Occurrence of Salmonella spp. in captive wild animal species in India is largely unknown. The purpose of this study was to determine the occurrence of different Salmonella serotypes, antimicrobial resistance patterns and genotypic relatedness of recovered isolates. A total of 370 samples including faecal (n = 314), feed and water (n = 26) and caretakers stool swabs (n = 30) were collected from 40 different wild animal species in captivity, their caretakers, feed and water in four zoological gardens and wildlife enclosures in India. Salmonellae were isolated using conventional culture methods and tested for antimicrobial susceptibility with the Kirby–Bauer disc diffusion method. Salmonella isolates were serotyped and genotyping was performed using enterobacterial repetitive intergenic consensus (ERIC) PCR and 16S rRNA sequencing. Animal faecal samples were also subjected to direct PCR assay. Salmonella was detected in 10 of 314 (3.1%) faecal samples by isolation and 18 of 314 (5.7%) samples by direct PCR assay; one of 26 (3.8%) feed and water samples and five of 30 (16.7%) caretakers stool swabs by isolation. Salmonella was more commonly isolated in faecal samples from golden pheasants (25%; 2/8) and leopard (10%; 2/20). Salmonella enterica serotypes of known public health significance including S. Typhimurium (37.5%; 6/14), S. Kentucky (28.5%; 4/14) and S. Enteritidis (14.3%; 2/14) were identified. While the majority of the Salmonella isolates were pan-susceptible to the commonly used antibiotics. Seven (43.7%; 7/16) of the isolates were resistant to at least one antibiotic and one isolate each among them exhibited penta and tetra multidrug-resistant types. Three S. Kentucky serotype were identified in a same golden pheasants cage, two from the birds and one from the feed. This serotype was also isolated from its caretaker. Similarly, one isolate each of S. Typhimurium were recovered from ostrich and its caretaker. These isolates were found to be clonally related suggesting that wildlife may serve as reservoir for infections to humans and vice versa. These results emphasise the transmission of Salmonella among hosts via environmental contamination of feces to workers, visitors and other wildlife.

Summary: Low pathogenic avian influenza virus (LPAIV) exhibits an ecological climax with the aquatic ecosystem. The most widely prevalent subtype ofLPAIVis H9N2. Wild aquatic birds being the natural reservoirs and ducks, the “Trojan horses” for Avian Influenza Virus (AIV), can contaminate the natural water bodies inhabited by them. The virus can persist in the contaminated water from days to years depending upon the environmental conditions. Various aquatic species other than ducks can promote the persistence and transmission ofAIV; however, studies on the role of aquatic fauna in persistence and transmission of avian influenza virus are scarce. This experiment was designed to evaluate the survivability of H9N2LPAIVin water with and withoutAtyopsis moluccensis(bamboo shrimp) for a period of 12 days. The infectivity and amount of virus in water were calculated and were found to be significantly higher in water withA. moluccensisthan in water withoutA. moluccensis. The study also showed thatA. moluccensiscan accumulate the virus mechanically which can infect chicken eggs up to 11 days. The virus transmission potential ofA. moluccensisrequires further studies.

Haemonchus contortus is a blood-feeding gastrointestinal nematode that significantly impacts the health and productivity of small ruminants. The burden of parasitism and the escalating incidence of anthelmintic resistance necessitate alternative control methods. Here, we characterize the enzymatic activities of five mammalian cell-expressed recombinant H. contortus cysteine proteases (HcCPs), which include two cathepsin B-like proteins (HcCBP1 and HcCBP2) and three cysteine protease 1 proteins (HcCP1a, HcCP1b, and HcCP1c). We hypothesize that these enzymes degrade host blood proteins, thereby facilitating the parasite’s nutrient acquisition and survival. Using synthetic cathepsin (cat) substrates, we show that HcCBP2 was the only protein that exhibited high catB/L but low catB or catK activity, which was inhibited by the cysteine protease inhibitor E-64. All mHcCPs degraded fibrinogen (Fg), which led to delayed plasma clotting, reduced clot density, and lysed plasma clots. All HcCPs partially degraded hemoglobin (Hb), except for mHcCBP2, which degraded Hb and bovine serum albumin completely and bovine IgG partially in the presence of a reducing agent. In conclusion, by sustaining blood feeding and facilitating immune evasion and nutrient acquisition, the HcCPs may play an essential role in the parasite’s survival. Thus, vaccines or cysteine protease inhibitors targeting these parasitic enzymes may mitigate or prevent infections.

Escherichia coli causes diarrhea and extraintestinal infections in humans and animals. Here, we report the draft genome sequences of Escherichia coli strains 360/16 and 646, isolated from neonatal calves.

Ostertagia ostertagi is the most pathogenic gastrointestinal nematode of cattle and causes major productivity losses. With rising anthelmintic resistance and significant economic impact, alternative control measures, such as vaccination, are urgently needed. This study aimed to generate functionally active recombinant cysteine proteases from O. ostertagi, enzymes involved in nutrient acquisition and immune evasion, to evaluate their potential as vaccine candidates. Two phylogenetically predicted cathepsin B (catB)-like proteases, OoCBP1 and OoCBP2, were cloned into the pcDNA3.1+ vector and expressed in FreeStyle 293-F cells. Purified proteins were assessed using fluorogenic substrates and various host protein substrates, including fibrinogen, albumin, hemoglobin, IgG, mucin, and gelatin, at pH 5.0 and 7.4 with or without a reducing agent. OoCBP1 was detected in the parasite across the life stages, while OoCBP2 was only detectable in adult worms. OoCBP1 partially degraded host proteins at pH 5.0, with reduced activity at pH 7.4, whereas OoCBP2 efficiently degraded all tested proteins at both pH levels except IgG, which was only partially degraded. OoCBP1 showed catB/L activity only at acidic pH, while OoCBP2 was active at both pH conditions. Activities were inhibited by catB, catB/L, or other cysteine protease inhibitors. OoCBP1, but not OoCBP2, required low pH-mediated autoactivation for substrate degradation. OoCBP1 had no effect on coagulation under physiological conditions, while OoCBP2 accelerated clot formation with reduced clot density. With in vitro activation, both proteases delayed coagulation. These findings indicate that OoCBP1 and OoCBP2 may contribute to nutrient acquisition and immune evasion, supporting their potential as targets for vaccines or chemotherapeutics against ostertagiosis.