 2005), and in the North, Pará state (Carneiro et al 2020).…”