Cryptosporidium spp. in caged exotic psittacines from Brazil: Evaluation of diagnostic methods and molecular characterization

Abstract

The aim of this study was to evaluate the prevalence of and diagnostic methods for Cryptosporidium spp. in caged adult exotic parrots from Southern and Southeastern Brazil. Oocysts were purified from fecal samples from 463 psittacines by centrifugal-flotation in Sheather's sugar solution. Cryptosporidium spp. were detected by malachite green negative staining and nested PCR targeting the 18S rRNA gene. Cryptosporidium species were identified by sequencing nested PCR amplicons. Samples were also tested by duplex real-time PCR targeting the 18S rRNA gene of Cryptosporidium galli and Cryptosporidium avian genotype III. The prevalence rates of Cryptosporidium spp. determined by microscopy and nested PCR were 3.0% (14/463) and 5.0% (23/463), respectively. The nested PCR/sequencing identified avian genotype III (1.7%; 8/463), Cryptosporidium parvum (0.9%; 4/463) and Cryptosporidium canis (0.2%; 1/463). Duplex real-time PCR was positive for gastric Cryptosporidium in 9.5% (44/463) of the samples. Among them, 1.9% (9/463) were positive for C. galli, 5.8% (27/463) were positive for avian genotype III and 1.7% (8/463) showed mixed infections with C. galli and avian genotype III. With regards to the positive detection of Cryptosporidium spp., there was no statistically significant difference between nested PCR and microscopic analysis (p = .1237), and a fair agreement existed between them (Kappa = 0.242). A statistically significant difference (p < .0001) and fair agreement (Kappa = 0.317) were obtained between nested PCR/sequencing and duplex real-time PCR for the detection of gastric Cryptosporidium. We determined that nested PCR and duplex real-time PCR are the best options for the detection of Cryptosporidium spp. and gastric Cryptosporidium, respectively, and that avian genotype III is the most common Cryptosporidium genotype/species in psittacines.

Molecular Prevalence of Cryptosporidium spp. among Companion Birds Kept in Pet Shops in Japan

“…Since these species are common as companion birds, Cryptosporidium spp. infections have previously been detected in the same or closely related bird species [ 12 – 20 ].…”

Cryptosporidiosis and Giardiasis in Buffaloes (Bubalus bubalis)

“…Additionally, the negative coloring observed with the malachite green technique ( 53 , 60 ) can be used. The centrifugal flotation technique with Sheather's solution ( 61 ), which uses brightfield or phase contrast optical microscopy, can be employed to visualize oocysts ( 8 ). However, differentiating between Cryptosporidium species/genotypes using microscopy is not possible because oocysts are similar in shape and overlap in size ( 37 ).…”

Dominance of the zoonotic pathogen Cryptosporidium meleagridis in broiler chickens in Guangdong, China, reveals evidence of cross-transmission

“…Currently, only five valid species, namely C. meleagridis , C. baileyi , C. galli , C. avium and C. proventriculi , and at least 15 genotypes including avian genotypes I–II, IV and VI–IX, goose genotypes I–V, black duck genotype, Eurasian woodcock genotype and C. xiaoi –like genotype have been documented in a wide range of birds worldwide [ 3 – 11 ]. In addition, mammal-specific Cryptosporidium species including C. hominis , C. parvum , C. andersoni , C. muris and C. canis are rarely detected in birds [ 12 – 16 ], partly because birds ingest oocysts from contaminated food or water and shed oocysts mechanically. Cryptosporidium baileyi infection usually occurs in the respiratory system, causing high morbidity and mortality, and C. meleagridis infects the gut and is associated with intestinal clinical signs (enteritis and diarrhea), whereas C. galli and C. proventriculi infect the proventriculus, manifesting symptoms associated with anorexia, weight loss and chronic vomiting [ 6 ].…”