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Open Veterinary Journal May 2024Young farm animals are susceptible to opportunistic infections which may cause economic losses due to mortality and poor weight gain. The development of antimicrobial...
BACKGROUND
Young farm animals are susceptible to opportunistic infections which may cause economic losses due to mortality and poor weight gain. The development of antimicrobial resistance and the desire to improve therapy efficacy and safety are the reasons to seek for new antibacterial drugs ensuring rapid recovery with minimum adverse events.
AIM
To estimate the efficacy of DOKSI AVZ 500 in respiratory pathologies in young pigs.
METHODS
The study was conducted in 65-70-day-old Yorkshire piglets with signs of bacterial respiratory pathologies. The animals were treated with the test drug for 3 or 5 days. The reference group received TETRAMAX 500 which is similar to the test drug in terms of chemical structure, mechanism of action, and activity spectrum. The animal's status was assessed using clinical examination, clinical blood count, and bacteriological tests.
RESULTS
Both test and reference drugs were well tolerated and ensured the animal recovery within about 4 days. The recovery was accompanied by normalization of hematological parameters and flora composition. The bacterium associated with the disease development, , was virtually completely eliminated in all groups. No adverse events were noted. After the treatment, all the animals readily gained weight and live market quality.
CONCLUSION
DOKSI AVZ 500 was a highly efficient therapy for respiratory pathologies caused by the resident opportunistic flora in piglets. It has also shown noninferiority TETRAMAX 500 in terms of all the health-related parameters and thus can be recommended for introduction in veterinary practice in pig farms.
Topics: Animals; Swine; Swine Diseases; Anti-Bacterial Agents; Respiratory Tract Infections; Female; Male; Tylosin
PubMed: 38938427
DOI: 10.5455/OVJ.2024.v14.i5.2 -
Microorganisms Jun 2024Numerous studies have reported a correlation between gut microbiota and influenza A virus (IAV) infection and disease severity. However, the causal relationship between...
Numerous studies have reported a correlation between gut microbiota and influenza A virus (IAV) infection and disease severity. However, the causal relationship between these factors remains inadequately explored. This investigation aimed to assess the influence of gut microbiota on susceptibility to human infection with H7N9 avian IAV and the severity of influenza A (H1N1)pdm09 infection. A two-sample Mendelian randomization analysis was conducted, integrating our in-house genome-wide association study (GWAS) on H7N9 susceptibility and H1N1pdm09 severity with a metagenomics GWAS dataset from a Chinese population. Twelve and fifteen gut microbiotas were causally associated with H7N9 susceptibility or H1N1pdm09 severity, separately. Notably, and were negative associated with H7N9 susceptibility and H1N1pdm09 severity, respectively. Moreover, and were associated with H7N9 susceptibility, while and were correlated with H1N1pdm09 severity. These results provide novel insights into the interplay between gut microbiota and IAV pathogenesis as well as new clues for mechanism research regarding therapeutic interventions or IAV infections. Future studies should concentrate on clarifying the regulatory mechanisms of gut microbiota and developing efficacious approaches to reduce the incidence of IAV infections, which could improve strategy for preventing and treating IAV infection worldwide.
PubMed: 38930552
DOI: 10.3390/microorganisms12061170 -
Microbial Pathogenesis Jun 2024Streptococcus suis is one of the major pathogens of pigs circulating worldwide, and the development of vaccines will help to effectively control streptococcosis in...
Streptococcus suis is one of the major pathogens of pigs circulating worldwide, and the development of vaccines will help to effectively control streptococcosis in swine. In this study, we evaluated the potential of three membrane associated proteins, histidine kinase (HK), glycosyltransferase family 2 (Gtf-2) and phosphate binding protein (PsbP) of S. suis as subunit vaccines. Bioinformatics analysis shows that protein ABC is highly conserved in S. suis. To verify the protective effects of these proteins in animal models, recombinant protein HK, Gtf-2 and PsbP were used to immunize BALB/c mice separately. The results showed that these proteins immunization in mice can effectively induce strong humoral immune responses, protect mice from cytokine storms caused by S. suis infection, and have a significant protective effect against lethal doses of S. suis infection. Furthermore, antibodies with opsonic activity exist in the recombinant proteins antiserum to assist phagocytic cells in killing S. suis. Overall, these results indicated that these recombinant proteins all elicit good immune protective effect against S. suis infection and can be represent promising candidate antigens for subunit vaccines against S. suis.
