Cryptosporidiosis outbreak on a dairy farm: Detection of Cryptosporidium parvum as a causative agent in the water source.

Diarrhea caused by parasitic agents is common in neonatal calves and leads to significant economic losses in cattle farms worldwide. Cryptosporidium spp. is one of the most frequently detected parasitic agents causing diarrhea in neonatal calves. The aim of this study was to investigate the presence of Cryptosporidium spp. on a dairy farm which a has major diarrhea problem. Samples were collected from calves, cows, drinking bowls, and two different artesian water sources, as well as from the environment. All fecal samples were investigated using Kinyoun acid-fast stained slides and real-time PCR targeting the Cryptosporidium spp. COWP gene. In addition, species identification was performed by nested PCR targeting the Cryptosporidium spp. COWP gene and sequencing. Cryptosporidium spp. was detected in 11 calves (30.55%; 11/36) by real-time PCR and the cows were negative. Among real-time PCR positive samples, only five were also found positive by microscopy. Moreover, Cryptosporidium spp. was found in one of the two artesian water sources and five environmental samples by real-time PCR. Among these positive samples, eight were sequenced. According to the RFLP pattern, BLAST and, phylogenetic analyses, all sequenced samples were Cryptosporidium parvum. These findings show the importance of C. parvum as a cause of calf diarrhea on dairy farms.

Molecular prevalence and subtyping of Blastocystis sp. isolates in stray cats of Izmir, Turkey: First report of "ST4 allele 42" in cats.

Blastocystis sp. is one of the most frequently detected intestinal parasites in humans and can inhabit a wide range of animals. Close contact with animals is one of the transmission factors of Blastocystis sp. infection in humans. In this study, we aimed to investigate the molecular prevalence and subtypes of Blastocystis sp. in stray cats living in Izmir, Turkey. The PCR target- ing the barcode region in the SSU rRNA gene was performed with DNA samples isolated from feces (n:465) to investigate the presence of Blastocystis sp. PCR positive samples were sequen- ced for subtyping analysis. Among the samples analyzed, Blastocystis sp. DNA was detected in 17 (3.65%) of them and sequence data were obtained from only seven isolates. Phylogenetic analysis showed that seven Blastocystis sp. isolates clustered with the reference Blastocystis ST4 isolates. Similarity rates were between 83.22% and 99.25%. In addition, Blastocystis database results confirmed that all of these were "allele 42" corresponding to ST4. As a result, the present study shows for the first time the presence of "ST4 allele 42", the prevalent subtype in humans, in stray cats in Izmir, Turkey. This finding supports the notion that stray cats can be a source of Blastocystis sp. infection in humans.

Behaviour of Toxoplasma gondii RH Ankara strain tachyzoites during continuous production in various cell lines.

Toxoplasma gondii is an obligate intracellular protozoan parasite. The objective of the present study was to examine the behaviour of Toxoplasma gondii RH Ankara strain tachyzoites in a cell culture environment. The study represents the first step in determining whether T. gondii RH Ankara strain tachyzoites, grown in cell culture, are of sufficient quality to allow cessation of in vivo tachyzoite production for diagnostic assays. In the present study, T. gondii RH Ankara strain tachyzoites were continuously produced in myeloma X63.Ag8.653, HeLa, Hep-2, and Vero cell cultures for 2 months. The average size of the tachyzoites was 3 x 5.7 microm prior to the first inoculation but after continuous production, a marked decrease was noted in average tachyzoite size. The smallest tachyzoite size, was 1 x 2.1 microm after 2 months, in myeloma cell cultures even though the yield of tachyzoites increased. With other cell cultures, tachyzoite yields were not as high as myeloma cell culture although decrease in size was less. The smallest decrease in tachyzoite size, averaging 2 x 3.8 microm after 2 months, was observed in tachyzoites produced in HeLa cell cultures. A virulence assay in small groups of BALB/c mice, using tachyzoites derived from cell cultures, was also conducted. The preliminary results of the virulence assay suggest that as the size of the tachyzoites decreased, the virulence in mice decreased. Future research will focus on the effect of the size of cell culture-derived T. gondii RH Ankara strain tachyzoites on the virulence, protein expression, and the reliability of diagnostic assays. Ultimately, the behaviour of tachyzoites from various T. gondii strains will be observed in cell culture to determine if size is altered.