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Abstract Pili have been demonstrated to contribute to the pathogenicity of many bacterial pathogens. Flp pilus encoded by the tad locus belongs to the type IVb pilus. Our previous study has revealed that the intact tad locus is essential for Flp pilus formation in Actinobacillus pleuropneumoniae , a very important porcine respiratory pathogen. To further investigate the functions of Flp pilus in A. pleuropneumoniae pathogenesis, the flp1 and tadD single deletion mutants were constructed by homologous recombination. Both of the mutant strains lost pilus on their cell surfaces. The abilities of biofilm formation, cell adhesion, resistance to phagocytosis, survival in swine whole blood, and in vivo colonization of the two mutants were significantly reduced compared with those of the parental strain. The corresponding complemented strains recovered the phenotypes. These results demonstrated that flp1 and tadD were essential for the biosynthesis of Flp pilus and that the pilus played important roles during infection of A. pleuropneumoniae. Highlights • The genes flp1 and tadD are essential for biosynthesis of A. pleuropneumoniae Flp pilus. • A. pleuropneumoniae Flp pilus is important for biofilm formation. • A. pleuropneumoniae Flp pilus is involved in adherence and anti-phagocytosis in vitro. • Flp pilus plays essential roles in A. pleuropneumoniae colonization in vivo. [ABSTRACT FROM AUTHOR]

Blastocystis is one of the important zoonotic parasites which can infect humans and various animals worldwide and has become a growing global public health concern. The study aims to obtain the data of Blastocystis infection and the information of the genetic characteristic. In the present study, 489 fecal samples were collected from diarrhea outpatients in Ningbo, Zhejiang province, and were examined the presence of Blastocystis by polymerase chain reaction combined with sequencing. A total of 10 samples (2.04%, 10/489) were positive for Blastocystis with no significant difference among sex and age groups, respectively. Eight samples were successfully sequenced, and five zoonotic ST3 and three zoonotic ST1 with two new sequences were identified. We first demonstrated the occurrence of Blastocystis infection in diarrhea outpatients in Ningbo, with two zoonotic subtypes (ST1 and ST3) and two new sequences being characterized. Meanwhile, mixed infection of Blastocystis and E. bieneusi was found which indicates the importance of investigation of multiple parasites. Finally, more extensive studies will be needed to better understand the transmission of Blastocystis at human-animal-environment interface and provide evidence for the development of one health strategies for the prevention and control of such diseases. • Blastocystis infection in diarrhea outpatients first reported in Ningbo. • Zoonotic subtypes of ST1 and ST3 and two new sequences characterized. • Mixed infection of Blastocystis and E. bieneusi identified. [ABSTRACT FROM AUTHOR]

Enterocytozoon bieneusi , Cryptosporidium spp. and Cyclospora cayetanensis are three important zoonotic pathogens which were a major cause of foodborne or waterborne intestinal diseases in humans and animals. However, very little data about occurrence and genotypes of the three parasites in Ningbo in the south wing of the Yangtze River Delta, China, which is important for a tourist city. In the present study, molecular characterization of E. bieneusi , C. cayetanensis and Cryptosporidium spp. in fecal samples from 489 diarrheal outpatients were carried out. As a result, a total of 35 (7.16%, 35/489) and three (0.61%, 3/489) samples were positive for E. bieneusi and C. cayetanensis respectively. No Cryptosporidium -positive sample or mixed-infections were detected. Four known E. bieneusi genotypes (Type IV, D, I and CHN4) and 8 novel genotypes (NBH1–NBH8) were identified with type IV was the dominant genotype (n = 14), followed by genotypes D (n = 5), NBH8 (n = 5) and NBH7 (n = 3). The remaining genotypes were found in one sample each, and these genotypes were belonged to the previously described high-potential zoonotic group 1. One novel sequence named NBC315, and the other two sequences (NBC30 and NBC370) identical with the reported sequence were detected. Therefore, the existence and importance of zoonotic potential of E. bieneusi and C. cayetanensis in diarrheal outpatients in Ningbo indicates the public health threats, and more investigations should be carried out in human populations, animals and other environmental sources from the One Health perspective. • First report on zoonotic protozoan from diarrheal outpatients in Ningbo. • High positivity of E. bieneusi with novel and known zoonotic genotypes was identified. • C. cayetanensis was first characterized in Ningbo. [ABSTRACT FROM AUTHOR]

Cryptosporidium spp. and Enterocytozoon bieneusi are common and important enteric parasites that can infect humans and animals, causing diarrhoea and systemic diseases. The objectives of the present study were to examine the prevalence and genetic variations of Cryptosporidium and E. bieneusi in pigs transferred from northeastern China to Ningbo city in Zhejiang Province. Cryptosporidium spp. was detected in 0.9% (2/216) of these samples and belonged to the zoonotic species Cryptosporidium parvum. A high E. bieneusi infection rate (25.0%, 54/216) was observed in this study, with 7 possible novel ITS genotypes (JLNB-1 to JLNB-7) and 10 known genotypes (EbpA, CM11, H, CM6, pigEBITS1, EbpC, CS-4, pigEBITS5, CHS5, and Henan-Ⅳ) identified, and zoonotic EbpA was the dominant genotype. Genotypes H and pigEBITS1 were reported for the first time in pigs in China. Phylogenetic analysis indicated that all the genotypes found in these samples belonged to zoonotic group 1. These findings indicated the potential threat of Cryptosporidium and E. bieneusi to humans or the environment during cross-regional transportation. An effective management control system should be built to avoid parasitic transmission as well as other animal diseases while travelling across different regions. In further studies, attention should be given to the transmission routes and the role of pigs as a potential source of human Cryptosporidium and E. bieneusi infections in China. • A high E. bieneusi infection rate with 7 possible novel ITS genotypes and 10 known genotypes belonged to zoonotic group 1. • Cryptosporidium parvum was identified in pigs. • Parasitic transmission during animals transportation across regions. [ABSTRACT FROM AUTHOR]