CRYPTOSPORIDIUM SPP. IN PET DWARF WINTER WHITE RUSSIAN HAMSTERS (PHODOPUS SUNGORIS SUNGORIS) IN CHINA

Identification of a novel GP60 subtype family of Cryptosporidium wrairi from capybaras (Hydrochoerus hydrochaeris) inhabiting urban areas in the state of Mato Grosso do Sul, Brazil

Capybaras (Hydrochoerus hydrochaeris) are hosts for several parasites of public health importance, including Cryptosporidium spp. Therefore, this study aimed to perform the molecular characterization of Cryptosporidium spp. in fecal samples from capybaras inhabiting urban areas. We analyzed 401 fecal samples from capybaras in two municipalities of the state of Mato Grosso do Sul, Brazil. Fecal samples were purified using centrifugal sedimentation with ethyl acetate. They were then screened for Cryptosporidium spp. by malachite green negative staining and a nested PCR protocol targeting the 18S rRNA gene. Samples positive by microscopy or PCR were examined by PCR protocols targeting the actin, HSP-70, and GP60 genes. Amplicons from all PCR protocols were subjected to genetic sequencing. Microscopic screening and 18S rRNA gene-targeted PCR identified 0.25 % (1/401) and 0.5 % (2/401) of samples, respectively, as positive for Cryptosporidium spp. The genetic sequences of the 18S rRNA, HSP-70, actin, and GP60 genes showed genetic similarity to Cryptosporidium wrairi sequences of 99.07 %, 99.69 %, 99.57 %, and 91.51 %, respectively. Genetic sequencing and phylogenetic analyses identified the novel GP60 subtype family VIIbA13 of C. wrairi. In conclusion, we report in this study a low prevalence of the novel GP60 subtype family VIIbA13 of C. wrairi in free-living capybaras from urban areas of the state of Mato Grosso do Sul, Brazil. We propose that capybaras act as a novel host for C. wrairi.

Molecular Detection of Cryptosporidium spp. and Microsporidia in Human and Animal Stool Samples

Cryptosporidium spp. and Microsporidia are opportunistic microorganisms with remarkable zoonotic transmission potential due to their capacity to infect humans and animals. The aim of this study was to evaluate the prevalence of these microorganisms in stool samples of animal and human origin. In total, 369 stool samples (205 from human patients with diarrhea and 164 of animal origin) were included in the study. Cryptosporidium spp. and Microsporidia presence were determined by using multiplex nested PCR. Positive results were analyzed by using Sanger sequencing of the amplicon, utilizing BLASTN and ClustalX software to confirm identification. Cryptosporidium spp. were found in 0.97% and 4.26% of human and animal samples, respectively. Enterocytozoon bieneusi was detected in human and animal stools in 6.82% and 3.05% of the samples, respectively. No associations were found when analyzing the presence of Cryptosporidium spp. and E. bieneusi and the demographic and clinical variables of patients and animals. This study demonstrates the presence of these microorganisms in human and animal samples from different species, and the most interesting findings are the detection of Cryptosporidium spp. in pets (e.g., rodents) that are not usually included in this type of study, and the identification of E. bieneusi in patients with diarrhea without underlying disease.

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

First report of rodent-adapted Cryptosporidium wrairi in an immunocompetent child, Spain

Cryptosporidiosis is a leading cause of childhood diarrhoea. Two species, Cryptosporidium hominis and Cryptosporidium parvum, are responsible for most confirmed cases globally. Close contact with pet animals can be an unnoticed source of children infections. We describe a case of infection by rodent-adapted Cryptosporidium wrairi in a 22-month-old immunocompetent toddler with no clinical manifestations in close contact with a pet guinea pig and poor personal hygiene practices in Majadahonda (Madrid, Spain). Attempts to determine the C. wrairi genotype family at the 60-kDa glycoprotein marker failed repeatedly. This is the first description of C. wrairi in a human host. Although a spurious infection cannot be completely ruled out, data presented here suggest that C. wrairi can be transmitted zoonotically.

Detection and molecular characterization of Cryptosporidium spp. in pet hairless guinea pigs (Cavia Porcellus) from China

Cryptosporidium spp. are common protozoan parasites that can infect humans and animals worldwide. Recently, the hairless guinea pigs (also called Skinny pigs) were introduced into China as pets. However, Cryptosporidium species and their prevalence in these exotic animals were not studied. In this study, fecal samples were collected from a total of 324 hairless guinea pigs from a pet market and four breeding facilities in four provinces of China. The infection rate of Cryptosporidium was 6.8% (22/324). Three Cryptosporidium species were identified, including Cryptosporidium homai (n = 16), Cryptosporidium wrairi (n = 5), and Cryptosporidium hominis plus C. homai (n = 1). Sequence analysis of the small subunit (SSU) rRNA gene showed that the C. hominis isolate was a C. hominis variant, which mostly infects equine animals. However, the identification of C. hominis was not supported by the analysis of other genetic loci. The C. hominis isolate was characterized as C. homai at both 70-kDa heat shock protein (hsp70) and actin genes, indicating a mixed infection. At the 60-kDa glycoprotein (gp60) gene, subtyping of the C. hominis isolate was not successful. Five C. wrairi isolates were identified as subtype VIIaA13T1, which was previously reported in a guinea pig in the USA. The Cryptosporidium spp. identified in this study have no or low zoonotic potential.

An Update on Zoonotic Cryptosporidium Species and Genotypes in Humans

The enteric parasite, Cryptosporidium is a major cause of diarrhoeal illness in humans and animals worldwide. No effective therapeutics or vaccines are available and therefore control is dependent on understanding transmission dynamics. The development of molecular detection and typing tools has resulted in the identification of a large number of cryptic species and genotypes and facilitated our understanding of their potential for zoonotic transmission. Of the 44 recognised Cryptosporidium species and >120 genotypes, 19 species, and four genotypes have been reported in humans with C. hominis, C. parvum, C. meleagridis, C. canis and C. felis being the most prevalent. The development of typing tools that are still lacking some zoonotic species and genotypes and more extensive molecular epidemiological studies in countries where the potential for transmission is highest are required to further our understanding of this important zoonotic pathogen. Similarly, whole-genome sequencing (WGS) and amplicon next-generation sequencing (NGS) are important for more accurately tracking transmission and understanding the mechanisms behind host specificity.

Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021)

The protozoan parasites Cryptosporidium and Giardia are significant causes of diarrhoea worldwide and are responsible for numerous waterborne and foodborne outbreaks of diseases. Over the last 50 years, the development of improved detection and typing tools has facilitated the expanding range of named species. Currently at least 44 Cryptosporidium spp. and >120 genotypes, and nine Giardia spp., are recognised. Many of these Cryptosporidium genotypes will likely be described as species in the future. The phylogenetic placement of Cryptosporidium at the genus level is still unclear and further research is required to better understand its evolutionary origins. Zoonotic transmission has long been known to play an important role in the epidemiology of cryptosporidiosis and giardiasis, and the development and application of next generation sequencing tools is providing evidence for this. Comparative whole genome sequencing is also providing key information on the genetic mechanisms for host specificity and human infectivity, and will enable One Health management of these zoonotic parasites in the future.