PubMed: 38906494
DOI: 10.1016/j.micpath.2024.106759 -
Veterinary Research Jun 2024Bacteria utilize intercellular communication to orchestrate essential cellular processes, adapt to environmental changes, develop antibiotic tolerance, and enhance...
Bacteria utilize intercellular communication to orchestrate essential cellular processes, adapt to environmental changes, develop antibiotic tolerance, and enhance virulence. This communication, known as quorum sensing (QS), is mediated by the exchange of small signalling molecules called autoinducers. AI-2 QS, regulated by the metabolic enzyme LuxS (S-ribosylhomocysteine lyase), acts as a universal intercellular communication mechanism across gram-positive and gram-negative bacteria and is crucial for diverse bacterial processes. In this study, we demonstrated that in Streptococcus suis (S. suis), a notable zoonotic pathogen, AI-2 QS enhances galactose utilization, upregulates the Leloir pathway for capsular polysaccharide (CPS) precursor production, and boosts CPS synthesis, leading to increased resistance to macrophage phagocytosis. Additionally, our molecular docking and dynamics simulations suggest that, similar to S. pneumoniae, FruA, a fructose-specific phosphoenolpyruvate phosphotransferase system prevalent in gram-positive pathogens, may also function as an AI-2 membrane surface receptor in S. suis. In conclusion, our study demonstrated the significance of AI-2 in the synthesis of galactose metabolism-dependent CPS in S. suis. Additionally, we conducted a preliminary analysis of the potential role of FruA as a membrane surface receptor for S. suis AI-2.
Topics: Streptococcus suis; Galactose; Quorum Sensing; Virulence; Animals; Bacterial Capsules; Lactones; Streptococcal Infections; Homoserine; Polysaccharides, Bacterial
PubMed: 38886823
DOI: 10.1186/s13567-024-01335-5 -
Methods in Molecular Biology (Clifton,... 2024Streptococcus suis is a bacterial pathogen that can cause significant economic losses in the swine industry due to high morbidity and mortality rates in infected...
Streptococcus suis is a bacterial pathogen that can cause significant economic losses in the swine industry due to high morbidity and mortality rates in infected animals. Vaccination with bacterins, which consist of inactivated bacteria and adjuvants to enhance the pig's immune response, is an effective approach to control S. suis infections in piglets. Here we provide a description of S. suis bacterins and the methods for vaccine preparation. Moreover, this chapter also describes the addition of recombinant Sao (rSao-L) protein to the S. suis bacterin, aiming to enhance the efficacy of the bacterins against S. suis in piglets. Furthermore, the methods for evaluating the immune response elicited by the bacterins are also covered in this chapter.
Topics: Animals; Swine; Streptococcus suis; Streptococcal Infections; Swine Diseases; Vaccination; Bacterial Vaccines; Adjuvants, Immunologic; Antibodies, Bacterial; Recombinant Proteins; Streptococcal Vaccines
PubMed: 38884916
DOI: 10.1007/978-1-0716-3898-9_11 -
Methods in Molecular Biology (Clifton,... 2024The economic impact of Streptococcus suis-associated disease at farm level is well known by the producers, but the cost in a region or a country is more difficult to...
The economic impact of Streptococcus suis-associated disease at farm level is well known by the producers, but the cost in a region or a country is more difficult to evaluate due to the lack of a centralized data system, the different incidences, and the control measures applied by each producer. In this chapter, we describe a method based on the information gathered through interviews with veterinary practitioners. A comprehensive questionnaire created specifically for the disease can help to conduct the interviews. The questions include information about the proportions of farms, batches and animals clinically affected, mortality, metaphylactic and therapeutic treatments, use of vaccines, and proportion of cases that are diagnosed at the laboratory. As the questionnaire is quite complex, the best option to obtain the data is send the questionnaire to the selected veterinarians to allow them to collect some data and make an interview with them some days later. The information allows to estimate the costs due to mortality, antimicrobial treatments, the use of autogenous vaccines, and analyses performed. Initially they are calculated per animal in each affected production phase, and later it can be extrapolated to estimate the annual cost per affected production unit and per country. The model does not consider indirect costs such as the cost as a zoonosis, the revenues forgone, or an increase of labor.
