Background: Giardia intestinalis is considered one of the principal causative agents of diarrhea and an important waterborne disease pathogen that infects animals and humans worldwide. Investigations such as host specificity and transmission patterns require the direct genetic characterization of parasites from fecal samples. G. intestinalis is distributed into eight distinct genetic assemblages (A-H), however only assemblages A and B are known to infect humans. The present study aims to investigate the distribution, among the infected subjects, of the genotypes A and B of G. intestinalis in the last 10 years (2009-2018) in a tertiary care hospital. Materials/methods: A total of 162 DNAs extracted from human stools positive for G. intestinalis was analyzed for the Assemblages identification. The DNA extracted was used to amplify, by a real-time PCR assay based on melting curve analysis, the translation initiation factor, and the cathepsin L precursor genes for assemblage A and B, respectively. Chi-square test was used for the comParison of the frequency of Assemblage A and B between Italians and foreigners, between adults and children and between male and female. Statistical significance was set at p< 0.01. Results: Out of 162 samples analyzed, 72 samples were assigned to Assemblage A, 37 to Assemblage B, 7 were mixed and 15 were not amplified. The frequency of Assemblage A in association with origin was 70.8% in Italians and 47.7% in foreigners, while the frequency of Assemblage B was 25% in Italians and 43.2% in Foreigners: this different Assemblages distribution resulted significant (p=0.0229). On the contrary, no significant difference was observed in the frequency of Assemblage A and B in association with age (p=0.119) and sex (p=0.3948). The 15 not amplified samples are at present under investigation to assess if they could be included in a non-A non-B Assemblage. Conclusions: The performed real-Time PCR was able to amplify G. intestinalis DNA in 90.7% of the tested samples. The result show that Assemblage A, related to a major risk of zoonotic transmission, is prevalent, as already described in Italy. Assembly B is less common in our area, whit a frequency attributable mainly to immigrants from developing countries.
Distribution during 10 years of the genotypes A and B of Giardia intestinalis among the infected subjects attending to an Italian tertiary care hospital / Calderaro, A.; Montecchini, S.; Buttrini, M.; Rossi, S.; Motta, F; Piccolo, G.; Antonaci, M.; Dell’Anna, M. L.; Arcangeletti, M. C.; Chezzi, C.; De Conto, F. - (2020). (Intervento presentato al convegno XXX European Congress of Clinical Microbiology and Infectious Diseases (ECCMID).).
Distribution during 10 years of the genotypes A and B of Giardia intestinalis among the infected subjects attending to an Italian tertiary care hospital
Calderaro A.;Montecchini S.;Buttrini M.;Rossi S.;Motta F;Piccolo G.;Arcangeletti M. C.;Chezzi C.;De Conto F
2020-01-01
Abstract
Background: Giardia intestinalis is considered one of the principal causative agents of diarrhea and an important waterborne disease pathogen that infects animals and humans worldwide. Investigations such as host specificity and transmission patterns require the direct genetic characterization of parasites from fecal samples. G. intestinalis is distributed into eight distinct genetic assemblages (A-H), however only assemblages A and B are known to infect humans. The present study aims to investigate the distribution, among the infected subjects, of the genotypes A and B of G. intestinalis in the last 10 years (2009-2018) in a tertiary care hospital. Materials/methods: A total of 162 DNAs extracted from human stools positive for G. intestinalis was analyzed for the Assemblages identification. The DNA extracted was used to amplify, by a real-time PCR assay based on melting curve analysis, the translation initiation factor, and the cathepsin L precursor genes for assemblage A and B, respectively. Chi-square test was used for the comParison of the frequency of Assemblage A and B between Italians and foreigners, between adults and children and between male and female. Statistical significance was set at p< 0.01. Results: Out of 162 samples analyzed, 72 samples were assigned to Assemblage A, 37 to Assemblage B, 7 were mixed and 15 were not amplified. The frequency of Assemblage A in association with origin was 70.8% in Italians and 47.7% in foreigners, while the frequency of Assemblage B was 25% in Italians and 43.2% in Foreigners: this different Assemblages distribution resulted significant (p=0.0229). On the contrary, no significant difference was observed in the frequency of Assemblage A and B in association with age (p=0.119) and sex (p=0.3948). The 15 not amplified samples are at present under investigation to assess if they could be included in a non-A non-B Assemblage. Conclusions: The performed real-Time PCR was able to amplify G. intestinalis DNA in 90.7% of the tested samples. The result show that Assemblage A, related to a major risk of zoonotic transmission, is prevalent, as already described in Italy. Assembly B is less common in our area, whit a frequency attributable mainly to immigrants from developing countries.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
