Clostridium perfringens poses a serious threat to small ruminants by causing moderate to severe enterotoxaemia. Due to its ability to produce a wide arsenal of toxins, it is ranked among the most prevalent and important pathogens in livestock. This study focused on the molecular characterization of different Clostridium perfringens types along with their antimicrobial resistance profile. An overall higher prevalence of C. perfringens (46.1%) was detected based on mPCR among sheep and goats (healthy and diseased) in the Punjab province, Pakistan. The majority of the isolates were characterized as type A (82%), followed by type D (18%). Among the isolates from diseased sheep and goats, 27% were positive for cpa, 49% for cpa and cpb2, 9% for cpa and etx, 15% for cpa, cpb2 and etx. In the case of isolates from healthy sheep and goats, 59% were positive for cpa, 34% for cpb2 and cpa, 4% for cpa and etx, and 3% for cpa, cpb2 and etx. The prevalence of the beta2 toxin gene in the diseased sheep and goat population was 64% as compared to 37% in healthy animals. All 184 isolates (100%) were sensitive to rifampin and ceftiofur; the majority (57%) was sensitive to teicoplanin, chloramphenicol, amoxicillin, linezolid and enrofloxacin. A lower proportion of isolates (43%) were sensitive to ciprofloxacin and only 14% were susceptible to erythromycin. The findings of this study highlight the higher prevalence of C. perfringens in small ruminants and indicate that detailed pathogenesis studies are necessary to understand the explicit role of various toxins in causing enteric infections in sheep and goats including how they might be exploited to develop vaccines against these diseases.

Cryptosporidiumspp., Giardia duodenalis, andBlastocystissp. are common intestinal protozoans that infect humans and animals worldwide. A survey that assessed the prevalence, molecular characteristics, and zoonotic potential of these pathogens was conducted on a variety of dogs in Guangzhou, southern China. A total of 651 canine stool samples from household (n = 199), shelter (n = 149), breeding (n = 237), and pet market dogs (n = 66) were collected from eight districts in Guangzhou.Cryptosporidiumspp., Giardia duodenalis, andBlastocystissp. were detected by PCR amplification of theSSUrRNA gene.Giardia duodenalis-positive specimens were further assigned into assemblages using the glutamate dehydrogenase gene. Cryptosporidiumspp.,G. duodenalis, andBlastocystissp. were found in 21 (3.2%), 20 (3.1%), and 35 (5.4%) samples, respectively. The overall prevalence of shelter dogs (40.28%, 60/149) was significantly higher than that of household (3.0%, 6/199), breeding (2.1%, 5/237), and pet market dogs (7.5%, 5/66) (χ² = 154.72, df = 3,P < 0.001). Deworming in the past 12 months had a strong protective effect on the risk of contracting parasite infections (P < 0.001). No significant differences were detected between age or sex groups (P > 0.05). Dog-specificC. canis(n = 19) and zoonoticC. parvum(n = 2) were the only twoCryptosporidiumspecies. Sequence analysis revealed the presence of threeG. duodenalisassemblages: dog-specific assemblages D (n = 14) and C (n = 5), and cat-specific F (n = 1). ZoonoticBlastocystisST3 (n = 28) was the dominant subtype, followed by ST1 (n = 6) and ST10 (n = 1). To our knowledge, this is the first large-scale investigation on the occurrence and molecular characteristics ofBlastocystissp. in dogs in China. Our results indicated that the dogs seemed to play a negligible role as reservoirs forCryptosporidiumspp. andG. duodenalistransmission to humans, but they are potential novel suitable hosts ofBlastocystissp. A strict sentinel surveillance system of dogs should be established to minimise the zoonotic risk of spreading blastocystosis among humans and dogs.

Avian coccidiosis is the most serious parasitic disease in the poultry industry. Therefore, the aim of the current study was to explore the effects of B. subtilis and live coccidiosis vaccine alone or in combination on the production performance and anticoccidiosis, as well as the dynamic changes of intestinal microbial community. Nine hundred ninty Mahuang chickens were randomized into 4 preimmune groups including control group, coccidiosis vaccine immunization group; B. subtilis administration group and a group that was administrated a combination of live coccidiosis vaccine and B. subtilis group. Intestinal mucosal scraps collected from all these experimental groups at the age of 8 d and 15 d for microbial community 16S rRNA gene sequencing. At the age of 25 d, 30 broilers from each preimmune group were randomly assigned to a subgroup infected with Eimeria spp. and renamed as CI, V-CI BS-CI, and VBS-CI group. The production performance was monitored at the age of 25 d, 35 d, 45 d, and 55 d for the rest broilers from each pre-immune group. Otherwise, in the Eimeria spp. challenge stage, intestinal mucosal scraps collected for microbial community sequencing, while duodenum, jejunum, and cecum collected for pathological examination after sacrifice at the age of 32 d. In addition, the oocysts per gram of feces (OPG) and intestinal lesion score of broilers after Eimeria spp. challenge were also counted. Overall, the probiotics and coccidiosis vaccine resulted in the significantly improvement of the production performance. Otherwise, the intestinal lesion score and OPG after Eimeria spp. infection was significantly decreased in the VBS-CI group (P < 0.05). Moreover, these protective effects may also be closely related to genus such as Romboutsia, Blautia, and Butyricococcus, as well as microbiota functions like the quorum sensing pathway. According to these results, a combination of B. subtilis and coccidiosis vaccines can improve performance and provide additional protection against Eimeria spp. infection.

Cryptosporidium parvum is a zoonotic intracellular protozoan responsible for the diarrheal illness cryptosporidiosis in humans and animals. Although a number of zoite surface proteins are known to be expressed during, and believed to be involved in, attachment and invasion of host cells, the molecular mechanisms by which C. parvum invades the host epithelial cells are not well understood. In the present study, we investigated the gene expression patterns, protein localization in developmental stages in culture, and in vitro neutralization characteristics of Cpgp40/15 and Cpgp40. Indirect immunofluorescence assay showed that Cpgp40/15 is associated with the parasitophorous vacuole membrane (PVM) during intracellular development. Both anti-gp40/15 and anti-gp40 antibodies demonstrated the ability to neutralize C. parvum infection in vitro. Further studies are needed to fully understand the specific role and functional mechanism of Cpgp40/15 (or gp40/15 complex) in the invasion of the host or in the PVM and to determine the feasibility of gp40/15 as a vaccine candidate for cryptosporidiosis in vivo.