Topics: Streptococcus suis; Animals; Streptococcal Infections; Swine; Surveys and Questionnaires; Swine Diseases; Humans
PubMed: 38884915
DOI: 10.1007/978-1-0716-3898-9_10 -
Methods in Molecular Biology (Clifton,... 2024Streptococcus suis is a swine bacterial pathogen that predominantly causes disease in weaned piglets characterized by swelling of joints, arthritis, septicemia,...
Streptococcus suis is a swine bacterial pathogen that predominantly causes disease in weaned piglets characterized by swelling of joints, arthritis, septicemia, meningitis, and sudden death. Intravenous, intramuscular, intraperitoneal, and intranasal infection models were developed to study the bacterial pathogenicity and efficacy of vaccines and various therapeutics. The selection of the appropriate infection model is a critical step in any study, as it may impact the outcomes of the study. Here we describe a method for infecting weaned piglets with S. suis using intraperitoneal route as a reliable, consistent, and reproducible animal model to evaluate vaccine protection against systemic bacterial infection.
Topics: Animals; Swine; Disease Models, Animal; Streptococcus suis; Streptococcal Infections; Swine Diseases; Injections, Intraperitoneal
PubMed: 38884914
DOI: 10.1007/978-1-0716-3898-9_9 -
Methods in Molecular Biology (Clifton,... 2024Multidrug resistance, due to acquired antimicrobial resistance genes, is increasingly reported in the zoonotic pathogen Streptococcus suis. Most of these resistance...
Multidrug resistance, due to acquired antimicrobial resistance genes, is increasingly reported in the zoonotic pathogen Streptococcus suis. Most of these resistance genes are carried by chromosomal Mobile Genetic Elements (MGEs), in particular, Integrative and Conjugative Elements (ICEs) and Integrative and Mobilizable Elements (IMEs). ICEs and IMEs frequently form tandems or nested composite elements, which make their identification difficult. To evaluate their mobility, it is necessary to (i) select the suitable donor-recipient pairs for mating assays, (ii) do PCR excision tests to confirm that the genetic element is able to excise from the chromosome as a circular intermediate, and (iii) evaluate the transfer of the genetic element by conjugation by doing mating assays. In addition to a dissemination of resistance genes between S. suis strains, MGEs can lead to a spreading of resistance genes in the environment and toward pathogenic bacteria. This propagation had to be considered in a One Health perspective.
Topics: Conjugation, Genetic; Interspersed Repetitive Sequences; Gene Transfer, Horizontal; Streptococcus suis; Anti-Bacterial Agents; Drug Resistance, Bacterial; Polymerase Chain Reaction; Genes, Bacterial
PubMed: 38884912
DOI: 10.1007/978-1-0716-3898-9_7 -
Methods in Molecular Biology (Clifton,... 2024Globally, the main molecular trials being developed to study the genetic determinants responsible for conferring resistance to bacterial organisms are...
Globally, the main molecular trials being developed to study the genetic determinants responsible for conferring resistance to bacterial organisms are amplification-based methods, hybridization-based methods, and sequence-based methods. In the specific case of Streptococcus suis, polymerase chain reaction is the only test tuned up until now for detecting resistant clinical isolates to macrolides and/or tetracyclines, the two main groups of antibiotics being ineffective against this human and animal pathogen.
Topics: Macrolides; Polymerase Chain Reaction; Humans; Anti-Bacterial Agents; Tetracycline; Drug Resistance, Bacterial; Animals; DNA, Bacterial; Microbial Sensitivity Tests
PubMed: 38884911
DOI: 10.1007/978-1-0716-3898-9_6 -
Methods in Molecular Biology (Clifton,... 2024Here were described the main three methods being used for analysis of antibiotic susceptibility or resistance of Streptococcus suis clinical isolates to antimicrobial...
Here were described the main three methods being used for analysis of antibiotic susceptibility or resistance of Streptococcus suis clinical isolates to antimicrobial agents: the Kirby-Bauer disk diffusion, the epsilometer test (E test), and the broth microdilution test. In each case, procedures, results, and interpretation are described, as well as their advantages or limitations when proceeds.
Topics: Microbial Sensitivity Tests; Drug Resistance, Bacterial; Humans; Anti-Bacterial Agents; Streptococcus suis; Disk Diffusion Antimicrobial Tests
PubMed: 38884910
DOI: 10.1007/978-1-0716-3898-9_5